The effect of the geometric shape of ellipsoids (covering a wide aspect ratio range from 0.003 to 60) on the structure of adhesive loose packings is investigated by the random ballistic deposition method with the hit-stick-freeze assumption. Statistical results show that the packing density of spherical particles is the largest, which is 0.1469. As the particle shape deviates from spherical shape, the packing density decreases rapidly. When the aspect ratio is below 0.1 and above 10, the packing density is approximately correlated with the aspect ratio in 1 and -2 power-law relations. The local coordination number is independent of the particle shape, which not only follows the Gaussian normal distribution, but also has a common average value of 2.001. This result indicates that for packing systems of non-spherical particles controlled by short-range interparticle contact interactions, 2 is the lowest coordination number for forming a mechanically stable structure. The radial distribution function shows that the local packing structure is dominated by local minor-to-major and major-to-major contact for oblate ellipsoids, and by local minor-to-minor and minor-to-major contact for prolate ellipsoids. Finally, analogous to the classical filling theory of spherical particles, a predicting correlation between the packing density and the aspect ratio is established.

In order to investigate the chemical reaction mechanisms of in-situ heavy oil upgrading during supercritical water flooding, batch reactor experiments were conducted to study the transformation of fraction distribution of upgraded heavy oil products in supercritical water at 380—420℃. The results showed that the vacuum residue content was significantly reduced after upgrading, while the content of various light components increased. Increasing the reaction temperature or extending the reaction time enhance the upgrading effect but also intensify coke formation. Based on the experimental results, a six-lumped kinetic model was established, revealing that reaction temperature has a significant impact on the reaction equilibrium. At 380℃, light fractions and gas are mainly produced from the cracking of vacuum residue, whereas at higher temperatures, vacuum gas oil and atmospheric gas oil sequentially tend to convert into lighter fractions. Integrating the kinetic model, reservoir numerical simulations were performed to evaluate the actual oil recovery performance of supercritical water flooding. The results indicate that at temperatures above 400℃, supercritical water flooding exhibits high efficiency of oil recovery. The content of light fractions in the produced oil increases with temperature. However, the effect of in-situ upgrading remains constrained due to the effects of fluid heat and mass transfer.

In deepwater oil and gas and "combustible ice" development, particle deposition and aggregate blockage in hydrate slurries are key challenges in flow assurance. This study conducts numerical simulations of flow aggregation and deposition processes of NGH slurries in water-based systems using the coupling of computational fluid dynamics (CFD) and discrete element method (DEM) via Fluent and EDEM. The research investigates the aggregation and deposition behaviors of hydrate particles under different slurry velocities and hydrate volume fractions, and the pressure changes inside the pipeline under conditions with and without particles are compared and analyzed. The simulation results show that at a low velocity of 0.5 m/s, particles form a stationary deposition layer on the pipeline inner wall, accompanied by significant axial and radial aggregation. At a higher velocity of 1.5 m/s, enhanced shear forces fragment particle aggregates, leading to uniform dispersion of single particles or small aggregates. As the hydrate volume fraction increases from 5% to 15%, the degree of particle aggregation intensifies, causing a nonlinear increase in pressure drop, and a pressure drop peak is formed in the middle section of the elbow due to the development of the deposition layer. Based on the simulation results, this paper proposes a mechanism for the influence of bend structure on hydrate deposition: at low flow rates, the fluid and particles are coupled. After hydrate aggregates break up at the flow field abrupt change, some of them adhere to the sedimentary layer on the pipe wall, forming a coupled blockage mechanism of adhesion, fragmentation, and redeposition.

The two-phase flow within flow channels of proton exchange membrane fuel cells is a critical factor affecting the performance, but the multi-physics coupling research considering detailed two-phase flow characteristics such as the evolution of the gas-liquid interface is still insufficient. By constructing a fuel cell model coupled with the volume of fluid model, this study quantitatively analyzes the impact of the surface wettability of the gas diffusion layer (GDL) on mass transfer and performance in fuel cells. The results show that neglecting the detailed two-phase flow in channels can overestimate both the fuel cell performance and the uniformity of physical quantity distribution. As the hydrophobicity of the GDL surface increases, the coverage area of liquid water on the GDL surface decreases, which initially enhances oxygen transport and fuel cell performance. However, this also leads to slower water drainage, causing slower performance recovery in the later stage. In this study, the fuel cell performance is best when the contact angle of the GDL surface is 160°, while the performance is lowest when the contact angle is 110°. The study provides theoretical and model support for understanding the mechanisms underlying the influence of two-phase flow within flow channels and for the design of high-performance fuel cells.

The dispersion stability of phase change microcapsules in liquid media is a key factor affecting the performance of latent heat functional fluids. The stability of latent heat functional fluids can be enhanced by adding dispersants, but the influence mechanisms and regulatory patterns of dispersants’ intrinsic properties and service environments on this stability remain unclear. Therefore, this paper constructs a coarse-grained molecular dynamics model of latent heat functional fluids to study the effects of nonionic, anionic, and cationic dispersants’ microstructure, composition, and temperature on the stability of latent heat functional fluids. The results show that adding dispersants can improve the aggregation of capsules in functional fluids, but there are significant differences in the stability effects of different types of dispersants and temperatures. The order of dispersant’s effectiveness in promoting the dispersion stability of latent heat functional fluids is as follows: nonionic polyvinyl alcohol (PVA), anionic sodium dodecyl sulfate (SDS), and cationic cetyltrimethylammonium bromide (CTAB).

To study the kinetics mechanism on supercritical water conversion of shale for gas production, the experiment was carried out in a batch reactor with high temperature and pressure, which the reaction temperature and reaction time were 450—550℃ and 0—480 min, respectively. The results show that the intermediate products have complex compositions, but are mainly dibutyl phthalate and naphthalene derivatives. The gases produced are mainly CH₄, C₂H₆, C₃H₈, H₂ and CO₂. The total gas production increases with temperature and reaction time. A simple iterative method based on Peng-Robinson (PR) equation is used to calculate the amount of substance in the gas mixture. Based on the experiment results and lumped parameter method, the reaction kinetics model of shale-intermediate-gas was established. This model can explain the oil and gas changes caused by chemical reaction of shale in supercritical water atmosphere, and can quantitatively describe the mutual conversion of gases. The determination coefficient of the calculated and experimental values of the model is greater than 0.98, which indicates that gas concentrations for different reaction times can be fitted within acceptable deviations over the experimental temperature range. In this study, the mechanism of shale transformation and gas production in supercritical water has been more deeply understood. This provides a deeper understanding for gas production mechanism of shale by supercritical water conversion.

In this study, a series of Cu-based monolithic catalysts with different Mn/Ce doping ratios were synthesized and used for catalytic combustion activity testing of dilute methane. Among them, the 4Cu-3Mn-1Ce catalyst exhibited the best methane catalytic activity with a conversion of 85.0% at 550℃ and achieved complete conversion at 600℃. The mechanism of the effect of Mn/Ce doping on the physicochemical properties of Cu-based monolithic catalysts was investigated by characterization analysis, including in situ Fourier Transform infrared spectroscopy (in situ FTIR), and density functional theory (DFT) simulation calculations. The enhanced methane catalytic combustion activity of the Cu-based monolithic catalysts can be attributed to the following: Ce doping forming a Ce-Cu solid solution, weakening the Cu—O bond, and promoting lattice oxygen diffusion at high temperatures, thus enhancing high-temperature catalytic activity; and Mn doping promotes the adsorption of O₂ on the catalysts, which strengthens methane oxidation at low temperatures; Mn/Ce co-doping strengthens the activation of O₂ and its dissociation to *O, which fills the oxygen vacancies and regenerates into lattice oxygen, the co-doping strengthens the cycle of oxygen species and thus significantly improves the catalytic combustion activity of thin and dilute methane.

Hydrogen storage in hydrates offers advantages of environmental friendliness and high economic efficiency, and has broad application prospects in energy storage. In the early stages of hydrate synthesis, gas molecules tend to form supersaturated states, which in turn induce the formation of nanobubbles and affect the hydrogen storage efficiency of hydrates. Therefore, this paper takes nanobubbles as the research object and adopts the molecular dynamics method to analyze the evolution law of nanobubbles and explore the influence of nanobubble evolution process on gas molecular diffusion, water molecular order and gas interaction during the synthesis of hydrogen-storage hydrates using a mixture of methane and hydrogen gases. The results show that the formation of nanobubbles undergoes an expansion phase and a stabilization phase, effectively promoting gas molecule diffusion. However, the promoting effect of nanobubbles on methane molecules is stronger than that on hydrogen molecules, which affects the hydrogen-storage density of hydrates. Nanobubbles improve the order of water molecules during the expansion phase, and the order of water molecules gradually tends to be constant during the stabilization phase. Hydrogen molecules tend to accumulate in the central region of the nanobubble, while methane molecules are enriched at the gas-liquid interface. Although this distribution is conducive to hydrate nucleation, it may affect the hydrogen content in hydrate structures.

Coarse-grained models are widely used to accelerate discrete element method simulations. For polydisperse particle systems, the number of particles increases with the cube of the particle size ratio. Traditional coarse-grained models cannot reduce the huge computational cost caused by the increase in particle size ratio because they use the same scale to scale particles of different sizes. To solve this problem, a variable-scale generalized coarse-grained model is proposed based on the consistency of the dimensionless contact equation, includes a new model named the constant surface energy (CSE) model, alongside the existing constant relative overlap (CRO) and constant absolute overlap (CAO) models. The applicability of the variable-scale generalized coarse-grained model in multi-particle simulations is verified through the angle of repose and uniaxial compression process. The CRO and combined CSE-CRO models show better consistency with the original bed using uniform and variable scaling ratios, respectively. The results show that the CSE-CRO model can reduce the calculation time by about 80% when the small particle scaling ratio is 2, and the mean relative error is less than 2%.

With the rapid advancement of 5G technology, electronic devices are evolving toward higher integration and miniaturization, leading to a significant increase in heat flux. However, traditional loop heat pipes (LHPs) face limitations in heat flux density due to inherent heat leakage issues, failing to meet emerging thermal demands. In previous studies, an innovative injector-integrated loop heat pipe (LHPI) was developed and demonstrated superior thermal management performance. However, early experiments utilized water as the working fluid, which suffers from low freezing points and ice formation in low-temperature environments, restricting its broader application. To address this, this study introduces a novel low-freezing-point refrigerant, HP-1, and systematically investigates the effects of heat loads (50—300 W) and heat sink temperatures (5—15℃) on LHPI performance. Experimental results reveal that the injector's operational modes—classified as low-efficiency, normal injection, restricted expansion, and superheated modes—significantly influence LHPI's heat transfer characteristics. At elevated heat sink temperatures, the transition to restricted expansion and superheated modes occurs earlier. Compared with water-based working fluids, HP-1 increases the heat flux of LHPI to 41.7 W/cm² at a base plate temperature of 85℃, and its low temperature adaptability is significantly enhanced, providing a new idea for passive heat dissipation of high-power electronic devices.

In industrial and agricultural settings, obliquely impacting droplets on a liquid film is a common phenomenon with significant scientific and practical importance. However, due to limitations in experimental techniques, the heat transfer characteristics associated with this oblique impact have not been systematically explored. In this study, we address this gap by employing a super hydrophobic guide rail to stably generate droplets at controlled impact angles, enabling a detailed experimental investigation into the heat transfer behavior of oblique droplet impact on a liquid film. The cooling performance across the observed region is quantitatively evaluated using the peak value and standard deviation of the wall cooling coefficient. The study found that the wall cooling process can be divided into a rapid cooling stage and a recovery stage, and the time scale of the rapid cooling stage is much smaller than that of the recovery stage. Both the peak value and standard deviation of the wall cooling coefficient decrease with increasing Weber number and impact angle, while they increase with higher heating power. During the recovery phase, at any given time, both parameters continue to decrease with larger Weber numbers and impact angles, and their rate of change grows more pronounced with increasing heating power.

The spouted fluidized bed has been widely applied in the fields such as the preparation of energy storage particles due to its ability to achieve stable particle circulation at the scale of the reactor. However, the circulation of particles is affected by operating conditions, container size and other conditions, which makes it difficult to scale up the bed. The idea of this paper is to abandon the concept of vertical independent spouting, and instead the use of the coordinated spouting dual nozzles as the basic unit to scale-up the bed. The research shows that in two-dimensional and three-dimensional rectangular spouted bed, the coordinated deflected spouting of dual nozzles has a higher gas-solid mixing efficiency and a wider operating range. After 20 seconds of gas-solid mixing in the two-dimensional spouted bed, the temperature drop of the dual nozzle compared with the single nozzle increased by 12%, and the variance of particle temperature decreased, demonstrating stronger uniformity. When the dual nozzle bed is longitudinally expanded to four nozzles, a slugging fluidized state is very likely to occur. By moderately reducing the gas velocity to 1.75—2.00 m/s, the four-nozzle spouted bed can achieve independent vertical jet movement of multiple nozzles and has an excellent gas-solid mixing effect. This study deeply reveals the important value of the coordinated spouting unit of dual nozzles in the scaling-up of the spouted bed, and opens up a new path for the scaling-up design of rectangular spouted beds.

In large-eddy simulations (LES) of gas-solid two phase turbulent flows, the absence of subgrid-scale (SGS) turbulence information introduces significant inaccuracies in predicting the motion characteristics of the dispersed phase. To date, all particle subgrid models are based on one-way coupling conditions. With the adaptive mesh algorithm based on wavelet discrete errors, this study addresses this limitation by developing a novel gas-solid turbulence large eddy simulation platform under two-way coupled conditions. The subgrid velocity model seen by particles based on differential filter (DF) was then applied to the simulation of decaying gas-solid homogeneous isotropic turbulence. Comparative analysis of particle-pair statistics in pre-/post-model implementation simulations demonstrates that the proposed approach effectively restores dispersed-phase accuracy while validating its efficacy under high-volume-loading two-way coupling conditions. The inclusion of the DF model achieves enhanced simulation accuracy for the dispersed phase while maintaining relatively low computational costs. It reduces the relative error of the particle pairs radial distribution function with moderate inertia by about 28%, and the relative error of the radial relative velocity by about 13%. This study establishes critical theoretical foundations for advancing engineering applications in industrial particulate systems, particularly enhancing predictive capabilities for fluidized bed dynamics and multiphase reactor optimization.

The flow boiling heat transfer characteristics of deionized water in open microchannels and smooth copper surfaces were studied. The boiling curves, heat transfer coefficient and pressure drop characteristics were obtained at different mass fluxes. The results show that at three mass flow rates, the critical heat flux and heat transfer coefficient of the open microchannel are generally higher than those of the smooth copper surface, while the average pressure drop characteristics are the opposite. Moreover, the open microchannel can improve the backflow phenomenon to a certain extent, thus reducing the wall temperature. Although the average pressure drop of the open microchannel is 23.6%—43.3% higher than that of the smooth copper surface, the average inlet pressure standard deviation is 54.0%—62.5% lower than that of the smooth copper surface, and the flow instability of the open microchannel can be greatly alleviated by reducing the mass flux compared with the smooth copper surface.

With the advancement of space nuclear power technology, sodium-cooled fast reactors have become a promising energy solution for space systems. However, the heat transfer mechanism of liquid metal sodium boiling in microgravity is unclear, and there is a lack of effective methods to prevent heat transfer degradation. This study conducts a numerical investigation on liquid sodium flow boiling in space sodium-cooled fast reactors under microgravity using a two-fluid model. A comparative analysis of heat transfer performance between microgravity and normal gravity conditions is performed, and the effects of inlet velocity and subcooling degree on boiling behavior in vertical channels under microgravity are systematically examined. The results demonstrate that, compared to normal gravity, microgravity degrades the boiling heat transfer performance of liquid sodium, advances the boiling onset time, and increases susceptibility to heat transfer deterioration. Enhancing inlet velocity or subcooling significantly improves heat transfer under microgravity. Notably, no heat transfer deterioration occurs when the inlet velocity reaches 2.0 m·s^-1 combined with an inlet subcooling of 300 K. This work elucidates the unique heat transfer characteristics of liquid sodium flow boiling under microgravity and provides critical theoretical insights for the safety design of the primary loop in space sodium-cooled fast reactors under microgravity environments.

Magnetic nanofluids have important applications in energy engineering due to their unique magnetically induced directional arrangement characteristics and heat transfer enhancement performance. A multi-force particle dynamics model, incorporating magnetic forces, was developed using the lattice Boltzmann method (LBM) coupled with the discrete element method (DEM). The orientation tensor was introduced to quantitatively characterize the spatial structure of particle chains under varying magnetic fields. The results show that the degree of particle alignment along the magnetic field direction increases with the strength of the applied field. Under magnetic field strengths of 200, 500, and 1000 G, the orientation tensor components in the magnetic field direction were 0.506, 0.758, and 0.972, respectively. Additionally, the thermal lattice Boltzmann method (T-LBM) was employed to simulate the thermal conductivity under magnetic field regulation. The mechanism by which the orientation tensor effectively quantifies anisotropic thermal conductivity through the characterization of the spatial configuration of particle chains was elucidated. A modified model incorporating the orientation tensor was proposed, demonstrating good predictive capability for magnetically induced anisotropic thermal conductivity.

Energy shortage and environmental pollution are particularly prominent problems in the aviation industry. Biofuels, as an emerging energy source, have the potential to directly replace traditional petroleum fuels. Based on the genetic algorithm, a multi-objective optimization of the proportion of RP-3 alternative fuel components was carried out using physical parameters such as density, kinematic viscosity, low level calorific value, hydrogen to carbon ratio and molecular weight as the selection criteria. The accuracy of the model was verified under atmospheric and critical pressure conditions. It is shown that the optimal alternative fuel consists of 32.78% n-butyl ether, 14.64% 2-methylfuran, and 52.58% second-generation biodiesel. The overall error in physical and chemical properties is within 3%. The model demonstrates high reliability of key physical properties under a wide range of environmental conditions. In addition, the chemical substitutability was verified by constructing a semi-detailed reaction mechanism for bioalternative fuels containing 192 components and 1482 radical reactions. The results showed that the model's ignition delay time was in good agreement with the experimental values, which is of great significance for the optimal design of biofuels.

This study investigates two-phase turbulent flow in square tubes using the Nek5000 solver using two-way and four-way direct numerical simulation coupled Lagrangian particle tracking (DNS-LPT). Compared with one-way coupling, two-way and four-way coupling reduce the average velocity of the fluid and accurately reflect the turbulence intensity of the flow field. For the particle phase, two-way coupling promotes particle accumulation near the wall and increases the streamwise velocity of high-inertia particles (St⁺ ≥25) in the core region. Four-way coupling suppresses the accumulation of high-inertia particles (St⁺≥25) near the wall and increases their streamwise velocity in that region.

The flexible and stable regulation of small module reactors is of great significance for the safe operation, and the dynamic characteristics of once-through steam generators with valve regulations in small modular reactors is extremely important for the regulation strategy. In this study, a dynamic model of the secondary loop was developed using the vPower platform. And the behaviors of the secondary side of the OTSG under step disturbances of the inlet and outlet valves were investigated, focusing on the main steam parameters at the outlet of the OTSG and the local heat transfer characteristics in the OTSG. Initially, disturbances in the inlet valve have a greater impact on the main steam parameters compared to the outlet valve. When subjected to a step disturbance of ±10%, ±15%, ±20%, the fluctuations in main steam mass flow rate, pressure, and temperature caused by the inlet valve are 2.09 to 14.09 times, 1.78 to 6.67 times, and -1.67 to -14.38 times larger than those caused by the outlet valve, respectively. Additionally, the buffering effect of the compressible volume in the OTSG on the flow rate and pressure was discovered, which limits the overshoot caused by valve disturbance to the vicinity of the valve. Furthermore, under inlet and outlet valve disturbances, the local pressure drop ratios and internal enthalpy rise rates of the steam generator vary, resulting in opposite trends in the impact of inlet and outlet valve disturbances on internal pressure and main steam temperature. The results have significant guiding significance for the operation control strategy of the OTSG in the secondary circuit.

Liquid-phase discharge plasma technology can break through the limitations of the traditional thermochemical pathway and realize rapid on-line decomposition of liquid fuels for hydrogen production at ambient temperature and pressure. In this study, a new high-voltage electrode based on porous nickel material was designed, and a visual discharge experimental platform was constructed to systematically carry out the characterization of methanol liquid-phase discharge plasma decomposition for hydrogen production, focusing on the analysis of the discharge mode, the bubble behavior, the energy-mass transfer characteristics and their effects on the hydrogen production performance. The experimental results show that in the sliding arc discharge mode, the use of porous electrodes significantly increases the plasma bubble volume and improves the spatial and temporal distribution of the discharge channel, which effectively enhances the reaction interface between methanol and plasma and the mass transfer efficiency. Compared with the traditional needle electrode, the use of porous electrodes increased the hydrogen production rate to 791.6 ml/min, a 38% increase. The unit energy consumption for hydrogen production was reduced to 1.45 kWh/m³ H₂, a 33.78% decrease. During the long cycle operation, the methanol decomposition performance decay rate of the porous electrode system was reduced by more than 72% compared with the traditional system, showing excellent operational stability and lifetime characteristics. The results provide a theoretical basis and key technical support for the design of liquid-phase plasma hydrogen generation reactor with high efficiency and stability.

Double-emulsion droplets are droplets that contain smaller droplets inside which are often used as reaction units to achieve various functions and have attracted much attention due to their unique core-shell structure. In this paper, we propose to use laser photothermal effect to induce thermocapillary flow to achieve core-droplet coalescence of double emulsion droplets. We use couple level set and volume of fluid method (CLSVOF) to track phase interface and study its characteristics of core coalescence. The results show that when the laser irradiates the centers of two internal droplets, the local thermal effect of the laser induces the formation of thermal capillary flow at the internal and external interfaces, which together drive the internal droplets closer to each other for coalescence. When the radius of laser increases from 20 μm to 50 μm, the thermal capillary migration is stronger due to the increase in heat absorbed by the internal droplets, leading the coalescence-begin gradually shortened. As the spot radius increases further, the onset of coalescence gradually delays. Lower laser power leads to later coalescence. The larger the radius of the internal droplet, the earlier the internal droplet coalesces due to the increased absorbed heat and the shorted initial interface distance.

A simultaneous measurement method for high-temperature gas flow velocity and temperature fields is developed based on phosphorescent particle tracing and full-field intensity ratio calibration. BaMgAl₁₀O₁₇∶Eu²⁺ (BAM∶Eu) phosphorescent particles are employed as dual-function tracers for both flow visualization and temperature sensing. The velocity field is extracted through cross-correlation analysis of time-sequenced phosphorescent images, while the temperature field is reconstructed using the intensity ratio method applied to dual-wavelength phosphorescent images. A dual-channel imaging system is developed based on the excitation spectral characteristics of BAM:Eu particles. To compensate for spatial non-uniformity in the optical response, a full-field calibration method is proposed, establishing a high-resolution temperature calibration database over the range of 27—500℃. To evaluate the feasibility of this method, a high-temperature air free jet experiment platform was built, and simultaneous measurement experiments were conducted under different operating conditions. Experimental results demonstrate that, within the temperature range of 100—500℃ and velocity range of 15—40 m/s, the relative error and relative standard deviation are below 0.98% and 1.17% for temperature measurements, and below 1.89% and 2.84% for velocity measurements, respectively.

In the process of oil exploitation, some crude oil will be difficult to extract clearly, resulting in a reduced recovery rate and waste of resources. Supercritical CO₂ is a green solvent with excellent properties. The use of supercritical CO₂ to drive oil flow can enhance oil extraction and improve oil recovery. It is important to investigate the microscopic mechanism of petroleum hydrocarbon extraction by supercritical CO₂ at the molecular level. The compatibility between supercritical CO₂ and various petroleum components was studied using molecular dynamics simulations. The dissolution process of petroleum molecules in supercritical CO₂ was analyzed, and the strengthening effect of cosolvents on the dissolution process was discussed. The results show that the solubility parameter value of supercritical CO₂ is less sensitive to pressure changes under low temperature conditions than to pressure changes under high temperature conditions. For different kinds of petroleum hydrocarbons, the solubility parameters of alkane and aromatic hydrocarbons gradually increased with the increase in carbon number. The solubility parameters of naphthene didn't change significantly with the increase in carbon number. Furthermore, the addition of cosolvent in supercritical CO₂ could effectively improve the solubility of petroleum hydrocarbon molecules, among which methanol has the best solubilization effect. Adding 10% methanol can reduce the solubility parameter difference between supercritical CO₂ and benzopyrene by 25.49%.

With the increasing demand for rapid, safe, and convenient nucleic acid detection technologies, this study designs a visual detection microfluidic chip based on the principle of nucleic acid precipitation and channel blockage. Inspired by the ethanol purification process of nucleic acids and the filtration principle of microfilters, this method utilizes the physical blockage effect of precipitated nucleic acids to achieve visual detection. After specific amplification of the target nucleic acids, ethanol is used to precipitate them, thereby enabling visual detection of the target nucleic acid. We designed the microfluidic chip using poly(methyl methacrylate) (PMMA) microspheres as the porous medium. Thirty repeated experiments were conducted on this microfluidic chip, all of which successfully detected the target within 10 minutes, demonstrating practicality and high accuracy. This qualitative reading method is applicable to all pathogens in principle and is compatible with both isothermal and non-isothermal amplification techniques. Additionally, the chip's internal environment is maintained under negative pressure throughout the process, and it is treated multiple times with alcohol, providing dual safety measures and enhancing the safety of its application in point-of-care testing (POCT).

A segmented micro-nano porous coating structure was fabricated on the inner wall surface of a stainless-steel heat transfer tube by a combined sintering and electroplating process. Flow boiling heat transfer experiments with R245fa as the working fluid were conducted in a horizontal tube. The experimental conditions were: saturation pressure of 0.6 MPa, mass flux ranging from 200 to 700 kg/(m²·s), heat flux ranging from 5 to 75 kW/m², and inlet vapor quality between 0.01 and 0.9. Experimental results indicate that constructing porous structures with different pore sizes along the tube flow direction can effectively enhance boiling heat transfer by adapting to flow pattern transitions. The enhanced tube exhibited a significant improvement in flow boiling heat transfer performance, with a maximum enhancement of up to 2.71 times compared to a smooth tube. The smaller pore structure at the outlet facilitates the capture of micro-droplets, enhancing their adsorption onto the heat exchange surface. This mechanism ensures efficient liquid replenishment, thereby mitigating the formation of wall dry-out. Flow visualization revealed the presence of three flow patterns during the experiments: stratified flow, annular flow, and dryout.

Water-cooled generators are extensively employed in nuclear, thermal, and hydraulic power plants. However, the hollow copper conductors within generator stators are susceptible to corrosion and plugging in the internal cooling water system, which can lead to abnormal system operation and even safety accidents. Uncovering the corrosion and plugging mechanism and developing corrosion and plugging control technologies based on this mechanism is of great significance. This review highlights the unique characteristics of stator internal cooling water systems and outlines the risks associated with corrosion and plugging. It systematically summarizes the underlying mechanisms, including the formation, release, and localized deposition of copper corrosion products, and reviews current water chemistry control strategies aimed at mitigating these issues. The review further re-evaluates the corrosion and plugging tendencies of copper conductors under varying water chemistry conditions, integrating both theoretical insights and field practices. The findings indicate that slightly alkaline water chemistry conditions are more effective in suppressing corrosion and minimizing plugging risks. Finally, the review discusses future research directions from both the aspects of mechanism study and engineering application. To better support the safe and economical operation of water-cooled generators, it is recommended to further investigate the kinetics of corrosion and plugging processes and to develop an integrated system status monitoring and fault diagnosis platform.

The mixture formed by refrigerants and lubricating oils is present in various components of the refrigeration system, and its phase equilibrium characteristics are of significant importance for the design optimization of thermodynamic cycles and components. Using the PC-SAFT state equation based on statistical associating fluid theory, the gas-liquid phase equilibrium of binary mixtures of seven low-GWP refrigerants such as R1234yf, R600a, R744, etc., with lubricating oils PEC4—PEC9 was calculated. The results show that the PC-SAFT model has good consistency with experimental results, and the average pressure deviation is mostly within 6%. Meanwhile, to further expand the model's predictive performance for complex multicomponent mixture phase equilibrium, a BP neural network model was used to train the binary interaction parameters of the PC-SAFT state equation, and the predicted binary interaction parameters were used for the phase equilibrium calculation of binary systems lacking experimental data, such as R1233zd(E)/PEC lubricating oil, multicomponent complex systems R744/POE lubricating oil, and R290/POE lubricating oil. The k_ij predicted by the neural network model was used to predict these complex multicomponent systems, with an average pressure deviation of 8.99%, indicating its applicability to practical engineering calculations.

In order to quantitatively describe the cleaning ability of ice-pigging, this study analyzes the characteristics of supercooled ice slurry cleaning through experimental research. Firstly, the morphology of supercooled ice slurry particles produced from a 5% NaCl solution was studied, and the interpolation estimation method was used to determine an average ice crystal particle size of 275 μm with a roundness of 0.64. The shear stress of ice slurry plungers with an ice volume fraction of 22.7%—33.5% was investigated, revealing that it is primarily influenced by ice fraction and pushing water flow velocity, with minimal dependence on solution salinity. This study primarily investigates the performance degradation characteristics of ice-pigging. Research on the permeability characteristics of ice slurry plungers revealed that both the pushing water flow rate and porosity significantly influence the permeability rate: the higher the pushing water flow rate and porosity, the faster the permeability rate. When the plunger length accounted for 10% of the total pipe length, at temperatures of 6, 9 and 12℃ respectively,the ice slurry plungers advanced 21.5 m along the pipe section, with pressure drop retention rates of 87.02%, 81.13% and 74.21%, respectively. The pressure drop retention rates decreases by 5.89% and 6.92%, respectively, for each 3℃ temperature increase. When the plunger length was 20% and the temperatures were 15, 18 and 21℃, respectively, the pressure drop retention rates decreased by 1.75% and 3.09%, respectively, due to the effect of a 0.02 m/s increase in the driving water velocity. The pressure drop reduction caused by the increase in driving water temperature cannot be ignored. Based on the impulse law, the retention rate of ice slurry plunger cleaning ability was defined, and its attenuation performance was studied. At plunger lengths of 10%, 20% and 30%, the ice slurry plunger advances 21.5 meters, with cleaning ability retention rates at 6℃ of 67.18%, 79.60% and 86.67%, respectively. For every 1℃ temperature increase, the cleaning ability decreases by approximately 1.1% at 10% and 20% plunger lengths and by about 0.9% at a 30% plunger length.

To investigate the dynamics and vaporization characteristics of droplet impact on a hot wall, a visualization experimental system was designed and built. The phase change characteristics of the droplet were studied, and numerical simulations were conducted for typical conditions. The investigations found that the wall temperature and droplet impact velocity are important factors affecting droplet deformation and wall heat transfer. An increase in impact velocity promotes droplet spreading, increases the contact area between the droplet and the wall, thereby enhancing heat transfer. At the same time, the thinning of the liquid film also facilitates heat transfer. An increase in wall temperature accelerates droplet vaporization, triggering the phase morphological evolution of the droplet, presenting six phase states: film evaporation, contact boiling, fragmentation and atomization, atomization bouncing, film splash, and central jet.

Liquid-centered swirl coaxial injectors can effectively increase the specific surface area of droplets and enhance the atomization effect, which is widely used in industrial technology. In this research, an experimental work was presented on the contribution of the aerodynamic effect (air assisting or not) and operating factors (liquid pressure, gas pressure and gas-liquid ratio) on droplet size distribution generated by single-fluid swirl nozzles and liquid-centered swirl coaxial (LCSC) injectors. The stable operating conditions were clarified, which could avoid the deterioration of atomization effect caused by pressure fluctuations during operation. The results show that, unlike the single-peak distribution of swirl nozzles, the droplet size distribution of coaxial gas-liquid centrifugal nozzles exhibits a bimodal distribution, and gas shear force significantly improves the atomization performance. When the gas-liquid outlet area ratio is 48, operating in gas pressure of 0.25 MPa and liquid pressure of 0.6 MPa, Sauter mean diameter (SMD) reaches a minimum of 36.5 μm, which is 84.3% lower than that without air assisting. Moreover, LCSC injectors can reduce the atomization dependence on operating pressure. When the gas pressure is over 0.1 MPa and gas-liquid ratio is over 0.28, SMD will be not sensitive to the liquid pressure. An empirical correlation for both single-fluid swirl nozzles and LCSC injectors is developed by dimensional analysis to predict the atomization droplet size. It is expected to improve the atomization efficiency, and reduce pressure dependence during operation.

Phase separation structure microchannels have attracted considerable attention due to their high heat transfer efficiency and minimal pressure fluctuations. The effect of phase separation structure on the heat transfer property and temperature uniformity of microchannel was studied, this paper conducts research on three types of phase separation hole counts: 10-hole N1 type, 20-hole N2 type and 30-hole N3 type, as well as three types of phase separation arrangement positions: midstream and downstream (Type A), upstream and downstream (Type B), and upstream, midstream, and downstream (Type C). Ethanol is used as the working fluid, and flow boiling experiments are conducted in a rectangular counterflow microchannel with a cross-section of 2 mm×2 mm under conditions of heat flux density ranging from 15.05 to 124.89 kW/m², inlet temperature of 40℃, and mass flow rate of 102.50 kg/(m²·s). Pulsating pressure is applied to the forward channel to achieve gas phase separation. The effects of the phase separation structure were analyzed by introducing parameters such as the heat transfer enhancement factor, along-line wall temperature distribution, average wall temperature, and temperature standard deviation. The research results indicate that, at a constant transmembrane pressure, the heat transfer coefficient reaches its maximum when the number of phase separation holes is 20, and further increasing the number to 30 does not significantly enhance the heat transfer effect. In comparison with the non-phase-separation operational conditions, the maximum heat transfer enhancement factor in the microchannel with phase separation structures reaches 1.92, while the maximum standard deviation of two-phase wall temperature along the path is reduced by 44%. This suggests that phase separation microchannels can effectively improve the heat transfer efficiency and temperature uniformity in microchannels.

During the transcritical depressurization process of a circulating fluidized bed (CFB), abrupt changes in fluid thermophysical properties within heating surfaces can lead to heat transfer deterioration, causing a sharp rise in wall temperature. It is imperative to conduct transient safety analysis under transcritical conditions to ensure system operational safety. To address this, a mathematical model was established to simulate the transcritical depressurization process of supercritical water in CFB heating surfaces, and a numerical program was developed using Fortran. The program employs one-dimensional transient governing equations to describe fluid flow, while transient heat conduction equations are utilized to simulate heat transfer in the tube wall. At the transcritical moment, critical temperature and critical enthalpy are adopted as criteria for local heat transfer mode transitions. A wetting front migration model is integrated to simulate the sequential temperature recovery in dried-out wall regions. Comparison with experimental results demonstrates that the program can accurately simulate the flow and heat transfer characteristics of the transcritical processes. The program effectively predicts varying degrees of heat transfer deterioration, providing a reliable means for safety analysis of heating surfaces during depressurization.

Floating offshore nuclear power plant is considered a promising solution to address marine energy shortages. However, their oscillatory motion under wind and wave conditions causes fluctuations in the void fraction of gas-liquid two-phase flow within steam generators, posing challenges to operational safety. To overcome the limited applicability of existing models for calculating cross-sectional void fraction under fluctuating vibration, this study proposes a novel prediction model integrating convolutional neural networks (CNN), gated recurrent units (GRU), attention mechanisms, and the whale optimization algorithm (WOA). Experimental results demonstrate that the proposed model has good applicability for predicting void fractions in both horizontal and vertical upward pipes under fluctuating vibration. Additionally, the model shows robust performance across varying flow patterns. This research provides a new method for accurate void fraction prediction in fluctuating gas-liquid two-phase flows, offering theoretical support for design and operational optimization of steam generators of floating nuclear power plant.

A mathematical model was established based on a sample of a novel rectangular printed circuit board heat exchanger (RM-PCHE). The coupled heat transfer characteristics of supercritical CO₂ within the RM-PCHE were investigated through numerical simulation. The reliability of the numerical model was validated against experimental data, with the maximum relative error in heat transfer performance quantified at 11.2% under the tested conditions. This result demonstrates the credibility of the simulation outcomes. Numerical analysis results show that under typical low-temperature regenerator operating conditions, the heat transfer performance of supercritical CO₂ is influenced by both specific heat and thermal conductivity. On the hot side, due to the approximately constant thermal conductivity, the heat transfer performance of supercritical CO₂ is primarily dominated by specific heat. Moreover, compared with turbulence intensity, the thermophysical properties of supercritical CO₂ are the primary factor affecting its heat transfer, leading to the heat transfer coefficient of supercritical CO₂ on the cold side of rectangular printed circuit heat exchanger consistently being higher than that on the hot side. Additionally, due to the baffle in rectangular printed circuit heat exchanger enhancing the fluid's turbulent diffusion capacity, the existing correlation consistently underestimates the heat transfer performance of supercritical CO₂. Therefore, based on simulated data and incorporating the effects of thermophysical property variations and turbulence intensity on heat transfer, modified heat transfer correlations for supercritical CO₂ were developed. Under the simulated conditions, the maximum deviations of the hot-side and cold-side correlations for the rectangular printed circuit heat exchanger using supercritical CO₂ as working fluid were 2.3% and 6.8%, respectively.

In order to solve the problem of easy inactivation of Cu⁺ in 1-amino-4-bromoanthraquinone-2-sulfonic acid (bromaminic acid) amination reaction, a basic copper carbonate electrocatalyst containing Mn to promote Cu²⁺ release was designed and prepared, and the amination of bromaminic acid was carried out by electrochemical reduction method in a two-electrode system. The effects of reduction voltage and electrocatalyst composition on the arylation reaction were studied by cyclic voltammetry (CV), scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS), and substrate expansion and amplification experiments were carried out. The results showed that the prepared basic copper carbonate electrocatalyst containing Mn could effectively promote the release of Cu²⁺, and could be reduced to Cu⁺in situ to catalyze the amination of bromaminic acid with 2,4,6-trimethyl-1,3-diaminobenzenesulfonic acid (M acid) at a reduction voltage of -0.4 V, with the yield reaching 93% and the debromination byproduct only 3%. The amination yields of aniline, 3-acetylaminoaniline and 4-acetylaminoaniline could reach more than 90% by this strategy. In addition, the amination reaction of bromaminic acid with M acid in 20 g (bromaminic acid) grade achieved 90% yield, which has excellent amplification potential.

To develop hybrid materials with strong affinity for 2-phenylethanol (2-PE), β-cyclodextrin-based metal-organic frameworks (β-CD-MOFs) were fluorinated using 1H,1H,2H,2H-perfluorooctyltriethoxysilane (13F) via silanol condensation. Subsequently, rutin (represented as LD) was grafted onto the fluorinated β-CD-MOFs through nucleophilic substitution and silanol condensation reaction to prepare L-13F-βMOFs. L-13F-βMOFs were added to polydimethylsiloxane (PDMS) matrix to prepare mixed matrix membranes for 2-PE pervaporation separation. The chemical structure and morphology of the filler were characterized by FTIR, XPS, and SEM. The chemical composition, cry stalline structure, and hydrophilicity/hydrophobicity of mixed matrix membranes were characterized by ATR-FTIR, solvent uptake measurements and contact angle analysis. Meanwhile, the effects of membrane preparation and separation process conditions on pervaporation performance were optimized, and the effect of maltol in the separation of 2-PE in a ternary system was investigated to explore competitive adsorption and permeation. Furthermore, the 2-PE separation mechanism of mixed matrix membranes was investigated. The as-prepared mixed matrix membranes demonstrated a total flux of 1398 g·m^-2·h^-1, a separation factor of 32.67, and a pervaporation separation index of 44270 g·m^-2·h^-1. These values are 1.69, 2.74, and 4.95 times higher than those of the pure PDMS membrane, and 1.47, 1.78, and 2.61 times of the PDMS-based mixed matrix membranes with added β-CD-MOFs, respectively. This performance enhancement is attributed to the hydrophilic/hydrophobic interactions, π-π interactions, and hydrogen bonding between the —Si—O—, phenyl rings, and F atomics in L-13F-βMOFs and 2-PE, which improve the affinity for 2-PE. When the concentration of maltol in the feed solution increased to 1.2×10^-3, the 2-PE flux and 2-PE/water separation factor of mixed matrix membranes decreased by only 19% and 21%, respectively, indicating excellent molecular recognition capability for 2-PE. During a 168 h stability test, the separation performance of the mixed matrix membranes showed no significant changes, demonstrating the great potential for 2-PE separation applications.

Hydrogen-driven electrochemical carbon capture systems (HECCS) have been widely attracted attention due to their low energy consumption and high selectivity. Establishing a quantitative relationship between the multiple ions coupled transport mechanisms in HECCS and operating parameters such as current density, capture concentration, and temperature is the key to elucidating the underlying carbon capture mechanisms. Based on the Maxwell-Stefan diffusion equation, this paper establishes a mass transfer-electric field coupled multiphysics model for the carbon capture process in the HECCS system, taking into account multi-ion coupling transport. The results show that the proposed model can effectively simulate the multiple ions transport in the HECCS system. By analyzing the coupled behaviors of pH distribution, electrolyte potential, and the transport of OH^-, \mathrm{H}\mathrm{C}{\mathrm{O}}_{\mathrm{3}}^{-} and \mathrm{C}{\mathrm{O}}_{\mathrm{3}}^{\mathrm{2}-} ions within the membrane electrode assembly, the rate-limiting steps under different operating conditions are identified. The influences of various operational parameters and key controlling factors on CO₂ capture flux and faradaic efficiency are determined, clarifying the mechanisms by which operating conditions affect carbon capture performance. This work provides a theoretical and computational foundation for the performance improvement and optimal design of electrochemical CO₂ capture system.

Solid oxide fuel cell (SOFC) is of great significance in promoting the development of low-carbon energy technology due to its high efficiency and clean energy conversion characteristics, while the optimization study of SOFC integrated system further improves the system efficiency and long-term stability through the synergistic regulation of multi-parameter, which is of great significance in promoting the development of low-carbon energy technology. In this study, based on the SOFC model with rectangular obstacles set up in the cathode and anode flow paths, the Plackett-Burman (PB) experimental design was used to screen the key operating parameters, and the parameter interactions were analysed using the response surface analysis methodology to determine the necessity of multi-objective optimization. The parameter ranges were determined by a one-factor test, and key factors such as operating temperature, pressure and oxygen concentration were screened and combined with auxiliary system parameters to establish a response surface model. The NSGA-Ⅱ and MOPSO-GA algorithms were used to perform multi-objective optimization of system efficiency and recession rate, and the results showed that: after NSGA-Ⅱ optimization, the system efficiency reached 87.19% (an increase of 22.62%), and the recession rate was 71.75% (an increase of 4.64%); after MOPSO-GA optimization, the efficiency was 83.89% (an increase of 19.32%), and the recession rate was 68.12% (1.01% increase).NSGA-Ⅱ is superior in terms of efficiency improvement, while MOPSO-GA is more suitable for long-term stable operation requirements.

Ultra-high-pressure dry gas seals, as non-contact seals operating under extreme conditions, are significantly affected by thermal deformation in high-temperature and high-pressure environments. Thermal deformation research is crucial for the long-term stable operation of the seals. Aiming at the extreme working conditions of high temperature and high pressure with high rotational speed, a performance analysis model of fluid-solid-thermal multi-physical field coupling is established, The influence of thermal coupling deformation on the sealing performance is studied, and the deformation compatibility analysis and optimization study is carried out to investigate the comprehensive influence of the optimized structure on the sealing performance, and obtain the suitable operating range of the ultra-high-pressure dry gas seals. A high-pressure sealing test device is established, and the accuracy of the model is verified in the test. The study shows that when the ratio of the axial thickness of the dynamic ring M_d is 1.05—1.10, and the ratio of the axial thickness of the static ring M_f = 1.20, the gap is nearly ideal parallel gap, and the sealing performance is the best. When the ratio of the friction force of the flooded ring at the equilibrium diameter to the elasticity of the spring S_f is 0.60—0.80, the sealing performance reaches the optimum. The suitable operating conditions are pressure 0—14 MPa, linear velocity 30—160 m·s^-1, and temperature 50—200℃, which provides theoretical references for the design of the structural parameters and working conditions of the ultra-high-pressure dry gas seal.

To address the poor wettability and insufficient interfacial activity of active components in brazing silicon nitride (Si₃N₄) ceramics to metals, we proposed replacing the traditional Ti active component with Sc. Using a modified sessile drop method, we systematically investigated the wetting behavior of Sn-xSc [x=1%, 2%, 2.5% and 3%(atomic fraction)] alloys on Si₃N₄ ceramics over the temperature range of 700—800℃. The experimental findings demonstrated that the incorporation of the active element Sc substantially decreased the contact angle of the Sn-xSc/Si₃N₄ system. The wetting performance exhibited a pronounced dependence on both temperature and Sc concentration. At 800℃, the contact angle of the Sn-3% Sc/Si₃N₄ system reduced to 0°, achieving complete wetting. Interfacial microstructural analysis revealed that a reaction layer approximately 1.3 μm thick formed at the Sn-3% Sc/Si₃N₄ interface at 800℃, primarily composed of ScN and ScSi compounds. Furthermore, the formation mechanism of the precursor film was identified as conforming to the rapid adsorption-thin layer diffusion mechanism. Thermodynamic and kinetic analyses indicated that the wetting behavior of the system was governed by the formation of ScN and ScSi. This investigation provides a theoretical foundation for enhancing the wetting and interfacial bonding of Sn-Sc alloys on Si₃N₄ ceramics.

To address the stability needs of aluminum alloys in extreme environments, this study proposes a green chemical-electrochemical etching technique with stearic acid in-situ modification. A micro-nano structure on 6061 Al alloy achieves 165° contact angle(CA) and 3° sliding angle(SA). It proved exceptional self-cleaning performance in air and oil. The icing time of the superhydrophobic alloy is prolonged to 384.19 s (vs 12.85 s for the untreated alloy), showing superior environmental stability. CA of superhydrophobic alloy still over 160° after ultrasonic vibration (40 Hz, 80 min), boiling water immersion (1.5 h), linear abrasion (400 cm distance) tests, as well as retained CA of 152°after sand impact test (200 g falling sand), showing the excellent mechanical durability.

Mn and Al co-doped calcium-based energy storage materials were synthesized using safe and non-toxic precursors through a modified sol-gel method. The energy storage performance of the materials was carefully studied, and the effects of preliminary scale-up synthesis on material properties were examined. The results demonstrate that the co-doped material Ca100Mn15Al10-Ac synthesized from calcium acetate exhibited excellent stability during 1000 energy storage cycles with only 23.2% performance degradation (mainly occurring in the initial stage), and the average solar absorptance reaches 70.1%. Morphology analysis revealed that the evolution of stable porous structure during cycling effectively suppressed performance decay. The initial scale-up synthesis of the material and the addition of microcrystalline cellulose binder will not have a negative impact on the stability of Ca100Mn15Al10-Ac, which is conducive to subsequent large-scale preparation.

This work employs a multiphase particle grid method to couple sub-models for heat transfer, mass transfer, and chemical reactions, and conducts a full three-dimensional numerical simulation study on the mixed combustion process of biomass and coal in a fluidized bed. By comparing the simulation results with experimental data, the rationality of the developed model is verified. Subsequently, the gas-solid flow, gas-solid component distribution, and particle temperature distribution characteristics of the biomass and coal mixed combustion process in the fluidized bed were studied, and the effects of different inlet air mass flow rates (0.01, 0.012, 0.014 kg/s) and different fuel blending ratios (1∶4, 3∶7, 2∶3) on the temperature distribution of particle, particle heat transfer coefficient and gas product concentration were explored. The results show that due to differences in particle size and density, significant particle segregation occurred within the reactor, and a large gradient in particle temperature distribution was observed in the dense phase. Increasing the inlet air mass flow rate significantly reduces the bed material particle heat transfer coefficient and shortens the residence time of fuel particles in the high-temperature zone. When the inlet air mass flow rate increases from 0.01 kg/s to 0.014 kg/s, the mole concentration of O₂ at the outlet increases by 3.7%, while the concentrations of other gas components decrease. When the biomass blending ratio increases from 1∶4 to 2∶3, due to the high hydrogen-carbon ratio and high volatile content of the biomass, H₂O and CO₂ are promoted to be generated, resulting in a decrease of 2.1% in the mole concentration of O₂ at the outlet, an increase in the concentrations of other gas components, and an increase in the full bed layer temperature of the biomass particles, but the overall heat transfer coefficient is not significantly affected.

Calcium-cycled biomass chemical chaining gasification (CaL-BCLG) technology uses CaO-based absorbents to capture CO₂ in situ, achieving the synergistic goals of high-purity H₂ production and carbon emission reduction. It holds great promise in the clean energy sector. However, the sintering-induced deactivation of sorbents during high-temperature cycling remains a major barrier to industrial application. In this study, a series of inert oxide-doped sorbents were synthesized via a wet-mixing and calcination method, using calcined carbide slag (CCS) as the CaO precursor. Comprehensive characterization, large-sample thermogravimetric analysis, and CaL-BCLG platform tests were employed to investigate the effects of dopant type on the physicochemical properties and CO₂ adsorption performance of the sorbents. The effect of doping modification on biomass cyclic H₂ production and gasification kinetics was also systematically evaluated. The results showed that CCS exhibited a relatively high initial carbonation conversion, but suffered significant performance degradation due to sintering. Among all samples, the CCS-Si2 sorbent (mass ratio CCS∶SiO₂ = 98∶2) demonstrated the best performance, with an average maximum CO₂ uptake of 0.32 g·g_sor^-1 and a peak carbonation conversion of 47.44% after 20 cycles. The hydrogen production efficiency of biomass gasification was jointly influenced by the CO₂ capture capacity of the sorbent and the diffusion efficiency of syngas within it. When the CaO-to-carbon molar ratio (CaO/C) is below 1.0 or the steam-to-biomass mass ratio (S/B) is below 30, increasing the sorbent and steam inputs could promote the gasification reaction. However, exceeding these thresholds might hinder syngas diffusion and disrupt the temperature stability within the reactor, leading to adverse effects. Under typical conditions (temperature 650℃, CaO/C = 1.0, S/B = 30), the CCS-Si2 sorbent delivered a H₂ yield of 357 ml·g{}_{\mathrm{b}\mathrm{i}\mathrm{o}}^{-\mathrm{1}} after 10 cycles, with a CO₂ yield of only 91 ml·g{}_{\mathrm{b}\mathrm{i}\mathrm{o}}^{-\mathrm{1}}, significantly outperforming both pure CaO and unmodified CCS. This study provides theoretical insights into the resource utilization of waste carbide slag and the development of efficient and stable sorbents for CaL-BCLG hydrogen production processes.

Facing the goal of dual carbon, the flexibility of cogeneration system has become the key, and the realization of thermoelectric decoupling is an urgent task at present. To this end, a combined heat and power model equipped with an electric boiler heat storage device was constructed based on Simulink, and the dynamic characteristics of the system were studied. The NSGA-Ⅱ optimization algorithm and the TOPSIS decision-making model were used to coordinately optimize the economy, environmental protection and power supply capacity. The research shows that the introduction of electric boiler heat storage device significantly improves the performance of cogeneration system. According to the load utilization rate, the differentiated operation strategy of the electric boiler is proposed: the heat storage priority strategy is adopted in the low load utilization rate stage (≤0.2), the direct supply priority strategy is adopted in the high load utilization rate stage (≥0.7), and the mixed mode is adopted in other periods. In addition, the strategy of heat storage tank releasing heat with maximum power during the peak period of electricity price shows the best economic benefits.

The domestic and international markets have a huge demand for green electricity, leading to the widespread application of large-scale industrial and commercial energy storage systems. However, batteries face challenges such as poor thermal stability, increased side reactions under high-temperature conditions, and the risk of thermal runaway. To more effectively control the operating temperature of battery packs within the optimal range of 20—35℃, the numerical simulation study was conducted on three key factors that significantly affect the temperature characteristics of battery packs, using an experimental calibration simulation model. The three factors are different aspect ratio hole types, the layout of the liquid cooling plates, and different inlet water flow rates. The research results show that the hole-type flow channels with different aspect ratios have little effect on the battery pack temperature, but have a greater impact on the liquid flow field pressure drop and energy consumption. Compared to the simple bottom cooling method, the layout of bottom+two side liquid cooling plates can significantly reduce the maximum temperature of the battery cells by 21.8%, while greatly improving the uniformity of the cell temperatures by 68.1%. The moderate bottom cooling water flow rate of 10—12.5 L/min can effectively constrain the high temperature of the battery cells through convective heat transfer and improve the temperature uniformity of the battery pack. The liquid flow pressure drop and the energy consumption of the liquid cooling system are also relatively low. Taking into account the three factors of hole shape W/H=3, the layout of the bottom and two side liquid cooling plates, and a water flow rate of 12.5 L, the battery pack exhibits the best performance in terms of maximum temperature rise and temperature uniformity. The cooling effect of the single bottom and two side cooling factors is very close to that of the multi-factor cooling performance, with a difference of only 0.1℃. In the multi-factor comprehensive cooling process of batteries, the cooling factors of a single bottom and two sides play a dominant role.

The liquid metal (LM)/β-cyclodextrin (CD) composite was prepared by compounding liquid metal (LM) with β-cyclodextrin (CD) through a solvent-free stirring strategy. This composite was used as an initiator to trigger the copolymerization of acrylamide (AAm) monomers, successfully synthesizing hydrogels with gradient LM/CD distribution. The hydrophobic cavity of CD can encapsulate LM droplets, and its surface hydroxyl groups form physical anchors with LM through coordination interactions. Combined with the steric hindrance effect to inhibit particle agglomeration, this method can effectively disperse 60% (mass fraction) of LM under stirring conditions of 2000 r/min for 30 min, allowing LM/CD to form a self-supporting and conductive lamellar structure. The bottom resistance of LM/CD hydrogel was changed by tapping to induce directional precipitation of LM. Electrochemical tests showed that the bottom resistance of LM/CD hydrogel was linearly related to the number of tapping, which could realize bionic memory function and keep the resistance stable during compression-release cycle. Compared with traditional conductive polymer-modified hydrogels, this material combines high conductivity (bottom surface resistance 0.808 Ω), excellent mechanical properties, and stable memory behavior, providing new ideas for the design of intelligent biomimetic materials.

CO₂ as one of the greenhouse gases has a significant impact on global climate change. It is crucial to develop efficient and economical CO₂ capture technologies. One potential approach is the adsorption of CO₂ using CaCO₃ due to its wide availability, low cost and the ability to optimize the adsorption properties by modulating the morphology and specific surface area. In this study, CaCO₃ materials were prepared using KCl, NaCl and LiCl as salt templates, and the CO₂ adsorption properties were systematically evaluated. The results showed that the specific surface area of CaCO₃-KCl was significantly higher than that of CaCO₃-NaCl and CaCO₃-LiCl, which were 72.6, 40.2 and 18.9 m²/g, respectively. The CaCO₃-KCl showed a porous nanosheet structure. The CO₂-TPD showed that the surface of CaCO₃-KCl possessed more adsorption sites. Importantly, the CO₂ adsorption amounts of CaCO₃-KCl, CaCO₃-NaCl and CaCO₃-LiCl were 0.39, 0.32 and 0.31 mmol/g, respectively. The CO₂ adsorption amount of CaCO₃-KCl only decreased by 7% in 10 breakthrough-cycling experiments and had a better separation effect on CO₂/N₂. The separation effect improved from 3.4 to 44.8. This study reveals the effects of salt templating agent on the morphology, specific surface area and CO₂ adsorption performance of CaCO₃, which provides an important reference for the design of efficient CO₂ adsorption materials.

With the rapid development of information and communication technology, electromagnetic radiation poses a threat to human health and the normal operation of electronic devices. To address the aforementioned issues, the development of high-performance electromagnetic wave absorbing materials has become a crucial research direction in current technological advancement. As an important part of magnetic absorbent, ferrite absorbing materials have attracted wide attention because of their simple synthesis process and good magnetic loss advantages. However, its relative dielectric constant is poorly matched with impedance, so it is difficult to meet the requirements of broadband wave absorption. In this paper, Fe₃O₄ was taken as the research object, and the in-situ growth of carbon nanotubes was realized by introducing nickel as the catalyst. Fe₃O₄/FeNi/CNT composites were successfully prepared, which enriched the loss mechanism and improved the electromagnetic wave absorption performance. At 4.88 GHz, the absorption of electromagnetic waves yielded a minimum reflection loss (RL_min) of -39.2 dB. When the thickness was 2.00 mm, the effective absorption bandwidth (EAB) was 3.5 GHz. The Fe₃O₄/FeNi/CNT composite material had been proven through radar cross-section (RCS) simulations to possess strong electromagnetic wave absorption capabilities, making it suitable for practical applications. This work provides a simple and effective method for optimizing the absorption bandwidth and impedance matching of ferrite.

Once a fire occurs, it can cause serious harm. To reduce the risk and improve firefighting capabilities, this study used a high-speed dispersion method to prepare a dry water fire extinguishing agent with a core-shell structure, consisting of a hydrophobic nanosilica-coated liquid. Ultrasonic oscillation was used to mix 5-aminotetrazole and potassium perchlorate to prepare a dispensing agent. Furthermore, a 100 g micro fire extinguishing bomb was fabricated using polylactic acid (PLA) using fused deposition modeling (FDM) 3D printing technology. In addition, seven different fire agent structures were designed, namely, the same shell wall thickness (0.6 mm) with varying parts of charging (bottom, center, top), and the same charging part (center charge) with different shell wall thicknesses (0.2, 0.4, 0.8, 1.0 mm), to optimize the spreading effect of the fire extinguishing agent structure and to carry out the various sizes of the n-heptane oil pan fire (200, 300, 400 mm) fire extinguishing experiments. The results show that spreading chemical on the pressure-resistant dry water damage is small. Compared with other conditions, the fire extinguishing agent using the center of the charge, the wall thickness of 0.6 mm, the shell can effectively rupture. The dry water is dispersed radially in a "flat elliptical column" shape, with a peak dispersion velocity of 57.95 m/s. 38.89% of the generated stringy fragments exhibit good elasticity, providing a cushioning effect and harming the surrounding environment. the fire extinguishing bomb extinguished a 300 mm n-heptane oil pan fire in just 106 ms. This study provides a theoretical basis for the structural optimization of dry water fire extinguishing bombs and can also serve as a reference for fire extinguishing bombs used to extinguish oil pool fires.