Energy is one of the most important problems for human society. In recent years, with the proposed goal of carbon neutrality, the development of new environmentally friendly energies has become a key development direction for China. Among the different kinds of new energies, hydrogen with its clean, efficient, pollution-free and other advantages, has become an important part of the national energy strategy development. Green hydrogen refers to the hydrogen obtained from renewable energies without producing extra carbon dioxide in the production process which can realize zero carbon dioxide emissions. With this, the green hydrogen is considered as one of the most promising clean energy sources in the future. Thus, the development of green hydrogen energy including electrolytic water for hydrogen evolution (HER) technology, becomes a focus in China. To meet the requirements of cheap price and stable hydrogen evolution rate in HER process, the design and development of catalysts in high activity is a key factor. Among HER catalysts, precious metal catalysts such as Pt-, Ir-, Ru-based catalysts possess high activity, while their scarcity makes them at a high price. Thus, the development of non-precious metal electrocatalysts has become a research hotspot. Among many non-precious metal catalysts, nickel phosphide based catalyst is one of the important water electrolysis catalysts. The presence of phosphorus can effectively reduce the Gibbs free energy of H^* adsorption or H₂ desorption, which makes its hydrogen evolution efficiency increase, and the catalytic stability can be enhanced. The presence of phosphorus holes (P_v) formed in nickel phosphide based catalysts can enrich electrons on the catalyst and improve HER performance by promoting the desorption of H^*. Moreover, the phosphorus element has a higher electronegativity than the nickel element, and can attract electrons from nickel components, which enables phosphorus atoms to capture positively charged protons during HER process. In addition, the electronegativity of phosphorus is lower than that of nickel, and the unpaired electrons in the d orbital of nickel can be transferred to the phosphorus atom to reduce the Ni—H bond energy, which can optimize the hydrogen evolution activity by regulating the hydrogen adsorption free energy of the catalyst. Nickel phosphide catalyst has excellent performance not only in alkaline solution, but also in acidic and neutral medium. Based on nickel phosphide electrolytic water catalyst, this paper introduces the principle of hydrogen production by electrolytic water and related catalyst types, and summarizes the mechanism of nickel and phosphorus elements of nickel phosphide in electrolytic water, which can provide certain theoretical guidance for the subsequent development of highly efficient nickel-based electrolytic water catalyst. On the other hand, according to the preparation method of nickel-based phosphide catalysts, the factors affecting the preparation of nickel-based phosphide catalysts, and the basic modification strategies for adjusting their catalytic activity are summarized, including doping with metal and non-metal elements, preparing multi-metal nickel-based phosphides, and constructing multi-component heterogeneous structures composed of other transition metal phosphides. Finally, the research progress of nickel phosphide in hydrogen evolution by electrolysis of water is discussed. Some ideas and suggestions are provided to improve the catalytic efficiency and stability of hydrogen production from water electrolysis with nickel-based phosphide.

This review aims to explore the thermodynamic and kinetic characteristics of CO₂ hydrates in seawater, with a focus on the influence of salinity on hydrate formation and stability. By comprehensively analyzing the existing literature, the effects of temperature, pressure and salinity in seawater on the formation and stability of CO₂ hydrates are discussed. Several common equilibrium condition models for CO₂ hydrates in saltwater systems were elaborated, followed by a summary of the effects of seawater systems on the formation rate and stability of CO₂ hydrates, as well as the inhibitory effects of different salt ions on CO₂ hydrate formation. Finally, through the evaluation and summary of seawater CO₂ hydrate storage in recent years, the main problem at present is that the research on CO₂ hydrates in seawater and marine mud systems is not sufficient. Future research directions mainly focus on marine mud as a porous medium that can replace hydrate formation promoters, in order to provide reference for the industrial application of CO₂ hydrate marine storage technology and the study of CO₂ hydrates.

Battery thermal runaway is a bottleneck in the development of electric vehicles and new-scale energy storage, and it is crucial to understand the triggers of battery thermal runaway and adopt corresponding countermeasure strategies to improve the battery safety. This paper first briefly introduces the causes and mechanisms of thermal runaway of batteries. Through the discussion of recent related literature, the research progress of thermal management of lithium-ion batteries is reviewed from two aspects: internal thermal management of batteries and external thermal management of batteries. The key component modification strategies inside the battery focus on cathode and anode material modification, electrolyte system optimization and separator modification, etc. In the study of the external battery thermal management system, three main methods of air cooling, liquid cooling, and phase change material cooling are introduced. Comprehensive analysis shows that the battery internal components are the source of heat generation and inhibition of thermal runaway, reduce the electrode heat generation and improve the material thermal stability, introduce functional additives and develop solid electrolyte, improve the separator thermal stability and develop flame retardant function to help improve the battery intrinsic safety. Battery thermal management systems through liquid cooling as well as combined with phase change material cooling are equally important in maintaining safe battery operation at the appropriate temperature.

With the acceleration of research in hydrogen fuel cell industry, the utilization of waste heat (about 70℃) has become an urgent problem to be solved. However, the generation temperature of traditional LiBr/H₂O working pair is too high to utilize low-grade heat energy and has the problems of crystallization. Therefore, a new organic working pair R1336mzz(Z)/TEGDME is proposed. The saturated vapor pressure, density, viscosity and specific heat capacity were measured. The mixing enthalpy and specific enthalpy were calculated by NRTL model. The above data are regressed using the least squares method, and the square of the correlation coefficient between the experimental value and the fitting value is greater than 0.999, which is in good agreement. The fitting formula can be used to design and calculate the waste heat refrigeration thermal cycle of the new low temperature working pair. Compared with the LiBr/H₂O working pair, the generation temperature of R1336mzz(Z)/TEGDME working pair is reduced by 12℃ and the viscosity by about 30%, which has strong practical application significance.

Monodisperse droplets are widely used in food, chemical, energy, medicine and materials, but the current methods and devices are difficult to balance high monodispersity and high efficiency preparation. Therefore, a three-dimensional fractal approach is proposed to achieve equal and high-density integration of coaxial flow microchannels. And experimental research is conducted on the droplet generation characteristics and size distribution patterns. The experimental results show that under the condition of the stable mode, the coefficient of variation (CV) of droplets prepared by single channel, single stage 4-channel, and single stage 8-channel are 1.5%, 1.9%, and 1.9%, respectively. The monodispersity of droplets is high. Under the condition of the transition mode, the monodispersity of droplets is relatively poor, with CV of 6.9%, 6.7%, and 6.6%, respectively. Regardless of the stable mode or the transition interval of droplet generations, both the 4-channel and 8-channel channels maintain the characteristics of single channel droplet generation, and the generation efficiency is increased to nearly 4 and 8 times that of single channel, respectively. The droplets prepared with double-stage 16 channels at 4 flow rates exhibit good monodispersity, with CV all within 3.5%. But the generation efficiency has increased to nearly 16 times that of a single channel. The three-dimensional fractal integrated coaxial flow channel structure proposed in this article can improve the preparation efficiency while maintaining the monodispersity of droplets in single channel preparation.

A particle tracing measurement system is proposed using magnetic tracer particles and magnetoresistance sensor. The composition, measurement principle, error analysis and influencing factors of the magnetic particle tracing experimental system are systematically studied, and its advantages, disadvantages and application range are summarized. It was found that magnetic particles and sensor systems still have good tracking effects, in the coupled environment of the earth's magnetic field and particle magnetic field. Based on the magnetic field induction law, a particle spatial position search algorithm can be established to measure the particle motion trajectory and obtain the fluidization parameters such as the flow direction, movement rate, and circulation frequency of a single particle. However, the magnetic field measurement is affected by many factors, and the development of highly magnetic materials and the improvement of measurement sensor sensitivity are still needed in the future. By measuring and analyzing the circulating rate of the tracer particles in the annular zone in the spouted fluidized bed, the reliability of this method has been demonstrated. This study is helpful for the design and optimization of fluidized bed reactors in the subsequent preparation process, and is a worthy research direction for high-density particle fluidized bed coating technology.

The accurate prediction of particle deposition in confined space is of vital importance in the environmental and industrial fields. This study focuses on correcting slip correction factor to elevate the accuracy of these models. Primarily, the slip correction factor, a pivotal parameter in closed chamber particle deposition, undergoes correction to bring the deposition coefficient into closer alignment with exact values, augmenting the reliability of predictive models. Furthermore, based on the log-normal size distribution theory, the moment method (MOM) is used to model the deposition model of aerosol particles, and the distribution results of particles in the transition zone size range are predicted. By comparing the corrected solutions with traditional moment method solutions as well as exact solutions, the new solutions of the moment method show higher accuracy in particle number concentration, mean geometric standard deviation, and particle distribution. The relative error of the new solution for particle number concentration is reduced by 43.43%, compared with the traditional moment method solution in the intermediate size range. At last, this research verified the corrected solutions with the experimental data from the literature.

Magnetite is an important raw material for direct reduced iron in mineral processing. Fluidized bed direct reduction of magnetite is widely used in metallurgical industry because of its advantages of significantly reducing carbon emission, efficient heat and mass transfer and high speed reaction. Based on the unreacted shrinkage core model of the multi-resistance network, the coarse-grained CFD-DEM-IBM (computational fluid dynamics-discrete element method-immersed boundary method) coupling method was used to simulate the fluidized reduction of magnetite in a hydrogen atmosphere. In the process, the effects of different coarse-graining rates on particles, gas flow, and reaction characteristics were investigated. It is shown that when the coarse-graining ratio is less than 4, the reduction characteristics of the whole particles in the coarse-grained system and the real system are similar, but the local flow characteristics of the gas and particles are different. When the coarse-graining ratio is 3, the calculation accuracy is within the allowable range, and the calculation amount can be significantly reduced.

As a highly efficient form of heat transfer, steam condensation is effectively used in a wide range of applications in industrial fields such as petrochemical, thermal and nuclear power, desalination and thermal energy management, and has a wide range of application backgrounds. Among them, the study of droplet distribution characteristics is the key to analyze the droplet evolution and heat transfer process. In this paper, based on the evolution of droplet behavior such as nucleation, growth, shedding, etc., a mathematical model of the whole process of droplet condensation evolution and heat transfer is constructed, and the positional distribution law of the largest droplet and the number distribution law of droplets of different sizes in the process of evolution are summarized to show the characteristics of the distribution of droplets on the vertical and curved hydrophobic wall, which provides corresponding theoretical basis for the enhancement of heat transfer in condensation.

As a novel single-well heat exchange technology, the super-long gravity heat pipe has broad application prospects in the development and utilization of geothermal resources. The rapid start-up of heat pipe is the basis for efficient and stable operation. However, the current research on the start-up characteristics of super-long gravity heat pipes is still in its infancy. This paper uses a visual experimental platform for super-long gravity heat pipes with a length of 40 m, an inner diameter of 7 mm, and an aspect ratio of 5714 to study the start-up process of the super-long gravity heat pipe and analyze its influencing factors. The results show that the start-up modes of the heat pipe vary with changes in the heating power and fill height, primarily categorized into gradual temperature variation, steady transition, and abrupt temperature change types. As the heating power increases from 100 W to 500 W, the rate of vapor-liquid phase change within the tube accelerates, and the start-up temperature rises from approximately 43.5℃ to 81.4℃. Consequently, the overall start-up time of the heat pipe is reduced by about 51%. When the power increases from 200 W to 300 W, distinct geyser boiling phenomenon begin to occur within the tube, leading to an increase in the resistance to the reverse flow of vapor and liquid. Consequently, the start-up time of the heat pipe does not decrease but instead increases. As the heating power continues to increase, the start-up time decreases. Under a fixed heating power condition (300 W), as the liquid fill height increases from 6 m to 15 m, the start-up time of the heat pipe initially decreases from 6455 s to 3354 s and then increases to 4575 s. Moreover, the shortest start-up time of the heat pipe occurs at the fill height of 9 m (3354 s). When the fill height is set at 3 m and the heating power is increased to 300 W, a significant amount of condensate is carried up to the adiabatic section and into the condenser section. This leads to localized dry-out in the evaporator section, making it difficult for the heat pipe to operate stably and ultimately resulting in start-up failure. Further experimentation revealed that under the same heating power and fill height conditions, shortening the length of the heat pipe's evaporator section can effectively reduce the start-up time (by approximately 56%), increase the start-up temperature, and result in a more stable temperature variation in the evaporator section.

Multidimensional population balance equations (MPBE) describe the size distribution of a granular process over two or more intrinsic variables. Since most PBEs lack analytical solutions, computationally expensive high-order or high-resolution (HR) methods are often used to obtain accurate numerical solutions. How to obtain numerical solutions efficiently and accurately is a challenge it faces. To address the above problems, an improved higher-order compact difference (HOCD) method combining dimensional splitting is proposed, which enables the numerical solution with fourth-order accuracy. Dimensional splitting methods are used to split the multidimensional problem into several one-dimensional problems. The split one-dimensional equations are then discretized in space and time to produce the tridiagonal format of the HOCD, which may be solved by using the Tomas algorithm. Variable substitution is also carried out in some cases. Furthermore, the stability was demonstrated by using the von Neumann stability analysis method. Compared with HR methods, the HOCD has higher computational accuracy and computational efficiency without numerical diffusion. The effectiveness of this method is demonstrated by multiple numerical simulations.

Spray cooling can meet the thermal management needs of electronic devices such as high-performance chips and power batteries, but the influence of spray parameters on heat transfer under vibration environment is still unclear. Therefore, a set of closed spray cooling test system was built, and the effects of spray flow rate and spray angle on the heat transfer performance of spray cooling under different vibration conditions were investigated by using low-boiling-point e-fluoride liquid HFE-649 as the cooling medium. The results show that the critical heat flow density (CHF) of spray cooling increases with the increase of frequency and flow rate, and the enhancement of CHF of spray cooling is most obvious under low-frequency large-amplitude condition, which is 18.8% higher than that of high-frequency low-amplitude condition. When the spray angle is 75°, it has the best heat transfer capacity under various vibration conditions. The correlation equation of heat transfer of spray cooling was fitted by using the dimensionless analysis method, and more than 95% of the experimental data points fell within the error range of ±12%, which is a good fitting result and provides a theoretical reference for the application of spray cooling to the thermal management of batteries.

Chemical looping reforming of methane is a novel low-carbon hydrogen production technology. The reduction characteristics of the oxygen carrier are key factors determining the hydrogen production rate of chemical looping reforming. The effect of different proportions of Sr doping on the reduction characteristics of LaFeO₃was discussed in detail. By characterizing the octahedral distortion and surface oxygen morphology of FeO₆, the effect of Sr doping on oxygen vacancy concentration and lattice oxygen transfer was analyzed. La_0.8Sr_0.2FeO₃ exhibits significant FeO₆ octahedral distortion, showing the lowest lattice oxygen reduction temperature at 750℃. In isothermal reduction, the maximum mass loss of La_0.8Sr_0.2FeO₃ is 2—3 times that of LaFeO₃. Kinetic fitting calculations revealed that the reduction process of La_1-x Sr _x FeO₃ is controlled by the nucleation and growth model, while also being influenced by the autocatalytic model. Among the four oxygen carriers, La_0.8Sr_0.2FeO₃ exhibits the lowest apparent activation energy. The mass gain rate of La_0.8Sr_0.2FeO₃ in steam oxidation experiments is about 4 times that of LaFeO₃, and it maintains its original phase after 20 cycles. The study of La_1-x Sr _x FeO₃ in chemical looping reforming and multi-cycle stability provides technical and data support for the selection of materials and process optimization in methane chemical looping reforming for hydrogen production.

Based on the analysis of the characteristics of high-temperature chlorination reaction of propylene, ideal (IR) and computational fluid dynamics (CFD) models are constructed, and the accuracy of reaction kinetics model and reactor model is verified. Taking propylene flow rate, chlorine flow rate, propylene preheat temperature, CSTR (continuous stirred tank reactor) volume, and PFR (plug flow reactor) volume as decision variables, we optimized the reactor using both single-objective and multi-objective optimization algorithms. The results indicate that the multi-objective optimization algorithm yielded better outcomes, with a more comprehensive global consideration. The optimized values for the five decision parameters are: F_{\mathrm{C}{\mathrm{l}}_{\mathrm{2}}} = 0.1 mol/s, F_{{\mathrm{C}}_{\mathrm{3}}{\mathrm{H}}_{\mathrm{6}}} = 0.6 mol/s, T_preheat = 347.0℃, V_CSTR = 0.0425 m³, and V_PFR = 0.0173 m³. The conversion rates of chlorine and propylene are 100% and 17.26%, respectively. The selectivity for 3-chloropropene is 97.177%, and the outlet temperature is 471.23°C. The reaction parameters and results obtained through multi-objective optimization of the IR reactor model exhibit significant advantages compared to current industrial data both domestically and internationally. These optimized parameters, such as reactor design, propylene/chlorine molar ratio, and material preheating temperature, provide theoretical guidance for industrial applications.

The magnetic carbonyl iron particles were used as the carrier and loaded with nano TiO₂ to prepare composite photocatalysts, and the surface of the composite catalysts was hydrophobically and lipophilically modified to prepare the loaded nano TiO₂ composite photocatalysts with hydrophobicity and lipophilicity characteristics, and the crystalline phase composition and microscopic morphology of the composite photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), infrared spectroscopy (FTIR), and ultraviolet-visible spectroscopy (UV). The hydrophobic and lipophilic properties of the catalytic materials were evaluated, the magnetic recycling properties were evaluated. The degradation effects of the common zeolite-loaded TiO₂ catalysts and the hydrophobically modified carbonyl iron loaded TiO₂ catalysts were comparatively investigated on the three petroleum hydrocarbon pollutants, and the influences of the loading amount of the catalysts and recycling on the degradation efficiencies of the petroleum hydrocarbons were further examined. The results showed that the hydrophobically modified carbonyl iron loaded TiO₂ catalyst has hydrophobic and lipophilic properties, which can make the non-polar petroleum hydrocarbon pollutants contact with the active sites of the catalytic material in a better way, and it is easy to be recycled under the magnetic field due to the magnetic nature of the catalytic material particles; the novel catalytic material has a better degradation efficiency of petroleum hydrocarbon pollutants in water, the maximum removal rate of the conventional TiO₂/zeolite catalysts for the pollutants was about 75%, while the maximum removal rate of TiO₂/modified carbonyl iron could reach 95%, and the degradation rate was faster. Degradation effect was improved with the increase of the catalyst concentration, but the degradation effect was decreased when the concentration was further increased to 4 g·L^-1, During repeated use, the activity of the composite photocatalytic material does not decrease significantly, indicating that the composite catalytic material has good stability.

In order to explore the feasibility of lithium extraction from salt lake brine by “adsorption-membrane” method, experimental study and “concentration-diafiltration” simulation calculation of lithium-magnesium separation in sulfuric acid desorption solution obtained from brine were carried out by using NF270 nanofiltration membrane. First, the basic structure and separation characteristics of NF270 membranes were determined, and the effects of pressure and pH on the flux and retention of Li₂SO₄ and MgSO₄ for the single salt solution were initially investigated. Secondly, the separation of magnesium and lithium at different pH and Li⁺ mole fraction (x_{\mathrm{L}{\mathrm{i}}^{+}}) was evaluated and an analysis of the separation was performed. The results showed that under neutral conditions, the strong electrostatic repulsion between the NF270 membrane and \mathrm{S}{\mathrm{O}}_{\mathrm{4}}^{\mathrm{2}-} resulted in high retention rates of Li⁺ and Mg²⁺. The separation could only be achieved by lowering the pH below the isoelectric point. Compared with x_{\mathrm{L}{\mathrm{i}}^{+}}, the effect of pH on the separation of lithium and magnesium was more significant. When x_{\mathrm{L}{\mathrm{i}}^{+}} was 0.40 and pH was 1.7, the separation factor could reach more than 10. Then, the separation performance of the NF270 membrane on lithium and magnesium for the simulated desorption solution with other ions was studied. It was found that ions of Na⁺, K⁺ and Ca²⁺ with low concentrations did not affect the separation factors of lithium and magnesium, and the membrane could achieve high retention to Ca²⁺ and Mg²⁺, reducing the risk of scaling in subsequent treatment. Finally, based on the composition and retention rate of the simulated adsorption solution, the selective separation of Li⁺ and Mg²⁺ by the NF diafiltration was simulated for the binary solution containing 0.023 mol/L MgSO₄ and 0.125 mol/L Li₂SO₄. After pre-concentration and diafiltration, the concentrations of Mg²⁺ and Li⁺ were 0.20 mol/L and 0.66 mol/L in the feed solution, and 0.0025 mol/L and 0.17 mol/L in the permeate, respectively. At this time, the Li⁺ recovery could be up to 75%, proving the feasibility of realizing the separation of magnesium and lithium in the desorption solution by the NF diafiltration process.

The metal hydride (MH) method is viewed as one of the promising methods for hydrogen purification. The properties of MH materials will be significantly degenerated by the poisoning effect of impurity gases, especially for CO with strong effect. However, the present work in MH reactor level mainly focuses on some impurities with relatively insignificant effect yet, such as CH₄, CO₂, N₂, etc. To gain further insight into the reaction-separation behaviours of MH reactor running in by-product mixture, a flow-through type MH reactor filled with LaNi_4.3Al_0.7 is designed to separate hydrogen from mixture containing 0.1%CO and 39.9%CO₂. The effects of operating parameters such as temperature and pressure are systematically investigated for performance optimization. The optimum temperature of heat transfer fluids during hydrogen absorption process is found to be about 120℃, which keeps a balance between better anti-poisoning ability in high temperature and greater reaction driving force in low temperature. The experimental results also indicate that the optimum hydrogen partial pressure in the mixture gas should be about 0.84 MPa, due to the insignificant improvement of higher pressure. In addition, self-produce hydrogen purging is conducted to remove the impurity. The results of the experiment found clear support for the superiority of self-produce hydrogen purging for the MH reactor running in by-product mixture. Unexpectedly, purging the MH reactor with pure hydrogen for impurity replacement only leads to negligible improvement for impurity remove. A possible explanation is that molecular diffusion and desorption of impurities on the MH surface play a more important role for impurity transport and separation in MH reactor, rather than the viscous flow. The final hydrogen purity can reach 99.999% through self-produced hydrogen purge, and the hydrogen recovery rate can reach 77.6%, which shows the broad application prospects of metal hydride absorption separation method in the field of hydrogen separation and purification.

The study aimed to analyze the uncertainties associated with kinetic model parameters and operating parameters in the crystallization model. Three simplified crystallization process models, based on the population balance equations, were considered to analyze the batch cooling crystallization process. The sensitivity of the parameters to the product crystal size distribution (CSD) and the formation of fine crystals was evaluated. The local and global sensitivities of 12 parameters to the three crystallization process models of crystal growth (CG), crystal growth-nucleation (CGN) and crystal growth-nucleation-dissolution (CGND) were quantitatively analyzed, while the convergence of the modified Morris screening method and PAWN method was ensured. And the parameter sensitivities were sorted. The results show that the sensitivity of parameters is different for model situations of different complexity. For product CSD, the parameters μ, C₀, b, and m₀ exhibit significant sensitivity in CG and CGN, while all parameters are insensitive in CGND. For fine crystals, the parameters b, g, and C₀ exhibit significant sensitivity in CGN, and parameters C₀, T₀, g, b and μ show sensitivity in CGND. Sensitivity analysis can be used to identify the most crucial disturbance parameters for various crystallization processes. This can guide the selection of the consideration of model errors and operating condition perturbations in robust optimization design.

N,N-dimethylformamide (DMF) and N,N-dimethylacetamide (DMAC) were used as the main solvents, and cyclodextrin (CD) was used as the additives to obtain the extractant DMF + CD (DMFM) and DMAC + CD (DMCM). At the same time, n-hexane and cyclohexane were used to represent the chain/cycloalkane mixture. The liquid-liquid equilibrium (LLE) data of n-hexane + cyclohexane + DMFM and + DMCM were measured within the temperature from 283.15 K to 303.15 K under atmospheric pressure. With the help of distribution coefficient and selectivity, the separation performance of two mixed extractants on the mixture of chain/cycloalkane was evaluated, and the viscosity of the mixed solvent was further measured to investigate its fluidity. The results showed that the selectivity of the mixed extractant for cyclohexane increased with the increase of CD content in the extractant, and the selectivity DMFM < DMCM and the distribution coefficient DMFM<DMFM. The viscosity of the compound extractant also increases with the increase of CD content, and DMCM>DMFM. The experimental LLE and viscosity data were satisfactorily correlated by NRTL and VTF models, respectively, and new model parameters were obtained. The results can provide basic data and theoretical support for the separation process design of chain/cycloalkane in naphtha.

Lithium resource plays an important role in energy strategy. Membrane extraction technology is expected to solve the green sustainability problem of liquid lithium resource extraction. Binary composite extraction membranes PT-PIMs (PTC-PIM /PTT-PIM/PTP-PIM) with 2-thiophenoyltrifluoroacetone (TTA) synergistically solvated carriers [trialkylphosphine oxide mixture (Cyanex923)/tributyl phosphate (TBP)/phenanthroline (PHEN)] were prepared. The mass transfer behaviour of \mathrm{P}\mathrm{T}-\mathrm{P}\mathrm{I}\mathrm{M}\mathrm{s}-\mathrm{L}\mathrm{i}(\mathrm{Ⅰ}) system by electric field enhancement was investigated under optimized membrane phase conditions, and the stability and Li/Na/K selective separation performance of the kerosene-modified \mathrm{P}\mathrm{K}-\mathrm{P}\mathrm{I}\mathrm{M}\mathrm{s}-\mathrm{L}\mathrm{i}(\mathrm{Ⅰ}) system were evaluated. The results show that the membrane phase composition has a large effect on the mass transfer rate of Li(Ⅰ), the main extractant TTA plays a dominant role in Li(Ⅰ) mass transfer, and the mass transfer rate increases with the voltage. The permeability coefficient of PTC-PIM-Li(Ⅰ) system increases linearly with increasing voltage. The permeability coefficient of PTC-PIM-Li(Ⅰ) system is 33.20 μm·s^-1 at 40 V. The permeation rate of Li(Ⅰ) in the PT-PIMs-Li(Ⅰ) system modified by kerosene decreased by <21% after four cycles; When the mass concentration ratio of Li(Ⅰ)∶Na(Ⅰ)∶K(Ⅰ) in liquid phase is 20∶20∶20, the separation factors S_{Li(Ⅰ)/Na(Ⅰ)} and S_{Li(Ⅰ)/K(Ⅰ)} of PT-PIMs system are 8.41, 4.88, 3.88 and 7.99, 4.64, 3.81, respectively, indicating the selective separation ability of Li. The combined permeability coefficient, stability and PK-PIMs-Li(Ⅰ) systems: PCK-PIM > PTK-PIM > PPK-PIM. This paper provides an important idea for sustainable extraction technology of lithium resources with green energy saving.

The renewable methanol is one of important ways in achieving sustainable development. The volatility and intermittency of renewable energy lead to frequent fluctuations in the operating conditions of the carbon dioxide hydrogenation to methanol process. To adapt to the fluctuations in renewable energy, it is necessary to enhance the flexibility of the methanol production system. In this work, a renewable methanol production system operating window regulation strategy for selecting appropriate equipment is proposed. The equipment database is established through the design and analysis of the operating window characteristics of key equipment under process conditions and operational constraints, and the operating window of the production system is expanded by optimizing the equipment set through the regulation strategy. The results indicated that the proposed method can effectively regulate the operating window of the methanol production system by maximizing the upper limit, minimizing the lower limit, and maximizing the range of operating window, and determine the optimal equipment combination and design scheme according to the application scenarios. These results are expected to provide guidance for flexibility improvement of methanol production system adapted to the fluctuations of renewable energy.

Fault prediction can indicate abnormal changes in variables and predict fault conditions in advance. Existing fault prediction methods primarily consider the global temporal dependencies of the complete sequence, which neglecting the dependencies between variables and the distinct local temporal features in the sampled subsequences. To address the above issues, a fault prediction architecture based on multi-sampled sequence feature extraction network (MSFEN) is proposed. First, a batch joint embedding mechanism is designed to better express the dependencies between variables while considering batch periodicity. Then, a sequence sampling mechanism is developed to divide the complete time series into sampled subsequences of different scales. Subsequently, the invert smoothing Transformer and the convolutional interactive extraction module are designed to comprehensively extract multi-scale temporal dependencies and variable dependencies. Finally, the multi-sampled sequence features are fused to obtain the final encoding features, and fault prediction is achieved through the feed forward layer. Experiments are conducted using the penicillin fermentation process, and the results show that this method has good fault prediction performance.

The safety interlock system (SIS) plays an important role in preventing hazardous accidents in chemical plants. Due to the complex working environment, SIS actuators are inevitably affected by aging degradation and external demand shocks, resulting in the assumption of constant failure rate in traditional reliability models no longer being applicable. To this end, based on failure modes and mechanisms, considering the time-varying characteristics of the degradation process, a universal dependent competing failure processes considering time-varying characteristics (DCFP-TVC) for KooN structures was proposed by introducing degradation rate acceleration factor, degradation sudden increment coefficient, and time-varying hard failure threshold to achieve stochastic failure process modeling of non-constant failure rate actuators. The application of this model to the hydrogen oxygen purity interlocking circuit of wind power generation shows that compared to the constant failure rate model and other competing failure models, the proposed model can effectively solve the difficulties in reliability analysis of non-constant failure rate actuators, and the sensitivity analysis is carried out with important degradation parameters to illustrate its influence on reliability and failure time distribution, and the suggestion of adjusting the proof test interval is proposed to realize the risk control of non-periodic detection of actuators.

The dynamic and nonlinear characteristics of chemical process in data often make it difficult even impossible for traditional soft sensing methods to accurately extract the dynamics and nonlinearity, which affects the prediction accuracy of key quality variables negatively and the overall control optimization of the system.Therefore, this paper proposes a soft sensor model, termed as the multi-head self-attention mechanism long short-term memory network (MHSA-LSTM). First, the LSTM is used to fully exploit the temporal characteristics of the data in order to extract the dynamic change information of the chemical process data. Second, a multi-head self-attention mechanism is used to weight the output features of LSTM hidden layer, and effectively capture the long-term correlation of feature vectors with different scales and improve the long-term memory ability of the model. Furthermore, the weighted results obtained by multiplying the extracted feature vector and its corresponding feature weight are input to the full connection layer. It can effectively improve the accuracy of prediction of key quality variables. Finally, the proposed method is simulated and verified in the debutanizer column process and sulfur recovery unit. The results indicate that the prediction accuracy of the constructed model is superior to gated recurrent unit, LSTM and self-attention LSTM soft sensing models.

Combined heat-mass exchange network (CHMEN) is an important field in system engineering. Processing the lean stream in the mass exchange subnetwork can effectively recover the excess heat in the mass transfer process and achieve efficient mass and heat transfer. The current simultaneous optimization methods ignore the impact of lean stream bypass on the structure and annual total cost of the CHMEN. Therefore, this paper proposes the intermittent heat exchange strategy based on the lean streams bypass transformation to develop the node-unstructured model, before that the coupling relationship between the mass exchanger sub-network and the heat exchanger sub-network is analyzed. On the one hand, the lean stream with single heat exchange property is divided into some streams to undertake stepwise heat exchange tasks, expanding network structure. On the other hand, the difference of the location of the lean streams bypass will also affect the optimization effect. Moreover, it is difficult to obtain the best solution due to the wide domain of the mathematical model, so random walk with compulsive evolution algorithm is adopted, where accepting bad solutions ensures the global search ability. The simultaneous optimization method proposed in this paper is used for two CHMEN examples. The results show that a new network structure can be found via changing the position of the lean streams bypass, improving the structural diversity. Meanwhile, the annual total cost is reduced through structure variation. This method is of great significance for the further promotion of energy conservation and emission reduction.

To address the issue of accurately measuring the effluent ammonia nitrogen concentration in real-time during urban wastewater treatment processes, this paper constructs a convolutional layer (CL) and squeeze-and-excitation attention mechanism (SEAM) based long short-term memory network (CSA-LSTM) model. First, by introducing the CL, nonlinear features within the data are deeply extracted. The SEAM adaptively allocates weights to feature channels, achieving feature decoupling. Secondly, the long short-term memory network (LSTM) extracts long-term dependencies in time-series data to realize real-time prediction of effluent ammonia nitrogen concentration. Then, a Bayesian optimization algorithm with an adaptive acquisition function is proposed to optimize model parameters, further enhancing model accuracy. Finally, the effectiveness of CSA-LSTM is tested based on benchmark experiments and actual wastewater treatment plant (WWTP) data. The results show that the model has high predictive accuracy for effluent ammonia nitrogen concentration, can effectively handle the strong nonlinearity, coupling, and time-dependency of data in urban sewage treatment, and has good generalization ability.

The open-type stern shaft seal achieves long service life and efficient operation due to its excellent opening performance, but it is very easy to cause serious lip wear due to unreasonable lip structure. Taking the open stern shaft lip seal as the research object, a lip seal numerical analysis model is established to analyse the sealing performance of the open stern shaft lip seal, and multi-objective optimization analysis of lip structure using response surface methodology for lip sealing experiments. The results of the study show that the lip excess has the greatest impact on lip seal opening performance and life, followed by spring radial force, anterior labial angle and labial angle, and the lip opens when the blowback gas pressure is at least 1.3 times greater than the working pressure under multiple force loads. Lip opening performance and lip life are affected by rotational speed, and lip opening performance is positively correlated with lip life. For the open stern shaft lip seal, the lip structure parameters are reasonably designed. By dynamically adjusting the back-blowing gas pressure, the lip wear can be effectively reduced and the sealing performance can be greatly improved, and the dependence of the lip opening on the rotation speed can be reduced. The optimized parameter combinations are: lip overfill 1.5 mm, spring radial force 70 N, anterior labial angle 45°, labial angle 40°, and through the reasonable optimization of structural design, the comprehensive lip wear reduction performance is significantly improved, and the lip life is increased by 173%.

α-bisabolene is a sesquiterpene compound mainly found in plant essential oils such as myrrh and lemon. Due to its multi-branched and cyclic structure, its alkylation product bisabolane can be used as a substitute for aviation fuel and has attracted widespread attention at home and abroad. The biosynthesis of α-bisabolene using Saccharomyces cerevisiae as a chassis is a green and sustainable alternative production mode. In this study, a α-bisabolene synthase AgBIS from Abies grandis was expressed in S. cerevisiae with the enhanced key genes of the mevalonate (MVA) pathway. The glucose inducible promoter P _HXT1 was used to dynamically downregulate the endogenous squalene synthase and fatty acid synthesis pathway. Further systematic enhancement of the expression of multiple genes in the MVA pathway, cofactor supplementary and ethanol utilization pathway systematically, the α-bisabolene production reached 510 mg/L in the flask. In a 3 L fermenter, the highest reported production of α-bisabolene was achieved at 120 h with ethanol supplementation, reaching 16.5 g/L. This study provides an effective strategy and research foundation for the efficient biosynthesis of α-bisabolene by microbial cell factories.

2-(2-Oxopyrrolidin-1-yl)-acetic acid (2-OAA) is an important precursor for the synthesis of piracetam and plays a significant role in the field of pharmaceutical synthesis. However, there is currently a lack of biological methods and reaction mechanism analysis for synthesizing it. To address this research gap, based on the principle of similarity reaction, the β-lactam synthetase (SfAsnA) from Streptomyces fulvorobeus was identified. This enzyme has the ability to synthesize 2-OAA in the aqueous phase, exhibiting an enzyme activity of 109.8 U/g and a total conversion number (TTN) of up to 79.02. Subsequently, the protein model construction of the SfAsnA was analyzed with the substrate to determine the combination of the substrate in the enzyme activity center. Next, the reaction mechanism of the non-enzymatic reaction for synthesizing 2-OAA was analyzed in detail to verify the chemical synthesis mechanism and relative energy profile of the target reaction. Finally, the enzymatic response mechanism is studied, and mutation verification is used to catalyze dual-combined bodies (Y254 and E288) to further determine the SfAsnA catalytic 2-OAA synthesis mechanism and the key role of the dual-connected body in the target response. It provides a solid theoretical foundation for enzyme synthesis of 2-OAA.

The liquid hydrogen has attracted significant attention in the field of hydrogen vehicles due to the advantages of high hydrogen storage density and good safety performance, especially in the application of long-distance and large-scale transportation for vehicles. As one of the core components of liquid hydrogen fuel vehicles, the vehicle-mounted liquid hydrogen bottle will directly affect the driving range of the vehicle. In the pipeline structure design of liquid hydrogen tank for vehicles, there is a localized large heat flow at the connection between the pipeline and the inner container, which has a significant impact on the non-destructive storage time of liquid hydrogen tank. In this paper, a three-dimensional numerical model is established. Under the premise of the same total heat leakage, the influence of three localized large heat flow positions at the top, middle and bottom and the uniform heat leakage conditions on the thermophysical field variation during the self-pressurization process of liquid hydrogen tank are numerically studied. The results show that the average pressurization rates within the 1000 s are 4.51, 3.01, 15.08 and 6.08 kPa·h^-1, respectively for the uniform heat leakage and the three localized large heat flow conditions at the top, middle, and bottom. Since the pressurization rate is the slowest under the top large heat flow condition, and the fastest under the middle large heat flow condition, it is recommended to set the connection position at the top of the inner container when designing the connection position between the pipeline and the inner container, so as to extend the non-destructive storage time of liquid hydrogen tank.

The cellulose-water model system was established and optimized by using Materials Studio software, and the molecular dynamic simulation of the cellulose hydrothermal reaction process was conducted by using LAMMPS software. The evolution law of the hydrothermal products and the hydrothermal reaction mechanism of the cellulose were simulated and studied. The results show that temperature is an important factor affecting the distribution of hydrothermal products of cellulose. With the increase of the hydrothermal temperature, cellulose decomposition intensifies, the relative content of hydrothermal solid products in the system decreases sharply, the aromaticity and calorific value of the solid products increase, and the hydrophilicity decreases. The relative contents of heavy tar and light tar increased first and then decreased, and the reaction of secondary cracking of tar into small molecules intensified. With the increase of hydrothermal temperature, the production of CO₂ and H₂ in the system continued to increase, the production of formic acid showed a trend of increasing first and then decreasing, and the difference of formaldehyde was small. The simulation results also show that H₂O molecules participated in the hydrothermal reaction of cellulose mainly in the form of hydrated hydrogen ions (H₃O⁺). With the increase of the hydrothermal temperature, the ionization reaction of water molecules and the dehydration reaction of cellulose were enhanced. The analysis of hydrothermal mechanism of cellulose showed that the cellulose depolymerization paths included the decomposition into glucose and the dehydration into L-glucan. During the rearrangement isomerization process of the glucose monomer, the main intermediates such as furans and aldehydes were formed by dehydration and retrograde aldol condensation reactions from the three transition state structures of enediol. The research on the cellulose hydrothermal reaction mechanism can provide a theoretical basis for the biomass hydrothermal conversion.

A two-dimensional heat transfer model was established for the variable density multi-layer insulation (VDMLI) with vapor-cooled shield (VCS) and catalytic conversion of para-ortho hydrogen (P-O) of the liquid hydrogen tank. The influence of the hydrogen temperature gradient in VCS on the thermal insulation system was analyzed in detail. The comprehensive performances of VDMLI, VDMLI + single vapor-cooled shield (SVCS), VDMLI + double vapor-cooled shield (DVCS), VDMLI + SVCS + P-O, and VDMLI + DVCS + P-O were compared from the perspectives of thermal insulation performance and additional mass. The results show that the optimal layout interval of SVCS is 42%—58% of VDMLI thickness, and the optimal layout intervals of DVCS's inner and outer shield are 12%—28% and 55%—72% of VDMLI thickness, respectively. Compared with VDMLI, the application of SVCS and DVCS reduces the heat flux by 69.91% and 74.50%, and increases the additional mass by 68.98% and 137.97%, respectively. After the introduction of para-ortho hydrogen conversion, the optimal layout range of SVCS is closer to the cold end, and the optimal layout range of DVCS changes less. The addition of para-ortho hydrogen conversion improves the insulation performance and the additional mass increases very little, so the insulation scheme without para-ortho hydrogen conversion does not have performance advantages. Comparing the performance of different adiabatic schemes, the VDMLI adiabatic scheme is recommended for short-term on-orbit missions, the VDMLI/SVCS/P-O adiabatic scheme is advised for medium-term on-orbit missions, and the VDMLI/DVCS/P-O adiabatic scheme can be adopted for long-term on-orbit missions.

Flexible-hole aeration is widely used in the aerobic process of sewage treatment to control the amount of dissolved oxygen in the water body. Reducing the size of microbubbles can help improving the oxygen utilization rate and microbial activity of the water body, and enhancing the efficiency of the aerobic process. Converting continuous gas supply to pulsed gas supply can significantly reduce the bubble size. However, the bubble formation mechanism of flexible-holes under pulsed flow regime is still unclear. This paper takes the pulsed air flow-flexible hole coupled bubble formation as the research object. Through a combination of mechanical analysis and optical observation, the impact of pulsed air flow on the flexible-hole bubble formation process was analyzed. The research results show that the pulse air flow strengthens the momentum force of bubble desorption, and at the same time triggers high-frequency and low-amplitude oscillations of the flexible membrane, which promotes early desorption of bubbles. Besides, pulsed air flow inhibited the vertical coalescence of bubbles, which together led to the reduction of bubble size.

To address the challenges of uneven electrolyte distribution among the plates of seawater activated battery and electrolyte flow adaptation, a new bio-inspired antler-like channel structure was proposed. Through orthogonal design and computational fluid dynamics (CFD) method, the flow characteristics and optimization of electrolyte flow path in seawater activated battery were studied under the interaction of multiple factors. The results show that the most impact on the characteristics of electrolyte liquid is the number of flow channels, followed by electrolytic liquid flow and flow channels. The best matching values are the number of channels, the flow rate of electrolyte and the deflection angle of flow channels are 12, 200 ml/min and 20°, respectively. After the optimization of the flow channel structure, the uniformity of electrolyte distribution between plates is obviously improved, and the peak regulation efficiency reaches 36.2%. The research results can provide reference value for the optimization design of seawater activated battery flow channel structure.

Recycling valuable metals from waste LiFePO₄ power batteries and realizing their resource utilization is an urgent problem at present. In this study, a mixed leaching system of phosphoric acid and tartaric acid was proposed, and the total component leaching recovery process of waste LiFePO₄ was studied. The approximate range of leaching conditions was obtained through the results of single factor experiments, and then the response surface method was used to optimize different leaching conditions to obtain the best leaching process. The results showed that the leaching rates of Li and Fe were 97.55% and 98.67% respectively when the concentration of phosphoric acid was 3.1 mol/L, the concentration of tartaric acid was 1.3 mol/L, the liquid-solid ratio was 6.8∶1, the stirring speed was 500 r/min and the reaction temperature was 65℃ for 5 h. The experimental results show that tartaric acid can be replaced with the Fe³⁺ released by phosphate, and the synergy of mixed acids will immerse all Li and Fe in the waste into the solution. By adjusting the molar ratio of Li∶Fe∶P in the leaching solution, the regenerated LiFePO₄ (RE-LiFePO₄) was synthesized by spray drying-sintering method. In the whole recovery process, there is almost no waste acid and waste gas emission, and the green recovery of all components of waste LiFePO₄ is realized.

The development of new, high -efficiency, and cheap anode materials is one of the main ways to solve the bottleneck problem of microbial fuel cells (MFCs) applications. The biomass-based carbon aerogel (CA) was prepared based on sugarcane using a simple direct carbonization method and used as an advanced anode in high-performance MFCs. The results showed that benefiting from the naturally ordered pore three-dimensional structure that ensured effective electroactivity and microbial accessible area, as well as good electrical conductivity and biocompatibility, the maximum power density of MFCs with CA-900℃ as the anode was 2.58 times of the MFCs higher than that of MFCs with two-dimensional carbon paper with the same volume. Furthermore, the activated biomass carbon aerogel (ACA) was obtained with the electrooxidation and reduction processes. The ACA-30min exhibited a higher degree of graphitization, significantly enhanced electrical conductivity, and a more optimized hierarchical pore structure. The specific surface area and pore volume of ACA-30min are 1.8 times and 2.35 times of the CA-900℃, respectively. The maximum power density and Coulombic efficiency of the ACA-30min MFCs were 1.11 times and 1.33 times of the CA-900℃ MFCs, respectively. These results will facilitate the development of green, efficient, and cost-effective three-dimensional carbon materials for MFCs. It also opens up new avenues for sewage treatment and recycling of agricultural resources.

The self-assembled structures and drug loading/release behaviors of KLA antimicrobial peptide and doxorubicin loaded by zwitterionic poly(carboxybetaine methacrylate) (PCBMA) or poly(ethylene glycol methacrylate)(PEGMA) modified poly(L-lysine-grafted-2,3-dimethylmaleic anhydride)-poly(lactic acid) copolymers PCBMA/PEGMA-PLL(-g-DMA)-PLA were investigated by dissipative particle dynamics simulations. The effects of copolymer block ratio, copolymer concentration, loading concentration and ionic strength on the micelle self-assembly were investigated. The results show that compared with the PEGMA system, when the block ratio changes, the PCBMA system always has good micelle structure stability and can form spherical micelles in a wider block ratio range. Moreover, at varying copolymer concentrations, the PCBMA system demonstrates a wider range for forming spherical micelles compared with the PEGMA system. With the increase in drug loading concentration, drugs in the PCBMA system exhibited a uniform spherical distribution, while drugs in the PEGMA system displayed an eccentric distribution when the drug concentration exceeded 3%. With the increase of ionic strength, the formation of spherical micelle structure of PCBMA system is accelerated, while PEGMA system cannot maintain the spherical micelle structure. Under the acidic pH condition, the drug release process of PCBMA system conforms to the mechanism of “dilatation-demicellation-release”, and the drug is evenly released into the aqueous solution; while the drug release behavior of PEGMA system is too fast and uneven. This study provides a reference for exploring the dual drug loading/drug release of antimicrobial peptides and anticancer drugs at the mesoscale, and has certain significance for guiding and optimizing the development of drug delivery materials.

The block copolymer mPEG₄₄-b-PBenEP₄₄ was prepared by the ring-opening polymerization of BenEP with monomethoxy polyethylene glycol (mPEG) as macroinitiator. A reduction-responsive polyphosphate-based paclitaxel prodrug mPEG₄₄-b-(PBenEP₃₄-g-SS-PTX₃) (PEBSP) was prepared by introducing the disulfide bond and paclitaxel into the pendant groups of PBenEP block, and the drug loading content (DLC) is 14.57%. The self-assembly behavior of PEBSP was studied by transmission electron microscopy (TEM), dynamic light scattering (DLS) and fluorescent analyses. The results show that PEBSP can form spherical particles with an average size of 71 nm in aqueous solution, and its critical micelle concentration is determined to be 60 mg∙L^-1. PEBSP spherical nanoparticles can exist stably under normal conditions, and in a reducing medium (10 mmol·L^-1 glutathione), the disulfide bond breaks and the drug paclitaxel is released in a controllable and continuous manner.

Phosphorene is a two-dimensional layered material with a special structure and has application prospects in the field of thermoelectrics. This study employed first-principles combined with density functional theory to investigate the thermal and electrical transport properties of bilayer heterostructures of phosphorene, comparing them with bilayer parallel phosphorene. The research revealed that the lattice thermal conductivity of phosphorene exhibits layer-dependent behavior due to interlayer van der Waals forces affecting out-of-plane phonon transport and increasing phonon group velocity. Disruption of crystal symmetry in bilayer antiparallel phosphorene leads to increased phonon scattering and decreased phonon group velocity, resulting in reduced lattice thermal conductivity. At 300 K, the lattice thermal conductivities for bilayer antiparallel phosphorene are {\kappa }_{\mathrm{Z}\mathrm{Z}}=113.251 W/(m·K) and {\kappa }_{\mathrm{A}\mathrm{C}}=32.315 W/(m·K). Increasing the number of layers in phosphorene reduces bandgap size and carrier scattering while enhancing its electrical transport performance. Compared to monolayer phosphorene, bilayer antiparallel phosphorene demonstrates higher thermoelectric figure of merit values; at 800 K in the AC direction, an N-type bilayer antiparallel phosphorene achieves a ZT value as high as 2.336. This study provides theoretical insights and references for regulating the performance of related thermoelectric materials.