Solid-liquid equilibria in the quaternary system LiCl-MgCl₂-CaCl₂-H₂O at 298 K were studied by the method of isothermal solution saturation method. Using the experimental data, the phase diagram and the relevant water diagram of the quaternary system were obtained. The results show that the phase diagram of the quaternary system consists of seven crystallization fields, eleven univariant curves, and five invariant points. In addition to four simple salts CaCl₂·6H₂O, CaCl₂·4H₂O, MgCl₂·6H₂O and LiCl·H₂O, the three double salts LiCl·MgCl₂·7H₂O, LiCl·CaCl₂·5H₂O and 2MgCl₂·CaCl₂·12H₂O also crystallizes from the saturated solutions. The crystallized area of single salt MgCl₂·6H₂O is the largest because of its smallest solubility. The solubility of the quaternary system at 298 K was calculated by Pitzer model using the parameters reported in the literature. The calculated results are basically consistent with the experimental data.

Hydrophobic surface embedded with arrayed hydrophilic dots can be prepared on a copper surface with mesh screen and Teflon solution. Completely hydrophilic copper surface, completely hydrophobic Teflon-coated surface and hydrophobic-hydrophilic hybrid surfaces are taken into consideration which are served as the bottom heat transfer area of 1.5 mm hydraulic diameter rectangular mini-channels. In this experiment, vapor mass velocity ranges from 10 kg·m^-2·s^-1 to 60 kg·m^-2·s^-1, while the vapor quality from 0.3 to 1. According to the experimental investigation, steam condensation heat transfer coefficient on hybrid surface is about 454.6% higher than that of completely hydrophilic surface and 107.3% higher than completely hydrophobic surface at most. High speed camera provided the photos of two-phase flow pattern, especially the periodic behavior of the droplets nucleation, coalescence and flushing which can explain the mechanism of heat transfer enhancement.

To investigate the influence of the structure of the reinforced fibers on field distribution in ionic membrane, the matter migration processes in the ion-exchange membrane (IEM) with the reinforced fibers in the presence of the electric field were simulated by using the percolation flow model in porous media, the transport of diluted species model and the secondary current distribution model. The convective velocity, concentration and current density in the ionic membrane were obtained. The effects of the shape, pitch and the mode of network of the reinforced fibers on the field distribution were studied. The ion concentration on the surface of the membrane after electrolysis was measured by photography and image processing technology. The experimental results were in good agreement with the simulation results. The results show that, the convective velocity at the central region encircled by the reinforced fibers is the highest. The closer to the reinforced fibers, the lower the velocity, the greater the concentration and the current density. Higher velocity and current density can be obtained in the ionic membrane by using the orthogonal reinforced fibers. The larger the distance between the ribs, the lower the current density, the more uniform the distribution. The highest value and the most inhomogeneous distribution of the current density can be obtained by using the ellipse reinforced fibers with its major axis vertical to the flow.

The rate-control step of the direct reaction of flue gas CO₂ with industrial solid waste phosphogypsum mineralization to form calcium carbonate and ammonium sulfate is the dissolution of phosphogypsum. Expressing exactly the dissolution characteristics provides theory basis for designing mineralize reactor under mass transfer controlling. In this study, the dissolution characteristics of gypsum particles which had wide size distribution were predicted through population balance model. The results were compared with classical average size model showed the influence of size distribution on dissolution rate. The variation of total volumetric mass transfer coefficient was calculated and in agreement with the experimental data to confirm the reliability of population balance model. In contrast, the average particle size model predicts that the dissolution rate value is larger than the experimental value, thereby explaining why the actual residence time of the material in the industrial reactor is greater than the calculated value of the model.

Compressed air class A foam is a two-phase compressible non-Newtonian fluid with unbalanced self-organization structure. Numerical simulation of laminar flow of compressed air class A foam was studied. Foam with various expansion ratio could be used in different practical engineering. For the sake of guarantee on the reliability of the simulation, it is necessary to study on the compressibility and the rheological property of compressed air class A foam. As one kind of compressible fluid, the internal pressure of foam surges exponentially with the increase of the compression on the volume. In the process of compression, foam with different expansion ratio could keep stable without coalescence and breakage. In addition, foam with various expansion ratio has property of shear thinning while rheological behavior of foam satisfies with the model of Herschel-Bulkley. Taking the above factors into consideration, the numerical simulation software named Fluent was used to simulate the laminar flow of foam with various expansion ratio in the horizontal circular pipe of which the diameter is 15 mm and 25 mm. The pressure drop gradually increases with the flow process of the fluid when diameter of pipe is 15 mm. The downward trend of pressure in the pipe with diameter of 25 mm is relatively slow, while the pressure drop per meter is approximate to the fixed value. Verified by the experiment of foam transportation in pipe, this method possesses reliability and accuracy in a certain degree. The deviation of simulation could be controlled within 10%.

Based on the Fluent platform, the gas-liquid two-phase flow of the sliding wall surface serpentine microchannel was numerically calculated by the CLSVOF method. The results of numerical simulation were in agreement with theoretical computation. At the same time, the slip phenomenon produced on hydrophobic surface was more significant in smaller microchannel which would reduce fluid flow resistance and achieve drag reduction. The calculation results of fluid flow in microchannel with different wall properties show that slip boundary has almost no effect on distribution of cross-section velocity. The location of maximum cross section velocity was influenced when contact angle of upper and lower wall was different. The contact angle and relative roughness had great effect on slip characteristics. Reasonable design of wall wettability and micro roughness element structure can maximize the drag reduction caused by slip phenomenon. Heat transfer effect was better in microchannel under boundary slip compared with no-slip surface. And it was enhanced with the increase of slip velocity.

Different drying patterns of modified SiO₂ nanofluid droplets have been observed and the effects of modified SiO₂ nanoparticle deposition layer formed in boiling on pure water boiling heat transfer have also been investigated experimentally. The different drying patterns of nanofluid droplets show that modified function groups can affect whether SiO₂ nanoparticles can be adsorbed to the liquid-air interface, and based on this result a conjecture has been made about the effects of modified functional groups on the way of nanoparticle deposition during boiling of nanofluids. From boiling experiments, it is found that polyethylene glycol (PEG) groups modified SiO₂ nanoparticles deposition layer on a heater surface can increase average roughness of the heater surface a lot from 160 nm to 977 nm, and it can also increase pure water boiling heat transfer coefficient. However, the sulfonic acid groups modified SiO₂ nanoparticles deposition layer on a heater surface affect average roughness of the heater surface a little (increased 60 nm), and it deteriorates the pure water boiling heat transfer coefficient. The effects of modified functional groups on the deposition of nanoparticles during the boiling process inferred by droplet evaporation experiments were verified by boiling heat transfer experiments.

Taking the NaCl aqueous solution as the working fluid, the mass transfer characteristic of which in a reverse electro-dialysis (RED) stack have been tested under the conditions of changing the current density and concentration difference between solutions through the RED stack. The RED stack used in the experiments was composed of 5 unit membrane cells with Selemion type of ion exchange membranes (IEMs). The results showed that the selectivity coefficient (a), solvent permeability ratio (v_w), solute ion transport flux (J_NaCl) and co-ion diffusion rate (D_NaCl) of IEMs were affected by stack current density and solution concentration. When the concentration difference increases, the a reduces, but the v_w, J_NaCl and D_NaCl increase. With the increase of the electric current density exported by the RED stack, the α and v_w reduce, but the J_NaCl and D_NaCl increase.

A one dimensional semi analysis model was developed based on accommodation theory to study the effect of electric field on liquid wetting characteristics in vertical rectangular capillary microgrooves heat sinks. The effects of electric field intensity, heat flux and microgrooves dimensions on liquid wetting characteristics are investigated. The results show that the electric field can be utilized to improve the wetting length of liquid in microgrooves heat sinks. The wetting length decreases with heat flux under the electric field effect. When the heat flux is relatively small, the enhancement of the wetting length due to the electric field intensity is higher, yet the enhancement due to the electric field decreases with the heat flux. The accommodation length and the corner flow length under the action of electric field are studied and compared. Both the accommodation length and the corner flow length increase with the increasing electric field intensity yet the enhancement in corner flow length is more distinguished. Since the liquid film in the corner flow stage is thinner than the accommodation stage, according to thin film theory, the enhancement of the corner flow length is important to the heat transfer enhancement of the rectangular microgrooves. Effects of microgroove dimensions on wetting length under electric field effect are considered. The length of wetting under the action of electric field increases and decreases with the increase of groove depth and groove width. Compared with microgrooves with smaller depth and width, when the groove size is larger, the electric field strength is more significant for with the liquid wetting strengthening in the microgrooves.

A three-dimensional model was built up to simulate the process of the refrigerant R410A falling film evaporation outside a horizontal tube. The influence of spray density, heat flux and the horizontal distance from the spray hole to the tube axle on falling film flow and the heat transfer was investigated. The results show that the liquid film thickness and local heat transfer coefficient decrease and tend to be stable along circumferential direction of the tube. The film thickness increases and the local heat transfer coefficient decreases near the bottom of the tube due to the local liquid accumulation. The total heat transfer coefficient decreases with the increase of heat flux and significantly increased with the increase of spray density when the spry density is low. After the liquid film Reynolds number reaches 2000, the total heat transfer coefficient increases slowly and tends to be stable with the increase of spray density. The increase of heat flux will also lead to the rise of the total heat transfer coefficient. As the eccentricity of the cloth liquid increases, the total heat transfer coefficient will rise slightly and tend to be stable, and then the total heat transfer coefficient will drop sharply due to local “dry” and liquid film accumulation areas. With the increase of the spray density, the critical point of the sharp decline in the total heat transfer coefficient will gradually shift to long horizontal distance from the spray hole to the tube axle.

To solve the problem of heat dissipation in high heat flux electronic devices, a flat-type loop gravity heat pipe (LGHP) with upper and lower surfaces connected by a plurality of square columns is designed. An experiment was performed to study the heat transfer performance and temperature uniformity performance under different heating loads. The effect of evaporator placement and different types of working fluid on heat transfer performance also was tested. The results show that using R134a as referigerant and placing the flat plate evaporator vertically has better heat transfer performance, and the critical heat flux(CHF) can reach 212.3 kW/m² while the heat transfer coefficient is 16.2 kW/(m²·K). This LGHP can ensure the working temperature of electronic compenents less than 60℃ and the temperature difference between each point at the flat plate evaporator wall are less than 5℃,which prove the excellent temperature uniformity performance.

The convective mass transfer coefficient on the outer surface of a building is an important parameter in the calculation of the heat and moisture coupling of the enclosure and the simulation of building energy consumption. To get the parameter directly and accurately, a method for measuring the mass transfer coefficient of the wall on the building surface is proposed. The mass transfer coefficient of the naphthalene specimen can be calculated by measuring the mass flux and surface temperature of the naphthalene specimen. To verify the accuracy and reliability of the method, 6 different wind speeds were set up in the wind tunnel, and two pieces of the same experimental wall were made. The naphthalene sublimation method was applied to compare with the traditional thermal balance method. The results show that the surface temperature of naphthalene specimen decreases with the increase of wind speed, and the convective mass transfer coefficient increases gradually. The results of the two methods are close to each other. The difference of the convective mass transfer coefficients between the two methods are less than 10%, and the average deviation is less than 5% under different wind speed conditions. It is considered that the method is feasible. The research can provide guidance for testing the mass transfer coefficient of building external surface under outdoor real conditions, and is also significant for the study of heat and moisture coupling calculation and the evaporation and heat transfer of walls.

Loop heat pipe (LHP), using the heat of phase change, is a high efficient heat transfer device, which can be applied for the high heat flux components such as CPU, data center, etc. During the operation of LHP, the pressure head due to evaporation cannot be ignored. The LHP is different from the LHP with capillary force, the wick is separated from the heating surface and then a steam chamber is formed, in which the pressure head due to evaporation can be effectively used. The influence of different charging ratios (15%-85%) on the operational characteristic of such a LHP is studied through experiment. The result showed such a LHP can operate in a wide charging ratio (20%-75%) and there existed an optimal charging ratio, which is 35%. Under the optimal charging ratio, the temperature of evaporator bottom was 65.1℃. Through the experimental research of different charging ratios, it can provide reference for the optimization of loop heat pipe design for different heat load heat dissipation and can guide the subsequent experimental research.

The effervescent atomizer is a gas-liquid two-phase atomizer. Due to the discrete distribution of gas phase, the gas-liquid flow parameters at the atomizer exit fluctuate violently. In this study, characteristics of both bubbly flow pattern and spray pulsating characteristics were investigated by experimental and simulation methods. A visual effervescent spray system and a gas-liquid two-phase flow simulation model were established, and the operating conditions corresponding to bubbly flow were determined based on the gas-liquid flow regime map. The results show that the bubble size is approximately normal distribution in bubble flow, and the bubble size decreased with the increase of liquid mass flow rate and gas-liquid mass ratio. Under the same operation conditions, spray morphology and gas-liquid flow parameters at the exit orifice section at various times were observed with great difference, and the spray half cone angle varied larger than 10°. When the number density of bubbles was small and the bubble diameter was large at the same time, the spray cone angle was relatively small, and the spray pulsation was intense as well. With the increase of bubble number density, the average spray half cone angle showed a rapid increase followed by a slowly increasing trend, whereas the variation coefficient of the spray half cone angle increased rapidly first, then gradually decreased and tended to stable. Complex flow field structure was the main reason for the variation of bubble shape in the atomizer and the pulsation of gas-liquid flow parameters at the exit section of the atomizer.

A method aiming to prepare more uniform Cu-Zn co-precipitate by coupling of diffusion and reaction process was probed in this article and Cu/ZnO co-precipitated catalysts with high catalytic activity were prepared by introducing water layer into the microreactor and adjusting the ratio of water layer to the total flow. The microstructures and evolution process of the catalysts were analyzed by HRTEM/EDS, X-ray diffraction (XRD), thermogravimetric analysis (TG), hydrogen temperature-programmed reduction (H₂-TPR), and N₂O chemical reaction methods. The results show that the proportion of water layer increases, the Cu-Zn distribution of the initial precipitate is more uniform, and zinc content in the precursor obtained by the aging is increased, the contact area of the oxide CuO and ZnO is increased, and the interaction force is continuously enhanced. Therefore, larger contact area between calcined oxides CuO and ZnO was achieved leading to better dispersibility and stronger interaction with the final catalytic activity of the catalyst significantly enhanced. Numerical analysis based on the model established by MATLAB revealed that the uniformity caused by slower reaction rate of Zn²⁺ can be inhabited by faster diffusion rate of its own. The diffusion-reaction equilibrium region, defined as capable to obtain uniform precipitate, was enlarged with the increasing ratio of water layer and larger proportion of uniform precipitate was achieved simultaneously.

The kinetics of ethanol deep oxidation over Pt/ZSM-5 catalyst was carried out under oxygen-rich conditions in a quartz tube burner with an inner diameter of 4 mm. The reaction temperature was controlled below 428 K. The Power-rate law model and the Langmuir-Hinshelwood model are established to characterize the ethanol deep oxidation for the low-temperature. The activation energy catalytic oxidation is 95.96 and 103.72 kJ·mol^-1 for the Power-rate law model and the Langmuir-Hinshelwood model respectively. The order of reaction for ethanol and oxygen is 0.38 and 1.38 respectively. In the Langmuir-Hinshelwood model, the adsorption constant of ethonal is larger than oxygen, indicating that the ethanol adsorption capacity of the catalyst surface is stronger than oxygen. Increasing the concentration of oxygen concentration is more conducive to increasing the reaction rate than ethanol, which is also reflected in the reaction order of oxygen is larger than ethanol.

The absorption-adsorption hybrid method has potential superiority on CO₂ separation and caption. In this work, the Patel-Teja equation of state coupled with the Kurihara mixing rule was used to describe the absorption equilibrium. The binary interaction coefficients between pure gas components and glycol were determined by correlating the experimental gas solubility data. Then, the Langmuir equation was applied to calculate the adsorption of gas in ZIF-8, and get the correlation of osmotic pressure of glycol liquid membrane on the surface of ZIF-8 with the equilibrium fugacity of gas component. Finally, the obtained model was applied to predict the separation of CO₂ from gas mixture using ZIF-8/glycol slurry.

Carbon quantum dots with uniform size distribution have broad application prospects in the fields of optoelectronic devices, ion detection, nano-sensors, biological imaging and catalyst's due to their good optoelectronic properties. An “ultrafiltration-nanofiltration” bi-membrane method was proposed for the separation and purification of carbon quantum dots (CQDs). The molecular weight cutoff (MWCO) of ceramic ultrafiltration (UF) and nanofiltration (NF) membranes was 2000 and 800 and the corresponding Stocks-Einstein sizes were 2.3 nm and 1.4 nm, respectively. The pure water flux of UF and NF membranes were 140 and 70 L·(m²·h)⁻¹, respectively. The effects of pH on the fluorescence intensity and particle size distribution of CQDs were studied. At pH=3, the carbon quantum dots were well dispersed and the fluorescence intensity is high. The ceramic UF membrane could effectively reject the large grained impurities. The average size of the CQDs in the permeate was about 2 nm with good dispersion and no agglomeration. Ceramic NF membrane played a great role in retention properties to CQDs. Small molecular impurities could be further removed in the concentration and washing process by using NF membrane. After bi-membrane treatment, the emission spectrum changed from multimodal to monomodal distribution, and the peak width narrowed. The luminous purity of CQDs was significantly improved.

The high-sulfur gas (HSG) sweetening process is large-scale and complicated. The acid component may cause great security risk. Applying real-time monitoring of the production process has important significance to ensure the system normal work and safety. Regarding to such chemical processes, the higher-order cumulants analysis (HCA) used the higher-order cumulants and their polyspectras of samples to construct the statistical index, which greatly improves the detection rate. Nevertheless, the different importance of independent components is not concerned in the construction of HS statistical indicators, which may lead to a certain degree of deviation of the monitoring results. Meanwhile, using multiple-indicators may cause the conflicting results among indicators so that the accuracy cannot be guaranteed. Therefore, a fault monitoring method based on contribution weighted higher-order cumulants analysis (CW-HCA) is proposed. The approach weights the sample's third order cumulant according to the contribution of independent components respectively, afterwards, the new weighted index and the residual spatial index are combined to realize the real-time monitoring. The results in TE and HSG sweetening process indicate that, compared with ICA and HCA, the proposed algorithm shows significant efficiency and superiority.

Based on the electron transfer in flowing water film and ion directional migration in electrical field, the size distributions and dust layer morphology of collected particles on wet fabrics collector were studied and compared with the collected particles on dry metal collector. To study the deposition and exfoliation characteristics of collected particles on wet fabrics collector, a test bench was built. Besides, the key factors on the deposition and exfoliation process of collected particles on wet fabrics collector were also investigated. The results showed that the collected particles on wet fabrics collector (6.900 μm) were smaller than the dry metal one (9.018 μm) at same position (sample point 15). Wet fabrics collector exhibited a higher collection efficiency. Different from the collected particles on the dry metal electrode, the dust layer pattern on wet fabrics had no relation to the discharge current distribution. Charged particles preferentially deposited on the convex spots and became the depositional centre on the fabrics collector. Eventually, the aggregated particles formed a point or pod like packing structures. The electrostatic force between wet fabrics electrode and dust layer was decreased while the bond force between collected particles increased by the flowing water over fabric collector. Drag force, liquid bridge force, electrostatic force and dust layer gravity were the key factors on the exfoliation process of collected particles on wet fabrics collector.

The real gas property of carbon dioxide was expressed by third term virial equation, both the choked flow effect and the variation of gas viscosity were taken into account, the influence of inertia effect on the steady characteristics of pumping-inward and pumping-outward spiral groove dry gas seal (S-DGS) under laminar condition have been numerically investigated by referencing the theory of gas thrust bearing which considering inertia effect. Compared with the assumptions of ideal gas and inertialess, the results show that inertia effect induce a stronger influence on carbon dioxide real gas S-DGS. Inertia effect reduced leakage rate and opening force of pumping-inward S-DGS but the opposite was obtained for pumping-outward S-DGS. Taken pumping-inward S-DGS as example, the influence of inertia effect on the steady characteristics of carbon dioxide S-DGS (i.e. leakage rate and opening force) gradually enhanced with the increase of sealed gas pressure and rotational speed, while it being weaken with increased gas film thickness. The relative deviations of leakage rate and opening force caused by the inertia effect are 62.21% and 35.03% when sealed gas pressure is 10 MPa, gas film thickness is 3μm and rotational speed is 20000 r·min^-1, and the critical entrance pressure which causes a choked flow at exit is improved. In addition, the closer the temperature of carbon dioxide is to its critical temperature, the more obvious the inertial effect is.

Monolayer films of 2-amino-5-mercapto-1,3,4-thiadiazole-4-hydroxy benzaldehyde (A) and 2-aminobenzimidazole-4-hydroxy benzaldehyde (B) were fabricated respectively on copper surface by molecular self-assembled process. The corrosion inhibition performance of the Schiff self-assembled films (SAMs) in 3% NaCl solution was examined by electrochemical methods. The results indicated that SAMs could effectively inhibit the corrosion on the copper. The best corrosion inhibition rate of Schiff base A reached to 98.9% with the concentration of 15 mmol·L^-1 and assembly time of 6 h at 25℃. The best corrosion inhibition rate of Schiff base B reached to 96.73% with the concentration of 20 mmol·L^-1 and assembly time of 12 h at 25℃. The surface analysis showed that a protective film on the surface of copper was formed, which effectively blocked the transfer of corrosive medium to the metal substrate. Quantitative calculation and molecular dynamics simulation were used to analyze the relationships between the molecular structure and corrosion inhibition performance of two inhibitors of A and B, and the adsorption form on copper surface. The results showed that two inhibitors had good corrosion inhibition performance. The inhibition effect of A was better than that of B, which was consistent with the experimental results.

For improving the enantioselectivity of Phaseolus vulgaris epoxide hydrolase1 (PvEH1) towards p-chlorostyrene oxide (pCSO), three mutations (PvEH1^W102L, PvEH1^P137K and PvEH1^I151V) were constructed by site-directed mutagenesis. Firstly, catalytic characteristics of the enzymatic hydrolysis of rac-pCSO by the whole cell of E. coli expressing PvEH1^W102L, PvEH1^P137K or PvEH1^I151V were studied respectively. After then, the rac-pCSO initial concentration in the kinetic resolution of rac-pCSO by PvEH1^W102L were optimized, in additional the course was monitored to determine the reaction time. At last, the mechanism of PvEH1^W102L's improvement in enantioselectivity towards pCSO was analyzed by molecular simulation. The result indicated that, the E value and relative activity of the best mutation PvEH1^W102L were 25.5 and 212.6%, which were 11.6 and 2.1 times of PvEH1, respectively. After four-hour reaction, the yield of (R)-pCSO in the kinetic resolution was 45.62% (ee_s=96.30%), when the yield of (R)-p-chlorophenyl-1,2-ethanediol was 50.91% (ee_p=90.26%). Molecular simulation analysis showed that the mutation of the tryptophan (W) at position 102 of PvEH1 to leucine (L) reduced the binding ability of the enzyme to (R)-pCSO, thereby increasing the enantioselectivity of PvEH1^W102L to pCSO.

Combining with the high-gravity distillation column, single screw compressor and new heat pump technology, and then the concept of high-gravity heat pump distillation was proposed. Firstly, high-gravity heat pump distillation heat integrated system was designed and built, which treatment capacity was about 300 kg·h^-1. Ethanol-water solution was taken as the actual research object. The single screw compressor was used to directly compress ethanol vapor. Afterwards, based on the full reflux experiments under the different rotational frequency of high-gravity distillation column, and different feed positions and reflux ratios experiments under the industrial condition, the changes of the affected parameters, energy-saving characteristics and economic benefits of the system were analyzed synthetically. Present results clearly show that the performance of the system is optimal when the frequency of high-gravity distillation column (f_HG) is operated at 40 Hz. By moving down the feed position or increasing reflux ratio, mass fraction of the vapor at the top of the column (y_D) can be improved. If only y_D is considered, feed location 03 (F_L03) is the best. In comparison with the low concentration of ethanol-water solution, it has a great advantage in treating the high concentration. In addition, energy-saving and economic benefits of the system are obvious, which can provide theoretical guidance for the high-gravity heat pump distillation in the selection, design and application of the ethanol distillation process.

Limestone decomposition and desulfurization in a circulating fluidized bed boiler occurs simultaneously with calcination/sulfidation. A random pore model, which considered the calcination of CaCO₃, the sintering of CaO and the sulfation of CaO simultaneously, was established, and the sulfation model of CaO was based on the solid state ion diffusion in the CaSO₄ product layer. The results of the model are well matched with the results from the TGA test, thus the model can be used to investigate the kinetics of the simultaneous calcination sulfation (SCS) reaction. The SCS reaction contains a mass loss stage and a mass gain stage, which were divided by the minimum mass point. The minimum mass point got higher with the increase of the SO₂ concentration. The calcination reaction occurred in a layer of the particle, which is different from the homogeneous reaction model or the unreacted-core shrinking model. The SO₂ in the calcination atmosphere can react with the CaO layer and form CaSO₄, which can fill the pore of the CaO layer and narrow the pore width, increase the CO₂ diffusion resistance and slow the calcination reaction. The sulfation of the calcined CaO got slower with the reaction time. For a particle with a radius of 200 μm sulfated in 0.4% SO₂ atmosphere, the decrease of the sulfation rate in the part of the inner 150 μm was mainly caused by the lower SO₂ concentration here. There was a zone where the SO₂ exhausted. With the sulfation reaction proceeding, more CaSO₄ accumulated in the outer layer of the particle, which increased the diffusion resistance of SO₂ in the outer layer of the particle, caused the exhausting zone of SO₂ being larger and the sulfation rate of the total particle being slower.

Pyrolysis experiments were conducted on a unit of thermogravimetric-infrared (TG-FTIR) spectrometry to examine the evolution characteristics of methane from pyrolysis of oil shale obtained from three locations (LK, NM, and WQ). The Fourier transform infrared (FTIR) spectroscopy was applied to investigate the functional groups of oil shale. The results show that the pyrolysis process of oil shale could be divided into four stages. The pyrolysis reactions and release of volatiles mainly occurred in the second stage (400-600℃). The evolution of methane was closely related to the content of aliphatic hydrocarbons in oil shale (the absorption band of 3000-2800 cm^-1). The higher content of aliphatic hydrocarbons, the more methane generated during pyrolysis process. By the peak fitting and binding kinetics analysis of the methane precipitation curve, it is concluded that the formation of methane is a result of a desorption process and four chemical reactions.

Hydrothermal state management is of great significance for improving the output performance of fuel cell stack. Based on the principle of electrochemical impedance spectroscopy, this paper combines the equivalent circuit model and obtains the response of two impedance spectrum characteristic frequency points to calculate the angle between the frequency response point connection line and the real axis (frequency secant angle) and proposes a frequency secant angle calculation method. The angle has a unique correspondence with the resistance change of the stack proved by theory. The simulation and experimental results show that the results of the frequency secant angle can describe the changes of the hydrothermal management state in the reactor and the effects of the operating conditions on the output performance of the reactor. This method avoids the deficiencies of complicated AC impedance test procedures, long time period, difficulty of parameter fitting, etc.. It provides an obvious, direct, and simple diagnostic method, which lays a foundation for the optimization of the operating conditions of the stack and the early warning of output performance failure. It has a good application prospect.

Pyrolysis-gas-chromatography/mass spectrometry (Py-GC/MS) was employed to investigate the thermal cracking evolution and thermochemical conversion pathways of the main carbon and oxygen-containing functional groups contained in sewage sludge under different pyrolysis temperatures. The results show that sewage sludge mainly contain carbon-carbon double bonds (C=C), carboxyl groups (—COOH), hydroxyl groups (—OH), aldehyde groups (—CHO) and benzene (π-π^*). Pyrolysis temperature has an evident influence on the functional groups evolution. At the stage of the pyrolysis with a temperature lower than 350℃, the increased temperature results in the largest decrease of —COOH content, which is approximately 33%. In the mid-temperature thermal cracking stage (350-550℃), the production of C=C, —OH, —CHO, and π-π^* in pyrolysis product increased significantly, while —COOH show a decreasing trend, but its mass ratio is still the highest. The benzene becomes the main functional groups when the pyrolysis temperature higher than 550℃. In the high temperature pyrolysis stage (>550℃), due to aliphatic hydrocarbon molecules. The chemical activity is enhanced, mainly due to aromatization polycondensation reaction such as dehydration, decarboxylation, decarbonylation and aldol condensation. In the range of pyrolysis temperature study, carbon-carbon double bonds, aldehyde groups and hydroxyl groups content are lower, but show obvious pyrolysis rules. Further, combining the pyrolysis rules of each functional group, the possible path of the pyrolysis evolution of carbon and oxygen-containing functional groups in sludge is proposed.

A sequencing batch reactor (SBR) was operated in this study to investigate the inhibitory kinetics of free ammonia (FA) on Nitrobacter. At the beginning of the experiment, FNA concentration in influent was changed to enrich Nitrobacter. Meanwhile, metagenomic species annotation and abundance analysis showed that Nitrobacter accounted for 40.3% of the total bacterial population. Then, the sludge enriched of Nitrobacter was used to study the variation rule of the specific oxygen uptake rate (SOUR) during nitrite oxidation process of batch tests. Furthermore, non-substrate inhibition model of FA inhibition on Nitrobacter activity was fitted. The results showed that the SOUR decreased with the increase of FA concentration as FA>7.3 mg·L^-1. In particular, the SOUR was maintained at 0 g N·(g VSS·d)^-1 when FA concentration was higher than 22.2 mg·L^-1. Moreover, maximum specific oxygen uptake rate was 0.62 g N·(g VSS·d)^-1. In addition, based on the degree of inhibition of Nitrobacter activity, the inhibition type of FA inhibition on Nitrobacter activity is in accordance with non-competitive reversible inhibition kinetics.

A four-carbon ring thiophene cluster model for characterizing petroleum coke surface was established. The B3LYP-D3 method of quantum chemical density functional theory was used to study the bromide oil from the microscopic level based on the 6-31g(d)/lanl2dz mixed basis set level. The reaction pathways of HgBr and HgBr₂ on the surface of brominated petroleum coke, the activation energy required for the reaction, the adsorption energy, and the Mayer bond orders were given. The synergistic effect of thiophene sulfur in petroleum coke and the bromine in mercury removal was revealed. The results show that Hg⁰ is mainly oxidized to HgBr on brominated petroleum coke and more bromine loading can both enhance the stability of adsorption and promote the occurrence of chemical adsorption. Thiophene sulfur does not directly participate in the oxidation reaction, but it can help to stably carry more bromine, thereby improving the efficiency of mercury removal.

Cu-Zn alloy was electrodeposited on nickel substrate in ChCl-urea-ZnO-Cu₂O deep eutectic solvents at 343 K. The voltammetric curve test shows that cluring the deposition process, the nickel matrix can induce the underpotential deposition of the metallic Zn, thus achieving the co-deposition of the Cu-Zn alloy. The effects of deposition potential on composition, surface and morphology of Cu-Zn alloy coatings were also studied. The results indicate that when deposition potential negatively shifts from -0.85 V(vs Ag) to -1.30 V (vs Ag), the Zn content in the alloy increases from 0 to 76.29%(atom). When deposition potential is located in the range of -1.10——1.15 V, the content of Zn is in the range of 12.5%(atom)-20.81%(atom), the alloy coating is golden. Thus, the imitating Gold plating can be achieved in ChCl-urea-ZnO-Cu₂O deep eutectic solvents by controlling a suitable deposition potential.

In this work, the effects of the electric fields on the flame propagation and combustion characteristics of methane-air mixtures were experimentally investigated in a constant chamber. The loading voltages were 0,-5,-10 and -12 kV, and the excess air ratios (λ) of mixtures were 0.8, 1.0 and 1.6, respectively, representing the three mixed gas states of rich combustion, equivalence ratio and lean combustion. The experiment was performed at room temperature and atmospheric pressure. When the electric field was applied, the flame front in the electric field direction was remarkably stretched, the flame development radius and flame propagation velocity were all accelerated significantly as the loading voltage increased, and the flame shape was changed remarkably. Especial for the lean mixture, the increase of flame development was most obvious. For the mixtures of λ=0.8, 1.0 and 1.6 at -12 kV, the maximum values of flame propagation velocity were increased by 42.3%, 29.7% and 111.7%, respectively. By analyzing combustion pressure variation, it could be seen that the time of peak combustion pressure (t_p) was advanced, and the peak pressure (P_max) of lean mixture increased with the increase of loading voltage. For the mixtures of λ=0.8, 1.0 and 1.6 at -12 kV, t_p were advanced by 13.4%, 7.5% and 24.6%, P_max increased by 2.2%, 1.0% and 8.1%, respectively, compared to that when no voltage was applied. The results could be explained by the ionic wind effects produced by the electric fields and its induced flame stretch on burning methane-air mixtures.

Molten salt as phase change materials can be used as thermal storage medium in concentrating solar power (CSP) system. It is possible to significantly improve the thermal properties of molten salt by adding nanoparticles to molten salt. Nanofluids were synthesized by dispersing 20 nm SiO₂ particles to potassium nitrate, sodium nitrate, and solar salt (60% NaNO₃ and 40% KNO₃, mass fraction) respectively. Nanofluids were prepared by water-solution, sonication, and evaporation. The thermo-physical properties (latent heat, specific heat and molting point) of nonofluids were characterized by DSC method, and the thermal diffusivity was analyzed by laser flash apparatus (LFA). Results show that mass fraction of 20 nm SiO₂ particles significantly enhanced latent heat, specific heat and thermal conductivities of potassium nitrate, sodium nitrate, and solar salt. Compared with base salt, the average specific heat improved of solar salt,potassium nitrate,sodium nitrate with 20 nm SiO₂ nanoparticles was found to be 4.7%-15.89%, 3.9%-33.5%, 1.9%-11.86% in liquid, and the maximum thermal conductivity increased by a maximum of 17.16%, 39.7%, and 9.5%, respectively.

Nanostructured lipid carrier (NLC) coated with two sunscreens, benzophenone-3 (BP-3) and octyl methoxycinnamate (OMC), was prepared by high pressure homogenization. The effects of the total oil content, liquid lipid content, sunscreen content, as well as the emulsifier type and dosage on the particle size, zeta potential and entrapment efficiency of NLC were investigated by single-factor experiments, and the technical formula was optimized. Moreover, the effects of electrolyte type and concentration as well as the amount of emulsifier on the aggregation behaviors of NLC were further investigated and the dynamic model was established. The results show that the electrolyte can compress the electric double layer of the colloid system and decrease the zeta potential, which also aggravate the aggregation and binding between the nanoparticles. The critical coagulation concentrations of NLC samples in the inorganic electrolyte solutions of NaCl and CaCl₂ were 538.2 and 95.8 mmol·L^-1, respectively. And the aggregation rate of NLC in the solution of CaCl₂ is faster than that in NaCl solutions. Besides, the proper amount of the emulsifier is also helpful to maintain the stability of the NLC system.

The magnesium phosphate based porous material (MPCPM) was prepared by chemical foaming method using NaHCO₃ as an air entraining agent. The MPCPM was characteristic of developed pore structure and high strength, hence it is possible to develop a multifunctional composite which is prepared by the MPCPM supportor and KOH electrolyte. The composite was sandwiched by two graphene electrodes, then a novel structural supercapacitor was fabricated. Experimental results show that electrochemical properties of the structural supercapacitor can be attributed to the pore connectivity of MPCPM. The MPCPM contains a great amount of connected pores which can provide paths for ion motion and ion storage. The effects of the NaHCO₃ content and the curing age on the electrochemical and mechanical properties of the structural supercapacitor were analyzed. CV, EIS and CD analyses reveal that the structural supercapacitor exhibits ideal capacitive behavior and charge/discharge performance. The maximum specific capacitance is as high as 62.2 F·g^-1 with the NaHCO₃ content at 2.5%, it is increased by 34.1% compared with the MPCPM without addition of NaHCO₃. Moreover, the structural supercapacitor exhibits a specific capacitance of 38.79 F·g^-1 and a compressive strength of 18.76 MPa with the NaHCO₃ content at 2%. It can achieve a balance between electrochemical performance and mechanical property. And this novel structural supercapacitor may have potential application in multifunctional civil engineering structures.

Based on forming mechanism of weld line, effects of air traps condition and melt temperature on bonding quality of weld line were taken into consideration. Thus, an optimization strategy of weld line assisted by improving air traps condition was proposed. And a multi-objective evaluation system was established to evaluate bonding quality of weld line from two aspects, namely area of air traps and temperature at flow front in weld line. A multi-objective optimization methodology based on Kriging surrogate model and nondominated sorting genetic algorithm Ⅱ (NSGA-Ⅱ) was proposed to optimize process parameters. Optimization of weld line of a perforated plate was given as an example. Latin hypercube sampling (LHS) was utilized to arrange experiments. A surrogate model based on Kriging was established and verified to map relationship between process parameters and optimization objectives. Then NSGA-Ⅱ was used to gain Pareto Front and optimal solution of multi-objective optimization problem. Simulated and practical confirmation experiments were carried out to verify validity of obtained optimal solution. Results show that established multi-objective optimization methodology is effective to multi-objective optimization problems of weld lines. And proposed optimization strategy of weld line assisted by improving air traps condition was proved to be highly effective.

Graphene oxide(GO) was obtained by improved Hummers method. Hydrated hydrazine, chitosan, potassium hydroxide was used to prepare different reduced graphene oxide (rGO), respectively, to choose the best reductant. The rGO was restored and modified by ionic liquid (NH₂IL) to obtain functionalized graphene (NH₂IL-rGO), the matrix (MBAE) was prepared from 4,4'-diaminodiphenyl methane bismaleimide in which diallyl bisphenol A (BBA) and bisphenol A bisallyl ether (BBE) were used as reactive diluents, NH₂IL-rGO/MBAE composites were prepared from NH₂IL-rGO and MBAE via in situ polymerization. The effect of graphene on the properties of composites was studied. The results showed that the micro-morphology of composite existed two-phase structure completely between the matrix and NH₂IL-rGO, Graphene gave the material excellent properties. The impact strength and bending strength of composites reached the maximum, 15.33 kJ/m² and 142 MPa, respectively, when the content of NH₂IL-rGO was 2%(mass). The thermal decomposition temperature of the composites was 435.73℃, the dielectric constant of the composites abruptly reached 84 when testing frequency range was 100 Hz-10 kHz.

The aging degree of emulsion explosive matrix (EEM), as the principal component in emulsion explosives (EE), has a significant impact on operational performance of EE. By analyzing aging mechanism of EEM, an aging equation was derived from the kinetic of crystallization. The equation was validated by previous experimental data. The results indicate that it fits well judging by the adjusted goodness-of-fit statistic. The characteristic time in the aging equation characterizes the time required for the EEM to reach amaximum in an external environment. It is a quantification of EEM stability, which is conducive to evaluate the storage performance of different products under the same aging condition.

α-Silicon nitride single-crystalline nanowires were prepared by direct nitridation of nano-Si powders in N₂-H₂ mixture gas under the catalysis of layered double hydroxide (LDH) flakes. The results show that when the H₂ content is less than 0.5%, the as-prepared Fe/Mg/Al LDH catalyst has excellent high temperature thermal stability, and can maintain its structural integrity and catalytic activity after calcination and reduction at 1250℃. Through decreasing the size and increasing the density of nano Fe particles on LDHs, via reducing the temperature, Fe content in LDHs and adding Mo element into LDHs, the diameter of as prepared a-Si₃N₄ nanowires can be decreased to 30-50 nm, with the aspect ratio higher than 1000. Further study shows that the growth of nanowires was controlled by the vapor-liquid-solid (VLS) mechanism.

Modified crumpled graphene balls (MCGB) with hydrophobicity were prepared through a reflux reaction with stearic and oleic acids. The structure and morphology were characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The dispersion properties and friction properties of different mass content of MCGB in base oil were studied, and the anti-friction mechanism of MCGB in lubricating oil was discussed. The results showed that the base oil with adding a small amount of MCGB can obviously improve the anti-wear and anti-friction capacity, and the optimal content of MCGB was 0.010%. But the anti-friction performance would be ineffective when adding excessive MCGB.

The characteristics of synags/air mixture explosion in half-open and closed ducts with various hydrogen fractions at the stoichiometric were comparatively studied by a self-made laboratory experimental facility. The results show that there is a significant difference in the premixed flame propagation structure of syngas explosion in open and closed pipelines. In the closed duct, the classic tulip flame is observed from all hydrogen fractions, and the distorted tulip flame can be observed at the hydrogen fraction of 70% and 90%, respectively. In the half-open duct, the classic tulip flame forms at hydrogen fraction of 10%, 30%, and 50%,respectively, and the distorted tulip flame can be observed at the hydrogen fraction of 10% and 30%,respectively. Both in half-open and closed duct, the flame propagation speed and maximum pressure increases with the hydrogen fraction increase. When the hydrogen fraction is low (f < 50%), the flame propagation speed and maximum pressure increase rapidly as hydrogen fraction increases, and at higher hydrogen fraction (f ≥ 50%), the flame propagation speed and maximum pressure increase slowly with increasing hydrogen fraction.