Methanogenic microbial electrolysis cell (MEC) is a new technology that uses microorganisms as catalysts to convert CO₂ or organic pollutants into methane by using external input electrical energy. MEC can treat a variety of pollutants such as sewage, sludge, biogas residue and produce methane while realizing CO₂ treatment and energy conversion. It is considered as one of the important solutions with high energy conversion efficiency, low cost and environment-friendly for energy shortages and environmental pollution problems. In recent years, MEC has received extensive attention in methanogenic biocathode structure, electron transport pathways, and methanogenic microbial communities. At the same time, new methanogenic technologies formed by MEC coupled anaerobic digestion or other wastewater treatment systems have been gradually developed and become researche hotspot. In this paper, the progress of research on methanogenic biocathode and the methanogenic microbial community of methanogenic MEC were reviewed. Furthermore, the new systems of the MEC coupled anaerobic digestion or other systems for methane production were also introduced. Finally, the research direction of methanogenic MEC and the technical problems that still need to be solved in the practical process were summarized and analyzed.

Three dicyandiamide-based ionic liquids with low viscosity were selected as absorbent for ethylene absorption. The physicochemical properties such as density and viscosity were measured at 293.15－333.15 K, and their properties were studied. The NRTL model was used to correlate the solubility data for the three binary systems. The average relative deviations (ARDs) between the experimental and calculated values of the three binary systems are 2.47%, 2.54% and 1.19%, respectively. The results show that the low viscous dicyandiamide-based ionic liquids presented good C₂H₄ absorption performance. The solubility of C₂H₄ in ionic liquids is improved by increasing the length of side-chain and introducing hydroxyl group in the imidazole cation. The C₂H₄ solubility would increase with decreasing temperature or increasing pressure. Furthermore, these ionic liquids such as [Bmim][DCN] exhibited outstanding reversibility after 3 times of absorption/desorption circulation. [Bmim][DCN] has the better C₂H₄ solubility than the other two, showing the potential to be C₂H₄ absorbent.

The flow pattern and stripping enhancement of CO₂ desorption from N-methyldiethanolamine solution were investigated in microreactor. It is observed that the gas-liquid two-phase flow patterns in the desorption process mainly include bubble flow, slug flow, annular flow and fine circulation. However, the periodic change of flow patterns resulted in the fluctuation of bubble velocity at high temperature. According to the results of stripping enhancement on the CO₂ desorption, it showed that CO₂ desorption rate was significantly enhanced at low solution rate by adding small amount of inert gas, while excessive gas will lead to a reduction in the solution residence time. The optimal inert gas flow rate was determined by calculating the stripping enhancement per unit gas flow rate.

Due to the lack of internal flow field information, the influence of structural parameters on fluid flow is not clear, which makes the heat transfer mechanism of the shell-tube heat exchanger shell side unclear and hinders the further standardization and generalization of its design criteria. Aiming at the above problems, geometry modeling and corresponding numerical simulations were carried out for the shell side flow of spiral wound heat exchangers. The feasibility and accuracy of these modellings were verified by comparing with experimental data in the literature. Then the flow field and characteristics of shell side fluid were investigated in detail. The heat transfer enhancement mechanism was further discussed based on the analysis of the influences of key structural parameters on the heat transfer and resistance performance. The results show that the fluid flow on the shell side can be described more accurately by using Realizable k-ε turbulence model. The Nusselt number increases linearly with the increase of the Reynolds number in a log-log coordinate system, while the friction factor f decreases linearly. The Nusselt number increases as the results of increased winding tube diameter d and average winding diameter D, and decreased pitch S. But it was opposite for the friction factor f. The heat transfer and resistance performance of the shell side are mostly affected by the winding tube diameter d, and the average winding diameter D does the least. Increased winding tube diameter d and average winding diameter D will break the boundary layer of the fluid flow. Then the fluid disturbance increases and hence the temperature increases faster. It is beneficial to enhance heat transfer on shell side. While increased pitch S will make the fluid flow much more smoothly, which causes velocity boundary layer to thicken. Thus flow resistance and temperature rising rate are reduced, it is not good for enhancement of heat transfer on shell side.

Based on the combination of theoretical derivation and empirical formula, the general formula of the bed expansion ratio of fluidized process of Geldart-B particles in fluidized bed is established, and the convergence iteration formula of bed expansion ratio is constructed in the whole value range. The formula has divergence when the initial bed height is small or the gas velocity is large and is not always available. Bed expansion ratio iteration formulas that converge across the full range of values are constructed by introducing power series and numerical processing. The calculation results are closed to the experimental data of silica, Diakon and a small Geldart-B particles. The relationship between bed expansion ratio and bubbling fluidized flow regimes is further discussed. At the critical point of the flow regime transitions, the critical expansion ratio can be obtained from particle properties and bed structure parameters. The main factors affecting bed expansion ratio can be divided into three aspects: operating conditions, particle properties and bed structure. It is difficult for the bed to expand when the Archimedes number of particles is large, the initial bed height is high and the bed diameter is small.

A visualization experiment is conducted to investigate the unconstrained melting process of phase change material (PCM, paraffin RT27) with void in a spherical container. Factors including the spherical container diameter, the heating temperature, the initial temperature and the filling ratio of PCM are discussed. Melting behaviors including the solid-liquid interface evolution and the solid PCM motion are revealed, in which a melting mode of floating melting following by close-contact melting is observed due to the existence of void in the spherical container. The quantitative results show that as the spherical container diameter increases, the floating melting time increase first and then decreases, while the total melting time shows a continually increasing trend. Increasing heating temperature or increasing initial temperature will decrease the floating melting time and total melting time. With the increases of PCM filling ratio, the PCM floating melting time and the total melting time increase first and then decrease. Finally, a dimensionless total melting time correlation in terms of Rayleigh number, Stefan number, filling ratio of PCM and dimensionless initial temperature is proposed.

The oscillatory heat transfer characteristics of supercritical water in vertical upward parallel channels were experimentally investigated under the condition of pressure from 26—30 MPa, time-averaged mass flow rate of 420 kg·m^-2·s^-1 and heat flux from 0—130 kW·m^-2. According to the experimental results, the effects of mass flow rate oscillation on wall temperature, oscillatory amplitude ratio ( A_f ) and oscillatory frequency number ( Wo ) on time-averaged Nusselt number were analyzed, and the time-averaged Nu of oscillatory flow was compared with the supercritical heat transfer correlation equations. The results show that the wall temperature fluctuates with mass flow rate oscillation at the same oscillatory period and opposite phase, and the larger amplitude of mass flow rate oscillation leads to the stronger fluctuation of wall temperature. At the occurrence of low frequency oscillation, the time-averaged Nu decreases with the increase of oscillatory amplitude ratio, and decreases firstly with the increase of oscillatory frequency number and then remains constant. At the occurrence of high frequency oscillation, the time-averaged Nu increases slowly with the increase of oscillatory amplitude ratio, and decreases with the increase of oscillatory frequency number. The values of Nu predicted by correlations is generally higher than that of experiments.

The heat transfer capacity of the ground heat exchanger is the key to designing the ground source heat pump system, and the effective thermal conductivity of the environmental soil is an important parameter affecting the underground heat transfer. To further investigate the impacts of mesoscopic structural parameters on the effective thermal conductivity of soil, this paper proposes three random fractal structures and applys lattice Boltzmann method to simulate the heat transfer procedure in the soil-like porous materials. By comparing and analyzing the simulation results with the experimental findings which are derived from thermal probe tests, it is found that porosity is still the dominant factor that affects the effective thermal conductivity of dry soil, while the impacts of fractal dimension and size ratio are minor. The randomness of phase distribution in the dry soil does have considerable effect on the variations of effective thermal conductivity. A slight change of the particle distribution can lead to a difference up to 24.5%.

Compared with glass-made optical products, polymer injection optical products have the advantages of light weight, easy processing, good impact resistance, and are widely used in high-end fields such as aerospace and precision lenses. However, due to the coupling effect of complex thermal fields and pressure fields in the forming process, injection molded transparent products usually have optical defects such as uneven refractive index distribution, angular deviation, optical distortion and so on. Therefore, the simulation and experimental investigation on the effect of injection molding process on the refractive behavior is of great guiding significance for the manufacture of transparent products with controllable refractive index. In this paper, the layered computational model for the refractive behavior in thickness direction of injection molded optical products was built based on the Hele Shaw injection molding theory and Lorentz Lorenz equation characterizing density and refractive index. The corresponding simulation program with VC++ was developed, and then was merged into the software system Z-Mold, a self-developed injection mould simulation software. Furthermore, the coupling analysis of injection molding filling, packing, cooling and refractive index distribution was successfully implemented based on Z-Mold. Taking the polycarbonate transparent square plate as an example, its refractive index distribution in thickness and flow direction was predicted and analyzed. According to Brewster's law, the refractive index values of square plate at different position were measured. The simulation results were in good agreement with the measured data, which proved that the prediction model for refractive index had high accuracy. This method had been successfully applied to the analysis of the "Shenzhou" extravehicular spacesuits mask.

The vibrating device is combined with the gas-liquid two-phase flow experimental loop to carry out experimental research on the gas-liquid two-phase flow in the horizontal channel under nonlinear vibration conditions. The influences of various vibration parameters on flow regime transition line and frictional pressure drop were analyzed. The flow transition boundary diagrams illustrate that flow conditions under nonlinear vibration is different from that under steady state. The whole flow pattern has an outward expansion tendency with the slug flow as the center as vibration frequency or amplitude increases. Vibration frequency has a significant effect on fluctuation degree of gas-liquid interphase, whereas vibration amplitude mainly affects void fraction. There was no obvious difference on the values and distribution between the calculation deviations in fluid flow under nonlinear vibration and the calculation deviations in fluid flow under steady state by using different empirical formulas. The results show that the empirical correlations for frictional pressure drop of two-phase flow under steady state are also suitable for the calculation of frictional pressure drop of gas-liquid two-phase flow under nonlinear vibration.

On the axis-symmetric water jet test bench, the flow field structure in the entrainment boundary layer with the Reynolds number in the range of 1849－2509 was measured by the single-frame long exposure image method. It is found that engulfing and nibbling entrainment model occur intermittently with time, in the region of L=2D－3.5D streamwise and H=D－1.25D radial direction. It concludes from analyzing that the occurrence probability of engulfing increases with Reynolds number when Re>1915, the influence of Reynolds number on the occurrence probability of this structure decreases when Re>2311.The occurrence frequency of this coherent structure obtained by fast Fourier transform is between 10 Hz and 19 Hz. Special vortex structures were observed in the flow field during the occurrence of engulfing. The jet flow field are measured using moving single frame long exposure image method in Lagrangian coordinate system, and it is found that the vortex structure generally existed near the interface of turbulent regions and non-turbulent regions.

The reason for the deactivation of catalysts in the process of preparing high value-added hydrogenated nitrile rubber by heterogeneous catalytic hydrogenation of nitrile rubber was investigated. It was found that the cause of the decrease in catalyst activity was not the loss, agglomeration or poisoning of noble metal nanoparticles. The reactants could not contact with the active sites, which was the real reason for the reduced activity. Therefore, the effective removal of the polymers from the active sites was the key to catalyst regeneration and reuse. Secondly, based on the similarity-intermiscibility theory, the recycled catalyst was treated with a single or a mixed solvent to elute the polymers and recover its activity. The results showed that the catalyst activity could be restored to 90% of the fresh catalyst activity by washing with ethyl acetate, butanone, N,N-dimethylfirmamide or N-methylpyrrolidone. When treated with a mixed solvent, its catalyst activity could be increased to 95% of the fresh catalyst activity, and could remain steady after recycling 4 times. SEM and TG characterization results showed that after the organic solvent regeneration, Pd active sites on the surface of the catalyst were exposed, thus its hydrogenation activity was remarkably improved.

Fe₂C is the main active phase of low temperature Fe-based Fischer-Tropsch catalysts. It is of great significance to study the mechanism of Fischer-Tropsch reaction. Herein, spin-polarized density functional theory(DFT) calculations are performed to investigate the mechanism of CH₄ formation and C—C coupling on the η-Fe₂C(011) surface, where this crystal phase is thermodynamically stable. The calculated results show that the effective barrier of CH₄ formation on such surface is 1.03 eV, lower than those of C—C coupling, and the C + CH₃ is the most likely C—C coupling pathways. Subsequently, the effective barrier difference between the CH₄ formation and C₁—C₁ coupling is used as a descriptor to compare the difference of the Ficher-Tropsch synthesis (FTS) selectivity between the η-Fe₂C(011) surface and other Fe-based catalysts surfaces. The FTS selectivity is found to be highly sensitive to the crystal phases and surfaces of Fe-based catalysts, and the η-Fe₂C(011) surface shows relatively high CH₄ selectivity.

Oxidative pyrolysis can effectively increase the volume reduction ratio of radioactive waste cation exchange resin, but higher pyrolysis temperature is likely to cause nuclides to volatilize. However, the high pyrolysis temperature can easily lead to the volatilization of nuclide. To lower the pyrolysis temperature, a series of resins containing an increasing Co loading were prepared by ion exchange method, using Co(NO₃)₂·6H₂O and cation exchange resin (Amberlite IRN-97H) as raw materials. The effect of Co with different contents on the pyrolysis of resin was investigated on a thermogravimetric analyzer. When the Co content was 10－40 g/L, the peak temperature of the mass loss peak of the copolymer matrix of resin was reduced by 232－263℃ compared to that of pure resin, while the volume reduction ratios were almost the same. The XRD, FT-IR, XPS and elemental analysis of the solid residue were performed. The results showed that the CoO formed by the conversion from Co²⁺ had a catalytic effect on the oxidative pyrolysis of the copolymer matrix, which promoted the breakdown of sulfurbridge (—S—).

Industrial helium is mainly extracted from natural gas by cryogenic, membrane separation and pressure swing adsorption（PSA） coupling of which PSA is the key to obtain high purity helium. It is helpful to overcome experimental limitations via adsorption process simulation, which can effectively guide engineering design and optimize process conditions. A helium/methane single-column pressure swing adsorption model was established by Aspen Adsorption software to obtain breakthrough curves. Based on the results, a two-column PSA process was established. The optimal operation time of adsorption, forward, reverse, flush, and boost step is 60, 180, 30, 60 and 180 s, through analyzing the changes of the gas phase composition in the adsorption column. In three-column PSA process, the optimal time of adsorption and pressure equalization for one cycle are 135 s and 90 s, helium purity can reach 98.42% and the recovery is up to 60.45%. It is necessary to optimize the cycle time in one cycle by considering the matching of each step time and the continuity of production in five-tower PSA process. When cycle time is between 300 s and 340 s, purity of helium reaches 99.07%.

To strengthen the gas-liquid centrifugal separation process and realize the high-efficiency separation of gas-liquid cyclone in the large-diameter separator, a multi-rotor gas-liquid vortex separation equipment was designed, which provided a new design for gas-liquid separation and large-scale design. It can provide a new idea to design for large-scale gas-liquid separator. The pressure drop characteristics are investigated in a large scale cold-separator model. The static pressure drop between the inlet and outlet was measured at different velocities of the swirling arm under pure air flow conditions. The velocities of the swirling arm ranged from 5.65 to 16.95 m/s, which can cover the operating conditions of the industry gas liquid separator. The experimental results show that the pressure drop and the velocity of the swirling arm presence a square relationship. The dimensionless standard deviation of the static pressure drop is maintained within 2%. Furthermore, the total pressure drop includes three parts, i.e., loss in inlet friction, loss in the separation space, and loss in outlet pipeline. It is found that the pressure drop occur in the separation space is the largest. A model between the pressure drop of each part and the velocity head of the swirling arm was then given. The resistance coefficient of this rig is 16, it has no significant increase compared to common cyclone separators. The total pressure drop is closely related to the velocity of swirling arm. The change of total pressure drop is slight after feeding liquid. The forecast equation of the resistance coefficient was obtained based on the experimental of four similar structures with different sizes. Compared to real resistance coefficient, the predicted results error is less than 0.5%.

To investigate the feasibility of nanofiltration technology to separate glyphosate solution containing high concentration of monovalent salt, a commercial Desal-DK nanofiltration membrane was used to carry out separation experiments and simulation calculations of glyphosate solution containing high concentration of NaCl. Firstly, effects of feed compositions and transmembrane pressures on the flux and the solute retention for single solutions were investigated by the NF filtration experiments. Membrane parameters were obtained by fitting the experimental results to the SK (Spiegler-Kedem) equations. The results showed that the Desal-DK NF membrane had a low rejection to NaCl and a high rejection to glyphosate for the single solutions. For the high-concentrated binary component solutions, volumetric fluxes of the mixed solution is significantly reduced compared to the single solutions, while the NF membrane presented higher retention rate (more than 90%) to glyphosate and a lower rejection (less than 10%) to NaCl. Finally the selective separation of NaCl and glyphosate by NF diafiltration was simulated for the binary solution containing 1 g/L glyphosate and 100 g/L NaCl. After pre-concentration and diafiltration, a highly concentrated solution of glyphosate (7.43 g/L) and a relatively pure solution of NaCl (89.02 g/L) were obtained. This work demonstrated that DK NF membrane is a practical way for the separation of glyphosate and NaCl in the industry.

Due to the frequent occurrence of major chemical accidents at home and abroad and the increasing demand for energy saving and consumption reduction in the chemical industry, it is of great significance to study multi-objective optimization of heat exchanger networks(HEN) with more secure nature. Evaluation index method was employed to quantify the inherent safety explosiveness, toxicity and inventory for the HEN. Mathematical programming was used to establish a mathematical model of HEN synthesis considering inherent safety. Normalization method was used to obtain the objective function of economy and safety. The case study shows that when explosiveness index is considered, the heat exchange among safer process streams is preferred. When toxicity index is considered, the heat exchangers with toxic process streams are preferred to be eliminated. When inventory index is considered, the number and area of heat exchangers are preferred to be reduced. Then the explosiveness, toxicity, inventory and economy of HEN was optimized simultaneously. And the case study shows that the optimal HEN relies strongly on the selection of economic weight in the proposed objective function.

The traditional local kernel principal component analysis (SLKPCA) does not consider the difference of samples when constructing the improved residual, so that the fault sample information is easily covered by other samples. This paper proposes a new fault diagnosis method of nonlinear chemical process based on weighted statistical local kernel principal component analysis (WSLKPCA). Firstly, the score vectors and the eigenvalues are obtained using KPCA and the residual function is constructed. Then, a weighting strategy based on the distance between the test sample and the training sample is designed to construct the weighting improved residual, which assigns larger weights to samples with strong incipient fault information to enhance the impact of fault samples. Finally, the contribution graph is constructed based on the weighted mutual information between the measured variables and monitoring statistics to identify the fault source variables. Simulation results on continuous stirred tank reactor and TE process show that the proposed method can effectively detect incipient faults, and has better fault recognition performance.

Aiming at the problem that the fuzzy neural network structure is difficult to adapt when there is no growth and pruning thresholds, this paper proposes a structure design method based on hybrid evaluation index (HEI). First, the initial number, centers and widths of rule neurons are determined by the fuzzy C-means clustering algorithm. Next, a novel relevance evaluation index (REI), which is composed of the Davies bouldin index (DBI) and the Dunn index (DI), is presented to calculate the correlation among the outputs of rule neurons. The learning ability of neural network will be determined by the change of root mean square error (RMSE) during the training process. Then, the HEI is presented based on REI and RMSE. The topology structure of the fuzzy neural network is adjusted according to the HEI. Finally, the feasibility and effectiveness of the structure design method are proved by using the Mackey-Glass time series prediction, nonlinear system identification and PM_2.5 concentration prediction.

In order to alleviate the negative impact of dual circulating fluidized bed agglomeration and plugging failure on biomass gasification reaction, a fault diagnosis model based on multi-scale feature energy-kernel extreme learning machine (KELM) was proposed. Firstly, wavelet decomposition is used to obtain the multi-scale signal in the fault state, then the feature energy of each scale is extracted as the feature vector, and finally input into the nuclear limit learning intelligent diagnosis model optimized by genetic algorithm to realize the intelligent diagnosis of dual circulating fluidized bed airflow blockage faults. Through the classification and analysis of the open bearing fault data set and the dual-circulating fluidized bed cold experimental system data, and compared with the KELM diagnostic model based on variational mode decomposition and sample entropy feature extraction, the results show that the model has higher fault diagnosis accuracy (82.5%), which can effectively extract fault characteristics and be used for efficient classification and identification of dual circulating fluidized bed airflow blockage.

Micro-emulsion is composed of water, oil, salt, surfactant and co-surfactant. Its phase behavior and solubilization performance are affected by each component. It is found that in the SDBS (SDS, SLS) / aviation kerosene / water / n-butanol / NaCl system, with the increase of NaCl content, the phase inversed from Winsor Ⅰ type to Winsor Ⅲ type to Winsor Ⅱ type. The effect of oil-water ratio on the phase behavior of microemulsion was studied by phase diagram.The micromorphology of the micro-emulsion under different phase conditions was characterized by cryo-electron microscopy. With the increase of oil-water ratio, the system changed from micelle solutin to Winsor type Ⅰ under low salinity. While, at high salinity, with the increase of oil/ water ratio, the phase inversed from Winsor Ⅱ type to Winsor Ⅲ type to Winsor Ⅰ type. When the salinity is constant, the amount of oil required for the formation and disappearance of the middle phase of the micro-emulsion will increase with the increase of surfactant concentration. In addition, among the three surfactants, the order of solubilization ability of surfactants is SDBS > SDS > SLS, and the order of sensitivity to kerosene is SLS > SDS > SDBS.

A DC magnetic field generator was assembled around the friction region in a four-ball tester. The tribological properties of 150SN base oil and lubricating oil containing modified nano-WS₂ under and without DC magnetic field were studied by modified tribo-tester. The morphology, the content and chemical species of typical elements on the worn surfaces lubricated with the tested oil were examined by SEM-EDS and XPS, and then the tribological mechanism was discussed. The results indicate that the modified nano-WS₂ has good stability in 150SN base oil. The lubricating oil containing nano-WS₂ exhibits better lubrication performance. In addition, when the nano-WS₂ content is the same, the anti-wear and friction reduction effect of the lubricating oil under DC magnetic field is better. The DC magnetic field had a certain aggregation effect on nano-WS₂ and could increase the possibility of tribochemical reaction.

The special properties of the supercritical carbon dioxide medium make the various practical effects in the high-speed supercritical carbon dioxide dry gas seal prominent, and ignoring these actual effects may bring large errors to the dry gas seal steady state performance solution. Taking spiral groove dry gas seal as the research object, the governing equation of film pressure considering inertia term and real flow state was derived. The film pressure distribution was obtained using finite difference method. The film stiffness and leakage rate of high-speed supercritical CO₂ dry gas seal based on the real modified model and classical simplified model were compared and analyzed. The effects of real gas effect, inertia effect and turbulent effect on film stiffness and leakage rate under different pressure and velocity conditions were analyzed. The independent and interactive effects of three effects on steady-state performance were revealed. Under the given conditions, the results show that the leakage rate calculated by the classical simplified model is smaller at low speed, and both film stiffness and leakage rate calculated by the classical simplified model are smaller at high speed. Under super-high speed condition, real gas effect significantly increases film stiffness and leakage rate of the gas film, while turbulent effect increases the stiffness of the gas film and reduces the leakage rate. Inertia effect slightly influences film stiffness and leakage rate. There is a strong interaction between real gas effect and turbulent effect on steady performance.

The theoretical analysis model of the axial micro-elliptical hole texture oil seal is proposed. The influence of micro-pore structure parameters on its performance is obtained by simulation. The results showed that the lubrication and anti-friction property of the micro-elliptical pores shaft texture are mainly reflected which will lead to significant dynamic pressure lubrication effect of the liquid film in the relative motion process, so non-contact sealing and lubrication are formed between the interfaces. And its seal reliability is reflected in the directivity of micro-ellipses, proper directional performance makes the flow of fluid longer in the pores area under the conditions studied, and it is blocked by the boundary to make dynamic pressure increase on one side of the pores and form cavitation zone on the other side of the pores, the low-pressure cavitation zone will quickly suck the fluid that is about to leak out, which can improve sealing reliability. Therefore, the performance of oil seal is controlled by changing the texture size. In order to improve oil seal life and reduce leakage rate, the axial surface micro-ellipses pores textured of γ≥0.8 (If the area ratio is constant), h₁=1.5—4 μm and α₁=0°—45° or 175°—215° shall be selected for the oil seal in the study scope.

The electrochemical behavior of T91 martensitic heat-resistant steel in Cl-contaminated atmosphere was studied by electrochemical noise (EN) technique. The statistical analysis of EN data was carried out to obtain the characteristic parameters of corrosion initiation and development. The atmospheric corrosion process is identified by using the standard deviation of electrochemical potential noise (EPN) and electrochemical current noise (ECN) together with noise resistance. Thevenin equivalent circuit is used to verify the correlation between statistical parameters and corrosion rate. Experimental results indicate that EN can be used to effectively monitor the atmospheric corrosion of T91 steel, the amplitude of current noise reflects the corrosion initiation and propagation. Theoretical analyses reveal that solution resistance can influence the measurement of potential noise and current noise, and the calculation of noise resistance. Spectral noise resistance is not equal to impedance module, and a relationship is derived. Experimental data further confirmed the theoretical predictions.

Cordycepin, as a kind of nucleoside antibiotic, has various biological and pharmaceutical activities, such as anti-cancer and anti-tumor activities. Cordycepin is mainly obtained from liquid culture of Cordyceps militaris, whose low yield restricted its further application though. Considering the high concentration of cordycepin accumulation to produce strong feedback inhibition on its biosynthesis process, a strategy to remove some cordycepin and weaken the feedback inhibition to increase the production of cordycepin by fermentation separation coupling technique was proposed. Next, static adsorption test was taken and macroporous resin NKA-II was screened, followed by optimization of adsorption conditions such as resin usage (60 g·L^-1), temperature (37℃), and desorption solvent (100% ethanol), giving 644.50 mg·L^-1 cordycepin in fermentation under 30 g·L^-1 initial glucose with repeated adsorption processing (twice), 32.07% higher than the control. To further improve the cordycepin yield, fed-batch fermentation coupled with resin adsorption separation was performed, giving a final yield of 787.50 mg·L^-1, which was 35.78% higher than the control. It was found that the strategy of submerged liquid fermentation coupled with macroporous resin adsorption could efficiently weaken the feedback inhibition of cordycepin, and dramatically enhance the productivity of product, providing novel ideas for industrial cordycepin production.

A large amount of cyanide slag is produced during the cyanidation and gold extraction process and is considered as a hazardous solid waste. Cyanide slag was mainly consisted of pyrite, quartz and silicate. The static adsorption method was applied to simulate the cyanide ion adsorption on several typical minerals and their complex minerals of cyanide tailing in this study. Results showed that the adsorption of CN^- by minerals is linear, but the adsorption capacity is different, and the adsorption amount of CN^- on unit mass could be classified as follows: pyrite > synthetic cyanide tailing>silicate mixture > quartz. Quartz had hardly any adsorption of CN^-. The CN^- adsorption capacity of silicate mixture, pyrite and synthetic cyanide slag were about 1.09, 13.89 and 6.89 mg/g, respectively. A mathematical model was developed to estimate the effects of quartz, silicate and pyrite on the CN^- adsorption capacity of cyanide tailing. The Fourier transform infrared spectroscopy showed that a significant CN^- adsorption peak appeared for silicate, pyrite and cyanide slag, and oxidation products of pyrite changed significantly after the adsorption of CN^-.

The κ-K?hler theory was used to study the hygroscopic properties of atmospheric aerosol systems in Xi an and Beijing. The aerosol model was established by choosing several typical inorganic (sulfate, nitrate, chloride) and organic components (cycloene, aromatic hydrocarbon, carboxylic acid) to mimic to the real complex atmospheric composition. The results show that, when air quality changes from clean state to polluted state, the content of organic components gradually decreases whereas the concentration of (NH₄)₂SO₄ and NH₄NO₃ gradually increases in both systems. This trend always promotes the overall hygroscopicity of the aerosol systems, which in turn enhances the adsorption of moisture and thus the formation of haze. The influence of different components on the hygroscopicity of the whole system was also quantitatively predicted. The trend of variation was revealed by the theory and the theoretical prediction was in a good agreement with that observed in practice.

Sodium dodecyl benzene sulfonate (SDBS) was used as a surfactant to prepare microemulsion for emergency treatment of crude oil contaminated soil and recovery of crude oil. Comparison between the original and the recovered crude oil and soil samples was done. It is found that the pH of the recovered soil is slightly higher, the Zeta potential is smaller, the volume fraction of clay reduced, indicating that the microemulsion treatment has little influence on the physical and chemical properties of the soil. The recovered crude oil has higher saturation fraction, lower aromatic, resin and asphaltene content, lower density and viscosity, and belongs to light crude oil. The effects of SDBS, n-butanol and NaCl contents on de-oiling effect were investigated. Experiments on effects of oil/water ratio, temperature, recycling and scaling-up were carried out by using the selected three types of microemulsions formula. The optimal microemulsion formula for the de-oiling of crude oil contaminated soil is w(SDBS)=10%, w(n-butanol)=4.8%, w(NaCl)=0.8%, w(diesel)=12.8% .

To develop more use of fly ash, fly ash is used to remove dye contaminants from water to achieve waste treatment. Methylene blue, a kind of dyes, was selected as a model pollutant to investigate the feasibility of the ultrasonic assisted fly ash process (US-FA system). The removal efficiency and the kinetics analysis of this combined system were studied. The experimental results show that the introduction of ultrasonic can improve the removal rate of methylene blue. The synergy effect between fly ash and ultrasound is significant. When fly ash dosage is 0.3, 0.5, 1.0 and 2.0 g, the synergistic factors are 1.05, 1.32, 1.55 and 2.27 respectively. In this experimental scheme, the thermal effect of ultrasonic can be ignored after constant temperature controlling. The pollutant is mainly removed by the adsorption role of fly ash and the degradation role of hydroxyl radicals. The enhancement effect of ultrasound on fly ash is mainly illustrated in aspects as follows: (1) ultrasound cavitation produces hydroxyl radical, and the interaction between ultrasonic wave and fly ash produces more hydroxyl radical, which has strong oxidation ability and non selectivity; therefore the dyes pollutant can be degraded by oxidation of hydroxyl radical. (2) Ultrasonic wave can promote to produce more active sites on the surface of fly ash, therefore ultrasound can greatly promote the adsorption performance of fly ash due to the chemical reaction is the controlling steps of adsorption process of fly ash. (3) Ultrasonic wave aggravates the solid-liquid mixing, promotes the movement of pollutants toward the solid surface, promotes more pollutants to enter into the pores of adsorbent particles, and hence increases the mass transfer of pollutant from liquid phase to solid phase.

In this study, addition of corn stover to the water suspension of Pt/TiO₂ significantly improved H₂ evolution from water splitting under UV light. The structural characteristics of corn stover after photocatalytic reaction were characterized by SEM, XRD, FT-IR and TGA. The effects of irradiation time, corn stover particle concentration, stover particle size and catalyst concentration on hydrogen production were studied by single factor experiment and orthogonal experiment. The results show that the catalyst concentration and corn stover particle concentration have a greater impact on hydrogen production. Under the experimental conditions in this paper, the hydrogen production rate and hydrogen yield increase first and then decrease with the increase of catalyst concentration, and the catalyst concentration is 4×10^-3 g/ml to 6×10^-3 g/ml. The highest hydrogen yield is obtained. When the concentration of stover granules is more than 0.5×10^-3 g/ml, the hydrogen production rate decreases with the increase of stover granule concentration. And the hydrogen yield shows different patterns of change with the irradiation time in different stover granule concentration. However, too small corn stover particle size will have a negative impact of hydrogen production.

A diffusion repatr model for the predicting bond strength between layers of fused deposition modeling (FDM) is introduced. The temperature-dependent diffusion model was determined based on the rheological data. The diffusion between the layers of the FDM components was predicted based on one-dimensional transient thermal analysis. The diffusion coefficient of temperature history was integrated with time to obtain the total diffusion of interfacial molecules, and then the interlaminar bond strength prediction model was obtained. The results showed that the predicted bond strength is in good agreement with the measured data under different printing conditions, which indicates that the prediction model is reasonable. Finally, the usability of the model is verified by a combination of three-point bending experiments and numerical simulations. Therefore, it can be used as an effective model for predicting the performance of FDM prints.

The Al₂O₃ film and the SiC film with an average pore diameter of 500 nm were hydrophobically modified by n-octyltriethoxysilane and ethanol as modifiers and solvents, respectively. The concentration and modification of the modifer were investigated by graft polymerization. The wettability and oil-solid separation performance of the modified Al₂O₃ and SiC MF membranes were investigated. The backflushing operation and long-term stability test for the modified membranes were conducted. Under the optimal modification conditions with grafting agent concentration of 0.2 mol·L^-1, grafting temperature of 40℃ and grafting time of 12 h，the water contact angles (WCAs) of the modified Al₂O₃ and SiC membranes were as high as 134°±1°and 140°±1°, respectively. It was found that the hydrophobic SiC membrane showed higher hydrophobicity than that of the Al₂O₃ membrane. For oil-solid separation experiments, both modified membranes exhibited excellent rejection to impurities in oil phase. However, the hydrophobic modification had a more significant effect on the flux of SiC membrane. The fluxes of hydrophobic Al₂O₃ and SiC MF membranes were 1134 L·m^-2·h^-1 and 1408 L·m^-2·h^-1, respectively, with transmembrane pressure of 0.25 MPa. Backflushing operation was beneficial to the flux recovery of ceramic membrane, especially hydrophobic SiC membrane.

Porous carbon materials have become one research hotspot due to their excellent electrical conductivity, superior stability and low cost. Using phenol, formaldehyde and melamine as raw materials, a high concentration of zinc chloride was used to provide a super-salt environment. After solvothermal reaction, a nitrogen-containing carbon aerogel(NCA) was obtained by pyrolysis at 800℃ in nitrogen. Scanning electron microscope (SEM), Raman and Brunauer-Emmett-Teller (BET) results demonstrate that the NCA sample has hierarchically honeycomb-like structure and its specific surface area reaches 729.6 m2/g. The as-prepared NCA, when tested in three-electrode system as supercapacitor electrode, exhibits a high specific capacitance of 350.7 F/g at 1 A/g and outstanding cycling stability with 97.8 % of the initial capacitance retained after 10000 cycles at 20 A/g in 0.5 mol/L H₂SO₄. Moreover, symmetric supercapacitor based on the NCA electrodes could deliver an impressively high energy density of 26.8 (W·h)/kg at a power density of 800 W/kg. Therefore, NCA is one promising material that can be used in supercapacitors.

A new organic-inorganic composite phase change material (PCM) was prepared, which is composed of trimethylolpropane (TMP), ammonium chloride (NH₄Cl) and H₂O, for the application of cold chain logistic. The composite materials with different ratios were measured by using differential scanning calorimetry (DSC), and a composite PCM with excellent thermal performance was selected, which has a mass ratio of 1.0∶2.0∶7.0 (TMP∶NH₄Cl∶H₂O). To further optimize its performance, the supercooling degree and thermal conductivity of the PCM were studied by adding nucleating agent ( nano-Al₂O₃, nano-Fe₂O₃, nano-TiO₂), and phase separation of the PCM was studied by adding thickener, i.e., carboxymethyl cellulose (CMC) or polyacrylic acid sodium (PAAS), and the thermal cyclic experiment was also conducted. The results showed that adding 0.40%(mass) and 0.50%(mass) nano-TiO₂ had a better effect on reducing supercooling degree and enhancing thermal conductivity, respectively. CMC and PAAS could eliminate the phenomenon of phase separation with a little influence of thermophysical properties. The final ratio of the PCM was TMP-NH₄Cl-H₂O mixed at a mass ratio of 1.0∶2.0∶7.0 + 0.4%(mass) TiO₂ + 1.0% (mass) PAAS, and the phase-change temperature, latent heat enthalpy and thermal conductivity of the prepared PCM were －19.9℃, 246.8 kJ/kg and 0.81 W/(m·K), respectively.

Carboxyl functionalized bridged-type organosilica membranes were prepared via the thiol-ene click reaction between 1,2-bis(triethoxysilyl)ethylene (BTESEthy) and mercaptosuccinic acid (MSA), using tubular α-Al₂O₃ microfiltration membranes as the supports. The membrane structure and surface properties were characterized by Fourier transform infrared spectroscopy (FT-IR), dynamic light scattering (DLS), intelligent gravimetric analyzer (IGA) and scanning electron microscopy (SEM). Quantum chemistry calculations show that the carboxylated modified silicone network has a denser pore structure and higher water affinity. The prepared BTESEthy-MSA membranes were applied to desalination by reverse osmosis. The reverse osmosis performance of BTESEthy-MSA membranes was systematically investigated. The experimental results showed that compared with the original BTESEthy membranes, both water permeability and salt rejection of the carboxyl functionalized BTESEthy-MSA membranes were improved. Meanwhile, the BTESEthy-MSA membranes exhibit superior hydrothermal stability and chlorine resistance. Moreover, the BTESEthy-MSA membranes exhibited high stability over long term reverse osmosis test of 250 h, and high water permeability of 3.2×10^-13 m³/(m²·s·Pa) and NaCl rejections of >94.7%.

Magnesium-doped lithium manganese phosphate(LiMn_1-xMg_xPO₄/C) electrode materials were successfully prepared by microwave-assisted solvothermal synthesis. X-Ray diffraction, scanning electron microscope, thermogravimetry and Brunaur-Emmett-Teller method were employed to characterize crystal structures and morphology, and the electrochemical characteristics of the as-prepared materials were evaluated by galvanostatic charge/discharge, cyclic voltammetry and AC impedance method. The results showed that the plate-like LiMn_1-xMg_xPO₄/C samples, which were synthesized from the microwave-assisted solvothermal method, possessed large specific surface area and well-defined mesoporous structure. In particular, Mg²⁺ doping exerts a significant effect on synthesizing flake-like nanocrystal which favors lithium-ion extraction/insertion reactions, improving the electrochemical activity and electrochemical performance of LiMnPO₄/C material. As a result, the LiMn_0.95Mg_0.05PO₄/C nanoparticle exhibited a high reversible capacity of 141.2 and 95.3 (mA·h)/g at 0.1 C and 5 C, respectively, exhibited outstanding charge/discharge performance and rate capability. Compared to conventional solvothermal synthetic route, microwave-assisted solvothermal approach led to a significant decrease in the reaction time and the as-prepared material possessed excellent electrochemical performance. It is extraordinary and remarkable for the preparation of high-performance LiMnPO₄ cathode material, providing a new method for the preparation of electrode materials for Li-ion batteries.

The effects of existence form and total concentration of chromium chloride (CrCl₃·6H₂O) and nickel chloride (NiCl₂·6H₂O) on the conductivity and viscosity of choline chloride (ChCl)- ethylene glycol (EG) deep eutectic solvent were investigated. The ESI-MS analysis indicated that six-coordinated complexes are presented in the form of [Cr(H₂O)₂Cl₄]^- and [Ni(H₂O)₂Cl₄]^2-. It is deduced that the complex anions are formed through d²sp³ hybrid orbitals of Cr³⁺ (or Ni²⁺) ion and six d²sp³ hybrid orbitals are all filled with lone pair electrons which are donated by Cl^- and O atoms of H₂O, respectively. With the increase of temperature or decrease of total metal ions concentration, the electrical conductivity increases. In addition, the viscosity of the solution changes with temperature and total metal ion concentration as opposed to conductivity. This is mainly due to the formation of ions in the solution due to the formation of nickel and chromium complex ions.

Cadmium selenide(CdSe) quantum rods are semiconductor nanomaterials with good optical properties. Quantum rods with different aspect ratios can be applied to optoelectronic materials and device fabrication. The CdSe quantum rods were prepared by high temperature oil phase synthesis. Under the premise of changing the reaction time of the precursors, the change mechanism of the length-diameter ratio of CdSe quantum rods was investigated and the optical properties were compared. The results show that the particle size of CdSe quantum rod increases with the increase of reaction time and the peak position of the emission peak produces a red shift phenomenon. After characterization by transmission electron microscopy, it was found that the quantum rod gradually became longer as the reaction time of the precursor increased, and the aspect ratio gradually became larger. Therefore, the growth of the quantum rod can be controlled by this method.

A small-size experimental platform was developed to study the effect of ignition position on horizontal flame spread of 2 cm thickness latex foam. The ignition position was 0 (x1), 3.54 cm (x2), 7.08 cm (x3), 10.62 cm (x4), 14.16 cm (x5) and 17.70 cm (x6) from the center point of the material surface. The characteristic parameters, such as surface temperature, mass loss, flame height and flame spread speed were measured during the tests. The results showed that the average flame spread rate is 0.24, 0.23, 0.19, 0.31, 0.42 and 0.51 cm·s^-1 for the tests that the ignition position is far from the center point of the material. At the x3 ignition position condition, the average flame height and mass loss rate was lower and the combustion time was longer than the other tests due to the difference of the heat transfer mode. Then the heat transfer mechanism of the combustion process with different ignition position was analyzed.

To study the coupling oscillation characteristics of the explosion flame and pressure of premixed gas, a transparent plexiglass explosive pipeline experimental platform with dimensions of 80 mm×80 mm×1000 mm was built. The results show that the coupling oscillation of CH₄/O₂/N₂ premixed gas explosion flame and pressure will be affected under the condition that the oxygen concentration E and the detonation area ratio S change. When the oxygen concentration E changes from 0.21 to 0.40, the flame propagation time decreases gradually, the flame structure evolves dynamically, the oscillation phenomenon in the later flame is more obvious, and the oscillation enhancement phenomenon also exists in the later stage of the measured pressure curve. When the detonation area changes from 0.125 to 1.000, the pressure curves of S=0.125 and S=0.250 under E=0.21 conditions are different from those of other working conditions, a higher pressure peak is observed, and new pressure peaks appear in S=0.125 under E=0.30 conditions, and the peak pressure of E=0.30 and E=0.40 two kinds of working conditions decreases gradually, the oscillation amplitude in the later stage of pressure is related to the explosion area ratio.