Microbial fuel cells (MFCs) are the technology that utilizes microorganism to convert chemical energy directly to electrical energy. MFCs have attracted more and more attention without external energy consumption and secondary pollution during operation. Soil is the “natural medium” for exoelectrogenic microorganisms, it contains various organic matters and large microbial population. In recent years, soil MFCs have shown great research and application potential in electricity generation, soil pollution evaluation and restoration. In this paper, recent research and application of MFCs in electricity generation, organic pollutants degradation, heavy metal pollution remediation, greenhouse gas reduction, biosensors etc, are comprehensively introduced; the reactor configuration, electrodes and the populations of exoelectrogenic microorganisms in the current research of soil MFCs are summarized; and the main issues in the research and application of soil MFCs and research prospects are proposed.

As a common room temperature inorganic hydrated salt phase change material(PCM), calcium chloride hexahydrate(CaCl₂·6H₂O) is being widely focused due to its low cost, easy availability and high thermal energy storage. CaCl₂·6H₂O was prepared in terms of mass ratio of anhydrous CaCl₂ and H₂O as 1.027:1, whose crystal structure was characterized by X-ray diffraction(XRD). CaCl₂·6H₂O was modified by adding nucleating agents SrCl2·6H₂O and Ba(OH)₂. The results showed that the combination of SrCl2·6H₂O and Ba(OH)₂ could suppress supercooling phenomenon. The average supercooling degree was 1.07℃ in the process of melting-cooling for 10 cycles. The phase change latent heat of CaCl₂·6H₂O before and after adding nucleating agents, characterized by differential scanning calorimetry(DSC), decreased from 223.54 J·g^-1 to 160.41 J·g^-1. In order to enlarge the scope of phase change temperature of CaCl₂·6H₂O, 5%, 10%, 15%, 20% and 25%(mass) magnesium chloride hexahydrate(MgCl₂·6H₂O) was added into CaCl₂·6H₂O respectively, which indicated the phase change temperature of CaCl₂·6H₂O decreased linearly with the increase of MgCl₂·6H₂O content, however, not exceeding 20%(mass). The modification of CaCl₂·6H₂O-20% MgCl₂·6H₂O binary eutectic salt phase change thermal energy storage material was designed by adding 1% SrCl2·6H₂O and 0.5% CMC, and the results suggested that the degree of supercooling was reduced to 0.57℃. The phase change latent heat of this material was 141.09 J·g^-1, which was lower than that of CaCl₂·6H₂O(223.54 J·g^-1) and MgCl₂·6H₂O(163.35 J·g^-1). The above study showed that inorganic hydrated salt CaCl₂·6H₂O had significant application value as an inorganic PCM.

R152a (ODP=0, GWP=124) is environmentally friendly and has good thermal performance. The absorbent, triethylene glycol dimethyl ether (DMETrEG), is less toxic, has high boiling temperature and good dissolution ability for more refrigerants. Therefore, the mixture of R152a and DMETrEG is considered as a potential absorption working pair. The vapor-liquid equilibrium(VLE) of R152a+DMETrEG in the temperature range of 293.15-353.15 K was studied by gas-liquid double-cycle method. NRTL model and Wilson model were used to correlate the experimental results. The results were in good agreement with the correlated results. The average relative deviation between the calculated results and the experimental results is 1.80% for NRTL model, and the average deviation between the calculated results and the experimental results is 1.83% for Wilson model. When mole faction of R152a in the solution of R152a and DMETrEG is larger than 0.8, activity coefficient of R152a is close to 1, therefore, this solution can be considered as an ideal solution approximately.

n-Propanol is widely used in different industries such as pharmaceutical manufacturing and agriculture. The thermophysical properties are the fundamentals for those processes. Viscosity is an important property which influences the design of process equipment, product quality monitoring and so on. However, the experimental data of viscosity are often obtained with discrete points. Correlating equations with these experimental data are prerequisite to use. To author's best knowledge, there is no such a viscosity correlation for n-propanol available in wide temperature and pressure ranges. The aim of this work is to develop the viscosity correlation of n-propanol with high accuracy, which can be used over the whole thermodynamic surface. Based on the selected reliable experimental data, the correlation for the viscosity of n-propanol was presented. The extrapolation behavior of the correlation is reasonable, and the temperature is valid from 150 to 400 K at pressures up to 120 MPa. The estimated uncertainties of this correlation are from 1% to 5%.

The viscosities of binary mixtures consisting of ethanol, propanol, ethylene glycol or 1,2-propanediol with N,N-dimethylformamide (DMF) were determined for the whole range of compositions at 288.15-313.15 K under atmospheric pressure by using Ubbelohde viscometer. The excess molar viscosity (△η) and excess Gibbs energy of activation of viscous flow (△G^*E) were calculated from the experimental data, and correlated by Redlich-Kister equation. The viscosities of binary mixtures were correlated and predicted with four different expressions (Frenkel, Grunberg-Nissan, Katti-Chaudhari and McAllister model). It has been using the theory of Eyring method to calculate the thermodynamic functions of activation of viscous flow, such as the flow activation free energy, the activation enthalpy and entropy. The results show that both △η and △G^*E are negative over the whole mole fraction range in the temperature range studied for all of the binary mixtures, and the deviation is greater as temperature decreases. All the viscosity deviations reached the minimum values at x₁(DMF)≈0.3. The three-body McAllister semi-empirical equation was found to be the best correlation to represent the viscosities of all binary mixtures, in which the average relative errors between predicted and experimental data were minimum. The differences of intermolecular interaction between monohydric and dibasic alcohol with DMF were compared and analyzed.

Methyl caprate, methyl laurate and methyl myristate were considered as the main components of biodiesel. The sound speed in fatty acid methyl esters (FAMEs) is one of the necessary parameter for optimizing the injection process and calculating the isoentropic compressibility. Nevertheless, the sound speed in methyl caprate, methyl laurate and methyl myristate are scarce in the literature. The sound speeds in the three FAMEs were measured by employing Brillouin light scattering method. The measurements were carried out at temperature ranging from 288.15 to 498.15 K along 4 isobaric lines 0.1, 2.5, 5.5 and 8.5 MPa. The change regularities of sound speed in methyl caprate, methyl laurate and methyl myristate with temperatures and pressures were analyzed, respectively. A rational function as function of pressure and temperature was used to correlate the experimental sound speed in the measured p-T region. Comparing the experimental sound speed with the correlation results, the absolute average deviations (AADs) are 0.17% for methyl caprate, 0.10% for methyl caprate and 0.15% for methyl myristate.

The influence of entrance effect on thermal and hydraulic characteristics for CC plate channel was numerically studied by adopting the lower Reynolds k-ε turbulence flow model. The simulation results indicated that the entrance effect significantly enhanced turbulent intensity at the first three unitary cells and the influence of entrance effect on heat transfer could be neglected after the fourth unitary cell. Because the increase of turbulent intensity in the inlets reduces with increasing Reynolds number, the heat transfer enhancement could be depressed. As the Reynolds number increases, the friction coefficients of entrance and fully developed section both decrease. In addition, the friction coefficient of inlet section is approximately 20% higher than that of fully developed section.

The volumetric three-component velocimetry (V3V) measurements and the large eddy simulation (LES) were used to study the flow field near the standard Rushton impeller in a stirred vessel. The results of V3V indicate that the Reynolds number has almost no influence on the normalized phase-resolved velocity and TKE when the flow field is absolutely turbulent. The structure and movement law of trailing vortices are discussed by reconstruction of the three-dimensional flow field with V3V. The distributions of radial, axial and tangential velocities in 30℃ross-section behind the impeller were analyzed. The distributions of vortex pair by V3V were in good agreement with these by 2D-PIV (particle image velocimetry), however the vorticity by V3V is about 37.5% larger. LES method was used to simulate flow field in stirred tank with Rushton turbine impeller. The velocity distribution and trailing trajectory of LES results are in good agreement with the 2D-PIV and V3V data. Complete structure of the trailing vortices had been obtained and a vortex, which is similar with trailing vortices, was discovered near the up surface of the impeller.

There are many strong endothermic chemical reactions achieved by super-high temperature, they need quickly quenching to avoid reverse reaction for obtaining substantial yield. Based on our experiments of CO₂ pyrolysis by thermal plasma, where a non-conventional quenching was achieved with setting a converging nozzle at the exit of reactor to lead the pyrolysis gas at high speed into cooling tube, the reverse reaction CO+O=CO₂ was unusually suppressed and very high CO₂ conversion was achieved. To understand the mechanism of the novel quench phenomena, a CFD Simulation was carried out. It verified that a quenching rate of 10⁷ K·s^-1 could be expected, but the quench phenomena cannot be understood only by gas dynamics principle. A deep analysis on simulation revealed that converging nozzle resulted in viscous fluid strong rotating eddy in the cooling tube, it is the strong rotating eddy that enhance greatly both of the fluid entrainment into body jet and the forced heat transfer of the fluid at the cooling tube before entrainment.

Based on the single frame and single exposure imaging (SFSE) method for flow field measurement, the motion single frame and long exposure imaging (MSFLE) method is proposed for measuring the coherent structure of turbulence in the plant turbulent boundary layer. The method is a Lagrangian property measurement technique. The camera moves at substantially the same speed as the migration speed of the coherent structure, and the trajectory of the particle is recorded by the method of long exposure. Experiments were carried out with this method to measure the development of the coherent structure in the turbulent boundary layer. The evolution of the coherent structure with time and space were intuitively recorded. The motion characteristics of the coherent structure are analyzed. The experimental results show that the interaction between the high and low speed streaks can lead to the displacement, merging and dissipation of the hairpin vortex. The existence of stagnation point and strong shear layer is the key to the evolution of coherent structure.

The application of ultrasound to liquid freezing got much attention over the last few years and its potential seems very promising. In order to make clear droplet freezing assisted by ultrasound, the heat and mass transfer characteristic was studied based on ultrasound theory, penetration theory of mass transfer and energy conservation. The ultrasound frequency, ultrasound intensity and operation time were studied in the process of the liquid drop freezing. The results showed that ultrasound could accelerate mass transfer and make droplet rapidly cooling. In the effect of ultrasound, the bubble size in the droplet was decreased with ultrasound frequency, and the bubble number in the droplet was increased with ultrasound frequency. Mass transfer coefficient of droplet was increased with ultrasound intensity and reduced with ultrasound frequency. For the mass transfer and heat transfer, the direction were same in the droplet freezing process, the heat transfer was strengthened by mass transfer in the droplet freezing process. Comparing with no ultrasound, droplet temperature with ultrasound (ultrasound frequency 20000 Hz and ultrasound intensity 400 W·m^-2) was lower 2.0-2.5℃ after the same time (60 s). Hence the ultrasound helps to cool and freeze droplet. This study is favor to understanding the freezing by ultrasound and its application.

Minimum fluidization velocity (U_mf) of three ultrafine particles (SiO₂, Al₂O₃ and TiO₂) was measured in a fluidized bed with inner diameter of 50 mm. The primary particle size (d_p) of these ultrafine particles was ranged from 30 nm to 5 μm and Geldart A reference particle was a size of 45 μm. Results show that all three particles have the same U_mf change pattern with increase of primary particle size. U_mf first increased gradually as d_p increased from 30 nm to 5 μm and then U_mf decreased sharply as d_p increased further to 45 μm. U_mf at d_p=45 μm was close to that of d_p=30 nm and 200 nm. U_mf of different materials decreased in the order of TiO₂, Al₂O₃, SiO₂. For particles of the same material, d_p effect on U_mf was similar to that of repose angle, which reached to a maximum at d_p=5 μm. Simulation by agglomerate force balance model shows that average size of fluidized agglomerates is changed similarly to that of U_mf with regards to different materials and primary particle sizes.

In order to enhance the solid-gas contact, a new bubbling fluidized bed with tower reactor is designed. The fuel reactor is divided into several chambers along the bed height direction by internal air distributor with caps. In the period of fluidization, a special phenomenon is caused by slugging, which could be named “gushing”. The forming and disappearing of gushing can be recorded on the basis of image with a digital video camera. By using fast Fourier transform (FFT) and wavelet packet transform methods, the pressure fluctuation signal is analyzed to investigate the characteristics on gushing, including fluidization conditions, dominant frequency and energy mode of gushing. The results showed that gushing fluidization appears under the fluidization number of 3.47 in this reactor. Its cycle period is lasting 1-2 s and dominant frequency is around 0.1-0.5 Hz. Changing of reactor structure, like adding one distributor to reach two chambers, adjusting the aspect ratio of lower chamber to be 3:1 and enlarging the valve opening on caps of distributors, is the better structures for gushing fluidization. Therefore, in order to obtain a satisfactory gushing property in the reactor, the inlet gas velocity and reactor structure must be kept in a suitable condition.

Liquid film breakup mode at disk rim of centrifuge particle generator directly determines droplet shapes and sizes, which is a key factor to affect product qualities. A critical transition coefficient for spinning disk particle generator was proposed to characterize liquid film breakup transition characteristics from film to ligament, to extend to other breakup modes, and to establish critical equations for transition from direct droplet to ligament, ligament to fully ligament, and fully ligament to sheet. The experimental results of three working fluids and two disks indicated that disk surface wettability played key role for liquid film to become direct droplet or to transit from direct droplet to ligament, which incomplete wetting caused random critical volume flow rate with no direct correlation between disk diameter and critical volume flow rate. Critical volume flow rate increased with increasing disk diameter in fully-ligament and film modes. In general, the increase of liquid flow rate, rotation speed, liquid density, and viscosity drove towards film breakup mode. However, high surface tension force maintained liquid film in direct drop or ligament even at large flow rate and rotation speed. Moreover, increasing disk diameter enhanced both centrifugal force and surface tension and breakup mode did not change unless the force balance was lost.

With a 405 m² annular sinter cooler as research objects, the two-dimensional steady-state numerical model of annular sinter cooler was established on the basis of the porous media and local non-equilibrium thermodynamics theory. The moving speed along with the moving direction of sinter trolley was defined into the numerical model with the help of user-defined functions in COMSOL. The main factors influencing the sinter waste heat recovery and influence laws were analyzed. The enthalpy exergy of outlet cooling air of annular sinter cooler was taken as the evaluation index of parameter optimization, and the suitable operating parameters combination of first and second stages in annular sinter cooler were obtained through the method of orthogonal experiment. The results show that when the other operating parameters are constant, the enthalpy exergy of outlet cooling air first increases and then decreases with the increase of inlet air velocity. The suitable operating parameters are as follows. The standard flow of inlet cooling air is 8.3×10⁵ m³·h^-1. The height of sinter bed layer is 1.6 m and the temperature of inlet cooling air is 424 K. Under this condition, the exergy of outlet heat carrier increases by 11.09% than existing working condition.

The processes of mixing and heat transfer between oil shale ash particles and oil shale particles in a non-reacting rotary retorting were investigated by using discrete element method combined with particle thermal conduction model. The mixing index, the average temperature of particles and the standard deviation of temperature were used as the quantitative indexes to evaluate the effect of mixing and heat transfer. The influences of fill ratio of particles, rotational speed of vessel, diameter of the oil shale particles and flights form on particles mixing and heat transfer characteristics were analyzed. Results indicated that the rotational speed of vessel and the diameter of the oil shale particles are the main factors which influence the mixing and heat transfer effect between particles, but the fill ratio and the flights form are relatively minor. When rotary retorting without flights equipped, with the increasing of the fill ratio or the diameter of oil shale particles, the more serious segregation phenomenon between two kinds of particles occurs, the worse the mixing and heat transfer performance are. But it goes up firstly then down with the increasing of vessel speed. Compared with the rotary retorting without flights, the flights forms have influence of disturbance on particle mixing inordinately, so that the mixing and heat transfer effect between particles can be improved remarkably.

Nanofluids have been found to be widely used in many fields as new heat transfer medium. The results indicate that the main factors leading to the change of the heat transfer performance of nanofluids are the deposition of nanoparticles on the heat transfer surface, the change of the surface roughness of the heating surface, the change of the surface tension of the medium, the internal energy transfer and the bubble formation condition. The experimental study on pool boiling of water-based SiO₂ nanofluids was carried out with different particle size of nanoparticles to obtain the difference of heat transfer characteristics between SiO₂/water nanofluids and deionized water in the state of nucleate boiling in the saturated state, and to compare the heat transfer characteristics of nanofluids with different particle diameters. The results show that the heat transfer characteristics of nano-particles are quite different from that of the pure base fluid in the same state. The change of heat transfer characteristics between different particle sizes is obvious and the change of heat transfer characteristics does not increase linearly with the increase of particle size.

Being one of the most widely used engineered nanomaterials well known for its ecological toxicity, silver nanoparticles have big potential to arise severe environmental problems on entry groundwater environment. Unfortunately, thus far how environmental factors may control the mobility of silver nanparticles remain unclear. In this study, column experiments were employed to investigate the interplay of flow rate (1 and 2 ml·min^-1) and granular size characteristics (glass beads of 0.605, 0.115 mm, and the mixture of the two) on the transport of nano silver in saturated porous media. The results suggested that transport of silver nanoparticles in the matrix of large grains (0.605 mm) was controlled mainly by deposition while that in the other two matrix (0.115 mm and the mixture) was controlled by both the deposition and straining processes. For the matrix of the mixed grains, straining was mainly controlled by the fraction of the grains with lower size. Increasing flow rate reduced deposition of the nanoparticles in the matrix with large grains, while for the other two matrices (with small grains or mixed grains), increasing flow rate reduced not only the deposition rate but also the straining rate, resulting in a more significant reduction in particle attenuation by the porous medium. Moreover, the intensified size exclusion effect accompanied by the rising flow rate can also increase the transport velocity of the silver nanoparticles in the matrix of small and mixed grains. These findings were critical to understanding the movement and distribution of nanomaterials in dynamic and complex groundwater environment.

Two novel magnetic mesoporous core-shell nanocomposites Ni@mSiO₂ and Ni-N₂H₄@mSiO₂ were prepared by a surfactant-templating method. Nickel nanoparticles were first obtained from nickel nitrate or nickel chloride by thermodecomposition and hydrazine hydrate reduction, then covered by a mesoporous shell, and finally by sinteration and hydrogen reduction. As a comparison, Ni/mSiO₂ carrier supporting catalyst was prepared by the traditional coprecipitation method. The core-shell nanocomposite of nickel nanoparticle core and mesoporous silica shell was characterized by transmission electron microscopy, X-ray diffraction and nitrogen adsorption-desorption. Temperature programmed H₂ reduction indicated that NiO in these catalysts were mainly present in bulk phase and some small NiO particles in Ni-N₂H₄@mSiO₂ were easily reduced. H₂-chemsorption results demonstrated that Ni/mSiO₂ had more active sites but lower TOF value compared to core-shell Ni@mSiO₂ and Ni-N₂H₄@mSiO₂ catalysts. Both Ni@mSiO₂ and Ni-N₂H₄@mSiO₂ showed higher activity and better selectivity than Ni/mSiO₂ in selective hydrogenation of cinnamyl aldehyde to hydrocinnamaldehyde, with over 90% yield of hydrocinnamaldehyde. Due to high magnetic saturation value of Ni-N₂H₄@mSiO₂, it can be easily recycled for reuse by an external magnetic field. Notably, Ni-N₂H₄@mSiO₂ showed better stability in hydrogenation.

Lithium carbonate (Li₂CO₃) is used as raw material to prepare various lithium compounds, so the reactive crystallization of lithium carbonate is the key technique in the lithium industry. Central composite design(CCD), a kind of response surface methodology, was used to explore the effects of temperature, feeding speed of sodium carbonate (Na₂CO₃), concentration of Na₂CO₃ and concentration of lithium chloride(LiCl) on the yield of Li₂CO₃ and the particle size of Li₂CO₃. Based on the regression analysis, regression equations related to response values and factors were established, respectively. The optimal simulated values were found as follows:yield of Li₂CO₃ 93.68%, the median particle sizes (d₅₀) 16.73 μm, while the corresponding experimental results were 94.01% and 16.91 μm, respectively. The errors between the predicted and experimental values were small, which showed that the established models were accurate and reliable for the analysis and prediction of the process of reactive crystallization. In the above conditions, battery-grade Li₂CO₃ were prepared and its purity reached 99.52%. No impurity peak could be observed in the XRD analysis of Li₂CO₃ product, and its main crystal faces were (-1 1 0), (-2 2 0) and (0 0 2).

The partially neutralized poly(ethylenimine)-grafted Sepharose FF, FF-PEI-R440, exhibited higher protein capacity and faster uptake rate than its starting resin FF-PEI-L740. In this work, the influence of counterions on protein adsorption onto and elution from the FF-PEI-R440 resin was investigated with sodium salts of SCN^-, Cl^-, HPO₄^2- and SO₄^2- at ionic strengths of 0.03 mol·L^-1 and 0.06 mol·L^-1. It was found that the static adsorption equilibrium of FF-PEI-R440 was significantly influenced by the counterions, and the adsorption capacity increased in the order of SCN^- < SO₄^2- < HPO₄^2- < Cl^- at the two ionic strengths. At the low ionic strength, the counterions had no significant effect on the uptake rate and dynamic binding capacity except for SCN^-. At high ionic strength, the uptake rate increased in the order of SCN^- < SO₄^2-≈Cl^- < HPO₄^2-. Dynamic binding capacity increased in the order of SCN^- < SO₄^2- < HPO₄^2- < Cl^-, the same of the order of adsorption capacity. The dynamic binding capacity kept the highest values when Cl^- existed at the two ionic strengths. Protein elution was little affected by counterions. The results indicated that the adsorption performance of FF-PEI-R440 was affected by counterions and the Cl^- was the most favorable couterion for column operation.

Extractive distillation is an effective separation process to deal with the separation of close-boiling compounds and azeotropic systems. The selection of appropriate solvent is the key factor for feasibility and economy in extractive distillation. A new method of screening mixed solvent of extractive distillation was proposed, which was according to the situation of forming the hydrogen bond and modified UNFAC model. To take the polar systems (ethyl acetate-ethanol, ethanol-water) and non-polar system (cyclohexane-benzene) as examples, the appropriate mixed-solvents and the optimal proportion were sought out. The vapor-liquid equilibrium data of solvents (single-solvents and mixed-solvents) and azeotropic system were determined by modified Othmer kettle. The results showed that the calculated values were in good agreement with the experimental data and the relative error was less than 9%. By taking into the synthetical evaluation to the solvents, the optimal mixed solvents to separate ethyl acetate-ethanol, ethanol-water, and cyclohexane-benzene were obtained respectively. Under the action of optimal mixed-solvent, the relative volatility of feed components reached maximum which was higher than the value by using any single solvent. At different feed components the trend of volatility of feed components changed by a mixed solvent was almost the same, which indicated that the mixed solvent could improve the volatility of feed components in any tray of extractive distillation column efficiently.

Measured data abnormality in multimode batch processes directly influences model accuracy of data-driven multivariate statistical analysis and decreases performance of process monitoring and controlling. A dynamic hypersphere structure change (DHSC) derived method was proposed for detecting such data abnormality. First, mode dicing according to membership change was achieved by introducing sequence-constrained fuzzy C-means (SCFCM). Then, for each mode, support vector data description (SVDD) was used to build a static hypersphere for training data and a dynamic hypersphere for testing data. Finally, important support vectors were chosen as structures of hyperspheres and detection of abnormal data was achieved by identifying structure change of hyperspheres. Simulation experiment of penicillin fermentation process shows that the present method can achieve mode division of multimode batch processes and reduce influence of mode switch on detection accuracy of abnormal data. Using structure change of hypersphere to detect abnormal data can decrease false detection rate with high detection accuracy.

Quantitative characterization of surface morphological evolution is critical for coating quality control. A hybrid MC-CFD (i.e., Monte Carlo coupled with computation fluid dynamics) method was developed to capture the complex coating formation process, which involves wet film formation through deposition of huge amount of droplets and the succeeding levelling process. The effects of the mean diameter, viscosity, density and surface tension of paint droplets on coating roughness evolution have been systematically and quantitatively explored. It was found that increasing mean drop diameter led to the increase of the initial surface roughness, hence increased levelling time; the increase of paint viscosity led to the increased initial and final surface roughness and hence increased levelling time; paint density had little influence on levelling time and final surface roughness; increasing surface tension of paint however led to the increase of levelling velocity and the decrease of levelling time, but had little effect on final coating roughness.

To address high-temperature corrosion at heating surface of coal-fired boilers, a composite ceramic coating on surface of 20G steel sheet was prepared by slurry method. After sintering, the composite ceramic coating had a relatively dense surface and good bonding to the substrate. Both uncoated and ceramic-coated steel sheets were studied for high-temperature corrosion resistance in sulfur dioxide (SO₂) by thermal kinetic analysis method. The results show that corrosion of the coated and uncoated steel sheets adheres to one dimensional diffusion reaction kinetic model at 400-500℃. Although activation energy of coated steel corrosion was lower than the uncoated one, the coating provided preferable high-temperature corrosion resistance. After exposure to SO₂, the appearance, element contents and phase structure of the sheets were characterized. Potassium sulfate (K₂SO₄) crystal grains were found to form on the coating surface. However, K₂SO₄ was not detected inside coating because relatively dense coating blocked sulfur diffusion.

A Gram-negative bacterium was isolated from the soil and sludge samples, which had high activity for enantioselective hydrolysis of (R, S)-metalaxyl. The strain was identified as Albibacters by 16S rDNA sequence analysis. It was named Albibacters sp. zjut528. At 37℃, 15 g·L^-1 of the wet cells (81% water content) catalyzed the hydrolysis of (R, S)-metalaxyl at the concentration of 50 g·L^-1 for 28h, the yield reached 47.1% and the main product was R-metalaxyl acid with ee_p > 99.9%. In order to isolate its intracellular esterase, the cells were disrupted by ultrasonic. After centrifugation, the supernatant was treated by ammonium sulfate precipitation, followed by ion-exchange chromatography and gel filtration chromatography. A SDS-PAGE electrophoresis-pure esterase protein was obtained with a molecular mass of about 40×10³. Its N-terminal amino acid sequence was determined as NH₂-Ala-Ala -Lys-Ala-Pro-Leu-Arg-Leu-Lys-Glu. Its optimum catalytic temperature and pH were 40℃ and 9.0, respectively. The enzyme was stable at 20-40℃ and pH 5.0-10.0. 0.2 mmol·L^-1 of Fe²⁺, Mn²⁺, Zn²⁺ can improve its activity, but Fe³⁺ inhibited it. Its activity was highly improved when some organic solvents, such as acetonitrile, isopropanol, acetone, isopropyl ether, cyclohexane and n-hexane, were added at the concentration of 20% (vol). The Michaelis-Menten kinetics parameters for the enzyme were V_m=0.18 mmol·L^-1·min^-1, K_m=2.29 mmol·L^-1 and K_cat=0.85 min^-1. A new process for producing R-matalaxyl from R,S-matalaxyl was established by using Albibacters sp. zjut528 cells as the catalyst. First, the cells catalyzed enantioeletive hydrolysis of (R,S)-matalaxyl to produce R-metalaxyl. After reaction, the R-metalaxyl acid and the unreacted S-matalaxyl were separated by extraction. R-Metalaxy acid was esterified with methanol to produce R-metalaxyl. Followed by some separation steps, the final product of R-metalaxy was obtained. Its purity was 96.2% and ee value was 99.3%. The unreacted S-metalaxyl can be reused by racemization. After heated for 6 h at 60℃, its ee value reduced from 99.4% to 4.2%.

The recycling and reuse of TiO₂ carrier from waste SCR catalysts used in coal-fired power plants was studied. The influence of reaction time, temperature, liquid-to-solid ratio and NaOH concentration on the leaching efficiency of Al, Si, V, W and Ti during leaching process, specific surface area and pore volume of leaching residue was investigated. The optimal leaching conditions were obtained with reaction time of 180 min, temperature of 160℃, liquid-to-solid ratio of 15 ml·g^-1 and NaOH concentration of 2.5 mol·L^-1. The main composition of the leaching residue obtained under optimal conditions was anatase TiO₂, which was then used to synthesize V₂O₅-WO₃/TiO₂ catalysts with various V₂O₅ loadings after acid washing. The activity evaluation revealed that the resynthesized 0.7% V₂O₅-WO₃/TiO₂ catalyst was almost recovered to the level of fresh catalyst with NO conversion being recovered to 97.8% at 300℃, and it also showed a good resistance to SO₂ and H₂O.

The coal gasification reactivity in the syngas (H₂O, CO₂, H₂ and CO) was carried out in a fixed-bed tube reactor at atmospheric pressure. The effect of reaction temperature, raw gas composition and coal amount on gaseous products composition and carbon conversion rate was studied. The experimental results indicated that the CO flow rate increased significantly, while H₂ flow rate increased a little under the experimental conditions. The reaction between CO₂ and coal char was inhibited significantly. The effective gas (CO+H₂) concentration of syngas was able to increase through the reaction and its largest increase was 3.3% in the experimental conditions. The inhibition effect of CO and H₂ and the competitive effect between H₂O and CO₂ were obvious. The maximum coal reaction rate in the mixture gas was only 49% and 69% of the maximum coal reaction rate in pure gasification agent (H₂O, CO₂) in 1100℃ and 1300℃, respectively. The effect of diffusion and adsorption in the pore on the gasification reaction was obvious in the syngas. The random pore model was suitable for the experimental conditions. However, the volumetric reaction model and core shrinking model were poor in fitting of data.

In this paper, a two-stage dilution sampling method was applied to collect PM_2.5 in flue gas before and after the WFGDs in a utility pulverized coal boiler, a utility CFB boiler and an industrial grate-fired boiler, respectively. PSDs (particle size distributions) of PM_2.5 number and mass concentrations were analyzed by ELPI (electrical low pressure impactor), microstructures of PM_2.5 were analyzed by SEM (scanning electron microscopy), and the contents of minor and tract elements and water-soluble ions in PM_2.5 were analyzed by XRF (X-ray fluorescence), ICP-OES (inductively coupled plasma optical emission spectroscopy) and IC (ion chromatography), respectively. The results showed that the mass concentrations of PM_2.5 generated from the pulverized coal boiler and the CFB boiler after desulfurization were higher than those before desulfurization, but the mass concentrations of PM_2.5 generated from the pulverized coal boiler and the CFB boiler after desulfurization were lower than those before desulfurization. There existed blocky, layered and finely columnar microstructures on the surfaces of PM_2.5 after the WFGDs, and several particles belonging to PM_2.5 were the agglomerates consisting of fine spherical particles. The attachment of the slurry composition and the desulfurization product will cause a significant change in the appearance of the PM_2.5. After desulfurization, the contents of Ca, S and Ca²⁺ and SO₄^2- in PM_2.5 were significantly increased due to the participation of desulfurization slurry, while the contents of Si and Al decreased. The As, Se and Hg in the flue gas will also undergo different chemical changes to enter PM_2.5. During the wet desulfurization process the slurry can trap particles in the flue gas, but the desulfurization slurry composition and desulfurization products will be dried to form particles or be collocated with the original particles to form new ones.

The chemical structures of Huolinhe lignite (HLHM) were characterized with ¹³C NMR & FTIR techniques. According to ¹³C NMR analysis, HLHM consisted of 34.32% aliphatic carbons, 61.25% aromatic carbons and 4.43% carbonyl carbons. Each aromatic cluster contained 1-2 rings on average and the number of substituents on each aromatic ring was 3-4. The length of average methylene chain was 1.4 and the branched degree of aliphatic chain was 25.47%, showing the aliphatic carbons mainly consisted in the form of short chain. Several structural parameters were obtained by calculation based on FTIR data and curve-resolved band. Structural parameters (average methylene chain length, substituted degree of aromatic ring, aliphatic chain branched degree) obtained by FTIR analysis were consistent with the results of ¹³C NMR analysis. Although aromatic carbon rate existed certain deviation between FTIR and ¹³C NMR results, FTIR analysis can still reflect the carbon skeleton structure characteristics of coal in some ways.

The effect of ORP regulation on batch fermentation by Kluyveromyces marxianus 1727-5 was investigated using glucose, xylose and glucose/xylose mixture under stress conditions caused by mixture of acetic acid, formic acid, furfural and 5-HMF. Moreover, batch fermentation from corn stalk hydrolysate was further conducted with the optimized ORP control strategy. The experimental results showed that the stress tolerance of cells to multiple inhibitors above was significantly improved together with enhanced cellular metabolic activities involved in both glucose and xylose utilization. For the fermentation from glucose/xylose mixture, the significant improvements were also achieved with respects to xylose utilization under ORP control conditions. Especially, with ORP controlled at -150 mV, the glucose fermentation time was shortened about 30% with the same ethanol. The yields of xylitol was increased from 3 g·L^-1 to 10 g·L^-1 compared to the control without ORP regulation. More important, when the ORP controlled at -100 mV, fermentation from corn stalk hydrolysate was greatly facilitated in terms of inhibitors tolerance, and the glucose fermentation time was shortened about 22% with the same ethanol. More important, xylose utilization and xylitol yield were increased to 10.27 g·L^-1 and 0.48 g·g^-1, respectively, compared to those of 4.88 g·L^-1 and 0.20 g·g^-1 in the control without ORP regulation.

A techno-economic analysis method for modern coal chemical projects under the condition of market uncertainty was established. With financial internal rate of return, payback period of investment, financial net present value, after-tax profits and the CO₂ emissions per unit of after-tax profit of coal to olefins investment project as the main objective indicators, and with polyolefin price, coal price, construction investment and carbon tax rate as four variables characterizing market uncertainty, the techno-economic analysis models of coal to olefins were established. Based on these models, the surface graphs and contour graphs of the simulated equations were drew. The sensitivity and uncertainty analysis were further carried out. Sensitivity analysis shows that the influence of polyolefin price and coal price changes on each objective indicator is most remarkable. The economy of coal to olefins technology and the influence of various risk factors on the objective indicators under the condition of market uncertainty were quantitatively analyzed using the Monte Carlo simulation method. The results show that coal to olefins project is still profitable under the condition of market downturn, when polyolefin prices are 6000-8000 CNY·t^-1, and coal prices are 100-300 CNY·t^-1.

In order to improve many disadvantages that the heat pump system has when it uses the reverse-cycle defrosting method in the low temperature environment, a new air-water double source composite heat pump system (AWDSHPS-N) was presented. This system has a new preheating and defrosting function. AWDSHPS-N has defrosted for 5 min and has 5 different defrosting ways, such as the condenser outlet refrigerant recooling defrosting, the low temperature-hot water defrosting, and so on. It can be put into different modes by changing some relevant valves or starting and stopping the pump of the low temperature water. In this way, the heat output power of AWDSHPS-N may be reduced dramatically, but the system can produce heating continuously. A test-bed including constant temperature and humidity environment storehouse and a low temperature water tank were set up to get operating data for coefficient of performance (COP) of AWDSHPS-N. The environment storehouse imitates the change in outdoor environment by keeping the temperature and the humidity at a certain level constantly, and the low temperature water tank with two electric heating bars can be thought as a low temperature heating source of a solar energy system or a waste heat system. By heating the water from 18℃ to 51℃, the COP of AWDSHPS-N was tested and analyzed in air source heating mode (ASHM), water source heating mode (ASHM), water source heating mode (WSHM) and air-water double source heating mode (AWSHM), respectively. By calculating, the COP of AWSHM is 6.1%-20.5% higher than ASHM. When the ambient temperature and the low temperature water are both above 15℃, the COP of AWSHM is the best one, and the COP of WSHM is the last one among these three heating modes.

Two self-propagation high-temperature synthesis systems (SHS), Al-Fe₂O₃ (thermite) and Mg-Fe₂O₃ (magnesium thermite), were utilized to immobilize the chromite ore processing residue (COPR) from lime-free roasting process. The solid waste-extraction procedure was adopted to evaluate the treatment efficiency of COPR. The results showed that the SHS was an effective remediation technology for COPR with maximum solidify rate of 80% and 85%, respectively. The leaching toxic concentrations of total Cr and Cr(Ⅵ) in solidified products were less than 4.5 and 1.5 mg·L^-1 respectively, and the final products could be disposed in the landfill site according to GB 16889-2008. During the SHS process, the reduction rate of Cr(Ⅵ) was higher than 90% and the reducing substance was dispersed in the solidified products in the form of amorphous state. Meanwhile, parts of the chromium ions were participated in the formation of minerals such as MgAlCrO₄ spinel. Eventually, the chromium element was incorporated into the wasteforms in the form of chemical immobilization and physical encapsulation.

Graphene-based 3D functional materials hold promise as electrode materials for high performance supercapacitors due to their unique porous network structure, large specific surface area and excellent electrical and thermal properties. The coal-based graphene oxide (CGO) was prepared from Taixi anthracite by catalytic heat treatment and modified Hummers method. With polyaniline (PANI) and CGO as the starting materials, 3D PANI/coal-based graphene composites (3D-PCG) were further prepared by the hydrothermal method. The morphology and structure of the as-made materials were examined by the techniques including FT-IR, XRD, Raman, SEM, and TEM, with a focus on the interaction of polyaniline with the graphene. The electrochemical performance of 3D-PCG as electrode materials for supercapacitors was evaluated by electrochemical test methods. The results show that rod-like PANI is uniformly embedded into the network structure of 3D coal-based graphene (3D-CG), yielding 3D-PCG that has the highest specific capacitance in comparison with PANI and 3D-CG, and a specific capacitance of 663 F·g^-1 can be delivered in the case of 3D-PCG made at 1:2 mass ratio of PANI and CGO.

Mixed matrix membranes (MMMs) were prepared by combining open metal sites-containing MIL-101(Cr) with three different kinds of polymers. CO₂ separation performance of these prepared MMMs was further examined from the aspects of filler structure, polymer properties, and filler-polymer interface conditions. Benefiting from the large pore aperture and strong Lewis acid-base interactions between the open Cr(Ⅲ) sites and CO₂ molecules, the incorporation of MIL-101(Cr) can greatly improve the gas permeability and separation factor of PSF membrane. The results indicate that when polymer with high selectivity and permeability is used, only the gas permeability is improved with the CO₂ separation factor slightly decreased. When polymer with high chain mobility is used, the surface pores could be blocked by the polymer chains, leading to obvious decrease in gas permeability of the MMMs.

Oxidized graphite (GO) prepared by modified Hummer's method was immersed in carbonic acid, and consequently stripped to a low grained reduced graphene oxide by microwave solid phase method. This method has simplicity for operator, energy efficiency and time saving, in which experimental conditions are mild with free of toxic strong reducer. As cathode composites for lithium-sulfur battery, reduced graphene oxide/nano-sulfur (MRGO/NS) were prepared by in-situ precipitation reaction at low temperature. The crystal structure and morphology of the MRGO and MRGO/NS composites were characterized by FT-IR, XRD, SEM, TEM and BET, respectively. The electrochemical performance of the composites was determined by galvanostatic charge-discharge test and impedance spectroscopy. The results show that the MRGO obtained from GO immersed in carbonic acid and stripped by microwave solid phase method is folding fan-like graphene, which can provide space to accommodate the active materials for lithium-sulfur batteries, and alleviate the shuttle effect to improve the cycle performance and the C-rate performance of the electrode material.

Gas-liquid two-phase fluid in membrane module of different column type was simulated by Euler model and porous medium model. The effect of the length of membrane module and the number of aerator holes (opening rate=1.92%) on gas-liquid distribution, wall shear stress, turbulent viscosity and velocity of liquid was investigated by CFD simulation. The simulation results showed good agreement with the experimental data. The results demonstrated that uniform distribution of gas-liquid and water velocity, the intensity of wall shear stress and turbulent viscosity was efficiently improved by decreasing the diameter of aerator holes and increasing the number of aerator holes; increasing the length of membrane module was significantly benefit to improve the capacity of a single membrane module, and make full use of gas scrub the wall of membrane. Considering installation, transportation, distribution of membrane flux and energy consumption, the membrane module with the diameter 250 mm that the diameter and the number of aerator holes respectively is 6.32 mm and 30, and the length of membrane module is 2-2.5 m exhibited a best performance.

Hierarchical ZSM-5 zeolite membranes were synthesized through secondary growth method in the presence of small amount of cetyltrimethylammonium bromide (CTAB). The results show that CTAB spherical micelles and molecular sieve particles self-assembled to form ordered mesoporous structure. At the same time, the presence of CTAB micelles and hydrophobic long chains suppresses the growth of crystals. By adjusting the CTAB/SiO₂ molar ratio, synthesis temperature or crystallization time, the crystal grain size and the crosslinking degree of the zeolite membranes were changed remarkably to realize the simple and effective regulation of the average pore size, ranging from 7 to 30 nm. Under the synthesis at 180℃ for 20 h and the CTAB/SiO₂ molar ratio about 0.05, the obtained zeolite membrane exhibited a high water permeability of 138 kg·m^-2·h^-1·MPa^-1, and a molecular weight cut-off(MWCO) of 28500, corresponding to the average pore size of 7.39 nm, achieving the standard of small aperture ultrafiltration.

Based on shear induces polymer orientation and increases its equilibrium melting temperature, a Nakamura equation based shear-induced crystallization kinetics model was presented. A model for injection molding simulation was also established, in which the influence of crystallization was considered into WLF-Cross viscosity coefficient. Three-dimensional shear-induced crystallization behavior was simulated by an improved finite volume method, which coupled flow field, melt pressure, temperature, induction time index and crystallinity. Experimental results show that the proposed method can clearly simulate the three-dimensional “fountain” flow behavior and the three-layer “skin-core” crystallization structure during injection molding process. The simulated shear-induction time index results and crystallinity results agree well with the theoretical and experimental results.

Based on generating mechanism and mathematical model of residual stress in traditional injection process, plane polarization and numerical simulation method were used to research residual stress distribution of ICM(injection compression molding)products with variety curvature qualitatively and quantificationally. The investigation has shown that residual stress distributions followed the shape of part except gate and end of part region. Well geometric asymmetry of stress fringe were detected in ICM-seq molding, while two layers of stress distribution states at end of part were found in ICM-sim molding. The phenomenon was different from tradition injection molding. Within the same plane, maximum residual stress values were reduced as the decrease of curvature. Meanwhile, inversely proportional relationships between average residual stress and part curvature were obtained for all different type of part (except for plate shape). It makes sense for optimizing design of optical products with variable curvature.

Lithium sulfur batteries are considered to be the most promising secondary battery because of its high theoretical specific capacity (1675 mA·h·g^-1). However, the sulfur cathode faces the challenges, such as poor conductivity, low utilization of sulfur and poor structure stability of cathode. Biomass-based porous carbon, with cheap and accessible agricultural waste corn bracts as raw material, was prepared by chemical activation with KOH, and then composited with sublimate sulfur through modelling-fused method to form sulfur/carbon composite. The microscopic structure and morphology of the composites were characterized by XRD, SEM, TEM, and BET. The results show that the biomass-based porous carbon material possesses lamellar structure, which is similar to graphene, and abundant mesoporous structure on the surface of carbon. Furthermore, sulfur particles homogeneously distribute in the carbon conductive network. In addition, the electrochemical properties were studied by galvanostatic charge-discharge tests and electrochemical impedance spectroscopy. The results show that the battery possesses high discharge capacity and good cycle-life performance. The main reasons are as follow:the porous carbon structure like graphene, enhancing conductivity of sulfur cathode; the huge specific surface area which make electrochemical reaction sites increased, improving the utilization of sulfur.

Diethanol ammonium carbamate (DEAC) was prepared by reaction of diethanolamine (DEA) with carbon dioxide. DEAC has onset decomposition temperature round 54℃. Addition of DEAC as reactive blowing agent into common rigid polyurethane foaming formulation gave foams with densities in the range of 90 to 150 kg·m^-3 and compressive strengths in the range of 0.02 to 1.65 MPa. DEA can be used as CO₂ absorbents in coal-burn power generation plant to reduce greenhouse gas emission. DEAC can be obtained as byproduct from coal-burn power station with low cost. This novel approach is environmentally friendly, cost effective and promising to open up a new platform for green foaming of polyurethanes.

Li₂ZrO₃ coated LiNi_0.8Co_0.1Mn_0.1O₂ cathode material for lithium ion battery was synthesized by a wet chemical method which using Zr(NO₃)₄·5H₂O and CH₃COOLi·2H₂O as raw materials, and the influences of the different content of Li₂ZrO₃ on the electrochemical properties of LiNi_0.8Co_0.1Mn_0.1O₂ was studied. SEM, TEM and EDS spectra showed that Li₂ZrO₃ coating was uniformly coated on the surface of LiNi_0.8Co_0.1Mn_0.1O₂ with a thickness of about 8 nm. Compared with the pristine material, LiNi_0.8Co_0.1Mn_0.1O₂ coated with 1%(mass) Li₂ZrO₃ exhibited excellent cycle stability with 91.77% capacity retention rate after 100 cycles at 1.0 C(the first discharge capacity was 184.7 mA·h·g^-1, and the specific capacity after 100 cycles was 169.5 mA·h·g^-1). The results of cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) tests demonstrated that the Li₂ZrO₃ coating suppressed the side reaction between cathode material and electrolyte, and reduced the charge transfer resistance of the material during cycling, thus improved the electrochemical properties of the material.

Graphite nanoplates were prepared by combining the modified Hummers and mechanical stripping method. Pd nanoparticles supported on graphite nanoplates were successfully synthesized by a simple one-step reduction method with sodium borohydride as the reducing agent. The results show that this new method for the preparation of graphite nanoplates is simple, fast and efficient. Pd nanoparticles with an average size of 11.5 nm are well dispersed on the surface of graphite nanoplates. The composite materials exhibited excellent catalytic activity and poison resistance for the electro-oxidation of methanol in alkaline medium, superior to the Pd supported on the reduced graphene oxide prepared by traditional modified Hummers method and commercial carbon black Vulcan XC-72, respectively.

In order to improve the low thermal conductivity performance of carbonate molten salt, it is proposed to dope metal magnesium powder with ternary carbonate molten salt (Li₂CO₃-Na₂CO₃-K₂CO₃) to strengthen the thermal conductivity. The static melting method was used to prepare the composite carbonate salts with 1%(mass) or 2%(mass) magnesium powder. The morphology, structure, liquid density, specific heat capacity, and thermal diffusivity were characterized by the scanning electron microscope-energy dispersive X-ray spectrometer (SEM-EDX), Archimedes method, the differential scanning calorimeter (DIN specific heat measure standard) and the laser flash method, respectively. The thermal conductivity was finally calculated based on the density, specific heat capacity, and thermal diffusivity. The results showed that the introducing of magnesium powder changed the morphology of pure eutectic (ternary carbonate salt), a large number of spherical particles (2-5 μm) were detected in the composite salts. Comparison with the pure eutectic, the liquid density, thermal diffusivity and thermal conductivity of salt compound doped magnesium powder were enhanced, and the liquid specific heat capacity was diminished. The mean thermal conductivity of salt compound doped with 1% or 2% magnesium powder was enhanced by 21.67% and 19.07%, respectively. So, the 1% salt composite should be the promising HTF due to the enhancement of density, thermal diffusivity and thermal conductivity.

The SO₄^2- modified TiO₂(25) and the unmodified TiO₂(150) have been prepared by sol-gel method via controlling the amount of introduced deionized water. Two series of C modified C_x/TiO₂(25) and C_x/TiO₂(150) samples were obtained by impregnating the TiO₂(25) and TiO₂(150) in carbon dots solution with various concentrations. The lattice spacing, crystalline, light absorption, pore size, specific surface area and element composition of the prepared catalysts were characterized by TEM, XRD, FT-IR, UV-Vis, BET and XPS. The results indicated that compared with the unmodified TiO₂(150), the SO₄^2- modified TiO₂(25) exhibited a distinct red shift phenomenon and broader visible light response for the light absorption. Moreover, the O_ads/O_latt ratios can be improved distinctly for the TiO₂(25) when the carbon dots were introduced. The catalytic performance showed that the addition of C can enhance the corresponding photocatalytic activity.

Gas sensors play a significant role in the fields of environmental monitoring, industrial production, safety, medical diagnosis, military and aerospace. Solid state gas sensors possess advantages of small size, low power, high sensitivity and low cost. They can detect very low concentrations of a wide range of gases in the range of parts-per-million (mg·L^-1). Graphene is a promising material for solid state gas sensors with high sensitivity due to its high carrier mobility, maximum surface-to-volume ratio, and low noise level. In this work, nano-grain graphene is grown on sapphire substrate by plasma enhanced chemical vapor deposition at a relative low temperature at 950℃ and a short time of 15 min. The as-prepared graphene shows bilayer structure with large amount of defects, which brings advantages for graphene gas sensors. The nano-grain graphene gas sensor on sapphire shows good response and recovery characteristics for formaldehyde gas, and exhibits good sensitivity of 3% response toward a concentration of formaldehyde gas of 20 mg·L^-1 at room temperature with a response time of 9.92 min. The recovery time of the nano-grain graphene sensor for formaldehyde gas of 20 mg·L^-1 is 17 min. Low energy barrier of the gas adsorption and desorption induced by large numbers of grain boundaries and wrinkles in the nano-grain graphene is the main reason for its good gas sense characteristics.

Five NaNO₃/diatomite composite phase change materials (CPCM) for thermal energy storage with different mass content of diatomite were prepared using the mixing and sintering method. Diatomite and NaNO₃ were employed as carrier material and phase change material respectively. The compressive strength, thermal properties, microscopic morphology, photoelectron spectroscopy and thermal analysis were carried out. The compressive strength of the CPCM was enhanced with the mass fraction of diatomite increasing from 30% to 35% and 40% and showed brittle characteristic. When the mass fraction of diatomite reached 45% and 50%, the NaNO₃/diatomite CPCM performed the paddy behavior. The DSC characterization results revealed that diatomite had little effect on the latent heat and phase-change temperature of NaNO₃. The obtained results of LFA tests showed that the thermal conductivity of the CPCM decreased with the increase of the temperature. At the given temperature, the thermal conductivity of the NaNO₃/diatomite CPCM showed upward trend with the mass fraction of diatomite increases. It was also observed that the enhancing rate of the thermal conductivity was eight times larger when increasing the mass fraction of diatomite increased from 30% to 35% compared with the mass fraction increasing from 35% to 50%. Compared with pure NaNO₃, with the diatomite mass fraction increasing from 30% to 50%, the average specific heat capacity of the NaNO₃/diatomite CPCM performed the upward and downward trend within the room temperature-phase transition and the end of the phase transition-the highest temperature range. The SEM and EDS results showed that the NaNO₃/diatomite CPCM have dense structure with NaNO₃ adsorbed uniformly inside the diatomite. The desirable compressive strength and thermal properties of the NaNO₃/diatomite CPCM can be achieved by optimizing the mass ratio of diatomite. The NaNO₃/diatomite CPCM with 35% (mass) diatomite behaved superior overall performance according to the work in this paper.

the characteristics of oil and gas explosion in volumetric semi-confined space under the condition of barrier is studied. The characteristics of flame shape and explosion overpressure during the explosion process are experimented by high-speed photography and other techniques. The flame shape, the flow field structure and the overpressure characteristic when the flame interacts with the obstacle are simulated accurately, and the results are compared with the experiment. The results show that the presence of obstruction will change the flame structure, the hemispherical→conical→brush-like transition will occur, and the flame vortex will be generated in the downstream of the obstacle due to the unburned gas. As a result of the coupling between the combustion rate and the pressure relief rate, the presence of obstructions in the oil and gas explosion can lead to changes in the combustion rate and the pressure relief rate, which in turn have an effect on the overpressure peak.

In order to further improve the suppression efficiency of water mist on methane explosion, a small-scale experiment platform was set up to inhibit methane explosion using water mist. The NaCl additive was introduced to the ordinary water mist, and then charge the water mist containing NaCl additive to carry out experimental study on suppressing flame propagation of methane explosion using charged water mist containing NaCl additive. The experimental results show that the inhibition effect of charged water mist containing NaCl additive on methane explosion flame propagation is better than that the sum of inhibition effect when NaCl additive and charging effects act individually in nomal water mist. With the increase of NaCl concentration and charge voltage, the flame propagation velocity of methane explosion is obviously reduced. The secondary peak of the flame propagation velocity of methane explosion is decreased by 10.747 m·s^-1 compared with that of ordinary water mist,and the drop radio up to 60.26% when the charge is 8 kV and the concentration of NaCl is 12.5%; The secondary peaks of the load of 8 kV and NaCl concentration of 12.5% decrease by 5.177 and 5.247 m·s^-1 respectively, and the sum of the two decreases is 10.424 m·s^-1. The analysis considered that there exists a coupling effect between the NaCl additive and the charging effect in the process of suppressing the flame propagation of the methane explosion by the water mist.

Venting system that can reduce risks under runaway reactions was one of the most economical and effective measures. The study of pressure mathematical model provided necessary parameters for vent calculation, and helped engineers design more reliable venting system by understanding pressure tendency. Moreover, this model supported to calculate vent area in different filling ratios with less experiment. The ARC (accelerating rate calorimeter) test of 20%DTBP (di-tert-butyl peroxide) was chosen as the standard test. Combined with theory, the mathematical model of pressure in closed container was first deduced, which was suitable for adiabatic condition. Then, according to the comparison between adiabatic corrected test data and model simulated data, the correctness for this model was verified. Combined with Leung method, vent calculation was carried out with the model pressure simulation data. From the calculation, the vent area reached its maximum, while the filling ratio equaled 20%. The established closed container pressure model was correct and reliable. Furthermore, this model can be applied to the calculation of vent area.

A semi-confined chamber was designed and an explosion suppression experiment on the effect of different spraying volume of methane-oxidizing bacteria and ultra-fine water mist on methane-air premixed mixture was studied. The methane-oxidative bacteria morphology, flame change visualization in the explosion suppression process, maximum explosion overpressure and the average pressure rise rate are analyzed. The results show that the ultra fine water mist containing methane-oxidizing bacteria-inorganic salt can effectively degrade methane, the larger the spray amount is, the faster the methane degradation speed is. With the methane volume being 9.5% and the flame propagation rate being 0.7 ml, when the methane had degraded after 360 min, the flame brightness and the flame propagation rate were lower than the situation caused by methane that had not degraded. When the spraying volume was added from 0.7 ml to 4.9 ml, the maximum explosion overpressure in the chamber decreased and the average pressure over the close part of the chamber decreased. The results indicate the synergistic effect of methane oxidizing bacteria-inorganic salt and ultrafine water mist on methane explosion. It can effectively degrade the methane in certain period of time.