As an important chemical raw material, succinic acid is widely used in many fields of modern industry with a huge market demand. Recently, the biological method for succinic acid fermentation has become a hot topic in research, since it has the advantages of renewable utilization of resources and environmental friendly production. From the perspective of metabolic control, the methods and strategies for succinic acid production with some strains, especially the recombinant E.coli, are summarized in this paper. Regulation of key enzyme gene in metabolism branch and the key factors in fermentation of succinic acid, such as regulation of redox force, carbon dioxide control, and metabolic pathways transforming are introduced. The progress of metabolic control of succinic acid fermentation is presented, and development of succinic acid fermentation in the future is proposed.

Solubilities and densities in the system Na⁺, K⁺, Mg²⁺// Cl^-, SO₄^-2-H₂O saturated with NaCl·2H₂O were investigated with the isothermal method at -15℃. Based on experimental data, phase diagram and density- composition diagram were drawn. The equilibrium phase diagram of quinary system consisted of three invariant points, seven univariant curves and five crystallization fields, corresponding to solids of KCl+NaCl·2H₂O, Na₂SO₄·10H₂O+NaCl·2H₂O, MgSO₄·7H₂O+NaCl·2H₂O, MgCl₂·8H₂O+NaCl·2H₂O and KCl·MgCl₂·6H₂O+ NaCl·2H₂O. Compared with the phase diagram at 25℃, in the phase diagram at -15℃, the crystalline regions of K₂SO₄·MgSO₄·4H₂O, KCl·MgSO₄·3H₂O, Na₂SO₄·3K₂SO₄, Na₂SO₄·MgSO₄·4H₂O, MgSO₄·(4-6)H₂O, K₂SO₄·MgSO₄·6H₂O did not exist, the crystalline region of Na₂SO₄converted into the crystallization field of Na₂SO₄·10H₂O and became larger, the crystallization fields of KCl, MgSO₄·7H₂O, KCl·MgCl₂·6H₂O decreased and the crystalline region of MgCl₂·6H₂O converted into the crystallization field of MgCl₂·8H₂O. The crystallization behavior of brines with different concentrations in the cooling process was studied. Such information could provide theoretical guidance for comprehensive utilization of salt-lake resource.

Cryogen spray cooling has been applied to protect epidermis from thermal damage during laser surgery. However, the presently used cryogen, R134a shows unsatisfactory efficacy in minimizing laser energy absorption by melanin in darkly pigmented human skins. Previous work of our group showed that R404a had the potential of improving cooling protection to epidermis, while there is few related research on the surface heat transfer during R404a spray cooling. This paper presents an experimental study on the temporal and radial variation in temperature and heat flux during spray cooling using R404a by a specially designed nozzle with expansion chamber, which significantly improved the atomization effect. The temporal and radial conditions strongly influenced uniformity of surface heat transfer. However, there existed a sub-region of uniform cooling with radius of 2 mm around spray center with high heat flux. The result of this experiment could provide guidance for guaranteeing uniform cooling protection during clinical laser surgery.

A direct contact dynamic type of fluidization ice-making technique was proposed. Through building a two-way couple model of combined continuum and discrete model (CCDM) and using a unstructured grid search method, the flow and heat transfer characteristics of fluid-particle multiphase about the process of fluidization ice-making were calculated and discussed. The data calculated based on CCDM were in agreement with experimental data, and the model accuracy was validated. A definition of particle freezing degree was presented as a simplification criterion of choosing particles collision model and equivalent calculating particle surface heat transfer. The effect of particles collision and coalescence on particle size further changed the velocity, residence time and axial density distribution of particles, which could not be ignored in studying multiphase flow and heat transfer characteristics of fluidization ice-making process.

The Hilbert-Huang transform method was used to analyze the differential pressure fluctuating signal in fluidized-bed, and the flow characteristics under different percentages of biomass and different gas velocities were investigated. With biomass percentage of 2%, marginal spectrum and energy percentage were analyzed at different gas velocities. The frequency of differential pressure fluctuating signals mainly concentrated in the low frequency band (0-5 Hz) and transfer of high frequency IMF energy percentage to middle frequency was found with the increase of gas velocity. With 1.01 m·s^-1 gas velocity, the energy of differential pressure fluctuating signals at different biomass percentages was extracted. Transfer of middle frequency IMF energy percentage to high frequency was found with the increase of biomass percentage. The flow state in fluidized-bed was analyzed through the flow-visualized images recorded by high-speed camera. Research results could provide useful experimental evidence for the further study in gas-solids two-phase flow in fluidized-bed.

To understand the influence of groundwater advection on the performance of borehole heat exchanger (BHE), an unsteady state coupled heat transfer model for a BHE with single U-tube was established by combining the transient moving finite line heat source model in porous medium outside the borehole and the steady state model for the heat transfer inside the borehole. The coupled model was validated by the data obtained in a soil thermal response test. The influence of groundwater advection on outlet water temperature and dynamic soil temperature responses was discussed. The heat transfer efficiency of BHE and the heat transfer rate per unit borehole depth were taken as two indices to assess the heat transfer performance of BHE. The heat transfer performances of BHE varied significantly with the type of soil in which it was buried. Ignoring the influence of groundwater advection in sand gravel would lead to a deviation of heat transfer rate per unit borehole depth up to 41% in the ground loop design; groundwater advection improved the heat transfer of BHE and an increase in advection velocity might help to shorten the time for the surrounding soil to reach a stable temperature. It was recommended that the mass flow rate of the inlet fluid to the BHE be more than 0.4 kg·s^-1, but within a certain upper limit; the influence of the rise in inlet fluid temperature on the heat transfer efficiency of BHE could be ignored. In addition, the effects of groundwater advection in different types of soil under typical hydrological conditions on the heat transfer efficiency of multiple BHEs connected in series were compared. Heat transfer efficiency was jointly determined by such factors as soil physical properties, ground water advection velocity and number of BHEs connected in series.

The flow structure dynamics of gas-liquid two-phase was analyzed with a novel approach, multi-scale complexity entropy causality plane (MS-CECP), derived from the information entropy theory. Firstly, the method was used to investigate typical chaotic time series and then to process the conductance fluctuating signals of three typical gas-liquid flow patterns, i.e., bubble flow, slug flow, and churn flow. The single scale CECP could discriminate the different flow patterns linearly. Furthermore, MS-CECP could describe the continuous information loss of flow structures with the increase of scale, which reflected flow structure stability and complexity of the gas-liquid two-phase flow system. The proposed approach (MS-CECP) was proven to be a useful analysis tool for understanding the nonlinear dynamics of flow structure in two-phase flows.

The flow field of two horizontal opposed liquid-liquid impinging streams was experimentally studied with the PLIF technology in order to investigate the stability of impingement plane and the oscillation characteristics of stagnation point at various nozzle separations and fluxes. Oscillation period was not regular and frequency concentrated on the low frequency region. While amplitude concentrated on 0.1d-0.5d. When L belonged to [1d, 3d] ( where L was nozzle separation and d was nozzle diameter ), amplitude increased with the growth of L, but when L belonged to [3d, 5d], amplitude decreased with the growth of L. The amplitude of impingement plane did not always grow up with increasing flux, which gradually decreased after reaching a peak. The oscillation characteristics of impingement plane and stagnation point were favorable to mixing and mass transfer.

Crosslinked polymeric microspheres GMA/MMA of glycidyl methacrylate (GMA) and methyl methacrylate (MMA) were prepared, and then N-hydroxyphthalimide (NHPI) was synthesized and immobilized on GMA/MMA microspheres through several polymer reaction steps, resulting in the functionalized microspheres GMA/MMA-NHPI. The solid catalyst GMA/MMA-NHPI in combination with Co(OAc)₂ was used in aerobic oxidation of benzyl alcohol. Experimental results showed that the composite catalyst consisting of GMA/MMA-NHPI and Co(OAc)₂ could effectively catalyze aerobic oxidation of benzyl alcohol by molecular oxygen under mild conditions (65℃ and normal pressure). Benzyl alcohol was deeply oxidized to benzoic acid. Although benzyl alcohol conversion rate was not very high, catalytic activity was satisfactory and benzoic acid selectivity was as high as 96%. The appropriate molar ratio of immobilized NHPI on GMA/MMA-NHPI microspheres to Co(OAc)₂ was 20:1, and the appropriate amount of GMA/MMA-NHPI was 10% (mol) of the substrate. The solid catalyst GMA/MMA-NHPI microspheres showed good recycling and reusing performance.

A series of heterogeneous Fenton-like catalysts, un-doped and doped Fe₃O₄ with Ti, Co, and Cu was prepared by co-precipitation method and used for the removal of elemental mercury in flue gas. The evaluation experiments were carried out in a laboratory scale reactor. The crystal structure and morphology of these catalysts were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). The effect of H₂O₂ concentration and acid gases such as SO₂ and NO on removal efficiency of mercury were systematically examined. The electron paramagnetic resonance (EPR) was employed to study the mechanism of mercury removal by heterogeneous Fenton-like catalytic reaction. The results showed that the catalysts doped with Ti and Cu show high activity for the removal of elemental mercury, and this high activity could be contributed to produce more radicals by these heterogeneous Fenton-like catalysts during Hg⁰ removal reactions.

The catalysts prepared by modifying SAPO-34 zeolite with alkali metals(Li, Na, K, Rb, Cs) in the way of incipient-wetness impregnation method were evaluated using methanol-olefin(MTO) reaction in the normal pressure continuous flowing fixed bed reactor. The structures of modified SAPO-34 catalysts were characterized by XRD, FT-IR, NH₃-TPD. The results show that lower olefins selectivity and lifetime are improved for 2% alkali-modified SAPO-34, compared with unmodified SAPO-34, except Cs-modified SAPO-34. Ethylene and propylene selectivity of Li-modified SAPO-34 catalyst are about 77% and its lifetime are prolonged by 2.5 times. After regeneration for three times, the selectivity of ethylene and propylene remains almost the same.

Roasting process with sulfuric acid plays an important role in extracting Al₂O₃ from coal fly ash. The results indicate that Al conversion rate increases with appropriately increased acid concentration, the mass ratio of acid to ash and the roasted temperature, while the effect of roasted time is relatively small. The Al conversion rate can reach 92%-93% at recommended processing parameters: sulfuric acid concentration 80%, acid-ash mass ratio 1.5:1, roasted temperature 270℃ and roasted time 60 min. An analysis for TG/DSC and XRD data demonstrates that the roasting process can be divided to 3 steps: the first step is Al(HSO₄)₃ formation and water evaporation; the second the formation of Al(HSO₄)₃ and Al₂(SO₄)₃·H₂O, and the third Al₂(SO₄)₃ formation from decompositions of Al₂(SO₄)₃·H₂O and Al(HSO₄)₃. The values of apparent activation energy for the three steps are 52.61, 74.11, and 96.08 kJ·mol^-1 respectively, an activation energy average of values obtained by Kissinger and Ozawa methods. Using the kinetics parameters estimated, such as activation energy, frequency factor, reaction order, three kinetic equations which correspond to three thermo-chemical reaction steps in the roasting process are established. These fundamental data and theoretical guideline provided in this paper could be used for the process design and optimization of sulfuric acid roasting process to extract alumina from coal fly ash.

The effective diffusivity of hydrogen in an industrial catalyst CuO/ZnO/γ-Al₂O₃ pellet was measured with a modified Wicke-Kallenbath steady-state diffusion cell at 373 to 413 K and 0.4 to 1.0 MPa. Through changing the flow rate of cyclohexane in a sequence from low to high to a maximum and then vice versa, the effect of relative vapor pressure of cyclohexane on the effective diffusivity of hydrogen was investigated in the presence of capillary condensation within the catalyst pores. Condensation started at the relative vapor pressure of cyclohexane of 0.42 at 373 K, while it was delayed to the relative vapor pressure of 0.6 at 413 K. Besides, shrinking of hysteresis loops was observed with the increase of temperature, and the effective diffusivity of hydrogen also displayed multiple hysteresis loops with respect to the relative vapor pressure of cyclohexane. A correlation between the effective diffusivity of hydrogen and catalyst internal wetting fraction was proposed, and it showed good agreement between calculation and experimental data.

Many industrial process variables have characteristics of high-dimension and not strictly obeying the Gaussian distribution. A method was proposed to solve these problems of the industrial process. The method was based on LTSA algorithm and combined index to improve monitoring performance. Firstly, the local tangent space alignment (LTSA) algorithm was used to get the sub-manifold of low dimension from the normal sample data to achieve dimensionality reduction. The two-step strategy was used to get the new statistical model. Then, the non-Gaussian statistical value and the Gaussian statistical value were constructed. Therefore, the new statistical value weighted by these two statistical values was intended to achieve monitoring of the process. Finally, the proposed method was applied to the Tennessee Eastman (TE) process and the ethylene cracking furnace to demonstrate its effectiveness.

Aiming at the problem that the soft sensing precision of key variables deteriorates when unmodeled dynamics and uncertain disturbances exist in the complex industrial process, an on-line soft sensor based on stable Hammerstein model (H model) was presented. H model was composed of wavelet neural network with time-varying stable learning algorithm as nonlinear gain and ARX model with RLS (recursive least square) algorithm as linear part. The boundedness of identification error for H model was proved according to the Input-to-State Stability theory. Wavelet neural network could represent strong nonlinearity of the process, and the stable learning algorithm could restrain the influences of unmodeled dynamics and uncertain disturbances and improve prediction precision and self-adaptability. Simulations based on a nonlinear system and the wastewater treatment process showed that the soft sensing method presented in this paper possessed high prediction precision.

A multi-model fusion modeling method based on improved Kalman filter algorithm was presented for soft sensor of key quality index or state variable in the polymerization process. First, a data-driven soft-sensor modeling method was proposed by combining mixtures of kernels principal component analysis (K₂PCA) with artificial neural network (ANN). Second, a parallel hybrid model was constructed by fusing the data-driven model with a mechanism model through an improved Kalman filtering algorithm. Moreover, a linear smoothing filter and a model variance updating method were adopted for optimizing the hybrid model, which could enhance performance and improve prediction stability of the hybrid model. The application of the proposed multi-model fusion modeling method in the vinyl chloride polymerization rate prediction verified that the hybrid model was more effective in comparison with single-model cases (thermodynamic mechanism model or K₂PCA-ANN model). The proposed multi-model fusion modeling method would provide basic conditions for control and optimization of PVC polymerization process in further research.

Since data collected from chemical processes always have high dimensions, modeling directly can be very complex. PCA can extract main features of the original data and obtain a more compact representation. However, the traditional PCA process monitoring scheme may cause information loss, since it only preserves principal components with large variance, which will greatly affect the performance of process monitoring. To handle this problem, a novel subspace monitoring method based on full variable information was proposed. Firstly, Based on the similarity level between each variable and principal component subspace (PCS) or residual subspace (RS), the original data space was divided into three low-dimensional subspaces, which preserved the whole process variables. Thus it could use the process information better. Secondly, the monitoring models were established respectively in each subspace, and then the Bayesian inference was introduced to integrate monitoring results of the subspaces. Finally, the feasibility and effectiveness of the FVI method were illustrated through a numerical example and the Tennessee Eastman process.

The traditional least squares support vector machine (LSSVM) is generally used to solve non-sparse problems. A sparse and parameter optimization method of LSSVM based on genetic algorithm was proposed. The basic idea of sparse was to give a probability value to each training sample, and if its probability value was less than 0.5 then the corresponding training sample was not a support vector. Samples that was not support vectors were treated as test samples. So, the set of total training samples was divided into the set of test samples and the set of training sample remained. A fitness function including sparse rate, training error and test error was defined. The first N dimensions of the population individual specified corresponding probability of each sample, the next m dimensions specified parameters to be optimized. All parameters including probabilities were optimized globally by mutation, selection, and crossover operations. A model of LSSVM was established by using the corresponding training sample remained and optimized parameters of the individuals with minimum fitness. The proposed method was applied to the soft sensor of 4-CBA concentration in the PX oxidation process. Simulation results with industrial data showed that by using the proposed method sparse rate was up to 87%, kernel parameters were identified automatically, and the sparse model had better generalization capability than that of the model before sparse.

The surface renewal in rotating disc reactor was investigated by using CFD. The liquid film surface renewal frequency was associated with the rate of film deformation. The spatial distribution of film surface renewal frequency was studied with the volume of fluid method. Based on the investigation of main factors influencing average renewal frequency, a correlation equation was presented. The difference of surface renewal frequency between free film and wall-bounded film was also investigated. The renewal frequency of the accelerating region was the fastest, about 150% faster than other regions and 75% faster than the average. An expression of renewal frequency was obtained. The renewal frequency of the free film was 40% faster than that of the wall-bounded film. The renewal frequency of the free film on round window was 34% faster than the fan-shaped free film, but the fan-shaped free film could intensify the wall-bounded film significantly.

The leakage ratio, compression recovery and stress-relaxation of flexible graphite corrugated metal composite gaskets with 316L and A3 steel as framework were tested on an automatic multi-function gasket testing rig. The effects of flexible graphite cover layer thickness, frame material and gasket stress on sealing performance and mechanical properties were investigated. The residual thickness of corrugated metal was determined at different thicknesses of cover layer and gasket stresses. The sealing performance of the composite gasket was mainly dependent upon the thickness of cover layer with flexible graphite, and optimal sealing performance was observed for the corrugated metal when the thickness of cover layer was 0.6 mm. The composite gaskets had good carrying capacity and sealing performance, which was especially suitable for complex applications, such as pressure and temperature fluctuations. Also outstanding recovery of the composite gaskets could be obtained by pre-compression. In addition, as gasket stress increased, sealing and compression recovery performance of 316L composite gaskets became obviously better than the composite gaskets with A3 steel as framework, and the former had distinct improvement than the latter in resisting stress relaxation and creep behavior.

Because of the significant influence of hydrostatic effect on the sealing performance of a regulatable gas lubricated seal (R-GLS), optimization of hydrostatic structural parameters of this type of seal was conducted. Based on the gas lubricated theory, Reynolds equation of the gas film between sealing rings was solved by using the finite element method (FEM). The pressure distribution of the gas film was obtained. The sealing performance, including balance gas film thickness, gas film stiffness, leakage rate and frictional loss of the seal were studied by varying hydrostatic structural parameters of R-GLS at different rotating speeds. The hydrostatic structural parameters were optimized. Analysis of sealing performance of hydrostatic gas lubricated seal (H-GLS), pumping-out gas lubricated seal (Po-GLS) and pumping-in gas lubricated seal (Pi-GLS) was made under the same operating conditions. Optimal working performance, including sealing ability, gas film stability and frictional loss could be achieved for a R-GLS when diameter of restrictive orifice was between 0.05 mm and 0.2 mm, dimensionless pressure equalizing groove depth was between 0.005 and 0.015 and dimensionless pressure equalizing groove width was between 0.02 and 0.05. Great working clearance and sealing ability could be achieved when dimensionless radius position of orifice was between 0.3 and 0.6, while excellent gas film stability could be achieved when dimensionless radius position of orifice was between 0.1 and 0.3 or between 0.55 and 0.7. Compared to H-GLS and Pi-GLS, Po-GLS was good with excellent axis gas film stiffness and balance gas film thickness, especially low leakage rate. Pi-GLS could realize zero outward leakage-rate of the regulative gas with rational design.

Fuel ethanol production using renewable cellulosic materials has attracted widespread attention by researchers. However, acetic acid released from the pretreatment process exerts severe inhibition on yeast cell growth and ethanol fermentation. Therefore, improvement of acid tolerance of industrial Saccharomyces cerevisiae benefits efficient cellulosic ethanol production. In this work, glutaredoxin encoding gene GRX5 was overexpressed in S. cerevisiae, and it was found that the GRX5 overexpression strain grew better than that of the control strain in the plates containing 5 g·L^-1 acetic acid. When ethanol fermentation in the presence of 5 g·L^-1 acetic acid was evaluated, it was found that the GRX5 overexpression strain consumed all glucose in the broth within 48 h, 12 h shorter than that of the control strain. Ethanol productivity of the GRX5 overexpressed strain was determined to be 0.897 g·L^-1·h^-1, with a 28.5% increase than that of the control strain. Analysis of the key metabolites showed that the GRX5 overexpression strain produced higher concentration of trehalose and glycerol, which might explain its improved cell viability in the presence of acetic acid stress.

p-Nitrophenol (PNP), a toxic and recalcitrant organic compound, has been widely used as an intermediate for preparing phosphororganic insecticides, medications, explosives and synthetic dyes. Control and removal of PNP is always a research focus. Soil aquifer treatment (SAT) system is a widely used wastewater treatment system with better efficiency and low cost, which is also used for artificial aquifer recharge. The present study investigated PNP removal in the SAT system under abiotic and bio-augmentation conditions using 1D columns. PNP was removed well in both cases. Soil adsorption was the main mechanism under abiotic condition. The depth of soil for effective treatment was 60 cm, and removal rates reached 10% for coarse, medium-coarse and fine sand columns. Under bio-augmentation condition, PNP removal rate with addtional bio-degradation increased to 88.5%.

The optimal removal efficiencies of COD, N and P were investigated by using denitrifying phosphorus activated sludge taken from an anaerobic/anoxic/oxic (A²O)-biological contact oxidation (BCO) system. Response surface methodology using Central Composite Design (CCD) of Design-Expert was used to evaluate the influence and specific function of four important factors (initial COD concentration, nitrate concentration, temperature and anoxic reaction time) on the three responses, which were marked removal rate of COD, N and P as Y_cod, Y_n and Y_p, respectively. Among all the factors, initial COD concentration greatly influenced the three responses. In addition, anoxic reaction time had a major impact on Y_n and temperature had a greater influence on Y_p than other two factors. The three response model equations were all significant, where R² were 0.9853, 0.9118 and 0.9972 respectively. When initial COD concentration, nitrate concentration, temperature and anoxic reaction time were 316.95 mg·L^-1, 42.26 mg·L^-1, 27.19℃, and 237.37 min respectively, the model predictions of Y_cod, Y_n and Y_p were 93.54%, 99.96% and 99.56%, and test responses were 92.03%, 91.15% and 81.64%, respectively.

Co-liquefaction behavior of wheat straw and Jingou lignite was investigated in an autoclave. The product distribution and sulfur transformation at different temperatures or different blending ratios of wheat straw and lignite were studied. Adding [Bmim]Cl would make the yield of n-hexane insoluble fraction lower, while make gas yield and total conversion higher during co-liquefaction of lignite and wheat straw in sub-critical water. When decreasing the blending ratio of wheat straw, oil yield, yield of n-hexane insoluble fraction, yield of tetrahydrofuran soluble fraction, gas yield and total conversion all decreased. Moreover, adding ionic liquid [Bmim]Cl also could make the relative content of sulfur in the residue increase, while decrease the relative content of sulfur in other products. Furthermore,with increasing temperature, the relative content of organic sulfur in residue and the content of COS and H₂S in gas all increased when adding ionic liquid during co-liquefaction of lignite and wheat straw.

This study was conducted on one-dimensional seepage in saturated porous media fixed on packed bed columns to investigate the fate of graphene oxide (GO) in the subsurface environment. In the present experiments, the fate of grapheme oxide (GO) was investigated as a function of cations composition (sodium absorption ratios, SAR) at 10 mmol·L^-1 constant ionic strength (IS). To analyze the migration deposition mechanism of GO, the deposition kinetics curve was determined by mathematical model and interface chemistry theory. When SAR increased from zero to ∞, maximum effluent concentration of sand columns and recovery of GO increased, however, deposition rate, removal efficiency and attachment efficiency of the breakthrough experiments decreased respectively from 0.356 min^-1 to 0.039 min^-1 、1.04×10^-2 to 1.1×10^-3 and 0.054 to 0.003. Accordingly, it was proposed that Brownian diffusion was the major mechanism which resulted in contacting between GO particles and quartz sand particles, and the change of Ca²⁺ concentration was the predominant factor which caused GO different migration behavior at different SAR. The charge neutralization and bridging between Ca²⁺ and GO could be responsible for the balance of electrostatic repulsion and attraction between the particles, which affected the size and shape of GO particles and strengthened the retention effect of sand column on GO.

Poly-b -hydroxybutyrate (PHB) production by halophilic mixed consortia has great advantage in cost. PHB production by the two-step production process using halophilic activated sludge cultured from estuary sediment was investigated. During the continuous 300 d, the ability of PHB storage at different F/F was assessed from the performance of the long-term tests, experiments of PHB production and the observed kinetics. The ratio of feast to famine (F/F) as an important parameter directly affected the capacity of the PHB-storing of halophilic activated sludge. At a high F/F the non PHB-storing bacteria became dominant in the enrichment reactor, while a low F/F was in favor of the selection and enrichment of PHB-storing bacteria. Moreover, the culture selected at F/F less than 0.33 showed the best PHB-storing capacity with a PHB content of 46.7% cell dry weight and a PHB yield of 0.358 mg PHB·(mg Ac)^-1. The results obtained in the study provided a guidance to the production of PHB by halophilic activated sludge.

On the basis of dilute hydrochloric acid pretreatment, recovery of rare earth from waste CRT phosphor was further studied, and a process route was developed. After dilute acid pretreatment, optimum conditions for recovering rare earth from waste CRT phosphor were: concertration of hydrochloric acid for hydrolysis of residual phosphor solids 5 mol·L^-1, reaction temperature 80℃, pH value of leaching liquor after hydrolysis reaction 5.5, ratio of diethyldithiocarbamate (DDTC) and phosphors dosage 6:1, calcination temperature of rare earth oxalate precipitation 900℃. The total content of rare earth products Y₂O₃ and Eu₂O₃ was 99.2%. The crystal particles of rare earth product possessed polyhedral structure built by the accretion of flaky crystals. The particles were embeded in each other with mosaic contact.

Soot dispersibility is an important performance index of diesel engine oil. The dispersion performance of biofuel soot (BS) and 0^# diesel soot (DS) in liquid paraffin (LP) and the influence of polyisobutylene succinimide dispersant (T154) were investigated by means of viscosity, spot experiment and particle size distribution. The dispersion mechanisms of BS and DS were investigated by means of X-ray photoelectron spectroscopy and Fourier infrared spectrometer. The surface of BS and DS contained some O-containing functional groups and the oxygen content of BS was higher than that of DS. The effect of oil thickening by DS was greater than that by BS. T154 has a good effect on dispersing BS and DS in LP. The influence of T154 on the BS and LP dispersing system was better than the DS and LP dispersing system. T154 could also be used as a dispersant to disperse BS into lubricating oil. Because of BS surface with O-containing acid groups, such as carboxyl group, and phenolic hydroxyl, it could adsorb T154 by the acid-base reaction with succinimide of dispersant. At the same time, because of BS surface with polar groups, it could adsorb T154 through forming hydrogen bonds with the giving electrons unit of N-H.

One of the most important orientations of preparation of high-performance graphite materials is to seek carbonaceous materials which have the properties of wide source, low cost and high purity. The influence of coal particle size and catalyst on the graphitization process of ultrafine Shenfu coal at 2500℃ under inert atmosphere was discussed. The degree of graphitization of the products was analyzed with XRD and Raman spectroscopy. The Shenfu coal could change to ultrafine graphite powder at 2500℃ under inert atmosphere, and the degree of graphitization of ultrafine graphite powder increased with decreasing particle size of the Shenfu coal. Furthermore, graphitization of the Shenfu coal with boric acid or ferric chloride as catalyst was compared, and the catalytic activity of boric acid was higher than that of ferric chloride. When the particle size (D₉₀) of the Shenfu coal was smaller than 20 μm, the degree of graphitizations of obtained ultrafine graphite powder from the Shenfu coal was 80.35% by using boric acid as catalyst.

With initial water at 26℃ and 15℃ and charge pressure at 3.6-4.2 MPa in the reaction kettle, the hydrates growth and cool storage characteristics of CO₂ hydrates produced in direct-contact way were studied. When initial water was at 15℃ and charge pressure was at 3.6 MPa, precooling time was short, about 11min, and sub-cooled temperature was about 1.3℃ but temperature increment was not obvious at the beginning of growth, and total cool storage average rate and efficiency were about 82.4 kJ·min^-1 and 4.34 respectively. At other temperatures and pressures, there were longer precooling time (between 20-55 min, but decreasing with the increase of charge pressure), higher sub-cooled temperature (at 5.5-9.7℃), rapid growth rate and dense hydrates. Temperature increment was obvious and the largest was at 4.0 MPa; hydrates average growth rate, total storage amount, total cool storage average rate and efficiency increased with the increase of charge pressure, and their maximum values at the experimental initial water temperatures were 77 and 154 g·min^-1, 3.725 and 3.791 MJ, 64.1 and 99.5 kJ·min^-1, 3.14 and 4.91 respectively. The hydrates decomposition releasing cool was a phase change process, and phase transition temperature was generally 10-14℃.

Corn stover was pretreated with liquid hot water (LHW) method using a batch rector in order to enhance cellulose digestibility. The effects of pretreatment process parameters (pretreatment temperature 180-220℃, reaction time 10-25 min) on the main components (hemicellulose, lignin, and cellulose) and cellulose digestibility were investigated. Multiple linear regression models or quadratic equation models (only for lignin removal) were established by analyzing hemicellulose removal, lignin removal, and cellulose loss as dependent variables and pretreatment temperature and reaction time as independent variables. Hemicellulose removal and cellulose loss increased with increasing pretreatment temperature and reaction time over the range of experimental conditions. Compared to lignin in raw corn stover, mass of lignin in pretreated corn stover increased (lignin removal was negative), also as a function of increasing pretreatment temperature and reaction time, probably because of the formation of pseudo-lignin. Sensitivity analyses showed that the significance level of pretreatment temperature was much higher than that of the reaction time on these three dependent variables. The maximum enzymatic digestibility (76.2%) of cellulose in raw corn stover was achieved after the pretreatment (210℃, 20 min). Higher severity conditions caused more hemicellulose removal, as well as more cellulose loss, thus lowering the enzymatic digestibility of cellulose in raw corn stover.

The characteristics of simultaneous calcination and sulfation of limestone in the atmosphere simulating circulating fluidized bed oxy-fuel combustion were studied using an experimental system that could measure sample mass changes at a preset temperature. The pore structure and conductivity of samples were measured to study the diffusion mechanism in the product layer. Compared with CaO that was calcined without SO₂, the porosity of CaO was easier to be blocked up and the process had a shorter duration before transfering into the diffusion control stage when limestone calcination and sulfation occured simultaneously. A higher sulfation rate and higher conversion were observed because of higher diffusibility in the product layer than that of CaO calcined without SO₂. Sintering of CaO would decrease its sulfation capability, especially when temperature was above 950℃. Particle size was an important factor that determined sulfation of sorbents, and higher sorbent utilization would be obtained for smaller particles. Also, higher SO₂ concentration would improve sulfation of sorbents. A grain-micrograin model was set up, and the effects of some factors, such as temperature, sorbent particle size and SO₂ concentration were simulated. The calculation results fitted well with the testing.

The depressurization-induced natural gas hydrate dissociation is limited by heat transfer. This research presented a numerical study of gas production to clarify the dissociation characteristics of depressurization combined with well-wall heating. A 2D cylindrical fully coupled simulator was developed for simulating the laboratory-scale gas production process with depressurization combined with well-wall heating. The simulation results were verified by experimental data. Well-wall heating was beneficial to increasing gas production, and gas generation rate of the depressurization combined with well-wall heating method was higher than the depressurization method alone. Well-wall heating could improve the thermal conditions of hydrate-bearing sediments, but the influence was not large because heat was transmitted to only a small dissociation area due to small heating surface and slow heat conduction. On the other hand, the effect of different heating temperatures on gas production could be neglected. Finally, gas production depended strongly on the boundary thermal conditions. The depressurization combined with well-wall heating method may not be feasible for hydrate exploitation in a surrounding with a lower geo-temperature gradient.

Calcium aluminate clinkers doped with Na₂O were synthesized using analytically pure reagents CaCO_3, Al₂O₃, and Na₂CO₃ at 1350℃ for 1 h. XRD, SEM and EDS were used to study the phase transformation of calcium aluminates and the leaching performance of clinkers from CaO-Al₂O₃ system doped with Na₂O. The results show that the main phases of clinkers from CaO-Al₂O₃ system are CaO·Al₂O₃ and 12CaO·7Al₂O₃, while those of clinkers from CaO-Al₂O₃ system doped with Na₂O are CaO·Al₂O₃, 12CaO·7Al₂O₃, Na₂O·Al₂O₃ and Na₄Ca₃(AlO₂)₁₀, when the molar ratio of CaO to Al₂O₃ is 1.0. Some of the Na₂O forms compounds containing Na₂O, the rest is doped in 12CaO·7Al₂O₃, meanwhile nearly none of Na₂O is doped in CaO·Al₂O₃. With the increasing of the Na₂O content in clinkers, the amounts of 12CaO·7Al₂O₃ and Na₄Ca₃(AlO₂)₁₀ increase while the amount of CaO·Al₂O₃ decreases, and the crystallinity of 12CaO·7Al₂O₃ and Na₄Ca₃(AlO₂)₁₀ decrease while that of CaO·Al₂O₃ increases. Due to the doping of Na₂O, the leaching performance of alumina in the clinkers using the sodium carbonate solution is improved and the space groups of CaCO₃ in the leached residues are changed from R-3CH and P63/MMC to only R-3CH.

It is still a challenge to elucidate the dominant reaction pathways of pyrolysis of polymer via utilizing experimental analysis alone because pyrolysis of polymer involves a number of complicated reactions. A complementary way to investigate pyrolysis of polymer is possible via combinating computer simulation with conventional experimental characterization. In this paper, ReaxFF molecular dynamics(ReaxFF-MD)simulations were used to clarify the pyrolysis process of a dipropargyl ether of bisphenol A based boron-containing polymer(PB). The results from ReaxFF-MD simulation were then compared with the data obtained from experiments. The order of the break of chemical bond in the PB thermoset was obtained by observing the structural changes during cook-off simulation. The main small molecule products found in the simulation included CH₄, H₂O, H₂ and CO. In addition, typical mechanisms for the formation of small molecules were observed via simulating and tracking their generation processes. This ReaxFF-MD simulation complemented experimental characterization of PB thermoset pyrolysis and provided detail predictions of evolution of pyrolyzed products at the atomistic level.

The carriers with core-shell structure have been widely used in the field of co-loading gene and drug. In this study, chitosan (CS) nanoparticles (CS NPs)/poly (L-lactide)-poly (ethylene glycol)-poly (L-lactide) triblock copolymer (PLLA-PEG-PLLA) composite microparticles (MPs) with core-shell structure were prepared by the combination of ion gelation and suspension-enhanced dispersion by supercritical fluids (SpEDS). The conditions for preparation of CS NPs and MPs were investigated and optimized, and the physicochemical properties and cytotoxicity of MPs were studied. The optimized condition for CS NPs were chitosan solution concentration of 2 mg·ml^-1, chitosan solution pH of 5.0, and tripolyphosphate (TPP) solution concentration of 1 mg·ml^-1. The ratio of solvent/non-solvent was the significant factor affecting sizes of MPs, and the optimized conditions for MPs were oil concentration of 5 mg·ml^-1, W/O ratio of 0.75:10.00, solution flow rate of 2 ml·min^-1 and solvent/non-solvent of 0.5:1.0. The MPs from optimized conditions had a size of 323.7 nm and the CS NPs were encapsulated in MPs, as observed by TEM. The results of experiments about physicochemical properties revealed that a reaction happened between CS and TPP. Little change occurred in the functional groups of materials used in the two processes, while the crystal forms of PLLA-PEG-PLLA in MPs were more uniform. The relative growth rates of Bcap-37 cells co-cultured with MPs with different concentrations of 0.25, 0.50 and 1.00 mg·ml^-1 for 3 d were 105.3%, 101.9% and 100.9%, respectively. The above results demonstrated that the MPs with good biocompatibility could be used in the field of co-delivery for gene and antitumor drug to evaluate the antitumor effect and would achieve a good synergistic effect in the treatment of cancer.

A series of soluble near-infrared absorption amino phthalocyanine dyes were synthesized with preparation of amino phthalonitriles firstly. The structure and performance of phthalocyanines were characterized by ¹H NMR, Fourier transform infrared spectroscopy (FT-IR), solution test, UV-visible absorption spectroscopy (UV-Vis), thermal gravimetric analysis (TGA). The results showed that amino phthalocyanines were successfully synthesized. The solubility of amino phthalocyanines was greatly influenced by substituents, position of the substituents and metal ions. When aliphatic amine was used as the peripheral substituent at α position and Mn²⁺ was used as the central substituent of phthalocyanine, solubility could greatly be increased. A red-shift of the Q-band was observed when aliphatic amine and Mn²⁺ were introduced into phthalocyanine, mainly due to the electron-donating ability of aliphatic amine. The 3, 3', 3", 3"'-tetra-n-butyl amine manganese (Ⅱ) phthalocyanine (a-TnBAMnPc) showed Q-band peak at 870 nm in chloroform. The near-infrared absorption performance of a-TnBAMnPc in poly(methyl methacrylate) (PMMA) and waterborne polyurethane (WPU) films was investigated. For PMMA-(a-TnBAMnPc) films, the transmission at 862 nm was near 0 when the content of a-TnBAMnPc was more than 0.60%(mass). The transmission at 866 nm approached 0 with the content of a-TnBAMnPc beyond 0.40%(mass) for WPU-(a-TnBAMnPc) films.

Pickering emulsion was obtained by using octadecyl trimethyl ammonium chloride (OTAC) in combination with nano SiO₂, and linear polysiloxane (PDMS) was synthesized with D₄ through ring-open polymerization under alkaline condition, and then cross-linking agent KH560 was added to prepare cationic water-based silicone rubber emulsion. The effects of SiO₂ and OTAC contents on Pickering emulsion were investigated. The absorption behavior of OTAC on the surface of SiO₂ was revealed by zeta potential, TEM and SEM. The structure of water-based silicone rubber was characterized with FT-IR, ²⁹Si NMR spectra. The effects of KH560 on the contact angle and Shore A hardness of the rubber film were also investigated. The emulsion possessed optimal liquidity and stability when w(SiO₂)=2.0%. When w(OTAC)=1.75%, the absorption of OTAC reached saturation on the surface of SiO₂, monomer conversion was about 89%, particle size was about 617 nm, zeta potential was close to zero, M_n and PDI for PDMS were 16036 and 1.485 respectively. When w(KH560)= 5.0%, PDMS hydrolyzed and condensed fully with KH560, and the obtained rubber film possessed optimal hydrophobicity and hardness.

Antimony doped tin oxide (ATO) has excellent optoelectronic properties. To obtain a small particle size and well-dispersed nano ATO materials in the drying process is a critical step in the preparation. In this paper, the supercritical drying time, temperature, pressure and CO₂ flow rate were studied as the main parameters affecting the nano ATO particle's size and specific surface area. In addition, the kinetic equations of drying curve were fitted. ATO nano particles with average particle size of 20-30 nm and high specific surface area of 75-80 m²·g^-1 were obtained with the supercritical CO₂drying process parameters: temperature (35-40℃), pressure (10-14 MPa), CO₂ flow rate (1.2-1.8 L·h^-1), drying time (5-6 h); and alcohol gel drying process could be divided into three stages: rising speed, uniform speed and decreasing speed. There was a critical point in the alcohol ratio (M_R) of alcoho gel, and when M_R was smaller than 0.4, drying slowed down from uniform speed to decreasing speed. However, large supercritical flow rate could not obviously increase drying rate on the other hand. In addition, the Weibull function was used to describe the kinetics of supercritical CO₂ drying process of alcohol gel. As a result, the kinetic model was built and the drying process could accurately be described by the Weibull function. The results could provide helpful reference for industrial production and control of wet gel dried by supercritical CO₂ in the preparation of well-dispersed nano particles.

A stable Ti/Zr composite polymeric sol with Ti:Zr molar ratio of 1:1 was synthesized through the polymeric sol route. Disk a-Al₂O₃ supported mesoporous g-Al₂O₃ membrane with an average pore size of 5-6 nm was used as support for nanofiltration membranes deposition. A defect-free Ti/Zr composite nanofiltration membrane superimposed on the support was fabricated via the dip-coating method followed by drying and calcination. The influence of calcination temperature on Ti/Zr powders was studied. The properties of Ti/Zr composite nanofiltration membrane were also investigated. Ti/Zr powders maintained amorphous state and microporous structure up to a calcination temperature of 500℃. The MWCO, mean pore size and pure water flux of Ti/Zr composite nanofiltration membrane calcined at 400℃ were 880, 1.49 nm and 4.3 L·m^-2·h^-1·MPa^-1, respectively. Under the condition of pH=6 and transmembrane pressure 0.8 MPa, the retention properties of Ti/Zr composite membrane towards 0.005 mol·L^-1 MgCl₂ and CaCl₂ solutions were 85% and 78%, respectively.

To address the disadvantage of suspended phase TiO₂ powder which is difficult to separate and recycle in the treatment of liquid pollutants and to further improve utilization of solar energy by TiO₂, Pr³⁺:Y₂SiO₅ powder, TiO₂ membrane and Pr³⁺:Y₂SiO₅/TiO₂composite membranes were prepared via the sol-gel method. XRD and SEM were used to characterize the properties of the samples. The relationship between efficiency of photocatalytic degradation of methylene blue by Pr³⁺:Y₂SiO₅/TiO₂ composite membrane and number of coating layers was investigated. Degradation rate could be as high as 96.43% with five coating layers of Pr³⁺:Y₂SiO₅/TiO₂ composite membrane, and the second and third degradation rates were 82.46% and 74.94%, respectively. With increasing area of Pr³⁺:Y₂SiO₅/TiO₂ composite membranes, degradation rate increased for a period of time then decreased finally. Degradation rate could be as high as 96.43% with eight coating layers of the membrane. Degradation rate would increase to 96.18% when illumination intensity reached 100 W. However, degradation rate decreased evidently with the increase of initial concentration of pollutions.

Based on the characteristics of gas compressibility, the concept of compressible gas-assisted extrusion was proposed. To verify the effect of compressible gas on polymer extrusion molding, the two-phase flow model polymer melt phase and compressible gas phase was established by means of finite element method, the non-isothermal viscoelastic numerical simulation of the compressible gas-assisted CG extrusion molding and the traditional without gas-assisted TWG extrusion method were performed. The density distribution of gas-assisted extrusion was not a constant value, but was different with the space distribution of pressure and temperature. Compared with the results of two kinds of extrusion methods, when the interaction of gas on polymer melts and gas compressibility were considered, all physical field distributions of CG extrusion method were obviously different from the TWG method. Shrinkage degree was more prominent when inlet pressure of gas phase increased, which was consistent with the results of experiments. These results and factors could not be reflected in the TWG extrusion simulation method.