Three dimensional numerical simulation of micro-droplet breakup in a T-shaped micro-fluidic chip was carried out using the VOF method, and the regimes of breakup and non-breakup were observed, respectively.For a droplet with a specific axial length, there existed a critical capillary number, which could be used to describe the transition between these two regimes.The results showed that micro-droplet would break up when the capillary number was high enough and turned into two daughter droplets.Otherwise non-breakup of droplet would occur while the capillary number was small and micro-droplet would flow into either side of the micro-channel randomly.The correlations between the critical capillary number and the non-dimensional length of micro-droplet were obtained based on numerical simulation.The critical capillary number decreased with increasing droplet size，when the droplet was large enough to obstruct the channel and the pressure accumulated to split the droplet and the critical capillary number was relatively small.When the droplet was too small to obstruct the channel and the pressure was released fast without helping to split the droplet, the critical capillary number was relatively high.Finally, the effect of viscosity ratio on the breakup was discussed and it was found that the higher the viscosity of continuous phase, the higher the capillary number which was needed to break up the droplets, and the critical capillary number decreased with increasing viscosity ratio.

Adsorption refrigeration is an environmental benign and energy saving refrigeration technology and has a great potential for the utilization of low-grade energy, such as solar energy and industrial waste heat below 100℃.For efficient utilization of these low-temperature heat sources, a two-stage adsorption refrigeration cycle was proposed based on the adsorption refrigeration process and resorption process. Refrigeration performance of the working pair of SrCl₂-NH₄Cl-NH₃ was tested at different evaporating and condensing temperatures.The results show that the two-stage adsorption refrigeration cycle can give the cooling output with the temperature of -25℃ when the temperature of the heat source is 70℃.The adsorption quantity of strontium chloride is 94% of the theoretical value.Under the condition of 80℃ heat source, 25℃ cooling source, and -25℃ refrigerating temperature, the COP and SCP are 0.250 and 160 W·kg^-1, respectively.At the same cooling and refrigerating temperatures, compared with the working pair of CaCl₂-BaCl₂-NH₃ with the heat source temperature of 85℃, the heat source temperature in this study decreases 5℃, and COP and SCP increase by 4% and 10%, respectively..

A series of sinusoidal wavy microchannels with different phase shifts and wavelengths were fabricated on the silicon wafer based on the MEMS technology.Flow frictions in these sinusoidal wavy microchannels were investigated experimentally.Results show that the flow friction in wavy microchannels is higher compared with the smooth straight microchannels with the same hydraulic diameter.Both the phase shift and the wavelength have effect on the flow friction in wavy microchannels.For the microchannels with the same wavelength, the flow friction increases as the phase shift increases.However, the influence of wavelength is complicated.For the microchannels with phase shift of 0, the flow friction normally increases as the wavelength decreases with the exception for the microchannel with the smallest wavelength.For the microchannels with phase shift of π, the flow friction decreases as the wavelength decreases due to the decrease of the throat size in the microchannels.The investigation also shows that as the wavelength decreases, the influence of phase shift on the flow friction decreases.For the wavelength of 0.5 mm, there is little difference in the flow friction between the microchannels with 0 and π phase shifts.

The latent heat transportation materials with high melting points, paraffin emulsions, can be used as heat storage and transfer media.Because paraffin emulsions can store their latent heat during phase change process in the temperature range of 80—90℃, their heat storage density is higher than water.They can be applied for waste heat recovery, solar energy utilization or central heating systems.In the forced convection heat transfer experiments, the thermal boundary conditions of constant heat flux were imposed.Although the paraffin emulsions have higher effective specific heat capacity, the convective heat transfer coefficients are lower than that of water and decrease with the increase of concentration.The results also show that the convection heat transfer coefficient increases with temperature slightly.The correlations of Nusselt number for paraffin emulsions are obtained according to the experimental data.

De-ionized water, used as working fluid, flows through a staggered micro-cylinders-group, which is made up of micro-cylinders with hydraulic diameter of 500 μm and height of 500 μm, and an experimental study is performed on the influence of tip clearance on heat transfer efficiency in the staggered micro-cylinders-group.Using an electricity heater, the flow rate and the temperature difference between the inlet and the outlet of micro-cylinders-group are measured and the friction factor and Nusselt numbers can be obtained over Reynolds numbers ranging from 8 to 400.The relationship between heat transfer efficiency and Reynolds number is grasped.The experimental results indicate that the tip clearance has a little influence on flow resistance and Nusselt number at low Reynolds number and these influences become apparent with the increase of Reynolds number.The heat transfer efficiency of micro-cylinders-group heat sink increases rapidly with Reynolds number for a start, and it increases slowly with the increase of Reynolds number, even begins to drop with the further increase of Reynolds number.However, the existence of the tip clearance promotes heat transfer efficiency in the micro-cylinders-group heat sink, though it reduces Nusselt number based on the experimental results.

A numerical study on a packed bed thermal storage unit with phase change material（PCM)having different melting points is presented.Paraffin is used as PCM and injected into polycarbonate spheres as phase change capsules.Hot water is used as heat transfer fluid（HTF)flowing from the top down to melt PCM and store latent heat.The capsules are placed in series in the tank based on melting points.PCM having higher melting temperature is placed closer with hot water inlet.One-dimensional Schumann’s model with steady-state flow field assumption is adopted to calculate HTF temperature, while the phase change of PCM is simulated using apparent heat capacity method.The energy and exergy performance in charging process of two arrangement modes containing two, three and four kinds different PCMs are investigated and compared with those of packed bed using only one kind of PCM.The energy comparison results indicate that the thermal storage unit with multiple PCMs has much higher charge rate and higher thermal efficiency than single PCM storage bed.In the exergy comparison, the storage bed with higher average melting point can store more exergy than that has lower average melting point.The utilization of multiple PCMs can dramatically reduce charge time, improving the storage performance.

A model for calculating condensation heat transfer of natural refrigerant R290 inside a tube is selected by analyzing and comparing the available correlations.The flow pattern of two-phase flow of natural refrigerant R290 condensation process inside the tube is obtained.The transition of mass velocity from stratified flow to stratified-wavy flow,from stratified-wavy flow to annular and intermittent flow,from annular and intermittent flow to mist flow,and from mist flow to bubbly flow as vapor quality changes are determined.Under the same condition,the experimental and predicted values of R290 condensation heat transfer coefficients increase with the increase of vapor quality,and their difference is not significant.The condensation heat transfer coefficients of R290 and R22 increase gradually with the increase of vapor quality,the condensation heat transfer coefficient of R290 is higher than that of R22,and their difference increases with the increase of vapor quality,so it is concluded that natural refrigerant R290 has good condensation heat transfer characteristic.

A mathematical model with coupled heat and mass transfer was solved numerically using the finite-difference technique for a porous material drying process with fluidized bed.The control-volume method with the fully implicit scheme was adopted for discretization of governing equations, and the tri-diagonal matrix algorithm was used to solve the linear equations.Physical properties of apple were applied to the present simulation.Under typical operating conditions, heat and mass transfer mechanisms were analyzed based on the profiles of temperature, saturation and pressure inside the material particles.Effects of gas inlet temperature, gas inlet velocity and bed area factor were examined under different operating conditions.Simulation results show that the main mechanisms for moisture transport during the drying are the capillary flow, evaporation-condensation and transition corresponding to the local moisture levels above its critical value, below the value and in between, respectively.The drying process can be significantly affected by coupled heat and mass transfer between gas and solid phases.The drying time decreases with the increase of the gas inlet temperature and velocity, and the bed area factor.

The phenomenon of unsteady condensation of moist air was studied in an ideal two-dimensional oscillation tube model-shock tube model with numerical method.The computational results were compared with the previous experimental data.The results obtained showed that the field structure and parameters changed dramatically with the interaction of condensation shock and flow field.Condensation occurred in the tail of expansion wave.The jump of temperature and pressure was more sensitive to the growth stage of drops than to the initial stage of nucleation.The space distribution of nucleation changed with time and gradually expanded.The rise of nucleation rate at the initial stage was larger than the drop of nucleation rate after the nucleation peak.Furthermore, the nucleation intensity, the space of nucleation and the location of its occurrence changed with the initial relative humidity and pressure ratio.

The numerical simulation of flow field was performed with Fluent, in order to indicate the effect of rotor cage rotary speed on classification accuracy in turbo air classifier.With the same wind speed and different rotary speeds of rotor cage, airflow velocity distribution in the rotor classifier was analyzed and compared， and a reasonable rotor cage rotary speed was obtained, which made a small velocity gradient both in the annular zone and between the neighboring blades, and a stable flow field.Moreover, the pressure distributions between the neighboring blades were analyzed.In this reasonable range of rotor cage rotary speed，the pressure between onward surface and regression surface of rotor blades was evenly distributed, and the formed vortex was weak, which helped to improve the accuracy of classification.Pulvis talci and quartz sand material experiments showed that when wind speed was 8 m·s-1, rotating speed was 600—800 r·min-1, the accuracy of turbo air classifier was high.These actual experimental results confirmed the simulation results using Fluent.Through this simulation, the corresponding reasonable range of the rotor cage speeds with different wind speeds could be obtained.For example, when wind speed was 20 m·s-1, reasonable rotating speed was 1000—1400 r·min-1 and when the wind speed was 30 m·s-1, reasonable rotating speed was 1500—2000 r·min-1.This provides a method to obtain suitable operating parameters of turbo air classifier.

A drag model based on energy minimization multi-scale（EMMS)approach was used in the numerical simulation for fast fluidized bed（FFB)containing Geldart A particles.The Johnson and Jackson boundary conditions（BCs)were used for solids phase.Parametric studies of the specularity coefficient were performed to evaluate its impact on the predicted gas-solids two-phase flow characteristics in term of S-shaped axial voidage profile, outlet solids flux, local voidage radial profile and local particle axial velocity.The experimental conditions of Fan were simulated and compared with experimental data on the aforementioned characteristics.It were found that the wall boundary condition for solids phase played a much important role in simulating the S-shaped axial voidage profile, and directly affected the capability of capturing the heterogeneous flow structure.A “wall-core-annulus” heterogeneous flow structure, which was significantly different from the commonly known “core-annulus” two-zone structure, could be captured in the bottom of the riser when the free-slip wall condition and EMMS-based model were used together.

NiO-TiO₂ catalyst was prepared with the modified citric acid sol-gel method.Carbon nanotubes（CNTs)was directly grown on the surface of the NiO-TiO₂ by fluidized bed chemical vapor deposition（CVD).The prepared CNTs-Ni-TiO₂ nanocomposite photocatalysts were characterized by XRD, SEM, TG, BET and PL.The photocatalytic performance of CNTs-Ni-TiO₂ was evaluated by degradation of methylene blue under UV light.The results indicated that CNTs-Ni-TiO₂ nanocomposite showed the highest degradation activity when the dosage of NiO was 5%.

Based on the lumping theory and catalytic reforming reaction mechanisms, a new kinetic model involving 38 lumped components and 86 reactions was developed for the industrial continuous catalytic reforming（CCR).In the proposed model the reactants were lumped into C6—C11+ according to the number of carbon atoms, the components with the same carbon atoms number were divided into normal-paraffin, iso-paraffin, 5-cyclanes, 6-cyclanes and aromatics respectively, and the cracking products were lumped into C1—C5 lumps.The reaction network of the model was on the basis of the reaction mechanism of bi-functional catalyst and related kinetic theory.As the detailed division of the lumped components, most of the reactants information could be covered, consequently the model could be more realistic.By making reasonable simplification, 86 model parameters were identified and estimated using the hierarchical strategy and BFGS algorithm from literature data.The model developed was used for simulation of a refinery reformer to validate the effectiveness.The prediction error of each component in the outlet products of the last reactor was within 0.7%, and that of temperature drop for each reactor was below 5℃. So, the reliability and accuracy of the model could meet the requirements of industrial applications.The model was then applied to predict the aromatics yield, and the average prediction error was only 0.42%. The result showed that the trend and precision of the aromatics yield prediction were satisfied in a long period of time.Finally, the process optimization was implemented based on the proposed model, and an increase of 0.17% on aromatics yield was obtained by a slight tuning of each inlet temperature.The optimization result could provide a guideline for the optimization of the CCR unit.

Ionic liquid 1-butyl-3-methylimidazolium chloride（IL)was used as an additive for methyl cellulose（MC)pyrolysis under microwave irradiation.The effects of reaction conditions, including IL amount, microwave power and reaction time and catalysts FeCl₃, HNO₃ and 5A-Ca molecular sieve on MC pyrolysis were studied.The results show that components in bio-oils obtained vary with the catalysts. 5A-Ca catalyst could promote formation of small molecules and reduce the oxygen content in product from 37.43% to 34.82%. HNO₃ catalyst could do that of methyl acetate, 1-butanol and methyl benzoate. Furfural and 5-methyl furfural are found for FeCl₃ catalyst.Comparing with conventional pyrolysis, the microwave pyrolysis with IL as additive but without catalysts could have higher yields of bio-oil in a short time.

Seven kinds of ionic liquids, N-methyl-imidazolium bisulfate（［Hmim］HSO₄),1-butyl-3-methyl imidazole phosphate（［Bmim］H₂PO₄), 1-butyl-3-methyl imidazole bisulfate(［Bmim］HSO₄), 1-butyl-3-methyl imidazole tetrafluoroborate（［Bmim］BF₄), N-butyl-pyridine bisulfate（［Bpy］HSO₄), N-butyl-pyridine phosphate（［Bpy］H₂PO₄), N-ethyl-pyridine bisulfate（［Epy］HSO₄), were designed and synthesized.The synthesis of dimethyl succinate catalyzed by ionic liquids was studied for the first time.It was shown that［Epy］HSO₄ had the best catalytic performance, and optimal conditions for the synthesis of dimethyl succinate were obtained, succinic acid and methanol molar ratio 1∶3.0, amount of catalyst 5%（g/g)of succinic acid, reaction temperature 70℃ and reaction time 2 h.Under the optimal conditions, the yield of dimethyl succinate was up to 91.83%, esterification rate was 96.32%.The catalyst was recycled 7 times without substantial decrease in activity.Moreover, compared to conventional industrial catalysts, ionic liquid catalyst had the superiority of smaller catalyst dosage, less by-product, mild reaction conditions, high yield, and recycled catalyst usage.Finally, the mechanism of esterification catalyzed by ionic liquids was discussed.

The enantioseparation of citalopram enantiomers was investigated using high performance liquid chromatography to optimize chromatographic conditions.Chiral stationary phases（CSPs)including derivatized polysaccharide CSPs, crosslinked diallyltartrinine amide CSPs and cyclodextrin-based CPSs were used as stationary phases.n-Hexane with a small amount of diethylamine（0.1%,volume)modified with methanol, ethanol and 2-propanol were used as mobile phase.The influence on retention factor, enantioselectivity, resolution, theoretical plates and asymmetry factor were studied.The effect of temperature was also investigated on the most favorable CSP and mobile phase.Chiralpak AD-H（derivatized polysaccharide CSP)and 2-propanol were proved to be the most favorable CSP and modifier, and 5%（vol)of 2-propanol was the preferred concentration.It was found that among the temperature range of 293.15—308.15 K, higher temperature was favorable to the enantioseparation.The adsorption isotherms of citalopram enantiomers were determined by frontal analysis chromatography under the optimized chromatographic conditions.The isotherms showed convex shape and well fitted by the Langmuir adsorption isotherm model.This work provides the basic data for separation of citalopram on SMB.

By far, the emission of CO₂ has become a key challenge for the sustainable development in the world.Amongst the CO₂ capture techniques, post-combustion decarbonization, which bases on the mature state of art of chemical solvent absorption process, is currently the only one that has access to the industrial test.And aqua ammonia, as a new, alternative absorbent, has attracted much attention in recent years.In this study, the gas phase volumetric overall mass transfer coefficients of dilute CO₂ absorption into aqueous ammonia（K_Ga_e)were measured to explore the mass-transfer performance in a structured packed column.The K_Ga_e value was evaluated over the ranges of main operating variables：gas flow rate, CO₂ partial pressure, liquid loading, and ammonia concentration.The results show that higher liquid loading of aqueous ammonia is beneficial to enhance the K_Ga_e value.On the contrary, K_Ga_e decreases as the CO₂ partial pressure increases.Gas loading has little influence on K_Ga_e.The experimental results are useful to guide the future work on the packed column design.

The experiments were carried out to investigate the effect of salts on the mass transfer performance and the effect of temperature on the salt-effect in the removal of ammonia from aqueous solutions by gas-membrane-based stripping-absorption process.The experimental results show that the mass transfer of ammonia is affected by the salt-effect and the viscosity of salt solutions.The stronger the salting-out effect is, the higher the membrane transfer coefficient（k_M）is; and the higher the viscosity of the feed is, the lower the liquid transfer coefficient（k_L)is.The change of the overall transfer coefficient depends on the change of kM and kL.Sodium chloride, sodium sulfate and ammonium sulfate exhibit a salting-out effect on ammonia and prompt the mass transfer.Although the viscosity of feed containing ammonium chloride becomes slightly smaller with the increase of the concentration, ammonium chloride exhibits a salting-in effect on ammonia, so the overall transfer coefficient changes little.Calcium chloride shows a significant salting-in effect on the gas-membrane-based ammonia stripping process.The temperature affects the salt-effect and the mass transfer performance dramatically.With the increase of temperature, the salt-effect of ammonium sulfate and calcium chloride becomes weaker and the overall transfer coefficient increases significantly.

Heat exchanger network is an important energy recovery system in chemical processes. Recently, simultaneous synthesis methods have been frequently applied to designing a cost-optimal heat exchanger network.Simultaneous synthesis problem is usually formulated as a mixed-integer non-linear programming model, which is non-convex, nonlinearity, non-continuous, and belongs to one of the toughest non-deterministic polynomial-time hard（NP-hard)problems.Medium or large-scale simultaneous synthesis problems in many cases cannot be solved in a reasonable time.A two-level approach was proposed for solving HENS problem.A hybrid methodology consisting of binary particle swarm optimization and genetic algorithm was utilized to generate the network structure in the upper level, while in the lower level, the heat load of exchangers and split-stream fractions were optimized by an improved particle swarm optimization.Two benchmark problems were solved to prove the efficiency of the proposed method.

Batch distillation is a widely used separation process in chemical engineering.Due to the comparatively small investment and flexibility in production, batch distillation has found various industrial applications in biopharmaceuticals, fine chemicals production and foods processing.To guarantee high product quality, modeling and advanced process control for batch distillation have received significant attention. As an unsteady state dynamic process with strong nonlinearity, however, it is still not easy for engineers to design a control system on the basis of a simple model to guarantee good control performance for batch distillation.In this paper, by using the batch distillation model in Aspen Batch Distillation（ABD)as prototype, the process data of tower residual liquid and distillate compositions under different reflux ratios were obtained firstly.Based on the process data, then, the distillate volume and concentration of the process were formulated by the steady-state spline interpolation models（SIM).To compensate the dynamic error caused by variation of reflux ratios, a simple dynamic model was identified and combined with the steady-state SIM, resulting in a simple dynamic SIM for batch distillation.The comparison of the responses of the proposed SIM and ABD model to the time-varying reflux ratio indicated the applicability and precision of the proposed SIM.By using the SIM as the prediction model, a model predictive control （MPC)algorithm was further proposed for the concentration control of batch distillation.Numerical simulations demonstrated the applicability and robustness of the proposed control scheme for batch distillation with different feed compositions.The proposed control scheme lays a solid foundation for the further studies on online optimization of batch distillation.

Multi-model predictive control has become an effective method for handling the process of nonlinear system.But the system using traditional multi-model predictive control has slow rise time and slow convergence speed when it is used for the MIMO nonlinear system solving the condition with large scale transition of operating condition.To solve these problems, a new structure of multi-model called multi-hierarchical 〖JP2〗model has been presented.This structure consists of many layers that each layer is comprised of multiple models.The number of sub-models in each layer is different.Under the condition of the same global operation space, the upper layer has a smaller number of sub-models, and the lower layer has a larger number of sub-models.Because of this structure, the models chosen from different layers can deal with the large scale transition of operating condition.In this paper, a new model switching method between different layers is presented.This method uses the error of output and the variation of output error as the rules for layer switching.In the end of this paper, the simulation results of pH neutralization process which is a MIMO nonlinear system demonstrate that the multi-hierarchical model using the new model switching method is superior to single-hierarchical model with faster rise time, better convergence speed and stability.

The trajectory model of dispersed drops and the model of basic flow for drop motion between two inclined parallel plates are derived and the calculation is optimized.The analytical results of numerical simulation indicate that with the variation of thickness of trickling film and plate distance, the density, viscosity and interfacial tension have different influences on the drop motion.The viscosity always has a great effect on the drop coalescence, while the effects of density and interfacial tension depend on the flow field.The variation of density, viscosity and interfacial tension may make the drop motion rotate tendentiously in the clockwise or anticlockwise direction with the axis parallel to a nearby plane wall. Hence, the density and viscosity may improve the coalescence condition in a certain extent.The simulation results match the experimental data well.The introduction of the basic flow is helpful for the model to reproduce the drop motion characteristics better in the stratified two-phase flow.

Self-assembly in thin films of block copolymer of polystyrene and poly(4-vinylpyridine) （PS-b-P4VP）derived by the immiscibility between the constituted blocks could create rich morphologies with nanometer scale periodic patterns over large areas,leading to potential applications in nanotemplates,nanopatterns,and selective separation membrance with well-defined channel size.The microphase separation behavior and the resulting morphological structure have attracted more attention from investigators.In this paper,diblock copolymer of PS-b-P4VP was synthesized using atom transfer radical polymerization(ATRP) and its structure was characterized by 1H NMR and GPC.The block copolymer was dissolved in chloroform and PS-b-P4VP thin film was prepared by spin coating.Atomic force microscope(AFM) was used to observe the microphase separation morphologies of PS-b-P4VP thin films obtained under different conditions of heat treatment.It was found that microphase separation occurred in PS-b-P4VP film,generating nanoscale microphase separation morphology with PS microphase as dispersion phase and P4VP as continuous phase matrix.The film exhibited different microphase separation morphologies under different heat treatment conditions.Increasing temperature and/or prolonging time in the heat treatment process of PS-b-P4VP film accelerated the microphase separation in the film.After being treated at 150℃ for 24 h,PS-b-P4VP film demonstrated a microphase separation morphology with column-shaped PS microphases projecting from the P4VP matrix.The column-shaped PS microphases were uniformly distributed on the surface of the film and the interface was clear.

The glycerol production by fermentation in flasks by Candida glycerinogenes was studied. Dissolved oxygen（DO)was one of the most important factors in the cultivation of the strain by influencing cell growth and metabolites generated.Based on this result, batch fermentation of glycerol under diverse DO levels in a 5 L stirred fermentor was investigated.The metabolic flux analysis explained the phenomenon that sugar consumption was fast and glycerol synthesis was relatively less under low dissolved oxygen levels, mainly due to generated ethanol.Metabolic flux analysis also showed that HMP pathway played an important role in glycerol synthesis. Analysis of carbon metabolization and energy metabolization（oxidative phosphorylation and substrate level phosphorylation)of C.glycerinogenes in the process of glycerol fermentation showed that a high level of ATP synthesis at high dissolved oxygen levels to a certain degree inhibited substrate level phosphorylation so that more carbon flowed to glycerol synthesis. The intracellular redox balance （NADH/NAD+ ratio)reflected the competition between glycerol production and ethanol synthesis.

Very high gravity（VHG)fermentation and using self-flocculating yeast are both advanced technologies to reduce the energy cost in fuel ethanol industry.Oxidoreduction potential（ORP)reflecting yeast momentary physiological status can be regulated for improving cell performance under severe stresses in VHG condition.Batch fermentations with initial glucose concentrations of 200 g·L^-1, 250 g·L^-1 and 300 g·L^-1, ORP setting values of -100 mV, -150 mV and no control, were undertaken to evaluate the effects of ORP and initial glucose on ethanol production.It was shown that biomass and viability under ORP control were higher than no control, which resulted in higher net ethanol accumulation and productivity.Moreover, since absence and excess of oxygen supply decreased yield, the best ORP level was found at -150 mV in 300 g·L^-1 initial glucose fermentation.ORP control had influence on flocculation as well.By using a multiple variables linear fitting approach, ORP seemed to have a positive correlation with size distribution though its effect is not direct.

Cell immobilization is the main means to realize cells reutilization in the biotransformation process.Immobilizing cells with superparamagnetic nanoparticles directly is a new method of immobilization.The carboxyl-functioned magnetic nanoparticles prepared by the coprecipitation method with oxidization by KMnO4 solution were directly adsorbed to the surface of Lactobacillus reuteri CG001, and the cells were immobilized in magnetic field.Based on the analysis of adsorption mechanism, it was deduced that the main interactions between superparamagnetic nanoparticles and cells were the small size effect of nanoparticle, and electrostatic.Immobilization conditions, such as temperature, pH, time and cell/particle ratio were investigated in detail.The optimum condition was that the cells were immobilized for 0.5 h at 25℃ with the mass ratio of cell/particle 2.25.Furthermore, the immobilized cells were cultured to compare its growth and metabolism properties with free cells.The similar growth and metabolism properties shown by the immobilized cells and free cells indicated that the superparamagnetic nanoparticles on the surface of cells had little adverse effect on cell activity.So the carboxyl-functioned magnetic nanoparticles could be used to immobilize microbial cells and realize cell reutilization with little impact on cell activity.

Taking the industrial pleuromutilin fermentation with strain Pleurotus mutilus as an example, the variations of small molecule metabolomes in different industrial fermentation processes were analyzed.The small molecule metabolomes in different processes were measured by gas chromatography coupled to time-of-flight mass spectrometry.Principal component analysis（PCA)was performed on the metabolome of P.mutilus.According to the score plot and loading plot obtained by PCA, the similarities and differences of metabolism of P.mutilus in two processes were extracted and classified.The analysis on characteristic metabolites indicated significant effects of different processes on cell viabilities.The higher level of TCA cycle intermediates and amino acids during the seed culture stage in the process two indicated higher carbon and nitrogen metabolism in P.mutilus before the inoculation.In addition, the analysis of the variations of metabolites during the two different fermentation processes suggested that nutrition utilization efficiency of P.mutilus in process two was higher than that in process one.This study indicates that metabolome analysis could be a new approach to evaluating the industrial bioprocess and is helpful in providing the feasible regulation scheme to improve the fermentation process.

N-Demethyl roxithromycin, 3-decladinosyl roxithromycin and roxithromycin Z are specified related substances to be controlled in European Pharmacopoeia 7.0, which are derived from roxithromycin. These compounds are required for its routine assay, however cannot be commercially available in China.The related substances were synthesized according to a new procedure developed from previous methods.In the producing process, erythromycin A 9-(Z)-oxime was produced from erythromycin A 9-(E)-oxime in the presence of a strong base.Roxithromycin Z was synthesized by the reaction between erythromycin A 9-(Z)-oxime and methoxyethoxy methyl chloride ether in ethyl acetate at a low temperature, such as lower than 5℃.Roxithromycin Z was then separated with silica chromatography and purified by semi-preparative HPLC.N-Demethyl roxithromycin was prepared by N-demethylation of roxithromycin with iodine and sodium acetate in aqueous solution of sodium hydroxide（pH=8—9), and was purified by two-stage recrystallization.And 3-decladinosyl roxithromycin was obtained through a process of acidic hydrolysis catalyzed by aqueous hydrochloride at room temperature, and was also purified by silica chromatography and semi-preparative HPLC.All three compounds, N-demethyl roxithromycin, 3-decladinosyl roxithromycin and roxithromycin Z were determined by HPLC to high purity of over 95%.Their structures were identified by MS,1H NMR and 13C NMR.In this paper, three producing routes of the compounds have been established successfully.The obtained compounds would provide a new standard reference of roxithromycin for drug assay in Chinese Pharmacopieia.

Nitrogen removal via nitrite pathway was investigated in a lab-scale modified University of Cape Town（MUCT)process treating real domestic wastewater with low C/N ratio.The experimental results of 121 d showed that nitritation was achieved at hydraulic retention time（HRT)of 8 h, dissolved oxygen（DO)of 0.3—0.5 mg·L^-1, sludge recycle ratio of 80%, anoxic recycle ratio of 120% and internal recycle ratio of 300% after startup period of 87 d.Nitritation was stabilized for 35 d with an average nitrite accumulation rate（NAR)of 62%, the highest NAR up to 80%, average ammonia removal efficiency of 65% and the highest of 87%.Mechanisms of nitritation indicated that the low DO concentrations and short HRT were really important to nitritation, whereas pH, free ammonia（FA)and free nitrous acid（FNA)had no effect on nitritation.And temperature and sludge retention time（SRT)possibly had a slightly positive effect on nitritation.The fluorescence in situ hybridization（FISH)assays demonstrated that the percentage of ammonia oxidizing bacteria（AOB)in biomass increased when the performance of MUCT reactor was converted from complete nitrification to nitritation, and the highest AOB percentage was up to 9.3%.Meanwhile, the percentage of nitrite oxidizing bacteria（NOB)decreased, and NOB were phylogenetically related to Nitrospira.Nitrogen removal via nitrite pathway saves the aeration costs and external carbon sources as compared to nitrate pathway.For the treatment of domestic wastewater, nitritation and denitritation are highly beneficial because the organic carbon source in it is typically limited.

Solid matrix structure, which has significant effect on its transfer properties, has not been systematically studied.In this paper, steam-exploded rice straw（SERS)and inoculum were used as the solid phase and liquid phase of substrates, the change of water retention, permeability and thermal conductivity of substrate with the variation of its three-phase structure was investigated within the particle size range（6.5—0.4 cm)and moisture content range（60%—85%)which was employed in industry.The results showed that liquid phase dominated the phase structure variation, therefore, a three-phase structural index（TPSI)was proposed based on weighted variation coefficient.Water evaporation rate of substrate showed exponential increase with the rise of TPSI, and obvious fluctuation was accompanied, indicating that there were some other factors influencing the water retention of substrate. The effect of particle size on substrates’ permeability weakened gradually with increase of water content, and its variation with TPSI accorded with Bidoseresp function（R2=0.9025).The thermal property of substrate, such as volumetric specific heat, thermal resistivity and thermal conductivity, varied with the increase of TPSI according to power exponent functions（R²=0.8991, 0.9135, 0.9053);small fluctuation indicated that the effect of water content was stronger than that of particle size.Statistical analysis also proved that the TPSI can reflect comprehensive influence of moisture content and particle size on substrates’ transfer properties.Therefore, the TPSI can be applied to effectively characterize the effect of substrate structure on its transfer properties.

Partially premixed combustion systems were widely used for the household hot water supply system.The purpose of this study is to investigate the combustion oscillation in a new gas storage water heater, which utilizes primary, secondary and tertiary air supply.The effect of each air stage is investigated by observing flow changes.The pressure fluctuation in combustion chamber is one of the characters of combustion oscillation that are visible most easily.Hence, the pressure was observed to determine the oscillation.Experimental result shows that the pressure fluctuation is larger than 400 Pa during the oscillation.The total air excess ratio and primary air excess ratio are the most important parameters affecting the combustion oscillation.In the experiment, seven zones appeared at different operation parameters.The oscillation occurred between two normal combustion zones as the primary air excess ratio increased from 0.4 to 0.8.With the CH4 concentration measured directly, the range of primary air excess ratio could be determined.It shows that combustion oscillation will occur when the primary air excess ratio is from 0.44 to 0.93, consistent with those measured directly.The investigation shows that the occurrence of combustion oscillation is influenced by the primary air excess ratio directly.

The fusion characteristics of blending ash of Baodian coal and rice straw, corn straw, cotton straw at different blending ratios（10%—90%, step 10%)were investigated respectively using X-ray fluorescence（XRF)spectrometer, X-ray diffractometer（XRD), and ash fusion point analyzer in reducing atmosphere.The characteristics of viscosity-temperature of blending ash at 10% blending ratio were also studied by high-temperature viscometer.The computer software package FactSage was used to predict the proportions of solid, the composition of the remaining liquid phase and the variation of phase.The results showed that the addition of 3 kinds of crop straw reduced the ash fusion temperature of Baodian coal at the blending ratio of 10%—30%.The fluctuation could be seen at the range of 40%—90%, but the fusion temperatures of blending ash were less than Baodian coal ash.The viscosity-temperature characteristic of Baodian coal ash was improved by the addition of crop straw, and the lowest operating temperature of gasifier can be reduced by 20℃.Due to the emergence of anorthite, the viscosity increased with decreasing the temperature of melting ash.

Evaluation method and risk control of CO₂ leakage are key issues for carbon capture and storage（CCS).In order to reveal affecting factors and features of CO₂ leakage during injection, a two-phase flow model was proposed to describe the leakage process, and numerical simulations were conducted using a commercial software COMSOL Multiphysics 3.5a.Based on comparison and extension of its solutions for a benchmark problem, the affecting factors, including distance between the injection well and leaky path, radius and permeability of leaky path, injection rate and injection depth, were investigated. The quantitative relationships between leakage rates and impact factors were obtained from simulations and data analysis.The results show that asymptotic leakage rates of CO₂ are linearly dependent on the reciprocal of distance between the injection well and leaky path, are quadratic with radius of leak path, and are linear with respect injection rates.The permeability of leaky path is the key factor controlling CO₂ leakage, whereas the increase of injection depth has little effect on decreasing CO₂ leakage rates.The proposed model and simulation results not only reveal the relationship between CO₂ leakage rates and impact factor quantitatively, but also provide analytical method and computational tools for site selection, evaluation of leakage and risk management of CO₂ injection into subsurface formations.

The auto-generation mechanism of persulfate was introduced into an anodic oxidation system. The formation of persulfate and the degradation of Congo red in a double anode system consisting of Ti/Ru-Ir oxide coated and Pt anodes were investigated in this paper.The results indicated that there was a competition relationship between them in the anode zone.The double anodes were favorable for Congo red degradation and persulfate formation.The degradation rate of Congo red was proportional to anode current density at coated metal oxide anode and SO2-4concentration, but inversely proportional to pH.The yield of persulfate was closely related to the current density, SO2-4 concentration and pH.Among them the current density was main factor.SO2-4 could be transformed effectively into S2O2-8 only when the current density was higher over 200 times at Pt-anode than at Ti/Ru-Ir oxide coated one.The persulfate produced in the electrolysis system can decompose organics in the solution under irradiation of simulated sunlight.The degradation mechanism of combined sunlight and persulfate was also investigated.The results showed that there could be intermediate materials of quinonoids imine type during  degradation, which is of photosensitivity and more sensitive to visible light.So, it can induce photosensitive reaction under irradiation of visible light, resulting in generation of singlet oxygen1O2 and peroxy radical O-2·.These species can promote formation of hydroxyl radicals ·OH and sulfate radicals SO-4· at low pH（acidic)condition, which can produce the species with strong oxidizability and make this system easy degrade organics.

Pharmaceuticals and personal care products (PPCPs) are received much attention due to potential adverse environmental & health impacts.The removal efficiencies of eight typical pharmaceuticals were studied in the pilot-scale granular activated carbon (GAC) process.The results showed that GAC removed Antipyrine, Disopramide, Sulpiride, Sulfamethoxazole, Tiamulin and Trimethoprim by approximately 50%—90%, and Indomethacin and Lincomycin by less than 35%.Typical pharmaceuticals removals were affected by filtration velocity, organic matters and pH.The removals of Indomethacin, Lincomycin and Tiamulin were affected mainly by filtration velocity while that of Sulfamethoxazole much by pH.Typical pharmaceuticals removals could be promoted or inhibited by organic matters.The physicochemical properties of typical pharmaceuticals had important influence on their removal efficiency by GAC, which is helpful to understand the removal mechanism of the pharmaceuticals by GAC at the molecular level.

Concentration of pollutants especially influent C/N in municipal wastewater is higher in the northern China than in the southern China.Therefore,it is difficult to keep efficient and stable removal of nitrogen and phosphorus by using conventional biological treatment processes because of the limitations and typical water quality in the southern China.In this study,a modified A/O step-feed process was operated at lab-scale to deal with the weak urban sewage and to remove simultaneously biological nitrogen(N) and phosphorus(P).Under the controlled conditions:influent COD/TN 5.16,HRT 8.7 h,SRT 15 d,MLSS 5.66 g·L-1,sludge reflux ratio 75%,the volume ratio of anaerobic/anoxic/aerobic 4∶8∶10,DO 1.0—1.5 mg·L-1 in three aerobic zones,continuous operation with six inflow distribution ratio 150 d,the optimal flow distribution ratio obtained was 20%∶35%∶35%∶10%,and the values of COD，ammonia nitrogen，total nitrogen，total phosphorus in effluent were 33.05 mg·L-1,0.58 mg·L-1,9.26 mg·L-1 and 0.46 mg·L-1, respectively.These values were up to Grade A discharging standard of pollutants for municipal wastewater treatment plant(WWTP)(GB 18918—2002).The majority of COD in raw water was used as carbon source of anaerobic phosphorus release and denitrification processes,and more than 74% of carbon sources was utilized effectively.At the same time,the experiment also found that collaborative control of DO and ORP are not only useful for anaerobic phosphorus release but also for anoxic denitrification and aerobic nitrification.

Sludge anoxic dermentation and denitrification（SAFD)system was established by adding NO-3-N into the typical sludge anaerobic fermentation system.In SAFD, denitrifiers can utilize the carbon source generated in waste activated sludge（WAS)fermentation for denitrification.This system was aimed at dealing with the carbon source shortage and WAS treatment difficulties in waste water treating plants（WWTPs).The results indicated that suspended solid（SS)and volatile suspended solid（VSS)decreased by 63.8% and 74.7%, respectively, presenting a remarkable effect in sludge reduction when SRT=60d.At the meantime, it showed a good denitrifying performance with complete removal of NO-3-N in the early period of the cycle.SAFD could achieve simultaneous fermentation and denitrification, indicating a better performance than typical anaerobic fermentation.Investigations into the denitrification rate during the cycle demonstrated that denitrification rate was higher in the early period（the 5th day）,while decreased gradually and denitrification was accompanied with the accumulation of volatile fatty acids（VFAs).Besides, pH and oxidation reduction potential（ORP)curves reflected the process capability level of fermentation and denitrification in SAFD system.Conclusions of this study could provide reference for technological upgrading of WWTPs.

 In order to improve the mechanical and chemical properties, especially the solvent resistance of the cast films formed from normal waterborne polyurethane (PU) dispersions, a novel ultraviolet (UV)-curable epoxy and acrylate-modified waterborne polyurethane dispersion (UV-EP-AC-WPUD) and its film with high crosslinking density and excellent film properties were prepared and studied.4% epoxy resin E-20 was introduced in PU chain by grafting reaction between epoxy resin and polyurethane prepolymer terminated with the –N=C=O group.The C=C bond was introduced in PU chain by the chain-extending reaction of —NCO in polyurethane prepolymer with two hydroxyl vinyl monomers PEDA and single-hydroxyl vinyl monomers PETA, and the obtained maximum C=C content was up to 4.65 meq·g-1. 3% photoinitiator Irgacure 2959 was used to initiate the polymerization of C=C bond in cast films, and the gel content of the UV-EP-AC-WPUD films could reach up to 91% after 12 s UV-radiation, which meant the polymerization rate and crosslinking rate of C=C bond was high, and the obtained UV-EP-AC-WPUD film was highly-crosslinked and insoluble in solvent.The water absorption, solvent resistance, gel content, pendulum hardness and tensile strength of the cured film were studied, and Fourier transform infrared spectroscopy (FTIR) analysis and film study results showed that the UV-cured EP-AC-WPUD films including epoxy resins and hydroxyl-containing vinyl monomers had excellent mechanical and chemical properties. Thermo gravimetric analysis (TGA) also indicated that the thermal stability of the film was improved significantly.

Crystallization morphologies and non-isothermal crystallization kinetics of isotactic polypropylene（iPP)modified by three α/β compounded nucleating agents（NAs)were studied by means of polarized optical microscope（POM)and differential scanning calorimeter（DSC).The size of spherulites in nucleated iPP appeared much smaller than that in pure iPP.However, iPP nucleated by different ratios of α/β compounded NAs showed different crystallization morphologies.Crystallization morphologies of nucleated iPP depended on ΔT_Cp(ΔT_Cp refers to the difference in crystallization peak temperature between nucleated iPP and pure iPP)of α and β NAs.The one with the higherΔT_Cp played a leading role in the crystallization process, resulting in that the crystallization morphology of nucleated iPP appeared close to that with the NA alone.Competitive nucleation would occur when the difference ofΔT_Cp between two NAs was not pronounced. ΔT_Cp was related to the concentration of NA.Thus crystallization morphologies could be adjusted by changing the ratio of α/β compounded NA.The Caze method was used to deal with non-isothermal crystallization kinetics obtained by DSC.The obtained parameters showed addition of α/β compounded nucleating agents could greatly raise crystallization peak temperature of iPP and shorten the crystallization half-time.Avrami exponent of α/β compounded nucleated iPP was close to that of iPP nucleated by the NA with the higherΔT_C pindividually, which demonstrated that the crystallization process of iPP nucleated with α/β compounded NAs also depended onΔT_Cp of α and β NAs within the compounded system.

Modified polyurethane（PU)based hollow fiber membranes were prepared by the melt-spinning method.Influences of drawing, heat-treatment temperature and heat-treatment time on the pressure-responsive behavior were studied by the relationships between water flux and test pressure.The results showed that the hollow fiber membranes exhibited obvious pressure-responsive behavior.With increasing theoretical draw ratio,the strength of the membrane was greater and the pressure-responsive behavior was stronger.While, membrane pore size on inner surface and mean pore size became larger, the pure water flux（PWF)increased, the porosity first increased then slightly decreased.With increasing heat-treatment temperature, membrane support became worse and the pressure-responsive behavior became weaker.While, membrane pore size became smaller, the PWF and porosity of membrane increased and then decreased.With extending heat-treatment times, the deformation-recovery ratio of membrane diminished and the pressure-responsive behavior became weaker.The PWF and porosity of membrane first increased, then decreased, finally achieved stability.

A new preparation method of waterborne polyurethane acrylate was developed.With this method the hydrophilicity of polyurethane acrylate was improved by assembling ionic groups on the molecular structure of chain extender, and the immiscibility of polyurethane acrylate with water was resolved.The polyurethane acrylate prepared by this method was characterized by Fourior-transformed infrared spectroscopy（FTIR)and 1H nuclear magnetic resonance（¹H NMR).Its stability with water, viscosity, electron beam curing behavior and cured properties were studied.The results showed that the as-prepared product had water storage stability and the emulsion particle sizes decreased with increasing water content in the range from 0.50 to 0.75.The product properties cured by electron beam, such as thermal stability, hardness, adhesion, gloss, flexibility were excellent.

A core-shell type nano-SiO₂/polyurethane-fluorinated acrylate（SiO₂/FPUA)hybrid emulsion was synthesized by seeded emulsion polymerization using polyurethane（PU)as seed, which served as shell phase in the hybrid emulsion mentioned above, with the core phase consisting of nano-SiO₂ modified by γ-(methacryloxy)propyltrimethoxy silane（KH-570), methyl methacrylate（MMA), butyl acrylate（BA)and dodecafluoroheptyl methacrylate（DFMA).The influence of the amount of nano-SiO2 and fluorine-containing monomer（DFMA)on emulsion polymerization process and surface hydrophobic properties of the latex films were discussed.The nano-SiO₂/fluorinated polyacrylate emulsion and the latex film were characterized by Fourier transform infrared spectrum（FT-IR), transmission electron microscopy（TEM), contact angle（CA), thermogravimetry （TG)， differential scanning calorimetry（DSC)and mechanical properties test（MPT）analysis.The results indicated that the latex particles showed a “reverse core-shell” structure, with PA as core and PU as shell, and the hydrophobicity and comprehensive properties of the latex film were greatly improved owing to the synergistic effect of DFMA and nano-SiO₂.

A simple method for preparation of Fe3O4/P(GMA-co-EGDMA)magnetic composite microspheres using microporous P(GMA-co-EGDMA)microspheres copolymerized with glycidyl methacrylate（GMA)and ethylene glycol dimethacrylate（EGDMA)as template is reported in this paper. The preparation process included soaking of ferrous ion and ferric ion and coprecipitation in the presence of OH-.The influences of soaking temperature, soaking time, coprecipitation temperature and deposition times on magnetic content of magnetic composite microspheres were studied.The optimum preparation process of microporous Fe3O4/P(GMA-co-EGDMA)magnetic composite microspheres was as follows：microporous P(GMA-co-EGDMA)microspheres were soaked at 50℃for 4 h, coprecipitation  temperature and time were 70℃ and 1 h respectively.The magnetic content of magnetic composite microspheres was 45.24% when the deposition process was repeated 4 times.The morphology, magnetic properties, magnetic content, pore performance and particle size distribution of Fe3O4/P(GMA-co-EGDMA)were determined by SEM, TGA, XRD, mercury porosimeter and laser particle sizer.It was found that the range of particle size of Fe3O4/P(GMA-co-EGDMA)was 100～200 μm and average particle size was 162 μm, specific saturation magnetization was 10.92 emu·g-1, average pore diameter and specific surface area were 60 nm and 116 m2·g-1 respectively.

The non-isothermal/TGIC curing kinetics of powder coating of polyester resin was investigated by differential scanning calorimetry（DSC).The curing process and thermal stability of this powder coating system were discussed based on the DSC and thermogravity（TG)results.The gelation temperature, curing peak temperature, and post-cure temperature were respectively calculated to be 113, 146 and 195℃ from the non-isothermal DSC results by extrapolating the graph of temperature versus heating rate.The DSC data were analyzed with the Kissinger，Doyle-Ozawa and Crane equations, and the curing kinetic model of the powder coating system was established.The kinetic parameters, including the apparent activation energy, frequency factor and order of reaction were estimated to be 65.71 kJ·mol^-1, 8.50×106 min^-1 and 0.95, respectively.The influence factors of curing reaction rate, degree of cure, curing temperature and time were discussed.This study provides a theoretical basis to understand and optimize the curing process of powder coating of polyester resin for aluminum electrostatic powder spraying.

Poly(styrenesulfonate)-poly(ethylene glycol)(PSS-MPEG)copolymers were prepared by using methoxypolyethylene glycol（MPEG), isophorone diisocyanate（IPDI), hydroxypropyl acrylate（HPA), and styrene sulfonic sodium（SSS)as raw materials.The resulting copolymers were characterized by Fourier transform infrared spectroscopy（FTIR), proton nuclear magnetic resonance（1H NMR)and gel permeation chromatography（GPC).The copolymer had a molecular weight between 40000—140000. Poly(3,4-ethylenedidxythiophene)(PEDOT)/PSS-MPEG aqueous dispersions were then synthesized by chemical oxidation using copolymer PSS-MPEG as the template and dopant.The kinetics of EDOT polymerization was investigated with gas chromatography（GC).Ultra-violet visible absorption, thermal stability and sheet resistance of the films of PEDOT/PSS-MPEG were investigated.The PEDOT dispersion with MPEG showed larger particle sizes than that of PEDOT/PSS.The PEDOT/PSS-MPEG dispersion showed better film formability and gave a smoother surface of the film than that of PEDOT/PSS.It was also found that the film of PEDOT/PSS-MPEG had a lower sheet resistance, which might be due to that PEDOT/PSS-MPEG provided a better film with less defects and MPEG improved the compatibility of PEDOT and PSS phases.