Sol-gel technology has been applied with considerable success in the production of high quality hollow glass microspheres(HGMs)for inertial confinement fusion(ICF)research in China.The specifications of HGMs,such as glass composition,diameter,wall thickness,sphericity,wall thickness uniformity,surface finish,strength and gas permeability,must meet the stringent requirements imposed by ICF targets.Meeting all of these sometimes conflicting specifications has been the driving force of the research in the fabrication of HGMs for ICF target.In this work,various technologies used for fabricating high quality HGMs were compared in terms of their advantages and disadvantages,and the basic principles of the preparation of dried-gel particles/microspheres by sol-gel technology and the transformation process from the dried-gel particles/microspheres to glass shells were further summarized.The progress in the fabrication of HGMs for ICF targets by dried-gel method over the past thirty years was presented.An overview of advances and technical bottlenecks in the control of glass composition,diagnostic element doping,diameter,wall thickness,surface finish,strength,gas permeability and batch uniformity were reviewed.Finally,the future research needs of producing HGMs for ICF targets by sol-gel technology and their possible solutions were also discussed.

Zein,one of the natural and edible biomacromolecules in plant,is renewable,nontoxic,biocompatible and biodegradable.Zein is capable of self-assembly into microspheres or nanoparticles because of its amphipathicity,and is an attractive drug carrier and has a promising prospect for drug delivery systems(DDS).Recently,the study of using Zein as carrier for drug delivery systems has become popular.The properties and advantages of Zein used as DDS carriers were introduced at first in this paper.Then,methods for the preparation of Zein-DDS and the characteristics of Zein-DDS were reviewed in detail.Moreover,the researches on the modification of Zein for carrier were also presented.In summary,Zein has a strong hydrophobicity and a good resistance to the digestive processes of stomach. Therefore,Zein-DDS can improve the stability of drugs,control and prolong drug release,and enhance drug targeting effectively.The future orientations could focus on broadening research fields,improving preparation methods and developing modification of Zein.

Solubility of cholesterol and desmosterol in mixed solvents was predicted via two thermodynamic models,NRTL-SAC and COSMO-RS.With experimental data as the basis,average relative deviation(ARD)was used to evaluate the prediction effects of the models.To fill the blank of solubility data,the solubilities of two sterols at 298.2 K in mixed solvent with different compositions were determined using the static method combined with high performance liquid chromatography(HPLC).The ARDs by NRTL-SAC for two sterols in mixed solvents are less than 50.58%.The prediction results by COSMO-RS are extremely dissatisfied,but the predicted values satisfactorily agree with the experimental values by using an experimental datum.The total ARDs for cholesterol and desmosterol in n-hexane + ethanol mixed solvents decrease to 12.77% and 21.32% from 80.57% and 82.30%,respectively.The results show that NRTL-SAC from limited experimental data and COSMO-RS with only one experimental datum can be used for solubility prediction for two sterols,and are useful in rapid selection of suitable solvents for industrial separation and purification processes.

The isothermal vapor-liquid equilibrium(VLE)for tetrafluoromethane(CF₄)+ propane(C₃H₈)system was measured and P,T,y data were collected at temperatures of 142.96,163.07,183.10,203.26,223.17,243.12,263.15,283.01 and 293.23 K.A vapor recirculation method was used to achieve quick equilibrium.The temperatures were measured with Pt100 platinum resistance thermometers and the uncertainty was less than ±0.005 K.The pressure was surveyed by two absolute pressure transducers,one by Keller PA33 pressure transducer with a full scale of 2 MPa and uncertainty of ±200 Pa,and the other by Mensor 6100 with a full scale of 10 MPa and uncertainty of ±1 kPa.The mixture composition measurement was performed by using a gas chromatograph(Agilent HP 6890N).After careful calibration,uncertainty was within ±0.002 in mole fraction over the whole range of concentrations.The experimental results were correlated with the Peng-Robinson equation of state and the van der Waals two-parameters mixing rule.The mean deviations between the correlated and measured vapor compositions were found satisfactory as 0.011 and the data showed good accuracy and consistency.

Catalytic oxidation of o-hydroxytoluene(ONT)is the main process to synthesize o-hydroxybenzaldehyde(OHBA),but the key problem is how to improve selectivity and yield of target product.In order to make more effective use of resources,the thermodynamic properties of o-hydroxytoluene oxidation were analyzed.The basic thermodynamic data of the reaction products were estimated through several group-contribution methods.According to the basic thermodynamic principles,the relationships between reaction temperature and reaction enthalpy change,reaction Gibbs free energy change,and reaction equilibrium constant were established.The calculation results were as follows:R₁:Δ_rH₂₉₈^Θ＝-158.36 kJ·mol^-1,Δ_rG₂₉₈^Θ＝-170.93 kJ·mol^-1; R₂:Δ_rH₂₉₈^Θ＝-214.53 kJ·mol^-1,Δ_rG₂₉₈^Θ＝-163.56 kJ·mol^-1; R₃,Δ_rH₂₉₈^Θ＝-259.35 kJ·mol^-1,Δ_rG₂₉₈^Θ＝-260.27 kJ·mol^-1.In the researched reaction temperature range,all the reaction steps were exothermic reactions and could proceed spontaneously,and a higher reaction temperature went against the reaction procedure.The thermodynamic analysis results provided the basic data for research on improving selectivity of target product,and could guide optimizing reaction conditions and commercialization.

Based on acoustic emission technique,the acoustic signals during pool boiling of water were measured and the relationship between boiling modes and acoustic signal characteristics was investigated by time-domain and frequency-domain analysis.The results showed that the values of acoustic energy,standard deviation(STD)and average absolute deviation(AAD)indicated extreme points when the boiling mode changed from natural convection to nucleate boiling at an excess temperature of 5℃.After transition boiling began at excess temperature of 30℃,the values of acoustic energy,STD and AAD changed irregularly.As excess temperature increased,the dominant frequency of acoustic signals showed two step decreases,at which excess temperatures were the turning points from natural convection to nucleate boiling and from nucleate boiling to transition boiling,respectively.Therefore,the step change of dominant frequency could be used as a criterion to identify the emergences of nucleate boiling and transition boiling.In comparison with the work published before,this work investigated transition boiling as well as natural convection and nucleate boiling.The criterion to determine boiling mode transition is proposed. Compared with conventional methods,this method was relatively fast,sensitive,accurate,non-intrusive and real-time online.

Granules are widely used in chemical,energy,food,pharmaceutical,mining and relevant industries. In solid processing systems,electrostatics could be commonly generated,which causes many problems,such as granule clustering,blocking,sparking and even exploding.So far,the functional dependence of electrostatic charge generation on granular size and shape has not been fully understood.In this work,granules made of polyvinyl chloride(PVC)with shapes of triangle or trapezium and mean size 2.0—5.0 mm,were studied.Granular shape factors,such as front-facing angle,length-ratio,area,and sliding orientation,relative humidity affected electrostatics greatly,but independent of how many times of granule sliding.

In carbonate acidizing,acid is injected down the wellbore to the treated formation to dissolve the rock so as to create worm holes.Due to the occurrence of acid-rock reaction,the temperature field of the near-wellbore region plays a very important role in influencing acidization results.However,the effect has not been investigated in literature.In this paper,this problem was studied based on a two-scale continuum model which concerned convection,diffusion and heat transfer in the pore and the reaction in the interface between acid and rock.The results showed that the required injection velocity for worm holes increased compared with the experimental ambient condition.Since the formation was deep and formation temperature was high,reaction rate was very high compared with that at ambient temperature according to the Arrhenius equation.In addition,breakthrough volume,which was the ratio of total injection volume to total pore volume,decreased greatly at high injection rate.Then,the acidization results of different boundary conditions(adiabatic condition and constant temperature condition)were compared.Under the adiabatic condition,since the released heat by the reaction could not be transferred to the outside,the temperature in the simulated regime was higher than that under the constant temperature condition,which led to low breakthrough volume.Finally,breakthrough volumes at different formation temperatures were very similar at a low injection velocity if acid did not exchange heat with the formation.However,breakthrough volumes would increase with formation temperature at a low injection velocity if acid did exchange heat with the formation.

In gas-liquid flow,slug flow can be related to other flow patterns,if the hydrodynamic model is developed from slug flow,models of different flow patterns can be unified.Momentum and continuity equations were developed based on slug flow,and simulation of bubble and droplet entrainment was optimized.For the important parameters(wall and interfacial friction factors,slug translational velocity and average slug length),the correlations of these parameters were optimized.Meanwhile,occurrence conditions and correlations of related parameters for liquid droplets and gas bubbles entrainment were given.Finally,a unified model based on slug flow for gas-liquid flow was developed.Experimental data from different sources were used to verify the model.The data with various flow patterns were taken from China University of Petroleum(East China),Daqing Oilfield and foreign researchers.The accuracy of this model was higher than the original model without improvement and optimization of correlations.The relative errors of most pressure drop and holdup data calculated with this model were within ±15%.

Capillary pump loop(CPL)heat pipe has high heat transfer capability and temperature control ability.Heat can transfer across a long distance under a minimal temperature difference,without mechanical pumping.CPLs have been applied in many areas,including the thermal management of advanced space platforms and the cooling of electrical and electronic devices.In this study,a CPL system with eight evaporators was designed and fabricated for the thermal management.Experimental investigations were conducted on operating characteristics of the CPL in the anti-gravity arrangement. Based on the experimental measurements,the heat transfer characteristics of the multi-evaporator CPL were analyzed and discussed.The results show that the multi-evaporator CPL demonstrates good thermal responses and reliable working behavior,applicable to a variety of operating conditions.

Due to the adsorption performance of porous metal foam structure,a salt hydrate/metal foam composite phase change material(PCM)was prepared by using barium hydroxide octahydrate(Ba(OH)₂·8H₂O)as latent heat storage PCM and copper foams as supporting matrix.The thermal properties of Ba(OH)₂·8H₂O were measured by differential scanning calorimetry after a number of repeated thermal cycles.As the number of thermal cycles increases,the phase change temperature of Ba(OH)₂·8H₂O is almost constant and the latent heat of fusion decreases slightly,which implies that Ba(OH)₂·8H₂O has a good thermal stability.An experimental setup was built to study the heat transfer performance of Ba(OH)₂·8H₂O with/without copper foams.The results show that the high porosity metal foam not only enhances the heat transfer rate of Ba(OH)₂·8H₂O within thermal storage units,but also reduces the supercooling of PCM effectively.The supercooling of salt hydrates can be improved significantly by using larger pores per inch(PPI)metal foams.

In order to test the anti-noise ability,inhibition cross-term interference and ability of concentrating energy,the smoothed Wigner-Ville tri-spectrum theory was applied to fractal sequence(Conway),chaotic sequence(Lorenz)and periodic sequence(sine signal).The results showed that the smoothed Wigner-Ville tri-spectrum had obvious advantages in these three aspects of performance compared with other Wigner-Ville spectral theories when it was applied to the analysis of field fluctuation signals.On this basis,the differential pressure signals of nitrogen-water two-phase flow in small rectangular channel were studied.By the analysis of the slice,contour and secondary slice of smoothed Wigner-Ville tri-spectrum of different flow patterns,the evolution of different flow patterns was revealed. At the same time,the smoothed Wigner-Ville tri-spectrum theory could provide a new approach to further revelation of flow mechanism and flow pattern identification of multi-phase flow of different media.

A liquid film of thickness less than 100 nm with soluble surfactant is subject to disjoining pressure or conjoining pressure induced by intermolecular forces,which determines its stability and wettability.In the present paper,based on three nonlinear partial differential evolution equations for film thickness,surfactant interfacial concentration and bulk concentration derived from the lubrication theory,the processes of droplet spreading driven by surfactant under the action of intermolecular forces in positive and negative systems were simulated numerically,and the effect of intermolecular forces,collectively called disjoining pressure or conjoining pressure,was analyzed.Disjoining pressure promoted droplet spreading stably and inhibited film dewetting occurrence in a positive system; disjoining pressure played a destabilizing role in a negative system by amplifying perturbations,and changing the effect of Marangoni stress.The droplet in a positive system presented unstable evolution characteristics under conjoining pressure,which led to film rupture ultimately; in a similar effect with disjoining pressure,conjoining pressure further enhanced the instability of droplet evolution in a negative system.

According to the cooling demand of the ethylene plant,cracking gas cooling-separation process is divided into a variable-temperature cooling process and a constant-temperature cooling process,corresponding to the precooling process of cracking gas and the overhead condenser of towers in the ethylene plant,respectively.In this study,the heat exchange composite curve of the original refrigeration system(ethylene-propylene cascade refrigeration systems)was obtained,indicating that the heat exchange temperature difference between cold and hot streams is massive in precooling process of cracking gas.The heat exchange losses can be reduced by a suitable mixed refrigerant system.Furthermore,a combining multiple mixed refrigerant and cascade refrigeration system was proposed.The combinatorial refrigeration system model was set up with Aspen Plus.And genetic algorithm was adopted as the optimization method,with system variables such as refrigerant components,outlet pressure of compressor,and pressure in outlet of the throttle.Eventually,the compression power in the optimal solution was 3025.5 kW,which was 14.7% lower than that in the pure refrigerant systems.

When the two-stage compression cycle coupled with dual-cylinder rolling piston compressor is used in the room air conditioner with the refrigerant of R410A,its heating/cooling capacity can be remarkably improved and the discharge temperature can be reduced.By analyzing thermodynamically the two-stage compression heat pump system coupled with dual-cylinder rolling piston compressor,simulated calculation indicated that the favorable volume ratio of higher-pressure chamber to lower pressure one was 4/5.The experiments for the developed prototype were conducted.The experimental results showed that the coefficient of performance(COP)for cooling conditions could go up to 3.81 and discharge temperature was lower than 91℃ when evaporating temperature kept 5℃ and condensing temperature varied from 35℃ to 45℃,and COP for heating conditions could rise up to 3.38 and discharge temperature was lower than 111℃ when condensing temperature was 40℃ and evaporating temperature varied from -5℃ to -10℃.COP could be improved by 6.8%—15.4% when compared with one-stage compression cycle.

Based on Kelvin-Helmholtz stability criteria for stratified flow in literature, the new criteria of transition from stratified flow to non-stratified flow for gas-liquid flow in horizontal wellbore was developed, in which the influence of wall inflow was considered.Experimental researches and prediction calculations were done in order to analyze how much wall inflow affected transition conditions.The volumetric flow rate per unit pipe length was small, and the influence of wall inflow might be neglected for the flow pattern prediction of local segment unit, but could not be neglected for the flow pattern prediction of downstream segments unit because it changed the value of flow parameters of downstream segments.Therefore, the transition criteria used for normal pipe flow might be directly used for gas-liquid flow in horizontal perforated pipe.But flow pattern prediction calculations should be done segment by segment in downstream units.

Numerical simulation of anodic bubble/electrolyte two-phase flow in the melts of aluminum reduction cells with the Euler-Euler two-fluid model was conducted based on computational fluid dynamics(CFD).A modified k-εturbulence model was used to describe liquid phase turbulence in the simulation,by assuming the pseudo turbulence resulted from anodic bubbles.The results of CFD simulation for traditional no-hole anodes were compared with the experimental data under similar conditions using particle image velocimetry(PIV).Good agreement was found between the CFD model and PIV measurements,which indicated that the current CFD model could be used to deal with two types of perforated anodes.The electrolyte velocity under perforated anodes could be reduced and the stability of bath flow could be maintained.Perforated anodes could make bath flow more stable.The maximum and average velocity of electrolyte in four-hole anodes were reduced by 9.53% and 12.89%,respectively.The global average bubble fraction in the melts,the local average bubble fraction in anode-cathode distance(ACD)and the thicknesses of bubble layer under the anode with perforated anodes were less than those with no-hole anodes,but the immersion depth of anodic bubbles in electrolyte was almost the same as that in the case of no-hole anodes.Both ACD and cell voltage could be lowered and energy consumption could be reduced.

The mixing performance of stirred tank is usually low for high-viscosity laminar flow mixing system.In order to intensify mixing performance,isolated mixing regions were experimentally destroyed by flexible impeller.Power consumption and mixing time were measured with viscous glycerin as working fluid,together with the shaft torque method and acid-alkali visualization technology.Comparison of power characteristics(P_V)and mixing performance between rigid Rushton turbine(RT)impeller and flexible RT impeller was analyzed with different flexible materials.The P_V of rigid and flexible impeller did not have significant difference at the same agitation speed(N=60 r·min^-1,P_V=340 W·m^-3 of rigid,P_V=346 W·m^-3 of flexible).Good mixing performance could be obtained by flexible impeller at θ_m=2 min,while the isolated mixing regions of rigid impeller still existed until θ_m=30 min.The mixing performance number of flexible was minimum(C_e=2.9×10⁶)and mixing performance was optimal at N=120 r·min^-1.Compared with the rigid impeller,mixing performance of silicone rubber flexible impeller was improved by 52.8%,and the mixing performance of PVC and rubber flexible impeller was improved by about 51.1%、50.5%,respectively.

Ammonia carbonation product control is the key of calcium sulfate conversion at low temperature for utilization of sulfur resources.Aspen plus software was used to simulate ammonia carbonation process.The results indicate that carbonate converts gradually into bicarbonate with increasing temperature from 273.15 K to 338.15 K. The conversion from bicarbonate to carbonate occurs at 0.01—0.13 MPa,but ammonia carbonation has no affect when pressure is above 0.13 MPa. If ammonia mole fraction is less than 0.04,bicarbonate mole fraction in products will be close to 1. When ammonia mole fraction is 0.1—0.15 or ratio of reaction ammonia to carbon oxide 2.2—2.8,carbonate is the major product of carbonation.If ammonia mole fraction is above 0.15,effect of ammonia concentration on ammonia carbonization is little.When ratio of reaction ammonia to carbon oxide is higher than 2.8,There will be more than 90% of ammonium bicarbonate in solution.On the basis above,control conditions of temperature-ammonia concentration,temperature-ratio of reactive ammonia to carbon dioxide were pointed out for preparing high contents of ammonium bicarbonate or ammonium carbonate.

The systhesis of 1,1,1,3,5,5,5-heptamethyltrisiloxane(MD^HM)from hexamethydi-siloxane(MM)and highly hydrogen-containing polyhydrosiloxane(D^H)was optimized after applying response surface methodology(RSM)in the presence of strong acidic cation ion exchange resin as catalyst.Based on the single-factor testing results,RSM measurements were performed with respect to mass concentration of MD^HM by regression analysis.The optimal conditions at which the highest yield of MD^HM(40.62%)was obtained,were in agreement with predicted value(41.23%).The reaction mass ratio of m(D^H):m(MM)=1:13.45,the amount of solid acid catalyst was 7.09%,and reaction temperature and time were 62.5℃ and 10 h,respectively.Furthermore,the research on polymerization kinetics at different temperatures was performed and the results showed that the optimal temperature and time were right.

It is a potential technology to separate CO₂ at a low temperature(40—80℃)by using amine functionalized porous material.For the application of this technology,it is crucial to realize continuous CO₂ separation using dual-fluidized bed reactors.In this work,a dual fluidized bed reactors system based on supported amine sorbent was built to simulate continuous CO₂ capture from flue gas.The supported amine sorbent was prepared by impregnating polyethylenimine(PEI)with molecular weight of 600 on porous silica gel Q-10.The experimental results indicated that the supported amine sorbent successfully circulated between the absorber and the regenerator and the long-term and continuous separation efficiency reached up to 84.4% without steam.And separation efficiency was improved about 97% with 1.0%(vol) steam introduced.

Six sorts of [C_3—8mim]Br/FeCl₃ ionic liquids were synthesized,and characterized with FT-IR and Raman spectroscopy.The extraction performance of ionic liquids during the removal of dibenzothiophene(DBT)was investigated.The extraction of DBT with [C₃mim]Br/FeCl₃ was the best. An increase of volume ratio of ionic liquid to oil and a higher temperature benefited the desulfurization performance.The removal ratio of DBT was up to 92% in 12 min and with volume ratio of ionic liquid to oil 1:1.Reacted ionic liquid without treatment was used again for 5 times,and the removal ratio of DBT decreased gradually to 60%.

Water-sparged aerocyclone(WSA)is a new type of gas-liquid mass transfer equipment with high efficiency,the mass transfer mechanism in WSA was investigated in this paper.The interfacial area(a)was determined by the chemical reaction method with CO₂-NaOH solution system,and the liquid mass transfer coefficient(k_L)was measured by the physical absorption method with CO₂-H₂O system.The a,k_L and k_La increase with gas inlet velocity(u_g)and liquid jet velocity(u_L)because of the gas-liquid intense interaction in WSA.The empirical formulae were developed for a,k_L and k_La,i.e, a=0.0024Re_g^1.25We_L^0.079,Sh_L=35.31Re_g^0.2303We_L^0.13,k_La=6.52×10^-8Re_g^1.48We_L^0.21,which fit the experimental data well and could be well used to predict the mass transfer characteristics in WSA.The mass transfer models of Whitman' double film theory,Higbie' penetration theory and Danckwerts' surface renewal theory can be well used to interpret the mass transfer mechanism of gas-liquid jet-aerocyclone system in WSA,and the surface renewal theory is the primary mass transfer mechanism.

By mixing nano-particles of Al₂O₃ and TiO₂ into the casting solution,the nano-modified PVDF flat ultrafiltration membranes with different nano-particle aggregates and proportions were prepared by means of the immerged gel phase inversion process.The effects of different nano-particle aggregates and proportions on membrane performance were discussed.The modification membranes were investigated with SEM and XRD.These modified membranes were used to dispose of the typical oily sewage from coastal oil depot.The hydrophilicity of membrane and its anti-fouling property were improved significantly.The toughness and strength of the membrane were improved effectively which tensile rupture elongation of membrane showed a maximum increase of 6.75% and tensile strength a maximum increase of 43.3%.The suitable total content of nanometer particles was 3% and the best proportion of two nanometer particles was 1:2.Optimized modified membrane showed good treatment for oily wastewater from coastal oil depot.The content of suspended solids in the effluent was less than 0.4 mg·L^-1,the content of petroleum hydrocarbon was less than 0.5 mg·L^-1,COD was between 60—70 mg·L^-1,complying with discharge standard.

Multi-objective optimization of wastewater treatment process was studied.According to a nonlinear dynamic model of wastewater treatment process,a multi-objective optimization model was established.The economic cost and integral square error between actual and desired outputs were optimized simultaneously to perform a wastewater treatment plant.The original multi-objective nonlinear problem describing the process optimization of a wastewater treatment plant was first transformed into a multi-objective linear programming by using the indirect optimization method(IOM).A powerful multi-objective optimization genetic algorithm was used to derive the Pareto optimal solutions,which could illustrate the whole trade-off relationships between objectives.The approach proposed not only obtained the approximate Pareto fronts of multi-objective optimization problem,but also had a low computational burden due to the use of multi-objective linear programming method.

A method of combining back propagation neural network (BP neural network)and genetic algorithm was proposed to optimize the process parameters and eliminate the voids in crankshaft.Mold temperature,melt temperature,packing pressure and gate size were taken as design variables and sink marks were taken as optimization goal.Computer aided engineering(CAE)simulation was performed based on the Taguchi method.A BP neural network model was developed to obtain the mathematical relationship between optimization goal and design variables,and genetic algorithm was used to optimize the process parameters.The optimal process parameters were mold temperature 80℃,melt temperature 210℃,packing pressure 110 MPa,gate size 1mm.Finally,the voids in the crankshaft could be eliminated by using the optimized process parameters in actual factory production.

The electrochemical reduction behavior of nitrobenzene on platinum electrode was studied with cyclic voltammetry(CV),chronoamperometry(CA),constant-potential electrolysis and in-situ Fourier transform infrared spectroscopy(in-situ FTIRS)in ionic liquid(N-butylpyridinium tetrafluoroborate,BPyBF₄)aqueous solution.The optimum water concentration(15 mol·L^-1)was determined through analyzing the peak current and peak potential of cyclic voltammetry in different ionic liquid solutions. Constant potential electrolysis was performed in a small beaker of 10 ml at the optimum water concentration using platinum foil,graphite and platinum wire as cathode electrode,anode electrode and reference electrode,respectively.Electrolysis products were extracted with ether and determined subsequently by GC-MS and GC.In-situ FTIR spectroscopic experiments were performed on Nicolet 670 FTIR spectrometer equipped with an MCT-A detector cooled with liquid nitrogen.Working electrode was Pt electrode with its surface pressed against the CaF₂ disk window to form a thin layer for IR measurements. Auxiliary electrode was Pt foil and reference electrode was saturated calomel electrode.The reference spectrum was acquired at 0 mV and sample spectra were collected on Pt cathode polarized from -100 mV to -1600 mV at a constant modulation potential(E=-100 mV).The experiment results showed that electrochemical reduction process of nitrobenzene was controlled by diffusion, the main reduction product was azobenzene and the selectivity was about 80%.The diffusion coefficient of nitrobenzene in BPyBF₄-H₂O was 3.1×10^-7 cm²·s^-1,and a suitable temperature and proper amount of water were favorable for the reduction of nitrobenzene.

The structural investigation model was presented based on the circle theory so as to study the influence of different constructions,sizes and positions of secondary sealing ring on torsion deformation of the typical mechanical seal ring.High pressure mechanical seal design theories and methods were discussed. The results showed that the method of analytical calculation instead of the finite element method was feasible and effective.The step on the complex section of sealing ring could be directly ignored when the step size of length or width was smaller than 4 mm.Different constructions and placements of the secondary sealing ring were important factors affecting torsion deformation of mechanical seal ring.A small variation of ring size would not affect torsional deformation.The design theory and method of high pressure mechanical seal were improved.

The Jakobsson-Floberg-Olsson(JFO)cavitation boundary condition was used to solve the problem that traditional Reynolds cavitation boundary condition can not accurately predict the mechanical seal leakage rate.The mathematical model of LaserFace liquid lubricated mechanical seal(LF-MS)was established based on mass conservation.Lubrication equation was solved by the streamline upwind finite element method.The comparison of sealing performance among four types of a LF-MS,a general face seal,a general face seal with "entry flow" structures,a general face seal with "return flow" structures was performed under different operating conditions.The mathematical model could accurately predict the mechanical seal leakage rate.LF-MS end face was easy to open at a low speed,Return grooves had obvious return pumping action at a high speed and low pressure.The leakage rate of LF-MS was significantly lower than a general face seal with "entry flow" structures.The friction coefficient of LF-MS was smaller than that of the general end face.The overall performance was significantly better than the others.

By referring to the measurement principle of individual anode current through obtaining the magnetic field near the anode,a new non-contact measurement of individual anode currents based on the principle of electromagnetic field,was developed.The error distribution of the anode current on various current risers in aluminum reduction cell was analyzed and the measurement method was optimized to realize anode current real time monitoring and on-line control.The relative errors of anode current in 300 kA cell were within ±0.25%,but the relative errors of anode current in 400 kA and 200 kA cells were ±0.8% and ±3% respectively.Current risers had an influence on the relative errors of anode current,but the maximal error was within 3%.Therefore,the non-contact measurement was applicable to online monitoring of individual anode current with different current risers and structures in aluminum reduction cell.

Based on the online monitoring experimental rig of water treatment technology for fouling prevention and corrosion inhibition,the effect of electromagnetic field on CaCO₃ fouling behavior was studied.The crystallization of CaCO₃ was studied by monitoring the change of fouling resistance.The crystal form and crystal appearance of calcium carbonate fouling were qualitatively and quantitatively analyzed by Quanta 200 SEM and X'Pert Pro XRD to describe the effect of electromagnetic field on calcium carbonate fouling.Electromagnetic field could reduce the rate of scaling on the surface of heat exchanger. The mass fraction of the calcite of scale sample decreased from 100% to 40.55%,and the mass fraction of aragonite increased to 59.45%.

To improve the corrosion resistance of magnesium alloys,corrosion inhibition of sodium benzoate(SB)for AM60 magnesium alloy in 3.5%NaCl solution and influence of temperature on inhibition efficiency were investigated with electrochemical impedance spectroscopy(EIS),polarization curves and immersion.Surface morphology of magnesium alloy after corroding with different concentrations of SB at different temperatures was observed with scanning electron microscope(SEM),and corrosion inhibition mechanism of SB was analyzed.SB reduced obviously the corrosion rate of AM60 magnesium alloy in 3.5% NaCl solution,and inhibition efficiency was more than 75% at 0.5 mol·L^-1 SB.Physical adsorption of SB occurred on AM60 magnesium alloy,and it belonged to an exothermic,entropy increase and spontaneous process.A multi-molecular adsorption layer was formed on the magnesium alloy surface to prevent the magnesium alloy from contacting corrosive solution.The activation energy for the corrosive reaction increased with increasing SB concentration,resulting in increasing inhibition efficiency.When SB concentration was up to 0.7 mol·L^-1,inhibition efficiency did not increase,because intermolecular repulsion dominated with increasing SB concentrations.Moreover,inhibition efficiency did not increase when temperature changed from 25℃ to 70℃.

Process oscillation is the main challenge in continuous very high gravity(VHG)ethanol fermentation,which could result in oscillation and decrease of ethanol concentration.In the present study,during continuous VHG ethanol fermentation by free cell Saccharomyces cerevisiae 4126 and self-flocculating yeast BHL01,sustained process oscillations of biomass,residual glucose,ethanol and glycerol,were observed with a period of 130—145 h.Furthermore,in the self-flocculating yeast system,ethanol concentration and productivity were higher than those in the free yeast system.VHG oscillation was significantly attenuated and then a quasi-steady state was developed instead,when gas stripping with fermentative off-gas was used to separate ethanol during continuous VHG ethanol fermentation by self- flocculating yeast.Finally,the residual glucose kept below 0.1 g·L^-1,and ethanol concentration and productivity were 110.87 g·L^-1 and 2.99 g·L^-1·h^-1,respectively.The present study provides a new strategy for the attenuation of oscillation in continuous VHG ethanol fermentation.

To investigate the mechanism of triphenyltin(TPhT)biodegradation through proteomic and ions release,the biodegradation of TPhT with concentration from 0.1 to 10 mg·L^-1 by Klebsiella pneumoniae,and the physiological responses and proteomic changes of K.pneumoniae to TPhT exposure in mineral salts medium(MSM)and deionized distilled water(DDW)were studied.Experimental results showed that K.pneumonia could effectively degrade TPhT to diphenyltin(DPhT),monophenyltin(MPhT)and tin(Sn),and increase TPhT removal rate from 46.7% to 73.6% and from 25.1% to 87.0% in MSM and DDW,respectively.In this process,TPhT activated membrane permeability and triggered cell membrane damage,which increased the release of intracellular ions and caused part of cell death. Moreover,the exposure of K.pneumonia to TPhT induced differential expression of some proteins that were responsible for proteolysis,metabolic processes,protein translocation,energy conversion,TPhT stress tolerance,and TPhT elimination.

Antibiotic mycelial dregs,existing as biomass supra-colloids,are not only a kind of serious hazardous pollutants but also a kind of biomass resource.Their treatment and utilization,however,are greatly hindered because of their high water content and poor mechanical dewatering property.The results shows that hydrothermal treatment of the dregs remarkably improved their sedimentation,dewatering and drying properties.The solid content and heating value of solid bio-fuel obtained greatly increase with going up temperatures and extending hydrothermal treatment,but it was found that tar and even carbonization of the material took place at too high temperatures.The optimized conditions gained are at 200℃ for 30—60 min,and solid bio-fuels produced had solid contents of 52%—55%(mass) and heat values of about 14 MJ·kg^-1.The solid recovery ratios fell in 65%—75%,and over 45% nitrogen in raw antibiotic mycelial dreg was removed via converting a part of non-Kjeldahl organic nitrogen(NKON)into Kjeldahl organic nitrogen(KON).As the form of ammonia nitrogen(NH₄⁺-N),most of removed nitrogen was dissolved in liquid product after hydrothermal treatment.The CODs of the liquid products were above 200000 mg·L^-1,which can be good feedstock for bio-gas production.These results demonstrate actually that hydrothermal treatment would be an effective way to safely dispose and pretreat process residues from bio-pharmaceuticals industries like antibiotic mycelial dregs.

Capturing CO₂ from coal-fired power plants using monoethanolamine(MEA)solution is a relatively mature and feasible technology at present.However,high energy requirement is its main drawback.The energy requirement can be reduced by modification of process and optimization.A rate-based model in Aspen Plus simulator is used to simulate the conventional flow path and its modification.The process modifications include absorber intercooling,rich split,lean vapor compression,split flow and the combination of rich split and lean vapor compression.The results show that combination of rich split and lean vapor compression as well as the rich split are the first and the second best process improvement,save of regeneration energy and decrease of equivalent work are 28.2% and 19.3% as well as 11.9% and 11.8%,respectively.For lean vapor compression,save of regeneration energy can be up to 14.1%,while the decrease of equivalent work is only 4.1%.The absorber intercooling and split flow is relatively limited for energy saving.

The hydraulic characteristics of integrated cage denitrification bioreactor were investigated using pulse-stimulus response technique.The flow pattern of the bioreactor tended to be complete mixed flow with hydraulic retention time 4 h,superficial velocity 0.145 m·h^-1,hydraulic load rate 6.0 m³·m^-3·d^-1.When it was simulated with tanks-in-series(TIS)model,N number was 1.55,1.56,1.54 and 1.55 at air flow rate 1.714,3.214,6.429,8.571 m³·m^-3·h^-1 respectively.When it was simulated by axial dispersion(AD)model,the corresponding Peclet numbers were 1.479,1.503,1.466 and 1.478 at air flow rate 1.714,3.214,6.429,8.571 m³·m^-3·h^-1respectively.The prediction of TIS model and AD model matched with each other.The mean value of total dead space of the bioreactor was 41.63%,and the hydraulic dead space was 21.99%.However,air flow rate had little effect on the hydraulic behavior of the bioreactor in this investigation.

In order to enhance the enzymatic hydrolysis effectiveness of sweet sorghum bagasse(SSB)pretreated by liquid hot water(LHW),the effects of anions,cations and Tween 80 on hydrolysis activity of enzyme and acting mechanism of Tween 80 were investigated.The tests of hydrolysis activity showed that Br^-,I^-,NO₃^-,Ca²⁺,Mg²⁺ and Co²⁺ could activate cellulase,but had little improvement on enzymatic hydrolysis of SSB.0.175 ml·(g dry material)^-1 of Tween 80 could make enzymatic hydrolytic efficiency of SSB increase from 16.6% to 37.9%,but higher concentration of Tween 80 would inhibit the enzyme activity,and thus hinder the enzymatic hydrolyzing process.Adsorption experiments showed that there was limit adsorption of Tween 80 and cellulase on SSB.Tween 80 could obviously reduce the adsorption of cellulase on SSB.By FTIR measurement,it showed that the adsorption of Tween 80 was stronger on lignin than on cellulase.

Mesophilic anaerobic digestion(AD)on the feedstocks of household kitchen waste(HKW)and restaurant food waste(RFW)was performed.Five kinds of dewaterability indicators-total solids(TS),total solids after centrifugation(CTS),normalized capillary suction time(NCST),specific resistance to filtration(SRF)and bound water content(BW)were used to evaluate the dewaterability of digestate produced from different stages of AD.TS of digestate ranged from 3.0% to 9.9%,CTS ranged from 10.9% to 31.0%,SRF was 2.1×10¹³—13.8×10¹³ m·kg^-1,BW was 2.3—15.1 g·(g TS)^-1 and NCST was 50.8—163.7 s·L·(g TS)^-1.The cumulative methane yield of the digester fed with RFW was always higher than the digester fed with HKW,maximum cumulative methane yield of the former was up to 381 ml·(g VS_added)^-1,while that of the latter was just 280 ml·(g VS_added)^-1.The dewatering performance of digestate was mainly affected by duration of anaerobic digestion and the digestate produced from RFW was able to achieve a higher dewatering degree,while the dewatering rate of the digestate from HKW was higher.Furthermore,there were significant correlations among TS,normalized CST,SRF and BW of digestate,but the correlation with CST was not significant.

The interaction of ferrous ions and phosphorous was studied under aerobic conditions in order to assess effectiveness and feasibility of phosphorous removal.Using Fe(Ⅱ)/O₂ and conventional technologies the removal effectiveness of phosphorous in a real electronic waste water and relative economic indicators was compared.For Fe(Ⅱ)/O₂ system the effect of co-existing cations in simulating natural liquid on efficiency of phosphorous removal was examined using variables analysis.The results show that there was no effect of NH₄⁺-N on phosphorous removal by Fe(Ⅱ)/O₂ oxidation.Precipitation could occur between Zn(Ⅱ) and phosphorous in the system,which could promote removal of phosphorous and decrease of ferrous iron consumption.Mn(Ⅱ)as well as OH^- could form complexes with Fe(Ⅲ)generated newly,the complexes are capable of hastening ferrous iron oxidation and also of improving the coagulation of Fe-P sedimentation.As the inventory of Mn(Ⅱ)increased from 0 to 1 mg·L^-1,the removal rate of phosphorous raised 11% after 60 min reaction.Cu(Ⅱ)could remarkably increase the efficiency of phosphorous removal by its catalytic effect.As Cu(Ⅱ)concentration increased from 0 to 0.05 mg·L^-1,the reaction time required 45% phosphotous removal could be reduced from 60 min to 5 min.For a real electronic wastewater the phosphorous removal was better for Fe(Ⅱ)/O₂ system in the presence of the above mentioned cations than for lime alone,while sludge production and economic cost was lower for the former than for the latter.

By combining the detailed reaction mechanism proposed by Richter et al. for hydrocarbon combustion and the removal methods of tar oil from biomass gasification by partial oxidation,a detailed reaction mechanism was put forward for partial oxidation of biomass tar.A comparison with the experiment results obtained by Jess confirmed the model's rationality and accuracy.Phenol that was chosen as a model component for biomass tar was converted i.e.partial combustion at condition of ER=0—0.2.The results show that oxygen can promote conversion of tar oil and its reaction rate,and proper oxygen content leads to higher production of combustible gases.Based on typical PAHs production rates obtained by ROP analysis it is found that cyclopentadiene plays an important role in the formation and growing of PAHs and active radicals such as H and OH promote tar cracking.

A stacking microbial fuel cell in series with serpentine flow field(MFCS-S)was constructed by using four started-up single microbial fuel cells.The performance of the MFCS-S was tested and several possible measures of improving MFCS-S performance were investigated.The experimental results showed that a maximal power density of 2226 mW·m^-2 was observed at a high voltage of 2.11 V.A cell with low performance in MFCS-S would present a reversed voltage at a certain current density and then result in a low stack cell,which was the main limitation of further improving MFCS-S performance.Although large improvement is impossible for the voltage reverse,an increase in the flow rate of the anolyte and catholyte in MFC-R can result in a significant improvement for power output of MFCS-S.By using a hybrid connection,the voltage reverse would be avoided,resulting in a largely increased stack performance. However,the voltage reverse cannot be improved by removing the MFC-R and even got worse after switching it into reverse in the series circuit.

Using domestic sewage with low C/N as treatment objective,the performance of modified A²/O process for denitrification and phosphorus removal was investigated.In order to suitable allocation of carbon sources required by anaerobic phosphorus release and anoxic denitrification,raw water was distributed into anaerobic tank and anoxic tank according to different proportion.To stabilize nitrification and denitrification processes and improve their efficiency some packing was filled in aerobic and anoxic tanks whose effluent flowed into aerobic tank to reduce the sludge flow path.Under the optimal conditions:average influent COD/TN ratio 5.54,HRT 11 h,SRT 15 d,MLSS 3000—4000 mg·L^-1,sludge reflux ratio 50%,the effect of inflow distribution ratio and internal reflux ratio on denitrification and phosphorus removal was investigated.The results showed that the optimal inflow distribution ratio was 5:5,at which iallocation of carbon source was reasonable for denitrification and phosphorous removal.And the optimal reflux ratio was 200%,if it is too high DO environment in anaerobic tank could be damaged and if it is too low the efficiency of denitrification in anoxic tank could not be full played.Under these optimal operating conditions,COD,NH₃-N,TN and TP in effluent were 29.7 mg·L^-1,0.1 mg·L^-1,11.8 mg·L^-1 and 0.42 mg·L^-1 respectively,the average removal efficiency reached 87.8%,99.7%,72.4% and 91.3% respectively.The effluent could be better than the first level A of the discharging standard of pollutants for municipal wastewater treatment plant(WWTP)(GB 18918—2002).At the same time,in anoxic tank noteworthy denitrification and phosphorus removal were observed.

Microwave radiation was used to break cell wall of penicillium fermentation residue.By measuring the changes of protein and polysaccharide content in the supernatant after centrifugation,the effect of different loading time,loading power and initial moisture content of the residue on wall breaking and dewatering performance was investigated.Orthogonal experiment was used to confirm the best loading condition.The results showed that microwave radiation could obviously break the cell wall and improve dewatering performance of the residue.For the penicillium residue with a moisture content of 90%,after radiation of 414 W for 120 s,the content of protein and polysaccharide increased from 110.25 μg·ml^-1 and 28.20 μg·ml^-1 to 265.76 μg·ml^-1 and 93.52 μg·ml^-1 respectively,and moisture decreased from 83.75% to 75.26%.The best loading condition by orthogonal experiment was that penicillium residue with an initial moisture of 90% could reach the best wall-breaking effect after radiation of 414 W for 120 s.

Radiation crosslinked product of bromobutyl rubber(BIIR)was achieved by electron beam(EB)irradiation curing.Gelling dose of BIIR was estimated to be 12 kGy.Various polyvinyl monomers were tested to enhance EB crosslinking of BIIR in order to obtain a high crosslinking degree at a low dose to avoid main chain degradation under high dose irradiation.It was found that TMPT(trimethylolpropane trimethacrylate)was the most effective crosslinking sensitizer to increase the crosslinking density of BIIR.The tensile strength of EB crosslinked BIIR was significantly improved by using TMPT as the sensitizer.

Polypropylene/halloysite nanotubes(PP/HNTs)nanocomposites with 33 phr HNTs were prepared by melt mixing using a co-rotating twin-screw extruder.PP/HNTs nanocomposite samples were taken from three positions along the extruder and from the die exit.Microstructure,rheological properties,and thermal stability of the nanocomposite samples were analyzed.The results showed that the sizes of aggregates of the HNTs rapidly decreased and the HNTs were dispersed more and more uniformly in the PP matrix due to the dispersive and distributive mixing provided by the screw configuration arranged in this work.As a result,the storage modulus and relaxation time at low frequency for the nanocomposite samples taken from three positions along the extruder increased gradually,whereas their terminal slopes decreased gradually.The thermal stability of the PP/HNTs nanocomposite sample taken from die inlet was better than that taken from die exit due to higher effectiveness of the entrapment of decomposition products into the nanotube lumens of more unoriented HNTs in the former sample.

With paraffin as phase change material(PCM) and expanded graphite with network structure as matrix,a composite phase change material was prepared through physical adsorption,and was compressed to a shape-stabilized cylinder block by the compacting tool set.The prepared composite phase change material was characterized with differential scanning calorimeter(DSC),scanning electron microscope(SEM),polarizing optical microscope(POM)and Hot Disk thermal analyzer.In addition,an experimental system was set up to measure its thermal cycling performance.The results showed that melting temperature of the shape-stabilized phase change material with 80% mass fraction of paraffin was 27.27℃ and its phase transition enthalpy was 156.6 kJ·kg^-1.The prepared shape-stabilized phase change material had many advantages over pure paraffin,such as a form-stable phase change process,higher thermal conductivity and heat storage capacity,excellent thermal stability and a longer service life.

The adsorption thermodynamics and kinetics of three dispersants(Morwet D-425,GYD-1252 and LG-3)onto pesticide imidacloprid particle surface were studied in order to compare adsorption properties.Adsorption data of three dispersants onto imidacloprid were fitted with Langmuir and Freundlich isotherm equations,and the former fitted better.The thermodynamic parameters:ΔH<0,ΔG<0,ΔS>0,indicated that the adsorption was a spontaneous exothermic process.Theoretically,higher temperature was not beneficial to adsorption process,|ΔH|<40 kJ·mol^-1 indicated that the adsorption process was physical adsorption.The conclusion obtained by comparing adsorption properties showed that Morwet D-425 had higher adsorption stability and was not susceptible to temperature effects,LG-3 had lower adsorption stability and was susceptible to temperature effects,adsorption stability of GYD-1252 was in between.The adsorption process followed the pseudo-second-order with a good correlation coefficient.The step of adsorption process included the external diffusion and adsorption onto particle surface,without intraparticle diffusion.Descending order of adsorption rate was Morwet D-425,GYD-1252 and LG-3.The result of adsorption layer thickness by XPS showed that Morwet D-425 had smaller adsorbed layer thickness which changed little with increasing temperature due to higher adsorption stability. GYD-1252 and LG-3 had larger adsorbed layer thickness which decreased significantly with increasing temperature due to weak adsorption stability.

Novel allyl-containing phenolphthalein benzoxazine(PT-ala resin)was synthesized from phenolphthalein,allylamine and paraformaldehyde.The chemical structure of PT-ala resin was characterized by FT-IR,¹H NMR,and the curing behavior of PT-ala resin was studied by DSC.TG and DTG were used to study the thermal degradation kinetics of PT-ala resin in N₂.The kinetic parameters were calculated by the methods of Kissinger and Ozawa,and the apparent degradation reaction order of PPT-ala was 1 in N₂,thermal degradation activation energies were 189.65 kJ·mol^-1 and 215.11 kJ·mol^-1 respectively.The temperature of 60 s lifetime was 285℃ in N₂.

NBRCNs was prepared by mixing nitrile butadiene rubber with protonated octadecyl amine modified clay to further expand the layer space and weaken the layer-layer interaction.Attributed to greatly improved dispersion uniformity of silicate layers,the prepared nanocomposites by protonated octadecyl amine modified clay demonstrated superior properties to those of nanocomposites prepared by the traditional long chain aliphatic quaternary amine modified clay.Compared with NBR/C₁₆-OC and NBR/S₁₈-OC nanocomposites,NBRCNs with 10phr loading of protonated octadecyl amine modified clay exhibited about 61.04% and 80.28% increase in tensile strength,51.79% and 49.57% increase in tear strength,30%/26.21% and 31.09%/34.72% increase in 100%/300% stress,and 7.27% and 11.32% increase in Shore A hardness.

Heterogeneous Z-N catalysts were prepared by loading TiCl₄ on a mixture of modified nanoclays and functionalized carbon nanotubes as effective composite nanofillers in magnesium chloride.The polyethylene nanocomposites were produced via in-situ polymerization.The properties of nanocomposites were studied by controlling the content of montmorillonite(MMT),multi-walled carbon nanotubes(MWCNTs)in MgCl₂.Highly active polymerization catalyst with the nanofillers containing MMT,modified MWCNTs and MgCl₂ could be obtained.Mechanical properties of polyethylene containing composite nanofillers were better than those of polyethylene resin containing only one kind of nanofiller.WAXD analysis of the composites indicated that composite nanofillers of low content were uniformly dispersed in PE matrix and played an effective enhancement effect.

Based on high-speed synchronous acquisition of flame dynamic propagation and overpressure signal,an experimental study on the coupled relationship between flame shape and overpressure of gas explosion under different conditions was performed.The experimental results showed that if there was no obstruction,flame front was always relatively smooth and its shape gradually developed into a finger-like shape from initial hemisphere appearance,generating a peak overpressure of 3.9 kPa.If there were central continuous obstacles,flame front changed into a tongue-like shape,and finally into wave-like shape,resulting in a peak overpressure of 12.5 kPa.With continuous obstacles on both left and right walls,flame front gave rise to a mushroom-like shape and at last to Christmas tree shape,producing a peak overpressure of 11.4 kPa.Once flame shape was folded or curled,flame surface area increased and then the burned and unburned gas mixtures were blended rapidly,so that combustion reaction rate and overpressure increased.Furthermore,a theoretical analysis clarified the interaction between flame shapes with transient overpressure.