Supercritical fluid assisted atomization (SAA) is a promising process in producing micronic particles of controlled diameter that uses supercritical fluids to assist atomization processes.This technique allows drug micronization by using water as liquid solvent,but can work by using organic solvents too.Very sharp particle size distribution (PSD) can be obtained, that lies in the particle size range of aerosolizable drugs.The characteristics and schematic representation of the SAA process were described in detail.Results on six kinds of pharmaceutical compounds were illustrated,including particle size (PS), PSD and morphology while varying process parameters in the process respectively.No chemical modifications occurred during the SAA process.The process was developed on the pilot scale, showing great potential in pharmaceutical industry. SAA and several supercritical fluids based techniques (RESS, SAS, PGSS) for the production of micronic and nanometric particles of pharmaceutical compounds were compared. Finally the necessity to emphasize fundamental research was prospected and the mechanism and process nature in SAA were analyzed.

In this paper,a non-equilibrium stage method,the differential unit method，which is suitable for the multi-stage separation technology of hydrate, is proposed to aim at separating hydrogen from H₂+CH₄ gas mixtures and using tetrahydrofuran as the promoter.The differential unit method is that a whole reactor is divided into a number of units whose number may converge at infinity; that is to say, every differential unit is regarded as an instantaneous reactor the moment its number converges at infinity.This method makes sure that the simulation is close to reality.A wetted column serves as the example to calculate the gas-solid composition as well as their load with the differential unit method.The effects of multi-stage separation are compared at different temperatures, pressures and flow rates.The lower the temperature is, the more highly hydrogen is purified, and the higher the pressure is, the more highly hydrogen is purified.

Molecular electronegativity distance vector (MEDV), based on the two-dimensional topological structure, consists of 10 parameters which express the interaction between four types of atoms. By introducing the concepts of atomic type and atomic attribute, MEDV is applicable to various molecular structures which contain the multiple bonds and heteroatoms. For six physical properties-boiling point (BP), water solubility ［lg (1/S)］, octanol/water partition coefficient (lgP), molecular total surface area (TSA), molecular volumes (MV) and molecular refractions (MR), the multiple linear regression using the MEDV can provide high-quality QSPR models. The correlation coefficients R are 0.9972,0.9925, 0.9975, 0.9998, 0.9997 and 0.9999,respectively.The standard deviations S are 3.2660, 0.1373, 0.1237, 0.0184, 1.0354 and 0.2084, respectively.To validate the prediction capabilities of these QSPR models for the external prediction set, the leave-one-out (LOO) cross-validation (CV) technique is applied. The corresponding correlation coefficient R²_CVfor the lg(1/S) is 0.9714, and the other R²_CV are all larger than 0.99.The results show that MEDV is an excellent topological index with high property correlation and good structural selectivity.

Nitrogen oxides emission from a series of turbulent methane jet non-premixed flames with different Reynolds number was numerically simulated, in order to investigate the influence of turbulence on the formation of nitrogen oxides.A two-scale k-ε turbulence model was adopted to calculate turbulent velocity field, and the probability density function (PDF) method was combined with the Lagrangian flamelet model to predict the turbulent scalar fields.Detailed chemical reaction mechanism GRI-Mech 3.0 was incorporated to describe methane oxidation and nitrogen oxides formation.The comparisons between nitrogen oxides predictions and measurements were made,and the influence of Reynolds number, scalar dissipation and flamelet time on the formation of nitrogen oxides was discussed. The numerical results were in good agreement with the measurements, and the trend that nitrogen oxides emission decreased with the increase of Reynolds number in the experiment was reasonably represented by the present numerical models.

Discussions were made on the fairness issue in experimentally assessing the cycle performances of various working fluids for refrigeration, air-conditioning, and heat pump systems with an experimental apparatus of a constant-speed compressor and fixed area heat exchangers.The additional temperature difference(Δt_plus),the partial heat transfer temperature difference，was identified to compare the working fluids at the same heat load to corrected area ratios in the evaporator and condenser respectively,and the equations for calculating Δt_plus and the thermodynamic perfection of the cycle (ε) were given.By adopting Δt_plus and ε,two modified experimentally assessing approaches were developed with much improved fairness and easy steps to operate.

The gas-liquid mass transfer characteristics of three-phase system consisting of air,water/paraffin and sand/quartz sand/catalyst XNC98 was studied in a mechanically agitated reactor. At atmospheric pressure, the influences of operational factors and physical property parameters such as liquid property, particle size, particle density on volumetric liquid-phase mass transfer coefficient k_La were investigated under the conditions of superficial gas velocity range from 0.10×10^-2cm•s^-1 to 1.5×10^-2 cm•s^-1, solid concentration from 0 to 0.34 g•ml^-1（solvent）, impeller speed from 450 r•min^-1 to 1500 r•min^-1.k_La was determined by a dissolved oxygen electrode.A dimensionless correlation of k_La with the above factors was proposed and the parameters in the correlation equation were obtained with the improved Gauss-Newton method. The statistical test showed that the values predicted by the correlation equation were in good agreement with the experimental data.The results would provide basic experimental data for the subsequent process analysis and mathematical simulation of the three-phase methanol synthesis in agitated slurry reactor.

An experimental study was performed to observe bubble behaviors and heat transfer mechanism of pool boiling of refrigerant R-113 at pressure 0.1 MPa.A transparent heater was used to observe bubble behavior on the entire heater surface with a high-speed camera placed beneath the heater surface.The departure diameter, departure time of bubbles and nucleation density at different heat fluxes were obtained. As a bubble grew up, the dryout area of microlayer under the bubble could be observed.It was also observed that there was no liquid recruit into the microlayer in the experiment.Even at a very high heat flux, vapor stem could not be observed, and the periodic generation and growth of primary vapor bubble is dominant. The relationship between nucleation density and heat flux was given.Based on the experimental results, boiling curve for R-113 was predicted by using the dynamic microlayer model.As a result, the agreement between the predictive result based on the dynamic microlayer model and the experiment data for boiling curve of R-113 is excellent.

In a gravity field, the changes of fluid density cause natural convection, while in a magnetic field, the apparent density of magnetic fluid changes markedly with the change of the intensity of external magnetic field.Therefore,magnetic field can influence the natural convection of the magnetic fluid.Through static calculation and analysis,a synthesized magnetic field can be established resulting from the coaxial superposition of a uniform magnetic field and a uniform gradient magnetic field.The change of the density of magnetic fluid caused by the synthesized magnetic field is equal everywhere in the fluid, and natural convection heat transfer is also equal everywhere.Thus the apparent density and the coefficient of natural convection heat transfer can be accurately measured and a correlation equation can be established between magnetic field intensity,apparent density and the Grashof criterion of the magnetic fluid.Accordingly, the increase of magnetic field intensity causes an increase of apparent density of magnetic fluid, which is magnetic fluid in a state of overweight.That is the mechanism of natural convection heat transfer of magnetic fluid enhanced by magnetic field.

Experimental study was reported for flow boiling heat transfer of a nonazeotropic mixture of R32/R134a［25%(mass)/75%(mass)］inside both smooth and microfin tubes with internal spiral grooves.The influences of mass quality，heat flux & mass flow rate on A_f(heat transfer enhanced coefficient)are discussed, respectively.The experimental results show that the microfin tubes have distinct performance advantages over the smooth tube at similar conditions,the varying of heat flux has the greatest effect on A_f,and A_f varied from 1.4—2.2.

There are still limited experimental data of liquid diffusion coefficients in literature.Therefore, the experimental investigation and prediction model are of practical and theoretical significance.The diffusion coefficients of L-serine, L-threonine,L-arginine,in aqueous solution at 298.15 K were measured respectively by holographic interferometer.The affecting factors of molecular structure and polarity were analyzed and discussed.Finally, a modified semi-empirical model for correlating the diffusion coefficients of solid organic compounds in aqueous solutions at 298.15 K was proposed with an adjustable parameter added.The average deviation between model prediction values and experimental ones is less than 0.2%, which shows a considerably satisfactory accuracy.

Due to its high chemical stability,good thermal resistance, ideal conductivity and ion-selective permeability, Nafion membrane has been used in many electrochemical systems.The significant progress has been made in the applied research of Nafion membranes in fuel cell, membrane separation and organic electro-synthesis.For organic electro-synthesis,the studies on permeation of organic compounds through the membrane were seldom reported in literature.3-methylpyridine is the main raw material for electrochemical synthesis of niacin.In this work, the permeating fluxes of 3-methylpyridine were measured in the H₂SO₄ aqueous solution at different concentrations and temperatures.The results showed that the permeating flux was directly proportional to the molar concentration of 3-methylpyridine at a given temperature.The relationship between the natural logarithm of proportional coefficient and the reciprocal of temperature was linear.The Arrhenius equation for the relationship between permeating flux and temperature was obtained.The apparent activation energy and apparent pre-exponential factor were estimated as 63.3 kJ•mol^-1 and 2.69×108 m•h^-1.

Local holdups in gas-liquid-solid fluidized beds with small size glass beads(density of 2460 kg•m^-3)and styrene resin(density of 1264 kg•m^-3) were measured simultaneously by improved micro-conductivity probe technique with air and water as the gas and liquid under a wide range of operation conditions.It was found that for the fluidized system, the distribution of local solid holdup showed a maximum at r/R=0.75—0.85, the cross-sectional average gas holdup showed a minimum with the superficial liquid velocity.In a certain range of axial distance from the gas distributor, radial profiles of local holdups showed severe radial mal-distribution.Such radial mal-distribution of local gas holdup disappeared with increasing axial height,while the local solid holdup did not disappear apparently.

On the basis of heterogeneous reaction on the interfaces between the gas and liquid films formed on the solid surface in a plasma flue gas desulfurization dry reactor,a wet type of reactor should be considered more reasonable.Simulation of the process in a wet reactor for flue gas desulfurization by corona discharges was provided.Through deriving the dependence of the desulfurization rate of flue gas,energy yield,mole energy consumption upon parameters of injected energy density,mass transfer efficiency factor and pH value of the liquid absorbents,it was found that under the conditions of given energy injection of corona discharges mole energy consumption could be remarkably decreased when pH value was appropriately adjusted and the inner surface of the wet plasma reactor was appropriately porous.The results were in agreement with previous experiments.Energy consumption could be reduced to an acceptable value.

The hydrodynamic cavitation generated through an orifice plate is used to decompose aqueous solution of KI in this work.By measuring the concentration of the iodine liberated in reaction, it was found that the decomposition reactions of the aqueous solution of KI could be induced by hydrodynamic cavitation.The effects of hydrodynamic conditions, geometric characteristics of the orifice plate and the concentration of solution on the decomposition of the aqueous solution of KI were experimentally examined and theoretically analyzed.It was concluded that some chemical reactions could be induced or enhanced by hydrodynamic cavitation,and the intensity acting on chemical reaction by hydrodynamic cavitation was decided by the cavitation conditions, the amount of free radicals and the concentration of reactants. It is important to optimize the hydrodynamic cavitiation conditions for the enhancement of chemical reactions.

The characteristics of pressure fluctuation in a submerged circulative impinging stream reactor (SCISR) were experimentally studied.The instantaneous signals of pressure fluctuation resulting from the turbulence in the SCISR were measured by sensors and recorded by a computer.The pressure signals at some special positions were sampled at different rotary speeds of propeller.After analyzing the signals with the Power Spectrum method，it was found that there was an inherent frequency in the dynamic pressure signals.The inherent frequencies of the point on the impinging plane were greater than 1000 Hz，so the pressure fluctuation was called high-frequency fluctuation.The fluctuation velocities with high inherent frequency resulted in a strong shear force field，which enabled the fluid to mix quickly on the micro-scale and the agglomerates of solid particles to disperse effectively.

H₃PW₁₂O₄₀/SiO₂(PW/SiO₂) was prepared by the sol-gel method and trimethylolpropane tri-heptanoate(TMH ) was synthesized by trimethylolpropane(TMP) and heptylic acid(HA) in the presence of H₃PW₁₂O₄₀/SiO₂.The results showed that the catalyst with 50%（mass）PW had good activity and stability.The optimal esterification conditions were as follows:n_TMP∶n_HA=1∶4,2%(mass)PW/SiO₂,reaction temperature 120—200 ℃ and 3 h.The structure of TMH was characterized by GC,IR,¹HNMR spectra and the rate of esterification was up to 95%.

Theoretical analysis of crystal size distribution was made for size dependent or dispersed crystal growth under the assumption of perfect mixing and neglecting secondary processes such as agglomeration，breakage and ageing.Several relations between population density,crystallization time and crystal size for the batch solution crystallization process were obtained with the method of separating variables based on the population balance equation.These relations could be used to select the mechanism of crystal growth and calculate the linear crystal growth rate，predict the crystal size distribution and optimize the crystallization process，and regress the crystal size distribution.The results showed that this method could be used in solution crystallization process.

Production of anhydrous magnesium chloride by dehydration of bischofite is one of the best ways to utilize the magnesium resource of salt lakes. Formation of magnesium chloride hexammoniate (MgCl₂&#8226;6NH₃) is the critical step of the coupled reaction crystallization process， which is an attractive dehydration process. Primary nucleation of MgCl₂&#8226;6NH₃ by reaction crystallization process was performed in this research. The induction period of MgCl₂&#8226;6NH₃ primary nucleation was measured by the laser method, and classical theory of primary nucleation was used to quantify the nucleation process. When supersaturation ratio (S=C/C*)S>2,homogeneous nucleation occurred; when S<2,heterogeneous nucleation occurred.The relationships among critical free energy of nucleation,critical size of nucleus and supersaturation was obtained.Critical free energy and critical size of nucleus decreased with increasing supersaturation.

A rapid method for designing water-using network with multiple contaminants is developed.It first arranges all processes based on their maximum outlet concentration，that is, list the limiting outlet concentration of each contaminant for each process, and mark their serial number by N_i,s(irepresents the water-using process, and s the contaminant), calculate the product of serial number of every contaminant in each process and list those processes by the product.For each process on the list, a linear programming model in GAMS (general algebraic modeling system) language is used to determine the minimum freshwater flowrate and reuse wastewater flowrate from its precursor set. Delete the process from the list after its requirement is satisfied and add its wastewater data to the available wastewater set. Repeat the process until the last process on the list has been taken care of. The new method has been tested in two cases. The obtained solutions are at least as good as reported ones.In general, global optimality is not guaranteed by the new method, but it is simple and can be used to rapidly find an optimal or suboptimal solution.

It is well known that to measure and estimate the chemical process variables in time has vital significance in ensuring process stabilization and effectively controlling its product quality.In this study, a soft sensor model of a chemical process was established by partial least squares method based on its time series data, and the model could be adjusted in the block-wise recursive way in the presence of new sample data. With a view to the time series data characteristics,a strategy of allotting different weight coefficients to the time series data was introduced, and an approach of how to ascertain the weight coefficients was provided in the meantime.Subsequently, the weighted block-wise recursive partial least squares regression (WBRPLSR) algorithm was developed and used to model the water content of solvent dehydration tower bottom drainage in a commercial purified terephthalic acid (PTA)unit.The experimental result showed that the algorithm was rapid and effective.Compared with some other methods, the WBRPLSR method increased modeling efficiency and improved prediction performance.

In this paper, the simulation of external carbon addition was studied in the continuous flow anoxic/oxic(A/O) nitrogen removal process for domestic wastewater of low carbon∶nitrogen(C/N). It is difficult to develop a parametric model for the complex non-linear relationship among additional carbon dosage, total recycling rate and effluent total nitrogen concentration in a treatment system, which makes it hard to turn the control strategies into reality. Aiming at this problem, back-propagation neural network(BPNN) was introduced into the research.A non-parametric model was developed by the training of BPNN with the experimental data. The external carbon dosage could be optimized with the model based on neural network. It provided an alternative way to the realization of on-line optimal control of a wastewater treatment system.

The initial nickel deposition for the direct electroless nickel plating on non-catalytically active magnesium alloy is critical.The surface morphology and composition of the initial nickel plating coating are obtained by means of the scanning electron microscopy (SEM) and the energy dispersive X-ray (EDS).In addition, the mass gain/loss in the initial nickel deposition process was measured by using the electro-balance.The results showed that the MgO coating was gradually corroded by the plating solution, at the same time, MgF₂ produced by F^-,H⁺ and MgO was deposited on the substrate during the initial electroless plating process.The nickel of the initial electroless plating was mostly growing on the boundary between the MgF₂ coating and the MgO coating of the activation substrate, and then came to two sides.After that, the Ni-P coating growth rate to cover with the MgF₂ coating was prior to the MgO coating.The electroless plating was in company with the substrate corrosion,but the electroless plating rate catalyzed by the exchanged nickel was more than the substrate corrosion rate.

On-line monitoring of self-flocculating yeast cell particles (SFYCPs) that were characterized by their weak strength, irregular morphology, special size distribution, and so on, was realized by using the Focused Beam Reflectance Measurement (FBRM) technique.The experimental results showed good correlation between the total counts of the FBRM chord length and the biomass concentration of SFYCPs, which could be used to measure the biomass concentration for the SFYCP system quantitatively.Furthermore, the mode of FBRM chord length distribution was linearly correlated to both the mean (R²=0.986) and the 95th percentile (R²=0.988)of the length-weighted chord length distribution, which could be used to evaluate SFYCP size distribution effectively.The CO₂ bubbles produced during cell growth/fermentation were observed and proved to create disturbance on on-line measurement of the SFYCP system.This disturbance could be excluded by estimating SFYCP size distribution based on the mode of FBRM chord length distribution.

Co-gasifying coal and natural gas is a new process based on methane steam reforming and coal gasification.Technological principle of synthesis gas preparation by co-gasifying coal and natural gas is illustrated. Experimental results indicated that the optimal outlet temperature of synthesis gas was 1000 ℃ and flame temperature declined obviously when O₂, H₂O(g) and CH₄ were feed into the gasification reactor at the same position.The concentration of CO and H₂ of synthesis gas obtained by theoretical calculation was more than 95%.Both the calculation and experimental results demonstrated that with the proper ratio of feed materials, this method can directly prepare synthesis gas with H₂/CO adjustable between 1.0 and 1.5.

The capacity of CaO for binding HCl from incineration of organic wastewater which contains C₂H₃Cl₃O₂ was investigated at 500—800 ℃ in a bubbling fluidized bed.The binding capacity was the largest at 600 ℃, and then decreased with increasing temperature.Scanning electron microscope (SEM) analyses showed that the rate-limiting step for the reaction altered with the extent of solid conversion in sequence at temperature exceeding 600 ℃: chemical reaction control,and simultaneous chemical reaction and product layer diffusion control for a long period of time.There was not a single product layer diffusion control.The experimental results were analyzed by using the unreacted shrinking core model.The activation energy of product layer diffusion was about 9.95 kJ&#8226;mol^-1 for the range of temperatures in the fluidized bed.

A novel high-temperature flow calorimetric system of conduction type was designed, and built in which chromatogram was used for on line analysis.The thermal constant at 700 ℃ of the calorimeter was calibrated by the sample electric energy method, and the average result was 21.67 W&#8226;mV^-1.The accuracy of the equipment was also validated by standard such as heptane, the result showed that this equipment was reliable.The heat sink values of six kinds of fundamental endothermic hydrocarbon fuels at 700 ℃ were determined by using this equipment.The results showed that the heat sink of NJ-4 was the highest one which is 3.0 MJ&#8226;kg^-1, and that of NJ-6 was the lowest one, only 2.6 MJ&#8226;kg^-1.

Gel polymer electrolyte was prepared by chemical cross-linking.The polyolefin membrane supported gel polymer electrolyte exhibited good electrochemical performance.Its room temperature conductivity was as high as 1.01×10^-3S&#8226;cm^-1, its lithium ion transference number was 0.41 and its electrochemical stability window on Al electrode exceeded 4.2 V. Polymer lithium ion battery was prepared by using the polyolefin membrane supported gel polymer electrolyte, and the influence of processing condition on the electrochemical performance of the polymer lithium ion battery was investigated.The processing conditions included: monomer addition amount and stacking methods of electrodes.The optimized polymer lithium ion battery had good electrochemical performance.Its discharge capacity at 1 C rate was 93.2% of the discharge capacity at 0.2 C rate. More than 80% of its discharge capacity retained after 100 times 1 C charge-discharge cycling.

In this study, the alumina supported copper oxide sorbents were prepared by the impregnation method.The influence of impregnation solution concentration was studied.Desulfurization- regeneration tests were made by using these sorbents.The surface microstructure changes of sorbents during desulfurization and regeneration were also analyzed.The results showed that 90% desulfurization efficiency was obtained by these sorbents and the performance of these sorbents was stable.

Electrochemical hydrogenation of anthracene was carried out in a divided three-electrode cell with spumous Pb as cathode, Pt as anode and saturated calomel electrode as reference electrode in CH3CN-EtOH-H₂O-Bu₄NBr electrolytic system.The curve of current-potential was determined and the effects of solvents, water content, supporting electrolyte, anthracene content and temperature were investigated.The optimum conditions were found as potential=-1900 mV, ［CH₃CN］/［EtOH］＝2/1(vol)，［H₂O］＝5.5 mol&#8226;L^-1,［Bu₄NBr］＝0.50 mol&#8226;L^-1 and T=35 ℃.The yield of dihydroanthracene was 91.37% for 6 h electrolysis under these conditions.Based on the result of electrochemical hydrogenation of anthracene,electrochemical hydrogenation of Daqing FCC diesel fuel was studied with spumous Pb as cathode in CH₃CN-EtOH-H₂O-Bu₄NBr system for 5 h electrolysis.Hydrogen content of diesel fuel increased by 1.1%,alkenes were saturated and polycyclic aromatics decreased apparently.

Nickel metal hydride batteries in bipolar design offer significant advantages as a power storage system for electric vehicles. This study deals with some aspects in structure design and development of bipolar nickel metal hydride batteries. An improvement on conventional bipolar structure was made, and some novel sealed bipolar nickel metal hydride batteries with 6 cells were assembled and studied.Testing results showed that the improved structure effectively protected the worst single cell of bipolar battery, and led to a better pressure and cycle performances of novel batteries compared with conventional ones.In addition, the improved bipolar batteries showed excellent discharge and recharge ability, and low resistance in electrochemical tests. As simulating hybrid electric vehicle working conditions, the batteries displayed good stability during pulse cycles, which indicated the possibility of being used on electric vehicles.

Based on the governing equation of filling stage, a continuous transient design sensitivity method was firstly developed and applied to injection molding.The sensitivity of pressure, temperature and velocity with respect to a design parameter was calculated.The numerical solution was based on a hybrid finite-element/finite-difference method, which was popular in filling simulation, to solve for the pressure, temperature and velocity sensitivity, and a control-volume method was adopted to obtain moving melt front sensitivity.The injection pressure sensitivity with respect to flow rate and melt temperature was obtained by using numerical methods.These results were found to agree reasonably well with corresponding numerical experiments.

The control of the morphology of nanoparticles is a hot issue all over the world.Organic-inorganic materials can be tailor-made with an infinite number of architectures and in diverse forms conveniently.A new type of organic-inorganic hybrid material was reported to be synthesized by emulsion polymerization by using the monomers which contained alkoxysilane groups.However,polymerization and morphology could hardly be controled during the emulsion process, because the alkoxysilane group was easy to be subjected to hydrolysis and condensation by sol-gel process which decreased the stability of the latex.In the present work, organic-inorganic hybrid core-shell nanoparticles were synthesized by seeded emulsion polymerization.Through morphology design, polystyrene, as seeded cores, was synthesized firstly, then 3-trimethoxysilyl propyl methacrylate (MPS) was added to form MPS-styrene copolymer shell on the surface of polystyrene core. Owing to the hydrolysis-condensation of organic alkoxysilane groups in MPS,the organic-inorganic hybrid shell was formed through sol-gel process.The core-shell structure was interpreted by thermodynamical representation and characterized by transmission electron microscopy (TEM).The nonionic surfactant used would decrease the stability of the latex.In acidic condition the latex turned into gel just after the addition of MPS,while,in basic condition the particle number decreased obviously, and the latex kept almost stable in neutral condition.The higher the MPS concentration in the emulsion was,the less stability the latex had.Adding MPS continuously could keep the latex more stable and the particle size could be controlled by this method.Then, the core of this kind of hybrid nanoparticles could be dissolved to yield hollow nanocapsules, with the proportion of the void volume 40.1%.

Bifunctional initiators with two labile groups (e.g. peroxides or azo groups) are frequently used in the polymer industry for the synthesis of vinyl polymers and resin curing. In general, there are two types of bifunctional initiators: one is symmetrical bifunctional initiators containing two labile groups of equal structure, the other is unsymmetrical bifunctional initiators containing two labile groups of unequal structure. One of the potential advantages of using bifunctional initiators is that high polymer molecular mass and high polymerization rate can be obtained simultaneously by controlling the initiator decomposition rate through optimal reaction temperature programming. For free radical polymerization of methyl methacrylate (MMA) with monofunctional initiators, the kinetics is reasonably well understood in both low and high monomer conversion regimes. However, the presence of an additional labile group in bifunctional initiators makes the polymerization kinetics very complicated. This is because labile groups such as peroxides become redistributed repeatedly in the growing and inactive polymers and they are engaged in further initiation, propagation, chain transfer and termination reactions during the course of polymerization. The effects of temperature and initiator concentration on the kinetics of MMA bulk polymerization initiated by 2,5-dimethyl-2,5-bis(2-ethyl hexanoyl peroxide) hexane (TX-141) were investigated.The energy of activation of MMA bulk polymerization initiated by TX-141 was about 91 kJ&#8226;mol^-1, and that of TX-141 decomposition was about 140 kJ&#8226;mol^-1, which was more close to the experimental data.The reaction order of TX-141 concentration was about 0.72,because there was mono- and bi-molecule termination. The kinetic comparison initiated by TX-141 and benzoyl peroxide (BPO) with the same half life period showed that the kinetics was the same when the concentration of TX-141 was half of that of BPO.But, the number-average molecular mass ratio of that initiated by TX-141 to that by BPO was from 1.2 to 1.33 increasing with the conversion.There was an exothermal peak in the DSC curve of polymer initiated by TX-141 at low conversion, but there was no peak at high conversion and no peak was observed for the polymer initiated by BPO.It was shown that the two functional groups of bifunctional initiator decomposed at different times during the polymerization process.

B-C-N nanotube with bamboo-like structure was synthesized by heating ball milled mixture of boron powder and graphite powder in flowing ammonia gas stream at 1200℃. The synthesized product was characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), electron diffraction (ED), high-resolution transmission electron microscopy (HRTEM), and electron energy loss spectroscopy (EELS).The diameter of nanotube was in the range of 50—180 nm and the length is about 20μm.The result of EELS suggested that the nanotube was composed of elements of B, C and N, and the calculated B/C/N atomic ratio was 0.49∶1.00∶0.11.The growth mechanism of B-C-N nanotube was also discussed tentatively.

The reverse microemulsion system of Span 80-Tween 80/liquid paraffin/acrylamide-H2O was prepared, and the effects of n-butanol，NaCl，NaAc were studied with the conductivity method.The stability of reverse microemulsion was reflected, and the information of its dynamic process was obtained by measuring its state changes continuously through testing its electronic conductivity by using electrochemistry.The results showed that the Span 80-Tween 80/liquid paraffin/acrylamide-H₂O system was most stable when the HLB value approached 7.5, and its stability was enhanced when 5.0% (mass) NaCl or 10% (mass) NaAc was added into this system.