Through monitoring the change in conductivity during the hydrolysis of 3-aminopropyltriethoxysilane (KH550) and using FT-IR spectroscopy, the optimum conditions for the hydrolysis of KH550 were investigated. Wet silica gel from which the physisorbed water was removed by azeotropic distillation or rapid solvent replacement was treated with KH550. The products were characterized by Fourier transform infrared spectroscopy (FT-IR), di-n-butylphthalate (DBP) oil absorption, laser particle size analysis and contact angle measurements in order to investigate the effect of modification. The results showed that the contact angle of the modified silica increased, and the DBP absorption value significantly increased by more than 70% compared to the unmodified products. The pore volume was twice that of the unmodified silica. The amount of products in the organic phase also increased significantly. The azeotropic distillation method for wet gel modification afforded more hydrophobic silica than the solvent replacement method, and the contact angle between modified silica and water reached as high as 140°. The optimal conditions for silica modification involved a modifier mass fraction of 17.5% of the weight of silica and the use of azeotropic distillation. 

Poly(D, L-lactide)(PLA) and poly(D, L-lactide)-poly(ethylene glycol) (PEG, M_n= 2000) were synthesized from D, L-lactide(LA) and PEG with stannous octoate as the catalyst in the presence of N₂ under the normal pressure. The effect of temperature of polymerization and catalyst content on the relative molecular weights of PLA, and the regularity of degradation at different media and for different molecular weights of polymers were discussed in detail. The polylactide and its copolymer were characterized by infared spectroscopy(IR), nuclear magnetic resonance(¹H-NMR) and gel permeation chromatography(GPC). The media used for testing of degradation were distilled water, 0.01mol/L HCl solution, pH=7.4 phosphate buffer solution and 0.01mol/L NaOH solution. The results show that the M_v of PLA which was polymerized in 5h, at the lactide/PEG mole feed ratio of 5000, at 160℃ under the nomal pressure is 6.3×10⁴ and PLA is degraded more rapidly in NaOH solution. the lower relative molecular weight of PLA is degraded more rapidly in the same medium. Compared with PLA, degradetion of the copolymer is more rapidly.

Melt electrospinning is an environmentally-friendly technique for the fabrication of nanofibers in the absence of solvent, which can be used in areas such as high performance non-woven materials, biomedicine and high efficiency filtration. This paper reviews recent research in this area, including processing characteristics, the latest processing techniques, materials, and devices, and applications of melt electrospinning. The melt differential electrospinning technique developed by our group is introduced. Ideas for future research on melt electrospinning are proposed in the hope of promoting new theoretical understanding, and the development of new techniques and new devices for the green preparation of ultrafine fibers.

Sodium aluminate was carbonated by CO₂ in a stirred tank reactor to form aluminium hydroxide, which was subsequently chemically modified with a special non halogen modifier under a high temperature and pressure to yield a substance X. By means of TG, TEM, XRD and FTIR, it is found that the substance X is a new flat rhombic substance whose decomposition temperature is higher than 340℃, weight loss approximately 50%,and enthalpy of thermal decomposition 2352.5kJ/kg. The main mechanism of the modification is coordination effect of aluminium atom with empty p oribit and oxygen atom with isolated pairs of electrons in the modifier.

Electrical conductivity data for ionic liquids (ILs) and potassium acetate in water, ethanol and mixtures thereof at 298.15 K were determined using a digital conductivity meter. The ionic liquids studied include 1-methyl-3-ethyl imidazolium bromide ([Emim]Br), 1-methyl-3-butyl imidazolium bromide ([Bmim]Br),1-methyl-3-butyl imidazolium chloride ([Bmim]Cl), 1-methyl-3-butyl imidazolium tetrafluoroborate ([Emim][BF4]), 1-methyl-3-ethyl imidazolium dimethyl phosphate ([Mmim][DMP]), 1-methyl-3-ethyl imidazolium diethyl phosphate ([Emim][DEP]) and 1-methyl-3-buyl imidazolium dibutyl phosphate ([Bmim][DBP]). The results show that the conductivity of ILs in water follows the order [Emim]Br>[Bmim]Cl[Bmim]Br[Bmim][BF4]>[Mmim][DMP]>[Emim][DEP]>[Bmim][DBP], which is inversely proportional to their viscosity. The conductivity initially increased and then decreased as the concentration of ILs increased. For a given ionic liquid, the conductivity in water is higher than that in ethanol. However, compared to potassium acetate, the variation in conductivity of ILs with change of solvent is much smaller. Furthermore, alkylimidazolium phosphate ILs can increase the volatility of ethanol relative to that of water in ethanol-water mixture. The salting-out effect of ILs in ethanol-water systems follows the order [Mmim][DMP]> [Emim][DEP], which is consistent with their relative conductivities in this solvent system.

The mechanism of the thermal decomposition of azodicarbonamide and the influence of zinc oxide on the decomposition process have been investigated by characterizing its thermal decomposition by TG-MS and IR. The results showed that azodicarbonamide undergoes a three-stage decomposition process: the first stage decomposition gaseous products are N₂, CO, and HNCO and biurea is present in the residue; the second stage decomposition gaseous products are NH₃and HNCO; the third stage decomposition gaseous products are NH₃ and CO₂ and urazole is present in the residue. The first stage of azodicarbonamide thermal decomposition was initiated at lower temperature and the second and third stages were delayed by addition of zinc oxide. 

The catalytic dehydration of ethanol to ethylene on a γ-Al₂O₃ catalystin a fixed bed reactor has been studied. The influence of varying the reaction temperature, feed flow rate, and concentration of ethanol was investigated systematically. The results show that in the temperature range 410 to 440℃, the selectivity of the γ-Al₂O₃ catalyst increases with reaction temperature at first and then remains constant, whilst, the yield of ethylene is not very sensitive to the reaction temperature over the entire range. The optimum temperature is about 420℃. As the feed flow rate decreases, the selectivity increases to nearly 100%, but the conversion decreases. The yield of ethylene is above 80% when the feed flow rate is less than 1.0mL/min. According to the experimental results, the optimum feed flow rate is about 1.0mL/min, and the optimumconcentration of ethanol is in the range 50% to 100%. At all ethanol concentrations, the yield of ethylene is 88% or higher, and the selectivity remains stable.

Software quality evaluation with quantitative method can help the managers' deci sionmaking, and reduces the unilateralism caused by qualitative evaluation or subjective evaluation. After analyzing quantitative index of software quality wi th quantitative method, the paper discusses quantitative methods for software qu ality evaluation, and improves the combined character of software quality and th e metric model of quantitative index based on the software quality standard ISO/ IEC9126. 

The pyrolysis characteristics of three main components of biomass, namely cellulose, xylan hemicellulose and lignin have been investigated by means of thermogravimetric analysis. Models of their pyrolysis kinetics were derived using the Coats-Redfern integral method. The results show that differences in the pyrolysis of the three components result mainly from differences in their molecular structures. The observed mass losses of cellulose, xylan hemicellulose and lignin wereapproximately 86%, 69%, and 51% respectively within the experimental temperature range (room temperature to 900℃), indicating that the extent of decomposition varies in the order cellulose >xylan hemicellulose >lignin. In each case two distinct temperature regions were observed. The pyrolysis of both lignin and xylan can be described by secondorder kinetics equations in both temperature regions. The best description of the pyrolysis of cellulose, however, involves a first-order reaction in the low temperature region and a second-order reaction inthe high temperature region. 

Copolymerization of butadiene (Bd) and styrene (St) were carried out by using a rare earth catalyst system. The microstructure, composition, and morphology of the copolymer were characterized by FTIR, ¹H-NMR, ¹³ C-NMR and TEM. The molecular weight, molecular weight distribution and the composition distribution of the copolymer were determined by GPC with RI and UV detectors. The results show that the copolymer is a block copolymer of butadiene and styrene with high cis-1,4 content. The cis-1,4 content of butadiene unit is 97.0%(mol),and the styrene content is 21.8%(mol).The phase-separated morphology is formed by polybutadiene(PB) and polystyrene(PS) sequences.

The solubility of gallic acid in binary mixtures of ethanol+water was determined at (283 to 323) K and atmospheric pressure using a dynamic method. The modified Apelblat equation and Jouyban-Acree model were used to correlate the solubility data, with the overall relative average deviation (RAD) values of 0.63% and 10.84%, respectively. The modified Apelblat equation thus shows the best agreement with experimental data. The solubility of gallic acid in binary mixtures increases with increasing temperature and mass fraction of ethanol in the mixed solvent and the maximum solubility of gallic acid can be reached with the mass fraction of ethanol 0.900.

A kind of high temperature organic silicone coating that can resist 700℃ was prepared. Two general trademark silicone resins were used. The effect of the low melting-point glass powder, talcum powder, aluminium powder and the silicon alkyl coupling agent on the performance of the coating and their mechanism of action were studied. The results showed that the performance of the coating is best when the mass of organic silicone resin, low melting-point glass powder, talcum powder, aluminium powder, and silicon alkyl coupling agent is 30～50g, 20～30g,1.5～6.0g, 10g and 1.5g, respectively.

The formulae of the deacetylating degree of chitosan are given by: y =203.195 x /(16.022 62+0.420 37 x),y =20.202 1 x /(16.022 62+0.041 794 x )(theoretical equations) ; y =0.015 53+ 12.645 34 x - 0.314 47 x ²+0.005 46 x ³,
y =0.015 53+1.257 22 x -0.003 11 x ²+5 362 65×10 ^-6 x ³ (fit equations),
where y is degree of deacetylation, and x is mass fraction of amino in the
first equation or percent of free amino of chitosan in the second . The coefficient of determination is 1 and standard deviation is 0.00663. The calculated valued of degree of deacetylation reflects the deacetylating degree of chitosan molecular accurately.

Different ways of controlling the flow in a centrifugal pump and the associated energy consumption under a constant flow, including outlet valve control, single pump control, double-pump frequency conversion control and a combination of fixed-frequency pump and variable-frequency pump control, have been experimentally investigated. The results show that for a single pump, the energy consumption of variable-frequency control is 62% of that of outlet valve control when the flow is decreased from 5.8m³/h to 4.7m³/h; for double pumps, the former is only 46% of the latter, and is 61% of that of a combination of fixed-frequency pump and variable-frequency pump control when the flow is decreased from 10m³/h to 7m³/h. It is therefore concluded that using frequency conversion technology to convert the speed of a pump gives the best performance and the lowest energy cost, irrespective of the number of pumps.

Using phenol and dicyclopentadiene (DCPD) as raw materials, DCPD-containing phenolic resin (DPR) was prepared via Friedel-Crafts alkylation and DCPD-containing epoxy resin (DER) was prepared via epoxidation of DPR with epichlorohydrin. Their reaction conditions and mode were optimized. The epoxy value of DER is 0.31~0.35. The content of organic chloride is less 0.02 mol/100g. MeHHPA as curing agent, the curing was carried out and the rate of curing was evaluated by FT-IR. When the curing temperature is 180 ℃, the yield of the opening of epoxy group was more than 92% after 3.5 h. DSC analyses found that the Tg of cured epoxy resin DER+E51(1:1) is higher than that of resin E51.

An effcient transesterification of β-ketoesters with ethyl 4-2［2-(phthalimido)ethoxy］acetoacetate and S-(+)-β-methoxy-phenylethanol as raw materials and boric acid as catalyst is described. The boric acid is the best one among the five selected catalysts: ZnO，Zn/I₂，B(OH)₃，I₂and t-BuNH₂ . The optimal conditions for transesterification can be carried out with boric acid as catalyst under 140-150℃, the ratio of two compounds (ethyl 4-2［2-(phthalimido)ethoxy］acetoacetate and S-(+)-β-methoxy-phenylethanol) could be set as 1∶1.2, and the reaction can be finished in 24?h，the yield is 33.3%.

A theoretical calculation of the atomic and electronic structure of nanosized rutile TiO₂ (110) surface was given using the density functional theory (DFT). It is found that the relaxation and restructure occur at (110) surface, and the corresponding distance of the relaxation decreases with increase in the atomic layer thiokness. The width of forbidden band gap at the surface decreases so that it shows the quasi-metal property. The highest occupied and the lowest unoccupied molecular orbits are composed of the p orbits and d orbits of the Ti atoms.The active sites are localized at the surface Ti⁴⁺ sites.

Barium titanate powders with size of 35nm were prepared by the high-gravity reactive precipitation (HGRP) process. The effect of heat treatment on the cubic to tetragonal phase transition of barium titanate powders was studied. XRD and TEM investigations confirmed that the phase transition occurred only when the heat treatment was above 900℃, and the particle size and the tetragonality (c/a) of the powder increased rapidly and reached 150nm and 1.009 at 1000℃, respectively. The studies also showed that the phase transition was essentially dependent on the powder size and indenpendent on the hydroxyl ions exisiting in the crystals.By means of the defects theory and the diffuse model of the crystal,the behaviour of rapod particle growth at higher heat treatment temperature(>900℃) could be explained

Monodisperse polystyrene microspheres were prepared by dispersion polymerization in ethyl alcohol reaction media using polyvinylpyrrolidone (PVP) as steric stabilizer and 2,2-azobisizobutyronitrile (AIBN) as initiator in a suitable condition. The effects of the initial monomer, stabilizer and initiator concentrations on the size and the size distribution of polymer particles were investigated through condition experiments. The results show that the size of polystyrene microspheres decreases with increase in amout of stabilizer,and an increase in the initiator and initial monomer concentrations will increase the particle size and broaden the size distribution.and the monomer added once in a lump administer is helpful to form the monidispere polystyrene microspheres.

A new method to synthesize trifluoroacetate, one of the intermed iate of celecoxib was studied by using acidic positive ion exchange resin D072 a nd high absorbent resin as catalysts with yield 93.7%. Then celecoxib was synth esized through Claisen condensation and cyclization successively. The total yiel d reached 35.5%. 