bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and Electrochemical Properties of LiFePO4C by a Novel Carbothermal Reduction Technology
Authors: Tan Fang Xiang , Meng Li Li , Wang Fan , Su Hai Feng , Long Yun Fei , Wen Yan Xuan , Yang Ke Di
Published: May 2011

LiFePO4/C composites were synthesized by a novel carbothermal reduction method based on the low-temperature solution reaction between LiNO3-Fe (NO3)3-NH4H2PO4-sucrose. The sucrose amount, sintering temperature, sintering time, and heating temperature for synthesis of LiFePO4/C cathode was optimized. The materials were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM) and charge–discharge tests. The results showed that sintering temperature and sucrose amount have more significant effects on discharge capacity than drying temperature and sintering time. Optimum LiFePO4/C was prepared by sintering the precursor obtained by heating at 60 with a sucrose amount of 5.0g at 800.0 for 12 h. Being charged–discharged at 0.5C between 2.5 and 4.2 V, the LiFePO4/C synthesized at the optimum conditions shows good electrochemical performances with an initial discharge capacity of 138.7 mAh·g−1and a capacity retention ratio of 98.6% after 50 cycles.
Determination of Heavy Metal Elements in Farm Products Taros and Agricultural Soil by Inductively Coupled Plasma-Optical Emission Spectrometry and Assessment
Authors: Cao Can , Ye Hua , Chen Guo Hui , He Li Na
Published: May 2011

This study was designed to determine the heavy metal concentrations in soils and food crops and estimate the potential health risks of metals to polluted food crops and soil, so agricultural soil for the cultivation and taro were main objects of study, taro were taken in the HNO3-H2O2 wet digestion, while soil were taken to HCl-HNO3-HF-HClO4 wet digestion by (ICP-OES),then coments and analysis on the samples were carried out by comparing with their limits of relative state standards. The analytical results indicate that for all of the analyzed elements the relative standard deviations (RSD) are 0.9-4.9% and the recoveries of most elements are in the range of 96.84-104.96%. Zn, As, Cd and other contents in soil samples were detectable beyond their limits of state standards, while heavy metals contents in the investigated samples were found at different polluted levels. Cd, Cr, As, Zn, Cu in taros also exceeded the national standard. It was found that there are enrichment of heavy metals in taro. It is concluded that the present techniques are suitable for the routine determination of heavy metals concentration in the food crops-soil systems.
Effect of Weld Line Defects on Electrical Conductivity of Injection Molded Parts with Carbon Nano Fibers/PP Composites
Authors: Xie Lei , Tian Xiao Yong , Wu Wang Qing , Li Di Chen , Jiang Bing Yan , Ziegmann Gerhard
Published: May 2011

As well known, the weld line defect in injection molding process results detrimental to mechanical properties and surface quality. However, the electrical conductivity of the injection molded part is influenced as well. In this study, in order to reveal the mechanism of the weld line affecting the electrical conductivity of injection molding parts, the conductive polymer composites with various carbon nanofibers filling contents were compounded. Those composites were formed as the tensile samples with and without weld line defects by injection molding process. According to the electrical resistance measurements for the samples, it can be found that at relative low filling content of 10wt%, the weld line contributes to increase the electrical conductivity of the injection molding parts due to its effect on nanofibers’ orientation. However, when the filling content is higher than 20wt%, this effect is not significant any more.
Kinetics and Equilibrium Studies on Adsorption of Dimethylformamide by Macroporous Chitosan Membranes
Authors: Li Si Fang , Chen Qiang , Liu Miao
Published: May 2011

The adsorption of dimethylformamide (DMF) by macroporous chitosan membranes using silica gel as porogen is studied. The morphology, porosity and DMF adsorption capacity of the macroporous chitosan membrane were measured. SEM photographs show the pores in the membrane dispersed uniformly. DMF adsorption capacity of the macroporous chitosan membranes reached 145 mg/g. Adsorption isotherm of DMF on the macroporous chitosan membranes was determined and correlated with Langmuir and Freundlich equations. The adsorption equilibrium data fitted well with Freundlich equation. The adsorption kinetics was found to follow the pseudo second-order kinetic model.
Novel Non-Phosphorous Antiscalants for Inhibition of Calcium Phosphate and Calcium Sulfate Precipitation
Authors: Fu Chang E , Zhou Yu Ming , Liu Guang Qing
Published: May 2011

A copolymer of acrylic acid (AA)/allylpolyethoxy carboxylate (APEC) was synthesized, characterized and examined as a non-phosphorous antiscalant for industrial cooling-water. Its ability to prevent calcium phosphate and sulfate precipitation was compared with inhibitory power of acrylic acid (AA)/allylpolyethoxy sulfate (APES) and polyamino polyether methylenephosphonate (PAPEMP). Results indicate that the presence of these antiscalants does reduce the extend of calcium phosphate and sulfate precepitation and AA/APEC exhibits the best performance with 99.59% calcium-phosphate inhibition when the dosage of AA/APEC was 6 mg/L and 82.88% calcium-sulfate inhibition at the dosage of 3 mg/L AA/APEC. AA/APEC has also been proven to be an effective inhibitor for calcium phosphate and calcium sulfate even at elevated solution temperature, pH and Ca2+concentration.
Micromixing Efficiency in High Gravity Reactor with Different Packing
Authors: Ji Jun , Song Hong , Liu Jiao
Published: May 2011

Micromixing efficiency in the high gravity(Higee) reactor with glass bead, rasching ring and pall ring was investigated respectively by using iodide-iodate test reaction as working system. The experimental results showed that segregation index of the Higee reactor increases while increasing volumetric flow ratio, size of pall ring and decreases with the increase of rotating rate, volumetric flow rate. The Micromixing efficiency of the Higee reactor with pall ring is better than glass bead and rasching ring.
Preparation and Characterization of TiO2 Nanoparticle with SiO2 Shell
Authors: Cai Hong , Chen Yan , Wu Yun Ying
Published: May 2011

Nano-TiO2 particles were prepared by sol-gel method, of which the surfaces were coated by SiO2. The coating was achieved by the hydrolysis of sodium silicate (Na2SiO3) in ammonium chloride (NH4Cl). The surface bonding, phase constitution and chemical components of the samples were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction(XRD) and X-ray photoelectron spectroscopy (XPS). The mechanism of the SiO2 coating process onto TiO2 surface was analyzed. Results show that SiO2 particles were immobilized on the TiO2 surface via Ti—O—Si bondings, which formed at the interface. The SiO2 layer on TiO2 surface was amorphous, the photocatalytic performance was decreased of the TiO2 while its stability was enhanced after surface modification.
Preparation of Chain-Like and Layer Rock-Like MgO Powders by Molten Salt Synthesis
Authors: Chen Hao , Sun De Si , Hu Qing Hua , Zhou De Zi
Published: May 2011

Particle-like MgO powders were first prepared using LiCl as reaction medium, MgCl2·6H2O and CaCO3as reaction materials. Soaked them by PEG and PEG-EDTA solution, different Mg(OH)2precursors were formed, which morphologies were fiber-like via PEG and tetrahedron-like via PEG-EDTA . Re-heated at 600 , Mg(OH)2was decomposed to MgO. Decomposed by fiber-like Mg(OH)2, MgO powders were chain-like, with 0.1-0.3 µm in diameter and 20-100 in length-to-width ration. On the other side, decomposed by tetrahedron-like Mg(OH)2, MgO powders were layer rock-like with vertex defected, which brim was up to 1.5 µm in length.
Judd-Ofelt Analysis of a Dendrtic Type Europium Complex/Silicone Rubber
Authors: Liang Hao , Xie Fang
Published: May 2011

A dendritic type europium complex/silicone rubber has been prepared. According to the luminescence spectrum, the Judd-Ofelt theory was adopted to calculate the intensity parameters Ω2and Ω4. The total radiative transition rate (640.1 s-1), radiative lifetime (1.562 ms) and the stimulated emission cross-sections (46.19×10-22cm2) of the5D0exciting state have been evaluated. Analysis reveals that the europium (III) chelating polymer is promising for use in optical devices.
Turbulent Drag Reduction in Journal Bearing by Polymer Additives
Authors: Wang Hai Lin , He Xiao Ping
Published: May 2011

In this paper, a single parameter family of hybrid ellipsoid-dumbbell models is proposed for the hydrodynamic behavior of a polymer molecule in dilute solutions. The model allows for rotation and partial deforming of molecule, but not for bending. The periodic fluctuations and shear thinning have been obtained by numerically integrating the equations of motion over a wide range of the dimensionless parameter, a ratio of polymer-spring and solvent-viscosity forces. The results show that the rotation frequency decreases with the increasing shear rate because of the deformation effect, which increase the stability of flow. The effects of polymer additives on flow viscosity and its application are also discussed. These results will be significant for drag reduction mechanism.
Study on Dispersion and Performance of Yellow Lake
Authors: Leng Xian , Li Lu Hai , Hu Xu Wei , Fang Hua , Li Shu Kun , Liu Shi Gang , Li Guang Jie
Published: May 2011

In order to study the dispersion and performance of tartrazine aluminum lake, 7 kinds of water-based resins are used to form disperse system. These systems are enviroment friendly (low VOC) and use edible yellow lake as colorant. If proper adjustment is added, these disperse systems can be made into ink and paint. The application field should be printing or coating on all the food or drug packages, toys and decorate materials, which will improve social safe level. Colorant, resin, wetting agent, co-solvent, emulsifier, and deionized water are mixed at certain ratio and pre-dispersed for 15min, then dispersed in GJ-2S high speed sanding mill for 3h. Size distribution, PDI, color characteristics (reflectance spectroscopy and color density), glossiness, abrasion performance, and stability are studied. Results demonstrate particle size of disperse system is 338.1~595.3nm (PDI<0.3) and changed to 428.6~551.2nm after 5 days or so. Reflectance spectroscopy is close to PANTONE standard yellow. Glossiness is referred as Gs(60°)≥32°. Viscosity is 0.2~2Pa·S. Relative stable disperse system is prepared.
Preparation and Absorbencies of Poly(acrylate-co-Acrylamide) Superabsorbent by Inverse Suspension Polymerization
Authors: Xie Jian Jun , Zhang Hui Ying , Zeng Nian , Ran De Long
Published: May 2011

Poly(acrylate-co-acrylamide)(PAAM) superabsorbent was prepared from partly- neutralized acrylic acid(AA) and acrylamide(AM) by inverse suspension polymerization. Its chemical structure and thermal property were characterized by Fourier-transform infrared spectrophotometer(FTIR) and the thermogravimetric analysis(TGA). The effects of various salt solutions on the absorbencies were studied systemically. Under the same ion strengths, the absorbencies of PAAM were in the order LiCl>NaCl>KCl in MCl (M=Li, Na, K) solutions and NaBr>NaCl>NaF in NaX solution, respectiverly. The tendency of absorbency of PAAM for the alkaline earth metal salt solutions was in the order MgCl2>CaCl2>BaCl2. PAAM resin is thermal stable before 320°C.
The Preparation of Silver-Coated Nickel Powders via Electroless Plating
Authors: Xu Rui , Chen Quan
Published: May 2011

A novel method via electroless silver coating on nickel powders was reported., which introduced reduction reaction using hydrazine as the reducing agent, had some advantages such as inhibiting the substitution reaction and reducing consumption of nickel powders. In the process of dispersion, PVP acted as the dispersant and prevented the nickel powders from agglomerating.The Zeta potential of slurry which determined the dispersibility and the reaction condition was tested.The investigation shows that the grain size of Ag-Ni bimetallic powders is similar to the nickel powders, bimetallic powders possesses fine dispersibility and a continuous silver film is formed on the surface of nickel powders by two-times coating. Morphology of Ag-Ni bimetallic powders, composition of the coated-surface are respectively characterized by SEM and EDX.
Dyeing Property of Shikonin on Wool Fabric
Authors: Lv Li Hua , Wei Chun Yan , Ye Fang , Zhang Huan
Published: May 2011

In this paper, wool fabric was dyed by Shikonin. The optimum conditions of dyeing wool fabric with Shikonin were obtained by the orthogonal and single factor analysis experiments. The specific process conditions are as follows: liquor ratio 1:40; dye concentration 80ml/L; pH 4; temperature 80; time 60min. The results indicated that fastness to washing and to rubbing of wool fabrics dyed with Shikonin was good and has reached more than three level.
Study on Magnesium Hydroxide-Based Hydrogen Peroxide Bleaching Process of Nigra poplar CTMP
Authors: Zhao Qiang , Sun De Zhi , Zhang Ming Yang , Kang Su Min
Published: May 2011

The Mg(OH)2-based peroxide bleaching process of Nigra poplar CTMP pulp was confirmed. The optimal bleaching condition were as follows: 4% H2O2,1% Mg(OH)2, 15% pulp consistency, the reaction temperature was 80°C and the suitable reaction time was 2 hours. The Mg(OH)2-based bleaching process shows significant benefits over sodium hydroxide process. In contrast, magnesium hydroxide bleaching generates higher pulp yield and lower effluent COD at the same chemical dosage. The study shows peroxide bleaching of CTMP pulp with magnesium hydroxide as alkali source is to be an option for the high-yield pulp bleaching.
Measurement and Correlation of Solubility for 2,4-Dinitrotoluent in Mixed Solvents of Water and Nitric Acid
Authors: Kong Ling Qi , Li Yu Gang , Zheng Shi Qing
Published: May 2011

The solubility data of 2,4-dinitrotoluent (2,4-DNT) in mixed solvents of water and nitric acid with nitric acid mass fraction vary from 0.1 to 0.5 were determined at 283.15-323.15K by the equilibrium method. It indicates that the solubility increases with the increase of temperature and decreases with the decrease of mass fraction of nitric acid. The experimental data were correlated with λ-h equation, Apelblat equation and C.L.Yaws equation, average relative deviations of which between the calculated values and the experimental values of 25 data points in 5 systems were 3.666%, 2.737% and 3.121% respectively. The results show that three equations could well correlate the solubility data of 2,4-DNT in above electrolyte systems and the accuracy of the correlation can satisfy the engineering requirement.
Turbulent Mixing and Scale-Up of Ejectors at High Schmidt Number
Authors: Ma Lian Xiang , Bi Rong Shan , Tan Xin Shun , Liu Zhen Dong , Chen Wen Wu , Zheng Shi Qing
Published: May 2011

Micro- and Macro-mixing models were built and numerical investigation of turbulent mixing in ejectors was carried out. Mixture fraction and its variance presented by Fox were remodeled to demonstrate micro- and macro-mixing performance. The length needed to reach 98% micro- and macro-mixing were founded is functions of uj/umand D/d. The mathematical scale-up models were presented based on the simulation results using least square method for micro- and macro-mixing and five different cases were used to validate the models. The results showed that macro-mixing scale-up model agreed well with CFD simulations but the micro-mixing scale-up model had a less precision compared with that of macro-mixing model. This because that the mechanism of micro-mixing process is very complexity but the CFD models we used in this work are fairy simple.
The Preparation of Environment-Friendly Compound Corrosion Inhibitor for A20 Steel in Citric Acid Pickling
Authors: Yang Dao Wu , Zhang Yun Yun , Wu Juan Juan , Tong Hai Xia , Li Jin Hui
Published: May 2011

A kind of efficient, environment-friendly compound inhibitor was prepared with 2-mercaptobenzimidazole (2MBI), potassium iodide, triethanolamine, polyoxyethylene nonylphenyl ether and peregal by weight loss through orthogonal experiment. The effects of the compound on corrosion of A20 steel in citric acid have been investigated in relation to it’s concentration by weight loss measurements, polarization curve methods and electrochemical impedance spectroscopy (EIS). The result of weight loss reveals that the compound is a good inhibitor whose efficiency can reach 98.8%. Polarization curve results show that the compound restrain the process of cathode and anode, belonging to anode control-oriented and charge transfer-controlled. EIS results show that the changes in the impedance parameters (Rp and Cd) with concentrations of the compound are indicative of the adsorption of these molecules leading to the formation of a protective layer on steel surface.
Fluorimetric Method to Determine Trace Anionic Surfactants Using a Novel Triazene Reagent
Authors: Feng Yong Lan , Tang Wen Qing , Zeng Rong Ying
Published: May 2011

Although widely applied in many industries, anionic surfactants (AS) have been shown to contaminate the natural environment. Therefore, the detection of trace amounts of AS in environmental samples is of great interest. Here, we report a novel fluorescence quenching method for the determination of trace AS, specifically, sodium dodecyl sulfate (SDS), using 1-(5-naphthol-7-sulfonic acid) -3-(4-pheny-lazophenyl)-triazene (NASAPAPT). Under optimum conditions, the degree of fluorescence quenching is linearly proportional to the concentration of SDS from 2.08×10-8 to 8.67×10-7mol L-1 with a detection limit of 8.35×10-9mol L-1. The proposed method exhibits high sensitivity and selectivity, yet it avoids the use of toxic organic solvents and tedious solvent extraction procedures. It has been applied to the determination of trace SDS in both natural water and industrial samples with recoveries between 99.04 and 103.58%. Results indicated that the hydrogen bonds formed between NASAPAPT and SDS played an important role in the detection process and that the π→π* transition was crucial for fluorescence of the NASAPAPT complex.
Using Polyoxyethylene Reduction the Flotation Temperature of Fatty Acid
Authors: Jiang Xiao Jun , Wang Xiao Yu , Xu Hong Bo
Published: May 2011

The separation of quartz from hematite adding the polyoxyethylene ether to the fatty acid has been investigated. The main factors affecting flotation temperature were found to be constitutes of collector and surfactants. The results indicate that the temperature of fatty acid anion reverse flotation of iron ore could be reduced to 22 from 45 . It can achieve purposes of saving energy and lowering carbon let.
Adsorption of Chitosan and Interaction with a Non-Ionic Surfactant on Silica
Authors: Liu Bing Tao , Fokkink Remco , de Keizer Arie
Published: May 2011

Optical reflectometry is applied as a tool for studying single and simultaneous adsorption of a carbohydrate, a nonionic surfactant, and a protein, For the nonionic surfactant poly(ethylene oxide) alkyl ether on a silica surface the adsorption process is fast and reversible, and the maximum adsorbed amount was 2.45 mg•m-2. Also, the effect of pH on the adsorption of chitosan on silica, and its interaction with C12EO5have been studied. The maximum adsorbed amount was obtained for pH ≥6.8 (0.80 mg•m-2). Changes in surface functionality upon adsorbing C12EO5on a chitosan layer and the protein, bovine serum albumin, are reported. The results are discussed in terms of adsorption kinetics, adsorbed mass plateau values, and reversibility of layer formation.
Study on Leaching Process of Activation Bastnaesite by HCl Solution
Authors: Bian Xue , Yin Shao Hua , Zhang Feng Yun , Wu Wen Yuan , Tu Gan Feng
Published: May 2011

Bastnaesite was activated at a temperature, and then the rare earths carbonate of the minerals was leached by HCl solution. When activation temperature was 400°C, activation time was 3h, HCl concentration was 3 mol•L-1, leaching temperature was 90°C, liquid to solid was 20:1, the leaching ratio of rare earths carbonate and rare earths fluoride was 94.6% and 0.07% respectively. The results of XRD and SEM showed that bastnaesite was powdered and coarseness in activation process, which made the leaching of rare earths carbonate by HCl solution become easy. The main components of leaching slag were rare earths fluoride, calcium fluoride and barium sulfate.
Reactive Distillation for Tert-Butyl Alcohol Dehydration with Dynamic Matrix Control
Authors: Lu Shi Qing , Zhang Hai Liang , Jiang Xue Dong , Lei Zhen , Ye Hao Miao , Yang Bo Lun
Published: May 2011

Reactive distillation fortert-butyl alcohol dehydration to isobutene and water catalyzed with the cation exchange resin was carried out. A mathematical model for simulating the process was developed and verified by the experimental results. Then, the dynamic matrix control (DMC) method was put into the process to achieve an efficient control for high purity isobutene from the top of the reactive distillation column. The tracking test and anti-disturbance test of the control system were carried out, and the effect of DMC parameters such as predictive length, control weighting matrix, error weighting matrix and reference trajectory coefficient on the performances of DMC were discussed. The results show that the tuning of these parameters has significant effect to the performances of DMC.
Progress in the New Fermentation Technologies of Fuel Ethanol
Authors: Shen Yu , Zhang Hai Dong , Zheng Xu Xu , Zhang Xian Ming , Guo Jin Song , Chen You Peng
Published: May 2011

Fuel ethanol converted from biomass is a reliable substitute for fossil fuels, and lays people’s hope on the sustainable development in the fields of energy and climate. The limitation in source of raw materials and production cost are bottlenecks which restrain the wide use of fuel ethanol. This article makes an overview of the current research progress in the new technologies from the directions in the exploiting of raw materials and energy saving and polluted water emission reduction in the production process of fuel ethanol, and analyzes the potential application prospects and advantages of various new technologies.
Microwave-Assisted Hydrothermal Synthesis of Mesoporous V-MCM-41 Materials with Good Hydrothermal Stability
Authors: Xu Jun Qiang , Chu Wei , Guo Fang , Quan Xue Jun
Published: May 2011

Mesoporous V-MCM-41 materials with good hydrothermal stability had been synthesized by microwave-assisted hydrothermal method. The samples by microwave-assisted hydrothermal synthesis and conventional heating remain the same mesoporous structure by XRD and N2adsorption analysis. The V-MCM-41 materials by microwave-assisted hydrothermal synthesis show the good hydrothermal stability, close to that of the materials by conventional heating. The high surface area of the sample by 720 W microwave treatment for 8 min was the same as that of the sample by conventional heating (110 °C for 12 h).
Photodegradation of Toluene by TiO2 Nanoparticles by Flame CVD Process
Authors: Xie Hong Yong , Chen Shen Wen , Ma Chang Wen , Wang Jing Rong , Zhu Lu Ping , Wang Ling Ling , Gao Gui Lan , Wang Li Jun , Yuan Hao
Published: May 2011

Photo-degradation of toluene at ppb levels by mixed-phase TiO2 nanoparticles, synthesized by the oxidation of TiCl4 in propane/air flame chemical vapor deposition (CVD) process, has been investigated experimentally by using a tubular photoreactor with thin TiO2 films coated on the reactor wall by sedimentation. Effects of toluene at initial concentration at ppb levels, rutile mass fraction and photoluminescence (PL) spectra of TiO2 nanoparticles on degradation degree have been investigated under the conditions of 5.7 seconds of residence time, 70% relative humidity, 38mg/cm2 of TiO2 loading, 25mW/cm2 of irradiation with main wavelength of 254nm.
Study on Preparation of Dissolving Grade Pulp and its Kinetics of Prehydrolysis
Authors: Hu Ke Xin , Zeng Guang Ming , Zhang Hai Chao
Published: May 2011

The possibilities of dissolving grade pulp production from reed were investigated in this paper. Two – stage prehydrolysis – kraft pulping and CEHA bleaching process of reed for preparation of dissolving grade pulp were studied in laboratory. The optimum cooking and bleaching conditions were found out. The mechanism and its kinetics of reed in prehydrolysis process were also discussed. The results showed that under the laboratory conditions the rate for removal of materials at about 175°C follow approximately a pseudo first order law with two distinct phrases: the bulk removal and the residual removal of the materials. The prehydrolysis-factor (P-factor) was established. The advantage of using P-factor is predict compensating adjustments in cooking time and/or temperature to give the same degree of pulping and to produce pulp with predetermined characteristics. It is found that three distinct delignification rate stages about 75% of pentosans and about 50% of lignin were removed. A CEHA four stage bleaching is used for dissolving grade pulp. Total chlorine charge in bleaching is 6% (to oven-dry pulp). The results show that all of the indices fitted the quality standards of dissolving grade pulp.
Highly Efficient Synthesis of Silicon-Containing (R)-Ketone-Cyanohydrin Catalyzed by (R)-Hydroxynitrilase Lyase from Prunus Domestic
Authors: Liu Sen Lin
Published: May 2011

The synthesis of chiral silicon-containing (R)-ketone-cyanohydrin by enantioselective transcyanation of acetyltrimethylsilane with acetone cyanohydrin was efficiently carried out using defattedPrunus domesticseed meal as (R)-hydroxynitrilase lyase for the first time. Under the optimal conditions including a reaction temperature of 25-35°C and a buffer pH of 5.0-5.4, both acetyltrimethylsilane conversion and enantiomeric excess of the product were above 99%. In contrast, this enzyme did not accepted its carbon counterpart 3,3-dimethyl-2-butanone as substrate. These results demonstrated that the silicon atom in substrate served as a more effective atom than the carbon atom to enhance the activity of the enzyme.
Synthesis of Mesostructured Materials of Different Heteroatoms and Their Catalytic Performances for Styrene Epoxidation
Authors: Zhang Rong Mei , Zhao Yu Xiu
Published: May 2011

FeS-1, VS-1 or CuS-1 precursors are loaded and highly dispersed on the surface of mesoporous materials SBA-15, MCM-41 or SiO2by impregnating method. The samples were characterized by X-ray diffraction, FT-IR spectroscopy, TEM and N2adsorption. Their catalytic performances for styrene epoxidation with anhydrous TBHP as an oxidant agent were studied. The results suggest that zeolite primary and secondary building units are highly dispersed on the samples and the samples have still retained mesoporous structure. All of the catalysts exhibit good catalytic activities, producing styrene oxide and benzaldehyde as the main products. Cu/SBA-15 shows high activity and selectivity, which are comparable with that of other samples. We find that, under the conditions of preferable precursors,n(TBHP)/n(styrene) =1.5, reaction temperature 80°C, and reaction time 2.0h, the conversion and yield of styrene epoxide reached 65.9% and 42.2%, respectively.
DRIFTS and NO-TPD Characterization and Catalytic Activities of CuO/TiO2/γ-Al2O3 in NO+CO Reaction
Authors: Li Hui Juan , Jiang Xiao Yuan , Zheng Xiao Ming
Published: May 2011

The catalytic activity in NO+CO reaction was investigated, and the structure and reductive properties of various CuO/TiO2-g-Al2O3catalysts were characterized by means of BET, XRD, NO-TPD and DRIFTS technologies. The NO-TPD profile showed that peak temperatures of NO desorption by the 12Cu15TA were lower than that by the 15TA, and no N2desorption species detected on 15TA, indicating that the NO decomposition activity of the catalysts was higher than that of the supports. DRIFTS analysis showed the N2O adsorption peaks appeared at 150for 12Cu15TA. And a peak for Cu+-NCO-species at 2205cm-1was detected on 12Cu15TA.
Effects of PEI as ATC on the Retention and Drainage of APMP
Authors: Chen Fu Shan , Xu Huan Fei , Jiang Xiu Ying , Wang Song Lin
Published: May 2011

The impact of highly cationic density polymers such as modified poly-ethyleneimine(PEI), as anionic trash catcher(ATC) on the drainage and retention properties of aspen alkaline hydrogen peroxide mechanical pulp(APMP) in differentCPAM(/bentonite) systems was studied. The results showed that ModifiedPEIcould improve the retention and drainage properties ofCPAM/ bentonite systems; when adding 0.02% dosage ofPEI, the drainage and retention rate were increased by 16.0% and 1.9% respectively as compared to control with 0.03% dosage of theCPAMwith 1.55 meq/g cationic charge density and 4.9 million molecular weight, which denoted byCPAM(W/W);the drainage and retention rate were increased by 28.6% and 3.0% respectively as compared to the control with 0.03% dosage ofCPAM(W/W) and 0.3% dosage of bentonite. TheCPAMwith more cationic charge density and higher molecular weight than theCPAM(W/W)is denoted byCPAM(W/O)in this paper. The microparticle system which consisted withPEIand theCPAM(W/O)(/bentonite) was slightly superior to thePEI/CPAM(W/W)/bentonite system. When 0.02% dosage ofPEIand 0.03% dosage ofCPAMwere added respectively,PEI/CPAM(W/O)made the drainage and retention rate increased by 9.5% and 1.9% respectively as compared withPEI/CPAM(W/W).
Effect of Ce3+/Ce4+ Couple on Selective Hydrogenation of Crotonaldehyde over Pt/CeO2 Catalyst
Authors: Xie Guan Qun , Dai Yan Hui , Liu Xi Jing , Luo Meng Fei , Li Xiao Nian
Published: May 2011

By pretreatment of Pt/CeO2catalysts with high temperature reduction and subsequent low temperature reoxidation, the concentration of Ce3+species in the Pt/CeO2catalysts could be adjusted, while at the same time the Pt particle size remained constant. Thus the pure effect of Ce3+/Ce4+couples on the selective hydrogenation of crotonaldehdye could be explored. The investigation provided direct proofs supporting that Ce3+species favors the crotyl alcohol selectivity.
Synthesis of Antiulcerative Drug Tenatoprazole
Authors: Yan Feng , Fan Kai Qi , Chi Cheng , Guan Jin
Published: May 2011

An improved synthetic approach of tenatoprazole, an antiulcerative drug, is reported. The first step in this synthesis involves the coupling of 2-mercapto-5-methoxyimidazo[4,5-b]pyridine with 2-chloromethyl-4-methoxy-3,5-dimethylpyridine hydrochloride to afford sulfide 4, and the subsequent step of oxidation using substoichiomitric amount of hydrogen peroxide to give sulfoxide 1 quantitatively. The overall yield is around 80% for both two-step synthesis. The progress in this process is no purification process and affords the target compound with 99% purity by HPLC.
Autofrettage Pressure Analysis of Carbon-fiber Wound Composite Gas Cylinders
Authors: Wu Xiang , Duan Cheng Hong , Luo Xiang Peng
Published: May 2011

Despite the widening use of the carbon fiber wound composite gas cylinder, the research on its structure is mainly focused on the experiment method. In this paper, the APDL language in ANSYS was used to create a model of carbon fiber wound aluminum alloy liner composite gas cylinders with the thickness and the wound angle of both heads varied. The autofrettage process of the cylinder was analyzed and the range of autofrettage pressure value was determined by the DOT CFFC standard. It is expected that the finite element analysis results would be conducive to the engineering practice.
Investigation of Suitable Pretreatment for Dry Reforming of Methane Over Ni/Al2O3
Authors: Alfatesh Ahmed , Fakeeha Anis
Published: May 2011

Carbon dioxide reforming of methane to synthesis gas over an alumina-supported 1% Ni-based catalyst was investigated at atmospheric pressure. The effects of activation and calcination temperatures and the addition of calcium promoted on dry reforming catalysts supported on low surface area alumina Ni/α-Al2O3 (SA-5239) were studied experimentally. In this study, the prepared catalyst was tested in a micro tubular reactor at temperature ranges of 500, 600, 700 and 800°C, atmospheric pressure, using a total flow rate of 33 ml/min. of feed gas 3 ml/min of N2, 15 ml/min of CO2 and 15 ml/min of CH4. The calcination was carried out in the range of 500-900°C. The catalysts were activated inside the reactor at 500-800°C using hydrogen gas. It was observed that calcination enhances catalyst activity which increases as calcination and reaction temperatures were increased. It was found essential activating reforming catalysts with H2.The highest process activity was obtained at 800°C reaction temperature by using catalyst calcined and activated at 900°C and 700°C respectively. The addition of Ca promoter decreases the coke formation on catalyst, however, It initially reduces the activity. The catalyst characterization conducted supported the observed experimental result
Study on Preparation under Microwave Radiation and Application of Chitosan Grafted Poly(acrylamide) Inverse Latex
Authors: Ma Yong Sheng , Wang Lin Tong
Published: May 2011

Inverse emulsion graft copolymerization of chitosan and acrylamide monomer under microwave radiation was studied. It was shown that when the microwave radiation power was 300W, the microwave radiation time was 150S, the volume ratio of oil phase and water phase was 1:1, the weight ratio of chitosan and AM was 1:7, the initiator concentration was 0.67mmol/L, the dosage of emulsification agent was 7% of the weight of oil phase and the weight ratio of Span-80 and OP-10 was 6:4, stable inverse latex could be gained. A good dry strengthening effect had been obtained by applying the above mentioned latex in wheat straw pulp as the strengthening agent. The breaking length and tearing index of paper was respectively increased by 23.5% and 15.1% when the dosage of the graft copolymer latex was 0.6%.