bluuebunny/crossref_metadata_2025 huggingface dataset:
The Magnetic Properties of Mixed Ferrimagnetic Spin System
Authors: Shen Shuang Juan , Jiang Li Qin , Zhong Ke Hua , Chen Zhi Gao , Huang Zhi Gao
Published: November 2010

Based on Monte Carlo (MC) simulation, the magnetization behavior of mixed ferrimagnetic spin system with single-ion anisotropy under external field is investigated. It is assumed that the element of the mixed system is composed of spin-1 and spin-3/2 by turns. The simulated results indicate that there exist the magnetization curves at the ground state on the one-dimensional spin chain, two-dimensional spin system as well as three-dimensional spin system. It found that the size, anisotropy constant and spin configurations influence evidently the magnetic properties of the mixed system. Moreover, the magnetic plateaus and the phase diagrams of the systems can be well interpreted in terms of the simple calculation of energy.
WO3-Based Sensor Based on Hall Effect for NO2 Detection: Designed and Investigation
Authors: Lin Jin Yang , Zhang Yong Ai , Wang Ling Jie , Guo Tai Liang
Published: November 2010

Novel tungsten oxide sensors were fabricated based on Hall Effect and their NO2 gas sensing properties were examined. Tungsten trioxide was grown by vapor evaporation of metal tungsten filament in an oxygen atmosphere. A WO3 thick film was deposited on the four Au electrode to be a WO3 sensor. The sensor was tested between magnetic field in a plastic test chamber. The gas sensing experiment revealed that at the NO2 concentration of 40 ppm, a sensitivity of 3.27, a response time of 36 s, and a recovery time of 45 s were observed at room-temperature. The effect of WO3 based on Hall Effect on the sensing characteristic is discussed.
Improved Photoelectrochemical Properties of Cu-Loaded TiO2 Nanotubes
Authors: Yang Xin Sheng , Kim Hern
Published: November 2010

Cu-loaded TiO2 nanotube arrays were fabricated by immersing the anodized nanotube arrays in Cu(NO3)2 solution and then post-annealed. Copper oxide with diameter about 20 nm was loaded on the nanotube arrays with tube diameter about 140 nm, the wall thickness about 40 nm and the length about 4 µm. Cu-loaded TiO2 nanotube arrays showed remarkable improvement of photochemical activity. The photocurrent of Cu-loaded sample soaked in 0.02 M Cu(NO3)2 solution was about 2.5 times higher than that of unloaded sample.
Preparation and Characterization of the Oxime Carbapalladacycle Complex Grafted onto Mesoporous SiO2@Fe3O4 Nanocomposite for the Heck Reaction
Authors: Shen Bin , Wang Yong An , Wang Zhi Fei
Published: November 2010

The magnetically mesoporous SiO2@Fe3O4 nanocomposites were synthesized by sol-gel method and extracted by ethanol solution. The support was characterized by high resolution transmission electron microscopy (HRTEM), N2 adsorption-desorption isotherms and vibration sample magnetometer (VSM). A long carbon chain Oxime Carbapalladacycle complex was grafted onto this support and the effect of the catalyst was investigated for the Heck reaction of aryl halides with olefins. The results demonstrated that the support with diameter 150 nm was superparamagnetic characteristics (saturation magnetization was 8.78 emu/g) and the thus recycled catalyst could be reused for 6 times with significant loss of activity in the coupling-reaction of iodobenzene and ethyl acrylate. In addition, the catalyst could be simply recycled with the assistance of an external magnet.
Preparation and Characterization of C@PSt Microspheres by High Speed Homogenization-Assisted Suspension Polymerization
Authors: Liu Hong Bo , Wang Ji Hu , Wen Shao Guo , Gan Wen Jun , Xu Qian , Shen Yan
Published: November 2010

Spherical C@PSt microspheres with average size around 2 μm were successfully prepared using high-speed homogenization-assisted suspension polymerization of styrene in the presence of carbon black modified by oleic acid. The effects of initiator varieties and initiators concentration on the fractional conversion were investigated. Compared with BPO, AIBN has higher efficiency to initiate the polymerization. LPSA, SEM and OM results showed the prepared microspheres had spherical morphology with the carbon black in the core and PSt in the shell. About 10 weight percentages of carbon black were encapsulated in the complex microspheres proved by TGA results.
Simulation and Test for Two Airfoils with Wind Guide Vane of VAWT
Authors: Wu Guo Qing , Chen Xinghua , Cao Yang , Zhou Jing Ling
Published: November 2010

Two airfoils of vertical axis wind turbine (VAWT) were designed, and the wind guide vane was added for VAWT. By using Fluent and the environment wind tunnel, some results were simulated and tested for two different types of airfoils and its wind guide vane. The performance data on certain condition was obtained. Research showed that utilization of wind energy with guide vane wind turbine was higher than those without guide vane structure. The performance of airfoil was more excellent than airfoil . Wind guide vane structure is a new structure for wind turbine which will have a wide prospect.
Preparation of a Novel Functionated POSS Nano-Particle Bearing the Perfluoro Aryl Ether Dendron
Authors: Song Li Yun , Peng Shun Jin , Shu Yang
Published: November 2010

In this paper, the perfluoro aryl ether dendrons were synthesized by mesylate reaction, and using the dendron as a modifier to prepare a novel fluorinated polyhedral oligomeric silsesquioxane ( F-POSS) nano-particle bearing this fluorine-containing dendron. In this approach, the Williamson ether synthesis technique was used as the generation enhancement step. Second generation perfluorobenzyl alcohol dendron was obtained from active mesylated precursors. This mesylate actiation technology has the advantage of short reaction times in the subsequent steps and avoids chromatographic purifiction. Second genenriation dendron was then built by repitition of Williamson ether synthesis reaction of mesylate derivative. It is possible for this new nano-particle to be used in the modification of polymer materials to make the durable superhydrophobic and oilphobic surface functional materials with excellent self-cleaning properties.
The Parametric Mesh Method Based on History and Process Parameters Optimization
Authors: Huang Ju Hua , Liu Ze Wen , Xie Shi Kun , Wu Jing Jing
Published: November 2010

In engineering technology, it is necessary to compare different designs in an optimization project. Therefore a big problem is how to obtain finite element analysis (FEA) data involving different parameters and how to acquire optimization parameters from the results of FEA to solve the optimization problem rapidly. The parametric mesh (Paramesh) method, automatically based on history of complicated special surfaces, is developed to obtain many results of FEA involving different parameters. This paper is presented to demonstrate the method of parametric finite element analysis (PFEA). The optimization method of process parameters optimization is based on combining PFEA/ ANN (artificial nerve net)/GA (genetic arithmetic) to find out optimization parameters. This allows one to rapidly obtain optimization parameters during a design by doing FEA only once. The research indicates that the parameters optimization method based on PFEA/ANN/GA in the product design can short the product development cycle, decrease material consumption and guarantee product quality, etc.
Activated Carbon from Bituminous Coal by Microwave-Assisted Heating in Different Gas Media for Supercapacitor Electrodes
Authors: He Xiao Jun , Wang Ting , Li Ru Chun , Zheng Ming Dong , Zhang Xiao Yong
Published: November 2010

Activated carbons (ACs) were prepared by microwave−assisted heating of bituminous coal with KOH as activation agent in different gas media for supercapacitors. The pore structure parameters of ACs are obtained by using nitrogen adsorption technique. ACs prepared in static nitrogen, flowing nitrogen and carbon dioxide are denoted as ACStatic-N2, ACFlowing-N2, ACFlowing-CO2. The specific surface area of ACFlowing-N2 is the biggest among the three ACs, which reaches 1201 m2g-1 with total pore volume being at 0.64 cm3 g-1. The specific capacitance of ACFlowing-N2 electrode and energy density of ACFlowing-N2 capacitor is the biggest among the three AC samples with specific capacitance being at 302.6 F g-1 and energy density being at 10.1 Wh kg-1 after 400 cycles. The microwave−assisted KOH activation of coal is an efficient approach to the preparation of ACs for supercapacitors.
Fuzzy Synthesis Evaluation of Weld Bead Stability for GMAW Prototyping
Authors: Meng Fan Jun , Zhu Sheng , Ba De Ma , Yang Hua , Xing Si Ming
Published: November 2010

Weld bead stability has an important effect on the quality of prototyped products .In the paper, hierarchy analytical theory, combined with the experiment, is employed to determine the weld bead stability synthesis evaluation weight coefficient of surface quality, weld reinforcement and weld width of weld bead. The membership degree tables of surface quality, weld reinforcement and weld width are created by using fuzzy theory. Thus a evaluation method of bead stability is established and applied to evaluate practical bead stability. It is approved that the calculation value accords with the actual result, which proves the evaluation method of bead stability is effective.
Electrochemical Properties of Nano Spinel LiCoXMn2-xO4 Prepared by Sol-Gel Process
Authors: Cai Yu , Zhao Sheng Li , Chang Qing Hua , Zhu Ji Ne
Published: November 2010

Spinel LiCoxMn2-xO4 powders were prepared by sol-gel combined with heating treatment process. The structure, morphology and electrochemical properties of LiCoxMn2-xO4 powders were characterized by XRD, TEM and constant current charge/discharge techniques. The results show that lattice constant and crystal size of LiCoxMn2-xO4 powder decrease and the crystal aberrance increase with the increasing of cobalt content which has less effect on its spinel structure. The initial discharge special capacity of LiCoxMn2-xO4 decreases slightly with the increasing content of Co but its cyclic performance is improved obviously resulted from the improvement of structure stability. Comprehensively the special capacity and the cycle performance, LiCo0.1Mn1.9O4 composed of about 80nm particles exhibits superior electrochemical property and may be used as the cathode material in new type Li-ion battery.
Preparation of TiO2 Supported Gold Nano-Clusters by Photo-Deposition
Authors: Wang Xue Ming , Wu Guang Jun , Li Lan Dong , Guan Nai Jia
Published: November 2010

TiO2 supported gold clusters are prepared by photo-deposition method. The effect of preparation parameters on the size and morphology of gold clusters are investigated. The as-prepared Au/TiO2 samples are characterized by means of ICP, XRD and TEM. Au/TiO2 samples with different gold cluster sizes are studied as possible catalysts in the selective oxidation of benzyl alcohol to benzaldehyde and smaller gold clusters are observed to exhibit higher catalytic activity.
Synthesis of Titania in a Spinning Disk Reactor
Authors: Chien Wen Chen , Jang Shyue Ming , Lin Yu Cheng
Published: November 2010

In this study, titania powders were prepared from 0.02M titanium tetrachloride and 0.08M sodium hydroxide in a high gravity rotary reactor. The preparation was combined with a precipitation, washing/centrifugation, hydrothermal and drying steps. The prepared titania powders were characterized by TGA, SEM, TEM, FTIR, and UV-vis analysis。TGA curves show that the titania yield was found to increase with rising hydrothermal time. TEM analysis show that the prepared titania crystalline in solution has a flake-like shape with a primary size 5~15nm and narrow size distribution. SEM images show that the primary titania crystalline aggregates to large secondary powders with a size 5~20μm。FTIR and UV-vis spectra show that the prepared precursor is titanium hydroxide that was transferred into titanium dioxide after hydrothermal process under a suitable temperature and time.
Poly (Divinylbenzene) Particles of Large Specific Surface Area Prepared by Dispersion Polymerization
Authors: Zhao Yu Zeng , Li Yong Sheng , Ge Hong Hua , Xu Qun Jie
Published: November 2010

Porous polydivinylbenzene particles were prepared by dispersion polymerization, using AIBN as initiator, acetonitrile as solvent, calcium carbonate and polypyrrolidone used as dispersion stabilizer and porogen. Ratio of dispersion stabilizer with monomer affects the specific surface area and porous structure. Calcium carbonate and polypyrrolidone used porogen were studied.
Synthesis and Characterization of Hollow Core-Shell ZrO2@void@BiVO4 Visible-Light Photocatalyst
Authors: Yao Bing Hua , Min Liu , Ma Zhan Ying , Wang Cheng
Published: November 2010

Monoclinic scheelite BiVO4 was synthesized from a mixture of aqueous Bi(NO3)3 and NH4VO3 solutions by hydrothermal method. Then using successive coating of BiVO4 with a carbon layer and a ZrO2 layer followed by heat treatment to remove the carbon layer prepared a core-shell(ZrO2@void@BiVO4) nanoparticles with a void layer between the BiVO4 core and the ZrO2 shell. TG-DTA and IR suggest that BiVO4 was coated with ZrO2. TEM shows that there was a void space between the BiVO4 core and the ZrO2 shell. The samples were characterized by XRD and the peaks of ZrO2@void@BiVO4 suits well with the pure phase monoclinic scheelite BiVO4. And its visble-light photocatalytic activity was evaluated by the photodegradation of methylene blue(MB). The results indicated that the photocatalytic activity of ZrO2@void@BiVO4 is similar to that of pure phase BiVO4, which makes it can be used for preparing liquid-gas phase boundary visble-light photocatalyst.
Inhibition Action and Adsorption Behavior of 3-Amino-1,2,4-Triazole on Copper in 3% NaCl Solution
Authors: Xu Qun Jie , Ding Si Jing , Yun Hong , Shi Shi Feng
Published: November 2010

The corrosion inhibition of copper in 3% NaCl solution by 3-amino-1, 2, 4-triazole (ATA) has been studied in relation to the concentration of the inhibitor using electrochemical (AC impedance and dc polarization) techniques. The results indicate that ATA has good corrosion inhibition for copper in 3% NaCl solution. The inhibition efficiency attains the maximum value of 97.65% when the concentration of ATA is 20 mg•L-1.Polarisation curves show that ATA behaves as a type of cathodal inhibition in 3% NaCl solution. Adsorption of the ATA is found to follow the Langmuir’s adsorption isotherm, and the adsorption mechanism is typical of chemisorption.
Mechanosynthesis of Silicon Nitride Nanowires
Authors: Ren Shu Xia , Ji Feng Qiu , He Xiao Lan
Published: November 2010

Silicon nitride nanowires have been synthesized by mechanosynthesis method. The silicon powders were first milled for 160 hours under the presence of ammonia gas with 300kPa. And then they were heat-treated at 1250 for 2 hours in the pure nitrogen gas. The phase and the microstructure of the as-prepared product were detected by X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscopy (TEM). The results showed that the product consisted of α-Si3N4 nanowires. The nanowires had the length of tens of millimeters and the diameters of 50～100nm. The vapor-solid (VS) mechanism was employed to interpret the nanowires growth.
Experiment Study on the Mechanical Properties of Shape Memory Alloy
Authors: Wang Yong Jun , Wang Zhen Qing , Lv Hong Qing , Wang Yu Long
Published: November 2010

In order to investigate the performance of shape memory alloy wire, two types of alloy wire were studied. The results showed that the phase transition temperature of the superelastic wire were: Ms and Mf were 21.18 °C and 7.08 °C; As and Af were 12.32 °C and 25.13 °C. The phase transition temperature of memory effect alloy wire were that Ms =- 11.85 °C, Mf =- 29.37 °C, As = 36.77 °C, Af = 43.35 °C. By the tensile test of the SMA wire, the stress - strain curves of the two kinds of alloy wire were obtained.
The Synthesis of Multi-Morphologic Nickel Sulfides Nanostructures by a Solution Chemical Route
Authors: Zhang Ya Hui , Cheng Xi , Wang Qing
Published: November 2010

The Multi-Morphologic nanostructures of nickel sulfides were synthesized successfully by a solution chemical route. The growth models of these materials and the most possible mutation process between these different morphologies were discussed.
Preparation and Properties of Electrospun Cellulose Acetate Nanofiber Mats
Authors: Zhou Wei Tao , He Jian Xin , Cui Shi Zhong , Gao Wei Dong
Published: November 2010

Four kinds of solutions were prepared by dissolving cellulose acetate in dichloromethane, formic acid, acetic acid and trifluoroacetic acid respectively, and then were electrospun into fibers. The solutions were characterized for their viscosity and conductivity using rotary viscosimeter and conductivity meter, respectively. The morphology and performance of the electrospun CA fibers were investigated by scanning electron microscopy (SEM), digital microscope and X-ray diffraction (XRD). Results showed that the important factors determining the electro-spinnability of the CA solutions were boiling point, viscosity and conductivity of the resulting solutions. 8% CA spinning solution with trifluoroacetic acid as solvent had good spinnability, and the average diameter reached 236nm; the obtained fibers were mainly amorphous, but characterized for good mechanical properties.
Photoactivity and Hydrophilicity of B and Ni Co-Doped TiO2 Films
Authors: Masae Mahamasuhaimi , Sikong Lek , Kooptarnond Kalayanee , Taweepreda Wirach , Saito Fumio
Published: November 2010

The effect of Ni doping in Ni and B co-doped TiO2 composite films on photocatalytic reaction and hydrophilic property were investigated. The TiO2 composite films were prepared by sol-gel and coated on glass substrates by dipping methods. These composite thin films were calcined at the temperatures of 400°C for 1 h. Phase formation of TiO2 was characterized by XRD. Morphology of TiO2 composite films were observed by using atomic force microscopy (AFM). The chemical composition and purity of the prepared films were analyzed by EDS, FTIR and FT-Raman spectrometers. The photoactivity of synthesized films was performed by means of degradation of methylene blue dye solution under UV and visible light irradiation. The hydrophilic property was measured in terms of a contact angle of water droplet on the films with and without the activation of UV irradiation. It was found that Ni doping seems to affect on TiO2 phase, crystallinity of the anatase phase, crystallite size of the composite films and band gap energy of the catalysts, resulting in their photocatalytic reaction and hydrophilic property. The crystallinity of anatase increased with an increase in Ni content varied from 0-3 mol% but decreased with an increase in Ni content above 3 mol%. It was found that 3 mol% Ni/B/TiO2 film, having highest crystallinity and smallest crystallite size shows the highest of photocatalytic reaction while 2 mol% Ni/B/TiO2 film provides the most hydrophilic effect. Only anatase phase was found at the calcination temperature of 400°C. The smooth film surfaces exhibits a high hydrophilic property. Super-hydrophilicity (contact angle equal to zero) of all B and Ni co-doped TiO2 films was found at UV irradiation for 25 minutes.
Synthesis and Characterization of Coordination Nano-Material Containing Vanadium with Helical Stracture
Authors: Bei Feng Li , Li Yang Mei
Published: November 2010

A novel coordinated nano-material containing vanadium with regular helical chains has been prepared via a hydrothermal procedure by using 2,3-Diaminephenazine (2,3-DAP) and vanadium pentoxide (V2O5) as starting materials without the aid of any surfactants and templates. Then the products of V2O5 nanohelix complexes were characterized by using XRD, SEM, FT-IR, NMR, and TEM. Furthermore, the electrochemical property of the V2O5 nanohelixes was determined by the voltammetric technique.
The Design of Three-Dimensional Vibration Sensor Based on SOI Microfabbrication
Authors: Shi Gui Xiong , Zhang Guo Jun , Xu Jiao , Wang Xiao Yao
Published: November 2010

Compared with the traditional vibration sensors, the micro-vibration sensor have many advantages, such as small size, high sensitivity and low noise which is based on micro-fabbrication.This paper introduced the micro-vibration sensors which sensitive structure are cilium and micro-elastic beams. The micro-vibration sensors were produced by the inductively coupled plasma technology (ICP), the maximal etching depth of which can be greater than 300μm, the thickness of beam is less than 20μm and the longth of cilium are more than 3000um.The sensitivity of the sensor is 102.5μV/g, the measurement range to +20g, and the resonant frequency is 2KHz.
A ZigBee-Based Smart Home System: An Energy-Saving Method
Authors: Zang Xuan , Sun Ying , Li Ke Jun
Published: November 2010

Smart Home technology promises enormous possibilities to our future life. It contains internal network, intelligent control and home automation. The paper describes a novel architecture for the smart home system employing ZigBee technology. Energy conservation is also a feature of smart home system. Based on the time-of-use (TOU) pricing, a new energy saving solution has been proposed.
Creep Properties of High Cr Resisting Weld Metal Alloyed with Co
Authors: Wang Xue , Pan Qian Gang , Zhan Liang  Fei , Liu Zi Jun , Liu Hong , Tao Yong Shun
Published: November 2010

A 9-12% Cr ferritic steel weld metal containing 1% Co partially substituted for nickel was prepared by submerged arc welding processing(SAW). The microstructures and creep properties of the weld metal have been investigated. The microstructure exhibited a fully tempered martensitic structure free of δ-ferrite. The creep properties of the obtained weld metal are inferior to that of the P92 base metal at 600 and 650 . The values of A and n for weld metal in Norton power law constitution at 650 are 1.12×10-21 and 8.14, respectively.
Study on the Stability in Laser Cladding Forming Process of Thin-Wall Structures
Authors: Hu Wei Wei , Kang Jin Wu , Ma Ji Yu , Huang Tian You , Li Di Chen , Zhang An Feng
Published: November 2010

The parameters obtained in the study of single layer of laser cladding forming are not suitable for the forming of actual structures. The cooling condition varies with the height of clad layers, which result in instability and then failure of cladding. Therefore, the stability of laser cladding forming is of significance. In this paper, melt pool depth is used as a criteria for stability. And the effect of processing parameters such as laser power and laser velocity on melt pool depth, are investigated by numerical simulation method. The results unveil that there is a transition zone from the beginning to stable stage during laser cladding forming. In the transition zone, laser power should be decreased or laser velocity should be increased to maintain the constant melt pool depth and to ensure the former clad layer would not be remelt. The optimized processing parameters are obtained for stable processing for a thin flat wall and a cylindrical wall, which successfully guide the manufacturing of the real structures.
Effects of ZnO-Bi2O3-B2O3-SiO2 Glass Additive on Dielectric Properties of CaO-Li2O-Sm2O3-TiO2 Microwave Dielectric Ceramics
Authors: Yang Liu Shuan , Wang Xiao , Huang Jin Liang , Li Fei Long
Published: November 2010

The effects of ZnO-Bi2O3-B2O3-SiO2(ZBBS) glass addition on the sintering behavior, crystalline phase, microstructure and dielectric properties of 16CaO-9Li2O-12Sm2O3-63TiO2(CLST) ceramics were investigated. The results show that ZBBS glass can effectively decrease the sintering temperature of CLST ceramics to 1 000 °C by liquid phase sintering. With the increase of ZBBS content, the second phase，Sm2Ti2O7 is found and increase, which causes the dielectric constant and dielectric loss of CLST decrease. The temperature coefficient of the resonance frequency shifts to positive. The optimum dielectric properties of r = 71, Tan = 0.006, TCF= 5×10-6/°C were obtained in 10wt% LBS glass-doped CLST ceramics sintered at 1 000 °C for 3 h.
Effect of Different Compacting Processes on the Microwave Sintering Behavior of LaNbO4/MoSi2 Composites
Authors: Ai Yun Long , Li Yan Yan , Liu Chang Hong , He Wen , Ding Jia Yuan
Published: November 2010

The green bodies of LaNbO4/MoSi2 composite materials were compacted by warm pressing and cold pressing processes, and then the composites were prepared by microwave sintering. Effects of the two different compaction processes on sintering process and sintered samples were analyzed. The results show that the density of the microwave sintered sample by cold pressing (5.599g/cm3) is similar to that of warm pressing (5.593 g/cm3). But cold pressing has some disadvantages, such as longer sintering time, incomplete sintered samples, peeling easily on the surface and delaminating, existing internal stress, having microcrack and impurities, and occurring distortion easily in sintered samples. The samples compacted by warm pressing have higher heating rate in the microwave sintering process, which have more homogeneous structures, no clear microcrack and big cavities, and higher fracture toughness after sintering. Compared with cold pressing, the comprehensive properties of warm pressing are better.
Synthesis and Properties Study of Pr Doped(Bi0.5Na0.5)TiO3 Produced Using the Soft Combustion Technique
Authors: Cheah Jun Yip , Khairunisak Abdul Razak , Sreekantan Srimala
Published: November 2010

In this work, Praseodymium (Pr) doped bismuth sodium titanate, (Bi0.5Na0.5)TiO3 (BNT) is successfully produced using the soft combustion technique. The effects of Pr doping on stoichiometry, microstructure, density and dielectric properties are studied. Pure phase can be obtained in all samples containing 0, 5, 10 and 20% Pr after calcination at 800°C for three hours. The powders are then pressed into pellets and sintered at 1050°C for three hours. The crystallite size and grain size decrease with increasing Pr amount because Pr acts as grain growth inhibitor. Maximum density is obtained in 5% Pr doped BNT, beyond which density decreasing. Maximum dielectric constant of 756 was obtained in 5% Pr doped BNT and decreases beyond that. Pr doped in BNT also causes dielectric loss to decrease. The result is in agreement with structural, microstructure and density analysis.
Synthesis of High Surface Area Porous Silicon Carbide by Employing Soft Template in the Sol-Gel Process
Authors: Wang Dong Hua , Fu Xin
Published: November 2010

High surface area porous silicon carbide was synthesized by a modified sol-gel method. In the sol-gel method, furfuryl alcohol and tetraethoxysilane were used respectively as carbon and silicon precursors for preparing a carbonaceous silica xerogel. Polymethylhydrosiloxane (PMHS) was employed as pore-adjusting agent in the sol-gel process. SiC was obtained by the carbothermal reduction of the carbonaceous silica xerogel at 1300 oC in argon flow and then purified by removing excess silica, carbon and other impurities. XRD、FTIR、SEM、HRTEM and BET were used to characterize the SiC samples. The results show that the SiC products are found to have high specific surface area of 135 m2 /g. PMHS has important effect on the surface area, pore volume of the SiC products. It is therefore suggested that PMHS plays the role of structure-directing agent that enhances the production of mesoporous pores in the SiC products.
Finite Element Analysis on Stress and Strain of Protected Fiber Bragg Grating
Authors: Xie Jian Feng
Published: November 2010

The stresses and strains on the protected FBG and protected layer under varied temperature were analyzed in theory. In order to verify the theoretical analysis of stress and strain,a finite element analysis software(ANSYS) was used to simulate the stresses and strains on the protected FBG and protected layer. Both simulation and theoretical analysis are show that the strain and stress on protected layer in r direction decreases with the increasing of radius(r), while the strain and stress in direction increases with the increasing of radius(r) . The results of theoretical analysis matches the ones form simulations well.
Effect of N-Isopropylacrylamide on the Structure and Swelling Behavior of Microporous Polyurethane Film
Authors: Lv Hai Ning , Cai Zai Sheng , Qian Cheng , Xue Yuan
Published: November 2010

Preparation of membranes from stimuli-responsive polymers, copolymers, and polymer-additive mixtures is an important approach in the design of responsive membranes. N-isopropylacrylamide(NIPPAm) was dispersed in polyurethane(PU) solution, crosslinked with N,N’-methylene bisacrylamide(BIS) and then cast in bathes to get a thermosensitive microporous film. The ratio of NIPAAm with BIS amount and the cast medium were varied. The structure, surface and cross-section images of polyurethane/poly(N-isopropylacrylamide) (PU/PNIPPAm) semi- interpenetrating networks (semi-IPNs) were characterized by FT-IR and SEM. The swelling behavior of pure PU films and PU/PNIPPAm semi-IPNs were compared. The results showed that incorporation of PNIPPAm had great effect on the structure and swelling behavior of composite films. This approach enables fabrication of membranes with the desired pore structure.
Preparation, Characterization and Photocatalytic Properties of Flower Like Bi2WO6 under Solar Light Irradiation
Authors: Sun Jian Hui , Feng Jing Lan , Tian Xiao Ke , Dong Sun Ying
Published: November 2010

Flower like Bi2WO6 powders were synthesized via a mild hydrothermal method. Analysis of X-ray diffraction (XRD) revealed that optimal calcination temperature was believed to be 400 °C at which the photocatalyst displayed high surface area and small crystallite size. Scanning electron microscope (SEM) showed that obtained Bi2WO6 with a flower like shape, which greatly enhance the surface area of catalyst and increase the contact area with dyes. The photocatalytic activity of as-prepared catalyst was investigated using Rhodamine B as a model compound under solar light irradiation. Results showed that the prepared photocatalyst was an effective photocatalyst and exhibited high photocatalytic performance. In the presence of 1 g/L Bi2WO6, 80.76% decolorization efficiency of RhB could be achived after 150 min irradiation
Effects of Nanoclays on the Biodegradable Nanocomposite
Authors: Wang Chun Hong , Ko Frank K.
Published: November 2010

Nanoclay/polylactide(PLA) nanocomposite was produced by the electrospinning process. The influences of nanoclays on the morphology and mechanical properties of the nanocomposite were investigated. The morphology and mechanical property of the nanocomposite were evaluated by scanning electron microscopy (SEM) and microtensile testing. SEM images revealed that submicron scale nanoclay/PLA nanocomposite fibers were fabricated and the introduction of nanoclay reduced the diameter of the nanofibers and improved the uniformity of the fibers. The addition of 1% nanoclay in PLA nanofibers leaded to simultaneous increases in the tensile strength, elongation at break and modulus for the PLA nanocomposite mat.
Thermodynamic and Kinetic Analyses of Calcined Kaolin Precursors Used for Synthesis of Mullite Nanocomposite
Authors: Chen Nan Chun , Ao Han Mei , Wang Wei , Li Quan Hong , Deng Ai Ping
Published: November 2010

Mullite precursor was prepared from kaoline when calcined at 1250 °C，when the concentration of sodium hydroxide of 3 mol/l; crystallization temperature of 80 °C; holding time of 3 h and precursor concentration of 0.15 g/ml, the morphology of the prepared mullite nanocomposite appears spherical-like, and it has good crystallization property and low agglomeration, and the average size of the particles is about 60.9 nm. Both the thermodymics and kinetics of mullite precursor have been studied. The results are as follows: the reaction started when the calcine temperature T﹥495°C; mullite precursor formed when the reaction system temperature 1000 °C; the activation energy of precursor Ea=928.3 KJ/mol; the reaction order n=1.33. We have reported our successful experiments to use kaolin to synthesize mullite nanocomposite with satisfying, spherical morphology, relatively homogenous grain average size of 60.9 nm, and little aggregation[1-2]. This paper presents an investigation of the thermodynamics and kinetics of the precursor preparation process.
Numerical Simulation and Experimental Study of AZ31 Magnesium Alloy Deformation Behavior in ECAP
Authors: Ren Guo Cheng , Zhao Guo Qun , Xu Shu Bo
Published: November 2010

This article investigated deformation behavior and microstructure of AZ31 magnesium alloy in equal channel angular pressing (ECAP) process at 250 C. The proper process parameters were obtained through investigating the deformation behavior and properties of AZ31 magnesium alloy by using finite element (FE) simulation under different deformation conditions. The ECAP experiments were also carried out by using the optimized design of the channel die. The micro-structures of experimentally pressed work-pieces are in good agreement with finite element analysis results. The research results provided reliable basis for the further development and use of magnesium alloy precision forming.
Development of High Strength Hull Plate by Normal Hot Rolling and High Rate Cooling Process
Authors: Lu Hai Na , Gao Xiu Hua , Jiang Zheng Yi , Wei Dong Bin , Liu Xiang Hua
Published: November 2010

This paper investigates the effects of normal hot rolling and high rate cooling (NHR+HRC) on microstructure and mechanical properties of the rolled EH 36 hull plate. Double-hit tests were carried out to study the effect of process parameters such as the deformation temperature and soaking time on microstructures of the tested steel, and explore optimal processing parameters. Single-hit compression with various parameters was developed and the microstructures of the tested steel are analyzed to determine the cooling rate and the final cooling temperature of the normal hot rolling and high rate cooling. This study will provide experimental and theoretical base on high-temperature rolling control system. Industrial trial was performed to produce regular products. The results show that the NHR+HRC is an effective and promising method to improve the product quality of high-strength hull plate.
Lubricating Characteristics of Circular Tilting Pad Thrust Bearing
Authors: Yu Xiao Dong , Jiang Hui , Meng Xiu Li , Xiang Hong Jun , Yu Hai Peng , Wang Jun Feng , Lou Xiao Zhong , Sun Xian Zhu , Yang Chang Qing
Published: November 2010

In order to solve lubricating problem of circular tilting pad thrust bearing in the heavy equipment, lubricating characteristics mathematical model is established based on the Computational Fluid Dynamics and lubricating theory, the Finite Element Method is used to compute the lubricating characteristics of a circular tilting pad thrust bearing, and figure out thickness distribution of oil film, pressure distribution of oil film, temperature distribution of oil film, power loss and fluid flow, etc. lubricating characteristics parameters by self-compiling software program. Experiments testify the validity of the lubricating characteristics mathematical model. Through this method, the safety of a circular tilting pad thrust bearing can be forecasted, and the optimal design of such products can be achieved, and provides reasonable data for actual design and experiment, and decreases economy loss.
The Application of Newton Iterative Calculation for Cold Rolling Control
Authors: Lei Song , Wang Jun Sheng
Published: November 2010

In this paper, Newton iterative calculation is adopted for the solution of non-line equation, which reverse calculation value of strip deformation resistance for process control of cold rolling as variable. The calculation speed, stability and accuracy of this algorithm are analyzed. The practical application verifies that Newton iterative calculation can meet the requirement of non-line calculation of process control of cold rolling.
Influence of the Performance of Power Ultrasonic Transducer on its Front Cover Shape
Authors: Zhang Ming , Wang Yu Qing , Zhao Chong Yang
Published: November 2010

Two sets of power ultrasonic transducer applied to ultrasonic machining are designed in this paper, whose surface location, the number of piezoelectric ceramics is identical. By changing the parameters of the quarter wavelength horn which connects with the power ultrasonic transducer, the transducer changes of performance parameters are compared. The influence of the performance of different structural power ultrasonic transducer on its front cover is studied.
Analysis on Thermal Efficiency and Softening Behavior of MIG Welding with Longitudinal Magnetic Field
Authors: Zhu Sheng , Wang Qi Wei , Wang Xiao Ming , Han Guo Feng
Published: November 2010

In the study, thermal efficiency in MIG welding of aluminum alloy with longitudinal magnetic field was analyzed, as well as softening behavior of heat-affected zone (HAZ) and base metal were investigated. The results showed that welding current decreased and resultingly total heat input reduced as the exciting current increased, meanwhile arc thermal efficiency increased and melting efficiency decreased. As a result of action of the magnetic field, the trend of grain growth of HAZ slowed down and the influence on base metal of heat input decreased. When the exciting current was 20A, microhardness of HAZ and base metal improved evidently. However, as the exciting current continued to increase, the effect of magnetic field on softening behavior did not change significantly.
Effect of Forward Extrusion and Heat Treatment on Microstructure and Mechanical Properties of as-Cast ZK60 Magnesium Alloy
Authors: Xue Yong , Zhang Zhi Min , Lang Li Hui
Published: November 2010

In the present research, the influences of different extrusion ratios (15, 30, 45, 60, and 75), extrusion temperatures (300 , 340 , 380 , 420 , and 460 ), and subsequent heat treatment on the mechanical properties and microstructure of as-cast ZK60 magnesium alloy have been investigated through the tensile tests and via metallographic observation. The results show that forward extrusion process can refine the microstructure of as-cast ZK60 alloy effectively. If as-cast ZK60 alloys have been extruded with the extrusion ratio 45 at 380 ,420 and 460 , respectively, and then post-heat treatment was conducted, the ZK60 alloy’s strength is higher under T5 than T6 treatment. For as-cast ZK60 alloy processed by extrusion and T5 method, the most appropriate temperature for extrusion processing is 300 , at which its tensile strength are highest provided the extrusion ratio is 30 but yet its plasticity is best provided the extrusion ratio is 45. If forward extrusions were conducted at 380 , mechanical properties of ZK60 alloy have little difference as the extrusion ratio varies. When T6 treatment was conducted for the extruded bars, their mechanical properties were improved little, moreover, the bigger the extrusion ratio is, the higher the tensile strength and elongation of the extruded bars become.
Applications of Efficient Energy-Saving Cement Grinding Technology and Equipment
Authors: Tian Jian , Zhao Xiao Yu , Wang Jin Di , Wei Tao
Published: November 2010

Joint grinding system is the preferred cement grinding system of current cement process design, the advantages are high productivity, low energy consumption of system and low noise, etc. It meets the industrial policy of domestic energy-saving and reduction emission, so the development prospects is broad.
Design of a Novel Experimental Appratus for Simulating Large Tectophysics Based on the Similar Theory
Authors: Ren Xu Hu , Yang Lei
Published: November 2010

Design of an experimental apparatus to simulate the geophysics is vital to understand the structural and evolutionary phenomena of a complex geological system. In China that lacking of a suitable comprehensive experimental apparatus for such purposes is a major factor that greatly restricts the developments of geological modeling towards the quantitative and repeatable requirements. In line with the analysis according to geological theories, and change rules of stress-strain of a geological body, the paper provides a design of a powering unit, by means of a PLC based controller, capable of performing functions specified by the experimental apparatus. Some results, obtained from using standard procedures for tectophysics simulation study, of using such an experimental apparatus are given, which showcase that the design is in properly functioning and therefore can be used for similar geological experimental study.
Airport Gate Assignment Model Based on Gate Occupied Efficiency
Authors: Zheng Pan , Hu Si Ji , Deng Wen
Published: November 2010

Airport gate assignment is to appoint a gate for arrival or leave flight and to ensure that the flight is on schedule. Assigning the airport gate with high efficiency is a key task among the airport ground operation. As the core of airport operation, aircraft stands assignment is known as a kind of complicated combinatorial optimization problem. In this paper, occupied gates in order to optimize the efficiency of the target index, the purpose of parking gates in order to save the resource utilization and to improve the speed of flight at the same time working to meet the requirements of the quality of passenger services, An integer program (IP) model is developed, and a tabu search algorithm was put forward to resolve the model. The algorithm results in the calculation of time and extent to optimize the effectiveness of certain.
Hybrid Genetic Simulated Annealing Algorithm with its Application in Vehicle Routing Problem with Time Windows
Authors: Zhang Qiang , Lin Qing Guo , Zhang Qin He , Fang Ji Chen , Wang Zhan Gen , Shi Meng Zhu
Published: November 2010

Under the situations of distribution center and customer demand, a mathematical model of Vehicle Routing Problem with Time Windows(VRPTW) is set up, where the main factors of less total distance of vehicles driving and less delayed time of vehicles are considered. For the "premature" convergence in Genetic Algorithms, Simulated Annealing Algorithm is introduced, and GSA is designed to optimize and analyse the VRPTW examples. It is shown that the performance of GSA is better than Genetic Annealing(GA).
Fabrication and Research of Electroless Nickel Plating on Carbon Fiber with Palladium-Free Activation
Authors: Luo Xiao Ping , Zhang Ming Gang , Lv Chun Xiang
Published: November 2010

A new procedure of surface activation without using palladium salt is proposed for electroless nickel plating (Ni-P) on carbon fiber. The optimal formula and technical conditions for palladium-free activated electroless Ni-P were obtained by orthogonal experiments. The effects of nitric acid processing time on the quality of nickel coating was investigated .The effects of varying concentrations of Ni2 + on the rate of weight gain during the Ni2 + complex adsorption process were also analyzed and the kinetic equation of the process was established. The theoretical values calculated by the equation were proven to be consistent with the experimental verification. The material characteristics of the deposited layers were analyzed by scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDX) and X-ray diffraction (XRD). The tensile strength of the carbon fibers was analyzed by the Weibull method, and this showed that when the thickness of the Ni-P coating reached 0.150μm, the tensile strength reached a maximum value. The experimental results showed that the nickel deposition on the carbon fiber surface obtained by this method, had the same uniformity, compactness and adhesive properties as the one by conventional electroless Ni-P.
A New Type Dynamic Vibration Absorber to Reduce Broad-Band Vibration in Plates
Authors: Xiao He Ye , Sheng Mei Ping , Lei Ye
Published: November 2010

A new type dynamic vibration absorber, which consists of steel layer and variable cross section rubber layer fitted to plate by bolt through L-shape connection, is introduced firstly and applied to control vibration of plates at multi mode frequencies in this paper. The aim of the present paper is to study the energy absorbing ability of the new type dynamic vibration absorber and apply optimization method to obtain parameters of absorber which is excellent in absorbing energy. The coupling model of composite beam and plate is established by power flow method and energy of plate attenuated by absorber is analyzed. To improve energy dissipated by absorber, the particle swarm method is used to optimize parameters of absorber to minimize vibration energy of the plate. An experiment is executed to certificate the energy mitigated by absorber to validate analytical modeling method. The test data are consistent with the analytical results, demonstrating that the new type dynamic vibration absorber can suppress the vibration energy at every mode of plate and achieve a goal of multi-mode control.
Effect of Water Rinsing Temperature for Steel Substrate on Corrosion Behavior of Hot-Dip Aluminizing Coatings
Authors: Yao Wen Li , Li Qian , Li Mou Cheng , Zhang Jie Yu , Chou Kuo Chih
Published: November 2010

The relationship between the morphology and protective action of hot-dip aluminizing coatings on Q235 steel have been investigated by SEM, EDS and EIS in 3.5 wt% NaCl aqueous solution. The results indicated that the anti-corrosion performance of the hot-dip aluminizing coatings using steel substrate rinsed by the distilled water at 25 oC was higher than that at 80 oC. The evolution of localized corrosion from pitting to exfoliation corrosion has been found on the aluminum coating surface during immersion, and corresponding equivalent circuit models were proposed to fit the EIS data in the initiation and propagation stages of corrosion process.
New Continuous Model of Reynolds Equation for Gas Film Lubrication
Authors: Ji Jia Dong , Shi Bao Jun , Yang Ting Yi , Song Shi Jun
Published: November 2010

Started from a widely used FK model of Reynolds equation, a new simplified model, called continuous FK (CFK) model, is proposed to simulate the ultra-thin air bearing film in hard disk drives (HDDs). The new model of Reynolds equation possesses simpler mathematical form than that of FK model. The new model is solved by using a least square finite difference (LSFD) method and the resultant numerical results are compared with those of FK model. It is found that numerical results of the two models are in very good agreement.
Dynamic Characteristic Analysis and Machining Error Study Based on Solid Vibration Beam Rate Sensor
Authors: Liu Yu , Lu Yong Le , Zeng Liao Liao , Du Xiao Peng , Li Lei Lei , Pan Ying Jun
Published: November 2010

Machining error of vibration beam rate sensor and its influencing to the performance of solid vibration inertial sensor were studied. The dynamics model was analyzed, and the mechanism error caused by the technology limit was studied and the theory of deducing the error was presented. Numerical calculations combined with 100mm alloyed vibration beam have been made. Results showed that quadrature error is the primary factor of affecting gyro’s performance; the error caused by mass center deviation of vibration beam change with angular acceleration, which can be ignored under the condition that small angular acceleration. The affects of parasitic Coriolis error on performance is minimal, which can be neglected. Finally, the quadrature error’s simulation results were consistent with expected results. The result also proved that restraining and compensating quadrature errors is one of the key technology to increase the performance.