bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of Vane Hydraulic Damp Dynamic Seal Mechanism and Performance Influencing Factors
Authors: Wang Wen Rui , Yan Xiao Qiang , Sun Zhi Hui , Jiang Qi
Published: June 2012

In this paper, the force, deformation and other factors of vane hydraulic damp dynamic seal are researched, which is used of theoretical, simulation about the lip seals sealing damping performance factors. In order to improve sealing performance vane hydraulic damp life, dynamic lip seal design, optimization and performance study is to provide the basis for the theory and engineering applications. The factors influencing sealing performance are considered, such as initial compressibility, sealing sping stiffness. The finite element analysis method can be effectively used to solve nonlinear material and sealing failure problem for the seal design, optimization and performance analysis, which provide a new approach and theoretical guidance to the rubber seal research.
Preparation of Low-Temperature Sintered Ba2Ti9O20 Ceramics Doped with B2O3 by Different Method
Authors: Li Qian , Jin Biao , Huang Jin Liang , Gu Yong Jun , Li Li Hua
Published: June 2012

Ba2Ti9O20 ceramics were prepared with different additives of B2O3 by liquid coating method and solid phase mix method. The sintering behavior, phase structure and dielectric properties of ceramics were investigated by X-ray diffraction, scanning electron microscopy and inductance-capacitance resistance analysis. The liquid coating method can reduce the amount of sintering aid and minimized the negative impact of sintering aid on dielectric properties. A ceramic composite which could be sintered well at 900°C for 3h and showed good dielectric properties of εr=42,tanδ=0.002 and TCF=-4ppm/°C（1MHz）was obtained when 1.0mol/l H3BO3 was added to the Ba2Ti9O20 ceramic.
Layered Cellulose Nanofibers Nanocomposites via Layer by Layer Assembling
Authors: Fu Shen Yuan , Song Pin Gan , Ni Zhong Jin , Wu Qiang
Published: June 2012

Native cellulose nanofibers with high strength ratio may create an alternative as the blade material for wind power field. In this work, cellulose nanofibers (CN) with high L/D ratio was fabricated by combined biological treatment and mechanical disintegration processes. Then, we created a high-performance cellulose layered nanocomposites via layer by layer (LBL) assembling strategy. Transmission electron microscopy (TEM) observations show that common paper pulp exhibits a nearly spherical or amorphous structure, while as-made cellulose nanofibers displays a high aspect ratio, with a length of ca. 10~100 μm and a diameter of ca. 30~100 nm. However, some relative big fibres bundles are still observed. Mechanical measurements demonstrate that the tensile strength, Young’s modulus and elongation at break of layered CN nanocomposites (CNLC) reach 114MPa. 7.0GPa and 68 %,respectively, while only 63MPa, 3.3 GPa and 27 % for layered common paper pulp composites (PFLC). Flexural tests results show that CNLC gives a flexural strength and modulus of 263 MPa and 19 GPa, while only 114 MPa and 11 GPa for PFLC. Fracture surface observations indicate that though layered structure can be observed for both PFLC and CNLC, much thinner layer and long fibrous structure only exist in CNLC, which results in high mechanical performance.
The Effect of Nano-Particles in Superconducting MgB2 Thin Films on Stainless Steel Substrates
Authors: Wang Yin Bo , Chen Yi Ling , Feng Qing Rong
Published: June 2012

We have fabricated several superconducting MgB2thin films on stainless steel substrates by using hybrid physical-chemical vapor deposition (HPCVD) in pure argon atmosphere. These films were observed by scanning electron microscopes (SEM) and used the energy dispersive X-ray spectroscopy (EDX) to make elements analyses. The film thickness is about 800~1000 nm. There were some cracks on the film surface when the film is bent by different angle. The number of cracks and their width increased with the increasing bending angle. Nevertheless, the films were attached to the substrates firmly. It concludes that the superconducting MgB2thin films have great ductility and adhesion to the stainless steel substrates. We found in these films many granules about tens of nanometers in size. These nano-granules can balance both the inner structure and the surface activity of the MgB2crystal. This might be an important reason for the ductility observed with the superconducting thin films. The exact explanation depends on further research.
Study for the Reason of Chromium Coating Seepage on Piston Rods and the Anti-Seepage by Using Ultrasonic Elliptical Vibration Burnishing Process
Authors: Qin Wei , Zhang De Yuan
Published: June 2012

In this paper the reason of chromium coating seepage on piston rods is analyzed. The results show that the chromium coating seepage is mainly caused by the net structure of micro-cracks produced in electroplating process. According to this special structure of chromium coating, experiments are made to study the feasibility that the chromium coating is burnished by using the ultrasonic elliptical vibration burnishing (UEVB) process to prevent seepage. The results of study demonstrate that the UEVB process make the micro-cracks on the surface of chromium coating closed or eliminated because the UEVB process could make the chromium coating plastic-forming. Thereby airtightness of piston rods is increased and seepage is prevented approximately. Compressive stress within the material of chromium coating will produce so that the micro-cracks propagation would be restrained and the life of parts is extended.
Normal Stress Distributions in a Single-Lap Adhesively Bonded Joint under Tension
Authors: He Xiao Cong
Published: June 2012

This paper investigates normal stress distribution of a single-lap adhesively bonded joint under tension using the three-dimensional finite element methods. Five layers of solid elements were used across the adhesive layer thickness in order to obtain an accurate indication of the variation of normal stress. All the numerical results obtained from the finite element analysis show that the spatial distribution of normal stress are similar for different interfaces though the stress values are obviously different. It can also be seen from the results that the left hand region, which is very close to the left free end of the adhesive layer, is subjected to very high stress and the magnitude of the normal stress oscillates in value close to the left end of the adhesive layer.
Friction and Wear Mechanism between Rubber and Nickel for Water Lubricated Bearings
Authors: Wang You Qiang , Shi Xiu Jiang , Ren Fu E
Published: June 2012

Water lubricated rubber bearing is one of the most appropriate bearings widely used in submerged pump for drainage. The water lubricated rubber bearings sometimes worked in absent-water conditions especially at the machine start or brake. The friction and wear characteristics of the water lubricated rubber/Nickel coating pair were tested under dry, wet and water lubrication conditions respectively on the high-speed ring-block friction and wear testing machine. The effect of load and speed on the friction coefficient was examined in the experiment. The friction and wear mechanism of the rubber/Nickel coating pair under different conditions was analyzed with the help of SEM in the paper. The results show that the adhesive wear mainly occurs under dry condition, the grain abrasion occurs under wet condition and boundary lubrication occurs under water lubrication.
A Kind New Materials ColorPro of Simplified the Coating Process
Authors: Yao Yu , Cao Xiao Gen , Cui Yu Shu
Published: June 2012

BASF successfully developed a kind of paint ColorPro Integrated Process II. By the judgment of its use conditions and the associated test, its appearance and performance can meet the requirements of coating. With advantages in energy saving, emission reduction, saving and other aspects of performance will lead to coating the progress of energy saving work.
Preparation of ZnCo2O4 Micro-Materials via a Solvothermal Route
Authors: Sun Ling Na , Wang Qiang , Hu Chang Wen
Published: June 2012

Different ZnCo2O4 micro-materials had been synthesized using surfactant (CTAB) in the solution of mixed solvents. Using CTAB as morphology-controlling agent, different morphologies of ZnCo2O4 are obtained successfully. The concentration of the reactants and the dosage of CTAB had significant effects on the morphology of the products. The morphologies of micro-cubes, micro-plates, and micro-particles were efficiently obtained, respectively, with careful control of the fundamental experimental parameters including the concentration of the reactants and the dosage of CTAB. X-ray powder diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize these products.
Synthesis and Crystal Structure of [(μ-Biphenyl-3,3'-Dicarboxylato)Manganese(II)]
Authors: Wang Guang Yin
Published: June 2012

Hydrothermal reactions of biphenyl-3,3'-dicarboxylate acid (H2bpda) with Manganese(II) chloride gave rise to one new coordination polymer, namely, [Mn(bpda)]n. It was characterized by elemental analysis and single - crystal X - ray diffraction methods. This compound has one Mn metal center and shows a 3D uninterpenetrating framework
Preparation and Characterization of Glycyrrhizin-Graphene Hybrid Materials
Authors: Wang Zong Hua , Gao Yan Li , Xia Jian Fei , Zhang Fei Fei , Xia Yan Zhi , Li Yan Hui
Published: June 2012

A glycyrrhizin decorated graphene hybrid materials (GL-G) was synthesized, which is a layer-to-layer sandwich construction. The results of characterization indicate that a photo induced electron transfer process or efficient energy transferring along the GL-G interface. Furthermore, the as-made hybrid material was used as a modifier of the glassy carbon electrode to construct a sensor (GL-G/GCE). Using p-nitrophenol as a model compound, the novel sensor demonstrated a highly enhanced electrochemical activity for it. The peak current of p-nitrophenol was significantly improved at the sensor.
Size Prediction of Carbon-Encapsulated Nickel Nanoparticles
Authors: Liu Fu Qiang , Hu Sheng Liang , Bai Pei Kang
Published: June 2012

A simple theoretical model to predict the size control of carbon-encapsulated metal nanoparticles is developed using heat transfer and carbon diffusion theories. Taking carbon-encapsulated nickel nanoparticles as an example, the minimum size of carbon-encapsulated structure that can be formed as a function of the ambient temperature is calculated and the effect of activation energies for carbon diffusion on the size of carbon-encapsulated nickel nanoparticles is examined. The theoretical results are in good agreement with the experiment, suggesting that our model can be used to guide the size-controlled synthesis of carbon-encapsulated metal nanoparticles.
Microstructure and Oxidation Resistance of Cr1-xAlxN Coating
Authors: Zhong C.L. , Luo L.E.
Published: June 2012

A series of Cr1-xAlxN coatings were deposited by reactive magnetron sputtering. The content, microstructure and surface morphology of the coatings were characterized by energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The effect of Al content on the microstructure, and the oxidation resistance and hardness was studied. It was found that Cr1-xAlxN compound coating exhibits a cubic structure with (1 1 1) preferred orientations. The oxidation resistance obviously improves with the increase of Al content.
Simulation on Ice Slurry Cooling High Integrated Electronic Chip as a Functional Material
Authors: Zhang Wen Wen , Zhao Jun , Cui Yi Lin , Gao Liu Hua , Ge Ming Hui , Wang Fei Bo
Published: June 2012

Traditional cooling methods for electronic chips cannot fully meet the increasing cooling requirement of chips with high heat flux at present, so finding high-efficiency and low-cost cooling functional materials, and cooling methods with high efficiency has been a hot spot to explore. In this article, using Fluent 6, we construct a grooved channel physical model and analyze cooling effects of ethylene glycol/water ice slurry as a functional material on the chips under conditions that baffle lengths are 60mm, 80mm and 90mm, the mass flow rates are 0.4kg/s, 0.3kg/s and 0.2kg/s, and the ice fractions are 15%, 20%, 25% respectively. The results show that the chip cooling rate is increasing effectively and the temperature uniformity is better as well as the utilization rate of the latent heat is increasing as the length of baffles, the mass flow rate and the ice fraction are increasing, but the pressure loss resulted from the local effects of the inlet and corners cannot be ignored. Considering the cooling effect and the uniformity of temperature field, the length of baffles should be 83%-93% of length of flow path. In practical projects, the temperature difference between inlet and outlet should be reduced and the diameter of pipes should be decreased in order to take full advantage of the huge latent heat of the ice slurry while the ice is completely melted. Therefore, ice slurry as a functional material has a great potential to cool high integrated electronic chips.
Study on the Hydrotreating Catalysts Containing Phosphorus of Coal Tar to Clean Fuels
Authors: Zhang Hong Hua , Cao Yi Min , Usman Muhammad , Li Li Jun , Li Chun Shan
Published: June 2012

The effect of phosphorus catalysts for hydrogenation reactions were studied in this work. Different catalysts supported on γ-Al2O3 containing phosphorus (WNiP/γ-Al2O3, MoNiP/γ-Al2O3, WMoNiP/γ-Al2O3 and WMoCoP/γ-Al2O3) were prepared through ultrasonic-assisted impregnation and temperature-programming methods. The catalytic hydrotreating reaction are under the reaction conditions of PH2=9MPa, Thf=370oC, space velocity=0.5h-1, and H2/oil ratio=1400. Gasoline (≤180oC) and diesel (180–360oC) are separated from the liquid product. The fractions were characterized by Elemental analysis, FTIR, KY3000 S/N and GC-MS analysis. Though analysis of test results, it can be concluded that the WNiP/γ-Al2O3 is the excellent hydrotreating catalyst in this series at this reaction condition.
Effect of Copper on Iron-Ruthenium Complex Catalyst for CO Hydrogenation
Authors: Tang Qing Jie , Wu Wen Rong , Yang Xiao Min , Zhao Na
Published: June 2012

A series of Iron-Ruthenium complex catalyst were prepared by precipitation and immersion. The effect of Copper was studied on Iron-Ruthenium complex catalyst for CO hydrogenation and temperature programmed reduction. The results show that the effect of Copper is important to Iron-Ruthenium complex catalyst for CO hydrogenation. The selectivity of Olefin improved obviously with copper adding into Iron-Ruthenium complex catalyst, and the intensity of reducing peak increased significantly
Development and Mechanism of Multiple Non-Phosphorus Corrosion Inhibitor
Authors: Yan Mei Fang , Liu Zhen Fa , Zhang Li Hui , He Rui
Published: June 2012

A multiple non-phosphorus corrosion inhibitor was prepared by mixing polyaspartic acid with itaconic acid homopolymer, sodium gluconate and surfactant alkylolamide in a certain proportion. The corrosion inhibition performance was tested and the mechanism was studied by electrochemical process. The results showed that synergies among components of the agent made the corrosion inhibition rate on carbon steel reach up to 96.96%. This mainly because that a dense adsorbed film formed on the surface of the carben steeel.
Observing of Surface Microstructure Pearl in Bionic Materials by Scanning Electron Microscopy
Authors: Shi Wei Lin , Jin Ye Fei , Xu Qian
Published: June 2012

We present the surface microstructure of pearls in bionic materials investigated by means of scanning electronic microscopy (SEM). We found that surface microstructure of pearls in bionic materials with superior luster and quality are built up by aragonite blocks with regular shape, such as around, polygon or diamond, while pearls high luster are composed of by spindly shaped blocks, and pearls with weak luster and quality are made of some undefined aragonite blocks. Clearly, the regular shaped aragonite blocks are the most idea blocks in crystallography for building high quality pearls. The study of surface microstructure pearl in bionic materials will be helpful for the development of bionic materials.
Effect of Ginkgo Protein on Moisture Content and Hardness of Bread
Authors: Sun Xiao Fei , Qiao Yu Hui
Published: June 2012

Ginkgo seeds were selected and used as experimental material to study protein compositions in ginkgo protein. Ginkgo protein was used as accessory to be added into flour to make bread. Effect of ginkgo protein on moisture content and hardness of bread were investigated. Experimental results showed that ginkgo protein contained water-soluble protein and salt-soluble protein which was 85.28 percents in total protein and contained small amounts of prolamin and alkali-soluble protein. The bread added with different ratios of ginkgo protein had higher moisture content and lower hardness. Therefore, adding appropriate amount of ginkgo protein could improve bread baking performances and bread shelf life.
Migration Behavior Research of Residual Melamine Monomer in Melamine Resin Tableware
Authors: Lin Zhi Dan , Guan Zi Xian , Li Quan Zhong , Wang Wei Wei , Li Bo Ping , Li Zheng Jun
Published: June 2012

Melamine formaldehyde resin was synthetized and mixed with different concentrations of cellulose to obtain moulding compounds, and finally molded into melamine resin tableware. The influences of several factors like cellulose content, molding temperature, molding time, soaking medium and soaking time on the migration of residual melamine monomer and the surface morphology change were studied
Biocompatibility of Polyhydroxyalkanoates Synthesized by Bacillus cereus BMH
Authors: Bian Ming Hong , Hu Wen Feng , Pang Xu , Zuo Yong
Published: June 2012

Polyhydroxyalkanoates (PHAs) are biological polyesters synthesized by many bacteria. The polyesters became the focus of research because of their biodegradability, biocompatibility and the similar physical and chemical properties to those of petroleum derived plastics. A gram-positive strain was isolated from domesticated activated sludge and identified as Bacillus cereus BMH. B. cereus BMH can synthesize PHAs using a wide range of carbon sources. After 36h cultivation in shaken flasks, cell dry-weight was 5.31g/l, PHAs content was 61.2% of cell dry weight which is higher than some other B. cereus reported. The PHAs films showed irregular porous structure under scanning electron microscopy. Biocompatibility of the polyester was evaluated in detail in this article. The polymer was proved of good biocompatibility through Scanning Electron Microscopy (SEM), Fluorescence microscopy observation and CCK-8 assay. It was indicated that the biological polymer had desirable material properties as tissue engineering biomaterials
Chemical Exploitation of Agricultural Residues as Novel Materials for Industrial Use
Authors: Sun Xiao Feng , Wang Guang Zheng
Published: June 2012

The paper reviewed how the major products were obtained from agricultural residues, particularly from cereal straws. The emphasis is on the new technologies of chemical exploitation of cereal straws as novel materials for industries such as productions of cellulose and hemicellulose, cosmetics, natural sorbents in oil spill cleanup, and natural sorbents for removals of metal ions and anionic dyes from industrial waste water.
Synthesis of Mg(OH)2 Nanoparticles from MgO Using Magnesium Acetate as Additive
Authors: Kong Qing Gang , Qian Hai Yan
Published: June 2012

Mg(OH)2 (MH) nanoparticles were synthesized by hydration of the light-burned MgO at low temperature (70°C) with the additive of magnesium acetate. Mg(OH)2 nanoparticles have platelet-like structure and approximately 20-40 nm in thicknesses. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were applied to characterize the crystal phase, size distribution and morphology of the crystal particles. The effect mechanism of magnesium acetate was proposed
Epoxy Modified with TDI to Cure Active Hydrogen Groups: Synthesis and Characterization
Authors: Liu Zhi Gang , Xu Jing Jing , Qin Yan Lan , Zhang Ju Sheng , Rao Qian Lan
Published: June 2012

Study on isocyanate-terminated prepolymer prepared by the reaction of toluene diisocyanate (TDI) with the hydroxy of epoxy resin. By the characteristics that isocyanate-group reacts with active hydrogen groups easily, the prepolymer could be as a curing agent for substance with active hydrogen groups like coal tar. IR spectra showed that the modification was achieved by cross-linking the hydroxy of epoxy resin and the isocyanate of TDI, but epoxy group had no change. In self-made coal tar coatings, the remaining isocyanate-groups played a curing agent role linking coal tar and epoxy resin. Tafel test showed the films with prepolymer was more corrosion resistance, combined the characteristics of the epoxy resin and coal tar.
Kinetics of Ethylenediamine Wastewater Oxidation in Supercritical Water
Authors: Zhang Jia Ming , Ma Chun Yuan
Published: June 2012

The decompositon of ethylenediamine (EDA) in supercritical water oxidation (SCWO) were investigated. The experiments were conducted in an isothermal and vertical continuous plug-flow reactor at 375-500°C, 25 MPa, residence time of 2-80 s, and excess oxygen of 150%. It was found that yields of nitrous oxide, nitrogen, and the denitrification rate increased as temperature and residence time increased. The kinetics for denitrification of EDA was described by a rate law involving first order reaction. The results calculated from kinetics equation reconciled the experimental data.
Numerical and Experimental Study of the Mechanical Properties of Photonic Crystal Film
Authors: Li Tian Long , Li Long Qiu , Wang Lin , Zhang Guang Yu , Li Yao
Published: June 2012

The photonic crystal which can perform total reflection for a range of frequencies of light can be used as thermal control coating, optical fiber and optical filter. The prediction and characterization of mechanical properties are crucial to improve the processing methods and optimize the structure of the films in order to sustain mechanical stresses. In terms of modeling and prediction of the mechanical properties, this work presents a finite element model for a photonic crystal film indented by a perfectly rigid sphere. In addition, the numerical solution is compared to the experimental results obtained by nanoindentation and shown a good correlation. The effect of the contact depth on the mechanical properties was also provided.
Reinforcing Analysis for the Lower Chord of Steel Truss Bridge Based on Thermosetting Resin Matrix Composite
Authors: Zheng Jia Guo , Zhao Yun Shu , Zhao Yue Ping , Chen Qi Jun
Published: June 2012

Thermosetting resin composite material has been widely used in strengthening the concrete members. However, there are only a few applications in strengthening steel structure. Based on the finite element analysis software ANSYS in this article, mechanical analysis are carried out for the lower chord before and after reinforcement of the long-span steel truss bridge and comparison are made. Interlaminar stresses in X, Y, Z three directions of the composite laminates are extracted. Compared with the results, the conclusion that application of composite materials for reinforcement of the lower chord can change the stress of the lower chord and improve the quality of the steel trussed bridge is drawn out.
Chaotic Motion of a Functionally Graded Materials Square Thin Plate
Authors: Li Shuang Bao , Hao Yu Xin
Published: June 2012

Chaotic motion of a simply supported functionally graded materials (FGM) square thin plate under one-to-two internal resonance is studied in this paper. The FGM plate is subjected to the transversal and in-plane excitations. Material properties are assumed to be temperature-dependent and change continuously throughout the thickness of the plate. The temperature variation is assumed to occur in the thickness direction only and satisfy the steady-state heat transfer equation. Based on the Reddy’s third-order plate theory and Hamilton’s principle, the nonlinear governing equations of motion for the FGM plate are derived by using the Galerkin’s method to describe the transverse oscillation in the first two modes Numerical simulations illustrate that there exist chaotic motion for the FGM rectangular plate.
The Analysis of Reinforcing the Bottom Chord around the Tapped Holes Based on the Thermosetting Resin Composite Materials
Authors: Han Xue Dong , Wei Li , Luo Gang , Chang Li Ping
Published: June 2012

The intensity of the joint in the bottom chord would affect the quality of the whole bridge because that the force of the bottom-through bridge is transferred mainly through the bottom chord, and the members of the truss connect each other by using the thread. In this paper, the bottom chord around the tapped holes is reinforced by composite material , and the stress on the bottom chord is analyzed before and after the reinforcement using the finite element analysis method, and the stress distributions in the directions of X,Y and Z on every layer of the composite material under the bilateral reinforcing condition are extracted and compared. The results show that: Reinforcing the bottom chord around the tapped holes using the composite material can change the stress level of the bottom chord effectively, helping to improve the quality of the construction of the steel bridge and the effect of the bilateral reinforcing is better than the unilateral reinforcing and providing certain reference for the security of the steel truss bridge
Study on the Optimum Pulse-Taking Pressure and Probe Film Material Parameters during the Pulse Image Condition Detection
Authors: Zhang Ai Hua , Liang Fei
Published: June 2012

Pulse image detecting device was applied to acquire radial dynamic pulse images. In this paper, we improved the probe structure of the pulse image detecting device with new film material. Four kinds of different thickness films, the different pulse-taking pressures and the different sealed chamber pressures were used to determine the optimum film. For different subjects, the pulse amplitude was extracted with the different pulse-taking pressures and different sealed cavity pressures. The experiment results had shown that the best pulse amplitude could be obtained with the film thickness for 0.504 mm, pulse-taking pressure for 3 N and the sealed cavity pressure for 120KPa. This work provided an important theoretical basis for the parameter choice of the pulse image detection device.
The Research of Thermosetting Resin Matrix Composite Reinforcing Application in the Web of Truss Bridge
Authors: Wei Li , Zhou Guang Qing , Zheng Jia Guo , Liu Kun Liang
Published: June 2012

A significant number of concrete members were strengthened by carbon fiber reinforced polymer (CFRP).However there are only a few applications in strengthening steel structure with CFRP. The three-dimensional model of the long span bridge is made by using the finite element software ANSYS and do the force analysis of it ,then make composites reinforcement in order to Improve the structure strength and increase bridge life. The conclusion received of this paper is that composite patch at the end of web is more effective than in the middle of web. By picking up the stress distribution of every layer, the law of stress is obtained.
Experimental Study on Fluidization Characteristics of Gas Quenching Steel Slag
Authors: Xing Hong Wei , Wu Jian Fei , Li Gao Liang , Zhang Yu Zhu , Li Jie , Long Yue , Chen Wei , Wu Jin Hu
Published: June 2012

In order to study the application of fluidized bed process for the gas quenching steel slag(GQSS) slag-iron separation, according to the principles of fluidized bed material separation, based on the all GQSS, this paper researches the influence law of fluidization characteristics and the fluidization performance of GQSS after adding 20% (calculated by volume) iron grains. The experiment uses single hood fluidized bed as experiment device, studies the GQSS and iron grains of critical fluidization and slugging fluidization of other characteristics in the fluidization process, and determinates the packing density in interior and exterior of the tube. The results show that: when the material is all GQSS, the appropriate fluidization thickness of material layer is 300~400mm ; after adding 20% iron grains in the tube, the appropriate fluidization thickness of material layer is 350~400mm. The results of this paper on GQSS slag-iron separation have important theoretical significance.
The Characterization of Porous Structure of Frozen Wool Keratin Membrane
Authors: Chen Xi , Yu Wei Dong
Published: June 2012

Use the keratin liquid which solved from wool with urea and 2-mercaptoethanol to prepare wool keratin porous membrane at different concentration and frozen temperature. Observe the morphological structure of the membrane by SEM and analyze the SEM pictures. The experimental results indicate that the liquid concentration and frozen temperature are inversely proportional to the porous membrane aperture and porosity, but proportional to the porous membrane density.
Preparation of Light-Weight Alumina-Spinel Refractory by Foaming Process
Authors: Li Xiao Xing , Li Yuan Bing , Zhao Lei , Yao Xu , Li Ya Wei , Li Shu Jing , Fan Zhi Hui , Liu Fang
Published: June 2012

In order to reduce energy costs, light-weight alumina-spinel refractories with tri-modal pores were prepared by foaming process. The inﬂuence of foaming agent and magnesia on the properties of light-weight alumina-spinel refractory was investigated. The rheology of the original slurry and the density, mechanical properties and microstructure of samples were evaluated. The results showed that light-weight alumina-spinel refractory contained a highly interconnected network of spherical cells, consisting of the large-sized cells (larger than 40 um), moderate-sized pores( averaging about 20 um) and small-sized voids, which mainly attributed to the foaming agent and in-situ formation of spinel. The cold compressive strength of the samples varied within the range of 2-12MPa, corresponding to densities of 0.8~1.2g/cm3,and the thermal conductivity changed from 0.273W/(m•K) to 0.315 W/(m•K) at the 500 °C. It was found that the density of the sintered samples was dependent both on the content of foaming agent and magnesia. With the help of magnesia, light-weight alumina-spinel refractories with good volume stability were prepared by foam method.
Microstructural Evolution and Mechanical Properties of Vertical-Cracked Thermal Barrier Coatings in Thermal Exposure
Authors: Lu Zhe , Myoung Sang Won , Jang Tae Sik , Lee Kang Hyeon , Lee Je Hyun , Jung Yeon Gil , Paik Ung Yu
Published: June 2012

The effects of intrinsic feature of feedstock in air plasma-sprayed (APS) coatings on the microstructure and mechanical properties of vertical-cracked thermal barrier coatings (TBCs) were investigated in thermal exposure. The microstructure after the thermal exposure for 400 h is densified, while after the thermal exposure for 800 h various defects such as interlamellar cracks and the vertical and horizontal cracks are newly developed, even though the total porosity is decreased. The microstructure of the TBC prepared with 204 C-NS is more porous than that of the TBC with 204NS, showing higher mechanical properties and better thermal stability in the TBC with 204 NS.
Effect of Anisotropic Conductive Properties on Heat Transfer and Temperature Distribution of Coatings and Substrates
Authors: Chang Zhen Dong , Ma Zhuang
Published: June 2012

Thermal conductivity was the main thermal parameter that greatly influenced temperature distribution of materials especially in coatings. Some materials such as plasma-sprayed coatings that had a lamellar microstructure displayed the anisotropy of thermal conductivity. Thermal conductivities of isotropy and anisotropy metallic ceramic coatings were calculated and analyzed using Markworth method and parallel plate model, respectively. The influence of anisotropy on heat transfer and temperature distribution of coatings using ﬁnite element analysis and Gaussian heat source modal applied locally was investigated. Results showed that in anisotropic coatings the ratio of transverse and vertical thermal conductivity had a maximum value when metal volume fraction was 50%. The temperatures on the edge of heat sources (Th) had a maximum value, and the highest temperatures of substrate (Ts) had a minimum value with the same fraction. The value decreased by 79°C compared to that in the isotropy coatings. The highest temperatures of coatings (Tc) decreased expectedly with metal volume fraction rised. The maximum width of heat affected zone (HAZ) of coating and substrate was 4.52 mm at the metal content of 40%. The minimum HAZ depth was 0.27mm which was very small at the content of 50%, compared with 1.25 mm in isotropic coatings. It revealed that anisotropic conductive properties caused more heat transfer to outer regions and provided better protection for substrate.
Synthesis and Optical Properties of Single-Crystalline Silicon Nitride Nanowires with Controlled Dimensionality
Authors: Wang Zhi Hao , Chen Fei , Shen Qiang , Zhang Lian Meng
Published: June 2012

Single-crystalline silicon nitride nanowires with high purity, controlled dimensionality have been prepared via nitriding the nanocrystalline silicon powders at 1300°C~1400°C. The nanocrystalline silicon powders with average particle size of 20-80nm were obtained by cryomilling with the liquid nitrogen as the medium. Scanning electron microscopy, high resolution transmitted electron microscope, X-ray diffraction and UV-lamp microzone Raman spectrometer were used to characterize the as-synthesized nanowires. The effects of nitridation process (reaction temperature and holding time) and the particle size of nanocrystalline silicon powders on the phase and microstructure of the silicon nitride nanowires were analyzed. The obtained results show that the diameter of the nanowires can be controlled in the range of 40~100nm, and the length of 10~80 μm. The formation of the nanowires can be explained by the vapor-solid growth mechanism. The room temperature photoluminescence spectra show that the silicon nitride nanowires exhibit a broad visible emission band which ranges from 370 nm to 700 nm.
The Composition and Hardness of the Coating Containing Zirconia Produced by Micro-Arc Oxidation on Aluminium Alloy
Authors: Xin Shi Gang , Le Jun , Song Li Xin
Published: June 2012

In this paper, a ceramic coating containing zirconia was produced by micro-arc oxidation (MAO) in a solution of K2ZrF6 and KOH. The composition and structure of the coating were investigated by XRD, EPMA. The results show that the coating consists of t-ZrO2, m-ZrO2, α-Al2O3 and γ-Al2O3. t-ZrO2 and m-ZrO2 distribute in outer layer of the coating, however, α-Al2O3 appears in inner layer of the coating. The coating surface consists of many micro-powders with a size of 1-2μm. It is because K2ZrF6 is unstable in the alkaline solution, and it can form zirconium hydroxide and takes part in the formation of the coating. The result of the hardness shows that the maximum hardness (1900HV) appears at around 30-50μm from the interface of substrate/coating.
Microstructural Characterization of Diamond/SiC Composites Fabricated by RVI
Authors: Yang Zhen Liang , He Xin Bo , Wu Mao , Ma An , Liu Rong Jun , Qu Xuan Hui
Published: June 2012

Diamond/Si/C porous preform was prepared with phenolic resin, Si, Diamond and graphite. Subsequent reactive vapor infiltration (RVI) of gaseous silicon at 1600 °C for 2 h in vacuum atmosphere resulted in the formation of a compact Diamond/SiC composite. The influence factors of perform porosity were investigated, including process pressure and raw materials. Density and microstructure of Diamond/SiC composites were also discussed. The results showed that the open porosity of preform was mainly influenced by the pressing pressure. It can also be affected by the content, morphology and the particle size of diamond. The preform with open porosity higher than 20% after RVI treatment can obtain Diamond/SiC composites with high density. However, over-high porosity of the perform will cause a mass of unreacted Si exists in the composite which is unfavorable for its application. In order to reduce the content of residual Si, open porosity of preform should be no higher than 40%.
Hot-Pressed Sintered SiC-Based Composites for Microwave Absorbing Application
Authors: Han Qian Fei , Fan Bing Bing , Ren Xiang Qian , Chen Hao , Zhao Biao , Zhou Hui , Zhang Ray
Published: June 2012

In recent years, with the development of the stealthy and anti-stealthy system, the electromagnetic pollution increasing, microwave absorbing materials with thermal resistance and wide absorption band have been the one of the hotpots in functional materials. Silicon Carbon as a semiconductor material having unique mechanical properties and high temperature stability, is one of the preferred absorbing materials. In this paper, we used silicon carbide, barium titanate and barium ferrite as the raw materials, which belongs to the absorbing mechanisms of resistance loss, dielectric loss and magnetic loss, respectively. The composites were sintered by hot pressed sintering method, and characterizated by XRD, DTA-TG and SEM techniques. XRD results showed that Ba2TiSi2O8 was turn up in the sintering composite materials, and the SEM-EDS photograph was clearly observed that Ba2TiSi2O8 whisker were equally distributed on the surface of silicon carbide. we can assumed that the SiC matrix complex absorbers may be promising candidate for microwave absorption materials with strong-absorption, light-weight, wide-band properties.
Comparison Analysis of Absorption Properties for Microwave Absorbent
Authors: Lü Xu Liang , Wu Chao , Zeng Zhao Yang
Published: June 2012

In order to compare the absorbing properties of different microwave-absorbing agents and their mixture, this paper has selected two typical microwave-absorbing agents which respectively are carbon fiber resistance microwave-absorbing agents and ferrite magnetism microwave-absorbing agents, and took them as monolayer absorbing materials. Then used MG formula to calculate the effective electromagnetic parameter of their mixture under different proportion at X band, and finally analyzed their absorbing properties separately. Then through contrasting the impedance matching characteristic and attenuation coefficient of the materials, it is proved that adding carbon fiber in ferrite can not improve absorption properties. Although the ability of attenuating electromagnetic wave would be enhanced when resistance materials and magnetism materials are blend with each other, doping will destroy the materials’ impedance matching characteristic because most resistance materials have high permittivity. It makes reflection strengthen and can not improve absorbing properties.
Preparation of Nano BaTiO3-Based Dielectric Ceramics by Different Sintering Methods
Authors: Gong Hui Ling , Wang Xiao Hui , Kim Jin Yong , Tian Zhi Bin , Yao Guo Feng , Li Long Tu
Published: June 2012

Microstructure control in thin-layer multilayer ceramic capacitors (MLCCs) is one of the nowaday challenges for increasing capacitive volumetric efficiency and high voltage dielectric properties. In this paper, the ultrafine-grained BaTiO3 dielectric ceramics with uniform grain size distribution were prepared by chemical coating approach. The doping effects of rare-earth element (Ho) on the microstructures and dielectric properties of the ceramics were investigated. The addition of Ho in nano BaTiO3-based ceramics was found to improve the temperature coefficient of capacitance (TCC) performance, which could be attributed to a significant reduction in the grain size. Moreover, the effects of two-step sintering (TSS) method on the microstructures and dielectric properties, compared with conventional sintering (CS) method, were also discussed. The dielectric constant of ceramics sintered by the TSS method was higher than that of ceramics prepared by CS method. The results reveal that the adoption of TSS method could control the grain size and suppress the abnormal grain growth more effectively, which improves the TCC characteristics.
Effect of Bi2O3-B2O3-CuO Additives on Dielectric Properties and Energy Storage of BaTiO3 Ceramics
Authors: Deng Wei , Nie Jin Feng , Xiao Xi , Yuan Jian Cong , Zhang Bo Ping , Lin Yuan Hua
Published: June 2012

High density BaTiO3ceramics have been prepared by the addition of CuO-Bi2O3-B2O3mixed oxide. The results indicate that the sintering temperature of BaTiO3bulk can be decreased by about 300°C and high dielectric behavior can be remained. The CuO-Bi2O3-B2O3additives can increase the breakdown strength, and leads to an obvious enhancement of the energy density, which is nearly 2 times of pure BaTiO3.
Preparation and Properties of Nano-Hydroxyapatite Derived from Sol-Gel Method for Cu2+ Polluted Water
Authors: Wang Shao Hong , Wang Hao , Hou Zhao Xia , Wang Cai , Hu Xiao Dan , Lu Hao Ran , Xue Zhao Lu , Niu Chang Lei
Published: June 2012

Nano-hydroxyapatite (HAP) were prepared by sol-gel method with Ca(NO3)2•4H2O and H3PO4 precursors. The result was shown that the powder was spherical with very little reunion and the particle size was around 50nm. The HAP adsorbent was utilized for copper removal from aqueous solutions using the batch technique. Some parameters that determine copper ion uptake including contact time, adsorbent dose, the solution temperature and initial concentration of the copper in the aqueous solution were evaluated. The experimental results shown that the removal efficiency was about 99.27% at pH 7, 40°C, contact time 60 min, adsorbent dose of 5g/L and initial concentration of 60mg/L.
On Preparation of SrTiO3 Thin Films with Self-Assembled Monolayers by Liquid Phase Deposition and its Dielectric Properties
Authors: Han Wei Guang , Tan Guo Qiang , Xia Ao , Ren Hui Jun
Published: June 2012

In this paper, titanium ammonium fluoride ((NH4)TiF6), strontium nitrate (Sr(NO3)2) and boric acid (H3BO3) were used as raw materials, the precursor solution was prepared with molar ratio of AHFT/SN/BA=1/1/3. SrTiO3 dielectric thin films were deposited with the self-assembled monolayers (SAMs) by the liquid-phase deposition on FTO substrate. X-ray diffraction (XRD), scanning election microscopy (SEM) and Agilent E4980A precision LCR Meter were used to characterize the SrTiO3 films. The precursor solution concentration and the pH values of precursor solution had the effects on the dielectric properties of the as-prepared thin films. When the precursor concentration was 0.0125mol/L, the crystallization of as-prepared SrTiO3 thin films was high and the grain sizes on the film surface were even and dense. When the frequency was 15~100KHz, the optimal dielectric constant was up to 1060, the minimal dielectric loss was 4.053. As pH=3.30, the frequency of the as-prepared SrTiO3 thin films was 15~100KHz. The optimal dielectric constant was up to 1060, too. The minimal dielectric loss was 1.914. The optimal dielectric constants were 346.3 and 424.1 when the pH was 3.1 and below 3.5 respectively. The minimal dielectric losses were respectively 18.10 and 54.82.
SAW Properties on X,Y,Z-Cut of Sr3(Nb,Ta)Ga3Si2O14 and Ca3(Nb,Ta)Ga3Si2O14 Piezoelectric Crystal
Authors: Huang Wen Qi , Yang Hong
Published: June 2012

We calculate the phase velocity(V), power flow angle(PFA) and electromechanical coupling factor(k2) on X,Y,Z-cut of Sr3NbGa3Si2O14(SNGS),Sr3TaGa3Si2O14 (STGS), Ca3NbGa3Si2O14(CNGS) and Ca3TaGa3Si2O14(CTGS)crystal,. The calculated results are in excellent agreement with the experimental results. As these crystals are denser than quartz, they have lower phase velocity. The results also indicates that they have high k2 and cuts of zero PFA. Taking various SAW properties into consideration, some typical propagation directions like 167.5° of X-cut SNGS ,0 of Y-cut SNGS, 170° of X-cut STGS, 0 of Y-cut STGS,11 of X-cut CNGS, 0 of Y-cut CNGS, 175.0 of X-cut CNGS and 0 of Y-cut CTGS are selected, which can be used in the application of SAW devices.
Properties of BiFeO3 Thin Films Prepared with Self-Assembled Monolayers by Liquid Phase Deposition
Authors: Yin Jun , Tan Guo Qiang , Song Li Hua , Xia Ao , Ren Hui Jun
Published: June 2012

Using iron nitrate, bismuth nitrate, citric acid and glacial acetic acid as the raw materials, the BiFeO3 thin films in crystalline state were prepared on FTO substrate with the self-assembled monolayers by liquid phase deposition after graded induction and annealing at 550°C for 30min. The physical phase composition, the surface morphology and dielectric properties of the thin films were characterized respectively by XRD, SEM, and Precision LCR Meter. This paper studied that the deposition temperature and the number of film layers had the effects on the thin films. The results show that the as-prepared thin films show the random orientation and good crystalline. When the deposition temperature is 70°C, the surface of the as-prepared thin film is smooth and uniform. The size of grain is 100nm. The thin film has a dense structure without the apparent pore phase. When the test frequency is between 1kHz and 1MHz, the loss of the thin films is decreased as the increase of the number of the film layers. When the number of the layers is 15, the dielectric constant of the thin films is 44 and the loss is 0.02 when the test frequency is 10kHz.
Density-Functional Studies of Cr Adsorbed on Polar ZnO Surfaces
Authors: Zhang Zi Nan , Gan Guo You , Wang Li Hui , Yan Ji Kang , Yi Jian Hong , Du Jing Hong , Zhang Jia Min
Published: June 2012

The atomic structure and electronic properties of Cr adsorbed on polar ZnO surfaces is studied using first-principles calculations based on density functional theory. It is found that the Cr atom at the on top of O forms a strong ionic bond, the electrons transfer from Cr to O atoms. The Cr atom is adsorbed at the hcp-hollow site on Zn-terminated surface forms metallic bonding with the surface Zn atom, shows a free-electron-like behavior. The adsorbed atoms could not effect more atoms in ZnO due to a strong screening of ZnO to the outside metal, the character of adsorption surfaces is only decided by the atoms near the surface.
Solid-State Reaction and Gas Sensor Properties of Porous SnO2-In2O3 Composites
Authors: Cao Yu , Zhou Xiao Long , Cao Jian Chun , Peng Yuan Yuan , Chen Jing Chao , Yu Jie
Published: June 2012

Mixtures of ITO and SnO2 powders were prepared by a solid-state reaction method in order to produce porous composite materials. X-ray diffraction, scanning electron microscope and gas sensing testing system have been used to analyze the microstructure and properties of it .It has been concluded that when the sintering temperature is 1573K,it has better gas-sensing properties. The pore structure and CO gas sensing property of porous SnO2-In2O3 composite materials can be improved with the increase of SnO2 contents.
The Electrocaloric Effect in BaTiO3 Thick Film Multilayer Structure at High Electric Field
Authors: Bai Yang , Ding Kai , Zheng Guang Ping , Shi San Qiang , Qiao Lie Jie , Guo Dong
Published: June 2012

We demonstrated the superior electrocaloric effect (ECE) in BaTiO3 multilayer structure. The sample fabricated by tape-casting process has 120 effective ferroelectric layers with average layer thickness of 1.7 μm. The ferroelectric hysteresis loops were measured in the temperature range from 30 to 180 oC, and then the temperature dependences of ECE adiabatic temperature change and heat absorption were obtained according to Maxwell relation. A peak ECE adiabatic temperature change of 0.027 K/V and heat absorption of 0.36 J/g were observed near the ferroelectric phase transition at 125 oC under Vmax=25 V. The BaTiO3 thick film can sustain an external electric field (>500 kV/cm) several times higher than bulk ferroelectric ceramics (~30 kV/cm). Although the EC coefficient of BaTiO3 is much lower than lead-based ferroelectric ceramics, the ultrahigh working electric field endows it a large ECE, higher than that of most reported lead-based ferroelectric ceramics. In addition, the lead-free composition provides it a promising future in solid-state cooling technology.