bluuebunny/crossref_metadata_2025 huggingface dataset:
Irradiation Damage of Electron-Beam on High-Power AlInGaP Red LED
Authors: Zhang Rui Bin , Huang Yi Ping , Liu Hai Lang , Peng Zhi Guo
Published: December 2011

In this paper, experimental results and Monte Carlo simulation methods used to study irradiation damage of Electron-beam on high-power AlInGaP red LED. The electron beam range and distribution of energy loss in the LED chip are analyzed by CASINO program in detail, the high-power AlInGaP red LED is irradiated by different energy and dose of electron beam irradiation produced by the low energy electron beam irradiation equipment. We contrast the optical parameter of the irradiated LED with the unirradiated LED. The experimental result is analyzed and discussed by the mechanism of electron beam irradiation. The results show that: the luminous flux and power change of the irradiated and unirradiated LED are showed by dose-response. In process of irradiation, the elastic collision and ionization are occurred between the incident particles and atoms within the material, which cause defect in the internal structure of the AlInGaP material and form the color centers.
Fluorescent Carbon Dots (CDs) as a pH Sensor
Authors: Lin Feng , He Wei Na , Guo Xiang Qun
Published: December 2011

The pH-dependent properties of carbon dots (CDs), decorated with surface carboxylic acid functional groups, are described. Absorption, fluorescence emission measurements were used to study the reversible pH-dependent spectral response. The pH-dependent emissions of CDs demonstrate a strong dependence on the excitation wavelengths and make the as-prepared CDs a good ratiometric pH-sensor candidate. This green material CDs-based probe shows promising potential for probing pH in real sample and in vivo intracellular imaging.
Microwave Absorption Performance of La0.7 Sr0.3 MnO3 with Different Sintering Temperatures
Authors: Zhang Shu Yuan , Cao Quan Xi
Published: December 2011

La 0.7 Sr 0.3 MnO 3 powders have been synthesized at different temperatures by the traditional solid state method. The crystal structures have been characterized by X-ray diffraction (XRD). The electromagnetic parameters were measured by vector network analyzer (VNA) within the frequency range of 5.85-18GHz. It’s found that the pure perovskite structure has been obtained at the temperature of 1000°C. The bandwidth for R<-6dB became thinner with the sintering temperature’s increase from 1000°C to 1150°C, and the absorbing peak moves to the higher frequency first and low frequency then, the absorbing peak is enhanced first and weakened then.
The Experimental Studies on Self-Heat Conserving Facade Panel with Waste Fibers
Authors: Wang Hong Cao , Yu Yong Ling , Lv Li Hua
Published: December 2011

This paper introduces the studies of self-heat conserving facade panel with abandoned polypropylene fiber. The optimum process conditions were studied. The tensile properties, bending and impact properties of external insulation panel were tested. The results show that when the hot-pressing temperature is 180°C , the tensile, bending and impact of external insulation panel are best. The optimum process is hot-pressing temperature of 180 °C, hot pressure of 10MPa, hot-pressing time 12 Min. The physico-chemical properties were tested. The results show that the data of each test is up to the china national standard .The heat insulation property was tested, the results show that the panels have good insulation performance. The wallboard is light and easy to transport. Because the raw material adopts recycled polypropylene fibers, the price is low and the insulation is good. Recycled fiber-plastic composite is filled with bright future prospects.
Research on Fractal Characteristics of Cement-Based Materials by Nitrogen Adsorption Method
Authors: Tang Ming , Li Jing Qi
Published: December 2011

In order to confirm the surface fractal dimension of the internal pore of complex porous materials by means of the FHH model and nitrogen adsorption method. Study the change rule on fractal characteristics of the pore of cement based materials further. The results shows that, surface area of the complex internal structure of cement based materials has the fractal characteristics observably. Testing and evaluating the fractal characteristics on surface area of the pore of cement-based materials is effective by nitrogen adsorption method. It is good for analyzing surface characteristics of pore structure further. Surface fractal dimension of pore structure and surface area have not good correlation. The characteristics and conclusion that quality fractal dimension of powder and surface area evaluating fineness of powder have not very good correlation is consistent.
Preparation and Photoelectric Properties of Spinel MCr2O4 (M = Cu, Ni) Nanopowders
Authors: Hu Zhi Qiang , Qin Ying , Liu Xian Qing , Zhai Shang Ru , Gao Hong
Published: December 2011

Spinel MCr2O4(M = Cu, Ni) nanopowders were synthesized by co-precipitation technique from alcohol-aqueous system and the performance of MCr2O4/TiO2 composite film electrodes was studied. The synthesized MCr2O4 nanopowders were characterized by X-ray diffraction (XRD) and UV-vis diffuse reflectance spectrum (UV-vis). The MCr2O4 nanopowders were doped into nanocrystalline semiconductor oxide film electrode of DSSCs and the influence of doping content was investigated. Compared with the pure TiO2 film electrode, the absorbance of different MCr2O4/TiO2 composite film electrode increased significantly. Furthermore, the light respondence of CuCr2O4/TiO2 composite electrode was better than NiCr2O4/TiO2 composite electrode. When the content of CuCr2O4 2%, the photoelectric conversion efficiency increased by 54%, and doping 1% NiCr2O4 nanopowders, the photoelectric conversion efficiency was improved 30%.
Thermodynamics of Phenol Adsorption onto Activated Carbon Fiber
Authors: Li Mei , Luo Yi , Xie Tao , Liang Ming Zheng , Wang Shuang Fei
Published: December 2011

The adsorption of phenol onto activated carbon fiber (ACF) from aqueous solutions were studied. The adsorption isotherms of phenol onto ACF at 298.15 K,303.15 K and 308.15K follow the Freundlich and Langmuir isotherm equation. The Freundlich model was verified to be the best to describe the adsorption data.Values of ∆G0 for phenol adsorption onto ACF are-8.549、-7.899 and -7.516 kJ•mol-1 at 298.15,303.15and 308.15K , respectively. The values of ∆H0 and ∆S0 are -39.30 kJ•mol-1 and -103.3 J.mol-1.k-1, respectively. The adsorption process is spontaneous and exothermic. Negative △S0 values suggested the randomness of phenol molecules at solid-liquid interface and an decrease in the degree of freedom of the adsorbed species.
Control of Surface Quality of if Steel Sheet
Authors: Wu Guo Rong
Published: December 2011

In order to solve the problem of mold powder entrapment which is one of the affecting factors on faint-sliver defect in IF cold-rolled steel sheet in casting process, continuous casting process is optimized. Based on the analysis of the defect, the composition of mold powder is optimized. Otherwise, surface tension and viscosity of mold powder are raised. With theses countermeasures, mold powder entrapment and casting subcutaneous slag is decreased obviously. In addition, the rate of faint-sliver defect in cold-rolled IF steel sheet has been reduced from 5.21% to below 1.0%.
Decolorization of Coking Wastewater by Mineral Adsorbents
Authors: Yu Kai Ning , Wang Cheng , Yu Yang , Li Yan
Published: December 2011

The decolorization of coking wastewater is an urgent issue for coking wastewater treatment. Using mineral adsorbents to deal with the coking wastewater is an effective way to solve the above problem. In this paper, fluidized bed combustion (FBC) ashes, diatomite and clinoptiolite were used to decolorize the coking wastewater. UV-Vis was used to estimate the decolorization efficiency of the FBC ashes. The materials were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that the sequence rule for the decolorization effect of three mineral adsorbents is FBC ashes > diatomite > clinoptiolite. In addition, the chroma of treated coking wastewater reduced from 320 times to less than 5 times in the comparison of raw wastewater. It is much lower than the chroma of GB8978-1996 1A discharge standard. The excellent decolorization effect of FBC ashes might be due to large contains of CaO and f-CaO.
Electrochemical Performance of LiFePO4/C Positive-Electrode Material Prepared via a Rheological Phase Method
Authors: Hong Jian He , Bai Chun Fang , He Gang , He Ming Zhong , Li Hai Feng , Sun Xin Yan , Wang Yan Fen
Published: December 2011

Positive-electrode material LiFePO4/C was prepared using FePO4•2H2O as raw material via a rheological phase method. Orthogonal experiment was designed to systematically investigate the effects of the ratio of raw materials, calcining temperature and holding time on the morphology and electrochemical performance of LiFePO4/C. The results showed that the optimal parameters were as follows: synthesis temperature 650 °C, time 10 h. The sample prepared with optimal parameters showed discharge capacities of 147.5 mAh•g-1 at 0.2 C and 133.7 mAh•g-1 at 1 C rate, with good cycle performance.
Control Technology of Internal Quality for CC Billet
Authors: Pan Hong
Published: December 2011

The effect of process parameters of secondary cooling and electromagnetic stirring (EMS) on internal quality for CC billet is investigated. With these studies, the continuous casting process is optimized, and the internal quality of square/round billet is improved as well. Comprehensive technologies for internal quality control of square/round billet in Panzhihua Steel have been proposed. The results of industrial tests show that the comprehensive rate below level 1.0 of internal defects of center porosity, center segregation and center cracks is more than 97%, and carbon segregation index is in the range of 0.93~1.09. The quality of square/round billet can meet the requirement of consumers absolutely.
Discussion on Pavement Recycling Techniques in China
Authors: Wang De Cai , Li Yu Mei , Wang Qing
Published: December 2011

This paper pointed out that regeneration is the necessary condition of achieving circular economy and sustainable development,aslo is the inevitable trend of the national highway development. By analyzing and comparison among four different ways, it is concluded that cold in plant recycling has more advantages on economic,rationality,energy-saving & environment-friendly and so on. On the basis of comparison in four different regeneration methods, the writer analysis technology and economic advantages and prospects of application of the emulsified asphalt cold in plant recycling, combining with the status quo of highway maintenance and improvement, and point out that emulsified asphalt cold in plant recycling is the ideal choice to solve our current semi-rigid base problem,which avoid reflective cracking and extend the pavement life.
Accelerated Aging Test and Study of Storage Life Prediction of NBR O-Ring
Authors: Pan Jun , Xu Shi Wei , Chen Wen Hua , Wang Xiao Yun , Qian Ping , Hu Qun Wei
Published: December 2011

Nitrile Butadiene Rubber (NBR) is a kind of common sealing materials for the electric hydraulic servo mechanism, there exists the aging failure problem in its storage environment, which is the key factor determining the storage life of the electric hydraulic servo mechanism. Through the analysis of aging failure mechanism of the NBR o-ring, the degradation path that varies with the changes of aging time based on compression set was established. And the Arrhenius equation, which is the acceleration equation of the aging reaction velocity varies with the changes of temperature, was established as well. In order to obtain the related parameters of the model, the accelerated aging test was conducted and its data were processed by applying the approximation standards and least square method. Also through the test the prediction of storage life of NBR o-ring under special storage conditions was made, and its predicted results were basically identical with the actual storage life.
Simulation of the Effect of Power on the Properties of Si-Based Films Deposited by PECVD
Authors: Jin Guo Jun , Li Gui Qin , Sun Yi , Lu Li Xin , Lin Song , Tang You Gen
Published: December 2011

Two-dimensional modeling and the computational fluid dynamics simulation are performed to investigate the deposition rate and the uniformity of the thin film under different power in PECVD reaction chamber using 13.56 MHz frequency. The results of the simulation show that as the power increased, the deposition rate of the thin film first increased gradually and then saturated, but the changes of power have little effect on uniformity.
Effects of Deposition Parameters and Annealing Temperatures on the Characteristics of the Sr0.6Ba0.4Nb2O6 Thin Films
Authors: Chan Chao Chin , Hsieh Yuan Tai , Chen Cheng Yi , Tzou Wen Cheng , Wu Chia Ching , Yang Chang Fu
Published: December 2011

Sr0.6Ba0.4Nb2O6 (SBN) thin films were prepared by radio frequency (RF) sputtering onto the SiO2/Si/Al and Pt/Ti/Si substrates to form the MFIS and MFM structures. Their deposition rates increased with decreasing oxygen concentration and with increasing RF power. Their optimal deposition parameters were the substrate temperature of 500°C, chamber pressure of 10 mTorr, oxygen concentration of 40%, and RF power of 120W, respectively. The rapid temperature annealing (RTA) process had large effects on the grain growth of the SBN thin films. The effects of different RTA temperatures on the leakage current density - electrical field curves and the capacitance - voltage curves of the SBN thin films were also investigated.
Effect of Cryogenic Treatment on Improving the Fracture Toughness of TiN Coated Cemented Carbide
Authors: Nie Chao Yin , Deng Ya , Ding Ying , Li Ning , Zhou Xiao Gang , Wei Li Dan
Published: December 2011

The 2μm thick TiN coatings were deposited by arc ion plating on YW2 cemented carbide substrate, and the system of TiN/YW2 was treated with cryogenic treatment at -196°C for 30 hours. The change of the Rockwell indentation's morphology of the system (the form and density of cracks, the spalling state of the coating)before and after the treatment were investigated by means of the Rockwell hardness tester. With metallurgical microscope and SEM, the change of the microstructure of the substrate and its influence on the fracture toughness of the system were investigated. The results show that after the treatment, the density of the radiated cracks in the substrate were obviously reduced, but the main cracks hadn’t any change, the spalling of the TiN coating along the indentation was lightened. After the cryogenic treatment the dispersed granular γ phase obviously decreased or even disappeared, the pores became smaller and the microstructure of YW2 became more compact，and the microcracks were merged during the cryogenic treatment. These are beneficial to improve the fracture toughness of YW2 substrate and the coating/substrate system.
XPS Study on Barium Strontium Titanate (BST) Thin Films Etching in SF6/Ar Plasma
Authors: Dai Li Ping , Zhang Guo Jun , Wang Shu Ya , Zhong Zhi Qin
Published: December 2011

Subscript textReactive ion etching of barium strontium titanate (BST) thin films using an SF6/Ar plasma has been studied. BST surfaces before and after etching were analyzed by X-ray photoelectron spectroscopy to investigate the reaction ion etching mechanism, and chemical reactions had occurred between the F plasma and the Ba, Sr and Ti metal species. Fluorides of these metals were formed and some remained on the surface during the etching process. Ti can be removed completely by chemical reaction because the TiF4by-product is volatile. Minor quantities of Ti-F could still be detected by narrow scan X-ray photoelectron spectra, which was thought to be present in metal-oxy-fluoride(Metal-O-F). These species were investigated from O1sspectra, and a fluoride-rich surface was formed during etching because the high boiling point BaF2and SrF2residues are hard to remove. The etching rate was limited to 14.28nm/min. A 1-minute Ar/10 plasma physical sputtering was carried out for every 4 minutes of surface etching, which effectively removed remaining surface residue. Sequential chemical reaction and sputtered etching is an effective etching method for BST films.
Study on FCAW Semi-Automatic Welding Procedure of Girth Weld Joint of Line Pipes
Authors: Wang Xiao Yan , He Xiao Dong , Han Xin Li , Li Na , Tong Ke , Hu Mei Juan
Published: December 2011

This paper investigate the mechanical property and microstructure of girth weldment of Lan Zhou to Cheng Du crude oil pipeline. The welding joint was bottomed by cellulose electrode E6010 and filled and covered by flux-cored wire AWS A 5.29 E71T8-Ni1. According to SY/T 4103-2006, test results show that the selected process parameters and welding method take on outstanding performance .Microstructure of weld joints is acicular ferrite, polygonal ferrite, proeutectoid ferrite and granular bainite, and widmanstaten ferrite dosn’t exsist in heat affected zone(HAZ). Microstrure of the whole weld joint is mainly polygonal ferrite and granular bainite, this is the reason that mechanical properties can meet the Lan Zhou to Cheng Du crude oil pipeline project requirement.
Experimental Research on Explosion-Protection Performance of Porous Meshy Aluminum Alloy Material
Authors: Xing Zhi Xiang , Zhang Yi Guo , Ma Guo Liang
Published: December 2011

This paper introduces the explosion-protection performance of a kind of meshy aluminum alloy material in different blank rates and different packed densities. Experiment results show that this material has the best explosion-protection effect when the packed density between 30~35 kg/m3. When the packed density is fixed the pressure increase quickly with the increase of blank rate, the flame becomes smaller after filled with the material so this material can decrease the spread of flame. Besides we get the empirical equation of the packed density, blank rate and pressure.
Influence on Structure and Composition of Carbon Supported PtCu-LaOx Composite Membrane Electrode by Acid Treatment
Authors: Yang Bin , Shen Ming Zhe
Published: December 2011

In order to reduce production cost of Fuel Cells, one of the key points was to reduce Pt loading in Pt/C catalytic electrode. In our study, a new type of Pt/C membrane electrodes, PtCu-LaOxcomposite structure, on the surface of carbonaceous substrates was manufactured by Ion Beam Sputtering technology, and also was treated in different concentration H2SO4solution. Phase composition, surface topography and microarea elements of these electrodes were analyzed by X-ray Diffraction, Scanning Electron Microscopy combined with Energy Dispersive Spectrometry, respectively. It was found that PtCu-LaOxcomposite membrane with Pt loading less than 0.045mg/cm2(the electrode area), and that the orientation growing of Pt(111) and Pt(200) would be promoted, and that Pt-Pt interval on surface of PtCu-LaOxwould reduce owing to Cu was dissolved from (Pt) through H2SO4solution treatment, and that average grain size of PtCu-LaOxdecreased and crystal face spacing steady along with rising concentration.
Measure of the Optical and Electrical Properties of Semiconductor SiO2 Nano-Crystalline by Using Photo-Acoustic Technology
Authors: Lie Guang Hua , Tang Zhi Lie , Lie Gan Wen , Yang Ting , Tang Xiu Wen
Published: December 2011

By using a new type of single-beam normalized photo-acoustic spectroscopy that with weak signal detection and non-invasive testing, the photo-acoustic spectroscopy of semiconductor SiO2 nano-crystals was measured，the measured spectra of semiconductor SiO2 nano-crystals absorption coefficient was 0.20, and powders band gap is 3.4eV. The TEM image shows that the semiconductor SiO2 nano-crystals are round lump structure, while the grain size of the semiconductor SiO2 nano-crystals is about 70x200 nm, and the average particle size after the reunion is 100x300 nm. Compared with their micron crystal, the optical and electrical properties of semiconductor nano-crystals and nano-particle size are closely related. By changing the size of semiconductor nano-crystals, the mix could achieve the goal of changing the optical and electrical properties. Because of the semiconductor SiO2 nano-crystals‘ special properties of optics and electronics and photo-semiconductor nano-materials, they are widely used in many areas of modern science and technology.
Use of Impact Testing to Assess the Softness of Bedding Materials
Authors: Zhao De Ling , Shao Xiao Hou
Published: December 2011

Bedding materials are very important for cows in freestalls, because they can provide a high degree of comfort to these cows. But techniques of assessing their surface comfort on in the field still remain rather subjective. The objective of this study was to assess softness of bedding materials for use in cow free-stall bases in China. The Clegg Impact values of rubber-coated slatted floor, Solid wood floor and concrete floor are measured in order to compare with the value of pasture. The softest bedding material was the wood (40.43CIV/L) followed by rubber-coated slatted floor (64.23 CIV/L). The hardest material was the concrete floor (132.21 CIV/L).Clegg Impact Tester with a 1-kg hammer was used in this study. The impact of the hammer on bedding materials results in a digital display based on peak deceleration of the hammer’s impact with the free-stall base in tens of gravities (CIV/L). The CIV/L value, as measured by the Clegg Impact hammer, is based on peak deceleration of the 1-kg hammer’s impact with the surface, from a height of 30 cm. The reasonable suggestions of bedding materials used as the free-stall bases are recommended for the farmer in China.
Failure Analysis of the Stuffing Box in a Super High Pressure Compressor
Authors: Li Xiao Hui , Zhang Yi Liang , Xu Xue Dong
Published: December 2011

In this paper, theoretical and experimental researches were done to find the repeated cracking reason of stuffing box in a super hyper pressure compressor. The mathematical expression of the assembly pressure was deduced in interference fit. From macro and micro perspectives, residual stresses were measured by X-ray diffraction in typical position of stuffing box when the packing box in combination and separation states. Besides, metallography and fracture examinations were carried out. The results showed that the real magnitude of shrink range of the failed stuffing box was only account for 12% of the designed size requirements, however, under this working condition this stress was not sufficient to cause cracking; Unqualified smelting process and tensile stress concentration in tank caused micro crack, which finally results in fracture of the stuffing box under fatigue mode.
Mixed-Mode Bending Test for Fracture Toughness of Composite Bonding Adhesive Layer
Authors: Hu Xiao Min , Han Ke Cen , Xu Fei , Xie Wei , Kou Jian Feng
Published: December 2011

This paper describes the mixed-mode bending test fracture toughness of composite adhesive J116-b. The test theory and experimental requirements are introduced. The fracture toughness of mode I, mode II, and different mode mixture of 0.4, 0.6, and 0.8 are obtained. It is found that the total fracture toughness is increasing with the increasing of mode mixture. It is also obtained that the technique of calculating fracture toughness by considering the influence of the weight of lever and attach apparatus is more accurate.
Synthesis of Alumina-Tungsten Carbide Composites by Self-Propagating High Temperature Synthesis Process
Authors: Wei Xin
Published: December 2011

Alumina-Tungsten Carbide (Al2O3-WC) composites were synthesized by self-propagating high temperature synthesis (SHS) from a powder mixture of WO3-C-Al. The reaction was carried out in a SHS reactor under static argon gas at a pressure of 0.5 MPa. The standard Gibbs energy minimization method was used to calculate the equilibrium composition of the reacting species. The effects of carbon mole ratio in precursor mixture and diluents of NaCl and Al2O3 on the Al2O3-WC conversion were investigated using X-ray diffraction and scanning electron microscope technique. The as-synthesized products of Al2O3-WC2-WC powders were concurrently formed and the reduction of W2C phase was found when added diluents in precursors.
Corrosion Behavior of Drilling Pipe Steels for High Sour Gas Field
Authors: Wan Li Ping , Meng Ying Feng , Li Gao , Zhou Hua
Published: December 2011

A polymer drilling fluid containing high content of hydrogen sulfide was used as the corrosive medium to investigate the effects of temperature, flow velocity, pH value and partial pressure ratio of CO2/ H2S on the corrosion behavior of high strength drill pipe steel S135 and G105. The morphology and composition of the corrosion products were analyzed as well. It was found that the average corrosion rate of the two types of steel increased with increasing temperature of the corrosive medium, with the corrosion rate to decrease slightly within 60°C-80°C and keep almost unchanged above 120°C. At the same time, the corrosion rate of the drill pipe steels had little to do with the flow rate but increased with decreasing pH value of the corrosive medium. Moreover, the partial pressure ratio of CO2/ H2S had a slight effect on the corrosion behavior of the drill pipe steel. However, the two types of drill pipe steel showed a larger corrosion rate in gas phase than in liquid phase corrosive medium, which was contrary to what were observed in gas and liquid phases corrosion tests of conventional acidic drilling fluids. In addition, it was confirmed by sulfide stress corrosion test that the drill pipe steel of a higher strength had smaller critical stress, and the resistance of the drill pipe to stress attack was ranked as G105(C)＞G105(D)＞S135(B)＞S135(A). It was anticipated that the present research results could be used to guide the selection of materials for drilling pipe steels used in natural gas field of high acidity.
Modeling of Hydrogen Weight Storage Capacity in Solid Porous Silicon
Authors: Song Xiao Zhong , Wu Jie
Published: December 2011

Silicon-hydrogen crystalline models are proposed to estimate theoretical hydrogen storage capacity in porous silicon media with nanostructure features like cubic nodules, columnar forests and thin wall honeycomb like networks. To simulate these nanostructure features and their hydrogen storage capacities, three basic crystalline types (cubic, column and plate) have been developed as building blocks for constructing H-Si weight storage models under the assumption of that hydrogen is chemically bonded to available surface silicon atoms. Using these models, the hydrogen weight storage capacity for all feature dimensions from unit to infinitely long can be estimated. According to these theoretical models, the best nanostructure for hydrogen storage is cubic nodule, columnar forest and thin wall network in that order. They have weight storage capacity limits of 5.77%, 5.21% and 2.78% respectively for infinitely large feature dimensions.
The Growth Mechanism of MgO in the ZnO Coated Mg2B2O5 Whisker Reinforced AZ31B Composite
Authors: Han Li , Jin Pei Peng , Wang Jin Hui , Zhu Yun Peng , Xie Jie
Published: December 2011

In this paper, the growth mechanism of MgO in the as-cast ZnO coated Mg2B2O5whisker reinforced AZ31B composite. The elements distribution of interfacial vicinity are analyzed by electron probe microanalysis (EPMA) and microstructures of MgO and MgZn2are observed by transmission electron microscope (TEM). The crystallographic orientation relationship between the Mg2B2O5and MgO in the ZnO coated Mg2B2O5whisker reinforced AZ31B composite is investigated to be [010]Mg2B2O5// [011]MgOand (102)Mg2B2O5//(111 )MgO. The formation of intermetallic phase MgZn2is discussed.
Study on the Densification Process of the High Density Graphite Materials
Authors: Di Cheng Rui , Wang Cheng Guo , Qiao Kun , Yin Xiang Yu , Gao Xiao Dong
Published: December 2011

The densification process is the key step in the producing of the high density graphite materials. This paper depend on the DSC-TGA analysis of the green petroleum coke to explore the roasting curve. The impregnating process parameters were optimized through orthogonal experimental design. Results show that the green petroleum coke polymerization severe between 200 to 600°C, the coking of volatile has basically completed and the system start densification in 600-850°C.Keeping Nitrogen pressure 1.5Mpa and impregnation temperature 200°Cfor 60min are the first optimization process parameters of impregnation.
Study of Diffusion-Homogenization on SiCp/Al Composites Prepared by Elemental Powder
Authors: Liu Yun Xia , Liu Yue , Wang Bao Yong , Xie Hui , Liu Si Da
Published: December 2011

SiCp/Al composites were prepared by vacuum hot pressing and sintering method. Optical microscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD) is applied to study the diffusion-homogenization process of various elements of powder, and the effect of the diffusion-homogenization temperature and holding time on the SiCp/Al Composites’ microstructure in state of vacuum hot pressing. The results show that the Enrichment of Cu-phase is existed in the composites organization which is in the state of vacuum hot pressing; Al2CuMg fully dissolve into the Al matrix, Cu fully diffused and the diffusion of various elements becomes homogeneous with the temperature increased and time extend. The best processing parameters for the diffusion-homogenization is at 500°Cfor 3h.
Microstructure Evolution in Preparation of Cu-Sn Contact Wire for High-speed Railway
Authors: Yan Ming , Wu Yu Cai , Chen Jing Chao , Zhou Xiao Long
Published: December 2011

The thesis studies the microstructure evolution rule during Cu-Sn alloy preparation and processing process and its influence on material performance, provides necessary theoretical support for industrialization development of Cu-Sn contact wire for high-speed railway.
Modified Model for Static Behavior of Microcantilever Gas Sensor Adsorbed with Monolayer Molecules
Authors: Wang Xiao Ming , Wang Fei , Zhao Xue Zeng , Jing Da Lei
Published: December 2011

The modified static bending model of microcantilever with monolayer molecules has been established based on energy method, in which the change in neutral layer position caused by adsorption-induced stress has been considered. On this basis, we have analyzed the relationship between the bending curvature radius of a microcantilever with its thickness, Young’s modulus and molecule-molecule distance of adsorbed molecules when it is adsorbed with monolayer water molecules. Additionally, we have investigated the effect of change in neutral layer position on the static behavior of microcantilever sensors and have found that: 1) the bending curvature radius of microcantilever is affected by its Young’s modulus, thickness and distance of adsorbed molecules respectively; 2)the predicted error of bending curvature radius caused by the change in neutral layer position slightly increases with decreasing Young’s modulus and thickness, whereas the effect of distance between adsorbed molecules on the error is significant.
Magnetic Induction Effect of Rare-Earth La Modified FeSiB Amorphous Ribbon
Authors: Zheng Guo Tai , Jiang Da Guo
Published: December 2011

Investigated AC frequency and the number of coil turns as well as their influence on the magnetic induction effect of rare-earth La modified FeSiB amorphous ribbon. The results show that the magnetic induction effect is increased with the increase of AC frequency and the number of coil turns, and changing amplitude of magnetic induction effect shows first increased and then decreased with increasing frequency and coil turns.
Experimental Study on Porous Metal Bonded Diamond Grinding Wheels - The Selection of Porosity Inducers and Agglomeration’s Parameter
Authors: Xu Hua , Liao Cui Jiao , Weng Qing Ming
Published: December 2011

To improve the self-sharpening ability and increase clearance for debris of metal bonded diamond grinding wheel, the porosity structure is applied to the diamond grinding wheel in this paper. By selecting different inducers diamond composites are burned under appropriate agglomeration condition. The experiment results indicate that diamond composites obtained through two certain inducers can meet both the demand of pore-creating and intensity, so can be used to make wheels. This conclusion lays a foundation for further study.
Preparation and Characterization of Ag Nanowires by Hydrohermal Method
Authors: Liu Li Gang , Wei Zhi Qiang , Wu Xiao Juan , Zhang Ge
Published: December 2011

In this paper, Silver nitrate(AgNO3) and polyvinylpyrrolidone (PVP) acted as the silver source and dispersant respectively, the silver nanowires including a small amount of folded structure of silver nanowires, were synthesized by hydrothermal method under the polyol system combined with traces of sodium chloride. The nanowires were characterized by X-ray powder diffraction(XRD), transmission electron microscopy(TEM), selected area electron diffraction(SAED), scanning electron microscopy (SEM), energy dispersive spectrometry (EDAX) and UV-vis absorption spectroscopy to determine the chemical composition, crystal structure, morphology,and the generation mechanism of Ag nanowires was also analysed. The experimental results showed that the crystal structure of the as-prepared Ag nanowires was fcc structure with uniform width, smooth surface, the diameter about 200nm,the average length about 15μm,and the aspect ratio up to 75.The folded structure of silver nanowires synthesized were due to the straight silver nanowires were connected in an end-to-end manner, with obvious spacing between them.
Effects of Pd and Ni Metals Electrolessly Deposited on Si Nanowires on Properties of Photoelectrochemical Solar Cell
Authors: Liu Wei Long , Hsieh Yu Lun , Hsieh Shu Huei , Chen Wen Jauh
Published: December 2011

A photoelectrochemical solar cell with a structure of modified Si nanowire anocle/K4Fe(CN)6+ K3Fe(CN)6/Pt cathode was prepared and studied. The Si nanowires were first formed by immersing n-Si chip in an etching solution of HF + AgNO3 and Pd and Ni metals were electrolessly deposited on the surface of Si nanowires. The modified anode was characterized by a scanning electron microscope for the surface and cross section view, and by an X-ray diffractometer for the phase and structure. The properties of the photoelectrochemical solar cell were measured under standard AM 1.5 simulated sunlight (100mW/cm2). The results showed that the total photoelectron conversion efficiency of the photoelectrochemical solar cell can be slightly increased when the Si nanowire anode was deposited with Pd metal, and can be greatly increased when deposited with Ni metal.
Dry Sliding Wear Behaviour of Fe-Based Powder Sintered Steel
Authors: Chen Hua , Sun Hai Ying
Published: December 2011

Fe-based system powder metallurgy in the as-sintered was investigated on pin-on-rolling wear tester for their dry sliding wear behaviour. The morphology of worn surfaces and wear mechanism were analysed by SEM. Results show the hot-forging deformation quenching and tempered considerably decreased the porosity and improved wear resistance, and compare with quenching microstructure, tempered microstructure has high wear resistance and match of strength-toughness. Fe-2.0Ni-0.4Mo-0.5C-0.6Cr alloy presented best wear characteristics. SEM observations of the worn surface revealed microploughing and plastic deformation and crack were the basic dry sliding wear morphology,and oxidative wear and delamination wear are dominant wear mechanism.
Effect of Laser Fluence on Siliver Nanoparticles Colloid
Authors: Xu Bing , Song Ren Guo , Wang Chao
Published: December 2011

In order to study the effects of laser fluence on silver nanoparticles colloid, the silver nanoparticles colloid was prepared by pulsed laser ablation of silver target for 10min in distilled water at different laser fluence. The particles size，morphologies and absorption spectroscopy of the obtained nanoparticles colloid were characterized by ultraviolet to visible (UV-Vis) spectrometer and transmission electron microscopy (TEM), the average diameter and its distribution were analyzed by Image-ProPlus software. The results shown that the average diameter of the silver nanoparticles prepared at the laser fluence of 4.2J/cm2 was the smallest (D=17.54nm), also, the distribution of particle size was narrowest (=36.86nm) and the morphologies were more homogeneous. It was confirmed that the nanoparticles size and shape could be controlled by pulsed laser ablation parameters.
Al Ion Implantation of SiC Coated Carbon Fiber-Reinforced SiC Matrix Composites by Metal Vapor Vacuum Arc Ion Source
Authors: Ma Guo Jia , Lin Guo Qiang , Wu Hong Chen
Published: December 2011

SiC coated carbon fiber-reinforced SiC matrix (C/SiC) composites were implanted with aluminum ions by metal vapor vacuum arc ion source to improve their oxidation resistance. Depth profile of the aluminum ions in the SiC coated C/SiC composites was checked by Auger electronic energy spectrum. Oxidation tests were performed in flowing dry air at 1300°C on the SiC coated C/SiC composites. The samples with ion implantation exhibited lower weight loss than those without aluminum ion implantation. The surface morphologies of the samples were obtained by scanning electronic microscope. As compared with the mechanical properties of the samples without ion implantation, those of ion-implanted samples changed little.
Study on Cooling Process of Hot Rolled Wire Rod with Dual Phase Microstructure
Authors: Xu Xiang Jun , Kong Jun Qi
Published: December 2011

In the present paper effect of post deformation cooling rates on microstructure of ER70S-6 steel was investigated by using Gleeble1500 simulator. From the results, a controlling cooling process for obtaining dual phase (DP) microstructure was designed to produce hot rolled wire rod with a diameter of 6.5mm in a continuous no-twist and high-speed wire rolling mill, and the microstructures and the tensile properties of the wire rod were analyzed. The results showed that ER70S-6 steel deformed at 845°C and cooled at a rate of faster than 10°C/s had a DP microstructure with grain size of less than 8.3μm and martensitic volume fraction of 9-11%. The hot rolled wire rod cooled by blowing air had a DP microstructure with a grain size of 8.2μm and martensitic volume fraction of 11.5%. The present wire rod was superior to that of the same steel with ferrite plus pearlite microstructure in tensile properties, with yield strength level of 335-345MPa, ultimate tensile strength level of 600-620MPa, plastic elongation of 26.5-31.5% and strain hardening exponent of 0.221, respectively. ER70S-6 steel wire rod with DP microstructure showed promise of meeting the requirements for grade 8.8 fastener.,In the present paper steel wire rod with DP microstructure showed promise of meeting the requirements for grade 8.8 fastener.
Based on Grey Prediction and Fuzzy PID Control Method
Authors: Fei Ye , Ning Jin , Wang Xing Kun
Published: December 2011

This paper fusions advantages of the grey forecast, fuzzy control and the traditional PID control, puts forward the grey prediction fuzzy PID control method. This method is based on PID Controlling Regulation determine interrelated parameters with the fuzzy reasoning, use online grey prediction theory forecast the system outputs which instead of the controlled object measurement value to exert feedback control for the system. The simulation results show that this control ways have more excellent control quality than traditional PID and Fuzzy PID.
Idealisation and Formulation in Structural Dynamics Using Modal Analysis
Authors: Danish Muhammad , Pingali Vinay Kumar , Chattopadhyaya Somnath , Singh N.K. , Ray A.K.
Published: December 2011

The crux feature of this paper is the equations of motion in a structural dynamics with respect to single reference frame that can be easily derived, and the results are well defined and converged. However, problem occurs, when the analysis of any complex, complicated structure is considered and its equation of motion is extracted with respect to single reference frame. The results are indecipherable, ambiguous and less converged. Thus, for such a complex structure, the results obtain with respect to multiple reference frames. In present study, an approximated model with a set of lumped masses, properly interconnected, along with discrete spring and damper elements are in consideration for continuous vibrating system. This results in dynamic equilibrium, which in turn results in formulation and idealization. As, rightly said by scientist Steve Lacy- “To me, there is spirit in a reed. It is a living thing, a weed, really and it does not contain spirit of sort. It’s really an ancient vibration”
Inhomogeneous 3D Finite Element Model for Prediction of Free Surface Roughening
Authors: Furushima Tsuyoshi , Masuda Tetsuro , Manabe Kenichi , Alexandrov Sergei
Published: December 2011

In this study, we evaluated the characteristics of 3D finite element (FE) model considering material inhomogeneity for prediction of free surface roughening. Free surface roughening behavior can be observed by this model. The variation in material inhomogeneity parameter value has a strong correlation with the rate of increase in the surface roughness. macroscopic strength coefficient K value does absolutely not affect the rate of increasing surface roughness. Strain hardening sensitivity index n value slightly affects the free surface roughening behavior. The true stress – true strain curve of the inhomogeneous FE model is in good agreement with those of the homogeneous FE model and the experimental result. As a result, the characteristics evaluation of suggested model considering material inhomogeneity is conducted.
Electrical and Flexural Properties of Copper and Graphite Filled Phenolic Resin Composites
Authors: Li Mi Dan , Niu Huan , Wei Shou Bin , Yang Hong
Published: December 2011

Composites made of phenolic resin filled with graphite platelets and copper particles (copper powder, copper fiber or both mixture), are fabricated by mechanical mixing. The electrical conductivity of composite composed of 30 wt% resin, 50 wt% graphite and 20 wt% copper powder is up to 600S/cm. The efficiency of copper powder is compared with copper fiber. The results show that copper powder is more effective than copper fiber in improving electrical conductivity. The particle shape is also a principal factor in influencing flexural strength. In this study, the flexural strength of composites tends to increase with decreasing the ratio of copper fiber/copper powder because the dendritic structure of copper powder enhances the probability of graphite platelets embedded in the dendritic arms, which in fact help to distribute the external load from matrix to copper powders.
Characterization of Bolt Hole Residual Stresses for Assessing Structural Behavior of Truck Frame Rails
Authors: Chinnaraj K. , Sathya Prasad M. , Rao C. Lakshmana
Published: December 2011

Chassis frame rails in a truck are load bearing structural members that integrate vehicle power train with superstructure to form a complete vehicle. Large numbers of bolt holes that are cut into these frame side members act as joineries and points of attachments for various sub systems of the truck. While bolt holes are unavoidable due to its primary functional importance, the near hole residual stresses remaining from hole cutting operations may play a significant role in deciding the life of frame rail sections as they lead to early initiation of fatigue cracks around bolt hole surface. In order to assess the extent of plastic deformation and resulting residual stress pattern in near hole areas of bolt holes, experimental investigation through microstructure analysis, micro-hardness and X-ray diffraction measurements has been taken up. The hole cutting operations considered for this exercise are drilling, punching, laser cutting and water jet cutting used to cut holes on truck frame rail sections. Apart from this, an assessment of shot-peened hole surface was also taken up to understand the effect of shot-peening on structural behavior of frame rail bolt hole sections. The experimentally measured near hole residual stress profiles can be considered as initial conditions for further numerical analysis to study the influence of bolt hole residual stresses on fatigue life of frame rail sections.
Measurement of Dynamic Resistance in Resistance Microwelding of Insulated Copper Wire
Authors: Mo Bing Hua , Qi Jun , He Bing Qiang , Chen Ping , Guo Zhong Ning
Published: December 2011

A measuring system of dynamic resistance in resistance microwelding (RMW) of insulated copper wire was developed. The system included a computer, data acquisition (DAQ) card, current sensor, digital trigger circuit and analysis software. Dynamic resistance patterns at the secondary circuit under both normal and abnormal welding conditions were successfully monitored by this system. The results show that the dynamic resistance during the RMW of insulated copper wire is a monotonously decreasing curve; a wave crest will appear when surface splash occurred. This peak characteristic can provide a sound approach to in-process monitor weld quality for RMW of the insulated copper wire.
Research on Roll Force for Variable Gauge Rolling
Authors: Zhang Guang Ji , Liu Xianghua
Published: December 2011

The production of materials saving products such as Longitude Profile plates (LP plate) and Tailor Rolled Blanks (TRB) needs to solve the problem of the calculation of variable gauge rolling (VGR) parameters. It has been proved that Karman differential equation of force equilibrium for simple rolling is a special case of VGR equations when vy＝0. Differential equations of force equilibrium for both upwards rolling and downwards rolling were solved and the rolling pressure distribution function for VGR was got in this paper. Finally, details of a set of experiments were presented and the theoretical model of rolling force was proved to be reasonable.
Effect of Temperature on Shear Strength of Adhesively Bonded Joints for Automobile Industry
Authors: Hu Ping , Han Xiao , Li Long , Shao Qi , Li Wei Dong
Published: December 2011

Due to the significant effect on vehicle lightweight, adhesively bonded joint in structural components is widely adopted in automobile industry in recent years, which leads to the benefits in fuel economy, reduced emissions and driving safety. In this paper, the performances of adhesively bonded joints with three different adhesive types after different temperature treatments are investigated through joint shear strength test. Visual inspection is performed on fracture surfaces after joint failure. Results showed that both low and high temperatures have impact on joint strength and lead to different fracture modes. Stiff and flexible adhesives also result in different fracture surfaces in the overlap zone as the temperature varies.
Research of Die Cavity Warm Extrusion on 3Cr2W8V Steel One-Off Forming Technology
Authors: Du Wei , Yuan Guo Sen , Li Cheng Bin
Published: December 2011

The problems of 3Cr2W8V steel concave die forging production must be solved, such as too many procedures, high cost and mold crack. Through the use of a warm extrusion forming method it could make one-off forming die cavity come true, more practical warm extrusion forming parameters and extrusion die structure parameters were obtained. A suitable lubricant was selected out so that the processed forging die organization was improved and forging streamline distribution was more rational. The service life of forging die increased, and warm extrusion forming technology was applied in the mold production.