bluuebunny/crossref_metadata_2025 huggingface dataset:
Different Cr Contents in Nanostructured Fe-Ni-Cr Alloys Prepared by Mechanical Alloying
Authors: He Qi , Liu Tao , Xie Jian Liang
Published: December 2012

Fe-Ni-Cr alloy powders with the different components were prepared by Mechanical Alloying (MA). The phase structure, grain size, micro-strain and lattice distortion were determined with X-ray diffraction. The morphology and particle size of the powders were observed and analyzed using a field emission scanning electron microscopy. The results showed that the Fe-Ni-Cr nanocrystalline powders could be obtained by MA. The ball milling time could be reduced with increasing amount of Cr, resulting the formation of Fe-Ni-Cr powders. With the increasing amount of Cr, the speed of Ni diffusion to Fe lattice approaching saturation became more rapid. The particle size got smaller as the ball milling went further; the extent of micro-strain and distortion of lattice intensified; the solid solubility of Ni and Cr in Fe was increased. Finally the super-saturated solid solution of Fe was obtained.
Preparation of LiTaO3 Nano-Crystalline Films by Sol-Gel Process
Authors: Gou Jun , Wang Jun , Huang Ze Hua , Jiang Ya Dong
Published: December 2012

Lithium tantalite (LiTaO3) thin film material shows good feasibility and potential for the application of high-performance detection system. In this paper, sol-gel process of LiTaO3 thin films on p-type (111) silicon substrates was described. Stable precursor solution with a desired viscosity was obtained using lithium acetate (LiAc) and tantalum ethoxide (Ta(OC2H5)5) as starting materials. Heat treatment process was optimized to fabricate LiTaO3 films of high crystallinity. Higher crystalline quality films were obtained when each spin-coating process was followed by an annealing operation. Microstructures and crystallization properties of LiTaO3 thin films were further studied. Nano-crystalline films were obtained after annealing at 700 °C for 5 min. The experimental results indicated that the crystallinity and mean grain size of LiTaO3 thin films were proportional to the film thickness.
Typical Materials’ Abrasion Rules and Failure Lives Prediction of Key Parts for Breech Mechanism Based on Virtual Prototype
Authors: Hu Hui Bin , Cao Li Jun , Cao Xin Wen , Chen Shu Xiao , Sun Yan
Published: December 2012

As a kind of complicated mechanical automation, most of key parts of breech mechanism are cams delivering forces and movements by parts’ outline and figure. The major fault mode of breech mechanism is grain abrasion caused by dry sliding friction. There are no feasible and practical technologies to simulate and predict the abrasion failure lives of key parts for breech mechanism. A new simulation and prediction method is firstly put forward in this paper. Based on Pro/E and ADAMS, the virtual prototype of breech mechanism of semiautomatic vertical sliding-wedge type is established. Key parts’ load spectrum can be obtained based on virtual prototype. Pin-on-disc friction and abrasion testing machine is designed and adopted to obtain typical materials’ abrasion rules. Finial simulation and prediction results are given as abrasion thresholds and operating items, which provide sufficient references for breech mechanism’s design and safeguard.
The Comprehensive, Effective Purification Strategy of Carbon Nanotubes
Authors: Liu Xuan , Bian Hua , Chen Hong Wu , Zhao Li Jie
Published: December 2012

It is known that the high purity of carbon nanotubes (CNTs) are hard to obtain because of the impurities, which directly affect their unique properties and potential applications. Some modern purification methods including physical separation methods and chemical oxidation methods have been developed for getting the CNTs. But either way, each method still has some deficiencies, such as structure damaged, complex steps and low yield. Now there is a comprehensive multi-step method to overcome this predicament, it combines the air oxidation, hydrochloric acid treatment, SDS dispersion, centrifugation process, mixed acid oxidation and H2O2 oxidation. In this paper, the whole procedures of comprehensive methods are discussed in detail.
Optimization of Fabrication Parameters to Prepare Tea Catechin-Loaded Liposomes by Fuzzy Orthogonality
Authors: Fang Jian Jun , Guan Rong Fa , Ma Jie Qing , Rui Chang , Shen Hai Tao , Zhang Jin Jie
Published: December 2012

The fuzzy orthogonal design is a method that the orthogonal results were fuzzed and then analyzed using fuzzy mathematical theory. It took the full advantage of the information from orthogonal experiments to obtain the optimal liposome preparation conditions by considering all the evaluation indexes. With the fuzzy comprehensive evaluation for the objective function, main technological parameters of process in liposome preparation were optimized using fuzzy orthogonal design. The optimal processing parameters were pH values of phosphate-buffer solution of 7,soybean phosphatidyl-choline and cholesterol proportion of 1:1,the concentration of Catechin of 5mg/mL,Oil­water proportion of 3:1.The catechin-loaded liposomes prepared under the optimized conditions has high encapsulation efficiency. The entrapment rate of catechin nanoliposome measured by validated test was 61.7%±0.015,while the mean diameter was 193.6±0.119 nm.
Influence of Radio Frequency Power on the Structural Properties of nc-Si Films Fabricated by VHF-PECVD
Authors: Guo Yan Qing , Wang Xiang , Song Chao , Huang Rui , Song Jie
Published: December 2012

In recent years, hydrogenated nanocrystalline silicon (nc-Si:H) film has received much attention due to its potential application in various optoelectronic devices. In the present work, nanocrystalline silicon (nc-Si) films were fabricated from SiH4 diluted with H2 in very high frequency (40.68 MHz) plasma enhanced chemical vapor deposition system. The influence of radio frequency (rf) power on the structural properties of nanocrystalline silicon films has been studied. Raman spectra show that the crystallinity of the nc-Si films can be increased by promoting the rf power. But over high rf power leads to the structural deterioration of nc-Si:H film. AFM images manifest that, with the increase of deposition time, the grain size becomes larger accompanied by the decrease of the number density.
Hydrothermal Synthesis and Photocatalytic Properties of Nano Bi2WO6/TiO2 Powers
Authors: Chen Hai Feng , Yan Ting
Published: December 2012

Using Bi(NO3)3•5H2O, Na2WO4•2H2O and Ti• (OC4H9)4 as the main raw materials, different alcohol solvent as medium, hexamethylene tetramine as sink set agent, tungsten bismuth and titanium dioxide composite powder were prepared by hydrothermal synthesis. It was characterized by XRD and DRS. The methyl orange imitated sewage, we study the impacts of calcinations’ temperature, catalyst amount, concentration, illumination time and pH on photocatalytic performance of Bi2WO6/TiO2 samples under visible light. The results showed that calcinations’ temperature 400 oC was the best, because the forbidden band gap decreased with temperature increased, but phase transition or decomposition exothermic of the samples would occurre at higher than 400 degree. The Bi2WO6/TiO2 prepared under acidic condition had only 2.41 eV as the smallest forbidden band gap of the samples.
The Laser Ablated Deposition of Si Nanocrystalline
Authors: Wu Yue , Meng Xiao Hong
Published: December 2012

The single crystalline Si target with high resistivity was ablated by a XeCl excimer laser (laser fluence 4 J/cm2, repetition rate 1 Hz), and at ambient pressure of 10Pa of pure Ar gas, the nanocrystalline silicon film was deposited on a glass or single crystalline Si substrate located at a distance of 3 cm from the Si target in 30 and 10min, respectively. The Raman and X-ray diffraction spectra of the film deposited on the glass substrate indicate the film is nanocrystalline, which means that it is composed of Si nanoparticles. Scanning electron microscope of the film on the Si substrate shows that the film has the mosaic structure of Si nano-crystallites of uniform size. The photoluminescence peak wavelength is 599nm with full width at half maximum of 56nm.
Synthesis of Amorphous Ti50Al50 by Mechanical Alloying
Authors: Zhang Jun Hong , Xu Guo Hui , Xu Ya Juan , He Yue Hui
Published: December 2012

Blended elemental powders with the nominal compositions (at%) of Ti50Al50, was mechanically alloyed in a planetary ball milling system for up to 100h, an amorphous Ti50Al50 phase was obtained in the process. The amorphization process as a function of time of milling was monitored by scanning electron microscope, X-ray diffraction and transmission electron microscope. It is shown that, as first, Al atoms diffuse into the host lattice of hexagonal Ti; subsequently, the milling accumulates a critical density of disorder that causes the Ti (Al) crystalline phase to collapse into an amorphous phase, it is suggested the grain size condition for formation of amorphous phase is 12nm. On the basis of thermodynamic models, the formation of the amorphous phase is discussed.
Study on Parameters of MEMS Accelerometer
Authors: Ma Shu Min , Chen Chao , Wang Tao , Zhang Huan , Zhou Hong Xi
Published: December 2012

An accelerometer is a micro- electromechanical device which can sensitive to acceleration . The sensing mechanism of accelerometer is that when accelerated , the mass moves in Z-axis, and the gap between parallel plates changed with the loads, which causes vary of the capacitance of the estimation. This paper presents a newly devel oped sensor for the conventional capacitive MEMS accelerometer in Z-axis . The principle of capacitive acceleration is based on the detection the change of capacitance which results from acceleration changes. The sensor is used for estimation of the size a nd loads variations for accelerometer. This paper has been focused on the design of the MEMS accelerometer and calculation of the major parameters of the sensor.
Titanium Dioxide Nanoparticles Induced Cytotoxicity in Rat Retinal Ganglion Cells under Ultraviolet B Irradiation
Authors: Guo Da Dong , Bi Hong Sheng , Wu Qiu Xin , Wang Dao Guang
Published: December 2012

Titanium dioxide (TiO2) nanoparticles have been widely used in many fields, including biomedicine, cosmetics and environmental engineering. Recently, it was reported that TiO2 nanoparticles could exert genotoxicity on organisms via the generation of reactive oxygen species (ROS). In the present study, we investigated the effect of TiO2 nanoparticles on RGC-5 cells with or without ultraviolet (UV) B irradiation through MTT assay and determination of hydroxyl radical production. The results demonstrated that TiO2 nanoparticles could efficiently inhibit the growth of RGC-5 cells in the presence of UVB irradiation, whereas there was little impact on target cells in the absence of UV irradiation; UV irradiation could apparently increase the level of hydroxyl radicals in RGC-5 cells and further efficiently inhibit the growth of RGC-5 cells, suggesting that UV irradiation plays an important role in growth inhibition in RGC-5 cells exposed to TiO2 nanoparticles.
Cytotoxicity Effects of CdTe Quantum Dots on Human Lung Cancer A549 Cells
Authors: Han Shuang , Li Qing Ning
Published: December 2012

In order to explore the possibility of the novel CdTe QDs (cadmium telluride quantum dots) as future delivery carrier material, the cytotoxicity effects of CdTe QDs was evaluated in human lung adenocarcinoma A549 cells and with normal HELF cells as control. The cell proliferation fraction was analyzed under the treatments of CdTe QDs by MTT and RTCA. The results showed that CdTe QDs present minor cytotoxicity on the proliferation of these two cell lines at the lower concentrations less than 0.18µmol/L within 72 h, and show toxicity effects under high concentrations. Besides, combination of CdTe QDs at lower concentration (<0.18µmol/L) together with DOX can enhance the killing fraction on A549 more than that of DOX alone, which indicated the drug carrier potential of CdTe QDs, and provided the important basic experiments for further development.
Characterization of Cr Doped Diamond-Like Carbon Films and Research on Mechanical Properties
Authors: Fan You Yu , Li Guang , Xia Yuan
Published: December 2012

Diamond-like carbon (DLC) films have been extensively studied for more than a decade due to their unique combination of properties. The internal compressive stress affects their adhesion and preventing wide usage of these films. Metal-containing DLC films are expected to relax internal stress. The present work focused on the synthesis, chemical bond and mechanical property characterization of Cr-containing DLC films. The films thickness, internal stress and composition were characterized by scanning electron microscopy, optical interferometry and X-ray photoelectron spectroscopy respectively. Incorporation of Cr into DLC causes an initial internal stress reduction and subsequent stabilization around 0.5 GPa. The hardness behavior was found to depend on Cr content. Films with less than 7.36 at.% Cr (no formation of C-Cr bond) showed a dramatically hardness reduction compared to pure DLC films. Above 7.36 at.% Cr (C-Cr bond formed) the hardness increases above 12 GPa.
Application of CIEDE2000 Color Difference Formula in Jet Fuel Silver Strip Corrosion Color Recognition
Authors: Tong Li Ping , Peng Bin , Fei Yi Wei , Yang Hong Wei
Published: December 2012

In order to eliminate the human eyes’ subjective differences in the level recognition of the jet fuel’s silver corrosion, chromatic aberration system is used to calculate chromatic aberration between the image of the standard colorimetric board and the experiment silver corrosion. By contrast, this paper chooses the least chromatic aberration to estimate the level of silver corrosion. The CIEDE2000 of the color difference formula, which can match with person vision theoretically, is applied in the chromatic aberration system at present, and can reflect the minor differences in color correctly. so this paper attempts to use CIEDE2000 color formula to determine the silver strip corrosion, which can reduce the influence of professionals’ subjective factors, and these results are more objective and accurate, which proves the actual feasibility of this method.
Delivery of miRNA Using Fe2O3 Nanoparticles Capped Polyethyleneimine as a Nonviral Carrier
Authors: Liang Gao Feng , Li Ping , Lei Wan Jun
Published: December 2012

An efﬁcient and safe delivery system of RNA interfering is required for clinical application of gene therapy. The study aimed to develop Fe2O3-based nanoparticles for gene delivery to overcome the disadvantages of polyethyleneimine (PEI) or cationic liposome as gene carrier including the cytotoxicity caused by positive charge and aggregation in the cells surface. PEI-capped Fe2O3 nanoparticles are successfully manufactured utilizing Fe2O3 as core, PEI as carapace, which bind miRNA at an appropriate weight ratio by electrostatic interaction and result in well-dispersed nanoparticles. The synthesized GFP tag with miR-26a expression plasmid was used for monitoring transfection efficiency in HepG2 cells. The nanocomplex exhibited higher transfection efficiency and lower cytotoxicity in HepG2 cells than the PEI/DNA complex and commercially available liposome. The delivery resulted in a significantly upregulation of miR-26a in HepG2 cells. Our results offer an alternate delivery system for RNA interfering that can be used on any gene of interest.
Abnormal Capacitance Hysteresis Phenomena in Stacked Nanocrystalline-Si Based Metal Insulator Semiconductor Memory Structure
Authors: Wang Xiang , Chao Song , Guo Yan Qing , Song Jie , Huang Rui
Published: December 2012

Stack nanocrystalline-Si (nc-Si) based metal insulator semiconductor memory structure was fabricated by plasma enhanced chemical vapor deposition. The doubly stacked layers of nc-Si with the thickness of about 5 nm were fabricated by the layer-by-layer deposition technique with silane and hydrogen mixture gas. Capacitance-Voltage (C-V) measurements were used to investigate electron tunnel and storage characteristic. Abnormal capacitance hysteresis phenomena are obtained. The C-V results show that the flatband voltage increases at first, then decreases and finally increases, exhibiting a clear deep at gate voltage of 9 V. The charge transfer effect model was put forward to explain the electron storage and discharging mechanism of the stacked nc-Si based memory structure. The decreasing of flatband voltage at moderate programming bias is attributed to the transfer of electrons from the lower nc-Si layer to the upper nc-Si layer.
Study on the Reliability Problem of UV-LIGA Technics
Authors: Liu Jia Kai , Qi Xing Lin
Published: December 2012

UV-LIGA technics which used in high aspect ratio micro-structure fabrication has been developed quickly currently, but there still exist many technical problems which may affect the reliability of production, especially in lithography and electroform process. According to analyzing the technical process of bi-layer micro-gear, the reliability problems have been studied from two aspects, including deep lithography and micro electroform. In the deep lithography technology, the adhesive property between SU-8 photoresist and substrate and the non-uniform thickness and bubble problems of SU-8 photoresist layer have been presented. In the micro electroform aspect, problems include non-uniformity, air holes, and adhesive property of electroformed layer. Aimed at these problems, the resolvents have been put forward and validated, which improve the reliability of technics and possess fine effect.
The Research of Gas-Sensing and Optical Characterization of Chlorinated Metallic Porphyrin Spin-Coated Films
Authors: Yang Wen Yao , Xu Jian Hua , Wang Si Yu , Chen Yan
Published: December 2012

In this text, the Chlorinated metallic porphyrin (TPPMncl and TPPFecl) thin films were fabricated by Spin-coated technique onto quartz substrates. In order to search for the gas-sensing characterization of Chlorinated metallic porphyrin Spin-coated films, the changes of UV-Visible absorption spectrums of TPPMncl and TPPFecl Spin-coated films respectively exposed in vapor of Chloroform, pyridine, Ammonia, triethylamine and dimethylamine were analyzed. The experimental results show that, the spectral response of TPPMncl and TPPFecl on organic gas molecular is obviously found. And we know that chlorinated metallic porphyrin film formed the J-aggregates. Moreover, through two kinds of chlorinated metallic porphyrin integral area rate of histogram, it is easy to identify and distinguish between the four kinds of volatile organic compounds. It indicates that these Chlorinated metallic porphyrin have gasochromic characteristics while responding with organic gas. Therefore, these materials can be prepared into gas sensor array for detecting VOCS.
The Humidity Sensitive Behavior of Poly(Ethyleneimine)/Multiwall Carbon Nanotube Composite Films
Authors: Zhu Tao , Xie Guang Zhong , Jiang Ya Dong , Liao Jian , Tai Hui Ling
Published: December 2012

In this paper, a novel humidity sensor based on polymer-carbon nanotube composites was prepared and characterized. Two different methods were adopted to fabricate the humidity-sensing film for these sensors. The surface of the films was observed by a scanning electron microscope (SEM). The sensing material made up of poly(ethyleneimine) and multiwall carbon nanotube was sprayed on the interdigitated microelectrode pairs(IDTs). The resistance between the two electrodes was measured at different relative humidity levels at 19°C. The data shows that the resistance increases with the rise of the relative humidity over the range of 5-90% RH and that, the resistance increases almost linearly in the range of 5-71% RH. The response of the sensors to NO2 and NH3 were also examined, and the results reveal that the sensor is not sensitive to both of them.
Microstructure and Mechanical Properties of a Nb-Microalloyed Medium Carbon Steel Treated by Quenching-Partitioning Process
Authors: Zhang Kai , Lu Shang Wen , Ou Yao Hui , Wang Xiao Dong , Zhong Ning
Published: December 2012

The recently developed “quenching and partitioning” heat treatment and “quenching-partitioning-tempering” heat treatment are novel processing technologies, which are designed for achieving advanced high strength steels (AHSS) with combination of high strength and adequate ductility. In present study, a medium carbon steel containing Nb was subjected to the Q-P-T process, and both the microstructure and mechanical properties was studied. The experimental results show that the Nb-microalloyed steel demonstrates high tensile strength and relatively high elongation. The microstructure of the steel was investigated in terms of scanning electron microscope and transmission electron microscope, and the results indicate that the Q-P-T steel consist of fine martensite laths with dispersive carbide precipitates and the film-like interlath retained austenite. The orientation relationships between martensite and retained austenite is as well-known Kurdjurmov-Sachs relationship and Nishiyama-Wasserman relationship.
The Specific Binding between Galactose Group and Ricinus Communis Agglutinin (RCA) Investigated with Microcantilever
Authors: Zhang Hui Yong , Hu Ji , Liu Hui Min
Published: December 2012

The specific recognization between galactose group and Ricinus Communis Agglutinin (RCA) was investigated by microcantilever. The gold side of the microcantilever was covalently bound with N-galactose, RCA and asialofetuin (ASF) via mixed self assembly monolayer of 11-mercaptoundecanoic acid and 6-mercaptohexanol, respectively. After adding RCA into the flowing cell, the deflection could be observed on the N-galactose or ASF modified microcantilever. Meanwhile, the deflection could also be observed after ASF bound to the RCA modified microcantilever. In order to prove that the deflection is caused by the specific interaction between the galactose group and RCA, bovine serum albumin (BSA) was introduced into the flowing cell as control experiment and no obvious deflection was observed. The specific interaction was also confirmed by the evidence that the bound protein layer can be mechanically removed with atomic force microscopy nanolithography technology.
Effect of Accumulative Roll Bonding Process with Inter-Cycle Heat Treatment on Microstructure and Microhardness of AA1050 Alloy
Authors: Dehghan Mojtaba , Qods Fathallah , Gerdooei Mahdi
Published: December 2012

Processes with severe plastic deformation (SPD) may be deﬁned as metal forming processes in which ultra-large plastic strain is introduced into a bulk metal in order to create ultra-ﬁne grained (UFG) metals. Accumulative roll bonding (ARB) is a SPD process that may be deﬁned as multisteps rolling process in order to create high strength metals with UFG structure. In this study, ARB process with inter-cycle annealing is carried out on the commercial purity aluminium (AA1050) sheet up to 13 cycles. The purpose of the present study is investigation of microhardness behavior and microstructural evolution in the ARB processed AA1050 sheet. Micro-Vickers hardness measurement is carried out throughout thickness of the ARB processed sheets. In addition, with increasing ARB cycles the grains size is reduced in nanometer level.
Study of Surface Roughness in Milling Carbon Fiber Reinforced Plastics Using PCD Tool
Authors: Zhang Yun Dian , Xiao Hui Hui , Teng Yue
Published: December 2012

The surface roughness of carbon fiber reinforced plastics (CFRP) has been studied at different cutting parameters by using PCD tools. The effect of cutting parameters such as cutting velocity, cutting depth, cutting width as well as feed rate on roughness are analyzed. A predictive model for surface roughness in milling was established by regression analysis method. Based on the experimental results, the regression coefficient was calculated and the significance check of the regression equation was carried out. Results show that cutting depth has a significant effect on surface roughness and the next one is cutting velocity, then it is cutting width, feed rate has a little effect under the current experimental conditions. The regression is significant for the prediction model. The parameters used in milling can be selected to improve the quality of the surface based on the model of the paper.
Microstructure, Interface and Hardness of Ti/TiN Nanolayered Coatings
Authors: Bai Xiao Ming , Zheng Wei Tao , Guo Xiu Juan , She Hui
Published: December 2012

The polycrystalline Ti/TiN multilayer films were deposited by magnetron sputtering. We investigated the effects of mixed discharge gas pressure, bias voltage and substrate temperature on the microstructural, interfacial, and mechanical properties of the polycrystalline Ti/TiN multilayer films. X-ray reflectivity and diffraction (XRR and XRD), and nanoindentation were used to characterize the structures and mechanical properties for the films.The period of multilayer, interface width and grain size decrease with increaseing of deposition pressure. The multilayer coating at floating voltage shows TiN (111), Ti2N (103), and TiN (200) preferred crystalline orientation, whlie those at other different substrate biases show only TiN (111) and Ti2N (103) preferred crystalline orientation. It was found that the hardness increased with increasing substrate temperature. This hardness enhancement was probably caused by the modulus difference in the interface between layer Ti and TiN or the preferred crystalline orientation TiN(111).
Preparation and Characterization of Nano-Porous SiO2/TiO2-SiO2 Thin Films on Glass Substrates by Sol-Gel Method
Authors: Zhao Qing Nan , Liu Ying , Hou Shao Hong , Zeng Wu , Sun Jie
Published: December 2012

Nano-porous bilayers structure antireflection films on glass substrate were prepared by sol-gel method, tetraethyl orthosilicate(TEOS) and tetrabutyl titanate(TEOT) as the main raw materials, cetyl trimethyl ammonium bromide(CTAB) and polyethylene glycol(PEG) as template. The relation of the template agent addition, pH, and aging time to surface morphology and optical properties were analyzed. When the CTAB/TEOS = 1/30, the average spectral transmittance in the visible wavelength is 93.69% and the peak transmission is up to 97.37%. All the bilayers antireflection films are amorphous structure, uniform surface morphology, dense nano-porous size distribution, pore size is about 10nm.
A Improved Stereo Matching Fast Algorithm Based on Dynamic Programming
Authors: Zhou Zi Wei , Li Ge , Li Chang Le , Fan Ji Zhuang
Published: December 2012

Compared with the local algorithm in stereo matching, the high quality disparity space image is calculated by the global algorithm, which is difficult to use in practical application for its long computation time. The dynamic programming is one of the global algorithms with a fast matching speed, but it has strip blemish in matching result. In this paper, a new dynamic programming based method is proposed to accelerate the matching speed and improve the matching quality. Firstly, the color feature of two images are calculated using the Laplacians of Gaussian pyramid algorithm, and the color feature of the image pair obtained are matched. Secondly, the matching points are taken as the ground control points of the scan line, which is cut into several short line segments. Finally, all line segments are matched to obtain the disparity of the scan line. The experimental results show that the matching speed is accelerated greatly with improved disparity image quality
Characterization on Primary Phase Morphology of Semisolid A356 Alloy during Isothermal Holding with Fractal
Authors: Liu Zheng , Liu Xiao Mei
Published: December 2012

Semisolid A356 alloy was prepared by low superheat pouring, and evolution of primary phase morphology in semisolid A356 alloy during isothermal holding was characterized by fractal theory. The results indicated that the primary phase morphology in the alloy had fractal character, and the evolution of the primary phase morphology in the alloy could be characterized by fractal dimension. The primary phase morphology at the different isothermal holding temperature and holding time had the different fractal dimension, which meant the effect of processing conditions on the morphology in the alloy. Solidification of the alloy was a course of change in fractal dimension.
Gray System Study on the Influence of Particle Size Distribution of Steel-Slag Powder on Performance of Cementitious Materials
Authors: He Tu Sheng , Zhao Xu Guang , Zhao San Yin , Li Zai Bo
Published: December 2012

Particle size distribution of converter steel-slag powder prepared by ball milling were tested by the Mastersizer2000 laser diffraction particle size analyzer, the strength and fluidity of the cementitous morter made of 30%(mass fraction) steel-slag powder into standard cement were tested, and grey system theory was used to analysis the relationship between particle size distribution of slag powder and properties of mortar, the gray model of GM (0,2) was established between 28d compression strength and 4~8µm particle content. The results show that: the volume fraction of 24~32µm particle has a maximum effect on mortar fluidity, 4~8µm particle has a maximum effect on 7d and 28d mortar compressive strength, positive correlation; The predicted values agree well with measured values according to gray model.
Test Research on Mechanical Property of GFRP Bolt under Freeze-Thaw Cycle Conditions
Authors: Tang Xie Xing , Luo Xiao Yong , Sun Qi , Kuang Ya Chuan
Published: December 2012

In this paper, GFRP bolts in diameter of 25mm are tested through freeze-thaw cycle by 50, 100 and 150 times to study their change law of appearance, weight, strength and elastic modulus. As reflected from the test results, after the freeze-thaw cycle, the appearance and weight of GFRP bolts are basically not changed. As the freeze-thaw cycle increases from 50 times to 100 times, the strength of bolts decreases gradually. After 50, 100 and 150 times of freeze-thaw cycle, the ultimate tensile strength of bolt decreases by 2.82%, 4.35% and 8.84%, respectively. During the process that the times of freeze-thaw cycle increase from 50 to 100, the elastic modulus of GFRP bolts grows gradually. After 50, 100 and 150 times of freeze-thaw cycle, the elastic modulus increases by 1.42%, 2.68% and 3.92%, respectively. The freeze-thaw cycle leads to embrittlement of GFRP materials and weakness of ductility, while not obviously.
Computer Simulation and Analysis on Fire Verification and Smoke Distribution of the Entertainment Areas
Authors: Chen Te Chi , Yu Chia Chun , Lin Cherng Shing
Published: December 2012

Along with the economic growth, more crowded entertainment places are growing dramatically and the safety concerns are no longer contained as usual. The huge property damage and heavy casualties of fire caused by the owner ignorance of safety management or the fall short of the fire resistance specifications. These factors caused serious casualties after fire occurred. This research utilizes Fire Dynamics Simulator (FDS) software to analyze and simulate the fire accident that occurred in a public entertainment places on Po-Li bar, KeeLung City, Taiwan. The computer simulation calculates the fire spread and smoke distribution at the fire scene, and is in reasonable agreement with the post report provided by the fire department and photos. Simulation results of the various important parameters - such as temperature, CO concentration and smoke layer height during the fire time domain are obtained. This study will provide the improvement of fire parameters and suggestions to avoid future unfortunate events.
A Study on TingBao Yang's Architectural Thoughts: Aiming at the Regionalism Concept
Authors: Qu Yi , Chen Ying , Wang Ying
Published: December 2012

This paper aims to analyze the regionalism concepts in Tingbao Yang's architectural thought on the Regionalism Concept. Firstly, this study examined Tingbao Yang's career to make clear what has influenced his architectural thought. Secondly, this study analyzed his most important works to find if any regionalism concepts available by each time. Finally, we summarized the transition of the regionalism concepts in Tingbao Yang's architectural thought. As a result of these analyses, this paper reveals that at least four regionalism factors, which are climate, landform, regional material and architectural tradition, are considered in his works. Furthermore, he has even created a special design technique on them. Due to the analysis above, we find Tingbao Yang's immigration to Chongqing in 1937 played a significant role on his transformed design thinking.
Study on the Copolymer Properties of Phenolic Resin-Epoxy Resin
Authors: Zhang Xiao Yan
Published: December 2012

The properties of phenolic-epoxy copolymer were studied in this paper. DSC was used to detect the possibility of copolymerization between phenolic resin and epoxy resin. FT-IR monitored the reactive process of mixed resin in various temperature stages. DMA revealed that the copolymer possessed high moduli and glass transition temperatures. The result showed that phenolic-epoxy copolymer can react in appropriate proportion. It is better for the copolymer system to avoid rich epoxy without curing agent. The properties of the copolymer could be increased when sacrificed some excellent properties of phenolic and epoxy. The copolymer 70% phenolic & 30% epoxy and 60% phenolic & 40% epoxy posses higher service temperature, lower volumetric shrinkage and excellent mechanical properties.
Finite Element Analysis and Structural Optimization of the Refrigerator Door Cover
Authors: Wang Wu Xin , Zhang Chun Liang , Zhu Hou Yao , Hu Lei
Published: December 2012

Refrigerator door cover cracking as a serious hazard in many new product development. This article describes a finite element study door cover cracking BCD268 example, the use of the ABAQUS finite element analysis of the cracking mechanism. Three kinds of different options to strengthen the tendons on the numerical simulation of the BCD268 the door cover, in the simplified model were carried out finite element analysis, experimental validation, and were come to give priority to the use of the method. The cover design out the door by the production and validation, and analysis of the ABAQUS program results are consistent. This paper is succeeded in finding a way to solve the door cover cracking, and engineering experiments to prove the validity of the method.
Robust Optimization for Tube Bending Process Based on Finite Element Method
Authors: Chen Xue Wen , Liu Ze Hu , Zhang Jing Li
Published: December 2012

The main causes of performance variation in tube bending process are variations in the mechanical properties of material, initial tube thickness, coefficient of friction and other forming process parameters. In order to control this performance variation and to optimize the tube bending process parameters, a robust design method is proposed in this paper for the tube bending process, based on the finite element method and the Taguchi method. During the robust design process, the finite element analysis is incorporated to simulate the tube bending process and calculate the objective function value, the orthogonal design method is selected to arrange the simulation experiments and calculate the S/N ratio. Finally, a case study for the tube bending process is implemented. With the objective to control tube crack (reduce the maximum thinning ratio) and its variation, the robust design mathematical model is established. The optimal design parameters are obtained and the maximum thinning ratio has been reduced and its variation has been controlled.
Study on Flux Pinned Vertical Force between High-Temperature Superconductor and Permanent Magnet
Authors: Zhang Ming Liang , Lu Yong , Gao Dong , Chen Wei
Published: December 2012

The flux pinned force attracts our eyes, where the levitating system is widely investigated for the transportable application. Although plenty of experiments can lead to many significant consequences, the mechanism has been not understood completely since the enormously complicated behavior and quantum effect involve. In this paper, in order to calculate the flux pinned force analytically, the image-dipole model is adopted and improved and the simple and precise expression of magnetic strength is utilized, so the flux pinned vertical force can be calculated in analytical form. In addition, the experimental data in case of zero field-cooling and field-cooling experiment can be collected in our experimental table and the comparison is completed between the precise and simple formula and the experimental data, the precise version of expression fro flux pinned vertical force can correspond to the experimental data well.
Infrared Two-Color Temperature Measurement System for AOD Bottom Lance
Authors: Chen Ge Hua
Published: December 2012

This study develops a two-color near-infrared non-contact temperature measurement system for AOD converter. We transmitted light ray by the gas path of bottom lance without additional optical unit. It eliminated errors caused by interfering factors such as long optical path, narrow spot or dust, unaffected by the emissivity of the measured object. This system improves the temperature measurement accuracy greatly. The real-time temperature measurement could better control the smelting process and improve the hit rate at the end point. The emissions of furnace slag are effectively reduced, energy consumption is lowered and the quality of steel is improved.
Research of Vector Control for Asynchronous Motor System Based on MRAS
Authors: Yao Qing Hua , Cao Miao
Published: December 2012

A new speed-adjustment approach of vector control for asynchronous motor is presented in the paper based on MRAS, It adopts a rotate speed calculating module which is designed specifically replaced Conventional rotate speed detecting system. The approach overcomes some shortcomings that comes from the precision and installation of rotate speed sensor. Motor rotate speed and torque curve are observed under different parameters based on MATLAB, and are analysed statically and dynamically. Simulation result showed touque ripple of this speed-adjustment system is small and timing is smooth, which can satisfy the demand of most electric equipment for speed-adjustment performance. Simulation result can realize asynchronous motor Control effectively.
Adaptive Fuzzy Neural Network of Cast-Rolling Hydraulic AGC
Authors: Wang Zhong Chu , Zhao Xin , Bi Ran
Published: December 2012

Cast-roll hydraulic AGC is the main control means of the strip t hickness. The control effect of traditional PID is poor for adjusting this kind of model parameters. Therefore, a new type of fuzzy neural network self-learning and adaptive controller is proposed, and analyze the composition and basic performance. The simulation results show that the new controller can effectively improve its response, what’s more it has a better dynamic performance more than another control strategies.
Review on Recent Research and Development of Cold Spray Technologies
Authors: Wang Qiang , Zhang Ming Xing
Published: December 2012

Cold spray (CS) is an emerging revolutionary technology for deposition of metal or composite powders at a low temperature. High quality deposits can be produced without heating related defects, such as oxidation, phase transformation and residual tensile stress due to the shrinkage during fast cooling. The present contribution demonstrates the state of the art of CS process. Since nozzle is a key component in the CS equipment to prompt the efficiency of particle acceleration, the progress of its design is summarized. Major issues regarding to the successful adhesion of particles and corresponding interaction with substrates and existing deposits are discussed, in terms of numerical simulation and experimental observation. Current implemented CS applications are presented, and potential industrial applications are discussed. Keywords: cold spray; coatings; rapid manufacturing; particle impact; bonding mechanism; nozzle design
Application of Supersonic Flame Spraying for Next Generation Cylinder Liner Coatings
Authors: Manzat Andrei , Killinger A. , Gadow R.
Published: December 2012

Rising demands for ecologically friendly automotive engines require a significant decrease in fuel consumption and emissions. Also the recent trend of downsizing engines demands for high performance materials for internal combustion engine applications. Tribologically functional coatings applied by supersonic flame spraying help in boosting the engine efficiency by reducing the internal friction and improving the durability and wear resistance of the cylinder running surface much-needed for engine downsizing tasks together with a high corrosion resistance enabling the use of bio fuels. In addition, the tailored surface topography of the thermal spray coatings help in supporting advantageous friction states and thereby show the benefit of reducing the oil consumption resulting in reduced emissions. The thermally sprayed coatings were applied using HVOF and HVSFS processes together with a specially designed spray gun trajectory in order to achieve a fast and cost efficient coating procedure. Several different coating materials, including novel nanostructured powders, have been investigated and compared to state-of-the-art cylinder liners. The performance of the coated cylinder liners regarding wear and corrosion resistance, friction coefficient and effects of the surface topography have been investigated in various test setups including engine tests.
High Velocity Thermal Spraying of Powders and Suspensions Containing Micron, Submicron and Nanoparticles for Functional Coatings
Authors: Killinger A. , Gadow R.
Published: December 2012

Thermal Spraying of submicron and nanoscaled powder materials require the application of agglomerated powders that can be processed with standard HVOLF (High Velocity Oxy Liquid Fuel Flame Spraying) equipment, or the conversion of these powders into a finely dispersed suspension together with an organic solvent, appropriate for suspension spraying (HVSFS: High Velocity Suspension Flame Spraying). Both methods are suitable for the manufacturing of finely structured and dense coatings and offer new possibilities in functional coating development for new application fields. Due to their refined microstructure, mechanical and physical coating properties can differ significantly from their conventionally sprayed counterparts. The paper gives an overview of HVOLF sprayed WC-Co cermets containing submicron and nanocarbides and HVSF sprayed nanooxide ceramics used in numerous technical applications.
Wet Removal of Post-Etch Residues by a Combination of UV Irradiation and a SC1 Process
Authors: Kesters Els , Le Q.T. , Simms I. , Nafus K. , Struyf H. , De Gendt S.
Published: December 2012

In back-end of line processing (BEOL), the polymer deposited on the dielectric sidewalls during the etch process must be removed prior to subsequent processing steps to achieve high adhesion and good coverage of materials deposited in the etched features [1, . Typically, this is done by a combination of a short plasma treatment and a diluted wet clean, or by wet cleans alone. On the one hand, for porous dielectric stacks, a mild plasma treatment that preserves the integrity of the low-k dielectrics would not be sufficient to effectively remove this residue. With regard to wet clean, diluted aqueous solutions (e.g. HF-based) are not efficient for polymer removal without etching the underlying dielectric to lift off the polymer, leading to unacceptable critical dimension (CD) loss. In addition, analytical techniques available for direct characterization of sidewall residues are limited. For a fast screening of potential chemistries capable of dissolving/removing polymer residues generated during the low-k etch, a model fluoropolymer was deposited on a blanket, checkerboard low-k substrate. The present study mainly focused on the characterization of model polymer after deposition (as-deposited) and after immersion in aqueous and solvent-based cleaning solutions. The polymer removal efficiency was influenced/ improved by UV treatments prior to wet clean processes. In the second part of the study, selected UV treatment conditions and cleaning solutions were applied to low-k patterned structures using Angle-resolved X-ray photoelectron spectroscopy (AR-XPS) to characterize the dielectric sidewall before and after UV modification and the subsequent cleaning process.
Dummy Oxide Removal in High-K Last Process Integration how to Avoid Silicon Corrosion Issue
Authors: Sebaai Farid , Veloso Anabela , Takahashi Hiroaki , Pacco Antoine , Claes Martine , Schaekers Marc , de Gendt Stefan , Mertens Paul W. , Struyf Herbert
Published: December 2012

The industry has diverged into two main approaches for high-k and metal gate (HKMG) integration. One is the so called gate-first. The other is gate-last, also called replacement metal gate (RMG) where the gate electrode is deposited after junctions formation and the high-k gate dielectric is deposited in the beginning of the flow (high-k first-RMG) or just prior to gate electrode deposition (high-k last-RMG) [1-. We can distinguish two RMG process flows called either high-k first or high-k last. In RMG high-k first, poly silicon is removed on top of a TiN etch stop layer whereas on high-k last poly silicon is removed on top of a dummy oxide layer. This dummy oxide has also to be removed in order to redeposit a novel high-k and work function metal (Figure 1).
UV-Induced Modification of Fluorocarbon Polymer: Effect of Treatment Atmosphere and Aging on Dissolution in Organic Solvent
Authors: Le Quoc Toan , Kesters E. , Conard T. , Struyf H. , De Gendt S.
Published: December 2012

In back-end of line (BEOL), the use of fluorocarbon-containing plasmas such as CF4 and C4F8 for patterning of low-k dielectrics with k-value ~2.3-2.5 can result in the presence of a highly fluorinated layer, deposited on the sidewalls and bottom of the trenches [1,. This polymer layer must be removed prior to subsequent processing steps to achieve good adhesion and coverage of materials (metals) deposited in the etched features. However, it is known that this type of fluorocarbon polymer is chemically inert to many existing wet clean solutions, including aqueous solutions such as fluoride ion-containing or highly alkaline solutions, and solvent mixtures [2]. Exposure of the polymer to UV irradiation (λ 200 nm) with doses 3 J/cm2 significantly modifies the polymer film, which results in substantial removal ability in a subsequent wet clean process. Polymer film modification was shown to be efficient either by using a narrow band single wavelength source with λ = 254 nm [ or by a broad band UV source with λ~200-300 nm [.
Selective High-Throughput TiN Etching Methods
Authors: Cooper Emanuel I. , Rajaram Rekha , Payne Makonnen , Lippy Steven
Published: December 2012

Titanium nitride (TiN) is widely used as a hard mask film protecting the inter-level dielectric (ILD) before metal or plating seed layer deposition steps. It is common practice to use a wet etch in order to remove residues formed during the ILD dry-etch step, and at the same time to remove some or all of the exposed TiN. From its thermochemical properties, it might be predicted that wet etching of TiN should be easy, since it is quite unstable with respect to both plain and oxidative hydrolysis. For example, in acidic solutions at 25°C [1, :