bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and Characterization of Amphiphilic Multiwalled Carbon Nanotubes Based on Linear Triblock Copolymer
Authors: Lin Bo
Published: April 2014

Amphiphilic multiwalled carbon nanotubes PMAA-g-MWCNT-g-PSt were prepared by grafting linear triblock copolymer PtBMA100-b-PGMA19-b-PSt101 onto the carboxyl multiwalled carbon nanotubes surface with an oxirane cleavage reaction. The ratio of intensity between D band and G band and the shifting of these bands in Raman spectroscopy showed good agreement with fourier transform infrared spectroscopy especially the appearance of the characteristic group of benzene ring at 673 cm-1 for PMAA-g-MWCNT-g-PSt. Thermogravimetric analysis showed that the contents of polymer grafted on the surface of carboxyl multiwalled carbon nanotubes were 36 % and 55 % for PMAA-g-MWCNT-g-PSt and PtBMA-g-MWCNTs-g-PDMAEMA, respectively. The introduction of the cinnamic group into PtBMA100-b-PGMA19-b-PSt101 induced the activation energy of PMAA-g-MWCNT-g-PSt much higher than that of PtBMA-g-MWCNTs-g-PDMAEMA after 238 oC during their thermal decompositions.
Synthesis of Spinous Spheres of Mn3O4 Nanoparticles and its Adsorption Behavior for 1-Naphthyl Ethylene Diamine-4-Azobenzene-4'-Sulfonic Acid
Authors: Yang Ming , Xia Juan Juan , Huang Yu , Wang Miao , Li Dai Xiong
Published: April 2014

Spinous spheres of Mn3O4 nanoparticles have been successfully prepared using cationic monomer doped manganese acetate as precursory solid and thermal decomposition at 400 oC. The product was characterized by X-ray powder diffraction and scanning electron microscope. The adsorption performance of spinous spheres composed of Mn3O4 for 1-Naphthyl ethylene diamine-4-azobenzene-4-sulfonic acid was investigated. The adsorbent showed high efficiency for the decolorization of 1-Naphthyl ethylene diamine-4-azobenzene-4-sulfonic acid for in contaminated water.
Fabrication of Al2O3 Particle Reinforced Aluminum Matrix Composite by In Situ Chemical Reaction
Authors: Sui Bin , Zeng Jian Min , Chen Ping , Gan Wu Kui , Lu Jin Bo
Published: April 2014

A new Al2O3 particle reinforced Al matrix composite was fabricated through in-situ chemical reaction between Al and glass powder. The microstructures and element distributions of the composite were observed and analyzed through OM, SEM and EDS, respectively. The results show the reinforced Al2O3 particle synthesized by in-situ chemical reaction are aggregated on the grain boundary. The grains can be refined with the increasing of powder. Eutectic silicone with granulous shape was found in the microstructure, which attributes to the modification of Na and Ca to eutectic silicone.
Inhomogeneous Chemical Composition of Semi-Continuously Casted ZK60A Billet
Authors: Jung K.H. , Kim Y.H. , Lee S. , Choi D.S. , Lee G.A.
Published: April 2014

Applying continuous casting to magnesium alloys is one of the recent issues due to relatively less defects inside the as-cast billet. In this study, homogeneity in the chemical composition of a commercial continuously-casted ZK60A billet was investigated. Density distribution depending on the distance from the center of the billet was measured, and the difference in density was analyzed based on the measured chemical composition.
Improved Optical Model for SiO2/Si Ultra-Thin Film Thickness Determination by Spectroscopic Ellipsometry
Authors: Fan Jiang Wei , Sun Qin Lei , Liu Mei Quan
Published: April 2014

Different optical models were adopted to fit theoretical simulation curves of a SiO2 ultra-thin film with a density of 2.2 g/cm3 and a thickness of 6nm grown on Si wafer. The results indicate that thickness obtained from fitting decrease linearly with increase of film density. An improved optical model (density of thin film of 2.4g/cm3, roughness of surface of 0.4nm, roughness of surface of 0.3nm) was obtained according to the above analysis and the GIXRR results of our previous work. The improved model could give more accurate thickness value of ultrathin film with thickness less than 10nm. It was employed in the thickness fitting for thermal oxidized SiO2/Si thin film with nominal thicknesses of 2, 4, 6, 8 and 10nm. The results were 2.61, 4.07, 6.02, 7.41 and 9.43nm, decreased by 13.8%10.3%8.1%7.3% and 6.6%, respectively, compared with the results calculated from the traditional model.
Microstructure and Mechanical Properties of (CrTiNb)N Films
Authors: Feng Yu , Zhang Jun
Published: April 2014

(CrTiNb)N hard reactive films are prepared by multi-arc ion plating technology using the combination of Ti-Nb alloy target and Cr target. The high speed steel (HSS) is adopted as substrate. The surface and cross-fracture morphology, the surface compositions and the phase structures of the as-deposited (CrTiNb)N films are observed and measured by scan electronic microscope (SEM) and X-ray diffraction (XRD). The mechanical properties including the micro-hardness, the adhesion between film and substrate, the friction and wear resistance of the as-deposited (CrTiNb)N films are systemically investigated. The effects of deposition bias voltage and the addition of Nb element on the as-deposited (CrTiNb)N films are discussed. It is revealed that the optimally comprehensive performances including the micro-hardness, the adhesion and also the friction resistance can be achieved by the (CrTiNb)N hard reactive films with bias voltage of 200V.
Microstructure and Mechanical Properties of (TiAlNb)N Films
Authors: Yin Li Yan , Zhang Jun
Published: April 2014

(TiAlNb)N hard reactive films are prepared by multi-arc ion plating technology using the combination of Ti-50Al (at%) and Ti-25Nb (at%) alloy targets. The high speed steel (HSS) is adopted as substrate. The surface and cross-fracture morphology, the surface compositions and the phase structures of the as-deposited (TiAlNb)N films are observed and measured by scan electronic microscope (SEM) and X-ray diffraction (XRD). The mechanical properties including the micro-hardness, the adhesion between film and substrate, the thermal shock resistance of the as-deposited (TiAlNb)N films are systemically investigated. The effects of deposition bias voltage and the addition of Nb element on the as-deposited (TiAlNb)N films are discussed. The optimally comprehensive performances, especially hardness and thermal shock resistance, exhibited by (TiAlNb)N films with bias voltage of 100V.
Study on Combination Method of Stochastic Load Processes
Authors: Shen Zhao Wei , Wang Xiao Hong , Jin Wei Liang
Published: April 2014

When more than one loads act on a structure,the combination of stochastic loads is generally considered in the design of the structure,Based on the theoretical derivation and numerical calculation analysis to the process of two common loads in Poisson square wave and Poisson impulse this paper presents the combination method of loads.i.e. The maximum intensity function of load combination is expressed by the cumulative distribution function in the limit state design. In addition,the result calculated during the limit state design is compared with those calculated by Turkstra and Monte Carlo methods and the analytical results show that the method proposed in this paper is feasible in the calculation of load combination.
Preparation of Freestanding TiO2 Nanotube Arrays via Controlling the Anodizing Voltage
Authors: Zhao Ming Hui , Zuo Yi , Li Yu Bao , Li Ji Dong
Published: April 2014

In order to assemble titania nanotubes arrays (TNTs) with better performance in solar cells application, hierarchical voltage-reduction was employed to reduce the thickness of barrier layer and acquire freestanding films simultaneously. Study of intratubular microenvironment and TiO2/Ti interface indicated that it might be H+ generated in anodizing process permeating into the Ti substrate that resulted in peeling off the whole tube layers. Our findings provide a promising way to fabricate freestanding TNTs membranes just by tailoring the applied voltage.
Preparation, Optical and Magnetic Properties of Ni-Doped CuAlO2 Nanocrystalline Films
Authors: Ding Juan , Sui Yong Ming , Tian Le Cheng
Published: April 2014

This letter reports the preparation of Ni doped CuAlO2 nanaocrystalline films on sapphire substrates by sol-gel processing and subsequent thermal treatment in vacuum. The crystalline phase in the films was identified to be the delafossite structure by X-ray diffraction. Field-emission scanning electron microscope (FESEM) shows the quasi-cubic shape architecture of the as-prepared CuAlO2 nanaocrystalline films. Upon increasing the band gaps of Ni-doped CuAlO2 nanaocrystalline films increased due to the Burstein-Moss shift. The influence of different Ni doped concentration on absorption spectrum and magnetic properties of CuAlO2 films was discussed.
Uncertainty Evaluation in Measurement of Thickness of SiO2/Si Using X-Ray Photoelectron Spectroscopy
Authors: Fan Jiang Wei , Han Xiao Gang , Wang Feng
Published: April 2014

Ultra-thin films of SiO2 (nominally 2, 4, 6, 8 and 10nm thick) on silicon, prepared by thermal oxidation, were investigated using x-ray photoelectron spectroscopy (XPS). The thickness of these thin films was obtained from a measurement of the photoelectron intensities originating from the substrate and the oxide layers by applying an appropriate quantitative model. The uncertainty budget of that thickness measurement method is given. The effective attenuation lengths or the corresponding electron inelastic mean free paths are of the most importance in the contribution of the uncertainties. For the SiO2 ultra-thin film with the nominal thickness of 2nm, it could generate 20% of the uncertainty.
Fabrication of Cu2ZnSnS4 Thin Films through Sulfurization of Co-Electrodeposited Cu-Zn-Sn Metallic Precursor
Authors: Xie Meng , Zhang Hai Tao , Zhang Shu , Xiang Yong
Published: April 2014

Cu2ZnSnS4 thin films have been synthesized through sulfurization of co-electrodeposited Cu-Zn-Sn metallic precursor. The obtained metallic precursor shows homogeneous surface. Combination of X-ray diffraction, energy dispersive X-Ray spectroscopy and Raman spectroscopy results shows that kesterite structure of Cu2ZnSnS4 is formed, demonstrating that co-electrodeposition-sulfurization is a viable process for the synthesis of Cu2ZnSnS4 film.
Influence of AlInGaN Blocking Layer on the Violet InGaN Laser Diodes
Authors: Dong Shao Guang , Chen Guo Jie
Published: April 2014

The advantages of AlInGaN as a blocking layer on the influence of violet InGaN laser diodes have been simulated, these results showed that the temperature characteristic (T0) of the violet InGaN laser diodes with AlInGaN blocking layer is lower than the T0 of the violet InGaN laser diodes with AlGaN blocking layer. These phenomenons are due to the improvement of electronics and holes distribution in the quantum wells with using AlInGaN blocking layer. Simulation results also showed that most optical characteristics of the violet InGaN laser diodes can be enhanced by using the AlInGaN blocking layer instead of the AlGaN blocking layer. The lower threshold current, carrier density, threshold gain and higher output power, slop efficiency of the violet InGaN laser diodes with the AlInGaN blocking layer have been obtained.
A Parametric Investigation on the Neo-Hookean Material Constant
Authors: Mohd Yusop Siti Hajar , Ab Patar Mohd Nor Azmi , Abdul Majeed Anwar P.P. , Mahmud Jamaluddin
Published: April 2014

This paper assesses the Neo-Hookean material parameters pertaining to deformation behaviour of hyperelastic material by means of numerical analysis. A mathematical model relating stress and stretch is derived based on Neo-Hookeans strain energy function to evaluate the contribution of the material constant, C1, in the constitutive equation by varying its value. A systematic parametric study was constructed and for that purpose, a Matlab programme was developed for execution. The results show that the parameter (C1) is significant in describing material properties behaviour. The results and findings of the current study further enhances the understanding of Neo-Hookean model and hyperelastic materials behaviour. The ultimate future aim of this study is to come up with an alternative constitutive equation that may describe skin behaviour accurately. This study is novel as no similar parametric study on Neo-Hookean model has been reported before.
Antheraea pernyi Silk Fibroin Microspheres Carried Lysozyme
Authors: Wang Juan , Li Gui Jun , Jiang Rui , Yin Zhu Ping , Lu Shen Zhou
Published: April 2014

A method was developed to prepare the Antheraea Pernyi silk fibroin (ASF) microspheres using lysozyme as a model drug to estimate the application of ASF in drug controlled release field. The structure of ASF microsphere carried drug was characterized by X-ray diffraction and FTIR. The morphology and the influence of the microspheres on the degradation of lysozyme were investigated using scanning electron microscope. The results show that encapsulation rate was increased and drug content was decreased with the addition of lysozyme increasing. In vitro release of lysozyme from the ASF particles we demonstrated that the release kinetics depends on the pH. The pH played important roles in controlling lysozyme release profiles. It also can be seen that the degradation speed of lysozyme ASF microspheres slightly larger than the pure ASF microspheres.
Effect of Dipping in Sodium Bisulfite Solution and Packaging under Nitrogen on Fresh Sweet Corn during High Temperature Sterilization and Shelf-Life
Authors: Yang Wei Qiao , Liu Hai Dong , Li Xi Hong , Shao Chong Xiao , Hao Mei Mei , Jia Xiao Yu , Li Yao Yao
Published: April 2014

The aim of this study was to determine the effect of dipping in 1% sodium bisulfite solution and packaging under nitrogen on qualitative properties of fresh sweet corn (Zea mays L.) sterilized at 121°C for 15 min and stored at 30°C for 90 days. Water content in all samples was maintained well during the storage. The samples either dipped in 1% sodium bisulfite solution or packaged under nitrogen all could better keep the content of soluble and reducing sugar than control and inhibit the browning caused by Maillard reaction during the sterilization.
Finite Element Analysis of Distinguish between Two Bone Materials in Femoral Fixation System
Authors: Dong Li Min , Gao Ya Lei , Chen Wei
Published: April 2014

This paper deals with the difference of finite element analysis of results between distinguishing bone materials modeling and single bone material modeling. The computed tomography (CT) data was used to build the model that can distinguish cortical bone, cancellous bone of the femur model, together with the plates could be used to set up internal fixation system and do the finite element analysis. The results indicated that the distributions of stress and strain were basically the same, so were the location of the maximum stress and strain. While, except under the axial loads the value of maximum stress and the value of maximum strain showed significant differences. Finally, study reached the conclusion that under the axial loads there were no significant difference between the two methods, thus the single bone material model could be used for easier computing, while, under the other 4 consequences paper recommended distinguishing bone material method for more practical results.
Optimization of Proliferation Conditions of Recombinant Escherichia coli BL21(DE3)/pET-28b(+)-aroGM150
Authors: Liang Rong , Liu Chang , Meng Xiu Juan , Lin Song Yi
Published: April 2014

Applying Escherichia coli (E. coli) for fermentation is a very common technology. However combined with genetic engineering techniques to construct the recombinant Escherichia coli and study their growth characteristics has become the hot spot now. The recombinant Escherichia coli BL21 (DE3) /pET-28baroGM150 had been constructed by our laboratory in the previous experiment. And the purpose of this study was to optimize the proliferation conditions of Escherichia coli BL21 (DE3) /pET-28baroGM150. In order to make the recombinant Escherichia coli grow stable under suitable conditions, using the density of bacteria and plasmid stability as indexes, three factors were tested including temperature, initial pH and loading volume. And the results indicated that the optimal proliferation temperature of the recombinant strain was 30°C, initial pH value was 6.5, loading volume was 150 mL medium of 1000 mL bottles.
Preparation and Characterization of Poly-γ-Glutamic Acid-Based Nanoparticles Biomacromolecules
Authors: Yang Ge , Lu Ke Shuai , Su Xue Yan
Published: April 2014

The present paper describes the preparation and characterization of novel biodegradable nanoparticles based on self-assembly of poly-γ-glutamic acid (γ-PGA). The nanosystems were stable inaqueous media at low pH conditions. Solubility of the systems was determined by turbidity measurements. Surface charge and mobility were measured electrophoretically. It was found that the size and size distribution of the nanosystems depends on the concentrations of γ-PGA solutions and their ratio as well as on the pH of the mixture and the order of addition. The average hydrodynamic diameters were between 150 and 330 nm. These biodegradable,self-assembling stable nanocomplexes might be useful for several biomedical applications.
Transfer Function Development of Uniaxial Horizontal Centrifugal Shaking Table
Authors: Wang Yong Zhi , Chen Zhuo Shi
Published: April 2014

Soil as a special material featured with nonlinear stress-strain relationship plays a critical role in determining the magnitude of hazards in an earthquake. For a unique capability of simulating a combined environment of high gravity and shake loading, centrifugal shaking table provides an effective and advanced testing method to dynamic characteristics and failure mechanism of reduced scale soil models. From construction both at home and abroad, shaking tables often suffer waveform distortion and instability after installed on a centrifuge. The knowledge of this phenomenon is a dearth while relative theory is absolutely blank. Practically the construction of centrifugal shaking tables is still in an exploratory stage. This paper develops a transfer function of geotechnical shaking table with soil model and bucket to offer fundamental cognition of inherent mechanism, and establishes a theoretical procedure to evaluate the influence of bucket on shaking table.
Research on the Whole-Progress Management of Medical Waste with Life Cycle Assessment
Authors: Chen Lin , Sun Jun Mei , Huang Zheng Wen
Published: April 2014

The management and treatment of medical waste directly affected the security of doctors, patients and human health. The hazard of medical wastes and domestic status of medical waste management were discussed, the countermeasures for achieving sustainable management of medical waste in China were put forward on the basis of the theoretical framework of life cycle assessment and whole-process management called Cradle-toGrave. Finally, the development direction and trend, appropriate suggestion and control measures of medical waste management was put forward combined with the international development requirements.
Simulation Analysis on Wastewater Anaerobic Tank Stench in Collecting Hood with Properties of Environmental Materials
Authors: Du Zhao , Du Ning , Chen Yu Jie
Published: April 2014

The relationship is very important between geometrical boundary parameters and mechanical ventilation airflow pattern of wastewater gas-collecting hood. Computational fluid dynamics (CFD) is an effective approach to study with standard κε turbulent model. CFD predominate results show that: the exhaust flow, tuyere pressure, velocity and pollutant concentration had a greater influence on the flow field distribution. Fiber Reinforced Polymer (FRP) stench-collecting hood can be used to anaerobic tank in long-term because of its environmental material properties for acid and wet.
Specifically Deoxyribozyme of the Protein Kinase C-δ Expression Treated in Human Hepatocellular Carcinoma HepG2 Cells
Authors: Wei Zhuo
Published: April 2014

The tumor suppressor function of protein kinase C isoforms (PKC-δ) was evaluated by design and synthesis the 10-23 deoxyribozyme (DRz), thio-modified DRz (DRz-s) and antisense oligonucleotide (asON) of the PKC-δ genomic mRNA to detect the catalytic cleavage activity for tumor cells. Firstly, the cDNA fragment of PKC-δ gene was amplified from total cellular RNA of the HepG2.2.15 cells by reverse transcription PCR (RT-PCR). Subsequently, the fragments were cloned to pcDNA3.1(+) plasmids and generated a recombinant plasmids, then sifted the positive recombinant plasmids out to amplify. The expression vector of PKC-δ mRNA was obtained in vitro transcription by using T7 RNA polymerase. The results of transfection indicated that when PKC-δ mRNA gamyed with deoxyribozyme which activity disappeared, and DRz-s had more intensive specific catalytic cleavage activity than DRz by cells transfecting, but the asON wasn't detected with this activity.
Synthesis of Fe2O3/CNTs for the Fast Removal of Tetracycline from Aqueous Solutions
Authors: Zhang Zhong Jie , Lu Chang Yu , Huang Wei , Guan Wei Sheng , Peng Yue Xin
Published: April 2014

The effective remove to tetracycline still remains a big challenge for scientists. In this work, we used a new method for preparing functional magnetic CNTS with ferrite nanoparticles. A wide range of techniques, such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and magnetic measurements were applied to characterize the obtained Fe2O3/CNTs. Moreover, we have also studied the properties of adsorbent to tetracycline. In addition, we have found that the Fe2O3/CNTs are better reusable adsorbent than other traditional adsorbents by magnetic separation recycling method.
Two Methods for Edge Reflection Problems in Circular Cylinders
Authors: Feng Fei Long , Shen Zhuang Zhi , Shen Jian Zhong
Published: April 2014

Two methods based on modal decomposition in circular cylinders are presented here. One is based on bi-orthogonality relation and the other is based on boundary discretization for mode matching. The two methods are comprised in numerical implementation and the efficiencies are evaluated.
Construction and Functional Analysis of Luciferase Reporter Plasmid Containing NF-H Gene Promoter
Authors: Zhang Tong Cun , Meng Yao , Wang Nan , Lin Feng , Qin Tao , Sun Zhe , Li Man
Published: April 2014

NF-H (a member of neurofilaments) is a protein widely expressed in all kinds of neurons after birth and can be used as one of the symbols of mature neurons. Constuction of NF-H promoter luciferase reporter plasmid will provide the theory basis for researching the effect of other transcription factors on regulating NF-H transcription. Here, human NF-H promoter luciferase reporter plasmid were successfully constructed. Then the effects of some key transcription factors were investigated by luciferase reporter assays in COS-7 cells. The results showed that retinoid X receptor α (RXRα) can enhance transcriptional activity of NF-H. Furthermore, ERK 1/2 (extracellular signal-regulated kinase 1/2) and STAT3 (signal transducer and activator of transcription 3) also show obvious impact in activating NF-H transcription.
Compared Study of Vascular Cell Response to Mg-Zn-Y-Nd and WE43 as Biodegradable Stents
Authors: Liu Xiao Li , Xi Ting Fei , Zheng Yu Dong , Guan Shaokang
Published: April 2014

To evaluate biocompatibility of Mg-Zn-Y-Nd alloy as vascular stent material, its influence on cytotoxicity, cell migration, cell chemotaxis and NO release of vascular endothelial cells and vascular smooth muscle cells were tested compared with WE43 alloy. Results show that Mg-Zn-Y-Nd alloy degraded slower and exhibited better cell viability and NO release than WE43; WE43 showed more significant effect on stimulating endothelial cells migration; Both alloys showed nonsignificant effect on vascular smooth muscle cells migration and chemotaxis. Mg-Zn-Y-Nd alloy exhibited great biocompatibility to vascular cells.
Comparison on Separation of Low-Content Nickel and Cobalt in Bioleaching Solution in Different Extraction System
Authors: Zhou Gui Ying , Liu Ji Hong , Wen Jian Kang , Song Yong Sheng
Published: April 2014

As an effective method for increase extraction efficiency and selectivity,synergistic extraction has been studied for many years because the theoretical and applicative importance. Using synergistic effect of two extractants, distribution ratios of their mixture can be obviously enhanced than those of their individual contributions. Separation of nickel and cobalt for bioleaching solution were studied using a synergistic extraction system with P507 andCyanex272. The test results indicate that the system has better extraction effect. Contrasts the separation effect on nickel and cobalt using three extraction systems of P507, Cyanex272, P507-Cyanex272. Identified during the initial pH value of 1.5-2.2, balance pH value under the condition of 4.0-5.0,synergistic extraction system of P507-Cyanex272 have a good separation effect of nickel and cobalt. The extraction kinetics was investigated using a constant interfacial cell with laminar flow. The effects of temperature, extractant and cobalt concentration were studied. Co extraction rate was compared in the different extraction systems of individual P507 and synergistic P507-Cyanex272 .The results indicated that the extraction apparent action energy in synergistic system was lower than that of signal P507.The separation factor of nickel and cobalt was increased in synergistic system.
Influence of Sieve Structural Parameters on Sieving of Shelled Buckwheat
Authors: Liu Chuang , Du Wen Liang , Quan Ya Jing , Xing Kai , Han Heng
Published: April 2014

The problems of high falsesieving rate and low productivity are encountered while sieving shelled buckwheat with traditional round plate sieve. This paper presents a design idea for improving the sieving effect by changing the plate structure. The improved designs consist of a round plate sieve with larger percentage of sieving area than the traditional round plate sieve and a triangular plate sieve with the approximately same geometry as shelled buckwheat grains. Tests are conducted to compare the sieving performance of traditional round plate sieve with the newly designed round plate sieve with different percentage of sieving areas and apertures. Also the traditional round plate sieve is compared with triangle plate sieve with different percentage of sieving areas and apertures. Compared to traditional round plate sieve, the falsesieving rate for newly designed round plate sieve with an aperture isφ4.4mm is reduced by 3.6.A round plate sieve with a percentage of sieving area of59.7%, aperture ofφ4.3mm, is used to sieve the shelled buckwheat of sizeφ4.6~4.7mm.A falsesieving rate of2.3, and non-sieving rate of17.4 are obtained and the sieving effect is found to be the best. For the triangle plate sieve a falsesieving rate of90.2 and non-sieving rate of92.1 are obtained. The triangle plate sieve is found unsuitable for the sieving of shelled buckwheat.
Vibration and Noise Analysis for a Motor of Pure Electric Vehicle
Authors: Bao Meng , Chen En Wei , Lu Yi Min , Liu Zheng Shi , Liu Shuai
Published: April 2014

To control the pure electric vehicle motors vibration and noise, the dynamic characteristics of the motor are analyzed. Dynamic characteristic include the natural frequency and response characteristics of different parts of the motors structural member. This paper uses three-dimensional software Pro/E modeling of the motor: By making appropriate assumptions and equivalent treatment of the motors stator, rotor core and coil winding, establish the finite element simulation model of the various components .Using the finite element analysis software Workbench analyzes the windings and motor model modal analysis, to get natural frequency of each mode. To make a modal analysis test, we can use hammering method done on the motor. By using real-time signal analyzer AWA6291 make spectral analysis of the motor online, comprehensive comparative analysis of the results and used to guide motor design.
Effects of Feed Angle on Mannesmann Piercing in Drill Steel Production
Authors: Zhao Yu Qian , Mao Jing Hua
Published: April 2014

Drill steel is a special steel specifically tailored for drilling rods. To understand the microstructure properties and dimensional accuracy of the drill steel, a rigid plastic finite element method was used to analysis Mannesmann piercing in steel drilling production. The three-dimensional thermal force coupling FEM models were computer generated with different feed angle. The metal deformation during the piercing process was analyzed in detail. The influence of feed angle on deformation, force, velocity and strain was obtained through simulations.
Diffusion in Glassy Metals
Authors: Mehrer Helmut
Published: April 2014

Firstly, this paper reminds the reader of some basic facts about the glassy state, then of the various ways to produce amorphous metals with particular emphasis on the route of vitrification from the melt. Vitrification of an undercooled melt is the most important route from the viewpoint of the application of metallic glasses. We compare diffusion in some metallic glasses with related crystalline metals. Glassy metals, also called metallic glasses, comprise conventional [1] and bulk metallic glasses [2,3]. We remind the reader of the major experimental techniques for diffusion studies in metallic glasses. The paper then reviews our current understanding of diffusion in glassy metals (see also [4,5,6]), including conventional as well as bulk metallic glasses and undercooled melts. We cover the temperature dependence of diffusion in metallic glasses and discuss the spectrum of activation parameters of glassy metals and its difference to the corresponding one of crystalline metals. We mention the pressure dependence and the isotope effect and we discuss tracer diffusion and viscosity diffusion for a bulk metallic glass and its undercooled melt. Finally we mention computer simulations of atomic jump processes. The diffusion mechanism in metallic glasses differs from that in crystalline metals and involves thermally activated, highly collective (chain-like or caterpillar-like) diffusion jumps. Finally, we mention diffusion along shearbands in a plastically deformed glassy metal.
Defects and Sintering-Induced Diffusion Processes in Yttria-Stabilised Zirconia Nanomaterials Studied by Positron Annihilation Spectroscopy
Authors: Procházka Ivan , Čížek Jakub , Melikhova Oksana , Anwand Wolfgang , Konstantinova Tetyana E. , Danilenko Igor A.
Published: April 2014

In the present work, zirconia (ZrO2) nanopowders doped with yttria (Y2O3) and chromia (Cr2O3) were prepared by a co-precipitation technique. The nanopowders were then subjected to a calcination and a successive sintering at elevated temperatures up to 1500 °C. The nanostructures in these nanomaterials were characterized by positron annihilation spectroscopy (positron lifetimes and Doppler broadening measurements) which is a non-destructive technique with a high sensitivity to atomic-scale open-volume defects. It was found that the zirconia-based nanomaterials studied contain vacancy-like defects and nanoscale pores. Diffusion processes induced in these nanomaterials by sintering were investigated also by depth sensitive positron annihilation studies using a variable energy slow positron beam. Sintering was found to cause intensive grain growth and a removal of porosity by a migration of pores from the sample interior toward its surface.
Mechanical Activation of Mn-O Oxides: Structural Phase Transitions, Magnetism and Oxygen Isotope Exchange
Authors: Fishman Anatoly Yakovlevich , Kurennykh Tatiana Eugenievna , Mitrofanov Valentin Yakovlevich , Pastukhov Eduard Andreevich , Petrova Sofya Aleksandrovna , Uporov Sergei Aleksandrovich , Vykhodets Vladimir Borisovich , Zakharov Robert Grigorievich
Published: April 2014

The mechanically activated oxides MnO2, Mn2O3, Mn3O4 and MnO were studied under ambient and non-ambient temperature conditions. Regimes of mechanical treatment were found that allowed one to preserve the single-phase state without an essential change of oxide chemical composition. New data about the temperatures and sequence of phase transitions in mechanically activated manganese oxides as well as about the kinetics of isotope exchange were obtained. Magnetic properties of the treated oxides were measured in the temperature range of 4-300К. It is shown that mechano-activation essentially influenced the temperature and field dependences of magnetization, temperatures of magnetic phase transitions and leads to the appearance of additional magnetic phases. New data on the rates of surface reactions during isotope exchange and oxygen self-diffusion coefficients are obtained.
Superstructure Transformations in High-Temperature Intermetallic Nanolayers: Atomistic Simulation
Authors: Kozlowski Miroslaw , Abdank-Kozubski Rafał Leszek , Goyhenex Christine
Published: April 2014

Superstructure transformation processes in intermetallics have beenstudied at the atomistic scale using Monte Carlo algorithms within two dis-tinct models: two-body interactions Ising-like system and Analytic Bond-Order Potentials. The transformation from “in-plane” to “off-plane” L10 vari-ant in [001]-oriented FePt nano-layers was observed and analysed by analyt-ical calculations providing clear explanation of the origin of the process, aswell as by “rigid-lattice” and “off-lattice” Monte Carlo simulations showingthe kinetics of the superstructure transformation.
A Morphology of Diffusion Zone from Entropy Production Calculations
Authors: Danielewski Marek , Wierzba B. , Tkacz-Śmiech K.
Published: April 2014

Interdiffusion plays a significant role in the formation and stability of metallic joints and coatings. It is also of critical importance in designing advanced materials. Because commercial alloys are usually multicomponent, the key target is prediction of a complex morphology of the diffusion zone which grows between the alloys, alloy-coating, etc. In a two-component system, the diffusion zone can be composed of single-phase layers of the intermetallic compounds and solid solutions. The evolution of the composition and thicknesses of such layers are fairly well understood and consistent with the phase diagrams. The situation is qualitatively different in multicomponent systems. For example, the diffusion zone in a ternary system can be composed of single-and two-phase sublayers. Their number and thicknesses depend on the initial conditions, i.e. composition, component diffusivities and geometry of the system. The usual way of presenting the sequence of the layers and their compositions is by drawing adiffusion path which is, by definition, a mapping of the stationary concentrations onto the isothermal section of the equilibrium phase diagram. The diffusion path connects initial compositions of the diffusion couple and can go across the single-, two-and three-phase fields. It starts at the composition of one alloy and ends at the other. The possibility of mapping the concentration profiles onto the ternary isotherm has been postulated in one from the seventeen theorems by Kirkaldy and Brown [] for the diffusion path. The detailed presentation of all theorems was recently done by Morral []. Here we remind the reader only of the chosen ones (shown in italics).
The Decisive Contributions by L. Boltzmann and C. Matano to the Quantitative Analysis of Diffusion Phenomena
Authors: Sprengel Wolfgang , Koiwa Masahiro
Published: April 2014

The origin of the analysis of concentration dependent diffusivities in solids is closely related to a method nowadays referred to as the Boltzmann-Matano method. This chapter recalls the scientific environment of the emergence of this method first described in a paper by C. Matano in 1933. The unique contributions by L. Boltzmann as well as by C. Matano, who were active in completely different scientific fields at different times, are presented. Some specific aspects related to the Boltzmann-Matano method are critically reviewed.
Molecular Dynamics of the Transport of Ions in a Synthetic Channel
Authors: Morton-Blake D.A.
Published: April 2014

Molecular dynamics investigations of ions in certain non-bulk media predict that they are capable of significantly greater mobilities than when in the liquid state. The entries of Li+, Na+, and K+ ions from electrolyte media into proposed synthetic channels consisting of fourteen 15-crown-ether-5 (CE) rings bonded in stacked conformations are described and their subsequent dynamics in the channel discussed. The importance of channel flexibility is established by investigating two CE channels that are structurally similar but vary in the rigidity with which their rings are connected. The dynamics of cation channel migrants are simulated across a bilayer membrane between two bulk aqueous salt solutions and also when the channel floats freely in an aqueous medium. Various features of ion behaviour are investigated in the presence, and in the absence, of an electric field applied along the channel axis. The novel oscillatory behaviour of the ions in the channel is investigated, together with the possibility of their exits into the liquid medium. The frictional forces opposing the ion trajectories are calculated, found to be ~10 nN and attempts to formulate frictional laws for nanoscale systems are discussed.
Grain Boundary Diffusion and Grain Boundary Segregation in Metals and Alloys
Authors: Bokstein Boris , Rodin Alexey
Published: April 2014

In the present article the authors make an attempt to survey briefly the main landmarks of the GBD, to set off the most interesting results of the last years, to underline some gaps between expected and observed experimental data and to direct possible ways of their explanation.
Synthesis, Optical and Electrochemical Properties of Cu Phtalocyanine (CuPc) Prepared from Microwave Irradiation
Authors: Belmokhtar A. , Benyoucef A. , Yahiaoui A. , Hachemaoui A. , Belbachir M.
Published: April 2014

Activated Cu phtalocyanine, using metal exchanged montmorillonite clay called Maghnite-Cu (Mag-Cu) as an effective catalyst, the rapid synthesis of Cu phtalocyanine was prepared from microwave irradiation. The effect of amount of catalyst and time on the cyclotetramerization output of the polymers was studied. The effect of time on the polymerization output of the polymers was studied. The formation of conducting and electroactive form of the Cu phtalocyanine was confirmed through UVvis, IR, and cyclic voltammetry.
Simulation, Measurement and Spectral Analysis of Night Sky Light Background
Authors: Macúchová Karolina , Zicha Josef
Published: April 2014

Spectral measurements of the night sky provide important information about natural light sources and light pollution. Analysis of spectral data enables identification of interesting events occurring in the atmosphere. We describe the used method and the technical solution, as well as first obtained results. Photometric and spectral simulations of the night sky light were performed under laboratory conditions. The results were compared with measured data of the whole night sky with respect to location and timing. The outdoor measurements provided spectroscopic data for examining the light pollution and night sky light background.
Resistance to Electrochemical Corrosion of Extruded Magnesium Alloy AZ61
Authors: Przondziono Joanna , Hadasik Eugeniusz , Walke Witold , Szala Janusz , Wieczorek Jakub
Published: April 2014

The purpose of the study was the evaluation of the electrochemical corrosion resistance of extruded magnesium alloy AZ61 in solutions with concentration of 0.012 M NaCl. Resistance to electrochemical corrosion was evaluated on the ground of registered anodic polarisation curves by means of potentiodynamic method. Immersion tests were performed in NaCl solution and time periods of 1-6 days. Scanning microscopy was used to obtain images of the alloy microstructure after immersion tests. Electrochemical impedance spectroscopy was used to evaluate phenomena that take place on the surface of the tested alloy. The results of all performed tests prove explicitly deterioration of corrosion properties of magnesium alloy AZ31 with the increase of molar concentration of NaCl solution. It was found that irrespective of molar concentration of NaCl solution, pitting corrosion can be detected on the surface of the tested alloy. Test results prove that it is necessary to apply protective layers on elements made of the tested alloy.
Effect of Tolerance in the Fitting of Rivets in the Holes of Double Lap Joints Subjected to Uniaxial Tension
Authors: Sadowski Tomasz , Golewski Przemysław
Published: April 2014

The study focused mainly on one of the parameters of mount technology - tolerance for fitting the rivet in the hole in riveted and hybrid (riveted adhesive) joints. The research included numerical simulations of double lap joints with four rivets arranged in two rows and subjected to uniaxial tension. Simulations were carried out in Abaqus both for the purely mechanical and the hybrid joints. The connections without clearance (neat-fit) and with clearance of 0.2 mm, as well as with interference of-0.2 mm. The presence of clearance in one of the holes in the hybrid joint causes a decrease in the capacity of the hybrid connection by about 15% in configuration 1 (Fig. 2). This decrease can be even higher (21%) in the worse clearance placement, i.e. in configuration 2 (Fig. 2). The study shows that the occurrence of clearance in the holes can lead to dangerous consequences, so it is recommended to use holes calibration or develop a special type of rivet.
On the Finite Element Modelling and Simulation of Carbon Nanotubes
Authors: Ghadyani Ghasem , Akbarzade Mojtaba , Öchsner Andreas
Published: April 2014

In this paper, two different beam elements (i.e. according to the Bernoulli beam and Timoshenko beam theory) for the modeling of the behavior of carbon nanotubes are applied. Finite element models are developed for this study with variation of chirality for both zig-zag and armchair configurations of CNTs. The deformations from the finite element simulations are subsequently used to predict the elastic stiffness and the critical buckling load in terms of material and geometric parameters. Furthermore, the dependence of mechanical properties on the kind of beam element and the mesh density is also compared. Based on the obtained results, Youngs modulus and critical buckling load of structures using Timoshenko beams are clearly lower than the Bernoulli beam approach for all chiralities.
Design and Evaluation of a High-Accuracy Measurement System for Sheet Resistance of Thin Films
Authors: Pan Hai Bin , Ding Jian Ning , Cao Bao Guo , Cheng Guang Gui
Published: April 2014

Inspection and measurement for the sheet resistance and resistivity play a pivotal role in the semiconductor industry. In this study, a high-accuracy measurement system for sheet resistance of thin films was designed based on dual-measurement with four-point probe method. The measurement system was composed of a special switching circuit, a digital output module, Keithley 2400 SourceMeter, and a computer running LabVIEW. The special switching circuit designed based on the multiplexer played an important role in current probes and voltage probes automatic switching under the control of virtual instrumentation software LabVIEW and National instruments digital output module hardware NI 9401. Keithley 2400 SourceMeter controlled by LabVIEW was used for two-times high-precision voltage measurement. Van der Pauw correction factor were calculated based on the results of the two-times voltage measurement. Then the sheet resistance of thin films was calculated by LabVIEW softwares powerful computing. The experimental results show that the designed and developed system can meet the needs of fast on-line measurement of thin films sheet resistance with a wide range, and moreover, the accuracy of measurements and the level of automatization have been dramatically improved compared to the conventional measurement system.
Fabrication and Characteristics of Silicon Bridge Magnetic Sensor Based on Cantilever Beam
Authors: Li Lei , Zhao Xiao Feng , Yu Yang , Wen Dian Zhong , Cao Jing Ya , Tian Lei
Published: April 2014

A silicon bridge magnetic sensor based on cantilever beam is presented in this paper. Thesensor is composed of the Wheatstone bridge that made up of nano-polysilicon thin-film transistors(TFTs) and a ferromagnetic magnet adhered to the free end of cantilever beam. Through building thesimulation model, the finite element analysis of the sensor is carried out by using ANSYS software.The results show that this sensor can realize the measurement to the external magnetic field. Accordingto the simulation results, fabrication and packaging of the sensor chip are achieved by using the microelectromechanical system (MEMS) technology. Experiment result shows that when the supply voltageis 3.0 V, the sensitivity of the sensor is 94 mV/T.
High Precision Double-Interferometry for Large Step-Height On-Line Measurement Using Waveform Transforming Technology
Authors: Ma Sen , Xie Fang , Wang Yun Zhi , Chen Liang
Published: April 2014

This paper focuses on obtaining high measurement precision for large step-height by double-interferometry using waveform transforming technology. The interferometer performing the measurement, which is stabilized by a feedback loop and is robust enough for on-line measurement, works simultaneously in both modes of single-wavelength interferometry (SWI) and two-wavelength interferoemetry (TWI). In order to make the peak point of the TWI signal prominent and unique, the cosine-amplitude-modulated TWI signal has been transformed to be a triangular signal with the same frequency as the cosine-amplitude modulating and being in phase with it. The positions of the one-to-one corresponding peaks of the TWI signal and the triangular signal are the same. As the peak point of the triangular signal can be addressed much more precisely than that of the TWI signal, by employing the shifting range of the peak of the triangular signal instead of that of the TWI signal to determine the amplitude of the step height while using the SWI signal to measure the value of it, the system could measure the height with high precision. The standard deviation of measuring a gauge block with the height of 0.5mm is 0.8nm.
Fabrication and Packaging of Electromagnetic 2D MEMS Scanning Mirror
Authors: Zhang Chi
Published: April 2014

The scanning mirror has two gimbals structure, which are supported perpendicularly to each other by torsion beams. Dual-axis movement of the mirror is achieved by the tilt of inner and outer structures, respectively. The electromagnetic 2D MEMS scanning mirror is fabricated using a bulk silicon process, mainly including the wet etching, electroplating and ICP dry etching process. The permanent magnets are packaged together with the electromagnetic 2D MEMS scanning mirror in a compact size of 18×28×28mm3. The electromagnetic 2D MEMS scanning mirror has advantages of small volume, low voltage and high frequency, which has a broad application in sensor networks, target detection and optical imaging.
Quartz Crystal Double-Ended Tuning Fork Resonator for High Resolution Force Sensing
Authors: Wang Jian , Zhao Cong , Zhang Shi Ming , Zou Jiang Bo
Published: April 2014

This paper reports a novel piezoelectric quartz crystal double-ended tuning fork (DETF) resonator with vibration attenuation structure, which is suitable for high resolution force sensing. The DETF resonator was designed to work in the fundamental flexure mode, and manufactured along the Y direction based on the Z-cut quartz crystal wafer using photolithographic and anisotropic chemical etching of quartz crystal. The resonance frequency of the DETF resonator is 39.1KHz. Vibration amplitude of the DETF resonator was measured and the experimental results show that vibration amplitude of the joint of DETF resonator is almost three orders of magnitude lower than that of midpoint of DETF, and the quality factor is up to 7750 at ambient condition and 59600 in vacuum, respectively.