bluuebunny/crossref_metadata_2025 huggingface dataset:
An Exploratory Study of Expectation in IT Skills in a Developing Nation
Authors: Lau Sim Kim , Winley Graham Kenneth , Leung Nelson K. Y. , Tsang Nicole , Lau Sim Yee
Published: March 2016

The purpose of this study is to explore expectations in information technology skills for organizations in Vietnam, a developing country in South East Asia. Previous research in Vietnam has mainly focused on information technology adoption; this study offers an insight into the demands of information technology skills in Vietnam. A theoretical framework consisting of five domains of expertise is used to examine the nature and structure of information technology profession in Vietnam. Results from the study show that there is an anticipated increase in demand for information technology professionals who possess deep skills in a broad scope of roles and experience both in information technology and other business domains. Technical skills in the technology infrastructure and services domain in combination with strong communication and problem solving qualities are highly valued by Vietnamese employers.
Virtual Space Co-Creation
Authors: Wang Yonggui , Li Dahui
Published: March 2016

By integrating theories and findings from prior user innovation literature, the authors examine how to improve a customer's co-creation and personalization performance of virtual products by means of harnessing the complementary effects of user characteristics (leading edge status, customer knowledge, and creative self-efficacy) and firm supporting factors (user toolkits and user communities). They tested an integrated research model using survey data collected from 308 Chinese consumers who personalized their virtual spaces by utilizing the tools and supports provided on a social network service site. The authors find that the integrated model that includes both user factors and firm factors was more powerful in terms of explaining a higher variance in personalization effectiveness. They also find that leading edge status, creative self-efficacy, and user communities had stronger impacts on personalization effectiveness than did customer knowledge and user toolkits. The findings provide a broader review of user factors and firm factors for business practitioners and researchers to understand co-creation and personalization.
Nucleation of Multicrystalline Silicon during Directional Solidification
Authors: Bi Ping , Chen Xiu Hua , Ma Wen Hui , Zhang Cong , Wei Kui Xian , Li Yu Ping , Liu Xue Mei
Published: March 2016

In this work, directional solidification was performed for multicrystalline silicon (mc-Si) ingot casting. The initial nucleation at the bottom of the silicon melt could be controlled by changing the cooling rate from 9 to 20μm/s. Metallographic microscope, X-Ray Diffraction (XRD), Microwave photoconductivity decay meter (μ-PCD) and four-point probe resistivity tester were used to investigate the microstructure, crystal orientation and electrical properties of the mc-Si ingots. The obtained results showed that cooling rate at 17μm/s is the optimum condition for the mc-Si ingots casting, under which the prepared ingot has lower dislocation density of 6×10-3 cm-2, better electrical properties, more uniformer resistivity distribution with an average value of 0.68 Ω×cm and higher minority carrier lifetime with a maximum value of 1.8 μs than that of in the other cooling rate conditions.
Thermoelectric Characterization of Ti and In Double-Doped Cobalt Antimony Thin Films
Authors: Li Ya Dan , Zheng Zhuang Hao , Fan Ping , Luo Jing Ting , Liang Guang Xing , Huang Bao Xiu
Published: March 2016

CoSb3 thermoelectric thin films were prepared on polyimide flexible substrate by radio frequency (RF) magnetron sputtering technology using a cobalt antimony alloy target. Ti and In were added into CoSb3 thin films by co-sputtering. The influence of Ti and In on the thermoelectric properties of CoSb3 thin films was investigated. X-ray diffraction result shows that the major diffraction peaks of all the thin films match the standard peaks related to the CoSb3 phase. The sample has best thermoelectric properties when the Ti sputtering time was 1min and In sputtering time was 30 seconds.
Producing Nano-Porous TiO2 Fibers by Electrospinning with Phase Separation
Authors: Liu Zhao Wei , Tang Yu Fei , Zhao Kang , Zhang Heng
Published: March 2016

TiO2 photocatalyst plays an important role in the degradation of sewage and cleaning the air. nanoporous TiO2 fibers have excellent photocatalytic properties due to their high porosity and specific surface area. Based on DMF and alcohol as solvent, nanoporous TiO2 fibers were produced by electrospinning with phase separation. The spinning dope advance rate, DMF/alcohol ratio and calcination temperature were investigated on the influence of micro-structure, porous structure, phase composition and photocatalytic performance of the nanoporous TiO2 fibers. It showed that nanoporous anatase TiO2 fibers had surface pores at 20nm by 550°C calcination. And when the proportion of DMF and alcohol was 1:3, the BET Surface Area of nanoporous TiO2 fibers was 40.75m2/g. They get photocatalytic degradation rate of 85.2% to 20mg·L-1 methyl orange solution after 35 min.
Structure of LaNi3.8AlMn0.2D3.2 Compound Studied by Neutron Powder Diffraction
Authors: Guo Hao , Han Wen Ze , Sun Kai , Chen De Min , Liu Shi , Wu Er Dong , Liu Yun Tao , Chen Dong Feng
Published: March 2016

The intermetallic alloy LaNi3.8AlMn0.2 and its deuteride LaNi3.8AlMn0.2D3.2 were studied by neutron powder diffraction. The experimental results show that the crystal structure of LaNi3.8AlMn0.2 is CaCu5 type with the hexagonal P6/mmm space group, the substituted Al atoms occupy 2c and 3g sites, while Mn atoms are only located on the 3g sites. For the corresponding deuteride LaNi3.8AlMn0.2D3.2, the P6/mmm space group gives the best refinement, but D atoms enter two interstitial sites 6m and 12n.
Effect of CaO on SNCR Reaction with NH3 as Reducing Agent
Authors: Zhang Yun Ning , Wang Ya Li , Cui Su Ping , Wang Wei , Zhao Yi Ning
Published: March 2016

Selective non-catalytic reduction (SNCR) is a denitration method in the high temperature area, and NH3 or urea is used for SNCR as reducing agents to react with NOX to produce N2 in the flue gas in the temperature ranged from 850°C to 1100°C. The SNCR deNOx technology has been well used in utility boiler, but compared with it, the lower denitration efficiency and the larger consumption of ammonia indicate a more complex process in cement pre-calciner. Unlike in utility boiler, the presence of high concentrations of cement raw materials may influence SNCR denitration reaction process in cement kilns. Therefore, studying the effect of CaO which occupy the major composition of cement raw material is very important in SNCR process. In this study the influence of CaO on the SNCR deNOx process was investigated by simulating SNCR reaction at temperature that ranges from 750°C to 1100°C with different normalized stoichiometric ratio. The experimental results demonstrate that the addition of CaO increases the optimum denitration temperature to 1100°C, but it has no effect on normalized stoichiometric ratio. In the whole reaction process NH3 not only restores NO to O2 but also reacts with O2 to NO. Since the adsorption of NH3 on CaO surface, in the temperature range of 750°C-850°C the addition of CaO promotes the reaction of NH3 and O2 and increases NOX concentration. However, in the temperature range of 850°C-1000°C it not only promotes NH3 oxidation but also inhibits the reduction reaction of NH3, thereby the denitration reaction is inhibited. In the temperature range of 1050°C-1100°C the denitration reaction is promoted due to the NH3 desorption from CaO surface.
Electrochemical Depolymerization of Chitosans Using the IrO2 Electrode with Interlayers as Anode
Authors: Deng Pei Chang , Wang Gui , Hu Jie Zhen , Tian Yu Wan , Weng Cheng , Gao Xiao
Published: March 2016

A IrO2 anode on titanium substrate with iridium–titanium oxide interlayer (Ti/ TiO2-IrOx/IrO2) was prepared through repeating brushing-drying-calcinating procedure. The TiO2-IrOx interlayer was prepared using a mixture of TiN nanoparticles and H2IrCl6 solution as the coating solution. The Ti/TiO2-IrOx/IrO2 had high catalytic activity, good catalytic stability and long service life. It was suitable for the application of electrochemical depolymerization of chitosans. The experimental results showed that chitosan could be effectively degraded using the Ti/ TiO2-IrOx/IrO2 as the anode. The influence of the current density on the degradation of chitosans was complicated. The power supply type obviously influenced on the degradation.
Lithium Storage Property of Metallic Silicon Treated by Mechanical Alloying
Authors: Fu Qiang Wei , Jiang Xun Yong
Published: March 2016

Theoretical capacity of silicon is 4200mAhg-1, but pure silicon had huge volume change during lithium insertion, which reduces the cycle life of silicon. In this paper, pure silicon was replaced of metallic silicon to relieve volume effect. Metallic silicon contains some alloying elements which improve the conductivity of the electrode material. The elements in metallic silicon will relief the volume change of silicon substrate during lithium insertion/ de-lithiation process. Metallic silicon was treated by mechanical alloying (MA) which is an effective method to reduce particle sizes of metallic silicon. The results show that MA can improve cycle performance of metallic silicon. Metallic silicon treated by MA performs a better cycling performance compared with the unsettled materials and a higher discharge capacity in the first cycle.
Research and Application of Ultra-High Cementing Slurry
Authors: Zhang Xing Cai , Cheng Xiao Wei , Guo Xiao Yang
Published: March 2016

With the exploration of oil and gas in depth, shallow wells already can’t satisfy the requirement, therefore to explore and develop deep reservoirs is necessary. In the case of deep wells the loop temperature of bottom can reach to 150°C-200°C, which put forward a higher requirement for the high temperature resistance property of cement slurry. At present, many problems existed in the most of high temperature cement slurry. For example, high temperature resistance is not well, cement thickening time can’t adjust easily, mega-thermal sedimentation stability is unsatisfactory, and ultra-retarding phenomenon appeared for the top prone. After research indoors, we developed the ultra-high temperature slurry system by means of the investigation on cementing additives and select proper materials from high temperature resistant fluid loss additives, retarders, flowable agent at the same time. This system needs a lots of properties, such as, adjustable slurry thickening time below 200°C, great slurry sedimentation stability, API loss can be controlled at the range of 0-50ml, insensitive to temperature and density, could be used in low-density and conventional density cement etc. This system be used successfully in the well that loop temperature of bottom reaches to 185°C and get a good effect finally.
Research on New Materials to Improve the Bonding Strength and Relieve Contamination of the Cement Slurry with Oil Based Muds
Authors: Li Zao Yuan , Liu Hong Hua , Guo Xiao Yang , Cheng Xiao Wei , Ou Hong Juan , Gu Tao
Published: March 2016

During shale gas well drilling and completion, the oil based muds (OBMs) would reduce the bonding strength of cement slurry by filter-cake and oil-wettability. At the same time, mixing cement slurry with the OBMs can lead to contamination, and subsequently creates significant problems, such as, reducing the normal thickening time and the compressive strength, and hence affecting the quality of the cementing of the shale gas well. Therefore in the present investigation, the mechanism of the interface displacement, wetting conversion and the contamination was explored by Atomic Force Microscopy (AFM), X-Ray Diffraction (XRD), scanning electron microscope (SEM) and other methods. And then the new materials with the enhanced bonding strength and the contamination relieving by OBMs were obtained. The results showed that the chemical composition of filter-cake determined the properties of chemical preflush, the combined systems (LSS) efficiently flushed filter-cake and increased the bonding strength. It has been found that the reverse wetting agent (APG) has better reverse wetting properties than Tarim Oilfield current application system, which effectively changes the wettability of cementing surface from lipophilicity to hydrophilic. The OBMs and cement slurry mixing generated the emulsion structure and honeycomb structure, and the structures can affect the rheology and the strength of cement slurry; the contaminative relieve agent (SCW) can form a thin film on the surface of the cement stone, the film covers the hole and improves cement compressive strength, thus the SCW can relieve the contamination by OBMs.
An Efficient Simple Hydrothermal Method to Synthesis FeS2 Microspheres and their Optical Property
Authors: Liang Yu Xuan , Bai Peng Peng , Zheng Shu Qi
Published: March 2016

Pyrite (FeS2) is an important semiconductor material which shows various excellent optical and electrical properties and extensive applied prospect as a new-type, photoelectrical functional materials. In this study, a low cost and efficient simple hydrothermal two-step synthetic method was given to obtain FeS2 microspheres with 2-3 μm in diameter. The obtained products were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and ultraviolet and visible spectrophotometer (UV-Vis). XRD showed that the synthetic sample consisted of two crystal structures of FeS2, pyrite and marcasite. SEM observation indicated that FeS2 microspheres were well crystallized and had good uniformity. UV-Vis spectrum had a strong optical absorption in the region of 200-400 nm wave length. The reaction temperature had an impact on the size of FeS2 microspheres. A possible mechanism for the size of the FeS2 microspheres generated at high temperature is smaller than that at low temperature is discussed.
Research on Preparation of Porous Silicon Powders from Metallurgical Silicon Material
Authors: Li Yu Ping , Chen Xiu Hua , Ma Wen Hui , Li Shao Yuan , Bi Ping , Liu Xue Mei , Xiang Fu Wei
Published: March 2016

Stain etching, one step metal assisted chemical etching (1-MACE) and two-step metal assisted chemical etching (2-MACE) were used for preparing porous silicon powders (PSPs) based on metallurgical silicon powder. The influences of different oxidants species and concentrations on the structure of PSP were discussed. The results indicated that the different oxidant species has an important effect on the morphology and structure of PSP. In stain etching, there is still a challenge for fabricating PSP with uniform and controlled pore size structure. In contrast, metal-assisted chemical etching method is easier to prepare PSPs sample with uniform depth and pore size than stain etching, In 1-MACE, the growth rate of the PSPs pore was between 0.05 and 0.10 μm/min, which is far less than that of 2-MACE (about 0.2~0.5 μm/min). Furthermore, 2-MACE showed more advantages than stain etching and 1-MACE in controlling of pore size range and structure.
The Effect of Temperature Elevation on Microwave-Transmitting Property of Organosilicone-Matrix Radome
Authors: Wang Qian
Published: March 2016

In this paper, both the permittivity and the microwave transmittance properties of organosilicon-matrix composites under different temperatures have been studied. In order to investigate the reason for the changing of dielectric property, both TGA and high-temperature dielectric spectrum measurement have been carried out. A theoretical model of radome, with a temperature gradient distribution, has been built to analyze the dependence of microwave transmittance property on temperature. Based on the experimental results, we can optimize the effective operating temperature of this kind of organosilicone-matrix composites.
Study on the Identification of Adulteration of Polycarbonate Drinking Bottles with Postconsumer Recycled Plastics
Authors: Wei Xiao Xiao , Liu Wei Li , Zhang Mei , Gao Xia
Published: March 2016

Adulteration of polycarbonate (PC) drinking bottles with postconsumer recycled PC materials was considerably difficult to identify due to similar chemical compositions and minute differences between virgin and recycled PC materials. In the present study, UV/Vis spectroscopy coupled with GC-MS analysis was carried out to identify the adulteration with recycled materials in PC drinking bottles. The minimum adulterating level which could be detected was 20 %. This strategy represents a rapid and promising analytical method for screening the adulteration of PC drinking bottles with postconsumer recycled plastics.
Enhanced Energy Harvesting from Piezoceramic Using Hybrid Stimulations
Authors: Zhang Bin , Ducharne Benjamin , Gao Jun
Published: March 2016

Energy harvesting from ambient environment vibration is a potential method to supply the low-power consumption devices. This paper demonstrates a new method to proceed energy harvesting using a piezoceramic. Both the mechanical and electrical excitations (hybrid stimulation) have been exerted on a piezoceramic. Current was measured though a current amplifier to calculate the induced polarization. By comparing the hybrid stimulation and the pure mechanical one, it can be found that the hybrid stimulation method enable to amplifier the harvested energy, which is promising to be used in energy harvesting and sensor applications.
Ionic Liquid-Assisted Synthesis of C@ZrSiO4 Ceramic Inclusion Pigment
Authors: Chen Ting , Jiang Wei Hui , Zhang Xiao Jun , Liu Jian Min , Jiang Wan , Xie Zhi Xiang
Published: March 2016

An innovative two-step route was successfully applied to the ionic liquid-assisted synthesis of C@ZrSiO4 ceramic pigments, which is able to reduce the reflux time from many hours to a few minutes. The structure and morphology of the inclusion pigments were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). And the chromatic value of the pigments was measured by the CIE color system. The results show that the pigment in the absence of ionic liquid (IL) exhibited homogeneous single t-ZrO2 phase, while the samples in the presence of IL showed coexistence of two crystal phases (m-ZrO2 and ZrSiO4). The CIE coordination L* value decreased with the increase of TEOS amounts due to the pure zircon formation. The as-prepared pigment showed high tinting ability, as L*=37.16, a*=0.71, b*=0.3, making it promising candidate for ceramic decoration.
Preparation and Properties of Up-Conversion Luminescent NaYF4:Yb3+, Er3+ Ceramics
Authors: Cheng Wen Yan , Gu Shi Jia , Zhou Bei Ying , Wang Lian Jun , Luo Wei , Jiang Wan
Published: March 2016

A series of ytterbium and erbium co-doped sodium yttrium fluoride (NaYF4:Yb3+, Er3+) ceramics have been successfully prepared by pressureless sintering. The ceramic samples were characterized by X-ray diffraction (XRD), photoluminescence (PL), density and field emission scanning electron microscope (FESEM). The results showed that the phases of the NaYF4:Yb3+, Er3+ ceramic samples transformed when the sintering temperature was changed. The ceramic samples sintered below 600 oC contained both cubic α-NaYF4:Yb3+, Er3+ and hexagonal β-NaYF4:Yb3+, Er3+. The sample sintered at 600oC is the pure hexagonal β-NaYF4:Yb3+, Er3+. When the sintering temperature is above 600 oC, the ceramic samples present the α-NaYF4:Yb3+, Er3+ again. The fluorescence intensity increased firstly and then decreased with the sintering temperature increasing. The luminous intensity of the sample sintered at 600 oC was the highest. The densities of as-prepared ceramic sample increased with the sintering temperature rising. The samples sintered at 600 oC with different holding time possessed the similar crystal phases (β-NaYF4:Yb3+, Er3+) and fluorescence intensity. As the holding time increased, the densities of the samples increased. To obtain more dense ceramics, the ceramics using β-NaYF4:Yb3+, Er3+ powders were prepared by spark plasma sintering (SPS). The maximum relative density reached 97%.
Influence of Bi2O3 on Microstructure and Properties of YSZ Solid Electrolyte Material
Authors: Luan Jun Peng , Zhang Jing De , Liu Ya Lei , Ding Chag Ku , Li Fei
Published: March 2016

Different contents of bismuth oxide doped in 3YSZ material and the mixed powder formed. After press forming,the samples were sintered at 850°C, 900°C, 1000°C and 1100°C respectively. The electrical properties,the thermal shock resistance,the phase components and the microstructure morphology were analyzed to study the solid solution mechanism of Bi2O3-Y2O3-ZrO2 three-phase system. It was found that the Bi2O3 can effectively reduce sintering temperature as a flux. Sintered at 1000°C, t-ZrO2 can be induced into m-ZrO2 by Bi2O3 doped. With the increasing of Bi2O3 content, system shock resistance decreases. The thermal shock resistance of the 2-3mol% Bi2O3-YSZ is the best. In the different content of Bi2O3 system, 3mol% doped materials has the highest conductivity.
Performance Improvement of Phase Change Memory Cell by Using a Tantalum Pentoxide Buffer Layer
Authors: Zhang Zhong Hua , Song San Nian , Song Zhi Tang , Li Le , Shen Lan Lan , Guo Tian Qi , Cheng Yan , Lv Shi Long , Wu Liang Cai , Liu Bo , Feng Song Lin
Published: March 2016

The performance of phase change memory (PCM) cell, based on Ti0.5Sb2Te3, was significantly improved by using a tantalum dioxide buffer layer. The presence of a buffer layer reduced the reset voltage of the PCM cell. The theoretical thermal simulation and calculation for the reset process were conducted to analyze the thermal effect of the titanium dioxide heating layer. The improved performance of the PCM cell with dioxide clad layer can be attributed to the fact that the buffer layer not only acted as heating layer but also efficiently reduced the cell dissipated power.
Optical Characteristic and Application of CH3NH3PbI3 Thin Film in Schottky Diode
Authors: Chen Liang , Deng Jin Xiang , Gao Hong Li , Yang Qian Qian , Kong Le , Cui Min , Zhang Zi Jia
Published: March 2016

CH3NH3PbI3 thin film was deposited by a dual-source evaporation system under high vacuum (∼10−4 Pa). The crystallographic phase was analyzed by X-ray diffraction and confirmed as the perovskite structure. The optical properties of the thin film have been investigated in the spectral range 300-1800 nm. The analysis of the absorption coefficient () reveals direct allowed transition with corresponding energy 1.58 eV. The surface morphology of the film was characterized by atomic force microscopy (AFM). The observed features exhibited by CH3NH3PbI3 give a vital chance to explore its application for various optoelectronic devices. To see its other potential utility, Al/CH3NH3PbI3 /ITO Schottky diodes were fabricated. Based on the analyzing the I-V measurement for the Al/CH3NH3PbI3/ ITO device, the basic device parameters such as barrier height and ideality factor were determined. At the low-voltage region, the current conduction in the device is ohmic type. The charge transport phenomenon appears to be space charge limited current (SCLC) at higher-voltage regions.
Investigation of Ni Doped Ge-Te Materials for High Temperature Phase Change Memory Applications
Authors: Cao Liang Liang , Wu Liang Cai , Song Zhi Tang , Zhu Wen Qing , Zheng Yong Hui , Cheng Yan , Song San Nian , Ma Zhong Yuan , Xu Ling
Published: March 2016

Ni-doped Ge-Te (Ni-GT) material was proposed and investigated for phase change random access memory (PCRAM) applications. With Ni addition, the crystallization temperature, data retention ability and crystallization speed were obviously improved. The surface roughness of crystalline Ni-GT films was decreased by Ni incorporation. Moreover, temperature dependent transmission electron microscopy (TEM) was applied to investigate the phase change behavior of Ni-GT films. All the experimental results demonstrated that Ni-GT material has potential for high-speed PCRAM applications in high temperature environment.
Investigation on Power Effect of Gallium-Doped Zinc Oxide Thin Film Semiconductor Performance
Authors: Shi Pan , Han De Dong , Yu Wen , Zhang Xing , Wang Yi
Published: March 2016

Gallium-doped zinc oxide (GZO) thin films were fabricated by radio frequency (RF) magnetron sputtering on glass and silicon substrate at room temperature. The fabrication process, structure, optical properties, and electrical properties of the thin films with different powers (50 W, 70W, and 100 W) were studied to obtain more knowledge about the semiconductor performance. X-ray diffraction (XRD) analysis indicated that the GZO films were polycrystalline and preferred c axis orientation. The average transmittance decreased form 93% to 84% in the visible range, and all the optical band gap was about 3.05 eV when the power increased from 50W to 100W. Simultaneously, the GZO thin film transistors (TFTs) with excellent transfer characteristic prove that GZO thin film is a potential semiconductor material candidate which can be used for the active layer in thin film transistors fabrication.
Reduction-Degradable Shell Cross-Linked Micelle with pH-Responsive Cores Prepared via Click Chemistry
Authors: Lin Lu Bin , Yu Qing Yun , Gu Zhuo Qun , Jiang Xiao Ze , Zhu Mei Fang
Published: March 2016

A well-defined poly [(ethylene glycol)-block-2-(dimethylamino) ethyl methacrylate-block-2-(diethylamino) methacrylate] (PEG-b-DMA-b-DEA) triblock copolymer was synthesized via atom transfer radical polymerization (ATRP) by successively polymerization of DMA and DEA monomers using a PEG-based macroinitiator, and obtained copolymer was then converted to be PEG-b-P(DMA-co-QDMA)-b-PDEA copolymer with “clickable” moieties in the middle block by the quaternization with propargyl bromide. Those copolymers prepared were characterized by proton Nuclear Magnetic Resonance (1H NMR) and Gel Permeation Chromatography (GPC), and its self-assembly behavior and subsequently fixation with bis-(azidoethyl) disulfide via click chemistry resulting reduction-sensitive shell-cross-linked (SCL) micelle in purely aqueous solution were investigated by Transmission Electron Microscopy (TEM) and Dynamic Light Scattering (DLS). The results show the micellar structure could be effectively cross-linked via click chemistry and also be dissociated at reduction condition, which may realize it's potential application as novel drug delivery carriers.
Two-Dimensional Composite Biomimetic Films with Wide Optical Spectrum Response and their Properties
Authors: He Xiao Chun , Bian Lin , Zhang Bo , Ma Lu Wei , Guo Bin , Gao Ming Jun , Ma Xing Fa , Li Guang
Published: March 2016

Since graphene was discovered, the biomimetic materials with laminated structure (such as, shellfish) had become one of the research-hot fields. Chitosan comes from shellfish, and was considered as a very promising abundant natural biopolymer. It holds not only outstanding mechanical properties, film-forming technology and low cost, but also has good applications in environmental fields due to its excellent adsorption properties to a broad range of organic pollutants and some heavy metal ions. Preparation of biomimetic materials with laminated structure utilizing chitosan have many advantages, however, to improve functional properties of chitosan based biomimetic materials is still a great challenge. Graphene has various applications, including storage energy devices, hydrogen production with photo-catalysts, and environmental fields because of its high charge mobility and good mechanical properties. However, graphene and its oxide have difficult re-dispersion properties in fabrication of nanocomposite. In this paper, the nanosheets stacking of metal oxide and grapheme oxide with aid of chitosan was carried out. Several characterizations were examined by SEM (scanning electron microscopy), XRD (X-ray diffraction), ultraviolet-visible spectroscopy (UV-Vis), and Fourier-Transform Infrared (FTIR) spectra. Photocatalytic tests were examined by selecting typical organic pollutants. The photoconductivity response of nanocomposite film to visible light and 808 nm laser with low-power were investigated based on interdigital electrodes of Au on flexible PET (polyethylene terephthalate) film substrate. The results indicated that the organic-inorganic film not only had wide visible light and NIR (near-infrared) responses, but also had good removal ability to organic pollutants. The nanocomposite film also exhibited clearly photo-response to visible light and 808 nm laser. It would be potential good applications in self-cleaning film, nanocoating, et al.
Study on High Pressure Sintering of Nanocrystalline Diamond with Nano Silicon as Additives
Authors: Deng Fu Ming , Zhan Chang , Zhao Ye , Deng Wen Li , Lei Qing
Published: March 2016

In this paper, nanocrystalline diamond with the average grain size of 50nm was prepared under different sintering pressure, temperature and sintering time. The microstructure of the sample was analyzed by SEM, EDS and XRD, and the mechanical properties tested by micro-hardness tester and wear ratio instrument. The results show that the sample sintered under the optimum conditions of oil pressure 87MPa, heating power 4000W and sintering time 120s possessed hardness of 706.41HV and wear ratio of 3280. It indicated that high performance n-PCD sintered from nanodiamond and silicon system can be formed hardly with diamond to diamond bonding but can be formed with diamond to silicon carbide bonding. The poor mechanical properties of the samples were due to the surface adsorption groups and surface graphitization of nanodiamond during high pressure sintering.
Preparation and Properties of La-Doped BiFeO3 Thin Films
Authors: Hu Bing Lin , Li Zong Zhen , Zhang Hui Qin , Chen Shui Yuan , Ye Qing Ying , Zhao Ji Fu , Zhao Yang , Huang Zhi Gao
Published: March 2016

Bi1-xLaxFeO3(x=0, 0.3) thin films were deposited on glass/ITO substrates through Sol-Gel Dip-Coating method and rapid annealing process. The structures were detected by X-ray diffraction patterns, Raman spectrometer and scanning electron microscopy. The magnetic, ferroelectric and optical properties of the films were studied by vibrating sample magnetometer, ferroelectric integrate tester and photovoltaic performance testing system, respectively. The experimental results indicate that BiFeO3 thin film presents rhombohedral perovskite structure and Bi0.7La0.3FeO3 films showed distorted perovskite structure, which were confirmed by XRD patterns and Raman spectrometer. The magnetism and ferroelectric properties of the films were obviously enhanced by La doping. Furthermore, the photocurrent response and photovltaic effect in BLFO thin films were detected.
Preparation and Superconductivity of Bi-O-S System
Authors: Cui Ya Jing , Lan Dong Rong , Su Yu Feng , Chen Yong Liang , Zhao Yong
Published: March 2016

Several Bi-O-S compounds with nominal composition of Bi4O4S3, Bi3O2S3, Bi2OS2 have successfully been synthesized. The superconducting properties present to be similar with each other for Bi4O4S3 and Bi2OS2 compounds, but much better than the Bi3O2S3 compound. The former two possess a zero resistance temperature at 4.1 K, whereas the latter one is 3.7 K. Two diamagnetic transitions have been observed in the M-T curve for all three compounds. The starting nominal composition definitely affects the superconductivity of the final products.
Structural and Magnetic Properties of Cr- and Fe-Doped CeO2 Nanoparticles Prepared by Sol-Gel Method
Authors: Yang Sheng Hong , Zhang Yue Li
Published: March 2016

A study of the structural and magnetic properties of Cr-and Fe-doped CeO2 nanoparticles produced by the sol–gel-based method was undertaken. The crystal structure and phase, morphology, and magnetic properties of the sample were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy (Raman) and physical property measurement system (PPMS). XRD and Raman studied showed that Cr-and Fe-doped did not change CeO2 original cubic fluorite crystal structure, and no ferromagnetic secondary phase was observed. SEM images showed that Cr-and Fe-doped CeO2 nanoparticles were spherical, uniform size, and good dispersion. The particle size was about 20 nm. The magnetic measurements showed that the Cr-and Fe-doped CeO2 nanoparticles presented ferromagnetic behavior at 10 and 300 K, indicating the Curie temperature was above room temperature. The magnetization diminished with the increase of the temperature. The saturation magnetization and coercivity of Fe-doped CeO2 nanoparticles were higher than that of Cr-doped CeO2 nanoparticles. Combined with the results of XRD and Raman, the ferromagnetic behavior can be attributed to the intrinsic properties of Cr-and Fe-doped CeO2 nanostructures.
Influence of Microstructure on Pass through Flux of High Purity Ni
Authors: Xu Guo Jin , Luo Jun Feng , Li Yong Jun , He Jin Jiang , Wan Xiao Yong , Ding Zhao Chong
Published: March 2016

Pass through flux (PTF) is an essential parameter for the magnetron sputtering process of ferromagnetic materials. In the present investigation the influence of deformation, recrystallized microstructure and thickness on PTF of Ni was examined by the analysis of microstructure and hardness of high purity Ni. The experimental results showed that PTF of rolled Ni increased significantly comparing to the annealing microstructure that is related to the dislocation and stress of microstructure. With the recrystallization and grain growth of deformed samples, PTF decreased to be about 30%. PTF was also associated with the thickness of material. It increased by 6% when the thickness of 0.5mm decreased. This research is useful to guide and improve the design, development and preparation of magnetic sputtering materials.
Preparation and Properties of TiO2/SiO2 Thin Films on Enamel Substrates
Authors: Chen Li Yun , Liao Xiao Ping , Jiang Wei Zhong , Ye Jia Yi , Jin Hui Le , Liu Ai Li
Published: March 2016

nanosize TiO2/SiO2 thin films were deposited by sol-gel dip-coating method on enamel substrates. Crystal structure, micro-structure, hydrophilic property, gloss property was investigated by X-ray diffract meter, scanning electron microscope, CCD camera, enamel gloss meter. The results show that the hydrophilic property of the enamel was greatly increased by heating the enamel with coating TiO2/SiO2 film; the gloss property of the enamel surface greatly increased after the enamel coated with TiO2/SiO2 film. The main crystals in TiO2/SiO2 film on the enamel were anatase when the baking temperature was below the 700°C.
Preparation and Characterization of Water Absorbing and Anti-Fogging Coatings
Authors: Wang Kai , Huang Min , Huang Yue , Zhou Zhong Hua , Shen Shirley
Published: March 2016

Anti-fogging functional coatings have a broad application prospective in the fields of construction and transportation vehicles. In this study, superior water absorbing and anti-fogging coatings were prepared by a cure reaction using epoxy resins as water absorbent resins, hydroxyethyl ethylenediamine as a curing agent, γ-ammonia propyl triethoxy silane as a coupling agent, organic silicon sol as filler. The impact of additional polyethylene glycol (PEG) on the properties of water absorbing and antifogging coating has also been studied. The anti-fogging experiments were conducted in a 40 °C water steam bath, and the result shows that the sample with additional 4.0 % PEG has an anti-fogging time of 315 seconds (s), which is better than that without PEG (the anti-fogging time being 240s). Infrared spectroscopy and scanning electron microscope structure characterization indicate that the sample with additional PEG has an obvious three-dimensional network structure with hydroxyl groups, which leads to a great saturated water quantity and a superior anti-fogging performance.
Effect of Heat Treatment on Microstructures and Properties of AZ40M Alloy
Authors: Lai Lin , Zhang Kui , Ma Ming Long , Shi Guo Liang
Published: March 2016

The influence of two-step homogenization on microstructures and properties of AZ40M magnesium alloy were investigated by the scanning electronic microscopy (SEM), X-ray diffraction analysis (XRD) and tensile experiment. Through comparing the microstructure and mechanical properties of the alloy before and after homogenization treatment, a two-step homogenization process of the semi-continuous casting AZ40M magnesium alloy ingot was determined. The result shows that the as-cast AZ40M alloy mainly contained two kinds of second phase, β-Mg17Al12 and Al8Mn5. Treating at temperature of 380 °C for 8 h as the first step homogenization treatment and then treating at temperature of 420 °C for 20 h as the second step homogenization treatment made the eutectic phase (α-Mg/β-Mg17Al12) completely eliminated and the alloying elements such as Al, Zn distributed uniformly. Al8Mn5 is the residual second phase in the homogenized AZ40M alloy. During the homogenization process, the β-phase dissolved which made the content of Al increased in the matrix. The decomposition of β-phase benefits the tensile strength and elongation of the alloy. The tensile fractures of as-cast and homogenization alloys are characteristic of ductile fracture.
Investigation of the Effect of Argon Arc Welding Parameters on Properties of Thin Plate of In Situ Titanium Matrix Composites
Authors: Mao Jian Wei , Han Yuan Fei , Lu Wei Jie , Wang Li Qiang
Published: March 2016

The weldability of in-situ titanium matrix composites (TMCs) was studied using the gas tungsten arc welding (GTAW). The effects of GTAW on the microstructure of fusion zone and heat-affected zone were discussed, and the changes of TiB whisker reinforcements in the welded joint were investigated by optical microscope (OM), scanning electron microscopy (SEM), XRD analysis and tension testing at room temperature. Research results show that the GTAW process is a suitable welding method for in-situ TMCs. Under reasonable welding parameters, the welded joints display goo weld seam formation, and TiB whiskers show distinctly smaller sizes and uniform distribution with a special network structure. The maximum tensile strength of welded joints can reach 92% of the base metal under optimum welding parameters.
Stress Rupture Properties and Fracture Behavior of DD6 Single Crystal Superalloy
Authors: Shi Zhen Xue , Liu Shi Zhong , Han Mei , Li Jia Rong
Published: March 2016

The stress rupture properties, fracture behavior and microstructure evolution of the second generation single crystal superalloy DD6 at different conditions were investigated. The results show that the alloy has excellent stress rupture properties. The fracture mechanism of stress rupture of the alloy at 760°C/785MPa, 760°C/750MPa and 760°C/720MPa shows quasi-cleavage mode and the fracture mechanism at 980°C/250MPa, 1070°C/160MPa and 1100°C/140MPa shows dimple mode, while the fracture mechanism at 850°C/550MPa shows quasi-cleavage and dimple mixture mode. Only a little change in the morphology of γ′ phase occurred at 760°C/750MPa. The γ′ rafts form at temperature above 760°C and the thickness of rafts increases with increasing temperature. The dislocation shear mechanism including stacking fault formation is operative at lower temperature and high stress. The dislocation by-passing mechanism occurs to form networks at γ/γ′ interface under the condition of high temperature and lower stress.
Effect of Mo Content on the Corrosion Resistance of Fe-Based Amorphous Composite Coating
Authors: Jiang Run Sen , Wang Yong Tian , Hu Lin , Xu Gang , Liu Zong De
Published: March 2016

A Fe-based amorphous composite coating doped by molybdenum was fabricated by the pulse laser cladding technology. The substrate was a low carbon steel plate. The nominal composition of the powder in the range from 100 to 200 meshes was (wt.%) Cr:14.95, Mo:25.7, B:1.24, C:3.45, Y:3.40, Fe:51.29, which was selected for the laser cladding process. The microstructure, phase composition, hardness and corrosion resistance of the coatings were characterized by means of SEM, EDS, XRD , DSC and potentiodynamic polarization test. The results show that the coating which was composed of amorphous and nanocrystal phases had the dense structure and metallurgical bonding with the substrate, meanwhile with low porosity and cracks. The addition of molybdenum played an important role in improving the corrosion resistance of the coatings. With the increasing content of molybdenum, the hardness had no significant change, while the corrosion resistance of the coatings significantly increased. From the results of polarization curves, the corrosion current density of the coating added 0 wt.% Mo is higher than that of the coatings added 2 wt.% Mo and 10 wt.% Mo. The molybdenum has a superior effect on the corrosion resistance in Fe-based amorphous composite coating.
Influence of Impact Damage on the Thermal Stress Distribution within the EB-PVD Thermal Barrier Coatings
Authors: Huang Tai Hong , Song Peng , Ji Qiang , Luo Heng , Lu Jian Sheng
Published: March 2016

Macroscopic holes often form on gas turbine blades surface by high velocity gas stream with some foreign impact particles during service. The influence of the impact-holes on the thermal stress distribution was investigated in this paper. The thermal stress distribution within the TBCs after impact-damages at high temperature was intensively studied by using finite element method. Analyze equivalent stress and thermal stress, it was found that the macroscopic holes on the surface of ceramic coatings could change the original temperature gradient and it transform the thermal stress distribution in the TBCs without impacting, resulting in the maximum tensile stress area expanding at the crest and promoting the generation of cracks and reducing coatings life. The impact-holes at the edge of the blades changed the former thermal stress distribution completely. The maximum thermal stress region existed in the alumina scale, severely decreases the life of thermal barrier coatings.
WC Particles Reinforced Co-Based Alloy Coatings Produced by Laser Cladding
Authors: Zhang Jia Zi , Wang Guang Yuan , Qin Yuan , Yang Sen
Published: March 2016

To extend the service life of hot die steel (H13), WC particles reinforced Co-based alloy composite coatings were produced by laser cladding. The microstructure evolution and performance of the cladding layer were investigated. The experiment results showed that there existed fine dendritic crystals and dispersive WC particles in the cladding layer. The coatings were mainly composed of γ-Co, WC and Co3W3C phases. The microhardness of the cladding layer was higher than that of the arc surfacing layer, and the microhardness gradually increased with WC content. Compared to the substrate, the friction coefficient of the cladding layer reduced greatly. The coatings with 15wt.% WC possess the best wear resistance.
Solar Reflection Characteristics of Phthalocyanine Green/TiO2 Composite Green Pigments Prepared via Different Approaches
Authors: Feng Xiao Juan , Mao Qian Jin , Lv Qiu Rui , Wang Zi Ming , Cui Su Ping
Published: March 2016

Near-infrared pigment is the key to control the near-infrared performance of solar heat-reflective coating which has good economic and application prospects as a new special coating. Green infrared reflective pigments were prepared through physical mixing, inorganic lake method and sol-gel processes in this study. Results show that the near-infrared spectral reflectance of composite pigments is improved when using inorganic lake method and sol-gel method. Chromaticity of composite pigment is the closest to phthalocyanine green when using sol-gel method. Physically mixing method is not suitable to prepare infrared reflective pigment. The coating materials have influence on the coating effect and the reflectivity of near-infrared spectral range in a certain extent.
SiO2 Cryogel Dispersion in Organic Solvent for the Application as Transparent Heat Insulation Coating on PET
Authors: Xu Jia You , Zhou Jian Hua , Miao Lei
Published: March 2016

SiO2 cryogels (SCG) with a low thermal conductivity was used for transparent heat insulation coatings. SCG dispersion in organic solvent was prepared by sand milling, and the paint was composed of SCG dispersion as a functional filler and polyacylic resin as a binder. The paint was coated on PET film and then pasted on a glass substrate to form the filmed glass. The results showed that the particle sizes of SCG in the dispersion were almost below 100 nm, and the organic dispersion had a good stability. The coating with SCG dispersion exhibited a remarkable shielding effect in the near infrared waveband as well as a high transmittance above 80% in the visible light. The heat insulation temperature of SCG filmed glass was 4 °C compared with the blank glass. The transparent heat insulation coating with SCG will be developed for solar control and energy saving applications.
Fine-Grained W-Ni-Fe Heavy Alloys Prepared by Spark Plasma Sintering
Authors: Wu Yan Jiao , Li Yun Kai , Yu Dong Hui
Published: March 2016

Fine-grained W-Ni-Fe heavy alloys (WHAs) with grain size of about 1-3μm were obtained by Spark Plasma Sintering (SPS) process. The composition of the alloy is consisted of 65 to 75 wt % W, with a Ni/Fe ratio ranging from zero to 7/3. In the lower sintering temperature range of 1100-1300°C, the WHAs showed the highest relative density of 98.6%, and when the sintering temperature was 1250 °C, the relative density of the WHAs prepared by the same techniques increased by decreasing of the content of W. Meanwhile the relative density of the alloy also increased with an increase of Ni /Fe ratio. The results show that the static tensile properties of the WHAs have a close relationship with the ratio of Ni / Fe. The tensile strength and the ductility of the sample W70-Ni21-Fe9 was 890 MPa and 3%. Furthermore, the dynamic compression strength of W70-Ni21-Fe9 was 1744 MPa.
Isothermal α Precipitation and Evolution in a Hot-Rolled near β Titanium Alloy
Authors: Sun Miao , Xue Xiang Yi , Kou Hong Chao , Hua Ke , Tang Bin , Li Jin Shan
Published: March 2016

Evolution of secondary α precipitates in a near β titanium alloy Ti-7Mo-3Al-3Nb-3Cr hot-rolled bars (Φ14mm and Φ22mm) with different rolling processes was investigated. The results indicated that the morphological evolution of secondary α phase was almost the same, despite of different rolling processes. While the precipitation kinetics of secondary α phase in short-term aging process changed significantly. Secondary α phase precipitated along β grain boundaries (αGB) and inside β grains as dot shape initially, when aged at 500oC. With time increasing, dot-shaped α phase precipitates connected together as line. And nucleation of α-laths from the grain boundaries (αWGB) appeared as time reached to 10 minutes. Meanwhile, chevron-shaped secondary α phase precipitated from β matrix. Secondary α phase evolved into acicular shape, when aging time was extended to 20min or much more, and the angle between each other was about 90o or 60o. The volume fraction of secondary α phase in Φ22mm bar was larger and changed faster than that of Φ14mm bar with the changing of aging temperature (500oC-600oC) and time (≤60minutes). αWGB formed both along high angle GB and low angle GB after aged at 500oCfor tenminutes, with two sides of αGB.
Fabrication of Zn Alloy Foam via Powder Metallurgical Approach
Authors: Chen Wei Ping , Yang Dong Hui , Lu Jun , Feng Yuan , Chen Jian Qing , Wang Lei , Jiang Jing Hua , Ma Ai Bin
Published: March 2016

Powder metallurgical (PM) route is one of the methods for metal foam fabrication. In this paper, we report the fabrication of Zn alloy foams with 0~50wt.% Mg via powder metallurgical approach by using CaCO3 as the blowing agent. The fabrication process included 5 steps: powders mixing, cool-pressing, heat treatment, hot-pressing, foaming and cooling. The effects of Mg addition, foaming temperature on the foaming process were discussed. Finally, the compressive behavior of Zn alloy foam was evaluated.