bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Hot Pressing and Deforming on the Microstructure and Properties of NdFeB Magnets
Authors: Li Chun Hong , Li Feng , Chen Deng Ming , Zhao Jiang Lin , Ma Yi Long , Zheng Qiang , Li Bing Bing
Published: April 2016

In this paper, the NdFeB magnets were prepared by hot pressing and deforming, the influence of pressing temperature, pressing strain, deforming temperature, deforming rate and amount on the density, hardness and magnetic properties of magnets were analyzed with the microstructure analysis. The results show that the density of the magnets and the hardness increase with the increase of the hot pressing temperature and pressure, but the hardness decreases when the pressing temperature reaches 800°C.After thermal deformation, the gap of the magnets reduced, the density is increased, the hardness becomes larger, and the grains are oriented in the direction of deformation, which leads to higher magnetic properties. However, when the deformation rate is too low, or the deformation temperature is too high, there is an abnormal phenomenon of grain growth, leading to the decrease of coercivity and harness of the material.
Effects of Zr on Microstructure and Conductivity of Er Containing Heat-Resistant Aluminum Alloy Used for Wires
Authors: Han Yu , Chen Bao An , Zhu Zhi Xiang , Liu Dong Yu , Xia Yan Qiu
Published: April 2016

It has particular heat-resistant property and conductivity of high-conductivity heat-resistant Aluminium alloys, which would be wildly applied in transmission and transformation flied. Al-Er-Zr alloys containing different content of Zr were prepared. The effect of Zr on microstructure of heat-resistance Aluminum alloy were studied by using of STEM, and thermodynamic behavior of Zr in Aluminium alloy was analyzed based on the theory of alloy phase formation. The results showed that the effect of Zr content on the grain size of heat-resistant aluminum alloy was remarkable, and the conductivity of heat-resistance Aluminum alloy was influenced.
Numerical Simulation of Quenching and Pre-Stretching Residual Stress in 7085 Aluminum Alloy Plate
Authors: Cao Hai Long , Li Xi Wu , Li Ya Nan , Yan Hong Wei , Li Zhi Hui , Zhang Yong An , Huang Shu Hui , Xiong Bai Qing
Published: April 2016

The finite element method (FEM) was used to study the quenching and pre-stretching residual stresses of the 7085 aluminum alloy plate, combining with experimental measurement. Quenching residual stress simulation results showed that the stress of the rolling-direction and transverse-direction in the center were 16.5MPa and 9.2MPa, respectively. The stress of the rolling-direction and transverse-direction on the surface were-33.8MPa and-40.4MPa, respectively. The quenching residual stress simulation results were in good agreement with the X-ray diffraction experimental results. As the pre-stretching ratio increases, the quenching residual stress reduction ratio increases. The ratio of 2.0~3.0% pre-stretching can effectively release the quenching residual stress in aluminum alloy plates. After 3.0% pre-stretching, the stress of the rolling-direction and transverse-direction in the center were 0.9MPa and 1.8MPa, respectively. The stress of the rolling-direction and transverse-direction on the surface were-3.6MPa and-7.1MPa, respectively. The quenching residual stress reduction ratio reached above 80%.
Preparation and Characterization of Conjugated Microspheres FeTCPP-SSA-TiO2
Authors: Peng Chao , Yao Bing Hua , Li Jun Xia , Niu Jin Fen
Published: April 2016

The novel photocatalyst (FeTCPP-SSA-TiO2) with chemical bond linking sensitized was successfully designed and fabricated. As bridging unite, sulfosalicylic acid (SSA) was used for grafting active functional groups onto TiO2 surface thereby improving the adhesion strength between trtra-carboxyphenyl porphyrin iron (FeTCPP) and TiO2. The morphology and structure of the photocatalyst was characterized. Finally, photocatalytic properties of the prepared samples have been investigated by the degradation of methylene blue (MB). The results indicated that FeTCPP-SSA-TiO2 possessed enhanced photocatalytic performance and long-term stability over four recycles.
Hydrothermal Synthesis and Photocatalytic Activity of TiO2-ZrO2 Hybrid Composite Microspheres
Authors: Yao Bing Hua , Han Xiu Ping , Lü Ying , Peng Chao , Zhang Cheng Jie
Published: April 2016

The hollow TiO2-ZrO2 hybrid composite microspheres were successfully synthesized by hard template-hydrothermal method. The resulting materials were characterized by SEM, XRD, DRS, FT-IR and BET techniques. The results showed that the TiO2-ZrO2 hybrid composite microspheres with hollow structure were piled by TiO2 (anatase) and ZrO2 (monoclinic) hybrid nanoparticles. The specific surface area and the average pore size of the as-prepared samples were determined to be 224.6 m2/g and 4.159 nm, respectively. The photocatalytic activity of the samples was also evaluated by degradation of methylene blue (MB) compared to the hollow TiO2. It was found that the resultant TiO2-ZrO2 hollow microspheres show higher photocatalytic activity than hollow TiO2-ZrO2. The degradation rate of MB can be up to 99.4% after 60min of a high pressure mercury lamp (125W) irradiation.
The Preparation of BaTi4O9  by Sol-Gel Method
Authors: Wei Zhao Rong , Shi Chao Yang , Shen Bin , Fan Ming , Wang Cheng
Published: April 2016

To promote the application of BaTi4O9 in higher-end fields, BaTi4O9 precursor has been prepared with sol-gel method (SGM. The objective products have been obtained at different temperatures and SSR-BaTi4O9 samples has been prepared for compare experiments. The studies of thermal analysis, XRD analysis, TEM analysis, specific surface area analysis, DRS analysis and FS analysis show: the crystalline of the product obtained by SGM is more purity than the product obtained by SSR; The SGM600 sample is amorphous, which can be used as an optical catalyst because of the maximum specific surface area; The SGM1000 sample is the most pure, uniform and complete in crystal.
Preparation and Electrochemical Properties of Nano Si-C Composite
Authors: Chen Xiao , Yang Yun , Yang Shui Jin , Feng Chuan Qi , Guo Zai Ping
Published: April 2016

nanoSi-C composite was prepared using eletronspinning technique. The microstructure and morphology of the Si-C composite were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The electrochemical performances of the Si-C composite were tested by battery testing system. The results showed that the Si-C composite not only behaved high initial capacity but also good cycle performances. The reversible discharge capacity could remain at 860 mAhg-1 when current density was 50 mAg-1. The rate reversible capacity is much higher than that of pure nanoSi anode at same condition.
Investigation on Ce Addition on Microstructure and Martensitic Transformation of a Ti51Ni49 Shape Memory Alloy
Authors: Liu Ai Lian , Mao Nan Nan , Xu Jia Wen , Cai Wei
Published: April 2016

The effect of rare earth element Ce addition on the microstructure and martensitic transformation behavior of Ti51Ni49 shape memory alloy was investigated by scanning electronic microscope (SEM), X-ray diffraction (XRD) and differential scanning calorimetry (DSC). The results show that the microstructure of TiNiCe ternary alloy consists of Ti2Ni phase, CeNi phase and the matrix. One-step martensitic transformation is observed in quenched TiNiCe ternary alloys, which is the same as that in quenched TiNi binary alloys. The martensitic transformation temperatures of Ti-rich TiNi alloy hardly increase with Ce addition.
Advance in the Fabrication of Ordered Ge/Si Nanostructure Array on Si Patterned Substrate by Nanosphere Lithography
Authors: Xin Zheng Hang , Wang Chong , Qiu Feng , Wang Rong Fei , Li Chen , Yang Yu
Published: April 2016

The recent process in the fabrication of the ordered Ge/Si quantum dots (QDs) is reviewed. The fabrication step generally started on the preparation of patterned substrate prepared in advance by using several interesting methods, such as photo lithography, focus ion beam (FIB), reactive ion etching (RIE), and extreme ultraviolet lithography (EUV-IL) et al, which are introduced briefly in this article. Here, we’d like to focus on the detailed process of nanosphere lithography (NSL) which has the advantages of less cost and higher product compared with the referred methods. The ordered Ge nanostructures always show as Hexagonal close-packed array on the patterned Si substrate and have the advantages of potential applications in electronic and optoelectronic devices.
Microwave Absorbing Properties of MnAlFe Magnetic Powder
Authors: Liu Ye , Pan Shun Kang , Lin Pei Hao , Liu Xing , Cheng Li Chun
Published: April 2016

MnAlFe alloy was prepared by the combined use of smelting, high-energy ball milling and tempering heat treatment process. The phase composition and microwave absorbing properties of MnAlFe alloy were investigated by X-ray diffractometer(XRD) and vector network analyzer. The results show that the powders consist of Al8Mn5 single phase with different Fe content; the dielectric loss and the magnetic loss increases with the addition of Fe, the resonant frequency and absorption peak of ε″ and μ″ moves towardslower frequency region simultaneously. The (Al8Mn5)99Fe exhibits preferably comprehensive microwave absorbing properties in the range of 6-18 GHz. The value of the minimum reflectivity and absorption peak frequency with the coating thickness of 1.5 mm, are -23.1 dB, 15.04 GHz respectively.
Owing to the wide applications of electromagnetic waves in the range of 1–4 GHz for mobile phone, local area network, radar systems and so on over the past few decades, the serious problems of the electromagnetic interference and electromagnetic compatibility have become increasingly prominent in recent years. Microwave absorbing materials, which possess special performance for absorbing electromagnetic wave, have been applied in both civil and military fields and play an important role in camouflage technology. In military field, stealth technology to reduce and eliminate the electromagnetic radiation and electromagnetic interference resulting from the broad applications of various kinds of electronic and microwave instruments, stealth technology plays an important strategic role in the wars in future[1-2]. The microwave absorbing materials can be used to reduce radar cross section for military use. For this reason, the microwave absorbing material is vitally important for both civil and military fields[3-7]. In view of this utilization, excellent microwave absorbing materials should exhibit strong microwave absorption properties over a wide frequency range and need to be thin and light in weight. It has an important meaning to the application of magnetic microwave absorbing materials.
MnAl alloy can be used as microwave absorbent. It has properties such as light in weight, good thermal stability and corrosion resistance[8-11]. But as permanent magnets, MnAl has shortcomings such as their difficulties of fabrication and high costs that prevent them from being used as permanent magnets. A great value would be brought to either theory or practice through proper treatments as further improvement in properties. In this paper, we will discuss the effects of changing relative content of Fe on absorption properties of Al8Mn5 alloy.
Recent Research Progress of Carbon Nanotube Arrays Prepared by Plasma Enhanced Chemical Vapor Deposition Method
Authors: Ding Er Xiong , Geng Hong Zhang , Mao Li He , Wang Wen Yi , Wang Yan , Luo Zhi Jia , Wang Jing , Yang Hai Jie
Published: April 2016

Preparing carbon nanotube (CNT) arrays by plasma enhanced chemical vapor deposition (PECVD) method can dramatically reduce the deposition temperature, which makes it possible for in-situ fabrication of CNT-based nanoelectronic devices. In this paper, up to date research progress of CNT arrays prepared by PECVD method was presented, including radio frequency PECVD, direct current PECVD and microwave PECVD. Then, morphology and quality of CNT arrays were compared. In the end, we analyzed the possible challenges encountered through CNT array preparation by PECVD method at the moment and in the future.
Kinetics of Carbothermic Reduction of Ilmenite
Authors: Chen Min , Xiao Xuan , Zhang Xue Feng
Published: April 2016

The reduction kinetics of ilmenite was investigated. Phase evolution during the reduction process was identified by XRD and morphology change was observed using SEM. Kinetic parameters of the activation energy and pre-exponential factor were determined by Kissinger-Akahira-Sunose (KAS) method and Coast-Redfern method&artificial isokinetic relationship (IKP) respectively. Results showed that when the reaction of titanium suboxides makes a growing contribution, the conversion dependence of activation energy has an ascending trend. When the conversion exceeded 0.7, the reactants almost consumed, and the process was controlled by diffusion.
Applications of Ceramic Materials in High Energy Laser Damage
Authors: Zhang Lei , Shao Bi Bo , Wu Yong , Yang Peng Ling , Tao Meng Meng , Yan Yan
Published: April 2016

With the consistent improvement of the laser power and energy, further enhancement of the laser resistant ability of the target board is becoming a more and more crucial task in high energy laser diagnostics and irradiation effect studies. Applications of ceramic materials in high energy laser damage were studied. An aluminum panel was coated with ZrO2 ceramic for high power laser proof. Reflectivity and diffuse reflection characteristics of the coating were investigated at different wavelengths. Numerical simulation was conducted to analyze the thermal response of the coating under high power laser radiation. And, related experiments were carried out with high power fiber lasers. Irradiation experiments indicate that the ceramic layer helps to delay the heat conduction and reduce the peak temperature of the target board.
Preparation and Performance of Chiral Polyaniline/Cobalt Ferrite Composites
Authors: Li Juan Bi , Hu Di Qiong , Wang Yu Huan , Li Liang Chao , Ding Yan
Published: April 2016

The cobalt ferrite and chiral polyaniline/cobalt ferrite composites were synthesized by co-precipitation and in-situ polymerization method, respectively. The crystal structure and composition, electrical conductivity, optical rotation, dielectric loss and magnetic loss of the as-prepared samples were researched. It was found that the optical rotation (levorotation) of composites is less than that of chiral polyaniline (L-PANI), and increased with the increasing of L-PANI content. The conductivity of the composites with a mass ratio of L-PANI to cobalt ferrite above 0.4 was better than of pure L-PANI, and their dielectric loss was in accordance with the conductivity in variation trend.
Effect of Dispersant on Preparation of Barium Strontium Titanate Nanopowders by Microwave Hydrothermal Processing
Authors: Chen Jie , Che Ming Chao , Yan Feng
Published: April 2016

Through the microwave-hydrothermal processing at 70 °C in 10 min, barium strontium titanate (BST) nanopowders are prepared by using butyl-titanate, barium nitrate and strontium nitrate as raw materials. Two kinds of dispersants namely polyethylene glycol 6000 and OP-10 are added, respectively. The dispersant mechanism and dosage on the crystal phase and microstructure are studied by X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM). The results show that the dispersive effect of OP-10 is better than the polyethylene glycol 6000. The long chain of OP-10 can be used to disperse nanopowders through a space steric hindrance mechanism, well-dispersed BST nanopowders are obtained when mass percent ratio of dispersant (OP-10) is 5%.
Fabrication and Magnetic Properties of Fe, Co and Ni Nanotube Arrays
Authors: Song Guo Jun , Li Xiao Ru , Li Mei Jing , Feng Sheng Yu , Zhou Chuan Jian
Published: April 2016

One-dimensional Fe, Co, Ni nanotube arrays ware fabricated successfully by the electrochemical deposit in porous anodic alumina oxide (AAO) templates. The microstructure of nanotubes were observed by scanning (SEM) and transmission electron microscopes (TEM) respectively. The obtained Fe, Co, Ni nanotubes are arranged orderly. The magnetic property of nanotubes was measured and analyzed. The results show that the residual magnetization of Ni nanotubes is the biggest, and that of Fe nanotubes is the smallest. It is easy to be magnetized along the axial direction.
Study on the Synthesis and Performances of Ultrafine Silver Powder Used as Silicon Solar Cell Front Silver Contacts
Authors: Fu Ming , Li Hong Yong , Wang Yue , Fan Lin , Chen Dong , Feng Zhao
Published: April 2016

High-performance ultrafine silver powder used as crystalline silicon solar cell front conductive paste was prepared by chemical liquid-phase reduction method using silver nitrate as metal source, ascorbic acid as reductant, and gelatin as dispersant. The effects of reducing agent concentration, doses of dispersant, PH value of reaction solution and reaction temperature on the performance of silver powder were studied. The morphology, particle size and dispersibility of silver powder were observed by scanning electron microscope (SEM). The size distribution of silver particles was characterized by laser particle size analyzer. The crystalline silicon solar cells were produced by screen-printing front conductive silver paste, made with the obtained silver powder. The photoelectric properties of the solar cells were measured by solar simulator. The processing parameters of preparation silver powder, which meets the requirement of making high conversion efficiency solar cells, were optimized.
The Electronic Structure and Optical Properties of Co,C Co-Doped AlN Nanosheet
Authors: Huang Bao Jun , Zhou Yi , Wang Pei Ji
Published: April 2016

The electronic structure, band structure and optical properties of Co,C co-doped AlN are investigated by first-principles calculations. The calculated results show that some impurity bands emerge near the Fermi level, and the degree of hybridization becomes stronger for Co 3d states and Al 3s states. Which indicates that the electron transition become more active from valence band to conduction band and the electrical conductivity is enhanced. Compared with intrinsic AlN, the optical properties of co-doped AlN improves a lot. There emerge some new peaks in the low energy region and the absorption coefficient, reflectivity and refractive index has large improvement in visible and infrared range.
Influence of Polymer Residues on the Double Resonance Process of Bilayer Graphene
Authors: Gong Xin , Jia Yue Hui , Peng Pei , Wang Zi Dong , Tian Zhong Zheng , Ren Li Ming , Fu Yun Yi
Published: April 2016

PMMA is commonly used for graphene transfer and device processing. However, it leaves a thin layer of polymer residues after standard acetone cleaning and causes electrical and thermal performance degradation of graphene devices. In this paper, we present a research of the impact of polymer residues on surface morphologies and electronic properties of bilayer graphene using Raman spectroscopy in combination with atomic force microscopy (AFM). The electronic structure of bilayer graphene is well captured in its Raman spectrum, of which the 2D band reveals four double resonance Raman scattering processes. The Raman analyses show universal blueshifts of the G band and the four 2D sub-bands P11, P12, P21, P22, as well as reduced intensity ratios of the sub-bands to the G band I(Pij)/I(G) after surface contamination by polymer residues, implying an electronic structure modulation in bilayer graphene. The effects are mainly attributed to p-type doping and extrinsic scattering induced by residual impurities and defects.
Effects of γ-Ray Irradiation on the Properties of Nano-Hydroxyapatite/Polyurethane Composite Porous Scaffolds
Authors: Jiang Jia Xing , Li Li Mei , Lin Li Li , Zuo Yi , Li Yu Bao , Li Ji Dong
Published: April 2016

To well understand the influence of the sterilization on the properties of biomaterials prior to application is pivotal. The effect of γ-ray irradiation on the mechanical and thermal properties of nanohydroxyapatite/polyurethane (n-HA/PU) porous scaffold for bone tissue engineering was studied in this paper. The mechanical testing, fourier transform infrared spectroscopy and thermal analysis were employed to determine the structure and properties change of these composite scaffolds after γ-ray irradiation with different doses.The results show that thermal stability, and mechanical properties of the composite scaffolds increase after γ-ray irradiation with doses of15 kGy to 25 kGy, especially the irradiation dose of 15kGy which imposed a remarkable effect on these properties. However, a reverse trend is found when the 50kGy irradiation dose was applied.In general, it can be concluded that sterilization using γ-ray irradiation with proper dose has no adverse effect on the properties of n-HA/PU composite scaffolds.
Microstructure Evolution of Hybrid TiO2 Nanowire-Nanotube Structure Fabricated by Anodization
Authors: Li Yun , Wang Nan Nan , Cheng Hai Feng , Zhou Yong Jiang , Li Ting Ting
Published: April 2016

Hybrid TiO2 nanowire–nanotube structure was synthesized by a facile anodization on Ti substrate. To study the origin and evolution of TiO2 nanotubes, the morphology of TiO2 nanotubes was investigated. It was found that nanotubes corrode gradually into nanowires, and the critical time was about 8.5 h after the beginning of anodization. Uniform nanotubes were obtained by ultrasonic cleaning. It was demonstrated experimentally that the inner diameter of TiO2 nanotube increased with the extension of anodization time, but the outer diameter of TiO2 nanotubes, which were fabricated under different anodization time, was almost the same.
Study of the Mechanical Deformation of Transforming Nanowires Constrained in Metal Matrix
Authors: Zheng Bin , Du Hui Ling
Published: April 2016

We report the results of a simulation study of the mechanical deformation of NiAl nanowires constrained in Al metal matrix. The constrained nanowires showed high elastic yield stress and nonelastic stretching via a transition from the B2 to BCT phase. The phase transformation mechanism was that of atomic shuffling, via the appearance, spreading, and aggregation of isolated defect atoms, instead of dislocation movement. Because of geometry constraints, the interphase energy between the new and parent phases is not readily released, which results in strain hardening.
Effects of Various Fluxes on Synthesis of Deep Red Emitting CaAl12O19:Mn4+ Phosphors
Authors: Zhang Qiu Hong , Ni Hai Yong , Wang Ling Li , Xiao Fang Ming
Published: April 2016

Deep red emitting CaAl12-xO19:xMn4+ phosphors were synthesized by solid state reaction method. Various fluxes (BaF2, H3BO3, Na2CO3 and NH4Cl) were added in preparation of the phosphors. The influences of the various fluxes on the crystal structure, morphology and luminescent properties of CaAl12O19:Mn4+ phosphors were studied. The results show that the obtained phosphors with fluxes possessed better luminescent intensity than that of the phosphors without fluxes. The maximum luminescent intensities were found with the following order: H3BO3 (2.0 wt%) > Na2CO3 (0.5 wt%) > NH4Cl (0.3 wt%) > BaF2 (0.1 wt%) > no flux. The H3BO3 flux can decrease the single phase forming temperature of CaAl12O19:Mn4+ phosphors by about 150°C.
A General Process for In Situ Formation of Iron-Matrix Composites Reinforced by Carbide Ceramic
Authors: Wang Xin , Zhong Li Sheng , Zhao Na Na , Ovcharenko Vladimir E. , Xu Yun Hua
Published: April 2016

Ceramic particles (such as VC, NbC, TiC, and WC), which exhibit high hardness and thermal stability, can be used for in situ fabrication of carbide-reinforced iron matrix composites with high macro-hardness and toughness. In this study, we describe a novel in situ process comprising infiltration casting and heat treatment to form carbide-reinforced iron matrix composites with hard ceramic particles. Our proposed approach was used to integrate different alloy wires, which can easily form carbides, into the metal matrix and cast a known amount of carbon, such as gray cast iron, ductile cast iron, or ordinary white cast iron, to form alloy-reinforced iron matrix composites. Thermal treatment of the resulting composites allowed the alloy elements of the wire to react with carbon in the matrix to form evenly distributed carbide particles. This approach can be applied to a wide range of materials with different morphologies for fabricating composites, machining tools, and wear-resistant components.
General Process for In Situ Formation of Iron-Matrix Surface Composites Reinforced by Carbide Ceramic
Authors: Zhang Xi , Zhong Li Sheng , Zhao Na Na , Ovcharenko Vladimir E. , Wu Hong , Xu Yun Hua
Published: April 2016

Ceramic particles with high hardness and thermal stability can be used to fabricate in situ carbide particulate-reinforced iron-matrix surface composites with high macro-hardness while retaining high toughness. This paper describes a general process by which in situ carbide particulate-reinforced iron-matrix surface composites with hard ceramic particles are readily formed by a novel in situ synthesis process that combines an infiltration casting process with subsequent heat treatment. The basis of our approach is integrating selected plates of different alloys that can form carbide easily into a metal matrix with a certain amount of carbon such as gray or ductile cast iron by casting to form alloy plates reinforced iron-matrix surface composites. Subsequent thermal treatment of resulting composites leads to alloy elements of plate reacting to the carbon in the matrix to form carbide particles. This approach is applicable to a wide range of materials and morphologies, and can be used in composites and machining tools, as well as in the wear-resistant component industry.
Influence of Ce on Microstructures and Mechanical Properties of HMn64-8-5-1.5 Brass
Authors: Wang Zi Wen , Chen Shao Hua , Li Yan Feng , Peng Li Jun , Xie Hao Feng
Published: April 2016

The rare earths are important modifier in copper alloy. This paper did research about the effect of Ce on microstructures and mechanical properties of HMn64-8-5-1.5 brass. The addition of Ce can refine the matrix grain of as-cast and extruded HMn64-8-5-1.5 brass, reduce the size and quantity of big hard phase , and contribute to the extraction of tiny hard phase, such as Mn5Si3 phase. When given tensile stress, hard phases can produce crack initiations. The addition of rare earth Ce can increase the number of hard phase and thus produce more crack initiations, so that the mechanical properties of HMn64-8-5-1.5 brass can be reduced.
Low-Cost Preparation of Graphene Quantum Dots by Liquid-Phase Exfoliation of Carbon Fibers
Authors: Zhang Yu Min , Zhang Jin , Zhu Zhong Qi , Liu Qing Ju
Published: April 2016

Graphene quantum dots, a kind of advanced carbon material, have become the frontier of condensed matter physics and material science. Here, we develop a plain and cheap preparation of graphene quantum dots by liquid-phase exfoliation of carbon fibers, which were prepared from absorbent cotton through an annealing process at 1000°C. The structure, micro morphology, chemical bond and optical properties of the as-prepared graphene quantum dots were characterized. Results show that the as-prepared graphene quantum dots present a green luminescence and have a narrow size distribution of 3-10 nm.
Improved Dehydriding Properties of NaMgH3 Perovskite Hydride by Addition of Graphitic Carbon Nitride
Authors: Tao Song , Wang Zhong Min , Li Jia Jun , Deng Jian Qiu , Zhou Huai Ying , Yao Qing Rong
Published: April 2016

NaMgH3 perovskite hydride and graphitic carbon nitride (g-C3N4) powder with multi-layer structure have been synthesized by high-energy ball-milling and heating-decomposition method respectively. In comparison with pristine NaMgH3 hydride, the as–milled NaMgH3+5wt.% g-C3N4 (NMH-5CN) composite presents better dehydriding kinetic properties and lower onset decomposition temperature. The onset decomposition temperature of NMH-5CN composite can be decreased about 87K, the hydrogen-desorbed amount is about 3.2 wt. % within 40min, and 1.4 wt. % within 10min at 638K, and the Kissinger analysis demonstrated that the activation energy (ΔE) of the first and second dehydrogenation step for NMH-5CN can be reduced about 40 kJ mol-1 and 22.4 kJ mol-1, respectively. The results suggest that g-C3N4 is an effective catalyst for the improvement of dehydriding properties of NaMgH3 perovskite hydride.
Effect of Different C Aids on the Formation of ZnO by Microwave Solid Reaction
Authors: Wang Yan Zhi , Liang Bao Yan , Zhang Wang Xi , Feng Yan Xiang , Mu Yun Chao
Published: April 2016

ZnO nanometer materials were synthesized by microwave reaction from ZnO micrometer powders with different C aids. Effect of C style on the morphology of ZnO products was studied. The result show that ZnO nanometer materials can not be formed by using directly high temperature evaporation from ZnO micrometer powders without C aids. Fine ZnO nanometer crystals can be obtained by using carbon black as aids. In this sample, most ZnO grains were nanometer particles with a size of about 100nm. And a small amount of ZnO grains were short rods with a length of 1~2μm and a average diameter of 100nm. Amounts of short columnar and long zigzag ZnO crystals can be obtained by using graphite as aids. One effect mechanism of ZnO crystalline was proposed. ZnO reacted C to form CO and CO2 gas. Concentration of CO/CO2 directly effects the morphology of ZnO in the products.
Research and Analysis on Dispersing Performance of Nano-TiO2 Powder in Water
Authors: Kuang Ya Chuan , Liang Wen Lei , Ji Xiao Yong
Published: April 2016

Due to the characteristics such as fine grain, large surface area, high surface free energy and serious insufficient of atomic coordinate, nanoTiO2 is easy to conglobated in solution and further affect its application seriously. The agglomerate mechanism of nanoTiO2 in solution was studied and the reason of agglomeration was analyzed. Experiments were conducted to research the influence law on dispersing stability of nanoTiO2 powder in water by factors of dispersant type, dispersant content and dispersing process of ultrasonic dispersing and high-speed stirring. The dispersing stability of nanoTiO2 powder in water is evaluated by combining gravity deposition method with electronic microscopy analysis. According to the research, dispersant type and dispersant mixing amount have great influence on the dispersing property of nanoTiO2 powder, and the inorganic dispersant sodium tripolyphosphate achieved better dispersing effect. Furthermore, ultrasonic dispersing and high-speed stirring can improve the dispersing stability of nanoTiO2 powder and after high-speed stirring at first and then ultrasonic dispersing, the dispersing effect of nanoTiO2 powder is much better.
Separation of Particles of Rare Earth Oxides by Dielectrophoresis
Authors: Chen Hui Ying , Hu Jing , Zhang Jian , Guo Kai , Li Yao , Lan Bi Hao
Published: April 2016

A major challenge in chemical engineering is the separation and purification of materials, especially of rare earth compounds. It has been reported that a dielectrophoretic (DEP) apparatus can be used for separating rare earth oxides. The DEP capture of REOs on screen electrode was observed with microscope. The concentration of ROEs was determined using a nephelometer and ICP-OES before and after injection into the DEP apparatus. The results show that three types of REOs, La2O3, CeO2 and Dy2O3, generate nDEP in the DEP capture apparatus. There are two factors: voltage and suspension concentration, that affect the capture rate. The capture rate increases as voltage rises within certain limits. The capture rate also increases with increase in the original suspension concentration. Different REOs show marked differences in the DEP capture conditions. Consequently, factors such as voltage and flow rate can be controlled to achieve separation of different REOs.
Oxidation of Formaldehyde over Birnessite-Type Manganese Oxides at Room-Temperature
Authors: Feng Li Li , Wang Jie , Han Xiao , Wang Hai Bo
Published: April 2016

A series of manganese oxides (Me-OL-1s, Me: Mg, Fe, Ni and Cu) were synthesized by static hydrothermal and ion-exchange method. The as-prepared samples were characterized by means of X-ray diffraction (XRD), Raman spectroscopy (Raman) and Scanning electron microscope (SEM). The catalytic activity of the Me-OL-1 samples for the formaldehyde degradation was investigated at room temperature. The synthetic Me-OL-1s belong to birnessite-type manganese oxides. All the Me-OL-1 catalysts show the activity for the catalytic oxidation of formaldehyde at room temperature and exhibit the activity order of Fe-OL-1 > Ni-OL-1 > Cu-OL-1 > Mg-OL-1. The removal rates of formaldehyde are increased with increasing contact time.
Research Development in Synthesis Methods of Silver Nanowires
Authors: Liu Bi Tao , Ge Liang Sheng , Xu Jia Fu , Jin Rong , Yang Liu , Tu Ming Jing
Published: April 2016

In this paper, the synthesis methods of silver nanowires including template, self-assembled, hydrothermal synthesis and polyol methods are reviewed. In addition, the application and development of the silver nanowires are introduced.
Investigation on the Reduction of Ilmenite at Lower Temperatures
Authors: Chen Min , Xiao Xuan
Published: April 2016

The solid state reduction of ilmenite was studied using thermogravimetric analysis by a combination of XRD, SEM& EDS methods. Results showed that MgTiO3 was the main impurity and influenced the reduction process of ilmenite. When the temperature was below 1000°C, reduction was controlled by the chemical reaction and the activation energy was 163 kJ/mol. Pretreatment of milling accelerated the solid reduction rate.
Controlled Synthesis and Ceramization of Well-Defined Fe/Si/C Ceramic Precursors by Living Anionic Polymerization
Authors: Zhang Qian Ce , Gou Yan Zi , Wang Yi Fei , Mao Teng Fei , Wu Nan , Tong Xuan
Published: April 2016

Two kinds of iron-containing ceramic precursors, PFS and PS-b-PFS, were synthesized via living anionic polymerization by using ferrocenyldimethylsilane and styrene as the monomers. The structures, elemental compositions and molecular weights were characterized by FT-IR, NMR, EDS and GPC, respectively. The homopolymerization of ferrocenyldimethylsilane was simulated using computational chemistry method. The copolymerization between ferrocenyldimethylsilane and styrene was investigated by altering the ratio between monomers and initiator (n-butyllithium). The experimental results indicated that the Mn, Mw and PDi of homopolymer PFS were 6.91×103 g/mol, 8.29×103 g/mol and 1.20, respectively. Moreover, the molecular weight, structure and composition of block copolymers PS-b-PFS, were successfully controlled by changing the ratio of styrene, n-butyllithium and ferrocenyldimethylsilane. Subsequently, using such iron-containing polymers as precursors, Fe/Si/C ceramics were obtained after sintering at 1400°C. The microstructures, morphologies and elemental compositions of ceramics were characterized by SEM and EDS. The results implied the controllable preparation of spherical Fe/Si/C ceramics was achieved via the self-assembly of precursors.
Evaluation of Thermal Degradation of High Density Polyethylene by Principal Component Analysis
Authors: Guo Jun Jun , Yan Hua , Dai Jun , Hu Zhi De , Yang Jian Jian
Published: April 2016

Principal components analysis (PCA) is a data analysis and reduction technique widely used in the method of statistical analysis,elucidation of the variation of five mechanical properties (tensile strength, bending strength, impact strength, tensile modulus and bending modulus) and five microstructure properties (carbonyl index, hydroxyl index, branching degree, chain scission degree and unsaturated value) that taken place when subjected to ultraviolet (UV) aging of high density polyethylene (HDPE) used as rotational packaging case by using PCA. The information of main components were extracted and studied. Also the relationships between performance properties were considered. Finally, the combined evaluating parameter Z was established and analyzed. The results show that the first and second components extracted by PCA can be determined on behalf of all components. Among the 10 performance parameters, tensile strength, bending strength and impact strength are strongly correlated, carbonyl index, hydroxyl index, branching degree and chain scission degree are strongly correlated, and the tensile modulus is non-correlated to other performance parameters. The trendy of the evaluating parameter Z show that the HDPE aged quickly in the first 20 days and leveled off in the following days.
Promoting Effect of Chemical Self-Assembled Polyaniline Nanofibers and Electro-Polymerized Polyaniline in Formic Acid Electro-Oxidizing Reaction
Authors: Yang Yong Sheng , Zhao Feng
Published: April 2016

In order to enhance catalytic properties of palladium or gold/palladium alloy on polyaniline surface, highly pure PANI nanofibers doped with phosphoric acid were synthesized via chemical self-assembled method. Its general morphology was observed by scanning electron microscopy analysis. The deposition of palladium or gold/palladium alloy on PANI nanofibers was accomplished through reducing reaction of PdCl2 or PdCl2/HAuCl4 in aqueous solution by NaBH4. Pd/PANI nanofibers or Au/Pd/PANI nanofibers have been evaluated for catalytic activity toward formic acid oxidation reaction. Palladium/PANI nanofibers or palladium/gold/PANI nanofibers on glass carbon electrodes exhibit effective electro-catalytic activity since the PANI nanofibers play excellent promoting role.
The Effects of Pb, Bi on the Anodic Properties of Al-Zn-Ga-In Series Alloy
Authors: Qian Xue Rong , Kong Xiao Dong
Published: April 2016

The electrochemical properties of Al-Zn-Ga-In-(Pb/Bi) anode alloy are studied by electrochemical test, including constant current test, polarization curve test, AC impedance test. Metallographic microscope is used to observe the microstructure of the alloy . energy spectrum technical is used to analyze the second phase elements. The results showed that the adding of element Pb or Bi both can attain more negative open-circuit potential; the adding of Bi makes the working potential shift positively, and reduces the current efficiency; 2% Pb content can attain more negative working potential, and current efficiency are increased slightly; the series anode the morphology of dissolution relatively uniformly in 3% NaCl solution; anodic polarization are all relatively smaller than cathodic polarization, and they have good anodic polarization properties. The overall electrochemical properties of Al-3Zn-0.015Ga-0.025In-2Pb alloy are the best in these five aluminum alloy anode.
The Preparation of Comb Polymer Rotaxanes and Study on their Self-Assembly Behavior
Authors: Sun Li , Zhu Lin , Xie Jun Peng , Guan Rui Fang
Published: April 2016

It is very important to form a stable, structure-controlled material by molecular assembly inthe fields of materials and life science. How cyclodextrins affect the self–assembly behavior of inclusion compounds becomes the focus recently, due to the advantages of selectivity, regulating, capability, biocompatibility and other interesting properties. In thispaper, polyoxyethylene ω-tristyrylphenyl methacrylate (SEM-25) and α-cyclodextrin (α-CD) form inclusion compound (AS) firstly, then copolymer of AS and methyl methacrylate (MMA) - the comb-like polyrotaxanes (CD-PR) were prepared through the redox initiationsystem of free radical polymerization. Furthermore, the self-assembling behavior of CD-PR is studied, it is found that solvent has an great impact on aggregation morphology of CD-PR without changing composition of the polyrotaxanes. Products were characterized by X-ray diffraction (XRD), nuclear magnetic resonance (1H NMR) and scanning electron microscope (SEM).
Study on the Synthesis and Properties of MAH-POE/LMW-EP/PP/CaCO3 Quadruple Composites
Authors: Wu Yu Liang , Zhang Xiao Bo , Ge Yi
Published: April 2016

This paper adopted the mixing modification to prepare MAH-POE/ LMW-EP/PP/CaCO3 thermoplastic composites, probed into the structure of composites, the system compared the modification made by composites and the single system of the rheological property, the influence law of flow rate, mechanical properties, dynamic mechanical thermal analysis (DMTA) and the network structure of the composite material etc. The results showed that the elastomer was preferably dispersed in the PP, the two phases have a strong interaction force, When the content reaches 20%, the tensile strength decreased by 7.37%, the elongation at break increased by 410.1%, the impact strength reached 546.3J.m2, there has been broad and strong low internal friction peak tanδ2 peak, and with the increase of elastomer content, liquidity blends decreases, MFR decreases. In short, quadruple composites have optimum overall performance.
Polypropylene (PP) is a source of abundant, excellent mechanical properties, good electrical insulation, and resistance to stress cracking and has good overall performance excellent chemical stability thermoplastics. Widely used in medical equipment, auto parts , building materials, home office supplies, as well as a large number of transport and packaging materials [1-3] . However, due to the strong ability of PP crystallization, resulting PP mold shrinkage, impact toughness is poor [4-5] , in order to solve this problem , the current modification methods often used are: copolymerization and blending modification , and blending is the most simple and effective toughening PP method . The main focus ① blended with a modified rubber or thermoplastic elastomer blends toughening ; ② Toughening with other organic polymers ; ③ rigid inorganic particle toughening ; ④ elastomer / toughening common inorganic particles [6-10] . POE because both thermoplastic plastics , but also the crosslinkable rubber , which has a small cohesive energy , high shear sensitivity , and good compatibility with PP machining , toughening modification of PP the effect is significant and widespread attention , but the larger POE elastomer modified PP viscosity , processing performance be affected [11-13] .
In this paper, LMW-EP and MAH-POE-modified PP, while adding CaCO3 prepared by a four-element composite elastomer material, by contrast, explores the compatibility of the quaternary blends, processing fluidity and mechanical properties
Thermal Properties of Poly(Lactic Acid) Modified Poly(3-Hydroxybutyrate-co-4-Hydroxbutyrate)
Authors: Li Mei , Li Zhi Qiang , Shao Wei
Published: April 2016

The thermal properties of poly (lactic acid)[PLA] modified poly (3 –hydroxybutyrate –co-4 -hydroxbutyrate) [P(3HB-co-4HB)], prepared by melt blending with different blending ratios were investigated by differential scanning calorimetry [DSC], thermogravimetry [TGA], melt flow rate [MFR] and tensile test measurements, and scanning electron microscopy [SEM]. The DSC tests showed that the glass transition temperature, Tg, of P(3HB-co-4HB) increased from-7°C to 56°C when mixed with 50% to 67% of PLA. A decrease in crystallization temperature, Tc, of P(3HB-co-4HB) broadened the melting interval. The MFR tests indicated the blends had good flow properties and the variation of the PLA content had little effect on the flow properties. The tensile tests showed that PLA improved the mechanical properties of P(3HB-co-4HB), including the tensile strength and elongation at break. The blends had the best mechanical properties when the percentage of PLA was 64%.
Reduce the Leakage Current of High Voltage Polymer Ta Electrolyte Capacitors
Authors: Tian Dong Bin , Pan Qi Feng , He Xiao Zhou , Zhang Xuan Hong
Published: April 2016

The leakage currents of high nominal voltage conductive polymer tantalum (Ta) electrolytic capacitors are the difficulties in the research and development processing. The optimized and improved forming technical of increasing current density with the voltage rising was used in the present paper, and silane coupling agent has been used to the dielectric surface of the electrode body before polymerization, and conductive slurry was used to forming the cathode electrolyte of capacitors. Low leakage currents and high breakdown voltage have been tested; otherwise, the endurance capabilities of reverse voltage have prodigious enhanced.
Development and Adsorption Properties for a Novel Lithium Ion-Sieve
Authors: Yang Shan Shan , Zhou Ma Li , Wu Jia Qi , Shen Jiang Nan , Gao Cong Jie
Published: April 2016

The lithium ion-sieve precursor was prepared with LiOH and Mn (CH3COO)2 as the starting reagents, H2O2 as the oxidant and ethanol solution (volume percent 2.5%) as solution by combination of sol-gel, hydrothermal and low-temperature solid state methods, and then changed into lithium ion-sieve after eluting Li+ by the mixture of HCl and Na2S2O8 solution. The influence of synthetic conditions on the structures and adsorption properties of lithium ion-sieve was investigated in detail. The results suggest that the pure phase lithium ion-sieve can be synthesized when Li/Mn molar ratio is 3/1, 3.2mL H2O2 is added after LiOH and Mn (CH3COO)2 react for 36h and the heat treatment way of programmed temperature from 410°C (2h) to 510°C (3h) is adopted in the progress of solid state reaction. The loss rate of dissolved Mn is less than 2.5% during pickling Li+. And the highest adsorption capacity can achieve 20.5mg/g.
Study on the Doped 1-Bromo-4-Nitrobenzene at Active Layer in Improving the Performance of Organic Polymer Solar Cells
Authors: Yang Shao Peng , Wei Li , Wang Tie Ning , Liu Bo Yang
Published: April 2016

The paper studied the effect on the performance of organic polymer solar cells at the active layer based on P3HT/PCBM from the addition of a solid derivative of nitrobenzene, 1-Bromo-4-Nitrobenzene, carried out experiment on 1-Bromo-4-Nitrobenzene doped with different doses in P3HT/PCBM active layer, and comparatively analyzed the performance parameters, absorption intensity, external quantum efficiency, fluorescence intensity, morphology characterization, and transient absorption of devices under different doses. Results showed that the organic polymer solar cells reached the maximum energy conversion efficiency, the energy conversion efficiency was improved from 2.2% to 3.4%, with an increase of 54 %, when the additive volume of 1-Bromo-4-Nitrobenzene was 25wt%. Addition of 1-Bromo-4-Nitrobenzene helped to improve the photoelectric conversion efficiency of organic polymer solar cells.
Study on the Hydrophobic Modification of Ammonium Polyphosphate and its Application in Flame Retardant Polypropylene
Authors: Tian Dong Bo , He Yong Jun , Wang Ting Ting , Gao Xiao Ning , Wang Qing , Liang Yao Dong , Guo Xiao Bin
Published: April 2016

In this paper, ammonium polyphosphate (APP) was modified by methyl hydrogen silicone oil and gas hydrophobic silica, hydrophobic ammonium polyphosphate (HAPP) was prepared. Then, HAPP was separately mixed with starch and melamine were introduced into polypropylene as flame retardants to prepare polypropylene (PP) retardant materials. The hydrophobic retention was of HAPP above 90%. According to the results from testing its wettability, its contact angle was 140.69°, which was increased by about 120°compared with APP, and this indicated the HAPP had better hydrophobic properties than that of the unmodified. And a comprehensive analysis is conducted on the scanning electron microscope (SEM) and infrared spectroscopy (FTIR).The results showed that the surface of APP is coated with methyl hydrogen silicone fluid and gas hydrophobic silica. The limited oxygen index (LOI) of the flame retardant PP material is measured by the oxygen index tester, and at a total flame retardant loading of 33wt%, the LOI value of PP retardant materials can achieve 29%, indicating that this flame retardant can better make the PP into the stable charred layer, and improve the performance of the flame retardant PP material greatly.