bluuebunny/crossref_metadata_2025 huggingface dataset:
Review of Polymer Surface Modification Method
Authors: Yu Li Yuan , Zhu Bo , Cai Xun , Wang Yong Wei , Han Rong Huan , Li Yong Wei
Published: April 2016

This paper reviewed a variety of methods of polymer surface modification, which mainly includes Solution processing method, Plasma treatment，Surface grafting method，Irradiation treatment and method of Atomic force microscopy probe shock , and the specific polymer material combined with the modification method and its modification mechanism was introduced in detail.Polymer has very extensive application both in chemical fields and in daily life, but due to its poor surface hydrophilicity and wear resistance, the further application of polymer materials were limited. In order to improve its surface properties, modification are needed on the surface of the polymer. Polymer surface modification means to operate on the surface of polymer within the scope of nanometer level, and give some new properties on material surface, such as hydrophilicity, scratch resistance, under the premise of without affecting the material ontic properties.There are many methods of polymer surface modification. This paper reviewed Solution processing method, Plasma treatment，Surface grafting method，Irradiation treatment and method of Atomic force microscopy probe shock . Different methods of modification combined with specific materials are introduced as follow.
Preparation and Organic Solvent Resistance of Water Soluble Hydantoin Epoxy/Organic Titanium Chelate Composite Coatings
Authors: Tang Gong Wen , Yan Zhi Shan , Huang Xin
Published: April 2016

As worldwide environmental and ecological regulations become strict, water soluble system presents great potential in the new VOC-compliant, high-performance anticorrosive coating systems. In this study, hydantoin epoxy resin (HE) was first synthesized. Then HE/titanium bis (triethanolamine) diisopropoxide (TE) composite resin was obtained by mixing HE and TE at a certain temperature. The structure was characterized by 1H nuclear magnetic resonance (NMR) and fourier transform infrared spectroscopy (FTIR). The curing behavior and thermal stability were assessed with differential scanning calorimetry (DSC) and thermo gravimetry (TG) analysis. The mechanical properties of the cured coatings were discussed under the corresponding standards. The chemical resistance properties were tested by immersion test. Our study revealed that the HE/TE composite resin was water soluble and could be self-cured by heating. It possessed well thermal resistant properties, excellent physical and mechanical properties, and good chemical resistance, which made it suitable for the surface coating industry.
Preparation and Performance Research of New High Toughness EVA Material
Authors: Yang Xiao Li , Wang Huai Qing , Lv Le , Yuan Sheng Lei , Cai Jian , Zhou Liu Yu
Published: April 2016

The blends of ethylene vinyl acetate (EVA) and thermoplastic polyurethane (TPU) were prepared by means of blending. The mechanical properties of EVA/TPU blends and thermal stability of the extrudates were investigated. The results show that the toughness of EVA/TPU has been improved after adding TPU into EVA, and doesn’t affect the thermal stability of material.
Preparation and Application of Colemanite Matrix Complex Flame Retardant
Authors: Zhong Jian Chu , Cui Yun Xia , Zhu Jun , Wang Hong Zhi
Published: April 2016

In this paper, stearic acid, titanate coupling agent (NDZ-311) and silane coupling agent (KH-570) were selected as modifiers to modify colemanite powder and the resulted products were characterized by XRD and FT-IR. The results show that the surfaces of colemanite particles were effectively modified by stearic acid and coupling agents. The modified colemanite /EVA composites were then prepared and the effect of coupling agent addition on the mechanical properties and flame retardancy of EVA composites was investigated. The EVA composite doped with 40% of modified colemanite (coupling agent accounting for 1% of colemanite mass) exhibits a tensile strength of 9.80MPa, a breaking elongation of 696.5% and a limit oxygen index of 29.6%. The complex flame retardant was obtained by means of grafting amine polyphosphate onto the surface of colemanite using polyphosphoric acid (PPA) and laurylamine as raw materials. The obtained product was analyzed by XRD and FT-IR. The EVA composite doped with 40% of the complex flame retardant has a tensile strength of 8.57MPa, a breaking elongation of 671.3% and a limit oxygen index of 32.6%.
Effects of Modified-Phenolic on the Tribological Properties of Carbon Fiber Reinforced Phenolic Friction Materials
Authors: Li Wen Bin , Huang Jian Feng , Fei Jie , Wang Wen Jing , Cao Li Yun
Published: April 2016

In order to make clear the effects of modified-phenolic on the tribological properties, three kinds of carbon fiber reinforced phenolic friction materials (cashew-modified phenolic, boron-modified phenolic and chemigum-modified phenolic) were fabricated with the ethyl alcohol as the solvent by vacuum filtration. The tribological properties of samples were studied by the QM1000-II wet friction performance tester. The scanning electron microscope was employed to analyze the micro topography of specimens. Results show that the dynamic friction coefficient and variable coefficient of cashew-modified phenolic friction materials are better than other two materials. The temperature is the most stable during the continuous engagements. The friction torque curve is the smoothest and most symmetrical. Thus, the comprehensive performance of cashew-modified phenolic friction materials is excellent.
Effect of Electric-Field on Spin Injection Efficiency in the Organic Semiconductors
Authors: Mi Yi Lin , Gao Jiang Nan
Published: April 2016

The spin injection efficiency in the ferromagnet/ organic semiconductors system (FM/OSE) was studied under an external electric-field. It is found that the spin injection efficiency can be strongly influenced by the spin-dependent electrical conductivity and the downstream spin diffusion length of polarons. With the increase of external electric-field, the downstream spin diffusion length increases and makes the spin-dependent electrical conductivity increase, too. So the spin injection efficiency is enhanced. When the external electric-field increases from 1 to 10 mV/μm at T=80K, the spin injection efficiency increases about 20%. It seems that the downstream spin diffusion length is an significant factor to affect the spin injection efficiency in the FM/ OSE under an external electric-field.
Progress of Graphene-Based Hydrogel
Authors: Xiang Yu , Liu Li Bin , Dang Zhao , Li Ting
Published: April 2016

Graphene, a typical two-dimensional planar monolayer of sp2carbon atoms, has attracted significant attention due to its outstanding physical and chemical properties. Nowadays, many graphene-based composites have been synthesized. Among them, graphene hydrogels (including graphene oxide hydrogel and reduced graphene oxide hydrogel) as a kind of graphene-based composites have a wide application prospect. In this paper, the progresses of graphene-based hydrogels are reviewed, and the prospects for the development of graphene-based hydrogels are also discussed.
Research of Atom Transfer Radical Polymerization of Methyl Polypropylene
Authors: Xu Yu Qing , Ke Yong , Hu Xiao Yong , Cui Jin , Lin Zhi Yuan , He Ming Jun
Published: April 2016

The methyl polypropylene was prepared bsaed on toluene as solvent, cuprous bromide (CuBr) / copper bromide (CuBr2)/tris (2-dimethylaminoethyl) amine (Me6TREN) as catalyst, azo dimethoxyisoquinolin heptanenitrile (V-70) as radical additive, 2-bromoisobutyrate (EtBiB) as initiator. The polymerization reaction was initiated by using the ultimate atomic radical polymerization (UATRPSM), whose chain reaction was manifested in linear first-order kinetics. In this study, the conversion of monomers, polymer dispersion coefficient and the relative molecular weight with monomer conversion rate changes were studied by gas chromatography (GC) and gel permeation chromatography (GPC). The results show that the final monomer conversion was 87%; with increasing monomer conversion, polymer dispersion coefficient (PDI) decreases and reaches the optimum value 1.19, while the relative molecular weight of the linear growth, and prove the reaction was precise control.
Contrast between Modification Methods for Magnetism Absorbents
Authors: Wu Chao , Cao Xue Song , Ji Jing Chang , Zhong Wei
Published: April 2016

Two methods are widely used to improve absorbing properties of the microwave magnetism absorbing agent: mixing with the other material such as resistance carbon fiber absorbent, or wrapping the microwave magnetism-absorbing agent in that material. However, do these two methods coincide with each other If not, which method should be used as better way to represent the absorbing properties of magnetism-absorbing agents To answer these questions, both methods are carried out on the same magnetism absorbing agents, of which the results are compared. Distinct difference between these measured results is found, and the possible reasons for the difference are also discussed.
Studies on Photoreactive and Fluorescence Properties of Polymers Composed of 3-Hydroxycinnamic Acid and Lactic Acid
Authors: Li Ji Hang , Zhou Xing , Yao Hui , Feng Fang
Published: April 2016

In this paper, a series of novel copolymers with photoreactive and fluorescence properties known as poly (3-hydroxycinnamic acid-co-lactide acid) (P(3HCA-co-LA)) were obtained by the thermal melt-polycondensation of 3-hydroxycinnamic acid and lactide acid. The chemical structures and average molecular weight of the P(3HCA-co-LA) copolymers were analyzed by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (1H NMR) and gel permeation chromatography (GPC). The P(3HCA-co-LA) copolymers showed good photoreactivities and fluorescent properties. Isomerization and [2+2] cycloaddition of the cinnamoyl groups occurred under UV irradiation. Furthermore, fluorescence intensity could be controlled by controlling the composition of P(3HCA-co-LA) copolymers.
Synthesis and Characterization of Phenanthroimidazole Derivatives as Light-Emitting and Ambipolar Materials
Authors: Liu Ya Jing , Zhao Xin , Qi Yu , Shao Jing , Wei Huai Xin
Published: April 2016

Novel phenanthroimidazole derivatives were designed and synthesized for in electroluminescent devices. They were characterized by means of 1H, 13C NMR, FTIR. The optical, electrochemical and thermal properties were also investigated. The relationship between the chemical structure and the properties of these materials was evaluated. Due to the conversion of the substituents onto the 2-imidazole position to the phenanthroimidazole ring, these compounds exhibite efficient emission from blue to yellow-green, red shifs in absorption and photoluminescence spectra. With respect to thermal properties and the oxidation potentials, it can be turned by varying the conjugation length of compounds and the length of alkyl chains. Mostly, all four compounds have suited HOMO and LUMO values, which can be used not only hole-transporting but also electon-tansporting materials in OLEDs.
High Sensitive and Selective Acetone Gas Sensor Using Molecular Imprinting Technique Based on Ag-LaFeO3
Authors: Du Teng Fei , Zhang Yu Min , Zhang Jin , Zhu Zhong Qi , Liu Qing Ju
Published: April 2016

Acetone is a highly volatile and colorless transparent liquid which is frequently and quantitatively represented in the composition of coatings, paints, adhesives and cleaning materials[1,2]. As good solvent and raw material for organic synthesis, acetone can volatilize easily and cause damages to eyes, noses, and central nervous system when the concentration is higher than 450 mg/m3 (173 ppm). Besides, acetone in human breath is a biomarker for diagnosis of diabetes[3]. Medical investigations have shown that the acetone concentration in exhaled breath from a healthy human body is lower than 0.8 ppm, while that for a diabetic patient is higher than 1.8 ppm[4–6]. Therefore, the development of gas sensors for rapid and selective detection of acetone attracts the interest of researchers in recent years. For the current contribution, lanthanum ferrite (LaFeO3) has been selected because of its good thermostability[7], controllable structure[8] and selectivity[9-10] for acetone.
Design Principles of Surfactants for Polymerization in Supercritical CO2
Authors: Zhan Shi Ping , Qi Qing Chun , Zhao Qi Cheng , Chen Shu Hua , Hou Wei Min , Ding Shi Qiang
Published: April 2016

In recent years, supercritical carbon dioxide, as a green chemical solvent, is widely used. The surfactants for polymerization in supercritical fluids have become one of the important issues. This paper mainly discusses the mechanism and influence of the surfactants in supercritical carbon dioxide system. The choice and design principle of surfactants and the recent development of surfactants were introduced in detail.
Study on Surface Modification of Mica Pearl Pigment with Stearic Acid
Authors: Yu Qian , Ke Yong Le , Tan Xu Kun , Luo Gao Dan , Han Sheng Bo , Yu Lin , Luo Guo Qing
Published: April 2016

Using stearic acid as modifier, the surface of mica pearl pigment organic modification technology are discussed in this paper, and the application effect of after modified. X-ray powder diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy and Scanning electron microscope (SEM) were used to characterize the effect of surface modification. Electrostatic spraying test (EST) and Chromatism test were used to characterize the application effect of after modified. The results showed that the stearic acid could be successfully grafted on the surface of mica pearl pigment and enhanced hydrophobicity. Besides, it was demonstrated that the mica pearl pigment treated with stearic acid could make the value of chromatism deviation are low, which also could significantly improve the powder spraying ratio at low spray voltages.
Using Localized Impedance Spectroscopy to Study the Effect of Loading Potential Variation on DMFC Anode Performance
Authors: Huang Nai Bao , Li Wan , Liang Cheng Hao , Xu Li Shuang , Wang Xiao Ye , Sun Tian Hang , Sun Min
Published: April 2016

By localized impedance spectroscopy (LEIS) and electrochemical impedance spectroscopy (EIS), the effect of loading potential variation on the performance of direct methanol fuel cell ( DMFC ) anode was studied. During surface scanning, the local impedance of the anode showed sawtooth-like distribution under potential loading, which meant the electrochemical activity in the anode surface was nonuniform. Meanwhile, the local impedance tended to increase with loading potential increasing. After loading 16h and 72h at 0.6V, the average size of catalysts changed from 3.4nm to 3.6nm and 4.4nm, increased by 5.88% and 29.41%. After loaded for 72h under 0.8V, the ratio of Pt:Ru in catalyst changes from 2:1 to 3.9:1. It is the change of the difference in local area, which showed impedance increase, catalyst particle size growing up and agglomeration, the loss of Ru, that contributed to the performance decay of DMFC anode.
First Principles Calculations of Double Metal Amidoboranes
Authors: Wang Yang , Wang Qiang
Published: April 2016

Double metal amidoborans are considered to the most promising candidates for metal amidoborans. In this paper, the crystal structures, electronic properties, chemical bonds, hydrogen removal energies, and HOMO-LUMO of NaAB, NaLiAB, and NaMgAB have been studied. The GGA corrected density functional theory have been employed in the first principles calculations. Due to the alkali and alkali earth metals coexisting, the crystal structures of these compounds change significantly and the B–H, N–H and B-N bond lengths shorten. Moreover, the band structures and density of states of NaAB, NaLiAB, and NaMgAB were calculated. The charge density distributions and bond populations are used to understand the nature of bonding. The hydrogen removal energy states removing H(B) and H(N) from NaLiAB more easily than NaAB and NaMgAB. In addition, the frontier molecular orbital reveals that the intermolecular and intramolecular dehydrogenation of NaLiAB and NaMgAB may concur. The calculated HOMO-LUMO energy gaps suggest that the chemical reactivity is: NaLiAB> NaAB> NaMgAB.
The Chloride Annealing for Back Contact Layer Free CdTe Solar Cells
Authors: Jiang Meng , Liu Zuo Lei , Lei Zhi , Gu Qiong Yi , Zhu Jian Guo
Published: April 2016

The large area CdTe thin film samples were used for chloride annealing. The CuCl2/NH4Cl solution was attached on the CdTe surface. After annealing treatment, the CdTe solar cells were prepared. The structure of the thin films and the properties of the CdTe solar cells were tested for studying the effect of the ratio of Cu/Cl, solution concentration and the annealing temperature. At last the performance of CuCl2/NH4Cl annealing cells, ZnTe back contact cells and C:Te,Cu back contact cells were compared. Without back contact layers the efficiency of the CdTe solar cells reached 11.13% with chloride annealing.
Influence of Carbon Inclusion on the Electrochemical Performances for Si Using as the Lithium-Ion Battery Anode
Authors: Ban Yue Qin , Shao Wei Quan , Chen Sha Ou , He Li Zhu , Zhu Hai Ling , Feng Jia Jia , Guo Xiao Jie , Li Yan Qiang , Zhang Ying Nan , Zhao Hai Feng
Published: April 2016

Si/C composite was prepared using different procedures and different C sources in this work. According to the electrochemical performances, it was found that the discharge capacity for Si/C composite (SC1) by the electrostatic spinning procedure using polyvinylpyrrolidone as the C source was 2200mAh/g. In contrast, the cell with the pure Si particle exhibited an initial discharge capacity of only 13mAh/g. Moreover, after 30 cycles, SC1 sample had the higher capacities and the better capacity retention performances than other samples because of its lower charge transfer resistance. The inclusion of carbon not only worked as a stable electric conductive pathway but also buffer the volume expansion of the silicon during the process of charging and discharging.
Preparation and Performance Characterization of a Large Area ScSZ Electrolyte Substrate
Authors: Gou Man Li , Yang Guo Quan , Wang Zhen Hua , Sun Wang , Qiao Jin Shuo , Sun Ke Ning
Published: April 2016

A thin ScSZ electrolyte with a large area was synthesized using the tape-casting method. The conductivity of 0.095 S cm-1 at 800°C was achieved. The maximum power density of a single cell reached 368 mW cm-1 at 800°C. To make a large electrolyte battery more suitable, our study improves the casting method of preparing a dense, porous electrolyte substrate that promotes surface roughness of the electrolyte. However, it is difficult to control the thickness of the substrate, meaning that further improvements are needed.
Microwave Synthesis of MOFs/Graphene Oxide Composites and Hydrogen Storage Properties
Authors: Yang Tian Bao , Sun Li Xian , Xu Fen , Wang Zi Qiang
Published: April 2016

Metal-organic frameworks (MOFs: copper containing CuBTC)-graphene oxide (GO) composite (CG) was synthesized using microwave heating. The parent material and the composite were characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), nitrogen sorption, scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), Fourier transform infrared spectroscopy (HRTEM) and Raman spectroscopy. Then their hydrogen storage properties were systematically tested. The composite material CG shows a remarkable H2 capacity up to 2.43 wt% (28.6% increases vs. CuBTC) and higher surface area and pore volume compared to the neat CuBTC. And the particle size of CG is down to nanometer scale.
Hydrothermal Synthesis of MnO2-Loaded Porous Carbons for Supercapacitors
Authors: Wang Zi Qiang , Sun Li Xian , Xu Fen , Peng Xiao Jun
Published: April 2016

The porous carbons have been prepared by chemical activation using commercial activated carbons as precursors and KOH as the chemical agent, and the MnO2 and MnO2-loaded porous carbons have been synthesized via the hydrothermal method using the Mn (SO4)2·H2O and (NH4)2S2O8 as the reagents. The morphology and structure of the obtained materials are characterized by the SEM, XRD and N2 sorption. The obtained MnO2 exhibits rod-like morphology, which can be indexed to a pure tetragonal phase [space group: P42/mnm] of β-MnO2. The porous carbons and MnO2-loaded porous carbons show a well-developed porosity. The electrochemical tests indicate that the samples have excellent performances for the supercapacitors.
Microstructures and Energy Storage Properties of Sr0.5Ba0.5Nb2O6  Ceramics with BaO–B2O3–SiO2  Glass Addition
Authors: Liu Yong , Yuan Chang Lai , Zhou Xing Xing , Meng Liu Fang , Zhou Chang Rong , Chen Guo Hua , Xu Ji Wen , Li Qing Ning
Published: April 2016

Sr0.5Ba0.5Nb2O6 (SBN) ceramics with the BaO–B2O3–SiO2 (BBS) glasses have been successfully produced for high energy-storage density capacitor applications. The phase evolution, microstructures, dielectric properties and energy storage properties of the SBN-based glass ceramics were investigated. X-ray diffraction analysis revealed all ceramic samples were of tetragonal tungsten bronze-type structures. As the mass ratio of glass in the glass ceramics increased from 0.1wt.% to 10 wt.%, the dielectric constant of the glass ceramics increased initially and then decreased with the increasing glass content. Compared to pure Sr0.5Ba0.5Nb2O6 ceramics, the glass ceramics with a small amount of BBS glass addition illustrated better energy storage properties. The glass-ceramic with 0.5wt. % BBS glass addition showed the highest breakdown strength of 194 kV/cm and a maximum energy storage density of 0.286 J/cm3.
Enhanced Energy Storage Properties of La and Zr Modified Bi0.5(Na0.82K0.18)0.5TiO3 Based Ceramics
Authors: Zhao Yang Yang , Xu Ji Wen , Zhou Chang Rong , Yuan Chang Lai , Li Qing Ning , Chen Guo Hua , Yang Ling
Published: April 2016

The [Bi0.5(Na0.82K0.18)0.5]1-xLaxTi1-yZryO3 (BNKLZT) energy storage ceramics were prepared by conventional solid-state reaction method. Structure, surface morphology, dielectric, ferroelectric and energy storage properties of the BNKLBZT ceramics were investigated. The BNKLZT ceramics showed perovskite, homogeneous and dense structure. Grain size was coarsened by Zr doping, and refined by La doping. Low remnant polarization (Pr) and coercive field (Ec), slim P-E loops were obtained by introducing La and Zr dopants. The optimum energy storage property was obtained for the composition of La=0.03 and Zr=0.03, with energy storage density of 0.84 J/cm3 at 80 kV/cm.
Synthesis and Electrochemical Performance of Tin-Copper Nanocomposites as a Superior Anode for Lithium-Ion Batteries
Authors: Chen Tian , Pan Jin , Shen Ren Cheng , Deng Jian Qiu , Yao Qing Rong , Wang Zhong Min , Zhou Huai Ying , Rao Guang Hui
Published: April 2016

The Sn–Cu nanocomposites composing of Sn, Cu6Sn5, Cu3Sn and SnO2 are synthesized by a facile precipitation method. Their morphologies and structures are characterized using X-ray diffraction (XRD) technique, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high resolution TEM. The electrochemical properties are investigated by charge–discharge testing, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) methods. The sample with a Sn/Cu ratio of 5:3 delivers good cycling stability. The discharge specific capacity is 447.5 mAhg-1 after 70 cycles at a current density of 100 mAg-1 and the coulombic efficiency is beyond 95%. The superior rate and cycling performance of Sn–Cu nanocomposites are also demonstrated, which may be rooted in their nanostructure and phase composition.
Cyclic Oxidation Resistance of Hot-Dipping Aluminized Steel
Authors: Lou Jin , Ruan Cheng Xiang
Published: April 2016

0Cr18Ni10Ti stainless steel was coated by hot-dipping in a molten aluminum bath, and then diffusing annealing at 950 °C for 2h. Aluminized steel was composed of three layers: outer layer FeAl2 phase and FeAl phase, intermediate layer FeAl phase, and inner solid solution with Al. The cyclic oxidation resistance of aluminized steel with outer layer and aluminized steel without outer layer were tested at 900 °C for 24 cycles using resistance furnace. Morphology, and phase composition, element distribution of the oxide scale were characterized by XRD, SEM and EDS. The oxidation result showed that weight loss on aluminized steel with outer layer was observed at early stage, weigh gain was obtained slowly at later stage, while the weight gain was observed on aluminized steel without outer layer during 24 cycles. The weigh gain of both samples was about 0.7mg/cm2 after 24 cycles. It was found that cracks on aluminized steel with outer layer were more than aluminized steel without outer layer due to thicker FeAl layer on aluminized steel with outer layer. A thin NiAl phase layer was found between FeAl layer and inner solid solution layer on both samples decrease the depletion rate of aluminum.
Efficiency Enhancement of ZnO Nanocrystalline Dye-Sensitized Solar Cells by Post-Treatment
Authors: Jiao Yu , Wang Guang Chao , Li Feng Rong , Xie Shu Hong
Published: April 2016

In this paper, ZnO nanocrystalline photoanodes were treated by zinc acetate aqueous solution. The effect of surface chemical modification processing on the photovoltaic performance and electrochemical properties of ZnO nanocrystalline dye-sensitized solar cells (DSSCs) were studied systematically. The SEM results revealed that the surface of the ZnO photoanode films were rough and some aggregations were formed after the surface chemical modification processing. The number of aggregations increased with increasing processing time, and showed wide grain size distribution simultaneously, which effectively increased the light scattering and decreased the grain boundaries to suppress the electron recombination. Moreover, the surface of these photoanode films were filled with micropores, which was benefit to the infiltration of electrolyte solution. The short circuit current density increased from 7.20 mA•cm-2 to 8.61 mA • cm-2 when post-treatment 20 min, and the maximum energy conversion efficiency reached 3.61%, which enhanced 43% compared with that without post-treatment.
Facile Synthesis of CoSe2 Nanoparticles and their Electrocatalytic Performance for Hydrogen Evolution Reaction
Authors: Qi Hong Xue , Song Yuan Qiang , Liu Zhong Ping , Ji Lan Xiang , Deng Jian Guo
Published: April 2016

For more energy-efficient and economical hydrogen production, highly active noble metal-free hydrogen evolution catalysts are a priority for all. Herein, we report a facile one-pot hydrothermal synthesis of CoSe2 nanoparticles with their electrocatalytic performance for hydrogen evolution reaction. The synthesized CoSe2 nanoparticles have an average diameter of 50-70 nm with a uniform distribution. They also exhibited good electrocatalytic performance for hydrogen evolution reaction with the onset overpotential and Tafel slope of 140 mV and 95 mV/dec, respectively. The results provide a facile and effective way for the exploration of efficient Co-based HER catalysts.
Homogeneous Growth of Ni(OH)2 Nanoparticle on Graphene Nanosheet for High-Performance Supercapacitor Electrode Material
Authors: Lin Huan , Zhao Dong Lin , Yao Ran Ran , Qiang Zhao Hui , Zhang Wan Xin , Dong Hui
Published: April 2016

A homogeneous Ni (OH)2/graphene nanosheet (GNS) nanocomposite with excellent supercapacitive performance has been synthesized by a facile chemical precipitation. The Ni (OH)2/GNS nanocomposite presented an ideal morphology with the nanosized Ni (OH)2 particles homogeneously growing on the GNS. Its microstructure, morphology were investigated by XRD, SEM and TEM. The electrochemical performance of the Ni (OH)2/GNS nanocomposite was test by cyclic voltammetry, galvanostatic charge−discharge and electrochemical impedance spectroscopy techniques. The homogeneous Ni (OH)2/GNS nanocomposite exhibited a high specific capacitance of 1667 F/g at a current density of 1A/g and maintained a good stability in 5000 cycles, suggesting that it can be a promising candidate for supercapacitor. The high specific capacitance and remarkable rate capability are promising for applications in supercapacitors with both high energy and power densities. The Ni (OH)2/GNS nanocomposite exhibited large specific capacitance, high rate capability and good cycling stability.
Study on Preparation of Si/C Anode Material by Spray Dying and Carbonization
Authors: Xiao Fang Ming , Peng Guo Ge , Wang Ying , Tang Ren Heng , Xiao Zhi Ping , Sun Tai
Published: April 2016

Si/C composites were prepared by spray dying and carbonization process using silica powder, artificial graphite and glucose as raw materials. The physicochemical property and electrochemical performance of composite materials were characterized by XRD, SEM, constant current charge-discharge and cyclic voltammeter (CA) test, respectively. The results show that composite anode materials have pure phase structure with particle size of 5~20μm, and its special structure that silicon and graphite particles are constructed can exhibit good electrochemical performance. The initial discharge specific capacity of Si/C composites is 1033.2mAhg-1 at a current density of 100mAg-1.While the current density is as high as 600mAg-1, the discharge specific capacity is 584.2mAhg-1, and the first cycle coulombic efficiency is 77.3% at 100mAg-1.The mechanism of capacity fading of Si/C composites is discussed by different morphology characterization after 100 cycles.
Semiconductor Nanocrystals for Photovoltaic Devices
Authors: Qiao Fen
Published: April 2016

Recently, photovoltaic devices based on colloidal semiconductor nanocrystals (NCs) have attracted a great interest due to their flexible synthesis with tunable band gaps and shape-dependent optical and electronic properties. However, the surface of NCs typically presents long chain with electrically insulating organic ligands, which hinder the device applications for NCs. So the major challenge of NCs for photovoltaic devices application is to decrease the inter NC space and the height of the tunnel barriers among NCs, therefore increase the transport properties of NCs. In this article, recent development of colloidal semiconductor NCs and possible routes for improving transport properties of colloidal NCs were reviewed. Among those methods, the thermal annealing approach provides a simple and cost-effective way to fabricate superlattice and to decrease the inter-space among NCs, which may be used for the preparation of other nanocrystalline superstructure and functional devices.
The Variable Super-Capacitor with Nano-Diamond Film Electrode
Authors: Zhang Xiu Xia , Wen Jun Xia , Fan Rong , Jiang Dao Jie , Lou Xiu Li , Li Chao Hui , Du Guan Nan
Published: April 2016

nanoDiamond was mixed with ethylic cellulose and other Material to form to paste. A series of sol-gel nanoDiamond film with different proportions were designed test intentionally. nanoDiamond film was fabricated on Aluminum substrates using two-steps sintering process. The moving terminal of the variable super-capacitor was the shaft which throughout each of monolithic capacitor plate. The low melting point glass powder possesses giant permittivity, low dielectric loss, good thermal stability and dielectric constant in a wide temperature range which applied very broad prospects in microelectronics. The low melting point glass powder was mixed with carboxymethyl cellulose and deionized water to paste. The low melting point glass powder insulation thick-film was fixed on nanoDiamond film .In this paper, the insulation thick-film preparation: sintering at 578K to 588K and keeping 11.5 h to 12.5 h. A variable super-capacitor was designed based on nanoDiamond film electrode and low melting point glass powder insulation thick. Insulation thickness was prepared on uniform nanodiamond film to increase insulation super-capacitor between the two plates.
Design and Experiment of Rare Earth Giant Magnetostrictive Piston Pump
Authors: Lu Quan Guo , Zhao Ya Peng , Nie Qin
Published: April 2016

A new piston pump structure was designed by incorporating a rare earth giant magnetostrictive material as the driving source into the basic working principles of piston pumps. The operational process of the proposed magnetostrictive piston pump was analyzed according to the overall structure design, which includes a magnetostrictive rod, drive coils, pump cavity height, one-way valve and pre-pressure mechanism. Analysis was conducted on both the seal and self-suction capacity of the proposed design. The magnetostrictive piston pump was designed to simplify the structure of a conventional piston pump by requiring fewer moving parts, a small volume, being of light weight, and utilizing a precise controllable flow, among other advantages. An experimental prototype was built and an experimental system was designed to test flow and pressure characteristics. Output flow and pressure curves were obtained to analyze the flow instability when exposed to high currents. Experimental results demonstrate that the magnetostrictive piston pump achieves a maximum output flow of 550.65mL/min when the excitation current frequency is 50Hz, and achieves a maximum output pressure of 0.65MPA when the excitation current frequency is 10Hz.
Studies of the Average Valence State of the Transition Metals and the Electrical Properties of LaSr3Fe3-xMnxO10-δ (x=0.0-0.8) Mixed Conductors
Authors: Li Qin , Wan Wei Bin , Li Shuai , Sheng Zhi Bing , Zhang Guo Guang
Published: April 2016

LaSr3Fe3-xMnxO10-δ (x=0.0-0.8) mixed conductors with layered perovskite structure were prepared via citric acid method. XRD analysis showed that the cell volume decreased with Mn content. The fraction of Fe4+ concentration to the concentration of tetravalent ions decreased with the increase of Mn content. The decrease of average valence state (VB) of transition metals of LaSr3Fe3-xMnxO10-δ samples with the increase of temperature gave rise to the drop of p type charge carriers and the increase of oxygen vacancies. According to the relationship between VB and the numbers of the configurations of transition metals in LaSr3Fe3-xMnxO10-δ , the possible filling states of 3d orbitals of Fe and Mn ions at 700 °C and 800 °C were given. The variations of conductivities of LaSr3Fe3-xMnxO10-δ samples were interpreted on the basis of the variation of VB and δ with temperature and Mn content, respectively. Scanning Kelvin probe measurement results revealed that the surface potential of x=0.6 sample was the highest while x=0.8 sample was the lowest. The higher the surface potential, the higher the energy needed for an electron to be released from the sample.
SiC/SiO2 Coating on Matrix Graphite Spheres of HTR Fuel Element Produced by a Two-Step Pack Cementation/High-Temperature Oxidation Process
Authors: Zhou Ping , Li Zi Qiang , Zhao Hong Sheng , Zhang Kai Hong , Liu Xiao Xue , Liu Bing
Published: April 2016

Graphite is one of the most important material for the reactor core and fuel elements of high temperature gas-cooled reactor (HTR). Improving the oxidation resistance of graphite is very essential for the research of new fuel elements and the development of HTR. In this study, a gradient SiC layer of 500~700 μm was prepared on matrix graphite spheres by a two-step pack cementation, and the outer SiO2 layer prepared by the high-temperature oxidation process. The phases, microstructure, bonding strength and oxidation resistance of SiC/SiO2 coated matrix graphite spheres were investigated. The SiC/SiO2 coated matrix graphite spheres were carried on rapid thermal shocking tests from 1773 K to room temperature for 50 times without any cracks. The SiC/SiO2 coated matrix graphite spheres exhibits excellent anti-oxidation properties. No obvious weight loss was found after isothermal oxidation in air at 1273 K for 50 h and the weight gain was less than 1% at 1773 K in air for 50 h due to the oxidation of SiC layer.
Electrochemical Performance of Li4Ti5O12/TiO2/Li0.4TiO2/C Composite Prepared by the Electrospinning Method Using as Lithium Battery Anode Material
Authors: Chen Chun Hua , Feng Jia Jia , Shao Wei Quan , Chen Sha Ou , He Li Zhu , Li Yan Qiang , Ban Yue Qin , Hei Fang , Guo Xiao Jie
Published: April 2016

Li4Ti5O12(LTO) and Li4Ti5O12/TiO2/Li0.4TiO2/C (LTO/C) composite were prepared by the electrospinning method using acetic acid, ethanol, butyl titanate, lithium acetate and PVP (K90) as the raw materials. The phase structure and the morphology were characterized by the X-ray diffraction (XRD) and the scanning electron microscopy (SEM), respectively. It was found that the specific capacity was 356mAh/g at 0.5C for the composite, which was higher than the theoretical specific capacity of the pure Li4Ti5O12 due to the inclusion of other phase. Moreover, the C-rate performance for the composite was also better than that of the pure Li4Ti5O12 resulting from the formation of carbon-based fiber structure. Electrochemical impedance spectra (EIS) revealed that the composite exhibited the improved electronic conductivity than that of Li4Ti5O12.
The Effect of Oxidized Time to Structure and Composition of Micro-Arc Oxidization Ceramic Coating of Pure Titanium
Authors: Xu Lin , Ding Jian Ning , Huang Zhen , Han Ni Na , Xu Xiao Jing , Huang Xing
Published: April 2016

The porous oxide TiO2 ceramic coating containing Ca and P is fabricated on the surface of pure titanium in the electrolyte of C4H6CaO4-NaH2PO4 by micro-arc oxidation (MAO) method. Scanning electron microscopy (SEM) and 3D profilometer are used to observe difference between morphology of coating surface under condition of different oxidized time. Energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) are used to discuss the effect of oxidized time to the ratio of Ca/P and phase composition of ceramic coating. Results indicate that the oxidized time has a little effect on structure and composition of MAO ceramic coating of pure titanium. After modified with MAO, pure titanium is rough and porous on its surface, its average aperture, porosity and roughness enlarge as oxidized time extends. The increase of oxidized time makes the ratio of Ca/P and the relative content of rutile TiO2 increases, but the relative content of anatase TiO2 shows opposite trend.
The Effect of Current Density to Surface Morphology and Component of Micro-Arc Oxidization Ceramic Coating of Pure Titanium
Authors: Xu Lin , Ding Jian Ning , Huang Zhen , Han Ni Na , Xu Xiao Jing , Niu Xiao Ya
Published: April 2016

The ceramic coating containing anatase TiO2 and rutile TiO2 is fabricated on the surface of pure titanium in the electrolyte of C4H6CaO4-NaH2PO4 by micro-arc oxidation (MAO) method. The effect of different current density to microscopic structure, elemental composition and phase components of Ceramic Coating are studied with scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), 3D profilometer and etc. Results indicate that the ceramic coating on pure titanium by micro-arc oxidation is a porous mixed crystal structure which is mainly composed of such elements as Ti, O, Ca and P. With current density increasing, the average pore diameter and roughness on film surface first increase and then decrease, the porosity increases, the ratio of Ca/P then decreases, the relative content of anatase TiO2 increases and that of rutile TiO2 decreases.
Revisiting the term neuroprotection in chronic and degenerative diseases
Authors: Orsini Marco , Nascimento Osvaldo J.M. , Matta Andre P.C. , Reis Carlos Henrique Melo , De Souza Olivia Gameiro , Bastos Victor Hugo , Moreira Rayele , Ribeiro Pedro , Fiorelli Stenio , Novellino Pietro , Pessoa Bruno , Cunha Mariana , Pupe Camila , Morales Pedro S. , Moreira Filho Pedro F. , Trajano Eduardo Lima , Oliveira Acary Bulle
Published: April 2016

Thanks to the development of several new researches, the lifetime presented a significant increase, even so, we still have many obstacles to overcome − among them, manage and get responses regarding neurodegenerative diseases. Where we are in the understanding of neuroprotection? Do we really have protective therapies for diseases considered degeneratives such as amyotrophic lateral sclerosis and its variants, Parkinson’s disease, Alzheimer’s disease and many others? Neuroprotection is defined by many researches as interactions and interventions that can slow down or even inhibit the progression of neuronal degeneration process. We make some considerations on this neuroprotective effect.
Self-reported study habits for enhancing medical students' performance in the National Medical Unified Examination
Authors: Idris Amr , Saadi Tareq Al , Edris Basel , Sawaf Bisher , Zakaria Mhd. Ismael , Alkhatib Mahmoud , Turk Tarek
Published: April 2016

Background: The National Medical Unified Examination (NMUE) is currently required for graduation, joining postgraduate medical training, and practicing medicine in Syria. Objective: To investigate self-reported study habits that correlate with high performance on the NMUE. Methods: First through 3rd year residents at the three main hospitals in Damascus, Syria, were asked to complete a retrospective cross-sectional survey investigating their study habits and previous scores. Results: Significantly higher score was associated with >15 study h/day and allocating 1–40% of study time for practicing questions. Mean NMUE score was not significantly different in relation to preparation months for examination or for those who reported spending all their time studying alone compared with spending any amount of time in a group setting. Scores of 231–240 on the Syrian scientific high school exam correlated with significantly higher NMUE performance compared with fewer scores, except scores of 221–230. For every 10 point increase in medical school cumulative grades, the NMUE score increased 3.6 (95% confidence interval 2.5–4.8). Conclusion: The NMUE score was significantly affected by hours spent studying per day, number of practice questions completed, percentage of study time allocated for doing questions, Syrian scientific high school exam scores, and the cumulative medical school class grades. It was not significantly affected by preparation months or studying in a group setting. More studies are needed to further describe and investigate the factors that might affect performance in the NMUE.
Comparative evaluation of salivary constituents and oral health status in children with Down′s syndrome
Authors: Dharmadhikari Priyanti , Thosar Nilima , Baliga Sudhindra , Rathi Nilesh
Published: April 2016

Aim: To evaluate and correlate salivary constituents and oral health status in children with Down′s syndrome. Materials and Methods: Seventy-five children in the age group of 4-14 years were included in the study. The control group consisted of 25 healthy children. The study group consisting of children with Down′s syndrome was divided into study Group I which consisted of 25 institutionalized children and study Group II consisted of 25 noninstitutionalized children. Caries score and oral hygiene status of each child were calculated. Unstimulated saliva was collected from each child, and salivary levels of sodium, potassium, calcium, magnesium, phosphorus, and zinc were evaluated. Results: Lowest decayed, missing, and filled teeth scores were found in noninstitutionalized Down′s syndrome children and highest oral hygiene index-simplified scores were found among institutionalized Down′s syndrome children. Levels of sodium ions were seen to be highest in the control group; magnesium levels were highest in an institutionalized group of children with Down′s syndrome, whereas potassium, calcium, phosphorus, and zinc levels were found to be highest among a noninstitutionalized group of children with Down′s syndrome. Salivary calcium showed a significant negative correlation with dental caries. Conclusion: Salivary calcium and zinc play a protective role against dental caries. Increased dietary calcium and zinc in addition to education regarding oral hygiene practices may improve overall oral health among children.
Oral manifestations of dengue fever: A rarity and literature review
Authors: Bhardwaj Vinay Kumar , Negi Nishant , Jhingta Pravesh , Sharma Deepak
Published: April 2016

Dengue is a viral infection with fatal potential complications. It is also called break-bone fever. Worldwide, dengue infection is the most common mosquito-borne viral disease. It is caused by vector Aedes aegypti and represents a major public health issue in more than 100 tropical countries. This may be associated with a variety of mucocutaneous manifestations, which may be of help in early diagnosis. Dengue viral infections are characterized by abrupt febrile illness, but can also lead to significant morbidity and mortality. Hence, it requires an early and correct diagnosis. Gingival bleeding is the most common oral manifestation of dengue infections. Many biochemical assays and hematological investigations may aid in the further diagnosis and treatment of the fatal disease. Although oral lesions are uncommon in dengue infections and if occur, may be mistaken for platelet abnormality or hemorrhagic disorders. This review emphasizes the significance of oral lesions as it may be the early indicators of dengue hemorrhagic fever.
Educator Sexual Misconduct: Exposing or Causing Learners to be Exposed to Child Pornography or Pornography
Authors: Coetzee Susan
Published: April 2016

The law recognises that non-contact sexual offences can cause harm and several offences were created to regulate non-contact sexual child abuse offences. Several of these offences deal with the exposure or causing exposure of children to child pornography or pornography. Sexual grooming of children and the “Exposure or display of or causing exposure or display of child pornography or pornography to children” are criminalised in sections 18(2) and 19 of the Criminal Law (Sexual Offences and Related Matters) Amendment Act 32 of 2007. And offences in relation to exposing children to disturbing, harmful and age-inappropriate materials are criminalised in sections 24A(2) and (4) of the Films and Publications Act 65 of 1996. In this article the author considered the content of the offences of “Exposure or display of or causing exposure or display of child pornography or pornography to children” in relation to the other offences dealing with exposure of children to child pornography or pornography. Benchmarked against these criminal offences the author then conceptualised exposing learners, or causing the exposure of learners to child pornography or pornography as forms of educator misconduct. The seriousness that should be attached to these forms of misconduct was considered in light of the various criminal offences. The review of the criminal offences and the forms of educator misconduct brought the ineffectiveness of current forms of serious educator misconduct to the fore. There is no form of serious misconduct that covers the transgression of educators who expose learners to child pornography or pornography that can be classified as “XX”. In conclusion a suggestion is made with regard to how a new form of serious misconduct could be worded so as to cover this gap, eg An educator must be dismissed if he or she is found guilty of – (g) exposing a learner to or causing exposure of a learner to material classified as “Refused” or “XX” in terms of the Films and Publications Act 65 of 1996.