bluuebunny/crossref_metadata_2025 huggingface dataset:
Prediction of Instability and Mechanism of Multi-Factor Comprehensive Action on Mine Goaf
Authors: Yu Wei Jian , Du Shao Hua , Wang Wei Jun
Published: December 2014

In allusion to phenomenon of large instability of underground goaf, research is carried on prediction of instability and mechanism of multi-factor comprehensive action. Firstly, according to large number of examples of instability disaster in mines at home and abroad, influence factors of goaf stability was analyzed, including characteristics of surrounding rock, conditions of engineering geology, engineering properties, structure parameters of goaf and other artificial mining and time etc; then, using BP neural network to establish the comprehensive function matrix RSE, and putting forward a prediction index Fi, this index can be real-time tracking on the actual change conditions of surrounding rock scene in mining goaf, showing the comprehensive action results of each factor on steady state of underground goaf engineering system; finally, on the basis of 36 samples, the stable value and interval value of the corresponding multi-factor comprehensive action index Fi can be obtained after calculation by using comprehensive function matrix RSE. An actual example showed that, value of multi-factor comprehensive action index Fi was-0.8159 in goaf of an iron mine, which was in instability state.
A Framework for the Development of a Manufacturing Resources Planning System
Authors: Oladokun V.O. , Olagunju F.T.
Published: December 2014

Many Small and medium scale enterprises (SMEs), because of the limited scope and size of their operations consider investment in proprietary Enterprise Systems unattractive. Meanwhile In-house development approach has been identified as a way deepening the adoption of these productivity enhancement systems among SMEs in developing economies. This paper presents a framework for developing Manufacturing Resources Planning software adaptable for SMEs in Nigeria and other developing economies. After the critical study and analysis of manufacturing systems, algorithms were developed for generating the material requirement plans for four different lot-sizing techniques. Subsystems for determining Labour and machine capacity requirements and costs, subsystems for material and running costs were integrated into the MRP algorithms. User friendly software of the resulting system was developed using visual basic. The system components were tested using a small-scale process and a middle-scale process to ensure proper functionality. The software which comes with various graphical reporting tools like tables and bar charts was shown to be flexible and accurate, suitable for small and medium enterprises.Keyword: Enterprise Systems, inventory, Material Requirement Planning, Resources planning
Fundamental Concepts and Principles for Robust Structures, Subjected to Dynamic Loading
Authors: Javed Raja Ahsan , Zhu Shi Fan , Guo Chun Huan , Jiang Feng Chun
Published: December 2014

The dynamic behavior assessment of material is very important before selecting the material for structural applications. In the modern world, Modified Hopkinson pressure bar apparatus is being widely used to investigate the dynamic behavior of engineering materials under compressive and tensile loading. Materials like ceramics, rocks, metals, concrete and soft material are being tested. The cost associated with the dynamic loading pressure bar apparatus are also low and can be easily built. For accurate measurement of material properties we need to understand the basic concepts associated with dynamic loading. With the advancement in computational capabilities, the dynamic load testing of materials is also performed in available commercial software's. In the current work, the basic concepts and components associated with dynamic compressive loading system are discussed and a test case studies are also selected for analyzing material specimen behavior during testing. For simulation of dynamic compressive loading ANSYS LS-DYNA software is used and the output of the simulation results is analyzed. The effects of changing the diameter of material specimen, and hollow bars on stress and strain values in the bar and setup are also discussed.
The Microstructural, Mechanical and Electro-Mechanical Properties of Graphene Aerogel-PVDF Nanoporous Composites
Authors: Zheng Guang Ping , Han Z. , Liu Y.Z.
Published: December 2014

Graphene aerogel-poly (vinylidene fluoride) (GA-PVDF) nanoporous composites with different concentrations of PVDF are fabricated. Scanning electron microscopy reveals that PVDF films with a typical thickness below 100 nm are coated at the graphene sheets in the nanoporous composites. The GA-PVDF composites show excellent compressibility, ductility and mechanical strength, as well as better sensitivity of stress-dependent electrical resistance compared with those of GAs. The improved mechanical and electro-mechanical behaviours of nanoporous composites are ascribed to the PVDF which possesses piezoelectricity. The structural properties of the graphene-PVDF nanosized hybrid scaffolds are analyzed by dynamical mechanical relaxation. The results demonstrate that the nanoporous composites could be used as high-performance sensors, actuators and kinetic energy harvesters.
Effect of Annealing Temperature on the Crystallization of Hematite-Alumina (Fe2O3-Al2O3) Nanocomposite and its Influence in EOR Application
Authors: Soleimani Hassan , Ahmad Latiff Noor Rasyada , Yahya Noorhana , Zaid Hasnah Mohd , Sabet Maziyar , Guan Beh Hoe , Lee Kean Chuan
Published: December 2014

Usage of magnetic materials is not unusual in oil and gas research, specifically in enhanced oil recovery (EOR) where various magnetic micro-and nanoparticles were used to enhance sweep efficiency, reducing interfacial tension and heat generation. Magnetic nanoparticles which are activated by a magnetic field are anticipated to have the ability to travel far into the oil reservoir and assist in the displacement of the trapped oil. In this work, magnetic Fe2O3-Al2O3 nanocomposite was synthesized and characterized for its morphological, structural and magnetic properties. At an annealing temperature of 900°C, this nanomaterial starts to exhibit magnetization as the composite structure crystallizes to the stable Fe2O3 and Al2O3. Subsequently, dispersion of the 0.01 wt% Fe2O3-Al2O3 nanocomposite in distilled water was used for displacement tests to validate its feasibility to be applied in EOR. In the displacement test, the effect of electromagnetic waves on the magnetization of Fe2O3-Al2O3 nanofluid was also investigated by irradiating a 13.6 MHz square wave to the porous medium while nanofluid injection is taking place. In conclusion, an almost 20% increment in the recovery of oil was obtained with the application of electromagnetic waves in 2.4 pore volumes (PV) injection of Fe2O3-Al2O3 nanofluid.
Electrochemically Exfoliated Graphene
Authors: Terence Mauro Cesar , Silva Ederson Esteves , Carrió Juan Alfredo Guevara
Published: December 2014

We analyze graphene obtained by electrochemical exfoliation. This showed an interesting process for obtaining fast and low cost exfoliated graphene. Within a few minutes a large amount exfoliated graphite oxide was produced. Analysis by Raman spectroscopy of the exfoliated graphene showed the effectiveness of the process and the factors that may intensify the disorder of graphene obtained.
Solid State Synthesis and Characterization of NiTe Nanocrystals
Authors: Campos C.E.M.
Published: December 2014

NiTe nanocrystals were prepared through facile and fast solid state reaction (mechanical alloying) of pure elemental tellurium and nickel powders in an argon atmosphere. The samples processed for 3 h, 5 h and 10 h were characterized by X-ray diffraction, transmission electron microscopy, magnetization and Raman spectroscopy. Hexagonal NiTe crystals with an average size of 30 nm can be obtained after only 3 h of processing time. Transmission electron microscopy images showed a broad crystalline size distribution in the agglomerated particles and selected area electron diffraction revealed its crystalline character. NiTe ferromagnetic behavior was confirmed and magnetic parameters were dependent on processing time. Raman spectra showed no unreacted Te or tellurium oxides, but it also showed that laser induced phases transitions (including Te re-crystallization) can be observed for modest laser power (<3 mW).
Potassium Sulfate Nanoparticles in Water Solutions: Experiment and Quantum Chemistry Simulation
Authors: Myrzakhmet Marat , Baimagambetov Kurmangali , Bekturganova Aliya , Kumisbek Gani , Yessengali Seitzhan
Published: December 2014

Pure potassium sulfate single crystals are transparent in a wide spectral range up to 155 nm and do not show fluorescence and absorption over a wide spectral range of 200-800 nm before and after X-ray irradiation of the samples. The centers of luminescence in thallium-doped potassium sulfate crystals showed a maximum absorption 216 nm and emission 285 nm at room temperature. These centers are singly charged thallium ions. It is interesting to research the optical properties with decreasing size of crystals (size effects). For this, we used a supersaturated aqueous solution of potassium sulfate, in which the crystallization begins. The results of computer simulations using Scigress quantum chemistry package show that the occurrence of macromolecules in a cooled supersaturated solution should result in an increased absorption. In supercooled saturated aqueous solutions of ionic crystals nucleation occurs. A decrease of transparency of saturated solutions with decreasing temperature is clearly seen. This is due to absorption and scattering in the medium with the growing small crystals in the solution.
Modeling Gas Barrier Property Improvements in Polymer-Clay Nano-Composites
Authors: Al-Abduljabbar Abdulhamid
Published: December 2014

Polymer-clay nanocomposites (PCNC) offer better properties at very low volume fraction of the nanofiller compared to conventional polymer composites, thus minimizing the effect on other favored properties of the polymer. The mechanism by which clay platelets, which have thicknesses of a few nanometers in size compared with several hundred nanometers in the other two dimensions, introduce mechanical and other properties improvement can be attributed to their high efficiency in introducing a discontinuity to flows through the bulk matrix polymer material. The extent of this improvement depends on the success of intercalation or separation of the clay platelets through the bulk matrix. This paper contains a general overview of polymer-clay nanocomposites in terms of properties and processing. The improvements in gas barrier properties are discussed in detail; and a model to represent the effect of introduction of nanofillers on the permeability is proposed. The model builds on previous models to explain the improvements in the gas barrier properties due to the presence of clay nanoparticles and by assuming a proper distribution of these particles.
Effects of Fe Doping on the Crystal Structures and Photoluminescence of ZnO Nanorods
Authors: Li Chun Ping , Ba Hao Ran , Jin Kun
Published: December 2014

The 5% Fe-doped ZnO nanorods (Zn0.95Fe0.05O) were prepared successfully by the wet-chemical synthesis method. Structure and morphology characterization were demonstrated by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Laser power dependent photoluminescence (PL) spectra were measured to study the electronic structures of the Fe-doped ZnO-based diluted magnetic semiconductors. The contraction of lattice constant and structured green-yellow-red emissions were analyzed. Such investigations confirmed that the induced defects or impurities originating from Fe ions.
Influence of Defects on Elastic Buckling Properties of Single-Layered Graphene Sheets
Authors: Li Bao Long , Zhou Li Jun , Guo Jian Gao
Published: December 2014

Molecular structural mechanics based finite element method has been applied to study the effects of two types of Stone-Wales (SW) defects and vacancy defect on elastic buckling properties of single-layered graphene sheets (SLGSs). The defect effect factors of critical buckling stresses are calculated for the defective SLGSs with different chirality and geometrical dimensions. It is proved that defect effect factors are size-dependent and chirality-dependent. The results show that the vacancy defects will always weaken the SLGSs’ stability, and two types of SW defects have different effects on zigzag and armchair SLGSs. What’s more, the positions of defects also have remarkable influence on the critical buckling stress of SLGSs.
Fabrication of Nanoporous Copper Ribbons through Dealloying of Al-Cu-Mn Alloys
Authors: Jiang Hua Wei , Zhang Jie , Li Mei , Geng Hao Ran , Zuo Min
Published: December 2014

We present a new Al-Cu-Mn system to fabricate nanoporous copper ribbons by dealloying. The microstructures of the nanoporous copper ribbons are characterized using X-ray diffraction, scanning electron microscopy and energy dispersive X-ray analysis. The results show that the compositions of the melt-spun Al-Cu-Mn alloys have an important effect on the dealloying process and microstructures of the nanoporous copper ribbons. The melt-spun Cu30Al40Mn30, Cu30Al35Mn35, Cu30Al30Mn40 and Cu30Al25Mn45 (at.%) alloys can completely form a bicontinuous interpenetrating ligament-channel structure. Compared with other alloys, the dealloying of Cu30Al40Mn30 alloys is more difficult. In addition, for Cu30Al35Mn35 and Cu30Al30Mn40 alloys, porous structures are relatively uniform. But for the Cu30Al25Mn45 alloys, porous structure is not uniform, occurring aggregation phenomenon.
Overexpression and Characterization of the Gene Encoding 1,3-Propanediol Oxidoreductase of Citrobacter freundii
Authors: Qi Xiang Hui , Zhu Jing Fei , Luo Yan , Lin Jing , Wang Xu , Ju Zhao , Chen Fang , Zhu Xiao Guan , Chen Hua You , Sun Wen Jing , Wang Liang
Published: December 2014

Glycerol can be biologically converted to 1,3-propanediol (1,3-PD), a key raw material required for the synthesis of polytrimethylene terephthalate and other polyester fibers. 1,3-propanediol oxidoreductase (PDOR) is the rate-limiting enzyme in 1,3-PD synthesis biologically pathway. In present study, the dhaT gene encoding PDOR was cloned from Citrobacter freundii and overexpressed in E. coli BL21. The recombinant enzyme was purified by nickel-chelate chromatography combined with gel filtration to study the enzymatic characterization. Specific activity of recombinant PDOR was 55.2 U/mg. Km and Vmax values were 8.9 mM, 40.2 U/mg respectively. Holoenzyme of PDOR maybe a decamer of which a monomer has a molecular mass of 43 kDa. This research may form a basis for the future work on biological synthesis of 1, 3-PD.
Extraction of Porphyran from Porphyra yezoensis for Gel Formulation Preparation
Authors: Cao Jin , Wang Shi Cheng , Xu Liu Wei , He Jia Bing , Xu Xi Ming
Published: December 2014

Porphyran, which structure is similar with carrageenan and agarose, has application potential in drug form developmentas a new pharmaceutical material. Orthogonal experiment was employed to optimizethe porphyran extraction conditions from porphyra yezoensis. The extraction temperature, pH, ratio of liquid to raw material and extraction time were confirmed as 90°C, 11, 30:1 and 3h, respectively.The polysaccharide structure detected by IR spectra was consistent with porphyran, which was suitable for gel formulation preparation.
A Novel Chitosan Microbubble as Ultrasound-Triggered Drug Carrier for Antitumor In Vitro
Authors: Shen Song , Ding Bei , Li Qing , Yu Xu Wei , Qi Xue Yong , Ge Yan Ru
Published: December 2014

Uniform Microbubbles (MBs) were routinely used as ultrasound contrast agents, but the MBs served for drug carrier showed well-marked advantage. In this study, we prepared a novel docetaxel–loaded microbubbles by carboxymethyl chitosan with W/O/W emulsion technique. Then, the surface morphology was characterized by scanning electron microscope (SEM). Ultrasound-triggered drug release experiments were performed with adjustable intensity and time. In the antitumor experiment in vitro, Ultrasound-assisted drug release from MBs exhibited good treatment of tumor. The results proved the combination of ultrasound and drug-loaded carboxymethyl chitosan microbubbles could be used as a potential strategy for anti-tumor therapy.
Biological Synthesis of D-Tagatose Using L-Arabinose Isomerase
Authors: Qi Xiang Hui , Zhu Jing Fei , Luo Yan , Zhang Huan Huan , Lin Jing , Wang Xu , Ju Zhao , Chen Fang , Sun Wen Jing
Published: December 2014

D-Tagatose is a ketohexose monosaccharide and recognized as a low-calorie substitute sweetener that could be used in nonchronic drugs, foods, beverages and dietary supplements. Currently, the biological production of D-tagatose using L-arabinose isomerase has caused extensive attention. In the article, properties and recent researches about D-tagatose and L-arabinose isomerase are described. The industrial application and existing problems are also stated.
Selective Sodium Removal from Lithium Chloride Brine with Novel Inorganic Ion Exchanger Li1.4Al0.4Ti1.6 (PO4)3
Authors: Sun Jian Zhi , Dong Yan , Kong Chun Yan
Published: December 2014

The powder of Li1.4Al0.4Ti1.6 (PO4) 3 has been synthesized by a solid phase reaction between Li2CO3, Al2O3, TiO2 and NH4H2PO4. Sodium removal was studied in an extensive series of tests involving different ionic exchange process variables such as time and temperature. The results indicate that the Na/Li ion exchange reaction rate increased obviously with increasing temperature, and the Na/Li ion exchange kinetics process of Li1.4Al0.4Ti1.6 (PO4) 3 in lithium chloride solution could be shown approximately by the equation of JMAK. Furthermore, it is concluded that the Na+-removed materials obtained from NASICON-type ceramics synthesized can serve as selective Na+ absorbent due to its high selectivity and larger ion exchange capacity.
Microstructure of ZrB2/6063Al In Situ Composite Processed by Forge
Authors: Jiao Lei , Zhao Yu Tao , Chen Jian Chao , Li Jia Chen , Chen Zhen
Published: December 2014

The prepared ZrB2/6063Al composites were forged on the small tonnage forging air hammer machine. The results indicate that the forged ZrB2/6063Al composites’ reinforced segregation of particles and the uniformity of the materials organization were improved; the grains were refined and the tensile strength ,yield strength and hardness were improved after ZrB2/6063Al composites forged, but the plasticity of the composites were decreased.
Simultaneous Determination of Pb2+ and Co2+ Based on Fluorescence Quenching of Bi-Color Quantum Dots with the Aid of Multivariate Calibration Techniques
Authors: Zhu Xin Feng , Feng Jue , Zhu Jun Wu , Li Bin , Xu Qin
Published: December 2014

Simultaneous determination of Pb2+ and Co2+ without separation has been successfully achieved by a bicolor quantumn dots mixture. This method takes advantage of the different degrees of the fluorescence quenching effects of Pb2+ and Co2+ to the bio-color quantum dots. Chemometrical approaches were applied to assist the discrimination and detection process. The construction of the multivariate calibration models, based on partial least squares (PLS), orthogonal projections to latent structures least squares (O-PLS) and kenel based orthogonal projections to latent structures (K-OPLS), allowed the simultaneous determination of Pb2+ (in the concentration range of 0-120 mM) and Co2+ (0-300 mM). The optimal number of factors in PLS and the optimal number of orthogonal components in O-PLS and K-OPLS were carefully selected. A comparison of prediction performances between these results was performed by relative prediction errors, square of the correlation coefficient and root mean squares error of prediction.
Electrochemical Performance Cr Doped Spinel LiMn2O4 Cathode for Lithium Ion Batteries
Authors: Wen Si Qi , Gao Liang Chao , Wang Jia Li , Zhang Lei , Yang Zhi Cheng , Zhang Shao Kang , Cui Yong Li
Published: December 2014

To improve the cycle performance of spinel LiMn2O4as the cathode of 4 V class lithium ion batteries, spinel were successfully prepared using the sol-gel method. The dependence of the physicochemical properties of the spinel LiCrxMn2-xO4(x=0,0.05,0.1,0.2,0.3,0.4) powders powder has been extensively investigated by using X-ray diffraction (XRD), scanning electron microscope (SEM), charge-discharge test and electrochemical impedance spectroscopy (EIS). The results show that as Mn is replaced by Cr, the initial capacity decreases, but the cycling performance improves due to stabilization of spinel structure. Of all, the LiCr0.2Mn1.8O4has best electrochemical performance, 107.6 mAhg-1discharge capacity, 96.1% of the retention after 50 cycles.
Removal of Heavy Metal Ions from Waste Water Using Modified Sands: A Brief Review
Authors: Qu Hui , Liu Shi Quan
Published: December 2014

The modified sands compared with plain quartz sands possessed larger surface area and higher specific affinity towards heavy metal ions in waste water. Methods to synthesize modified sands have been briefly reviewed. Emphasis has been on the adsorption mechanisms and the characteristics of the modifying coatings which influence the absorbents’ efficiency and speciality.
The Crystallization of Lithium-Iron-Phosphate Glasses Containing Alkali and Alkali-Earth Metal Oxides
Authors: Yang Rui Juan , Wang Ying Hui , Liu Shi Quan
Published: December 2014

The crystallization activation energies and crystalline phases of lithium-iron-phosphate (LIP) glasses with alkali and alkali-earth metal oxides have been studied and compared. The results indicate that the alkali and alkali-earth metal oxides reduce the glass crystallization. Moreover, the alkali metal oxides result in the changes in the crystalline phase, while the alkali-earth metal oxides make the glass crystallization more sensitive to the thermal treatment conditions.
Preparation and Performance of Self-Healing Epoxy Composites by Microcapsulated Approach
Authors: Yuan Xin Hua , Su Qiu , Han Li Yin , Zhang Qian , Chen Yan Qiu , Liu Yong Qiang , Liu Tian Tian , Gao Lei
Published: December 2014

Microencapsulated E-51 epoxy resin healing agent and phthalic anhydride latent curing agent were incorporated into E-44 epoxy matrix to prepare self-healing epoxy composites. When cracks were initiated or propagated in the composites, the microcapsules would be damaged and the healing agent released. As a result, the crack plane was healed through curing reaction of the released epoxy latent curing agent. In the paper, PUF/E-51 microcapsules were prepared by in-situ polymerization. The mechanical properties of the epoxy composites filled with the self-healing system were evaluated. The impact strength and self-healing efficiency of the composites are measured using a Charpy Impact Tester. Both the virgin and healed impact strength depends strongly on the concentration of microcapsules added into the epoxy matrix. Fracture of the neat epoxy is brittle, exhibiting a mirror fracture surface. Addition of PUF/E-51 microcapsules decreases the impact strength and induces a change in the fracture plane morphology to hackle markings. In the case of 8.0 wt% microcapsules and 3.0 wt% latent hardener, the self-healing epoxy exhibited 81.5% recovery of its original fracture toughness.
Friction Properties of PTFE Matrix Composites Reinforced by PPS and PPTA Fibers
Authors: Yuan Xin Hua , Yang Jing , Chen Yan Qiu , Zhu En Bo , Xu Hong Xing , Han Zhi Rui , Jiang Jing Ying , Zhao Jie , Xia Zhen , Song Hao Jie , Hu Jie
Published: December 2014

The polytetrafluoroethylene (PTFE) matrix composites reinforced by polyphenylene sulfide (PPS) fiber and poly-p-phenelenferephthalamide (PPTA) fiber were prepared by the processes of mechanical blending, compression molding and sintering. The fractured surfaces of impacting specimens were examined by scanning electron microscopy (SEM). The tribological properties of the composites were investigated on M-2000 wear tester at dry friction condition. The wear mechanism was also discussed and the wear surfaces were examined by SEM. The result indicates that fibers which diffused in PTFE matrix wind with PTFE molecule chain, and then form grid structure. The load-bearing capacity of composites can be obviously enhanced and the trend of block fragmentation’s slide is inhibited, so that the tribological properties are improved markedly. The friction coefficient of composites is reduced by adding graphite which also prevents fibers leaving. The tribological properties of PTFE matrix composites is greatly improved because of the synergistic effect between fibers and graphite, which has good prospect for low loading application.
Deep Oxidative Desulfurization of Dibenzothiophene by Functional Tungsten-Containing Mesoporoussilica from Polyoxometalate-Based Salts
Authors: Zhang Ming , Zhu Wen Shuai , Li Meng , Li Yan An , Xun Suhang , Qin Rong Xiang , Li Hua Ming
Published: December 2014

Tungsten-containing functional mesoporousW-SiO2 have been successfully synthesized by an one-pot and facile room-temperature procedure. These materials presented a high dispersion of tungsten species and excellent catalytic activity on the removal of sulfur compounds without any organic solvents as extractants. The catalytic performance on sulfur compounds was investigated in detail. After recycling for 8 times, the removal of the oxidation desulfurization system could still reach 92.0%.
Preparation and Performance of Polypropylene/Modified Carbon Fibers by Physical Blending Method
Authors: Chen Hai Feng , Miao Ying , Ke Shan Shan
Published: December 2014

The films of polypropylene/ modified carbon fibers (PP/MCF) were made by physical blending method under refluxing and stirring for 3h at 130 °C. The structure of chemical bond in PP/MCF was investigated by fourier transform infrared spectroscopy (FT-IR), and optical properties were characterized by UV-Vis reflective spectroscopy, UV-Vis transmission spectroscopy and Polarizing microscope. We focus on the effects of MCF content on the material hardness properties according by GB/T6739-2006/ ISO 15184: 1998, and the mass loss, crystallization and melting behavior of the samples were test by TG and DSC. The results show that increasing MCF content is conducive to reduction in the hardness and improve the smoothness, and to reduction the crystallization peak temperature and improve the melting point. So we can adjust MCF content to prepare the films used for the gasket within prosthetic socket.
Nanoscale Hollow-Bubbly Polypyrrole Obtained via Interfacial Polymerization with Phase Transfer Catalyst
Authors: Dong Deng Pan , Yang Qing Hao , Yang Lin Tao , Hou Zhen Zhong , Tu Zhong Yi
Published: December 2014

Crown ether 18C6 was used as a phase transfer catalyst (PTC) for the interfacial polymerization of polypyrrole (PPy). Usually, in interfacial reacting system, oxidant FeCl3was dissolved in deionized water to form aqueous phase, while pyrrole was dissolved in chloroform to form organic phase. The 18C6 PTC can efficiently form complexes with Fe (III) and transfer Fe (III) from aqueous phase into organic phase, resulting in nanoscale hollow-bubbly PPy with better electronic properties. UV-vis was used to confirm the phase transfer ability of composed Fe (III). Cyclic Voltammograms (CVs) were used to characterize capacitance property of PPy. Fourier Transition Infrared (FT-IR) spectroscopy and Scanning Electronic Microscopy (SEM) were carried out to investigate the microstructure of PPy. Finally, defect control migration growth mechanism of PPy during the polymerization has been carefully discussed.
Influences of Reaction Temperature on Structure and Performances of SnO2 Nanocrystals Prepared by Microwave Hydrothermal Method
Authors: Yin Li Xiong , Wang Fei Fei , Huang Jian Feng , Wang Dan , Li Jia Yin
Published: December 2014

SnO2nanocrystals were synthesized using SnCl4•5H2O and NH3•H2O as the main raw materials and distilled water as the solvent by microwave hydrothermal. Reaction temperature on the structure and photocatalytic activities of the SnO2nanocrystals by microwave hydrothermal process was studied. The phase composition, morphologies and photocatalytic activities of the product were characterized by XRD (X-ray diffraction), SEM (scanning electron microscope), TEM (transmission electron microscope) and photochemical reaction instrument. Results show the crystalline and conglobation of the product have significant effect on its photocatalytic properties. The homogeneous low-agglomerated and well crystallined SnO2nanocrystals prepared at 180 °C has good photocatalytic activities during photocatalytic degradation of RhB process.
Research on Preparation of Barium Titanate Nano Powder by Sol-Gel
Authors: Li Xiao Chi , Yang Qiao
Published: December 2014

The barium titanate nanopowder was widely applied to many fields because of its excellent performances. The homogeneous barium titanate nanosized powder with high purity and small size was achieved by sol-gel. Effects of different amount of the hydrolysis of acetic acid solution on gelation process and particle size of the powder, PH value on gel time and heat preservation temperature on gelatinization were studied in the paper. The amount of the hydrolysis of 36% acetic acid solution was 25ml and the amount of Glacial acetic acid used for PH adjustment was 25-30ml. The heat preservation temperature was 95-100 °C.
Preparation of Nanoparticulate ErFeO3 by Microwave Assisted Process and its Photocatalytic Activity
Authors: Tang Chao Wan , Ying Jia Ni , Ni Dong Jing , Yang Qian , Wu Li Mei , Tang Pei Song
Published: December 2014

Using Er (NO3)3·5H2O and Fe (NO3)3·9H2O as major materials, the ErFeO3 nanoparticles were prepared by successive microwave processing and high temperature calcination. The samples were characterized by thermogravimetric and differential thermal analysis (TG-DTA), powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-visible diffuse reflectance spectroscopy (DRS). It was found that the single phase ErFeO3 can be obtained through the calcination of microwave processed ErFeO3 precursors at 800°C, and the resulting product was approximation flake of 20-80 nm. The visible-light photocatalytic activity of ErFeO3 nanoparticles was investigated in experimental simulation wastewater containing 10 mg/L methyl orange (MO). The results show that ErFeO3 nanoparticles appear high photocatalytic activity for the decomposition of MO under visible-light irradiation.
Preparation and Characterization of Mg-Doped GaN Nanowires by Au-Catalyzed Magnetron Sputtering Deposition
Authors: Liang Ru Guo , Liang Rui , Cao Gang , Shi Feng
Published: December 2014

Mg-doped GaN nanowires have been successfully synthesized on Si (111) substrates by magnetron sputtering deposition through ammoniating Ga2O3/Au thin films at 900 °C for 15 min. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and photoluminescence (PL) spectrum were carried out to characterize microstructure, morphology, and optical property of GaN sample. The results demonstrate that the nanowires are single-crystal Mg-doped GaN with hexagonal wurtzite structure and high crystalline quality, which have the size of 40 nm in diameter and several tens of microns in length and good emission property. The growth procedure mainly follows the VLS mechanism, and Au plays an important role as catalyst, and more defect energy is formed due to metallic Au and thus promote the growth of GaN nanowires.
Synthesis of Mesoporous Silica Microspheres by PICA and Pseudomorphic Transformation Using Silica Fume as Silica Source
Authors: He Jia Li , Chen Xiu Hua , Zhu Wen Jie , Ma Wen Hui , Xiao Yong Yin , Li Jiao , Zhang Hui
Published: December 2014

Monodisperse mesoporous silica microspheres (MSM-SF) were successfully prepared through PICA and pseudomorphic transformation using silica fume as original silica source. The structure and morphology of spheres were quantitatively investigated by Zata potential and particle size analyzer, N2 sorption isotherms, XRD, SEM and TEM. The results showed that the monodisperse spherical mesoporous silica microspheres (MSM-SF) exhibited uniform spherical morphology, worm-like mesoporous, large BET surface area of 559.9m2/g; its BJH average pore size diameter and total pore volume are 3.3nm and 0.12cm3/g, respectively. This preparation method provides a new synthetic strategy to control the particle morphology and structure simultaneously, meanwhile this method can also significantly reduce the cost of synthesis of mesoporous silica microspheres.
Synthesis of a Novel Lanthanide Oxide Nitrate Compound with 3D Structure
Authors: Li Hua , Yu Yan Min , Gong Zhao Yuan , Chen Hui Ying , Wang Wen Zhong
Published: December 2014

One lanthanide nitrate (Ln = Tb) with a novel three dimensional structure have been prepared through hydrothermal method. Single crystal X-ray diffraction structures were obtained. The compound crystallizes in the orthorhombic,Pnmaspace group. The lanthanide ions are eight-coordinate with six oxygen atoms coming from nitrate ions and two from bridge oxygen atoms. If the bridge oxygen atoms could be ignored, the compound can be described as a rare microporous 3D Lanthanide nitride with the open framework.
Hollow Polymer Nano-Latex Microspheres Prepared by In Situ Polymerization with the Method of Encapsulation Non-Solvent
Authors: Shao Qing Hui , Yuan Teng , Chen Zhuo , Hu Jian Qing , Tu Wei Ping , Wang Feng
Published: December 2014

In this paper, the hollow polymer nanolatex microspheres with uniform size and good monodisperse made by in-situ polymerization with the method of encapsulation non-solvent,and the effect of crosslinking monomer (DVB) dosage in the shell on the morphology and opacity of the hollow polymer nanolatex microspheres were investigated by the characterization methods of particle size analysismeter, viscosity meter, acid value analysis, SEM, TEM and UV-Vis spectrophotometry. The results show that under the other conditions and MAA dosage of the shell unchanged, when the crosslinking monomer dosage of the shell was less than 15wt%, with the reduce of the crpsslinking monomer dosage in the shell, the strength of the shell of the hollow polymer nanolatex microspheres trends decrease, when pore-swelled, the hollow polymer nanolatex microspheres were easily cracked and collapsed; when the dosage was greater than 20wt%, with the increase of the crosslinking monomer dosage in the shell, the strength of the shell and particle size of the hollow polymer nanolatex microspheres trends increase and decrease respectively, it becomes difficult to swell; when the dosage is between 15-20wt%, the dry film of the emulsion containing the hollow polymer nanolatex microspheres obtained the the optimal opacity performance.
Fabrication of Highly Ordered Two-Dimensional Graphene Arrays on Patterned Substrate
Authors: Chang Meng Jie , Liu Jun , Li Ying
Published: December 2014

We report a facial and straightforward method to fabricate highly ordered two-dimensional graphene arrays. A monolayer molecule pattern with alternative hydrophilic/hydrophobic wetting property was first formed by using micro-contact printing (μCP) and self-assembly techniques. Water droplets were condensed on the hydrophilic areas under saturated water atmosphere, which could be used to construct the ordered graphene arrays. The optical microscopy and atom force microscopy results indicate that ring and porous arrays of graphene can be obtained with low and high concentration of graphene solutions, respectively. Without the water droplet template, graphene patterns with square structure were produced.
Enhancement of Hydrophobility and Thermal Property of Graphene Oxide by Paratoluidine Chemical Functionalization
Authors: Luo Zhi Jia , Geng Hong Zhang , Zhang Song Ting , Du Bao Tan , Zhang Xing , Wang Jing , Lu Zhan Guo , Ma Su Jun , Zhang Jin Qiu , Yang Hai Jie , Wang Jie
Published: December 2014

Graphene oxide (GO) is typically synthesized by graphite powder under strong oxidizing reaction, possessing with the same set of functional groups: epoxy and hydroxyl in basal plane and carboxyl and hydroxyl groups existence on the flake edges which endow GO with amphipathy. GO and its functionalized derivatives have been successfully tested in many domains, such as polymer composites, biosensors, drug delivery systems, etc. In this paper, GO was prepared by a modified Hummers method employing improved process (preparation and separation), aiming at industrialization with the lowest cost. Moreover, some novel functional groups with different properties were controlled chemically grafted onto GO to modify the wettability and reaction activity with other materials. The hydrophobicity and the thermal property of graphene oxide were enhanced by chemical functionalization.
Variation Law of Temperature Field and Pressure Field in Synthesis of SiC by Carbothermal Reduction Method
Authors: Li Yang , Chen Jie
Published: December 2014

Through numerical simulation of temperature field and pressure field in synthesis of SiC by carbothermal reduction method, the variation law of temperature and pressure with time in furnace was studied. Research results show that the high temperature isothernal face expands outside gradually with the prolong of the synthesis time, so the temperature field area compatible to the production of SiC increase gradually, but too long synthesis time not only increase energy consumption, but also generate SiC product yield decreased. Compared with single heat furnace, the pressure is comparatively more uniformity in three-heat-source and the pressure is 140~200kPa, which is useful for synthesis of SiC and can prevent furnace spewing. At the bottom of single heat furnace should pay attention to charge ration when charging, adding a little sawdust can increase the porosity and release pressure.
Lubrication Mechanism of Nanoparticles in Metal Hot Deformation
Authors: Niu Tai Long , Sun Jian Lin , Wang Ya Dan , Zhu Zuo Xin , Li Yan
Published: December 2014

Effect of nanoparticles to improve the lubrication load capacity and resistance to extreme pressure of water-based rolling liquid was studied by four-ball tester. Compression experiments were conducted in different lubrication conditions with nanoparticles using Gleeble hot compression simulation machine. Then the residual nanoparticles characteristics and the surface morphology of the compressed sample were analyzed by SEM and EDS. The results show that water-based nanoTiO2lubricant can efficiently reduce the friction during metal deformation. nanoZnO is preferred to adhere to metal surfaces and employed to isolate the surfaces. A new lubricating mechanism of nanoparticles in metal hot deformation named convex peak extreme pressure buffering mechanism is thereby proposed, which is verified by the surface morphology of compressed sample.
Preparation and Characterization of Fibri-Form Silica from Short Chrysotile Fibers by Mix-Roasting
Authors: Song Peng Cheng , Peng Tong Jiang , Sun Hong Juan , Yu Yu Cao
Published: December 2014

Fibri-form silica was extracted from short chrysotile fibers by mix-roasting with ammonium bisulfate. The fibri-form silica were characterized by X-ray fluorescence analysis (XRF), X-ray diffraction (XRD), thermogravimetry and differential thermal analysis (TG-DTA), scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FT-IR) and N2 adsorption isotherms. The results show that the fibri-form silica with disordered crystalline structure, but also in fibrous morphology. The surface area and pore volume of fibri-form silica are 181.66 m2/ g and 0.44 cc/ g, respectively. The structure of fibri-form silica is stable, no phase transformed from 50 to 1200 oC.
First-Principle Studies Al-Fe-Ti-Cr-Zn-Cu High Entropy Solid Solutions with Pressure-Induced
Authors: Wang Lan Xin , Yao Shan , Wen Bin
Published: December 2014

The structural properties, elastic properties, mechanical stability, and phase transition of equiatomic Al-Fe-Ti-Cr-Zn-Cu high entropy solid solutions from binary (Al-Fe) to hexanary (Al-Fe-Ti-Cr-Zn-Cu) composition with pressure-induced have been analyzed using density functional theory calculations. The results indicate that the lattice parameters decrease, the mass densities increase with the pressure-increased. The mechanically stability may improve with the pressure increased appropriately for ternary Al-Fe-Ti and quaternary Al-Fe-Ti-Cr. The Young’s modulus has nothing to do with the pressure-induced, but the bulk modulus increases with the pressure increased. The elastic properties were also calculated using Voigt-Reuss-Hill (VRH) approximations. The brittle and ductile properties were studied by Poisson’s ratios and the ratios of shear modulus to bulk modulus. The calculated results of the enthalpy indicate that the binary to hexanary high entropy solid solutions transform the FCC structure to the BCC structure at a certain pressure.
Study on the Mechanical Properties of Single Crystal Aluminum by Ohno Continuous Casting
Authors: Guo Yi Ping , Guo Xiao Hui , Deng Jun Ping
Published: December 2014

In this paper, tensile properties at room temperature and bending rupture properties of single crystal aluminum wire, 4mm in diameter, fabricated by ohno continuous casting were studied, and its fracture was analyzed. The results showed that: Compared with polycrystalline aluminum samples, the yield strength of Ohno Continuous Casting single crystal aluminum changed little; Ultimate strength decreased by 42.7%; Elongation and reduction of area increased by 111.5% and 575%; Bending fatigue strength have been enhanced distinctly. Fracture of single crystal aluminum were flat tip shape, the slip line near fracture parallel to each other and uniformly distributed, the fracture is typical dimple structure and the dimple size were relatively uniform, appeared as parabolic.
Phase Transition of Ball-Milled Ni50-xMn37In13Cox (x=0,5) Alloy Powders
Authors: Fei Xiao Ping , Li Wei , Liu Jun , Xu Feng , Tang Guo Dong , Tan Wei Shi , Li Shan Dong
Published: December 2014

Ni50-xMn37In13Cox(x=0,5) alloy powders were obtained by ball-milling from the corresponding ribbon precursors. The as-milled Ni50Mn37In13and Ni45Mn37In13Co5powders show disorderedfctandfccstructures respectively, due to the larger lattice distortion in Ni45Mn37In13Co5. DSC and XRD results show that the high-temperature annealing will lead to a one-step ordering process fromfctto Heusler structure in Ni50Mn37In13, and a two-step ordering process, includingfcctobccandbccto Heusler phase transitions in Ni45Mn37In13Co5. After annealed at 400°C and 650°C, the martensitic transformation behavior is gradually and partially restored in Ni50Mn37In13powders. As modulated by the annealing temperatures, the martensitic transformation temperatures increase with the grain sizes of Ni50Mn37In13powders. However, the martensitic transformation is almost completely suppressed in 650°C annealed Ni45Mn37In13Co5powders with only some weak reflection peaks from 7M martensitic phase observed in XRD pattern.
Research on Intergranular Corrosion Behavior of Welded Joints of Nuclear Grade Stainless Steel
Authors: Chai Meng Yu , Liang Can , Wang Dong Dong , Duan Quan , Zhang Zao Xiao
Published: December 2014

The intergranular corrosion (IGC) behaviors of welded joints of 316LN stainless steel with different welding heat input were investigated in this study. The boiling nitric acid method was chosen to provide the IGC environment. The corrosion rates of different specimens were studied and the micro-structures of each zone (base material, heat affected zone and weld zone) were analyzed in detail. The results show that welding heat input affects IGC resistance remarkably and low welding heat input can reduce the IGC tendency. The IGC test can be divided into three stages, i.e. the initial corrosion stage, stable corrosion stage and rapid corrosion stage. The IGC resistance of WZ for 316LN stainless steel is better than that of BM and HAZ due to the beneficial role of delta ferrite.
BPW91 Method Used in Analyzing Electronic Structures and Magnetic Properties of Nin (2-13) Clusters
Authors: Yu Mei Yan , Wang Wan Xia , Chen Shou Gang
Published: December 2014

The bond length, average binding energy, magnetic moment per atom and the ionic potential of Nin(2-13) clusters were calculated in detail. The variations of magnetic moment per atom and the ionic potential agree well with experimental data. Theoretical results show that BPW91/Lanl2dz method is the best method and basis set for nickel clusters research, respectively. The ground state configurations and electronic structure properties of Nin(2-13) clusters were investigated using the BPW91/LanL2DZ level of DFT method. Through the molecular orbital, we could explain the paramagnetic and diamagnetic to the influence of the magnetic moment after different nickel cluster molecular hybridization.
Study on the Development of Pretreatment Processes of Electroless Nickel Plating on Al Alloy Surface
Authors: Wei Xiao Cui , Wang Jia Bo , Zhang Xiao Meng , Wang Xiao Gang
Published: December 2014

Aluminium alloy is difficult to be plated because of high chemical activity. In order to obtain electroless nickel plating with excellent adhesion to the substrate, the key lines is the pretreatment process. This study introduces several significant pretreatment processes of aluminium alloy surface at home and abroad for these years, and describes the principles of pretreatment processes. Finally, the development direction of pretreatment processes for aluminium alloy is forecasted.
Electroless Fabrication of Nd-Fe-B/α-Fe Heterostructured Composite Magnets and their Magnetic Properties
Authors: Fan Xiao Dong , Tian Na , You Cai Yin
Published: December 2014

Electroless plating was used to coat Fe layers on the hard magnetic Nd-Fe-B powders to fabricate Nd-Fe-B/α-Fe heterostructured magnetic powders. The heat treatment was performed to study the property evolution of the heterostructured magnetic powders. The results show that Fe coating was oxidized to Fe2O3while drying; through the hydrogen reduction annealing, Fe2O3was reduced to α-Fe. The coercivity of the heterostructured magnetic powders increased from 111.3 kA/m (1.4 kOe) to 524.7 kA/m (6.6 kOe) after annealing at 650°C. However, the demagnetization curve of powders presents a kink due to un-ideal coupling between hard and soft magnetic phases because of the aggregation of α-Fe. The magnetization processes of the heterostructured powders transferred from the dominant nucleation mechanism to domain wall pinning mechanism after the heat treatment.
Effects of Ni/Co Metal Binder Phase on Mechanical Properties of Ti(C,N)-Based Cermets
Authors: Zhang Pei , Sun Wan Chang , Yang Qing Hao , Li Pan , She Xiao Lin
Published: December 2014

Ti(C,N)-based cermets were prepared by pressureless sintering using micron-sized TiC and TiN powders as main starting materials and Ni and Co as metal binders. The fracture micrographs of Ti(C,N)-based cermets were observed by SEM. The effects of metal binder phase content on porosity and mechanical properties of Ti(C,N)-based cermets were investigated. The results show that when sintering at 1450 °C for 50min, typical core/rim microstructure is observed in the cermets, which is compact and distributed homogeneously, the density and relative density are 5.9 g/cm3 and 95.6%, respectively. Intergranular fracture is the main crack propagation mode, with a few of the transgranular fracture, and there are more dimples and tearing ridges in the fracture surface. Using the same sintering process, Ti(C,N)-based cermets with metal binder content of 10%Ni5%Co has a compact microstructure and fine grains, the metal binder phase is dispersed more evenly, the best vicker hardness, bending strength and fracture toughness of Ti(C,N)-based cermets are 15.8 GPa, 885.5MPa and 9.7 MPa·m1/2, respectively. However, Ti(C,N)-based cermets with Ni replaced of high Co content will generate some brittle intermetallic compound, its toughness is inferior to the metal binder phase, which reduces the strength and toughness of Ti(C,N)-based cermet materials.