bluuebunny/crossref_metadata_2025 huggingface dataset:
Molecular Dynamics Simulations of Structures of Amorphous Carbon Films via Deposition
Authors: Lan Hui Qing , Kang Zheng Ling
Published: February 2011

The growth of amorphous carbon films via deposition is investigated using molecular dynamics simulation with a modified Tersoff potential. The impact energy of carbon atoms ranges from 1 to 50 eV and the temperature of the diamond substrate is 300 K. The effects of the incident energy on the growth dynamics and film structure are studied in a detail. Simulation results show that the mobility of surface atoms in the cascade region is enhanced by impacting energetic carbon ions, especially at moderate energy, which favors the growth of denser and smoother films with better adhesion to the substrate. Our results agree qualitatively with the experimental observation.
Study of Mg(Zr0.05Ti0.95)O3 Dielectric Thin Films by Sol-Gel Method
Authors: Tseng Ching Fang , Yang Pai Chuan , Lai Chun Hung , Lee Chih Wen
Published: February 2011

Electrical properties and microstructures of Mg(Zr0.05Ti0.95)O3 thin films prepared by sol-gel method on n-type Si(100) substrates at different annealing temperatures have been investigated. The diffraction pattern showed that the deposited films exhibited a polycrystalline microstructure. All films exhibited Mg(Zr0.05Ti0.95)O3 peaks orientation perpendicular to the substrate surface and the grain size with the increase in the annealing temperature. A low leakage current density of 1.1×10-4 A/cm2, a dielectric constant of 9.4 and an optical bandgap of 3.6 were obtained for the prepared films. It may find application in dynamic random access memories and wireless communication devices.
Electromagnetic Properties of Polyaniline Co-Doped with CSA and Ni2+
Authors: Zhu Shi Bu , Jiang Man , Zhao An , Wei Wei , Zhou Zuo Wan
Published: February 2011

In this work, polyaniline co-doped with (IS)-(+)-10-camphorsulfonic acid (D-CSA) and Ni2+ was synthesized via in situ polymerization. The structure, conductivity and electromagnetic parameters of the resulting polyaniline were characterized by FTIR, SZ82 digital multimeter and AV3618 network analyzer. The conductivity of polyaniline at room temperature increases with increasing of Ni2+ loading. Moreover, the resulting polyaniline co-doped with Ni2+ displays obvious magnetic loss at the microwave frequency. So, we suppose that this conducting polymer can be used as microwave absorbing material with wide-range and good effect.
Surface Modification of Starch and its Application in Rubber Composite with Low Heat Generation and High Fatigue Resistant
Authors: Fang Qing Hong , Li Tian Yu , Wang Na , Jin Li Jun , Liang Yue
Published: February 2011

The surface modification of corn starch and the use of modified starch as reinforcing filler partly replaced carbon black in rubber composites were studied. The surface of starch was modified with 3, 4-2H-dihydropyran and maleic anhydride by grafting reaction in organic solution, that is, the process of etherification and the esterification of the starch. The structure of the ether ester starch was investigated by FTIR, SEM. Based on the results of the mechanical and heat building up properties of composite, it is showed that using modified starch as reinforcement filler filled into the rubber partly replaced CB, the characteristics of high flex life and low heat building up for composite can be obtained.
Study on Analysis Methods of Tear Propagation of Fabric Laminates
Authors: Meng Jun Hui , Liu Dong Xu , Zhang Yi , Jia Zhao , Lv Ming Yun
Published: February 2011

Tear propagation is a typical breakage modality of fabric laminates. In this paper, analysis methods and their empirical formulas about tear propagation of a kind of fabric laminate which is used in high altitude lighter-than-air vehicle (LTA) is studied. The methods include Griffith’s energy balance method, Thiele’s empirical formula method, Stress field consideration method and critical stress intensity factor method. Testing about tear propagation strength in biaxial stress is done by a tailor-made testing machine to study on the methods. And then a comparison is drawn between these formulas and results of the experimentation. Subsequently, advantages and disadvantages of these formulas and their scope of application are concluded. While by using the empirical formulas, the analysis of tear propagation of different incision shapes is given. It is useful for the further study on different fabric laminates.
Effect Analysis of Ar-N2 Flow Rates on ZrNX Film by Pulsed Magnetron Sputtering Using Design of Experimental Method
Authors: Wen Hung Jiun , Wen Fuh Liang , Chang Kuo Hwa , Wen C.H. , Lo Yu Lin
Published: February 2011

The various nitrogen gas (N2) flows for depositing zirconium-nitride (ZrN) films on the substrate of a p-type (100) silicon wafer are investigated through reactive magnetron sputtering by a pulsed-DC power. The results, based on the design of experimental (DOE) method, indicate that the deposition effect of the ZrNx film is obviously affected by various flow rates of nitrogen gas at the specific pulsing duty cycles. The crystal orientation of the zirconium-nitride film has a less order microstructure which is similar to an amorphous microstructure. Although the composition ratio of chemical elements is not identical in Zr and N, the surface roughness, grain size, and resistivity are the better feature. The deposition rate is inversely proportional to the nitrogen flow rate and the chamber pressure is also an important factor. The basic effect of N2 flow rate on the surface roughness is rougher when more nitrogen gas is supplied. The resistivity of ZrNx thin film has a positive relationship to N2 flow rates at the reactive vacuum chamber.
Study on Effects of Pretreatment on Carbide of a Medium-Alloy High Carbon Steel
Authors: Dai Yu Mei , Ma Yong Qing
Published: February 2011

The effect of pre-treatment on carbide transformation and morphology of a medium-alloy high carbon steel (0.86C, 0.84Cr, 1.85W, 0.95Mo, 0.31V) with multi-elements was investigated in this paper. The results show that there are multiple types of carbides (M3C、M23C6、M7C3、M6C、MC) in the annealed steel. The morphology of carbide in the annealing microstructure largely relate to the process before annealing. Carbides with disperse spherical and short rod-like distribution exist in the ferritic matrix when the steels are annealed at 820−860°C. The spherical carbides in the ferritic matrix can be obtained by isothermal annealing at 680−720°C after heating at 800°C. The morphology of carbides with different pretreatment process relate to carbide transformation, which can be described by calculating based on phase equilibrium thermodynamic.
Effect of Mold Flux for Casting on Microstructe of Mould Powder
Authors: Liu Li Na , Han Xiu Li , Li Chang Cun , Yang Hui Ping
Published: February 2011

The microstructe of mold fluxes of low-carbon steel and mould powders were researched by means of polarizing microscope. The result shows that the mineral compositions of the mould fluxes primarily are glass phase, wollastonite, quartz, melilite, pyroxene and feldspar. The main mineral compositions of mould powders is melilite. The quartz, pyroxene and glass phase are helpful to reduce the crystalline portion of mould powder, but the melilite, wollastonite help to improve the crystalline portion and promote crystallization of melilite. It is good for the crystalline portion when the casting speed droop.
Cold Model Study of Raceway in COREX Melter Gasifier
Authors: Di Zhan Xia , Han Li Hao , Luo Zhi Guo , Zou Zong Shu
Published: February 2011

In this paper, the method of cold model is applied to study raceway in COREX Melter-Gasifier drawing on the experience of raceway in blast furnace. The influence factors, blasting volume, charging rate which simulates coke consumption, bed packing height have been considered. The results show that the shape of raceway is ellipsoidal and blasting volume, charging rate, bed packing height have effect on raceway. The raceway penetration depth and raceway height expand with increasing blasting volume and charging rate. However, the size of raceway decreases with increasing bed packing height.
Effects of Mn on the Precipitation Behaviors in High-Nitrogen Austenitic Stainless Steels
Authors: Shi Feng , Qi Yang , Liu Chun Ming
Published: February 2011

Precipitation behaviors of Fe-18Cr-12Mn-0.48N and Fe-18Cr-18Mn-0.43N high-nitrogen austenitic stainless steels isothermally aged at 800°C were investigated by using optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results show that precipitation both display discontinuous cellular way and the major precipitates are both M2N phases accompanied by scattered M23C6 phases at grain boundary in the experimental steels. Increment of Mn content can not change the precipitation way and precipitation type. Increment of Mn content makes M2N precipitates obviously increase and increment of Mn and C contents makes M23C6 precipitates increase.
A Study on Flow Characteristics of Coherent Jet Oxygen Injector
Authors: Lv Zi Qiang , Ma Qing Yuan , Su Xiao Jun
Published: February 2011

Oxygen injector is oxygen supply equipment for steelmaking process. Based on the numerical simulation of the flow field of a new coherent jet oxygen injector and traditional supersonic oxygen injector, the authors contrasted the axial and radial velocity decay of them. After a discussion on the influence of structural parameters on the jets, the authors pointed the impact of the jet characteristics of oxygen injector due to structural wear from the angle of practical operation.
Effect of Pulsed Electric Field on the Distribution and Migration of P, S, and Si Elements of Fe-Based Alloys
Authors: Liao Zhi You , Wang Hai Chuan , Hong Peng , Li Xin , Lie Jie , Wang Shi Jun , Wang Gui , Dargusch Matthew S.
Published: February 2011

Pulsed electric field has been effectively used to control and modify the solidification process in castings. In this study, a pulsed electric field at 8 volts and 19 kHz has been applied to Fe-P, Fe-S, and Fe-Si binary alloys, and microstructure and elements distribution of the three alloy samples have been inspected. The results indicated that P migrated from cathode to anode while S and Si migrated from both electrodes to the center under the pulsed electric field during the solidification process.
Carbon Nanotubes with Uniform Wall Thickness Synthesized Via a Solid-Liquid Reaction
Authors: Yin Cai Liu , Wen Guo Fu , Huang Qi Zhong , Wang Xiu Fei
Published: February 2011

Carbon nanotubes(CNTs) with uniform wall thickness were synthesized by a solid-liquid reaction route. Calcium carbide block and carbon tetrachloride as double carbon sources were enclosed in a 100ml stainless steel autoclave at 400°C for 8 hours. The fabricated products were characterized using X-ray diffraction (XRD), scanning electron microscope (SEM), and Transmission electron microscope (TEM). The research results indicate that the synthesized CNTs have lengths on the order of 10μm and external diameters in the range of 120-200nm. The nanotubes are typically the uniform inner diameters of 70nm and grow in the same direction. The growth mechanism is simply discussed.
Research on Ultrafine PTFE Particles with Grease Tribological Properties
Authors: Ma Zhen Jiang , Yin Ji Hui , Jiang Yang
Published: February 2011

This article presents a research on friction and wear properties of titanium composite lubricating grease containing ultrafine PTFE particles by using scanning electron microscopy to observe surface morphology of the worn steel balls and EDS to analysis the main elements in the worn surface of steel ball. The results show that the compound titanium grease with 3% ultrafine PTFE has the best wear and friction reduction properties. Its friction coefficient decrease about 25.5%, the diameter of wear scar decrease about 23.2%. The appropriate amount of PTFE particles go into the frictional surface with the grease, form the PTFE particle layer on the frictional surface, which reduces the direct contact of metal to metal, effectively reduces the friction and wear.
Synthesis of Nanocrystalline TiC1-xNx by High Energy Milling
Authors: Zhu Jian Feng , Ye Lan , Tong Hai , Wang Fen
Published: February 2011

The nanocrystalline TiC1-xNx powders were synthesized by high energy milling from the mixture of Ti and carbon black in nitrogen milling atmosphere. The phase transformation and powder morphology characteristics were studied by using XRD and SEM. The results show that nanocrystalline TiC1-xNx powders were fabricated successfully by milling for 24 h at a rotational speed of 450 rpm in planetary ball-mill. The formation mechanism was mechanically induced self-propagating reactive synthesis (MSR). According to changing the mole ratio of C to Ti, serial TiC1-xNx powders can be produced, including TiC7N3, TiC5N5, and TiC3N7.
Fabrication and Characterization of Nanocrystalline NiO Prepared by Sol-Gel Process
Authors: Cai Yu , Wu Zhao Yang , Zhao Shen Li , Zhu Ji Ne
Published: February 2011

The nano-NiO powder was prepared by sol-gel method combining heat treatment technology and its structure and morphology were explored. In addition, the NiO powder electrochemical properties were tested by constant current charging and discharging. The results show that the stable performance sol can be composed by nickel acetate as source of nickel and PAA as chelating agent. Nano-NiO powder of crystal structure integrity, particle uniformity can be prepared by the sol. The gel decomposes completely and gradually forms nanocrystal at 430οC. Its grain size is gradually increasing when the annealing temperature rise. The nano-NiO powder sintered at 600°C exhibits uniform particle, integrity crystal structure, low aggregation and superior electrochemistry performance and may be used in Li-ion battery as the anode material.
Ni-Al2O3 Nanocomposites Electroforming Process under Ultrasonic and Agitation
Authors: Lei Wei Ning , Jiang Bo , Liu Wei Qiao , Wang Xing Xing
Published: February 2011

Ni-Al2O3 nanocomposite coating, which was fabricated by eletrodeposition technique with the aid of ultrasonic and agitation. The effect of ultrasonic and agitation on the characteristics of the deposits was investigated by scanning electron microscopy (SEM) and microhardness tester. The results shows that ultrasonic and agitation result in decreasing of Al2O3 nanoparticles aggregation and increasing of Al2O3 nanoparticles uniformly dispersed on the matrix of the composite coating. The ultrasonic and agitation improved the Ni crystallization in the Ni-Al2O3 nanocomposite electroforming coating. Compared to the process of without ultrasound, the nanocomposite is prepared with ultrasonic and agitation, which has a higher stiffiness by the same current density and electrolyte. The average microhardness of the deposit reaches to 461.9 HV with ultrasonic and agitation, which is double of the conventional electroforming coating.
Numerical Simulation for Direct Reduction of Pure Zinc Oxide Pellet Containing Carbon
Authors: An Xiu Wei , Wang Jing Song , She Xue Feng , Ding Yin Gui , Xue Qing Guo
Published: February 2011

Based on the equations of mass conservation, energy conservation and chemical reaction rates, a mathematical model of direct reduction for pure zinc oxide pellet containing carbon was built. On the basis of verifying the accuracy of the model by comparing calculated values with experimental results, the effects of furnace temperature, porosity and radius of pellet on the reduction were investigated. The calculated results revealed that the furnace temperature and the radius of pellet have significant effect while porosity has only a little. Thus it can be inferred that the rate-determining step for direct reduction in the pellet containing zinc oxide and carbon is heat transfer.
Carbon Nanotube Templated Growth of the Nano-Crystalline NaY Zeolite
Authors: Tang Ke , Hong Xin , Qi Jin Gang
Published: February 2011

FAU-type(NaY) zeolites nanocrystals have been synthesized through crystallization of gel in mesoporous system of carbon nanotubes(CNTS) with a internal diameter of 20~30 nm. Investigation by using X-ray diffraction (XRD), Fourier transform infrared (FT-IR), transmission electron microscope (TEM) shows that the nanocrystals possess the typical nanosized zeolites structural characteristics which is different from those of microsized zeolites.
Facile Fabrication of Single Crystalline Fe3O4 Nanorods and its Magnetic Properties
Authors: Li Gui Lian , Liu Xian Ming , Yin Wei Dong
Published: February 2011

Single crystalline Fe3O4 nanorods were fabricated in high yield via a facile hydrothermal route in the presence of sodium citrate as addition agent. The phase structures, morphologies, and sizes of as-prepared products were investigated in detail by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). The diameter of magnetite nanorods is about 50~80 nm and its length is more than 2 μm. Room-temperature magnetic measurements showed that Fe3O4 nanorods exhibited high saturation magnetization and coercitivity of 77.8 emu/g and 98 Oe, respectively, while the as-obtained nanoparticles had low coercitivity value.
The Tribological Properties of PA6/UHMPE Blended Short Carbon Fiber Nanoclay Filled Nanocomposites
Authors: Li Jian , Cai Chi Lan
Published: February 2011

The sliding wear behavior of polyamide6/ultrahigh molecular weight polyethylene (PA6/UHMWPE, 90/10) blends loaded with 20 % carbon short fibers (CSF) as reinforcement and varying amounts of nanoclay filled nanocomposites were reported. Sliding wear loss, specific wear rate and coefficient of friction were investigated. 3 % nano clay filled composite exhibits better wear behaviour. Morphological study was evaluated for wear out surfaces of the composites using scanning electron microscopy.
Preparation of ZnO Nano-Suspension and its Antibacterial Effect on Escherichia Coli
Authors: Li Xi Hong , Jiang Yu Qian , Jiang Yun Hong , Li Wei Li , Ding Yu Long
Published: February 2011

Ultrasonic oscillation and nanometer grind were used to treat ZnO suspension, and the effects of treatment time on preparation of ZnO were investigated. PEG400 was chosen as a suitable surfactant to reduce aggregation problem because PEG400 is not only effective at keeping the stability of ZnO suspension, but also has no influences on diameter size of ZnO nanoparticles or antibacterial ability. The effects of concentration and particle size on antibacterial ability of ZnO suspension were evaluated. The results demonstrated that the optimum time of ultrasonic oscillation for reducing aggregation is 0.5 h, and diameter size exhibited linear decline during the first 1 h of nanometer grind. Antibacterial ability increased with the increasing of the concentration of ZnO nano-suspension until it reached 0.25 g/L, and antibacterial ability was inversely proportional to diameter size of ZnO nanoparticles.
Synthesis Pathway of Dioxins in Iron Ore Sintering Process
Authors: Long Hong Ming , Li Jia Xin , Wang Ping , Wei Ru Fei
Published: February 2011

Dioxins are a kind of extremely toxic and Persistent Organic Pollutants (POPs). Sintering process has become one of the most dominant unintentional discharge sources. The dioxins synthesis pathway and mechanism being described, related research indicate that: in the low temperature sector (200-500ºС), chlorobenzene and chlorphenol are the representation precursors of dioxin’s precursor catalytic reaction, the dioxins formed in this temperature sector cased by the “de novo” under catalyst (like Cu2+) on the surface of smoke particles; high-temperature gas phase reaction mechanism of dioxins satisfied the first-order kinetic model, the formation of gas related with suitable precursors, it is the result of chlorinated precursors’ pyrolytic rearrangement like chlorobenzene and chlorophenol in the temperature sector 500-800ºС in the gas.
Petal-Like Morphology on the Surface of Porous Anodic Alumina
Authors: Song Ye , Ye Qiu Mei , Liu Peng , Hu Jun Jun , Zhu Xin Hua
Published: February 2011

The formation process of a petal-like morphology on the surface of porous anodic alumina (PAA) is discussed in detail. During the anodizing process, the electronic current is produced within the growing oxide, which results in the oxygen evolution at the pore bottom. The pressure of the oxygen bubbles increases along with the anodizing process, and their high pressure acts as a driving-force of the micro-gas-flow, resulting in the micro-liquid-flow in the pores of PAA. The micro-liquid-flow can flow into each other between a center pore and the nearest neighboring pores. The nanogroove between two pores can be formed due to the dissolving effect during the process of micro-liquid-flow between the two pores. This leads to the formation of the petal-like morphology on the PAA surface. As the micro-liquid-flow leaves off the pore bottom, there a local vacuum is formed. This local vacuum behaves as a driving-force of the micro-liquid-flow, making the electrolyte renovated in the nanopores. The renovated electrolyte can provide enough anions or impurity centers, which are the cause of the generation of the electronic current. The self-organizing for the petal-like morphology on PAA surface is mainly dependent upon the high pressure of the oxygen bubbles and the local vacuum produced at the pore bottom. The present results may help us to understand the nature of the self-organization in the porous anodic oxides.
Study of Rubber Asphalt Modification Mechanism
Authors: Wang Xiao Feng
Published: February 2011

The paper studies the modification mechanism of asphalt rubber blending system by means of scanning electron microscopy, infrared spectroscopy, differential thermal analysis, component analysis and chemical analysis. The results indicate that the swollen rubber powder is mutually-adhered to form a network structure and the matrix asphalt changes from homogeneous body into a two-phase continuous blending structure system constituted by rubber powder and asphalt; physical swelling dominates the system, accompanied by a little chemical reaction and with the prolongation of time, the chemical reaction becomes more obvious; the swollen rubber powder forms damping effects to improve the viscosity of rubber asphalt. The modification of asphalt comes from two aspects: firstly, the network structure formed by swollen rubber powder, secondly, the modification of the asphalt composition resulting from rubber powder desulphurization degradation; the natural rubber has better performance in modifying asphalt than synthetic rubber.
In Situ Observation Microstructure Character Changes in the Carbonation Process of Hardened Cement Paste Using ESEM/EDS
Authors: Han Jian De , Pan Gang Hua , Sun Wei
Published: February 2011

Environmental Scanning Electron Microscope (ESEM) and Energy Dispersive X-ray Spectroscopy (EDS) were used to in situ observation microstructure character changes of hardened cement paste due to carbonation. Three types water-to-cement ratio of 0.53, 0.35 and 0.23 were research. When w/c=0.53, Carbonation enlarged the cracks, and some calcium carbonate spots appear on the calcium hydroxide crystals. When w/c=0.35, less cracks appear, and some white flocculent calcium carbonated appear on the calcium hydroxide crystals than above w/c=0.53 cement paste. When w/c=0.23, the microstructure character before and after carbonation have distinct changes, and some cracks become small or disappeared. Unhydrated cement clinkers continue to hydrate reactions and there are many white SiO2•nH2O (silica gel) after C-S-H gel carbonation in cement paste matrix.
The Function Study of TiO2 Catalysts on Zinc Air Battery
Authors: Zhou Chun Sen , Zhu Pei Xian , Guo Jia Xin
Published: February 2011

Adopt the titanium sour D ester water solution legal system have of the Na rice TiO2 does the zinc-air battery cathode catalyst. Shoot line Yan to cast light a table method(XRD) and scan an electronic microscope method(SEM) with the X, and deeply shoot an electronic microscope method(TEM) to carry on token to the TiO2 powder sample of making,[1] result enunciation titanium sour D ester water solution method legal system have of TiO2 catalysts is the Rui titanium mineral type structure, grain the path be not the biggest over 50 nms.Adopt cathode very in the meantime to turn curve, the Heng electric potential turn on electricity with the Heng electric current turn on electricity etc. electricity chemistry test means, result detection,The TiO2 has a better electricity catalyst an activity in the alkalescence lie the quality 6 mols/LNaOH, in keeping with do the zinc-air battery cathode catalyst.
Study on the Hydraulic Conductivity of Sand-Bentonite mixtures used as Liner System of Waste Landfill
Authors: Xu Si Fa , Wang Zhe , Zhang Yong
Published: February 2011

A liner system such as liner sheet underlying impermeable soil layer having hydraulic conductivity less than 1*10-7 cm/s and a thickness larger than 100 cm is often used in china. As there is very little natural clay having such low permeability, bentonite is usually mixed into sand to decrease the permeability. In this paper, the compaction tests and permeability testing using flexible-wall permeameter are conducted. The test results show that the value of critical benonite ratio depends on bentonite ratio, and the hydraulic conductivity of the sand mixed with critical bentonite ratio for distilled water shows of the order of 1*10-8 cm/s that satisfies the china standard requested as compacted soil liner of waste landfill. Finally, the permeability testing used leachate including calcium component was conducted.
Effect of Pore Structure of Sandstone on Hydrophilic Characteristicis
Authors: Zhou Li
Published: February 2011

Pore structure of sandstone has much influence on its hydrophilic characteristics. The results of pressured-mercury testing for sandstone are discussed in the paper with the help of fractal geometry theory. The effect of pore structure for sandstone is mainly discussed, combined the results of hydrophilic experiment. Results show that the pore structure of sandstone has single and multiple characteristics within some pore size. Four typical fractal characteristic are defined in the paper and it is found that characteristic of pore structure has much relation with its hydrophilic characteristics: hydrophilic rate of Sandstone with A or C-type fractal microstructure changes little and the double logarithmic hydrophilic relationship curve is always linear; however, the hydrophilic rate of ones with B and C-type fractal microstructure changes greatly and always taken as concave-convex.
Photoinitiated Emulsion Polymerization of P(MMA-co-DVB) Microspheres with Low Power Ultraviolet Light
Authors: Tao Li Jun , Sun Feng Qiang
Published: February 2011

Poly (methyl methacrylate-co-divinylbenzene) [P(MMA-co-DVB)] microspheres were first synthesized by a simple photoinitiated emulsion polymerization methods. In this polymerization system, MMA, DVB, AIBN, isopropanol and hexahydrobenzene constituted the oil phase, SDS acted as the stabilizer and an 8 W Ultraviolet lamp was employed as the light source. Under the irradiation of the UV light, AIBN could be decomposed to produce radicals and initiate the polymerization of MMA to produce P(MMA-co-DVB) microspheres.The morphologies and structures of the products were characterized by Fourier transform infrared spectroscope (FTIR),size distribution, scanning electron microscope (SEM). The average diameters of the spheres increased with the content of DVB. The research may provide a quick, green and facile room-temperature approach to prepare polymer microspheres.
3-D Numerical Modelling of Mesoscopic Configuration and Cracking of Concrete
Authors: Hu Le Sheng , Chen Shui Fu
Published: February 2011

This paper presents a numerical strategy for realistic modelling of the internal material configuration and cracking of concrete on mesoscale. Polyhedron shapes resembling crushed rocks are adopted to represent the aggregate. A packing approach in which the particles are heaped up layer by layer is proposed for 3-D condition. A cubic representative volume element (RVE) is generated using the method. The cohesive approach, in which zero thickness cohesive elements are inserted into the ordinary finite element mesh along the potential cracking path, is adopted to model the cracking developing process. The cracking behaviours of created RVE under uniaxial tension are well simulated using the current approach.
Supercapacitor Electrode Materials Based on Activated Carbon /Polyaniline Doped with Nickel Salt
Authors: Tian Yan Hong , Zhang Xue Jun , Zhao Yu
Published: February 2011

Two types of supercapacitor electrode materials have been synthesized: AC/PANI, activated carbon composites polyaniline by in-situ polymerization of aniline on the surface of activated carbon, and Ni-AC/PANI, the AC/PANI composite dopes with nickel. The microstructure of composites has been examined by scanning electron microscope (SEM). Fourier transform infrared spectroscopy (FI-IR) has been used to determine the molecular structure and chemical bond of the composites. The nickel content has been measured by atomic absorption spectrometry (AAS). The electrochemical performance of the composite has been characterized by cyclic voltammery and galvanostatic charge-discharge in 6mol•L-1 KOH solution using Hg/HgO as reference electrode. Due to the doping of nickel salt, Ni-AC/PANI shows desired microstructure, good high-current charge-discharge performance and good electrochemical behavior with an capacitance of 535F•g-1, 38.2% higher than that of AC/PANI.
Zr-Catalyzed Hydrogen Chemisorptions on an Al Surface
Authors: Zhang Wen Xue , Hu Xin , Lin Xiao Bin , He Cheng
Published: February 2011

The most promising hydrogen storage materials are perhaps complex metal hydrides. Thus, a plausible first step in the rehydrogenation mechanism is proposed by simulating the reversible hydrogen storage in Zr-doped NaAlH4. It provides insight into the catalytic role of Zr atoms on an Al surface in the chemisorptions of molecular hydrogen. It is found that the diffusion of hydride species on Al-metallic phase and formation of Al hydride species is probably the key to syntheses the next products in the rehydrogenation reaction.
Novel Co3O4/Carbon Nanofiber Composite Electrode with High Li-Storage Capacity for Lithium Ion Batteries
Authors: Yao Wen Li , Chen Jin Qing , Li An Yun , Chen Xin Bing
Published: February 2011

The platelike Co3O4/carbon nanofiber (CNF) composite materials were synthesized by the calcination of β-Co(OH)2/CNF precursor prepared by a surfactant-free hydrothermal method. As negative electrode materials for lithium-ion batteries, the platelike Co3O4/CNF composites can deliver a high reversible capacity of 900 mAh g-1 for a life extending over hundreds of cycles at a current density of 100 mA g-1. The high Li-storage capacity and excellent cycling performance for Co3O4/CNF composite materials may mainly attribute to the beneficial effect of the CNFs addition on enhancing structural stability and electrical conductivity of Co3O4 platelets.
Effect of Solution Treatment and Extrusion on the Microstructure and Mechanical Properties of a Mg-2Gd-Nd-0.4Zn-0.3Zr Alloy
Authors: Nie Jing Jiang , Meng Liang , Zhu Xiu Rong , Xu Yong Dong , Wu Yue Yi , Wang Rong , Wang Jun , Zhang Hua , Chen Min , Zhang Li Jun
Published: February 2011

The effect of the combined action of hot work and heat treatment on the microstructure and mechanical properties of a Mg-2Gd-Nd-0.4Zn-0.3Zr (wt. %) (E21) alloy was investigated. Results showed that the solution treatment time of the ingot played a great effect on the mechanical properties of the extruded alloy. With solution treating time of the ingot increasing, the tensile strength of the extruded alloy decreased gradually, but the elongation increased greatly. The best combination of strength and ductility was achieved for the extruded alloy after the ingot solution treated at 520°C for 3 h, extrusion at 400°C and aging at 200°C for 16 h, namely ultimate tensile strength = 331MPa and elongation = 7.1%.
Fabrication of the Effective Counter Electrode for Dye-Sensitized Solar Cells
Authors: Liu Rui , Yang Wein Duo , Wu Jian Fu , Qiang Liang Sheng
Published: February 2011

Pt-counter electrodes were manufactured by dip coating, spin coating and sputtering methods for dye-sensitized solar cells (DSSCs). Their properties were analyzed with cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), energy disperse spectroscopy (EDS). We also fabricated the TiO2 nanotubes of 1.04 μm length as photoanode. The analytic results show that spin coating method has higher Pt content deposited on FTO glass, better performance of charge-transfer, more positive potential of tri-iodide reduction and higher efficiency of DSSCs.
Study on the Inclusion Behavior of Cucurbit [n] uril with Phenylalanine
Authors: Chen Ning , Li Ya Bin
Published: February 2011

The characteristics of host-guest complexes between cucurbit[n]uril (CB [n]) and phenylalanine were investigated by UV-visible absorption spectroscopy in acetate buffer solution at room temperature. It was found that the UV-visible absorption increased steadily with constantly dropping the high concentration of cucurbit[6]uril (CB [6]) and cucurbit[8]uril (CB [8]) in the phenylalanine solution which indicates that there are some interaction betweenCB [n] and phenylalanine.Then CB [6] and phenylalanine at molar ratio of 1:1 to weigh while CB [8] and phenylalanine at molar ratio of 1:2, respectively, are both demonstrated by 1H NMR spectra. 1H NMR spectrum of complexes was obtained, indicating an enthalpic driving force for host-guest complexes. The possible interaction mechanism and inclusion mode were also discussed. This work may extend the application range of CB [n] in supramolecular and pharmaceutical analysis.
The Effect of Intumescent Flame Retardant Contained Microencapsulated Red Phosphorus on the Flame Retardance and Thermal Degradation Behaviour of Epoxy Resin
Authors: Wu Zhi Ping , Hu Yun Chu , Chen Mei Qin
Published: February 2011

The effect of intumescent flame retardant (IFR) contained microencapsulated red phosphorus on the flame retardance of E-44 epoxy resin (EP) was studied. The test results indicated that good flame retardancy can be realized when epoxy resin treated with 30% IFR. Thermogravimetric analysis showed that the charring amount at high temperature of EP can increase substantially when IFR was incorporated. In order to further explain this phenomenon, Dolye integration method of thermal degradation dynamics was employed to study the thermal degradation process of EP treated with IFR based on the microencapsulated red phosphrous according to the thermal gravimetry analysis results.The activation energy and reactor order of different thermal degradation stages were obtained. The results of thermal degradation dynamics implied the intumescent flame retardants can improve the flame retardance of the epoxy resin through decrease the degradation speed and increase the activation energy of the second thermal degradation stage.
New Waterborne Polyurethane Dispersions from the Soybean-Oil-Based Polyols by Ring Opening of ESO with Glycol
Authors: Wang Kun Peng , Yang Li Ting
Published: February 2011

A series of polyols (GSOLs) with a range of hydroxyl numbers based on epoxidized soybean oil (ESO) were prepared by ring opening with glycol. These Polyols of hydroxyl (OH) numbers ranging from 111 to 162 mg KOH/g were obtained. The environmentally friendly soybean-oil-based waterborne polyurethane dispersions (SPU) with very promising properties have been successfully synthesized from a series of soybean-oil-based polyols (GSOLs) with different hydroxyl numbers by a polyaddition reaction with toluene 2,4-diisocyanate (2,4-TDI). The structure and thermophysical properties of the resulting SPU films have been studied by Fourier transform infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis, and hardness testing. The experimental results showed that the functionality of the GSOLs and the hard segment content play a key role in controlling the structure and the thermophysical properties of the SPU films.
Preparation of Lignosulfonate-Chitosan Polyelectrolyte Complex
Authors: Wang Chun Hai , Fang Gui Zhen , Ai Qing , Zhao Yin Feng
Published: February 2011

Sodium lignosulfonate -chitosan (SLS-CS) polyelectrolyte complex was prepared by alkaline lignin and chitosan as raw materials. The structure and thermal stability of SLS-CS polyelectrolyte were characterized by FTIR, XRD, DSC. The results indicated that NH3+ was formed by the protonated amino groups of chitosan and then came into SLS-CS polyelectrolyte complex with -SO3Na of sodium lignosulfonate through electrostatic adsorption. Compared with the sodium lignosulfonate and chitosan, the thermal decomposition temperature of SLS-CS raised and thus improved the thermal stability; the amorphous peak tends to decrease; SLS-CS polymer arrangement appeared more ordering, and the molecular interaction were enhanced.
Bismaleimide (BMI) Resin Modified by PEEK Bearing Pendant Reactive Propenyl Groups
Authors: Ding Fu Chuan , Chen Qing Song , Lai Shou Lian , Li Xiao Yan
Published: February 2011

A reactive poly (ether ether ketone) PEEK with pendant propenyl groups was prepared by nucleophilic aromatic substitution of 4, 4’-Difluorobenzophenone (DFBP), diallylbisphenol A (DABPA) and bisphenyl A (BPA) as monomer. The prepared reactive PEEK with varying proportion was introduced to toughen bismaleimide (BMI) resin composing of 4,4'-bismaleimidodiphenyl methane (BMDM) and DABPA by melt technique without any solvent. The properties of the BMI resin as a function of the reactive PEEK concentration were evaluated. The presence of PEEK heightened the temperature of “ene” reaction for BMI and DABPA and slightly lowered the glass transition temperature (Tg) of the blends. The impact strength and fracture toughness were highest elevated from 9.0 KJ/m2 and 186 J/m2 to 15.2 KJ/m2 and 239 J/m2 by 10 phr PEEK, respectively. At the same time, the thermal stability was improved by increasing the proportion of the PEEK. Scanning electron microscopy (SEM) of fracture surface revealed that the blends have good interfacial adhesion.
Statistical Analysis of Micro-Crack Parameters for PPy-Coated Fiber Strain Sensors Applicable for Large Deformation
Authors: Wang Jun Pu , Xue Pu , Tao Xiao Ming
Published: February 2011

The conductive fibers have great potential as flexible sensors. In our previous study, based on the experimental studies on sensing behavior of PPy (polypyrrole)-coated Lycra fibers, the mechanism of the strain sensing behavior was identified as open-close mechanism of the cracks on the coating layer when experiencing large deformation. In order to modeling its strain sensing behavior and describe quantitively the development of the micro-cracks, statistical analysis is conducted by image processing technique in MATLAB software. It was concluded that the variation of resistance is related to the micro parameters of the surface cracks, suck as the number, width and length of micro-cracks. These will be used in our further modeling work.
Study on Stress-Strain Behaviour of Mud Stone from Triaxial Test
Authors: Xu Bao Tian , Yan Chang Hong
Published: February 2011

This paper systematically analysis the stress-strain behaviour of mud stone under different confining pressure. The relationship between the mechanical behaviour of mud stone and confining pressure is established, and the curves of stress-strain relationship of mud stone are fitted. The results indicate that the failure pressure and the elastic modulus increase with the increasing of confining pressure conforming to the linear function. The stress- strain of mud stone is divided into four different stages which are fracture closing, elastic strain, fracture expanding and plastic strain stage. The stress-strain behaviour in different stage has different function law, the stage of fracture closing can be fitted by polynomial function, the stage of fracture expanding can be fitted by hyperbola function, the fitting result is ideal.
Calcium Phosphate Cement Modified with Sodium Citrate for Bone Repair
Authors: Qi Xiao Peng
Published: February 2011

An injectable calcium phosphate cement (CPC) modified with sodium citrate was developed in the present study. The effects of sodium citrate concentration on the injectability, mechanical strength, and the self-setting properties of CPC were systematically investigated. The addition of sodium citrate significantly improved injectability and compressive strength of CPC. The specimens have an injectability of 93% and compressive strength of 36.43 ± 2.64 MPa at 15 wt% sodium citrate concentration, compared to injectability of 75% and compressive strength of 23.15 ± 2.12 MPa of the specimens without sodium citrate. XRD spectra indicated that addition of sodium citrate did not change the hydration reaction of CPC and the reaction product was mainly poorly crystallized hydroxyapatite. In conclusion, CPC developed in this work exhibited excellent injectability and high strength, which should be a promising material for bone repair.
Design and Compare of the Three Cabin Air Fiber Filter Testing Methods for Removal of PM2.5
Authors: Liu Shu Sen , Wang Rui , Xiao Hong Xiao
Published: February 2011

This study evaluates the filtration efficiency of a cabin filter and according filter media for fine particle (PM2.5) through laboratory tests and on road tests. Two testing system for the filter media test and filter tests were designed according to the international standard (EN1822 and ISO 11155).On road tests were completed on the real roadway conditions. In cabin particle concentration and ambient particle concentration was gotten by DustTrak(TSI). And then the filter efficiency was calculated according to the I/O ratio. The results showed the filter media’s efficiency was highest, compared the lowest efficiency of filter total efficiency. The real particle removal total efficiency on road was higher than the laboratory test result. According to the experiment data, the on road testing results (particle reductions) are approximately equal to geometrical mean of filter media efficiency and filter total efficiency.
Preparation of Porous ZrO2-Al2O3 Composite Ceramic with High Strength and Good Corrosion-Resistance
Authors: Chang Qi Bing , Liu Xing Qin , Wang Xia , Wang Yong Qing , Zhou Jian Er
Published: February 2011

In order to develop porous ceramics with high strength and corrosion resistance as the support for the preparation of asymmetric ceramic membranes, porous ZrO2-Al2O3 composite is designed and fabricated by adding Zr(OH)4.as sintering aid. The content of Zr(OH)4, the sintering temperature and the bending strength before and after corrosion of the composite are discussed. The results shows that 10wt% ZrO2-10wt% Zr(OH)4 -80wt%Al2O3 composite bar fabricated by cold press with the porosity of 32% can be fabricated in 1550°C for 4 h. The bending strength of the composite is 111.2MPa. After corrosion, the quality lose and the bending strength lose is no more than 1%. The tubular composite is suit for the preparation of micro-filtration membrane.
An Analytical Solution for Anisotropic Composite Plate of Crack under Bending and Twisting
Authors: Zhang Xue Xia , Cui Xiao Chao , Yang Wei Yang , Zhao Wen Bin
Published: February 2011

Analysis of mechanical behaviors near crack tip for linear elastic anisotropic composite plate under bending loadings and twisting loadings was done. By introducing proper deflection function, the mechanical problem reduced to the boundary value problem of partial differential equation. The mixed mode stress intensity factor at the crack tip were presented under bending loadings and twisting loadings at infinity. By solving boundary value problem of partial differential equation and using a complex variable function method, the expressions for bending moments, strains and displacements near crack tip are derived. The obtained results are used to the theoretical research and experimental analysis of the fracture problems of composite plate.
Study on Fracture Toughness Prediction of Non Power Law Hardening Material by Using Local Approach
Authors: Hui Hu , Cao Yu Peng , Li Pei Ning
Published: February 2011

A new method of fracture toughness K1C prediction of non power law hardening material by using cleavage fracture local approach is proposed in this paper. The fracture toughness of A508-Ⅲ 16MnR at different cleavage fracture probability are predicted by using the method. To most of pressure vessel carbon-manganese steels, cleavage fracture is likely to occur at the load corresponding to 62% cleavage fracture probability. Hence, the fracture toughness corresponding to the load is the most possible fracture toughness of the steels. The values of fracture toughness corresponding to 62% cleavage fracture probability is close to that of testing fracture toughness. The work of this paper expends the application of Beremin cleavage fracture model in predicting fracture toughness.
Multifunctional Y203:Yb3+/Tm3+/Li+ Nanocrystals with Enhanced Near-Infrared to Near-Infrared Upconversion Photoluminescence
Authors: Li Dong Yu , Li Jun , Wang Yu Xiao , Kun Yang , Zhang Xue Ru , Shao Le Xi , Song Ying Lin
Published: February 2011

Rare earth ion-doped Y2O3 nanoparticles are attractive for biological imaging applications due to their non-toxicity, resistance to photobleaching, and possibility for upconversion. Y2O3:Yb3+/Tm3+ nanocrystals display photoluminescence (PL) with a peak at ~811nm if excited at ~980nm. This Near-Infrared to Near-Infrared (NIR-to-NIR) upconversion (UC) process provides deeper light penetration into biological specimen and results in high contrast optical imaging due to absence of an autofluorescence background and decreased light scattering. Here, we report that NIR-to-NIR UC PL intensity of Y2O3:Yb3+/Tm3+ nanocrystals are enhanced by doping with different Tm3+ ions and Li+ ions concentration. When the Tm3+ ions concentration reaches 0.25 mol%, the NIR-to-NIR UC PL intensity is the strongest. And the NIR-to-NIR UC PL intensity of Y2O3:5 mol % Yb3+ ions, 0.25mol% Tm3+ ions and 5mol% Li+ ions is maximum, which is more that about 14 times than that of no doped Li+ ions. This material may show promise for use as probes for biological imaging.
Experimental Investigation of Corrosion-Induced Cover Cracking in Reinforced Concrete Structures
Authors: Lu Chun Hua , Jin Wei Liang , Mao Jiang Hong
Published: February 2011

Concrete cover cracking induced by reinforcement corrosion is an important problem in reinforced concrete structures. Several existing analytical models for cracking time are discussed, and it is found that the penetration of corrosion products into corrosion cracks is neglected in these models. Based on our study, a theoretical model that takes the ingress of rust into cracks into account is proposed to predict the cracking time. In order to analyze the amount of corrosion products deposited in cracks, an accelerated corrosion test was performed. Based on the experimental results, the parameter k, which deal with the ingress of corrosion products into cracks, is calibrated to be 0.1~0.3 for accelerated corrosion test. By comparing the predictions with the test results, it is found that the proposed model has high accuracy in analyzing the cracking time and that the mean absolute error between predictions and observations is about 9.4%.
Dynamic Propagation of Mode Ⅲ Interfacial Crack Subjected to Variable Moving Concentrated Loads
Authors: Jin Cheng , Ba Ying , Lin Min , Guo Bao Ke
Published: February 2011

Dynamic propagation of mode Ⅲ crack under variable moving loads on the crack surface is investigated using the theory of complex functions. Using the approaches of self-similar functions, the problems are readily transformed into Riemann-Hilbert problems. The paper presents a new mechanical model for dynamic crack propagation, in which the crack is under the conditions that the variable concentrated loads Pt3/x2 and Px/t move along x-axial with velocity β. At last, analytical solutions of stress, displacement and stress intensity factor are attained, respectively.