bluuebunny/crossref_metadata_2025 huggingface dataset:
The Pervaporation Performance of Polyimide-Block-Polyethylene Glycol Membranes for Gasoline Desulphurization: Effect of PEG Groups
Authors: Lu Fu Wei , Kong Ying , Lv Hong Ling , Ding Jun , Yang Jin Rong
Published: November 2010

Polyimide-block-polyethylene glycol (PI-b-PEG) copolymers were synthesized and membranes were prepared for sulfur removing from model gasoline by pervaporation. The result of the pervaporation performance using the polyimide (PI) membrane and the PI-b-PEG membranes showed that the polyethylene glycol (PEG) groups were effective to increase the permeation flux with less decreasing of sulfur enrichment factor. And the permeation flux was increased by the increasing of weight content and the decreasing molecular weight of PEG groups. The copolymerization of PI with PEG is an effective method to enlarge the permeation flux of the PI membranes.
Response of Concrete Beams Partially Prestressed with External Unbonded Carbon Fiber-Reinforced Polymer Tendons
Authors: Du Jin Sheng , Yang Dong , Ng P.L. , Au Francis T.K.
Published: November 2010

To assess the behavior of concrete beams partially prestressed with external unbonded carbon fiber-reinforced polymer (CFRP) tendons, three specimens prestressed with CFRP tendons and one reference specimen prestressed with external steel tendons were tested to failure under third point loading. It was found that the load-deflection curve of all specimens exhibited three stages, namely, elastic, cracked-elastic and plastic. The transition from the elastic to the cracked-elastic stage was caused by the development of cracks at the bottom of the beam, while the transition from the cracked-elastic to the plastic stage was caused by yielding of the non-prestressed steel. For beams prestressed with external CFRP tendons and that with external steel tendons, the relationships between the stress increment in external tendons and the mid-span deflection of specimens were linear or approximately linear. Although CFRP materials are brittle in nature and behave linearly elastically until failure, proper combination of external CFRP prestress tendons with internal steel reinforcing bars can impart ductility to the beams.
Migration of Cations in Mortar under an Electrical Field Controlled by a Constant Current Density
Authors: Wang Wei Chien , Liu Chih Chien , Lee Chau
Published: November 2010

In this study, an Accelerated Lithium Migration Technique (ALMT) was applied to simultaneously drive alkali out and lithium into concrete as a remedy for alkali-silica reaction (ASR) problem. The mortar specimens used in the experiments contained 2.0% Na2Oeq. Constant current denities were applied during the ALMT testing process. The anolyte and catholyte solutions consisted of LiOH．H2O and Ca(OH)2, respectively. The results show that there are a well correlated linear relationship between the applied current density and the steady flux and migration coefficient of the Li+. During the process of ionic migration, K+ was first removed completely from the specimen, followed by Na+, after which the Li+ flux remained steady. The system resistance initially decreased, and then increased gradually. The time corresponding to when the Li+ concentration in the cathode/Li+ in the source cell was equal to 0.1% indicates the time-span needed for Li+ to penetrate throughout the specimen. Furthermore, the accumulated charge carried by the cations and the accumulated charge applied during testing showed a similar in all test cases.
Load Carrying Capacity Analysis of Multi-Spiral Reinforced Concrete Column
Authors: Wu Jing , Wang Fa Zhou , Yang Wen , Ding Qing Jun
Published: November 2010

The behavior of confined concrete is highly dependent on the confinement type of transverse reinforcement, spiral hoops are generally believed to have better confined effect in concrete than rectangular hoops. It is verified through experiments and the oretical calculations that multi-spiral confined concrete columns have better mechanical properties than single spiral columns, the multi-spiral significantly increase the column’s strength, plasticity, ductility and anti-seismic capability. Based on the three-direction stress law of confined concrete, the load carrying capacity of the rectangular cross section concrete column with multi-spiral is analysed in this paper, and the calculated equation of the load carrying capacity is proposed, which provide a theory and calculation basis for multi-spiral confined concrete column design and research.
Fabrication of ACF/CNT Composites by CVD Method
Authors: Wang Li Ping , Huang Zhu Cheng , Zhang Ming Yu , Huang Qi Zhong
Published: November 2010

Aiming at a novel adsorption agent material, ACF/CNT composites were fabricated by growing carbon nanotubes (CNTs) on the surface of activated carbon fibers (ACFs) with chemical vapor deposition (CVD) method. The characteristics of ACF/CNT composites were investigated by SEM. The variables effects on CNTs size, uniformity and density were evaluated. Three major variables were optimized as the concentration of catalyst precursor 0.07 mol/L, pyrolysis temperature 750 and pyrolysis time 40 min respectively. The results show that CNTs are uniform distribution on the surface of ACFs and the diameter of CNTs is in the range of 30-60 nm and BET specific surface area is 65.39 m2/g. ACF/CNT composites are looked forward to be a promising materials for wastewater and flue gas treatment and hydrogen storage for proton exchange membrane fuel cells.
Thermal Properties and Flame Retardancy of Wood Treated with a Series of Stannates
Authors: Qu Hong Qiang , Wu Wei Hong , Liu Lei , Xu Jian Zhong
Published: November 2010

A flame retardant wood was prepared using a series of insoluble stannates through the double bath technique. The flame retardancy of the wood samples was studied with the LOI method. The relationships between the flame-retardant performance and the thermal property of wood were studied by the thermogravimetric analysis (TGA), differential thermogravimetry (DTG), differential thermal analysis (DTA) and scanning electron microscopy (SEM) methods. The results show that the insoluble stannates, which were precipitated into the wood by the double bath technique, can obviously improve the flame retardancy of wood. Na2SnO3 can catalyze the intermolecular dehydration reaction and increase the stability and amount of the char residue, and the metal ions not only catalyze the intermolecular dehydration reaction in the second stage but also changed the degradation reaction of the char residues in the third and fourth stages.
Seismic Behavior Analysis on the Steel Cold-Formed in Modular House
Authors: Chu Yun Peng , Yao Yong , Deng Yong Jun
Published: November 2010

The cold-formed thin-walled steel has such advantages as light-weight , good seismic capability and is suitable for reconstruction in seismic disastrous area. Nonlinear analysis by software ANSYS on the performances of static and dynamic of a 2 -story building has been done. The analysis reveals that: (1) under the conditions of participation in the earthquake, the top lateral value of structural is large and the maximum is 9.985 mm, but all lateral displacement values standard requirement. (2) Based on the analysis under three kinds of seismic waves, the corner roofing of second independent room has much larger displacement values than others, torsion has been happened on structure. (3) Under the seismic wave, the maximum value is 2.47 which happened on the 400cm/s2 of Taft wave; structure has obviously response under Taft wave。
Experimental Study on Damage Diagnosis of Reinforced Concrete Beam with Acoustic Emission
Authors: Jiang Alan
Published: November 2010

The concretes non-destructive inspection technology take does not harm the concretes component's operational performance as the premise, the application many kinds of physics principles and the chemical phenomenon, carries on the effective examination and the test to the structural element, in order to appraises their continuity, the integrity, the security reliability and certain physical property, including is examined in the material and the component whether to have the flaw, and to the flaw shape, the size, the position, the orientation, the distribution and situations and so on content carries on the judgment. The acoustic emission technology is one kind of dynamic non-destructive inspection technology, moreover sound transmitting message from flaw itself, therefore, may judge the flaw with the sofar efflux the gravity. A similar size, uniform quality flaw, when they receive the stress condition and locates when the position is different, is also different to the structure extent of damage, therefore their acoustic emission characteristic also has the difference.
Tensile Properties of Aluminum Matrix Composites Reinforced with Submicron SiC Particles
Authors: He Chun Lin , Lou De Yuan , Wang Jian Ming , Cai Qing Kui
Published: November 2010

The submicron SiC particulates reinforced aluminum metal matrix composites (Al MMCs) were fabricated by powder metallurgy technique, and their microstructure and tensile properties were investigated. The results show that the Al MMCs obviously exhibit an increase in ultimate tensile strength and yield strength due to both dislocation density strengthening and dispersion strengthening mechanisms, and a decrease in elongation with increasing concentration of SiC particles compared with those of the unreinforced Al due to the agglomeration of SiC superfine particles. The tensile fracture surfaces show that the damage mechanism of the Al MMCs can change with the concentrations of SiC superfine particles and the cracks easily originate from the SiC agglomerations.
Hydrophilic Modification of PES Hollow Fiber Membrane via Surface-Initiated Atom Transfer Radical Polymerization
Authors: Shen Yong Bo , Zhang Ya Tao , Qiu Jian Hua , Zhang Yan Wu , Zhang Hao Qin
Published: November 2010

Hydrophilic poly((poly(ethylene glycol) methyl ether methacrylate) (P(PEGMA)) brushes were grafted from chloromethylated polyethersulfone (CMPES) hollow fiber membrane surface by surface-initiated atom transfer radical polymerization(SI-ATRP) to improve the membrane’s hydrophilic property. The CMPES hollow fiber membrane was prepared by phase inversion process. The benzyl chloride groups on the CMPES membrane surface could afford effective macroinitiators for grafting the well-defined polymer brushes. Attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy confirmed the grafting of P (PEGMA) chains. Field emission scanning electron microscopy (FESEM) was used to characterize the surface morphology of the CMPES membrane and modified membrane. The grafting yield of P (PEGMA) was determined by weight gain measurement. The results showed that the number-average molecular weight (Mn) of P (PEGMA) increased with the polymerization time. It was found that the grafting of P (PEGMA) brought higher pure water flux, improved water uptake ratio and better anti-protein absorption ability to CMPES membrane after modification.
Fabrication and Performance of Al-NaI Radioactive Transmutation Targets
Authors: Liu Hui Qiang , Feng Yi , Zhang Xue Bin , Li Bin , Zhu Yan Fang , Yu Dong Bo , Liu Xiao Yan , Pan Xiao Bing , Tu Jing , Ouyang Xiao Ping , Cao Liang Zhi , Wu Hong Chun
Published: November 2010

Al-NaI radioactive transmutation target was prepared by powder metallurgy. The existing way of the phase of target was analyzed by the application of XRD and its microstructure and morphology was observed by SEM. Then EDS was used for micro-area energy spectrum analysis and the property of target with different NaI was measured and compared. The results show that NaI is uniformly distributed within the aluminum matrix. The relative density and bending strength of transmutation targets decrease with the increasing content of NaI. The hardness and electrical resistivity of transmutation targets increase with the increasing content of NaI.
Effect of Material Properties on Plastic Shrinkage of Ultra-Fine Sand Pumping Concrete
Authors: Zhang Yuan Yuan , Lou Zong Ke , Zhang Xiang Bin
Published: November 2010

The influence of mixing fly ash, admixture(including pumping agent, water reducing agent, air-entraining agent), polypropylene fiber on plastic shrinkage of ultra-fine sand pumping concrete by using slab test in this paper. The results show that mixing fly ash can significantly reduce plastic crack area of ultra-fine sand pumping concrete, and plastic crack area begins to reduce slowly when the content of fly ash is up to 20%; When the content of water reducing agent is between 0% and 1.5%, inhibition effects of water reducing agent on plastic shrinkage of ultra-fine sand pumping concrete increase gradually with the content., and the optimum content of water reducing agent is 0.75%; Compared with the water reducer, the effect of mixing pumping agent or air-entraining agent is better; Mixing polypropylene fiber can reduce plastic crack area of ultra-fine sand pumping concrete, slenderizing the crack, and the effect becomes greater with the content of polypropylene fiber.
Effect of Density on Physical and Mechanical Properties of Reconstituted Small-Sized Bamboo Fibrous Sheet Composite
Authors: Zhu Rong Xian , Yu Wen Ji
Published: November 2010

The effect of density on physical and mechanical properties of phenolic-impregnated cold-pressing reconstituted small-sized bamboo fibrous sheet composite was evaluated. The results indicated that with the density increased from 0.85g/cm3 to 1.20 g/cm3: water absorption decreased, thickness swelling increased first and then decreased; the value of modulus of rupture(MOR) increased from 120MPa to 230MPa, R2 was 0.885; the value of modulus elasticity(MOE) increased from 1.8×104MPa to 2.8×104MPa, R2 was 0.978; the shearing strength (perpendicular loading) increased from 6.5MPa to 18MPa, R2 was 0.978;the shearing strength( parallel loading) increased from 6.3MPa to 26MPa, R2 was 0.973;the compression parallel to grain values increased from 80MPa to 120MPa.
Study on the Properties of Epoxy Thermosets Cured by ImHBPs under Lower Temperature
Authors: Zhang Bao Hua , Chen Bin , Xu Hong , Weng Yan Qing
Published: November 2010

The 2-methylimidazole (Im) -terminated hyperbranched polyesters (ImHBPs) with different generations were prepared and used in diglycidyl ether of bisphenol A (DGEBA) as curing agents and tougheners in this work. It was found that the ImHBPs had better latent property than Im which indicated that the ImHBPs were proper to be used as low temperature curing agent in epoxy curing system. It was also found that the tensile strength, the flexural strength and impact strength of epoxy thermosets cured by ImHBPs under 90 were much higher than those of CYD-128/2-methylimidazole thermoset, which indicated that the ImHBPs obviously improved the mechanical properties of epoxy thermosets, and the thermoset cured by ImHBP with two generation had the best performance among the thermosets.
Effect of Deformation and Annealing on Microstructure and Properties of Composite Cu-10Fe-3Ag Wire
Authors: Li Yong , Yi Dan Qing , Liu Rui Qing , Sun Shun Ping
Published: November 2010

A Cu–10Fe–3Ag alloy was produced by means of induction melting. The effects of aging processes on microhardness and conductivity of Cu–10Fe–3Ag alloy were studied. The microstructure of the alloy was examined using transmission electron microscope (TEM). The results show that: presence of Ag can accelerate γ-Fe precipitation from in the Cu matrix, but also reduces the thermal stability of Fe fibers. As the annealing temperature increasing, the microhardness and conductivity of Cu-10Fe-3Ag in-situ composite increase at first and then decrease. Annealed at 475 for 6h, the alloy has an excellent combination of microhardness and conductivity, the microhardness and conductivity reach 209HV and 58.4% IACS, respectively. The Fractures of the alloy are all ductile rupture and the dimples are smaller with the annealing temperature increasing.
Photoluminescence of Eu3+-Doped TiO2 Thin Films Prepared by Sol-Gel Method
Authors: Wang Dan Hong , Zhao Xiao Ru , Sun Hui Nan , Duan Li Bing , Chen Chang Le
Published: November 2010

The sol-gel method was employed to prepare the Eu3+-doped TiO2 thin films. The influence of doping concentration and annealing temperature on the structures and photoluminescence (PL) properties was investigated. The result of X-ray diffraction revealed that all the films are of anatase phase. It is shown that the PL intensities of the films increased with Eu3+ concentration and reached the maximum at 1.4 mol%, then decreased with the concentration. Observed anatase phase appeared at temperature above 400 °C, and the luminescence intensity increased with the increase of annealing temperature.
Novel Cementious Materials from Industrial Solid Waste for Silt Soil Solidification
Authors: Xie Guo Hua , Du He Qing , Zhu Shu Jing , Xue Yong Jie
Published: November 2010

Four kinds of industrial solid waste, granulated blast furnace slag (GBFS), electric furnace steel slag (EFSS), semi-dry flue gas desulfurization slag (FGDS) and gypsum were activated by mechanochemistry to prepare a novel kind of cementious material, DA type soil solidification agent (DA agent). Compared to the traditional cementious materials, this paper evaluated DA agent used in silt soil solidification project. Test results showed that DA-4 was prepared with adding the 40% CFBA, 39% GBFS, 11% OPC clinker and 10% gypsum by mill and more superior in material characteristics. It was found that compressive strength of DA-4 paste and mortar specimens at 28-days cured age were 46.0 and 27.3 MPa respectively; 5% of DA-4 was used to stabilize the silt soil in lab and the maximum dry unit weight, optimum moisture content, unconfined compressive strength and CBR value were 1.754 g/cm3, 15.35%, 1.15 MPa and 95.5% respectively. The hardening mechanism of prepared cementious materials is explained by two points: the sulfite or sulfate activation on alkali blast furnace slag; and the hydration product produced from cement clinker hydration process. Besides test programs of the trial pavement section in site showed that stabilized and solidified silt soils by DA-4 can meet the requirement of subgrade of pavement for strength and stiffness.
Effects of CeO2-Rich Mixed Rare Earth on the Mechanical Properties of Al2O3-Mullite Based Foam Ceramics
Authors: Ji Shu Jun , Guo Xue Yi , Dong Jian Xiong , Su Peng
Published: November 2010

Using corundum, quartz, kaoline, etc, as base components and CeO2-rich mixed rare earth as modifier, foam ceramics were fabricated adopting the organic foam impregnation process. The mixed rare earth addition had much improving effects on the matrix mechanical properties owing to much glass phase and acerate mullite growing. While 3wt% was considered to be the optimal addition, in this case, homogeneous and compact ceramic microstructure with maximal glass condensation and minimal porosity formed, with the matrix compressive strength and the flexural strength at room temperature reached 0.87MPa and 0.66MPa respectively, which were 52.6% and 73.7% higher than the original samples respectively. As the mixed rare earth addition exceeded further, the compressive strength increased slowly and the flexural strength descended gradually. XRD and SEM were used to structure strengthening mechanism analysis.
The Experimental Studies on the Prepartion of Steel Slag Cement by Gas Quenching Steel Slag
Authors: Long Yue , Zhang Yu Zhu , Xing Hong Wei , Li Jun Guo , Li Gao Liang , Lei Yun Bo
Published: November 2010

According to a series of experimental studies such as the content of the f-CaO, the relative grindability index of the gas quenching steel slag, the properties of gas quenching steel slag cement and a detailed analysis of the potential economic benefits of steel slag cement. It was found that it has a huge economic benefits in preparing the cement with gas quenching steel slag.The results showed that the content of f-CaO in slag particles less than 2mm were no more than 2.7% and there exists a well proportional relation between it and the grain size; the grindability of gas quenching steel slag is much better than heat-stew steel slag; what's more,because of the high hydration activity of gas quenching steel slag, it can be produced the perfect steel slag cement with excellent hydration, stability and strength.
Thermal Stresses in a ZrO2/FGM/Ti-6Al-4V Composite ECBC Plate with Temperature-Dependent Material Properties
Authors: Tu Dai Hui , Xu Yang Jian , Jia Jian Hui
Published: November 2010

The steady thermal stress distributions and effect factors in a ZrO2/FGM/Ti-6Al-4V composite ECBC plate with temperature-dependent material properties under convective heat transfer boundary were investigated by the NFEM and the Sinpson method. From numerical calculation, when , T0=300K, Ta=350K and Tb=1 750K, the thermal stress distributions in the composite FGM plate were obtained. The results are as follows. With the increase of the FGM gradient layer thickness and when M=1, the temperature distributions in the composite plate are more reasonable. With the increase of the FGM gradient layer M, the thermal stresses on the ceramic surface tend toward reduction, and compared with the thermal stress of M=0.2, the thermal stress of M =5 reduces by 17.8%. When we take into account the effect of temperature-dependent material properties, compared with the results of constant material properties, the maximum compressive stress on the surface of metal reduces by 74.2%, and the maximum compressive stress on the surface of ceramics reduces by 45.3%. With the increase of FGM layer porosity P, the change of stress at the bonding interface of the three-layered plate increases, and the stress curves appear peak values. Compared with A=0, when A=3.99, the compressive thermal stress on the metal surface reduces by 42.0%, and the compressive thermal stress on the ceramic surface increases by 154.7%. Compared with the nongraded two-layered ceramic/metal composite plate, the thermal stress of the ZrO2/FGM/ Ti-6Al-4V composite plate is very gentle. Compared with , when , the maximum compressive stress on the surface of metal reduces by 49.98%, and the maximum compressive stress on the surface of ceramics increases by 182.3%. The results provide the foundations of theoretical calculation for the design and application of the composite plate.
Similarity of Deuterium Absorption at Room Temperature for Different Ti-Zr-Ni Quasicrystals
Authors: Huang Huo Gen , Li Rong , Chen Liang
Published: November 2010

Ti-Zr-Ni icosahedral quasicrystals (IQCs) have been regarding as potential hydrogen storage materials due to their high hydrogen ability. Nevertheless, their hydrogen capacities are largely different as reported by different researchers, which is toughly understood.We investigated in this paper deuterium absorption at room temperature for quasicrystalline alloys Ti45Zr38Ni17, Ti41.5Zr41.5Ni17, Ti40Zr40Ni20 with corresponding phase structures of IQC+β(Ti,Zr), IQC+C14(TiZrNi), IQC. The results indicated the same solid solution state for the deuterium in these alloys, whose deuterium concentration was 12~13mmol/g. Given that all these alloys are in a single IQC phase, we believe very similar deuterium capacities for them, which surely needs more strict experimental evidence.
The Structural and Morphology of (La0.7Sr0.3)MnO3 Thin Films Prepared by Pulsed Laser Deposition
Authors: Rao Wei , Yu Jun
Published: November 2010

(La0.7Sr0.3)MnO3 (LSMO) thin films were prepared on Si (100) substrate by pulsed laser deposition (PLD). Both structure and surface morphology of the films were investigated by X-ray diffraction (XRD) and atomic force microscopy (AFM). Furthermore, the chemical states and chemical composition of the films were determined by X-ray photoelectron spectroscopy (XPS) near the surface. The results indicate that the films grown on Si (100) substrates have a single pseudo cubic perovskite phase structure with a high (100) orientation. The XPS results show that La, Sr and Mn exist mainly in the forms of perovskite structure and a SrO layer was found on outermost surface.
Study on Adsorption Mechanism and Dehumidification Property of Composite Desiccant
Authors: Jia Chun Xia
Published: November 2010

A new composite desiccant composed of ceramic fiber, silica gel and lithium chloride was developed. The adsorption mechanism of the new composite desiccant was analysis based on the adsorption isotherm and the micro character. Compared with the silica gel the chemical absorption accounted for a leading role for composite desiccant. Furthermore the dynamic dehumidification property of the wheel fabricated by composite desiccant was tested. The result showed the composite desiccant wheel need longer time to reach stable dehumidification amounts.
Fabrication of ZnO Nanodot Arrays by Sol-Gel within AAO Template
Authors: Gao Bo , Zhang Hai Ming , Li Xiao Jie , Hu Guo Feng , Li Yu Jie , Zhu Yan Jun
Published: November 2010

ZnO nanodot arrays were fabricated by using AAO template combining with sol-gel method. Structure and optical properties of ZnO/AAO composite structure were investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD) and photoluminescence (PL). The SEM results indicated that the pores in the template were arranged in a regular hexagonal lattice and ZnO nanodots were assembled into the AAO template. The XRD patterns demonstrated that the AAO template had an amorphous structure, and the ZnO nanodots had wurtzite structures. The PL spectrum revealed that ZnO/AAO composite structure had a strong ultraviolet emission at 390 nm.
Preparation, Characterization and Thermal Properties of Polyacrylonitrile/Alpha-Zirconium Phosphate Nanocomposites by Gelation/Crystallization
Authors: Yang Dan Dan , Xu Hai Ping , Zhu Lu Ping , Wu Yi Hua
Published: November 2010

Nanocomposites of polyacrylonitrile (PAN) and Organophilic alpha-zirconium phosphate (OZrP) were prepared by gelation/crystallization. OZrP was prepared using cetyl trimethyl ammonium bromide (CTAB). The structure of PAN/OZrP nanocomposites was characterized by X-ray diffractometry (XRD) and high resolution transmission electron microscopy (HRTEM). The results showed that an intercalated or exfoliated structure was formed. Thermogravimetric analysis (TGA) was applied to characterize thermal stability property, which indicated that the thermal stability of PAN/OZrP nanocomposites was improved compared with that of pure PAN. HRTEM and Laser Raman spectroscopy were used to analyze the microstructure of the chars of PAN/OZrP nanocomposites.
Effects of Thermal Cycling and Freezing after Water Absorption on Tensile Properties of Green Composites
Authors: Kim Hyojin , Sakiyama Masataka , Takemura Kenichi
Published: November 2010

The effects of thermal cycling and freezing after water absorption on tensile properties of green composites were examined. Jute fiber and matrix were used as the reinforcement and the matrix. The thermal fatigue was conducted as a fatigue test. Heating and freezing process are performed alternately for 0.5h, 1h and 24h during 10 cycles, heating and freezing temperature were 60 and -20 . In a freezing after water absorption, the damage by an expansion of water was examined. The freezing after the water absorption during 1-5 days was performed in a day under the environment of -20 . In thermal cycling, tensile strength and modulus were significantly decreased as the time passes. In 24h-treated test, the decrease rates of tensile strength and modulus were about 50 % compared with that of room temperature. In freezing after water absorption, tensile strength and modulus were decrease compared with that of the room temperature.
Improved Photoluminescence from Ar+ and N+ Ions Co-Implanted Porous Silicon
Authors: Lv Xiao Yi , Mo Jia Qing , Zhong Fu Ru , Jia Zhen Hong , Xiang Mei , Jiang Tao
Published: November 2010

We have measured photoluminescence of porous silicon which is electrochemically prepared on single crystal silicon wafer with co-implantation of Ar+ and N+ ions. The results show that the photoluminescence intensity of porous structure of co-implanted silicon was enhanced that we attribute these to the enhanced formation of porous silicon microstructure induced by ion implantation and from the analysis by scanning electron microscopy, it is demonstrated that the different density of the pores with different doses ion implantation
Behavior of Carbide Dissolution and Precipitation in WD1 Steel Used for Warm Work Dies
Authors: Zhao Xin , Yang Xiao Ling
Published: November 2010

A new kind of die steel, WD1 used for warm work dies, was developed. The behavior of carbide dissolution and precipitation in WD1 steel during heat treatment was investigated by using optical microscopy, X-ray diffractometer and transmission electron microscopy. The results show that there are three types of carbide, namely MC, M6C and M7C3 carbide, in the annealed WD1 steel; and M6C and M7C3 carbides are dissolved totally during heating for quenching; then MC, M2C, M6C and M7C3 carbides are precipitated during tempering. The secondary hardening peak is reached after tempering at 520°Cfor two hours. This hardening is mainly caused by the precipitation of Mo2C carbide.
Effect of Friction Temperature on Spheroidization and Refinement of Si Particles in Hypereutectic Al-Si Alloys
Authors: Lu De Hong , Zhou Ming , Wei Shao Sheng , Jiang Ye Hua , Zhou Rong
Published: November 2010

The effect of the temperature at the friction surface on spheroidization and refinement of Si particles in hypereutectic Al-30Si alloys was investigated. Al-Si samples as cast were first preheated to 15°C, 100 °C, 300 °C and 500 °C, respectively, then rubbed against a steel counterface for 5 min under a normal pressure of 50N. Refined layers where all the Si particles were broken to 0.71-0.87μm in diameter and spheroidized simultaneously to 0.69-0.74 in shape factor were found in the friction surface of the samples. As the preheating temperature increased, the refinement effect was gradually weakened, and the spheroidization effect was enhanced. The reason of the simultaneous spheroidization and refinement were discussed.
Green's Function Approach to Crossover Properties for Interaction Parameters of an N-Layer Ferroelectric Thin Film
Authors: Lu Zhao Xin , Teng Bao Hua , Yang Xin
Published: November 2010

Utilizing the higher order decoupling approximation to the Fermi-type Green’s function, crossover properties of interaction parameters of an n-layer ferroelectric thin film from the ferroelectric-dominant phase diagram (FPD) to the paraelectric-dominant phase diagram (PPD) are investigated on the basis of the transverse Ising model. The curved surfaces for crossover values of interaction parameters of a thin film with certain layers are constructed in the three-dimensional parameter space. Because both the z-component  (the polarization) and the transverse component  of the spin are further included in the eigenfrequency, the results are in agreement with that of the effective-field theory with correlations to some extent. It shows that the higher order decoupling approximation diminishes the ferroelectric feature of a ferroelectric thin film compared with the usual mean-field approximation.
Mechanism Analysis of Rutting at Urban Intersections Based on Numerical Simulation of Moving Loads
Authors: Dong Ze Jiao , Sun Zong Jie , Gong Xiang Bing , Liu Hao
Published: November 2010

Frequent starting and braking of vehicles causes rutting of asphalt pavement at urban intersection. As a result, dynamic response of pavement subjected to these kinds of vehicle loadings can be used to analyze rutting mechanism. At first, vehicle loading at urban intersection was described by a vertical and horizontal combined moving pressure with variable speeds. Then, three-dimensional finite element model in transient dynamic mode is developed based on the practical pavement structure. And the moving load, boundary conditions and material parameters were briefly introduced. Finally, through the comparison of time histories and spatial distribution among accelerating, decelerating and uniform motion, mechanism of rutting of asphalt pavement at urban intersections was illustrated according to the finite element simulation. It shows that frequent starting and braking of vehicle at urban intersections, obviously change the stress distribution within pavement structure compared with uniform motion case. The distribution and amplitude of maximum shear stress and horizontal shear stress was observed during the passage of the loading, which will result in shear flow deformation. Pavement structure subjected to moving load exhibits an alternative characteristic which will accelerate the rutting damage of pavement.
A ZnO/Chitosan Composite Film: Fabrication and Anticorrosion Characterization
Authors: Lin Zhi Feng , Wang Peng , Zhang Dun , Wang Yi
Published: November 2010

A composite film consisting of ZnO and Chitosan (CS) is obtained on carbon steel via cathodic electrodeposition. Optimal CS concentration of electrodeposition of ZnO/CS film is determined by the method of polarization curves. It is shown that the ZnO/CS film obtained at the concentration of 0.6 g/L has the best corrosion resistance. The deposit is studied by scanning electron microscopy (SEM), Fourier transform infrared spectra (FT-IR) and X-ray diffraction (XRD). XRD results indicate that ZnO could be fabricated by electrodeposition in composite film. FT-IR results evidence the existence of CS in composite film. SEM results demonstrate that the quality of film is improved because of the addition of CS. The anticorrosion property can be attributed to that the existence of the CS macromolecules can improve the stability of the composite film. This kind of composite film has an anticorrosion application for metal corrosion protection.
Design and Implementation of BMS Based on STC12C5A60S2
Authors: Huang Ju Hua , Guo Hang , Cao Ming
Published: November 2010

In connection with adverse effects of the single battery’s performance inconsistency of Lithium-ion batteries for electric vehicle, we’ve designed the battery management system and its balanced module. The systems based on MCU(Micro Controller Unit) STC12C5A60S2 accurately real-time capture and analyzes processing on the parameters of the battery pack, and then carry out function of balanced charge and discharge, management and protection by control circuit for battery pack. The results show that the system not only could make the charge and discharge of battery balance but also could effectively compensate the battery’s inconsistency, so that each battery has played the best performance.
Experimental Investigation of Microsegregation in Low Frequency Electromagnetic Casting of Al-4.5%Cu Binary Alloy
Authors: Chen Dan Dan , Zhang Hai Tao , Wang Xiang Jie , Cui Jian Zhong
Published: November 2010

Al-4.5%Cu ingots were prepared by a process of low frequency electromagnetic casting (LFEC) and conventional direct chill (DC) casting, respectively. The effects of low frequency electromagnetic field on the microsegregation were investigated from eutectic analysis and electro probe microanalysis (EPMA). It was found that the amount of the nonequilibrium eutectic and the dimension of the nonequilibrium eutectic were decreasing markedly. In contrast, the solute content in the α-Al phase increased to a certain extent in the presence of the low frequency electromagnetic field, and it increased with the incerasing electromagnetic.
Experimental Study of Rolling Contact Fatigue Life of Zirconia Ceramic Ball
Authors: Zhou Jing Ling , Zuo Wei Ming , Chen Xiao Yang , Wu Guo Qing
Published: November 2010

A newly developed pure rolling fatigue test rig with three contact points for bearing balls was used to perform rolling contact fatigue (RCF) tests and the fatigue properties of two kinds of zirconia ceramic balls produced with different materials composition and identical technologies were compared. Ball surfaces were examined after failure with optical microscopy and scanning electron microscopy. It was identified by tests that the failure mode of zirconia ceramic balls was surface spall. Life tests data, summarized in accordance with the Weibull theory, showed that the life of two kinds of zirconia balls was close, and no remarkable difference in the divergence between the tested two kinds of balls was found
Simulation and Microstructure Predict during Hot Die-Forging of Cast Mg-7.0Al-0.2Zn Magnesium Alloy
Authors: Wu Li Hong
Published: November 2010

Employing the dies for aluminum alloy parts, the hot die-forging forming and numerical simulation of semi-continuous casting Mg-7.0Al-0.4Zn (AZ70) were carried out. It was indicated that AZ70 has a worse fluidity during forging and is consequently difficult to fill fully compared to aluminum alloys. The microstructure of the AZ70 forgings is in good agreement with the strain distribution generated by simulation, and strain distribution can predict the microstructure evolution. The comparison results can give a guideline on developing forging process and controlling forgings quality of the AZ70 alloy.
Study on the Relationship between Transparency and Morphology of Shoushan Stone
Authors: Jiang Guo Jian , Tao Qing , Liu Wei Dong , Xu Jia Yue , Zhao Hong Yang , Xiong Ying Fei , Fang Yong Zheng , Zhang Cheng
Published: November 2010

The Shoushan Stone is one of the famous craft carving stones in China and the transparency is one of the decisive factors to appraise its value. The better the transparency is, the higher the value is. In this paper, the mineral compositions and morphology of some Shoushan Stone samples were investigated by XRD and SEM methods. Combining with the characterization of Shoushan Stone, the relationships between the morphology and the transparency of Shoushan Stone were studied. The results show that the transparency of Shoushan Stone samples was determined by their microstructures, such as the mineral particle sizes and its arrangement, the gaps and porosity. The Shoushan Stone samples with high transparency are those with good arrangement, bigger crystal particle and less porosity and gaps.
Synthesis of Star-Shaped PLA via Direct Melt Polycondensation: 2. Using D,L-LA as Starting Material
Authors: Wang Zhao Yang , Hong Wen Kun , Luo Yu Fen , Wang Qun Fang , Xiao Xin
Published: November 2010

Using 1,3,5-benzenetrioxyundecanol (mTU) as the core, and more cheaper D,L-lactic acid (D,L-LA) as starting material, a novel star-shaped poly(D,L-lactic acid) (SPDLLA) was synthesized via direct melt polycondensation with simple process and low-cost. The obtained biodegradable polymer SPDLLA was systematically characterized with the intrinsic viscosity [η], FTIR, 1H-NMR, GPC and XRD. The Tg and crystallinity of all SPDLLA were much lower than that of the linear poly(D,L-lactic acid). When n(D,L-LA) : n(mTU) was 120 : 1, the biggest Mw was 10800, which was bigger than that obtained from L-lactic acid (L-LA). All Mw meet the requirement for drug delivery application.
Families of Exact Solutions for Two-Component Bose-Einstein Condensates
Authors: Cao Dong Bo , Pan Liu Xian , Sun Yan Bin , Yan Jia Ren
Published: November 2010

Two-component Bose-Einstein condensates systems are investigated in the presented work, using the trigonometric function transform method, and several families of exact solutions are obtained for coupled two-component nonlinear Gross Pitaevskii equations. The solutions obtained in this paper include four kinds of soliton solutions and ﬁve kinds of trigonometric function solutions. Finally, the corresponding exact solutions of the uncoupled NLS equations are easy derived in fiber optics.
Study on Preparation of Activated Carbon from Corncob Furfural Residue with ZnCl2 by Microwave Irradiation
Authors: Chen Cong Jin , Wei Long Bin , Zhao Peng Cheng , Li Yue , Hu Hua Yu , Qin Yu Ben
Published: November 2010

In this paper, the feasibility of preparing activated carbon from corncob furfural residue with ZnCl2 by microwave irradiation was studied. The effect of the ratio by weight of ZnCl2 to corncob furfural residue, ZnCl2 solution soaking time, microwave irradiation time and the pH value of ZnCl2 solution on the quality of activated carbon was investigated. On the condition that the microwave power is 800 W and ZnCl2 solution mass concentration is 50%, the best technological parameter on preparing activated carbon with ZnCl2 by microwave irradiation is obtained: at the ratio of 3.5:1 by weight of ZnCl2 to corncob furfural residue, microwave irradiation time is 20 min, ZnCl2 solution soaking time is 12 h, the pH value of ZnCl2 solution is 2, the activated carbon yield reached 33.1% and the decolorizing capacity for methylene blue is 202.5 mg/g, the product is used in treating Cr6+ solution(pH value 4.0, concentration 50 mg/L), its adsorption capacity of Cr6+ is 7.583 mg/g.
Electrospun Antibacterial Chitosan/Poly (Vinyl Alcohol) Nanofibers Containing Silver Nanoparticles
Authors: Zhuang Xu Pin , Li Zheng , Kang Wei Min , Cheng Bo Wen
Published: November 2010

New chitosan/poly (vinyl alcohol) (PVA) nanofibers functionalized with silver nanoparticles were electrospun using solutions of PVA blended with silver nanoparticles-chitosan composites. The structure of the electrospun fibers were studied with the aid of scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. The results indicated that the electrospun fibers smoothly with 220 to 650 nm diameter, and the silver nanoparticles were successfully embed into the fibers which show high antibacterial activity against E.coli.
Preparation of High-Porosity NiTi Alloys by Powder Sintering with NaCl Pre-Forming
Authors: Sun Hong Bo , Zhao Xing Ke , Lan Lan , Huang Ji Hua , Zhang Hua
Published: November 2010

High-porosity NiTi shape memory alloy has pseudo-elasticity and shape memory effect for energy absorption and convenient on-line repair without replace. In this paper, high-porosity NiTi alloys with interconnected and well distributed pores were fabricated successfully by sintering, using NaCl as temporary space-holders. Optical microscope, SEM and XRD have been used to investigate the porosity and pore structures. The results show that porosity can be up to 88%.The size and porosity of the pores depend mainly on the addition of salts in the compacts, and are also related to temperature and forming pressure.
The Influenceof Rare Earth Element on α-Solidification of A356 Alloy
Authors: Zheng Zhi Qiang , Xiong Xin Gen , Chen Ke Ming , Li Xu Wen
Published: November 2010

The Influenceof Rare Earth Element on α—Solidification of A356 Alloy has been discussed in the paper . It is showed by the research, that the condition of interphase is changed by Rare Earth element asymmetry distribution, which influences the process ofαphase growing and facilitates the growth of αphase in sphere, and leads to a optimal Rare Earth quantity for facilitative effect, which is 0.5% in this experimentation, and that αphase grain will be change to small by adding Rare Earth.
Production of Lactic Acid by Simultaneous Saccharification and Fermentation Using Steam Pretreated Lespedeza Stalks as Inexpensive Raw Materials
Authors: Qi Xiang , Tang Yong , Jian Hong Lei , Li Xue , Jiang Jian Xin
Published: November 2010

The lespedeza stalks with steam pretreatment were fermented to lactic acid by simultaneous saccharification and fermentation (SSF) in this study. Orthogonal design methodology was used to evaluate the optimum SSF conditions that give maximum lactic acid yield. We have investigated the following relative factors, such as temperature, loading of cellulase, calcium carbonate and concentration of substrate. The optimum operating conditions were found to be temperature of 43 °C, cellulase loading of 30 FPU/g substrate, calcium carbonate of 3 % and substrate of 6 %. Comparisons of different steam pretreated conditions on lactic acid yield from lespedeza stalks were also made. The results showed that lactic acid yields from lespedeza stalks with 4 min pretreatment at pressure of 1.0, 1.25, 1.5 and 2.0 Mpa were 41.8 %, 42.5 %, 50.6 % and 64.0 % of the theoretical, respectively. The lactic acid yield from steam pretreated lespedeza stalks was much higher than that of lespedeza stalks without pretreatment (23.9 %). It can be concluded that the lactic acid yield was remarkably improved by steam pretreatment. The yield of lactic acid from steam pretreated lespedeza stalks was 1.68 times higher than that of untreated ones. Additionally, the lactic acid yield could be further promoted from 64.0 % to 89.4 % by washing pretreated stalks with water, which suggested that water processing is a promising method to remove inhibitors in broth to improve lactic acid yield.
The Influence of Elastic Modulus on the Adhesion of Fouling Organism to Poly(Dimethylsiloxane) (PDMS)
Authors: Zhang Jin Wei , Lin Cun Guo , Wang Li , Zheng Ji Yong , Peng Yan Lei , Duan Dong Xia
Published: November 2010

It’s important to prevent the happening of biological fouling because it can increase friction and accelerate corrosion to the marine ships. In this paper, PDMS elastomers with different modulus between 0.43 and 2.35MPa were prepared by hydrosilylation reactions, and the effect of modulus on the adhesion of diatom (Navicula sp) and ulva spore (Pertusa) were investigated. Results reveal that the density of adhered diatoms and ulva spores have no relation with elastic modulus(E), but the removal ratio of adhered diatoms and ulva spores increase significantly with the decrease of elastic modulus, and the deep study find it decrease in proportion to E1/2.
Rheological Behaviour of Core-Shell Emulsion/Amine Crosslinking Process
Authors: Lu Jia , Easteal Allan. J , Bolt Clive. J
Published: November 2010

Isothermal kinetics studies of thermal-induced gelation for epoxy functionalized poly(vinyl acetate) emulsion and diamine were investigated rheologically. The change in the viscoelastic material functions such as elastic storage modulus, G’, viscous loss modulus, G” and complex dynamic viscosity, η* during the gelation process was evaluated. The isothermal gelation kinetics was also analyzed using an isoconversional method that was based on replicated experimental data and model-free kinetics calculations. This isoconversional method evaluated an effective activation energy.
Research and Development of Deep-Sea Pipeline Steel
Authors: Xu Jin Qiao , Guo Bin , Zheng Lin , Li Yin Hua , Yu Le
Published: November 2010

This paper provides a detailed description of deep-sea pipeline steel developed at Wuhan Iron and Steel Company(Group), WISCO for short. The thickness of the trial produced plates is 28mm. The chemical composition of low C-high Mn-Nb-Ti with proper content of other alloys and thermo-mechanical controlled process were applied. The results show that the deep-sea pipeline steel developed at Wuhan Iron and Steel Company has a good match of high strength, low temperature toughness and excellent deformability with fine uniform microstructure. The LSAW line pipe manufactured by JCOE method has high strength, good low temperature toughness and low yield ratio which comprehensively meet the requirements of the South China Sea Liwan pipeline project.
Controlling the Wall Thickness and Pore Size of SBA-15 by Using PPG and PEG as Additives
Authors: Su Ji Xin , Zhang Ming Bo , Ma Li Yuan , Zhang Shen Ping , Dong Fei Fei
Published: November 2010

Ordered mesoporous silica SBA-15 with controlled pore size and wall thickness was synthesized using polypropylene glycol (PPG) and polyethylene glycol (PEG) as different additives. The final samples were characterized by low-angle X-ray diffraction, N2 adsorption-desorption and transmission electron microscopy. The SBA-15 used PPG or PEG as additive all could maintain the two-dimensional hexagonal structure. The addition of PPG could expand the pore size and decrease the wall thickness and the addition of PEG could reduce the pore size and increase the wall thickness of SBA-15.