bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on the Reaction Mechanism of (α-Al2O3+TiB2+TiC)/Al Composites Fabricated by Al-TiO2-B4C System
Authors: Zhu He Guo , Min Jin , Chu Da , Wang Huan
Published: November 2010

The composites (-Al2O3+TiB2+TiC)/Al has been fabricated by using exothermic dispersion synthesis. Thermodynamic analysis indicated that the reaction between the Al and TiO2 can spontaneously occur due to the negative Gibbs free energy of the Al-TiO2 reaction system. With the increase of B4C/TiO2 mole ratios, the exothermic peaks increase move to the higher temperature and the corresponding ignite temperatures also increase. The reaction results indicate that when the B4C/TiO2＝0, the reinforcements are composed of -Al2O3, Al3Ti, with the increase of B4C/TiO2, the amount of Al3Ti decreases and the TiC and TiB2 form simultaneously. When the B4C/TiO2 increases to 1/3, the Al3Ti almost disappear and the reinforcements of the composites are consisted of -Al2O3, TiC and TiB2.
A Novel Nanocomposite Based on Recycled Poly(Ethylene Terephthalate)/ABS Blends and Nano-SiO2
Authors: Shi Guang , He Li Jun , Chen Chu Zhi , Liu Jian Fu , Liu Qin Zhong , Chen Hong Yu
Published: November 2010

Recycled PET is an important resource of waste, which reused with polar or crystallization polymers, such as PC, PA and PE, by melting blend method have been well studied. But the study of rPET blend with nonpolar and amorphous polymer is still inadequate. In the present work, nano-SiO2 particles were introduced to recycled PET/ABS/AES (55/40/5) blends by extrusion processing. It has been investigated how nano-SiO2 particles influences the morphology and mechanical properties of rPET/ABS blends by the use of AES as compatibilizer. It showed a uniform dispersion of the nano-SiO2 components, and the two-continuous phase of rPET/ABS was more evenly when the content of nano-SiO2 particles at a low level. The tensile strength and beam impact strength of rPET/ABS/AES blends were increased at the same time by adding nano-SiO2 particles..
Thermal and Mechanical Properties of Boron-Containing Bisphenal-A Formaldehyde Resin Composites
Authors: Gao Jun Gang , Li Xing , Sun Bei Bei
Published: November 2010

Boron-containing bisphenol-A formaldehyde resin (BBAFR) with different amounts of boron was synthesized from bisphenol-A, formaldehyde solution and boric acid. The fiber-glass reinforced laminates were prepared. The thermal, electric and mechanical properties were determined. The results show that the BBAFR has a better thermal stablitity. The residual rate of BBAFR is 18% at 900 oC, which is higher 300 oC than ordinary phenolic resin. The tensile strength of BBAFR fiber-glass laminates is higher 19.07MPa than ordinary phenolic resin fiber-glass laminates. The volume resistivity and surface resistance of BBAFR laminates increased, but the dielectric loss tanδ and dielectric constant ε decreased.
Thermodynamics of Solvent Extraction of Perrhenate with N235 at High Concentration
Authors: Jiang Ke Xu , Fang Da Wei , Wang Han , Wang Bao Xin , Xiong Ying , Zhai Yu Chun
Published: November 2010

In solvent extraction system of perrhenate with the extractant of N235 at high concentration, the equilibrium molalities of ReO4- were measured at ionic strengths from 0.2 to 2.0 mol.kg-1 in the aqueous phase containing Na2SO4 as the supporting electrolyte from 278.15K to 303.15K. The standard extraction constants K0 at various temperatures were obtained. Thermodynamic quantities for the extraction process were also calculated.
Self-Assembled Stratified Structure in Polyalkylthiophene-6 and Polyvinylcarbazole Blend Film
Authors: Tan Nai Di , Zhang Yan Lin , Li Zhong Yu , Olihara Katsuo , Zhang Fu Shi
Published: November 2010

Layered films of polyalkylthiophene-6 (PAT-6) and polyvinylcarbazole (PVK) which are expected to be a photo-electronic device were fabricated from blend solution by self-assembly at only one casting process. Cross-section structure of the blend polymer films were observed by digital microscope and analyzed by using Energy Dispersive Spectroscopy (EDS) and FT-IR spectrometer. Stratified structure with component distribution along thickness direction was found to be self-assembly at the suitable casting condition. It was considered that the structure was controlled by the evaporation speed of solvent and properties of the solubility parameter and density of the polymer.
The Experimentation and Imitation Study on Flow Field of Coherent Jet
Authors: Liu Kun , Han Ren Zhi , Yang Chun
Published: November 2010

By oxygen lance measuring system, under the normal temperature (cold condition) systematic study is carried on traditional supersonic jet flow field that is simulated by compressed-air and on coherent jet flow flied which is accompanied by low density helium in this paper, By commercial software FLUENT, associated with experimental data, the standard double equation K- model is revised appropriately with C1=1.45，C2=1.88. The behavior of axis symmetric jet can be predicted better by simulated results. The flow state of traditional supersonic jet and the characteristic of coherent jet flow flied under vice-hole helium low density concomitance situation are analyzed systematically.
Study on Network Structure C-Cu Composites of Pantograph Slide Plates
Authors: Wei Qiang , Xu Li Xin , Shi Hui Juan , Shao Li Feng , Hao Xiang Zhong
Published: November 2010

novel pantograph sliding plate, the network of carbon-copper composites, composed of carbon fiber cloth, copper powder, graphite powder, et al. The physical and mechanical properties of the new samples were tested. Compared with the commonly used pantograph sliding plate, the novel one has lower resistivity, higher bending strength, enhanced impact toughness and better mechanical properties. The new material is suitable for producing the pantograph sliding plate of the electric locomotive.
The Electrochemical Behavior and Microstructure of Chromium-Free Passivation Film on Galvanized Steel
Authors: Li Yu Peng , Wu Lin , Liu Min
Published: November 2010

In this paper, the chromium-free passivation solution was prepared by organic / inorganic process. The surface morphology and corrosion resistance of the composite films were investigated by scanning electron microscopy (SEM), atomic force microscope (AFM), and electrochemical impedance spectroscopy (EIS). The chromium-free passivation film was immersed in 3.5% NaCl solution, and the EIS changed with the immersed time. The results showed that the total impedance of chromium-free passivation film increased more than one order of magnitude compared with the galvanized steel, which is the same as that of chromate passivation film.With immersed time increasing, the impedance decreased, and the impedance stabilized after 8h. AFM and SEM results indicated that the film surface that was very flat was uniformly suspended by a lot of solid particles, in which the little hollow portion was 8nm. The framework structure of the film was cross-linked by resin emulsion and organic silane. After 96h NSS test, the galvanized steel surface appeared only a little pitting corrosion, which proved that corrosion resistance of galvanized steel increased obviously by the chromium-free passivation.
Study on Curing Behavior of Low Molar Ratio Urea-Formaldehyde Resins with Different Curing Agents
Authors: Dong Yao Hui , Gao Qiang , Zhang Yue , Li Jian Zhang
Published: November 2010

In order to characterize the curing behavior of low molar ratio urea-formaldehyde (UF) resin, the curing time and thermal analysis in curing reaction of the UF resins and the bonding strength and formaldehyde emission of plywood bonded by five kinds of low molar ratio UF resins with six different curing agents were studied. The results indicated that the UF resins with the molar ratio of formaldehyde to urea more than 1.0 could get reasonable curing time. The heat enthalpy of UF resins significantly increased with the enhancing the acidity of curing agent. The plywood manufactured by the UF resins with 1.1 molar ratio showed much higher bonding strength and lower formaldehyde emission.
Effect of Elements on Hot Tearing of Directionally Solidified Ni-Based Superalloys
Authors: Wang Yan Li , Huang Zhao Hui , Zhao Xi Hong , Li Jia Rong
Published: November 2010

The effect of elements such as Ti, Al, Hf, Zr and B on hot tearing susceptibility during directional solidification was explored by tube-like samples with thickness of 1.0 mm, 1.5mm and 2.0mm in wall. Results of SEM of elements on solidification of casting Ni-based superalloys were presented. The influential extent among the investigated elements is found to be: the largest is Ti, then Zr, B and Al, and Hf is the smallest. Titanium promotes the formation of (γ+γ´) eutectic, increases sizes of the eutectic. Increasing Al content results in the size of γ+γ´ eutectic and the number of γ´. Increasing Zr content promotes γ+γ´ eutectic.Varying B content shows little microstructural evolution.
Synthesis of Latent Curing Agent for Epoxy Resin
Authors: Zhang Xue Jun , Kang Su Mei , Liu Zhan Qing
Published: November 2010

A new kind of latent curing agent (LCA) for epoxy resin was synthesized by the reaction of Ethylenediamine with Butylacrylate in equal molar ratios, and the chemical structure and thermal property of the LCA were studied with FTIR and TGA, respectively. Moreover, LCA was also used to modify the epoxy sizing agent for high modulus carbon fiber. The results show that the wettability of sized carbon fiber tends to increase due to the increase of the polymer film on the surface of the carbon fiber, and interlaminar shear strength (ILSS) of the sized high modulus carbon fiber/epoxy composites is improved to 78MPa, which is increased by 8.6% compared with the composites reinforced by high modulus carbon fiber with unmodified sizing agent, indicating that using LCA modified epoxy resin as polymer coating for carbon fiber is a feasible method to improve the interfacial performance of high modulus carbon fiber/epoxy composites.
Ductile Damage Evolution Analysis of Lead-Free Sn-Zn Solder Based on Meso Topography
Authors: Liu Cai Ping , Duan Qing Quan , Mao Ling Tao
Published: November 2010

Meso topography is used to examine the damage degree of lead-free Sn-Zn solder. Real-time meso topography is observed using scanning electronic microscope(SEM), which is assembled in a loading machine. The solder’s deformation and fracture is simulated using a damage accumulation process. The observed meso-structure evolutionary processes of the solder material is then analyzed according to the macro-meso combined mechanism. Some image processing technique are used. A new model of fracture mechanism and degree of damage is proposed.. that We show that the proposed meso structure evolution equations can accurately model the degree of material damage.
Preparation and Characterization of Water Based and Double Enveloped Nano-Fe3O4 Magnetic Fluids
Authors: Li Lai Qiang , Wang Shu Lin , Liu Jie , Li Sheng Juan , Zhang Jun Jing
Published: November 2010

The nanoparticles of Fe3O4 were prepared with chemical precipitation method, and then used sodium oleate and the lauryl sulfonic aid sodium as bilayer to envelope the ultra-fine Fe3O4 particles. Then stabilized water base magnetic fluid was obtained. The crystallization behavior and the surface of Fe3O4 nanoparticles after the modification were investigated with XRD and IR respectively; the particle size was studied with TEM; the magnetic properties were studied with VSM. The mechanism of bilayer surfactants that modified Fe3O4 magnetic nanoparticles was explained, and influencing factors of the magnetic fluid were discussed.
Effect of Minor Sc, Zr and Ti Additions on the Microstructures and the Mechanical Properties of Pure Aluminium
Authors: Zuo Xiu Rong , Cui Hai Chao
Published: November 2010

Different alloys with the minor Sc, Zr and Ti additions were prepared. Microstructures and mechanical properties of the alloys were studied. The results show that the Al-0.25%Sc-0.2%Zr alloy has smaller grain than that of the Al-0.25%Sc alloy, grains of which change from the columnar structure to the fine equiaxed structure because of 0.2%Zr addition. The as-cast Al-0.25%Sc-0.2%Zr-0.03%Ti alloy has the finest grain and the highest hardness of all the studied as-cast alloys. This behavior can be attributed to the fine Al3Sc, Al3(Sc,Zr) and Al3(Sc,Ti) particles, which not only act as the ideal nuclei for α(Al) but also produce grain-size strengthening and dispersion strengthening. The strength of the Al-0.25%Sc-0.2%Zr alloy is not higher than that of the Al-0.25%Sc alloy after hot extrusion because of the presence of Al3(Sc,Zr) particles with smaller misfit with Al than Al3Sc, which brings the transition of dislocation moving mechanism from Orowan bypassing to shearing of the particles.
Research on Microstructure and Oxidation Resistance of Double Glow Plasma Discharge Surface Titanizing on CrZrCu Alloy
Authors: Tu Fang , He Bo Lin
Published: November 2010

CrZrCu is extensively used as high electrical, thermal and mechanical performance in spot welding. But when CrZrCu electrode is used in spot welding of galvanized steel sheet, the abrasion, corrosion and oxidation shorten the electrode life rapidly. The electrode is not able to meet the needs of spot welding of galvanized steel sheet .In the paper, double glow plasma discharge surface titanizing was carried out on CrZrCu alloy. The processes of double glow plasma discharge titanizing, surface alloying layer structure were also analyzed elementary. The properties of high temperature oxidation were also researched. The experimental results indicated that in the plasma titanizing alloying layer, the diffusion of titanium element toward the interior of the CrZrCu alloy substrate forms the intermetallic compound named Cu4Ti, which is beneficial to the reinforcement of CrZrCu substrate. The experimental results confirmed that double glow plasma discharge titanizing could greatly improve the high temperature oxidation resistance of CrZrCu alloy. Under the temperature of 450oC and 700oC, the oxidation rate of CrZrCu is about five times of plasma titanzing sample.
The Influence of pH Values on Corrosion Properties of 316L Stainless Steel in Simulated Circulating Cooling Water
Authors: Cheng Xue Qun , Lv Sheng Jie , Liu Zuo Jia , Li Xiao Gang
Published: November 2010

Effects of pH values on corrosion properties of 316L stainless steel were investigated to clarify the usability of 316L SS in circulating cooling water system. The polarization, EIS and Mott-Schottky measurements showed the superior corrosion resistance of 316L SS in the simulated cooling water solution with NaCl+Na2SO4. The Fe hydroxides and oxides products resulted in the passive film of 316L SS thicker during the cooling water convection, as the pH increased from 6.5 to 9.0.
Numerical Simulation of Forming Force in Lateral Bend Forming
Authors: Zhang Chuan Min , Fu Wen Zhi , Liu Fei , Li Ming Zhe , Liu Qi Qian
Published: November 2010

The lateral bend forming is a new flexible forming method which bend section steel into parts with all kinds of curvature. The main principle and advantages of lateral bend forming is introduced. Mathematical model of lateral bend forming is established based on finite element method. Contact problem is treated. The law of forming force versus process parameters is analyzed by numerical simulation technology. The results shown as follows: the forming force is increased with the increment of the pressing quantity; the higher yield limit of material is, the bigger forming force is; the forming force of angle steel is bigger than sheet metal without changing other parameters.
Research on Surface Modified Micro/Nano-MgO Particles Improve Tribological Characteristics of Lubricating Oil
Authors: Wang Peng , Ma Ke , Zhu Xin He
Published: November 2010

This paper applies the sol-gel method (Sol-Gel) ，uses Poly Vinyl pyrrolidone (PVP) as dispersant，oleic acid as modifier to prepare and modify micro/nano-MgO particles. The characterization results of micro/nano-MgO particles by using XRD and SEM verified that micro/nano-MgO particles prepared above are FCC and the average particles size is 50nm. In the process of friction and wear experiment, the results show that at the significant effect of anti-friction and anti-wear is obtained after adding micro/nano-MgO particles in the 4012 marine lubricant. Especially under higher loads, the friction-reducing effect is more prominent.
Preparation of C/SiC Composites by SLA-Intergrated Liquid Silicon Infiltration Method
Authors: Jin Jie , Wang Shen Hao
Published: November 2010

Phenolic resin was used as the raw material, formed a mold for complex-shaped component by rapid-prototyping. It was composed of SiC, C and Si. The sample hardness was analyzed through statistical comparison. The phase composition of C/SiC composite was investigated by XRD and microstructures of C/SiC ceramic components were observed with scaning electron microscope. The ceramic components obtained at 1500 by reactive infiltration of Si into porous C-template. The porous structure formed by photecurable resin and starch powders pyrolysis could effectively prevent the C-template from cracking and reduce the stress. It also facilitate penetrating Si to the C-template to form SiC.
3D Braided Geometry Structures Based on Space Group
Authors: Ma Wen Suo , Yang Bin Qian , Ren Xiao Zhong
Published: November 2010

3D braided group theory is dissertated. The analysis procedure is described from the existing braided geometry structure to the braided space group; 3D braided geometrical structures are finally described by means of group theory. Some of novel 3D braided structures are deduced from the braided space groups. By describing the 3D braided materials with braided space point and braided space groups, the braided space groups are not always the same as symmetry groups of crystallographic because novel lattices can be produced and the reflection operation cannot exist in braided space point groups. Braided point and space groups are theoretical basis for deriving the novel braided geometry structure.
Characters of Expressway Widened Engineering Reinforced with Geotextile
Authors: Liu Jin Long , Liu Jie Qun , Chen Lu Wang
Published: November 2010

Based on nonlinear finite element method, the character of expressway widened engineering reinforced with geotextile is studied. It is found that the main vertical settlement, lateral displacement and failure surface of embankment occurred in the widened part of embankment. The lateral displacement decreased, the total incremental of displacement reduced and the stability of embankment enhanced when expressway widened engineering reinforced with geotextile. It also can be found that the axial force of geotextile get its maximal value at the intersection of old and new part of embankment, which is controlled by the differential settlement and normal stress mainly. In order to reinforce the embankment effectively, it is advised that the geotextile should be paved on high-stress zone.
Expandable Tubing R&D on the Material of FMA Multiphase Alloy Steel
Authors: Ma Jian Min , Liu Yong Hong , Li Hang , Shao Shuai
Published: November 2010

Basing on the performances analysis of the expandable tube material, the paper introduces the FMA multiphase alloy steel, the new type of expandable material. The conclusions were presented at the detailed analysis of material microstructure, chemical composition, heat treatment, mechanical properties and other aspects. This paper will promote the application of this new material.
Drying Shrinkage of Concrete Affected by Content of Stone Powder in Proto-Machine-Made Sand
Authors: Li Feng Lan , Zhu Qian
Published: November 2010

To improve the application of the new proto-machine-made sand in structural engineering, tests are carried out to study the drying shrinkage of concrete affected by stone powder in proto- machine-made sand. The target cubic compressive strength of concrete is 55 MPa, the main factor varied in mix proportion of concrete is the contents of stone powder by mass of proto-machine-made sand from 3 % to 16 %. The drying shrinkage strains of concrete are measured by the standard method at the ages of 1 d, 3 d, 7 d, 14 d, 28 d, 60 d, 90 d, 120 d, 150 d and 180 d. Based on test results, the drying shrinkage of concrete affected by the contents of stone powder in proto-machine-made sand is analyzed and compared with that of similar test of concrete with traditional machine-made sand, which shows that there is the optimum content of stone powder resulting in the lower drying shrinkage of concrete. The formula for predicting drying shrinkage strain of concrete is proposed.
The Performance of Barium Sulfate/Nature Rubber Composites Using in Sport Shoes
Authors: Wang Ji Hu , Liu Hong Bo , Wen Shao Guo , Shen Yan
Published: November 2010

Modified barium sulfate (MBS) /nature rubber(NR) composite materials were prepared by direct blending methods. Barium sulfate was modified by coupling agent Si-69, titanium esters and stearic acid. Tensile property, hardness and wear resistance of composite materials were studied by various methods. The results showed that the modified barium sulfate fillers had great effect on the reinforcement of the composites.
A New Method for Manufacturing Composite Ingot of 3004/4045 Aluminum Alloy
Authors: Jiang Hui Xue , Zhang Hai Tao , Qin Ke , Cui Jian Zhong
Published: November 2010

A method for manufacturing composite ingot of 3004/4045 aluminum alloy using direct-chill (DC) casting was introduced. The casting process, the temperature distribution near the composite interface and the macro- and microstructures were investigated. The results show that composite interface is well-bonded, planar and clean with little evidence of porosity, which belongs to a kind of metallurgical bonding. Also semi-solid layer with a certain thickness is formed under the effect of cooling plate, which can ensure the realization of casting process of composite ingot.
A Statistical Constitutive Model for the Strength of Brittle Fiber at Different Strain Rates
Authors: Huang Wen , Huang Zhong Wei
Published: November 2010

A statistical constitutive model, which takes account the effect of strain rate, was presented to describe the stress-strain relationship of brittle fiber bundles. To verify its reliability, tensile tests on two kinds of brittle fibers: glass fiber and SiC fiber, were carried out at different strain rates, and the stress-strain curves were obtained. It was found that the modulus E, the strength and the fracture strain of these fiber bundles all increase with increasing strain rate. The simulated stress-strain curves, derived from the constitutive model, fit the tested results well, which indicates that the model is valid and reliable.
Mechanical Wear of SnO2-C Morph-Genetic Composite Materials
Authors: He Xin Hai , Shen Ming Qian , Qi Le Hua , Wang Jun Bo , Yang Min Ge , Chang Wei
Published: November 2010

Five series SnO2/C Morph-genetic composite materials were prepared using ramie fiber as biological templates, Sn(OH)4 sol as impregnant, and phenolic resin as supplementary adhesive. The influences of calcination temperature, holding time, and phenolic resin treatment on the mechanical wear property of the SnO2/C morph-genetic materials were studied. The results showed that when the calcination temperature reached 630 and holding time increased, SnO2 was reduced by C and CO to needle-like flakes and pellet mixed SnO/SnO2 tissue, and their pinning and supportive effects significantly increased wear resistance of the samples. Glass Carbon derived from phenolic resin decomposition and ramie carbon were difficult to distinguish, but glass carbon had obvious supportive and strengthening effects on ramie carbon walls. With the formation of homogeneous carbon membrane in the process of friction, the alternative distribution of soft carbon and hard carbon could effectively improve wear resistance of the matrix ramie carbon.
Synthesis and Characterization of Fluorine-Substituted Hydroxyapatite Powder by Polyacrylamide-Gel Method
Authors: Luo Yan , Li Wen Xu , Wang Fu Ping , Zou Jing
Published: November 2010

Fluor-hydroxyapatite (FHA) powder was synthesized using polyacrylamide gel method with Ca(NO3)2•4H2O as raw material of calcium, (NH4)2HPO4 as raw material of phosphor, and different amounts of ammonium fluoride (NH4F) acting as fluorine source. XRD and FT-IR results showed that, the F- enter the crystal lattice of hydroxyapatite and substitute for some of the OH-, and result in the change of the symmetry of crystal structure. As the fluorine addition was increased, the a-axis of the apatite decreased gradually while the c-axis does not obviously changed, and the content of the β-TCP decreased gradually. So addition of fluorine ions effectively suppresses the decomposition and enhances the thermal stability of pure HA. The lattice parameter has a good liner relationship with fluorine content: a = -1.29×10-3 x + 0.94063; c = 4.3×10-4 x + 0.68772(R2≥0.95). But addition of F- has no effects on microstructure of HA, and fluorine-substituted hydroxyapatite remains hexagonal morphology.
Influences of Complex Modification of RE and P on the Microstructure and Impact Toughness of Hypereutectic Al-24Si Alloy
Authors: Liu Niu Can , Li Hai Dong , Liu Zhong Xia
Published: November 2010

The influences of RE and P complex modification on microstructure and impact toughness of hypereutectic Al-24Si alloy are investigated. The result shows that the coarse block primary silicon is refined obviously and its edges and angles are blunted under the influences of the complex modification of RE and P. The large needle eutectic silicon is modified to the short-rod or particle ones also. The alloys have the finest microstructure and highest impact toughness when adding about 0.10% P and 0.9% RE into alloys. Compared with the unmodified alloy, the average size of primary silicon in the modified alloys refined from 93.5μm to 24.1μm and the impact toughness of alloys increases to 11.0062J/cm2 from 7.3572J/cm2. The excellent impact toughness of alloys can be attributed to the increase of initiation energy and expand energy of the cracks caused by the refinement of primary silicon and eutectic silicon after complex modified with P and RE.
Antibacterial Property and Mechanism of Copper Alginate Fiber
Authors: Wu Yan , Han Guang Ting , Gong Ying , Zhang Yuan Ming , Xia Yan Zhi , Yue Chang Qing , Wu Da Wei
Published: November 2010

To apply copper alginate fibers in medical as a new alginate fiber, copper alginate fibers were researched and evaluated against Escherichia coli (E.coli) and Staphylococcus aureus (S.aureus), using antibacterial zone and flash shaking method to analyze anti-bacterial mechanism by the scanning electron microscopy (SEM). The results showed that copper alginate fibers had antibacterial effects, the antibacterial rate against E.coli and S.aureus were 97.4% and 66.2%, respectively; SEM images indicated that bacteria obviously changed after contacting with fibers, the main reason was that copper ion had a damaging effect on pericellular and cell wall. Furthermore, bacterial osmotic pressure was changed and protein synthesis were impeded, and then the normal metabolism of bacteria was destroyed, and finally, bacteria died.
Effect of Combined Electromagnetic Field on Microstructure and Surface Quality of (Al2O3+Al3Zr)P/Al Composites
Authors: Wang Hong Ming , Li Gui Rong , Zhao Yu Tao , Zhang Zhao
Published: November 2010

In the experiment Al-Zr(CO3)2 components were utilized to in situ synthesize the Al2O3, Al3Zr reinforced aluminum matrix composites. Low frequency and high frequency electromagnetic fields were combined and introduced into the fabrication of particulates reinforced aluminum matrix composites. The average size of particulate and grain size of matrix were refined to 0.5~1μm and 20~40μm separately. The particulates distributed uniformly in matrix. The Lorenz force improved the kinetic condition and accelerated the nucleation of endogenetic particulates. At the meniscus of solidifying billet the high frequency electromagnetic field was applied. The surface quality of billet was enhanced obviously.
Electronic Structure and Bonding Characteristic of NdMgNi4H4
Authors: Wang Bao Jun , Li Rui Ying , Dong Xiao Ping , Guan Li , Niu Jian Gang
Published: November 2010

We performed first-principles calculations to the electronic structure and bonding characteristic of NdMgNi4H4. The calculation results show that the H—Ni units are formed by the covalent H—Ni bonds, the surrounding Mg and Nd atoms provide electrons to the H—Ni units, and the Ni-Ni bonds between the different H—Ni units are covalent, making the H—Ni units not isolated. These bonding characteristics show that NdMgNi4H4 is similar with interstitial metal hydride in some aspects, and similar with complex metal hydrides in other aspects, indicating NdMgNi4H4 is the intermediate between interstitial metal hydrides and complex metal hydrides.
Microstructure and Mechanical Properties of Al-Cu-Mg-Ag Alloy during Thermal Exposed at Elevated Temperature
Authors: Liu Xiao Yan , Pan Qing Lin , Lu Zhi Lun , Cao Su Fang , He Yun Bin , Li Wen Bin
Published: November 2010

The thermal stability of Al-Cu-Mg-Ag alloys under-aged and peak-aged was analyzed by tensile testing and transmission electron microscopy (TEM). And the microstructural evolution and mechanical properties of Al-Cu-Mg-Ag alloy during thermal exposed at elevated temperature were also studied. The results show that the under-aged Al-Cu-Mg-Ag alloy possessed better thermal stability compared with the peak-aged alloy when exposed at 150 . The tensile strength of the peak-aged alloy decreased with prolonging the holding time. While that of the under-aged alloy increased and then decreased with a peak of 524 MPa after exposed for 20 h, which was 19 MPa higher than that of the peak-aged alloy. Meanwhile the precipitations were distributed dispersively and amount of fine phases were observed. The tensile strength of the under-aged alloy was 434 MPa after exposed for 1000 h at 150 . When exposed at 200 , the tensile strength of the under-aged sample decreased and the prolongation increased with prolonging the thermal exposure time. The tensile strength of the sample decreased dramatically when exposed at 250 and 300 and the strengthening phases coarsened dramatically and evolved to the equilibrium phases . The width of the precipitation free zone (PFZ) increased with increasing the thermal exposure temperature and the distribution of the precipitations on the boundaries became discontinuous.
Two Nickel-Bipyridinedicarboxylate Organic-Inorganic Hybrid Materials: Hydrothermal Synthesis, Crystal Structure and Thermal Properties
Authors: Song Yan Xia , Wang Chong Chen , Wang Yuan Lan
Published: November 2010

Two two-dimensional and three-dimensional coordination-polymer, [Ni(2,2′,5,5′-bpdc) (H2O)]•H2O (1) and[Ni(2,2′,6,6′-bpdc)2]•4H2O (2) were obtained via hydrothermal reaction between NiCl2•6H2O and 2,2′-bipyridine-5,5′-dicarboxylic acid (2,2′,5,5′-bpdc), 2,2′-bipyridine-6,6′-dicarboxylic acid (2,2′,6,6′-bpdc) respectively, and were characterized by infrared spectra, thermogravimetric analysis and single crystal X-ray diffraction. The 2,2′,5,5′-bpdc and 2,2′,6,6′-bpdc ligands in compound 1 and 2 show different coordination modes respectively. The 2,2′,5,5′-bpdc ligand acts as pentadentate connector to coordinate with three different Ni(II) ions, and further extend to form square grid framework of compound 1; while 2,2′,6,6′-bpdc acts as tridentate ligand to chelate one Ni(II) ion to construct discrete monomeric unit, and those discrete units of [Ni(2,2′6,6′-bpdc)2]•4H2O are joined into 3-D framework via rich hydrogen bonding interactions. Thermogravimetric analysis revealed that both complex (1) and (2) display considerable thermal stability. CCDC 773845 & 773846.
Micro-Magnetic Field at the Surface of Surgical Materials for Biocompatibility Improvement
Authors: Liu Qiang , Cheng Xiao Nong , Fei Huang Xia
Published: November 2010

TiO2 thin film containing SrFe12O19 powders on the surface of 316L stainless steel and NiTi alloy was prepared through sol-gel method and micro-magnetic field was established by the magnetization process applied on the coating. The coating film was characterized by x-ray diffraction (XRD) and the surface morphology of the coating was observed by scanning electron microscope (SEM). This blood compatibility thin film was evaluated by dynamic cruor time of blood test.The results show that dynamic cruor time of blood is prolonged by the micro-magnetic field of the thin film, indicating improved blood compatibility.
The Configuration Design and Biodegradation Test of Biodegradable Material Dishware
Authors: Jia Xiu Jie , Li Jiang Feng , Li Fang Yi
Published: November 2010

Biodegradable material is a kind of green material, which is easily reclaimed and reused, and does not pollute the environment and can decompose quickly, there is not insurant produce after trash. This study aims to looking for new material and low price to produce dishware. Food dishware we produced using different biodegradable material cooperating with Jiufa Group Company, the main material is pure plant fiber and starch, additive edible material, and degradable material. (1) The mix of the dishware material technology and the spark technology has been studied. (2) The test of biodegradable of the dishware has been studied, and the result shows this packaging material can be separated to carbon and water finally after disused by the action of animalcule, in the water and air. The energy sources and resource can more reduce for this degradable material to produce dishware, so as to green and keep environment friendly, safe to use.
A Novel Synthesis of Acetophenone Benzopyran Derivative
Authors: Qi Xiao Yan , Wu Lin , Wang Jian Guo , Yi De Lian
Published: November 2010

The development of a novel synthesis of acetophenone benzopyran is reported. A acetophenone benzopyran derivative was prepared from 1-(2,4-dihydroxyphenyl)ethanone (3) through O-prenylation and Lewis acids catalyzed intermolecular cyclization reaction. The structure of product 1-(3,4-dihydro-4,4-dimethyl-7-hydroxy-2H-1- benzopyran -6-yl)- ethanone (1) was characterized by UV, IR, 1H-NMR, 13C-NMR and elemental analysis.
Toxoplasma gondii DNA Sensor Based on a Novel Ni-Magnetic Sensing Probe
Authors: Miao Heng , Xu Shi Chao , Yang Yue Qian , Zhang Ji Mei , Dai Zhao , Sun Bo , Sun Shu Qing , Zheng Guo , Feng Tei Lin , Zi Yan , Liang Chu , Luo Hao
Published: November 2010

we introduced a fast, specific, and sensitive sensing probe to detect Toxoplasma gondii DNA based on mechanism of fluorescence resonance energy transfer (FRET), and a multifunctional and magnetic-fluorescent CdTe/Ni quantum dots (mQDs) was prepared as energy donor, and BHQ2 was used as energy acceptor, respectively. CdTe/Ni mQDs were synthesized with a more simple method using Ni nanoparticles as core material and CdTe as shell material. The sensing probe was fabricated through labeling a stem-loop Toxoplasma gondii DNA oligonucleotide with CdTe/Ni mQDs at the 5′ end and BHQ2 at 3′ end, respectively, and the resulting sensing probe can be conveniently isolated and purified with a common magnet. Properties of mQDs and sensing probe were investigated by transmission electron microscopy (TEM), X-ray diffraction (XRD), and fluorescence spectrum (FS) methods. The TEM data demonstrated that the size of Ni nanoparticles was estimated to be ~10nm, and size of CdTe/Ni is 15nm. XRD data showed similar spectrum of CdTe and CdTe/Ni, intensity of Ni (111) typical diffraction peak was detected, which inferred the formation of CdTe on surface of Ni core. An obvious fluorescence recovery (FR) was observed when the complete complimentary target Toxoplasma gondii DNA was introduced comparing with the target DNA with one-basepair-mismatch, this result revealed the sensing probe has high sensitivity and specificity. The current sensing probe will has great potential applications in the life science and gene diagnostics.
Synthesis and Application of Polyurethane Hydrogel Carrier on Nitrobacteria Immobilization
Authors: Dong Ya Mei , Jin Yong Wei , Zhang Zhen Jia
Published: November 2010

A new microorganism immobilization method involving preparation and gelation of waterborne polyurethane (WPU) was developed. The WPU prepolymer was synthesized by polyether polyol, isophoronediisocyanate (IPDI), 2-hydroxylethyl methacrylate (HEMA) were prepared by radical polymerization. The feasibility of the proposed immobilization method was tested by nitrifying bacteria. The effects of WPU prepolymer and gelation process on the activity of nitrifying bacteria were investigated by relative respiratory activity. The microbial growth and distribution of immobilized nitrobacteria were observed with a scanning electron microscope (SEM) before and after acclimation. The results verified that the waterborne polyurethane is an ideal microbial immobilization support material and has a great potential for a variety of biological wastewater treatment applications.
Orthogonal Experimental Study on Frost Resistance of Polypropylene Fiber Concrete
Authors: Huo Jun Fang , Yang Hui , Shen Xiang Dong , Cui Qi
Published: November 2010

The orthogonal test method is used to research effect of the factors on the concrete’s frost resistance performance. The factors include volume fraction of fibers, water-binder ratio, fly ash and water-reducing agent. The results show that the polypropylene fiber influences on the mass loss of concrete noticeably, which can improve the frost resistance of concrete. The match ratio of the concrete is optimized. Finally the best match ratio is found out, which meets strength and frost resistance of concrete.
Influence of Ultrafine Limestone Powder on the Performance of High Volume Mineral Admixture Reactive Powder Concrete
Authors: Liu Juan Hong , Song Shao Min , Sun Yong Mei , Wang Lin
Published: November 2010

The effects of ground limestone powder on the fluidity, strength and viscosity of reactive powder concrete(RPC) were studied. The results show that, the flexural strength of RPC greatly increases with the increase of the content of ground limestone powder at the W/B of 0.16, 0.18 and 0.20 when ground limestone powder content is less than 30%; for fresh RPC, the maximum compressive strength is 160MPa and the maximum flexural strength is 36.9MPa when the limestone powder content is 158kg/m3 at the W/B of 0.20, with 20cm good fluidity and very compact microstructure; the viscosity of RPC greatly decreases with the addition amount of ground limestone powder, the viscosity of RPC mixture changes from 60,000MPa•S to 18,000MPa•S when cement content decreases from 388kg/m3 to 150kg/m3 and the addition amount of limestone powder increases from 0 to 238kg/m3.
Synthesis, Characterization and Properties of Poly(L-Lactic Acid-Co-α- Phenylalanine) Obtained by Direct Melting Copolymerization
Authors: Wang Pei , Liu Lian , Wei Zhi Yong , Xu Qiang , Qi Min
Published: November 2010

A new poly(ester amide)s (PEA) derived from L-lactic acid and L- phenylalanine have been synthesized by melting copolymerization with p-toluenesulfonic acid (TSA), stannous chloride (SnCl2) as catalyst. The products were analyzed by NMR, FT IR. The effects of the content of L-phenylalanine on the copolymers structure were studied. Being the phosphate buffered saline (pH=7.2) as the degradation solution, it had been found that the degradation rate speed up with the increasing the content of the L- phenylalanine.
Carbonation of High-Temperature Calcined Hydroxyapatite by Solid-Ion-Exchange Reaction
Authors: Zhu Qing Xia , Jiang Wei Hui , Xu Qiong Qiong
Published: November 2010

Carbonated hydroxyapatite (CHA) was synthesized by solid-ion-exchange reaction of hydroxyapatite (HA) powders in CO2 atmosphere. The effects of the treatment atmosphere, temperature and time on carbonate substitution were investigated. The phase composition of the powders were characterized by X-ray diffraction and the content and type of the carbonate substitution were studied using Carbon-sulfur elemental analysis and Fourier transform infrared spectroscopy, respectively. The results show that the carbonate ion can enter the HA crystal lattice to form CHA giving priority to A-type by controlling the treatment temperature, atmosphere and time. Wet atmosphere treatment favors the reconstitution of hydroxyl and treatment in dry CO2 atmosphere favors the formation of A-Type substitution. The appropriate reaction temperature is 900 . Carbonate content increases with the treatment time and a further extension of treatment time tends to a slower increase of carbonate content.
Synthesis of Polyvinyl Formal Sponge for Wound Care Dressing Application
Authors: Yang Qing Hao , Cheng Guang Xu , Zhang Zhi Cheng
Published: November 2010

In an effort to seek poly(vinyl formal) (PVFM) foams based wound dressing pad material, a series of foamed PVFM materials have been synthesized under varied conditions. The influence of conditions on the properties of PVFM foam, such as mechanical properties, water absorption, pore structure and bulk density, is well discussed individually. It has been shown that both the reactant and acid catalyst affect the degree and speed of acetalization, therefore the mechanical properties, pores continuity and water absorption of the resultant sample. The addition of Na2CO3, surfactant and CMCNa are mainly influencing the porous structure as well as the mechanical properties and water absorption. One best sample with balanced properties is obtained. It possesses higher mechanical strength and water absorption while the other properties are similar, comparing with a commercial surgical PVFM sponge (YJ-1) currently used.
Effects of Various Sugars on the Mineralization of Microbiologically Induced Calcium Carbonate
Authors: Zhu Wen Kun , Luo Xue Gang
Published: November 2010

Sugar is one of the key nutrients required to microorganism growth. In this paper , the effects of various sugars on the mineralization of calcium carbonate induced by Bacillus pasteurii . The precipitation amount, forms and structures of calcium carbonate were characterized. The results indicated that the induced calcium carbonate precipitation are mainly calcite as irregular aggregated bodies and rhombus blocks and aragonite appeared when the culture medium was added with dextran. The calcium carbonate precipitation reached a maximum of 2.32 g when glucose was added into the culture.
A Novel Scaffold from Recombinant Spider Silk Protein in Tissue Engineering
Authors: Wang Hong Xin , Xue Zheng Xiang , Wei Mei Hong , Chen Deng Long , Li Min
Published: November 2010

As a new biomaterial, recombinant spider silk protein has attracted much attention in tissue engineering. The pNSR-16/ BL21(DE3)pLysS strains fermented and produced the recombinant spider silk protein, which was then cast into scaffolds. NIH-3T3 cells were cultivated with extractions of the scaffolds in vitro. The cytotoxicity of scaffolds was analyzed with a MTT assay. The performances of cells adhesion, growth and expression on the scaffolds were observed with SEM, HE staining and immunohistochemistry. Compared with the control, the extract fluid of materials culturing the NIH-3T3 cells was not apparently different. NIH-3T3 cells could adhere and grow on the scaffolds and secret FGF-2. The pNSR-16 recombinant spider silk protein scaffolds has satisfactory cytocompatibility and the scaffolds are ideal scaffold material for tissue engineering.
Semi-Solid A356 Alloy Slurry Prepared by Slightly Electromagnetic Stirring with Ti-Based Refiner
Authors: Liu Zheng , Liu Xiao Mei , Mao Wei Min
Published: November 2010

The semi-solid A356 alloy slurry is prepared by slightly electromagnetic stirring with Ti-based refiner. The effects of the refiner on the morphology and the grain size of the primary phase in the slurry are researched. The results indicate that the slurry with particle-like and rosette-like primary phases can be prepared by slightly electromagnetic stirring with the refiner. Compared with the A356 alloys without the refiner, the grain size and particle morphology of primary phase as well as the distribution of the grain with particle-like or rosette-like along radial in the ingot in A356 are markedly improved by the refiner.
In Situ TEM Observation of Phase Transformation for Bio-Medical Shape Memory TiNbSn Alloy
Authors: Li Yan , Qi Jie , Fan Rui Rui , Zhai Chuan Xin , Xu Chun Hua
Published: November 2010

TiNbSn alloy has high specific strength, low modulus of elasticity, excellent corrosion resistance, no side effects, such as toxic and exhibits shape memory effects after appropriate technical processing. This alloy may substitute as NiTi shape memory alloy to become the new generation of biological materials. It has been reported the studies of this alloy, such as the component and proportion, processing technology, mechanical properties and corrosion resistance. Based on the previous research, the bio-metal material, Ti-10Nb-5Sn alloy was heated and cooled repeatedly in a heater system located in TEM chamber and, at the same time, was observed in situ using a high resolution transmission electron microscope to study the memory property of the alloy and the mechanism of the transformation between austenite β and martensite phase. The results show that, during heating stage from 295K to 400K, the martensite began to dissolve at 355K, and the martensite disappeared completely at 385K, meanwhile, the austenite was created. During cooling stage from 400K to 295K, the martensite begins to take shape at 353K and the transformation was completed at 333K. The alloy can memory the room and high temperature structures, showing two-way memory functions. The high-temperature austenite of Ti-10Nb-5Sn alloy shows body-centered cubic β phase with the unit cell parameter a=0.3283nm; the martensite at room temperature shows orthorhombic NbTi4 phase (M) with the unit cell parameters a=0.3152nm, b=0.4854nm, c=0.4642nm. The orientation relationship between M phase and β phase is , , , , and . The crystal plane , as the habit plane, transforms into during the transformation from β to M phases. The martensite transformation mechanism is that the and transform to and through the tiny migration of atoms.
Compatibility of L-Tyrosine Derived Biodegradable Polycarbonate/Chitosan Blends
Authors: Huang Xia , Chen Jia Chang , Shen Chang Yu , Liu Chun Tai , Zhang Shi Xun
Published: November 2010

In the present study, the compatibility and degradability of L-tyrosine derived polycarbonate(PC)/Chitosan（CTS）blend were investigated. The PC was synthesized in our laboratory. Blends of the polymers with compositions 4/1, 3/1, 1/1,1/3 and 1/4 w/w were prepared by solution-casting. The blends were characterized by FT-IR,DSC,XRD,SEM. No obvious two phases were observed. DSC and SEM analysis implied that all those components in consideration were compatible well in the blend formulation systems.Tg of the blends decreased with increasing PEG content. With the increase of the CTS content, the water retention ratio increases from 15% to 61%.
Preparation of Novel Ag/Bacterial Cellulose Hybrid Nanofibers for Antimicrobial Wound Dressing
Authors: Yang Jia Zhi , Yu Ju Wei , Sun Dong Ping , Yang Xu Jie
Published: November 2010

In this work, we describe a novel facile method to prepare long one-dimensional hybrid nanofibers by using hydrated bacterial cellulose nanofibers (BCF) as template. Silver (Ag) nanoparticles with an average diameter of 1.5 nm were well dispersed on BC nanofibers via a simple in situ chemical-reduction between AgNO3 and NaBH4 at relatively low temperature. The bare BCF and as-prepared Ag/BCF hybrid nanofibers were characterized by a range of analytical techniques including transmission electron microscopy (TEM), X-ray diffraction (XRD), and UV–vis absorption spectra (UV–vis). The results reveal that Ag nanoparticles were homogeneously precipitated on the BCF surface. The results indicate that Ag/BCF hybrid nanofibers are promising candidate materials for functional antimicrobial agents.