bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and Properties of N,N-Dimethyl-O-Quaternary Ammonium Chitosan
Authors: Cao Zhi Ling , Liu Wei Wei , Xiong Jian Jun , Qu Na , Li Hong Xia , Yao Guo Wei
Published: November 2010

N,N-dimethyl-O-quaternary ammonium chitosan(NNQAC) was synthesized from chitosan by N-dimethylation then quaternized by 2,3-epoxy propyl trimethyl ammonium chloride. The structure of NNQAC was characterized by FTIR. Properties of quaternary ammonium chitosans, including solubility, antimicrobial activity, water-absorption and water-retention ability, were investigated. The results showed that NNQAC was water–soluble in neutral and basic environments. The moisture-absorption and retention abilities of NNQAC were higher than that of chitosan and equivalent to hyaluronic acid. The antibacterial activities of NNQAC were tested against Bacillus subtilis, Escherichia coli and Staphylococcus aureus. In water medium, NNQAC exhibited MIC values in the range of 10 to 2.5 μg/mL.
The Influence of Electroless-Silver Coated Cenosphere Powders on the Electromagnetic Shielding Interference Effectiveness and Mechanical Properties of the Silicone Rubber
Authors: Hu Yong Jun , Zhang Hai Yan , Cheng Xiao Ling , Li Feng , Chen Tian Li
Published: November 2010

Silver plating cenosphere powders were developed by electroless plating method. After being mixed with silver plating cenosphere powders and curing agent, silicone rubber composites was obtained. The surface morphology, microstructure and cross-section of Ag-coated cenosphere powders and composites were analyzed using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The influence of different concentration of Ag-coated cenosphere powders on the conductivity, electromagnetic shielding interference effectiveness and mechanical properties of the silicone rubber was discussed from the point of view of condition of Ag-coated cenosphere powders and silicone rubber. The results showed that the smooth and compact silver coating was deposited on the surface of cenosphere powders. The Ag-coated cenosphere powders possessed good oxidation resistance and enough strength to resist being crushed during the preparation of composites. The adhension between the silver film and cenosphere powders was good. There existed the extreme shielding effectiveness (SE) of silicone rubber composites filled with Ag-coated cenosphere powders. The electrical conductivity no longer plays an important role in enhancing the SE of composites when the SE of composites reaches the extremum. When the content of the Ag-coated cenosphere powders was 180 parts per hundred of rubber (phr), the SE values of composites were typically above 80 dB and close to the extremum across the tested frequency range from 2.6 GHz to 3.95 GHz. And the mechanical properties of composites with 180 phr were not degraded obviously.
Effect of Intercritical Quenching on Microstructure and Mechanical Properties of Ultra Low Carbon Heavy Steel Plate
Authors: Zou De Hui , Peng Zhi Fang , Li Ping He , Guo Ai Min
Published: November 2010

The Effect of intercritical quencing on microstructure and mechanical properties of ultra low carbon heavy steel plate were studied by utilizing SEM, TEM, tensile and impact tests. The specimens were firstly subjected to an annealing treatment at 930 oC followed by quenching to ambient temperature, then were repeatedly annealing at the temperatures being varied in the range of 600~870 oC, and then repeatedly quenched to ambient temperature in cold water. When the intercritical quenching was just slightly above Ac1, the strength and low temperature toughness were remarkably deteriorated attributing to the massive grain and some twins in the bainite islands. However, the more when the annealing temperature increased higher than Ac1 but still below Ac3, the more regions can be austenized, which cause the average of carbon content in the austenized regions to be relatively low. So it was difficult that these austenite regions changed into twin martensites after interctitical quenched. Then the comprehensive properties including low temperature toughness became good again.
Effect of Niobium on the Microstructure and Mechanical Properties of Low Carbon Steel Plate with Intercritical Quenching
Authors: Zou De Hui , Peng Zhi Fang , Li Ping He , Guo Ai Min
Published: November 2010

The microstructure and mechanical properties of the low carbon steel plates containing Niobium content of 0.038%, 0.063% and 0.082% with intercritical quenching were studied by SEM, TEM, tensile and impact tests. The results showed that the intercritical quenching steel with high Niobium content can gain the fine microstructure , but also easily obtain the martensite, which made the strength very high but low temperature toughness very low, however, the steel with low Niobium content can not reach enough austenitization level, which caused both low temperature and yield ratio high relatively. So in the given rolling and heat treatment process, there was suitable Niobium content can contribute to obtain the optimal austenization level resulting in the good combination of strength, yield ratio, elongation and low temperature toughness after intercritical quenching in the low carbon steel.
Effect of La2O3 on the Microstructure and Electrical Properties of (Ti,Sn)O2 Varistor Ceramics
Authors: Wang Mao Hua , Li Gang , Yao Chao
Published: November 2010

(Ti,Sn)O2 varistors doped with different amount of La2O3 were obtained by ceramic sintering processing at 1250 . The effect of La2O3 on the microstructure and nonlinear electrical behavior of the (Ti,Sn)O2 ceramics were investigated. The ceramics have nonlinear coefficients of α=6.2–8.5. Experimental evidence shows that small quantities of La2O3 improve the nonlinear properties of the samples significantly. It was found that an optimal doping composition of 1.0mol% La2O3 leads to a low breakdown voltage of 18.1V/mm, a high nonlinear coefficient of 8.5, which is consistent with the highest and narrowest grain boundary barriers of the ceramics.In view of these electrical characteristics, the (Ti,Sn)O2 varistors with 1.0mol% La2O3 ceramic is a viable candidate for low voltage varistor devices. The characteristics of the ceramics can be explained by the effect of the substitution of La3+ for Ti4+ or Sn4+.
A Novel Mixed Hydroxide Method for Hydroxyapatite Preparation
Authors: Zhang Mei Mei , Zhao Hong Shi , Liu Hong , Liu Jian An , Han Xiu Xiu , He Wen
Published: November 2010

Hydroxyapatite(HAP) nanoparticles were synthesized by a mixed hydroxide method using calcium nitrate tetrahydrate[Ca(NO3)24H2O] and phosphoric pentoxide(P2O5) as raw materials. The synthesized nanoparticles were analyzed by x-ray diffraction (XRD), infrared spectroscopy (IR) and transmission electron microscopy (TEM) methods. The effects of reaction temperature, time and concentration of reactants on the microstructure of the nano-particles have been discussed. The results show that the hydroxyapatite particles synthesized have features of uniform morphology, pure phase and well crystallized nano size. The particle size is in the range of 30-200 nm.
Development of a Novel and Bi-Functional Quantum Dots as FRET Energy Donor
Authors: Yang Yue Qian , Xu Shi Chao , Miao Heng , Zhang Ji Mei , Dai Zhao , Sun Bo , Sun Shu Qing , Zheng Guo , Feng Tei Lin , Zi Yan , Liang Chu , Luo Hao
Published: November 2010

A novel CdTe/Ni QDs which combined both magnetism and fluorescence was successfully synthesized and its optical properties were investigated. Ni magnetic nanoparticles (MNPs) were synthesized and used as magnetic core, CdTe quantum dots (QDs) were applied as fluorescent shell material, the qualified magnetic CdTe/Ni quantum dots (mQDs) were achieved via layer-by-layer process using 1,6-hexylenediamime as linker, surface charge types of MNPs and mQDs were confirmed with a delsa nano beckman coulter. Morphology of the prepared Ni MNPs and CdTe/Ni mQDs was characterized by transmission electron microscopy (TEM), and optical properties were investigated with fluorescence spectrum (FS). Qualified CdTe/Ni mQDs with high fluorescence and narrow maximum emission peak width were obtained under the optimum conditions. Surface zeta-potential of CdTe QDs and Ni MNPs were estimated to be -36.2 and 27.97mV, respectively. TEM data indicated that ca 20nm of Ni MNPs and ca 25nm of CdTe/Ni mQDs were prepared, respectively; the size-increasing indicated the formation of CdTe shell on the Ni MNPs core. Narrow half peak width of emission peak was detected and calculated to be about 50nm via FS. High fluorescence intensity of CdTe/Ni mQDs was determined and brilliant yellow solution was observed when excited under UV360nm. The synthesized CdTe/Ni mQDs showed excellent magnetic property, and can be magnetically concentrated with a common magnet. The obtained data indicated that the prepared bi-functional CdTe/Ni mQDs possess excellent magnetic and fluorescent properties, and it can be used as a energy donor in DNA sensing based on fluorescence resonance energy transfer (FRET).
Biomass Biodegradable Food Boxes and Hot Temperature Field of Structural Optimization
Authors: Jia Xiu Jie , Li Jiang Feng , Li Fang Yi
Published: November 2010

There is a great potential market for biodegradable materials products and process equipment, long time molding, lower heat transfer efficiency, uniform temperature distribution and other issues have been studied focused, combined with biomass biodegradable food boxes forming technology research. The die temperature distribution and the temperature difference between upper and lower template have been analyzed by simulation model in this paper. According to analyzing, the die structure has been changed, so as to meet the requirements of the upper and lower temperature.
Cytotoxicity and Antiviral Activity of Calcium Alginate Fibers and Zinc Alginate Fibers
Authors: Gong Ying , Han Guang Ting , Li Xin Ling , Wu Yan , Zhang Yuan Ming , Xia Yan Zhi , Yue Chang Qing , Wu Da Wei
Published: November 2010

The cytotoxicity and anti-influenza virus (IFV) activity of calcium or zinc alginate fibers were investigated to explore the feasibility of them to be used as biomaterials. African Green Monkey kidney cell (Vero) and human cervical cancer cell (Hela) cultured with alginate fibres were used to screen cytotoxic effects. After 48 h, MTT (3-(4,5-dimethyl-2-thiazol)-2,5-diphenyl-2H tetrazolium bromide) assays were performed. Then cytotoxicity was evaluated with six grades according to cell relative growth rate (RGR). In anti-IFV activity assay, IFV were added to all fibers and the Vero cell survival were detected by MTT assays with calculating the percentage of protection. The cytotoxity of calcium alginate fibers on Vero were grade 0 or 1 in contrast to zinc alginate fibers which was grade 0. The cytotoxity of calcium or zinc alginate fibers on Hela were grade 0. Furthermore, partial calcium or zinc alginate fibers could promote Vero or Hela cell growth. In antiviral assay the highest percentage of protection of calcium alginate fibers was 34.42%, while that of zinc alginate fibers was 59.42%. The results showed that calcium or zinc alginate fibers had a good cellular biocompatibility and the large weight zinc alginate fibers had a better anti-IFV activity than calcium alginate fibers, which is potential for tissue engineering.
Strength Development of Concrete with Proto-Machine-Made Sand
Authors: Li Feng Lan , Zhu Qian
Published: November 2010

The proto-machine-made sand is a new artificial material for environmental protection with grain size smaller than 5 mm made of water cleaned crushed stones or gravels broken and separated by machines, in which the stone powder maintains as prototype and certain content by improving the production technology. The paper introduces a series of test results of grade C50 concrete mixed by proto-machine-made sand with stone powder in mass content of 3 %, 7 % and 13 %. Based on the cubic compressive strength of concrete at different ages of 3 d, 4 d, 7 d, 14 d, 28 d, 56 d, 90 d, 120 d, 150 d and 180 d, the developing regularities of strength affected by the content of stone powder are analyzed, the formula for predicting the cubic compressive strength of concrete at any ages is proposed. It is proved that the effect of stone-powder in proto-machine-made sand on concrete strength is virtually different from that of the stone powder mixed with powdered mud in ordinary machine-made sand, and the limit value of stone powder content lower than 5 % is not suitable to proto-machine-made sand for mixing concrete with grade of C50.
Purification and Characterization of a Natural Lectin from the Seed of Peanut Arachis hypogaea
Authors: Sun Jie , Yang Qing Li , Bi Jie , Zhang Chu Shu , Yu Li Na , Zhu Feng
Published: November 2010

A natural lectin from the seed of peanut Arachis hypogaea was purified by singlestep affinity chromatography using galactoside-coupled agarose. This lectin was named PN-L and its inactive form had a molecular mass estimate of 29 kDa. The lectin PN-L was detected for agglutinating activity, glycoinhibiting action and thermostability. The influence of pH on those activities was also tested. The results showed that PN-L could not agglutinate three kinds of human erythrocytes. But it showed a strong affinity for human A/B/O erythrocytes (RBC) by neuraminidase treated. Agglutinating activity of PN-L to neuraminidase treated human O erythrocytes was inhibited by lactose , raffinose, melibiose and D-galactose. The agglutinating activity of peanut seed lectin was inhibited at temperatures greater than 55 and at a pH less than 5 or greater than 11.
The Yield Criterion for Processing Bamboo Fiber under Rolling Load
Authors: Zhang Wei , Yao Wen Bin
Published: November 2010

Processing bamboo fiber by rolling bamboo is a main methods in bamboo fiber making. However, present the basic research for making bamboo fiber by rolling are rarely work. In rolling method, plastic property of bamboo and rolling force are important factors.In this paper, strength property variation of moso bamboo with different moisture content after alkali treatment were studied. Based on the HILL-Tsai Strength theory,the yield condition of bamboo under rolling load was found. The research provided a theoretical basis to found mechanical model of rolling method in bamboo fiber making.
Preparation of Eucommia ulmoides Leaves Antioxidant and its Antioxidation Activity In Vitro
Authors: Dong Wen Bin , Liu Di , Yang Jin , Xu Xian Meng
Published: November 2010

The adsorption and desorption efficiencies on flavonoids and polyphenols from Eucommia ulmoides leaves by different resins were investigated, and the most suitable resin for preparation of Eucommia ulmoides leaves antioxidant was chosen. Then the crude extract of Eucommia ulmoides leaves was adsorbed by resin, and the resin was eluted by 20%, 40%, 60% and 80% (in volume) ethanol elution solution, and then the antioxidants were gotten. The flavonoids and polyphenols in the antioxidants were tested for content. The antioxidation activity in vitro was studied by testing the scavenging capacities on HO•, O2-• and DPPH•. The result showed: the 20%, 40% and 60% ethanol elution solution had good scavenging capacities on HO•, O2-• and DPPH•, and there was a good correlation between the contents of flavonoids and polyphenols and scavenging efficiency on each free radical; the antioxidation activities in vitro of the antioxidants was related to flavonoids and polyphenols, and the polyphenols was the leading working material; there was more polyphenols in 20% ethanol elution solution, and more flavonoids in 60% ethanol elution solution, so different antioxidant on different component content could be gotten by collecting different elution solution.
Fabrication and Characterization of a Toxoplasma gondii DNA Sensing System
Authors: Xu Shi Chao , Miao Heng , Yang Yue Qian , Zhang Ji Mei , Li Hong Jun , Dai Zhao , Zheng Guo , Yang Juan , Sun Bo , Feng Tie Lin , Zi Yan
Published: November 2010

We presented a fast, specific, and sensitive DNA sensing system, which composed of a CdTe/Fe3O4 magnetic core-shell quantum dots (energy donor), a commercial quencher (BHQ2; energy acceptor), and a designed single strand Toxoplasma gondii DNA. The designed single strand Toxoplasma gondii DNA was applied to link the energy donor and acceptor, and target DNA was detected based on mechanism of fluorescence resonance energy transfer. The CdTe quantum dots, Fe3O4 magnetic nanoparticles, CdTe/Fe3O4 magnetic core-shell quantum dots, and sensing probe were step-wisely prepared. Properties of synthesized quantum dots were investigated by transmission electron microscopy, fluorescence spectrum, nano zeta potential and submicron particle size analyzer, and X-ray diffraction, respectively. Specificity and sensitivity of sensing probe was determined by measuring the recovery of fluorescence intensity. The obtained sensing probe with magnetic properties can be simply separated or concentrated from the hybridized solution with a common magnet. The resulting data revealed the sensing system was successfully fabricated, and which has high sensitivity and specificity.
Vacuum Flat Bed Filter Control System for Cold Strip Rolling Mill
Authors: Lei Song , Wang Jun Sheng , Shen Min Gang , Chen Xue Bo , Li Sheng Li
Published: November 2010

The vacuum flat bed filter is important equipment for the cold strip rolling because the surface quality of cold rolled strip is paid more attention by customer. In the paper, the function, mechanical structure and operation modes of the vacuum flat bed filter for cold strip rolling mill are introduced. The control logic of emulsion liquid level in the filter is discussed. The filter fabric running modes are designed. The control system for vacuum filter is developed based on PCS7 software and S7-400 PLC hardware of SIMENS.
Experiment Analysis on Transient Braking Factor of Drum Brake
Authors: Wang Ren Guang , Wang Bin , Sun Han Wen
Published: November 2010

To find transient braking factor changing model affected by its three main operation factors. A type of drum brake of passenger car was taken as the testing object, a series of practical tests were conducted in brake dynamometers with combination of orthogonal and recursive methods, a formula described transient friction coefficient of drum brake was deduced from test data on the basis of three main factors which are pressure, speed and temperature, which can reflect the drum brake’s performance changing condition influenced by three main factors.
Failure Analysis and Strengthening Method for Circular Diamond Saw Blade
Authors: Lou Bai Yang , Li Pei Hua , Li Le Guo
Published: November 2010

The main causes of segment failure of diamond saw blade are studied in this paper. The segment material, the microstructure and the wear resistance of saw blade material were studied with scan electronic microscope, energy disperse spectroscopy, hardness meter, optical microscope. The results shows that the addition of alloying elements could refine grains, improve the holding force of matrix to diamond, enhance wear resistance of matrix to diamond, and decrease wear coefficient about 20%.
First Principles Calculations of Phase Stabilities of YNi2 and YMgNi4
Authors: Niu Jian Gang , Xiang Hai En , Dong Xiao Ping , Guan Li , Xie Fei
Published: November 2010

First-principles calculations were performed to study the relative stabilities of YNi2 and YMgNi4.The calculated results show that YMgNi4 has the higher stability than YNi2, duing to stress relaxation and ionic contribution. The preferential stability of YMgNi4 has been confirmed by calculating elastic constants and melting points.The calculated results show that YMgNi4 has the larger bulk modulus and melting point than YNi2.
Studies on Related ms Magnitude Rate Models in Triangular Wave Unloading Section of Calcium Medium-Fine Sandstone
Authors: Liu Jie , Li Jian Lin , Li Ying Xia , Yang Shan Shan , Zhou Ji Fang , Zhang Chao Feng
Published: November 2010

Specific to the improvement in the present research of mechanical response under cyclic loading, this paper, taking the calcareous middle- coarse sandstone as the research subject and the RMT-150C experimental system in which data is recoded by ms magnitude as the platform, develops several related models concerning the unloading rate of triangle waves. The unloading process is divided into lag time segment and non-lag time segment, with criterions and related parameters provided as well. The term apparent elastic modulus is defined. The test data analysis shows that there exist a linear relationship between the apparent modulus and instant vertical force before load damage in non-lag time segment. On the preceding basis, a rate-dependent model of triangular wave un-installation section in non-lag time segment is established. Due to the inability of the loading equipment to accurately input the triangle wave, the average loading rate is amended and a constant term is added into it. The model is proved to be reliable, as the predicted value of the deformation rate and the stress strain curve coincides with measured value. At the same time, the impact of the lag time is pointed out quantitatively and a predication model of lag time segment is set up.
Synthesis, Characterization and Crystallization of Poly(Ethylene Glycol)-b-Poly(ε-Caprolactone)
Authors: Liu Lian , Wang Pei , Qu Chao , Wei Zhi Yong , Qi Min
Published: November 2010

A family of poly(ethylene glycol)-b-poly(ε-caprolactone) (PEG-PCL) were synthesized in high yields by the ring-opening polymerization of monomethoxy-terminated poly(ethylene glycol) (mPEG) with ε-caprolactone in the presence of stannous octoate (Sn(Oct)2). Their crystallization behaviors were studied by DSC, XRD. The results illustrated that crystallization behaviors of the copolymers depended on the copolymer composition and the relative length of each block in copolymers. The melting peak of PCL block appeared gradually in the XRD patterns and DSC curves in copolymers, with increasing of the length of PCL blocks.
Biomorphic SiC Prepared from Carbonized Millet by Sol-Gel and Carbothermal Reduction Processing
Authors: Wang Qing , Zhang Ya Hui
Published: November 2010

Biomorphic silicon carbide (bioSiC) was prepared by high temperature pyrolysis and sol-gel and carbothermal reduction processing at 1600 oC. The morphology and microstructure of carbon-silica composites and purified bioSiC samples were characterized by scanning electron microscopy. The phase composition of the resulting sample was analyzed by X-ray diffraction. The results suggest that the bioSiC mainly consists of cubic ß-SiC, and principally replicates the shape and microstructure of the carbon template.
Study on Band Gap Structure of One Dimensional Phononic Crystals﻿
Authors: Wang Yan Lin , Chen Ming Wen , Wang Zi Dong
Published: November 2010

The vibration noise control is critical in engineering fields and the phononic crystal provides a new mean to control the vibration noise. The band gap structure of one dimensional phononic crystal is studied in this paper. By using the equivalent masses method we obtain the band gap structure which depends on M, m and β, the influences of initial frequency of vibration band gap via the material density, the diameter of rod and the lattice constant are analyzed. The results show that the low-frequency broadband gap characteristic is obtained by increasing M and reducing m, β. The initial frequency of vibration band gap decreases as the metal material density, the diameter of metal rod or the lattice constant increase. Some conclusions from numerical calculation are examined by the vibration experiment.
Self-Made Gas Diffusion Electrodes for Dye Wastewater Treatment
Authors: Li Shan Ping , Lian Jun Feng , Cao Han Lin
Published: November 2010

Gas diffusion electrodes (GDEs) were selected for the reactive brilliant red X-3B simulated wastewater treatment, perovskite oxide LaNiO3 as the catalyst. And a satisfying degradation effect was achieved. The optimal conditions for the catalyst preparation with sol-gel method were 1.5 as the molar ratio of citric acid and metal ions, 10 as the pH, and 750 °C as the roasting temperature. The optimal conditions for the electrodes preparation were 1 g pore-forming agent, 0.6 g catalyst, 3 g PTFE and 300 °C as the roasting temperature. Scanning electron microscope, X-ray diffraction were applied to analyze the performance of catalyst and electrodes, and the results were satisfying.
Thermo-Structural Analysis of CLAM Steel and SS316L in the First Wall for ITER during Thermal Cycling
Authors: Liu Fu Bin , Yao Man , Zhang Peng Bo , Zhao Ji Jun
Published: November 2010

The temperature and strain distributions of the mockup composed of Be, Cu-alloy with distinct structural material (SS316L and China Low Activation martensitic steel (CLAM)) were calculated and analyzed during thermal cycling, based on a high heat flux (HHF) test recently reported with heat flux of 1.5MW/m2. The calculated temperature and strain results, in which SS316L is as the structural material, showed a good agreement with HHF test. By substituting CLAM steel for SS316L the contrast analysis indicates that the thermo-mechanical property for CLAM steel is better than that of SS316 at the same condition. Furthermore, the temperature and strain distributions of the FW were calculated under the condition of normal ITER operation: the surface heat flux is about 0.5MW/m2 and volumetric heating due to neutron radiation is on the order of 15~20 MW/m2.
Research on Anti-Friction Mechanism of Ni60A/MoS2 Composite Coating
Authors: Zhao Yun Cai , Yu Dong Ling
Published: November 2010

Based on the research of the tribological properties of the Ni60A/MoS2 composite coating, this paper has studied and discussed the self-lubricating effect and mechanism of the MoS2 film in the Ni60A /MoS2 composite coating. Research shows that when self-lubricate coating rub, MoS2 solid lubricant can be precipitated, forming lubricating film on the friction surface through dragging. The Solid lubricate film of MoS2 is an important factor that lead the friction coefficient of Ni60A/MoS2 composite lubricate coating decrease. Meanwhile we analyze the formation phenomenon and friction and wear properties of self-lubricate coating, which show forming mechanism of the lubricating film contain four stages, that is, the friction beginning stage, MoS2 precipitating stage, MoS2 covering stage and MoS2 forming stage.
Extraction and Antioxidant Activity of Collagen from the Chinese Soft-Shelled Turtle (Pelodiscus sinensis)
Authors: Liu Cheng Chu , Liu Yan , Jin Yin Zhe , Ding Zhuo Ping , Li Ying Sen , Li Jia Le
Published: November 2010

Collagen is regarded as one of the most useful biomaterials. Collagen was extracted from wild Chinese soft-shelled turtles (Pelodiscus sinensis) and its molucular patterns and antioxidant activities were investigated. The SDS-PAGE analysis revealed that the collagen had three α bands with an approximate molecular weight of 400-410 kDa, which was similar to type V collagen with a molecular pattern of α1(V)α2(V)α3(V) or α1(V)[α2(V)]2. The antioxidant activity of collagen were examined by the radical-scavenging activity (RSA) assay and reducing power (RP) methods respectively. In the RSA assay, the DPPH free radical scavenging capability of the sample collagen was positively correlated with its concentration with a IC50 of 1.95mg/ml. The same trend was found in the RP assay. The reducing power of the sample collagen was also dependent with its dose employed.
The Combustion Process and Characteristic Analysis of the Refined Oil-Water Coal Slurry in Diesel Engine
Authors: Ren Lan Zhu , Fang Yang , Li Ao , Zhang Hong Xing
Published: November 2010

Based on analyzing the thermodynamic processes in the cylinder when the engine is working, the combustion characteristic of the refined oil-water coal slurry is studied and summarized, and then the reasonable micro-thought explanation of the combustion process is given. Furthermore, the feasibility of the refined oil-water coal slurry combustion in the engine is illustrated through the calculation of the refined oil-water coal slurry in all stages of the ignition temperature and thermal efficiency.
The Atomizing Experimental Study of the Refined Oil-Water Coal Slurry on the Diesel Engine of the Large-Scale Ship
Authors: Wei Xiao Hua , Zhang Hong Xing , Ren Lan Zhu , Fang Yang
Published: November 2010

At present almost all low-speed diesel engines burn heavy fuel oil or low-quality fuel oil, the viscosity, low calorific value and impurities are similar as oil-water coal slurry, so, oil-water coal slurry is possible as the fuel of large marine diesel. This article has carried on the description about atomized characteristic of oil-water slurry, and it’s atomizing performance and analysis to the nozzle of type ZCK154S432 and type ZCK154S423 is studied experimentally from different spurting pressure, the different spray nozzle type as well as the different density of refined oil-water slurry, obtained the main factors of affect oil-water slurry’s atomization, illustrated the importance of developing coal instead of oil.
The Experimental Research on the New Compound Inhibitor for the Coal Heap
Authors: Du Cui Feng , Li Hong Shuang , Shi Xiao Song
Published: November 2010

In this paper, aimed at the characteristic of the coal heap spontaneous combustion, the coal heap inhibitor component was initially determined through the requirements analysis of the inhibitor’s properties, the orthogonal experiment of film–forming property and heating were conducted, and the experiment of inhibition rate and permeability test about the optimal formula were carried on. The results showed that the inhibition rate of this inhibitor could reach 88%. This showed that a new measure was provided to hold back the coal heap spontaneous combustion, the inhibitor also had a function of restraining coal dust raising as a result of the inhibitor’s film-coverage property.
Study on Strength Distribution and Failure Probability Estimation of Structural Part of Foam Material
Authors: Xie Li Yang , Cho Jae Ung , Lin Wen Qiang
Published: November 2010

With structural reliability assessment as the scenario, a structural part made of foam material was treated as a series k-out-of-n system. The strength random variable of a large-size part was characterized by the strength random variables of virtual elements with certain size, as well as the number of the elements determined by part size. Specially, the statistical dependence among element failures was expounded with respect to the virtual elements. A series k-out-of-n system failure probability model was presented, and the failure probability of a structural part of foam material was described in terms of the size parameters of the part in two dimensions: the number of elements in width direction and that in length direction. It was shown that strong dependence among element failures exists, the failure probability of a large-size part will approaches to an upper bound with the increase in part length.
Influence of Substrate Temperature on Structure and Optical Property of Cu3N Thin Films
Authors: Xiao Jian Rong , Jiang Ai Hua , Liang Ye Guang
Published: November 2010

Copper nitride thin films were prepared by reactive radio frequency magnetron sputtering at various substrate temperatures. The surface morphology and crystal structure of the thin films were characterized by atomic force microscope (AFM) and X-ray diffraction (XRD), respectively. The AFM images demonstrate that the films have a compact structure. The XRD test indicates that growth orientation of the thin films prefers the (111) or (100) at different substrate temperature. The optical transmission properties of the thin films were obtained by an ultraviolet visible spectrometer. The optical band gap of the thin films decreases with increasing substrate temperature.
Thermal Degradation of Hydroxyl-Terminated Poly(L-Lactic Acid) Oligomer into L-Lactide
Authors: Shen Jun , Wei Rong Qing , Liu Ying , Liu Xiao Ning , Zhong Yu
Published: November 2010

This study investigates the thermal degradation of poly(L-lactic acid) (PLLA) oligomers into L-lactide（LA）by modification of the oligomer terminal groups. Pure PLLA oligomer (OLLA) was synthesized by condensation polymerization of L-lactic acid. Poly-hydroxyl-terminated OLLA (OLLAPOH) and two-carboxylic acid-terminated OLLA (OLLACOOH) were prepared by adding a small amount of polyfunctional substance, such as 1,4-butanediol, pentaerythritol, or adipic acid, to L-lactic acid. The thermal degradation behaviors of these oligomers were compared at 210-220 °C under 0.3-0.5 kPa. The results show that OLLAPOH has a 10-20% higher yield than OLLA and OLLACOOH. The order of decreasing yield is as follows: OLLAPOH>OLLA >OLLACOOH. The hydroxyl ends of the chains induce the reaction. OLLAPOH simultaneously starts depolymerization from each hydroxyl end to speed up the reaction, to shorten the time the substance remains at high temperature, and to reduce the byproducts. This results in an increased L-lactide yield. A practical approach for L-lactide production by thermal degradation of OLLAPOH is adopted by using a degradation mechanism, which is an unzipping reaction beginning from the hydroxyl ends of the chains.
The Study of Liquid-Liquid Structural Transition of PbSnBi Ternary Alloy
Authors: Yu Jin , Yang Hui Zhen , Zu Fang Qiu , Xu Wei
Published: November 2010

The electrical resistivity of liquid PbSnBi alloy has been precisely measured by the Direct Current (DC) four-probe technique in our experiment. It was found that the electrical resistivity-temperature (ρ-T) curves changed discontinuously at several-hundred degrees above liquidus. However, the ρ-T curves was linear before this turning point with increasing temperature. Moreover, the ρ-T curve of the different composition alloys showed different turning points. The anomalous behavior of electrical resitivity indicates the alteration of the electron transport properties and the mean free path LZ of conduction electrons, since resistivity as one of the physical properties sensitive to the structure and this discontinuous alteration induced by temperature suggests the liquid-liquid structural transition taking place in PbSnBi melts. This present Letter makes a beneficial attempt at studying electrical resistivity to investigate liquid-liquid structural transition.
Microstructures and Properties of Bainitic Nodular Cast Iron Treated by Controlled Cooling and Austempering Treatment
Authors: Liu Ke Gao , Xu Ai Min , Xiang Dong , Xu Bin
Published: November 2010

The mixed structures of bainite matrix, austenite and nodular graphite were obtained in nodular cast iron treated by controlled cooling and austempering in electric oven instead of nitrate salt bath. The relations between bainitic morphology and mechanical properties were investigated. Experimental results show that, the nodular cast iron treated by controlled cooling in water bath and austempering has microstructures of upper bainite and austenite, the mechanical properties fluctuate greatly due to its relatively narrow temperature region in processing. The consistency of mechanical properties of lower bainite nodular cast iron is superior to upper bainite nodular cast iron. The comprehensive mechanical properties of lower bainite nodular cast iron are improved by tempering. However, the brittleness increases greatly when martensite appears in mixed structures, while good mechanical properties can still be obtained by tempering at elevated temperatures.
Error Model and Simulation to Arbitrary Point of Automobile Panels in Normal Mechanical Parameter Measurement Instrument
Authors: Sun Zhen Zhong , Hong Zeng , Chen Sheng Gui
Published: November 2010

By using homogenous coordinate transformation principle and Denavit-Hartenberg analysis method, a measurement kinematics model and a error model to arbitrary point of automobile panels in normal mechanical parameter measurement instrument, which the movement of the probe center is relative to machine reference frame is construct. On the basis of using wielding matrix function total differential method, building up the error delivery relation of parameter error of measuring motion model transform to the probe center, and having verified what be built the error model correctness by simulation. The error is enlarge mainly in the process of delivery from angle error, while length error are very minor in error effects. This research can establish a base for studying the measuring-error of portable type measures instrument and it's measuring accuracy.
Element Selection and Meshing in Finite Element Contact Analysis
Authors: Bai Run Bo , Liu Fu Sheng , Xu Zong Mei
Published: November 2010

Contact problem, which exists widely in mechanical engineering, civil engineering, manufacturing engineering, etc., is an extremely complicated nonlinear problem. It is usually solved by the finite element method. Unlike with the traditional finite element method, it is necessary to set up contact elements for the contact analysis. In the different types of contact elements, the Goodman joint elements, which cover the surface of contacted bodies with zero thickness, are widely used. However, there are some debates on the characteristics of the attached elements of the Goodman joint elements. For that this paper studies the type, matching, and meshing of the attached elements. The results from this paper would be helpful for the finite element contact analysis.
Experimental Study on Polyphosphoric Acid (PPA) Modified Asphalt Binders
Authors: Cao Wei Dong , Liu Shu Tang , Mao Hong Lu
Published: November 2010

Polyphosphric acid (PPA) modified asphalt binders were produced in the laboratory using one base asphalt and four levels of PPA contents (0.6%, 1.0%, 1.5% and 2.0% by weight of base asphalt). Penetration test, softening point test, rotation viscosity test, creep test with bending beam rheometer (BBR) and four components test were carried out to study the performance of PPA modified asphalt binders and possible modification mechanism. The results indicate that the high-temperature performance of PPA modified asphalt binders are obviously improved and temperature susceptibility are decreased, but the low-temperature performance slightly decline compared with base asphalt. The PPA content has a very significant effect on softening point whereas it has no significant influence on low-temperature performance according to variance analysis (ANOVA). Finally, four components test reveals that the primary modification mechanism of PPA is the change of chemical composition of asphalt binder.
Study on Lamellar Precipitates of the Austenitic Valve Steel
Authors: Liu Ke Gao , Xu Ai Min , Xiang Dong , Xu Bin
Published: November 2010

Dual-phase lamellar precipitates can be easily occurred in the austenitic steel valve in heat treatment and use. They affect seriously the performance of the valve at high-temperature, which is one important reason leading to valve failure. The morphology and precipitation location of lamellar precipitates of the 5Cr21Mn9Ni4N (21-4N) exhaust valve were investigated by scanning electron microscopy, and the influencing factors and precipitating mechanisms were analyzed. Experimental results show that, the lamellar precipitation is very sensitive to using or aging temperature, the higher temperature the more precipitates. The lamellar precipitation consists of continuous and discontinuous precipitation. The latter mainly appeared at the locations with larger deformation. Slip bands and deformation twins at high-temperature deformation and grain boundaries are important locations for precipitation.
Analysis on Chaotic Behavior in Rock Damage Rheological Process under Uniaxial Stress
Authors: Liu Ning , Zhang Chun Sheng
Published: November 2010

The evolutional laws of rock under uniaxial stress are studied based on damage mechanics, rock rheology mechanics and chaos theory. Firstly, the damage rheological evolution equations are set up on the base of damage mechanics under the isotropic and orthogonal anisotropy conditions. The chaotic characters are tested in the process of evolution and the chaotic effect is analyzed. The root reason of rock damaged is made clear. The creep curve of Kelvin model considering damage is illustrated by FLAC3D, and the deformation process is explained by chaos theory. It will be help to understand the mechanics property of rheology of damaged rock and predict development phases. It is also much value in solving various practical problems of geotechnical engineering and acquainting other materials’ rheology evolution..
Parameter Simulation for Quenching and Pre-Stretching about Aluminum Alloy Thick Plates Based on MARC Finite Element
Authors: Yuan Wang Jiao , Wu Yun Xin
Published: November 2010

To predict the three-dimensional residual stress distribution of 7075 aluminum alloy thick plates, the quenching and pre-stretching process were simulated by using MARC finite element software. In order to simulate quickly according to different reality conditions, the parametric model was realized by using defining parameters and selecting objects by inputting coordinate value with the box mode. In the quenching process, a non-linear thermo-mechanical direct coupled analysis of the aluminum alloy thick plates was carried out, by taking into account of the temperature dependence of the thermo-physical properties. In the pre-stretching process, the clamp and release of the clamp of pre-stretch machine were simulated by using life and death element technology. The study demonstrates that the theoretical predictions agree well with the experimental values of residual stresses measured by the X-ray diffraction method. The simulation results provide the user a tool for analyzing and studying on quenching and pre-stretching technique using virtual reality method.
Effect of Volume Fraction of NiMnGa Powders on Magnetic-Field-Induced Strain in NiMnGa/Polymer Composites
Authors: Sun Xiao Gang , Xie Chao Ying
Published: November 2010

Polymer composites inserted with high volume fraction of NiMnGa powders were fabricated and their magnetic-field-induced strain (MFIS) was investigated. It is found that MFIS of NiMnGa/polymer composites increases with the increase of volume fraction of NiMnGa powders in composites. Large MFIS of 950 ppm has been obtained along the orientation magnetic field while only 220 ppm was on the perpendicular orientation magnetic field.
Photodegradation of Ammonia by TiO2 Nanoparticles Produced by Flame CVD Process
Authors: Xie Hong Yong , Wang Ling Ling , Zhu Lu Ping , Gao Gui Lan , Wang Li Jun , Yuan Hao
Published: November 2010

Photodegradation of ammonia by mixed-phase TiO2 nanoparticles, synthesized by the oxidation of TiCl4 in turbulent propane/air flame chemical vapor deposition (CVD) process, has been investigated experimentally by using a tubular photoreactor with thin TiO2 films coated on the reactor wall by sedimentation. Effects of ammonia initial concentration from 2-40mg/m3, relative humidity from 30-75%, rutile mass fraction from 20-50% of TiO2 nanoparticles on degradation degree are examined under the conditions of 38g/cm2 catalyst loading, 24mW/cm2 UV irradiation of 254nm, and 5.7sec residence time in the reactor. Results show that photocatalytic activity is higher when rutile mass fraction is from 0.2 to 0.4, corresponding higher PL intensity, and 60% conversion is achieved at initial ammonia concentration of around 5mg/m3 and 70% relative humidity. Based on experimental results, separation of photoinduced electron (e-) and hole (h+) pairs by rutile phase is discussed.
Recent Advances in the Bioactivities and Structural Analysis of Chondroitin Sulfate
Authors: Xiong Shuang Li , Li An Lin , Huang Ni
Published: November 2010

Recent research data on chondroitin sulfate have suggested that they have many new biological functions such as anti-atherogenesis, anticoagulation, prevention and cure of arthritis, protection and repair of neuron during CNS development, morphogenesis and cell division. They are widely applied to functional food, clinical medicine and biomaterial. However, these bioactivities and applications are dependent on their fine structure with different monosaccharide unit and sulfation patterns. This review provides information on intimate relationship between these biological functions and the structure. Moreover, we overviewed the newly analytical methods about the composition and fine structure of them, including chromatometry, high performance liquid chromatography, mass spectrum and nuclear magnetic resonance before and after enzymolysis.
Application of Calculus Equation in Solving Thermal Decomposition Kinetics Parameters of Fire-Retardant Foam
Authors: Sun Cai Yun , Ren Chun Huan , Gao Ming
Published: November 2010

The fire retardants were used in flexible polyurethane foam (PUF) to get fire retardant PUF, whose kinetic parameters activation energies (E) were calculated by Ozawa integral method and the Kissinger differential method. The results show that the correlation coefficient (R) is above 0.95, which shows good reliability of the two methods for solving E. E for the fire retardant foam is decreased by 80 kJ•mol-1, which shows that the fire retardant can catalyze decomposition and carbonization of flexible PUF.
Visible-Light Activity Evaluation of p-n Junction Photocatalyst NiO/TiO2 Prepared by Sol-Gel Method
Authors: Liu Wei , Chen Shi Fu
Published: November 2010

P-N junction photocatalyst NiO/TiO2 photoexcited by visible light was prepared by sol-gel method using Ni(NO3)2•6H2O and tetrabutyl titanate [Ti(OC4H9)4] as the raw materials. The p-n junction photocatalyst NiO/TiO2 was characterized by UV-Vis diffuse reflection spectrum, fluorescence spectra (FL), X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). UV-Vis spectrum showed that the absorption wavelength range of NiO/TiO2 is extended to the visible region, making it an effective photocatalyst photoexcited by visible light. This was demonstrated by photocatalytic reduction of Cr2O72- and photocatalytic oxidation of methyl orange (MO) under visible-light (λ>400 nm) irradiation. Doped-NiO effectively suppressed the phase transformation of anatase to rutile and the growth of titania crystallites. The optimum percentage of doped NiO is 0.5% (mole ratio of Ni/Ti). Effects of heat treatment on the photocatalytic activity of p-n junction photocatalyst NiO/TiO2 were investigated. The mechanisms of influence on the photocatalytic activity were also discussed by the p-n junction principle.
Effect of Soft Foamed Polyethylene on the Property of Portable Mini-Cold Storage
Authors: Xing Ya Ge , Li Xi Hong , Xu Qing Lian , Yun Juan , Li Wei Li
Published: November 2010

Effect of PE materials on environmental temperature, frost accumulation and electricity consumption of mini store-room prepared with the new type foamed polyethylene was investigated. The application of portable mini cold storage room made of this material on the quality of “Fuji” apples was also studied. The fruits of apples had good quality after 150 days storage. Our findings reveal that soft foamed PE insulation material has a good potential to prepare mini store-room for the preservation of fruits.
Preparation and Characterization of Si3N4/TiCN Composite Ceramic Tool Material
Authors: Zheng Guang Ming , Zhao Jun , Zhou Yong Hui , Gao Zhong Jun
Published: November 2010

Si3N4-based composite ceramic tool materials reinforced with TiC0.5N0.5 particles were fabricated by using hot-press-sintering technique with Al2O3 and Y2O3 as sintering aids. The effects of the content of TiC0.5N0.5 on the microstructure and properties of composite ceramic were investigated. The experimental results show that optimal mechanical properties were achieved for the composite with the addition of 20 vol.% TiC0.5N0.5 microparticles, with the flexural strength, fracture toughness and Vicker's hardness being 838 MPa, 8.5 MPa•m1/2 and 15.6 GPa. The fracture surface microstructure of the composites is characterized by scanning electron microscopy (SEM). Phase identification was carried out by X-ray diffraction (XRD). It was found that the microstructure of the material was homogenous and the elongated grain of β-Si3N4 was interlaced. And the fracture surfaces were observed to exhibit a mix of intergranular and transgranular fracture.