bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of CuO Additive on Physical Properties of BaTiO3 Ceramics
Authors: Zhang Zong , Zhang Jia Liang , Shao Shou Fu , Zheng Peng , Wang Chun Lei
Published: June 2011

Various ceramics were prepared by the conventional solid-state reaction technique according to the compositional formula of (1-x) BaTiO3+xCuO withx= 0.00 ~ 0.05. The influence of CuO additive on microstructure, crystalline structure and dielectric and piezoelectric properties were investigated. It has been found that CuO acts like a sintering aid in the CuO-modified BaTiO3ceramics to promote the ceramic densification and suppress the abnormal grain growth during sintering process, and decreases the orthorhombic-tetragonal phase transition temperature. The CuO-modified BaTiO3ceramics show desirable microstructures with high density, small average grain size and uniform grain size distribution. For the one withx= 0.01, it has the good piezoelectric properties ofd33= 300 pC/N,kp= 0.49,k33= 0.62 andQm= 425 at room temperature, and exhibits aε'peak at -5°C and ad33maximum of 353 pC/N at 0°C, respectively.
Microstructural and Dielectric Properties of SrTiO3-Doped CaCu3Ti4O12 Ceramics
Authors: Mu Chun Hong , Liu Ying Li , Song Yuan Qiang , Zhang Huai Wu , Liu Peng
Published: June 2011

CaCu3Ti4O12presents colossal dielectric permittivity within a large temperature and frequency range, which makes it to be a suitable material for technological applications, such as components of capacitive memories and mobile phones. In this investigation, SrTiO3-doped CaCu3Ti4O12ceramics were prepared by solid-state reaction. The influence of doping on the structures, compositions and dielectric properties of the materials were investigated by X-ray diffraction, scanning electron microscopy and dielectric measurements between 40 Hz and 110 MHz. The material presents colossal response (εr~104−105) and the dielectric loss tangent decreased with doping level increase at high frequency. The microstructure analysis showed that the second-phase particles segregated in the doped CaCu3Ti4O12grain edges. Cole-Cole modeling correlated well the effects of this segregation with the relaxation parameters obtained. The extrinsic contributions for the dielectric response were discussed together with the structural and compositional evolution of SrTiO3-doped CaCu3Ti4O12material. The experimental results indicated that SrTiO3doping is a suitable method to optimize the dielectric response and electrical properties of CaCu3Ti4O12for the applications in microelectronic devices.
Performance of Piezoelectrets Made of Non-Porous Polytetrafluoroethylene and Fluoroethylenepropylene Layers
Authors: Sun Zhuan Lan , Zhang Xiao Qing , Cao Gong Xun , Lou Ke Xing , Xia Zhong Fu
Published: June 2011

The thermal stability of piezoelectricd33coefficients and charge dynamics in the piezoelectret films with tailored microstructure, made of non-porous polytetrafluoroethylene (PTFE) and fluoroethylenepropylene (FEP) layers, are investigated by the measurements of the isothermal decay of piezoelectricd33coefficients at elevated temperatures and the analysis of thermally stimulated discharge (TSD) current spectra in short circuit, respectively. The results show that the quasi-static piezoelectricd33coefficient up to 300 pC/N is achieved and its Young's modulus is about 0.28 MPa. Thed33values in the present studied films show improved thermal stability compared with the films without regular microstructure. The drift path for the most of detrapped charges in the films is through the solid dielectric layer.
High Stability of Dielectric Permittivity for Pb(Mg1/3Nb2/3)O3-Based Composite Ceramics Prepared by Coating Method
Authors: Zhao Jing Bo , Du Hong Liang , Qu Shao Bo , Zhang Hong Mei , Xu Zhuo
Published: June 2011

To improve the temperature stability of PMN(Pb(Mg1/3Nb2/3)O3)-based ceramics, PMN-based composite ceramics were prepared by co-sintering two kinds of ceramics with different curie temperature. One unit is MHT(0.82PMN (Pb (Mg1/3Nb2/3) O3) -0.18PT (PbTiO3) (the curie temperature Tm=74°C)), and the other unit is MLT (0.88PMN (Pb (Mg1/3Nb2/3) O3)-0.12BT (BaTiO3) (the curie temperature Tm=-50°C)). The effects of the sintering temperature and the ratio of high and low Tm units on dielectric temperature stability were studied. The results show that the temperature stability can be improved greatly by co-sintering and coating method. The results show that PMN(Pb(Mg1/3Nb2/3)O3)-based composite ceramics are promising candidate for practical applications.
Research on the Properties of Nano Core-Shell Ni/TiO2/Urea EMR Fluid
Authors: Tan Suo Kui , Song Xiao Ping , Li Qiao , Guo Hong Yan , Ji Song , Zhao Hong
Published: June 2011

In the present paper, mechanical properties test and morphology observation，the effect among electric field, magnetic field and electromagnetic field, shear ratio on the Ni/TiO2/Urea core-shell particles electrorheological fluid properties were studied. It is found that with increasing electric field, magnetic field and shear ratio in the same composition electrorheological fluid, the property of electrorheological fluid can be increased. However, there is a critical value for shear ratio. When shear ratio is larger than 20s-1, the property of ER is nearly certain value for same composition ER fluid. Electromagnetic field reciprocal effect can increase the properties of ER fluid, and make the particles chain become thicker and interweaved each other.
A Novel pH-Sensitive Microsphere Composed of CM-Chitosan and Alginate for Sulforaphane Delivery
Authors: Wang Hui , Liang Hao , Yuan Qi Peng , Wang Tian Xin
Published: June 2011

Sulforaphane (SF) has been proved to be an effective anticancer agent according to its experiments bothin vitroandin vivo. To date, there is few reported method to deliver SF for increasing its bioactivity and stability. In this study, a novel pH-sensitive microsphere composed of water-soluble carboxymethylated chitosan (CMCS) and alginate mixed with sodium sulfate was developed for SF delivery. Swelling studies and release characteristics under different pH values of microspheres were investigated. Then, the release of SF from test microspheres was studied in simulated gastric and segmented intestinal media. It has been found that the SF cumulated release in 5h was increased from 55.89% to 76.73% when the microspheres mixed with sodium sulfate. In addition, the stability of SF embedded in CMCS/alginate microspheres was also significantly improved. Under pH 7.4, free SF had a severe degradation of approximate 100% within 210 min, whereas the change of the SF in microspheres was only a decrease of about 10%. The results suggested that the microspheres of CMCS and alginate could be a suitable pH-sensitive carrier to increase the stability of SF in the segmented intestine.
Development of Microcapsules Containing Oil-Based Contrast Medium
Authors: Uehara Masumi , Hamakawa Syotaro , Maki Yasuyuki , Dobashi Toshiaki
Published: June 2011

For efficient transcatheter arterial embolization therapy for hepatocellular carcinoma, we have developed microcapsules containing oil-based contrast medium, as obstructing materials. The microcapsules were prepared by means of the interfacial polymerization to make a wall membrane consisting of polyureaurethane with Lipiodol in the core. The average size of the particles was 80 μm, and the size distribution was fairly small. The extent of X-ray absorption of the microcapsules was controlled by the ratio of the amounts of triisocyanate monomer and Lipiodol in the oil phase on the interfacial polymerization.
Effect of Carbon-Doping on Microstructure and Friction/Wear Behaviors of TiB2 Films
Authors: Xin Xi Ling , Xu Xiao Jing , Fan Zhen , Tian Kun , Chen Dan , Yu Chun Hang , Sheng Xin Lan
Published: June 2011

In this paper, both the TiB2/SiC bilayer films and the carbon-doped TiB2(TiB2-C)/SiC bilayer films (SiC films as interlayer) were successfully deposited on quenched Cr12MoV steel substrate through magnetron sputtering technology, and the carbon-doping effect on microstructure and friction/wear properties of TiB2films were investigated. The results show that the doped-carbon presented in manner of sp3C-C and sp2C-C bonds i.e. DLC (diamond-like carbon). As sliding against steel balls under dry frictional condition, the doped-carbon strongly decreased the friction coefficient of the films and the material transfer from the friction pairs to the films. At the same time, the doped-carbon reduced the wear rate of the films, the wear rate of the TiB2films and the TiB2-C films were both in the magnitude order of 10−5 mm3m−1N−1, this is due to more material transfer significantly adhered on TiB2films than on TiB2-C films.
Study on Tribological Performance of the TiNi Modified Layer on the Surface of the Ti6Al4V Alloy
Authors: Wang Zhen Xia , He Zhi Yong , Wang Ying Qin , Liu Xiao Ping , Tang Bin
Published: June 2011

TiNi alloyed layer was prepared on surface of Ti6Al4V substrate by plasma surface alloying process. Micro-structure, composition distribution, phase structure and hardness distributing of TiNi modified layer were analyzed. Tribological performance of TiNi alloyed layer and Ti6Al4V substrate was observed by Pin-on-disc test. The results indicated that surface microhardness of TiNi alloyed layer was about 620HV. Coefficient of friction (CoF) and relative wear rate (RWR) of TiNi alloyed layer were lower than Ti6Al4V substrate, and wear resistance of TiNi alloyed layer was improved obviously. The wear mechanism of Ti6Al4V alloy is abrasion and adhesion wearing, while TiNi alloyed layer shows abrasion wearing.
Formation and Evolution of Intermetallic Compounds in Solder Joint for Electronic Interconnect
Authors: Du Chang Hua , Zhao Hai Jian , Yin Li Meng , Chen Fang
Published: June 2011

As solder joints become increasingly miniaturized to meet the severe demands of future electronic packaging, the thickness of intermetallic compounds (IMC) in solder joint continuously decreases, while, the IMC proportion to the whole solder joint increases. So IMC plays a more and more important role in the reliability of microelectronic structure and microsystems. In this paper, the formation and growth behavior, along with the composition of IMC at the interface of Sn-based solders/Cu substrate in soldering were reviewed comprehensively. The effect of isothermal aging, thermal-shearing cycling and electromigration on the interfacial IMC growth and evolution were also presented. Furthermore, the formation mechanism of Kirkendall voids during thermal aging was introduced. In addition, the effect of the interfacial IMC on mechanical properties of solder joints was in-depth summarized. Adopting an appropriate flux to control the thickness of the IMC to improve the reliability of solder joints and electronic products was proposed in the end of this paper.
Growth of Wafer Size Graphene on SiC Substrates
Authors: Chen Xiu Fang , Wei Ru Sheng , Gao Yu Qiang , Peng Yan , Song Sheng , Wang Li Huan , Hu Xiao Bo , Xu Xian Gang , Jiang Min Hua
Published: June 2011

Graphene, as strict two-dimensional material, exhibits exceptionally good electronic properties. In this paper, graphene was prepared on SiC substrates at different temperature based on two types of pre-treated surface. The surface morphology was characterized by atomic force microscopy (AFM) and scanning electronic microscopy (SEM). The results on SiC surface pre-treatment showed that chemical mechanical polishing (CMP) was an effective surface treatment method for reproducible and controlled growth of graphene. Images of the Si-surface revealed that the thickness of graphitic layers increased with annealing temperature. Meanwhile, a mesh-like network of wrinkles tended to tent-like features with the increase of temperature. The residual stresses, average crystallite size and number of graphene layers were analyzed by Raman spectroscopy. Little shift of 2D-band indicated the presence of certain stresses. Results among four samples showed that graphene layers grown on MP C-surface substrates had the thickest layers，contained the smallest average crystallite size La and exhibited no stresses. While graphene layers grown on Si-surface under 1600°C built upon compressive stresses, exhibited largest La and least number of graphene layers, indicating perfect quality.
Facile Controlled Synthesis of Manganese Oxide Hierarchical Microspheres by Hydrothermal Method
Authors: Li Dong Yan , Chen Yun Fa
Published: June 2011

MnO2hierarchical microsphere has been synthesized by a facile and direct hydrothermal reaction between KMnO4and HCl without the aids of catalysts, surfactants or templates. The as-prepared microsphere, as characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) analysis and nitrogen adsorption and desorption, is in form of K0.27MnO2(H2O )0.54, with a flower-like hierarchical microsphere structure and a BET surface area value of 52 m2/g. The morphology of the product can be simply tailed by controlled by reaction temperature or period and crystallinity can be modified by changing the concentrate of KMnO4. In general, excessive KMnO4and low hydrothermal temperature are favor to forming flower-like hierarchical structure. Besides, the formation mechanisms of the hierarchical schemes are proposed.
Preparation and Characterization of MWCNTs/FSiPUA Hybrid Film
Authors: Miao Mei , Qi Yu Hong , Zhang Zhan Ping , Zhang Zheng
Published: June 2011

CNTs/polymer hybrid films have been studied for hydrophobic surface in recent years. In this paper MWCNTs/FSiPUA hybrid films based on the excellent hydrophobicity have been prepared for the long term objective to prevent the marine fouling. MWCNTs/FSiPUA hybrid emulsion was prepared respectively by the methods of solution mixing with ultrasonic excitation and in-situ emulsion polymerization. Chemical and physical properties of the films were investigated by FTIR, contact angle meter and water absorption. The results showed that lauryl sodium sulfate（SDS）was a better dispersant than BYK-154 prepared via solution mixing with ultrasonic excitation. The performance of hybrid films approached by solution mixing with ultrasonic excitation was better than that by in-situ emulsion polymerization when same amount of MWCNTs was ﬁlled. The study indicated that the film surface properties reached best by both technologies when the content of MWCNTs was equal to 0.15wt%.
Preparation of Carbon-Encapsulated Fe Core-Shell Nanostructures by Confined Arc Plasma
Authors: Wei Zhi Qiang , Wang Xiao Yun , Yang Hua
Published: June 2011

Special carbon encapsulated Fe core-shell nanoparticles with a size range of 15–40 nm were successfully prepared via confined arc plasma method. The composition, morphology, microstructure, specific surface area, particle size of the product by this process were characterized via X-ray diffraction (XRD), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), X-ray energy dispersive spectrometry (XEDS) and BET N2adsorption. The experiment results shown that the carbon encapsulated Fe nanoparticles with clear core-shell structure, the core of the particles is body centered cubic (BCC) structure Fe, and the shell of the particles is disorder carbons. The particle size of the nanocapsules ranges from 15 to 40nm，with an averaged value about 30nm, the particles diameter of the core is about 16nm and the thickness of the shells is about 6-8 nm, and the specific surface area is 24 m2/g.
Study of CO2 Capture Using Triethanolamine-Modified Mesoporous Silica
Authors: Zhang Hong Li
Published: June 2011

Novel functionalised absorbents have been synthesized by immobilization of triethanolamine on synthetic mesoporous silica for CO2capture. Mesoporous silica material with a uniform pore size of 20-50nm and a surface area of 200~300 m2/g was used as loader for capturing agents. The capture of carbon dioxide from simulated flue gas streams has been achieved by using triethanolamine immobilized mesoporous silica. Preliminary attempts have also been made to determine the CO2adsorption capacities of these newly developed materials. The results revealed that maximum adsorption capacities was 28.01mg/g for immobilized triethanolamine mesoporous silica at room temperature,and the rate of desorption is 99% at 90°C.Recycle of adsorption-desorption have many times,and the ability of capturing CO2was stable. The results suggest that immobilized triethanolamine have a good affinity for the capture of carbon dioxide from simulated flue gas streams.The performance of these immobilized and triethanolamine-mesoporous silica solid sorbents decreased with regeneration.
Controlled Synthesis of Mn3O4 and MnOOH by a Hydrothermal Method and Their Electrochemical Behaviors
Authors: Zhou Zi Cheng , Xing Sheng Tao , Ma Zi Chuan , Wu Yin Su
Published: June 2011

Nanostructured manganese oxides (Mn3O4, MnOOH) were successfully prepared by a hydrothermal method using MnCl2as manganese source, NaOH as precipitation agent and H2O2as oxidant. The composition and morphology of the products were determined by the dripping speed of NaOH solution, the adding order of reactant and the hydrothermal time. Single phase of Mn3O4nanoparticles can be prepared by dropwise addition of the NaOH solution to the solution of MnCl2and H2O2. While single phase of MnOOH nanorods can be obtained by pouring the NaOH solution into the reaction system quickly or changing the adding order of NaOH and H2O2. When the dripping speed of NaOH solution was 6mL/min, and an appropriate amount of surfactant (C18H29NaO3S) was added, Mn3O4nanorods can be obtained. The hydrothermal method can be readily controlled to synthesize Mn3O4and MnOOH with different morphologies. The Mn3O4sample had higher capacitance than the MnOOH sample. The morphologies of thesesamples had little effect on their electrochemical performance.
White-Light-Emitting Phosphate Phosphors of SrZn2(PO4)2: Eu2+, Mn2+ Synthesized through Combustion Process
Authors: Yan Xiao Song , Li Wan Wan , Sun Kang
Published: June 2011

The SrZn2(PO4)2: Eu2+, Mn2+ phosphors were synthesized through combustion process with varying mixture ratio of Eu2+, Mn2+. The SrZn2(PO4)2: Eu2+, Mn2+ phosphor presents three emission bands under 365nm radiation: the blue emission band of 416 nm from Eu2+ occupying the Sr2+ site, the green emission band of 538 nm and the red emission band of 630 nm from Mn2+ occupying two different Zn2+ sites. Compared with the SrZn2(PO4)2: Eu2+, Mn2+ phosphor prepared through solid state reaction, the luminous intensity of the phosphor is greatly improved through the combustion reaction. White emission light with a high color rending index of 84.7 can be obtained from the phosphor of SrZn2(PO4)2: Eu2+, Mn2+, and the emission color tone of the phosphor varies from blue, white, and finally yellow by increasing the ratio of the concentrations of Eu2+ and Mn2+.
Effects of Two-Step Annealing on the Magnetic Properties of Iron-Based Nanocrystalline Soft Magnetic Material
Authors: Song Qiang , Qin Shu Qing
Published: June 2011

In the present paper, the effects of two-step annealing on the soft magnetic properties of nanocrystalline Fe73.5Cu1Nb3Si13.5B9 melt spun ribbons were studied. The two-step annealing comprises low-temperature preannealing (first step) for an α-Fe(Si) phase nucleation in an amorphous matrix, and a subsequent high-temperature annealing (second step) for the growth of precipitated crystallites. Compared with a nanocrystalline alloy obtained by conventional one-step annealing at 550 °C for 1 h, the grain size of α-Fe（Si）crystalline phase in the Fe73.5Cu1Nb3Si13.5B9 alloy decreased greatly after it is pre-annealed at 480°C for 1 h followed by annealing at 550°C for 40 min. It has been shown that the soft magnetic properties can be significantly improved by applying two-step annealing. The decrease of grain size of α-Fe(Si) crystalline phase may result from the nucleation rate increase during the crystallization of pre-annealed.
Synthesis and Characterization of Co2+-Doped Fe3O4 Nanoparticles by the Solvothermal Method
Authors: Sun Xue Jiao , Liu Fu Tian , Jiang Qing Hui
Published: June 2011

Co2+-doped Fe3O4magnetic nanoparticles were synthesized via the solvothermal method with reaction system of H2O and glycol in a high pressure autoclave. The products are of the inverse spinel structure confirmed by X-ray Diffraction. Fourier Transform Infrared Spectroscopy, Transmission Electron Microscope, Particles Size Analyzer and AC Gradient Magnetometer are also used to characterize the particles. The obtained Co2+-doped Fe3O4magnetic nanoparticles display well crystalline state. Those particles are globular of which the diameter is above 15 nm with homogeneous size distribution, smaller than 20 nm of the non-doped products. Co2+-doped Fe3O4magnetic nanoparticles show superparamagnetic behavior, and the saturation magnetization is 76.84 emu/g, which is higher compared with 54.42 emu/g of the non-doped. In the crystals structure of Fe3O4magnetic nanoparticles, ferric ions occupy the tetrahedral sites and one-half of octahedral sites, and the ferrous ions occupy the remaining half of the octahedral sites. The magnetic moments of cations on tetrahedral and octahedral sites are anti-parallel. Therefore, the net moment is provided by the divalent ions. In the preparation process, bivalent cobalt ions replace the partial sites of the ferrous ions and the ferric ions, and enhance the net magnetic moment. Above all, the doping of Co2+could improve properties of the Fe3O4magnetic nanoparticles, i.e., enhancing the saturation intensity, decreasing the particle size and making the size distribution homogeneous.
Effect of Pulsed Magnetic Field Treatment on the Magnetic Properties of the Fe-Nd-Al-B Alloys Prepared by Suction Casting
Authors: Bai Qin , Man H. , Tang Y.J. , Xu H. , Xia S.
Published: June 2011

The magnetic properties of the (Fe0.53Nd0.37Al0.10)96B4bulk amorphous alloys annealed in the temperature range of 293-623K for 30 min with and without an external pulsed magnetic field of 5T were studied. The results reveal that the remanence and coercivity of the samples are obviously improved with a pulsed magnetic field when annealed below the Curie temperature of the alloy. The increment of remanence reaches 25.9% for the sample annealed at 523K with a pulsed magnetic field, because of the enhancement of exchange coupling roles between the soft and hard magnetic phases. It provides a new way to improve the magnetic properties of the bulk amorphous alloys produced by pulsed magnetic annealing at temperatures below the Curie point of the alloys.
Kinetics-Controllable Hetero-Precipitation Process on the Nanoscale Solid-Liquid Interface of Spherical Particles
Authors: Wu Xiao Feng , Liao Yu Chao , Yue Ren Liang , Chen Yun Fa
Published: June 2011

Based on the growth kinetics of the SiO2particles, we studied the kinetic hetero-precipitation process on the interface of polystyrene (PS) microscale particles. The nanoscale SiO2shell thickness increased with increasing time and was proportional to the square root of the initial concentration of TEOS precursor while governed by hetero-precipitation process. Moreover, the hetero-precipitation process followed the first-order growth mechanism of silica onto the surface of templating PS pariticles. Properly controlling the reagent concentrations could alleviate and even avoid, to a certain extent, aggregation among PS@SiO2particles that could otherwise have an adverse effect on the properties and applications of those composite particles and the corresponding SiO2hollow products.
Effect of Modification by WTP-08 on Dispersity of Nanosized CalciumCarbonate and Its Mechanism
Authors: Ding Hao , Wang Bai Kun , Liang Ning , Liu Kun
Published: June 2011

The dispersity of nanosized calcium carbonate modified by alkyl amine dimethyl phosphonic acid (WTP-08) through mechano-chemical method in different media was investigated. The modification mechanism was investigated by analyzing the surface energy and its thermodynamic effect on dispersity of nanosized calcium carbonate. The results show that the free energies of nanosized calcium carbonate modified by WTP-08 and its interfacial free energies in air and non-polar media decrease significantly, while the interfacial free energy in water increases remarkably. It can be concluded that modification by WTP-08 improves the dispersion tendency of nanosized calcium carbonate in air and non-polar medium, while it decreases in water. Therefore, modification by WTP-08 makes the dispersity of nanosized calcium carbonate increase in air and non-polar medium and decrease in water.
Atomic and Electronic Scale Simulation on Low Index Face Growth of Nano CVD Diamond Films
Authors: An Xi Zhong , Liu Guo Quan , Li Chao
Published: June 2011

The growth of nano CVD diamond films on low index faces such as (111) face and (100) face under different proposed surface chemical reaction model was simulated by using Kinetic Monte Carlo (KMC) method from atomic scale. The results, for example the influence of deposition timet, substrate temperatureTs, and atomic hydrogen concentration [H] on the film deposition rate, surface roughness, andHembedded in the film under different processing conditions, were systematically analyzed and compared. And the adsorption of various species on {111}-oriented diamond cluster was preliminarily computed from electronic scale by Local Density Approximation (LDA) method to assist understanding the surface adsorption mechanism. It is indicated that the film morphology and quality obtained from atomic scale KMC simulation varies according to the chemical reaction models. And our initial electronic scale computation on {111}-oriented diamond cluster showed that single-carbon species can be adsorbed on the activated site more easily than double-carbon species and the former will result in a more stable state than the latter. In order to reveal the nano CVD diamond film growth mechanism, more work about various species adsorption on many different morphological CVD diamond surfaces is needed.
Surface Structure and Electronic Property of Sulfur Passivation of InAs(001) Surface: A First-Principles Study
Authors: Li Deng Feng , Guo Zhi Cheng , Deng Bo , Dong Hui Ning , Gao Fei
Published: June 2011

Using density functional theory, we have studied surface structural and electronic properties of sulfur adsorption on As-terminated and In-terminated InAs(001) surfaces with the coverage (Θ) of 0.5ML and 1ML. Based on adsorption energy calculations, we found that atΘ=0.5ML, S adatoms preferred to replace the As atoms at As-terminated InAs(001)(2×1) surface. For 1ML S adsorption on InAs(001)(2×1) surface, the most stable adsorption geometry is S-S dimers covered on the In-terminated surface. This result is different from that for 1ML S adsorption on GaP(001) and InP(001) surfaces, and it is consistent with the experimental results. The electronic band structure analysis showed that the surface state density around the Fermi level was considerably diminished for 0.5ML S adsorption on As-terminated InAs(001)(2×1) surface at substitution site. The surface state density of S-S dimer adsorption on In-terminated (2×1) surface was strengthened due to one excess valence electron on the surface.
Enrichment Behavior of ω Clusters in Cold-Drawn Ti-45Nb Filaments
Authors: Tang Bin , Kou Hong Chao , Zhu Zhi Shou , Li Jin Shan , Shang Guo Qiang , Zhou Lian
Published: June 2011

The enrichment behavior of ω clusters in cold-drawn Ti-45Nb (wt.%) filaments is observed and discussed in this paper. The ω phase precipitates as the colonies of almost the same orientation variants near the grain boundary with the size of single particle less than 3 nm in diameter. The enrichment of ω clusters leads to the formation of embrittlement regions in micron dimension along the grain boundary. After polishing and etching, the embrittlement regions transform into macroscopic necklace-like structure along the grain boundary. Furthermore, the volume fraction and mean width of embrittlement regions are measured accurately as a function of diameters. After recrystallization annealing, the enrichment regions disappear and ω particles equally distribute in the matrix.
Evaluation of the Properties of Polyaspartic Polyurea Coated Concrete Subjected to the Co-Action of Freeze-Thaw Cycles and NaCl Solution Immersion
Authors: Huang Wei Bo , Liu Xu Dong , Lu Ping , Zhang Jing
Published: June 2011

The deterioration of coated concrete subjected to co-action of freeze-thaw cycles-NaCl solution immersion double factors exposure was investigated in this study. Adhesion, chloride content and resistance of chloride ion diffusivity of two types of polyaspartic ester polyurea coated concrete were analyzed. Test results showed that the adhesion of QF-1 (PAE-b-H12MDI prepolymer H66) and QF-2 (PAE-b-H12MDI prepolymer H62) coated concrete reduced about 5% respectively which kept excellent under the double factors exposure after 200, 300 days and 25, 50 times of cycles. The degradation process of coated concrete simultaneously exposed to co-action exposure was significantly accelerated. In co-action exposure tests, the average chloride ion content of coated concrete increased about 33% and 87% after 25 and 50 times of cycles compared with single NaCl solution immersion exposure; the chloride ion diffusion coefficient of concrete substrate increased with the increase of exposure time and freeze-thaw cycles. Freeze-thaw cycles results showed a severe influence on chloride ion diffusion and permeation of surface protection coating of concrete. Research also showed that the chloride ion diffusion of coated concrete subjected to the co-action of freeze-thaw cycles-NaCl solution was coincided with the Fick’s second law.
Fabrication and EIS Characterization of Titania Nanotube Arrays with Top Non-Tube Layer
Authors: Li Xiang Li , Xu Chun Hua , Wen Zhi Lei , Zhang Wen Jie
Published: June 2011

TiO2nanotube arrays were fabricated in the electrolyte containing 0.25wt% NH4F, 2.5vol% water and the ethylene glycol for various hours at room temperature by anodization of Ti foil in this paper. Some anodized specimens were annealed at 450°C for 3 hours. Electrochemical Impedance Spectroscopy (EIS) was employed to measure electrochemical parameters of anodized specimens. The morphology and crystalline structure of anodized products were characterized by Field Emission Scanning Electronic Microscopy (FESEM), X-ray Diffraction (XRD) and Transmission Electronic Microscopy (TEM). A non-tube layer appears on nanotube arrays with the increase in anodization time. Anodized TiO2nanotube arrays have an amorphous structure, which transfers to anatase structure after annealing at 450°C. A new equivalent circuit R(CR(R(QR)(CR))) was proposed to fit EIS data. The results show that the charge transfer resistance at the electrode/electrolyte interface controls the electrochemical process of TiO2nanotubes.
Application of High Temperature Quantitative X-Ray Powder Diffraction on Determination of Ternary System
Authors: Xiao Qiu Guo , Ding Gang Cheng , Long Tang Zhong , Shen Shao Hua
Published: June 2011

This paper has put forward a high-temperature quantitative X-ray powder diffraction analysis method for the determination of an isothermal section of a ternary system in comparison with a conventional method. In a three-phase region of the isothermal section at 1150 °C of Cu2O(CuO)-Al2O3-SiO2 pseudo-ternary system, the compositions of the solid phase points of three system points are determined according to the quantitative analysis of the crystalline phases in the samples carried out by Rietveld method. Then the liquid phase point of the three-phase region is determined according to the crosspoints of the tie lines of every pair of system point and solid phase point. The precisions of the analytical results have reached to be 0.1 ~ 5.0 %. By comparison, a good result is obtained for the determination of the liquid phase point of the three-phase region in the isothermal section at 1150 °C when the analytical results of high-temperature RQA analysis are used in determination of the isothermal section of the pseudo-ternary system.
Effect on the Characteristic and Properties of Carbon Coated LiFePO4/C Composite
Authors: Zhang Yu Li , Liu Zhi Jian , Xia Jian Hua , Lin Xi , Chen Lu Xing
Published: June 2011

LiFePO4/C composite with different types of organic carbon sources has been synthesized by carbon thermal reduction technique. The physical characteristics and electrochemical properties of LiFePO4/C composite have been studied compared with commercial products. It is shown that good carbon-coated LiFePO4/C composite can be obtained with 13wt.% glucose as carbon source, which has effected on the good processing performance due to its suitable specific surface area of 26.3m2/g and high tap density of 1.3g/cm3. Furthermore, it has contributed to the high-rate electrochemical property with discharge capacity of 128mAh/g at 1C (1C=170 mAh/g).
Influence of Colorant on Ink-Jet Printing Quality
Authors: Leng Xian , Cui Bing Rong , Li Lu Hai , Du Peng , Zhao Wen , Hu Xu Wei
Published: June 2011

This study aims to analyse how inks of different colorant present unlike printing quality on selected substrates in inkjet printing. Applying Epson piezoelectric inkjet printer, experiments of printing pigment-based ink and dye-based ink on various substrates (coated art paper, porous photo paper, swellable photo paper, PP synthetic paper, xuan paper and PET-based coated film) were carried out respectively. Using digital microscope, the spreading, penetrating and distributing of ink drops were observed. Water fastness and light fastness were evaluated through aging test and water-immersing test, by measuring the decreasing of optical solid density. Taking the formula of inks and the composition of coating layers into consideration, contrast and analysis of print quality with different black inks on substrates of diverse support body were studied. The result demonstrates: Both dye-base and pigment-base inks present ideal optical density in special-purpose photo paper (swellable or porous type), exhibit distinct writing picture edge, and excellent water fastness and light fastness. While, coated art paper, PP synthetic paper, xuan paper and PET-based coated film, which shows relatively rough surface or weak ink absorbancy, are more suitable to use pigment-based ink.
Research on the Al3+，V5+ Double Ionic Substitute Negative Thermal Expansion Compound Zr1-xAlxMoW1-yVyO8
Authors: Shen Shao Hua , Qin Xian Zhi , Xiang Shao Bin , Hao Fu Heng , Tan Jing , Xiao Qiu Guo
Published: June 2011

The ZrW2O8family of materials has been shown to display the unusual property of an isotropic bulk contraction in volume with the rising of temperature. They have a number of potential applications, for example, they would be widely used in composite material and solid electrolyte based on its characteristic of negative thermal expansion and ionic conductive property. In this paper, an Al3+，V5+double substitute negative thermal expansion (NTE) solid solution Zr1-xAlxMoW1-yVyO8was synthesized by co-precipitation method. The phase composition, the micromorphology and the thermal expansion coefficient were obtained by using X-ray diffraction (XRD), scanning electronic microscope (SEM) and thermal mechanical analyzer (TMA), respectively. The results show that the sample’s density rises with the increasing of the content of V5+, while, its porosity declines. The thermal expansion coefficients of the samples are between -3.0~4.0×10-6 K-1, it indicates that their negative thermal expansion behavior is a little lower than that of ZrMoWO8. And the experiment also shows that these samples have displayed a fine behavior of heat shock resistance.
Study on Fluorocarbon Antifouling Coatings with Low Surface Energy
Authors: Qiu Chun Hong , Qi Yu Hong , Zhang Zhan Ping , Gao Hui
Published: June 2011

To develop non-toxic marine antifouling coating, a series of antifouling coatings were prepared based on fluorocarbon copolymer. Based on the measurement of roughness and water contact angle, the attachment test of marine diatom and bacteria before and after dynamic testing in seawater, it has been investigated that the influence of three functional fillings and silicone resin on the performance of the antifouling coatings with low surface energy. The erosion rate of the coatings was measured by the samples rotated 72h at the 12 knots of simulating sailing speed. The results showed that the roughness of coatings changes from 0.2um to 3um, it does influenced slightly by the rotating test. Water contact angle of all coatings is about 100° before rotating test. It decreases to about 70° after the rotating test in seawater. Due to the increase of surface energy of the coatings, both the amount of diatom and bacteria on samples increases after rotating test in seawater.
Chemical Bond and Property of TiC-TiB2 Composite
Authors: Min Xin Min , Wang Tao
Published: June 2011

The relation among electronic structure, chemical bond and properties of TiC-TiB2 composite was studied by the first principle method. The ionic interaction between the ions in the interface of the TiC-TiB2 composite is stronger than that of the inner ions or of the related single phase. There is stronger covalent interaction between the ions in the interface of the TiC-TiB2 composite. There are differences of densities of state (DOS) among of TiC-TiB2 composite and related single phases as the interaction between of TiB2 and TiC phases. The width of DOS for interface Ti 3d is obviously larger than that of corresponding TiB2 or TiC phase, as the interaction between Ti 3d in interface and others is larger than that between Ti 3d in TiB2 or TiC phase and others.
Energetics and Properties of Vacancies, Anti-Sites, and Atomic Defects (B, C, and N) in Ductile B2-YM (M=Ag, Cu, Rh) Intermetallics
Authors: Wu Yu Rong , Hu Wang Yu
Published: June 2011

The first-principles calculation have been performed to investigate the trends in the energetics of single, double, and triple-like defects in ductile B2-YM(M=Ag, Cu, and Rh) alloy. A systematic study of vacancy, boron, carbon, and nitrogen substituting Y or M atoms in a super-cell structure consisting of 16-atoms is presented. The site preference of each type of defects is determined from the total energy calculations. In addition, the influence of those defects on the ductility of the YM intermetallic compounds is discussed.
Distribution of 5-Hydroxymethylcytosine in Different Human Tissues
Authors: Li Weiwei , Liu Min
Published: June 2011

5-hydroxymethylcytosine (5-hmC) is a modified form of cytosine recently found in mammalians and is believed, like 5-methylcytosine, to also play an important role in switching genes on and off. By utilizing a newly developed 5-hmC immunoassay, we determined the abundance of 5-hmC in human tissues and compared 5-hmC states in normal colorectal tissue and cancerous colorectal tissue. Significant differences of 5-hmC content in different tissues were observed. The percentage of 5-hmC measured is high in brain, liver, kidney and colorectal tissues (0.40–0.65%), while it is relatively low in lung (0.18%) and very low in heart, breast, and placenta (0.05-0.06%). Abundance of 5-hmC in the cancerous colorectal tissues was significantly reduced (0.02–0.06%) compared to that in normal colorectal tissues (0.46–0.57%). Our results showed for the first time that 5-hmC distribution is tissue dependent in human tissues and its abundance could be changed in the diseased states such as colorectal cancer.
How Fitch-Margoliash Algorithm can Benefit from Multi Dimensional Scaling
Authors: Lespinats Sylvain , Grando Delphine , Maréchal Eric , Hakimi Mohamed-Ali , Tenaillon Olivier , Bastien Olivier
Published: June 2011

Whatever the phylogenetic method, genetic sequences are often described as strings of characters, thus molecular sequences can be viewed as elements of a multi-dimensional space. As a consequence, studying motion in this space (ie, the evolutionary process) must deal with the amazing features of high-dimensional spaces like concentration of measured phenomenon.

To study how these features might influence phylogeny reconstructions, we examined a particular popular method: the Fitch-Margoliash algorithm, which belongs to the Least Squares methods. We show that the Least Squares methods are closely related to Multi Dimensional Scaling. Indeed, criteria for Fitch-Margoliash and Sammon's mapping are somewhat similar. However, the prolific research in Multi Dimensional Scaling has definitely allowed outclassing Sammon's mapping.

Least Square methods for tree reconstruction can now take advantage of these improvements. However, “false neighborhood” and “tears” are the two main risks in dimensionality reduction field: “false neighborhood” corresponds to a widely separated data in the original space that are found close in representation space, and neighbor data that are displayed in remote positions constitute a “tear”. To address this problem, we took advantage of the concepts of “continuity” and “trustworthiness” in the tree reconstruction field, which limit the risk of “false neighborhood” and “tears”. We also point out the concentration of measured phenomenon as a source of error and introduce here new criteria to build phylogenies with improved preservation of distances and robustness.

The authors and the Evolutionary Bioinformatics Journal dedicate this article to the memory of Professor W.M. Fitch (1929–2011).
Diversity of Bacterial Communities in Contrasting Aquatic Environments: Lake Timsah, Egypt
Authors: Bahgat Magdy
Published: June 2011

Effect of pollution on diversity of attached and free-living bacteria in two contrasting stations, namely, Suez Canal and outlet of West Lagoon to Lake Timsah was investigated. Bacillus was the most abundant genus especially in West Lagoon station where higher organic agricultural and municipal loads was discharged. Bacterial species richness differed among water depths and was higher in subsurface samples. In Suez Canal more Gram negative populations were isolated. The possible influences of pollution in the West Lagoon station on the bacterial community composition were discussed.
Review: Supplementation of phytase and carbohydrases to diets for poultry
Authors: Woyengo T. A. , Nyachoti C. M.
Published: June 2011

Woyengo, T. A. and Nyachoti, C. M. 2011. Review: Supplementation of phytase and carbohydrases to diets for poultry. Can. J. Anim. Sci. 91: 177–192. Feedstuffs of plant origin contain anti-nutritional factors such as phytic acid (PA) and non-starch polysaccharides (NSP), which limit nutrient utilization in poultry. Phytic acid contains phosphorus, which is poorly digested by poultry, and has the capacity to bind to and reduce the utilisation of other nutrients, whereas NSP are indigestible and have the capacity to reduce nutrient utilisation by encapsulation. Supplemental phytase and NSP-degrading enzymes (carbohydrases) can, respectively, hydrolyze PA and NSP, alleviating the negative effects of these anti-nutritional factors. In feedstuffs of plant origin, PA is located within the cells, whereas NSP are located in cell walls, and hence it has been hypothesized that phytase and carbohydrases can act synergistically in improving nutrient utilization because the carbohydrases can hydrolyze the NSP in cell walls to increase the accessibility of phytase to PA. However, the response to supplementation of a combination of these enzymes is variable and dependent on several factors, including the type of carbohydrase supplement used, dietary NSP composition, calcium and non-phytate phosphorus contents, and endogenous phytase activity. These factors are discussed, and areas that need further research for optimising the use of a combination of phytase and carbohydrases in poultry diets are suggested.
SNPknow: a web server for functional annotation of cattle SNP markers
Authors: Wang Qishan , Zhao Hongbo , Pan Yuchun
Published: June 2011

Wang, Q., Zhao, H. and Pan, Y. 2011. SNPknow: a web server for functional annotation of cattle SNP markers. Can. J. Anim. Sci. 91: 247–253. Single nucleotide polymorphisms (SNP) microarray technology provides new insights to identify the genetic factors associated with the traits of interest. To meet the immediate need for a framework of genome-wide association study (GWAS), we have developed SNPknow, a suite of CGI-based tools that provide enrichment analysis and functional annotation for cattle SNP markers and allow the users to navigate and analysis large sets of high-dimensional data from the gene ontology (GO) annotation systems. SNPknow is the only web server currently providing functional annotations of cattle SNP markers in three commercial platforms and dbSNP database. The web server may be particularly beneficial for the analysis of combining SNP association analysis with the gene set enrichment analysis and is freely available at http://klab.sjtu.edu.cn/SNPknow .
The Rise and Fall of the Jumbo Breakfast Roll: How a Sandwich Survived the Decline of the Irish Economy
Authors: Share Perry
Published: June 2011

This paper examines a specific food item - the Jumbo Breakfast Roll [JBR] - through a sociological lens, in order to trace the factors that contributed to its rise to prominence in Irish food culture in the ‘Celtic Tiger’ period of the late 20th/early 21st century. It also examines the development of these factors in the period following the crash of the Irish bubble economy. It is argued that the JBR arose at the intersection of a number of key trends in the food technology, retail, transport, distribution and construction sectors. Yet the JBR also had its antecedents in established foodways and traditions. It reflects on how the JBR could be interpreted as a ‘national dish’ that symbolised a particular moment in contemporary Irish society, and raises the possibility that a sociologically-informed analysis of such emblematic dishes allows us to explore aspects of national society, culture and economy within a globalised world.
The Biographical Illumination: A Bourdieusian Analysis of the Role of Theory in Educational Research
Authors: Burke Ciaran Thomas
Published: June 2011

The intention of this paper is to serve as a reflexive comment as to my ongoing empirical processes and epistemological position concerning research on university graduates’ aspirations and expectations of graduate employment. This paper will illustrate the inevitable role of social theory in empirical research, and from a Bourdieusian position, consider the use of theory in creating a break with common sense, the danger of replacing common sense with learned bias, and processes that may aid to avoid this problematic issue. Using educational research as a tangible basis, this paper will discuss the empirical application of the habitus in creating a break with common sense, whilst not losing itself to social theory. However, in an effort to depart from simply offering a comment on the need for the application of theory in educational research, this paper intends to demonstrate how the neo-positivist biographical narrative interview method can, contrary to BOURDIEU's (1987) comments, illuminate the habitus, offering an opportunity for its empirical application in educational research and also for the wider academy.