bluuebunny/crossref_metadata_2025 huggingface dataset:
3D Modeling and Motion Simulation of Mine Skip Getting through Dump Rail Based on Pro/E
Authors: Yan Ming Xia
Published: July 2012

3D modeling, virtual assembly and motion simulation of an up-open fan gate mine skip were completed with Pro/Engineer software. During virtual design, faults of a mine skip such as static and dynamic interference can be found out prior to be made, which is helpful to optimize it. Furthermore, it is effective to shorten design period of mine skip and save development cost and improve design quality.
Laser-Induced Thermal Bubble-Mixing on a Microfluidic Platform for Lab-on-a-Chip Applications
Authors: Dong Xuan Xuan , Zhang Lei , Fu Jian
Published: July 2012

This paper discusses the study of the multimode evolution of microfiber taper and its potential application of micromixer in the lab-on-a-chip. By using numerical simulation, multimode interference effects are demonstrated in the taper transition of a micro-nano fiber. Due to the leaked optical energy gasifies the solution surrounding the taper and produces air bubbles, the laminar flow effect is destroyed with the help of disturbance of air bubble and two solutions are mixed quickly. Therefore, it will be used in microfluidic platform for chemical analysis & testing, chemical synthesis and environmental monitoring.
A New Model for the Simulation of CO2 Absorption in an Industrial-Scale Packed Column
Authors: Li Wen Bin , Yu Guo Cong , Liu Bo Tan , Yuan Xi Gang
Published: July 2012

A new computational mass transfer model is proposed for simulating the chemical absorption process with heat effect by solving the average fluctuating mass flux in turbulent mass conservation equation and the average fluctuating heat flux in turbulent heat conservation equation, so that the concentration profile and the temperature profile of column can be obtained. The feather of the proposed model is to abandon the conventional way of introducing the unknown turbulent mass transfer diffusivity Dtand the turbulent thermal diffusivity αtin the mass and heat conservation equations. By using the proposed model, the simulated results of CO2absorption by aqueous monoethanolamine (MEA) solution in an industrial scale column is presented, including MEA concentration, CO2loading and liquid phase temperature. The simulations are in agreement with the published experiment data.
Mechanical Performance and Fracture of 3-Ply Cu/Al/Cu Clad Metals
Authors: Kim In Kyu , Ha Jong Su , Hong Sun Ig
Published: July 2012

The mechanical performance and fracture of roll-bonded Cu/Al/Cu clad metal were investigated after heat treatment in the temperature range 200~500OC. In the roll-bonded 3-ply Cu/Al/Cu clad metal, no visible interfacial reaction compound and defects were observed at the interfaces, ensuring the well-bonded Cu/Al interface until the final moment of fracture in tension. The reaction layer was observed at the Cu/Al interface after annealing at and above 400OC, which deteriorated the ductility of clad metals. The thickness of the reaction layer increased with increasing heat treatment temperature. The periodic cracks were formed perpendicular to the tensile direction due to the strain mismatch between metal layers and the reaction compound layer in the clad heat treated at high temperatures at 500oC. The slip localization and delamination induced premature crack formation in Cu and Al layer, resulting in the decreased clad metal fracture strain, especially after heat treating at 500oC.
Simulation of Process for Preparing Sodium Methoxide Using Aspen Plus
Authors: Shao Dan Dan , Wang Cheng Xi
Published: July 2012

An equilibrium stage model for preparing sodium methoxide from sodium hydroxide and methanol in a reactive distillation column was developed using Aspen Plus simulator. The simulation was in good agreement with plant data. Effects of bottom-to-overhead feed ratio, content of water in bottom feed and methanol-to-NaOH mass ratio in overhead feed were discussed. The results is of reference value for prediction and optimization of industrial process.
Research on Defect Diagnosis and Repair of LCD
Authors: Liu He Jian , Chen Zai Liang , Xu Ya Xin
Published: July 2012

With the research on LCD production process, a low cost practical tool was developed to solve the problem of v-line defect detection, and the yield is improved from 95% to 97%. A new method was proposed to repair bright spot with laser without disassembling LCD panel. The repair time is shortened to seven minutes from twelve minutes, and the repair success rate reaches 94.85%.
Effects of Mg, Si and Multiple Rare Earth Addition on Microstructures of Al3Ti /A356 Composites
Authors: Bi Jian Hua , Zhao Yu Tao , Jia Zhi Hong , Zhang Song Li , Chen Gang
Published: July 2012

In-situ Al3Ti /A356 composites were synthesized by direct melt reaction method in Al-K2TiF6 system. The preparation techniques was discussed and the effects of Si, Mg, La (0.30%), Ce (0.30%) and multiple rare earth (0.15% La + 0.15%Ce) addition on microstructures of Al3Ti /A356 composites were investigated by X-ray diffraction and scanning electron microscope. The results show that the morphology and size of Al3Ti reinforcement are influenced significantly by Si, Mg and the optimal preparation process is composition with latter Si, Mg alloying. The Al3Ti precipitations during solidification process are restrained by 0.30% La addition or 0.30% Ce addition and lead in the uniform of Al3Ti size and morphology. The radial growth of Al3Ti is strongly restrained by rare earth composite addition, and the main morphology is slender-spherical like.
Study on Technology of Bamboo Processing
Authors: Li Xin Gong , Zheng Xia , Wu Yi Qiang
Published: July 2012

This paper introduced characteristics and sorts of bamboo composite materials, elaborated processing technology and technological features of different bamboo composite materials, analyzed current status of bamboo processing industry in China, brought up some problems, and to look into the research direction and future of bamboo composite materials in China.
Effect of CNTs on Properties of Cu-Based Composites and Mechanism
Authors: Liu Gui Min , Li Bin , Du Jian Hua , Zheng Xiao Hui
Published: July 2012

The Carbon nano-tubes (CNTs) reinforced Cu-based (CNTs/Cu) composites were obtained by powder metallurgy processes. The effects of CNTs content on the microstructure, density and hardness of the Cu-based composites were investigated. The tribological properties of the composites were studied by using a ball/disk friction tester. The results indicate that the density values of the composites gradually decrease with the increment of CNTs content, while for the hardness values, firstly increase and then decrease; and the maximal hardness values was obtained when the composite contains 0.75% CNTs. The CNTs content exerts a great effect on the friction coefficient of the composite. It has been found that the anti-wear property of the CNTs/Cu composites is excellent, at the same time, the hardness and density values are also in the reasonable ranges when the CNTs content is relatively low. The concerning mechanism has been analyzed in the present paper.
Preparation of Conductive PANI/Modified CIP Composites via In Situ Polymerization
Authors: Wen Shi Bao , Li Guo Wei , Wu Qi Ye
Published: July 2012

A conductive PANI/CIP composite with core/shell structure was prepared by in-situ polymerization of Aniline(Ani). In order to reduce the acid corrosion on carbonyl iron powders(CIP) in polymerization of Ani, the surface of CIP was modified by (3-aminopropyl)-triethoxysilane (APTES) before the polymerization. The influences of modification on Ani polymerization, the morphology changes of core/shell structure and conductivity of PANI/CIP composites were characterised and discussed. The results show that after CIP modified by APTES, the reaction process of Ani polymerization is more stable; the PANI particles on the surface of CIP are smaller, and more uniform and more compact; The coating effect of PANI on the surface of CIP is significantly improved; The composite conductivity changes slightly with the modification.
Thermal and Mechanical Properties of Poly(methyl methacrylate) Nanocomposites Containing Polyhedral Oligomeric Silsesquioxane
Authors: Zhao Chun Bao , Wang Xin , Yang Xu Jie , Zhao Wei
Published: July 2012

A series of poly(methyl methacrylate) (PMMA) composites containing polyhedral oligomeric silsesquioxane (POSS) were produced by bulk polymerization. The morphology, thermal and mechanical properties of the composites were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analyses (TGA) and dynamic mechanical analyses (DMA). Results show that the octa(3-chloropropyl)-POSS (ocp-POSS) and trisilanolphenyl-POSS (triol-POSS) have high compatibility with PMMA and can be uniformly dispersed into PMMA matrix. The separate incorporation of these two types of POSS contributes to the improvement of thermal stability of PMMA composites. When the content of POSS was 7.5 wt%, the thermal decomposition temperatures (5% mass loss) of PMMA composites with ocp-POSS and triol-POSS were increased by about 104 °C and 130 °C, respectively. The increase of triol-POSS content in the PMMA matrix gave slight enhanced storage modulus before glass transition.
Influence of Double-Doped Admixtures on Asphalt Mixture Performance
Authors: Zheng Zhong Run , Zhao Chao , Zhao Yi Feng , Song Pei
Published: July 2012

This paper introduces an asphalt mixture that mixed with different admixtures, rutting resistance agent and lignin fiber, at the same time. Rutting test and freeze-thaw splitting test are used to analyze rutting resistance on the high temperature and low temperature cracking of the asphalt mixture. The experiments with different mixes material composition are conducted to analysis various properties of the two admixtures on the mixture, especially the high temperature stability, low temperature crack resistance and the law of improvement effect. In addition, the experiments also determine the optimal asphalt content of different type of mixtures. The results showed that the single-doped KTL rutting resistance or lignin fibers have some improvement in water temperature performance of asphalt mixture, stability improvement of double-doped admixture asphalt mixture is better than the single-doped asphalt mixture, such as KTL rutting resistance agents and lignin fibers
Analysis on Stability of Dongchuan Landslide and the Comprehensive Management Measure
Authors: Xia Jiang Tao , Yang Cheng Zhong , Wang Shu Fang
Published: July 2012

Based on the investigation and analysis of the causes of Dongchuan landslide, as well as on the stability analysis of Dongchuan landslide No. 1 and No. 2,it was presented by use of surface drainage, anchor pile, prestressed anchor cable lattice beam and other engineering measures on Dongchuan landslide to conduct comprehensive management. The deformations of treatment landslide were monitored and analyzed. The monitoring results show: the greatest deformation of the landslide is 8mm and the slope is a basically stable. Therefore, combined anchor piles, prestressed anchor cable lattice beam with drainage can well manage landslid
Fabrication of Nb-Based Alloy via Spark Plasma Sintering
Authors: Zhang De Zhi , Qin Ming Li , Zhang Lin , Lu Xin , Qu Xuan Hui
Published: July 2012

Nb-5 at.% W-5 at.% Mo-2 at.%Zr-2 at.% C (Nb5522) bulk alloys were prepared using blended powders or ball-milled powders via spark plasma sintering. The differences between blended powder compacts and ball milled powder compacts with respect to their density, microstructure and mechanical properties were studied. The results showed that ball milling enhances the sinterability of Nb5522 powders. After sintered by SPS at 1873 K, the milled powders achieved a near-full densification density. The SPS process favors the precipitation of (Nb, Zr)C particles.
Preparation and Characterization of Electrospun CPVC Nanofiber Nonwovens
Authors: Jiang Ting Ting , Kang Wei Min , Cheng Bo Wen
Published: July 2012

In this paper, the chlorinated poly (vinyl-chloride) (CPVC) nanofiber were successfully prepared via electrospinning of the proper spinning solution, which was obtained by dissolving CPVC granules in N,N-dimethylformamide (DMF) and tetrahydrofuran (THF) mixture. The results indicates that the morphology of the fibers is influenced by solution concentration and applied voltage. The finer and uniform nanofiber is electrospun from total solid content of the spinning solutions at 16wt.% and the spinning voltage at 26kV. The surface potential of CPVC nanofiber nonwovens increases with the spinning voltage and the filtration efficiency increases firstly and then decreases. In spinning voltage of 26 kV, filtration efficiency reaches a maximum of 99.925%.
Preparation, Purification and Properties of Carbon Nanotubes
Authors: Yu Yong Peng
Published: July 2012

At present, CNTs can be a variety of methods in the system, including arc discharge, chemical vapor deposition and laser evaporation method, which arc discharge and chemical vapor deposition method is used in two wider. No matter what kind of prepared CNTs, not high purity, containing the catalyst particles or amorphous carbon particles, graphite particles and other impurities. These impurities mixed with CNTs, it is difficult to meet the research and application needs of CNTs, and thus the study of CNTs purification is necessary. CNTs are made of carbon atoms to SP2 hybrid-based, mixed with SP3 hybrid built into the ideal structure, it can be seen as a sheet of graphene rolled into a cylinder. Therefore inevitable graphite excellent intrinsic properties: such as heat transfer, electrical conductivity, heat resistance, corrosion resistance, thermal shock resistance, lubricity, and biocompatibility, such as a series of excellent performance. In conclusion, CNTs unique structure gives superior performance and broad application prospects
Assessment of Nanocatalyst Dispersibility in a Polymer by Employing Relative Standard Deviation
Authors: Yang Yi , Bai Hua Ping , Yu Xin Jie , Wang Jun
Published: July 2012

A relative standard deviation (RSD) method has been developed to evaluate the nanocatalyst dispersibility in an energetic polymer. The dispersibility of nanocatalyst and thermal characteristics of the polymer exhibits high dependence on the RSD of the concentration distributions of nanocatalyst. The improvement of the dispersibility of nanocatalyst, which is dependent on kneading time, can be presented by a decrease in the RSD of the concentration distributions. Moreover, the decomposition temperature and the combustion heat of the polymer is reduced gradually and enhanced distinctly, respectively, with the decrease of the RSD of the nanocatalyst distributions. However, over-kneading may lead to a reunion of nanocatalyst and a decline of thermal characteristics of the energetic polymer, and presented with an increasing of the RSD of the concentrations of nanocatalyst. The optimal kneading time is 3 h and an acceptable value of the RSD is approximately 1% of the concentration distributions of nanocatalyst for the energetic polymer with nanometer copper oxide catalyst.
Size Controlled Synthesis of 2-6 nm Gold Nanoparticles via Controlling Concentration of the Reducing Agent and Temperature
Authors: Luo Wei , Wang Fei , Zhang Xue Ao , Shao Zheng Zheng , Fang Jing Yue , Chang Sheng Li , Qin Shi Qiao
Published: July 2012

We reported a facile synthesis route for size controlled preparation of gold nanoparticles (Au NPs) by controlling concentration of the reducing agent and temperature. Nearly monodisperse Au NPs with mean diameters of 2-6 nm are acquired via the reduction of HAuCl4by NaBH4in the presence of tri-n-octyl amine and dodecanethiol in solvent of toluene. Results indicate that concentration of the reducing agent and temperature are key factors to tune the particle size and uniformity in the synthesis of Au NPs. The as-synthesized Au NPs show size dependent surface plasmonic properties between 510 and 525 nm, while Au NPs with size smaller than 3 nm do not clearly show the property.
Hydrothermal Synthesis and UV Absorption Property of Firewood-Like CeO2 Nanostructures
Authors: Zou Yun Ling , Li Yan , Zhang Nan , Zhou Qing Jun
Published: July 2012

In this paper, we reported that firewood-like CeO2nanostructures were synthesized via hydrothermal method in the present of cetyltrimethylammonium bromide (CTAB) for the first time. X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) were used to characterize the as-obtained sample. The UV absorption property of the product was investigated by UV-vis spectrophotometry. XRD result shows that the product was a cubic fluorite-type CeO2phase with good crystallinity. FE-SEM and TEM analysis indicate that the firewood-like CeO2nanostructures were composed of CeO2nanoparticles with the average size of about 6-10 nm. The CeO2shows excellent UV absorption for that the transmittance (T %) of the sample in the UV region almost equal to zero.
Preparation of Polyvinylpyrrolidone (PVP) Nanofibers Supported CaCO3 Nanoparticles
Authors: Bai Jie , Li Chun Ping , Zhang Yong Feng , Zhang Jian Bin
Published: July 2012

In this paper, a new method for the preparation of composite nanofibers surface containing calcium carbonate nanoparticles using electrospinning technology was described. In detail, firstly, the type solution is formed by the aqueous solution of CaCl2which contains polyvinylpyrrolidone (PVP) and the other is the aqueous solution of K2CO3. Two types of solution were mixed completely, and then Ca2+and CO32−generated CaCO3nanoparticles. Secondly, composite nanofibers with CaCO3nanoparticles were successfully prepared by above solution electrospun. The resulting composite nanofibers were characterized by field-emission scanning electron microscopy (FE-SEM), it determination showed that perfect mono-dispersed spherical CaCO3nanoparticles were dispersed on polyvinylpyrrolidone (PVP) nanofibers.
The Effect of Amino-Functionalization on the Structure and Properties of MWNTs
Authors: Liu Tao , Wei Yi Zhe , Ling Xin Long , Zou Li Ming
Published: July 2012

Oxidized MWNTs were obtained by the oxidization in the mixture of concentrated HNO3 and H2SO4. Amino-functionalized MWNTs were obtained by the oxidized MWNTs reacting with aliphatic amines. The structure and properties of functionalized MWNTs were characterized by FT-IR, TGA, XRD and nanoparticle size analyzer.
Constitutive Model of Epoxy Resin Filled by Nano-Rubber Particles
Authors: Liao Shao Kai , Zhou Jing Nan
Published: July 2012

In the MTS testing machine, Quasi-static tensile mechanical testing is carried on to different Nano rubber epoxy, and have gained its mechanical properties; basing on the testing figures, ZWT constitutive model is used to descript the tensile mechanical properties of materials, and five parameter values are gained under low frequency of the model through numerical fitting; With the comparison of the test data , the numerical fitting result is in good agreement with test, at the same time, it also show that ZWT constitutive model can well descript the Quasi-static tensile mechanical properties of epoxy resin filled by nano-rubber.
Synthesis of Porous Cubic Nickel Oxide Nanostructures and their Electrochemical Property
Authors: Wang Shao Mei , Pang Huan , Zhang Hang , Ma Ya Hui , Li Xue Xue , Li Guo Chang , Zhang Jiang Shan
Published: July 2012

Monodispersed porous cubic nickel oxide nanostructures have been synthesized by a simple method. TEM have been employed for the morphology and structure characterization. Electrochemical data prove that the monodispersed porous cubic nickel oxide nanostructures contain a good specific capacitance.
Electrochemical Corrosion Characterization of As-Cast Mg-7Li Alloy
Authors: Li Jun Gang , Lv Ying , Wang Hong Wei , Zhu Zhao Jun , Wei Zun Jie , Meng Xiang Cai
Published: July 2012

The electrochemical corrosion behavior of as-cast Mg-7Li alloy in 3.5wt% NaCl aqueous solution was investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD) and electrochemical workstation. Results showed that the Ecorr and the Icorr of Mg-7Li alloy were -1.5857V and 2.235×10-4A/cm2, respectively. The cathode process was chiefly the hydrogen evolution reaction, and the corrosion rate of Mg-7Li alloy was mainly controlled by anode dissolution. The corrosion products on the alloy surface consisted of Mg(OH)2, Li2O2 and Al(OH)3. The electrochemical impedance spectroscopy (EIS) of Mg-7Li alloy contained two capacitive loops and one inductive loop. The inductance value increased to 250 ohm•cm-2 with a rise in frequency at low frequency region. The value of capacitive reactance decreased with increasing frequency at medium frequency. The capacitive reactance maintained the value of 50 ohm•cm-2 with increasing frequency at high frequency region.
Synthesis and Characterization of Nano-Sized AlN Powders by CRN Route from a Sol-Gel Low Temperature Combustion Precursor
Authors: Yang Qing Hua , Wang Huan Ping , Zhang Wen Juan , Wang Shi Feng , Xu Shi Qing
Published: July 2012

Nano-sized aluminum nitride (AlN) powders were synthesized through a carbothermal reduction nitridation (CRN) route from a sol-gel low temperature combustion precursor. The precursor was precalcined at 600-1200 °C and then nitrided at 1400-1550 °C for different holding time to obtain AlN powders. During the whole preparation process, the amorphous alumina in the precursors first transformed to γ-Al2O3, then to α-Al2O3, and AlN was obtained through the nitridation of α-Al2O3with the reduction of carbon. The results show that the appropriate precalcination benefits the activity of precursors and promotes the formation of AlN phase due to the transition of amorphous alumina to γ-Al2O3, and the optimum precalcination temperature is 1000 °C. The effects of different nitridation parameters on the microstructure of AlN powders were also investigated. By being nitrided at 1500-1550 °C for 2 h, the AlN powders present a good distribution and small particle size of 30-90 nm from the precursor precalcinated at 1000 °C.
A Novel Red Phosphor (Sr0.68Ba0.3)4Al2O7: Eu3+ for UV Light-Emitting Diode Application
Authors: Wu Su Li , Li Lian , Zhang Shu Fen
Published: July 2012

Study on phosphor materials is the key for the development of solid-state lighting, especially finding alternative red phosphor for white light emitting diodes (LEDs). In this paper, a novel Eu3+-doped (Sr0.68Ba0.3)4Al2O7red phosphor was synthesized by solid-state reaction, and its photoluminescent property was measured by fluorescence spectrophotometer. The effect of Eu3+doping concentration on photoluminescent property of (Sr0.68Ba0.3)4Al2O7was investigated, and the optimum concentration of Eu3+was found to be 4mol%. XRD patterns indicated that all the peaks of (Sr0.68Ba0.3)4Al2O7:Eu3+could be attributed to the Sr4Al2O7phase and the luminescence intensity increased with the increase of temperature.
Fabrication and Characterization of OLED with Magnesium Complex of Benzimidazol-2-Yl Pyridine as Emission Layer
Authors: Lin Yu Feng , Cheng Pin Wen , Chiu Shih Hsuan , Wang Chen Hao , Yang Shung Jim , Cherng Shen , Yeh An Chi
Published: July 2012

A bright blue emission material, bis {(benzimidazol-2-yl) Pyridenato} magnesium (MgBIP) used for organic light emitting devices, has been synthesized. The decomposition temperature was observed at 517 °C and no melting transition (Tm) of MgBIP was observed up to 400 °C. For three-layer LED devices with the configuration of ITO/NPB/MgBIP/ Alq3/MgAg, the white light emission covering the whole visible region from 400 to 750 nm with the maximum brightness of 2770 cd/m2and current density of 304 mA/cm2was observed.
Preparation and Photophysical Properties of Two-Photon Absorption Materials Containing Quinoline Ring as Electron Acceptors
Authors: Wang Ping , Li Liang , Zhang Yi Chi , Wu Yi Qun , Chen Zhi Min , He Chun Ying
Published: July 2012

Two-photon absorption materials containing quinoline ring as electron acceptors: 9-ethyl-3-(2-quinolin)viny-carbazole (4) and 9-ethyl-3,6-bis(2-(quinolin)vinyl)–carbazole (5) have been prepared by the Vilsmeier reaction of formylation and Knoevenagel condensation. Their one-photon properties including linear absorption, fluorescence spectra, fluorescence quantum yields and fluorescence decay behaviors and the two-photon ﬂuorescence excited by 120 fs pulse at 800nm Ti: sapphire laser operating at 1 kHz repetition rate were investigated, and two photon absorption cross-section was measured. It was showed that material 5 containing two quinoline rings as electron acceptors exhibited high two-photon absorption activity and the two-photon absorption cross-section (δTPA) was 364×10–50cm4s/photon, which was about as four times as that of material 4 containing one quinoline ring as electron acceptor (δTPA=81×10–50cm4 s/photon); material 5 possessed longer fluorescence lifetime (τ) of 21.4 ns and larger fluorescence quantum yield (Φ) of 0.81 than those of material 4 (τ=10.03 ns, Φ=0.77). Influence of chemical structure on the two-photon absorption was discussed. Based on the optical properties, sample 5 might be a promising candidate material for the application in super-high-density three-dimensional (3D) two-photon data storage and two-photon 3D nano/micro structure fabrication.
Influences of Processing Factors on Pore Structure of Aluminum Foams
Authors: Wang Lu Cai , Ai Jin Qiang , Wang Yan Li , You Xiao Hong
Published: July 2012

Orthogonal experiments were employed to confirm the interactive effect of the addition of magnesium powder, milling time of aluminum powder, oxidization time of TiH2 on the pore structure of Aluminum foam, which prepared by PCM method. The results show that the three factors arragned in important order as the follows: oxidization time, milling time, and the quantity of magnesium powder. The high quality aluminum foam samples, with average porosity of 84.2%, average equivalent circle diameter of 1.9 mm and average circularity of 0.754, was made on the condition of milling time as 85 minutes, oxidization time as 10 minutes and magnesium powder content as 0.5 wt%.
Application and Curing Mechanism of Soil Stabilizer
Authors: Zhang Tao , Xu Yun Yun , Wang Hao
Published: July 2012

As a kind of energy saving and environmental protection new type material, the application of soil stabilizer is widely. The development of the soil stabilizer is analyzed. The curing mechanism and construction technology of soil stabilizer is stated. Specially, the chemistry reaction is expounded. Then application foreground of soil stabilizer is pointed out.
Preparation of Construction Bricks from Iron Ore Tailings
Authors: Du Gao Xiang , Zuo Ran Fang , Guo Wei Juan , Liao Jing Hui
Published: July 2012

Based on the background that large amount of iron ore tailings are stockpiled in China, the utilization of iron ore tailings to prepare sintering brick was studied. The main objective of this paper was to investigate the influence of sintering temperature on sintering bricks from iron ore tailings, in the presence of clay, coal refuses and bentonite. Sintering bricks were prepared at different temperature with 40 wt% iron ore tailings. Drying was investigated as well as the loss on ignition, bulk density and compressive strength of the specimens. Their mechanical and microstructure properties were also investigated by radioactivity, scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results showed that compressive strengths of the specimens produced were higher than that required by the standards MU20 of GB5101-2003, up to 128.0Mpa at 1100°C corresponding to its higher bulk density completely.
Adsorption Behavior of Naphthalene Sulfonate Formaldehyde Condensate with Different Molecular Weights on the Cement Particle Surface
Authors: Qin Yan Lin , Bai Meng Xian , Zhang Zhi Ming , Yang Dong Jie
Published: July 2012

Naphthalene sulfonate formaldehyde condensate (FDN) is a kind of anionic surfactant which is consists of the hydrophobic naphthalene groups and hydrophilic sulfonate groups. Four FDN fractions with different molecular weights were prepared by using ultrafiltration and were determined by Electro Spray Ionization-Mass Spectroscopy (ESI-MS).The adsorption behavior of different fractions was investigated by means of ultraviolet spectrophotometer (UV spectroscopy), ZetaPlus and X-ray photoelectron spectroscopy (XPS). The results show that the adsorption of FDN with high molecular weight follows Langmuir model and belongs to monolayer adsorption on cement surface. However, the adsorption characteristic for FDN without ultrafiltration displays the multilayer adsorption. The greater adsorption amount and the adsorption layer thickness of FDN with higher molecular weight can provide sufficient steric hindrances between the particles. The electrostatic repulsion of particle surface has been found to increase with increase in the molecular weight of FDN.
Effect of Composition of Calcium Lignosulfonate on Setting of Portland Cement with Anhydrite
Authors: Wang Xiao Ping , Pang Yu Xia , Yang Dong Jie , Lou Hong Ming , Qiu Xue Qing
Published: July 2012

Calcium lignosulfonate (CL) was separated into three fractions with different molecular weight by using ultrafiltration membranes, and the effect of the composition of commercial CL on the setting time of Portland cement with anhydrite was studied in this paper. Results show that the CL fraction with the cut-off molecular weight of less than 150 (CL-A) shortens setting time most. Further analysis indicates that the content of reducing sugar in CL-A reaches to 15.3%, including mannose, glucose, galactose, xylose and arabinose, and these five kinds of monosaccharides are found to be the main components of inducing quick set of cement. Ultrafiltration is an effective method to remove most of the reducing sugar in CL and weaken the quick set of Portland cement with anhydrite.
The Adsorption and Dispersion Performance of Superplasticizers on Cement Particles
Authors: Zheng Da Feng , Qiu Xue Qing , Sun Xiao Hong , Qin Yan Lin , Lou Hong Ming , Yang Dong Jie
Published: July 2012

The adsorption of two superplasticizers, SNF and CE, on the cement particles were investigated. The results shown that, the adsorption of the superplasticizers could be described with Langmuir isothermal adsorption equation. The saturated adsorptive capacity of SNF and CE was 11.35 and 5.24 mg/g at 20°C, respectively. The adsorption of SNF was faster than that of CE. When the concentration of superplasticizer was 1.0 g/L, the ζ potential of the cement surface with SNF was -28.8 mV, while that with CE was -20.6 mV, indicating that the electrostatic repulsive force of SNF was stronger than that of CE. XPS spectrum disclosed the thickness of adsorption layer of CE and SNF on the cement surface was 9.8 and 1.5 nm, thus the steric repulsive force of CE was stronger. The dispersion experiment displayed that, the dispersion capacity of CE on the cement paste was much better than that of SNF.
Effects of Chitosan-Based Coating and Modiﬁed Atmosphere Packaging (MAP) on Browning of Sweet Persimmons (Diospy kakiLinn.f)
Authors: Jiang Zhong Li , Wang Ai Li , Li Xi Hong , Zhu Min Peng , Wang Jun Wei
Published: July 2012

The present study studied the effect of chitosan coating with antibrowning agents, including naphthylacetate and cinnamon oil, and modiﬁed atmosphere packaging (MAP) on browning of sweet persimmons stored at - 0.3 ~ 0 °C for 3 months. The browning on the surface of sweet persimmons was effectively inhibited by chitosan - based coating and MAP treatment. After 3 months’ storage, samples coated + MAP exerted the lowest browning index(BI), polyphenol oxidase (PPO) activity and malondialdehyde (MDA) content, which indicated that the coated + MAP treatment could offer an excellent inhibitory effect on the browning. Both edible coating and MAP treatment cause changes in respiration rate of sweet persimmons. This research could be valuable for the development of application to edible coating and MAP for improving the shelf - life properties of sweet persimmons.
Thermal Stability of a Novel Polytriazoleimide
Authors: E Yan Peng , Wan Li Qiang , Huang Fa Rong , Du Lei
Published: July 2012

A new polytriazoleimide (PTAI) was prepared from 1,2,3-triazole-containing diamine and 4,4’-(hexafluoroisopropylidene) diphthalic anhydride by polycondensation. The thermal stability was investigated. The PTAI was pyrolyzed at 400 °C and 750 °Cseparately and the pyrolysis was traced by the Py/GC/MS combined technique. Nitrogen and related compounds which result from the cleavage of C-N and N-N bonds in the polymer are found in the pyrolysis products at 400 °C. The further decomposition of PTAI would take place at imide rings and the chain units between imide rings at 750 °C. A degradation mechanism of the PTAI is proposed.
Parameters of Interaction with Vacancies in Tungsten of Homovalent Atomic Probes from the VIB and VIIB Groups of the Periodic Table
Authors: Klotsman S.M. , Tatarinova G.N. , Timofeev Alexander N.
Published: July 2012

The Volume Diffusion of Homovalent Atomic Probes (APs) from the VIB Group of the Periodic Table of Elements (PTE): Сr, Mo, W and from the VIIB Group of the PTE: Mn, Tc, Re in W Single Crystals Has Been Studied by Using Secondary Ion Mass Spectrometry (SIMS) and Radiometric Layer-by-Layer Analysis. the Enthalpies Q of the Bulk Diffusion of Homovalent APS from the VIB Group (Сr, Mo, W) and from the VIIB Group (Mn, Tc, Re) of PTA Increase with the Growth of N Numbers of their Periods in each Group whereas the Relaxation Volumes  of the Complexes “va-Cancies- VIB, VIIB Aps” in the W Lattice Do Not Differ Practically. the Detected Change of En-Thalpies Q Is Conditioned by the Difference in Magnetic Moments of Homovalent Aps from the VIB and VIIB Groups of PTA in Complexes with Vacancies in the W Lattice.
Pressureless Sintering and Characterization of Al2O3-SiO2-ZrO2 Composite
Authors: Mebrahitom Asmelash G. , Mamat Othman
Published: July 2012

An Oxide Ceramic-Based Composite in the Al2o3-Sio2-Zro2(ASZ) System Was Developed and Investigated Using a Pressureless Sintering Route. the Effect of the Content of each Component and Sintering Temperature upon the Microstructure, Density, Hardness and Strength Was Studied. X-Ray Diffraction (XRD) and Field Emission Scanning Electron Microscopy (FESEM) Were Used to Investigate the Phase Transformation Sequences of the ASZ Composite System. the Flexural Strength Was Measured Using Three-Point Bending Method on a Universal Testing Machine, while the Indentation Fracture (IF) Method Was Used to Determine the Fracture Toughness of the Composite. the Results Showed that, with Varying Zro2Content, Keeping the Silica Content Constant and the Alumina as a Matrix, Densification Tends to Decrease as the Content of Zirconia Increases from 20 Wt. % of the Composition. X-Ray Diffraction Peaks Indicated Fully Developed Alumina, Mullite and Zirconia Phases due to Solid-Phase Reaction and Liquid-Phase Sintering of the System. the Experimental Results Also Revealed that, for a Sintering Temperature of 1500°C, the Hardness Value Ranged from 12 Gpa to 14 Gpa and the Flexural Strength Was 420±31MPa.The Fracture Toughness (KIc) Was Also Reported to Be between 4.5 and 5.1 Mpa.m1/2, for Samples Sintered at a Temperature of 14500C.
Theoretical Investigation of the Spin Hamiltonian Parameters for the Tetragonal [Fe(CN)4Cl2]5– Complex in NaCI
Authors: Song Bo Tao , Wu Shao Yi , Kuang Min Quan , Hu Yue Xia
Published: July 2012

The Spin Hamiltonian Parameters (the G Factors and the Superhyperfine Parameters) for the Tetragonal [Fe(CN)4Cl2]5- Complex in Nacl Are Theoretically Investigated from the Perturbation Formulas of these Parameters for a Low Spin (S=1/2) 3d7 Ion in Tetragonally Elongated Octahedra. this Impurity Center Is Attributed to the Substitutional Fe2+ (in the Form of [Fe(CN)6]4–) on Host Na+ Site Reduced by Capturing One Electron during the X-Ray Irradiation Process, with the Two Axial Ligands CN– Replaced by Two Cl–. since the Crystal Fields of the Axial Ligands Cl– Are Weaker than those of the Perpendicular Ligands CN–, the [Fe(CN)4Cl2]5- Complex Exhibits a Tetragonally Elongated Octahedron. this System Shows the Low Spin S=1/2 of the Strong Crystal Field Case, which Is Unlike the High Spin S=3/2 of the Weak and Intermediate Crystal Field Case for Fe+ in Conventional Chlorides. the Theoretical Spin Hamiltonian Parameters Are in Reasonable Agreement with the Experimental Data, and the Results Are Discussed.
The Diffusion Problem of New Phase Inclusion Growth in Bounded Regions of Oversaturated Solid Solution
Authors: Sidorenko S.I. , Berezovsky A.A. , Voloshko S.M. , Zamulko S.O. , Konorev S.I.
Published: July 2012

The Problem of Solving Diffusion Equation with Free Boundary which Appeared during the Modeling of the Spherical Inclusion Formation Process within Spherical Domain Is Examined. the Algorithm and the Software Were Developed on the Basis of the Rothe Method in Combination with the Integral-Equations Method for their Numerically-Analytical Solution. Results of the Calculations Are Illustrated Graphically.
Cell-Secreted Matrices Enhance Osteogenesis in Adipose-Derived Stem Cells Undergoing Lineage Specification
Authors: Coan Heather B. , Teli Thaleia , Booth Christoper , Lively Mark O. , Van Dyke Mark
Published: July 2012

Osteogenic differentiation of mesenchymal stem cells (MSC) is important in the field of bone tissue engineering. The identification of biological factors that influence osteogenesis is vital for developing a broader understanding of how complex microenvironments play a role in differentiation. The aim of this study was to demonstrate that adipose-derived stem cell (ADSC) osteogenesis is enhanced through interaction with extracellular matrices (ECM) secreted by ADSC undergoing osteogenesis. ADSC were obtained from human patients following elective abdominoplasty. Cells were selected for plastic adherence, characterized, and induced to differentiate using osteogenic supplements (OS; dexamethasone, ascorbic acid, and beta-glycerol phosphate). Cells were removed at several time points during osteogenesis and the secreted ECM was isolated. Undifferentiated cells were re-seeded onto the cell secreted ECMs and induced to differentiate with OS. At several time points, cells cultured on ECMs or tissue culture plastic controls (i.e. uncoated surface) were collected and RNA isolated. QPCR and gene array analysis revealed enrichment of osteogenic markers and more rapid progression through osteogenic maturational phases in cells seeded onto ECM secreted at the midpoint in differentiation (ca. 15 days). Our results demonstrate that the cumulative deposition of ECM reaches a critical point at approximately 15 days, before which there appear to be no definitive osteogenic cues from the matrix, and after which, strong drivers of osteogenesis are present. The creation of microenvironments that contain essential morphogenic matrix signals is an important step towards methods of growing and differentiating MSC in a rapid effective manner, particularly for bone-related clinical applications.
A Novel Dynamic 3-Dimensional Construct for Respiratory Tissue Engineering
Authors: Poon Christine , Zhang Mei , Ruys Andrew John , Hong Angela , Catuogno Christelle , Boughton Philip
Published: July 2012

Tissue engineering of airway tissues poses many complex challenges. As tissue form is determined by function and vice versa, it is necessary to consider mechanical and physiological constraints in conjunction with standard biologic and biochemical factors when culturing tissues in vitro. This study involved the development and validation of a novel 3-dimensional (3-D) construct with the capacity to periodically expose a cell scaffold to air and medium at application of physiologic strain rates. The ultimate objective was to mimic respiratory conditions experienced by airway tissues during breathing whilst ensuring compatibility with proven cell culture techniques. The Biaxx design consists of an elastomeric porous synthetic scaffold integrated with a unique biopolymer coupling unit which engages with an IAXSYS bioreactor actuator. Uniform biaxial strain was imparted by the coupling unit whilst simultaneously creating a periodic air-liquid interface. Biaxx scaffolds with and without a coating of particulate 45S5 bioglass were employed in an assay to assess cell attachment and proliferation whilst subject to periodic strain. Physiologic lung tissue strain of 5-15% was achieved for over 200,000 cycles at 0.2Hz. Preliminary biological studies with H460 human lung carcinoma cells confirmed cell attachment, growth and proliferation on this promising construct.
Fractal Analysis and Biophysical Investigation of Muscular Tissue Damaged due to Low Temperature: A Pilot Study
Authors: Bianciardi Giorgio , Buonsanti Michele , Pontari Antonella , Tripodi Sergio
Published: July 2012

Severe damage is produced in tissues by freezing and thawing. Until now, a great majority of the studies are performed qualitatively, lacking any quantitative approach. An important step is to choose the best option among different freezing methods. To approach the complex problem of damage produced in tissues by freezing, in this paper we present the classical mechanics approach and a quantitative study making use of a fractal methodology (evaluation of fractal dimension by box-counting method). A comparative fractal analysis between two different steps of freezing the human thoracic diaphragm muscle has been performed to quantify the voids and cracks produced by freezing (samples were placed in a cryostat chamber). Moreover, a standard Euclidean morphometry was performed to determine area and shape of the muscle nuclei after the two steps of freezing. Fractal dimension of the ice-tissue interface structures increased with decreasing temperature (p<0.0001), percentage of cell muscle decreased (p<0.01), while standard morphometry of the nuclei didnt show any modifications. Our results show the ability of the fractal approach to accurately quantify the damage produced by freezing and reveals that the lowest temperature produces the most damage.
Molecular Biocompatibility Evaluation of Poly-L-Ornithine-Coated Alginate Microcapsules by Investigating mRNA Expression of Pro-Inflammatory Cytokines
Authors: Chen Ai Zheng , Bai Yan , Wang Shi Bin , Liu Yuan Gang , Chen Zong Xiang
Published: July 2012

Following a polyelectrolytical complex reaction, the poly-L-ornithine (PLO)-alginate microcapsules were prepared by coating PLO on calcium alginate beads which were produced by a high-voltage electrostatic droplet generator. The biocompatibility of the microcapsules at the molecular level was evaluated through investigating the mRNA expression of pro-inflammatory cytokines; that is, the effect of the PLO coating of alginate beads on the mRNA expression of TNF-α, IL-1β, and IL-6 were measured using the RT-PCR method. The resulting PLO-coated alginate microcapsules have a smooth surface with a mean diameter of 309µm. The molecular biocompatibility studies show that coating microcapsules with PLO has no significant effect on the biocompatibility of alginate microcapsules (p>0.05), and both alginate microcapsules and PLO-coated microcapsules are significantly different from the positive control (p<0.05); however, both are also capable of causing an inflammatory response at a molecular level since both are significantly different from the blank control (p<0.05). Furthermore, with the increase in concentration of microcapsules or co-cultured time, part of the mRNA expression of cytokines is significantly increased. The results also demonstrate that the method used in this study, co-incubating the microcapsules with macrophages and measuring the mRNA expression of cytokines by RT-PCR, may be a useful method for evaluating the biocompatibility of coating materials of microcapsules.
Effect of Heat Treatment Temperature on Microstructure of Sol-Gel Derived Wollastonite Coating
Authors: Bao Quan He , Liu Jia Kuo
Published: July 2012

Wollastonite coatings on titanium alloys substrates were prepared by sol-gel with different heat treatment temperatures. Microstructures of the specimens were analyzed by XRD. SEM was used to observe surface morphologies of wollastonite coatings. The results show that with the heat treatment temperature increasing, the amorphous coating transforms to a crystalline coating. There are many pores in coatings prepared by sol-gel when heat treatment temperature higher than 900°C with the PH value to 2.5. There are no cracks in coating under such conditions.
Densification and Hardness Behaviour of Nanocrystalline Hydroxyapatite/β-Tricalcium Phosphate Composite Powders
Authors: Mehdikhani Behzad , Mirhadi Bahman
Published: July 2012

In this study, dense, fine-grained biphasic calcium phosphate bioceramics were designed via sintering method. nanosize hydroxyapatite / β-tricalcium (HA/β-TCP) phosphate powders with average grain size of 80 nm were prepared by the wet chemical precipitation method with calcium nitrate and di-ammonium hydrogen phosphate as calcium and phosphorus precursors, respectively. The precipitation process employed was also found to be suitable for the production of sub-micrometre HA/β-TCP powder in situ. The sinterability of the nanosize powders, and the microstructure, mechanical strength of the prepared HA/β-TCP bioceramics were investigated. Bioceramic sample characterization was achieved by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR), and density measurements. Powders compacted and sintered at 800, 900, 1000 and 1100°C showed an increase in relative density from 57% to 93%. The results revealed that the maximum hardness of 229 HV was obtained for HA/β-TCP sintered at 1100°C.
Development of Photocatalytic Ceramic Materials through the Deposition of TiO2 Nanoparticles Layers
Authors: Carneiro J.O. , Teixeira V. , Azevedo S. , Fernandes F. , Neves J.
Published: July 2012

Urbanism and communities centralization enlarges atmospheric pollution that affects both human beings as well as their constructed buildings. Different scientific and technological studies are being conducted, both in academic and construction industry, aiming the development of new construction materials with properties that can decrease visual pollution of cities, reducing also the number of cleanings required. The present research work aims the study and the production of self-cleaning ceramic surfaces in an economical and viable way without changing aesthetical aspect of material substrates used. The use of TiO2 nanoparticles (TiO2-NNPs) represents an attractive way to generate self-cleaning surfaces, therefore promoting the degradation of pollutant agents and reducing cleaning maintenance costs. In order to impart self-cleaning properties to ceramic surfaces, TiO2-NNPs based layers were deposited on different ceramic material substrates using the dip-coating method. The Photocatalytic activity (degradation of pollutants adsorbed on the surface) of the TiO2-NNPs based layers was characterized via the decomposition rate of an aqueous solution of Methylene blue (MB) under UV light irradiation. Colourless layers were successfully produced onto gray and white ceramic substrates using this sol-gel technique, without changing their aesthetical appearance. It was observed that the best photocatalytic activity was exhibited by the most porous ceramic substrate (gray); nevertheless, all the TiO2-NNPs coated ceramic surfaces showed good photocatalytic efficiency.