bluuebunny/crossref_metadata_2025 huggingface dataset:
Promoted and Un-Promoted Co/SiO2 Fischer-Tropsch Catalysts
Authors: Prangsri-Aroon Sanya , Viravathana Pinsuda , Bangmek Waritsara , Worayingyong Attera , Kangwansupamonkon Wiyong , Deutschmann Olaf , Schulz Hans
Published: July 2011

Un-promoted and promoted Co/SiO2 catalysts with ZrO2 and Ru were prepared and the catalytic performances for Fischer-Tropsch synthesis were investigated. The prepared catalysts were characterized by XRD, N2 adsorption/desorption, and X-ray absorption techniques. XRD suggested that the cobalt species presence in all prepared catalysts was Co3O4. Promoted catalyst with ZrO2 and Ru showed high distribution of cobalt on silica surface resulted in smaller Co3O4 crystalline size than un-promoted ones. From the reaction testing, the obtained products of C1 to C9 from un-promoted and promoted Co/SiO2 were studied.
Numerical Simulation of Coupled Heat and Moisture Transfer in Porous Building Material
Authors: Zhang Xiao Bin , Zhu Wei Bing , Tan Si Peng
Published: July 2011

Building envelope is a typical porous medium. The internal accumulation of moisture will not only affect the structural strength, but also cause the growth of bacterial in the structure, which can seriously affect the indoor air quality. In this work, the modified Luikov coupled heat and moisture transfer equation is derived by using finite difference method. A FORTRAN computer code is developed based on the supplied experiment conditions. The effect of various parameters (include temperature gradient, sorption isotherm, specific humidity etc.) on the coupled heat and moisture transfer and the relationship between the temperature gradient and the moisture gradient are discussed. The results show that the simulation results agree well with the experimental data.
First-Principles Study of the Electron Transport Behavior of Short Graphene Nanoribbon
Authors: Li Yan Wei , Yao Jin Huan , Zhong Sheng Kui , Jiang Ji Qiong , Huang Xiao Xi
Published: July 2011

The electron transport behavior of a short graphene nanoribbon sandwiched between two gold(111) electrodes is investigated using density functional theory calculations and nonequilibrium Green’s function technique. The calculated current-voltage characteristic of the graphene nanoribbon junction shows an obvious negative differential resistance (NDR) phenomenon. The mechanism of this NDR behavior of graphene nanoribbon is discussed in terms of the evolution of the molecular energy levels, the spatial distribution of frontier molecular orbitals, and the electron transmission spectra under various applied biases. It is found that the changes of the spatial distribution of molecular orbitals near Fermi level with the applied bias lead to such NDR behavior.
The Effect on Adsorption Performance of Molecularly Imprinted Polymer Using the Different Functional Monomers
Authors: Yin Xiao Ying , Xu Xiang Hong , Jiang Yi Fan , Luo Yong Ming , Luo Ling Ying
Published: July 2011

To prepare molecularly imprinted polymers (MIPs) with good recognition properties，the effect on the MIPs adsorption performance were investigated from the different functional monomers. The MIPs were synthesized by using andrographolide as template, and α-methyl acrylic acid (MAA), acrylamide (AM) and 1 - vinylimidazole were used as functional monomer. Before polymerization, the interaction between the template molecule and the two functional monomers was studied by UV spectrum. After polymerization the different adsorption properties of MIPs prepared by the three types of functional monomers were compared by equilibrium binding. The results showed that the adsorption properties of the MIPs by 1-vinyl imidazole as functional monomer were similar to the MIPs by AM as functional, which the former is slightly higher than the latter and significantly higher than that of the one by MAA as functional monomer.
Electrochemical Inspection of the Interaction of Double Strand ds-DNA with Carmine on Nanometer TiO2 Doped Carbon Paste Electrode
Authors: Ma Ming Ming , Tong Zhi , Yang Jia Biao
Published: July 2011

The interaction of the single azo dye, carmine with ﬁsh-sperm dsDNA is inspected in pH 3.2 H2SO4 with electrochemical method on the surface of nanometer TiO2 modified carbon paste electrode. After the addition of dsDNA, the peak currents of oxidation and reduction peaks of carmine decrease with a positive shift of potential, indicating that intercalation interaction between the dye and dsDNA is taken place. This is consistent with ﬂuorescence spectra results. The binding constant and binding ratio is calculated as 4.92×108 and 1:2, respectively. Furthermore, the decrease in the oxidation peak currents is found proportional to dsDNA concentration in the range of 21.24-127.44 μg·mL-1 with a detection limit of 16.04 μg•mL-1.
Preparation of RPSL-01 Type Photosensitive Resin for Stereolithography and Study on its some Properties
Authors: Huang Bi Wu , Weng Zi Xiang , Liu Shi Min , Chen Wei Qing
Published: July 2011

RPSL-01 type photosensitive resin for Stereolithography was prepared with 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexanecarboxylate (UVR 6110), bisphenol A type epoxy diacrylate (EA-612), tripropylene glycol diacrylate (TPGDA), pentaerythritol triacrylate(PETA), triethylene glycol divinyl ether (DVE-3), benzil dimethyl ketal (Irgacure651) and a mixture of triarylsulfonium hexafluoroantimonate salts (UVI-6976) as raw materials. Some properties of the photosensitive resin were investigated. The viscosity of the photosensitive resin at 30°C was 425mPa.S, The glass transition temperature (Tg ) of the UV-cured specimen was 47°C, and the weight loss of the UV-cured specimen at 200°C was less than 5%. The photosensitive resin and its UV-cured specimen were also characterized by infrared (IR).
Shock-Cushioning and Energy Absorption Performance Research of Aluminum Foam-Polyurethane Composite
Authors: Qi Ming Si , Zhang Wen Dong , Yang Wei , Wang Hong Mei , Li Bo
Published: July 2011

The paper researched stress and strain of aluminum foam, polyurethane and aluminum foam-polyurethane composite via Ansys software, researched energy absorption capacity of the three material via energy absorption curve method, and researched energy absorption capacity of the aluminum foam-polyurethane composite under different shock and different thickness. The research results are obvious: under the same material parameter and 7800gn shock conditions the energy absorption of the aluminum foam-polyurethane composite is better than the monomer of the aluminum foam and the polyurethane. Under the same shock conditions, the thicker the composite is, the more energy it absorbs. Aluminum foam-polyurethane composite can plays cushioning and energy absorption roles when the acceleration speed reaches 7800gn
Microstructure and Performance of Nanocrystalline Nickel Parts
Authors: Chen Jin Song
Published: July 2011

Jet electrodeposition orientated by rapid fabrication were introduced , The nanocrystalline nickel parts were fabricated using jet electrodeposition . The microstructure and phase transformation of nanocrystalline nickel were observed under the scanning microscope and X-ray diffraction instrument . The results show that the jet electrodeposition can greatly enhance the limited current density, fine crystalline particles and improve deposition quality. The nickel parts prepared by jet electrodeposition own a fine-grained structure with a smooth surface and high dimensional accuracy under the optimum processing parameters.
The Effect of Ultrasonic Field on Synthesis of Nanometer Calcium Carbonate and its Growth Mechanism
Authors: Xue Jin Zhu , Huo Chao , Shen Jia Yuan , Xia Qing Hua , Cheng Xiang Wei
Published: July 2011

The effects of ultrasonic and Baumé degree of Ca(OH)2 suspension on the size of nano-CaCO3 prepared by carbonization were studied. The results indicated that ultrasonic could improve the dispersibility of powder, reduce the aggregation and decrease the particle size of nanometer calcium carbonate. The fine particles synthesized at 40 kHz were smaller but rougher than that obtained at 20 kHz. The frequency hardly influenced the morphology of nanometer calcium carbonate. Moreover, the lower Baumé degree of Ca(OH)2 suspension was adopted, the smaller the size of nano-CaCO3 were obtained. And in the process of carbonation, we were using SEM and XRD to study the nucleation and growth mechanism, it indicated that amorphous calcium carbonate particles acted as nuclei in the initial stage oriented absorption calcium hydroxide to form wirelike substances. In the end, these botryoidal shape crystals were disaggregated into calcium carbonate with the particle diameters of 30nm.
Study of Carbon Fiber/Polycarbonate (CF/PC) Material Sandwich Structure for Vehicle Hood
Authors: Teng Tso Liang , Liang Cho Chung , Shih Chien Jong , Nguyen Manh Trung
Published: July 2011

Traffic accidents are the worldwide problem. Based on many reports in the word, the front parts of vehicle is the most likely to strike at pedestrians when the accident occurs. And the fatal injuries almost occurred to pedestrians when their head impact to the vehicle hood. So it’s necessary to reduce the pedestrian injuries as much as possible to enhance the safety characteristic, one of the most importance criteria for vehicles manufactures. In this study, the effect of sandwich structure with material of carbon fiber reinforced polycarbonate (CF/PC) will be concerned as vehicle bonnet change. The finite element model of headform impactor and Honda vehicle model was analyzed detail by LS-DYNA as simulation. The impact between headform impactor and original vehicle model or the carbon fiber reinforced polycarbonate material bonnet vehicle model was executed and the comparison result was shown. This study, the European Enhanced Vehicle-safety Committee/ Working Group 17 (EEVC/WG17) and NCAP requirements was adopted.
Research on Traffic Organization Evaluation Method Based on Simulation
Authors: Duan Guo Qin , Zang Xiao Dong
Published: July 2011

Building a simulation network of road based on VISSIM and road planning of Guangzhou bio-island. According to the field data and statistic method to calculate the confidence interval of the calibration Parameters, at the same time, calibrating and verifying the simulation model, then using the simulation model calibrated to play the simulation and collect the traffic flow data, setting up four traffic organization projects, using improved AHP method to evaluate the effect of whole road network based on the data collected on the simulation network, then getting the sequence of all kinds of traffic organization projects.
Effect of Resin on the Property of the Fluorescent Inkjet Ink
Authors: Gao Shao Hong , Wei Xian Fu , Huang Bei Qing
Published: July 2011

Digital printing ink imaging is one of main technical fields in digital printing technology development, fluorescence inkjet digital printing is provided with favorable anti-falsification, which is used widely in Securities anti-counterfeiting and labels anti-counterfeiting etc[1]. Printings coated with fluorescence inkjet ink that emits fluorescence under using short-wave ultraviolet light excitation get more favorable anti-falsification. Green fluorescent inkjet ink is composed of phosphor, resin, solvent, assistant agent etc, resin is main one of green fluorescent inkjet ink, which has a significant implication for its property. In order to discuss resins to green fluorescent inkjet ink properties, five samples of fluorescent inkjet ink are prepared, and test various performance parameters of ink samples, such as luminous intensity, surface tension, adhesive force, aridity, and so on. The study result indicated that resins have a great influence on luminous intensity, surface tension, aridity of fluorescence inkjet ink samples, surface tension and viscosity of resins immediately impact surface tension and viscosity of fluorescent inkjet ink.
Grafting of 4-Vinyl Pyridine onto Polyesters Initiated by Potassium Diperiodatocuprate(III)
Authors: Zhang Jian Ping , Zhao Yong Guang , Zhao Ying , Liang Li Man , Ren Yan Jun , Bai Li Bin
Published: July 2011

In this article, the graft copolymerization of 4-vinyl pyridine onto poly (ethylene terephthalate)(PET) via the potassium diperiodacuprate(III)–PET redox system as an initiator was investigated in an alkaline medium. The graft copolymer was characterized with Fourier-transform infrared spectra analysis. A mechanism is proposed to explain the generation of radicals and the initiation. The effects of reaction variables, such as the initiator concentration, the ratio of monomer to PET, pH, and reaction temperature and time, are investigated, and the grafting conditions are optimized. Graft copolymers with high grafting efficiency are obtained, thus indicating that potassium diperiodacuprate(III)-PET redox system is an efficient initiator for this graft copolymerization. The quaternized PET-g-PVP (QPEVP) is proved to be an excellent adsorbent to heavy metal ions.
Research on Properties of Ca3-x La xCo4O9 Thermoelectric Material with Adding La
Authors: Zhang Li Peng , Yu Xian Jin , Ge Zhi Wei , Dong Yun Hui , Li Dang Gang
Published: July 2011

Ca3Co4O9 and Ca3-xLaxCo4O9 powders were prepared by sol-gel process. The Ca-Co-O thermoelectric material ceramics were prepared. The ceramics materials were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The microstructure and thermoelectric properties of ceramics were researched. The results indicate that the crystal of Ca3-xLaxCo4O9 with La adding growth ideally, the material had high density and low pore rate. The Ca3-xLaxCo4O9 ceramics contain directional array plate-shaped grains with layered structure. The thermoelectric properties of Ca3-xLaxCo4O ceramics were excellent. There were high Seebeck coefficient and high electrical conductivity for Ca3-xLaxCo4O9 ceramics. The power factor increased with temperature increasing.
Mixed Potential Type Sensor Using Stabilized Zirconia and La0.75Sr0.25Cr0.5Mn0.5O3 Sensing Electrode for NO2 Detection
Authors: Wu Yin Lin , Zhao Hai Yan , Dai Lei , Wang Ling
Published: July 2011

Electrochemical sensors based on tubular yttria-stabilized zerconia (YSZ) with the perovskite-type oxide as a sensing-electrode (SE), which is prepared by sol-gel method, were fabricated and examined for NO2 detection in the temperature range 673~973K. The results show that La0.75Sr0.25Cr0.5Mn0.5O3, shows extreme sensitivity to NO2. The EMF varies linearly as a function of the concentration of NO2 (0~ 463 ppm) at 773K.
Effect of the Different Structure of the Chiral Core on Phase Behaviors of Cholesteric Star-Shaped Liquid Crystals
Authors: Tian Mei , He Xiao Zhi , Yao Dan Shu , Ding Bao Hong , Zhang Bao Yan
Published: July 2011

In the present work, a ester of glucose (a) with 4-(4-(ethoxybenzoyloxy) phenoxy) -6-oxohexanoic acid side–arms has been synthesized. Compared with b and c, reported previously, a had the same side-arms but different chiral core. The phase behaviors of three star-shaped liquid crystals (a, b, c) have been compared and studied, and the effect of the different structure of chiral core on the phase behaviors of the star-shaped liquid crystals has been discussed. a, b and c displayed cholesteric phase, unlike the nematic side arm. a, b and c were all laevo-rotationary, unlike their parent cores. The melting temperature of a, b and c decreased with the increase of the sugar ring of the chiral core. The mesomorphic region of a on cooling cycle was wider than that on heating cycle. For b and c, the case was similar.
Thermal Expansion Behavior and Characteristic of SiCp/Al Composites
Authors: Zhou Xian Liang , Li Duo Sheng , Zou Ai Hua , Hua Xiao Zhen , Ye Zhi Guo , Chen Qing Jun
Published: July 2011

SiCp/Al composites were fabricated by ceramic mold freedom infiltration and pressureless infiltration, respectively. The microstructure and phases are analyzed by metallurgical microscope and coefficient of thermal expansion of SiCp/Al composites were tested by thermal dilatometer. The results show that SiCp/Al composites are compact and uniform. SiC particles were dispersed uniformly in Al matrix, and SiCp segregation was not found in composites. Under a certain SiCp size range, space between SiCp decreases with decreasing of SiCp size, and CTE of SiCp/Al composites also decreases with decreasing of particles size. Compared with CTE of composite with pure aluminum as matrix, CTE of composite with ZL101 as matrix is less. Under the annealing process, CTE of SiCp/Al composites with ZL101 as matrix is less than that with the solution and aging, which indicated that its dimensional stability of resisting to temperature fluctuation is better, and thermal expansion behavior and characteristic of SiCp/Al composites are also better.
New Oil-Absorbing Material
Authors: Shi Yan Jin , Feng Yan
Published: July 2011

With the development of industry, water pollution is increasingly severe. The research and development of oil-absorbing materials plays an important role in solving the ecological environment protection. Various oil-absorbing materials are introduced. Then, the new oil-absorbing materials are introduced mainly, including classification, production methods, oil-absorbing mechanism and properties. The limitations of the new oil-absorbing materials are pointed. And the development direction of oil-absorbing materials should be toward the high efficiency, low-cost, environmentally friendly and biodegradable.
Study on Finite Element Nonlinearity Calculation of Folding Rudder
Authors: Xiong Yi , Zhang Cheng Hong , Zhang Cheng Guang
Published: July 2011

This paper introduces material nonlinear finite element method and the establishment of finite element equation and realizes accurate modeling and calculation of folding rudder using material nonlinear finite element method. According to calculation and analysis, it is shown that the stress in contact part is relatively large due to stress concentration and material enters plastic deformation area. The influence of material nonlinearity on deformation calculation cannot be neglected. In this paper, deformation calculation results well coincide with experimental results.
Preparation, Characterization and Catalytic Properties of the Different Types of Nanometer Crystal Manganese Dioxide
Authors: Chu De Qing , Dong Yun Na , Yu Zhi Ri , Su Liang Ci , Wang Li Min
Published: July 2011

The different types of nanometer crystal manganese dioxides was prepared by hydrothermal method, and was characterized by scanning electron microscopy and X-ray diffraction. Meanwhile, the catalytic properties of the samples were investigated in catalytic degradation of methylene blue. The results showed that the different types of nano-crystal manganese dioxide had uniform crastallinity and good dispersion. And the degradation rate of methylene blue has reached more than 60%.
The Process and Property Characteristic of Electromagnetic Shielding Functional Warp Knitted Composite Fabrics
Authors: Lin Jia Hornag , Huang Yu Tien , Lin Chin Mei , Yang Yi Chang , Lou Ching Wen
Published: July 2011

The scientific progress has improved human life quality, meanwhile today's high-stress lifestyle has resulted in a rising demand for health care and well-being products. The high technology products and innovation make our life more convenient and at the same time the negative effects, such as electrostatic and electromagnetic wave. High electromagnetic wave affects the human body in different ways. Technological innovation and product aesthetics are both important for modern life quality. Companies have invested in research, development and essential household items to improve the lives such as thermal retentivity and antistatic. In this study, PET fiber was used as warp, and PET fiber, bamboo charcoal nylon fiber and stainless steel fiber employed as weft to weave three groups of resilient warp knitted fabrics. Then various examination have been conducted, including electromagnetic shielding effectiveness, tensile strength test, tearing strength test, burst strength test. The results indicate that the electromagnetic shielding effectiveness of bamboo charcoal / stainless steel resilient warp knitted fabrics attained 35 dB and the shielding achieved 99.9 %. The tensile strength of bamboo charcoal / stainless steel resilient warp knitted fabrics (weft) reached 26 MPa.
Effects of Micro Fines Content on Performances of Mortar Prepared with Mill Tailings from Magnetite
Authors: Cai Ji Wei , Lü Zheng Hang , Gao Guang Liang , Wu Ji Xu
Published: July 2011

In production of manufactured fine aggregate (MFA) from magnetite mill tailings (MT), the micro fines (particles smaller than 75 microns) was strictly eliminated. This results in lower utilization of the resources and worse micro grading of MFA. The mortar samples were prepared with MT at various micro fines contents to investigate the effects on their fluidities and strengths. In optimal water-to-powder ratio (w/p, all powders included), the fluidities of mortars reached maximum and the strengths of mortars could be improved at suitable content of micro fines in MFA. The application proves that MT can be used as MFA to prepare construction mortars up to standard and micro fines can be substituted for mineral admixture to prepare composite mortars for improving workability. So more MT can be utilized and micro fines in the tailings can take effect.
The Effect of CFG-Pile Caps and Cushion to Stability of Embankment
Authors: Wu Zhen Hua , Yuan Jian Yi
Published: July 2011

Subgrade diseases are exposed more and more serious with raising speed of existing railway in wide range. Dynamic numerical simulation had been done to analyze the effect of CFG-pile caps and cushion in composite foundation with CFG-pile in low embankment of Beijing-Shanghai high-speed railway. Distribution rules of dynamic displacement and dynamic stress of the subgrade surface and ground surface on the cross section, attenuation rules of dynamic response and dynamic stress ratio between pile and soil on the vertical section were studied. It shows that the dynamic stress of pile and soil generally attenuates in depth and attenuation of dynamic stress ratio between pile and soil mostly concentrates in the scope of 10m beneath the ground and dynamic stress caused by train load is undertaken by the pile. Moreover the scheme of CFG-pile with no pile caps and rigid cushion scheme is superior to that of pile caps and flexible cushion scheme for enhancing dynamic stability and reducing dynamic displacement and stress in low embankment. It will be instructive to control design and construction for the low embankment in Beijing-Shanghai high-speed railway.
Experimental Study of Fly Ash Concrete Attacked by Sulphuric Acid
Authors: Pan Li Yun , Li Yong , Li Feng Lan
Published: July 2011

Experiments were conducted to study fly ash concrete (FAC) attacked by sulphuric acid. The cubes with dimensions of 100 mm were cast and immersed in sulphuric acid solution with different pH values of 2, 3 and 4, and tested at exposure times of 28 d, 56 d, 90 d, 150 d and 365 d respectively. The compressive strengths of concrete were tested, and the SO42- contents of concrete at different depths were measured with powder samples by the chemical titration method. The results show that FAC has certain ability to resist corrosion of sulphuric acid though exposed surfaces were damaged at long-term exposure times, the concrete strength at same exposure time decreases with the increasing density of sulphuric acid solution, the SO42- mainly contains in shallow layer of concrete while the content decreases obviously with the increasing depth of concrete. With the increasing density of sulphuric acid solution, phenomena of surface cement paste peeling off surface of concrete and crystal CaSO4 separated out of concrete became seriously. The deterioration mechanisms of FAC attacked by sulphuric acid are discussed.
Study on Microstructure and Properties of CuZn37Mn3Al2FeSi Alloy
Authors: Mu Si Guo , Dai Jiao Yan , Wang Yong Ru , Chao Guo Hui , Hong Xi Ping , Su Yu Chang
Published: July 2011

The microstructure of Cu-37%Zn-2%Mn-1.6%Al-0.7%Fe-0.7%Si (mass fraction)alloy was studied by scan electron microscopy, X-ray and optical microscopy. The α phase ratio and micro-hardness of this alloy after aging treatment were investigated. The results show that three kinds of phases, such as α phase, β phase and hexagonal club-shape Mn5Si3 phase were observed. The needle α phase ratio increases with aging temperature under 420°C and reach peak value 25 percent after aging at 420°C×1h. The α phase ratio begin decreases when the aging temperature over 420°C. The micro-hardness varying with aging temperature is the opposite.
Variation of Carbonation Coefficient of Pumping Concrete with Moist-Curing Time at early Ages and Fly-Ash Content
Authors: Ye Qing , Song Zhi Wei , Yu Guo Rong
Published: July 2011

Based on accelerated carbonation test, the variation of carbonation resistance of pumping concrete (C40 grade) with moist-curing time at early ages and fly-ash content was studied. Results indicate that the carbonation coefficient and the accelerated carbonation depth of the concrete increased obviously with a reduction in the moist-curing time at early ages and with an increase in the fly-ash content. For example, in conditions of curing schedules with 28, 7, 3, 2 and 1 d moist-curing at 20 0C with above 95% RH at early ages and then 0, 21, 25, 26 and 27 d air curing at 20 0C with 60% RH, respectively, carbonation coefficients of the concrete incorporated with 30% fly-ash were 2.04, 2.49, 3.16, 3.86 and 5.42 mm/a0.5 respectively, and thus it can be seen that the calculated times when concrete cover (25 mm) was completely carbonated naturally in now atmosphere (0.04% CO2) were 164, 104, 66, 44 and 21 years respectively. The results suggest that for the carbonation resistance of the C40 concrete incorporated with up to 30% fly-ash, the moist-curing time of 7 days at early ages should be necessary.
The Influence of Aggressive Environment with a High Content of Fluoride Ions on the Alloy TiAl6V4 with a Protective Ti-Al-Si Layer
Authors: Kubatík Tomáš , Kadlecová Marcela , Eremiáš Boleslav , Kalabisová Eva
Published: July 2011

This work presents results on the influence of fluoride ions on the behavior of layers whose main component is the phase TiAl0.3Si1.7 (called t2 phase), formed on TiAl6V4 substrate. Layers were prepared in AlSi20 melt at 650 ° C for 60 min. Potentiodynamic curves were measured in a chloride solution with 0 and 5000 ppm fluoride. Layer were shifted corrosion potential to more negative values and at the some time reduce the corrosion current density (Im). Values of Im are in the potential range of 300 – 1500 mV (SCE) for TiAl6V4 with Ti-Al-Si layers significantly lower in comparison with Im values found for TiAl6V4 in chloride solution containing 5000 F-. The electrochemical tests showed that Ti-Al-Si layer had marked positive effect on corrosion resistance of TiAl6V4 alloys in aggressive environment with high content of F-.
Basic Properties of Masonry Cement Mortar Affected by Content of Stone Powder
Authors: Li Chang Yong , Liang Na , Li Feng Lan
Published: July 2011

Experiments were carried out to study such basic properties as workability and strength of masonry cement mortar affected by mass content of cement equally replaced by stone powder. The mortar was designed in strength grade of M20 with three kinds of mix proportions, three replacing ratios of cement by stone powder. The results show that part of cement equally replaced by stone powder irregularly influences consistency and layering of fresh mortar but still brings fresh mortar into better workability; the optimum mass content of cement equally replaced by stone powder relates to the water to binder ratio of mortar, which are 5 %, 10 % and 15 % successively corresponding with 1.0, 0.9 and 0.8 water to binder ratio. Comprehensively concerned about the ratio of bending to compressive strengths of mortar, the referenced mix proportions of mortar with stone powder are proposed for application in practices.
Mixture Proportion Design of Reactive Powder Concrete by Means of Liquid Limit
Authors: Ji Yu Yan , Ma Xin Wei , Xia Yuan Yuan
Published: July 2011

Close packing of the fine particles is one of the core technologies of preparation of reactive powder concrete. This paper introduces the concept of soil liquid limit in close packing evaluation. Theoretically, the closer of particles pack, the lower is the water demand. The mixture with a lower water demand is expected to have a lower liquid limit. Mixtures were obtained by measuring the cone penetration at different moisture content. By means of numerical fitting and linear interpolation, the liquid limits of the mixtures were obtained，where the software of Matlab was used. The close packing condition of the powders particles could be predicted according to the liquid limits. Strength test confirmed that application of liquid limit in mixing proportion design of reactive powder concrete is feasible. So, this may be a new way for the preparation of reactive powder concrete.
A Useful Curve Fitting Method for Concrete Uniaxial Compressive Experiment Data
Authors: Jin Chong , Wang Hong , Xia Xiao Zhou
Published: July 2011

Based on the superiority avoiding the matrix equation to be morbid for those fitting functions constructed by orthogonal base, the Legendre orthogonal polynomial is adopted to fit the experimental data of concrete uniaxial compression stress-strain curves under the frame of least-square. With the help of FORTRAN programming, 3 series of experimental data is fitted. And the fitting effect is very satisfactory when the item number of orthogonal base is not less than 5. What’s more, compared with those piecewise fitting functions, the Legendre orthogonal polynomial fitting function obtained can be introduced into the nonlinear harden-soften character of concrete constitute law more convenient because of its uniform function form and continuous derived feature. And the fitting idea by orthogonal base function will provide a widely road for studying the constitute law of concrete material.
Investigation on Nonlinear Constitutive Relationship for a Honeycomb Sandwich Composite
Authors: Liu Qiang , Huang Zheng Ming
Published: July 2011

This paper investigates nonlinear responses of honeycomb sandwich composite under externally applied loads theoretically and experimentally. In the experimental work, honeycomb sandwich composites made of an aluminum honeycomb core and glass fiber reinforced polymer (FRP) laminate surfaces were loaded under in-plane tension and out-of plane bending up to failure. Stress-strain curves or load deflection plot together with elastic moduli and ultimate strengths were obtained. An energy approach was used to establish a nonlinear constitutive relationship for the honeycomb sandwich composites. Making use of the superimposition ability of the strain energies of all of the walls of the RVE, a nonlinear constitutive relationship for the honeycomb core was obtained. The thus obtained relationship was incorporated with a laminate theory and the bridging model to analyze nonlinear responses of the honeycomb core and FRP surface sandwich composites up to failure. The composite failure was detected micromechanically, i.e., based on the failure status of its constituent aluminum core, reinforcing fiber, polymer matrix, and adhesion layer. Stiffness discount was applied respectively to the failed composing element. The predicted nonlinear stress-strain curves under tension and load-deflection relationship under three-point bending were compared with the experimental measurements. Favorable correlations have been obtained.
Hot Deformation Behavior and Fracture of As-Extruded 7075 Aluminum Alloy
Authors: Sun Zhi Chao , Wang Jiang Hui , Wang Yu , Yang He
Published: July 2011

Based on the isothermal compression experiment under constant strain rate, the deformation behavior and flow stress of as-extruded 7075 aluminum alloy at high temperature was studied. Then the fracture behavior and mechanism of 7075 aluminum alloy were investigated, the results showed that longitudinal cracking was easy to occur at a high temperature due to additional tensile stress and low melting point alloy in grain boundaries melting. Through analysis and comparing of C&L and Oyane fracture criteria, it was proved that C&L fracture criterion was more reasonable to predict fracture in 7075 aluminum alloy hot deforming, and the critical damage factor in a forming temperature range(300~450°C) for 7075 aluminum alloy was obtained.
Vacuum Forming Refrigerator Inner Liner Structural Optimization
Authors: Su Wen Bin , Sun Xiang Bing , Li Tao , Liu Bao Jian
Published: July 2011

Thickness thinning is the principal quality problem in the vacuum forming process of the refrigerator inner liner. In this paper, the structural parameters of refrigerator inner liner were analyzed based on orthogonal experiments and numerical simulation. Optimized structural parameters combination scheme and the significance level of structural parameters to thickness were obtained by analyzing the results of orthogonal experiments. Validation experiment results shown that the quality of refrigerator inner liner based on the optimized structural parameters combination scheme improved effectively.
Fracture Analysis of Pipe Sleeve on Extrusion Flare-Less Pipe Joints for Aircraft Hydraulic Pipe
Authors: Xue Feng Mei , Li Fu Guo , Li Jiang , Yu Wen Jun , Li Jian Fei
Published: July 2011

The forming process of aircraft hydraulic pipe joints is investigated through experiments and analyses to solve the cracking problem of pipe sleeve on extrusion flare-less pipe joints. It can be concluded that the internal cause of the fracture failure is connected with the content, shape and distribution of δ-ferrite in 0Cr12Mn5Ni4Mo3Al high strength stainless steel, and the external cause is associated with the bearing behavior in the extrusion-bulging process of pipe sleeve. The crack is formed in the criss-crossing section of δ-ferrite on the function of shear stress in the stress concentration position, which belongs to ductile deformed crack. It eventually induces the intergranular fracture of pipe sleeve along the long axis with the expanding of subsequent crack.
Influence of Aging on Creep Rupture Properties of Heat Resistant Steels for Steam Turbine Rotors of Thermal Power Plants
Authors: Niu Li Bin , Matsushima Ippei , Akiu Tetsuji
Published: July 2011

Influences of aging on the creep rupture properties of super-clean 9%CrMoV steel and 1%CrMoV steel, the heat resistant steels for steam turbine rotors of thermal power plants, are investigated. Using the as-received and the aging-treated materials of the two steels, creep rupture tests are carried out at 566°C. Creep rupture lives, creep fracture modes as well as the microstructural changes of the specimens are examined. It is made clear that the creep strength and the microstructural stability of super-clean 9%CrMoV steel are superior to those of 1%CrMoV steel in long-term services.
Study on Fracture Energy of Cement Stabilized Aggregate
Authors: Wei Xiao Hang , Zhang Peng
Published: July 2011

A series of parametric tests have been conducted to investigate the effect of curing period and cement content of the specimen on fracture energy of cement stabilized aggregate. By means of three-point bending method, the fracture energy of cement stabilized aggregate was measured. Four specimen curing periods (14 d, 28 d, 60 d and 90 d) and four different cement contents (4%, 5%, 6% and 7%) were used. The results indicate that the fracture energy of cement stabilized aggregate is increasing with the increase of specimen curing period. Besides, with the increase of cement content, there is a tendency to decrease in the fracture energy of cement stabilized aggregate. The ability of cement stabilized aggregate to resist crack propagation becomes weaker and weaker with the increase of cement content.
Study of Shear Fracture Behaviours on 6061 Aluminum Alloy
Authors: Zhu Hao , Zhang Yang , Yu Shen Wei
Published: July 2011

The mechanics properties and fracture behaviors of 6061 aluminum alloy were investigated by the tensile shear tests and in-situ tensile shear tests with tensile shear specimen devised. The results indicate that a lot of slip bands parallel to tensile direction are produced on specimens’ surfaces. With shear strain rates increasing, the shear yield stress and shear ultimate stress of 6061 aluminum alloy remain constant basically, but the shear fracture strain decreased obviously. The grain boundaries of 6061 aluminum alloy are the weakest area and microcracks initiate at the grain boundaries parallel to tensile direction under shear stress. With shear stress increasing, the microcracks extend and coalesce. The fracture of specimens is due to coalescence or shearing between the microcracks.
Study on Crack Prevention for Concrete Rapid Construction
Authors: Liu Min Zhi , Qiang Sheng , Wang Bing Lei , Zhen Zhan Qiang , Wang Xiang Rong
Published: July 2011

Pier concrete is vulnerable to cracking when using concrete rapid construction after long off period. In order to solve this problem, crack mechanism and effects of several temperature control measures of thin-walled structure concrete is analyzed. Through analyzing the temperature and stress time-space variation using 3D finite element method, it can be found that stress is more sensitive to controlling concrete placing temperature than other measures. It also shows that under the condition of taking other proper temperature control measures, low placing temperature can not be spared.
A New Constitutive Model for Anisotropic Sheet Metal with Isotropic Ductile Damage
Authors: Guo Jun Hang , Murakami Riichi , Zhao Sheng Dun
Published: July 2011

In this paper, a new constitutive model for anisotropic material with isotropic damage is proposed by extending the Rousselier’s model. In this new model, the damage of anisotropic material is treated as a scalar and the Hill 1948 yield function is employed. A full-implicit integration algorithm which can be used in the finite element (FE) simulation is developed. The integration formula is coded into FE model by Abaqus/Explicit using User Material Subroutine and the fracture process is simulated by element deletion. The tensile tests of sheet metal of two different materials, 08 boiling steel and 1Cr18Ni9Ti, are taken under 3 directions. By simulations for specimen under tension, the evolutions of the damage variable are obtained. By comparing the load-displacement curve of the experiments with the simulation results, the validation of this model is verified.
Construction of a Finite Element Multiresolution Method Based on the Second Generation Wavelets
Authors: Lin Yun , He Yu Min , Zhang Xiao Long
Published: July 2011

The second generation wavelet transform has shown the property of high flexibility in multiresolution analysis. Based on this powerful tool, a new finite element multiresolution method is proposed. By using this method, the equation can be resolved in the low-resolution space, and then the coarse solution can be refined by adding the detail solutions in the detail spaces gradually till the solution in a high-resolution space satisfies the expected accuracy. This method is easy to achieve self-adapting algorithm and is suited for solving the singular problems. Numerical tests demonstrate the validity of this method.
A Model for the Effects of Strain Rate and Temperature on the Deformation Behavior of Ultrafine-Grained Metals
Authors: Xie Zi Ling , Sun Lin Zhu , Yang Fang
Published: July 2011

A theoretical model is developed to account for the effects of strain rate and temperature on the deformation behavior of ultrafine-grained fcc Cu. Three mechanisms, including dislocation slip, grain boundary diffusion, and grain boundary sliding are considered to contribute to the deformation response simultaneously. Numerical simulations show that the strain rate sensitivity increases with decreasing grain size and strain rate, and that the flow stress and tensile ductility increase with either increasing strain rate or decreasing deformation temperature.
Variational Problem of Unloading Fractured Rock Mass
Authors: Yu Li , Fu Ming Fu , Tu Bin
Published: July 2011

This article mainly introduced variational problem about stress-strain relationship of unloading fractured rock mass in the excavation. In this paper, research is carried out on variational principle of unloading fractured rock mass in the stage of linear elasticity.
Dynamic Simulation of Cycloid Wheel at Two Support Points of Needle Gear pin for New Three-Gear Pin-Cycloid Driven Speed Reducer
Authors: Sun Ying Shi , Guan Tian Min , Zhang Xu
Published: July 2011

Pin-cycloid driven speed reducer with three cycloid gears adopts the new driving structure of three cycloid gears at eccentric angle of 120 between each other. Three main stresses act on the cycloid gears: the stress between pin gear and cycloid wheel gear, the stress on cycloid wheel by cylinder pin of output mechanism and the stress on cycloid wheel by bearing of rotating arm. In this paper, the stress between needle gear and cycloid wheel gear is analyzed mainly by analysis.
Surface Modeling Design and Temperature Field Analysis about Air Intake Cover Based on Pro/E Software
Authors: Liu Han Wu , Liu Zhao Hui , Chen Tian Xiang
Published: July 2011

As an outer covering of cooling aircraft engines, the air intake cover very much effects the aerodynamic performance of the aircraft under the condition of high-speed air current striking on it. In order to improve the aircraft's aerodynamic performance, the temperature field distribution of the gypsum-based Investment casting process of the air intake cover was analyzed by ANSYS software, which the Pro/E software was used as the three-dimensional modeling software. In the modeling process with Pro/E software, three default datums must be firstly established. In the same time, it is necessary to appropriately use some temporary datums. Some functions, such as Protrusion> Use Quilt> Solid or Thin,Reorder,Redefine,Reroute, are very important to generate complex curved surfaces and entities. The results of the temperature field simulation showed that the process of filling and solidification reflected the actual casting situations, forecast possible defects in casting and defective locations of the castings, order solidification was obtained which a rising head was put close to casting heat knots and final solidification positions, and ensured the feasibility and quality of the air intake cover casting.
Evaluation Method for Fabric Non-Iron Pleat Plasticity
Authors: Zhao Li Huan , Wang Fu Mei
Published: July 2011

Fabric non-iron pleat plasticity is a shaping element of garment. In order to better grasp the performance, its quantitative evaluation method was designed in the paper. It was believed that fabric non-iron pleat plasticity was actually the crease retention of fabric, therefore, crease retention ratio was used for characterizing the fabric non-iron pleat plasticity. The results showed that, all of "PTT shape memory fabrics", PET imitation memory fabrics and cotton fabrics had higher crease retention ratios; followed by Nylon fabrics, next was silk fabrics; wool fabrics had the smallest crease retention ratios. The results proved that crease retention ratios of different kinds of fabrics differ substantially, and the index could basically reflect the non-iron pleat plasticity of different kinds of fabrics.
Determination Methods of the Minimum Safety Thickness of Acrylate Waterproof Membrane
Authors: Zhao Ju Mei , Li Guo Qing , Wang Yu Suo , Yang Qi Xin , Liu Dong Min , Ren Xiao Ping
Published: July 2011

The energy method was used to analysis the flexural property of acrylate waterproof membrane in local loads during the period of construction and service. The membrane was formed by spraying-membrane waterproof technique for tunnel engineering. The maximum central deflection of the clamped circular plate was calculated in the uniformly distributed and concentrated loads. The minimum safety thickness was calculated in theory during the course of using. It was expected to provide theoretical reference for the further improving of spraying-membrane waterproof technique.
An Experimental Setup to Test Thermal Contact Conductance Across Solid/Solid Interface
Authors: Liu Sheng Wang , Zhang Wei Fang , Tang Qing Yun
Published: July 2011

This article describes an experimental setup to measure the TCC between interfaces of two contact solid materials. This apparatus consists of loading and load bearing subsystem, water-cooling subsystem, heating subsystem, temperature measurement and control subsystem and thermal insulation subsystem. A new kind of design scheme of the compensation heater is put forward. An experimental investigation of TCC is conducted with pressed pairs of TC4/30CrMnSi contacts in the range 40~140MPa. The results show that TCC over this condition increases with load, and is greater in the process of unloading than that of loading under the same condition.
Infrared Thermography Non-Destructive Testing of Composite Materials
Authors: Wu Cui Qin , Wang Wei Ping , Yuan Qi Gang , Li Yan Jun , Zhang Wei , Zhang Xiang Dong
Published: July 2011

To detect the delamination, disbond，inclusion defects of the glass fiber composite materials applied in the solid rocket motor, active infrared thermographic non-destructive testing(NDT) is researched. The samples including known defects are heated by pulsed high energy flash lamp. The surface temperature of the samples is monitored by infrared thermography camera. The results of the experiments show that the active infrared thermography technique is a fast and effective inspection method for detecting the defects of delamination, disbond，inclusion of the composites. The samples are also detected by underwater ultrasonic c-scans. The paper concludes that the active infrared thermography NDT is more suitable to rapidly detect the defect in large-area and the underwater ultrasonic c-scans is more suitable to quantitatively identify the defect in local-area.
Hybrid Control for Isolation and Energy Dissipation Systems of Flexible Pile
Authors: Zou Li Hua , Huang Kai , Sun Qi , Wang Li Yuan
Published: July 2011

In this paper, a hybrid control system of the energy dissipation and isolation of flexible pile(EDIPF) is proposed, the dynamic analysis model of system is established, and its vibration and control equations are derived. Taking a typical flexible pile base-isolated structure for example, the isolation performance, control effect and main control parameters are studied. The results show that: the isolation and energy dissipation system of flexible pile can effectively reduce the seismic responses of structure, and to apply active control to this system can reduce the possibility of collision between pile and wall of pile hole. At the same time, the vertical loads and the stiffness of superstructure and piles have a significant influence on the control effect of structures.
Mechanism Study on the High-Phosphorus Hematite Carbothermal Reduction in Microwave Field
Authors: He Zhi Jun , Zhang Hui , Jin Yong Long
Published: July 2011

In the paper, the research on raising the grade of iron ore and dephosphorization for high-phosphorus oolitic hematite by coal-based carbothermal reduction in microwave field was carried out. The microwave action mechanism was analyzed by the aspects of ionic crystal lattice energy and thermodynamics and dynamics[1]. The possibility of the application of microwave in raising the grade of iron ore and dephosphorization for high-phosphorus hematite was discussed. The research indicated that the primary structure of the high-phosphorus hematite was changed by the high-phosphorus hematite carbothermal reduction in microwave field, meantime the carbothermal reduction reaction activation energy was decreased and the reduction rate was speeded up[2-4].