bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation and Characterisation of a Compatilizer of PP-RTV Blends
Authors: Sun Yi Ming , Li Hu An , Li Man
Published: February 2011

A compatilizer PP-g-Vi-PDMS for PP/RTV blends was prepared through a melt extrusion-grafting method. The tentative mechanism of the enhanced compatibility effect was discussed. The interfacial tension of PP/RTV blends was calculated based on contact angle method. The results indicated the grafting reaction between PP and Vi-PDMS, which was demonstrated by both the decreasing melt flow rates with increasing Vi-PDMS contents and the appearing of IR peaks at 1260cm-1、1100~1000cm-1、800cm-1 ascribed to Vi-PDMS′s characteristic IR absorption. The compatilizer significantly decreased the interfacial tension of PP/RTV blends. The compatibility of PP/RTV blends was improved successfully using the compatilizer PP-g-Vi-PDMS.
Numerical Simulation of Temperature and Creep of Concrete Surrounding Spiral Case in a Hydraulic Plant
Authors: Xu Xin Yong , Luo Quan Sheng , Ma Zhen Yue
Published: February 2011

The transient temperature field and thermal creep surrounding concrete are analyzed with a three-dimensional FEM model that simulates the construction process of spiral case, based on program development of ABAQUS. The effect of hydration and cooling pipes on temperature is studied. The comparison of temperature difference in schemes is performed, and then the reasonable construction scheme has been defined. The distribution of thermal creep stress with construction is given. It is concluded that the control measures is effective to temperature crack prevention.
Material Test on Aluminum Alloy Round Pipe for Building Structure
Authors: Gao Yong Tao , Hu Xiao
Published: February 2011

With the unilateral extending test on 4 teams*12 aluminum alloy round pipes, compressing test on 4 teams*4 pipes and repeating extending/compressing test on 4 teams*4 pipes, get the stress-strain relationship of the aluminum alloy round pipe, and get the elastic modulus f0.1 and f0.2. At the same time, get the conclusion that the damaging type is brittleness. The test result is the foundation for follow-up studies on the loading capacity of the aluminum alloys.
Study on the Influence of Chloride Ion Content on Pavement Performance of Base Material with Fly-Ash-Flushed-By-Seawater
Authors: Bao Long Sheng , Zhang Xiao Fang , Yu Ling , Zhu Guang Shan
Published: February 2011

In order to study on the influence of chloride ion on pavement performance of base material with fly-ash-flushed-by-seawater and the feasibility of fly-ash-flushed-by-seawater material used to road construction, the analysis and evaluation on the influence of chloride salt content on pavement performance of material base course are obtained through the laboratory test on pavement performance of base course with adding different content of chloride salt. The study shows that the chloride salt content in fly-ash-flushed-by-seawater influences slightly on the early strength of base course and even plays a function of early strength agent; the chloride salt content in fly-ash-flushed-by-seawater has an inhibiting effect on the growth of strength when it is more than 1.3%; the dry shrinkage coefficient increases with the aggrandizement of chloride salt content and the anti-erosion performance of material is sensitive to the chloride salt content, but temperature shrinkage coefficient and anti-freeze performance are slightly influenced by it. Fly-ash-flushed-by-seawater used to base course construction is feasible because the pavement performance of fly-ash-flushed-by-seawater base material satisfies the request of Specifications for Design of Highway Asphalt Pavement JTG D50-2006.
Experimental Study on Expansive Soil Improved with Cation Modifier
Authors: Li Zhi Qing , Fu Le , Xie Fang , Tan Ru Jiao , Wang Yan Ping , Zhong Duo
Published: February 2011

The improvement of expansive soil with chemical medicine has been concerned by geotechnical engineers. The cation modifier is used to improve the expansive soil in embankment engineering of an express highway in Yunnan province. The modified test results indicate that the hydrophilic nature and swelling-shrinkage properties of samples are changed drastically. The free swelling ratio decrease and the particle size gradation, strength characteristics and hydrological properties of the treated expansive soil are improved by a wide range. The clay content decreases, but the silt content increases. The void ratio decreases sharply, but the fabric becomes more compact. The change of dry density with water content changing is less, but the water stability of modified soil is improved. The indexes are satisfied with the project requests and the engineering cost reduces.
A Study on Mechanical Performance and Mechanism of Cement Asphalt Mortar
Authors: Li Yun Liang , Tan Yi Qiu , Ou Yang Jian
Published: February 2011

This paper studies the effects of proportion of emulsion asphalt and cement, sand gradation and sand-to-cement ratio on 28d strength of CA mortar solidified body according to compressive strength. Results show that compressive strength of CA mortar evidently decreases with increase of quality ratio of emulsion asphalt and cement, and increases with sand gradation attenuated. 28d compressive strength of CA mortar obviously reduces when the sand-cement ratio is above 1.4. Mechanical performance and intensity capability of CA motor solidified body are determined by microstructure of solidified body and content of free asphalt, encapsulation and cementation state of microstructure.
Experiments and Study on Proportioning Design of SMA-13 Warm Mix Asphalt
Authors: Miao Sheng Jun , Li Pei Liang , Li Yuan , Liao Xiao Kang
Published: February 2011

Materials, include polymer modified asphalt, coarse aggregate, fine aggregate, packing and lignin fiber, of SMA-13 Warm Mix Asphalt used in maintenance engineering of Jing-Shen expressway (K17-K22), were tested in quality. Based on different grading Marshall tests of stone matrix asphalt of HMA (no additive) and WMA (with additives), materials proportion, asphalt aggregate ratio and target densities of SMA-13 WMA were designed, which will be applied in expressway surface maintenance. Through rutting test, water immersion Marshall test, tensile strength ratio test, seepage test and other proportioning examinations, it shows that the designed asphalt can meet code requirements and guarantee good high temperature stability and water stability.
Synthesis of LiFePO4 Cathode Materials by a Chemical Method
Authors: Sun Yuan , Zhao Xiu Juan , Li Guo Jun , Ren Rui Ming
Published: February 2011

The olivine-type LiFePO4 powder was prepared by a chemical method using the synthesized FePO4 1.78H2O, LiOH, citric acid and PEG as raw materials. The synthesized FePO4 1.78H2O precursor powder was obtained by co-precipitation method. LiFePO4 powder was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermo-gravimetric analysis (TGA)/differential scanning calorimetry (DSC). The results showed that the calcined LiFePO4 was in a single phase when fabricated by using the synthesized FePO4 1.78H2O powder at pH of 3.5 in argon atmosphere.
Facile Synthesis and High Activity of Novel Ag/TiO2-NTs Composites for Hydrazine Oxidation
Authors: Dong Bin , Chai Yong Ming , Liu Yun Qi , Liu Chen Guang
Published: February 2011

Novel Ag/TiO2-NTs composites have been synthesized using titanium dioxide nanotubes (TiO2-NTs) modified by (3-aminopropyl)trimethoxysilane (APS) as supports. The composites have been characterized by TEM and XRD. The better dispersion of Ag on TiO2-NTs modified by APS can be observed than that of TiO2-NTs without being modified by APS, which implies that APS is helpful for uniform nanoparticles. The electrocatalytic properties of Ag/TiO2-NTs for hydrazine oxidation were investigated in details. Excellent electrocatalytic activity was observed. The results showed that TiO2-NTs have a very good application potential as supporting materials for noble catalysts.
Study on Modification Mechanism of Antimony in Al－Si Cast Alloys
Authors: Li Hui Ling , Chai Qiu Yan
Published: February 2011

The effects of modification by antimony on Al－Si cast alloys have been extensively used, but the modification mechanism has not been well accepted. 0.2wt%Sb has perfect modification effects at the existence of of Mg, while much enough Sb for example 1wt % has effects on modification as well without Mg. The cooling process of alloys and the existence manner of elements in cast Al-Si alloy of different content of Sb is studied in this paper. Viewed from the results of DSC thermal analysis, crystallization supercooling increases, nucleation supercooling reduces and eutectic latent heat increases when the content of Sb reaches 0.2wt %. HCombiningH the existence manner of elements in cast Al-Si alloy analyzed by energy - dispersive spectrometry, it is found that the actual modification agent is the clustered Sb in free state. Mg can intensify the modification effects of Sb because Mg added to alloy decreases the solubility of Sb, which allow enough Sb left over to effect modification of alloy.
Thermoelectric Properties of Directionally Solidified Bi2Te3 Alloys under High Thermal Gradient
Authors: Feng Song Ke , Li Shuang Ming , Luo Qing Yan , Fu Heng Zhi
Published: February 2011

Thermoelectric Bi2Te3 bulk alloys were directionally solidified successfully at the pulling rate ranging from 1 μm/s to 50 μm/s under a high temperature gradient of 200 K/cm. Preferred crystal orientations of (0 1 5), (1 0 10) and (1 1 0) faces appeared at the pulling rate of 50 μm/s. In the Bi2Te3 alloys directionally solidified at 5 μm/s, the maximum Seebeck coefficient of -253 μV/K was obtained and the maximum electrical resistivity of 2.26 mΩ•cm was measured at 300 K. Besides, the optimum Power Factor (PF) value reached 3.83×10-3 W/K2m at 1 μm/s and the measured results show that the thermoelectric Bi2Te3 bulk alloys grown at low growth rates supply the large PF value at ambient temperate, while at high temperature, the alloy grown at 50 μm/s has a better PF value.
Study on Preparation and Application of a Novel Composite Phase Change Material
Authors: Jiang Cong Cong , Li Guo Zhong , Gao Zi Dong
Published: February 2011

A novel composite phase change material (PCM) was prepared with phase change material (paraffin), storage medium (expanded perlite) and coating material (VAE emulsion), which was added to the gypsum to prepare the gypsum-based energy storage material(GESM). The microstructure and thermal properties of samples were characterized by scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). The results showed that the expanded perlite had good adsorption of paraffin, and the best adsorption capacity was 50%. The prepared samples had good thermal physical properties.
Microwave Assisted Carbothermal Reduction Synthesis of Nano-Sized LiFePO4/C
Authors: Jia Xiao Lin , Ma Mei Pin , Liu Wei , Tian Li , Mo Xiao Peng
Published: February 2011

LiFePO4/C nano-particles were synthesized by microwave assisted carbothermal reduction method, using LiOH•H2O,FePO4•2H2O and sucrose as raw materials. LiFePO4/C samples with different particle sizes were prepared by heating at different temperatures in an industrial microwave oven. The samples were characterized by X-ray diffraction, field emission scanning electron microscopy, laser particle sizer analysis and electrochemical performance test. The results showed that the average size of samples is about 100 to 300 nm. The first discharge capacity decreased with the increase of temperature. The LiFePO4/C particles prepared at temperature of 700°С for 15 min exhibited the best capacity of 156.9mAh/g at 0.2C rate, and had just ~6% capacity loss after 50th cycles.
Study on PLA/PBS Blends
Authors: Chuai Cheng Zhi , Zhao Nan , Li Shu , Sun Bing Xin
Published: February 2011

Poly(lactic acid) and Poly(butylenes succinate) grafting glycidyl methacrylate (PLA-g-GMA and PBS-g-GMA) and PLA/PLA-g-GMA/PBS and PLA/PBS-g-GMA/PBS blends were prepared by melt mixed method. The morphological structures of the blends were characterized by SEM and ESEM. The effects of graft polymer on the mechanical, dynamic mechanical and the rheological properties of the blends were studied.
Preparation and Mechanical Properties of Polyurethane/Modified Kaolin Foam Composites
Authors: Chen Xing Gang , Sang Xiao Ming , Hou Gui Xiang , Yu Shou Wu
Published: February 2011

Polyurethane/modified kaolin foam composites were prepared via in situ polymerization with calcined kaolin as well as intercalated kaolin by one-step procedure. The lattice structures of the kaolin were characterized by XRD. The calcined kaolin under 600°C became amorphous structure and were well dispersed in the polyurethane (PU) matrix. The interlayer spacing of intercalated kaolin with potassium acetate shifted from 0.715nm to 1.407nm and were occurred clusters in the PU matrix. FTIR showed that the two kaolin had tiny effect on the structure of the PU and the hydrogen bonding played less role on mechanical performance. The mechanical properties induced by the addition of both of modified kaolin were analyzed. The mechanical properties of the foams with calcined kaolin were better than that with intercalated kaolin. The distribution of modified kaolin were analyzed by TEM. The dispersed particles of calcined kaolin were smaller than that of intercalated kaolin and the dispersion of kaolin played more role on mechanical performance.
Effect of Sodium Periodate Selective Oxidation on Crystallinity of Cotton Cellulose
Authors: Xu Yun Hui , Huang Chen
Published: February 2011

The cotton fiber was oxidized to dialdehyde cellulose by sodium periodate oxidation reaction. The oxidized cotton samples having different oxidation level were obtained with adjusting the periodate concentration and oxidation time. The wide angle X-ray diffraction analysis indicated the crystallinity of the cotton cellulose by the slight oxidation increased, whereas the crystallinity decreased significantly with increase in the degree of oxidation of the cotton cellulose. Differential scanning calorimetric curves of the oxidized samples showed that the slightly oxidized cotton cellulose decomposed at a somewhat higher temperature than the original cotton cellulose in the endothermic decomposition stages up to 350 . However, as the periodate concentration and oxidation time were enhanced further, the endothermic decomposition peak of the oxidized cotton cellulose shifted fast to lower temperature. Furthermore, the changes in the structure and crystallinity were also reflected in the mechanical property studies of these oxidized cellulose samples. The mechanical strength of the cotton thread, which was oxidized by periodate at the concentration of 0.0–1.0 mg/ml and oxidation time for 0–3 h, was found to be almost the same as the original cotton thread, but it decreased remarkably when the oxidation conditions became stronger. These results obtained suggest information in understanding the crystalline structure changes of cellulose in periodate oxidation and planning applications of the oxidized cellulose products.
Characterization and Physical Properties of Chitosan Modified Bamboo Pulp Fiber Fabric
Authors: Liu Xin , Xu Yun Hui , Zhang Wei Wei
Published: February 2011

With science and standard of living progressing, functional textile become more and more popular. We reported that a new bamboo pulp fiber fabric with the chitosan modification (CMBPFF) was prepared by the selective oxidation of sodium periodate and then treatment with a solution of chitosan aqueous acetic acid. The resulting CMBPFF is a nonpolluting and eco-friendly fabric product through the method of natural raw materials and no additives, which not only increase the added value of the product but also achieve natural ecological fabrics. This research using Kjeldahl nitrogen analysis showed that the maximum percentage of chitosan crosslinked on bamboo pulp fiber fabric was 10.52% (w/w). FT-IR spectra characterization suggested that the imine covalent bond between the chitosan and the oxidized bamboo pulp cellulose was formed through a series of reaction. The breaking strength of the modified fabric remained basically unchanged when the concentration of sodium periodate was less than 2.0 mg/ml. Furthermore, the chitosan modified bamboo pulp fiber fabric had the good antibacterial property. The wrinkle recovery angle and moisture regain of the chitosan modified fabric were improved. Meanwhile, a model experiment for the controlled release the drug was investigated using cactus extracts, a component of a Chinese medicine, indicated the extensive applicability of CMBPFF as a carrier for the controlled release drugs.
Effect of Soft Finishing on the Wearability of Fabric
Authors: Yang En Long , Shi Jing Jing
Published: February 2011

For investigating effect of soft finish on the handle of polyester fabric, the study shows physical properties on polyester fabric before and after finishing, then making some comparison base on the test results. KES-F (Kawabata Evaluation System for Fabric) system was used in the test. The study shows that the fabric samples exhibit noticeable improvement on wearable property after soft finish.
Direct Preparation of Activated Carbon from Coal and its Electrochemical Properties for Electric Double Layer Capacitor
Authors: Zheng Ming Dong , Zhang Xiao Yong , Li Ru Chun , Wu Ming Bo , Geng Ye Jing , He Xiao Jun
Published: February 2011

Direct preparation of activated carbon (AC) from coal was reported by microwave heating with potassium hydroxide as activation agent. Electrochemical properties of AC electrodes were investigated by cyclic voltammetry, constant current charge–discharge. The results show that functional groups on AC include –C=O, –O–H and –C–O. The micropore volume of AC from different coal totals 48.5–95.6%. The total pore volume of AC from different coal passes through a maximum with the decrease of volatile mater content in coal. The specific surface area and total pore volume of AC from Qing ting coal reach 1874 m2 g-1 and 1.00 cm3 g-1, respectively. The specific capacitance and energy density of AC from higher coal rank is usually bigger than that of AC from lower coal rank.
Influencing Factors of Modified PVDF Grafted onto a Blended PAMPS(PVDF-G-PAMPS) Membrane
Authors: Xu Jia , Guo Gui Bao , An Sheng Li
Published: February 2011

A proton exchange membrane of blended poly (acrylamido-2- methylpropane sulfonic acid) grafted onto modified poly (vinylidene fluoride) membrane (PVDF-g-PAMPS) was prepared The influences of Na4SiO4 content, reaction temperature and time, content of ammonium persulfate and AMPS on PVDF-g-PAMPS membrane were discussed. The results show that the optimal reaction conditions are as follows: Na4SiO4 is 8%; ammonium persulfate is 0.016 mol / L; AMPS is 30 %; the reaction temperature is 80 °C and the reaction time is 1h. On the condition, PVDF-g-PAMPS membrane conductivity can reach to 1.27×10-2 S/cm.
Effect of Heat-Setting Temperature on the Structure and Performance of Ultra-Fine Denier PET Full Drawing Yarn
Authors: Shen Feng Lei , Chen Guo Qiang , Ding Jiang Zhong , Dai Ju Yan
Published: February 2011

The ultra-fine denier PET full drawing yarn (PET-FDY) with monofilament linear density equal to 0.38dTex was produced. During the practical process of ultrafine denier PET-FDY, the yarn should be heat-set at certain temperature following the drawing process in order to improve the mechanical properties and reduce the boiling water shrinkage. The influence of heat-setting temperature on the structure and performance of ultra-fine denier PET FDY was studied in this paper. With heat-setting temperature increasing, crystalline in PET FDY became perfect and crystallite size became bigger. According to the density method, crystallinity was augmented. Crystal orientation factor and overall orientation factor were both increased. The tenacity and tensile stress at 10% strain of PET FDY were increased and the breakage percentage and boiling water shrinkage were reduced with the heat-setting temperature increasing.
Study on Morphology and Mechanical Properties of Polyaspartic Esters Based Polyureas
Authors: Huang Wei Bo , Lu Ping , Zhang Jing , Li Xin Mao
Published: February 2011

The morphology, shock absorption and dynamic mechanical properties of a new architectured multifunctional materials- polyaspartic esters (PAE) based ployureas were investigated through FTIR, atomic force microscope(AFM), drop-weight test and dynamic mechanical analysis(DMA). The PAE based polyureas were prepared from synthesized PAE and hexamethylene diisocyanate（HDI）trimer /polytetramethylene ether glycol (PTMG) prepolymer. The FTIR results indicated that hydrogen-bonded urea carbonyl of PAE based polyurea was 76.1%, and the length of hydrogen bonding was 0.306nm. The microphase separation phenomenon of the PAE based polyureas were observed directly through AFM topography studies. PAE based polyureas exhibited unique shock absorption and dynamic mechanical properties.
Structure and Properties of Konjac Glucomannan Solved in Alcohol/Water
Authors: Wang Chao , Zhong Xiao Ling , Chen Mao Bin , Li Dong Sheng , Lv Wen Ping
Published: February 2011

The rheological performance of konjac glucomannan (KGM) sol was investigated in alcohol/water solution, and the structure of KGM films were analyzed. The results showed that the dependent relation between the rheological properties and alcohol concentraiton, the viscosity increased with the concentration of alcohol increasing until the inflexion point of 11%. The results of KGM films analyzing indicated that alcohol promoted KGM film partially formed ordered layer arrangement, and the crystallinity gradually increased with the increase of alcohol concentration, then the transmittance and water absorption decrease.
Synthesis of Thermotropic Polyurethanes Containing Biphenylnate and Imide Units and their Mesophase Behavior
Authors: Huang Zhi Yi , Lu Shao Rong , Yang Zhi You , Guo Dong , Luo Chong Xi
Published: February 2011

A series of novel liquid crystal polyurethanes containing biphenylnate and imide units were synthesized through the polyaddition reaction of 4,4′-Bis-(2-hydroxyhexoxy)biphenyl (BP2), 2,4-toluenediisocyanate (2,4-TDI) with N,N′-bis(2-hydroxyhexyl)-dicarboxyimide (BHDI) by altering the molar ratio of BP2 and BHDI. The effects of structure difference molar ratio between BP2 and BHDI on the liquid crystalline behavior and thermal stability were studied. Results showed that all of the polyurethane polymers exhibited thermotropic nematic liquid crystalline textures in the range of 160~190°C. The melting temperatures (Tm) and the thermal stability increased with increasing BHDI content.
Fatigue Behavior Analysis of Cruciform Welded Joints by Infrared Thermographic Method
Authors: Guo Xing Lin , Fan Jun Ling , Zhao Yan Guang
Published: February 2011

Fatigue tests were carried out at different stress levels on cruciform welded joints made from mastensitic stainless steel. The purpose of the present paper was to verify the validity of the thermographic method and to extend its capability on welded structural evaluation, considering the real operating situations. Due to limitations of the traditional fatigue test, the infrared thermographic technique was developed to predict and assess the fatigue limit and the entire S-N (Stress-Life) curve of cruciform welded joints. Through the comparison, the predictions of the fatigue behavior by the thermographic method (TM) manifested good agreement with the traditional method. The present research paper concludes that the TM as a promising method enables us to rapidly obtain reliable fatigue characteristics of welded structural components.
Experimental Investigation of Dilatancy-Bulking Behavior of Weak Sandstone
Authors: Lu Xing Li , Liu Quan Sheng
Published: February 2011

The process of stress-induced fracturing around underground excavations is associated with dilatancy-bulking behavior of the fractured rock. Due to the importance in earth science and engineering design, this paper presents an experimental investigation of rock dilatancy-bulking behavior based on triaxial loading and unloading tests carried out on weak sandstone samples from the Gubei colliery. Through experimental and theoretical analyses, it is found that the volume increase of stress-fractured rock can be divided into two groups: (1) pre-peak dilatancy due to crack opening and propagation, (2) post-peak bulking by the sliding, rotate or detachment of rock blocks. And the post-peak bulking deformation is the main cause of the rock volume expansion. Moreover, the evolution of characteristic stresses and dilation angle show strong pressure dependence, which means that confining pressure strongly inhibits dilatancy-bulking behavior. It also indicates that the rock response under loading and unloading conditions is substantially different.
Investigation into Shear Experiment on Interface between Asphalt Pavement and Concrete Bridge Deck
Authors: Liu Hong Fu , Zheng Jian Long , Qian Guo Ping , Huang Yun Yong
Published: February 2011

This paper describes the laboratory measurement of shear interface properties between asphalt pavement and concrete bridge deck using the shear test. The main factors affecting shear strength are interface frictional resistance and adhesive stress from material of waterproof layer. Firstly, we simplify the whole system by considering the asphalt pavement as an elastic layer and the cement concrete deck a rigid base. And make a sensitivity analysis on interface contact state and the material modulus of waterproof layer. The maximum shear stress increases as interface contact state changes from continuous to smooth and as modulus of waterproof layer material decreases. Secondly, an interface shear experiment is conducted with the application of portable shear apparatus. With interface shear strength as evaluation indicator, shear strength of different interface treatments is arranged in descending order, i.e. cleaning up laitance and spreading aggregate between layers; only cleaning-up laitance; leaving the surface untreated. While the descending order for shear strength of different waterproof materials can be listed as follows: SBS modified asphalt, penetration grade of 70 asphalt. Therefore, based on the laboratory test results, it is recommended that before applying waterproof adhesive layer, laitance and dust on concrete deck surface should be cleaned up and keeping it dry. And the material for waterproof adhesive layer should be SBS modified asphalt with one-size aggregate of 4.75mm-9.5 mm spreading on.
Fatigue Crack Initiation Life Prediction of Backup Roll of Four High Mill
Authors: Tan Wen Feng
Published: February 2011

By using of closed-form solution for predicting fatigue crack initiation life of a beam subjected to the transverse bending load in large range damage， fatigue crack initiation life of backup roll of four high mill is predicted. The method adopted in this paper is simple and effective. A new method is provided for predicting fatigue crack initiation life backup roll of four high mill.
The Impact of Different Dosage of Additives on the UF Resin Used in Plywood
Authors: Wang Wei , Zhu Li Bin , Gu Ji You , Weng Xiang Li , Tan Hai Yan
Published: February 2011

Through the study of the effects of different dosage of additives on the properties of urea formaldehyde resin adhesive prepared at low mole ratio of formaldehyde/urea, optimize the synthetic process of the UF resin which is used at the E0 grade plywood. The results showed that the product synthesized under the following condition: the mole ratio of formaldehyde/urea is 0.99:1, the dosage of the specific additive is 1.0% and that of melamine is 3-4%, had a good comprehensive performance and the formaldehyde emission of the plywood meets the E0 grade which is environmental-friendly.
Surface and Porous Characteristics of Spray Dried Hydroxyapatite Microspheres
Authors: Wang Ai Juan , Li Jun Ming , Jiang Bai Ling , Lv Yu Peng
Published: February 2011

Surface and porous characteristics of spray dried hydroxyapatite microspheres were studied by surface area and pore size analyzer, field-emission scanning electron microscope, Fourier transform infrared spectroscope, etc. The results indicated dehydration did not happened for those samples calcined at 1000°C, and the intensity of OH- absorption bands increased. Hydroxyapatite microspheres were composed of near-spherical crystals with the diameter of 20-50nm. Besides, it was interesting to find that hydroxyapatite crystals formed small aggregate firstly during drying, and then the small aggregate united together and formed particles with spherical structure.
Effects of Temperature and Crack Tip Constraint on Cleavage Fracture Toughness in the Weld Thermal Simulated X80 Pipeline Steels
Authors: Xu Jie , Fan Yu
Published: February 2011

This paper studies the effects of temperature and crack tip constraint on cleavage fracture toughness of the weld thermal simulated X80 pipeline steels. A large number of fracture toughness (as denoted by CTOD) tests together with 3D finite element analysis are performed using single edge notched bending (SENB) and tension (SENT) specimens at different temperatures. Coarse-grained heat-affected zone (CGHAZ) is considered as the material microstructure in preparation of the weld thermal simulated fracture mechanics specimens.
Fatigue Properties of Casting TC4 Alloys Treated by Hot Isostatic Pressing
Authors: Yao Yu Hong , Shangguan Xiao Feng , Liu Jiang Nan , Wang Zheng Pin , Wei Jian Feng
Published: February 2011

With the aircraft structure design criterion from traditional static strength design to damage tolerance design and with the independent research and development of new-type civil turbofan regional aircraft and the implement of the plan to develop the country's own large passenger jets in China, it is essential to do some researches on casting TC4 alloys for the lack of the data of fatigue properties. The detail fatigue rating cut-off (DFRcutoff) values of casting TC4 alloys are measured and calculated by double dots method, the thresholds in fatigue crack propagation and the fatigue crack growth rates at different stress ratios are studied and the fatigue fracture at different stress ratios are observed by scanning electron microscopy. The results show that DFRcutoff value by double-dot method is 375.83 Mpa. The thresholds of fatigue crack propagation decrease with the increase of the stress ratio, whereas the fatigue crack growth rates increase with the increment of the stress ratio and the relationship curves between fatigue crack propagation rates and the stress intensity factor range have been obtained. Moreover, SEM observations indicate that the fatigue trips become wide with the increasing of the stress ratio.
Research of Cement Stabilized Secondary Recycling Materials
Authors: Wu Jian Min , Zong Wei
Published: February 2011

Cold recycling technology has been widely used in road maintenance projects. Many roads which have been reconstructed with cold recycling technology have emerged some diseases after a long-term used. In this condition, these roads can be rebuilt by secondary recycling technology. The microstructure characteristics of secondary recycled road materials after cement stabilizing were observed by SEM; then, material properties after being long-term used and secondary recycled were analyzed. CBR value and aggregate crush value are put forward for the evaluation indexes of secondary recycling. The unconfined compressive strength, splitting strength and modulus of cement stabilized secondary recycling materials are determined by laboratory tests. The results indicate that the existence of asphalt components lead the strength lower than ordinary base materials stabilized by cement. And temperature exerts an obviously influence on the compressive strength. Frost resistance, water stability and anti-erosion resistance are also determined by laboratory tests. The results indicate that the strength and pavement performance of cement secondary recycling materials can meet the requirements for base and sub base in asphalt pavement.
Effect of HCO3Concentration on CO2 Corrosion for Q235 Steel
Authors: Wei Ai Jun , Huo Fu Yong , Jiang Hua Yi
Published: February 2011

The effects of HCO3- concentration on CO2 corrosion for Q235 steel were investigated by weight loss tests and potentiodynamic polarization curve and EIS (Electrochemical Impedance Spectroscopy) techniques. The results showed that the corrosion rate of Q235 steel decreased wih on increase of HCO3- concentration when [HCO3-] was lower than 600mg/L. An evident active-passive behavior exhibited in anodic process at 1000mg/L·HCO3- .The cathodic reactions were promoted by increasing [HCO3-] when it reached 1000mg/L, H2CO3 and HCO3- become the most important cathodic reaction. Anodic behavior was an active process at higher [HCO3-] concentration and the anodic current density increased with the increase of [HCO3-] concentration.
Preparation and Gas-Sensing Property of Coppertetra-Iso-Propoxyphthalocyanine Spin-Coating Film
Authors: Li Qiang , Huo Li Hua , Gao Shan , Qi Xiao Juan , Zhao Hui
Published: February 2011

The thin films of copper 2, 9, 16, 23-tetra-iso-propoxy phthalocyanine (i-pro-CuPc) were prepared by spin-coating technique. The surface morphology and spectroscopy property of the thin films were characterized by AFM, UV-Vis and FT-IR spectra. The results show that good films can be obtained under certain spinning speed. The gas-sensing properties of the multilayers to three alcohols gas were measured at room temperature. The spin-coating thin films exhibited high sensitivity and rapid response- recovery characteristics to these gases. The response and recovery time of the thin films to 30*10-6 v/v of C2H5OH vapor is only 28 s and 55 s, respectively.
Influence of Metal Electrode(Ag,Au,Pt) on the Dielectric and Electrical Properties of HfTaO Capacitors
Authors: Yu Tao , Wu Xue Mei , Zhuge Lan Jian
Published: February 2011

HfTaO-based MOS capacitors with different top electrode (Ag、Au、Pt) were successfully fabricated by dual ion beam sputtering deposition (DIBSD). We presented the effect of different metal gate on the capacity, flat band voltage shift, leakage current and conduction mechanism. It has been found that the Pt-electrode capacitor exhibited the highest accumulation capacitance. In addition, the largest hysteresis loop in Pt/HfTaO/Si capacitor during the forward-and-reverse voltage sweeping from +2.5V to -2.5V was observed. The result indicates the presence of a large amount of fixed charges or oxygen vacancies exist in interface Pt/HfTaO, which is consistent with the prediction from Qf results. It is proved that even though Eot of the Pt-electrode capacitor is lower than that of the Ag, Au-electroded, and that of leakage current still has the smallest value at a high electric field due to Pt with a high enough work function Φms(Pt)=5.65eV.
Effects of Ca2+ Concentration on Calcium Carbonate Crystallization in Egg White Protein Solution
Authors: Zhu Wen Kun , Luo Xue Gang , Lin Xiao Yan , He Jing
Published: February 2011

The calcium carbonate crystallization were controlled by Ca2+ concentration in the 10% (V/V) egg white protein solution and the morphology, structure and thermal decomposition of which were characterized by FT-IR, SEM, XRD and TG. The results showed in egg white protein solution system, concentration of Ca2+ had significant effects on the crystallized morphology, orientation and crystallinity of calcium carbonate. Calcium carbonate particles have more uniformed calcite and vaterite mixed crystallization in low Ca2+ concentration while calcium carbonate tends to form mixed particle sizes and more complete calcite crystallization in high Ca2+ concentration.
Influence of Sintering Temperature on the Electrical Properties of (La, Ta)-Doped TiO2 Capacitor-Varistor Ceramics
Authors: Qin Qun , Wang Tian Guo , Zhang Wen Jun
Published: February 2011

An investigation was made of low voltage TiO2 varistors doped with Ta2O5 and La2O3. TiO2 ceramics doped with 0.7 mol% La2O3 and 0.1 mol% Ta2O5 were sintered at different temperature ranging from 1350 to 1450°С . The influence of sintering temperature on microstructure and nonlinear properties of the (La, Ta)-doped TiO2 ceramics was studied. The varistor of 99.2 mol%-0.7 mol%La2O3-0.1 mol% Ta2O5 composite sintered at 1380°С has a maximal nonlinear coefficient of α =5.2 and a low breakdown voltage of 7.6 V/mm, which is consistent with its highest grain-boundary barriers. According to these results, it is suggested that the sample sintered at 1380°С forms the most efficient boundary barrier layer. Therefore, the sintering temperature is a very important varible which should not be despised in the project of TiO2 based varistors production.
Dielectric Properties of La, Sm Ion-Doped BZT-Based Ceramics
Authors: Zheng Zhan Shen , Li Rui Jiao , Yan Pei Qi , Hu Hong Kui , Li Yuan Liang , Hao Li Jing
Published: February 2011

It is important to develop a new special material to satisfy the requirement of producing capacitor with higher property. BZT(Ba(ZrxTi1-x)O3) ceramics of La2O3 and Sm2O3 doped was fabricated by the conventional method of solid reaction. These ceramics were tested by X-ray diffraction (XRD), Impedance Tester, and LCR Tester with temperature controlling systems. The results indicate that dielectric property of BZT ceramics doped 0.05mol% La2O3, 0.2mol% Sm2O3 simultaneously and calcined in 1280°C is the best. Moreover, it was found that Sm2O3 had the functions of moving Tc of matrix material to a low temperature and making the peak wider.
The Comparison of Magnetic Leakage of Different Teeth Structures in Magnetic Fluid Seal
Authors: Xing Fei Fei , Li De Cai , Yang Wen Ming , Yang Xiao Long
Published: February 2011

Based on the theoretical model, magnetic field distribution of rectangular teeth, two-sides dilated shape and one-side dilated shape teeth structure with common other conditions were calculated using finite element method when the sealing gap was 0.1mm and 0.12mm. The comparison of their results with the same sealing gap showed that rectangular teeth structure had the highest magnetic leakage. Moreover, the magnetic field distribution of sealing structures with rectangular stages on both the shaft and pole pieces under the same design and sealing gap were also calculated using the same method, whose result was compared with rectangular stages on pole pieces only. The comparison showed that the former did not have higher pressure capability obviously but led to higher magnetic leakage.
Syntheses and Properties of an Unsymmetrical Photochromic Diarylethene with a Methoxy Group
Authors: Jiang Duo Hua , Pu Shou Zhi , Liu Wei Jun , Yan Pei Jian , Liu Ming
Published: February 2011

A novel unsymmetrical diarylethene derivative bearing both phenyl and thiophene moieties, in which a trifluoromethyl group was substituted at the meta-positions of the terminal phenyl ring, was synthesized. At the same time, its photochromic properties and fluorescence switch were investigated in detail. The results showed that this compound exhibited reversible photochromism, undergoing reversible cyclization and cycloreversion reactions upon alternating irradiation with UV and visible light both in solution and in PMMA film, and its absorption maxima were observed at 584 nm in hexane and at 593 nm in PMMA amorphous film, respectively, upon irradiation with 297 nm UV light. The fluorescence intensity of diarylethene decreased dramatically along with the photochromism from open-ring isomer to closed-ring isomer upon irradiation with 297 nm UV light in PMMA. In hexane solution, the open-ring isomer of the diarylethene 1 exhibited relatively strong fluorescence at 420 nm when excited at 322 nm.
Synthesis, Photochromism and Application of a Novel Diarylethene Bearing a Thiazole Unit
Authors: Wang Ren Jie , Xia Hong Ying , Pu Shou Zhi
Published: February 2011

A new photochromic diarylethene compound 1-(2, 4-dimethyl-thiazole-3-yl)-2- [2-methyl -5-(3-cyanophenyl)-3-thienyl]perfluorocyclopentene 1a was synthesized and its photochromic properties, such as phoochromism, fluorescence switch and optical recording were investigated detail. The result showed that this diarylethene compound showed good reversible photochromism. Upon irradiated UV light it changes from colorless to orange both in solution and in PMMA amorphous film. In addition, the fluorescence spectra of diarylethene 1a were nearly quenched with the concentration increased. Finally, using diarylethene 1c as recording medium, polarization optical recording was carried out successfully.
A Novel Chelating Resin, Polystyrene-Supported Glucosamine: Preparation and Adsorption Properties for Ag(Ⅰ)
Authors: Huang Hai Lan , Wang Guo Ming , Qu Rong Jun , Bo Xu
Published: February 2011

A novel chelating resin, crosslinking polystyrene-supported glucosamine (PS-GA), was prepared and its static adsorption properties for Ag(Ⅰ) were studied. The results indicated that this resin had excellent adsorption capacity for Ag(Ⅰ). The adsorption dynamics indicated that adsorption was controlled by the liquid film diffusion and the apparent activation energy Ea was 11.83 kJ/mol. Both Langmuir model and Freundlich model could describe the adsorption isothermal process of Ag(Ⅰ), and ∆G, ∆H, ∆S values were calculated. Increasing the temperature was beneficial to adsorption. The chelating resin can be easily regenerated by 2% thiourea in 0.1 mol/L HNO3 with higher effectiveness. Five adsorption–desorption cycles demonstrated that this resin was suitable for repeated use without considerable change in adsorption capacity.
First-Principles Calculations on Structural, Electronic, and Optical Properties of 2H-CuAlO2
Authors: Feng Li Ping , Liu Zheng Tang , Liu Qi Jun
Published: February 2011

Structural, electronic and optical properties of 2H-CuAlO2 were computed, using the plane-wave ultrasoft pseudopotential technique based on the first-principles density functional theory (DFT). The equilibrium lattice parameters, band structure, densities of states (DOS) and charge densities of 2H-CuAlO2 have been obtained. The equilibrium lattice parameters, band structure and DOS are found to be in good agreement with the available experimental and calculational values. The charge densities and the chemical bonding of 2H-CuAlO2 are analyzed, which show that bonding between Cu and O is mainly covalent due to Cu 3d and O 2p hybridization and that bonding between Al and O is mainly ionic. The complex dielectric function, refractive index and absorption coefficient of 2H-CuAlO2 have been predicted. The calculated static dielectric constant and static refractive index of 2H-CuAlO2 is 7.1 and 2.66, respectively.
Characteristics of Intergrown Superlattice Bismuth-Layered-Structure Ferroelectrics Thin Films Prepared by Sol-Gel Method
Authors: Wang Hua , Li Jian , Xu Ji Wen , Yang Ling , Ren Ming Fang
Published: February 2011

Intergrown superlattice Bi3TiNbO9–Bi4Ti3O12 (BTN–BIT) and SrBi4Ti4O15–Bi4Ti3O12 (SBT–BIT) ferroelectric thin films have been prepared on p-Si substrates by sol-gel processing. The precursor thin films are crystallized in the desired intergrown superlattice BTN–BIT and SBT–BIT structures annealed at 700°C. Synthesized BTN–BIT and SBT-BIT thin films exhibited good ferroelectric properties and excellence fatigue endurance. BTN–BIT thin films showed a Pr value approximately 19.1µC/cm2 and a memory window of 0.7V. Although a little smaller Pr value and memory window were observed for the SBT–BIT thin films, the squareness of a P–E hysteresis loop was superior to that of BTN–BIT thin films. Also, the SBT–BIT thin films had more excellence fatigue endurance compared with BTN–BIT thin films.
Electroless Plating of Silver on Microorganism Cells
Authors: Lan Ming Ming , Zhang De Yuan , Cai Jun , Zhang Wen Qiang , Li Hai Yang
Published: February 2011

In this paper, microorganism cells (Spirulina platens) were used as forming templates for the fabrication of the helical functional particles with standard shape by electroless silver plating method. The cell form, components and the dielectric properties were observed and analyzed using various tools including optical microscopy, scanning electron microscopy (SEM), energy dispersive spectrometer (EDS) and vector network analyzer. The results indicate that the silver coatings on the surfaces of spirulina platensis cells are continuous and compact. The coating thickness of the cells increases with increasing plating time and load, in turn resulting in the increase of the dielectric constant. Furthermore, when the coating thickness is larger than 0.42μm, the samples exhibit significantly percolation phenomenon, indicating that the cells deposited silver form conductive network or electron tunneling in the composites.
The Effect of Lubricant on Tribological Properties of Carbonyl Iron-Based Magnetorheological Fluids
Authors: Hu Zhi De , Yan Hua , Wang Xue Mei , Qiu Hai Zhe
Published: February 2011

Magnetorheological fluid (MRF) is a new kind of smart material, it is very necessary for us to study its tribological properties because it will be widely used in engineering application. In this paper, the tribological behavior of Carbonyl Iron-based magnetorheological fluid (MRF) was investigated on a four-ball tribological tester, the influence of lubricant on friction coefficient and wear scar diameter was discussed, the morphology of the wear steel surfaces lubricated with MRF were observed by a scanning electron microscope. The results show that the addition of MoS2 can significantly improve the tribological properties of clay-based MRF. However, the friction and wear properties of silica-based MRF become bad after the addition of MoS2. The morphology of worn surface lubricated with the MRF added MoS2 is similar to that without additive, but the groove of wear marks lubricated with clay-based MRF is more shallower and the area of the worn surface is smaller in the condition of adding MoS2.
Compressive Properties of Hot-Rolled Mg-Zr-Ca Alloys for Biomedical Applications
Authors: Zhou Ying Long , Luo Dong Mei , Hu Wang Yu , Li Yun Cang , Hodgson Peter D. , Wen Cui E
Published: February 2011

This paper investigated the microstructures and compressive properties of hot-rolled Mg-Zr-Ca alloys for biomedical applications. The microstructures of the Mg-Zr-Ca alloys were examined by X-ray diffraction analysis and optical microscopy, and the compressive properties were determined from compressive tests. The experimental results indicate that the hot-rolled Mg-Zr-Ca alloys with 1% Ca are composed of one single a phase and those alloys with 2% Ca consist of both Mg2Ca and a phase. The hot-rolled Mg-Zr-Ca alloys exhibit typical elongated microstructures with obvious fibrous stripe, and have much higher compressive strength and lower compressive modulus than pure Mg. All the studied alloys have much higher compressive yield strength than the human bone (90~140 MPa) and comparable modulus with the human bone, suggesting that they have a great potential to be good candidates for biomedical applications.
Study on the Chemical Modification of the Walls of Carbon Nanotubes by K2Cr2O7 and HNO3
Authors: Wang Min Wei , Wang Jian , Qu Jia Wei
Published: February 2011

CNTs was opened and surface modified by K2Cr2O7 and HNO3. The ratio of CNTs weight loss was used to show the effect of oxidation and the morphologies of CNTs was observed by TEM and IR. The results showed that the concentration of K2Cr2O7, oxidation temperature and oxidation time all affected the oxidation results. Among these three factors, oxidation temperature produced the largest effect; As the CNTs was oxidized, the wall of CNTs was corroded firstly and made the wall of CNTs thinner, then the curved-site of CNTs was attacked by oxidant and made the CNTs break in several section. So the solution would enter into the cavity of CNTs. Hydrophilic groups would be introduced in the inner and outer surface of CNTs with the oxidation reaction continuing. It would be good to the compatibility of CNTs with other materials.