bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis, Characterization, and Microwave Absorption Properties of SrFe12O19 Ferrites and FeNi3 Nanoplatelets Composites
Authors: Zhang Ze Yang , Liu Xiang Xuan , Wu You Peng
Published: November 2010

M-typical SrFe12O19 ferrites and FeNi3 nanoplatelets were successfully prepared by the sol-gel method and solution phase reduction method, respectively. The crystalline and morphology of particles were studied by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The composite coatings with SrFe12O19 ferrites and FeNi3 nanoplatelets in polyvinylchloride matrix were prepared. The microwave absorption properties of these coatings were investigated in 2-18GHz frequency range. The results showed that the M-typical SrFe12O19 ferrites and FeNi3 nanoplatelets were obtained and they presented irregular sheet shapes. With the increase of the coating thickness, the absorbing peak value moves to the lower frequency. The absorbing peak values of the wave increase along with the increasing of the content of FeNi3 nanoplatelets filling fraction. When 40% SrFe12O19 ferrites is doped with 20% mass fraction FeNi3 nanoplatelets to prepare composite with 1.5mm thickness, the maximum reflection loss is -24.8 dB at 7.9GHz and the -10 dB bandwidth reaches 3.2GHz.
The Application and Development of Intelligentized Concrete
Authors: Shi Yang Hang , Wu Chong , Wu Ze Jin
Published: November 2010

Intelligentization is the development direction of functional materials and the intelligentized concrete is the advanced stage of the development of concrete, which is the product of the intelligentized era. This paper aims at explaining the background of the intelligentized concrete, briefly describing the state of the field and the hot spot issue of three kinds of intelligentized concrete which is of unitary function, and looking forward to the development trends and prospects of the Intelligentized concrete.
Intelligent Control and Simulation of Piezoelectric Smart Plate
Authors: Wang Xiu Mei , Wang Ju Zheng , Zhu Xiao Jin
Published: November 2010

Active vibration control based on fuzzy algorithm for piezoelectric smart plate is studied. After the characteristic of piezoelectric ceramic (PZT) is analyzed, modal and transient analysis are developed in this paper with finite element model of the piezoelectric smart plate constructed in ANSYS. Fuzzy logic control rules are established by the analysis of the deformation of the plate. With mode shape and displacement response curve obtained, active vibration suppression for the smart plate system is achieved by using commercial finite element programs. The simulation results illustrate that analysis of piezoelectric smart plate using ANSYS is practicable and the intelligent control method is effective.
Nitrogen-Incorporated NaY Zeolite as Promising Basic Microporous Catalytic Material
Authors: Wang Tao , Li Lan Dong , Wu Guang Jun , Guan Nai Jia
Published: November 2010

A promising basic microporous catalytic material is prepared by nitridation of dehydrated NaY zeolite. The base strength of zeolite framework is enhanced due to the replacement of oxygen by nitrogen with lower electronegativity. Various characterization methods, including XRD, CHN elemental analysis, SEM and FTIR spectra of CO adsorption, are employed to analyze the physico-chemical properties of the nitrogen-incorporated NaY zeolite. High crystallinity and high specific surface areas of NaY are well preserved in nitrogen-incorporated NaY. Compared to parent NaY zeolite, the nitridized materials exhibit improved basic catalytic performances in Knoevenagel condensation reaction and side-chain monomethylation reaction of phenylacetonitrile.
Preparation and Field Emission Properties of Ag-CNTs by Electroless Plating
Authors: You Yu Xiang , Ye Yun , Su Yi Jing , Tang Qiao Zhi , Guo Tai Liang
Published: November 2010

Carbon nanotubes (CNTs) demonstrate attractive characteristics as cold cathode emitters for high aspect ratio, small radius of curvature, high mechanical strength and chemical stability. In this article, Ag-CNTs were prepared by a series of processes including acid-treating, sensitizing, activating and electroless plating. Then Ag-CNTs cathode were sucessfully fabricated by electrophoresis deposition (EPD) method. The morphologies of Ag-CNTs cathode and pristine CNTs cathode were observed by scanning electron microscopy (SEM). The results showed that the field emission properties of Ag-CNTs cathode were better than pristine CNTs cathode, for presenting lower turn-on field, larger emission current density, more stabilization and longer lifetime. Thus it can be seen that the Ag-CNTs cathode can improve the characteristics of carbon nanotubes field emission display (CNT-FED).
The Study of Several UV Curable Polyurethane Acrylates
Authors: Zhong Ying Li , Yang Xin , Zhou Wu Yi , Zhu Qi Ping , Yang Zhuo Hong
Published: November 2010

In this paper, several UV curable polyurethane acrylates were synthesized by using isophorone diisocyanate(IPDI), polyethylene glycol(PEG) , Dipropylene Glycol Diacrylate (DPGDA), trimethylolpropane triacrylate (TMPTA), and hydroxyethyl acrylate(HEA) as the raw materials and dibutyltin dilaurate(DBTDL) as the catalyst. The structure was confirmed by the Fourier transform infrared spectroscopy (FTIR). The characterization showed the coatings have a good property.
Experimental Study on Flexural Strength of Polyvinyl Alcohol (PVA) Fiber Reinforced Cementitious Composites
Authors: Liu Shu Guang , He Cun , Yan Chang Wang , Jiang Hai Jun
Published: November 2010

Flexural strength of cementitious composites containing polyvinyl alcohol (PVA) fiber, fly ash (FA) and silica fume (SF) is studied in this paper. The parameters studied include volume fraction of fiber, the substitution ratio of cement by fly ash and the substitution ratio of cement by both silica fume and fly ash, which have an influence on the compressive strength and flexural strength of cementitious composites. The research findings show that with the increase of volume fraction of fiber, the flexural strength of cementitious composites are improved .When the volume fraction of fiber rises from 0 to 2% ,the flexural strength increases by 51.8%. When the volume fraction of fiber remains 2%, cement substitution with fly ash reduces the flexural strength of cementitious Composites, while which is improved by cement substitution with both silica fume and fly ash.
Prediction of the Strength Development of Fly Ash Concrete
Authors: Liu Ming Hui , Wang Yuan Feng
Published: November 2010

The effect of fly ash in improving the mechanical properties of concrete is investigated and the existing concrete strength development models are studied. Based on the chemic reactivity properties between fly ash and cement, an appropriate concrete strength model are chosen, and a new model for the fly ash strength factor combing Maturity method is built up and the factors are regressed by existing experimental datum. A total of 24 concretes, including two concretes were produced with two partial fly ash replacement ratios (23.7%, 32.7%). The cubic samples produced from ash fly concrete were demoulded after a day, and cured at standard temperature ( in GB/T 50081-2002) with 100% relative humidity until 28 days, then cured in water. The compressive strength tests were carried out on the cubic specimens at different ages. The compressive strength with time was evaluated by using the new predicted model. It was found that the calculated results by new method are fit the experimental data well.
Morphological Properties of Poly(Trimethylene Terephthalate)/Maleated Styrene-Butylene-Co-Ethylene-Styrene/Organoclay Ternary Nanocomposite
Authors: Wang Kun Yan , Tang Pei Song , Cao Feng
Published: November 2010

PTT/SEBS-g-MA/organoclay ternary nanocomposites were successfully prepared using melt blending. The effect of organoclay platelets on morphologies properties of PTT/SEBS-g-MA/organoclay ternary nanocomposites had been studied by XRD and SEM. The nanocomposite forms an exfoliated structure, which can be observed by XRD. The dispersed domain size (D) of SEBS-g-MA is affected by organoclay. The high aspect ratio of the organoclay platelets induced the average size of the dispersed domain to become smaller.
Study and Application on Quick Repair Materials for Concrete Pavement
Authors: Wang Ling , Li Fan , Tian Wen Ling , Chen Pei
Published: November 2010

In combination with the property of the freeze-thaw damage of Qinhuangdao concrete pavement，polymer modified cement mortars were developed through the system's mechanical properties and durability compared laboratory tests; On this basis,the mechanics performance of the polymer emulsion and the bonding tension performance of the new-old concrete are studied; The construction techniques were provided and they have been applied in the projects of Qinhuangdao concrete pavement, and through experiments road more than one year of test result to indicate that they have received good economical and social effects.
Microstructure and Thermal Properties of Diamond-Al Composite Fabricated by Pressureless Metal Infiltration
Authors: Cui Yan , Xu Song Bo , Zhang Lei , Guo Shun
Published: November 2010

For obtaining materials with high thermal conductivities and suitable thermal expansion coefficient for thermal management applications, diamond/Al composites were fabricated by the low-cost pressureless metal infiltration. The resulting composites exhibited thermal conductivities as high as 518.7 W/m•K and thermal expansion coefficient as low as 4.61×10-6/K friendly matching with semiconductors materials like Si or GaAs. The diamond particles were not only well embedded, but also uniformly distributed in the metallic matrix along with SEM observations of the composites. Fractograph of the composites illustrated that aluminum matrix fracture was the dominant fracture mechanism and the stepped breakage of diamond particles indicated strong interfacial bonding between diamond and the Al matrix. The Si skeleton with coralline morphology in the interface between diamond and the matrix were found to play a role of bridge in the interfacial structure and result in distinctive interfacial bonding. Also a little content of Al4C3 were realized to have positive effect on the improved thermal conductivities for promoting interfacial bonding between aluminum and diamond. In addition, the excellent mechanical behavior of the composite was illustrated. The results shows a superior Young’s modulus of 286 GPa compared with traditional thermal management materials and relatively high bending strength of 306MPa.
Properties of Particleboard Manufactured with Modified Urea-Formaldehyde Resin
Authors: Zhang Ji Zhi , Li Jian Zhang , Zhang Shi Feng
Published: November 2010

This study modified urea-formaldehyde (UF) resin with a modifier, and focused on properties of particleboard manufactured with the modified UF resin. The orthogonal design was used to analyze the effects of different levels of hot-pressing temperature, hot-pressing time, glue content, and waterproof agent content on the modulus of rupture (MOR), internal bonding strength (IB), and formaldehyde emission (FE) of the particleboard, and thus determined the optimum technical parameters of hot-pressing. The conclusions were as follows: (1) the modifier used in this study could significantly reduce the free formaldehyde content of UF resin and the formaldehyde emission of particleboard; (2) the optimum hot-pressing technical parameters of particleboard manufactured with the modified UF resin were hot-pressing temperature 180°C, hot-pressing time 50s/mm, glue content 12%, and waterproof agent content 0.6%. The MOR and IB under the optimum technical parameters could reach 20.7 and 0.47 MPa, and the FE was 0.85 mg/L.
Effect of Silane Concentrations on Mode I Interlaminar Fracture of Woven Silk/Epoxy Composites
Authors: R. Zulkifli , Azhari Che Husna
Published: November 2010

The aim of the project is to study the effect of silane concentrations on the interlaminar fracture toughness, GIC of silk/epoxy composites. Woven silk fibre has been treated with five different silane concentrations and fabricated into a panel with two layers of silk fibre. The processing technique used to prepare the sample is by a vacuum bag in an autoclave. Six sets of panels were fabricated based on different 3-aminopropyl triethoxysilane silane concentrations which include one sets of specimens without treatment for comparison. Mode I test based on double cantilever beam specimens (DCB) method has been used over all the specimens. The results of the GIC were plotted and compared with the untreated composites panel. GIC of the composite has been found to increase when the silane concentrations exceeded certain minimum silane contents of 15 ml. During the test, crack propagation is stable and no fibre bridging occurred between both sides of fracture surfaces. All the failure that occurred were at the fibre-matrix interface. The GIC of woven silk/epoxy composites can be enhanced by surface treatment using coupling agent. Surface treatment has affected the properties of the composite panel by increasing the interlaminar fracture toughness by a maximum of 53% at a 5.8vol% silane concentrations.
Technology of Processing Mineral Superfine Powder Used in High Performance Concrete by DHM Grinder and its Characteristics
Authors: Xu Xia , Ding Hao , Liang Ning , Wang Bai Kun , Zhang Xiao Jing
Published: November 2010

In this paper, the requirements for processing equipments and technologies of mineral superfine powder used in HPC are analyzed. Mechanism and properties of DHM grinder and processing natural zeolite, slag and fly ash by DHM-160 grinder are investigated. Natural zeolite and slag achieve the fineness that 90% of which are smaller than 0.038 mm by DHM grinder. 99% of fly ash processed by it is smaller than 0.038 mm and 45% of that is smaller than 10 μm. Superfine powder processed by DHM grinder can meet the requirement of HPC, and its energy consumption is lower than using conventional equipments.
Quantum Chemical Calculation of Propylene Oxide Ring-Opening Esterification
Authors: Zhang Ming , Huang Wen Chao , Qin Yan , Huang Zhi Xiong
Published: November 2010

The reaction of Propylene oxide(PO) ring-opening esterification was calculated by Gaussian03. The Density Function Theory (DFT) method was employed to study the geometries of PO and Maleic anhydride(MAH) reaction product obtained with the ethanol induced on the base of B3LYP/6-31G in the paper. The transitional states(Ts1,Ts2) of PO ring-opening esterification were found by TS method and were proved by IRC calculation. The results showed that from the reactant to product, the energy reduced about 799.07093 kJ/mol, The computation result showed that the reaction was exothermic.
Characterization and Photocatalytic Properties of Porous BiVO4-SiO2 Composites
Authors: Zhang Yu Dong , Su Xun Jia , Hou Gen Liang , Bi Song , Guo Feng , Mei Zhen Xing
Published: November 2010

Visible-light-induced BiVO4-SiO2 composites photocatalysts with monoclinic scheelite structure were successfully synthesized via a sol-gel method, and were characterized with XRD, XPS, DRS, SEM and BET. The result indicated that BiVO4-SiO2 composite photocatalysts exhibited relatively high BET surface areas, consisting of primary nanocrystals with average size of 44 nm. The band gap of the sample was estimated to be 2.56 eV, representing an obvious blue-shift compared with that of the SSR-BiVO4 sample. The photocatalytic activities were also evaluated by decolorization of methylene blue (MB) under blue light. The photodegradation rate of BiVO4-SiO2 composite photocatalysts was quite high, up to 69% in 2 h, which was much better than that of the reference sample prepared by solid-state reaction (5.5%) under the same conditions.
First Principles Calculations of Optical Properties of Cu3N and Cu4N
Authors: Niu Jian Gang , Gao Wei , Dong Xiao Ping , Guan Li , Xie Fei
Published: November 2010

First-principles calculations were performed to study the electronic and optical properties of Cu3N and Cu4N. The calculated density of states show that Cu3N is a semiconductor with a 0.5ev gap while Cu4N is metallic. The dielectric functions, absorption coefficients, refractive coefficients and extinction coefficients of Cu3N and Cu4N were obtained and compared with some experiment results. It shows the calculated results agree well with the experimental values.
Shear Reinforcement of Air Plasma for GFRP-Wood Composite
Authors: Xiong Yu Lin , Gu Ji You , Hu Ying Cheng
Published: November 2010

A study of the effect of air corona plasma treatment on the surface of GFRP (glass-fiber reinforced polymers) has been carried out. The aim is to alter the surface in a manner and scale resulting in stronger shear strength between GFRP and wood. The specimens are exposed to air corona discharge with the irradiation time and power being variables. Goniometry is employed to determine the contact angle of GFRP surface. The results show that the plasma treatment leads to the surface contact angle decreasing significantly. The shear strength of shear test specimens using isocyanate adhesive is stronger than that of specimens using epoxy adhesive. The interface of the GFRP-wood composites is also studied by using Fourier transform infrared spectroscopic (FTIR).
Analysis on the Microstructure Characteristics of Steel-Slag Based Ceramics
Authors: Bai Hao , Liu Pu , Ai Xian Bin , Zhao Li Hua , Tang Qi , Zheng Shu Long
Published: November 2010

As by-product of steeling making, steel slag accounts for 10% to 13% of steel production. Utilization of it as resource has been tried in many fields. For example, it can be used as building materials, most for paving and backfilling. However, utilization level of steel slag is still low, and to find a novel way to utilize steel slag efficiently is urgent. Steel slag includes much calcium and silicon, similar to those of clay, which means that it can be one of the raw materials for ceramic sintering. In this research, the process of steel-slag based ceramics sintering was developed. The ceramic tiles with excellent performance were obtained, with up to 36% steel slag added. By EPMA, the possible crystal phases that exist in the ceramic samples have been discussed. By XRD analysis, the main crystal phases of steel slag ceramics were identified, which are anorthite, α-quartz and magnetite. The clinoenstatite can be obtained through increasing the proportion of steel slag in the formula. The diopside can be obtained if the talc was added. These are key factors to obtain excellent performance ceramic tiles under low sintering temperature.
Toughening of Thermosetting Resins with Thermoplastic Polyimide: Thermal, Morphological, and Mechanical Characterization
Authors: Wang Da Ming , Zhao Xiao Gang , Jia He , Yu Xiao Hui , Li Qing Ming , Wang Li Na , Zhou Hong Wei , Dang Guo Dong , Chen Chun Hai
Published: November 2010

Synthesize a thermoplastic polyimide (TP-PI) by 4, 4’-Bisphenol A dianhydride (BPADA) and 4, 4’-diaminodiphenyl ether(ODA) to toughen thermosetting polyimide(TS-PI) of BPADA and 3-aminophenylacetylene (APA) system. Improve the toughness of matrix resin by control morphology of blends. The results show that the system has been phase separation, TP-PI as a continuous phase, blends is part miscibility or immiscibility. Compose materials anysis show that the adhesion of resin and fiber have been improved, toughness of resin-based composite materials has been improved at the same time without sacrificing original thermal properties and modulus.
Monte Carlo Simulation of Magnetic Properties of Multilayer with Amorphous Surfaces
Authors: Feng Qian , Huang Zhi Gao , Du You Wei
Published: November 2010

Monte Carlo simulation studies are performed to examine the effects of amorphous surfaces and the size of the system on magnetic critical properties of a face-centered cubic magnet modeled with a Heisenberg Hamiltonian. A Gaussian probability distribution of the exchange integrals is applied for the description of amorphous surfaces. The Spontaneous magnetization and magnetic susceptibility are calculated for both the inner and surface. A variety of phase diagrams have been also obtained. The simulated results can well explain the experimental facts.
Effect of Arc Discharge on Friction and Wear Behaviors of Stainless Steel/Copper-Impregnated Metalized Carbon Couple under Electric Current
Authors: Ding Tao , Chen Guang Xiong , Shen Ming Xue , Zhu Min Hao , Zhang Wei Hua
Published: November 2010

Friction and wear tests of stainless steel rubbing against copper-impregnated metalized carbon with electric current were carried on the pin-on-disc tester. The result indicates that arc discharge occurs in the process of experiments, and the intensity of arc discharge of interface increases with increasing of electric current and sliding velocity. As increasing of the arc discharge intensity, friction coefficient shows a tendency of slightly increase. While the rate of copper-impregnated metalized carbon material increase significantly with the increase of arc discharge intensity. Through observing the worn surface morphology of pin samples, it is found that the abrasive wear is dominant at small arc discharge due to worn particles and arc ablation craters, but arc erosion and oxidation wear are the main wear mechanisms in condition of large arc discharge due to arc discharge and its producing high temperature. The materials transfer of contact couple occurs in the process of friction and wear.
Experimental Study on Effects of Temperature on Characteristic Parameters of CFRP-Confined Concrete Prisms
Authors: Zhang Yan , Xu Zhi Sheng
Published: November 2010

The stress-strain model of concrete prism after high temperature confined by CFRP is scarce, which gives great trouble to the study of mechanical properties of compressed concrete member after fire strengthened by CFRP. This paper presents the results of an experimental study on effects of temperature on characteristic parameters of CFRP-wrapped concrete prisms at elevated temperature. Experimental results indicate that strength and ductility of CFRP-confined concrete prism after high temperature have a large certain extent increase as the result of the action of CFRP. The results reveal that transitional stress, transitional strain, ultimate stress and ultimate strain are related to width of CFRP strip, the greatest temperature, corner radius and layers of CFRP. This has established reliable foundation for the accurate calculation of concrete structures strengthened by CFRP after high temperature or post fire.
Study on the Processing Technology of Bamboo Mat/Bamboo Particle Composite Board
Authors: Li Xin Gong , Hu Nan , Wu Yi Qiang
Published: November 2010

Small diameter bamboo and bamboo processing residues were cut into particles; bamboo particles and bamboo mat were constructed into a composite mat; the composite mat was hot-pressed to form a composite board. A study was made of the hot-pressing process for bamboo mat bamboo particle composite boards, taking its hot-pressing time, hot-pressing temperature and glue consumption as the process variables. An analysis of the variance and regression of the test results shows that, among the three variables, glue consumption has the largest effect on every quality index of the product, hot-pressing time has less, and hot-pressing temperature has the least. Based on this, the optimal variables have been determined.Hot-pressing time is 70s/mm, hot-pressing temperature is 170 , and glue consumption is 12%. Prediction and verification of the variables show that these variables are reasonable and helpful in bettering product quality. Advantage of the presented technology was to make full use of character of bamboo mat and bamboo particle, and to raise the rate of bamboo utilization.
Thermo-Physical Properties of Copper Matrix Composites Reinforced with 3D-SiC Network
Authors: Xing Hong Wei , Zhang Jin Song , Cao Xiao Ming
Published: November 2010

Copper matrix composites reinforced with 3D-SiC network (15v% and 20v% SiC) were fabricated by squeezing copper alloy into 3D-SiC network preforms. The thermo-physical properties of the copper matrix composites were investigated. The specific heat capacities of the composites were about 0.39~0.50 J•g-1•K-1. The coefficients of thermal expansion (CTEs) of the composites were found to be lower than 6.9×10-6 -1 at Room Temperature. The composites exhibited high thermal stability for 3D-SiC network advent. The thermal conductivity of the composites was in the range of 50~80W•m−1•K−1. The thermo-physical properties of Cu matrix composites had a great relationship with the structures of 3D-SiC network preforms. The thermal conductivity of the composites decreased with an increase in the volume fraction of SiC or the structures of the limbs changing compacted, but the CTEs were not completely according this rule.
Analysis on Dynamics Characteristics of ICPF for Micro-Robot
Authors: Nie Lin , Zhang Xing Lan , Nie Rong
Published: November 2010

ICPF (Ionic Conducting Polymer Film) is a kind of smart film and has the characteristics of flexibility, good response and being driven by a low voltage. In order to illuminate the deformation dynamics of ICPF, the curvature of a thin strip ICPF under stepwise application of electric field is formulated according to Flory’s gel swell theory. The interplay mechanism of the deformation of gel, permeation of water and the transport of ions is described. A novel fish-like flexible micro-robot whose tail is actuated by ICPF is presented. According to the Pseudo-Rigid-Body-Dynamic-Model (PRBDM) the frequency analysis of the micro-robot is investigated, and then, the relation between the structure parameters and the natural frequency of the tail is theoretically derived and some analysis and experiment graphs about the angle displacement of the tail are performed.
Novel Antibacterial Nanofibers of Chitosan and Polyurethane Prepared by Electrospinning
Authors: Kang Wei Min , Cheng Bo Wen , Li Quan Xiang , Zuo Fang Fang
Published: November 2010

The chitosan(CS)/polyurethane(PU) blend nanofibers have been prepared for the first time by electrospinning. Formic acid (FA) and Hexafluoroisopropanol (HFIP) were found to be the co-solvent for electrospinning. The CS/PU blend solutions in various ratios were studied for electrospinning into nanofibers. The diameter and morphology of the fibers were shown by scanning electron microscope (SEM). It was found that the average diameter of the chitosan/PU blend fibers became larger, and the morphology of the fibers became finer with the content of PU increasing. To show the molecular interactions, CS/PU fibers were characterized by Fourier transform infrared spectroscopy (FT-IR). Moreover, the antibaterial activity of blend nanofibers against Escherichia coil (E.coil) was measured via optical density method. The blend nanofibers exhibited satisfying antibacterial activity against E.coil, even the chitosan concentration was only 5wt%. Therefore, the spun nanofibers are expected to be used in the native extracellular matrix for tissue engineering.
Effect of Zr on Thermal Stability of Cu-Fe In Situ Composite
Authors: Guo Jun Qing , Yang He , Liu Ping , Jia Shu Guo , Bi Li Ming
Published: November 2010

The DPCC(deformation processed Cu-based in-situ composite) behaved better combined performance. In this paper, Cu-10Fe-1.5Ag and Cu-10Fe-1.5Ag-0.1Zr in-situ composites were prepared using different forming processes and annealing techniques. The microstructure evolution was explored by SEM during the plastic deformation. It was found that Fe fibers were produced during drawing process and changed from trees dendrite to fiber structure in the form of flake. The effect of Zr on thermal stability of composite was analyzed also. It was shown that the adding of Zr element was helpful to increase the thermal stability of Cu-Fe composite by multi elements compound.
Study on Synthesis of Methyl Methacrylate/Styrene Copolymer by Suspension Polymerization
Authors: Feng Hui Xia , Zhang Jian Qiang , Liu Sheng Li
Published: November 2010

It was reported that suspension polymerization experiment of methyl methacrylate/ styrene copolymer in inorganic/organic ternary composite system. Some factors on modification of methacrylate/styrene copolymer were studied and optimized synthesis technics was found. The configuration and thermal performance of round bead copolymer products was analyzed by FT-IR and thermogravimetry. Methyl methacrylate/Styrene copolymer dispersed in O-MMT suspension polymerization system showed there was evident improvement about its thermostability.
Synthesis and Thermal Property of Linear Chloromethylated Polystyrene
Authors: Zhao Hong Chi , Guo Juan Li , Li Jiang Tao , Gao Ling Ling , Bian Cong Cong
Published: November 2010

Polystyrene (PS) was synthesized by emulsion polymerization. 1,4-bis(chloromethoxy)butane (BCMB) was synthesized using 1,4-butanediol, formaldehyde and phosphorus trichloride as raw material. The linear poly(p-chloromethyl styrene) (PS-Meyl-Cl) was prepared high effectively using BCMB and anhydrous aluminium trichloride as the chloromethylation reagent and catalyst, respectively. In this method, carcinogenic compound (chloromethyl ether etc.) was avoided. The resultant polymers were characterized by gel permeation chromatography (GPC), Fourier transform infrared spectrometer (FTIR) and thermogravimetric analyzer. The results show that the molecular weight (Mw) of PS is big. BCMB has been prepared because of the strong absorption band observed at 1130cm-1 (due to C-O-C bond stretching vibration) and two new bands at 640 and 1315cm-1 (due to the bending vibration of C-Cl bond and stretching vibration of C-H bond in -CH2Cl, respectively). Chloromethyl groups were introduced into benzene ring of PS because of the appearance of the absorption peaks at 676 and 1419cm-1 (due to the bending vibration of C-Cl bond and stretching vibration of C-H bond in -CH2Cl, respectively) in the FTIR spectra. The thermal stability of PS-Meyl-Cl was decreased with increasing chloromethyl group. Moreover, there are two decomposing stages. The reaction condition is gentle and the operation is safe, simple and economical.
The Super-Capacitor Properties of Aligned Carbon Nanotubes Array Prepared by Radio Frequency Plasma-Enhanced Hot Filament Chemical Vapor Deposition
Authors: Chen Yi Ming , Zhang Hai Yan
Published: November 2010

Aligned carbon nanotubes (ACNTs) array is synthesized by plasma-enhanced hot filament chemical vapor deposition of the stainless steel substrate covered by ferric nitrate. The morphology and structure of the carbon nanotubes array are characterized by Scanning Electron Microscope and Transmission Electron Microscope. Cyclic voltammetry, constant current charge-discharge technique are employed to test the electrochemical performance of the button-like super-capacitor fabricated using the ACNTs array as electrode. The specific capacitance of the ACNTs array electrode reached 160.9F/g in the potential range of -0.2~+0.8V, at a scan rate of 1mV/s in 1mol/L Na2SO4 aqueous electrolyte.
Immobilization of MSWI Fly Ash with Geopolymers
Authors: Jin Man Tong , Huang Cai Ju , Chen Liang , Sun Xin , Wang Lian Jun
Published: November 2010

The geopolymer was chosen to immobilize the municipal solid waste incineration (MSWI) fly ash because of its strong fixing capacity for heavy metals. The fly ash-based geopolymer was synthesized from metakaolinite with MSWI fly ash under activation of sodium silicate solution, and then cured at relative humidity (RH) between 40% and 90% at 20°C. The ability of immobilization of heavy metals in MSWI fly ash with the geopolymer was evaluated in terms of the compressive strength and leaching concentration. The experimental results confirmed that the compressive strength of the resulting solidified body could achieve 35.13 MPa after 7 days of curing. Meanwhile, the leaching concentrations of Pb, Zn, Cu and Cr were 0.0230 mg/kg, 0.186 mg/kg, 0.231 mg/kg, and 6.56 mg/kg, respectively. We confirm that geopolymerisation is an effective alternative in the disposal of various hazardous wastes containing heavy metals.
Influence of the Magnetic Interaction among Particles on Distributions of Magnetic Fluids Using Computer Simulations
Authors: Peng Xiao Ling , Wei Hai Biao , Yang Xiao , Yue Rui Ping , Ge Hong Liang
Published: November 2010

Magnetic fluid is a stable colloidal dispersion of ferromagnetic particles in a liquid carrier. Once a magnetic field is applied to magnetic fluids (MF), various structures of MF are formed. A detailed understanding of structures and particle distributions in gradient magnetic fields is much important. But very few works have been done on this. In the present study, the effects of magnetic field gradient and magnetic interaction among magnetic particles on the structures of MF are investigated using a two-dimensional Monte Carlo simulation. The results show that a gradient distribution of magnetic particles is formed under gradient magnetic fields. However, as the interaction between magnetic particles increases, the distribution gradient decreases, accompanied by the formation of chain-like clusters. Moreover, with increasing the magnetic interaction, particle distribution changes from grass-like clusters to needle-like ones.
Dynamic Properties of Lead Rubber Bearings and its Seismic Isolation Applications in High-Speed Railway Bridge
Authors: Chen Ling Kun , Jiang Li Zhong , Liu Peng
Published: November 2010

Lead rubber bearing (LRB) is a new type of earthquake-resistance rubber bearings, formed by inserting lead-core into ordinary laminated rubber bearing, vertical supporting, horizontal displacement and hysteretic damping are hung in single unit together. For lead-core can dissipate seismic energy and increase stiffness under load simultaneously, and most of the requirements of the Seismic isolation system can be satisfied, the material-device has been found widespread application prospect in bridge engineering. Hysteretic behaviors, ductility, and energy dissipation of LRB are mainly determined by some dynamical parameters such as characteristic intensity of LRB, post-yield, pre-yield stiffness and so on. Equivalent linear model of hysteretic characteristics, computational method and the varying range of dynamic parameters of LRB are presented. Dynamic responses of high-speed railway bridge fabricated LRB are calculated, and calculation results are compared with those fabricated common bearings, factors which influence seismic isolation are analyzed.
Study on Modification of the Magnesium Phosphate Cement-Based Material by Fly Ash
Authors: Li Dong Xu , Feng Chun Hua
Published: November 2010

Fly ash can improve the physical and mechanical properties of the magnesium phosphate cement (MPC) paste. The influence of fly ash on the strength, the mortar fluidity, the durability and the setting time of MPC paste were studied in this paper. The results show that: The function of fly ash to the MPC is as followed: physical fill, superplastic and chemical reactions; the optimal content of fly ash is about 30% by weight, and MPC with 30% fly ash has excellent mechanical property and high fluidity; the fineness of magnesia affected the mechanical properties of MPC.
Electrochemical Copolymerization of Triphenylene and 3, 4-Ethylenedioxythiophene and Characterization of the Copolymer
Authors: Lei Wu , Xie Xin Gen , Wang Feng Yun , Xia Ming Zhou
Published: November 2010

A novel conducting copolymer, was successfully achieved by electrochemical oxidation of the monomer mixtures of 3, 4-ethylenedioxythiophene (EDOT) and triphenylene (TP) in the acetonitrile solvent system containing 0.1 mol/L LiClO4. The resulting copolymer possesses the advantages of both polytriphenylene and poly(3, 4-ethylenedioxythiophene), such as good redox activity, considerable fluorescence property and relatively high electrical conductivity. Ultraviolet-visible, FT-IR and scanning electron microscopy were used to characterize and investigate the structure of the copolymers. Fluorescence spectra revealed that the copolymer dissolved in common organic solvents was a good blue light emitter, with a strong emission at 439 nm. All these results indicate that the copolymer films as obtained have many potential applications in various fields, such as organic light-emitting diodes (OLEDs).
Application of S2O82-/FexOy Solid Super Acid as a Heterogeneous Fenton-Like Catalyst for the Degradation of Orange IV in Water
Authors: Zhang Ying Jie , Tian Yue Xiao , Li Da Peng , Liu Guo Rui , Zhang Li , Li Li , Ma Jun
Published: November 2010

A new Fenton-like catalyst was prepared to degrade Orange IV in water by catalytic decomposition of H2O2. The optimal preparation conditions were discussed. The catalytic activity of catalyst was evaluated by the degradation of Orange IV and the decomposition of H2O2. The results show that solid super acid (S2O82-/FexOy) soaked in (NH4)2S2O8 is the most effective catalyst among the synthesized iron oxides soaked in other oxidants. The optimal conditions for solid super acid preparation are calcined at 500 for 2 h in the air.
Synthesis and Properties of Fluorinated Polyimide Films Based on 1,2,3,4-Cyclobutanetetracarboxylic Dianhydride
Authors: Lu Yun Hua , Kang Wen Juan , Hu Zhi Zhi , Wang Yong Fei , Fang Qing Xu
Published: November 2010

The alicyclic dianhydrides 1,2,3,4-cyclobutanetetracarboxylic dianhydride(CBDA) was polymerized with four kinds of fluorinated aromatic diamine, 2,2’-bis(trifluoromethyl)-4,4’- diaminobiphenyl(TFDB), 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene(6FAPB), 1,4-bis(4- amino-2-trifluoromethylphenoxy) diphenyl ether (6FAPE) and 1,4-bis(4-amino-2-trifluoromethyl- phenoxy)diphenyl(6FBAB) respectively, via a two-step polycondensation procedure to prepare four series of fluorinated polyimides(PIs) derived from CBDA. The obtained PIs displayed excellent solubility in aprotic polar solvents, such as NMP, DMAc, DMF and DMSO. These PIs showed good thermal stability with the 10% thermal decomposing temperatures higher than 457 in nitrogen and the glass transition temperatures higher than 267 . In addition, the PI films exhibited good optical transparency in the visible light region(400-700nm) with the transmittance higher than 80% at 450nm, and the PI films showed little absorption at the optocommunication wavelengths of 1.30µm and 1.55µm.
Microstructure and Mechanical Properties of Sn-Bi Alloy Treated in the Semi-Solid State by Mechanical Stirring Process
Authors: Li Feng , Hu Yong Jun , Cheng Xiao Ling , Xiao Xiao Ting
Published: November 2010

In this work, the effect of stirring time on the solidifed microstructures and mechanical properties of semi-solid Sn-Bi slurry was investigated by the mechanical stirring method. The results indicated that a fine round granular solidifed structure of Sn-Bi semi-solid slurry was obtained at 142 and stirred for 8 min. Compared with the Sn-Bi alloy prepared conventional die casting, the mechamical properties of semi-solid Sn-Bi alloy was improved prominently. The percentage elongation of semi-solid Sn-Bi alloy was increased 67 % compared with that of the Sn-Bi alloy prepared conventional die casting.
Research on Blue-Algae Removal from Eutrophication Water by Modified Clay
Authors: Wang Li Ping , Lu Lei , Gao Nai Yuan , Xu Xia , Zhang Yong Yin , Guo Yu Chuan
Published: November 2010

In recent years, the problem of contaminated source water is increasingly outstanding with the rapid development of industry，agriculture and population. Especially, the eutrophication of river and lake is severer. The modified clay was studied to remove algae in lake type raw water in which average concentrations of turbidity, TN, TP and Chl-a were 33NTU, 4.002 mg/L, 0.263mg/L and 29.02 mg/m3. The results showed that the average removal efficiency of turbidity, TN, TP and Chl-a were 88.53%、26.61%、87.45% and 87.97% respectively when the dosage of modified clay was 0.8 g/L.
Influence of Rare Earth Oxides on Crystallization Behavior and Sintering Performance of Fused Quartz Ceramic Materials
Authors: Bu Jing Long , Ma Fei , Zhang Yun Hong , Zhao Hong Yan , Wang Rong Lin , Wang Zhi Fa
Published: November 2010

Fused quartz granule (d50=0.033mm) was used as raw material, Pr6O11, Sm2O3, Gd2O3, Dy2O3 and Ho2O3 were used as additives with dosage of 2% each. Fused quartz ceramic materials were fabricated in reduction atmosphere at 1300°C, 1400°C and 1500°C for 1h. Samples were examined apparent porosity, bending strength, thermal expansion rate (RT~1200°C), and analyzed by XRD and SEM. The results indicated that additives Pr6O11, Sm2O3 and Dy2O3 had a bit inhibiting effect on crystallization of fused quartz sintered at 1300°C and 1400°C, Ho2O3 and Gd2O3 had more inhibiting effect on crystallization in samples sintered at various temperatures, sample containing Ho2O3 had least thermal expansion rate. Pr6O11, Sm2O3 and Dy2O3 had few facilitating effect on sintering, Gd2O3 and Ho2O3 had more facilitating effect on sintering of fused quartz ceramic materials, samples with Gd2O3 and Ho2O3 had lower apparent porosity and higher bending strength and more compact microstructure. It can be deduced that Gd2O3 and Ho2O3 play the excellent role as the crystallization inhibitor to fused quartz materials.
Effect of Bamboo Fiber Modification on Tribological Performance of Brake Composites
Authors: He Fu Shan , Gao Cheng Hui , Ye Shao Yan
Published: November 2010

In this paper, a novel no-asbestos brake composite reinforced by natural bamboo fibers is studied. The bamboo fibers are modified by heat treatment, alkali treatment and coupling treatment respectively. Tribological performance of different fibers reinforced composites are developed by means of friction test and microstructure observation. The results show that heat treatment of bamboo fibers at 140 for 4 hours makes the friction and wear characteristics of brake composites more stable than the untreated ones, but poor wear resistance at low temperature and heat fade still exist. There is no significant change on fiber surface. The alkali treatment of 17% NaOH solution for 12 hours contributes to desirable combination of higher friction coefficients and lower wear rates, and the surface morphology shows a number of deep grooves that avail the interface bonding. The effect of coupling treatment with KH550 on tribological performance of composites have the similar rule to that of the alkali treated ones except of heat fade, and the fiber surface is evenly coated with the coupling agent, which enhances the bonding of fibers and resin but fails at elevated temperature.
Study on the Mechanical Properties and Handle of PTT/Wool Blended Fabrics
Authors: Xu Guang Biao , Zhao Lian Ying , Wang Fu Mei
Published: November 2010

The low-stress properties of PTT/wool blended fabrics were investigated by comparing with PET/wool blended fabrics. The results show that, the elongation of PTT/wool fabrics at the maximum load is higher, especially in filling wise, which means PTT/wool fabrics have better elastic. The bending hysteresis, shearing rigidity and shearing hysteresis of PTT/wool fabrics are higher than those of PET/wool fabrics, determining the fabrics having good formability. PTT/wool fabrics are easier to be compressed, and has a little higher surface friction coefficient, giving the fabrics better feeling of softness and fullness. The hand values show that PTT/wool blended fabrics are softer, and have the good bulkiness but not as good as that of PET/wool fabrics.
Wear Mechanism Analysis and Microstructure of Vanadium Carbide Coating by Thermal Diffusion Process
Authors: Liu Xiu Juan , Li Qin Liang , Jiang Jun Xia , Liu Bai
Published: November 2010

In this paper, the typical cold work die steel Cr12MoV was used as substrate material for vanadizing treatment. And the coating structure and bonding strength were studied. Moreover, comparison experiment of wear resistance between the coating and the substrate material was performed, and based on the experiment results, wear failure mechanism of vanadizing layer was analyzed. The results showed that vanadium carbide coating is dense, with fine grain structure and high bonding strength. These features help to improve the wear resistance of coatings. Comparision of wear performance between coating and substrate showed that vanadizing surface layer can significantly improve wear resistance of substrate material. Friction coefficient decreased from the 0.48 to 0.33 and wear weight loss decreased by 95%. Wear Failure analysis showed that the vanadium carbide layer of the wear mechanism is fatigue spalling wear.
Axial Compression Experimental Research of RPC Filled Steel Tube Columns
Authors: Yan Zhi Gang , Huang Yan , An Ming Zhe
Published: November 2010

Reactive Powder Concrete (RPC) is a new kind of building material with high strength and other good performance. The combination of RPC and steel tube will compensate the brittleness of RPC and enhance the stability of steel tube, and the loading capacity of the RPC filled steel tube will be improved. Five RPC filled steel tube columns are designed and tested to obtain the ultimate load bearing capacity, the deformation and the strain information. During the loading process, the concrete and the steel tube of the RPC filled steel tube columns are loaded simultaneously. The loading results show that the deformation of the RPC filled steel tube columns are mainly in elastic phase before the loading capacity is up to the ultimate value. The test load decreases to be 80%~90% of the ultimate loading value and then it changes to be smooth. The failure mode of the RPC filled steel tube columns is ductile. The test loading capacity is compared with the formula from the reference. The tested ultimate load bearing capacity of the steam cured RPC filled steel tube columns is higher than the calculated value. The calculated value is safe for the engineering application. The study is useful for the research and application of RPC filled steel tube column.
Room-Temperature Electrical Conductivity Property of Si3N4/TiN Composite Ceramics
Authors: Zhang Shu Hui , Kang Zhi Qiang , Lu Qing
Published: November 2010

Room-temperature electrical conductivity property of Si3N4/TiN composite ceramics fabricated by Si3N4 powders from iron ore tailing and high titanium slag was investigated. Si3N4/TiN composite ceramics were machined by electrical discharge machining. The results show that the minimum amount of TiO2 in initial raw materials is about 20wt% for the formation of electroconductive network in the composites, of which the electric resistivity is 4.25×10-2•cm. The electric resistivity decreases slightly with increasing the sintering temperature. Surface roughness enhances significantly with the speed of the electrical discharge machining rising.
Prediction on Autogenous Shrinkage of Self-Consolidating Concrete
Authors: Long Wu Jian , Khayat Kamal Henri , Xing Feng
Published: November 2010

Proper estimate of autogenous shrinkage of self-consolidating concrete (SCC) can provide engineers with the information necessary for producing high quality products manufactured with SCC. An experimental program was undertaken to evaluate autogenous shrinkage of precast, prestressed SCC. Sixteen SCC with slump flow of 680 ± 20 mm were evaluated. These mixtures were made with 440 to 500 kg/m3 of binder, Type MS cement or HE cement and 20% Class F fly ash, 0.34 to 0.40 w/cm, viscosity-modifying admixture content of 0 to 100 mL/100 kg of binder, and 0.46 to 0.54 sand-to-total aggregate volume ratio. Two high-performance concretes (HPC) with 0.34 and 0.38 w/cm and slump of 150 mm were also investigated. HPC developed similar autogenous shrinkage at 56 days compared to SCC made of a given binder type. Shrinkage was compared to prediction models proposed by Tawaza and Miyazawa 1997, Jonasson and Hedlund 2000, and CEB-FIP 1999. The Tazawa and Miyazawa model was modified to provide adequate prediction of autogenous shrinkage for precast, prestressed SCC.