bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation about Corrosion Properties of AZ31 Magnesium Alloy Coupled with Nitrided 40Cr Steel
Authors: Zhao Wei Lin , Wang Zhen Lin , Tang Li Wen , Zhang Jin
Published: September 2009

Corrosion properties of magnesium alloys coupled with foreign metals impose much influence on the life of the parts. In this paper, the corrosion properties of AZ31 magnesium alloy coupled with nitrided 40Cr steel were investigated through immersion test in saline solution and weight loss test combining with optical microscope (OM) and scanning electronic microscope (SEM) analysis. The results indicate that the anticorrosion properties of the AZ31 magnesium alloy coupled with nitrided 40Cr steel are higher than those of the AZ31 magnesium alloy coupled with unnitrided 40Cr steel. The mechanism is attributed to the resultant nitrided layer which reduces the conductive properties.
Resolution Wavelet and Online Damage Detection for Composite Material Structure Dynamic Response Signal
Authors: Hu Wei Bing , Deng Qiang
Published: September 2009

In this paper, using piezoelectric patches bounded or embedded in composite material structures as actuators and sensors, the system for exciting the structure and sensing its dynamic response can be established. Extracting damage information from the response and monitoring the perturbations of structural dynamics can be implemented using wavelet analysis. This will conduce to the capture of the accurate time of damage occurrence. The method developed in this paper can help to build the system of online damage detection and health monitoring of composite material structures when they cannot be directly observed or measured.
Effects of Ultrasonic Vibration Treatment on Microstructure of Heat-Resistant Al-Si Alloy
Authors: Zhong Gu , Wu Shu Sen , Jiang Hua Wen , Sha Meng , An Ping
Published: September 2009

The influences of ultrasonic vibration (USV) treatment on the refining effects of primary Si particles and acicular five-element compounds with rich RE in high silicon Al-Si alloy with complex modification of P and RE were studied. The primary Si particles in this alloy was about 20 μm in size under direct USV for 2 min in the semi-solid temperature range, compared to about 30 μm in the alloy without USV. The primary Si particles in the former distributed more homogeneously and in regular shape, but had lower volume fraction of primary Si than that of the alloy without USV for the solid solubility of Si in α-Al matrix increased with USV. The eutectic Si of this alloy was modified moderately with 0.6% RE and long acicular compounds with rich RE formed which decrease the mechanical properties of alloy for the effect of cutting the matrix. Short rod-like compounds with rich RE about 10~15 μm in length were obtained with the combined effects of USV and T6 heat treatment.
Preparation and Property of Wood Polymer Composite with a Two-Step Method
Authors: Li Yong Feng , Liu Yi Xing , Yu Hai Peng , Chen Wen Shuai
Published: September 2009

Wood as a porous structure has weak durability and unsatisfactory mechanical properties which limits its utilization. For this reason, the study presents a two-step method to prepare a new modified wood material—Wood Polymer Composite. Maleic anhydride(Man) firstly penetrates into the porous structure of wood, followed by a reaction with wood cell walls. Then, Styrene(St) with some Man and a few amount of initiator, AIBN, permeate through the whole wood and react with the above modified wood. The structural characterization of wood polymer composite with SEM and FTIR indicates that Man reacts successfully with the hydroxyl group of wood cell wall by its anhydride group, and further reacts fully with styrene as a free radical copolymerization form by its double bond; and thus the polymer fills in wood cell lumina as a solid form, which combines the wood cell walls without any evident crack. The testing results of properties show that the mechanical properties of wood polymer composite increase by about 50%-250% over those of unmodified wood, and its durability improve 1.9-4.89 times than untreated wood.
Preparation and Characterization of Ga2xIn2(1-x)O3 Films Deposited on α-Al2O3 (0001) by MOCVD
Authors: Kong Ling Yi , Yang Fan , Ma Jin , Luan Cai Na , Zhu Zhen
Published: September 2009

Ga2xIn2(1-x)O3 thin films with different gallium content x [x = Ga/(Ga+In) atomic ratio] have been prepared on -Al2O3 (0001) substrates at 650°C by metalorganic chemical vapor deposition (MOCVD). Structural, electrical and optical properties of these films have been investigated in detail. The XRD analysis revealed that, as the gallium content increased, the crystalline quality of the films decreased. The highest Hall mobility of the films was 41.32 cm2v−1s−1. The absolute average transmittance of the Ga2xIn2(1-x)O3 thin films in the visible range exceeded 91%. The band gap could be tuned from 3.59 to 4.87 eV as gallium content increased.
Research of Electromagnetic Wave Absorbing Characteristics of Structures Consisting of LHM and RHM
Authors: He Xing , Wang Hong Xia , Zhu You Zhang , Zhao Yun Fang , Hang Yong Zhong , Yue Kai Feng
Published: September 2009

On the basis of the theory of electromagnetic wave propagation in monolayer construct of left-handed material(LHM) and right-handed material (RHM), a calculation method based on recurrence is proposed, this method can be used in the computation and forecasting of the absorbing efficiency of multi-layer materials .Then, the results are consistent with another derived from traditional transmission-line method. But compare to the later, the new calculation method is simpler and more direct. Furthermore, using in Structure consisting of LHM and RHM is also referred. At last, we use this model analyzes the effect by the LHM’s electromagnetic parameter to absorption, from that, we obtain some useful conclusions. Our research results indicate that when LHM is combined with conventional RHM to form a LHM-RHM double-layer structure absorber, the reflection loss will be increased and the absorbing band will be widened. This indicates that the LHM is hopeful to be one of the wave-absorber composite materials, which has better absorbing effect.
The Research of SOL Treated Cantilever Beam Based on Analytical Methods and ANSYS
Authors: Cao Yin Ping , Shi Xiu Hua
Published: September 2009

SOL (stand-off layer) damping treatment is the most effective method to improve the damping characteristics of the base structure compared with unconstrained and constrained layer damping treatment. In this case, the viscoelastic layer is sandwiched between the SOL and the constraining layer. During vibration, the SOL acts as a strain magnifier which magnifies the shear strain in the viscoelastic layer by increasing the distance between the viscoelastic layer and the neutral axis of the base structure thus dissipates more vibration energy. The equations of motion root in kinematic equations, constitutive equations and equilibrium equations of force and moment, and constitute one variable (lateral deflection) with order differential equation and two variables (axial deflections of the base beam and the constraining layer) with order differential equation of motion. Together with the boundary conditions, the transfer function method and the finite element method are adopted to analyze the damping characteristics of the composite structure. In distributed function method, the equations are transferred to state space form. In finite element method, the lateral deflection is interpolated by Hermite interpolation function and the axial deflections of the base layer and the constraining layer are interpolated by Lagrange interpolation function. At last, the predictions of the two analytical methods are validated against the commercial software ANSYS. Close agreements are found among the three methods. To achieve the expected effect, the SOL must have high shear stiffness and low bending stiffness so it does not significantly influence the flexural rigidity of the base structure but does not absorb the shear stress desired to be passed on to the viscoelastic layer. This paper is focus the application of SOL damping treatment on cantilever beam model, but it is essential to note that the model can be extended to complex structures such as plates and shells. We can select the slotted SOL damping treatment which could effectively avoid the increase in bending stiffness but also maintain high shear stiffness as the substitute.
Research on the Anti-Static and Anti-Radiation Properties of Fabrics Containing Stainless Steel Microfilament
Authors: Zhang Zeng Qiang , Ye Yu Hui
Published: September 2009

The anti-static and anti-radiation properties of functional fabrics containing stainless steel microfilament were investigated in this paper. Three specifications of stainless steel microfilaments( diameter: 0.035mm、0.040mm and 0.050mm ) and cotton yarn were twist into composite yarns. The functional fabrics were woven by cotton yarn as warp, both cotton and the composite yarn as weft. The fabric performances were tested after woven and some treatments, especially the anti-static and anti-radiation properties. The results showed that with stainless steel microfilament increases in fabric, the amount of electrostatic charge on fabric becomes smaller. The results also showed that these fabrics had a good anti-radiation ability. So these functional fabrics have good application prospects in protective clothing and technical textiles.
Switching Porphyrin Fluorescence on and off through Redox
Authors: Zhu Pei Hua , Zhu Cheng , Zhao Yang Fang , Wei Qin , Chen Yan Li
Published: September 2009

Three new zinc porphyrins ( [5,15-bisferrocenyl-porphyrinato]-zinc(II)(4), [5,15-bisferrocenyl-10,20-bis(4-nitro-phenyl)-porphyrinato]-zinc(II)(5), and [5,10,15,20- tetraferrocenyl-porphyrinato]-zinc(II) (6)) with ferrocenyl units at the meso-positions of porphyrin ring have been prepared and characterized. Towards further understanding the fluorescence quenching and recovery of ferrocene-porphyrins, the fluorescence spectra of these compounds was detailedly studied.
Studies on Preparation and Property of 2.5D SiO2f/ SiO2 Composites
Authors: Han Shu Ang , Jiang Kai Hui , Tang Jun Wu
Published: September 2009

In this paper, 2.5D SiO2f/SiO2 composites were fabricated via sol-gel process employing 2.5D braided silica fiber fabrics as reinforcements and high pure silicasol as slurry. The process parameters are optimized and the optimal parameters are as follows: the silicasol of 30.8 wt. % as slurry, microwave drying, and sintering at 900 °C. Utilizing the optimal process parameters, the density and the flexural strength of the composites can reach 1.65 g•cm-3 and 80.68 MPa respectively. Dielectric properties of the 2.5D SiO2f/SiO2 composites were also measured, and the real part of the permittivity is 3.40 at 5 GHz. The excellent mechanical and dielectric properties of the 2.5D SiO2f/SiO2 composites can well meet the requirements of radome materials.
Microstructure Evolution and Mechanical Properties of 7A09 Aluminum Alloy during Rapid Solidifications
Authors: Wang Wei Wei , Jia Bin Bin , Yu Jing Bo
Published: September 2009

Microstructure evolution and mechanical properties of 7A09 aluminum alloy ribbon prepared by rapid cooling solidification are studied. Single roller is applied to produce rapid solidification ribbon of 7A09 aluminum alloys. Microstructure characteristics and mechanical properties of the rapid solidified ribbon of 7A09 aluminum alloys are studied by means of X-ray diffraction (XRD), scan electron microscopy (SEM) and hardness measurement. The results show that the rotate speed of the roller is the key factor affecting the ability of the forming ribbon. At a roller rotate speed of 1500rpm, the ribbon with a good quality can be obtained. Microstructure features of the rapid solidification ribbon are refined with the increase of the cooling rate, all of the crystals translate into nanocrystalline. All the hardness of the rapid solidification ribbon of 7A09 aluminum alloys is higher than that of the original alloys and increases with the rotate speed of the rotor.
Sedimentation Equilibrium of Ultrafine A1(OH)3 Particles in Aqueous Solution
Authors: Zhao Su , Ma Qian , Qiu Li Yuan , Yu Bo
Published: September 2009

The influence of dispersant on sedimentation performance of ultrafine Al(OH)3 aqueous suspension was studied by the determination of settlement rate and Zeta potential. And the settlement rate formula of powder particle in water solution was modified. Results showed that 0.2% addition of DP-270 has better dispersion effect on Al(OH)3 aqueous suspension. As for spherical powder particle with electricity at size range 0.55~ 1.67μm, the settlement rate in aqueous solution can be calculated with modified formula: V=V0 [esp（ζn-ζ0）/ζ0]-1
Study on the Viscoelastic Property of Soybean Protein Fibers
Authors: Tian Lin , Yang Qing Bin
Published: September 2009

The soybean protein fiber is a new textile material. Thanks to its fine denier, light specific gravity, high strength and silk-like luster，it has so excellent cashmere handle, silk softness and heat resistant properties that it has been called manmade cashmere and found wide application. In order to understand the relationship between the inner structure and the mechanical property and the effect of bleaching and dyeing to the soybean protein fibers，four mechanical models are chosen. The tensile and relaxation property of the soybean protein fibers are analyzed. The tensile and relaxation cures are fitted with the suitable model. It shows that the relaxation property of SPF is in accordance with the standard linear solid model. Estimates of the Hookean spring modulus at 8% and at 10% are different, so some structural modifications could be produced by the strain. Bleached fibers show a higher level of relaxation than raw fibers and dyed fibers. Bleaching has a remarkable influence on decreasing tenacity at break for each test modality. Knotted and looped modalities decrease fiber tenacity remarkably in all three samples.
Plastic Deformation and Damage Behavior of AL6XN Super-Austenitic Stainless Steels
Authors: Ma Chao Qun , Duan Qi Qiang , Li Xiao Wu
Published: September 2009

Tensile and compressive deformation and damage behaviors of Al6XN super-austenitic stainless steels were examined at different strain rates. The deformation and fracture surfaces were characterized by scanning electron microscopy (SEM). It was found that the uniaxial deformation (tensile or compressive) behaviors of Al6XN stainless steel shows a low strain rate sensitivity over the range of 10-4s-1 - 10-2s-1. The tensile and compressive yield strengths measured are nearly comparable. The steel shows a good tensile plasticity. Dislocation slip deformation is the main characteristic of uniaxial deformation. All fracture surfaces induced by tensile deformation at different strain rates can be divided into two parts, i.e., fibrous zone and shear lip zone. The fibrous zone consists of dimples with a bimodal size.
New Methods of Preparing Multi-Functional Nanocomposite Coatings
Authors: Figovsky Oleg
Published: September 2009

Nanostructured coatings based on interpenetrated polymer network of polyurethanes, polyacrylates or epoxide resins and containing nanoparticles of SiO2, TiO2 and other metal oxides introduced into a polymeric matrix was elaborated. Technology of the unique coatings provides control of their micro-and nano-structures. Formulation of a new class of nanocomposite materials is characterized by the absence of contaminants in the polymers technology [1]. The main components of the technology are branched (dendro)-aminosilanes which serve as curing agents for many oligomers. Additional hydrolysis of aminosilane oligomers creates the secondary nano-structured network polymer that improves performance of the compound.
Microstructural Evolution and Mechanical Properties of Powder Hot Extruded Al-Zn-Mg-Cu Alloy
Authors: Wang Shao Qing , Yu Hua Shun , Zhang Zhen Ya , Min Guang Hui , Yu Hui
Published: September 2009

In this study, an ultrastrength Al-10Zn-3.2Mg-2.3Cu alloy was fabricated by powder hot extrusion technique. The microstructures of powder, extruded and subsequently heat treated rods were investigated by means of X-ray diffractometer (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) with energy dispersive spectrometry (EDS) for compositional analysis. During extrusion, more MgZn2 compounds were precipitated from the supersaturated Al matrix and observed on the grain boundaries and in the grain interiors. The microstructure of as-extruded alloy is composed of Al matrix and MgZn2 phases in different shapes. After solution treating, the MgZn2 phases were mostly dissolved into matrix and the major constituent are Al7Cu2Fe phase as well as oxides. The mean size of grains was controlled to 2.5μm, and the major precipitates were GP zones and/or η’(MgZn2) phases in the Al matrix after peak-aging (T6) treatment (120°C for 20h). The ultimate tensile strength (σb), yield strength (σ0.2) and elongation (δ) are 745Mpa, 690MPa and 9.0%, respectively.
In Situ Observation of the Growing Surface Morphology of KDP Crystals by Microscope
Authors: Zhong De Gao , Teng Bing , Li Ming , Wang Qing Guo , Zhao Yan Shuai , You Fei , Xu Hui , Zhang Shi Ming
Published: September 2009

A kind of in-situ crystal growth observation system for solution temperature reduction method was designed. The growth surface morphology of KDP crystal was observed by this system. Dislocation hillocks with elliptical shape were clearly distinguished on the {100} face. The dynamics process of morphology evolvement on growth surface of KDP crystals was recorded and analyzed. The growth velocity of the step trains generated from dislocation hillocks was about ~10-4.
Synthesis and Characterization of Water-Soluble Cu2+-Doped ZnSe Quantum Dots
Authors: Li Shan Shan , Liu Fu Tian , Wang Qun , Chen Xiu Xiu , Yang Ping
Published: September 2009

Cu2+-doped ZnSe quantum dots (ZnSe:Cu) were prepared via a green and simple route, namely the chemical coprecipitation method. Under 365 nm UV excitation, green emission is observed. X-ray powder diffraction (XRD) shows that ZnSe:Cu nanoparticle is cubic zinc blende structure; the transmission electron microscopy (TEM) exhibits that the average diameter of ZnSe:Cu nanocrystals is less than 10 nm. UV-vis spectrophotometer and fluorescence spectrophotometer indicate that ZnSe:Cu nanocrystals have good fluorescence effects.
Study of the Morphology and Antibacterial Properties of Nano Silver Films Prepared on Regenerated Cellulose Substrate
Authors: Wang Xue , Zhang Yu Hui , Ji Quan , Liu Zeng Ji
Published: September 2009

Nano size silver films were deposited on the surface of regenerated cellulose films by magnetron sputtering, to impart antibacterial functionality to the cellulose films. Field emission scanning electron microscopy (FESEM) images revealed that the silver films were composed of nano size compact grains and the surface shape of the grains changed with changing sputtering power. As the power increased, the size of the nano silver grains increased and the number of grains decreased. Surface elemental analysis by energy dispersive spectrometry (EDS) showed a small amount of elemental silver on the surface. The antibacterial activity of the films was assessed by the shake flask test which measured the number of Staphylococcus aureus bacteria. The percentage reduction of the bacteria reached >99.9%.
Synthesis, Characterization and Photocatalytic Performance of Novel Composite Ag/ BiVO4 Photocatalysts
Authors: Zhang Xian Hua , Ge Lei
Published: September 2009

The novel visible-light-driven Ag/BiVO4 composite photocatalysts were successfully prepared by photo-deposition method. The as-prepared Ag/BiVO4 samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and UV–vis diffuse reflectance spectra (DRS). The photocatalytic activities of the Ag/BiVO4 powders were determined by degradation of methyl orange molecules in water under visible light irradiation (λ>400nm). The photocatalytic experiments indicated that the composite samples enhanced photo-activity under visible light irradiation.
Epoxy Curing System with Liquid 1,3-Bis(3-aminopropyl) tetramethyl Disiloxane as Curing Agent for Advanced Electronic Package
Authors: Li Hai Yan , Xie Chuan Hai
Published: September 2009

, 1,3-bis(3-aminopropyl) tetramethyl disiloxane (DS) is used as liquid epoxy curing agent of epoxy molding compounds(EMCs) for high-reliability semiconductor devices. Experimental results indicated that DS could be effectively used as epoxy curing agent and greatly lower the viscosity of epoxy system, in which way, the coefficient of thermal expasion(CTE) of EMCs can be lowered effectively by increasing the filler loading. The concentration of DS strongly affected the mechanical properties of the thermally cured epoxy composites. As expected, the flexural modulus of epoxy composite decreased and the toughness was improved.
Tribological Characteristics of Surface Treatment for Piston Pin
Authors: Seo Joon Ho , Kim Jin Yong , Park Seung Uk , Kim Hyun Chul , Na Byung Chul , Lim Dae Soon
Published: September 2009

The piston pin contact in a typical automotive engine is an example of a highly loaded. Therefore, for piston pin design several aspects are important. Among them are function, cost, NVH, fuel economy, durability, and impact on other design aspects of the engine. Continuously contacting with piston pin, the face of connecting rod, brings about abnormal wear such as unfairwear or earlywear. because the engine get more powered and one requirement for a good fuel economy is to achieve a low level of mechanical friction. In this study, modern low friction coatings and treatment at the piston pin interface aimed to investigate the potential. The profile of coated specimens were observed by non-contact type optical surface measuring system and the friction-wear behaviors of coated specimens were investigated by using piston pin wear tester. Piston pin wear test was performed to analyze the friction and wear behavior. The results showed that the application of low friction coatings and treatment effectively improved tribological performance of the piston pin
Electronic Structure Study of Metal Complex {1,1’-[ o-Phenylenebis(nitrilomethylidyne)]di-2-naphtholato}Copper(II)
Authors: Xue Rui Ting , Chen Shou Gang , Gao Guan Hui , Yin Yan Sheng
Published: September 2009

The complex {1,1’-[ o-phenylenebis (nitrilomethylidyne) ] di-2-naphtholato} copper(II) was optimized by the DFT method at B3LYP/LANL2DZ level, and the frontier molecular orbitals, natural bond orbitals, nonlinear optical properties and Mülliken charge population of the optimized complex were exploited and analyzed. The calculated results show that the complex has stable structure and it keeps some potential applications in optic materials field.
Influence of Calcining Temperature on the Microstructure of LaPO4 Powders
Authors: Liu Zi Feng , Wang Xin , Yin Yan Sheng , Liu Qiang
Published: September 2009

Nanometer LaPO4 powders were synthesized by liquid-liquid direct precipitation method. La(NO3)3•6H2O and (NH4)3PO4•3H2O were used as raw materials. The calcining temperature was 900°C, 1000°C, 1100°C, respectively. DTA result shows that the LaPO4 precursor is LaPO4•4H2O. The calicined powders were characterized by X-ray powder diffraction (XRD) and Scanning Electron Microscope (SEM), and exhibited a pure LaPO4 phase with a monazite structure about 50-100 nm in diameter size. With the calcining temperature increasing, the crystallization of the LaPO4 became better and the grain shape changed from elongated grain shape to spherical grain shape.
Molten Salt Synthesis of LaPO4:Eu3+
Authors: Liu Qiang , Wang Xin , Liu Zi Feng , Liu Hao Quan , Gu Song Tao , Jiang Tao , Zhou Meng
Published: September 2009

Eu doped LaPO4 nanocrystals were successfully synthesized by molten salt method calcined at 700°C. The structure, morphology and photoluminescence of as-synthesized product were characterized. The results reveal that all the doped samples are well crystalline at 700°C and assigned to the monoclinic monazite-type structure of the LaPO4 phase. It has been shown that the obtained nanocrystals to be long rod-like with diameters of 5-10 nm and length of 100-150 nm. The luminescence intensities strongly improved due to the high crystallinity because of the molten salt as the medium in thermal treatment posscess.
Fly Ash-Activated Carbon Powder Composites for Dyes and Heavy Metals Removal
Authors: Visa Maria , Isac Luminita , Duta Anca
Published: September 2009

Advanced wastewater treatment requires highly efficient substrates, able to insure in a single step process the water discharge requirements. The paper the results obtained in the simultaneous removal of heavy metals and dyes, using a composite powder of fly ash and activated carbon. The results show that adding a small amount of activated carbon in a powder mixture with modified fly ash is highly effective in removing cadmium from wastewaters also containing dyes (methylen blue or methyl orange). Chemisorption is the likely mechanism governing this process.
Study on the Tribological Properties of the Diesel Engine’s Lubricating Oils Containing Nanoparticles
Authors: Gu Cai Xiang , Zhu Guan Jun , Tian Xiao Yu , Ji Gui Jun , Li Wei
Published: September 2009

The morphology and diameter of Cu and La2O3-Ce2O3 nanoparticles were observed and measured by TEM. The tribological properties of the lubricating oils containing nanoparticles were examined by MRS-1J four-ball tribotester. A 300-hour contrastive experiment was carried out in KDE5000E diesel engine.The results show that lubricating oils containing nanoparticles have optimal tribological properties, when WCu:WLa2O3-Ce2O3=2:1,WCu+ La2O3-Ce2O3=0.8%. Wear values of friction pair using 40CD oil with Cu and La2O3-Ce2O3 nanoparticles decrease by 88.6%-100%,compared with using 40CD oil. The consumptions of diesel oil reduce by 9.29%.
A New Type of Rubber Sandwich Coated Onto Ship for the Use of Underwater Explosion Shock Mitigating
Authors: Du Zhi Peng , Wang Yu , Chen Yong , Hua Hong Xing
Published: September 2009

How to moderate ship the damages caused by the underwater explosion (UNDEX) is of great interest to the modern ship designers. A new type of rubber sandwich with periodic honeycomb core was developed to mitigate the ship shock due to UNDEX. A ship with or without the rubber coat was tested under “near combat conditions” by igniting a 8 kg charge of TNT underwater at varying standoff distances from the ship. The effects of the shocks to ship systems were observed and the responses of the ship were monitored and recorded for each shot. The pressures in the water around the ship were also recorded to explore the fluid-structure interaction and UNDEX shock wave reflection with different targets. Acceleration and strain records indicate that the rubber coat is capable of moderating the high-frequency response excited by shock wave efficiently. Pressure records show that the core crushing and water cavitation promote superior energy absorption that yields an increased resistance to UNDEX.
Study on Vibration Band Gap Characteristics of Phononic Crystal Consisted of Ti and Rubber
Authors: Wang Yan Lin , Wang Zi Dong , Song Zhuo Fei
Published: September 2009

The vibration band gaps of one dimensional phononic crystal of rod structure consisted of Ti and Rubber were studied using the lumped-mass method and finite element simulation, the influences of vibration band gap by the periodicity and volume fraction were discussed. The results show that the initial frequency and cutoff frequency have little influence by the periodicity, but the anti-vibration effect is more effective as the periodicity increases; the cutoff frequency gradually decreases, the initial frequency decreases first and then increases as the volume fraction increases.
Ultrasonically Assisted Synthesis of Tin Sulfide Nanorods at Room Temperature
Authors: Pan Jun , Li Jiang Ying , Xiong Sheng Lin , Qian Yi Tai
Published: September 2009

A simple ultrasonic method was developed to synthesize rod-like SnS nanocrystals, using tin chloride and thioacetamide as starting materials, ethanolamine and water as solvents. The as-obtained nanostructures were characterized by X-ray diffraction (XRD) study, energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and Ultraviolet-visible spectrophotometry (UV). From the XRD pattern, the reflection peaks of the as-obtained samples can be indexed to the orthorhombic structure with lattice constants a = 3.99, b = 4.34, c = 11.20 Å , which are very consistent with the values in the standard card of SnS phase (JCPDS No. 39-0354). No characteristic peak was observed for other impurities such as SnO2 and SnS2, implying the formation of single-phase tin monosulfide. The quantification calculation shows the ratio of Sn/S to be 51.30/48.70 via the EDS analysis. These data clearly indicate that the as-prepared rod-like nanostructures are exactly SnS. TEM results show that, the SnS nanorods have length about 100nm and width less than 30nm. The direct and indirect band gaps of the SnS nanorods are determined to be 1.53 eV and 1.34 eV, respectively. The band gaps of the as-obtained SnS nanorods showed blue shifts due to the quantum size effects. The ultrasonic condition is believed to be critical for the formation of SnS with pure phase. For it provides the energy to form rod-like nanostructures and helps preventing the hydrolysis of Sn2+ to form tin oxides and hydrates. Also, it prevents oxidation of the final products.
Preparation, Characterization and Photocatalytic Performance of Nano-TiO2/Diatomite
Authors: Su Ying Ying , Yang Pei Shan , Zhu Xiao Bin
Published: September 2009

Diatomite supported nano-TiO2 composite was prepared by sol-gel method with titanium (Ⅳ) isopropoxide as precursor. The composite was characterized by XRD, SEM and FT-IR. The TiO2 coated on the surface of diatomite was the mixed crystal of anatase and rutile, the average particle size was 11 nm. The photocatalytic activity of composite was larger than that of the Degussa P25-TiO2. The stability of TiO2/diatomite was good and the photocatalytic activity reduced only 12.4% after repetitive-use the catalyst for 15 times.
Large Scale Synthesis of BaTiO3 Nanorods by a Template Way
Authors: Deng Zhao , Dai Ying , Liu Hai Rui , Chen Wen
Published: September 2009

Large scale BaTiO3 nanorods were successfully synthesized by a template method based on a precipitation process. The templates used in our method are H2Ti8O17 nanorods, which can be synthesized from K2Ti4O9 fibers. The unique process of the synthesis is BaC2O4•0.5H2O shell was coated on the 1-dimensional H2Ti8O17 nanorods (the core). The as-prepared products were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results show that the BaTiO3 nanorods are ~100-300 nm in diameter and ~2-10 m in length. The process described provides a general route to fabricate this kind of perovskite 1-dimensional nanostructures, such as SrTiO3 and PbTiO3.
Preparation and Characterization of Hollow TiOX Nano-Spheres for Electrophoretic Displays
Authors: Tan Ting Feng , Wang Shi Rong , Bian Shu Guang , Li Xiang Gao
Published: September 2009

Hollow TiOX nano-spheres have been successfully prepared using hollow core-shell latex particles as template, which involves the deposition of inorganic coating on the surface of hollow core-shell latex particles and subsequent removal of the latex particles by calcinations in air or ammonia gas. The formation route of hollow core-shell polymer particles is presented as follows: Firstly, poly-methyl methacrylate (PMMA) seed emulsions are prepared as the 'core'. Subsequently, the outer shell poly(styrene-co-methyl methacrylate) (PS-co-MMA) particles wrap on the surface of the core, the microspheres with core-shell have been prepared. Finally, Ti(OBu)4 is used as precursor for the preparation of hollow TiOX nanospheres.
Transmission electron microscopy (TEM) and atom force microscopy (AFM) images of seed emulsions show they have the uniform size of about 470 nm. TEM of hollow core-shell polymers particles show they have an average diameter of about 500 nm. X-ray diffraction (XRD) analysis of TiO2 sample calcined presents that the strong absorptions is coordinated with the standard chart of rutile TiO2. TEM of TiO2 and TiO show hollow spheres well-dispersed with the diameter range of 300-400 nm and 350-400 nm, respectively. The density (in the atmospheric pressure, 20 °C) of TiO2 and TiO hollow spheres was 2.49 and 2.37 g∙mL-1, respectively. The Zeta potentials were 6.20 mV and 20.39 mV, respectively. Uniform hollow spheres show low density and good electrophoretic displays. The electrophoretic mobilities of white TiO2 and black TiO hollow spheres in tetrachloroethylene show they are suitable for electronic paper as background and display particles, respectively. It is anticipated that this method would present a potential toward the road of large-scale industrial production of TiOx hollow spheres.
Fabrication of Metal Matrix Nanocomposites
Authors: Tolochko N.K. , Andrushevich A.A. , Shienok Yu.A.
Published: September 2009

Novel semisolid casting technique allowing producing the cast composites with highly homogeneous structure is suggested. In according with this technique specially prepared metal bil-lets containing reinforcing nanoparticles are subjected to partial melting and compacting and fol-lowing solidifying. Some model systems were used in order to demonstrate the potential possibili-ties of this technique in principle.
Hydrothermal Synthesis and Characterization of Nanocrystalline Anatase Titania from Ti(OC4H9)4
Authors: Gao Rong Jie , Wu Ping Wei
Published: September 2009

Titania powders consisting of well-crystallized nanosize anatase phase were prepared by the hydrothermal synthesis from Ti(OC4H9)4 at T=568K and P=15.5MPa in the presence of C2H5OH and CO(NH2)2. DTA-TG, XRD and TEM were employed to characterize the samples. The results show that the crystallization temperature of the well-crystallized nanosize anatase phase to rutile is about 1123K, the particles distribute from 10nm to 50nm and it’s average diameter is about 30nm.
Fabrication of SiO2@Au Core-Shell Multi-Functional Nanoparticles (MFNPs) for Imaging and Thermotherapy
Authors: Chang Yea Huey , Bau De Tian , Lee Ying Shiung , Chen Chien Yu , Huang Hung Jin , Tsai Fuu Jen , Tsai Chang Hai , Chen Calvin Yu Chian
Published: September 2009

In this study, we aimed at producing a MFNP consist of a dielectric core encapsulated fluorescein coating by a thin gold shell, which facilitate it with highly favorable optical and chemical properties for biomedical imaging and therapeutic applications. We have composed a novel multi-functional nanodesign, Sample A3, with fluorescein encapsulated in SiO2 nanoparticles with gold shell. The A3 nanoparticles were uniform in size, no aggregation, homogeneous and stable in the solution under the SEM image system. We have also investigated its cytotoxicity to A10 human smooth muscle cell line by MTT assay, and found that the novel sample A3 were of little cytotoxic to the cells. In conclusion, we have proposed a novel method of preparing multi-functional nanoparticles assemblies, which has added fluorescein to SiO2 in a gold shell, to make it simultaneously have the functions of photothermal therapy and tracer.
The Effect of Heat Treating on the Microstructure and Mechanical Properties of Cr-Cu-N Nanocomposite Thin Films
Authors: Lee Jyh-Wei , Zeng Zhi Fan , Wang Chaur Jeng
Published: September 2009

The Cr-Cu-N nanocomposite thin films with copper contents ranging from 1.6 to 24.1 at.% were deposited on silicon wafer substrates using a bipolar asymmetry pulsed DC reactive magnetron sputtering system. A dense and compact structure was observed for the thin film containing higher than 10.2 at.% Cu, whereas columnar structures were revealed on the coatings with less than 10.2 at.% Cu. Heat treatments of the as-deposited thin films were held in a vacuum tube furnace at 400, 450 and 500oC for 30 minutes, respectively. It was observed that the copper atoms would diffuse to the surface to form oxide particles on the coating contained higher Cu content after heating higher than 450oC. The quantity and size of the oxide particles increased with increasing heating temperature and Cu content in the thin film. The hardness of coatings increased after heating except #D thin film containing 24.1 at.% Cu, which the softening effect was found after heating at 500oC. A granular and less dense cross-sectional morphology was observed on #D coating after heat treating at 500oC, which was responsible for the lower hardness of thin film.
ZnS:Ag Luminescent Nanoparticles Synthesized with Different Molar Ratio of S/Zn
Authors: Qu Hua , Cao Li Xin , Su Ge , Liu Wei , Sun Yuan Guang , Dong Bo Hua
Published: September 2009

ZnS:Ag (Ag+-doped ZnS) nanoparticles have been synthesized through the hydrothermal route, and the effects of the molar ratio of S/Zn in reagents have been studied. The products are all cubic sphalerite structure, and the crystallinity is generally increased as this ratio rises. The ratio less than 1 leads to small particles less than 10 nm, and the ratio more than 1 leads to large particles between 20~30 nm. Luminescence properties of samples show significant dependence on the ratio. The sample synthesized using stoichiometric reagents during hydrothermal preparation exhibits the strongest blue emission in this series. There is significant defect luminescence in samples synthesized using nonstoichiometric reagents and the Ag-related luminescence is quenched in them.
Study on the Surface Modification and Dispersion of Multi-Walled Carbon Nanotubes
Authors: Gao Guan Hui , Chen Shou Gang , Xue Rui Ting , Yin Yan Sheng
Published: September 2009

The potential applications of carbon nanotubes are reviewed in this paper. With the development of modification and purification of carbon nanotubes, the scope of carbon nanotubes applications is expanded greatly. This paper pays attention to the modification and dispersion of multi-walled carbon nanotube (MWNTs). The results show that the acid treated MWNTs are highly pure and the surface of treated MWNTs is rough comparably. In addition, treated MWNTs are homogeneously dispersed without any surfactants present in organic solvents of acetone, toluene, and ethanol; the dispersive stability of carboxylic MWNTs dispersions is investigated over 2 weeks.
Experimental Investigation to the Displacement Instability of TGO Near Surface Groove in TBCs due to Thermo-Mechanical Cycles
Authors: Ding Jun , Huang Xia , Li F.X. , Kang K.J.
Published: September 2009

The present paper reports the experimental results for the displacement instabilities occurring near the surface grooves of substrate of Fecralloy material in thermal barrier coatings (TBCs). Two groups of groove with different orientations were carved on the surfaces of specimens. The specimen were then mounted on micro-creep tester and subjected to thermo-mechanical cycling for various holding temperatures and tensile stresses. The result shows that the displacement instability near the horizontal groove decreases significantly as the tensile stress increases, while that near the vertical groove increases with the tensile stress. The higher temperature can cause bigger displacement instability for vertical and horizontal grooves. It is also found that the addition of the yttrium into the substrate considerably improves the interface roughness leading to smaller displacement instability compared to that without yttrium doped.
Characterization of Nanostructured ZnO Thin Films Deposited by Sol-Gel Spin Coating
Authors: Quan Shan Yu , Tian Ming , Yang Lin Mei
Published: September 2009

ZnO thin films have been deposited onto the glass substrates by the sol-gel spin coating method at different chuck rotation rates. The effect of deposition parameters on the structural, optical and electrical properties of the ZnO thin films was investigated. The crystal structure and orientation of the ZnO thin films were investigated by X-ray diffraction (XRD) patterns. The optical absorbance and transmittance measurements were recorded by using a double beam spectrophotometer. The optical absorption studies reveal that the transition is direct band gap energy. The I-V plots of the ZnO thin films were carried out in dark and under UV-illumination. The result shows the obtained ZnO thin films can be used as a photovoltaic material.
Crystal Orientation and Hardness of Au/NiCr/Ta Films on Si-(111) Substrate Prepared by Magnetron Sputtering
Authors: Tang Wu , Yin Xue Song , Deng Long Jiang , Lu Jian
Published: September 2009

Au/NiCr/Ta soft multi-layered metal films were deposited on hard Si-(111) substrate by magnetron sputtering. The crystal orientation, Hardness (H) and Elastic modulus (E) were investigated as a function of substrate temperature by XRD and nanoindentation techniques. The XRD revealed that all films on Si-(111) substrate are Au-(111) preferred orientation, indicating there are no alloying phases in the films, which is different from Au/NiCr/Ta films on Al2O3 substrate with a mixture of Au-(111) and Au-(200) orientation. Nanoindentation tests at shallow indentation depths (h≤t/4) where the hardness is reliable for metal films on hard substrate. Au film at substrate temperature 200°C has the highest hardness 4.2GPa. Meanwhile, the H/E value also indicated that the Au/NiCr/Ta films have preferable wear resistance at substrate temperature 200°C.
Optimization of Hemocompatibility of Silicon Oxynitride Films
Authors: Wang Qi Yi , Yang Ping , Huang Ju , Liang Jun , Sun Hong , Huang Nan
Published: September 2009

Low hemocompatibility is a major problem of biomaterials that come in contact with blood. Surface modification has become an important way to improve the hemocompatibility of medical implants and interventional devices. Recently, researchers attempt to investigate the possibility of silicon oxynitride (Si-N-O) films to be applied as novel coating of blood-contacting biomaterials. However, no detailed investigation has been conducted. In this study, our work was focused on the optimization of the hemocompatibility of Si-N-O films prepared on single-crystal silicon wafers by unbalance magnetron sputtering (UBMS). The structure and chemical composition of films were characterized by X-ray photoelectron spectrometry (XPS), and their physical chemistry property was characterized by contact angle measurements. Platelet adhesion test was performed to investigate the platelet adhesion and activation. Our results suggested that films composed of Si3N4 and SiOx (x<2) exhibited better hemocompatibility than low temperature isotropic pyrolitic carbon (LTIC) that is a common material used in blood-contacting implants. It was also revealed that the higher N/O ratio in films composed of Si3N4 and SiOx (x<2) was attributed to the lower platelet adhesion and activation, and the interaction of samples with plasma proteins was demonstrated to play an important role in the adhesion and activation of platelets.
Electrochemical Behavior of Non-Equilibrium Coatings by Electric Arc Spraying
Authors: Liu Kui Ren , Zhu Qi , Chen Jian She , Ma Peng Cheng
Published: September 2009

In this present work, non-equilibrium coatings (like glassy state but not amorphous texture) were prepared by electric arc spraying using Zn-Al-Mg-RE-Si powder core spun alloy, and the effect of Mg content on corrosion resistance of coatings and the electrochemical properties of alloy coatings in corrosion process were investigated by CASS test, weight-loss test, XRD, SEM, polarization curves and electrochemical impedance spectroscopy. The results indicate that: The corrosion process of non-equilibrium coatings in CASS test includes corrosion inhibition stage and substrate corrosion stage; There appears much micro-crystallite and exists grain refinement in corrosion process; Before CASS test, the corrosion potential of non-equilibrium coatings shuffles when Mg content increases; Before CASS test and after CASS test at 120h and 216h, the corrosion current density approaches the minimum value and the corrosion rate is slowest when Mg content is 2%. Before CASS test, there appears the feature of Warburg impedance, but there did not appear the feature of Warburg impedance after CASS test at 120h and 216h. When Mg content is 2%, the charge-transfer resistance of coating is obviously higher than the coatings with other Mg content. Finally, an optimization composition of non-equilibrium coating—Zn-Al-2Mg-RE-Si coating is obtained by synthesis comparing.
Single Crystalline SnO2:In Films Prepared on Sapphire by MOCVD
Authors: Song Zhen Guo , Ji Feng , Ma Jin , Ning Ti , Pei Xu An , Tan Yong Liang
Published: September 2009

1-12% {atomic ratio of In/(In+Sn)} indium-doped tin oxide (SnO2:In) films were successfully prepared on sapphire substrates by MOCVD method. HRTEM image showed that the obtained films were single crystalline films. The X-ray photoelectron spectroscopy showed the existence of non-stoichiometric oxide on the film surface. The Hall mobility and carrier concentration of the SnO2:In films varied with the In content increasing.
Temperature Control Using MR Fan Clutch for Automotive Application
Authors: Kim Eun Seok , Sohn Jung Woo , Choi Seung Bok
Published: September 2009

This paper presents temperature control of engine cooling system using a controllable magnetorheological (MR) fan clutch. An appropriate size of MR fan clutch is devised and modeled on the basis of Bingham model. Subsequently, an optimization to determine design parameters such as width of housing is undertaken by choosing the reciprocal of the controllable torque as an objective function. This has been performed using a finite element analysis. A sliding mode controller is then designed to control the angular velocity of the MR fan clutch using experimentally determined parameters. The designed controller is implemented and control performances of the MR fan clutch system are evaluated.
Study on Lightweight Composited Electromagnetic Shielding Materials of Flakeboard with Electroless Copper
Authors: Huang Jin Tian , Zhu Jiang , Jia Jin
Published: September 2009

In order to obtain the electromagnetic shielding material, the lightweight flakes of poplar are selected to be the substrate. After the electroless copper plating, the flakes turn to electric cell which is made by hot-press with bicomponent epoxy, and it turn to electromagnetic shielding materials. In this paper, the electromagnetic shielding effectiveness of electromagnetic shielding materials is investigated. The results indicates that the reasonable ratio of main components of the electroless copper plating is: copper sulfate 80g/L, reducing agent 90 g/L, K-Na tartrate (TART) 65 g/L, EDTA•2Na100 g/L, α, α'-dipyridyl 10mg/L, potassium ferrocyanide 50 mg/L. In the testing of Hertzian waves between 9 kHz～1.5GHz, the average effectiveness of electromagnetic shielding is 60.4dB.
Deposition of Fluorocarbon Thin Films on Polypropylene Substrate by RF Magnetron Sputtering
Authors: Zhang Yu Hui , Ji Quan , Chen Wen Fei
Published: September 2009

Radio frequency (rf) magnetron sputtering of polytetrafluoroethylene (PTFE) using argon as the working gas was used to prepare hydrophobic fluorocarbon films on a polypropylene substrate. The morphology, structure and hydrophobicity of the fluorocarbon films were analyzed by means of SEM, AFM, XPS and contact angle determination. The growth pattern in this system was a typical one-dimensional (1-D) Volmer-Weber growth mode. The films demonstrated dependence of structure and hydrophobicity on the conditions of preparation. The contact angle decreased with increasing discharge power and increased with increasing pressure. Those trends are attributed to the presence of differing proportions of -CF3, -CF2-, -CF-, and -C- in fluorocarbon thin films prepared with different energy.