bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on Macro Simulation of Surface Grinding Based on FEM
Authors: Wang Wan Shan , Guan Peng , Xian Yuan Suo , Yu Tian Biao
Published: September 2011

Compared with other metal edged cutting, grinding research is immature on aspect of grinding mechanism and experimental research. With the development of computer technology, FEM is widely used in research of metal cutting process. In this paper, macro simulation of surface grinding is researched with the software MSC.Dytran, and the corresponding experimental study is carried out. On the basis of discussing the simulation cases, the simulation result, especially, grinding force, are analyzed. The simulation and experimental result are basically consistent with the theoretical result.
Preparation and Characterization of Self-Lubrication CBN Grinding Wheel Containing Graphite as Lubricant
Authors: Ding Wen Feng , Xu Jiu Hua , Huang J.L. , Chen Z.Z. , Su H.H. , Fu Y.C.
Published: September 2011

Self-lubrication CBN abrasive composite blocks and corresponding grinding wheels were made through the sintering process of CBN grains, graphite particles and Cu-Sn-Ti alloy at 920° for 30 min. The mechanical strength of the composite blocks was measured by means of the three-point bending experiments. Scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and X-ray diffraction (XRD) were employed to characterize the fracture morphology and the interfacial microstructure of the composite blocks. Dressing experiments were carried out and the graphite film on the CBN grain surface was observed. The results obtained show that the bending strength of the composite blocks with 5 wt.% graphite particles reached 116 MPa, which met the mechanical requirements of the working layer of the grinding wheels. Chemical joining has taken place at the interface of CBN/Cu-Sn-Ti and graphite/Cu-Sn-Ti during the sintering process. Graphite film has been formed and spread to the grain surface after dressing.
Effects of Cutting Edge Truncation on Ultrasonically Assisted Grinding
Authors: Hara Keisuke , Isobe Hiromi , Ismail Mohd Fauzi , Kaihotsu Shoichi
Published: September 2011

Dies for injection molded parts require high-quality surface finishes in terms of both appearance and integrity. Manual finishing by skilled workers is required to produce such surfaces, but this takes several days. To minimize the amount of polishing required, a new finishing technique that employs ultrasonically assisted diamond grinding was proposed in a previous report. Cutting edge truncation prior to grinding is required to produce a mirror surface. In this study, the effect of cutting edge truncation was investigated and the relationships between the ground surface roughness and the cutting torque and the thrust force were considered to optimize the grinding conditions for mirror surface finishing.
Microwave Augmented Fabrication and Evaluation of CNT-Reinforced Nanohydroxyapatite
Authors: Akram Muhammad Aftab , Khan Mohammad Bilal , Hussain Rafaqat , Iqbal Nida
Published: September 2011

Bioactive CNT reinforced hydroxyapatite nano-composite is synthesized by in-situ precipitation for use in load bearing orthopedic applications. Microwaves augment the synthesis, enhance the reaction rate, and institute energy savings. Heat and acid treated purified CNTs in microwaves are functionalized and dispersed in calcium nitrate tetrahydrate. Diammonium hydrogen phosphate is incorporated in calcium ion solution to furnish the required Ca:P ratio. Refluxing of the precursor solution is accomplished under microwaves. XRD shows the phase purity and crystallinity, FTIR spectroscopy indicates the fucntionalization of CNTs and SEM analysis depicts the nanoporous nanomorphology of synthesized powder. TGA measures the thermal endurance of product, showing good CNTs retention at high temperatures (1100°C) in nitrogen ambient, otherwise they get oxidized in air in that temperature range. CNT reinforced sintered biomaterial exhibits excellent consolidation and a Vicker hardness increment of 30%. The relation of between mechanical properties and sintering time is correlated by SEM.
Microstructure and Microwave Dielectric Properties of BaTi4O9 Ceramics Derived from a Sol-Gel Precursor
Authors: Huang Xian Li , Wang Fu Ping , Song Ying
Published: September 2011

In the present work, the microstructure and microwave dielectric properties of BaTi4O9 ceramics derived from a sol-gel precursor were presented. Density measuring results demonstrated that the largest densities of ceramic sample about 96.7% could be reached by virtue of a cool iso-static press and a sintering process at at 1300 °C for 6 hours. The dielectric constant (εr), quality factor (Q×f) and the temperature coefficients (τf) of the BaTi4O9 ceramic samples were 36.65, 28000 GHz, +20.2 ppm/°C, respectively. XRD, SEM and XPS were used to characterize the microstructure of the ceramics samples. Substantial Ti3+ was proposed to be the cause of dielectric loss.
Molecular Beam Epitaxy of Cu-Doped BaSi2 Films on Si(111) Substrate and Evaluation & Qualification of Depth Profiles of Cu Atoms for the Formation of Efficient Solar Cells
Authors: Khan M. Ajmal , Saito T. , Takeishi M. , Suemasu T.
Published: September 2011

The doping of Cu in the BaSi2 films grown by molecular beam epitaxy (MBE) with various Cu concentrations for the suitability of the solar cells was studied in this paper. The main objective of the present work is to investigate and compare the carrier concentration of Cu-doped BaSi2 films grown with different Cu Knudsen cell temperatures and qualify as a potential candidate for more efficient solar cells. The reflection high-energy electron diffraction (RHEED), X-ray diffraction (XRD) measurements and secondary ion mass spectroscopy (SIMS), were used to determine the structure, depth profile and composition of the grown samples. The electrical properties like resistivity as well as carrier concentration were measured by using a four point probe method and Van der Pauw technique, respectively. During the MBE growth, different temperatures for Cu Knudsen cell ranging from 800 to 1200 °C were chosen and the optimum growth condition for both heavily doped n-type as well as p-type in the MBE was investigated. In our previous work, the Al, Sb doped BaSi2 were used as a potential candidate for the formation of pn-junction for solar cells, but the result was not encouraging one due to diffusion and segregation problems in the surface and BaSi2/Si interface regions. In the present work n-type BaSi2 layers with their dopant atoms uniformly distributed in the grown layers for the formation of high-quality of BaSi2 pn-junction with single crystal nature were successfully developed. The realizations to develop cost effective and more efficient solar cells are inevitable for both terrestrial as well as space applications.
Wear Behaviour of HVOF Sprayed WC-Cobalt Coatings
Authors: Mateen A. , Khalid Fazal Ahmad , Khan T.I. , Saha G.C.
Published: September 2011

Tungsten carbide cobalt coating has been extensively used for cutting and mining tools, aerospace, automotive and other wear resistance applications. These coatings not only have superior mechanical properties like high hardness, toughness and compressive strength but have also excellent controllable tribological properties. In this paper a comparison of wear properties and structural phases has been presented to consider for tribological applications. It is found that nanocrystalline duplex coatings have shown much superior properties as compared to the microcrystalline coatings. Evidence of clusters of WC particles was found in microcrystalline coating as compared to homogeneous dense coating structure observed in the nanocrystalline coating. These results are discussed to assess their suitability for super hard wear resistance applications.
Effect of Deposition Mechanism and Microstructure of Nano-Ceria Oxide Addition on Ni-P Coating by Pulse Electrodeposition
Authors: Zhou Xiao Wei , Shen Yi Fu , Jin Hui Ming
Published: September 2011

Pulse current (PC) electro-deposition combined with the ultrasonic (U) field has been used to fabricate pure nickel and nickel-ceria composite coatings. Morphology, ceria (RE) composite, and crystal-texture were observed and analyzed by using environment scanning electron microscopy equipped with energy dispersive X-ray analysis (ESEM/EDAX) and transmission electron microscopy (TEM). Experimental results indicate that it produced the alloying coatings, exhibiting compact grain and be of amorphous state. Nano-sized RE would preferentially occupy and pad the defective area between the cracked gap and micropores to limit the growth of the original Ni grain, and far from coarse grain. Furthermore, during annealed at 500 °C for 2 h, dispersing a solid-solution precipitated phase named NiCexO1-x (0<x<0.5), it would make diffused sufficiently to promote densification and microhardness greatly.
Development of Parametric Model and Warping Analysis of Composite Beam with Multiple Rigid Regions
Authors: Tariq Muhammad Mushtaq , Mehmood Zahid , Mansoor Mohtashim , Ahmed Malik Nazir , Pasha Mustafa
Published: September 2011

Composite materials are used extensively in aircraft structures, automobiles, sporting goods, and many consumer products. Thin-walled multicell beams made of composite materials, have important applications in aerospace structures. The torsion load on these beams is caused due to distance between Centre of Pressure (CP) and Centre of Gravity (CG) of aerospace vehicle in flight. Warping is a result of torsion load and its analysis is important to predict actual behavior of multicell beams. Study of warping displacements is necessary because prevention of warping leads to stress development. Enhancement in design requires design optimization generated by parametric modeling. Problem of cross-sectional distortion can be controlled through use of rigid diaphragms equally spaced along the length of beam. The aim of present study is to establish a procedure for parametric modeling in presence of rigid regions and simulate warping effects caused by torsion on multicell beams. Quasi-isotropic composite material has been used in multicell beams. Four models of multicell beams analyzed have same length and thickness, but different number of rigid regions and corresponding compatible mesh size. Warping is simulated by FEM based computational program ANSYS, and one; ten and seventy rigid regions inside beam were analyzed. Numerical simulations results show that beam with single rigid region has higher axial warping and more uniform rate of change as compared to beams with multiple rigid regions. It was found that first beam model with one rigid region has warping error 41.6%, second and third model each with ten rigid regions (but different edge size) have 2.5% error in warping, fourth model has 70 rigid regions and it has 0% error in warping. Results show that inaccurate interlaminar shear stresses do not affect the warping behavior of multicell beams. Once the parametric model is defined, then it becomes very quick and easy process to perform warping analysis of composite multicell beam with rigid regions.
Aging Response to Microstructure and Properties of Ferromagnetic Shape Memory Alloys
Authors: Bhatty M.B. , Abbas Zameer , Khalid Fazal Ahmad
Published: September 2011

Ni-Mn-Ga magnetic shape memory alloys are employed for applications in actuators and sensing devices. Ni-Mn-Ga single crystalline alloys exhibit ferromagnetic shape memory effect with large reproducible strains in moderate magnetic fields. The cost for producing single crystals is high and there is a requirement to investigate the polycrystalline Ni-Mn-Ga alloys for similar applications. This work presents a study of the effect of composition and heat treatment on the microstructure, in polycrystalline off-stoichiometric compositions of high Ni, Ni-Mn-Ga alloys. Cast polycrystalline alloys were homogenized and analysed using optical microscopy, X-ray diffraction, and thermal analysis. Stability of the martensitic transformation temperature was studied by aging the alloys at different temperatures. Martensitic structure was found in both the alloys (~ 54at% and 58 at%). The alloy with high Ni~58 at% content was found to be having a dual phase structure (martensite and FCC γ). Single phase Ni-Mn-Ga alloy has shown transformation at temperature >400K while the dual phase alloy with Ni ~58at% has transformed at temperature >700K thus making it suitable for high temperature applications. Martensitic stabilization effect was observed in alloy with Ni ~54 at% after aging treatment while it was absent in alloy with ~58at% Ni.
Study on the Moisture Distribution within the Wood Treated with Microwave
Authors: Yu Jian Fang , Guo Ji Long , Nan Jing Ya , Sun Bing Hu
Published: September 2011

In this paper, Siberian elm (Ulmus pumila L) which was regarded as our research object was measured with the technology of Nuclear Magnetic Resonance (NMR) before and after being treated with microwave at different periods of time. By comparing the spin - spin relaxation time of hydrogen nuclear (T2) which can reflect the mobility of water molecules, the states and changes of the moisture distribution within the wood in the process of microwave treatment have been analyzed. The results indicate that in the initial stage of drying, the degree of the decline in bound water is greater than that in free water, for there may be a process of the transformation from bound water to free water; With the drying going on, the movement and expulsion mainly happen to free water above the fiber saturation point (FSP); In the later stage of drying, when the moisture content decreases near the FSP, bound water has also begun moving significantly on the expulsion of plenty of free water. In the final stage of drying, the decrease of hydrogen bonds in water molecules resulting from a plentiful reduction in free water, as well as the increased permeability within the wood caused by the microwave drying makes the relaxation time of free water to rise up.
Rheological Behavior of Silver Paste Prepared from Nanoparticles
Authors: Luo Shi Yong , Chen Juan , Xu Wen Cai , Zhang Xin Lin , Huo Li Xia
Published: September 2011

A paste with as low as 300°C sintering temperature was prepared by using nano silver particles and ethyl cellulose solution. The rheological and thixotropic behaviors of the typical paste were characterized and their effects on the screen printing ability were analyzed in details. The paste demonstrates a typical shear thinning rheological behavior and thixotropic of pseudoplastic fluid. The apparent viscosity decreased rapidly with the increase of the shear rate. The paste is proper for the manufacturing electrical components at a low temperature as low as 300°C.
The Application of Thermosensitive Gel Nano-Material in Neurosurgery
Authors: Zhang Bing Jie , Wang Li Mei
Published: September 2011

Thermo-sensitive gel is a kind of macromolecular material with temperature sensibility character. It is liquid under room temperature, and it can be changed to semisolid gel under animal body temperature. Then the medicament in the gel can be released gradually, to gain the sustained-release. We can make use of this character. The makeup of thermo-sensitive gel has a lot of ways, and recently the most in common use is PNIPA. It can be used in tumor cavity’s coating sustained-release chemotherapy after surgical operation, all use methods including：1. Brain glioma re-growing always be happened in tumor local site after neurosurgery operation, and inosculate the chemotherapy medicament into chitosan nanospheres slow-releasing particulates. Then mix into the thermosensitive gel , to be made to spray. During neurosurgical operation, after the surgical treatment for tumor, we spray it in the brain parenchyma cave remain after cutting tumor. When the thermosensitive gel meets the animal temperature, it is changed to membrane-wise glue attached to the tumor cave face. Then after surgical it can absorb moisture nearby, and gel membrane and chitosan nanospheres will release medicament continually. After glioma surgical treatment, the chemotherapy is slowly released partially. 2. Stereotactic surgery injection release interstitial chemotherapy. Under stereotactic apparatus inject gel into the centre of tumor, then the gel changes to colloid from liquid, and then the gel no outflow from tumor. The stereotactic technology offers the effective biopsy, diagnose and accurate and safe administration route for malignant glioma in brain’s depth which cannot be surgical treatment. 3. Embolization chemotherapy in tumor vasculature. Inject the thermosensitive gel into tumor artery, and some parts of gel curdle gradually, then it can embolize tumor capillary network, to interdict the blood to tumor, to control tumor’s growth. In the meantime medicament in gel release gradually, to win the chemotherapy. 4. Cerebral aneurysms and cerebral arteriovenous malformation embolization. Thermosensitive gel makes use of the difference between room temperature and animal heat to make embolism.
The Application of Image Stitching in the Robot Target Recognition
Authors: Guo Lan Shen , Dong Nai Qiang , Tian Wei , Li Cai Xiao , Zhang Fang Zhong
Published: September 2011

Images are widely used in engineering work and scientific research, therefore, it is necessary to identify the image. The image recognition technology is one of the core technologies in traditional production and life, but the identify limitations can not meet the needs of many aspects of the identification problem. Use image stitching technology can increase the angle range of the target image and enhance the image definition, to achieve the identification of target image accurately.
The Application of ADRC in the Ship Main Engine Speed Controller Based on Genetic Algorithm
Authors: Wang Chang Shun , Zhou Ying Bing , Pan Wei Gang , Han Yao Zhen , Zhou Feng Yu
Published: September 2011

Marine diesel engine electronic governor is an important component of the main engine monitoring system, the major problems of current electronics governor is that there is generally more obvious variable gain self-tuning in the main marine, as well as large changes in operating environment, vary speed requirements under different sea conditions. Traditional control methods can’t be satisfactory. To get a better effect, auto disturbance rejection control techniques is introduced. In this paper, the question of ADRC parameter setting is solved combined with genetic algorithm.
The Inertia Force of Insect-Like Flapping Wing Micro Air Vehicle
Authors: Zhu Dan , Wang Qiang , Hu Ming Lang
Published: September 2011

We used the method of theoretical modeling and simulation to study how changes in wing kinematics influence the production of inertia forces and moments in flapping flight. We examined 153 separate sets of kinematic patterns that differed with respect to stroke amplitude, mid-stroke angle of attack, acceleration and deceleration duration of flip rotation and acceleration and deceleration duration of azimuthal rotation. For each pattern, we also calculated mean stroke- or quarter - averaged values of the inertia forces and force moments. The results of the analysis may be divided into three main point: (i) The insect wing’s chordwise inertia is much higher than its spanwise inertia--higher by an order of magnitude; (ii) The influence of inertia moment of azimuthal rotation is much higher than that of inertia moment of flip rotation, so the inertia moment of flip rotation can be ignored; (iii) Consider the flapping motion is approximate symmetrical if the stroke is symmetrical and the flapping motion is absolute symmetrical if the stroke and the flip is both symmetrical, then the inertia force can be ignored.
Design and Implementation of Motor Servo Control System with Analysis of Scientific Materials
Authors: Li Xiao Guang , Huang Hui Ying
Published: September 2011

A servo-motor control system of robot based on ARM9 processor and LM629 are introduced. With the features of fewer electronic components, stable performance and higher real-time, the system greatly simplifies software and hardware design of the motor servo control system. The experimental results show that the system has high accuracy and stability relatively and the system design is reasonable and feasible.
Synthesis, Properties and Optical Recording of a Novel Unsymmetrical Photochromic Diarylethene
Authors: Wang Li Qin , Pu Shou Zhi , Yan Liu Shui , Cui Shi Qiang
Published: September 2011

A new unsymmetrical photochromic diarylethene, 1-(2-methyl -3-benzothienyl)-2-(2-nbutyl-5-methylol-3-thienyl)perfluoroncyclopentene (1a), was synthesized and its optoelectronic properties, such as photochromism in solution as well as in poly-methylmethacrylate (PMMA) amorphous films and fluorescences were investigated. Using diarylethene 1b/PMMA film as recording medium and a linearly polarized 633 nm laser diode for recording and readout, polarization multiplexed image recording can be carried out in this film, which illustrated that the diarylethene can be potentially used as holographic optical recording medium.
Efficient Synthesis and Properties of a New Photochromic Diarylethene Bearing a Thiophene Moiety
Authors: He Shang Hua , Liu Gang , Wang Ren Jie
Published: September 2011

A novel photochromic diarylethene based on thiophene moiety was synthesized and its photochromic and fluorescent properties were also investigated. This compound exhibited reversible photochromism, changing from colorless to violet after irradiation with UV light. It underwent reversible cyclization and cycloreversion reactions upon alternating with UV and visible light both in solution and in poly-methyl methacrylate (PMMA) amorphous film. Also, it exhibited remarkable fluorescence switching in the solid state. Using this dithienylethene 1c as optical storage was performed successfully.
Inverse Arithmetic of the Equivalent Heat Transfer Coefficient of Mine Goaf
Authors: Heng Shuai , Gao Feng , Liu Xing Guang
Published: September 2011

In order to calculate the dissipating capacity of heat sources and improve the veracity of airflow temperature forecast of mine, the equivalent heat transfer coefficient of mine goaf was calculated by means of inverse arithmetic based on the law of conservation of momentum and measured data from a high temperature working face. The results of calculation show that the equivalent heat transfer coefficient of mine goaf can reflect the heat dissipating characteristics generally and reduce the calculating method of the heat dissipating capacity of mine goaf, then it can be used better in the airflow temperature forecast.
The Dynamic Response of the Clamped Beam under Low Velocity Impact
Authors: Long Wen Gui , Tan Zhu Hua , Liu Yang , Wang Fu Rui
Published: September 2011

A simplified theoretical model about the impact energy and maximum deflection was acquired based on the principle of virtual work while clamped beam subjected to low velocity impact. Finite element simulations have been undertaken to further understand the response of the clamped beam, the results show that: A good agreement has been obtained between theoretical model and numerical results, the dynamic response of the clamped beam is divided into four stages: elastic fluctuation, the overall structural response, unloading response and free vibration, the formation of plastic hinge occurred in the overall structural response stage.
A Creative and Practical Study on the Theory of Developing Work Process
Authors: Zhong Chang Zhen , Jiang Liang Fu
Published: September 2011

In the developing process of an applicative system or a professional knowledge system, first we collect the required information by investigation, next study fully all kinds of rules, information, methods, programs and tasks, then abstract a general logic pattern so as to develop a matching applicative system or a professional knowledge system, finally perfect and optimize the system by means of relevant assessment criterion and methods. The system developed as above can efficiently imitate, reflect and realize the real work process. As for improving the efficiency of system and its development, improvement and creation of the theory and method of gaining and analyzing the required information in its developing process, the formation of the system’s general logic model, the system’s actual development and the design, assessment and perfection of the system are needed. Combined with practice, this article has showed some related creative research in every step in the base of the developing theory.
Microwave Absorbing Properties of Radar Absorbing Structure Composites Filling with Carbon Nanotubes
Authors: Zhang Zheng Quan , Wang Li Ge , Wang En Ze
Published: September 2011

Radar absorbing structures (RAS) can’t only load bearing but also absorb electromagnetic wave energy by inducing dielectric loss and minimizing reflected electromagnetic waves. Therefore, the development of the RAS haves become important to reduce RCS of the object. These composites possess excellent specific stiffness and strength. The electromagnetic wave properties of RAS can be effectively tailored by controlling the content of the lossy materials. Radar absorbing structures composed of glass fibers, carbon fibers and epoxy resin filling with carbon nanotubes (CNTs), was designed and prepared. Permittivity of the composite was measured by using a network analyzer, HP8510B. The contents of composites were observed to be different from each composite. Reflection of electromagnetic waves energy of RAS was calculated by using the genetic algorithm, it was discovered that the composites can be applied to design an optional RAS composites filling with CNTs.
A Special Manufacture of Nanowires with High Precision and its Concrete Implement
Authors: Zhe Wang , Xian Qin , Fan Jiao Rong
Published: September 2011

This paper describes a way to realize the manufacture of nanowires in detail, which would be discussed mainly on the implement methods as well as the specific craft. Accounting for the cost, this way relied relative fewer on the high-precision photoetching machine, while it took use of the excellent surface of Si and SiO2, applying oxidation to diminish the width of these wires[1]. The paper would cover some regulations of conditions and concrete steps to present a whole technical process.
Study on Phase Structure and Electrical Properties of La-Doped (K0.5Na0.5)0.94Li0.06NbO3 Ceramics
Authors: Liu Yong , Chu Rui Qing , Xu Zhi Jun , Chen Qian , Shao Lin , An Kang , Li Guo Rong
Published: September 2011

Lead-free piezoceramics (K0.5Na0.5)0.94-3xLi0.06LaxNbO3 were synthesized by the conventional solid-state reaction process. The effect of La-doping on the phase structure and electrical properties of (K0.5Na0.5)0.94Li0.06NbO3 ceramics was investigated. X-ray diffraction analysis showed that the crystal structure of the ceramics changed from coexistence of orthorhombic and tetragonal phases to pseudo-cubic phase with the increase of La-doping level, and the change of phase structure seriously weakened the dielectric, ferroelectric and piezoelectric properties of the ceramics. In addition, it was found that the La-doping improved the density of the ceramics and the ceramics became dense. Meanwhile, the ceramics with La-doping displayed a relative lower loss tangent (tanδ) from room temperature to approximately 350°C.
A Rotary Magnetorheological Damper for a Tracked Vehicle
Authors: Yang Lin , Chen Si Zhong , Zhang Bin , Feng Zhan Zong
Published: September 2011

A rotary magnetorheological (MR) damper for a semi-active suspension was developed, laboratory tested. The working principle and features of the rotary MR damper was outlined and its theoretical model was developed. Full optimization of the magnetic design was accomplished with the help of magnetic finite element software ANSYS in the limited space. The parameters of the MR damper’s theoretical model were identified by a series of harmonic loading tests. It is demonstrated that the damping capacity of this MR damper is a function of strain amplitude and field strength, and it is feasible to use for the life application in terms of force characteristics.
Creep Properties and Damage Study of Ni-Based Alloy C276 at High Temperature
Authors: Mao Xue Ping , Guo Qi , Zhang Sheng Yuan , Hu Su Yang , Lu Dao Gang , Xu Hong
Published: September 2011

One of the two challenges about Supercritical Water-Cooled Reactor is material, especially for the fuel cladding. High temperature creep tests of Ni-based alloy C276, one of the candidate materials for the fuel cladding, were carried out at 650°C~750°C, with stress 130MPa~430MPa. The effects of temperature and stress on creep were investigated, the change laws of steady state creep rate with stress and time to rupture were analysed, and creep damage factors were separately calculated based on Kachanov’s formula and Norton’s formula. The results indicate that there exist two types of primary creep characteristics in C276: Type I creep characteristic at lower stress level and Type II at higher stress level respectively. C276 shows excellent high temperature creep resistance, and Kachanov’s damage factors D vs normalized time are basically coincident at 650°C, 700°C and 750°C. The damage obtained by Norton’s formula starts at about 40% of lifetime, and the damage factors calculated by Kachanov’s formula are relatively conservative.
Research for Damping Behavior and Microstructure of Interpenetrating Polymer Networks Based on Multi-Components
Authors: Li Yong Qing , Zhu Xi , Luo Zhong , Sun Wei Hong
Published: September 2011

Based on the molecule design and energy absorption theory of polymer macromolecule materials, we synthesized a kind of multicomponents interpenetrating polymer network(IPN) which composed of polyurethane(PU), epoxy(EP) and unsaturated polymer resin(UPR). In order to further widen the damping temperature region of polymer materials, we introduced the polydimethylsiloxane (PDMS) into polyurethane(PU). Because of solubility parameter difference between PDMS and PU, we synthesized PDMS modified PU by blocking and grafting PDMS chain into PU main chain firstly. Then, a serious of interpenetrating polymer networks (IPN) which composed of PDMS-PU, EP and UPR were designed and synthesized. The damping performance and microstructure were characterized by using the spectrum of dynamic mechanical thermal analysis (DMTA) and the scanning electron microscope(SEM) respectively. The tested result indicated that the multicomponents IPN which modified by PDMS has wider temperature range and higher damping loss factor, and the PDMS grafting PU/EP/UPR shows good damping performance and microphase compatibility specially.
Numerical Calculation on Flaw Response in Inhomogeneous Media
Authors: Zheng Gang Feng , Wu Bin , He Cun Fu
Published: September 2011

Ultrasonic methods are used in a wide variety of applications including medical studies, geological mapping, and nondestructive evaluation (NDE) tests. In the field of ultrasonic NDE, it is necessary to treat inverse problems of various types. The objective of this paper is to predict the flaw response in an inhomogeneous solid medium. A mathematical modelling of the testing situation is very valuable for a number of reasons. The modelling helps in developing physical intuition and in the interpretation of tests. Multi-Gaussian Beam (MGB) model is used to represent the incident ultrasonic beam. The effect of ultrasonic attenuation and phase velocity dispersion due to grain scattering is included in the predictions. The variation of received voltage is analyzed against the distance of the flaw from the transducer for different dimensions of a square cylinder void. The effect of variation of mean diameter of the grains on the received voltage for different domain of interest is also studied.
Solution-Based Doping of Cobalt into ZnO Nanorods Membrane
Authors: Ma Pei Yan , Wu Yan , Fu Zheng Yi , Wang Wei Min
Published: September 2011

Co-doped ZnO nanorods membrane was deposited at glass substrate in a simple chemical water bath. The morphology and crystal structure of the samples were characterized by SEM, TEM and XRD. It is shown that the ZnO rods membrane exhibits an excellent orientation along the c axis. X-ray diffraction study also indicates decrease in the lattice parameter after Co doping. The results of EDS and XPS verify that Co2+ is successfully doped into the lattice of nano ZnO rods. 2at% and 5at% Co doped ZnO rods behave stronger UV emission and weaker visible emission.
Effect of Nano-Filler Network on the Rheological Behaviours of Poly(vinylidene fluoride) Nanocomposites
Authors: Tang Xue Gang , Hou Meng , Zou Jin , Truss Rowan
Published: September 2011

A nano-filler network constructed by layered silicates and multi-wall carbon nanotubes (MWCNTs) has been prepared. The structure of the network was confirmed by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), transmission electron microscopy (TEM), and dynamic rheological test. The results showed that a plateau in the storage modulus at low frequency occurred, which indicated the pseudo solid-like behaviour for the sample with nano-filler network, and the jamming effect due to the nano-filler network dominated the viscoelatic behaviour at low frequency. This effect was sensitive to the frequency and decreased quickly with the increase of frequency. At the same time, the introduction of nanofillers and the presence of nano-filler network affected the complex viscosity and shear thinning too, especially at low frequency.
Exploration of the Defect’s Effect on the Mechanical Properties of Different Orientated Nanowires
Authors: Zhan Hai Fei , Gu Yuan Tong
Published: September 2011

Molecular dynamics (MD) simulations have been carried out to investigate the defect’s effect on the mechanical properties of copper nanowire with different crystallographic orientations, under tensile deformation. Three different crystallographic orientations have been considered. The deformation mechanism has been carefully discussed. It is found that the Young’s modulus is insensitive to the defect, even when the nanowire’s crystallographic orientation is different. However, due to the defect’s effect, the yield strength and yield strain appear a large decrease. The defects have played a role of dislocation sources, the slips or stacking faults are first generated around the locations of the defects. The necking locations have also been affected by different defects. Due to the surface defect, the plastic deformation has received a large influence for the and orientated nanowires, and a relative small influence is seen for the nanowire.
Two High-Speed and Large-Drive-Current BiCMOS Analog Switches
Authors: Cheng Li , Xi Jia Jian , Li Ning , Yang Ning
Published: September 2011

In order to obtain high-speed and large-drive-current during operation, this paper proposed two structure-advanced BiCMOS analog switches. On the key parts of the circuit, a few Bipolar Junction Transistors (BJTs) were used while for the main parts, the Complementary Metal Oxide Semiconductor (CMOS) devices were configured. The component parameters were optimized and the measures for accelerating the operation and raising the drive-current were taken. The performance of the proposed two analog switches was tested through simulation and experiments of hardware circuits. The results indicated that the Delay-Power Product (DP) of the BiCMOS operating in the voltage range of 2.5V~3.5V is reduced by an average of 26.1pJ and the driving current is more than 1.38mA as compared with those of the conventional CMOS analog switches. These advantages show the great potential of the proposed two BiCMOS analog switches in the digital communication systems which require low-voltage, high-speed and large-drive-current.
The Key Technology in the Parallel Control of Inverter
Authors: Qin Juan Ying , Wang Quan , Zhou Jun Hua
Published: September 2011

Flow equalization is one of the key technologies in the parallel control of inversion module. This paper presents the multi-inversion module parallel flow equalization system with TMS320LF2407A as the main control chip, which adopts the control strategy of “synchronous control of seizure and coincidence”, gains the data communication in the multi-module parallel connection and the multi-inversion module parallel flow equalization control with CAN controller embedded in TMS320LF2407A. It can be seen from the experimental data and experimental wave that it can effectively restrain the ring current and achieve the equipartition of load in the condition of resistive load and inductive load or capacitive load to achieve the data communication among the parallel inversion modules.
Comprehensive Evaluation on Technical Economic Performance and Scheme Optimization for Asphalt Mixture
Authors: Chen Zhong Da , Xing Lei , Wang Wei
Published: September 2011

The pavement performance of asphalt mixture and its adaptability to features of application area, cost estimation and harmonic relationship between performance and cost were studied and analyzed in this paper, evaluation model of technical and economic performance of asphalt mixture was constructed, evaluating indicators of technical and economic performance of asphalt mixture as performance matching coefficient, cost conversion demarcation coefficient and harmonic factor of performance and cost and corresponding calculation methods were proposed. On this basis, discrimination function of performance and cost was built to provide theoretical basis and decision support for selecting a satisfactory asphalt mixture scheme which had the best pavement performance and economic performance under certain natural and constraint conditions, it can provide a reference for the development of assist decision function of managerial system of pavement maintenance as well.
The Effect of Preparation Conditions to Crystall of Ti Film
Authors: Lai Qi , Huang Shuang Hua
Published: September 2011

Ti film on AISI 201 was prepared by plasma. The film was characterized and analyzed by using XRD. it was found that of Ti film has a different microstructure in different condition. With negative bias increased from 15V to 260V, the diffraction peaks of Ti films changed from planes (111) to planes (200). With power increased from 8W to 145W, the diffraction peaks of Ti films decrease at planes (002), the diffraction peaks of Ti films decrease at planes (102) and (103). The result suggests that negative bias and power contributed to form an different phase throughout the films. The vacuum, distance and time have no effect to crystal of Ti film.
Experimental Study on Synthesis of High Purity Mullite
Authors: Shi Zhen Wu , Xie Nian Suo
Published: September 2011

In this paper, the influence of sintering temperature on the output rate of the mullite which was formed from andalusite ore of Mei County Shaanxi at different constant temperature 1350°C, 1450°C, 1550°C and the mechanism which mullite was transformed were studied. The morphology of mullite formed at 1450°C was obtained by SEM, and the phase composition of andalusite ore sintered at different temperature was analyzed by XRD. The results shows that the mullitization effect of andalusite ore of Mei County Shaanxi is excellent, and the yield of mullite mineral can reach the desired results of 100% after andalusite mineral of Mei County Shaanxi is kept warming for 3 hours at the sintering temperature of 1450°C and cooled naturally with box-type resistance furnace. The mullite phase synthesized by andalusite ore of Mei County Shaanxi depends on not only the decomposition of andalusite, but also the secondary mullitization and the dissolution mechanism.
Leaching and Detecting Free Magnesium Chloride for Magnesium Oxychloride Cement
Authors: Li Ying , Yu Hongfa
Published: September 2011

The content of free MgCl2 is one of the key indicators of deliquescence, dehalogenation and efflorescence for Magnesium Oxychloride Cement (MOC). A range of possible techniques for assessing the free MgCl2 content of MOC have been investigated. The techniques are based on mixing powdered samples with absolute ethyl alcohol and measuring the amount of MgCl2 passing into solution. The influence of temperature of solvent, extraction time, fineness, agitation and liquid to solid ratio (L/S) are discussed. The results of recovery tests ranged 96.37% or above. The method is successfully applied to leaching and detecting free MgCl2 in commercial magnesium oxychloride cement fireproof board.
Experimental Study on the Anti-Cracking Property of Basalt Fiber for Cement-Based Materials
Authors: He Jun Yong , Huang Xiao Qing , Tian Cheng Yu
Published: September 2011

Basalt fiber has the advantages of non-pollution and omnipotence, and will be widely used in the 21st Century. Therefore, more and more attention is paid on experimental research on the basalt fiber in the world. First,according to the requirements of the fibers used in the cement-based materials, the contrast testing of the plastic shrinkage between fiber cement mortar and pure mortar was made. The experimental results showed that basalt fiber , polypropylene fiber and polyacrylonitrile fiber can be preliminarily chosen as reinforced fibers in cement-based materials. Finally, taking both characteristics of basalt fiber and the increase of cement-based materials costs into account, it can be drawn that top priority should be given to the basalt fiber rather than to other fibers for cement-based materials.
Study on the Preparation of Nano-Cu2O and its Morphology Control
Authors: Zhao Bin , Ma Di
Published: September 2011

Nano-Cu2O has wide application prospects in the fields of chemical industry and engineering due to its special optical, electrical and catalytic properties. The nano-particles with different morphological structure and particle size have different physical-chemical properties and different application fields. Therefore, this article reviewed the preparation methods of Nano-Cu2O at high/room temperature and the key point of its morphology control.
Preparation and Microstructure of Co-Ferrite Fine Powder
Authors: Zhang Chang Sen , Yang Lei , Zhou Feng
Published: September 2011

Cobalt ferrites were prepared by citrate sol-gel method, chemical co-precipitation, mechanical grinding, respectively. The grain size, morphology, and the size of crystal particles were studied by x-ray diffraction (XRD) and scanning electron microscope (SEM). Cobalt ferrite showed different morphologys when prepared by different methods, It was tapered corners which prepared by sol-gel method; It was tetrahedral which prepared by mechanical grinding method; It was sphere which prepared by chemical co-precipitation method. The average grain size of cobalt ferrite was less than 100nm, while particles prepared by chemical precipitation method were the smallest. The size of Cobalt ferrite prepared by sol-gel method was decreased with the cobalt content increased.
The Influence of Friction on Forming Accuracy of Tubular Parts by Hydroforming with Radial Crushing
Authors: Yang Lian Fa , Lei Pan , Guo Chen
Published: September 2011

Forming accuracy is one of the important indicators to evaluate the forming quality of a tubular part by tube hydroforming. However, shape asymmetry on cross-section of tubular part produced by hydroforming with radial crushing (THFRC) inevitably appears due to the friction between the die and the part. In this paper, a circular tube is formed into a square cross-section one by THFRC under the various loading paths and the influence of friction on the forming accuracy of cross-section of the bulged parts is analyzed by using numerical simulation. The results show that the larger the tube is expended to, the lower the forming accuracy is under the identical coefficients of friction (COF); the larger the COF value is, the lower the forming accuracy is under a constant maximum hydraulic pressure. In a word, a reasonable loading path and a low COF value can observably improve the forming accuracy of the bulged tube.
Thickness Optimization of SPF for Titanium Alloy Negative Angle Parts
Authors: Shao Zong Ke , Huang Zhong Guo , Jin Shun Yao , Yuan Qing Hua , Zhou Yu
Published: September 2011

With the Superplastic forming technology, the problem that the forming of the complex titanium alloy parts is difficult has been solved. The high temperature forming characteristics of the titanium alloy material and the establishment of the constitutive model of material that will be used as the material model of the simulation of the material forming (the minimum thickness is larger than 0.8 mm) about the negative Angle parts are based on high-temperature tensile test. The influence of the thickness of the parts is analyzed from three different SPF schemes, which are simulated by the MSC.MARC software. The results demonstrate the parts taking advantage of two-stage SPF, which is consisted of concave die SPF method and convex die SPF method can meet the requirement of minimum thickness and improve the thickness distribution on the die draft sides. Furthermore, the thickness distribution of the parts is more uniform with the convex die SPF method.
Different Thickness of Honeycomb Paperboard Vibration Frequency of Testing and Simulation
Authors: Wang Bao Zhong , Cao Li Jie
Published: September 2011

This paper measured the vibration transmissibility of several honeycomb paperboards and the attenuation coefficient. Laboratory was used to determine the natural frequency of the thickness of 10mm, 20mm, 30mm, 40mm Honeycomb Paperboard. The test results show that the honeycomb paperboard resonance frequency decreases with increasing thickness, while the vibration transmissibility increases with increasing thickness. We have also established finite element model of honeycomb paperboard to simulate its vibration properties. The result of simulation is in good coincidence with the experimental result. In addition, some cases can use computer simulation instead of laboratory testing to obtain the natural frequencies of honeycomb paperboard.
Study on Parametrical Modeling about Free-Surface Based on UG Customization
Authors: Geng Tie , Ren Qing Hai
Published: September 2011

First, the topology of free-form surface of an electronic vacuum product was analyzed and studied. Then, the parametrical modeling about such complex free-form surface was realized by using UG/KF customization. So, the repeatability of modeling about such complex free-form surface with same or similar topology was reduced, and the modeling time was saved, and the design efficiency and quality were improved too.
Nonlinear Cumulative Fatigue Damage Model
Authors: Zou Hua , Li Qiang , Sun Shou Guang
Published: September 2011

Cumulative fatigue damage is an important consideration in determining the fatigue life of structures. A cumulative linear damage rule cannot provide a reasonable explanation for cumulative fatigue damage, but a damage curve method based on nonlinear cumulative fatigue damage model can give a reasonable explanation. In this paper, a specific mathematical model is put forward, which is based on the damage curve method. In the model, miner formula is modified properly and an exponent formula is give out to fit the damage accumulate. According to a two-step fatigue test of aluminum–alloy welded joint, the comparison between the calculated results and the testing results is less than 5%. It shows that the model is reasonable and accuracy.
The Effect of Cerium Substitution on Electromagnetic Properties of NiZn Ferrites
Authors: Zhong Hui , Yang Jie , Wang Hua Lei , Shi Yu
Published: September 2011

An extensive investigation of electromagnetic properties has been carried out on the CeO2-doped NiZn ferrites, (Ni0.44Zn0.56Fe2O4), prepared by solid-state reaction technique. X-ray diffraction (XRD), scanning electron microscopy (SEM), and LCR meters were used to analyzed the ceramic phase, microstructure, permeability, permittivity, and quality factor. The results show that the real dielectric constant increases by proper amount of CeO2 substitution, and the magnitude of this increase is not linear with the content of CeO2. Initial permeability decreases with the increasing Cerium content. The quality factor reaches the maximum value (194 at 1 MHz) when the added CeO2 content is 2.0 wt%. CeO2 substitution increase the resistivity of NiZn ferrites.