bluuebunny/crossref_metadata_2025 huggingface dataset:
Future Transmissions for Wind Turbines
Authors: Höhn Bernd Robert
Published: August 2011

Most transmissions for wind turbines are set up by multiple consecutively arranged planetary gear sets and/or normal gear sets. Therefore these transmissions have a constant ratio. In order to feed the electricity produced by the wind turbines into the grid, an electric conversion to a constant frequency of 50 Hz is necessary. FZG developed a new concept for transmissions of wind turbines based on a planetary gear. By superposition of a small electric engine the transmission ratio is continuously variable. This makes an electric conversion unnecessary and thereby increases the efficiency of the wind turbine.
Load-Excursion Failure Analysis of the Gearbox’s Input Pinion
Authors: Ning Feng Lian
Published: August 2011

In this paper, the failure of gearbox’s input pinion was introduced. According to gearbox structure, the factor of load-excursion was analyzed and a method of correcting gear’s helix angle was proposed. Finally, the problem was solved by correcting the gear’s helix angle and thinking about the influence of the bushes matting under heat conditions. The calculation method of correcting gear helix angle was proven to be valid by other gearbox tests, and provided a reference for correcting the gear’s helix angle of other gearbox’s.
New Calculation Method for the Load Capacity of Bevel And Hypoid Gears Based on Loaded Tooth Contact Analysis
Authors: Höhn Bernd Robert , Stahl Karsten , Wirth Christian
Published: August 2011

At the FZG (Gear Research Centre, Munich, Germany) a research project was carried out to analyze the influence of the hypoid offset on the load capacity of bevel gears by systematic theoretical and experimental investigations. For the experimental investigations two types of bevel gears were designed, one for the pitting tests and one for the tooth root tests. The results of the tooth root tests showed as expected an increasing load capacity with higher offsets. In contrast the pitting tests showed an increasing, but after reaching a maximum, a decreasing load capacity with higher offsets. Regarding the test results a new calculation method was developed that is based on a loaded tooth contact analysis (LTCA). The method is able to consider the local stresses on the flank and in the tooth root. The local strength values are derived out of the standard ISO 6336 for the calculation of helical gears. For bending the local geometry of the tooth root is considered to adopt the strength values of helical gears to bevel and hypoid gears. As a result the local safety factors might be calculated along the face width of pinion and wheel. For pitting the local sliding conditions are taken into account in order to appraise the local lubrication conditions as well as the risk of crack initiations due to shear stresses and higher contact temperatures. The recalculation of the test showed for both types of failure a good correlation between the test results and the calculated values.
Dynamic Analysis of Combined Gear Drive
Authors: Wang Ying , Liu Hai Xia , Wang San Min
Published: August 2011

Combined gear drive is a common transmission form for high power drive systems. In order to study its behaviors of redundant drive, which improve the system reliability but lead to a problem of inter-excitation of vibrations, dynamic analysis becomes very necessary. First, considering the influences of gear meshing errors, backlashes and time-varying meshing stiffness, a nonlinear dynamic model of sixteen degrees of freedom is developed by using lumped parameter method. Then a nonlinear differential equation set is derived for calculating the steady-state forced response to the internal sinusoidal excitation. After that, time history wave of displacement responses, phase graphs, Poincaré maps and FFT (Fast Fourier Transform) spectra are analyzed. Finally, some useful conclusions are obtained.
Dynamic Modeling of Multi-Stage Planetary Gears Coupled with Bearings in Housing
Authors: Xiao Zheng Ming , Qin Da Tong
Published: August 2011

This work develops an analytical model of multi-stages planetary gear transmission (PGT) coupled with bearings in housing based on analyzing the displacement relationships of gearing system. The model adopts three planar degree-of-freedom for each of the central components, and the rotational degree-of-freedom for the planets of each stage. Considering the gyroscopic effects, the modified transverse-torsional model is established in the rotating Cartesian coordinates by lumped-parameter method, which is more accurate and may match with the physical model better than the purely torsional model. According to the design parameters of the 3-stage planetary gears of main reducer of shield tunnelling machine, the natural frequencies and vibration modes are investigated by using this transverse-torsional model.
Design and Manufacture of Helical Planetary Gear Reducer with Small Module and Big Helical Angle
Authors: Deng Jia Ming , Shen Hui Ping , He Lun , Zhu Wei , Tang Da Mei , Ding Lei , Li Ju , Zhou Wen Zhong
Published: August 2011

Aiming at the helical planetary gear reducer with the small module (m≤0.8mm) and big helical angle (β≥20°) applied widely, a novel method of the design and manufacture is come up. The developed reducer matched with the suitable motor not only reduces output speed and inertia of the motor, but also increases greatly stability of tooth meshing. Thus, it could reduce transmission noise and favorably increase the output torque of the motor. So it has a wide application prospect.
Globoidal Indexing Cam’s CAD/CAM Development on Pro/E
Authors: Xu Nian Fu , Xu Feng , He Wei
Published: August 2011

Because of the design and manufacture of the globoidal indexing cam mechanism is very difficult, this paper developed a globoidal indexing cam CAD/CAM system by using Pro/ Engineer’s further development module Pro/Toolkit, which can simplify the process of designing the globoidal indexing cam. The main idea is that designing cam by parameters and generating the data points of the indexing cam automatically by the computer.
Application of Contact Analysis in Strength Analysis of Helicopter Transmission System
Authors: Li Wei
Published: August 2011

Taking the strength analysis of the tail rotor transmission system for one type helicopter as an example, the implicit nonlinear finite element contact analysis was taken to the control arms and flange of the tail rotor pitch control system using MSN/NASTRAN in this paper. It was pointed out that rightly modeling the actual load and boundary conditions of components is essential in the strength analysis of the transmission system.
Investigation and Application of the Helicopter Typical Flight States Identification
Authors: Wan Zhen Hua
Published: August 2011

Typical flight states are the most important checking items during the helicopter flight-test. This article intends to illustrate the typical flight states identification method via introducing the basic theory and characteristics of helicopter control, and then apply this method to load analysis and compilation of loads spectrum.
Mechanisms of Synchronous Belt Tooth Failure due to Fatigue Shear Fracture
Authors: Guo Jian Hua , Jiang Hong Yuan , Li Dong Sheng
Published: August 2011

Conformal mapping with complex function based on plane elasticity mechanics is an analytical method for resolving stress and displacement at any point of a half-plane domain. Using complex function conformal mapping method in this article we investigated the relationship between load on tooth surface and maximum stress at tooth root for calculating the maximum compressive stress on the opposite side of working flank and maximum tensile stress on working flank side when loads are applied to tooth top and root of working flank side, respectively. The maximum tensile and compressive stress at the tooth root are the main forces that cause fatigue cracking of the tooth root, which may extend along the elastomer compound-cord interface resulting in shear cracking of the belt tooth. The results of our calculation reveal the mechanisms whereby tooth shear cracking causes fatigue failure of synchronic belt, which are consistent with the experimental research results of Lizuka.
Effect of Atomic-Scale Roughness on Contact Behavior
Authors: Duan Fang Li , Qiu He Bing , Yang Ji Ming , Wu Cong Ying
Published: August 2011

Large-scale molecular dynamics simulations are performed to study the effect of atomic-scale surface roughness on nano-contact. The modeling system consists of rigid spherical tips with different surface roughness and elastic flat substrate. Our results show that atomic-scale multi-asperity can change the contact behavior from consistent with the Hertz model to the Persson model. However, adhesion will reduce the influence of surface roughness, to the extent that the two tips with different roughness show similar variations of real contact area with applied load. The maximum compression and tensile stress of the rough tip is about 2 times and 1.5 times that of the smooth one, respectively. Moreover, the rough tip exhibits larger repulsive force and attractive force in the entire range of simulated load. Our simulations suggest that pull-off force cannot characterize the extent of the influence of adhesion on contact behavior at the nanoscale.
The Design of the Tooth Shape Silence Chain
Authors: Yang Guo Xian
Published: August 2011

This article briefly introduces the structure of the tooth shape silence chain. The touch point of the roll pins separate when the chain goes around the sprocket gear. It deduces the dimensions of the offset angle α and the roll pin angle θ with mathematics method. This preface shows when the outer circular arc R≈0.5P, the fluctuation of the chain transmission speed is the least. When R＝0.5P, We deduce the size of the roll pin by the value of α、θ、R and the ultimate tensile strength, then we can get the structure parameter of the chain plate hole by the method of geometrical construction.
Study on Dynamic Load Sharing Behavior of Two-Stage Planetary Gear Train Based on a Nonlinear Vibration Model
Authors: Li Tong Jie , Zhu Ru Peng , Bao He Yun
Published: August 2011

The nonlinear torsional vibration model of a two-stage planetary gear system is established taking errors of transmission, time varying meshing stiffness and multiple gear backlashes into account. The solution of the equations is determined by using ODE45. The influences of transmission errors on the load sharing behavior are assessed and some useful theoretical guidelines for the design of planetary gear systems are provided at last.
Numerical Analysis on Transmission Characteristics of Stephenson’s Six-Bar Punching Mechanism with Servo Input
Authors: Hu Jian Guo , Sun You Song , Cheng Yong Qi , Ruan Wei Ping
Published: August 2011

Punching mechanisms with servo input are typical variable-input controllable mechanisms. By means of extending the output link infinitely, the Stephenson Ⅲ six-bar linkage is evolved into a six-bar punching mechanism with a slide. A virtual prototype model of this novel punching mechanism was established by using the software ADAMS. The model includes geometry, load and drive, total three sub-models. Based on the model, the kinematic and dynamic characteristics of the slide with variable-input crank motion and instantaneous large load were simulated. The numerical results showed that the Stephenson’s six-bar punching mechanism had good transmission characteristics, improving the working performances and production efficiency, reducing the manufacturing costs of servo mechanical presses.
Research on the Knowledge Fusion Technology Based Optimized Design of the Drive Axle Differential Gear
Authors: Chen Ke , Yao Chang Wen , Yin Guo Fu
Published: August 2011

To better apply FEA technologies in product development, viewing on the knowledge reusing, a knowledge fusion based method was worked out to analyze and optimize product structure. Dynamic knowledge templates were brought into design activities, which could be used to optimize product solution for more developers conveniently. Therefore, the product design knowledge and optimizing method could be accumulated constantly in enterprises. This method was applied to develop some kind of Drive Axle Differential Gear. Actual application shows that the stress concentration area was found, and the unreasonable expanding mechanism was corrected. And then the design of Differential gear was optimized to improve the carrying capacity of base. Thus, the fracture failure rate would be cut down.
A Discrete Lumped-Parameter Dynamic Model for a Planetary Gear Set with Flexible Ring Gear
Authors: Zhang Jun , Song Yi Min , Xu Jin You
Published: August 2011

A discrete lumped-parameter model for a general planetary gear set is proposed, which models the continuous flexible ring gear as discrete rigid ring gear segments connected with each other through virtual springs. The ring-planet mesh is analyzed to derive equations of motion of ring segments and planet. By assembling equations of motion of each individual component, the governing equations of planetary gear system are obtained. The solution for eigenvalue problem yields to natural frequencies and corresponding vibration modes. The simulations of example system reveal that the ring gear flexibility decreases system lower natural frequencies and the vibration modes can be classified into rotational, translational, planet and ring modes.
Modeling and Controlling of Anti-Slip Regulation Based on Limited-Slip Differential
Authors: Hu Jian Jun , Ge Peng , He Zheng Bin , Qin Da Tong
Published: August 2011

The dynamic models of whole rear-wheel drive vehicle, limited-slip differential, hydraulic control system and electronic throttle were established. Simulations of acceleration course on split-µ road, checkerboard-µ road, low-µ road and step-µ road were carried out combining electronic throttle PI controller and limited-slip differential fuzzy controller. The results show that the Anti-slip Regulation quickly works according to the road adhesion coefficient, effectively inhibits the slip of driving wheels on low adhesion coefficient road, the acceleration performance driving on bad roads was improved obviously, and show a good adaptability.
The Design of Power Transmission of Electric Screw Press Directly Driven by Permanent Magnet Disc Synchronous Motor
Authors: Liang Jin Tao , Zhao Sheng Dun , Zhao Yong Li , Sun Zhen Yu
Published: August 2011

Screw press is a significant forging equipment, its most important advantage is exact energy control which ensures high process reliability and repeatability, furthermore, using low speed large torque motor directly driving the press can remove the clutch, gear, belt, et al driving device, so that the power consumption could be reduced effectively. In this paper, a novel electric screw press directly driven by permanent magnet disc synchronous motor is presented, Referring to the technical parameters from the J58K electric screw press, the method which calculates the structure and electromagnetic parameters of the power transmission is introduced.
Study on 18Cr2Ni4WA Gear Contact Fatigue Experiment and Data Analysis
Authors: Wu Zhi Fei , Wang Tie , Zhang Rui Liang , Li Hong Mei
Published: August 2011

This paper introduces the installment method of experimental machine and gears, and the definition of stress levels, based on the contact fatigue experiment of 18Cr2Ni4WA carburizing and quenching gears, the few experimental points combination method was applied. The experimental points data was obtained by failure criteria. The S-N curve is fitted according to experiment data, and the experimental points data processing method is also explained in the paper.
Thermal Effects Analysis on DCT Driven Plate in Vehicle Initial Condition
Authors: Huang Jing Ying , Liu Zhen Jun , Sun Wei , Qin Da Tong
Published: August 2011

The Dry-type Dual Clutch system is designed for a certain Dual Clutch Transmission (DCT), and transient analysis is performed to investigate the thermal influence on driven plate in sophisticated slip conditions, which is determined by control strategy of DCT. First, a clutch engagement model is developed to obtain transient friction power corresponding to selected control strategy, and the distribution of time-varying heat flux is derived. On that basis, the thermal effects on the driven plate are simulated by finite element method. Finally, the temperature and thermal stress distributions on the frictional surfaces are acquired, which shows that the previously designed clutch system agrees with thermo requirements. This new approach which is more superior to the traditional clutch analysis, can adjust to different control strategies, thus it can be applied to facilitate the thermo analysis and practical design of DCT system.
Experimental Investigation on Related Properties of Asphalt Mastic Containing Recycled Cement Mortar Powder
Authors: Zhu Ji Qing , Wu Shao Peng , Zhong Jin Jun , Wang Dong Ming
Published: August 2011

Some properties of asphalt mastic containing recycled cement mortar powder (CMP) were investigated in this paper. CMP was used as filler in asphalt mastic. The investigated mastic consisted of asphalt and filler at a mass ratio of 1:1. Penetration, softening point and high-temperature viscosity were tested. Dynamic Shear Rheometer (DSR) was used to conduct frequency sweep test of asphalt mastic. The introduction of CMP resulted in reduced penetration, increased softening point, apparent activation energy, complex shear modulus in the low frequency area and high-temperature viscosity. Results indicate that CMP may have some positive effect on high-temperature properties but some negative effect on low-temperature properties of asphalt mastic. It is also believed that the average mixing and compacting temperature of asphalt mixture containing CMP is higher than that containing limestone mineral filler (LMF).
Pond Ash: An Alternative Material as Fine Aggregate in Concrete for Sustainable Construction
Authors: Ganesh Bharathi , Sharada Bai H , Nagendra Ramaswamy , Bagade Shivaram
Published: August 2011

Consequent upon increased generation of electricity through thermal route involving combustion of pulverized coal/ignite, concurrent generation of fly ash/pond ash in bulk quantities is a matter of serious concern not only because of issues associated with its disposal and utilization, but also because of its threat to public health and ecology. Though a lot of research has been carried out for the effective utilization of flyash like its use in construction industry etc, little literature is available on pond ash utilization particularly its use as a constituent material for concrete in construction industry. Hence pond ash - a waste material, if supplements shortage of fine aggregate (river sand) in mortar and concrete, reduces the demand for disposal of thermal power plant waste, reduces its environmental impact with proper utilization of huge quantity of waste in construction industry. Researches are being carried out worldwide which shows the suitability of Pond Ash as FA. This paper summerises various characteristics of Pond Ash as fine aggregate in concrete with its engineering properties such as its shape, gradation, texture, physical, chemical and also morphological aspects when used in concrete
Influence of Compounding Malic Acid with Plasticizers on Hydration Heat of α-Calcium Sulphate Hemihydrate
Authors: Wang Pei Ming , Pan Wei
Published: August 2011

On condition of formulating malic acid (Malic) with super plasticizers (SPs), the hydration heat of α-calcium sulfate hemihydrate (α-HH) was studied. The results show that: Malic and SPs mainly adsorb on gypsum surface to exert inhibition; influence of compositing SPs on hydration process mainly depends on the adsorption of SPs and the effect of SPs on Malic adsorption; formulation of sulfonate melamine formaldehyde plasticizer (SMF) limits the adsorption of Malic.
Heat Transfer Analysis of the Micron-Scale Agglomerates of TiO2 Precursor during the Detonation Process
Authors: Qu Yan Dong , Li Xiao Jie , Yan Hong Hao
Published: August 2011

Removing water excessively could result in the formation of sphere-like agglomerates of TiO2 precursor with 1-2 μm in size, which was used to prepare TiO2 nanoparticles by detonation method. Different temperature distributions of TiO2 precursor agglomerates influenced the components of detonation products. In order to obtain the temperature distributions, a mathematic model was introduced to study the heat transfer behaviors of the TiO2 precursor agglomerates during the detonation process. The temperature history at spherical center with different spherical radiuses and time was also studied. The calculation results were in good agreement with the experimental results. The heat transfer analysis laid the foundation for the synthesis mechanism research of TiO2 nanoparticles, and it was also helpful to design and optimize experimental procedure.
Research on Optimization Design of Shearer Sliding Shoes by Plasma Cladding Cr28MnV
Authors: Liu Jin Long , Wu Gao Feng , Liu Hong Tao
Published: August 2011

The formidable and multivariate coal-mining conditions during the production often lead to various improper damage and inactivation of guide foot. Wear is the most severe problem. We do the research on optimization design of the materials by plasma cladding technic to improve the wear resistance: The Cr28MnV ferrous alloy overlay was deposited on the surface of 45# tempered steel backing. The martensitic structure with high strength, high hardness, and high abradability evenly distributed alloy carbide can be gained after cooling the overlay. The combined backing has a good obdurability which can satisfy the requirement of coal mine complex conditions after modifying treatment.
Preparation and Characterizations of Na2Ti3O7, H2Ti3O7 and TiO2 Nanobelts
Authors: Wang Yan Min , Liu Hong
Published: August 2011

In this paper, the Ti-O-Compound nanobelts from commercial TiO2 (annatase phase) were synthesized via the alkali-hydrothermal process. The as-synthesized nanobelts are sodium titanate, hydrogen titanate and anatase with general formula Na2Ti3O7, H2Ti3O7and TiO2, respectively. The nanobelts are characterized by Thermogravimetric/Differential Thermal Analysis (TG/DTA), X-ray Diffraction (XRD), Infrared Spectra (IR) and Scanning Electron Microscope (SEM) apparatuses. The characterization indicates that the nanobelts with typical widths of 50 to 200 nm, thicknesses of 20 to 50 nm, and up to a few millimeters in length. The conversion mechanisms between the layer titanate and anatase of nanobelts have been discussed in this study.
The Microstructure of Zinc Oxide Films Prepared by Hydrothermal Method
Authors: Xia Zhi Lin , Xu Qi , Zhao Li Xin
Published: August 2011

In the solutions which are prepared by mixing zinc nitrate hexahydrate, strong ammonia and methenamine in water bath at 90 Centigrade, lamellate and granular zinc oxide films have grown on different substrates such as B270 glass, glass based PAA films, pure aluminum foil and aluminum based PAA films. Films microstructures were characterized by scanning electron microscope (SEM). The influences of substrate and pH on the films microstructure were analyzed. Results reflect that: Ammonia plays an important role in the growing competition of grainy crystal; the more concentration of ammonia, the more zinc oxide crystals grow into granular. Because of the high specific area and adsorption capacity, lacunaris zinc oxide films have great application perspective in gas sensor, catalyzed sorption and biochemistry.
Preparation and Characterization of Poly(Acrylamide)/Silica Nanocomposite Gels
Authors: Wu Li Li , Zeng Ling Zi , Chen Hai Bo , Zhang Chao Can
Published: August 2011

A series of PAM/silica nanocomposite (NC) gels using silica sol as the inorganic component were prepared by in situ free-radical polymerization. The addition of silica sol was first used to bring silica nanoparticles to form organic (polymer)/inorganic system. Results from the swelling experiment indicated that the effect of silica particle was nevertheless rather complex as polymer/particle binding. Additionally, it revealed that the swelling ratio of the NC gels with a certain silica content increased with the increasing pH value. Moreover, it exhibited absorption of the polymer onto silica because the chemical cross-linked PAM has changed to the organic/inorganic system. The spectroscopic results showed that the silica nanoparticles formed by silica sol promoted high degree of attachment to the polymer chain. The AFM micrographs displayed that silica particles were of nano degree and in the monodisperse. Both evidences proved that the organic/inorganic system was effectively formed through the addition of silica sol.
A Solid-State Reaction Route to Synthesize Crystallinic FeB Nanoflowers and their Magnetic Properties
Authors: Li Jing Fa , Yan Yan , Qian Yi Tai
Published: August 2011

In this paper, crystallinic FeB nanoflowers were successfully prepared at 500°C for 8h with FeCl3 and NaBH4 as the reactants. Field-emission scanning electronic microscope (FESEM) and transmission electronic microscope (TEM) images showed that the flowers composed of thin flakes are in the thickness of about 30 nm. More significantly, this is the first time to synthesize crystallinic FeB nanoflowers self-assembled by thin flake. Magnetic measurement showed that the flowers were a kind of soft magnetic materials (Hc = 600 Oe, Mr = 34.6 emu/g).
A Novel Method for Preparing High Efficient Fluorescence-Encoded Microspheres with Semiconductor Nanocrystals
Authors: Yu Hang , Tao Lei
Published: August 2011

A novel method with two steps for preparing high efficiency fluorescence nanocrystals (NCs)-encoded microspheres was developed. First, a series of polystyrene (PS) microspheres from 1 μm to 5 μm in diameter were prepared by dispersion polymerization; then, after a swelling process with CdSe NCs of different size the PS microspheres were encoded quantitatively. This method for fluorescence-encoding of microspheres was shown to have the following outstanding characteristics: (1) An emulsion containing CdSe NCs and swelling agents (chloroform) are firstly used for introduction of NCs into microspheres. (2) The embedded nanocrystals remain their original properties and they are not simply absorbed onto the surface of the microspheres but being carried into the inner of microspheres and so the NCs cannot be released or leaked out easily. As-prepared fluorescence-encoded microspheres could conjugate with proteins by some further surface modification, so they have a great potential to be applied to such fields as biochemistry, molecular biology, cell biology, immunology, etc. In addition, the method could be operated easily and reproducibly.
Synthesis of CdTe and CdTe/CdS Core-Shell Quantum Dots and their Optical Properties
Authors: Lu Juan Juan , Ge Shen Guang , Wan Fu Wei , Yu Jing Hua
Published: August 2011

This paper describes the synthesis of CdTe and CdTe/CdS core-shell quantum dots (QDs) in aqueous solution. The quantum dots are prepared by using thioglycolic acid (TGA) as stabilizers. The synthesis procedure is simple and controllable. Different sized CdTe QDs with tuned PL wavelengths from 550 to 640 nm was synthesized by controlling reaction time within 5 h in aqueous solutions at a temperature of 100 °C. We also investigated the influence of precursor Cd/Te molar ratio for the prepared QDs. It was showed that the core-shell CdTe/CdS QDs have larger photoluminescence (PL) emission intensity than the original CdTe QDs. The synthesized core-shell CdTe/ZnS QDs have high quality, water-soluble and will be useful in applications of biolabeling, biosensing, and imaging.
Preparation and Characterization of BCN–TiO2 Nanoparticles
Authors: Zhang Ling , Li Ling , Mou Zong Gang , Li Xi Feng
Published: August 2011

BCN–TiO2 was prepared by doping Ti(OH)4 with graphite-like structure BCN in an annealing process at 400[°C] for 2[h]. The catalyst samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM). Graphite-like structure BCN was detected by XRD. The results showed that with graphite-like structure BCN doped in, the crystal size became smaller than pure TiO2. Also B, C, N were detected in crystal lattice of TiO2, in which Boron was in the form of Bx+, Carbon substituted some of the lattice oxygen atoms as Ti-C, and Nitrogen was in the form of Ti-N and Ti-O-N.
A Study on Mechanism of Tribological Behavior of Carbon Nanotubes
Authors: Li Rui , Hu Yuan Zhong , Wang Hui
Published: August 2011

This paper investigates mechanism of tribological behavior of carbon nanotubes by using universal tribometer-II and molecular dynamics simulations. The experiment results indicate that multi-walled carbon nanotubes film with mixed acid treatment has better surface quality and less impurities but higher friction than pristine carbon nanotubes film. The reason is that mixed acid treatment introduces carboxyl group and more defects which increases dangling bonds of carbon nanotubes. Breaking of dangling bonds increases friction force when sliding and shearing occurs. Molecular dynamics simulation of shearing between silicon surfaces and single-walled carbon nanotube bundles without defect shows low lateral forces because only van der walls force exists between silicon surfaces and carbon nanotubes owing to no dangling bonds. The result is consistent to the conclusion inferred from experiment. Therefore excellent performance is expected when carbon nanotubes treated with little defects are used as lubricant or addictives.
Research Progress in Protective Organic Silane Films
Authors: Ran Xiao Li , Li Tian Yi
Published: August 2011

The silane treatment is a new kind of metal surface treatment technique. Compared with the traditional chromate and phosphate treatment, organic silane treatment is friendly to environment. In this paper, the structure, classification and corrosion protection mechanism of silane films were introduced. The application and research progress of protective organic silane films were reviewed．The prospect of organic silane treatment technique was put forward．
The Application of Peroxide in the Degumming Process of Ramie
Authors: Liu Guo Liang , Li Zheng Fan , Ding Ruo Yao , Yu Chong Wen
Published: August 2011

In this paper, the application of peroxide: sodium percarbonate and hydrogen peroxide, in the chemical degumming process of ramie was discussed. Two kinds of effects of peroxide degumming process were analyzed. On the basis of that, the fiber properties of degummed ramie of oxidation degumming process and the traditional chemical degumming process were compared. The result showed that two kinds of peroxide can be effectively applied to the chemical degumming process of ramie. In comparison with the traditional chemical degumming process, there are many advantages in the oxidation degumming process, for example, short flow, saving in energy, less environmental pollution, high single fiber strength, high whiteness, less fiber strand and so on.
Growth and Photovoltaic Performance of Single-Crystal TiO2 Nanorod Array Directly on Transparent Conducting Substrates
Authors: Gu Xiu Quan , Zhao Yu Long , Qiang Ying Huai
Published: August 2011

In this study, single-crystal TiO2nanorod (NR) arrays were used as the photoanodes of dye sensitized solar cells (DSSC). The post-annealing treatment was carried out in air, O2, N2and vacuum atomsphere. X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) have been used to characterize the structure, morphology and crystallity of these samples. Although the nanorod arrays which undergo annealing remained the single-crystal structure without any change in the morphology, considerable improvement in the nanorod solar cell performance was obtained. The high efficicency of 4.42 % was achieved in the cells containing nanorods which were annealed in air at 500 °C for 30 min. In comparison, the cell fabricated using TiO2samples without post- annealing treatment exhibited a low efficiency of just 2.1 %. Such a large improvement (280 %) was mainly attributed to the faster electron transport and the lower charge recombination rate after annealing due to an increase of the depletion width. Otherwise, the cell performance improvement may result from an enhancement in the adhension and electrical contact at the TiO2/FTO interface. The in-depth study shows that the solar cell efficiency was strongly dependent on the annealing ambience, too.
Mathematical Modeling and Numerical Simulation of Fouling Processes of Polymeric Ultrafiltration Membrane
Authors: Song Wei Chen , Jia Yu Xi , Shi Tong Fei
Published: August 2011

Based on the fouling mechanism of polymeric ultrafiltration membrane, the mathematical model to describe the fouling process of polymeric surface active layer is established according to resistance equation, Darcy’s law, convection-diffusion equation and dynamic adsorption equation. The effect of solution concentration on permeating flux is investigated by means of finite element simulation, and the validity of the research approach is verified. The reasons why the flow flux declines are analyzed quantitatively, which gives a vivid description of the fouling process.
Synthesis and Characterization of Highly Regioregular Poly (3 - Hexylthiophene)
Authors: Zhou C.Y. , Yan Lu Ting , Zhang L.N. , Ai X.D. , Li T.X.
Published: August 2011

Regioregular poly (3-hexylthiophene) was synthesized by exchanging with Grignard agent followed by coupling with catalysis of Ni (dppp)Cl2. A nearly 100% HT-HT structure was verified from 1H-NMR and 13C-NMR data analysis. This highly regioregular structure gives P3HT outstanding stability and certain redshift of absorption spectra was found in contrast to materials with lower regioregularity.
The Properties and Hydrolysis of Polysiloxanes with Cyanoethyl Groups
Authors: Guan Rui Fang , Dong Yu Rong
Published: August 2011

Polysiloxanes with cyanoethyl groups (PDMS-CN) is a useful functional polysiloxanes. In this paper, the polysiloxane with various number average molecular weight (Mn) and cyanoethyl groups were prepared. Mns of PDMS-CN were determined by GPC. The contents of cyanoethyl groups were determined by 1H NMR. The dynamic mechanical properties and thermal stability of PDMS-CN were investigated by DSC and TGA respectively. The hydrolysis of PDMS-CNs give the polysiloxanes with carboxyl groups. The factors influencing the hydrolysis of cyanoethyl groups were discussed by orthogonal array and the optimal reaction conditions were confirmed. This template explains and demonstrates how to prepare your camera-ready paper for Trans Tech Publications. The best is to read these instructions and follow the outline of this text
Synchrotron Radiation X-Ray Absorption and Optical Studies of Cubic SiC Films Grown on Si by Chemical Vapor Deposition
Authors: Tu Yu Li , Huang Yan Hao , Kong Ling Min , Lee Kung Yen , Jang Ling Yun , Tin Chin Che , Liu Chee Wee , Feng Zhe Chuan
Published: August 2011

Synchrotron radiation extended X-ray absorption fine structure and Raman scattering were used to characterize a series of 3C-SiC films grown on Si (100) by chemical vapor deposition. EXAFS can probe the physical and chemical structure of matters at an atomic scale and Raman parameters such as intensity, width, peak frequency and polarization provide fruitful information on the crystal quality and properties of these film materials.
Preparation and Properties of Enzymatic Hydrolysis Lignin Modified Thermoplastic Starch Composites
Authors: Liu Bin , Lv Qiu Feng , Fang Run , Cheng Xian Su
Published: August 2011

Thermoplastic starch composites modified by enzymatic hydrolysis lignin (EHL) were prepared via a simple and environmentally-friendly process. Starch and EHL were plasticized with urea and methanamide as plasticizers in the preparation. The effects of the amount of plasticizers and EHL on the mechanical and water-absorption properties were investigated. The fractured surfaces of the composites were studied by using scanning electron microscopy (SEM). Properties of the composites were improved with adding plasticized EHL into pure thermoplastic starch. It was attributed to the good compatibility of modified EHL with plasticized starch.
Structural and Optical Properties of CdS Thin Films Grown by Sputtering
Authors: Zhang Xue Yan , Liu Xiao Yu , Wang Han Bin , Zhang Xi Jian , Wang Qing Pu , Ma Hong Lei
Published: August 2011

Cadmium sulfide (CdS) thin films with (111) preferential orientation were grown on glass substrates at room temperature by radio frequency (R.F.) magnetron sputtering. The structural and optical properties of CdS films have been investigated by X-ray diffraction, Scanning Electron Microscope micrographs, PL spectra and transmittance spectra. The grain sizes have been evaluated. The transmission spectra of the obtained films reveal a relatively high transmission coefficient (80%) in the visible range. All these results show that the grain sizes increased while the optical band gap decreased with increasing the thickness of CdS films.
Growth and Properties of Cubic Potassium Tantalate Niobate Crystals
Authors: Wang Xu Ping , Wang Ji Yang , Liu Bing
Published: August 2011

Cubic KTa1-xNbxO3single crystals with difference compositions have been grown by Czochralski technique in KTaO3- KNbO3solid solution system. Growth habit, morphological feature, and other properties of two different composition KTN crystals, KTa0.65Nb0.35O3, and KTa0.63Nb0.37O3are investigated in this work. The X-ray diffraction (XRD) experimental results show that all crystals belong to cubic phase at room temperature, lattice parameterais 3.993 and 3.994Å corresponded to the composition of x (Nb) =0.35, 0.37, respectively. HXRD and AFM measurement results show all KTN crystals are in high integrity and good quality. The transmittance spectra of KTN crystals show that the cut off wavelength of KTN crystals decreased with the Nb increasing in the crystal. The dielectric-temperature measurement results shows KTN crystal have optimal performance on Kerr effect at the Currie temperature of the crystal. All the results show that the KTN crystals we grown are in good quality and have a broad application prospects
Improvement of Concrete Materials by Bacterial-Mediated Precipitation
Authors: Li Pei Hao , Qu Wen Jun
Published: August 2011

Microbial carbonate precipitation had been proposed as alternative technique for improvement in concrete materials. Laboratory experiments were conducted by bacterially mediated carbonate deposition on the surface and subsurface of concrete specimens. The crystal phase, morphology and growth of the crystal deposited on specimens as well as the efficiency of bonding and protection were analyzed by means of X-ray diffraction (XRD), scanning electron microscope (SEM), and ultrasonic test. Water absorption and the resistance of carbonation of concrete were analyzed by water absorptivity test and concrete accelerated carbonation test, respectively. Results show that phases of crystal are calcite and vaterite. The crystals are deposited uniformly on the surface of specimens. Biodeposotion effectively reduces capillary water uptake and carbonation rate constant.
Microstructure and Mechanical Behaviors of AZ91 Magnesium Alloy with Thermal Rate Treatment Technique
Authors: Zhou Yong Zhi , Geng Hao Ran , Sun Yu Jie , Li Mei
Published: August 2011

Microstructure and mechanical behaviors of AZ91 cast magnesium alloys with melt superheating and thermal rate treatment technique were studied. Alloy grains thicken at 820°C and refine at 870°C when they contains Mn element and the crucible had no coating on the internal surface. Moreover, the strengthening γ phase is more dispersive and uniform at 870°C. Thermal rate treatment significantly improved the microstructure, mechanical behaviors and casting quality of AZ91 alloy as microstructure of AZ91 alloy reserves some characteristics of the high temperature melt.
Effect of Mg-Zn-Y Quasicrystal Master Alloy on Microstructure and Mechanical Properties of AZ91 Alloys
Authors: Teng Xin Ying , Liu Teng , Zhou Guo Rong , Liu Li Yan
Published: August 2011

Series of AZ91 alloy samples are prepared by adding different levels of Mg-Zn-Y quasicrystal master alloy under normal casting condition. The microstructure and mechanical properties of these samples are investigated by using of XRD, SEM, EDS and tensile test. It is shown that morphology of β- Mg17Al12 phase changes from continuous nets to discontinuous nets or even to particles. As results of these changes, the mechanical properties of AZ91 alloys are significantly improved until the addition level passes 6%.
Preparation of Straight and Orderly Polypyrrole Microrods through Soft Template Methods
Authors: Sun Li Bo , Shi Yuan Chang , Chu Lin Ya , Zhang Bing Chang , Liu Jiu Rong
Published: August 2011

The straight and orderly microrods of polypyrrole(PPy) was synthesized in a microemulsion system consisted of cetyltrimethylammonium bromide(CTAB), n-pentanol, water and pyrrole by chemical oxidative polymerization, in which CTAB was used as soft templates and APS was used as the oxidant. Fourier-transform infrared spectroscopy (FTIR) was used to characterize the structure of the PPy microrods. Transmission electron microscopy (TEM) and high resolution transmission electron microscopy (HRTEM) was used to characterize the morphology of the samples. We discussed the impact of temperature, the adding way of the oxidant, the amount of cosurfactant n-pentanol to the morphology of PPy microrods. The results showed that straight and orderly PPy microrods with a diameter about 300nm and a length up to 20μm were synthesized when the temperature was kept at room temperature (25°C), the dropping time of APS was more than 1.5h, the ratio of CTAB to n-pentanol was 0.6:1, and the polymerization time was about 24h. We studied the growth process of PPy microrods by HTEM analysis. HTEM images revealed that the growth process of PPy changed from hollow microrods, semi-hollow microrods, and finally solid microrods.
Application of Interpenetrating Silicone Waterproofing Material in the Protection of the Concrete
Authors: Liu Jie Sheng , Liu Jie Sheng
Published: August 2011

A cost-effective better performing silicone waterproofing agent interpenetrating polymer network coating for the protection of concrete has been developed. The working mechanism of the silicone polymer on the concrete was revealed and the effect of the material on the water absorption, chloride diffusion coefficient of concrete was analyzed. The results showed that the deep penetration of silicone material formed a hydrophobic layer and provides an effective protection against water corrosion and chloride ingress. A long-term protection can be guaranteed in case the surface of the concrete is waterproofing.
Structure and Properties of Organic-Vermiculite/Polyimide Composite Films
Authors: Feng Xue , Lv Feng Zhu , Zhang Yi He , Wu Yue Ying
Published: August 2011

A series of organic-vermiculite/polyimide (OVMT/PI) hybrid films were successfully prepared by in situ polymerization using hexadecyltrimethyl ammonium bromide (CTAB) modified vermiculite (VMT) as filler. XRD analysis showed the OVMT were exfoliated in the polymeric matrix below 1.5wt%. The tensile strength and elongation at break increased with the addition of OVMT and up to maximum at 1.5 wt%. The Tgs of the films were nearly 400°C indicating that the incorporation of OVMT did not obviously affect the thermal stability of PI films.
Study on Processes and Properties of Continuous Woven Roving Reinforced Polyurethane Composites
Authors: Dai Xiao Li , Wang Xiang , Wang Jun
Published: August 2011

E-glass fiber woven roving reinforced polyurethane composites were manufactured by three different processes: hand lay-up, compression molding and vacuum infusion to assess the feasibility of all the processes. The results showed that all composites led to significant improvements in both flexural and tensile properties except elongation at break in comparison with the neat PU. Among the three processes, the best bending strength was exhibited by the hand lay-up process. This is attributed to higher PU mass fraction leads to a better fiber–matrix interfacial adhesion. Mechanical properties of the composite molded by vacuum infusion were superior to that produced by compression molding process. The SEM morphology revealed that vacuum infusion composite had more homogeneous micro- structure.
Research on Aircraft LY12CZ Aluminum Alloy Corrosion Damage Prediction Based on ARIMA Model
Authors: Liu Zhi Guo , Mu Zhi Tao
Published: August 2011

The corrosion of LY12CZ aluminum alloy in aircraft under service environment is regarded as a stochastic process and the time series theory is used to analyze and to predict the corrosion depth of LY12CZ under airport environment by means of ARIMA(3,1,1)model.The application result show that the ARIMAmodel can predict the value and propagation trend of corrosion depth realistically and effectively,demonstrating the expedient and easy application of time series theory and method.
Optimization of Powertrain for Large Commercial Vehicle for Passenger Transportation Based on Optimus
Authors: Li Chen , Li Xing Hu , Zhou Wei , Zhang Lu , Ren Chun Xiao , Chen Lin
Published: August 2011

In this paper, an simulation program of power performance and fuel economy of large commercial vehicle for passenger transportation is programmed, and high credibility of the program is validated by experiment verification. Comprehensive fuel consumption is firstly introduced as the objective function, joint optimization of powertrain parameters is performed by using multi-disciplinary optimization platform Optimus and MATLAB. The result shows optimization efficiency is greatly improved and the outcome has great satisfaction.
Study on Optimal Methodology of RMS Roughness in Super Smooth Surfaces by CCI
Authors: Wu Li Qun , Chao Yan
Published: August 2011

Roughness parameters such as the root-mean-square (RMS) roughness in super smooth surfaces are heavily influenced by evaluation ways and measuring method. With the help of CCI6000, relationships were investigated respectively between the RMS roughness with the instrument parameter set and cutoff wavelength. The study revealed that there was an optimal set of measurement parameters and a dynamic cutoff wavelength that would identify different wavelength regimes when measuring super smooth surfaces. It was found that the proposed scheme greatly reduced the influences of CCI instrument parameters and cutoff length on RMS roughness in the measurement of hard disk surfaces. RMS roughness exhibited a steady-state trend and the processed surface morphology conformed to the arrangement of atoms and the polishing feature of CMP technique.
Aero-Engine Blade Deformation Control of Milling Process
Authors: Chen Hui Xian , Li Hao , Feng Hai Tao , Du Min Juan
Published: August 2011

The leaf blade manufacture precision's influencing factors are numerous, and they have coupling relationship each other. So it is difficult to peel out a single factor on the influencing regularity of the blade's machining accuracy. By researching the engine blades of helical milling state under the existing fixture, the leaf blade deformable model based on the instantaneous milling strength was established. Meanwhile, the off-line multi-level error compensation plan was proposed based on the processing surface static error forecasts and compensation. In order to revise the primitive NC tool path code and eliminate the processing distortion inaccuracy, the elastic deformity on each knife position spot is solved on the basis of iterative solution, using the finite element simulation and milling strength model. By using ANSYS finite element simulation, it receives the real-time error compensation of the tool path. And then The experiment has proven the accuracy and the usability of the compensation plan.