bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental Study on Inhibitory Action of Inhibitors on the Tungsten Carbide Leaching of the Cemented Carbide Tool
Authors: Jia Xiao Ming , Zhang Xiu Ling , Song Yue Xing , Chen Xiao Xin
Published: September 2010

The influence of some commonly used inhibitors on the tungsten carbide leaching of the cemented carbide tool was studied by energy spectrum analysis and electrochemical gaging. And the mechanism of the tungsten carbide leaching and be inhibited of the cemented carbide was discussed. The test results showed that when cemented carbide tool were soaked in tri-sodium phosphate and sodium carbonate anhydrous the tungsten carbide in the cemented carbide tool leached out for hydration. And benzotriazole has a good inhibitory effect on the tungsten carbide leaching of the cemented carbide tool.
Springback Variation Principles in Materials Forming Processes
Authors: Fu Bao Lian , Chen Ying Jie
Published: September 2010

The conceptions of springback anti-couple systems and equations are initially given. By the use of the weighted residual method to the springback anti-couple equations, the springback principles of minimum potential energy and minimum complementary energy are established. Meanwhile, the springback principle of minimum potential energy is applied to calculating springback deformations of a curved beam under the radial and circumferential forces and end bending moments.
Combination Mechanism of Ni-Al Sprayed Coating under Median Temperature Sintering and Valid Evaluation for its Bonding Strength
Authors: Zhou Wei , Zhang Xiao Xia , Li Xiao Tong
Published: September 2010

After Ni-Al mixed powder is sprayed on surface of pure Fe using oxy-fuel spraying, the as-sprayed coatings are processed by median temperature sintering in hydrogen atmosphere. SEM image and element distributions cross the interface of sintering coating are characterized using scanning electron microscopy (SEM). The results show that the sintering coating have a good combinaton and there is a transition zones of about 10 μm in width with metallurgical binding cross the coating interface. Under the protection of hydrogen, the oxidation-reduction reaction of Fe, Ni and Al could be occurred cross the coating interface, and contribute to combination of the coating interface. In view of the low sterngth of glue, the high adhesion strength coating could not be evaluated by ASTM C633-79. As a result, a modified experimental method and corresponding finite element (FE) analysis was conducted to evaluate the adhesion strength of high-strength coating. The parallel testing between the new method and ASTM C633-79 on specimens with same condition for low adhesion strength coatings has been conducted and the valid is proved.
The Global Solution of Viscoelastic Thin Rectangular Plate Equation
Authors: Wang Dan Xia , Zhang Jian Wen
Published: September 2010

In this paper, we consider a class of nonlinear viscoelastic plate equation with strong damping which arises from the model of the viscoelastic thin rectangular plate with four edges supported. By virtue of Faedo-Galerkin method combined with the priori estimates, we prove the existence and uniqueness of the global strong solution under certain initial-boundary data for the above-mentioned equation.
Effective Young’s Modulus of Syntactic Foams with Hollow Glass Microspheres
Authors: He Chang Jun , Li Hui Jian , Yu Wei , Liang Xi , Peng Hai Yan
Published: September 2010

. The Young’s modulus of syntactic foams were studied both the experiment and the theory. The compressive test and dynamic mechanical analysis were progressed for a few of specimens, which were made of the syntactic foams with the epoxy resin and hollow glass microspheres (HGMs). the equations for Young’s modulus of concentrated particulate composites were derived using a differential scheme of an infinitely dilute system, and were employed to prediction the Young’s modulus of syntactic foams. The computed effective Young’s moduli were compared with the experimental results, the prediction values were between the lower and upper bounds of the experimental data, and the prediction model was acceptable and can estimate the Young’s modulus of syntactic foams.
Experimental and Theoretical Study of Metallic Hollow Sphere with Medium Thick Wall
Authors: Yu Wei , Li Hui Jian , He Chang Jun , Liang Xi
Published: September 2010

. Metallic hollow sphere (MHS) material is a new type of cellular material characterized by super-light, high specific stiffness and strength, the ability to absorb noise and energy, thermal insulation. It had been widely used in engineering, i.e. automobile, aircraft, civil and military. The basic unit of MHS cellular material was small metallic hollow sphere in macro, and the instability of sphere shell is always the most difficult problem in mechanical field. In this paper, we explored the internal factors and the principle of this phenomenon though the methods of theoretical and experimental. The equation of deformation of MHS was derived. It had shown that the nominal strain was related to the radius of the shell and loads, and the nominal stress was connected with the radius, load and the thickness of shell wall. A series of quasi-static uniaxial compression tests were progressed for a group of single MHSs, which radii were 4mm, 5mm and 7mm. It was found that the deformation planes are circle and symmetry both top and bottom, and the curves of nominal stress-strain were similar to a half parabola. There was a perfectly uniformity of the theoretical model and the experimental results.
Study of the Modeling of the Gear Dynamics Considering Mesh Stiffness and Sliding Friction
Authors: Gu Cheng Zhong , Wu Xin Yue
Published: September 2010

Time- varying mesh stiffness and sliding friction between teeth are the great excitation for vibration and noise in gears system. But, there are rarely studies on this topic. This paper proposes a new dynamic modeling of gear system, which is effect of mesh stiffness variation, sliding friction and distribution of load. Firstly, the expression of time-varying mesh stiffness is gained, which is a period function. Secondly, a new friction modeling has the same period as mesh stiffness, is proposed. Thirdly, friction torque of each gear pair is calculated respectively, which is considering the distribution of load and time-varying friction arm. Finally, because all parameter have the same cycle, it is easy to get the approximate analytical solution to non-line model of gear dynamic by fourier transform.
Study of Compatibility of the Nano Lubricating Additives with the Electroless Deposited Ni-W-P Coating
Authors: Chen Min , Cheng W.S. , Zhao Zu Xin , Huang X.B.
Published: September 2010

Tribological properties as well as antiwear and friction reduction mechanism of wear self repair nano-ceramic and nano-Cu lubricating additives are researched using ring-block abrasion testing machine and Energy Dispersive Spectrometer. Research results show great difference between friction reduction performances of the above two additives, because their friction reduction mechanism are different, the former is ball bearing effect and the latter is soft film shear effect. In terms of wear-resistance, as for 45 steel, under heavy load, the self repair rate to the worn surface with the nano additives is less than the wearing rate of the friction pair. An effective way to solve the problem is electroless deposited Ni-W-P alloy coating on the surface of the 45 steel. The Ni-W-P alloy coating has high hardness, high wear resistance, and has excellent compatibility with nano lubricating additive, the wear resistance of Ni-W-P alloy coating (with heat treatment and the oil with nano additives) has increases hundreds times than 45 steel as the metal substrate with basic oil, zero wear is achieved, which break through the bottleneck of previous separate research of the above-mentioned the two.
The Non-Linear Contact Finite Element Analysis of Seal Structure on Large Scale Cutting Tube Machine
Authors: Chen Min , Jiang X.M. , Zhao Zu Xin , Huang X.B.
Published: September 2010

According to structural feature and seal requirement for large scale cutting tube machine, the non-standard rubber lip seal ring was self-designed. The nonlinear finite element contact analysis was utilized to model, calculate and optimize the structure of the lip seal ring, so as to improve the seal performance of the lip-shaped seal ring, and to determine the criterion for failure of seal performance of the lip seal ring, therefore to lay a foundation for the optimal design and performance research of the lip seal ring. According to the actual working pressure for the cutting tube machine, the stress and deformation for the lip seal ring were simulated. It has been testified by the practical use that the finite element analysis is correct. The method to optimal design of the seal structure with finite element analysis is feasible.
Moldflow Software in a Complex Plastic Shell Injection Mold Design
Authors: Zhao Zhen Yu , Liao Long , Tang Fei , Liu Bai
Published: September 2010

The paper describes the important role of Moldflow technology and status. Through the application of Moldflow / MPI (Moldflow Plastics Insight) software for CAE under a comprehensive analysis of the shell molds, injection molding parameters such as mold temperature, melt temperature, injection time and injection pressure are used to simulate the actual production process. This shows the Moldflow technology plays a significant role in the mold development process for optimizing plastic products design, plastic mold design and injection process parameters, etc.
Calculating Method for the Solid Phase Effect Coefficient of the Solid-Fluid Two Phase Flow Centrifugal Pump
Authors: Li Chuan Jun , Yu Gang , Wang Xin
Published: September 2010

In order to acquire the solid-fluid two phase flow centrifugal pump’s slurry head according with the fact, the solid phase effect coefficient must be calculated precisely. By analysising the acting forces on the solid particle, its moving differential equation was established. And the calculating formula of the solid phase effect coefficient was deduced based on the equation. For the sake of verifying its validity, a test of contrast and comparison on the calculating slurry heads by some ways was carried out. The results shows that the relative error values of the slurry head calculated are less than 2.00% with a small and stably error band. The method has the advantage of simple calculating process, high accuracy, low randomness and good practicability.
Research on Fault Recognition for Centrifugal Compressor Using Entropy Weight-Based Gray Relational Analysis
Authors: Li Lan Yun , Yang Zhuan Zhao , Li Xiao , He Zhi
Published: September 2010

A new fault recognition method for centrifugal compressor was proposed by using entropy weight-based gray relational analysis (EW-GRA). Firstly, the weight values of all fault features were calculated objectively by the entropy method to avoid the influence of subjective factors. Secondly, an improved local gray relational coefficient (LGRC) formula with weight measures was designed to reflect the contributions of different fault features. Thirdly, according to the relationship between similarity degree and Euclidean distance, the local gray relational distances (LGRD), the global gray relational distances (GGRD) and the global gray relational grades (GGRG) were calculated, and consequently, the fault recognition result was obtained by using the max membership degree principle. Finally, the engineering practicability and validity of the EW-GRA method was demonstrated by a centrifugal compressor fault diagnosis example, and the results show that the EW-GRA method is more effective and accurate than the traditional gray relational analysis (T-GRA) method and the weighted gray relational analysis (W-GRA) method.
CFD Analysis of Turbulent Flow in Typical Rod Bundles in Rolling Motion
Authors: Yan B.H. , Gu Han Yang , Yang Y.H. , Yu L.
Published: September 2010

The influence mechanism of rolling motion on the flowing and heat transfer characteristics of turbulent flow in typical four rod bundles is investigated with FLUENT code. The flowing and heat transfer characteristics of turbulent flow in rod bundles can be affected by rolling motion. But the flowing similarity of turbulent flow in adiabatic and non-adiabatic can not be affected. If the rolling amplitude is big or if the rolling period is small, the radial additional force can make the parameter profiles and the turbulent flowing and heat transfer change greatly. And the frictional resistance coefficient and heat transfer coefficient can not be solved by the correlations in steady state. In rolling motion, as the pitch to diameter ratio decrease, especially if it is less than 1.1, the flowing and heat transfer of turbulent flow in rolling motion change significantly.
Solving Obstacle Problem Based on Potential-Reduction Interior Point Algorithm
Authors: Yong Long Quan
Published: September 2010

This text studies a kind of obstacle problem. Combining with difference principle, we transform the original problem into monotone linear complementarity problem, and propose a novel method called potential-reduction interior point algorithm for monotone linear complementarity problem. We establish global and finite convergence of the new method. The reliability and efficiency of the algorithm is demonstrated by the numerical experiments of standard linear complementarity problems and the examples of obstacle problem with free boundary.
Inverse Dynamics of 2UPS-2RPS Parallel Mechanism Based on Virtual Work Principle
Authors: Wang Wen Hua , Feng Zhi You , Yang Ting Li , Zhang Ce
Published: September 2010

Inverse dynamic equations of the 2UPS-2RPS mechanism are formulated by utilizing the virtual work principle. Kinematic analysis of the mechanism is presented, on the basis of which the Jacobian matrices of the limbs and the mechanism are deduced. By combining the dynamics of the limbs and the moving-platform, the inverse dynamic model of the mechanism is obtained. Finally a computer simulation is carried out to demonstrate the dynamic analysis of the moving platform.
Chaotic Behavior of the Nonlinear (3+1)-Dimensional Burgers System
Authors: Ma Yu Lan , Li Bang Qing
Published: September 2010

Based on the non-traveling wave solution and Rossler chaos system, chaotic soliton excitations are established for the nonlinear (3+1)-dimensional burgers system. The chaotic behavior and chaotic evolution of the system are investigated.
Extended Kalman Filter Based Identification of Dynamic Model for Underwater Robots
Authors: Liang Xiao , Zhang Jun Dong , Li Wei , Su Lin Fang
Published: September 2010

In order to obtain a precise mathematical model of underwater robots, model identification based on extended kalman filter is proposed in this paper. Parameter estimation is carried out with experiment data of zigzag motion in ocean experiments, and the hydrodynamic derivatives of underwater robots are identified by using extended kalman filter, and the nonlinear dynamic model of an underwater robot is established. The simulation system based on the model is established to verify the validity. The results show the model is credible, which is very useful for the research of maneuverability and adaptive control of underwater robots.
Mesh Exponential Stability of Look-Ahead Interconnected System
Authors: Cao Zheng Li , Li Tian , Zhang Ji Ye
Published: September 2010

Mesh stability is the property of damping or eliminating disturbances as they travel in an interconnected system. In this paper, the mesh stability of a class of look-ahead vehicle following system is studied under the assumption that the all isolated subsystems are exponentially stable. Via idea of vector Lyapunov function theory and by using of Cauchy inequality technique, the sufficient condition to ensure the global mesh exponential stability is obtained. The obtained condition which shows the relationship and domain of the parameters is convenient to apply to design controller in practice.
Vehicle Lateral and Longitudinal Velocity Estimation Using Coupled EKF and RLS Methods
Authors: Chu Liang , Zhang Yong Sheng , Shi Yan Ru , Xu Ming Fa , Ou Yang
Published: September 2010

In order to meet the cost requirement of lateral and longitudinal velocity measured directly in vehicle active safety control systems, based on 3-DOF vehicle model and the Recursive Least Squares (RLS) which can identify the tire cornering stiffness online, a control algorithm using Extended Kalman Filter(EKF) to estimate lateral and longitudinal velocity is proposed. The estimation values are compared with simulator values from CarSim. The compared results demonstrated that the proposed algorithm could estimate the lateral and longitudinal velocity accurately and robustly.
The Registration Detection System of Rotary Screen Printing Machine Based on the Machine Vision Technology
Authors: Jing Jun Feng , Li Peng Fei , Wang Jing
Published: September 2010

With the development of the computer and the digital image processing technology, application of machine vision technology to make online detection research has been gradually developed, so the machine vision technology has been introduced into the registration detection of rotary screen printing, in order to enhance the accuracy and speed of the registration error’s detection, that is a very significant research topic. Firstly, general planning about the rotary screen printing machine registration detection system has been designed. In addition, texture noise of printing picture has been analyzed, which has been collected by smart camera. Finally, based on mean shift arithmetic for color image segmentation has been put forward. Experiments show that the algorithm based on mean shift segmentation method for color image segmentation textile printing can achieve good results, moreover that can accurately carry out the fabric chromatic region segmentation, which for the registration error detection system design on rotary screen printing machine lays the foundation.
Development of Hybrid Electric Vehicle Control System Based on V-Cycle
Authors: Hu Fei , Zhao Zhi Guo
Published: September 2010

The development of control system for hybrid electric vehicle (HEV) is a complex project and should be guided using an efficient development procedure. In this paper, the V-cycle development approach has been applied to the development of HEV control system. The five steps of V-cycle including function design, rapid control prototyping (RCP), production code generation, hardware-in-loop simulation (HIL) and calibration have been analyzed in detail and realized by using tools such as MATLAB/Simulink/Stateflow, dSPACE MicroAutoBox, MATLAB/Embedded Target for Motorola MPC555 and Vector CANape. The results of the investigation show that this method can help to shorten the development period, ease the labor of experiments and reduce the development cost.
An Improved Artificial Immune Network Algorithm to Solve Multi-Project Scheduling Problem in Product Development
Authors: Chen Ting Gui
Published: September 2010

An improved artificial immune network algorithm used to solve multi-mode resource constrained multi-project scheduling problem in product development process is put forward. Firstly, the mathematic model of multi-project scheduling problem is set up. And then, Operations including clonal selection, negative selection and network suppression are used to realize the local searching and global searching which will assure that the algorithm has a powerful searching ability and also avoids the possible combinatorial explosion. Finally, a randomly generated case is used to test its performance and the result shows that the algorithm is effective and efficient.
Nonlinear Diffusion Equation for Image Denoising Method Based on Gradient Fidelity Term
Authors: Wu Da Sheng , Wen Qing Qing , Rao Yu Ping
Published: September 2010

This article introduces the gradient fidelity term into the functional model of the image denoising to obtain a new denoising functional model and derive the relative nonlinear diffusion denoising model. The new model has been proved that the bounded variation function is integrable, which will get rid of the problem of edge leaking. According to the experimental results, the application of this model is to prevent the "ladder" effect, the result of piecewise smooth can be acquired with more natural visual effects, meanwhile, the method has been proved more stable for the value calculation and has higher computational efficiency.
Combining Production Planning Model of Product Line Based on Genetic Algorithm
Authors: Jiang Guo Zhang , Kong Jian Yi , Li Gong Fa , Xie Liang Xi
Published: September 2010

At present, iron and steel enterprise develops towards the direction with many procedure, many process, many variety and many specification, and reaches hundreds and thousands of product series and product mix, how to plan, organize and control steel production, production schedule of its product line is a key issue. Mixed production plan model of product line can be summed up in a kind of network flow plan issue. According to the characteristics of network flow plan issue, the production schedule model of product network flow is established through describing digraph-connected graph of production procedure of iron and steel enterprise. Its goal function is the biggest profit of production of product line, restrain functions are the capacity limiting conditions, the balanced condition of the middle peak point, capacity restrain with supply and sell production and restrain with enterprise procedure process resources. Several key resource production procedure processes are chosen to calculate by using standard library function of the Matlab7.0 genetic algorithm toolbox to program. Penalty function is adopted in the course of getting solution. These parameters of scale of father population, crossover probability, mutation probability and penalty factor are combined and optimized. Results indicate that goal value reach convergence after finish 119 iterative operations. It accords with the actual conditions of this enterprise basically that the optimization solution to production plans of real iron and steel enterprise by using the algorithm.
Numerical Simulations and Analysis on External Flow Field of Van Body Truck Based on ANSYS
Authors: Liu Na , Zheng Zhong Cai , Gao Yan
Published: September 2010

The three dimensional model of a van body truck is established, and then the aerodynamic characteristics of the truck is analyzed using finite element method with ANSYS software. Through the analysis, the velocity vector distribution charts, the velocity nephograms and the pressure nephograms are obtained respectively under two different vehicle speeds; then the results are compared which provide necessary guides for the optimal design of the van body.
Solving the Inverse Position Problem of a 7R Robot
Authors: Huang Xi Guang , Li Duan Ling , He Guang Pin
Published: September 2010

In this paper a new computational technique for the inverse position problem of a 7R robot is presented. Instead of reducing the problem to one highly complicated input-output equation, we work with a system of 10 very simple polynomial equations. We show the total degree of the system is 16, in agreement with previous works. Moreover we present a numerical example confirms the technique. The whole process is simple and easy to program.
A Novel SVM-Based Method for Seismic First-Arrival Detecting
Authors: Chen Ming , Li Yong , Xie Jun
Published: September 2010

First arrivals detecting on seismic record is important at all times. A novel support vector machine (SVM)-based method for seismic first-arrival pickup is proposed in this research. Firstly, the multi-resolution wavelet decomposition is used to de-noise the seismic record. And then, feature vectors are extracted from the denoise data. Finally, both SVM and artificial neural network (ANN) models are employed to train and predict the feature vectors. Experimental results demonstrate that the SVM model gives better accuracy than the ANN model. It is promising that the novel method is very prospective.
Chitin/TiO2 Composite for Photocatalytic Degradation of Phenol
Authors: Wan Kun , Peng Xiang Hong , Du Ping Jing
Published: September 2010

Chitin/TiO2 composite was prepared through colloid TiO2 deposited on the chitin by controlling the pH value of the system, while colloid TiO2 was synthesized by the sol–gel method using tetrabutyl titanate as a precursor. The structures and morphologies of the chitin/TiO2 composite were characterized by FT-IR, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The photocatalytic degradation of phenol was investigated by HPLC method. The results revealed that the chitin/ TiO2 composite was an efficient photocatalyst for the degradation of phenol, and 99.2% of the phenol was degraded after 6h under UV light. The TiO2 was adsorbed on the chitin by hydrogen and titanoxane bonds between them. Colloid TiO2 was gradually deposited to form the anatase crystallographic structures, showing 2θ = 25.3, 37.8, 47.8 and 54.6. Such biocompatible photocatalyst might be applied in the field of various phenol pollutants abatement.
Studies on the Catalytic Activity of Sulfated Zirconia Promoted with Cerium Oxide
Authors: Lugo del Ángel F.E. , Silva-Rodrigo R. , Vázquez Rodríguez A. , García Alamilla R. , Navarrete Bolaños J. , Castillo Mares A. , Melo-Banda José Aarón , Térres-Rojas Eduardo , Rivera Armenta J.L.
Published: September 2010

Pure zirconia, sulfated zirconia and sulfated zirconia modified with 2, 3, 5 and 10 wt. % of cerium oxide were synthesized by sol-gel method. Pt phase was impregnated on the supports using the incipient wet technique. Sulfated zirconium oxide showed tetragonal phase only. Addition of cerium to sulfated zirconia did not modify the tetragonal phase but produced a marked effect on the surface area. Low cerium content may greatly increase the surface area; however, too high cerium content (10 wt.%) may decrease the surface area. Pore size had influence on the catalytic activity and ZrO2 acidity was favored by the sulfate ion incorporation. All catalysts having Brönsted and Lewis acid sites were active in the n-hexane isomerization. The highest n-hexane conversion (40%) and selectivity towards DMB (26%), 2-methyl pentane (61%) and 3-methyl pentane (13%) were reached over the catalyst with 10 wt. % cerium oxide. In addition, sulfated zirconium oxide presented high selectivity of light products (< C6), which indicated that the addition of this doping agent (CeO2) made the catalysts more selective toward the desired reaction products.
A Novel La2O3-ZnO/ZrO2 Solid Superbase and its Catalytic Performance for Transesterification of Soybean Oil to Biodiesel
Authors: Li Xu , Lu Guan Zhong , Guo Yang Long , Guo Yun , Wang Yan Qin
Published: September 2010

A novel solid superbase catalyst of La2O3-ZnO/ZrO2 was prepared, and its H– value (Hammett function) of surface basic strength reaches 26.5. The catalytic activity of La2O3-ZnO/ZrO2 was evaluated for the transesterification of soybean oil (SBO) with methanol to biodiesel in a fixed bed reactor under atmospheric pressure. The results show that the chemical composition of the La2O3-ZnO/ZrO2 catalyst influences both its H– value and catalytic performance, the appropriate content of ZrO2 is 60 wt.% and the La2O3/ZnO molar ratio is 4~5/1. La2O3-ZnO/ZrO2 is an effective catalyst for the transesterification of SBO, and the SBO conversion reaches 71.3% at 70°C for 12h.
Refinery Oil Fraction Fuels Obtained from Polyethylene Catalytic Cracking Employing Heteropolyacid-MCM-41 Materials
Authors: Hernández Alberto , Noreña-Franco Luis E. , Chen Li Fang , Wang Jin An , Aguilar Julia
Published: September 2010

We report the thermal and catalytic decomposition of low density polyethylene (LDPE) as a recycling route of plastic solid waste. The reaction system consisted of a fixed-bed reactor at a 450 °C reaction temperature and a 40 min reaction time. Tungstophosphoric acid (H3PW12O40)-functionalized ordered mesoporous materials MCM-41 were employed as catalysts. Results show that using this technical approach, on one hand, environmentally unfriendly waste can be disposed and, on the other hand, valuable and widely used fuels can be obtained.
Synthesis Optimization of SAPO-34 in the Presence of Mixed Template for MTO Process
Authors: Ye Li Ping , Cao Fa Hai , Ying Wei Yong , Fang Ding Ye , Sun Qi Wen
Published: September 2010

A series of SAPO-34 materials were synthesized hydrothermally in the presence of mixed templating agent (named TEDE) of tetraethyl ammonium hydroxide (TEAOH) and diethylamine (DEA). The effects of template amount, SiO2/Al2O3 and P2O5/Al2O3 molar ratios and the crystallization temperature on the structure and acidity were studied by XRD, nitrogen adsorption and NH3-TPD techniques. The results showed that SAPO-34 and SAPO-5 are competing phases at low template concentration. Pure SAPO-34 with high crystallinity and large BET surface area were obtained at a TEDE/Al2O3 ratio of 2.0. Varying the SiO2/Al2O3 ratio at 0.1~1.0 did not change the purity of SAPO-34, but affected its crystallinity and acidity. An optimal synthesis procedure giving a homogeneous SAPO-34 framework with high crystallinity, consists of heating a gel of composition Al2O3:P2O5:0.6SiO2:1.0TEAOH:1.0DEA:53H2O at 100 °C for 24h firstly and 200 °C for 72h later. Such a reproducible procedure gave rise to an acidic catalyst active in the MTO reactions with 100% methanol conversion, 85.2% ethylene and propylene selectivity and a longest lifetime.
A Novel Non-Metal Oxygen Reduction Electrocatalyst Based on Platelet Carbon Nanofiber
Authors: Zheng Jun Sheng , Zhang Xin Sheng , Wen Sun , Li Ping , Ma Chun An , Yuan Wei Kang
Published: September 2010

A novel non-metal electrocatalyst based on platelet carbon nanofiber (p-CNF) is prepared, and a palladium electrocatalyst supported on activated carbon (AC) is also synthesized. The physico-chemistry properties of the p-CNF and palladium catalyst on AC (Pd/AC) are investigated by high resolution transmission electron microscopy, N2 physisorption and Raman spectra analysis. From cyclic voltammetric studies, it is found that p-CNF is more active than Pd/AC in acidic media. The p-CNF shows a more positive oxygen reduction reaction (ORR) onset reduction potential and a higher oxygen reduction current density than Pd/AC. Moreover, the ORR is controlled by a surface reaction process when Pd/AC is used, while it becomes diffusion controlled when p-CNF is used.
Comparative Studies of the CoMo/MgO, CoMo/Al2O3 and CoMo/MgO-MgAl2O4 Catalysts Prepared by a Urea-Matrix Combustion Method
Authors: Wu Li Bao , Jiao Dong Mei , Chen Li Fang , Wang Jin An , Cao Fa Hai
Published: September 2010

Three CoMo supported catalysts with different supports, Al2O3, MgO and MgO-MgAl2O4, were prepared by a urea matrix combustion method. The physicochemical properties of the catalysts were characterized by N2 isothermal adsorption–desorption, powder X-ray diffraction (XRD) and temperature programmed reduction (TPR) techniques. The activity of these catalysts was evaluated in a fixed-bed high-pressure reactor using hydrodesulfurization of dibenzothiophene as a model reaction. The urea matrix combustion preparation method greatly favored the formation of highly dispersed Co- and Mo-oxo species on the support, which had significant influence on the hydrodesulfurization (HDS) activity. XRD analysis showed that MgO was more sensitive to the deposition of Co-O or Mo-O species than Al2O3 and MgAl2O4; the former might be potentially used as an indicator of the Co- and Mo-oxo species formation. Among these catalysts, CoMo/MgO-MgAl2O4 exhibited a high HDS activity.
ZnAlFe Mixed Oxides Obtained from LDH Type Materials as Basic Catalyst for the Gas Phase Acetone Condensation
Authors: Mantilla Angeles , Tzompantzi Francisco , Manríquez María , Mendoza Guadalupe , Fernández Jose L. , Gómez Ricardo
Published: September 2010

ZnAlFe mixed oxides with high surface area were obtained by the calcination (723 K) of ZnAlFe layered double hydroxides (LDHs). The calcined materials proved as basic catalysts in the gas phase acetone condensation exhibited high activity and high selectivity towards the formation of mesityl oxide.
Structure Sensitivity of Sol-Gel Alkali Tantalates, ATaO3 (A= Li, Na and K): Acetone Gas Phase Condensation
Authors: Torres-Martínez Leticia M. , Meza-de la Rosa M. Elena , Garza-Tovar Lorena L. , Juárez-Ramírez Isaías , Tzompantzi Francisco , Del Angel Gloria , Padilla Juan M. , Gómez Ricardo
Published: September 2010

Perovskite-type compounds such as alkali tantalates, ATaO3 (A = Li, Na and K), prepared by the sol-gel method are reported as heterogeneous basic catalysts for the acetone aldol condensation. It has been proposed that the activity order and the selectivity patterns (LiTaO3 > > KTaO3 > NaTaO3) depend on the octahedral arrangements of the TaO6 tantalates.
Phase Stabilization of Mesoporous Mn-Promoted ZrO2: Influence of the Precursor
Authors: Hernández-Pichardo Marcello L. , Montoya J.A. , Del Angel P. , Paredes S.P.
Published: September 2010

Mesoporous zirconia-Mn oxides were prepared by surfactant-assisted precipitation using different zirconia precursors and cetyl-trimethyl-ammonium bromide (CTAB) as a synthetic template. The objective of this work was to find out the influence of the zirconia precursors over the structural and textural characteristics of Mn-doped mesoporous zirconia solids. A series of syntheses were carried out by two methods using different zirconia precursors, modifying the Zr:surfactant ratio and the hydrolysis rate of the precipitate. After calcination at 500 °C, the samples were characterized by XRD, DTA, TEM and nitrogen adsorption-desorption isotherm. The use of the zirconium nitrate leads to materials having higher surface areas and narrow pore size distributions in the range of mesoporous materials; however, the preferential formation of the zirconia in the metaestable tetragonal phase was identified as the effect of the particle size allowed by the preparation method rather than the effect of the precursor. It was also found that the Mn and surfactant addition enhances the stabilization of the tetragonal crystalline phase and porosity.
Development and Test of CVD-Diamond Microgrinding Wheels
Authors: Hoffmeister Hans Werner , Wittmer Ronald
Published: September 2010

CVD-diamond microgrinding wheels can be used in the microsystems technology, e.g. to produce microarrays consisting of glass. These novel tools have the same advantages as CVD-diamond microgrinding pins, but they can even be used with higher cutting velocities and higher material removal rates. Furthermore, micro cracks and chipping could be minimized and better surface qualities could be achieved.
The tool body consists of cemented carbide. After designing a suitable geometry for these novel micro grinding tools, they had to be produced with cup wheels. The design, which has already been tested, is a grinding wheel of the type “1A1”. The CVD-diamond microgrinding wheels were analyzed with a scanning electron microscope (SEM) due to their topography and crystallite size.
The microgrinding wheels were tested with regard to their grinding behavior. During the investigations, cutting forces were measured and afterwards analyzed. In addition, surface roughnesses were measured, so that the materials could be compared with regard to their grindability.
The tool wear was evaluated by means of SEM-pictures. They showed the wear resisting behavior of the CVD-diamond microgrinding wheels. Even after grinding a high material removal rate in the hard ceramic aluminum nitride, only a small clogging of the microgrinding wheel was monitored. The slight increase of the cutting force is another indicator for the clogging.
It can be summarized that novel grinding tools could be successfully developed and tested with hard and brittle materials. During these tests, the cutting forces and surface roughnesses as well as wear behavior and end of tool life were determined and will be shown in this publication.
Polishing Mechanism of Glass Substrates with its Processing Characteristics by Cerium Oxide and Manganese Oxide Slurries
Authors: Yamazaki T. , Doi Toshiro K. , Kurokawa Syuhei , Isayama S. , Umezaki Yoji , Matsukawa Yoji , Kono H. , Akagami Yoichi , Yamaguchi Yasuhide , Kawase Y.
Published: September 2010

With an aim to reduce the consumption of cerium oxide (CeO2) used in large quantity for the polishing of glass substrates applied for HDD and display, we have attempted to obtain the processing characteristics of glass substrates by CeO2 slurry. We also paid attention to manganese oxide abrasives to replace cerium oxide abrasives.
As a result, we have found Mn2O3 abrasives potential to replace disappearing CeO2 for the polishing of glass substrates.
Investigation on Influences by Adapting Additives to Electrolytic In-Process Dressing (ELID) Grinding
Authors: Lou Ning , Marinescu Ioan D. , Weismiller Michael C.
Published: September 2010

As demand for high-quality machined tools considerably grows, ELID, a new and efficient technology, has been successfully brought into the precise manufacturing industry of hard and brittle materials with mirror surface finish. Hence, besides conventional functions like lubrication, fluid solutions in this grinding process are required to serve more functions, especially as electrolyte. Writers of this paper mainly work on the methodology to optimize this kind of fluid by adding various related chemical additives. By varying the pH, the accretion of additives is controlled and consequential effects are studied which is the metallic oxide layer variation before and after each test. Corresponding experiments have been carried out with procedures and results analysis included in the paper.
Machined Surface Characteristics and Removal Mechanism of Soft and Brittle Solids
Authors: Zhang Zhen Yu , Irwan Rudy , Huang Han
Published: September 2010

Surface characteristics of CZT wafers machined using wire sawing, free abrasives lapping and polishing and ultra-precision grinding were investigated. Wire sawing resulted in the removal of material in both ductile and brittle regimes, but both polishing and grinding led to a ductile removal. The grinding produced very smooth surfaces free of embeddings and scratches, which is thus considered to have better machinability than the free abrasive machining. The nanoindentation and nanoscratch on MCT wafers at nanometric scales resulted in considerable plastic deformation, but no fracture features. The hardness of the MCT wafer was 500 to 550 MPa, and the coefficient of friction was particularly high, ranging from 0.45 to 0.55.
Effect of Tool Cone Angle on Micro Machining Based on the EMR Effect
Authors: Liu Yi , Yan Qiu Sheng , Lu Jia Bin , Kong Ling Ye , Gao Wei Qiang
Published: September 2010

Aiming at micro machining of 3D microstructure of brittle materials with a novel tiny-grinding wheel based on the electro-magneto-rheological (EMR) effect, five conical tools with different cone angles are designed to reveal the effect of the cone angle on the machining characteristics. The distribution of the magnetic and electric fields in the polishing area is simulated using the finite element analysis software, and the machining experiments of micro groove were conducted to confirm the simulation results. Experimental results indicate that the material removal rate increases first and decreases afterwards with the increase of the cone angle, and the section width of micro groove increases but the section depth of micro groove shows a fluctuation phenomenon within a certain range. The intensities of the electric and magnetic fields on the tip of the conical tool with the 45° cone angle are at a larger level in the five tools, which is helpful to form a stable tiny-grinding wheel based on the EMR effect and obtain a better machining effect, so the tool with the 45° cone angle is an effective and ideal machining tool for the machining of 3D microstructure.
On-Machine Heat Treatment System Using YAG Laser: Laser Hardening of Micro-Cutting Edge
Authors: Ogawa Keiji , Nakagawa Heisaburo , Ohtsuka Akira
Published: September 2010

This paper describes the laser hardening of micro-cutting edges using an on-machine heat treatment system with a YAG laser. Various laser conditions were evaluated to perform laser quenching on a machine tool without melting at the edges. We also investigated the influence of the motion accuracy of the machining center on the quenching characteristic of micro-cutting edges after laser irradiation. We clarified that we could quench both the straight and curved corner parts by arranging proper laser irradiation conditions considering the motion accuracy of the machining center.
Fabrication of Ultraprecision Millimeter-Thick Elliptical Neutron Focusing Mirror Substrate by Local Wet Etching
Authors: Yamaga Fumiya , Nagano Mikinori , Zettsu Nobuyuki , Yamazaki Dai , Maruyama Ryuji , Soyama Kazuhiko , Yamamura Kazuya
Published: September 2010

Numerically controlled local wet etching (NC-LWE) is a novel technique to fabricate the ultraprecision optical components and/or finishing the functional materials. In this technique, a figuring is performed by controlling the dwelling time of the combination nozzle, which consists of a supply and a suction part of an etchant, on the workpiece. In this paper, we proposed fabrication process of millimeter-thick elliptical neutron focusing mirror substrate by applying NC-LWE figuring involving CeO2 slurry polishing. We fabricated a millimeter-thick elliptical neutron focusing mirror substrate with a figure error of less than 0.2 μm and obtained a surface roughness of less than 0.15 nm rms.
Effect of Substrate Heating in Thickness Correction of Quartz Crystal Wafer by Plasma Chemical Vaporization Machining
Authors: Ueda Masaki , Shibahara Masafumi , Zettsu Nobuyuki , Yamamura Kazuya
Published: September 2010

Quartz resonator is a very important device to generate a clock frequency for information and telecommunication system. Improvement of the productivity of the quartz resonator is always required because huge amounts of resonator are demanded to install to various electronic devices. Resonance frequency of the quartz resonator is determined by the thickness of the quartz crystal wafer. Therefore it is essential to uniform the thickness distribution of the quartz crystal wafer with nanometric level. We propose the improvement process of the thickness distribution of the quartz crystal wafer by numerically controlled correction using atmospheric pressure plasma which is noncontact and chemical removal technique. We have already succeeded in obtaining a thickness uniformity of 33.1nm within 2 min in the thickness correction of an AT-cut quartz crystal wafer with an area of 24 mm × 24 mm. However, increase of removal rate and improvement of correction accuracy are required for industrial manufacturing. Heating effects of the quartz crystal wafer in the removal rate and the correction accuracy were investigated. The heating of the substrate and compensate of the scanning speed of the worktable in accordance with the variation of the surface temperature enabled an increase of 50% in removal rate and 10-nanometric-level accuracy in correction of the thickness distribution of the quartz crystal wafer.
Electrical Discharge Machining of Submicron-Diameter Micropins
Authors: Ueno Hiromitsu , Kono Yuki , Egashira Kai
Published: September 2010

The wire electrodischarge grinding (WEDG), which is one of the electrical discharge machining (EDM) methods, of submicron-diameter zinc micropins was attempted using a relaxation-type pulse generator. Tungsten wire of 30 µm diameter was employed as the tool electrode. The open-circuit voltage was set at lower than or equal to 15 V in the finish machining step. The electrostatic capacitance of the pulse generator was its stray capacitance only. As a result, a micropin of 0.3 µm diameter was processed. They are the smallest-diameter micropins fabricated by EDM, to the best of our knowledge.
The Function Deployment of EDM Machine Tools
Authors: Xue Rui , Guo Chang Ning , Yang Xiao Xin , Pei Jing Yu
Published: September 2010

This paper addresses the further developing and utilizing about the functions of EDM machine tool on the basis of researching the numerical controls of EDM machine tool itself. Experiments of testing critical gap distances, single pulse discharges and single pulse discharge gap distances have been performed by the machine tool without any extra help of auxiliary instruments or equipments. The measuring accuracy and repeated testing accuracy is the numerically controlled displacement precision of the machine tool itself. The development of this function would have a great impact on enlarging the utilizations of EDM machine tools, on evaluating the behavior of EDM effectively and on designing the jumping displacement of electrodes reasonably.
Study and Optimization of Polymer Lapping on D2 Steel
Authors: Zhang Yi Ying , Marinescu Ioan D. , VandenBoom Rick
Published: September 2010

Experimental research on surface roughness and material removal rate of D2 steel lapping is carried out using a polymer plate. The tribological mechanism of lapping for ductile materials is presented and the polymer-based lap plate is described in this study. Thus, an investigation is conducted using ANOVA method to determine the effects of lapping time, lap rotation speed, applied load and abrasive particle size on the lapping process for D2 steel discs with the polymer-coated plate. Regression models are put forward and verified for predicting surface roughness and MRR (material removal rate) as a result of the control variables. An optimal combination of process parameters is given for optimizing the lapping process.
Study on Influence of Stray Inductance in Micro EDM Using Electrostatic Induction Feeding Method
Authors: Yang Xiao Dong , Wan Yong , Hu Fu Qiang
Published: September 2010

In the micro EDM method by electrostatic induction feeding, a pulse generator is coupled to the tool electrode by a capacitor, since the negative influence of the stray capacitance in the circuit can be eliminated, and the discharge energy per pulse can be minimized, thereby realizing discharge craters of nanometer order. However, there is still the stray inductance in the discharge circuit, other than the stray capacitance. In this study, in order to examine the influence of the stray inductance, experimental investigation was conducted.
High Spindle Speed Wire Electrical Discharge Grinding Using Electrostatic Induction Feeding Method
Authors: Yahagi Yuna , Koyano Tomohiro , Kunieda Masanori , Yang Xiao Dong
Published: September 2010

This paper describes machining characteristics of high spindle speed WEDG using the
electrostatic induction feeding method. In this method, non-contact electric feeding allows the
workpiece rod to be rotated at a high speed of up to 50000rpm. Since the temperature rise on the
workpiece surface is low, the material removal rate was two times higher and the surface roughness
was also improved compared to the normal RC discharge circuit where the rotational speed was
1000rpm at the highest due to contact electric feeding using a brush. Furthermore, micro rods thus
prepared were used as tool electrodes to machine micro-holes with the same rotation speed of
50000rpm. It was found that smaller gaps and better straightness can be obtained due to the high
flushing efficiency at the high spindle speed.
Optimal Vacation Policy for a Manufacturing Facility Using Retrial System
Authors: Yeo Wee Meng , Yuan Xue Ming
Published: September 2010

We consider a manufacturing system which takes vacation and subjects to breakdown. Items arrive to the production facility according to a compound Poisson process. Using supplementary variables we determine the probability generating function (p.g.f) of the system size. Under the Long Run Average Cost formulation, we show that the optimal vacation policy is either single or multiple vacation policy.