bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of the Flow and Regeneration Characteristics of Screen Mesh and Parallel Wire Regenerators
Authors: Guo Yong Fei , Chen Xi , Zhang Hua
Published: December 2010

An analysis has been made for the flow and regeneration characteristics in screen mesh and parallel wire regenerators. A model is put forward by taking the matrix as an anisotropic porous medium. The regeneration characteristics are investigated by comparing the Nu, hsf and NTU between the both regenerators under oscillating flow conditions. It is indicate that the heat transfer performance in screen mesh regenerator is better than the one in parallel wire regenerator at the same oscillating flow condition. The mass flow distribution homogeneity factor Fm is conceived and derived to reflect the gas flow distribution in the porous matrix, and heat penetration depth δt and porosity are also indicated to be the indexes of optimizing the matrix geometry.
Study on the Credit Classification of Practicing Qualification Personnel in Construction Market Based on PNN
Authors: Sun Hui , Fan Zhi Qing , Zhou Ying
Published: December 2010

Combining with the characters of the practicing qualification personnel in construction market, probabilistic neural network is brought out trying to analyze the credit classification of the practicing qualification personnel. And the impact factor of the number of neurons on the credit classification of the practicing qualification personnel is studied. Then a probabilistic neural network is built. At last, a case study is conducted by taking practicing qualification personnel as an example. The research result reveals that the method can efficiently evaluate the credit of the practicing qualification personnel, thus it could provide scientific advice to the construction enterprise to prevent relevant discreditable behaviors of some practicing qualification personnel.
An Integrated Variant Design Method of Dimension and Dimensional Tolerance
Authors: Liu Fu Yun , Xiao Li Zhi , Kuang Bing
Published: December 2010

To improve the efficiency of variant design, it is not only needs dimension variant design but also needs dimensional tolerance design method. The method to extract tolerance information from parametric model of a part, the method to calculate tolerance value of a dimension according to its accuracy class, the method to place tolerance information to a dimension are researched. A dimensional tolerance variant design method of part based on the above three methods and parametric technology is put forward. The dimensional tolerance variant design method is integrated into dimension variant design method and an integrated variant design method is obtained. An integrated variant design module which can be integrated into SolidWorks is developed. As an example, the methods and the integrated variant design module is applied to an output shaft and the methods and the variant design module are verified.
A Research of Stereo Vision Positioning under Vibration
Authors: Chen Yan , Cai Wei Liang , Zou Xiang Jun , Xu Dong Feng , Liu Tian Hu
Published: December 2010

To improve the positioning accuracy of picking manipulator, research of stereo vision positioning for picking object in dynamic was studied. And system composition and positioning principle of stereo vision for vibratory object were introduced. Moreover, experimental platform, which simulated the vibration while picking, was designed for the stereo vision positioning experiment in static condition or vibratory condition. Therefore, influence of vibration condition on the depth information of vision positioning can be analyzed and the regression equation of depth error can be built. The results showed that when the object vibrating, the depth error increased. The vibratory frequency was the most important factor, and the depth error would increase with the frequency increased. The influence of vibratory direction and amplitude on depth error was also significant, but much less than frequency.
Study of Combination Character Based ANN and one Dimensional Optimization in Axial-Flow Water Turbine
Authors: Wang Li Ying , Wei De Hua , Xu Xiao Long
Published: December 2010

This paper uses artificial neural network (ANN) and one dimensional optimization method to get an auto-analysis method on combination character test data in the axial-flow turbine. It can obtain the combination character of hydraulic turbine automatically based on the test data. Compared to the classical method of artificial computation, it can shorten mach computing time and avoid the character conversion of different water head, it also can increase the computation accuracy. So it can supply the method to reference use in processing character test data of hydraulic turbine.
Research on Product Development Resource Allocation Modeling Based on Hierarchical Colored Petri Net
Authors: Deng Qian Wang , Yang Li Ping
Published: December 2010

The resource restrict in product development processes greatly influences on the cost and progress of the whole project. In this paper, a task priority algorithm that can solve the problem of resource competition, taking the related theory of project management into consideration comprehensively, is proposed. A ﬂexible model of product development process is described based on hierarchical colored Petri net. And then a resource coordination mechanism is modeled according to the characteristic of modern product development processes. Finally, a resource allocation process is analyzed and optimized in order to enhance the utilization efficiency of resource and to shorten the product development time.
Design of Remote Controller Using Code Matching and Frequency Hopping Technology
Authors: Zheng Geng Sheng , Li Cheng Liang
Published: December 2010

This paper presents the design and implementation of a RF remote controller using code matching and frequency hopping technology. The proposed controller supports access to different random channels under disturbance environment. The work process of RF remote controller is composed of code matching, running state, handover state, and sleep state. Four system states can transform each other under corresponding external conditions. The suggested controller is more reliable than conventional ones especially during emergency condition such as noise and co-channel interference. The feasibility of the architecture has been demonstrated with a prototype implementation and presented in details.
Research and Realization on the Voice Command Recognition System for Robot Control Based on ARM9
Authors: Gao Mei Juan , Yang Zhi Xin
Published: December 2010

In this paper, based on the study of two speech recognition algorithms, two designs of speech recognition system are given to realize this isolated speech recognition mobile robot control system based on ARM9 processor. The speech recognition process includes pretreatment of speech signal, characteristic extrication, pattern matching and post-processing. Mel-Frequency cepstrum coefficients (MFCC) and linear prediction cepstrum coefficients (LPCC) are the two most common parameters. Through analysis and comparison the parameters, MFCC shows more noise immunity than LPCC, so MFCC is selected as the characteristic parameters. Both dynamic time warping (DTW) and hidden markov model (HMM) are commonly used algorithm. For the different characteristics of DTW and HMM recognition algorithm, two different programs were designed for mobile robot control system. The effect and speed of the two speech recognition system were analyzed and compared.
Engineering Design and Analysis for Four-Legged Steel Trellis Column
Authors: Chen Jian Bin , Xue Hai Jun
Published: December 2010

In this paper, the design process of the four-legged steel trellis column is introduced for an actual project. The internal force calculation including of axial pressure and bidirectional bending moment are discussed. The strength and stability satisfy the requisition by code. Confirm that the stability of sub pillar is key element for design of trellis column. The simulations show that the design method is safety and reasonable by STAAD.pro software. Different gridding is chosen based on length, width and thickness of members; excess larger or smaller gridding is improper. The conclusions and methods can be referred by later engineering.
Research on Harmony of Interior System of Railway Passenger Cars
Authors: Zhang Bing Chen , Guo Wei Min , Wang Yan Qun
Published: December 2010

The development of interior design is an important aspect of improving the quality of railway transportation services. The interior design system of the railway passenger cars may do better in reflecting the interrelations among the passengers, the facilities and the environment of the compartments with the harmony idea to considerate relationship between the passengers, the facilities and the environment. In this way, we may have the optimized performance of the interior system and improve the interior system design of the railway passenger car effectively.
Green Design Based on the Concept of Ecological Holism
Authors: Zhan Ying
Published: December 2010

Ecological Holism regards the overall interests of the ecosystem as the highest value, advocating the integrity, harmony, stability, and balance of the ecosystem to be maintained and preserved. Only with the concept of eco-holism guiding Green Design, can its ultimate goal come into reality. In this paper, the significance of setting up the notion of Ecological Holism in Green Design is discussed, and the directing role of Ecological Holism is elaborated via thoroughly Green Design process analysis.
Evaluation on Environmental Corrosion Damage of Steel Domes
Authors: Chen Bo , Wei Jian Feng , Zheng Jin
Published: December 2010

The evaluation on environmental corrosion damage of steel domes is carried out in this study through an integration of knowledge in material science and structural analysis. The refined exponential model for estimating corrosion of steel materials is presented based on long-term experimental data available. The formula for relating structural natural frequency sensitivity to structural member thickness is then derived to assess the sensitivity of natural frequency to variation of member thickness due to corrosion. The nonlinear static analysis is conducted to evaluate effects of atmospheric corrosion on the stress of structural members and the safety of steel space structures. A real steel dome built in China is taken as the case study to examine the feasibility of the proposed approach and to assess the potential corrosion damage to the structure..
Study of Electrochemical Finishing with High-Frequency Group Pulse
Authors: Yin Liang , Zhang Wei Min , Yan Yong , Zhang Zhi Jing
Published: December 2010

The methods and mechanisms of electrochemical finishing with high-frequency group pulse was studied. With the high-frequency group pulse power designed, an equipment with high precision and easy operation was designed. In the experiment, The influence of power frequency, machining voltage, machining gap and so on to the result was analyzed. With some orthogonal experiments, we obtained the best combination of process parameters, from the Ra value of 2Cr13 stainless steel surface.
Nonlinear Behavior in Current Mode Research of Z-Source DC/DC Converter
Authors: Guo Ke , Chen Yan , Zhou Lin , Dai Lu
Published: December 2010

Z-source converter as a kind of power converter will be responsible for the energy transmission, the paper focuses on the nonlinear characteristic analysis of Z-source DC/DC converter, in the continuous conduction mode (CCM), take Z-source converter with peak current control as the research object, establish stroboscopic mapping model for analyzing its nonlinear characteristic. the experiment result proves that Z-source converter stroboscopic mapping model is correct for analyzing its nonlinear behavior, which provides a theoretical basis for optimal design and control.
Kinematics and Strength Analysis on Variable Propeller Pitch Mechanism of a Wind Turbine Generators
Authors: Zhang Suo Huai , Jia Kun , Zhang Ping Man
Published: December 2010

Kinematic accuracy of the pitch mechanism of a wind turbine was analyzed. The results show that the difference of the pitch angle and speed existed between the actual and theoretical value due to the elastic deformation of the parts and the hydraulic oil. Monitoring sensors were proposed, which was fixed on the blade plate and used to control the hydraulic cylinder motion and compensate the moving error. A file related with loads information of the key parts was created after motion simulation. After the file was input in ANSYS, the strength of the key parts was analyzed. Based on the results, the location, where the material was easy to yield or had the maximum stress, was found.
Topological Optimization of Frame of High Speed Hydraulic Press Based on Generalized Finite Element Modules
Authors: Duan Zhi Dong , Wu Jian Jun
Published: December 2010

In order to increase value of the first natural vibration frequency, as well as gain more economic benefits by lightening the weight of combined frame of high speed hydraulic press, on the basis of proposing concept of generalized finite element module, topological optimization of prestressed combined frame was carried out with limited computing resource by means of combination of cut boundary interpolation of submodeling with generalized finite element modules. Process and results convinced that the approach was effective and highly efficient at large machine design.
Optimal Kinematic Design of a 2-DOF Planar Parallel Manipulator
Authors: Zhu Xiao Rong , Shen Hui Ping , Zhu Wei
Published: December 2010

This paper addresses geometry design and operating mode optimum design of a new kind of 2-DOF parallel manipulator actuated horizontally by linear actuators. The forward and inverse kinematics of this manipulator are derived. The four groups of inverse solution correspond to four different operating modes which cannot transit to each other smoothly. The workspace and the singularity trajectory of each mode are discussed. Based on the desired workspace, the geometry of the mechanism is determined. The operating mode of the mechanism is optimized according to distributing of all global and local performance indices on the workspace. The results are very useful for the design and application of the new manipulator with multiple forward and inverse solutions.
3-D Mechanical Analysis of Magnetic- Pneumatic Microfabrication Stage
Authors: Liu Xue Peng , Zhao Dong Mei
Published: December 2010

3-D mechanics of magnetic- Pneumatic microfabrication stage includes X, Y-direction horizontal force and vertical direction force. Horizontal force can be resolved by analytical method with magnetic equation while vertical force can be done by isentropic equations.The acceleration is expected to be 8m/s2, and working gap of air bearing is to be 10 um. Experiments show that magnetic flux air gap is below 3.9mm with the current of 2A and working gap of air bearing is 20um with the supporting force of 16kgf to match the dynamic characteristic requirements.
The Simulations of Movements in the Process of Machining the Lathe Spindle
Authors: Liu Hong Xia
Published: December 2010

In this paper, the processes of the lathe spindle are firstly introduced. Next, 3DS MAX software is used to model the lathe spindle with actual sizes. Based on the 3D model of the spindle, the 3D model of its blank is established according to the characteristics of the spindle. All used cutting tools are modeled in 3DS MAX software. Then the changes in the allowance and the movements of cutting tools and the workpiece are simulated in this software. At last, all animations are composed with appropriate explanations. The synthetical animation is saved as a .avi type file to play the machining simulation. And also, the file may be loaded into a multimedia courseware to explain the whole process to students in class. The machining simulation can improve the efficiency and effectiveness of learning. It can be given to students as a tutorial to use to teach oneself.
Numerical Investigation of the Influence of Friction Coefficient on Brake Groan
Authors: Meng Xian Jie
Published: December 2010

A two degrees of freedom nonlinear dynamics model of self-excited vibration induced by dry-friction of brake disk and pads is built firstly, the stability of vibration system at the equilibrium points is analyzed using the nonlinear dynamics theory. Finally the numerical method is taken to study the impacts of friction coefficient on brake groan. The calculation result shows that with the increase of kinetic friction coefficient /or the decrease of difference value between static friction coefficient and kinetic friction coefficient can prevent or restrain self-excited vibration from happening.
Mechanical-Design-Oriented Knowledge-Driven Model
Authors: Liu De Fang , Wang Bin , Wu Hong Pan
Published: December 2010

According to the characters of mechanical product design, product design knowledge is classified into explicit knowledge and indefinite knowledge. A knowledge-driven product design system model was proposed based on the knowledge management. To meet the normal product design process, the design system structure was built on four layers. A mixed knowledge reasoning strategy was proposed, which is combined by design cases, models, and rules. The system provides a public integration interface, so different design tools such as UG NX, Catia and Pro-E can be applied. To resolve the design conflict in product design process, a collaborative design technique was put forward that the CAD, CAPP, CAM engineers worked togeth
Improve the Free-Piston Stirling Engine Design with High Order Analysis Method
Authors: Lin Chen , Wang Xian Zhou , Chen Xi , Zhang Zhi Guo
Published: December 2010

Stirling engine is a heat engine which is enclosed a fixed quantity of permanently gaseous fluid as the working fluid. The free-piston Stirling engine is noted for its high efficiency, quiet operation, long life without maintenance in ten years and the ease with which it can use almost any heat source. Stirling cycle analysis method has been successfully applied to improve the free-piston Stirling engine design by its step-by-step development on order. This study presents the development and application of Stirling cycle analysis method. Discussions about use of multi-dimension CFD software simulating free piston Stirling engine when there’s not any available experimental data for its design will provide. Since it needs less computing resource and time to get 1D simulation results with some accuracy, the application of multi-dimension CFD could be very helpful to improve accuracy of 1D result with the details of the different simplified model parameters used in 1D model. The research demonstrates that with the combination of high order Stirling cycle analysis method, the design of the free-piston Stirling engine with the aid of numerical method could be much more effectively and accurately.
Structural Dynamic Analysis and Optimization of Precision NC Machine Tool Bed Based on the Unit Structure
Authors: Wang Fu Qiang , Rui Zhi Yuan , Wu Qin
Published: December 2010

The theory of structural dynamic analysis is put forward in this paper. The dynamic performance of a precision machine tool bed is analyzed by means of finite element method, and the analysis result shows that the natural frequency is too low is the main reason of the vibration of the bed. In order to improve the dynamic performance of the bed, the dynamic performance of the unit structure of the precision machine tool bed is analyzed. Based on the analysis of the unit structure, two structural optimization schemes for the machine tool bed are obtained. Furthermore, two optimization schemes are analyzed by means of finite element method too. Compared to the original machine tool bed, the dynamic performance of two structural optimization schemes is significantly improved.
Influence of Porous Media Property on Stirling Engine Performance
Authors: Jiang Feng Jian , Wu Xiao Guang , Zhang Zhi Guo , Lin Chen
Published: December 2010

Porous medium is playing an important role in technological advances nowadays. They exist everywhere in nature and were widely used in lots of engineering projects due to their huge internal surface area and ultrafine pore size. These properties allow them to achieve good performances in heat and mass transfer. So, the regenerator of Stirling Engine uses porous medium as the matrix to get higher heat transfer efficiency. In this study, the regenerator of a 55W Stirling engine was calculated using the 1D numerical model to find the most efficient porous media from kinds of options with different structures and different parameters.
Design, Preparation and Application of Dual-Color HgCdTe Infrared Sensor
Authors: Tan Qiu Lin , Xue Chen Yang , Zhang Wen Dong , Xiong Ji Jun , Liu Jun
Published: December 2010

In the paper, the principle, the preparation and the performance of the dual-color infrared HgCdTe detector is introduced. The detector is a combination of different wave band filter and different respond wave band element. The application of the dual-color infrared HgCdTe sensitive element for methane gas detection sensor is developed. A two-element HgCdTe methane detector which responds between 3.13~3.53μm and 3.91~4.09μm wave bands respectively was reported. The performance of each detection channel was presented. The experiment test and analyze are fulfilled. The experiment result indicates that under the refrigeration temperature the dual-color HgCdTe detector not only has a favorable response ability and repetition but also can realize the response and distinguish ability to methane gas through integrate narrow band filter on the front of the detector sensitive element.
Finite Element Analysis of Different Flexure Springs
Authors: Chen Xi , Liu Ying , Zhang Hua
Published: December 2010

Flexure spring suspensions have demonstrated the ability to provide long operating lifetimes for cryocoolers. The good flexure spring need high radial stiffness and high fatigue life. The profile curves are very important for flexure spring. In this paper, based on the finite element analysis software (ANSYS), geometrically nonlinear static structural analysis and nonlinear dynamics structural analysis were made to several different flexure springs. The fatigue strength, axial and radial stiffness, modal frequency were calculated and listed. The different performance between linear flexure spring and spiral flexure spring were discussed, which would provide an advisory opinion for the design and application of flexure spring in space cryocooler.
Research of Fault Feature Extraction Based on High Order Cyclic Statistics for Reciprocating Compressor Gas Valves
Authors: Liu Shu Lin , Tang You Fu , Liu Ji Cheng , Liu Ying Hui
Published: December 2010

. This paper proposes an approach of fault feature extraction for reciprocating compressor gas valves based on theory of cyclic statistics. First, the strength and weakness of the third-order cyclic statistics in extracting signal features are investigated by simulation signals. Since vibration signals for reciprocating compressor gas valves are of typical cyclic stationary, a new method of fault feature extraction is then proposed based on the simulation results. The method utilizes the cyclic bi-spectrum to extract fault features for the corresponding frequencies. The results show that the cyclic bi-spectrum characteristics for typical faults of gas valves are apparently different, and that the typical faults of reciprocating compressor gas valves can be diagnosed exactly. So the new method proposed in this paper is effective and feasible.
Optimize the Structure of Air Sparger for Stirred Bioreactor
Authors: Zhou Zhi Wei , Song Bo Yan , Wang Yu Kui , Li Zun Tao , Wang Yang
Published: December 2010

During the whole process of cell culture, it needs enough air, especially oxygen supply. Therefore, the research about air sparger became significant. There are many influence factors of air sparger are important, including air sparger structure, installation location, ventilation rate. In order to solve these problems, the finite element numerical calculation is used to set a numerical model of air-liquid two-phase flow. This analysis makes clear that the distance between air vent and the bottom of bioreactor has little effect on the air voids, and the air voids is higher by adopting the structure of single air vent compared with the one of distribution ring structure. But the ventilation structure of big distribution ring avoids flooding effectively. The air voids of bioreactor increased with the velocity of ventilation is increased within limits. However, it causes air incomplete dispersion in bioreactor, overflowing from head top of the liquid, flooding and low air voids, if the ventilation velocity is over speed.
Synthesis and Characterization of Nano-Calcium Titanate-Based Coated Aluminum Oxide and its Application in Water Analysis of Cr(III) and Cr(VI) Concentration
Authors: Zhang Dong
Published: December 2010

Nano-calcium titanate-based coated aluminum oxide (ACCTO) was successfully prepared by the citrate acid sol-gel method and characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM). Its application in speciation of Cr(III) and Cr(VI) from water was studied. The conditions of adsorption and elution were investigated. The results show that nanometer calcium titanate could be immobilized on the aluminum oxide firmly, becoming a composite adsorbent. Two forms of chromium showed different adsorption capability at different pH values, Cr (III) selectively retained at pH 8-14, whereas Cr (VI) retained at pH≤2. So separation of the Cr(III) and Cr(VI) is possible. Retained species were eluted with 5mL of 1 mol•L-1 HCl and NaOH. The Cr(III) and Cr(VI) concentration was measured by atomic absorption spectroscopy. The adsorption agent has a promising prospect in removal or enriching and separation of Cr(III) and Cr(VI) in water.
Thermal Expansion Coefficient of Ni Base Alloy Composite Coating Containing Spheroidal Ceramic Grains
Authors: Liu Xie Quan , Ni Xin Hua , Zhang Shu Qin , He Wan Heng
Published: December 2010

Ni base alloy composite coating containing spheroidal ceramic grains can be fabricated by a vacuum fusion sintering method. Composite coating was mainly composed of Ni base alloy and spheroidal ceramic grains with random orientation. The three-phase model is used to determine the thermal expansion coefficient of the composite coating. First, Eshebly-Mori-Tanaka method was used to determine thermal disturbance strain in two-phase cell aroused thermal inconsistency. Then, average thermal strain in the two-phase cell aroused by thermal inconsistency is gained by the means of volume equilibration. The two-phase cell is transverse isotropy and has two independent thermal expansion coefficients. Finely, based on mean strain of Ni base alloy ceramic composite coating containing spheroidal ceramic grains, the effective thermal expansion coefficient of the composite coating is obtained by considering random orientation of two-phase cells. Ni base alloy composite coating containing spheroidal ceramic grains is isotropy and has one independent thermal expansion coefficient.
Preparation of Ag–Polyacrylamide Nanocomposites by Ultraviolet Irradiation Technique
Authors: Pan Wei , Chen Yan
Published: December 2010

Polyacrylamide (PAM)/silver (Ag) nanoparticle composites were prepared via ultraviolet irradiation of a mixture solution of silver nitrate (AgNO3) and PAM. The resultant composites were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM) thermogravimetric (TG) and Fourier transform infrared (FT-IR). XRD results showed that pure phase Ag was obtained in the prepared nanocomposites. TEM results showed that the Ag particles were in sphere shape with 8-25nm diameter in the as-prepared nanocomposites. FTIR characterized the interaction between polymer chains and Ag particles in hybrid nanocomposites. The TGA results showed improved thermoresistance and high thermal stability behavior of hybrid composites.
Strength Analysis of Damaged Composite Laminates Repaired by Scarf Bonding Method Based on Three Dimensional Model
Authors: Liu Feng
Published: December 2010

The three dimensional finite element model of composite laminates made of carbon fiber reinforced bismaleimide resin is built, and the stress state of the composite laminates under unidirectional tensile force is presented based on finite element analysis. The strength criterion and initial damage mode are given based on the stresses of material principal direction. The three dimensional finite element model of the same laminates with non-penetrating damage repaired by scarf bonding method is built, and the stress state is also analyzed. Annular solids are used to simulate the resin between the mother laminates and the patches. The strength criterion and the damage mode of the scarf bonding composite laminates are also given. The strength and the damage mode of original laminates are compared with that of the repaired laminates. The influence of the annular shape resin is considered in the repaired model. It is showed that the three dimensional models can simulate the geometric and physical features of the real composite laminates. It is concluded that the original composite laminates and the repaired one both damage first in the laminar whose second material principal direction coincides with the axial tensile force. And the damage mode is resin crack under tensile stress. The strength of the bonding patches is higher than the repaired laminates. After scarf bonding repairing, the strength of the damaged laminates can recover up to about 88%.
Methods to Describe Optical Polarization State in Reflective Fiber Optic Current Sensor
Authors: Wang Li Hui , Wu Xue Feng , Sun Jian , Lu Yu Ping
Published: December 2010

Evolution process of optical polarization state in reflective fiber optic current sensor(R-FOCS) is complex, light wave travels from polarization maintaining (PM) fiber with linear polarization state, and light wave travels from sensing head with circular polarization state. Focused on characteristics of optical polarization state in R-FOCS, we analyze the characteristics of optical polarization state in R-FOCS, and demonstrate the methods to build optical polarization models by using Poincare sphere and Jones matrix respectively. Jones matrix provides a mathematically rigorous method of tracking optical polarization state, however, it often leads to a less intuitive description. Despite the mathematical complexity of some phenomena observed in R-FOCS, the Poincare sphere provides elegant and simple geometrical interpretations. The two methods are combined and offer both a mathematical representation and an intuitive interpretation of nonreciprocal polarization effects in R-FOCS.
Studies on the Dye-Uptake of Fraxinus Mandshurica Veneer with Reactive Dyes
Authors: Guo Ming Hui , Liu Xiao Jian , Li Zhi Yong
Published: December 2010

In order to explore the factors of fraxinus mandshurica veneer dye-uptake, the discourse made use of reactive dyes. The result showed that significant effects of fraxinus mandshurica veneer dye uptake are reactive dye concentration, dyeing temperature, dyeing time and sodium chloride concentration. The artificial dyeing technology of fraxinus mandshurica was defined finally. Using reactive dyes, reactive red X-3B 10 g/L, temperature 95 °C, the dyeing time 240 min, sodium chloride 30 g/L. The study provided a theory gist and a practical guidance role for imitation precious wood.
Research on Control Performance of Micro-Milling System Based on Linear Motor
Authors: Cao Zi Yang , Li Hua
Published: December 2010

To improve the dynamic performance of developed micro-milling system, the servo parameters were adjusted and the PID values were optimized respectively by considering the different characteristics of the servo driver under the position, velocity and torque control modes. Then, the different effects of three control modes on the micro-milling system were comparatively analyzed by means of orthogonal test. A control mode with better dynamic performance was chosen properly for the micro-milling system. Given the acceleration of 30m/s2 and feed speed of 200mm/s, the positioning error of micro-milling system was less than 1μm.
Preparation and Photodegradation of Humic Acid by a Y3+-Doped ZnO/TiO2 Composite
Authors: Zhu Zhi Ping , Zhou Yi
Published: December 2010

Aim to remove soluble humic acid (HA) in super-critical boiler make-up water, Y3+-doped ZnO/TiO2 composites were prepared using a solid-phase synthesis method, Their properties were characterized by x-ray diffraction, transmission electron microscopy, and UV-visible diffuse reflection spectroscopy (DRS); their visible light photoactivities were evaluated by the photodegradation of humic acid in an aqueous solution under sunlight irradiation.. The experiment results showed that Y3+-doped samples had a higher absorbance than pure TiO2, and a red shift appeared in the DRS spectrum; The Y3+-doped ZnO/TiO2 multiplex nanocomposite can expand the wavelength range for light absorption and increase the sunlight utilization efficiency. Samples with 3% Y3+ and 27% ZnO have the highest photoactivities.
Preparation and Friction Feature of TiAl-Based Wear-Resisting Self-Lubricating Composite
Authors: Geng Hao Ran , Wang Min , Wang He , Guo Hua
Published: December 2010

In this paper, TiAl intermetallic compound superfine powder is prepared through mechanical alloying and heat treatment, of which the content of TiAl intermetallic compound may reach 95%, and TiAl-based wear-resisting composite are obtained via hot-press sintering process and addition of solid lubricant, furthermore the preparation process, microstructure and friction and wear property of TiAl-based wear-resisting composite are studied. The experimental results show, the solid lubricant in the composite is stable and doesn’t react with components of TiAl-based materials. The friction coefficient of the composite will gradually decrease with the increase of the amount of solid lubricant CaF2+BaF2, and the minimum value 0.386 will appear when amount of addition is 15%, where the adhesive wear of materials decreases. When the amount of the addition is 15%, the wear rate is up to the lowest, but it’ll increase instead in case that the amount of addition is more than 15%.
Numerical Simulation on Dynamic Cushion Properties of Spruce Wood in Three Kinds of Impact Directions
Authors: Zhong Wei Zhou , Song Shun Cheng , Xie Ruo Ze , Huang Xi Cheng , Chen Gang
Published: December 2010

Numerical simulation on container cushion behavior in three impact loading directions is implemented in the present work. The results show that the energy absorption abilities are different in axial, radial and tangential loading directions. For certain deformation condition, energy absorption in axial loading is the most. And energy absorption abilities along radial and tangential loading are nearly equal. For certain energy absorption quantity, the deformation in axial loading is the least and the deformations in radial and tangential loading are larger. It can be concluded that wood grain should be perpendicular to protected object for low velocity, small energy absorption case. And wood radial or tangential direction should be perpendicular to protected object for high velocity, large energy absorption case.
Experiment Study on the Deformation of Reinforced Concrete Slabs
Authors: Jiang Lei , Yao Ji Tao
Published: December 2010

Reinforced concrete slab has the property of two-way bending. In this paper, four test specimens of reinforced concrete slabs were set up to be determined the strain and deflection at corresponding position. The results show that the bending of reinforced concrete slab does have two-way nature and the moment in one direction will cause the deformation of the other orthogonal direction, which can be reflected by the changes of curvature. At last, the conclusions are given: The calculation formula, which was derived from deflection calculation of beams and now is applied to the slabs, will result in no small calculation errors. The moment on one direction will cause the deformation of the other orthogonal direction and its size is related to the poisson’s ratio of the compressed concrete. And the size also is related to the strength grade of concrete and the reinforcement ratio, and so on. And the idea is further pointed out that it also can be used to solve the deflection calculation of concrete two-way slab.
Workability Evaluation of Self Compacting Concrete
Authors: Wang Li Jiu , Gu Xin , Hu Min
Published: December 2010

The compactibility, mobility and segregation stability of self compacting concrete (SCC) is essential for its quality control. Completely and reasonably workability evaluation to SCC has an obviously influence in concrete engineering field. The paper introduced the rheology and workability mechanism of SCC. Ten workability assessment methods, such as Slump Flow test, U-box test, J-ring test, L-box test, VSI method, Oriment test, V-funnel test, Inverted Slump Cone test, were presented and the advantages and disadvantages of each appraisal procedure and the evaluation practice were analyzed. It also put forward the prospect direction of workability evaluation of SCC.
Structure and Properties of Ag–Polyacrylamide Nanocomposites by Heat Treatment
Authors: Zhang Hui Qin , Zhang Li Yan
Published: December 2010

Polyacrylamide (PAM)/silver (Ag) nanoparticle composites were prepared via heat treatment of a mixture solution of silver nitrate (AgNO3) and PAM. The resultant composites were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and differential scanning calorimetry (DSC). XRD results showed that pure phase Ag was obtained in the prepared nanocomposites. TEM results showed that the Ag particles were in sphere shape with 8-25nm diameter in the as-prepared nanocomposites. DSC results showed that the glass transition temperature of the nanocomposites was enhanced by the incorporation of Ag.
PVA/MWNTs Composite Nanofibers Prepared by Electrospun
Authors: Zhang Hui Qin , Li Ai Mei
Published: December 2010

The Polyvinyl alcohol (PVA)/ multiwall carbon nanotubes (MWNT) nanofibers were prepared by electrospun assisted by high-energy sonication. The morphological structures and characterized of the nanofibers were observed via scanning electronic microscopy (SEM), thermogravimetric analysis (TGA) and Fourier transform infrared (FTIR). Electrical properties and mechanical properties of the film have been tested. The results indicate that the introduction of ATO nanoparticles into the polymer matrix has a significant effect on the thermal stability properties of PVA and a strong interaction between PVA and MWNTs.
Experimental Study of Assembly Clamping Pressure on Performance of PEM Fuel Cells
Authors: Wang Le Ping , Zhang Lian Hong , Jiang Jun Peng
Published: December 2010

The compression induced by the assembly of proton exchange membrane (PEM) fuel cells causes partial deformation of the gas-diffusion layers (GDLs) and, consequently, influences the performance of PEM fuel cells. In order to investigate how assembly pressure affects electric efficiency of PEMFC, performance of PEMFC experiments with a miniature self-humidifying, breathing PEMFC stack are conducted under different clamping pressures. The polarization and power efficiency curves of PEMFC under different clamping pressures show that the best performance can be obtained at the allowable lower limit of working parameters. The research shows that the effect of assembly clamping pressure is significant, and the low clamping pressure is beneficial to improve the performance of the PEMFC stack while keeping sealing. The experimental results indicate that a clamping pressure of 1MPa improves the fuel cell performance in this paper.
Synthesis and Properties of a Novel Borate Ester Surfactant Containing Nitrogen as Textile Oils
Authors: Li Xiao Ning , Zheng Guo , Yang Hong Xiang , Sun Yu
Published: December 2010

Dodecyl-borate ester (LB) was prepared by using laurel alcohol and boric acid as starting materials. The novel borate ester surfactant containing nitrogen (LNB) can be formed by reacting with diethanol amine and dodecyl-borate ester. The chemical structure of the product was identified by 1H NMR spectroscopy and IR spectrum. The stability of the foam formed was also evaluated. As expected, these surfactants exhibit good surface properties and show low foaming power. This paper mainly studies its antistatic behavior at different temperatures and in the different treatment. At the same time, we study foaming power at the optimal antistatic condition and scanning electron microscopy research it in textile fibers.
Effect of Autoclaved Aggregate Structure on Strength of Concrete
Authors: Ma Hai Long , Cui Chong , Zhang Bi Xin
Published: December 2010

This paper focuses on studying the physical and mechanical performance of propylene oxide sludge aggregates having no shell (POSA-0), single storey shell (POSA-1) and gradient shell (POSA-2) prepared by hydrothermal synthesis and autoclave curing process. The effect of the aggregate structure on strength of their concrete has been examined and discussed in case of a fixed water cement ratio. The results show that all the autoclaved propylene oxide sludge aggregate (POSA) were light-weight and high-strength regardless of the aggregate structure and all three structured POSA have no wall effect with the cement mortar. Aggregate structure has little influence on the physical and mechanical performance of POSA and splitting tension strength of POSA concrete, however, it plays important role in dictating the compressive strength of concrete because of their different extent of influence on the improvement of interface and relieving the stress concentration. 28d compressive strength of the concrete with the POSA-2 as coarse aggregate can reach 82 MPa, which is 13.9%, 2.5% and 10.8% higher than that of the concrete with POSA-0 as coarse aggregate, the concrete with POSA-1 as coarse aggregate and common concrete, respectively. 28d splitting tension strength of common concrete can reach 7.76 MPa, which is higher 22.6%, 16.3%, 15.8% than that of concrete with POSA-0 as coarse aggregate, concrete with POSA-1 as coarse aggregate and concrete with POSA-2 as coarse aggregate, respectively.
Utilization of the Surplus Materials from the Processing of Bamboo Flooring by Enzyme
Authors: Jin Chun De , Ye Jie Wang , Li Song , Liu Li , Ye Jie Wang
Published: December 2010

Three kinds of particles which produced by the processing of bamboo flooring were taken as the raw materials and analyzed of chemical constituents. Cellulose crystallinity and the reactive oxygen species (ROS) free radicals produced from laccase-treated bamboo were examined by X-ray Diffraction (XRD) and Electron Spin Resonance (ESR), respectively. Physical and mechanical properties of laccase treated bamboo particle boards which made from surplus materials of bamboo flooring process were investigated. In order to provide some theoretical basis for producing particle board with the surplus materials of bamboo flooring process by using laccase, the relations between physical properties and chemical constituents, cellulose crystallinity or the ROS free radicals of bamboo particle boards were researched.
Aluminum Car Wheel Molding Methods and Numerical Simulation of Forming Process
Authors: Qiao Yin Hu , Zhang Chun Yan , Chen Jie Ping
Published: December 2010

Weight reduction at wheels is important due to its unsprung mass and the associated reduction of fuel consumption and the better ride-and-handling comfort. Especially in the front of the car, a weight reduction is necessary to ease the critical mass distribution at the front axle and therefore increase driving safety. The casting defects that are caused by molten metal were cold shut formation, entrapment of air, gas, and inclusion. But the control of casting defects has been based on the experience of the foundry engineers. In this paper, computer simulations have been carried out to analyze the flow of molten metal. Using Anycasting software to numerical simulating the process of car wheel molding filling and solidification, materials selecting and casting process characteristics and defects of the parts are studied, the causes of casting defects are analyzed.
VOF Simulations of Gas Bubbles Motion in a Reciprocally Stirred Flow
Authors: Liu Hong , Xie Mao Zhao , Yin Hong Chao , Wang De Qing
Published: December 2010

This paper reports progress in the numerical simulations of movement and the coalescence of two neighbor bubbles (leading and trailing bubble) in a reciprocally stirred liquid flow field. The full Navier-Stokes equations are solved by the volume-of fluid (VOF) method for tracking the interface between the bubble and the liquid flow. A dynamic mesh method was used to predict the gas-liquid flow in a two-dimensional foaming tank. Results indicate that the motion and merge behavior of the bubbles is dominantly influenced by the initial locations and the sizes of the bubbles as well as by the surface tension, while the reciprocating effect is insignificant.
Fabrication of TiN/Al2O3 Composites by a Novel Method
Authors: Zhu Jian Feng , Ye Lan , Li Xi Hong , Wang Fen
Published: December 2010

A novel method of the combination of high energy milling and hot pressing was adapted to fabricate dense titanium nitride-alumina (TiN/Al2O3) in situ composites using Ti, Al and TiO2 as raw materials. Full dense and pure TiN/Al2O3 composites were fabricated at 1300 °C for 1 h under 10 MPa. The composition, microstructure and mechanical properties of the as-fabricated products were investigated. The results show that the synthesized TiN/Al2O3 composites possess high purity. The TiN/Al2O3 composites have a good combination of mechanical properties of hardness of 18.0 GPa, the flexural strength of 500 MPa, and the fracture toughness (KIC) of 5.2 MPa•m1/2. The strengthening and toughening mechanisms are also discussed.
Digital Imagine Correlation (DIC) Method for Detecting Crack Development in Construction Materials Subject to Loading
Authors: Sung Wen Pei , Shih Ming Hsiang , Zhao Yu Kuang
Published: December 2010

The digital image correlation (DIC) technique is developed for identifying the crack development in brick wall and reinforced concrete beam. This method is tested on brick wall and reinforce concrete beam to evaluate the observation with various strain quantities and mesh sizes. The analysis results reveal that using the von Mises strain field will lead to fine precision of crack observation, and that clearer imagines can be obtained with smaller mesh sizes. This technique is capable of judging crack loading to predict crack occurrences.
Joining Aluminium to Red Copper by High-Frequency Induction Brazing with Argon Shielding
Authors: Zhang Hong Tao , Chen Bo , Zhai Ming Zhi , Li Lei
Published: December 2010

Joining Cu to Al has been carried out by high-frequency induction brazing without filler metal. Experimental results showed that the eutectic structure was the main phase of the brazing seams and a regular Cu-Al intermetallic compound layer also appeared near the Cu side. The maximum shear strength of the dissimilar materials joint could be reach 22.5MPa.
Preparation of Activated Carbon from Waste Particle Board by K2CO3 Activation Treatment
Authors: Yu Wu , Zhi Ming Yu , Jin Xiao Juan
Published: December 2010

Activated carbons were prepared from waste particle board (WPB) by K2CO3 activation. The effects of different parameters, such as chemical/WPB ratio, activation time and activation temperature on yield, the methylene blue adsorption, Iodine number of activated carbon were investigated. The optimum conditions were determined by the method of factor analysis and the orthogonal design as follows: activation temperature 900°C, K2CO3 (50% concentration)/ WPB 4.0, activation time 60 min. Amount of methylene blue adsorption, Iodine number, phenol adsorption, BET surface area and the yield of activated carbon prepared under optimum conditions were 82.5mg/g, 1234mg/g, 185mg/g, 1026m2/g and 30.4%, respectively.