bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on the Hand Spinning Wheel in a Copy of the Mural Painting Collected by Mr. Liu Xianzhou
Authors: Li Qiang , Li Bin , Yang Xiao Ming
Published: July 2011

Many scholars have too much ignored the studies on the hand spinning wheel in ancient China, they drew some wrong conclusions based primarily on the hand spinning wheel in a copy of the mural painting collected by Mr. Liu Xianzhou. We aim to explain the history of hand spinning wheel in ancient China objectively. We made a complete investigation on the image information on the hand spinning wheel from the art works of the Han Dynasty, at the same time we analyzed referenced materials about the hand spinning wheel in ancient China. It is concluded that the mural painting itself is a counterfeit, and the process of shape changes of the hand spinning wheels in ancient China experienced three stages: the finger spinning wheel rotated by the spokes, the crank spinning wheel rotated by the spokes, the hand spinning cord wheel.
Research on the Development of Botanical Pesticide Based on Analysis of Scientific Materials
Authors: Meng Fan Lei
Published: July 2011

This paper describes the history and development of botanical pesticides, analyze the active ingredients of plant pesticide and the application in pest control and with the work practice make ​​a proper study on the future development of botanical pesticides, in order to promote the development of botanical pesticides, developed more and better economic, efficient and pollution-free new pesticides, the benefit of mankind.
Research on Wool Improvements in Modern Shanxi
Authors: Xiao Ai Li , Guo Xing Mei
Published: July 2011

This article researched on wool improvements in Modern Shanxi, compared the qualities of Merino wool, Shanxi wool and three generations of hybrids wool. It made a comprehensive analysis on wool fineness, wool length, crimp contraction, impurity content, grease content, wool color and etc. The results showed that after the three times’ hybridization, the wool qualities had great improvements, the third generation hybrid’s wool qualities were close to the Merino wool. The wool length was 0.023mm, the percent of fine wool was 100%, the crimp contraction in 3cm length was 15~21, the average wool length was 11.2cm, impurity content was 13.9%, grease content was 25.6%.
Design of Dangerous Emergency Escape System Based on IOT
Authors: Zhou Shu
Published: July 2011

Considering the shortcomings of the current personal safety system, the novel dangerous emergency escape system based on IOT is proposed in the paper. The design scheme of the system is suggested. Meanwhile, the topology structure and components of system are given. In the end, the development of this technology was prospected, which can create a new platform for economic growth and greatly improve our lives and serve users better. In the end, the development of this technology was prospected, which can provide mankind with the better services of personal security and make people work and live safer, more effective and more comfortable.
Solving 0-1 Knapsack Problems by Greedy Method and Dynamic Programming Method
Authors: Liu Lu
Published: July 2011

The 0-1 knapsack problem is typical problem in computer science and its solution is a hot spot in algorithms design and verification. Because it is very hard to solve, it is very important in the research on cryptosystem and number theory. In this paper, the 0-1 knapsack problem and its algorithm is analyzed firstly. And then this paper presents two kinds of expand form, and proposes two efficient algorithms based on dynamic programming and greedy algorithm to solve the proposed problems. Simulation results show it is effective.
An Analysis for Effect Factors of Ultrasonic Guided Wave Tomography in Structural Health Monitoring
Authors: Zhang Hai Yan , Yu Jian Bo , Chen Xian Hua
Published: July 2011

Localized flaws such as corrosions in petroleum pipelines often cause fragility, impairing integrity and shortening service lifetime of the structures. There has been much interest recently in monitoring the integrity of the pipe structures. Ultrasonic guided waves provide a highly efficient technique for rapid pipe inspection because they can be made to propagate significant distances in pitch-catch configurations. Crosshole tomographic geometry is formed in such pitch-catch configurations when transmits and receivers are respectively laid along two parallel circumferential belts around the pipe. Considering the pipe as an unwrapped plate, we investigate the adapation of the tomographic reconstruction in seismology to the guided wave inspection of a pipe. Various effects such as transducer arrangement, mesh precision, sampling interval and iterative algorithm on tomographic reconstruction are analyzed. The results provide a theoretical basis for quantitative detection of pipeline flaw using guided wave tomography.
Synthesis of NdFeO3 Perovskites in a Reverse Microemulsion and its Visible Light Photocatalytic Activity
Authors: Hao Ying Juan , Li Bo , Liu Rui Hong , Li Fa Tang
Published: July 2011

The synthesis of NdFeO3 perovskites in a reverse microemulsion and its photocatalytic property for visible light degradation reaction of methylene blue were investigated, respectively. When the irradiation time prolonged from o to 90 minutes, the degradation rate for methylene blue could achieve 60%. XRD pattern shows that a well-crystallized perovskite structure is observed for the NdFeO3 sampled prepared. The TEM characterization result indicates that the dimension of NdFeO3 nanopowders is in the range of 35~45 nm, which is consistent with the calculation result using the Scherrer equation.
The Synchronization of Super-Chen Chaotic Scheme with a Sort of Oscillating Parameters
Authors: Li Ying Kui
Published: July 2011

Most properties of Super Chen’s chaotic system satisfy with the requirements of secure communication and cryptography. Implusive stabilzation for control and synchronization of Super Chen’s chaotic systems can be applied in secure communication. Super Chen’s Chaotic synchronization control can be the kernel technology in chaos-based secure commu-nication. In this paper we propose a hybrid Super Chen chaotic synchronization scheme control which contains both continuous chaotic system with a sort of oscillating parameters and discrete chaotic system. If oscillating parameters approach to 0, we proved that two systems can get synchronized without control signal transmitting.
Nonlinear Vibration Characteristics Analysis of Transmission Gears
Authors: Fan Qin Man , Wu Yong Hai
Published: July 2011

In allusion to a truck transmission gears, a nonlinear vibration model of transmission gears was constructed based on the theory of gear system dynamics and nonlinear dynamics. Basing on the computing platform Matlab and using the Runge-Kutta method to calculate the time history response of gear vibration when the gap exists, and the case of non-resonant and load gear backlash vibration frequency of gear changes were studied. The results of this paper have an important significance to improve the movement of transmission gears to pass accuracy, reduce noise, reduce failures and increase gear life.
The Methods of Soil Heavy Metal Pollution Evaluation Using GRA
Authors: Shao Xiao Yan , Li Xiang , Li Ling Ling
Published: July 2011

To assess the soil heavy metal pollution, there are so many methods, such as the mono pollution-factor, the comprehensive Nemerow pollution-factor and so on. Grey Relational Analysis (GRA) is one of the major contents of gray system theory. The method of GRA was used in the application of environmental impact assessment, such as water pollution research. In this paper, we designed the new practical method of the heavy metal pollution evaluation, which is focus on six soil heavy metals (Cd, Hg, Pb, Cr, Cu, Zn). According to the consenting range of environment level by the National Environmental Standard (GB15618-1995), we have done our researches.
A Visualization Interface Programming
Authors: Zong Si Sheng , Yu Yong Ling , Shi Jin Fa
Published: July 2011

In the domestic manufacturing enterprises, ERP application integration with other enterprise system has become a hot topic. In this paper we propose a new approach of visualization service integration based on ERP. Also, based on the actual needs of the system, a Visualization Interface is designed, in which programming is realized. This implement provides a reference for the similar visual integration.
Study of Shaped Charge Jet Penetration into Concrete Target
Authors: Wang Zai Cheng , Jiang Chun Lan , Li Ming
Published: July 2011

Based on the application of tandem weapon used to destroy concrete target this paper presents the results of simulation and experiment that investigate the penetration performance of shaped charge to runway. Jet formation and penetrating into multi-layer target was calculated by hydro code LS-DYNA3D. Jet tip velocity and jet length, also the penetration performance are studied. The damage performance of shaped charge is validated by experiment. The analysis demonstrates the shaped charge can create a big borehole for subsequent projectile to follow in.
Study on the Effect of Different Rear Windscreen Angles on Aerodynamic Characteristic of the Automobile
Authors: Bao Hai Tao
Published: July 2011

The automobile resistance reduction problem is the major topic in the automotive industry because of its link with economy and safe. Taking Computational Fluid Dynamics software as the platform, the automobile as the research object, the simulation models are established based on unsteady, viscous Reynolds averaged k-ε equations, by using dynamic grid and finite volume method. The aerodynamic characteristics of the automobile were studied with the different rear windscreen angles, such as 30°,35°,40°and 45°respectively. Analysis of trailing vortex automobiles for resistance. The results show that the different angle of the rear window, the flow separation and re-attachment points for the different, the resistance coefficient is also different. The conclusions of analysis provide the theoretical foundation for styling optimization of automobile，it is of certain guiding significance for practical application.
The Relationship between Entrepreneur Psychological Capital and Employee’s Innovative Behavior: The Strategic Role of Transformational Leadership and Knowledge Sharing
Authors: Zhu Yu , Wang Yan Fei
Published: July 2011

This research is to explore the relationships among entrepreneur psychological capital; innovative behavior; transformational leadership and knowledge sharing. Chinese enterprises participated in this investigation. We found that entrepreneur psychological capital influenced transformational leadership, while transformational leadership influenced employee’s innovative behavior positively. Besides, entrepreneur psychological capital influenced employee’s knowledge sharing positively while knowledge sharing influenced employee’s innovative behavior positively, but the direct influence between entrepreneur psychological capital and employee’s innovative behavior wasn’t exist. As anticipated, the intervening effect of transformational leadership and knowledge sharing between entrepreneur psychological capital and employee’s innovative behavior was significant. Implications, limitations and future research directions for the study are discussed.
Multiple Sequence Alignment Based on Profile Hidden Markov Model and Quantum-Behaved Particle Swarm Optimization with Selection Method
Authors: Long Hai Xia , Wu Li Hua , Zhang Yu
Published: July 2011

Multiple sequence alignment (MSA) is an NP-complete and important problem in bioinformatics. Currently, profile hidden Markov model (HMM) is widely used for multiple sequence alignment. In this paper, Quantum-behaved Particle Swarm Optimization with selection operation (SQPSO) is presented, which is used to train profile HMM. Furthermore, an integration algorithm based on the profile HMM and SQPSO for the MSA is constructed. The approach is examined by using multiple nucleotides and protein sequences and compared with other algorithms. The results of the comparisons show that the HMM trained with SQPSO and QPSO yield better alignments than other most commonly used HMM training methods such as Baum–Welch and PSO.
Research on Simulation of Operation of DSG Collectors Based on Analysis of Scientific Materials
Authors: Gao Teng , Zhao Jun , Yang Bin , Wang Fu
Published: July 2011

In this paper, a direct steam generation (DSG) collector is researched. To determinate the DSG collector efficiency, a simplified heat loss correlation is applied. A one-dimensional steady state heat transfer model and an energy balance equation for DSG collector are developed. A Visual basic program coupled with fluid parameters is compiled to compute fluid temperature, heat transfer coefficient and heat loss along the absorber tube by iterations for given accuracy. The variation trends of many kinds of fluid parameters along the absorber tube are revealed. The effect of length of dry steam region on collector efficiency is accounted for also.
Research on Second Harmonic Generation in Two-Dimensional Periodical Nonlinear Photonic Crystals Based on Intelligent Materials
Authors: Li Jing Juan , Wang Li
Published: July 2011

The works are focused on finding out proper shape of reversed domains to obtain effective harmonic generations with high conversion efficiency. The conversion efficiency of second harmonic wave in two-dimensional nonlinear photonic crystals consisting of square lattice and reversed domains of various shapes are studied numerically. The shapes of reversed domains are extended from circle, square to ellipse and rectangle. The conversion efficiency of different order quasi-phase matched process can be maximized by adjusting the orientation of noncircular reversed domains. Moreover, a cross-shaped reversed domain is utilized to improve the conversion efficiency of two-order non-collinear quasiphase matching.
The Design of Off-Grid Multi-Energy Complementary Power System
Authors: Xu Lin , Ru Jing Yu , Zhang Xi Jian , Chen Ya Qiang , Mu Xi Qing
Published: July 2011

One kind of multi-energy off-grid hybrid power system is designed. The system combines highly efficient solar photovoltaic power generation system, ultra low wind speed electric power facility, pedal-powered electricity generating device with the function of automatic reciprocating type. The signals are selected and controlled by STC12c2052 single chip, then the electric energy is delivered to the storage battery through the DC/DC module. Thus, a system with high efficiency and multi-energies complementary is obtained. It can be conclude that this system, cost-effective and environmentally friendly, has great potential in saving energy and environmental protection.
Genetic Algorithm and Support Vector Regression for Software Effort Estimation
Authors: Lin Jin Cherng , Chang Chu Ting
Published: July 2011

For software developers, accurately forecasting software effort is very important. In the field of software engineering, it is also a very challenging topic. Miscalculated software effort in the early phase might cause a serious consequence. It not only effects the schedule, but also increases the cost price. It might cause a huge deficit. Because all of the different software development team has it is own way to calculate the software effort, the factors affecting project development are also varies. In order to solve these problems, this paper proposes a model which combines genetic algorithm (GA) with support vector machines (SVM). We can find the best parameter of SVM regression by the proposed model, and make more accurate prediction. During the research, we test and verify our model by using the historical data in COCOMO. We will show the results by prediction level (PRED) and mean magnitude of relative error (MMRE).
Fabrication of Ultrahydrophobic ZnO by Vapor Phase Transport
Authors: Xi Zhi Jun , Li Gang , Lu Li Ming
Published: July 2011

A ultrahydrophobic ZnO film was synthesized on the Si substrates by a novel vapor phase transport method. The surface structural properties of as-synthesized ZnO film was characterized using scanning electron micrograph (SEM). The contact angles and the rolling angles on such films were measured through an optical contact angle meter. Wettability studies revealed the films exhibited a ultrahydrophobic behaviour with a higher contact angle of 166.8°±6.8° and lower rolling angle of less than 2°-a water droplet moved easily on the surface. SEM showed that compared with pure smooth nickel surface, a lotus-like structrure with micro-nano hierarchical papillae was obviously observed on the ultrahydrophobic ZnO film surface. Such a speccial surface microstructure may result in the ultrahydrophobicity.
Designment and Implementation on Bullet-Data-Acquisition System
Authors: Qi Chun Qing , Suo Ji , Cao Feng Wen , Wang Yi Wang
Published: July 2011

Measurement of bullet data is very important to the target trial. The reliable signal acquisition and analysis is the bases of the design of weapon. When the ordinary photoelectric target work, firelight or ambient light will bring an error trigger signal or cannot capture the shot off target signal. These may affect accuracy and sensitivity of the system. A system of the data acquisition and process based on PCI local bus is introduced in this paper. The device of hardware and data acquisition base on PCI local bus is in detail. Introduce how to design the PCI driver. This system has been successfully used to measure several kinds of projectiles’ velocity.
The Research and Design of Two-Level Load Balancer Based on Web Server Cluster
Authors: Wei Li Feng , Ji Jian Wei , Zhao Li Qiang
Published: July 2011

At present, the extendible Web server clusters are the important framers for the high performance network servers. The architecture based on load balancer is often used on web server clusters. The load balancer is the main bottleneck in improving performance of cluster. For it is hard to complete the task of assigning the requests from the client while collecting the real load information of the web servers efficiently. In this paper, we propose a model of two levels load balancer for web cluster to resolve the contradiction. When web requests are arrive, the first-level balancer continuously assigned them by to the second-level which consist of some load balancers connect to real web servers and receive real-time load information of them. Round robin algorithm is used at the first-level load balancer to schedule the client’s requests in order to shorten the response time. The proposed algorithm in our model is run at the second-level load balancers to schedule the requests to real web servers according to the real load information. At last, a simple test is carried out to make sure the performance of the model. The result of the test shows that the model has made better load balancing.
Corrosion Properties of Plasma Electrolytic Oxidation Ceramic Coatings on an A356 Alloy Tested in an Ethanol-Gasoline Fuel (E85) Medium
Authors: Peng Zhi Jing , Chen Ying , Nie Xueyuan
Published: July 2011

Ceramic oxide coatings were prepared on an aluminum A356 alloy by a plasma electrolytic oxidation (PEO) technique under unipolar, bipolar and duplex unipolar/bipolar current modes. Cross-sectional morphologies of the coatings were studied using a scanning electron microscope (SEM). The corrosion behavior of the coated and uncoated samples was evaluated in ethanol-gasoline E85 fuels through potentiodynamic polarization and zero resistance ammeter (ZRA) testing methods. The results indicated that all the coatings had a better corrosion resistance compared to the uncoated substrate. The unipolar current mode created the PEO coating with a thicker coating microstructure and thus a better corrosion resistance, compared to a bipolar current mode. The duplex treatments of unipolar/bipolar or bipolar/unipolar current modes produced the best performance of the coatings against galvanic corrosions caused by a steel/Al coupling in the E85 fuel medium.
An Empirical Research on HRM Practice Promoting Innovation Operation in China
Authors: Sun Rui
Published: July 2011

Innovation research has advanced recently, scholars tried to uncover the antecedent factors of organizational innovation. It is argued that innovation in firms should be associated with the intelligence and the capabilities of the workforce, nevertheless, there are still few empirical research explore the relationship between human resource management practice and organizational innovation operation in china.Drawing on review of relative literature, the study examines the human resource management practice promoting organizational innovation, and give a clue to understand how these factors shape innovation in organizations.
Design and Realization of an Intelligent Protection Circuit for Li-Ion Batteries
Authors: Ji Xiao Peng , Guan Xing Feng , Wang Zhen Hong
Published: July 2011

Li-ion batteries have been widely used. However, the safety concern is always serious due to its high energy density. In order to improve the safety of the batteries, it is necessary to use the protection integration circuit. In this article, the concept for realizing the safety protection of Li-ion batteries during charging and discharging is described briefly. A circuit design using Seiko BMS chip S-8209 is purposed. Based on this, a simulation was performed and verified using Pspice program, which provides a theoretical basis for the circuit design.
Synthesis of H-In2O3 and C-In2O3 by Different Methods and Gas Sensing Properties
Authors: Wang Bin , Gu Fu Bo , Han Dong Mei , Guo Guang Sheng
Published: July 2011

In(OH)3 and InOOH were prepared through a simple hydrothermal method at different volume ratios of En and H2O. C-In2O3 and H-In2O3 were obtained by annealing these two precursors at 400°C in air, respectively. One-step In2O3 was also synthesized via solvothermal process using DEG as solvents. The effects of reaction conditions on phase structures and morphologies were studied. The gas sensing properties of the obtained materials toward ethanol were measured and X-ray diffraction, field-emission scanning electron microscope and PL were used to characterize the as-obtained products.
Research on Key Technologies of 38CrMoAl Steel Produced by BOF-LF-RH-CC Process
Authors: Chen Yong , Zeng Jian Hua , Zhang Min , Pan Hong
Published: July 2011

Nozzle blockage is easy to take place in continuous casting process when producing 38CrMoAl steel due to high content of aluminum ([Al]=0.7%~1.1%). Slag-steel reaction will lead to large transformation for composition of molten steel and performance of slag on the condition of traditional high content of SiO2 in slag. And it will reduce the cleanliness of steel as well. The control target of refining slag and tundish powder has been gotten through the analysis of refining & continuous casting characteristics of high aluminum steel. Based on this, the content of Si and Al in molten steel can be controlled accurately, and the cleanliness of steel has gone to a higher level. Moreover, mold powder with high basicity and vitrification ensures the stability of slag after sorbing Al2O3 inclusions in theory. Continuous casting can be carried out successfully with the control of inclusion morphology through slag washing during tapping. Industrial practice shows that Si content is 0.25%~0.40%, Al content is 0.80%~1.00%, S content is below 0.004% and T[O] is below 0.0015% in steel products. Moreover, casting bloom with good surface quality is achieved, and the rate of bloom without cleaning is as high as 100%. With all these countermeasures, 38CrMoAl steel can be continuously cast for more than 6 heats.
Pressureless Infiltration Fabricated Steel Matrix Composites Reinforced with WC by the Local Electromagnetism Induction Heating
Authors: Niu Li Bin , Sun Wan Chang , Fan Zi Min
Published: July 2011

A pressure-less infiltration technique was introduced to fabricate WC particles reinforced steel matrix composites through rapidly melting matrix by local electromagnetism induction heating. The four specimens were attained by adjusting the moving speed of sand mould and comparatively investigated. The results showed that the thickness of composite layer was about 4.0 mm. While the moving speed of sand mould was 3.0 cm/min, the reinforced particles had the better homogeneous distribution into the matrix and the metallurgical bonding with the matrix. The wear amount of composites firstly decreased up to a lower value and then increased. Except the sample produced under the speed 1.0 cm/min, the wear-resistant behavior of other three samples were superior to that of high chromium cast iron.
Effect of Austempering Temperature on Microstructure and Properties of Carbidic Austempered Ductile Iron
Authors: Liu Jin Hai , Li Guo Lu , Zhao Xue Bo , Hao Xiao Yan , Zhang Jian Jun
Published: July 2011

The microstructure and properties of austempered ductile iron with carbides was studied to increase the abrasive resistance of ADI. It was proven that the austempering temperature influences greatly the microstructure, impact toughness, hardness and abrasion resistance of CADI. With increase of austempering temperature, the acicular ferrite becomes thicker and bigger, the impact toughness rises, and the hardness decreases. But there is a complicated effect of austempering temperature on wet abrasion resistance. In addition, the CADI grinding balls were cast and the field testing was performed. The CADI ball is one third of abrasion loss of low chromium cast iron, zero rate of breakage and no loosing round.
SEM In Situ Investigation on Fatigue Cracking Behavior of X80 Pipeline Steel with Inclusions
Authors: Tong Ke , Zeng Yan Ping , Han Xin Li , Feng Yao Rong , He Xiao Dong
Published: July 2011

The micro-mechanical behavior of inclusions in X80 pipeline steel under fatigue loading was investigated by means of SEM in situ observation. The influence of sizes and shapes of inclusion on crack initiation and propagation was analyzed. The result shows that for large-size single-particle inclusion, cracks initiate from the interior under the fatigue loading. When a certain circulation cycles are reached, cracks initiate at the matrix near the sharp corner of the inclusion. The cracks extend at the matrix during the stable extension period and unstable extension period following the crack initiation, until fracture occurred. For chain inclusion, cracks first initiate at the interface between inclusion and matrix within the chain area, and the circulation cycles needed for initiation are far less than single inclusion. Cracks steadily extend after the initiation, and then fracture after very short circulation cycles. A chain of inclusion with the shape corners is serious harmful to the fatigue properties.
Numerical Simulation of Temperature in the Freeboard of COREX Melting Gasifier
Authors: Sun Ye , Di Zhan Xia , Li Hai Feng , Luo Zhi Guo , Zou Zong Shu
Published: July 2011

The freeboard, which is an important region in COREX melter gasifier, has drawn more and more attentions, and as a key parameter for COREX melter gasifier operation, the temperature in freeboard must be within a certain range. In this paper, the temperature field of freeboard is simulated with computational fluid dynamics(CFD). The results show that the temperature in bottom is lower than that in upper. The temperature when oxygen nozzles are open is higher than that when oxygen nozzles are off, and the temperature under different operation conditions is all about 1000 °C.
Precipitation Hardening of Titanium Carbides in Ti Micro-Alloyed Ultra-High Strength Steel
Authors: Huo Xiang Dong , Lv Sheng Xia , Mao Xin Ping , Chen Qi Lin
Published: July 2011

New 700MPa hot rolled ultra-high strength steels were successfully developed by using Ti micro-alloying technology in CSP line. Experimental methods, such as OM, TEM and chemical phase analysis, were used to study the experimental steel. The microstructure is composed of quasi-polygonal ferrite grains, whose average grain size is about 4μm. Large number of nanometer TiC particles distribute along dislocations. The mass fraction of MX phase is 0.0793wt%, in which the particles smaller than 10nm account for 33.7%. The contribution of precipitation hardening resulting from nanometer particles is calculated as approximate 158MPa.
Effects of Modification on Stress Field of the Inclusions in Large Rudder Arm Steel Casting
Authors: Xie Jing Pei , Zhao Yong Rang , Wang Ai Qin , WANG W.Y. , Li Ji Wen , Yang Di Xin , Zhang Ke Feng , Ma Dou Qin
Published: July 2011

The influences of non-mentallic inclusions on the quality and properties of the steel are depended not only on the quantity of inclusions, but also on the type、shape、size、deformation behavior and distribution condition. The effects of lanthanide rare earth(RE) on the shape、size and distribution condition of inclusions in large rudder arm steel casting is investigated. It was proved that the shape and distribution of inclusions could be improved in the large rudder arm steel casting, and the plastic and toughness of the steel can be increased obviously by the rare earth modification. By means of ANSYS finite element analysis software, the stress field distribution around matrix was simulated, and the reaction mechanism of inclusions by modification was clarified.
Preparation of Fine Ag2WO4 Antibacterial Powders and Its Application in the Sanitary Ceramics
Authors: Wang Qian Ping , Guo Xiang Xiong , Wu Wei Hua , Liu Shu Xian
Published: July 2011

Superfine Ag2WO4 antibacterial powders, which are prepared by supersonic assisted homogeneous precipitation method, is added 1.0-1.5wt.% to sanitary ceramics, having 90% antimicrobial action, and achieve good bactericidal effects. The antibacterial ceramics with Ag2WO4 were soaked into acid and alkali for 3 months, and antibacterial activities had little change, keeping good antimicrobial durability. Finally, the antibacterial mechanism of Ag2WO4 ceramics is advanced.
Fabrication of High-Porosity Silicon Nitride Ceramics with Excellent Mechanical Properties
Authors: Shan Shao Yun , Jia Qing Ming , Wang Ya Ming , Peng Jin Hui
Published: July 2011

High-porosity silicon nitride ceramics with excellent mechanical properties were fabricated by the carbothermal reduction of SiO2. The influences of sintering conditions on microstructure and mechanical properties were studied. The results showed that microstructure and mechanical properties of porous silicon nitride ceramics were dependent mostly on the sintering conditions. The sintered porous silicon nitride ceramics exhibited the formation of fibrous microstructure with submicrometer-sized, high-aspect ratio b-Si3N4 grains, and uniform pore structure. Porous Si3N4 ceramics with a porosity of about 70%, and a flexural strength of about 70 MPa were obtained by sintering at 1750°C, with lower rate of temperature rise and no retaining time. The high strength was attributed to fine, high-aspect ratio b-Si3N4 grains and uniform pores between grains.
Effects of Second Phase and Defect on Electrical Properties in Bi0.5Na0.5-xKxTiO3 Lead-Free Piezoelectric Ceramics
Authors: Chen Pin Yi , Chen Cheng Sao , Chou Chen Chia , Tseng Tseung Yuen , Chen Haydn
Published: July 2011

Second phase and defect formation mechanism of (Bi0.5(Na1-xKx)0.5)TiO3 (BNKT100x) ceramics were investigated using electron microscopy, x-ray photoelectron spectroscope (XPS) and electrical properties measurements. Experimental results indicated that second phase formation induces Bi-rich regions and compositional inhomogeneity within matrix due to thermodynamic stability of potassium titanate. Ti valence transition for BNKT ceramics sintered in air might be ascribed to formation of the secondary phase, rather than simply attributed to volatilization of bismuth. Li substitution at A-site in BNKT ceramics suppresses formation of the second phase and Ti valence transition. Appropriate Li doped BNKT ceramics suppress oxygen vacancies and titanium valence transition, and therefore decrease the leakage current.
Effect of Compound Additives of Li2O-B2O3-SiO2 Glass and LiF on the Properties of CaO-Li2O-Sm2O3-TiO2 Ceramics
Authors: Yang Liu Shuan , Wang Xiao , Wang Yu Bin , Huang Jin Liang , Li Fei Long
Published: July 2011

Using Li2O-B2O3-SiO2 (LBS) glass and LiF as a liquid phase sintering additive, the effects of it on the microstructure and properties of 16CaO-9Li2O-12Sm2O3-63TiO2（CLST）ceramics were investigated. The results indicated that the compound sintering aids of LBS glass and LiF reduced the sintering temperature of CLST from 1300 °C to 950°C. Compared with the sample doped single LBS glass, the optimum dielectric properties, Kr=81, Tanδ=0.0073 could be obtained when the CLST ceramic samples doped 3 wt% LBS glass and 0.25 wt% LiF were sintered at 950°C for 3 h.
The Influence of Different Particle Size of Carbon Powders on the Preparation of Porous Silicon Carbide Ceramic
Authors: Han Fei , Chen Yu Hong , Guo Sheng Wei , Ma Jian Jun
Published: July 2011

On the preparation of porous ceramics with composite sintering auxiliaries Y2O3-Al2O3 , the main ingredient of SIC , and CMC as the porous agent . Having studied the C content of composite structure and mechanical properties , And analysised the composite fracture morphology with SEM . The results show that, when using different particle size of carbon powders mixed the porous silicon carbide ceramic sample size powdered carbon than a single sample of micro skeleton intact, the shapes of holes, and more rules are uniformly distributed, comprehensive mechanics performance is better.
The High-Performance of Cerium Doped Sodium Bismuth Titanate Aurivillirs Phase Material
Authors: Feng Yuan Yuan , Zhang Yong , Gai Zhi Gang , Hu Ping , Zhou Yu Fan , Wang Li Hai , Zhao Ming Lei
Published: July 2011

The effect of Ce substitution at the A-site on the properties of Na0.5Bi4.5Ti4O15 (NBT)–based ceramics was systematically investigated. The substitution at A-site caused distortion of lattice and improved piezoelectric activity correspondingly. The piezoelectric coefficient d33 of the Na0.5Bi4.5-xCexTi4O15 (x=0.03) ceramic was found to be as high as 26 pC/N, together with high mechanical quality factor Q ( 2769 ), and stable piezoelectric properties, demonstrating that the Ce-modified NBT-based materials are promising candidates for high-temperature applications.
The Study of Welding Power-Arc System Stability Based on DFCD
Authors: Li Chun Tian , Du Chang Hua , Luo Yi , Xu Hui Bin
Published: July 2011

Regarding welding power-arc system stability (WPSS) as the research object, the paper uses differential theory and considers the full load conditions from the external circuit on the course of dynamic welding, and some models about WPSS are found, they can obtain the analytic expression of system stability coefficient, and a qualitative analysis of WPSS' conditions is so born, on this basis, by the method of the relative conversion of current deviation, a dynamic factor of current deviation (DFCD) is obtained by analytical equation，then to quantify stability of the system by the way of decay time of deviation. Test's results, based on analysis of voltage and current waveforms, are the same to quantify the WPSS based on DFCD.
Influence of Different Precursors upon Characterization of Bismuth Titanate Powders Prepared by Chemical Methods
Authors: Li Bao Rang , Liu Dong Yu , Chang Hui Bin
Published: July 2011

Bismuth titanate Bi4Ti3O12 powders had been successfully prepared from different starting materials by chemical methods and characterized by XRD, SEM and DTA. Our efforts in this paper were directed to disclose the influence of precursors on the particle characterization. It was shown that different precursors affected the crystalline temperature, particle nucleation and growth rate greatly, leading to different particle size and morphology. Excess addition of Bi2O3 was found to be dominant in lowing crystalline temperature while spherical particles was probably attributed to large growth rate and use of glacial acetic acid as a solvent medium.
Molten Salt Synthesis of Anisotropic Bi4Ti3O12 Particles
Authors: Guo Chen Jie , Zhang Chang Song
Published: July 2011

Plated-like Bi4Ti3O12 particles with anisotropic properties were prepared by the NaCl-KCl molten salt method. The effect on microstructure and patterns of Bi4Ti3O12 particles was investigated by adjusting salt quantities, calcined temperature and excessive Bi2O3 content. The results show that the size of Bi4Ti3O12 particle and the degree of anisotropy of pure perovskite structure of Bi4Ti3O12 particles prepared at 750°C simultaneously increased with the quantities of molten salt and the temperature of the calciner. Excessive Bi2O3 content also shows a positive effect to obtain the anisotropic Bi4Ti3O12 particles whose preparation process was optimized.
Analysis of PZT Piezoelectric Ceramics Based on Finite Element Softeware ADINA
Authors: Zhang Chang Song , Guo Chen Jie
Published: July 2011

Using traditional experiment means on piezoelectric ceramic device has certain limitations due to the complicated boundary conditions and stress situation. In this paper, the finite element model of piezoelectric ceramics in line with the experiment results was established according to piezoelectric structure field and the coupling of the electric field, deformation of representative PZT piezoelectric ceramics under the voltage was analysed in using finite element analysis software ADINA according to establishing geometric model, defining boundary conditions and materials, Coupling calculation. Consistency between simulation results and experimental results is improved and lay the foundation for the realization of the piezoelectric ceramic shapes and vibration control.
Research on Transient Behavior of Aluminium in Laser Micro-Molton Pool
Authors: Cui Ai Yong , Hu Fang You , Zhao Pei Zhong , Lu Chang Liang , Hu Bin , Fu Peng Fei
Published: July 2011

To explore reaction mechanisms and proper effects of aluminium in laser micro-molton pool, experiments of laser cladding (Ti+1-8%Al) on Ti-6Al-4V by pulsed Nd:YAG had been carried out. The microstructures, microhardness and phases of the cladding layers with different weight percentage of Al were investigated. The content of Al was quantitatively determinated when ordering α2 ceramic phase (Ti3Al matrix) were formed. And the friction and wear properties of the cladding layers were examined in atmosphere. It was found that the microstructure of the cladding layers included cellular crystals, columnar crystals, arborescent crystals and dispersive white granules. The α2 ceramic phase was formed when the content of Al was 6%wt. With the increasing of weight percentage of Al, the number and size of arborescent crystals increased obviously, as well as the microhardness, the maximum was 957.9Hv, 1.3-1.5 times of the layers with below 6%wt Al. Inversely, the wear resistance of the laser cladding layers was improved gradually. Friction coefficient, wear extent and wear rate decreased. 0.55-0.7 times of the layers with below 6%wt Al.
Influence of Boron on the Micro-Organization Mechanism of Zirconium Containing Aluminium Alloy
Authors: Yang Sheng , San Peng
Published: July 2011

In this paper, the influence of B on the existence form and the phase composition of Zr in alloy were studied. And the influence mechanism of B on Zr in alloy was analyzed. The results show that the addition of B makes part of Zr become precipitation present in grains and grain boundaries as the small plate sheet of second phase from solution. It reduced the lattice distortion, improved the ordering of Al matrix and the conductivity of the alloy.
Study on Over-Burnt Temperature and Heat Treatment of a New Al-Mg-Si-Cu Alloy
Authors: Meng Yi , Zhao Zhi Hao , Cui Jian Zhong
Published: July 2011

The over-burnt temperature of a new Al-Mg-Si-Cu Aluminum alloy was studied by means of DSC and microstructure analysis, as a result of the homogenization temperature being obtained. A favorable homogenization time was got by the way of the dependence of area fractions of remnant phases on homogenization time being calculated. According to experimentation results, the over-burnt temperature of the new Al-Mg-Si-Cu Aluminum alloy was 570°C, and the way to homogenize the new alloy at 560°C for 24h was excellemt.
Effect of Desorption Hydrogen Pressure on Anisotropy of HDDR-Treated Nd-Fe-B Powders
Authors: Han Guang Bing , Fu Shuang , Liu Min , Su Hao , Gao Ru Wei
Published: July 2011

Anisotropic Nd13.5Fe79.5B7 magnetic powders are obtained by varying the desorption H2-pressure of the hydrogenation disproportionation desorption recombination (HDDR) process. The magnetic powders with a desorption H2-pressure of 10 kPa have the magnetic properties of Br =0.61 T and Mr/Ms =0.67, whereas the magnetic powders obtained with a higher and a lower desorption H2-pressure are isotropic. A lamella crystal is observed in the 10 kPa desorption H2-pressure products and may be related to the anisotropy in the HDDR-treated powders. It suggests that the desorption H2-pressure has great effect on the formation of crystal texture in the HDDR Nd-Fe-B powders.
Influence of Y Element on Microstructure and Mechanical Properties of ZK60 Alloy
Authors: Li Yong , Xu Fang , Liu Hui Ping
Published: July 2011

Mg-4.9Zn-0.9Y-0.7Zr alloy and Mg-4.9Zn-0.7Zr used as compared alloy were prepared by ingot metallurgy method. The influence of Y addition on microstructure and properties was studied. Phase analysis, microstructure and morphology of second phases were investigated by XRD, OM and SEM. The component and morphology of the second phases was analyzed by EDAX and TEM. The results showed that, Y was an effective element strengthening Mg-Zn-Zr alloy, a large number of Mg3Zn6Y phase was formed due to the addition of Y. During the process of hot rolling, Mg3Zn6Y phase was pulverized into large amount of dispersion particles, which pinned dislocation effectively, so ultimate strength and yield strength at room temperature were improved, as well as good plasticity was remained.
Study on the Intergranular Corrosion Behavior of Welding Joint of A7N01-T4 Al-Alloy for High-Speed Train
Authors: Wang Xiao Min , Gou Guo Qing , Zhao Jun Jing , Liu Yan
Published: July 2011

This paper studied the intergranular corrosion behavior of A7N01-T4 Al-alloy and its welding joint through corrosion rate test by chemical analysis and morphology observation by metalloscope, LCSM and element analysis by EDS. The results showed that the corrosion rate of welding joint was higher than that of the base, and HAZ was the worst corrosion part of welding joint. Zn2Mg strengthening phase of HAZ segregated continuously along grain boundary under the affected of heat-input of welding, and the low potential of this zinc-rich phase made it to be anode in corrosion cell and dissolved preferentially, an active corrosion route along grain boundary was formed, which made further corrosion develop into inner alloy.
Investigation on the Microstructure and Mechanical Properties of Hot Forged Mg−8Gd−2Y−1Nd−0.3Zn−0.6Zr Alloy
Authors: Hou Xiu Li , Cao Zhan Yi , Wang Li Dong , Wang Li Min
Published: July 2011

The influences of hot forging and ageing treatment on the microstructure and mechanical properties of Mg−8Gd−2Y−1Nd−0.3Zn−0.6Zr (wt.%) alloy have been investigated. The results showed that the grains were significantly refined after hot forging. And the secondary phases in this alloy i.e. Mg5(Gd1-x-yNdxYy) and Mg24(Y1-x-yGdxNdy)5 phases were fragmented to small particles due to the large strain during hot forging. Tensile tests revealed that mechanical properties were improved due to grain size refinement. Moreover, the as-forged alloy exhibited remarkable age-hardening response and mechanical properties were further improved by ageing treatment. The ultimate tensile strength, yield strength and elongation of the peak-aged (T5) alloy are 286 MPa, 245 MPa and 5.6 % at room temperature, and 211 MPa, 103 MPa and 19.4 % at 300°C, respectively.
Experimental Study of Squeeze Casting of ZK60 Magnesium Alloy
Authors: Guo Zhi Hong , Qu Shu Wei
Published: July 2011

Tensile behaviors of extruded and rolled AZ80 Mg alloy were investigated with elongation-to-failure tensile tests at constant temperatures of 300 °C, 350 °C, 400 °C, and 450 °C, and constant strain rates of 10-2 s-1 and 10-3 s-1. Experimental data show that the material exhibits tensile ductilities of over 100% at 400 °C and 450 °C, featured by long steady state deformation. Microstructure studies show that annealed coarse grains were remained in the gauge region during the tensile tests, and the enhanced tensile ductilities resulted from dislocation creep, other than dynamic recrystallization or grain boundary sliding. Cavity evolution and recrystallized coarse grains near fracture end caused premature failure of the material.
Materials with Thermo-Diffusive Hardening
Authors: Sluzalec Andrzej
Published: July 2011

Hardening problems in thermoplastic materials are presented. The examples of thermo-diffusive hardening are analyzed. Theoretical considerations are recalled to determine the combined effects of thermoplasticity with thermo-diffusion term considering gradients in interstitial concentration, in solvent composition, in stress and in temperature.
Removal of Methyl Orange from Aqueous Solution by Using Exfoliated Graphite/ZnO Composites
Authors: Yue Xue Qing
Published: July 2011

Exfoliated graphite/ZnO composites (EG/ZnO) were prepared by heating a mixture of EG and zinc acetate, and under UV irradiation, used for removing methyl orange (MO) from aqueous solution. The composites synchronously have the adsorption efficiency of EG and decomposition efficiency of ZnO. The removal efficiency is influenced by the ZnO content, initial MO concentration and pH of solution. After selection of desired operation parameters, the complete MO removal can be achieved after 3 h UV irradiation.
Miscibility Study of Polymer Blends Composed of Polyethylenimine, Polyethyleneglycol, and Carboxymethyl Chitosan
Authors: Chen Yong Sheng , Shen Jiang Nan , Qiu Jun Hong
Published: July 2011

Miscibility of ternary polymer blends composed of poly(ethyleneimine) (PEI), poly(ethylene glycol) (PEG), and carboxymethyl chitosan (CMCS) was investigated by dilute-solution viscometry, FTIR spectrum, and scanning electron microscope (SEM) techniques. The results of these measurements indicate that PEG is immiscible in the ternary CMCS/PEI/PEG polymer blend.
Studies on Methyl Methacrylate Grafted onto Chitosan by Ceric Ion Initiation
Authors: Liu Lian , Chen Xie Wei , Wang Pei , Wang Chong
Published: July 2011

Chitosan-g-MMA was prepared with methyl methacrylate using ceric ammonium nitrate (CAN) as an initiator under nitrogen atmosphere in aqueous solution and characterized by FTIR spectroscopy. The effects of concentration of CAN, the amount of MMA, reaction temperature on graft copolymerization were studied by determining the grafting percentage and grafting efficiency. The maximum grafting percentage and grafting efficiency obtained under these conditions were 790 % and 83 %, respectively.
Synthesis and Characterization of Polyesteramides Containing 5-Fluorouracil in the Main Chain
Authors: Chang Jun , Li Cheng Wu , Li Gang
Published: July 2011

A series of polyesteramide containing 5-fluorouracil in the main chain were prepared by reacting potassium salt of 5-fluorouracil with N-(2-chloroacetoxylalkyl)-chloroacetamide.The copolymers were characterized by FT-IR, 1H-NMR, VPO and UV spectroscopy. The drug release profile in vitro of the copolymers were studied, the results showed prodrug could slow release 5-FU or 5-FU units in different solution, they may be likely to become potential antitumor prodrug.