bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on Characteristics of Water Waves in Bohai Sea Using SWAN Model
Authors: Wang Dao Sheng , Lv Xiang Cui , Yuan De Kui
Published: February 2014

The SWAN (Simulating WAves Nearshore) model was applied to study the characteristics of water waves in the Bohai Sea. The model was calibrated against both short-term and long-term field measured data from six different stations in the Bohai Sea and the computational results are in good agreement with the measured data. Then the wave process during 1999 to 2009 in the Bohai Sea was simulated using the calibrated model. The wave characteristics such as significant wave height, average period, dominant wave direction and their seasonal variations were analyzed based on the simulated results. The distributions of wave height and wave period are similar to those of the previous studies, but the wave height is slightly smaller than that given by other researchers.
Lightweight Study on Axial Crushing Thin Cylindrical Tubes of Steel and Aluminum Alloy Based on Equal Energy Absorption
Authors: Wang Chuan Qing , Wang Deng Feng , Zhuang Wei Min , Zhang Ming Xin
Published: February 2014

A thin cylindrical tube model was established. Its energy absorption property was analyzed when crushing through finite element method. Then its validity was verified through the corresponding experiment. On the basis of the above research, two different material tubes were selected which were aluminum alloy 6060 and cold-roll steel B340LA. Considering the mechanical performance of these two materials might change during dynamic crushing, so the tubes were crushed in three modes including low speed, medium speed and high speed. In order to predict the wall thickness of the two different material tubes when their energy absorption was equal, two methods were proposed which were overall energy method and the stress-strain energy method. Then get the mass ratio of the two different material tubes when they absorbed equal energy. The results showed that the mass of aluminum alloy 6060 tube was about 86%-90% to B340LA tube when they absorbed equal energy. More than 10% lightweight effect could be obtained when cold-roll steel B340LA tube was instead with aluminum alloy 6060 under the condition of their absorbing equal energy.
Study on the Compensated Capacitance for the Wireless Power Transmission System
Authors: Liu Xiu Quan , Li Yan Hong
Published: February 2014

The working principle of a Wireless Power Transmission technology (WPT) system and compensated capacitance topologies were introduced. Then, based on MATLAB SIMULINK software, capacitance compensated in the primary and secondary winding on the influence of the WPT system performance were studied. The results show that the primary compensated capacitance in series can improve the voltage of the load, the primary compensated capacitance in parallel can reduce the primary winding current; the secondary compensated capacitance can also improve the load voltage, but the rate is not obvious; in the SP model, the load voltage and power factor are the biggest, the influence of the variational capacitance in the primary on the output power is bigger than in the secondary
A Study of Cooling and Heating Energy Reduction Effects for Applying of Blind-Integrated Window System in Buildings
Authors: Choi Bo Hye , Choi Gyeong Seok , Kang Jae Sik , Song Seung Yeong
Published: February 2014

Recently, the window-to-wall ratio in the building envelope has gradually increased. In summer, as a result, cooling load significantly increases because of a large amount of sunlight coming through the windows. And in winter, thermal comfort can decrease at night because of heat loss and cold radiation which take place through the windows which have relatively low thermal resistance. To evaluate on characteristics of cooling and heating energy consumption under the blind-integrated window system which can fundamentally block this kind of cooling and heating load, this study has measured inner & outer surface temperature of glazing, electricity consumption and heat flux after installing the general and blind-integrated window systems in the test bed. According to the inner & outer surface temperature of glazing, the blind-integrated window system was 20.4°C while the general one was 14.4°C in summer. And in winter, the blind-integrated window system was 2.1°C while the general one was 0.8°C. Under the blind-integrated window system, in other words, electricity consumption was saved by up to 26% (about 11% daily), and heat flux decreased by approximately 34%. In addition, it's been confirmed that heater electricity consumption in winter could be saved up to 17%.
Heating Energy and Cost Evaluation of Sandwich Insulation Concrete System
Authors: Kim Yumin , Lee Ho Yeol , Lee Yong Jun , Choi Gyeong Seok , Kang Jae Sik
Published: February 2014

It is essential to eliminate heat loss through the building envelope to reduce the energy consumption in buildings. However a significant loss of heating energy caused by thermal bridge between slab and external wall in internal insulation systems which were applied in the most apartments in Korea. To improve the performance of envelope, a sandwich insulation system was proposed. This paper evaluates the thermal performance, energy performance and economic efficiency of sandwich insulation system by comparing with internal insulation system. When the sandwich insulation system was applied, heating energy consumption was reduced by 17.8% compared with internal insulation system.
Experimental Study on Performance of Phase Change Thermal Storage Kang
Authors: Li Gang , Pang Kai , Chi Lan , Liu Chang Xiang , Jiang Li , Mo Li Qun
Published: February 2014

In this paper, the author build a new type of Kang with paraffin as its heating surface. Paraffin is a kind of phase change material ,which can stroage and release heat at a relatively constant temperature. It can make full use of the heat of the smoke in the Kang and extend the Kang heating period. We do comparison test of the the traditional Kang room and the phase change Kang room and related temperature was recorded. The tested result shows that the average temperature of the head, medium and tail of traditional Kang varies greatly,the maximum difference of the temperature is over 20°C. While the average temperatures of the head, middle and tail of the phase change thermal storage Kang are 32.59°C, 28.38°C and 26.12°C, Kang surface temperature distribution is more uniform, which improves the comfort of Kang surface. The indoor temperature with phase change thermal storage Kang shows an upward trend after the fuels burnt out until the wee hours. And the average indoor temperature is 1 °C higher than the comparision room. The phase change thermal storage Kang greatly improves the thermal comfort of its heating surface and indoor temperature.
Effects of Steel Fiber Volume Fraction on Compressive and Flexural Behaviors of Alkali-Activated Slag (AAS) Concrete
Authors: Yun Yeon Jun , Ahn Kyung Lim , Lim Won Gyun , Yun Hyun Do
Published: February 2014

This paper describes the experimental results on compressive and flexural behavior of alkali-activated slag (AAS) concrete reinforced with hooked end steel fiber. Two different fiber volume fractions of 0.5 and 1.0% were used for AAS concrete and Ordinary Portland cement (OPC) concretes were also mixed for comparison. Test results indicated that compressive and flexural performance of AAS concretes with water-to-binder (W/B) ratio of 0.55 are equivalent to those of OPC concrete. The addition of steel fiber to AAS concrete improves more compressive and flexural performance than those of steel fiber reinforced concrete.
Modeling a Thermo-Stressed State of the Cast-in-Situ Low Carbon Footprint Alkali Activated Slag Cement Concrete Hardened under Hot Environment
Authors: Weng Lu Qian , Cao Hai Lin , Krivenko Pavel V. , Guo Yue , Petropavlovsky O.N. , Pushkar V.I. , Kovalchuk A.Yu.
Published: February 2014

Alkali activated slag cement concretes are low carbon footprint building mateirals, which can meet the requirements for sustainable development. The paper covers the results of modeling a thermo-stressed state of the cast-in-situ massive alkali activated slag cement concrete structure hardened under hot environment to meet the requirements for marine engineering application. The results show that alkali activated slag cement concretes have a substantially lower heat release than that of Portland, are suitable for cast-in-situ massive alkali activated slag cement concrete structure even under hot environment.
Different Heating Methods of Rural Northern Indoor Thermal Environment Simulation Analysis
Authors: Li Hui Xing , Zheng Xing Zhi , Feng Guo Hui , Cao Chi Hong
Published: February 2014

With the rapid development of the rural economy, social progress and indoor heating methods also will be diversified, but given the limitations of technical means, resulting in lower rural energy efficiency, energy consumption is rising. To achieve the purpose of building energy efficiency in rural areas, two common ways of heating in rural areas are to compare. Select the same farm house kang - firewall and kang - soil heating in two different heating methods comparative analysis and apply fluid dynamics software to simulate two heating methods on the indoor temperature field, comparing two ways of heating of the room temperature at different heights .Kang firewall in a joint operation is better than kang - soil heating joint operation on indoor temperature distribution ,it was more uniform high comfort, you can save about 424Kg of standard coal annually. Compared to soil heating that firewall has a higher thermal efficiency and it is an energy efficient way of heating buildings in rural. Firewall heating consistent with sustainable development concept, which use renewable energy as fuel for lower cost. In-depth study can be important for social, environmental and economic value.
Questionnaire Survey on Boilers Adoption in Residential Sector in Korea
Authors: Won An Na , Hong Won Hwa
Published: February 2014

An actual condition survey was conducted based on literature review and a questionnaire survey in this study. In a literature review, the overview and characteristics of the Korean boiler market were investigated and the efficiency of the boilers used in Korea was organized. A questionnaire survey was prepared on the basis of these contents. A questionnaire survey was conducted for 2,250 households in Korea. An analysis was made on the basic information such as the family members, income level, residential area and living floor area of survey respondents as well as boiler status such as the possession and use of boilers, a boiler replacement cycle and fuel expenses. Lastly, the implications for the spread of high-efficiency boilers were identified based on the types of boiler possession and the use characteristics of boilers by housing type.
The Sensitive Fluorimetric Method for the Determination of Curcumin Using the Enhancement of Mixing Micelle
Authors: Huang Wei , Wang Feng , Zhu Hong Long
Published: February 2014

It is found that the fluorescence of curcumin is greatly enhanced by La3+ in the prescence of sodium dodecyl benzene sulfonate (SDBS). Based on this, a sensitive fluorimetric method for the determination of curcumin in aqueous solution is proposed. In the HOAc-NaOAc buffer, the fluorescence intensity of curcumin is proportional to the concentration of curcumin in the range of 0.0074-7.4μg·mL-1 and the detection limit is 3.66ng·mL-1. The actual samples are satisfactorily determined.
Structure Design and Analysis of Moving Character for Detect Robot for Underground Coal Mine
Authors: Xue Tong , Liu Rong , Zhai Shi Min
Published: February 2014

Aiming at the environment of the underground coal mine combined with the advantage of the articulated-tracked mobile robot at present, a flameproof mobile robot which can detect and rescue for underground coal mine is designed. By analyzed of obstacle crossing mechanism for the robot, necessary conditions for robot obstacle crossing successfully were proposed, and the gait of robot obstacle crossing was programmed. The conclusion can be provided for the same type robots structural design and optimization.
Containerless Processing in the Study of Metastable Solids from Undercooled Melts
Authors: Herlach Dieter
Published: February 2014

An undercooled melt possesses an enhanced free enthalpy that enables to crystallize metastable solids in competition with their stable counterparts. Crystal nucleation selects the crystallographic phase whereas the growth dynamics controls microstructure evolution. We apply containerless processing such as electromagnetic and electrostatic levitation to containerlesss undercool and solidify metallic melts. Heterogeneous nucleation on container-walls is completely avoided leading to large undercooling with the extra benefit that the freely suspended drop is direct accessible for in situ observation of crystallization far away from equilibrium. Results of investigations of maximum undercoolability on pure zirconium are presented showing the limit of maximum undercoolability set by the onset of homogeneous nucleation. Rapid dendrite growth is measured as a function of undercooling by a high-speed camera and analysed within extended theories of non-equilibrium solidification. In such both supersaturated solid solutions and disordered superlattice structure of intermetallics are formed at high growth velocities. A sharp interface theory of dendrite growth is capable to describe the non-equilibrium solidification phenomena during rapid crystallization of deeply undercooled melts.
Research of Speed Regulating System Based on Expert PID Control
Authors: Wang Hui , Liu Hong Xia
Published: February 2014

In order to further improve on the static and dynamic performance of the permanent magnet linear synchronous motor speed regulating system, the traditional PID controller is combined with the expert system technology to achieve optimum control of the control systems. In light of defects of the traditional PID controller, the expert system is introduced into the control system of motor on the basis of the incremental PID algorithm, and it is applied to the permanent magnet linear synchronous motor to adjust the motors speed. The simulation results prove the new PID controller combined with the expert system technology has small overshoot, rapid response and good robust stability.
Simulation and Design of Control and Display Unit for Full Flight Simulator
Authors: Xiao Zhi Jian , Xu Jiang Jun
Published: February 2014

In order to solve the problem of simulation difficulty of the control and display unit (CDU) for full flight simulator, it is real significance to design the CDU. The principles and design methods are expounded about the CDU in detail. The simulation CDU is tested on full flight simulator. The results show that the simulation CDU can establish flight plan, modify flight route, and set the performance parameters. The component has correct logic, high fidelity and reliable performance. The simulation CDU can meet full flight simulator design requirements.
Research on Milling Parameters Optimization Based on Surface Residual Stress for Aviation Stainless Steel
Authors: Liu Wei Wei , Wang Dong Fang , Li Feng , Chen Hao , Wang Cheng Zhou , Ren Jun Xue
Published: February 2014

In order to control surface residual stress in milling aviation stainless steel, orthogonal experiments were conducted to investigate the effects of milling parameters on surface residual stress in milling of 1Cr11Ni2W2MoV. The empirical formula of surface residual stress was established to analyze the sensitivity of surface residual stress on milling parameters. The milling parameters stability region and instability region were acquired. Using the extreme difference analysis method, the optimum selection of the milling parameters interval was proceeded. The results show that residual stress along X direction is most sensitive to the feed per tooth, residual stress along Y direction is most sensitive to the milling speed. The optimum milling speed ranges from 25m/min to 40m/min, the optimum milling depth ranges from 0.4mm to 0.45mm, and the optimum feed per tooth ranges from 0.06 mm/z to 0.08mm/z, surface residual stress can be effectively controlled.
A Research of Full-Automatic Experiment Platform Using Machine Vision for Water Quality Monitoring
Authors: Zheng Hong Yuan , Zhang Rong , Hu Yan Qing , Liu Rong
Published: February 2014

Japanese medaka (Oryzias latipes) is highly valuable in the field of monitoring the quality of drinking water. But as a result of the limitation of experiment platform and realization technology, the previous study cannot extract the characteristics which can reflect the toxicity of water real-time and accurately. This paper discusses a new experiment platform which can replace the fish tank, adjust the focal length of the camera and measure the swimming speed of medaka automatically. In order to achieve these functions, a precision positioning system using feedback technology, a pair of autofocus mechanism, a new observation method and a set of machine vision algorithm were adopted in this platform. The preliminary test results show that the designed platform and machine vision algorithm for extracting the characteristic information of medaka are effective and feasible. The platform can be widely applied to study some toxic substances' effects on medaka and to assess the degree of risk of the drinking water.
Analytical Investigation on the Current Quality of Safety Belts
Authors: Cao Jian Xiao , Cao Ye , Fu Jian Hua , Pei Jing
Published: February 2014

On the basis of two test results of safety belt from national spot check. This paper analyzes safety belt products in domestic market and data bases from each testing center. Searching and studying the existing problem with safety belt products. The results showed the quality of safety belt in market is good expecting two batches. And the test data is better than the standard value. This research has important practical significance on analysis of safety belt quality.
Study on the Security Strategy of Digital Information – Take our School Library as an Example
Authors: Wang Hai Xia
Published: February 2014

In this paper, we propose a general discussion on the digital library security from the perspectives of management risk, security demand and target, the security architecture of library digital information. The specific solution for implementation is presented for the information security of library digital information in the aspects of hardware infrastructure security, firewall technology, encroachment test, access control, virus protection, data backup and security management.
A Hybrid Approach Based on ACO and Ga for Multi Objective Mobile Robot Path Planning
Authors: Oleiwi Bashra Kadhim , Roth Hubert , Kazem Bahaa I.
Published: February 2014

In this study, we developed an Ant Colony Optimization (ACO) - Genetic Algorithm (GA) hybrid approach for solving the Multi objectives Optimization global path planning (MOPP) problem of mobile robot. The ACO optimization algorithm is used to find the sub-optimal collision free path which then used as initial population for GA. In the proposed modified genetic algorithms, specific genetic operator such as deletion operator is proposed, which is based on domain heuristic knowledge, to fit the optimum path planning for mobile robots. The objective of this study is improving GA performance for efficient and fast selection in generating the Multi objective optimal path for mobile robot navigation in static environment. First we used the proposed approach to evaluate its ability to solve single objective problem in length term as well as we compared it with traditional ACO and simple GA then we extended to solve Pareto optimality ideas based on three criteria: length, smoothness and security, and making it Multi objective Hybrid approach. The proposed approach is tested to generate the single and multi objective optimal collision free path. The simulation results show that the mobile robot travels successfully from one location to another and reaches its goal after avoiding all obstacles that are located in its way in all tested environment and indicate that the proposed approach is accurate and can find a set Pareto optimal solution efficiently in a single run.
High-Speed Brushless DC Motor Current-Loop Sampling System Design for Three-Axis Turntable
Authors: Liu Guan Da , Mo Bo , Zhou De Zhi , Du Shu Cen
Published: February 2014

Brushless DC motor (BLDCM) is adopted in the driving of a three-axis turntable. A high-speed current sampling system plays a vital role in intelligent control. This article firstly describes the working principle of a triple-closed-loop regulation system and emphatically dissects the characteristic of the current-loop among speed-loop and position-loop. Secondly, a signal acquisition-alignment circuit of three phases’ current and voltage is designed. Based on ADS8365, a scheme of high-speed current loop’s precise and synchronous sampling system is provided. Finally, experimental results have proved the validity and practicality of the scheme applied in the control of three-axis turntable.
Flow Regime Identification for Wet Gas Flow Based on Kurtosis Feature of Flow-Induced Pipeline Vibration
Authors: Hua Chen Quan , Pan Hua Wei , Geng Yan Feng , Xing Lan Chang
Published: February 2014

Flow-induced vibration occurs widely in flow pipelines, and pipeline vibration signals have various frequency characteristics corresponding to different flow regimes. Therefore, an novel noninvasive approach to flow regime identification for wet gas flow in a horizontal pipeline is presented in this paper. The vibration signals were collected by a transducer installed on external wall of pipeline. Empirical mode decomposition (EMD) was used to decompose the vibration signal into different intrinsic mode functions (IMFs), and then the kurtosis of each IMF component for each experimental data was calculated. Finally, the IMF kurtosis feature vector was input to the support vector machine (SVM) to identify three typical flow regimes for wet gas flow including stratified/stratified wavy flow, annular/annular mist flow and slug flow in a horizontal pipeline 50 mm in diameter. The experimental results show that the proposed approach can identify flow regimes effectively, and the identification rate is 80.6%.
Effect of Coarse Aggregate Type on the Residual Velocity of Rigid Projectile Perforating Concrete Target
Authors: Zhang Zhao Jun , Wang Xiao Ming , Li Wen Bin
Published: February 2014

Algorithms for generating and distributing random 3D sphere coarse aggregates were proposed. The 3D finite element mesoscale concrete model, which consists of mortar matrix and coarse aggregates, was established based on the theory of background element and material identification. The interfacial transition zone was simplified as a kind of contact between elements. Based on this model, continuous finite element code was used to simulate the process of rigid projectiles perforating concrete targets and the effect of 3 different coarse aggregate types on residual velocities was analyzed. This work indicates that the strength and density of coarse aggregates affects the residual velocity under lower and higher impact velocity respectively.
Parameters Identification of Johnson-Cook Constitutive Equation for Aluminum Brass
Authors: Di Chang Chun , Cui Kai Bo , Qin Jun Qi , Wu Da Lin
Published: February 2014

Aluminum brass HAL66-6-3-2 is abrasion-resistant alloy with high strength, hardness and wear resistance, corrosion resistance is also well, commonly used in the field of marine and ordnance industry. The quasi static and dynamic mechanical properties were tested through the use of electronic universal testing machine and Split Hopkinson Tension Bar (SHTB). Meanwhile, the material stress-strain curve at different temperatures and different strain rates is also obtained. Based on Johnson-Cook constitutive model, using the method of least squares fitting the experimental data to determine the model parameters, fitting and experimental results agree well.
Study on the Fractal Behavior and Fractal Characterization of Guide Way Joint Surface
Authors: Yang Zhu , Wang Li Hua , Shi Hai Song , Wang Peng Cheng
Published: February 2014

The characterization of guide way joint surface micro-topography is very important for the study of real guide way joint surface. Based on fractal theory, fractal characteristics of rough surface are investigated. The 3D surface topography of specimen which is closed to machine tool guide way both in material and processing condition is obtained by atomic force microscope (AFM). The structure function method is employed to gain fractal dimension and the analysis of fractal characteristics. The results show that meet the processing conditions, the guide way joint surface in the region which can scale show good linear relationship and has obvious fractal.
Optimization of Cutting Conditions of YG15 on Finish Cutting in WEDM Based on Taguchi Method
Authors: Chen Zhi , Zhang Zhen , Ming Wu Yi , Huang Hao
Published: February 2014

Wire electrical discharge machining (WEDM) is extensively used in the mold, instrument and manufacturing industries, and rough cutting operation in WEDM is treated as a challenging process because improvement of more than one machining performance measures viz. metal removal rate (MRR), roughness (Ra) are sought to obtain a precision work. In this paper, first of all, a set of Taguchi experiment (L18 21×34) is carried out based on the Taguchi method. Secondly, two groups of ANOM are completed to obtain the influence trends of each parameters on material removal rate (MRR) and roughness (Ra), respectively. Eventually, three groups of best process parameters combination are acquired to meet high material removal rate (MRR) and low roughness (Ra) simultaneously, it can provide guiding significance to actual machining process.
Influence on BTA Boring Bar Transverse Vibration Considering Inner Cutting Fluid Velocity and Axial Force
Authors: Zhao Wu , Zhang Quan Bin , Jia Wei Tao , Hu Zhan Qi
Published: February 2014

A new simulation model on frequency is proposed, to analyze mutual relationship between intrinsic frequency and other factors in system. The study is mainly focused on the axial press effect, inner cutting fluid velocity and its Coriolis inertia effects acting on boring bar. The whole system is assumed to conform to the continuous equal span beam model synthesized with liquid-solid coupling vibration model inner the work and Timoshenko beam model outer the work. Simulations show that system vibration frequency is determined by mechanical properties, axial force, inner cutting fluid velocity and density. Three aspects influence BTA boring bar lateral vibration considering inner cutting fluid velocity and axial force, who are transverse inertial mass, inertia and self-excited vibration on the bar. Inner flowing of the cutting fluids also lead to instability on bar.
The Straightening Scheme Analysis for the Copper-Clad Steel Tube
Authors: Xia Liang Yu , Sun Dong Ming , Kang Gui Rong , Sun Jian
Published: February 2014

In this paper, we studied the large deformation and the small deformation method based on the research of the existing system of straightening theory and considered the characteristics of copper-clad steel to find a proper straightening scheme for this new composite materials. the advantages and disadvantages of the method are also compared. the straightening scheme for straightening effect and parameters is a decisive role before all kinds of straightening parameter determination. But at present, there isnt a equipment for the straightening of this new material.
The Cutting Parameter Affecting to Surface Roughness in Single-Point Diamond Turning
Authors: Hao Wang , Zhang Yu , Xie Qi Ming
Published: February 2014

Single-point diamond turning (SPDT) is a machining process making use of a monocrystal diamond tool which possesses nanometric edge sharpness, form reproducibility and wear resistance. The process is capable of producing components with micrometre to submicrometre form accuracy and surface roughness in the nanometre range. The cutting parameters that can make an effect on surface finish and form accuracy of SPDT such as spindle speedfeed ratedepth of cut and so on.
Fast Prediction Model for Closure Pressure in Hot Isostatic Pressing
Authors: Zhang Dong Qiao , Zhou Jian Xin , Tang Jun Li , Wang Hong
Published: February 2014

Simulation of hot isostatic pressing (HIP) process with complex castings was rarely referred for its time-consuming and difficulties existed in meshing by commercial software. A fast prediction model was proposed to overcome those limitations in present work. The relationship of holes size, shape, and closure pressure was established by analysing the closed hole in ZTC4 castings with simple structures based on the software. Then the fast prediction model was applied to a complex casting. A relative error of 4.09% was obtained between this model and result calculated by the software, which verified its effectiveness in predicting ZTC4 castings with complicated structures.
Influence of High Energy Ball Mill Technology on Cube Texture Formation of Ni-8at.%W Alloy Substrates for YBCO-Coated Conductors
Authors: Meng Yi Chen , Suo Hong Li , Tian Hui , Ma Lin , Wang Yi , Liang Ya Ru , Liu Min
Published: February 2014

Ni8W alloy ingots were prepared by SPS technic, followed by homogenizing, cold rolling and recrystallization annealing. The influence of ball milling on cold rolling and cube texture formation of Ni8W alloy substrates was investigated during the course of preparation. Finally, high quality cube-textured Ni8W alloy substrates were successfully obtained using this powder metallurgy process, and characterized by electron backscatter diffraction technic. It indicated that the cube texture fraction was as high as 90% (<10o) when it annealed at 1350°C for 2 h.
Influence of Heat Treatment on Mechanical Properties and Microstructure of Low Alloy Cast Steel (ZG25MnNi)
Authors: Liu Teng Shi , Yang Yi Tao
Published: February 2014

In this paper, the influence of heat treatment temperature on the microstructure and mechanical properties of cast steel (ZG25MnNi) was investigated. The results showed that normalizing treatment can effectively refine cast microstructure of ZG25MnNi and maximum hardness achieved at 900°C. After normalized at 900°C, the sample tempered at 500°C,530°C,560°C, 590°C, 620°C, 650°C respectively. With the tempering temperature increasing, the samples tensile strength increased gradually and elongation decreased gradually. When tempered at 530-590°C, the sample had a relatively high strength plastic product. The results showed that the best normalizing temperature is 900°C and the optimum tempering temperature is 530-590°C.
Research and Implementation of the Data Fitting Algorithm for Testing the Metallurgical Performance of Iron Ore
Authors: Wang Hua Bin , Shi Jin Liang , Xie Dong , Xue Di Jian
Published: February 2014

In the data processing of iron ore metallurgical properties, the polynomial least squares method or the assumed functions are usually employed to fit the performance curve. This is stuck at a high degree of the polynomial, where the equation group is prone to morbid problems. To solve this problem, the use of orthogonal functions as the least squares method may help draw out the reductioln metallurgical performance curves.
Investigation on Electrical Properties of CaCu3Ti4O12-Modified (Na,Bi)TiO3-BaTiO3 Lead Free Piezoceramics
Authors: Zhao Jing Chang , Zhou Zhen Lai
Published: February 2014

(Na,Bi)TiO3-BaTiO3lead free piezoelectric ceramics were fabricated with modification of CaCu3Ti4O12additives. The phase structure, morphology, dielectric and piezoelectric properties of prepared samples were investigated, respectively. It was found that CaCu3Ti4O12additives evidently improve the polarization properties of (Na,Bi)TiO3-BaTiO3lead free ceramics and the obtained samples exhibit an excellent piezoelectric properties (electromechanical coupling factorKp=31%, mechanical quality factorQm=151 and piezoelectric constantd33=160pC/N). According to results, the effect of CaCu3Ti4O12additives on electrical properties of (Na,Bi)TiO3-BaTiO3lead free piezoelectric ceramics is discussed.
Research on Compressive Behavior and Deformation Heating of 7075-T6 Aluminum Alloy during Hot Compression
Authors: Wang Dong Ge , Mei Rui Bin , Cai Ban , Zhang Chun Li , Bao Li , Zhang Bo , Li Chang Sheng
Published: February 2014

The flow stress behavior of the 7075-T6 aluminum alloy was studied through single-pass compression experiment by using MMS-300 simulator within temperature range of 300-450°C and strain rate range of 0.01-40s-1. Then a simulation of compression was carried out and the influence of deformation velocity on load and deformation heating was investigated according to the relationship between stress and strain. The results show that dynamic recrystallization occurs in hot compression of 7075-T6 alloy and the stress-strain curves are presented as wave. Furthermore, the flow stress curves have the same wave period and the fluctuation range increases with an increase of strain rate and a decrease of strain. Increasing of deformation velocity results in higher critical strain but the value decreases when the deformation velocity is much higher. The temperature rise increases with the increase of deformation velocity and decrease of deformation temperature. The maximum of temperature rise is more than about 30°C, so that the deformation heating is significant.
Influence of Etchants on Phase Morphology of Casting Ni-Based Superalloy
Authors: Li Juan Juan , Zang Shu Jun , Zhang Jian Bin
Published: February 2014

K4169 is the Nickel-base superalloy that is the most widely used in the turbine components. The article selects three kinds of etching solution to corrode, in order to achieve the purpose that studies on its morphology. Etchant1 is the mixed solution of 15mlHCl, 10mlAcetic acid, 5mlHNO3and 2drop glycerin. Etchant2 is the mixed solution of 3ml glycerin, 3mlHCl, 1ml HNO3. Etchant 3 is the mixed solution of 20mlHNO3, 60mlHCl. The results showed that we can mainly observe strengthened phase γ'' (Ni3(Ti, Al)) and matrix γ (Fe-Ni-Cr) phase with etchant1 to corrode. Using the etchant2 to corrode, we can clearly see its dendrite structure. Using the etchant3 to corrode, we can obverse its grain boundary that includes white inter-metallic compounds. We also respectively discussed the K4169 morphology when magnifications are 200times and 500times.
Dynamic Strain - Induced Boundary Migration during Dynamic Recovery at a High Temperature Deformation with a Lower Strain Rate
Authors: Ji Feng Qin
Published: February 2014

Conventional hot compression deformation and water quenching experiments were applied to investigate the evolution of austenite grain structures before the initiation of dynamic recrystallization. The experimental results reveal an interesting phenomenon that dynamic strain induced boundary migration can lower dislocation density and coarsen austenite grains. The results show that dynamic recovery is not the only way to decrease dislocation density, the mechanism of which for dynamic recovery is related to dislocations climb and annihilation, resulting in the formation of sub-grains and regular sub-boundaries. However, the mechanism of decreasing dislocation density for dynamic strain induced boundary migration is different from dynamic recovery. Therefore, dynamic strain induced boundary migration should be another softening mechanism before the initiation of dynamic recrystallization.
The Thermally Stimulated Current (TSC) Technique on Evaluating Degradation of ZnO Varistors
Authors: Fan Ji Wei , Zhang Xiao Li , Zhao Hui Jun
Published: February 2014

Thermally stimulated current (TSC) is a simple and effective test technique to study the thermal activated charge, electron trap and activation energy of dielectric and semiconducting materials. It is well known that the addition of glass frits can improve the degradation property of ZnO varistors. An activation energy of 0.45 eV has been found on the ZnO varistors with/without glass frits after the DC degradation by using TSC method. The tested quantity of thermal activated charges, QTSC, may represent the numbers of migrated zinc interstitials. ZnO visitors doped with glass frits have less QTSC. Experiment indicates that TSC test is a convenient method to evaluate the degradation behavior of ZnO varistors.
The Study of Impact Rule of Si Element on Cu/Al Composite Interface Compounds
Authors: Wang Min , Wang Ping , Chang Dong Xu , Zhang Qian , Zhang Xin , Liu Guo Ping
Published: February 2014

The present paper has discussed the growth inhibition role of silicon additions in Copper / Aluminum composite interface compounds. With different Si content of the aluminum composite sample after the comparison group, and interface with metallographic microscopy and by scanning electron microscopy analysis carried out and found that the Si incorporation can significantly inhibit the Copper / Aluminum interface compounds generated.
Analysis and Design of Transparent Microwave Absorbing Materials Based on the Destructive Interference at the Microwave Range
Authors: Ye Yi , Song Li Xin , Song Xiang Lian , Zhang Tao
Published: February 2014

An optically transparent microwave absorbing material based on the destructive interference theory was studied in this paper. The destructive interference phenomenon has been discussed and verified in the transparent microwave absorbing material. According to the destructive interference theory, we designed a type of three-layer microwave absorbing structure to enlarge the absorbing bandwidth. And its reflection coefficient curve stays below -10dB in the range of 7.5GHZ to 17.0GHz.
Current Research of Biodiesel Used on IC Engine and Improved Measures of Emissions
Authors: Chen Lei , Ni Hong Jun , She De Qin , Yuan Yin Nan
Published: February 2014

The emission mechanism of biodiesel used on IC engine is analyzed, as well as the summary of the research of domestic and abroad situation about biodiesel used on IC engine. The improved measures, which is under the premise of not affecting power performance and economic efficiency of IC engine, combining the emission process of IC engine was presented, it needs some measures to improve the quality of biodiesel and the system of IC engine to control the emission of the harmful substances, in this way the problem of energy shortage and environmental pollution can be ameliorated.
Preparation and Thermal Properties of Polybenzoxazine/TiC Hybrids
Authors: Ramdani Noureddine , Wang Jun , Liu Wen Bin
Published: February 2014

In this work, typical polybenzoxazine, as new class of phenolic resin, has been used as a matrix for preparing a series of high performance hybrid materials using various amounts of titanium carbide (TiC) ranging between 0-10 wt% as fillers, via a solution blending technique. The thermal properties of bisphenol A-aniline base benzoxazine monomers (BA-a) and TiC mixtures have been studied by differential scanning calorimetry (DSC). The thermal stability of their cured hybrids has been tested by means of thermogravimetric analysis (TGA). The result showed that the glass transition temperature of the prepared composites increased with increasing the amount of TiC to reach a higher value at 194°C. Also, the incorporation of TiC nanoparticles has considerably improved the thermal stability of the hybrids including the char yield which increase by 50 % at 10 wt% TiC content.
Glutaraldehyde Cross-Linked Silk Fibroin Films for Controlled Release
Authors: Wang Yu Xiao , Qin Yan Ping , Kong Zhi Jie , Wang Ya Jing , Ma Lin
Published: February 2014

Glutaraldehyde (GA) cross-linked silk fibroin (SF) films were prepared and the structural change were investigated by Fourier transform infrared spectroscopy and differential scanning calorimetry. The results were utilized to reveal the influence of GA cross-linking on the release properties of SF materials. It was found that GA induced conformational transition of SF from random coil to beta-sheet and had influence on the interaction between the peptide chains of SF, resulting in great changes in mechanical and dissolution properties, as well as drug release feature of the films. With increasing GA content, tensile strength of films first increases and then decreases, reaching a maximum around 7.5 %. The cross-linking was found to increase the flexibility and stability of SF films in water, and reduce the burst release of Rhodamine B, a model compound for small drug. The release of Rhodamine B exhibited a continuous and steady release after the initial burst, of which the release rate had a good linear fit to beta-sheet content in the matrix, suggesting that the silk II crystal could be used as a natural regulator for drug release from SF material.
Physicochemical Characterization of Oxidatively Degraded Calcium Lignosulfonate via Alkaline Hydrogen Peroxide
Authors: Hu Li Hong , Zhou Jing , Bo Cai Ying , Liang Bing Chuan , Zhou Yong Hong
Published: February 2014

In order to increase the application prospect of calcium lignosulfonate in phenolic resin, Calcium lignosulfonate was oxidatively degraded by Hydrogen peroxide under alkaline condition. Both lignins were characterized by FT-IR,1H NMR, UV, GC-MS and GPC. The optimal degradation conditions are: lignosulfonate:water=1:1, wt/wt, pH=10, temperature 60 °C, reaction time 2 h, and H2O2dosage 6 wt% (based on weight of lignosulfonate). The results show that the degraded resultant is higher in phenolic contents, and lower in methoxyl content. Number molecular weight (Mn) of calcium lignosulfonate sharply decreases to 2294, versus 17774 before oxidative degradation.Guaiacly monoer content increased and kinds of phenolic compounds occurre in oxidative degradation fractions, mainly due toβ-O-4 andβ-5 cleavage. And reactive activity of the oxidatively degraded compounds is sharply increased.
Technique Status and Prospect of Synthetic Rutile
Authors: Liu Song Li , Xiang Jun Yi
Published: February 2014

Synthetic rutile is an important intermediate in the manufacture of titanium dioxide, sponge titanium, and other areas of chemical industry. Due to the limitation of raw material and technology, the production of Chinas synthetic rutile still cant meet the need. Using the low grade ilmenite ore as a raw material to manufacture high grade synthetic rutile is extremely urgent. The technology of producing synthetic rutile at home and abroad, the prospect of Chinas industrial process and some suggestions are introduced.
To Measure the Absorbance at 328nm by Ultraviolet-Visible Spectrophotometer - an Alternative Pathway to Measure the Activity of Acetylcholinesterase
Authors: Wu Di , Li Hao , Zhang Di , Wu Min
Published: February 2014

Acetylcholinesterase (AChE) is an important enzyme in mammalian nervous systems. The Ellman assay is usually used to measure AChE activity and calculate the inhibition rate by measure the absorbance at 412nm by UV-Vis spectrophotometer. However, an alternative absorbance at 329nm which assigned as S-S of 5,5'-dithio-bis-2-nitrobenzoic acid (DTNB) was found, and it negatively correlated with the absorbance at 412nm. Therefore, the absorbance at 329nm was also possible used to measure AChE activity and calculate the inhibition rate. In addition, the reaction time should be considered in the process to transfer the relationship of these two absorbance values, because Cu (II) would combine with 5'-mercapto-2'-nitrobenzoic acid (5-MNBA).
Experimental Study on the Effective Separation of Chromium-Iron Ions in Multi-Component Solution System by Ihleite Method
Authors: Liu Cheng Jun , Zhang Qing Song , Shi Pei Yang , Zhang Bo , Jiang Mao Fa
Published: February 2014

As one of the raw material resources in China, chromium salt production has been paid to close attention. Alkali process of chromium salt produces serious environmental pollution, while acid production of chromium salt has separation problems of chromium-iron ions. The separation process of chromium-iron ions in acidic solution by the combination technology of hydrothermal method and ihleite method is studied in this paper. which finds that: with the increase of reaction temperature or with the extension of reaction time, precipitation rate of iron increases, while loss rate of chromium decreases.
Study of Synergistic Effects of Cerium Oxide on Intumescent Flame Retardant Polypropylene System
Authors: Wang Ya Li , Tang Xiao Ping , Tang Xu Dong
Published: February 2014

Melamine salt of pentaerythritol phosphate (PPM) was synthesized with phosphoric acid, pentaerythritol and melamine. This flame retardant polypropylene containing cerium oxide (CeO2) can be used as a synergistic agent for the flame retardancy of intumescent flame retardant polypropylene system. The pendulum impact tester and universal material machine were used to evaluate the mechanical properties of intmescent flame retardant system, the limiting oxygen index (LOI), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) were used to evaluate the synergistic effects of CeO2. The LOI value of the system increased when reasonable amount of CeO2 was added, and it reached maximum (30%) when the mass fraction of PPM was 20% and CeO2 added was 1% of the PPM/PP system. The TGA data shows that CeO2 can enhance the thermal stability of the intumescent flame retardant polypropylene system at high temperature and effectively increase the char residue formation. The morphological structures observed with SEM demonstrate that reasonable amount of CeO2 can improve the morphologies of intumescent char layer and the properties of heat insulation and barrier material. The reasonable amount of CeO2 in the system can increase its impact strength and decrease its tensile properties.
The Thermal Decomposition Characteristics of Sodium Pyroxenite Gangue in Baiyunebo Iron Ore
Authors: Luo Guo Ping , Wu Sheng Li , Nie Xiao Long , Wang Yi Ci , Wang Yue Cong
Published: February 2014

The changes of physical and chemical properties of sodium pyroxenite gangue such as decomposition and phase transformation were researched by means of differential thermal analysis and X-ray diffraction. The results show that the natural sodium pyroxenite gangue contains the main mineral of aegirite(NaFe+3Si2O6), and it contains a number of BaSO4 and Na3Ca2(SO4)3F, etc. The water of crystallization decomposes at 554.7°C. The Na3Ca2(SO4)3F decomposes into the composite sulfate and CaF2 over a wide range of temperatures. The main mineral of aegirite(NaFe+3Si2O6) reacts with CaF2 into NaF gas at 993.4°C. The sodium pyroxenite gangue is melts and releases a small amount of SiF4 gas in the range of 1193.5-1300.7°C.
Thermal Error Measurement, Modeling and Compensation for Motorized Spindle and the Research on Compensation Effect Validation
Authors: Fu Yu Qing , Gao Wei Guo , Yang Jin Yu , Zhang Qing , Zhang Da Wei
Published: February 2014

The motorized spindle is a primate part of the machine tool and its thermal characteristics have great influence on the accuracy of the machine tools. The thermal errors of the spindle of a certain type of precision horizontal machining center were measured with PLC acquisition system. By multivariate linear regression method, the axial thermal error model was built. Online real-time error compensation was implemented by applying the FANUC 18i CNC system external machine coordinate system shift function. A verification method was proposed which include three steps: model validation, compensation validation and experimental machining verification. The accuracy of the model was 84.1%, 64.9% and 49.4% respectively. The quantitative analysis results showed the precision was effectively improved and the compensation method was reliable.