bluuebunny/crossref_metadata_2025 huggingface dataset:
FEM-Based Modeling to Simulate Thermal Deformation Process for High-Speed Ball Screw Drive Systems
Authors: Yang A.S. , Chai S.Z. , Hsu H.H. , Kuo T.C. , Wu W.T. , Hsieh W.H. , Hwang Y.C.
Published: December 2013

Along with increasing speed and acceleration of numerically controlled machine tools, the influence of thermal dynamics characteristics on operating accuracy becomes more and more important. Improvement of thermal dynamics characteristics has turned out to be one of the crucial problems to develop machine tool of high performance. The positioning error of a feed drive system, mostly caused by the thermal deformation of a ball screw shaft, can directly affect the working accuracy of the machine tool. In this study, we applied the computational approach using the finite element method (FEM) to simulate the thermal expansion process for estimating the deformation of the ball screw system. In the numerical analysis, the deformation of the ball screw shaft and nut was modeled via a linear elasticity approach along with the assumption that the material was elastic, homogeneous, and isotropic. To model the reciprocating motions of the nut at a speed of 60m/min respecting to the screw shaft, we utilized the three-dimensional unsteady heat conduction equation with the frictional heat from the sources of the ball screw shaft, nut and bearings to calculate the temperature distributions for determining the temperature rises and axial thermal deformations in a ball screw shaft under operating situations. Simulations were conducted to explore the connection between the temperature increase of nut and the thermal deformation of the ball screw drive system, revealing the need of a compensation scheme for thermal error to improve the operating accuracy of machine tools.
Bio- and Psychophysical Audiology as a New Direction of Computer Technologies: The Substantiation and Possibilities
Authors: Ovchinnikov Evgeny L. , Ivanov Vladislav V. , Ovchinnikova Yuliya V.
Published: December 2013

Audiometry, which is currently used in medical practice, is based on the experiments of the last century. Using numerous clinical tests, it's played a major role in the auditory disorders diagnosis. But its capabilities are very limited.Theoretical justification of the experimental facts accumulated by now, today allows to solve many problems of hearing, including the tasks of computational biology. Using the physical processes that are realized at sound transduction in the inner ear, we created an alternative (acoustic-wave) hearing model on pre-receptor level. Its main result is the analytical matching of the sound frequency for the corresponding coordinates of the spiral organ.This cochlear tonotopicity represents the ratio between stimulation frequency f and place l along the cochlea by the equation of the acoustic-wave hearing model at pre-receptors stage l (f) = Lo.22log (f/fmo), where Lo= 32 mm the cochlear duct length, fmo=20 kHz maxima frequency of audible sound.Biophysically is a substantiated age-related effect which attributable to changes in person perception the sound frequency. Age-related frequencies standards can be represented by f (t)=fmoert, where r=0.01 year1high-frequency loss factor sound. Using both relations together, we get the length of the cochlear duct for T years LT=Lo.22log (fT/fmo). It can help you calculate the new biological parameters of inner ear in prognostic and reconstructive processes of hearing's change and to determine its quality. It can be used in the monitoring study, the effectiveness of therapeutic procedures and any pharmacological and physical therapy interventions, in assessing the impact of environmental factors on the person.The modern complex hearing audiology should be based on all-pass sound generator with constant power, should include the database and displays the information and tools under the new bio-and psychophysical capabilities.
Single Machine Scheduling with Resource-Dependent Ready Times and Positional Deterioration Effect
Authors: Wang Dan , Yin Na
Published: December 2013

The paper deals with the single machine scheduling problems with positional deterioration effect. It is assumed that the release time of a job is a positive strictly decreasing continuous function of the amount of consumed resource. We present a polynomial solution for the total resource consumption minimization problem under the constraint that the makespan does not exceed a given limit.
Numerical Analysis of Junction Point Pressure during Droplet Formation in Y-Junction Microchannel
Authors: Liu Zhao Miao , Liu Li Kun
Published: December 2013

Junction point pressure changes during droplet formation in Y-junction microchannels with differed Y-angles, wetting property and capillary number of the liquid by using a three dimensional numerical simulation. The pressure of the junction point fluctuates throughout the droplet formation process, and it can be used to depict exactly and directly different stages of droplet in microchannels. And the pressure of junctions with different Y-angles of microchannel, different contact angles of dispersed phase with the surface, and different capillary numbers of continuous phase could thus be investigated via the droplet formation mechanism.
Aluminium Induced Crystallization of Amorphous Silicon via Solution Derived Catalyst
Authors: Bu Ian Yi Yu
Published: December 2013

In this paper, aluminum induced crystallization (AIC) was studied by examining the effect of using solution derived AlCl3 catalyst. Such catalyst preparation method offers possibility of low-cost, non-vacuum solution process and allows examination of the role of alumina on the AIC process. The deposited AIC films were examined by using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), Raman spectroscopy, X-ray diffraction (XRD) and four probe measurements. It was found that AIC process is highly dependent on annealing temperature and can occur at annealing temperatures above 500°C through Al2O3 formation. Based on the presented data, a possible growth model is proposed to clarify AIC mechanism.
Synchrotron XANES Spectra of Superparamagnetic Iron Oxides Synthesized by Ultrasonic-Assisted Co-Precipitation
Authors: Tangwatanakul W. , Sirisathitkul C. , Muensit N. , Monnor T. , Yimnirun R.
Published: December 2013

Iron oxide nanoparticles were synthesized by employing an ultrasonic homogenizer in conjunction to the co-precipitation of Fe (NO3)3·9H2O, FeCl2·4H2O and NaOH. Synchrotron X-ray absorption near edge structure (XANES) spectra could be fitted with the contributions from hematite (α-Fe2O3) and, to a lesser extent, metallic Fe. The increase in reagent concentrations increased the Fe fraction which partly explained the change in magnetization of superparamagnetic particles. Nevertheless, the α-Fe2O3 composition was increased by using a longer reaction time.
The Vibration Characteristic Analysis of Feed System of CNC Machine Tool
Authors: Wu Qin , Yang Jian Jun
Published: December 2013

The mathematical model of feed system of CNC machine tool was established base of Lagrange Equation and energy principle, then uses the Runge-Kutta method to solve the equation, and analyzes the influence that the parameters to the vibration displacement of ball screw. According to the result of orthogonal test, it is concluded that the most important three factors which influence ballscrew vibration displacement were the ball screw's lead h, the table quality m and the longitudinal contact stiffness kn in the connection of workbench and ballscrew. On the feed system test-bed, the longitudinal amplitude, torsional amplitude and horizontal amplitude of ball screw were measured, the results show the larger the ball screw's lead and the quality of workbench, the greater the amplitude of ball screw, the bigger the longitudinal contact stiffness kn, and the smaller the amplitude of screw.
Correlation Analysis of CPT Parameters and the Physico-Mechanical Parameters of the Loess-Like Silty Clay Soil
Authors: Zhang Ming , Wang Bao Ming , Wang Song Jiang
Published: December 2013

The cone penetration test (CPT) for loess-like silty clay soil in western Henan province was done to obtain the tip resistance and sleeve friction. Then, the relationship of CPT and physico-mechanical parameters of loess-like silty clay soil was analysis. At last, the empirical model for physico-mechanical parameters of loess-like silty clay soil in western Henan province was established. The physico-mechanical parameters of loess-like silty clay in western Henan province could be calculated by sing the empirical model from CPT, including water content, void ratio, plasticity index and compressibility coefficient. The results provide the foundation for reliability analysis of parameters of loess-like silty clay soil in geotechnical investigation, design and construction.
Mistuning and Structural Coupling Effects on Flutter of Turbomachinery Blades
Authors: Fu Zhi Zhong , Wang Yan Rong
Published: December 2013

A fast numerical method based on aeroelastic eigenvalue analysis is applied to study the effects of mistuning on the aeroelastic stability of turbomachinery blades in which the structural coupling is included by a simplified method and an influence coefficient method is employed to deal with the unsteady aerodynamic effects. Results show that there exists an optimal mistuning amount at which the system has the best aeroelastic stability. Structural coupling almost has no effects on aeroelastic stability of a tuned system. But the benefit of alternate frequency mistuning to aeroelastic stability is inhibited drastically when structural coupling is introduced into the bladed disk system.
Research on and Applications of Au/Pt Thermocouples
Authors: Zhao Guo Chang , Zhao Chun Lei , Song Li Ping , Tong Xian Yi
Published: December 2013

Elemental thermocouples are capable of meeting the demanding requirements of high temperature measurement with high accuracy, wide temperature measurement range, and long operational life. With an ever increasing need for more accurate, more precise temperature measuring devices over a wide spectrum of temperatures, elemental thermocouples show great promise when compared with its counterparts. The Au/Pt thermocouple, one of the more effective elemental metal combinations, is the ideal standard thermometer in the range of 0°C - 1000°C due to its reproducibility, accuracy, stability, and durability, causing the US and Korea to standardize its use. Much academic work has been done on the accuracy, stability, thermoelectric properties, structural design, and calibration methods of Au/Pt thermocouples to develop it to its current state. This paper summarizes research done on Au/Pt thermocouples, both domestically and internationally, in order to provide a foundation for future improvement.
Effects of the Preparation Parameters on the Properties of Graphite/Carbon Fiber/Copper/Phenolic Resin Composites
Authors: Li Mi Dan , Niu Huan , Yang Hong
Published: December 2013

The polymer composites consist of phenolic resin, natural graphite, carbon fiber and copper powder, are fabricated by hot compression moulding or compression moulding followed by post-curing. The density, electrical conductivity and flexural strength of composites are analyzed to determine the influences of post-curing temperature and preparing method on the physical, electrical and mechanical properties of composites. It is found that the density, electrical conductivity and flexural strength of composites increase with increasing post-curing temperature for composites prepared by compression moulding followed by post-curing. The flexural strength is more strongly dependent on post-curing temperature. At 170 °C, the density, electrical conductivity and flexural strength of composites were 1.85 g/cm3, 2.94 × 103S/m and 40 MPa respectively. The cross-linking skeleton structure well established in the composites could be the main reason for the largely increasing of flexural strength as post-curing temperature increases. The results also show that the properties of composites prepared by hot compression moulding are higher than those of composites prepared by compression moulding followed by post-curing.
Application of Normal Forms to a Laminated Composite Piezoelectric Rectangular Plate with One-to-Three Internal Resonance
Authors: Chen Shu Ping
Published: December 2013

Normal form theory is very useful for direct bifurcation and stability analysis of nonlinear differential equations modeled in real life. This paper develops a new computation method for obtaining a significant refinement of the normal forms for high dimensional nonlinear systems. In the theoretical model for the nonlinear oscillation of a composite laminated piezoelectric plate under the parametrically and externally excitations, the theory of normal form is applied to find the explicit formulas of normal forms associated with a double zero and a pair of pure imaginary eigenvalues.
Energy Spectra of the Low-Lying State in N-Layer Quantum Dots
Authors: Wang An Mei
Published: December 2013

A method is proposed to exactly diagonalize the Hamiltonian of a N-layer quantum dot containing a single electron in each dot in arbitrary magnetic fields. the energy spectra of the dot are calculated as a function of the applied magnetic field. We find disco-ntinuous ground-state energy transitions induced by an external magnetic field in the case of strong coupling. However, in the case of weak coupling, such a transition does not occur and the angular momentum remains zero.
A Surface Roughness Model in Radial-Mode Abrasive Waterjet Turning for High-Tensile Steels
Authors: Li Wei Yi , Zhu Hong Tao , Wang Jun , Huang Chuan Zhen
Published: December 2013

Abrasive waterjet (AWJ) machining is an emerging machining method to process all kinds of difficult-to-cut materials. In this paper, a mathematical model for the surface roughness generated by a radial-mode AWJ turning process on a high-tensile steel specimen is developed using a dimensional analysis technique. To verify the model, a series of statistically designed experiments are carried out where feed speed, water pressure, abrasive flow rate, nozzle tilt angle, and workpiece surface speed are considered as variables. The model predictions are found to be in good agreement with the experimental results with the average error of 4.3%. Future research to advance the knowledge about this new machining process is also proposed.
A Three-Dimensional Numerical Analysis on the Effective Permittivity of Composites Including Ellipsoids
Authors: Zhang De Yuan , Yuan Li Ming , Xu Yong Gang , Cai Jun
Published: December 2013

To investigate the effective permittivity of composites composed of ellipsoidal inclusions, three-dimension numerical models for ellipsoidal inclusions distributed randomly are built with the finite-element modeling software Comsol Multiphysics. After calculating the effective permittivity for different cases and comparing the results with analytical results from the Maxwell-Garnett mixing rule, we find that the finite-element method has an advantage in detecting details of the interaction among inclusions, which have some impacts on the effective permittivity and could not be accurately taken into account in the analytical model. The finite-element method is expected to solve more complex problems on electromagnetic computation.
Precise Ultrasonic Motor Driver Design and Analysis
Authors: Wang Ji Hui , Chen Ming Fang , Han Gang , Hou Bai Min
Published: December 2013

In this paper, it was put forward the reversing pulse width adjustment scheme. Precision DSP PWM technology is a good solution to the dead band protection problem, and the piezoelectric feedback link is a good solution to the problem of resonant point temperature drift. Experiments show that the reversing pulse width adjustment method is a good speed regulation method, the dynamic, wide speed range and good linearity governor.
Stability Analysis of Nonlinear Stiffness Rotor-Bearing System with Pedestal Looseness Fault
Authors: Luo Yue Gang , Zhang Song He , Wu Bin , Hu Hong Ying
Published: December 2013

The dynamic model of nonlinear stiffness rotor-bearing system with pedestal looseness fault was set up, taking the linearity and cube item as the physics nonlinear factors. The periodic solution of system was analyzed by continuation-shooting algorithm for periodic solution of nonlinear non-autonomous system, and the stability of system periodic motion and unsteady law are discussed by Floquet theory. The unstable form of it is Hopf bifurcation. In the region of critical rotate speed, the main motion of the system is periodic-4; and it of ultra critical rotate speed, the main motion of the system is periodic-3 and chaotic motion. The conclusions provide theoretic basis reference for the fault diagnosis of the rotor-bearing system.
Stress Analysis of Asymmetric Spur Face-Gear Pair Based on Finite Element Method
Authors: Zhao Ning , Zhang Meng Qi , Guo Hui
Published: December 2013

According to the theory of gear geometry, the equations of teeth surface of double pressure angles asymmetric face-gear were conducted. Discrete points were generated in MATLAB according to the surface equations, and then the author established contact finite element models of single-tooth pair in ANSYS. The calculated value of contact pressure of the single tooth contact finite element model and the calculated value of contact pressure which given by the point-contact Hertz theory were compared to verify the effectiveness of the contact finite element method. Several groups of parameters were calculated and the results showed that the use of reasonable asymmetric design can effectively reduce the max surface contact pressure and the max tooth root bending stress.
Stability and Oscillation Phenomena Analysis in Microbial Continuous Fermentation Time-Delay System
Authors: Wang Yan , Li Xiao Hong , Li Xiao Ming
Published: December 2013

Based on 1,3-propanediol production from continuous fermentation of glycerol by Klebsiellapneumoniae, the dynamic behaviors of a kinetics system with continuous time-delay are analyzed. At first, a six-dimension kinetics system concerning the intracellular substance is proposed by introducing weak nuclear continuous time-delay into the specific cellular growth rate. Second, taking the inverse of average time-delay as parameter, the local stability of the positive equilibriums and the existence of Hopf bifurcation are discussed. Finally, the period solution of biomass and the parameter region of Hopf bifurcation are pictured numerically taking some special number in substrate concentration in feed medium and dilution rate.
Successive Loop Closure Based Controller Design for an Autonomous Quadrotor Vehicle
Authors: Singh Ansu Man , Lee Deok Jin , Hong Dong Pyo , Chong Kil To
Published: December 2013

In this paper, a new systematic approach for designing a self-tuning controller for an autonomous quadrotor robot is introduced.In order to design the self-tuning controller, first, a linearized dynamic model of a quadrotor about hovering positions is derived, and thenthe successive loop closure approach is applied to design the self-tuning PID controller of the attitude, altitude and velocity for the autonomous flying capability of the flying robot. In addition, nonlinearities of the design model are also imposed in the control loop by takinginto account the saturation of actuators. For the verification of the effectiveness of the proposed controller, various simulation studiesare carried out in terms of the accuracy and robustness.
The Application of ICA-SVM Method for Identifying Multiple Faults in Asynchronous Motors
Authors: Zhu Hou Quan , Fang Rui Ming , Peng Chang Qing
Published: December 2013

Vibration signal of asynchronous motors are detected with multiple sensors and used to identifying multiple faults of motors in this paper. Independent components analysis method (ICA) is applied to compress measurements from several channels into a smaller amount of channel combinations and separate related vibration signal from interfering vibration sources, and support vector machine (SVM) based multi-class classifiers are used to identify multiple faults of asynchronous motors. Adventures of the proposed methods are that they are data-based and are not necessary to build an analytical model, and SVM-based identification can provide better performance with few datasets. Experiment results are provided to illustrate the performance of the detection and identification methods.
The New Technology of Preparation Activated Carbon from Lignite
Authors: Yuan Yang , Chen Zhuo , Qin Hao Li , Han Zhao Wu
Published: December 2013

The lignite resource is rich in Xilingol League in Inner Mongolia. The two new methods were achieved to preparation activated carbon which used lignite as raw material. Firstly, the lignite was acidized by hydrochloric acid to prepare activated carbon. The catalytic materials in the ash as calcium, magnesium, iron and other elements were significantly reduced after that and the activated speed of the coal was significantly lower than the original coal, which are conducive to the development of uniform porous carbonized compound and decrease the hole broken. And a better surface area and adsorption properties of activated carbon was obtained. Secondly, with the carbonization and activation temperature at 800°C and 45 min, we can get the activated carbon with the excellent adsorption performance through fluidized catalysis of lignite.
Design of PSO Based PI Controller for Wind Turbine Systems
Authors: Perng Jau Woei , Chen Guan Yan , Tsay Der Min , Kuang Jao Hwa , Lin Bor Jeng , Hwang Guan Shyong
Published: December 2013

This paper implements a strategy to obtain the proportional-integral (PI) optimal operating point and find the description of the stability regions in the parameters space. In order to do this, the particle swarm optimization (PSO) algorithm has been used in this study. The intelligent algorithm which is artificial learning mechanism could find optimal operating points and generates the function of the best operating parameter in the PI control stability region. Then the graphical method can provide boundaries of the PI type controller space for close-loop wind turbine generator (WTG) systems. The proposed techniques are presented by using simulation results to the WTG model.
Failure Probability Calculation of Tower Crane Hoisting Mechanism
Authors: Zheng Xi Jian , Wang Yu Yan , Xie Zheng Yi
Published: December 2013

Tower crane as the main equipment of building trades, the failure of Hoisting mechanism is particularly important for complete machine working performance and device safety. In this paper, the failure of tower crane hosting mechanism is analyzed, the failure mode of hoisting mechanism is researched, the failure probability of hoisting mechanism is built, the various factors in the work influence on the tower crane hoisting mechanism is analyzed, use coefficient modification method to correct influence factor of hoisting mechanism, according to the series system theory to calculate the failure probability of tower crane, Provide the basis for the whole risk assessment.
Numerical Verification of Model Multibody Systems
Authors: Svoboda Martin
Published: December 2013

The article deals with the influence of manufacturing and geometric asymmetry on the vertical oscillation of symmetric and asymmetric systems consisting of rigid bodies linked flexibly with different kinematic excitation. The solution was performed using experimental and numerical analysis (with application of oscillation of vehicles and flexibly coupled machines). Numerical solutions were carried out by finite element method (FEM) on a simple model and experimental solutions on laboratory model of a mechanical system. The aim of the work was to create a numerical model and its solution using the finite element method. The experimental solution was used to verify the numerical model.
Evaluation of Operational Testing of Agricultural Trailer
Authors: Uhlíř Roman , Mossóczy Pavel , Malý Pavel
Published: December 2013

Article summarizes evaluation of operational testing of developed agricultural trailer. Measurement was made to determine operating load of trailer. Experiment was made in static and dynamic mode. Sensors were installed on front hitch and selected components of axle and frame of trailer. Furthermore, this report describes comparison of results of FEM analysis and experimental measurement.
Influence of Water Content in the Hardened Cement Paste Mixtures with Different Proportion of Fly Ash on the Material and Mechanical Properties
Authors: Zobal Ondřej , Padevět Pavel
Published: December 2013

Above average amount of fly ash production in the Czech Republic compels us to process it. Part of this waste material has some potential for use in various industries. The largest part is used in construction. One option is the use of larger replacement of cement with fly ash than as required by current standards. This paper is dedicated to the cement paste with different fly ash cement replacement. Specifically, are observed properties of hardened mixtures depending on the water content. There are presented the results of measurements of volume density and compressive strength.
A Modified Strip Method to Speed up the Tangential Stress between Wheel and Rail Calculation
Authors: Lack Tomáš , Gerlici Juraj
Published: December 2013

The articles deals with the way of calculation of tangential stresses over non-elliptical contact patch, where is possible to utilize with advantage the Kalkers simplified method FASTSIM. This method named FASTSTRIP is adapted for non-elliptical contact area calculated by means of the Strip method. This method is almost quick as FASTSIM and the results are similar to the CONTACT results. This method may be useful for rail vehicles in track dynamics computation.
Realistic Simulation of Railway Operation on the RAILBCOT Test Stand
Authors: Gerlici Juraj , Lack Tomáš , Harušinec Jozef
Published: December 2013

The aim of the article is to present the necessity of completion of the test stand of brake components of railway vehicles with the equivalent railway operation load simulator for the research of the wheel wear on it. The other aim of presented research needs is to perform the analysis of the equivalent conicity as a parameter for the rail vehicles in operation ride properties prediction. The sub aims are the change of frame, wheel, braking forces load via SIMRAIL simulator program load collection performance.
Mechanical Resistance of Triple Glass Facade Panels
Authors: Bouška Petr , Pukl Radomír , Špaček Miroslav , Vokáč Miroslav , Bittner Tomáš
Published: December 2013

Loading tests of triple glazed facade panels with dimensions of 1.5 x 2.64 m were carried out. The purpose of the tests was to examine mechanical resistance of the glass panes, namely the deformations caused by a local load, to determine degree of interaction between the panes of triple glazing exposed to the loading action and to prove the load bearing capacity of the panels. This experimental investigations were accompanied by finite element analysis.
Based on the Orthogonal Design to Study the Design and Optimization of Material Composition for Curing Compound
Authors: Han Cong Сong , Tian Bo , Song Jing Liang , Hou Zi Yi
Published: December 2013

Wax emulsion was modified by adding high polymer latex,in order to improve the film-forming ability and sealing ability of wax emulsion,and improve the brittleness of parafilm to prevent it from cracking. By orthogonal design experiment to analysis the dosage of various materials for curing compound,and based on effective water retention and concrete compressive strength ratio the two indicators to determine the optimal mixture ratio of curing compound.
Statistical Analysis of Early-Age Crack Data from Continuously Reinforced Concrete Pavements in China
Authors: Zhang Xiao
Published: December 2013

Extensive crack width and crack spacing data from recently constructed continuously reinforced concrete pavements (CRCP) sections in China were collected and statistically analyzed in this study. A total of 29 CRCP sections were observed which lead to 1171 crack data. Kolmogorov-Smirnov test result shows that CRCP crack spacing follows a four-parameter Dagum distribution. ANOVA tests show that slab thickness does not have a significant impact on crack spacing. However, slab thickness does have a significant impact on crack width. Further ANOVA test shows that crack width reduces with the increasing of slab thickness. This preliminary result is not consistent with the crack spacing formula in MEPDG where the crack spacing is directly related to slab thickness.
Cement Concrete Pavement Condition and Construction Quality Control in Hengshui City
Authors: Yang Shui Sheng , Su Jin Cai , Yang Xiao Qian , Zhang Wei
Published: December 2013

This article overviews the general condition of roads and cement concrete in Hengshui City; Summarizes the characteristics of cement concrete pavement; Analyses the causes of current route status. Take the cement concrete pavement of Hengde Highway Jingzhou Connecting Line as an example, the article introduces the cement concrete pavement construction technology, construction quality control measures and effects, and the changes of construction quality two years after opening to traffic.
Experimental Study on Gap-Graded Concrete Mixing Uniformity
Authors: Gao Hai Peng , Tian Bo , Hou Zi Yi
Published: December 2013

Combining with the concrete mixing process of twin-shaft mixer, this paper studied the gap-graded concrete mixing uniformity variation under different time. The study found that: under different mixing time, the relative error of coarse aggregate weight in per unit volume decreases, the compressive strength of concrete specimens change from increase to decrease, and they respectively reach the minimum and maximum at 40s, according to this, we get to optimum stirring time is 30~40s; Torque can reflect the condition of concrete mixing to a certain extent, but when the torque becomes stable, it does not stand for the uniformity of concrete mixing, keep stirring about 8s, the concrete mixing will be uniform completely.
The Existence of Retrograde Orbits for the Four-Body Problem with Various Choices of Masses
Authors: Li Chong
Published: December 2013

In this paper, we study the planar Newtonian four-body problem with various choices of masses. We prove that there exist infinitely many periodic and quasi-periodic orbits with certain topological type, called retrograde orbits, that minimize the action functional on certain path spaces. On these orbits, two particles revolve around each other in one direction, while the other two particles travel on themselves orbits in opposite direction, respectively. Our proof is based on variational methods inspired by the work of Kuo-Chang Chen.
Preparation of Ni-Doped MoS2 Microsphere and its Superior Electrocatalytic Hydrogen Evolution Ability
Authors: Xie Yue Chan , Li Yue Ming
Published: December 2013

To find a cheap and effective hydrogen evolution reaction catalyst, a series of Ni-doped MoS2 microspheres consisting of MoS2 nanosheets have been prepared via hydrothermal synthesis and characterized by scanning electron microscopy (SEM), and X-ray powder diffraction (XRD). Their performance as electrochemical hydrogen evolution reaction (HER) catalyst was studied. It is found that the Ni-doped MoS2 exhibited superior electrocatalytic activity in the HER to undoped MoS2 catalysts. The overpotential of Ni-doped MoS2 has decreased compared with that of undoped sample, indicating an improved activity in HER. Furthermore, the cathodic current for the Ni-doped MoS2 catalyst is about 9 times as much as that for undoped MoS2. Based on our findings, the resulting Ni-doped MoS2 might be promising inexpensive alternative to platinum catalysts in hydrogen production.
Abnormally Fast Migration of Substance at Shock Loadings
Authors: Abylkalykova R.B. , Kveglis L.I. , Kalitova A.A. , Noskov F.M.
Published: December 2013

This research work is investigates the processes of structure formation in the samples were 110Г13Л subjected to shock loads. The processes of structure formation, initiated by shock waves are explained from the terms of new theoretical developments. Analysis of the results can be extended to a wide range of materials.
Research on Dynamic Characteristics of Anti-Reverse Valve for Hydraulic Excavator Rotary Motor
Authors: Luo Yan Lei , Xu Cong Guo , Zhang Qiu Yan
Published: December 2013

Hydraulic excavator slewing system is an important component of the excavator and its core-component is the rotary motor. When the rotary hydraulic system starts, stops, and reciprocating works, dynamic characteristic of rotary motor anti-reverse valve has a great influence for working condition of the whole system. Through researching working principle of hydraulic system anti-reverse valve, establish dynamic mathematical model of anti-reverse valve, analyze dynamic response of the model, and get the theoretical foundation of the impact of anti-reverse valve middle chamber throttle opening on hydraulic system. According to the actual working condition of the excavator slewing hydraulic system, establish the system AMESim simulation model, take different parameters of the anti-reverse valve throttle opening, conduct simulation and analysis of the anti-reverse valve characteristics, and validate throttle opening has a great influence on dynamic characteristics of the hydraulic system.
A Numerical Analysis of the Interaction between the Piston Oil-Film and the Elastic Structure in an Internal Combustion Engine
Authors: Redha Mazouzi , Ahmed Kellaci , Abdelkader Karas , Benyoucef Khelidj
Published: December 2013

The piston secondary motion significantly influences the tribologicalcharacteristics in an internal combustion engine, such as the piston slapphenomenon and the frictional power loss.An analytical treatment was conducted to investigate piston motion and a computer program was written to predict optimum designs for high mechanical efficiency. This paper focuses on an analysis of the piston dynamic response. By coupling FDM for thehydrodynamic pressure field with the FEM for the piston deformation, wenumerically approximate the lubricantstructure interaction in an internalcombustion engine.
Method for Analysis of Dynamic and Strength in Internal Combustion Engine Crankshaft
Authors: Han Ben Bao , Zhang Hong Xin
Published: December 2013

Dynamic and strength analysis of crankshaft is the basis of structural design. The paper discussed the dynamic simulation method using software of ADAMS, at same time compared the three traditional stress analysis methods: simply supported beam or continuous beam model, single crank model and overall contact model. A new method was proposed, firstly to establish the oil film model with Reynolds equation and obtain the oil film stiffness, then to treat it as the equivalent stiffness of spring impacting on shaft neck, lastly to create the finite element model of the whole crankshaft. The model will be more precisely reflect the real conditions and can be use to the optimization of crankshaft.
Interference Effect Tall Building to Fluctuations Wind Load
Authors: You Ki Pyo , Kim Young Moon , You Jang Youl
Published: December 2013

The construction of another tall building in the close vicinity of existing building may lead to a modification in its response. Therefore, the wind loads on buildings in realistic environments may be considerably different from these measured on isolated buildings. Neighboring buildings may either decrease or increase the flow-induced forces on a structure, depending mainly on the geometry and arrangement of these buildings, their orientation with respect to the direction of flow and upstream terrain conditions. In this study deals with mean and fluctuating as well as their spectra on a building due to an adjacent building of side ratio 1 for wind direction from 0 to 45 degree and separation distance between two models. Interference effects were presented in the form of interference factors. And experiments were compared to these measured on isolated building.
Complex Catalysts for Direct Synthesis of Dimethyl Ether from Synthesis Gas. Part I: Study of the Catalytic Properties
Authors: Kosova Natalia I. , Musich Pavel , Kurzina Irina A. , Vosmerikov Alexander
Published: December 2013

The results of the development of combined process for production of dimethyl ether (CuO/ZnO/Al2O3) and methanol dehydration (γ-Al2O3, zeolite (ZSM-5 type) with a silicate modulus (М) 20, 30, 60, 80, 100, and 200) are presented. The experiments on the influence of the catalysts loading and catalytic conditions were carried out (Р=3 MPa, Н2/СО=2, Т=553 К). It was established that the use of ZSM-5 zeolite catalysts with silicate modulus of 30 allows obtaining the yield of dimethyl ether up to 39%. It was stated that catalytic systems were stable during 180 h.
Physical Base of the Metallic Gradient Surface Layers of Titanium Alloys Formed under Ion Implantation
Authors: Kurzina Irina
Published: December 2013

The results of microstructure and phase composition investigations of titanium in different structural states (with average grain sizes of 0.3 μm, 1.5 μm, 17 μm, 38 μm) implanted by Al ions using the «Raduga-5» and MEVVA–V.RU sources are presented. The size, shape and localization of the formed phases (TiO2, Ti2O, TiC, Ti3Al, TiAl, Al3Ti) depend strongly on the grain size of titanium target. In polycrystalline titanium after implantation by Al-ions the secondary phases (Ti3Al, TiAl, TiO2, TiC) formed in the body of grains of titanium matrix. It is shown that the nanostructural particles of TiO2 phase are located mainly on dislocations in the body of target grains. An ordered Ti3Al phase is located at a depth of more than 200 nm in the implanted layer along the boundaries of the titanium grains. The TiAl3 phase formed on the grain boards in subnano- and microstructural state of titanium targets. The improvement of the mechanical properties of titanium due to formation of the gradient structure of ion-alloyed surface layer was obtained.
Fragmentation, Texturing and Plastic Flow in the Subsurface of Friction-Processed Copper Single Crystal
Authors: Chumaevsky Andrey V. , Lychagin Dmitry V. , Tarasov Sergei Yu. , Melnikov Alexandr
Published: December 2013

Copper single crystals grown according to the Bridgman method and having their axes [] or [11 aligned with the normal load axis were processed by dry sliding. As shown, sliding-induced severe plastic deformation occurred in the subsurface of single crystals and caused formation of a lip by mechanism of texture formation. The SEM structure of this lip was found to be composed of fragments with their shapes dependent on the single crystal orientation with respect to normal load and friction force.
Modeling the Cluster Organization of Al2O3 for Obtaining more Perfect Materials
Authors: Klishin Andrey , Kovancev Alexander , Zakutaev Alexander , Vereshchagin Vladimir
Published: December 2013

This paper considers the issues of building a model of the cluster organization of Al2O3 on principles immediately associated with the involvement of a non-Euclidian technique of describing. As a model space which most adequately describes the internal structure of a real crystal, a finite closed space with elliptic metric and constant positive Gaussian curvature (K=1) was chosen, which assumes the realization of lattice systems in compliance with Fedorov groups of transformations. An algorithm for generating the cluster structures is presented, which determines the sequence of filling of the model space with cations and anions, taking into account the symmetry of a microstructure (a Fedorov group) and the electrostatic parameters of ions. Calculations are given of the geometrical sizes of nanoand microcrystalline complexes of Al2O3, taking into account the structural features of their formation at the cluster level. Practical applications connected with improving the structural characteristics of crystalline materials are discussed.
Pattern of the B4C Ceramics Surface Deformation at Local Loading
Authors: Dvilis Edgar S. , Khasanov Oleg L. , Bikbaeva Zulfa G. , Polisadova Valentina V. , Struts Vasiliy K. , Omarov G. J. , Khasanov Alexey O.
Published: December 2013

Formation of cracks in the lateral indentation of brittle ceramic materials is described in several researches [1, 2]. Occurrence of such cracks and the associated side small cracks formed at the surface of the sample in the form of "petals" was observed and analyzed in this research on the samples of boron carbide ceramics and monocrystalline silicon. The experimental results for the determination of the sequence, the direction and nature of crack propagation, the size and shape of areas of spall fracture surface formed at indentation of monocrystalline silicon and polycrystalline boron carbide samples by scanning electron microscopy are presented. A comparison of the experimental results with the modeling results of indentation zone deformation, as well as analytical evaluation of the shapes and the maximum size of the spall fracture zones have been carried out, which showed good coincidence.
Production of Precursors for Ceramics Materials on the Base of Aluminum Nanopowders in Mixtures with Some Simple Substances
Authors: Amelkovich Yuliya A. , Nazarenko Olga B.
Published: December 2013

Chemical activity parameters for aluminum nanopowder in mixtures with zinc, graphite, silicon, iron and copper powders are explored. The study of the phase content of combustion products shows that these mixtures can be used to produce precursors for ceramic materials.
Influence of Atomic Defect on the Deformation Properties of Nanowires Subjected to Uniaxial Tension
Authors: Wang Fen Ying , Sun Wei , Dai Yan Feng , Chen Yi Wang , Zhao Jian Wei , Lin Xiao
Published: December 2013

Atomic defects play an important role in the brittle deformation of nanowires at low temperatures. With molecular dynamics simulations, we study the influence of vacancy defects on the deformation and breaking behaviors of [10 oriented single-crystal gold nanowires at 50 and 150 K. The size of the nanowire is 10a × 10a × 30a (a stands for lattice constant, 0.408 nm for gold). It is shown that good crystalline structure appears in the whole deformation process, and it is in a brittle way at low temperature. The nanowire breaking behavior is sensitive to atomic vacancies when the atomic vacancy ratio is 1% in single-layer crystalline plane. Within the limitation of vacancy-induced breaking of the nanowire, the mechanical strengths increase under atomic vacancies. However, it decreases with the defect ratio increasing.
Morphology and Magnetic Properties of NiCuZn Ferrite Synthesized by Solid-Molten Salt Method
Authors: Feng Jing , Liu Tian Di , Chen Yan , Wang Yu Ting , Ren Yue Ming , Lv Yan Zhuo , Fan Zhuang Jun
Published: December 2013

Cu doped NiCuZn ferrite Ni0.4-xCuxZn0.6Fe2O4 (x=0.16~0.28) have been prepared by the solid-molten salt method using NaCl as flux. The structure and properties were investigated by X-ray diffraction (XRD), scanning electron microscope (SEM) and vibrating sample magnetometer (VSM) techniques. It is found that addition of Cu2+ results in the particles size growing up because of the tend of crystal structure to be a normal Zn ferrite.The Ms values of NCZF are decrease gradually with increasing of Cu content. Curie temperature (Tc) increases with Cu2+ content in the range of x<0.20, and then decreasing rapidly. This can be ascribed to that the lower magnetization moment Cu2+ ion amount of B-site increasing leads to weaker super-exchange effect.
Sol-Gel Processing and Novel Physical Properties of PLZT 7/57/43 Ferroelectric Ceramics
Authors: Zheng Ke Yu , Ding Ya Li , Shao Ren Zhi
Published: December 2013

The sol-gel process was employed to prepare (Pb1-xLax)(Zr1-yTiy)O3 (PLZT) ceramics with nominal composition Pb0.93La0.07(Zr0.57Ti0.43)0.9825O3. The structure and physical properties such as dielectric, piezoelectric and ferroelectric properties were investigated. X-ray diffraction results showed that the perovskite phase PLZT was formed when the sol-gel processed powders was calcined at 600°Cfor 4 hours. nanocrystalline particles with a size of ~50nm were found. TG-DTA studies were used to analyze the thermal properties of nanopowders for understanding the reaction kinetics in them. Wafered bulk ceramic samples prepared from the sol-gel derived powders were subjected to electrical measurements, in order to determine the dielectric, piezoelectric and ferroelectric properties. The dielectric properties of the PLZTBST system are further improved and the dielectric piezoelectric properties of PLZT ceramics are found to be sensitive to the particle size of PLZT nanopowders. The dielectric piezoelectric properties of polarized PLZT ceramics can be improved with the lessening of PLZT nanopowder size. Meanwhile, the grain size of PLZT ceramics decreases.
Effect of Drawing Speed on Properties of the Anti-Reflective SiO2 Film Based on Glass
Authors: Cang Li Min , Jiang Bing Jie , Yan Tao , Wan Zhi Gang
Published: December 2013

The anti-reflective SiO2 film on glass was prepared by sol-gel process and dip-coating method.The effect of drawing speed on properties of the SiO2 film was studied. The transmittance was tested by light spectrum transmittance testing system,the thickness and refractive index of SiO2 film was tested by spectroscopic ellipsometer. With increasing of the drawing speed from 100mm/min to 300 mm/min, the average of transmittance increment at first increased and then decreased, which reached the maximum 4.24% at the speed 150mm/min. The relations among transmittance, thickness (d) and refractive index (n) of the SiO2 film was dicussed.
Research Progress of Diamond/Al Composites
Authors: Liu Yong Zheng
Published: December 2013

Due to the good physical properties of diamond, diamond/Al composites as a new generation electronic packaging material receive more and more attention. It is one of the greatest potential for the development of packaging materials. The paper on the diamond/Al composite materials research at home and abroad was summarized in detail.
Influence of Sputtering Power on Molybdenum-Doped Zinc Oxide Films Grown by RF Magnetron Sputtering
Authors: Xiu Xian Wu , Xu Li , Zhang Cheng Qiang
Published: December 2013

Molybdenum-doped zinc oxide (MZO) films have been prepared by RF magnetron sputtering on glass substrates at room temperature. The structural, electrical and optical properties of the films vary with sputtering power from 15 W to 70 W are investigated. X-ray diffraction (XRD) analysis reveals that all the films are polycrystalline with the hexagonal structure and have a preferred orientation along the c axis perpendicular to the substrate. The resistivity increases with the increase of the RF power. The lowest resistivity achieved is 5.4×10-3 Ω cm at a RF power of 15 W with a Hall mobility of 11 cm2 V-1 s-1 and a carrier concentration of 1.1×1019 cm-3. The average transmittance drops from 85% to 81% in the visible range and the optical band gap decreases from 3.26 eV to 3.19 eV with the increase of the RF power.
Effect of Magnetic Field Treatment on Dielectric Properties of LDPE Composites with Carbon Nanotube and Nanographite
Authors: Han Bao Zhong , Zhou Wei , Liu Chang Lin , Liu Dan , Wang Xiang
Published: December 2013

Magnetic phenomenon is one of the most fundamental phenomena of substances. All substances possess strong or weak magnetic property, and have different responds to external magnetic field. Development of high performance materials by using external magnetic field is an important research field of material science. In this study, a static magnetic field is applied during thermoforming processing of low density polyethylene (LDPE)/carbon nanotube (CNT), LDPE/nanographite composites. The effect of magnetic field treatment on dielectric property of these composites is investigated. Experimental results indicate that CNT and nanographite orientate in melted LDPE under the magnetic field. The electrical conductance, the dielectric constant and the dielectric loss angular tangent value of LDPE/CNT and LDPE/ nanographite composites along the magnetic field direction all increase.