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Copyright of China Mining Magazine is the property of China Mining Magazine Co., Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Chongqing University of Technology (Natural Science) is the property of Chongqing University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Advanced Engineering Science / Gongcheng Kexue Yu Jishu is the property of Advanced Engineering Science Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Sciencepaper is the property of China Sciencepaper and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

With the complex variable function method and the Schwarz-Christoffel transforma­tion, a conformal mapping function was constructed to address the anti-plane problem of regu­lar polygon holes with radial edge cracks in ID hexagonal piezoelectric quasicrystals. Firstly, the constitutive equations, equilibrium equations and geometric equations for ID hexagonal pie­zoelectric quasicrystals were employed to derive the governing equations subjected to anti-plane loading. Under the electrically nonconductive boundary conditions, the Cauchy integral formula was applied to solve the problem of an arbitrary regular polygon hole with a radial edge crack. The analytical solutions of the stress intensity factor and the electric displacement intensity fac­tor were obtained, and the numerical examples in special cases of n = 3,5,6 were demonstrated to be consistent with the existing results. The research shows that, the value of the effective in­tensity factor increases with side length a and crack length L/a. Parameter a has a significant effect on effective field intensity factor K, which is critical to damage. The results are general and suitable for calculating the effective intensity factor of an arbitrary regular polygon hole with a radial edge crack, thereby providing a good theoretical basis for engineering mechanics, material preparation and application. [ABSTRACT FROM AUTHOR]

China is the largest producer and exporter of Lentinus edodes in the world. To improve its market value, twin-screw extrusion and expansion machine has been developed to further process the Lentinus edodes. To resolve the problems of blockage, low prematurity and missing operation parameters of this machine in producing Lentinus edodes pufferent, we presented an improved twin-screw extrusion and expansion machine in this paper to lower puffer ability, improve water absorption and reduce its hardness. The equipment consists of a frame, a mixing device, a feeding device, a tempering device, a heating device, an extruding and bulking device and a rotary cutting device. It is equipped with a cooling system, a lubricating system, a transmission system, a control system and a pressure detection system. Design and determination of the anti-blocking device for the feed mixing device, the pre-maturing and tempering device, and the structural parameters of the twin screw were conducted. In order to investigate the influence of operation parameters on swelling performance of the product, the Box-benhnken combined test method was used to study the working parameters of the double screw extruder. The effects of screw speed, extrusion temperature and water content on the swelling rate, hardness, brittleness and water absorption of the expanded product were analyzed, and the determinants were optimized. The results showed that, based on the level of the significance, 1) factors affecting the expansion rate were ranked in material water content > expansion temperature > screw speed, 2) factors affecting hardness were ranked in material moisture content > screw speed > swelling temperature, 3) factors affecting brittleness were ranked in material moisture content > screw speed, 4) factors affecting water absorption were ranked in material moisture content > swelling temperature > screw speed. The optimal operating parameters were: screw speed 167.23 r/min, swelling temperature 151.68℃, material moisture content 16.83%. Under these conditions, the swelling rate, hardness, brittleness and water absorption of the product were increased by 4.04%, 18.61 N, -8.46 mm/cm2 and 313.86% respectively, compared to the traditional machine. Practical application of the optimized parameters revealed that the error between the optimized productivity and real productivity was less than 4%, with the maximum productivity being 165 kg/h. Compared with the existing equipment in the laboratory at School of Mechanical Engineering in Yangzhou University, the designed machine increased the swelling rate, brittleness, water adsorption and brittleness by 25.00%, 40.55% and 62.35% respectively, while reducing the hardness by 48.21%. Therefore, the design of this machine can provide relatively mature technical equipment for the development of mushroom swelling products. [ABSTRACT FROM AUTHOR]

It is an effective way to transform scientific research achievements into teaching project examples, to make students participate in the development process of CDIO project and to improve students innovation and entrepreneurship ability. Viscometer development based on miniaturized, compact 3D printing flexure hinge and optical fiber displacement sensor can measure viscosity and elasticity of viscoelastic fluid. As a practice teaching example, it fuses precision machinery, engineering mechanics, sensor, digital signal processing and other professional knowledge, and involves in 3D graphics, finite element simulation, Matlab, Lab view software, and has many advantages, such as comprehensive knowledge, significant, innovative, modular analysis and design, etc. Using CDIO teaching mode, the project makes students grasp the basic rule and process of scientific research project, understand the scientific research methodology, and make use of professional knowledge and systems thinking to decompose goals, identify key technology and to design solutions. [ABSTRACT FROM AUTHOR]

During the launching process of electromagnetic rails, the armature slides along the rails, and high-temperature friction occurs on the rail-armature interface, so the rail is liable to damages due to wear, erosion and strength loss. Thus, copper-based composite materials are used to enhance the strength and ablation resistance of the inner surface of the rail. The steel- copper composite electromagnetic rails were studied. While electrified, the armature and the rails constituted a closed loop, and a strong magnetic field formed between the rails, then the armature moved along the rails under the pushing force from the magnetic field. In this process, due to the interaction between the current and the magnetic field, a repulsive force acted be­tween the 2 rails. At the same time, the armature was greatly heated by the strong current, and the thermal expansion of the armature brought extrusive forces on the lateral rails. According to this force condition, the composite rails were simplified as a mechanical model of double-layer beams under a uniformly distributed load and a rigid stamp force. The forces by the armature on the rail surface were solved and the stress state of the composite layers was obtained with the basic equations in the elastic half plane. Hence, the polynomial fitting of the copper-steel inter­facial stress was got with the MATLAB software. The boundary conditions of the copper layer surface were determined, the local stresses of the copper layer surface were analyzed, and the relationships between the stress and the loading voltage, as well as the thickness ratios of com­posite layers, were acquired. The results provide a foundation for the strength design of com­posite launching electromagnetic rails [ABSTRACT FROM AUTHOR]

The liquid bridge is the main reason for image distortion of an atomic force microscope (AFM) in the atmospheric ambiance, meanwhile the capillary force resulting from the liquid bridge dominates the adhesion force in this condition. Investigation of the liquid bridge is of great importance to understand the imaging mechanisms and the sample properties. Herein, 3 different growth processes were presented and analyzed for the growth mechanisms of the liquid bridge in AFMs, including the squeezing process, the capillary condensation and the motion of thin liquid film. The characteristic equilibrium times of the 3 processes are of great importance to the understanding of the liquid bridge's growth dynamics. The equilibrium time of the squeezing process depends on the contact mode, that of the capillary condensation is at the μs order of magnitude and that of the liquid film motion varies drastically with different viscosities of the liquid film. The contribution of the corresponding 3 growth mechanisms to liquid bridge volume, capillary force and energy dissipation was comaratively studied in different AFM operation modes. [ABSTRACT FROM AUTHOR]

The Falkner-Skan flow equation is a strongly nonlinear differential equation, which describes the flow around a wedge. In order to overcome the difficulties originated from the semi-infinite interval and asymptotic boundary condition in this flow problem, transformations were simultaneously conducted for both the independent variable and the correponding function to convert the problem to a 2-point boundary value one within a finite interval. The deduced new-form nonlinear differential equation was subsequently solved with the fixed point method (FPM). The present analytical results obtained with the FPM agree well with the previous referential numerical ones. The accuracy of the present solution is conveniently improved through iteration under the FPM framework, which shows that the FPM makes a promising tool for nonlinear differential equations. [ABSTRACT FROM AUTHOR]

The basic theory of unstressed state control method was addressed through introduction of the principle of co-rotational formulation. Based on the co-rotational formulation analysis, the differences of the reference frame between the traditional incremental method and the unstressed state control method were discussed, and the basic equations of the unstressed state control method were derived. The resulting formulas show that the co-rotational formulation procedure is appropriate for analysis of the basic equations of the unstressed state control method, and the derivation process has a clear mechanics concept. Moreover, the case analysis demonstrates validity and advantage of the co-rotational formulation in application of the unstressed state control method. [ABSTRACT FROM AUTHOR]

To research the formation and variation mechanism of the additional load,a mathematical model of the additional load is established,and the differential and integral formula of additional load are derived. The main factors which affect the additional load are obtained,such as pressure in adaptive base, horizontal projected area of upper face,and horizontal projected area of touchdown zone. The theoretical formula of additional load is verified by the numerical model. The analytical solution is well consistent with the numerical solution,and the relevant error is less than 1. 9%. The relationship between the integral area and the expression form of the additional load is studied according to the integral formula of the additional load. The results indicate that there exists corresponding relationship between the direction of the additional load and the kind of the integral area,and that situation of that the direction is opposite in some areas may happen. When the ground subsidence is small or the shear failure exists in some area, the additional load may stays the same. When the ground subsidence is large,the amplitude and direction of the additional load may change. [ABSTRACT FROM AUTHOR]

For morphing flight vehicles, the changes of sweep angle and span have great influence on key parameters such as aerodynamic forces, inertial moments, pressure center and gravity center. A dynamic model of morphing vehicle with variable sweep and span is established based on Newton-Euler method. The additional force and moment generalized by morphing are deduced. The dynamic response aroused by morphing is studied using decoupled longitudinal equations and quasi-steady aerodynamic model. The results indicate that the changes of sweep and span influence the dynamic characteristics severely; however, the effect of different morphing speed is not remarkable. Appropriate strategy of morphing could weaken the fluctuation of dynamic parameters and relieve the burden of control system. [ABSTRACT FROM AUTHOR]

A mechanical-electrical-hydraulic coupling dynamic model of ramming system was built by using MSC. Adams and Easy5. Its confidence was proved by using VV&A. A virtual prototyping-Monte Carlo simulation-support vector machine (VP-MCS-SVM) method was proposed to reduce the large computational volume of MCS method in solving the random dynamics of complex system, and the random dynamics simulation of ramming system was carried out efficiently and precisely. Based on the theory of statistic inference and reliability, the action reliability of ramming system was analyzed and the distribution parameters' shift was considered. It provides a new idea for the action reliability evaluation for large complex system. [ABSTRACT FROM AUTHOR]

Considered the coupling effects of classical interior ballistic equations and band's engraving process, the solution of interior ballistic equations was taken as the boundary condition of the simulation for engraving process, and the results of the simulation were taken as the initial conditions for the interior ballistic equations in the next step iteratively. A coupled constitutive model considered visco-plasticity and ductile damage and based on continuum damage mechanics was introduced to simulate the band's damage process. The Von Mises yield criterion, Johnson-Cook hardening model and Johnson-Cook fracture strain model were adopted, and the model considered large strain, high strain-rate, thermal softening and damage evolution. The model was implemented in the explicit finite element code by using VUMAT subroutine of Abaqus\Explicit module. The band's engraving processes of two different bore structures were simulated, and the influences of different engraving conditions on the stress state of the band were analyzed. The effects of band's stress state and bore structure on the interior ballistic performances were pointed out. It is very useful for the design of bore structure. [ABSTRACT FROM AUTHOR]

The hydro-ballistic trajectory and cavity of the half sphere bullet and general pistol bullet are experimentally researched by a high speed digital video recorder when they entrain water at six speeds and at two depths of water. The experimental results show that the shape of a bullet has important influence upon the hydro-ballistics stability of the bullet motion. The hydro-ballistics of the half sphere bullet is stability, but the stability is not well for pistol bullet. The shape of pistol bullet cavity is "lotus root". The velocity attenuation law of the bullet have similarity at a range of bullet entraining water speeds. The velocity attenuation law in water has similarity for both of the half sphere and pistol bullet. The speed of bullet in water decreases very quickly. A calculation model is established to predict the velocity attenuation law of the bullet. The calculation results are compared with the experimental results, they agree well with each other. [ABSTRACT FROM AUTHOR]

The magnetic-elasticity buckling problem of a current plate with applied mechanical load in a magnetic field is studied by using a special function, Mathieu function. Based on the non-linear magneto-elastic equations of motion, physical equations, geometric equations, expressions of Lorenz forces and electro-dynamic equations, the magneto-elastic dynamic buckling equation of a current plate under the action of mechanical load in a magnetic field is derived. Then the buckling equation is transmitted into a standard form of the Mathieu equation by using Galerkin method. Thus, the solving of buckling problem is changed to the solving of Mathieu equation. According to the solution' s stability of Mathieu equation and the eigenvalue relation of the coefficients λ and η in Mathieu equation, the criterion equation of the buckling problem is also presented here. And the map of the stability areas is shown when the coefficient η is small exciter. [ABSTRACT FROM AUTHOR]