Applied Mechanics and Materials Vols. 105-107

Abstract: Establishing the evaluation entity scientifically is very important to regulating the environmental protection behaviour of the party and government leaders of counties and municipalities ("hereinafter referred to as "the leaders") and motivates them to protect environment. The article points out that, there is problem with the entity for evaluation of the environmental protection performance of the leaders; for example, the entity is too single; the structure of the entity is unreasonable; there is a lack of independence; the information is unsymmetrical; the entity lacks professional ability and knowledge; the scope of public participation is limited; this is because of the lack of service awareness on the part of the leaders, the public's insufficient participation under the influence of traditional culture, institutional barriers, relatively closed evaluation system, and less theoretical research and practice exploration of the evaluation entity.

Abstract: Lattice Boltzmann methods (LBM) have become an alternative to conventional computational fluid dynamics (CFD) methods for various systems. In this paper, flow field of mean flow past a circular cylinder was simulated based on the lattice Boltzmann method. The streamline of air past the cylinder illuminated that the fluid adhere on the boundary and doesn’t separate from the surface of cylinder when Re number less than 5. When Re number equal 40, flow separated to form a pair of recirculating eddies can be observed. With the Re number increasing, the trailing vortex length is growth accordingly. When Re number come up to 80, the trailing vortex begin to shed regularly. This result is consistent with the experiment data. Drag coefficient that fluid act on the surface of cylinder was calculated. The calculated results were same as the experiment data. Simulation indicate that LBM can simulate the vortex taking place and shedding effectively.

Abstract: The article discussed the advantages and disadvantages of the traditional long wall top coal caving (LTCC) first, then proposed a new technique of top coal caving with vibration. The theoretical basis of the technique was elaborated.The top coal vibration system and its control system have been designed as such when the system works, the emulsion pump station provides power for whole system, the current pulse generator provides current pulse. This technique has been applied to the 5209 top coal caving working face in Wang Zhuang coal mine (Shanxi Province). Based on the experiment, the vibration can easily destroy the arch structure which is formed during the top coal caving process. The top coal caving with vibration technique has a higher coal recovery ratio. This technique improves the top coal broken effect and lowers the waste content rate. The significant economic and social benefits proved it to be a promising technique.

Abstract: In order to effectively improve the equipment maintenance material procurement management efficiency, improve economic efficiency of using the procurement funds, strengthen mathematical theory applications in the area of procurement, the neural network used in evaluation of organizational change is one of the most effective means. In this paper, a class of stochastic Cohen–Grossberg neural networks with reaction-diffusion terms, discrete time delay and distributed time delay is investigated. First, we describe the modeling, illuminate the significance of the system and introduce some preliminary definitions and lemmas which will be employed throughout the paper. Then, by using the Lyapunov functional method, M-matrix properties, nonnegative semimartingale convergence theorem and some inequality technique, sufficient conditions are obtained to guarantee the exponential stability of the system.

Abstract: Abstract: On the basis of Reddy’s higher order shear deformation plate theory and the von Kármán’s geometry nonlinear theory, governing equations for nonlinear thermal buckling and post-buckling of cross-ply laminated composite beam subjected to a temperature rise are derived, in which the stretching-bending coupling terms produced by the non-homogenous distribution of the material properties are included. By using the shooting method to solve the corresponding nonlinear boundary value problem, numerical solutions for thermal post-buckling of cross-ply shear deformation laminated composite beam with its both ends immovably simply supported under uniform temperature rise are obtained. As an example, equilibrium paths and configurations for laminated composite beam paved in term of 0/90/0 are presented and characteristic curves of the nonlinear deformation changing with the thermal load were plotted. The effects of the geometric and physical parameters on the deformation of the beam are also examined. The theoretical analysis and numerical results show that different thermal expansion coefficient ratio, elastic moduli ratio, shear stiffness ratio will influence of the non-dimension critical buckling temperature.