螺位错场的非线性力学解

本文以非线性连续体几何场论为理论基础，分析了无限大体中一个螺位错引起的应力场。结果揭示了非线性高阶效应的影响。当不考虑高阶效应时，所求得的应力场可退化为经典线弹性理论的结果。本文还对螺位错引起的体力矩场进行了求解。获得了无限大体中单个螺位错引起的体力矩的解析表达式。作为理论结果的应用，本文研究了界面附近螺位错的应力场和体力矩场。揭示了它们对界面力学性能的影响。

Evolution of Cooperation in Public Goods Games

We investigate the evolution of cooperation with evolutionary public goods games based on finite populations, where four pure strategies： cooperators, defectors, punishers and loners who are unwilling to participate are considered. By adopting approximate best response dynamics, we show that the magnitude of rationality not only quantitatively explains the experiment results in [Nature （London） 425 （2003） 390], but also it will heavily influence the evolution of cooperation. Compared with previous results of infinite populations, which result in two equilibriums, we show that there merely exists a special equilibrium cooperation. In addition, we characterize that loner＇s and the relevant high value of bounded rationality will sustain payoff plays an active role in the maintenance of cooperation, which will only be warranted for the low and moderate values of loner＇s payoff. It thus indicates the effects of rationality and loner＇s payoff will influence the cooperation. Finally, we highlight the important result that the introduction of voluntary participation and punishment will facilitate cooperation greatly.

Effective-Field Theory for Kinetic Ising Model on Honeycomb Lattice

As an analytical method, the effective-field theory （EFT） is used to study the dynamical response of the kinetic Ising model in the presence of a sinusoidal oscillating field. The effective-field equations of motion of the average magnetization are given for the honeycomb lattice （Z = 3）. The Liapunov exponent A is calculated for discussing the stability of the magnetization and it is used to determine the phase boundary. In the field amplitude ho / ZJ-temperature T/ZJ plane, the phase boundary separating the dynamic ordered and the disordered phase has been drawn. In contrast to previous analytical results that predicted a tricritical point separating a dynamic phase boundary line of continuous and discontinuous transitions, we find that the transition is always continuous. There is inconsistency between our results and previous analytical results, because they do not introduce sufficiently strong fluctuations.

Fluid solid coupling model based on endochronic damage for roller compacted concrete dam

According to the characteristics of thin-layer rolling and pouting construction technology and the complicated mechanical behavior of the roller compacted concrete dam （RCCD） construction interface, a constitutive model of endochronic damage was established based on the endochronic theory and damage mechanics. The proposed model abandons the traditional concept of elastic-plastic yield surface and can better reflect the real behavior of rolled control concrete. Basic equations were proposed for the fluid-solid coupling analysis, and the relationships among the corresponding key physical parameters were also put forward. One three-dimensional finite element method （FEM） program was obtained by studying the FEM type of the seepage-stress coupling intersection of the RCCD. The method was applied to an actual project, and the results show that the fluid-solid interaction influences dam deformation and dam abutment stability, which is in accordance with practice. Therefore, this model provides a new method for revealing the mechanical behavior of RCCD under the coupling field.

Dynamic characteristics of a WPC-comparison of transfer matrix method and FE method

To find the difference in dynamic characteristics between conventional monohull ship and wave penetrating catamaran (WPC), a WPC was taken as an object; its dynamic characteristics were computed by transfer matrix method and finite element method respectively. According to the comparison of the nature frequency results and mode shape results, the fact that FEM method is more suitable to dynamic characteristics analysis of a WPC was pointed out, special features on dynamic characteristics of WPC were given, and some beneficial suggestions are proposed to optimize the strength of a WPC in design period.

Research on reliability of turbine disk with random structure

Structure of a rotor and other design parameters are all viewed as constant using finite element software to analyze reliability of the rotor. In this case,reliability analysis of the rotor can't be realized for design parameters as random. Based on theory of elastic mechanics,starting with the micro element of the rotor,stress formulas on arbitrary point of turbine disc with equal and variable thickness are deducted under the influence of centrifugal force and temperature field on rotor system simultaneously. Considering the random of structural size of the turbine rotor,temperature stress,rotating speed,external loads and material strength,the reliability of a rotor is studied with stress-strength interference model,integral stochastic finite element method(ISFEM) and Gram-Charlier series method,and random structural reliability of the rotor is computed with higher accuracy.

NUMERIC ANALYSIS ON INFLUENCED FACTORS OF DISCONTINUOUS SURFACE DEFORMATION DUE TO STEEPLY-INCLINED SEAM MINING

This paper deals with the shape and influenced factors of surface non-continuous deformation due to mining. With finite element method, analysis are made to derive the relations between discontinuous deformation and mining affection, weak plane’s position & thickness, and mechanical property of weak-plane medium. The mutual affection of multiple weak-planes is also discussed. The results of the paper lay a foundation for constructing the calculation method of surface discontinuous deformation.

Parton physics from large-momentum effective field theory

Parton physics,when formulated as light-front correlations,are difficult to study non-perturbatively,despite the promise of lightfront quantization.Recently an alternative approach to partons have been proposed by re-visiting original Feynman picture of a hadron moving at asymptotically large momentum.Here I formulate the approach in the language of an effective field theory for a large hadron momentum P in lattice QCD,LaMET for short.I show that using this new effective theory,parton properties,including light-front parton wave functions,can be extracted from lattice observables in a systematic expansion of 1/P,much like that the parton distributions can be extracted from the hard scattering data at momentum scales of a few GeV.

Modeling and performance analysis of energy selective electron (ESE) engine with heat leakage and transmission probability

A model of an energy selective electron (ESE) engine with linear heat leakage and Lorentzian transmission probability is established in this paper.The expressions for the main performance parameters of the ESE engine operating as a heat engine or a refrigerator are derived by using the theory of finite time thermodynamics.The optimum performances of the ESE engine are explored and the influences of the heat leakage,the central energy level of the resonance,and the width of the resonance on the performance of the ESE engine are analyzed by using detailed numerical examples.The optimal operation regions of power output and efficiency (or cooling load and coefficient of performance (COP)) are also discussed.Moreover,the performances of the ESE engine with Lorentzian transmission probability are compared with those with rectangular transmission probability.It is shown that the power output versus efficiency (or cooling load versus COP) characteristic curves with and without heat leakage are all closed loop-shaped ones.The efficiency (or COP) of the ESE engine decreases as the heat leakage increases.It is found that as the resonance width increases,the power output and efficiency (or cooling load and COP) increase to a maximum and then decrease due to the finite range of energies which contribute positively to the power generation or refrigeration in the electron system.Especially,when heat leakage is taken into account,the characteristic curves of maximum efficiency (or maximum COP) versus half resonance width are parabolic-like ones,which are quite different from the monotonic decreasing characteristic curves obtained in previous analyses without considering heat leakage.The results obtained in this paper can provide some theoretical guidelines for the design and operation of practical electron energy conversion devices such as solid-state thermionic refrigerators.

Power output analyses and optimizations of the Stirling cycle

Based on the finite time thermodynamics theory,the entransy theory and the entropy theory,the Stirling cycles under different conditions are analyzed and optimized with the maximum output power as the target in this paper.The applicability of entransy loss(EL),entransy dissipation(ED),entropy generation(EG),entropy generation number(EGN) and modified entropy generation number(MEGN) to the system optimization is investigated.The results show that the maximum EL rate corresponds to the maximum power output of the cycle working under the infinite heat reservoirs whose temperatures are prescribed,while the minimum EG rate and the extremum ED rate do not.For the Stirling cycle working under the finite heat reservoirs provided by the hot and cold streams whose inlet temperatures and the heat capacity flow rates are prescribed,the maximum EL rate,the minimum EG rate,the minimum EGN and the minimum MEGN all correspond to the maximum power output,but the extremum ED rate does not.When the heat capacity flow rate of the hot stream increases,the power output,the EL rate,the EG rate and the ED rate increase monotonously,while the EGN and the MEGN decrease first and then increase.The EL has best consistency in the power output optimizations of the Stirling cycles discussed in this paper.

Progress in optimization of mass transfer processes based on mass entransy dissipation extremum principle

The mass entransy and its dissipation extremum principle have opened up a new direction for the mass transfer optimization. Firstly, the emergence and development process of both the mass entransy and its dissipalion extremum principle are reviewed. Secondly, the combination of the mass entransy dissipation extremum principle and the finite-time thermodynamics for opti- mizing the mass transfer processes of one-way isothermal mass transfer, two-way isothermal equimolar mass transfer, and iso- thermal throttling and isothermal crystallization are summarized. Thirdly, the combination of the mass entransy dissipation ex- tremum principle and the constructal theory for optimizing the mass transfer processes of disc-to-point and volume-to-point problems are summarized. The scientific features of the mass entransy dissipation extremam principle are emphasized.

A new interpretation of internal-variable theory in finite thermo-viscoelasticity

Based on the non-equilibrium thermodynamics,an internal-variable theory in thermo-viscoelasticity at finite deformation was proposed by Huang in 1999.In this theory,a modified stretch of the molecular chain was introduced,and hence the molecular network model in rubber elasticity was extended to take into account the viscous and thermal effects of the material.The viscous dissipation of the material can then be described by means of these internal variables,which appear in the expression of the modified stretch.In order to give a clearer explanation on the physical implication of the internal variables,a connection between the internal-variable theory and theoretical formulation based on the multiplicative decomposition of the deformation gradient in existing literature is presented in this paper,which allows the above internal-variable theory to be more systematic.