雇主责任理论基础之再思考

近现代民法以个人“自负其责”为理念,但雇主要对其雇员的侵权行为承担替代责任。对此,学者提出了各种不同的理论来加以论证,然而这些理论都因其自身固有的缺陷而不能提供令人信服的解释。民事责任的财产性、雇主对雇员的监督和控制、权利和义务相一致原则、保护受害人利益的价值取向等因素应是雇主责任的理论基础。

异议股东股份收买请求权探析

异议股东收买请求权制度发源于美国,我国原公司法中没有相关规定,新公司法新增了异议股东股份收买请求权的规定。文章对异议股东股份收买请求权的历史发展、概念、我国引入该制度的必要性以及新公司法中的具体规定和不足几个方面的问题进行探讨。

Nonequilibrium Statistical Modeling of Fatigue Crack Growth Behaviour

In order to study the influence of microstructural texture on the growth of short fatigue cracks in metals, the nonequilibrium statistical theory of fatigue fracture correlating a microscopic mechanism with the macroscopic properties is modified to take into consideration the microstructural features of a material, thereby allowing a rationalisation of the experimental data of short fatigue crack growth and long fatigue crack growth. The nonequilibrium statistical theory thus developed relates the growth of cracks with a dislocation mechanism to simulate short fatigue crack growth with the long fatigue crack growth behaviour and predicts the fatigue crack growth rates throughout the fatigue lifetime. The results is finally compared with that of other fatigue theories.

Nonequilibrium Statistical Nature of Intergranular Brittle Fracture in Polycrystal

The brittle fracture probability and reliability are obtained in terms of dislocation mechanism of microcrack evolution. The statistical distribution functions and statistical deviations of elongation, strength, plastic work, crack extension force, fracture foughness, critical and crack length, can be derived in a unified fashion.

Nonequilibrium Statistical Theory of Fracture

Nonequilibrium statistical theory of fracture is a theory of fracture that macromechanical quantities can be derived from the microscopic atomic mechanism of microcrack(or microvoid)evolution kinetcs by means of nonequilibrium statistical physical concepts and methods. The microcrack evolution equation is the central equation in the theory.The coefficents of the equation, the microcrack growth rate and the microcrack nucleation rate,come from microscopic atomic mechanism.The solution of the equation connects with macromechanical quantities by the model of the weakest chain. All the other formulas and quantities, for instance, distribution function,fracture probability, reliability, failure rate and macromechanical quantities such as strength, toughness, life etc. and their statistical distribution function and statistical fluctuation are derived in a unified fashion and expressed by a few physical parameters. This theory can be widely applied to various kinds of fracture, such as the brittle, fatigue, delayed and environmental fracture of metals and structural ceramics. The theoretical framework of this theory is given in this paper.

Research on adsorption mechanism of wall climbing robots based on internally balanced theory

The internally balanced theory proposed by the Japanese researchers,solved the contradiction between adsorption ability and moving capability of the permanent magnetic adsorption mechanism.However,it still has some problems when applied to wall climbing robots.This paper analyzes and improves this theory,and the improved internally balanced theory satisfies the requirements of the adsorption mechanism significantly.Finally,a practical prototype is proposed based on this method,and both the analysis using ANSYS and the experiment results justify the design validity.

A Method Combining Numerical Analysis and Limit Equilibrium Theory to Determine Potential Slip Surfaces in Soil Slopes

This paper describes a precise method combining numerical analysis and limit equilibrium theory to determine potential slip surfaces in soil slopes. In this method, the direction of the critical slip surface at any point in a slope is determined using the Coulomb’s strength principle and the extremum principle based on the ratio of the shear strength to the shear stress at that point. The ratio, which is considered as an analysis index, can be computed once the stress field of the soil slope is obtained. The critical slip direction at any point in the slope must be the tangential direction of a potential slip surface passing through the point. Therefore, starting from a point on the top of the slope surface or on the horizontal segment outside the slope toe, the increment with a small distance into the slope is used to choose another point and the corresponding slip direction at the point is computed. Connecting all the points used in the computation forms a potential slip surface exiting at the starting point. Then the factor of safety for any potential slip surface can be computed using limit equilibrium method like Spencer method. After factors of safety for all the potential slip surfaces are obtained, the minimum one is the factor of safety for the slope and the corresponding potential slip surface is the critical slip surface of the slope. The proposed method does not need to pre-assume the shape of potential slip surfaces. Thus it is suitable for any shape of slip surfaces. Moreover the method is very simple to be applied. Examples are presented in this paper to illustrate the feasibility of the proposed method programmed in ANSYS software by macro commands.

Mechanism of energy limit equilibrium of rock burst in coal mine

With the increase of mining depth,the effect of rock burst on coal mining is becoming more and more obvious and the rock burst mechanism becomes more and more complicated.Scholars from many countries had put forward different mechanisms,but no one gave a reasonable explanation to the mechanism of rock burst.In this paper,based on the energy theories,we studied the energy limit equilibrium（ELE） of coal mine rock burst The coal seam with rock burst is divided into energy limit equilibrium zone（ELEZ）（A） and elastic zone（B）;we also determined the position where the rock burst occurs,including the roof and floor of coal seams;in addition,we derived the limit width of ELEZ and the mathematic relationship between the limit width and occurrence mechanism of rock burst：the energy difference function（EDF）,w（x） = w_j - w_p,because first-order derivative w＇（x）,is less than 0.So EDF is a monotonically decreasing function.The graph of the energy difference function was also determined, through which we analysed the occurrence mechanism of rock burst.

Application of cusp catastrophe theory to reliability analysis of slopes in open-pit mines

A method of slope reliability analysis was developed by imposing a state equation on the limit equilibrium theory, given the basis of a fixed safety factor technique. Among the many problems of reliability analysis, the most important problem is to find a performance function. We have created a new method of building a limit state equation for planar slip surfaces by applying the mathematical cusp catastrophe theory. This new technique overcomes the defects in the traditional rigid limit equilibrium theory and offers a new way for studying the reliability problem of planar slip surfaces. Consequently, we applied the technique to a case of an open-pit mine and compared our results with that of the traditional approach. From the results we conclude that both methods are essentially consistent, but the reliability index calculated by the traditional model is lower than that from the catastrophic model. The catastrophe model takes into consideration two possible situations of a slope being in the limit equilibrium condition, i.e., it may or may not slip. In the traditional method, however, a slope is definitely considered as slipping when it meets the condition of a limit equilibrium. We conclude that the catastrophe model has more actual and instructive importance compared to the traditional model.

Some Special Types of Solitary Wave Solutions for （3＋1）-Dimensional Jimbo-MiwaEquation

Using the extended homogeneous balance method, we find some special types of single solitary wave solution and new types of the multisoliton solutions of the (3+1)-dimensional Jimbo-Miwa equation.

Solitary Waves for Cubic-Quintic Nonlinear Schroedinger Equation with Variable Coefficients

The cubic-quintic nonlinear Schroedinger equation （CQNLS） plays important parts in the optical fiber and the nuclear hydrodynamics. By using the homogeneous balance principle, the bell type, kink type, algebraic solitary waves, and trigonometric traveling waves for the cubic-quintic nonlinear Schroedinger equation with variable coefficients （vCQNLS） are derived with the aid of a set of subsidiary high-order ordinary differential equations （sub-equations for short）. The method used in this paper might help one to derive the exact solutions for the other high-order nonlinear evolution equations, and shows the new application of the homogeneous balance principle.

Determination Method for Shear Strength Parameters of Rock-Soil Mixtures Using Close-Range Photogrammetry and 3-D Limit Equilibrium Theory

Using a combination of close-range photogrammetry and three-dimensional(3-D) limit equilibrium theory, a determination method for the shear strength parameters of rock-soil mixture is presented. A close-range photogrammetry method is used for measurement of the 3-D terrain of the experimental target. Auto CAD Lisp and EXCEL VBA are used to perform 3-D limit equilibrium analysis of the stability of sliding mass and perform backanalysis of shear strength parameters. The presented method was used to determine the shear strength parameters of rock-soil mixtures at the Liyuan Hydropower Station. The 3-D terrain of sliding surface could be measured notably well using of closerange photogrammetry. The computed results reveal that the cohesion and friction angle of rock-soil mixtures were 3.15 k Pa and 29.88o for test A, respectively, and 4.43 k Pa and 28.30o for test B, respectively, within the range of shear strength parameters, as determined by field and laboratory tests. The computation of shear strength parameters is influenced by the mesh grid number, especially the cohesion of the rock-soil mixture. The application of close-range photogrammetry can reduce the siteworks and improve the computational efficiency and accuracy.

Compacton, Peakon, and Foldon Structures in the （2＋1）-DimensionalNizhnik-Novikov-Veselov Equation

By the use of the extended homogenous balance method,the B(?)cklund transformation for a (2+1)- dimensional integrable model,the(2+1)-dimensional Nizhnik-Novikov-Veselov (NNV) equation,is obtained,and then the NNV equation is transformed into three equations of linear,bilinear,and tri-linear forms,respectively.From the above three equations,a rather general variable separation solution of the model is obtained.Three novel class localized structures of the model are founded by the entrance of two variable-separated arbitrary functions.

Stability analysis of a concrete gravity dam and its foundation

The stability of dams and their foundations is an important problem to which dam engineers have paid close attention over the years. This paper presented two methods to analyze the stability of a gravity dam and its foundation. The direct analysis method was based on a rigid limit equilibrium method which regarded both dam and the rock foundation as undeformable rigid bodies. In this method, the safety factor of potential sliding surfaces was computed directly. The second method, the indirect analysis method, was based on elasto-plastic theory and employs nonlinear finite element method (FEM) in the analysis of stresses and deformation in the dam and its foundation. The determination of the safety degree of the structure was based on the convergence and abrupt the change criterion. The results obtained showed that structures' constituent material behavior played an active role in the failure of engineered structures in addition to the imposed load.

Bearing characteristics of coal pillars based on modified limit equilibrium theory

There are two states for the coal-mass on the goal-side which is in stress equilibrium： the state of limit equilibrium （the bearing stress in the coal-mass equals its ultimate bearing stress） and the state of non- ultimate equilibrium （the bearing stress in the coal-mass is less than its ultimate bearing stress）. To ana- lyze the bearing characteristics of a coal pillar in the state of limit equilibrium and guide the design of pillar width, we established a mechanical analytical model of the non-ultimate equilibrium zone in the coal-mass on the goal-side combined with the limit equilibrium theory as well as adopting the methods of theory analysis and mechanical analysis based on the assumption of a state of non-ultimate equilibrium. The width correction coeffident of the limit equilibrium zone has been given. The influence of mining depth, stress concentration coefficient of the surrounding rock, the non-limit strength of the coal-mass and stability of the coal rock interface has been studied. On this basis, we have confirmed that when the width ofa longwall mining face roadway protection coal pillar is between 11.6 m and 13.16 m in No. 4 coal seam of Xinrui coal mine in Lvliang in Shanxi province the elastic core region in the coal pillar can be assured and the roadway will be located in the area of lower stress which is outside the peak stress. So the revised width of the limit eauilibrium zone is more oractical.

Local dynamic balance theory and technology of flow field in multilayer gob area

Flow field in multilayer gob area, which formed in small hiden-depth, multi-coal layer groups, close distance, hard coal layer, and hard roof, possesses characteristics such as complex, changeable and unstable. Dynamic balance theory of local flow field in multilayer gob area was built based on the realistic requirement that the serious threat on current mining coal layer by large-scale spontaneous combustion fire on close spontaneous combustion coal layer group of Datong Coal mining area at the ＇di-hard＇ conditions was caused by small coal pit mining. The kernel was in dynamic balance between flow field pressures of working face and local flow field in multilayer gob area was kept by transformation. Corresponding technology and set of devices were developed.

Suitable layout of gate roads related to slice mining in an ultra-thick unstable coal seam

We determi：ned a suitable gate road layout in slice mining in an ultra-thick unstable coal seam, using theoretical anallysis and numerical calculations. Based on plasticity theory in terms of limiting equilibrium, the width of chain pillar in the upper slice was calculated to be 18 m. The stress distribution in the chain pillar after the upper slice was mined out was described with numerical simulation. The extent of the effect of stress on the upper chain pillar on the lower solid coal was obtained on the basis of an elastic solution of a distributed force loaded on a half-plane. Three layout designs for lower gate roads were pro- posed and a stability factor was introduced to analyze the stability of the lower pillar with numerical calculation. Gate road translation was determined as the most suitable layout method, which maximizes the extraction rate on the basis of the pillar stability.

Is Terzaghi's effective stress a stress variable under seepage conditions?

From the continuum mechanics perspective, an attempt was made to clarify the role of Terzaghi's effective stress in the theoretical analysis of saturated soil subjected to seepage. The necessity of performing a coupled hydromechanical analysis to solve the seepage-deformation interaction problem was illustrated by examining the equations of static equilibrium among the effective stress, seepage force, pore-water pressure and total stress. The conceptual definition of stress variable that satisfies the principles of continuum mechanics is applied in the coupled hydromechanical analysis. It is shown that Terzaghi's effective stress is in fact not a stress variable under seepage conditions, and the seepage force acting on the soil skeleton cannot be viewed as a body force. This offers a clue to the underlying cause of a paradox between the real Pascal's hydrostatic state and the hydrostatic state predicted by a class of continuum hydromechanical theories.

（Anti-）de Sitter Black Hole Entropy and Generalized Uncertainty Principle

We generalize the method that is used to study corrections to Cardy-Verlinde formula due to generalized uncertainty principle and discuss corrections to Cardy-Verlinde formula due to generalized uncertainty principle in （anti）- de Sitter space. Because in de Sitter black hole spacetime the radiation temperature of the black hole horizon is different from the one of the cosmological horizon, this spacetime is a thermodynamical non-equilibrium spacetime.

A new calculation method for axial load capacity of separated concrete-filled steel tubes based on limit equilibrium theory

A new calculation method for axial load capacity of separated concrete-filled steel tubes based on limit equilibrium theory was proposed,which took into account the decrease of confinement effect by steel tube and the non-uniform distribution of ultimate stress in cored concrete.The accuracy of the analytical result is validated through running the numerical result by finite element method (FEM) and experimental data as well.The influences of the key parameters on the load capacity of the concrete-filled steel tube (CFST) was studied,including the separation ratio,concrete compressive strength,and steel strength.The results indicate that the load capacity of the tube increases with concrete strength and steel strength under the separation ratio less than 4%,while decreases with a higher separation ratio improved.