Molecular field theory analysis of R3Co11B4 compounds

The temperature dependence of magnetization of the R₃Co₁₁B₄ compounds has been analysed using the two-sublattice molecular field theory. The molecular field coefficients, n_CoCo, n_RCo, n_RR, have been calculated by a numerical fitting process. The analytic form of the exchange field H_R(T) varying with temperature for each of the R₃Co₁₁B₄ compounds is presented, and some results are discussed.     

HSAB theory and acute metal ion toxicity and detoxification processes

The theory of hard and soft acids and bases (HSAB theory) can be used to correlate information on metal ion toxicity and the relative effectiveness of therapeutic chelating agents with parameters used to characterize “hardness” and “softness”. HSAB considerations appear to govern at least some of the non-specific aspects of metal ion toxicity. They are also useful in explaining some of the known patterns of metal ion detoxification and how situations arise where the rate behavior, rather than equilibrium factors, may be of importance in determining the success of a given chelating agent in enhancing the excretion of a given toxic metal. In many instances an effective evaluation of the applicability of HSAB theory to such systems is prevented by the limited availability of the necessary biological data. The correlations found can be used to estimate the toxicity of chemical species for which HSAB parameters but not toxicity data are available, as well as to preselect the most promising chelating agents for therapeutic testing.     

$\mathbb{Z}_+^k$-作用的方向原像熵

In this paper,a new type of entropy,directional preimage entropy including topological and measure theoretic versions for■-actions,is introduced.Some of their properties including relationships and the invariance are obtained.Moreover,several systems including■-actions generated by the expanding maps,■-actions defined on finite graphs and some infinite graphs with zero directional preimage branch entropy are studied.     

Optimal investment and reinsurance for an insurer under Markov-modulated financial market

This study examines optimal investment and reinsurance policies for an insurer with the classical surplus process. It assumes that the financial market is driven by a drifted Brownian motion with coefficients modulated by an external Markov process specified by the solution to a stochastic differential equation. The goal of the insurer is to maximize the expected terminal utility. This paper derives the Hamilton–Jacobi–Bellman (HJB) equation associated with the control problem using a dynamic programming method. When the insurer admits an exponential utility function, we prove that there exists a unique and smooth solution to the HJB equation. We derive the explicit optimal investment policy by solving the HJB equation. We can also find that the optimal reinsurance policy optimizes a deterministic function. We also obtain the upper bound for ruin probability in finite time for the insurer when the insurer adopts optimal policies.     

Risk application research on risk warning mechanism in organizational crisis management – taking Vanke Real Estate Co. Ltd., as an example

With the changes in domestic and international economic environment, the increasingly dynamic and complex environment has become the pressures and challenges that enterprises have to face. From the perspective of healthy development of companies in long-term running, it’s urgent to build an enterprise risk warning system.This paper takes daily operational risks and crises in Chinese enterprises as the research object, synthetically using the relevant knowledge of risk management theory, early warning management theory, the strategic management theory, the analytic hierarchy process, and fuzzy mathematics to build a daily management risk early warning system for Chinese enterprises. By constructing the system, the enterprises can make dynamic tracking for different stages in business management, so as to realize the risk before crises, take some actions during and after crises.     

The influence of interface disorder on the electronic structure of a quantum well: A theoretical study

We present a theoretical analysis of the lowest electronic states in a quantum well whose thickness takes the random values of n−1, n or n+1 monolayers. We calculate the average electronic propagator using a two dimensional muffin-tin version of the coherent potential approximation. For scarce but large “terraces”, the electronic structure is strongly perturbed and the density of states at zero wave vector exhibits three peaks. For abundant but small terraces the nominal n-monolayers electronic structure is recovered. This should allow one to characterize, from luminescence experiments, the statistics of interface disorder in different growth conditions.