公司治理的系统依赖性:一个内生化分析框架

公司作为与市场相替代的一种产权交易制度,只有注入合理的治理结构,充分响应交易各方的利益,才能在降低交易费用方面比市场更具优势,公司才具有稳定性。公司治理的本质就是通过特定的产权交易制度安排来协调交易各方的利益,降低交易成本,提高交易效率。同时,作为内生于社会经济契约系统中的一个子契约,公司治理结构的选择依赖于制度、行业特征以及公司自身属性等因素,并在与这些因素的相互作用中动态演进。

基于摩擦学特性的边坡问题思考

分析了边坡稳定性问题与摩擦行为的关系,指出了边坡稳定性分析中需要注意的几个问题,同时探讨了自组织理论在边坡稳定分析中的适用性。认为:边坡稳定对系统和时间的依赖性都可以用摩擦学的内容来解释;系统依赖性揭示了边坡系统不同部位的力学性质;时间依赖性揭示了摩擦时变系统的生命周期正好与边坡的变形阶段相对应,存在着蠕变、等速变化、加速变化等阶段。

化脓性链球菌碳水化合物代谢及毒力影响研究进展

化脓性链球菌(Streptococcus pyogenes)是一种引起人类多种疾病的革兰阳性病原菌,在宿主体内获取营养物质是其生存和繁殖进而损伤宿主的前提,其中碳水化合物是营养物质的主要成分。化脓性链球菌具有糖酵解、非完全糖酵解及磷酸烯醇丙酮酸依赖性磷酸转移酶系统(Phosphoenol pyruvate-dependent phosphotransferase pathway,PTS)等的葡萄糖、乳糖和苹果酸摄取途径,具有碳分解代谢物阻遏、分解代谢物控制蛋白A和PTS等碳代谢调节方式,并且宿主体内葡萄糖、乳糖和苹果酸浓度的变化都会使其毒力发生改变。主要对化脓性链球菌碳水化合物摄取途径、代谢调节和对毒力影响等方面进行综述,为化脓性链球菌碳水化合物摄取所影响的调控网络和代谢通路的深入研究提供依据。

电子文件的种类与特性

目前,信息技术日新月异,电子文件渐渐地无可争议地成为信息社会的主要文件形式,并将成为档案部门管理的主要档案类型。然而,电子文件的产生机理、载体形式等与传统档案有着完全不同的特点,不可能完全照搬传统档案管理理论。因此,了解、掌握电子文件的种类与特性,对信息时代档案的管理非常重要。一、电子文件的种类 1、文本文件通过软件的编辑,生成由ASCII标准代码、GB2312-80标准汉字代码等,按相应文件格式标准构成存储内容的文件,又分为字处理文件、数据文件、源程序文件。字处理文件是指使用文字处理系统生成的,由字符、制表符、段落符等构成的文件。字处理系统是现代办公自动化中最常见的电子信息系统。

Quantum Systems Connected by a Time-Dependent Canonical Transformation

We study both classical and quantum relation between two Hamiltonian systems which are mutually connected by time-dependent canonical transformation. One is ordinary conservative system and the other is timedependent Hamiltonian system. The quantum unitary operator relevant to classical canonical transformation between the two systems are obtained through rigorous evaluation. With the aid of the unitary operator, we have derived quantum states of the time-dependent Hamiltonian system through transforming the quantum states of the conservative system. The invariant operators of the two systems are presented and the relation between them are addressed. We showed that there exist numerous Hamiltonians, which gives the same classical equation of motion. Though it is impossible to distinguish the systems described by these Hamiltonians within the realm of classical mechanics, they can be distinguishable quantum mechanically.

Generalized Harmonic Oscillator and the Schrdinger Equation with Position-Dependent Mass

We study the generalized harmonic oscillator that has both the position-dependent mass and the potential depending on the form of mass function in a more general framework. The explicit expressions of the eigenvalue and eigenfunction for such a system are given, they have the same forms as those for the usual harmonic oscillator with constant mass. The coherent state and its properties corresponding effective potentials for several mass functions, for the system with PDM are also discussed. We give the the systems with such potentials are isospectral to the usual harmonic oscillator.

Dependency-based importance measures of components in mechatronic systems with complex network theory

To compensate for the limitations of previous studies,a complex network-based method is developed for determining importance measures,which combines the functional roles of the components of a mechatronic system and their topological positions.First,the dependencies among the components are well-represented and well-calculated.Second,a mechatronic system is modeled as a weighted and directional functional dependency network(FDN),in which the node weights are determined by the functional roles of components in the system and their topological positions in the complex network whereas the edge weights are represented by dependency strengths.Third,given that the PageRank algorithm cannot calculate the dependency strengths among components,an improved PageRank importance measure(IPIM)algorithm is proposed,which combines the node weights and edge weights of complex networks.IPIM also considers the importance of neighboring components.Finally,a case study is conducted to investigate the accuracy of the proposed method.Results show that the method can effectively determine the importance measures of components.

Thermal preference, thermal tolerance and the thermal dependence of digestive performance in two Phrynocephalus lizards （Agamidae）, with a review of species studied

We reported data on thermal preference, thermal tolerance and the thermal dependence of digestive performance for two Phrynocephalus lizards （P. frontalis and P. versicolor）, and compared data among lizards so far studied worldwide. Mean values for selected body temperature （Tsel） and critical thermal maximum （CTMax） were greater in P versicolor, whereas mean values for critical thermal minimum （CTMin） did not differ between the two species. The two lizards differed in food intake, but not in food passage time, apparent digestive coefficient （ADC） and assimilation efficiency （AE）, across the experimental tem- peratures. Four general conclusions can be drawn from published data. Firstly, thermal preference and thermal tolerance differ among lizards differing in distribution, temporal activity pattern and habitat use. Lizards in thermally more variable regions are better able to tolerate low and high temperatures. Diurnal lizards generally select higher body temperatures than nocturnal lizards, and lizards using habitats with direct sun exposure generally selected higher body temperatures and are better able to tolerate high temperatures. Secondly, CTMax is positively correlated with Tsel. Lizards more likely exposed to extremely high temperatures while active select higher body temperatures than those using shaded habitats. Thirdly, the effects of body temperature on food intake, food passage time, ADC and AE differ among lizards, but it seems to be common among lizards that ADC and AE are less thermally sensitive than food intake and food passage time. Lastly, ADC is dependent on the type of food ingested, with insectivorous lizards digesting food more efficiently than herbivorous lizards

Quantitative sufficient conditions for adiabatic approximation

Two linear In this letter, we prove the following conclusions by introducing a function Fn（t）： （1） If a quantum system S with a time-dependent non-degenerate Hamiltonian H（t） is initially in the n-th eigenstate of H（0）, then the state of the system at time t will remain in the n-th eigenstate of H（t） up to a multiplicative phase factor if and only if the values Fn（t） for all t are always on the circle centered at 1 with radius 1; （2） If a quantum system S with a time-dependent Hamiltonian H（t） is initially in the n-th eigenstate of H（0）, then the state of the system at time t will remain c-uniformly approximately in the n-th eigenstate of H（t） up to a multiplicative phase factor if and only if the values F,（t） for all t are always outside of the circle centered at 1 with radius 1-ε. Moreover, some quantitative sufficient conditions for the state of the system at time t to remain ε-uniformly approximately in the n-th eigenstate of H（t） up to a multiplicative phase factor are established. Lastly, our results are illustrated by a spin-half particle in a rotating magnetic field.

Discovery of a new nontoxic cuprate superconducting system Ga-Ba-Ca-Cu-O

Superconductivity is observed in a new nontoxic cuprate system Ga-Ba-Ca-Cu-O,with T_c=82 K for Ga Ba_2Ca_5Cu_6O_(14+δ)(Ga-1256)and T_c=116 K probably for Ga Ba_2Ca_3Cu_4O_(10+δ)(Ga-1234)or Ga Ba_2Ca_2Cu_3O_(8+δ)(Ga-1223),respectively.All compounds are fabricated by solid state reaction method under high pressure and high temperature.Samples are characterized by resistivity,magnetization and X-ray diffraction(XRD)measurements.The temperature dependence of magnetization measured in both zero-field-cooled and field-cooled processes on one sample(S1)shows two superconducting transitions at about 82 K and113 K.The estimated shielding fraction for the phase with T_cof 82 K is about 67%,while the fraction for another phase with T_(c )of 113 K is quite small.The XRD Rietveld refinement for S1 indicates two main phases existing in the sample,Ga-1256 with fraction of about 58%and non-superconducting Ca_(0.85)Cu O_2with fraction of about 42%respectively.Thus,we can conclude the superconducting phase with transition temperature of 82 K is due to Ga-1256.The resistivity measurement also confirms the superconductivity for S1,and the resistivity reaches zero at about 82 K.The temperature dependence of magnetization for another sample(S2)shows much higher superconducting shielding fraction for the phase with T_cof 116 K,which may be a promising prospective for the synthesis of Ga-1234 or Ga-1223 phase.

ROBUST H_∞ FILTERING FOR UNCERTAIN DISCRETE-TIME STATE-DELAYED SYSTEMS: A PARAMETER-DEPENDENT LYAPUNOV APPROACH

This paper is concerned with the problem of robust H∞ filtering for linear discrete-time systems with multiple state delays and polytopic uncertain parameters. Attention is focused on the design of full-order, reduced-order and zeroth-order robust H∞ filters on the basis of a recently published parameter-dependent Lyapunov stability result. Sufficient conditions for the existence of such filters are formulated in terms of linear matrix inequalities, upon which admissible filters can be obtained from convex optimization problems. The proposed methodology has been shown, via a numerical example, to be much less conservative than previous filter design methods in the quadratic framework.