配合力理论及其在水稻育种中的应用

配合力理论是玉米育种的重要理论。介绍配合力理论,明确一般配合力与特殊配合力的关系。介绍配合力的测定方法,强调发现和改良具有较高一般配合力的核心亲本在水稻育种中的重要意义,用配合力理论指导水稻核心亲本改造。从杂交籼稻、杂交粳稻、常规粳稻育种3个侧面说明配合力理论在水稻中的应用。

大学生思想政治教育合力理论研究与模式构建

加强和改进大学生思想政治教育工作是一项实践性很强的系统工程。文章从新形势下大学生思想政治教育合力的问题出发,深入剖析了专业教学、管理育人、服务育人、社会家庭环境等方面与思想政治教育工作不够协调的根本原因,构建了形成思想政治教育合力"六位一体"的工作模式。

区域教育中心构建中大学生思想政治教育合力理论研究与模式构建

基于区域教育中心构建的基本理论,并结合当代社会实际条件,研究并推进针对大学生的思想政治教育合力理论,从思想政治教育主体的协调性、教育内容的衔接性、教育方式的配合性以及教育手段的综合性等方面来开展这项实践性很强的教育系统工程。从理论研究过渡到模式构建,全方位的验证在区域教育中心构建模式下大学生思想政治教育合力论的有效性。

从历史合力理论视角解读亨利八世推行宗教改革的原因

亨利八世推行宗教改革的原因决非是婚姻案的单极刺激的使然,也不是资本主义生产发展与国王权力强大的自然结果,而是一系列内生因素"合力"促成的结果。主要源于民族尊严的捍卫、资本主义生产关系的推进、民众对罗马教皇的不满情绪的呼应以及王权强大的应然反应与婚姻案件的刺激。

非定常气动力理论

从经典的飞行器瞬态流到振荡流,再到千奇百怪的生物推进与飞行模式和无人飞行器、微型飞行器,非定常气动力问题涵盖十分广泛的流动范畴,涉及复杂的非定常分离流,如自由剪切层和集中涡等局部流动结构的演化与相互作用。为了根据计算或实验得到的复杂非定常流场做出理性诊断,查明每个局部结构对合力的贡献,极有必要发展在流体中任意运动与变形的物体所受的气动力(包括水动力)的一般基础理论。本文首先提出两个原则:一是局部结构对合力的贡献要满足伽利略不变性要求;二是物体的自主运动需要给出物体的质量分布与惯性矩,同时考虑合力与力矩。然后介绍几类主要的理论及其应用案例。最简洁而广泛的理论是不涉及动量方程的冲量理论,包括经典的全域理论、经典与现代的无黏理论、最小域冲量理论及其可压缩推广。第二类理论是动理学的因果型理论,包括扩散型和边界型合力公式。第三类理论是加权型理论,包括几种投影理论和虚功理论,重点是能自动满足局部伽利略不变性的加权压力源理论。随着非定常气动力诊断需求的继续发展,可以期待未来还会出现新的理论。

新自由主义与世界经济危机

2008-2010年世界经济金融危机,并不单纯是由美国次贷市场的崩溃所引发的,其根源深植于新自由主义的资本主义。目前现存的国际制度体系与其说有助于全球秩序,不如说催生了全球混乱。应该从根本上重建日益相互依存的世界经济所赖以运行的制度架构。未来世界的经济,即相互关联的全球经济,需要的是能够进行包括政治在内的全球协调的制度。

Recent advances in micro-alloyed wrought magnesium alloys:Theory and design

Micro-alloying design of wrought magnesium(Mg) alloys is an important strategy to achieve high mechanical properties at a low cost. In the last two decades, significant progress has been made from both theory and experiment. In the present review, we try to summarize recent advances in micro-alloying design of wrought Mg alloys from both theoretical and pragmatic perspectives, and provide fundamental data required for establishing the relationship between chemical composition and mechanical properties of Mg alloys. We start with theoretical attempts for understanding the mechanical properties of Mg alloys at different scales, by involving first principle calculations,molecular dynamics, cellular automata, and crystal plasticity. Then, the role of alloying elements is discussed for a series of promising Mg alloys such as Mg-Al, Mg-Zn, Mg-RE(rare-earth element), Mg-Sn, and Mg-Ca families.Potential challenges in the micro-alloying design of Mg alloys are highlighted at the end. The review is expected to provide helpful guidance for the intelligent design of novel wrought Mg alloys and inspire more innovative ideas in this field.

Positively Charged Exciton in Double-Layer Quantum Dots

The Hamiltonian equation for positively charged exciton in double-layer harmonic quantum dots is solved numerically by using the exact diagonalization techniques. We find that the correlation energy Ec of positively charged exciton increases with increasing the confinement strength and the binding energy decreases obviously for the heavy hole.

The kinematics modeling based on Spinor theory for CT-guided hybrid robot

This paper focused on a simplified method for solving the hybrid robot kinematics in CT-guided （computerized tomography, CT） surgery. By position constraint introduced, the hybrid robot can be transformed as a redundant serial 7-DOF robot. The forward displacement calculation was developed based on the product-of-exponential formula （POE）. Because of the kinematics complexity of the hybrid and redundant robot, the combination technique of Ulrich two-step iteration method and paul variables detachment method （UTI-PVD） was introduced to fulfill the inverse kinematics of redundant robot, the novelty of which lay in the flexibility of various robots structures and in high calculation efficiency for realtime control. The process of solving the inverse displacement was analyzed. The UTI-PVD method can be applicable to kinematics of many robots, especially for redundant robots with more than 6DOF. The kinematics simulation was provided, and robot dexterity analysis was presented. The results indicated that the hybrid robot could implement the minimally invasive CT-guided surgery.

Research on replacement depth of black cotton soil based on cracking behavior of embankment

In order to analyze the influence of replacement depth of black cotton soil(BCS)foundation on the initial cracking depth of a highway embankment,the laboratory tests were performed to construct the constitutive relationship between state variables and stress variables of BCS,and the coupled consolidation theory for unsaturated soils was employed to simulate the change in the major principal stress of the subgrade soils caused by water loss shrinkage of BCS with the help of Abaqus 6.11 codes.The simulation results indicate that the water losing shrinkage of BCS causes tensile stress within the subgrade,which leads to embankment cracking.The crack depth decreases with the increase in the BCS replacement depth and the embankment height,and increases with the increase in the burial depth of BCS.In the distribution area of deep BCS,the key values of foundation replacement depth for controlling the crack depth of the embankment with the height of 1 to 4 m are 1.2 and 1.5 m.In the low filling section,when the buried depth of BCS is 2,3 and 4 m,the key values of the foundation replacement depth to control the crack depth of the embankment are 0.8 and 1.2 m.In order to control the embankment cracking induced by the water losing shrinkage of BCS,a reasonable replacement depth of the foundation should be selected while slope protection is carried out well.

A Possible Experimental Test on Five-Dimensional Gravitation Theory of Complex Field

By appropriately choosing additional dimensions of space-time, the mass spectrum of mesons is obtained, and the calculated results agree with the experimental data.

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.

Influence analysis of flow rule in mine fire during injecting inert gases

According to the action law of gas flow during injecting inert gases as the research main line, and hydromechanics and thermodynamics theories, the characteristic of gas delamination that was caused by injecting inert gases to closed fire zone was analyzed. The criterion was brought forward, which could scale disappearing probability of turbulent state. Formation mechanism of gas layer in turbulent state was discussed primarily. Simultaneously, the condition was pointed out, which could makc the gas in turbulent state by injecting different gases. The mathematical model about dynamic changes of oxygen and methane concentration in the process of injecting gases was erected. The mixture mechanism about injecting different flow inert gases and flammable gas layer in closed fire zone was revealed.

Measurement of Economic Power： An Engineering Approach

Business Directory defines economic power as ＂conditions of having sufficient productive resources at command that give the capacity to make and enforce economic decisions, such as allocation of resources and apportioning of goods and services＂. This qualitative definition may be sufficient for general discussions, but it does not offer any quantitative measurements for management and control. Is there a way to measure economic power for analysis and synthesis of economic systems in this 21st century？ This paper answers this question by introducing a set of quantitative terms from the field of electrical engineering, used in power measurement and control of electrical systems. Circuit theory concepts are introduced to show how the relationship between cash and cash flow in finance is analogous to that of electric charge and electric current and how education level, as economic potential, is analogous to electrical potential that causes current to flow in a circuit. An individual is identified as the basic cash flow source in the economy. Circuit models for an individual as well as a typical production facility are developed and demonstrated with an example. Equations for the measurement of economic power, losses, efficiency, and power factor are presented. It is shown that the individuals are the basic cash flow sources and producers of economic power.

Dispersion Relations in Binary Gas Mixtures From a Kinetic Theory

Sound propagation and the initial value problems in gas mixtures of two components are investigated. By using the eigen theory of linearized Boltzmann equations, a model equations is formed, with the use of the Fourier-Laplace transform for model equations derived, the dispersion relations for both components are obtained.

Spontaneous Emission of a Polarized Atom in a Medium Between Two Parallel Mirrors

Using the photon closed orbit theory, the spontaneous emission rate of a polarized atom in a medium between two parallel mirrors is derived and calculated. It is found that the spontaneous emission rate of a polarized atom between the mirrors is related to the atomic position and the polarization direction. The results show that in the vicinity of the mirror, the variation of the spontaneous emission rate depends crucially on the atomic polarization direction. With the increase of the polarization angle, the oscillation in the spontaneous emission rate becomes decreased. For the polarization direction parallel to the mirror plane, the oscillation is the greatest; while for the perpendicular polarization direction, the oscillation is nearly vanished. The agreement between our result and the quantum electrodynamics result suggests the correctness of our calculation. This study further verifies that the atomic spontaneous emission process can be effectively controlled by changing the polarization orientation of the atom.

Study of Thermodynamics of Liquid Noble-Metals Alloys Through a Pseudopotential Theory

The Gibbs-Bogoliubov （GB） inequality is applied to investigate the thermodynamic properties of some equiatomic noble metal alloys in liquid phase such as Au-Cu, Ag-Cu, and Ag-Au using well recognized pseudopotential formalism. For description of the structure, well known Percus-Yevick （PY） hard sphere model is used as a reference system. By applying a variation method the best hard core diameters have been found which correspond to minimum free energy. With this procedure the thermodynamic properties such as entropy and heat of mixing have been computed. The influence of local field correction function viz; Hartree （H）, Taylor （T）, lehimaru-Utsumi （IU）, Farid et al. （F）, and Sarkar et al. （S） is also investigated. The computed results of the excess entropy compares favourably in the case of liquid alloys while the agreement with experiment is poor in the case of heats of mixing. This may be due to the sensitivity of the heats of mixing with the potential parameters and the dielectric function.

On Multi-Modality in English Listening Teaching

Listening is the breakthrough for conquering English castle, it is not only the requirement of English test, but also the practical use of English knowledge and the embodiment of English comprehensive ability. Listening teaching plays a crucial role in foreign language teaching. However, the effect of listening teaching is undesirable. In recent years, multi-modality theory has been focused by many researchers. In view of particularity of the listening teaching, it is urgent to apply the multi-modality theory to English listening teaching which will produce very good teaching result.

切实増强中国特色社会主义制度自信

恩格斯指出,任何一个历史事件发展的结果都不是单个意志的产物,而是无数个力的平行四边形共同作用的结果。这个历史合力理论清楚地说明了我国选择社会主义制度、走上社会主义道路的历史必然性。

Multi-recurrence and van der Waerden systems

We explore recurrence properties arising from dynamical approach to the van der Waerden theorem and similar combinatorial problems. We describe relations between these properties and study their consequences for dynamics. In particular, we present a measure-theoretical analog of a result of Glasner on multi-transitivity of topologically weakly mixing minimal maps. We also obtain a dynamical proof of the existence of a C-set with zero Banach density.