杆件内力的一种计算方法

为了让学生能够更好的理解各种变形条件下杆件的内力,将杆件截面上的分布内力系向形心简化得到主矢和主矩,主矢和主矩分别沿三个坐标轴分解得到三个分力和三个分力偶矩矢。基于空间任意力系的平衡方程,确定各种变形条件下杆件的内力。教学实践证明,该方法能够较好的帮助学生理解杆件内力的概念,从而提高教学质量和教学效果。     

Radiation reaction forces and the expanding universe

The expanding universe is described in terms of the known forces of classical physics. It is shown that great clouds of stars are non-conservative systems and that radiation reaction forces play a part in guiding stellar motions. The forces are of importance in unsymmetrical stars and evidence is collected to show that perhaps all stars are possessed of deep seated thermal asymmetries. The forces continually act to increase the mean velocity of the stars and the galaxy is calculated to expand at a rate which closely approximates the observed rate of expansion. From a relation connecting the mean velocity of the stars and their age, it is deduced from the observed motions that the age of the galaxy is about 10¹⁰ years. The deduced rate of expansion of the galaxy agrees well with the observational data and is identical in form and numerical constant with Hubble's relation connecting the velocity of recession and distances of nebulæ.Because of the relative size and spacing of the extra galactic nebulæ and the short time scale it is supposed that the nebulae were formed by fission from a parent-super nebula and this resulted in thermal asymmetries which brought the newly considered forces into action.The resulting expansion was produced by slow evolutionary radiation processes which bear no direct relation to the properties of space or atomic constants.The calculations suggest that in describing the motions of typical stars over long periods of time, radiation reaction forces are as important as the classical gravitational forces.     

中蒙俄经济走廊背景下中俄能源合作进展、驱动力、挑战及对策

中俄能源合作是中俄全面战略协作伙伴关系的重要内容,是意义重大的地缘战略合作。自1996年中俄能源合作拉开序幕以来,虽几经波折,但也取得了较大进展,且随着中蒙俄经济走廊的规划实施,中俄能源合作迎来新机遇。基于此,本文回顾了中俄能源合作取得的进展,从供求关系、能源政策、国际劳动地域分工、比较优势、区域发展政策、国际地缘环境变迁等角度全面分析了中俄能源合作的内在契合因素和外部推动因素,指出中俄利益诉求的内在契合性是中俄开展能源合作的决定性因素,外部推动因素则加速了中俄能源合作的进程。虽目前中俄能源合作态势良好,但仍面临合作体制机制欠缺、国际地缘环境变迁等诸多挑战,在国际地缘环境日益复杂的新时期,中俄应增强互信,深化中俄能源的地缘战略合作;抓住中蒙俄经济走廊的政策契机,拓宽合作模式与合作领域;制定中俄能源战略长期合作规划,完善中俄能源合作机制;兼顾周边地区,创建区域性能源共同体。     

产业势力、治理模式与集群式产业链升级研究

 论文创新而独特地以集群式产业链升级作为研究视角,紧密结合实际,综合运用产业经济学、技术创新、产业链理论、产业集群等多学科理论交叉研究方法,在分析集群式产业链、产业势力与治理模式互动演进机理的基础上,以经济全球化为研究背景,构建一个更全面的内外因素结合与互动的分析框架：基于集群式产业链的内外互动升级模型,开辟新的研究领域,丰富产业集群与产业链的研究内容;同时,为地方政府制定与实施相关创新升级政策提供思路与理论依据。     

CAS, Guangxi to join forces for eco-environmental restoration in Karst areas

CAS has recently signed a protocol with the Government of the Guangxi Zhuang Autonomous Region to jointly rehabilitate the depleted ecosystem in the local Karst areas. Early and effective partnership has been formed between the two sides to eliminate the local poverty with S&T means and improve the ecological setting in the Karst areas of the Region. Since the conclusion of a cooperative pact between the two sides to exploit the stony mountains of the region in 1993, for example, a batch of key research results and effects of applicable demonstration has been achieved.     

On the lamb problem with long-range elastic cohesion forces

The Lamb two-dimensional problem involving a nonlocal medium is solved by taking the constitutive equations in the Kroener—Eringen form. The Fourier exponential transform procedure leads to the equations for stresses which are subject to time-dependent boundary conditions. In the particular case of a concentrated line force, the displacements at the surface of the half-space become associated with Rayleigh, longitudinal and shear waves whose velocities in the nonlocal case and for short waves are, by about 36%, less than those of their conventional counterparts.     

试论人力资源管理在部队管理中的重要性

人力资源是一个国家、一支军队发展和创新的核心资源、第一资源.在军队人才建设跨越式发展的同时,军队人力资源管理也应与时俱进,积极吸收现代管理理论的成果,建立具有我军特色的人力资源管理和开发制度,特别是在军事战备中,人始终是关键因素.因此,人力资源管理也一直成为许多部队重点关注的领域.本文试着从人力资源管理在部队管理中所发挥的作用和意义来阐述人力资源管理在部队管理中的重要性.