排序方式： 共有110条查询结果，搜索用时 15 毫秒
41.
记得小时候,家附近有一个好高好高的台阶,那时的我常常一个人莫名地跑到那里,从高高的台阶跳下去,然后从侧旁的台阶跑上来,再一次次地跳下去。脚落地时,身体的疼痛和心的刺激感我到现在还记得。除了跳台阶,我还会一个人偷偷地爬户外的水管,把它看作一种本领。给生活加点兴奋剂,在平淡之中制造一点点刺激,这就是Free Running这项运动创始人的初衷。生活固然需要激情,人身安全无疑更重要。在模仿这项运动的高手们飞檐走壁的绝技之前,先老老实实地练好你的基本功。任何时候都要记住,只有活着,生活才有激情可言。——Lavender 相似文献
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The research into the origins of domestic animals is of significance not only for understanding their development per se but also for making clear the human society evolution. Although there are evidences to show that pigs were independently domesticated in a variety of places throughout the world the detailed scenario of the origin dispersal of domestic pigs in East Asia remains unclear.…… 《中国科学院院刊(英文版)》2008,22(1):7-7
The research into the origins of domestic animals is of significance not only for understanding their development per se, but also for making clear the human society evolution. Although there are evidences to show that pigs were independently domesticated in a variety of places throughout the world, the detailed scenario of the origin and dispersal of domestic pigs in East Asia remains unclear. 相似文献
43.
A research team led by YANG Hui CHEN Lianghui with the CAS Institute of Semiconductors 《中国科学院院刊(英文版)》2008,22(1):8-9
Aresearch team led by YANG Hui and CHEN Lianghui with the CAS Institute of Semiconductors （ISCAS） has made breakthrough progress in addressing key technological problems for the GaN-based laser diodes development. The research results were spoken highly at a panel meeting of experts held on 26 November, 2007 in Beijing. 相似文献
44.
Under the auspices of the CAS Center for Project Supervision Evaluation a panel of experts recently conducted an ex-post evaluation on a research project entitled "the electrical system for an electric vehicle." The appraisal is the first of its kind in project management at CAS.…… 《中国科学院院刊(英文版)》2008,22(1):55-55
Under the auspices of the CAS Center for Project Supervision and Evaluation, a panel of experts recently conducted an ex-post evaluation on a research project entitled “the electrical system for an electric vehicle.” The appraisal is the first of its kind in project management at CAS. 相似文献
45.
Twenty-nine prominent Chinese scientists have been elected as CAS Members five of their colleagues from US France Russia as CAS Foreign Members in . The announcement was made by CAS Vice President LI Jinghai at a press conference held on December in Beijing. CAS President LU Yongxiang was present at the meeting. …… 《中国科学院院刊(英文版)》2008,22(1):26-28
Twenty-nine prominent Chinese scientists have been elected as CAS Members and five of their colleagues from US, France and Russia as CAS Foreign Members in 2007. The announcement was made by CAS Vice President LI Jinghai at a press conference held on 27 December, 2007 in Beijing. CAS President LU Yongxiang was present at the meeting. 相似文献
46.
The CAS Institute of Automation 《中国科学院院刊(英文版)》2008,22(1):56
The CAS Institute of Automation(CASIA)will join hands with the Media Development Authority of Singapore(MDA)to establish the China-Singapore Institute of Digital Media in Singapore.The agreement was inked by CAS Vice Secretary-General and CASIA Director-general TAN Tieniu and MDA Chairman Tan Chin Nam on 相似文献
47.
北京理工大学党委宣传部 The Propaganda Department Beijing University of Posts Telecommunications 《北京教育(高教版)》2006,(4):56-59
雷达,被人们形象地称为“千里眼”。在第二次世界大战中,雷达首次在战争中发挥威力,从那以后,世界各国充分认识到雷达在军事上的重要作用,纷纷投入巨大的力量来研究雷达。如今,雷达已经广泛地应用在国防、航天、航海、地形测量、气象等各个领域,其科研成果不断进步。国内不少实 相似文献
48.
Numerical Derivation of Strain Rate Effects on Material Properties of Masonry with Solid Clay Bricks
In this paper, numerical method is used to study the strain rate effect on masonry materials. A typical unit of masonry is selected to serve as a representative volume element (RVE). Numerical model of RVE is established with detailed distinctive modeling of brick and mortar with their respective dynamic material properties obtained from laboratory tests. The behavior of brick and mortar are characterized by a dynamic damage model that accounts for rate-sensitive and pressuredependent properties of masonry materials. Dynamic loads of different loading rates are applied to RVE. The equivalent homogenized uniaxial compressive strength, threshold strain and elastic modulus in three directions of the masonry are derived from the simulated responses of the RVE. The strain rate effect on the masonry material with clay brick and mortar, such as the dynamic increase factor (DIF) of the ultimate strength and elastic modulus as a function of strain rate are derived from the numerical results. 相似文献
49.
In order to improve the present aviation ejection escape system, the application of explosion cutting technique to aviation escape system is proposed to weaken the strength of canopy before ejecting it. A series of mini cutting explosives are designed to investigate the process of splitting PMMA plate. The phenomenon of spallation in PMMA is observed. The effects of different parameters of mini cutting explosives on the cutting depth are obtained. Consequently the appropriate material of half-circular metal covers, explosive types and the ranges of charge quantities are determined. On the other hand, the cutting process of aviation PMMA plate by mini cutting explosives is simulated by means of nonlinear dynamic analysis code LS-DYNA. In finite element analysis,Arbitrary Lagrangian Euler (ALE) algorithm is used to depict the fluid property of high energy explosives. Continuous damage material model is used to simulate the complicate dynamic damage behavior of PMMA due to explosion shock waves. Only sliding contact option is defined to fulfill the fluid-structure interaction between explosives and PMMA plate by distributed parameter methods. Phenomenon of spallation observed in the experiment is presented in the simulation. The relationship between the penetration depth of PMMA plate and charge linear density obtained by numerical simulation agrees well with experimental result. 相似文献
50.