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排序方式: 共有9101条查询结果,搜索用时 15 毫秒
991.
Consider a nonlinear discrete-time system, we obtain a sufficient condition such that all solutions of this system converge to the equilibrium. 相似文献
992.
The atomic-scale diffusion mechanism of boron in diamond is investigated by molecular dynamics simulation. A substitutional boron atom diffuses to the self-interstitial site when there exists a self-interstitial carbon atom in its nearest tetrahedral center and the system temperature is high. More important, the bond between boron and the self-interstitial carbon atom is never broken during the diffusion process, indicating that Bs-Ci pairs diffuse in the lattice by the interstitial mechanism. The results suggest that boron diffusion is mediated by carbon self-interstitial and not by the vacancy mechanism. In addition, the estimated activation energy and the diffusion exponential prefactor of boron diffusion in diamond are found to be 0.23 eV and 1.123×10−6cm2/s, respectively. 相似文献
993.
994.
Zong Zhaojun Hu Feng 《高校应用数学学报(英文版)》2007,22(3):253-258
A modified classical model with a dividend barrier is considered. It is shown that there is a simple approximation formula for the time of ruin when the level of dividend barrier is high and the claim sizes have a distribution that belongs to S(γ) with γ 〉0. 相似文献
995.
He You HAN De Hong HU Jian Gong LIANG Zong Hai SHENG College of Science MOA Key Laboratory of Food Safety Evaluation Huazhong Agricultural University Wuhan 《中国化学快报》2006,17(7):961-964
QDs (also called semiconductor nanocrystallines) were attracted considerable attention in the past decade1, 2. They have been used as luminescent probes in biology, medicine and more recently in analytical chemistry3-5. The interaction between QDs and ino… 相似文献
996.
The spectral radiation characteristic of a non-luminous flame is analyzed. The apparatus and the calibration procedure based on infrared emission spectrometry for measurements of the flame are introduced.The influence of background radiation and stray light on the measurement results could be reduced and suppressed by the design of thermolator and digital lock-in technique. A blackbody cavity was used as reference emission source to calibrate the system that completed absolute measurement. The spectral measurement range is 1-20 μm. The least measuring distance and the lowest power detected at the entrance pupil are 550 mm and 10-9 W/cm2, respectively. The experimental results show that the measure error is less than 10%. 相似文献
997.
根据H2上的双曲距离在拟共形变换下的拟不变性,给出了K-拟共形抛物循环Fuchs群的收敛指数的估计. 相似文献
998.
R. Bernabei P. Belli R. Cerulli F. Montecchia M. Amato A. Incicchitti D. Prosperi C.J. Dai H.L. He H.H. Kuang J.M. Ma 《The European Physical Journal C - Particles and Fields》2002,23(1):61-64
In this paper, the model independent annual modulation effect observed by DAMA during four independent experiments of one
annual cycle each (57986 kg day total statistics) is analysed in terms of a particle dark matter candidate which can only inelastically scatter by making
a transition to a slightly heavier state, as previously suggested in the literature.
Received: 4 October 2001 / Revised version: 16 November 2001 / Published online: 20 December 2001 相似文献
999.
1000.
存在固有线双折射光纤费尔德常数的测量 总被引:4,自引:2,他引:2
从理论上分析、计算了扭转光纤对小信号电流灵敏的影响,提出了一种新的更为简便的方法测量费尔德常数、并用实验验证。结果表明当光纤扭转率与固有线双折射的比值大于一定数值时,用本方法测量得到的费尔德常数值与理论值十分接近。这一方法为测量具有线双折射光纤的费尔德常数提供了一种新的途径。 相似文献