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991.
Ping Yan BIE Cheng Lu ZHANG Xuan Jia PENG Xin Fu PAN* Department of Chemistry National Laboratory of Applied Organic Chemistry Lanzhou University Lanzhou 《中国化学快报》2002,13(9)
Celaphanol A was a diterpene isolated from the stems of Celastrus stephanotifolius1, which have been the subject of continued and growing interest, due to the range of biological activities shown by many members of this family2. Some have been used in traditional medicine3 or as a stimulant4 from ancient times. In order to further study the relationship between the structure and biological activity of the diterpene compound and as an extension of diterpenoid synthesis in our laboratory5, 6, … 相似文献
992.
Acta Mathematica Hungarica - 相似文献
993.
Nguyen Xuan Uy 《Arkiv f?r Matematik》1979,17(1):19-27
994.
Hg2Cl2 undergoes a second order phase transition around 185 K. All the elastic constants have been measured above (tetragonal phase) and below (orthorhombic phase) the transition point. The results support the hypothesis that the transition is induced by the condensation of a transversal acoustical mode at an X point of the first Brillouin zone in the tetragonal phase. The coefficients of the coupling terms in the free energy are evaluated and the relative values of the spontaneous deformations are evaluated. 相似文献
995.
Wang CF Xie SY Lin SC Cheng X Zhang XH Huang RB Zheng LS 《Chemical communications (Cambridge, England)》2004,(15):1766-1767
Single crystalline SnO(2) nano-needles with length up to 6-7 microm and diameter less than 300 nm are synthesized on an Au-coating porous silicon substrate from SnH(4) source via a glow discharge process. 相似文献
996.
Akerib DS Alvaro-Dean J Armel-Funkhouser MS Attisha MJ Baudis L Bauer DA Beaty J Brink PL Bunker R Burke SP Cabrera B Caldwell DO Callahan D Castle JP Chang CL Choate R Crisler MB Cushman P Dixon R Dragowsky MR Driscoll DD Duong L Emes J Ferril R Filippini J Gaitskell RJ Haldeman M Hale D Holmgren D Huber ME Johnson B Johnson W Kamat S Kozlovsky M Kula L Kyre S Lambin B Lu A Mahapatra R Manalaysay AG Mandic V May J McDonald R Merkel B Meunier P Mirabolfathi N Morrison S Nelson H Nelson R 《Physical review letters》2004,93(21):211301
We report the first results from a search for weakly interacting massive particles (WIMPs) in the Cryogenic Dark Matter Search experiment at the Soudan Underground Laboratory. Four Ge and two Si detectors were operated for 52.6 live days, providing 19.4 kg d of Ge net exposure after cuts for recoil energies between 10 and 100 keV. A blind analysis was performed using only calibration data to define the energy threshold and selection criteria for nuclear-recoil candidates. Using the standard dark-matter halo and nuclear-physics WIMP model, these data set the world's lowest exclusion limits on the coherent WIMP-nucleon scalar cross section for all WIMP masses above 15 GeV/c2, ruling out a significant range of neutralino supersymmetric models. The minimum of this limit curve at the 90% C.L. is 4 x 10(-43) cm2 at a WIMP mass of 60 GeV/c2. 相似文献
997.
Bennett GW Bousquet B Brown HN Bunce G Carey RM Cushman P Danby GT Debevec PT Deile M Deng H Deninger W Dhawan SK Druzhinin VP Duong L Efstathiadis E Farley FJ Fedotovich GV Giron S Gray FE Grigoriev D Grosse-Perdekamp M Grossmann A Hare MF Hertzog DW Huang X Hughes VW Iwasaki M Jungmann K Kawall D Khazin BI Kindem J Krienen F Kronkvist I Lam A Larsen R Lee YY Logashenko I McNabb R Meng W Mi J Miller JP Morse WM Nikas D Onderwater CJ Orlov Y Ozben CS Paley JM Peng Q Polly CC Pretz J Prigl R 《Physical review letters》2002,89(10):101804
A higher precision measurement of the anomalous g value, a(mu)=(g-2)/2, for the positive muon has been made at the Brookhaven Alternating Gradient Synchrotron, based on data collected in the year 2000. The result a(mu(+))=11 659 204(7)(5)x10(-10) (0.7 ppm) is in good agreement with previous measurements and has an error about one-half that of the combined previous data. The present world average experimental value is a(mu)(expt)=11 659 203(8)x10(-10) (0.7 ppm). 相似文献
998.
接触分析的光滑模型及迭代算法 总被引:8,自引:0,他引:8
利用变分不等式和基于信息熵的凝聚函数把有摩擦接触问题模型化为一个标准的凸二次规划问题,极大地简化了这一复杂的问题,同时引入摩擦方向约束并构造了以无摩擦解为初值的迭代算法,在较摩擦系数时计算也能保证收敛,算例表明算法高效可靠。 相似文献
999.
Supersaturated Design with More Than Two Levels 总被引:9,自引:0,他引:9
gO. IntroductionA fractional factorial design is called supersaturated if the number of factors includedexceeds the limitation for keeping all the factors estimable, ignoring interactions. Sincesupersaturated designS can accommodate large nUInbers of factors, they are thought usefulin screening experhoellts.The research work on tWO-level supersaturated design was st8lted in the late fifties andearly staies (see [1,101). The subject has been gaining more and more renewed interest inthe last … 相似文献
1000.
设Ω是 Galois环 GR(2~d,r)的 Teichmuller代表集,则 GR(2~d,r)上每条序列a有唯一的权位分解, 其中a-i是Ω上序列,同时也可自然视为有限域F-(2~r),上序列.设f(x)是环 GR(2~d,r)上强本原多项式,G(f(x))表示 GR(2~d,r)上以f(x)为特征多项式的序列的全体,是F-(2~r)上一类d-1元多项式, 本文证明了压缩映射是单射,即对 a= b当且仅当对所有 a,b ∈ G(f(x)). 相似文献