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991.
992.
Justin T. Russell Yao Lin Alexander Bker Long Su Philippe Carl Heiko Zettl Jinbo He Kevin Sill Ravisubhash Tangirala Todd Emrick Kenneth Littrell Pappannan Thiyagarajan David Cookson Andreas Fery Qian Wang Thomas P. Russell 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2005,117(16):2472-2478
993.
江汉平原上空QTEC变化特征的统计分析 总被引:1,自引:0,他引:1
提出了一种观测台网用多接收机性能一致性的标定方法,并利用江汉平原GPS接收台网的观测数据,分析了该地区上空QTEC的日变化、季节变化、年变化和逐年变化的统计特征.标定结果表明,不同接收机之间的仪器偏差是从双频GPS卫星信标推算QTEC的主要误差来源之一,必须校正.统计分析证实,江汉平原上空QTEC的日变化特征同时受电离层和等离子层控制,其年变化以半年周期为主,峰值和谷值分别出现在两分点和两至点附近,QTEC值的逐年变化从太阳活动峰年到低年逐年下降,与以太阳黑子数为代表的太阳活动密切相关. 相似文献
994.
A new complex {[Na2(H2O)3(µ‐L)2Cu]4}∞ (L = N‐methyliminodiacetic acid) has been synthesized and structurally characterized. The complex crystallizes in the monoclinic, space group C2/c, with the unit cell parameters a = 16.556(3) Å, b = 8.0622(13) Å, c = 12.671(2) Å, α = 90°, β = 95.849(2)°, γ = 90°. The central metal Cu (II) ion is coordinated with two nitrogen atoms and four oxygen atoms belonging to two ligands. Simultaneously, the sodium is six‐coordinated with oxygen atoms coming from the ligand and water molecule; the sodium atoms related are bridged by oxygen atoms, forming a sodium chain. The structure consists of CuL2 moieties linked by sodium chain via the exo oxygen atoms of two ligands, forming a novel three‐dimensional structure. Moreover, elemental analysis, IR, UV‐vis, ESR spectroscopy and thermal stability were determined. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
995.
Jing Ping YANG Shi Hong CHENG Xiao Qian WANG 《数学学报(英文版)》2007,23(3):467-478
This paper investigates bivariate recursive equations on excess-of-loss reinsurance. For an insurance portfolio, under the assumptions that the individual claim severity distribution has bounded continuous density and the number of claims belongs to R1 (a, b) family, bivariate recursive equations for the joint distribution of the cedent's aggregate claims and the reinsurer's aggregate claims are obtained. 相似文献
996.
997.
Cheng Zhi GU Qian Rong LI Hao YIN 《中国化学快报》2005,16(12):1573-1576
Tin-indium were employed in the propargylations of various aldehydes with propargyl bromide in the presence of SnCl2 and C6H5(CH3)3NBr under microwave irradiation to afford the corresponding homopropargyl alcohols exclusively in high yields. All the reactions were completed smoothly in predominantly aqueous media in 200 seconds only. 相似文献
998.
999.
D. Qian Yinwan Li D.M. Casa Y.-D. Chuang T. Tohyama H. Eisaki 《Journal of Physics and Chemistry of Solids》2005,66(12):2212-2215
Momentum dependence of charge excitations across the effective Mott gap in several quasi-low-dimensional model cuprates with different effective dimensionalities is studied using high resolution inelastic X-ray scattering by working near Copper k-edge resonance which allows us to extract the dispersion relations of the particle-hole pair excitations at the gap edge. Besides electron-electron correlation, momentum dependence of the gap-excitations is found to be strongly dependent on the effective dimensionality (or topology) of the 3dx2−y2 network. 相似文献
1000.
The effects of vacuum-induced coherence (VIC) on the properties of the absorption and gain of the probe field in an equispaced three-level ladder atomic system are investigated. It is found that lasing without inversion (LWI) is remarkably enhanced due to the effect of VIC in the case of the small incoherent pump rate. 相似文献