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991.
Chen-Zhong Dong Jin-Bao Zhao 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1992,23(3):211-213
Some terms of the 4s4p 4 configuration in RuXII, RhXIII and PdXIV ions can be improved and all the energy values of the configuration in AgXV can be predicted theoretically by means of a configuration-interaction ab initio analysis for the level structure of the 4s4p 4 configuration along the AsI sequence of KrIV-AgXV ions. Calculations of the wavelengths and oscillator strenghts are presented for the 4s 24p 3-4s4p 4 transition in AgXV. 相似文献
992.
Kang EJ Cho EJ Ji MK Lee YE Shin DM Choi SY Chung YK Kim JS Kim HJ Lee SG Lah MS Lee E 《The Journal of organic chemistry》2005,70(16):6321-6329
(+)-SCH 351448 (Na+ salt A) was synthesized employing ring-closing olefin metathesis reaction of an open diene diester intermediate for construction of the 28-membered macrodiolide structure. The open diene diester was prepared from the monomeric hydroxy carboxylic acid and two different olefin fragments. The monomeric hydroxy acid was synthesized via Julia-Julia coupling reaction of intermediates derived from the same olefinic fragments. Oxane units in these fragments were prepared by radical cyclization reactions of beta-alkoxyacrylates. Analogous SCH 351448 salts incorporating other mono- and divalent cations may be prepared. Under acidic conditions, SCH 351448 (Na+ salt A) was the most stable complex, but SCH 351448 (Ca2+ salt) and (Na+ salt B) appear to be physiologically important species. 相似文献
993.
994.
端视等离子体原子发射光谱仪的性能评价 总被引:4,自引:0,他引:4
端视等离子体原子发射光谱仪与侧视等离子体原子发射光谱仪相比在分析性能方面所表现出来的差异一直是光谱分析工作者所关注的一个重要方面。此文较系统的总结了近年来在此方面所做的研究工作,引用47篇文献。 相似文献
995.
Terbium copper disulfide, TbCuS2, has been synthesized in the reaction of the elements in a KI flux at 850 ℃. The compound crystallizes in space group P21/c of the monoclinic system with four formula units in a cell of dimensions of a= 0.639 3(1) nm, b=0.702 5(1) nm, c=0.670 8(1) nm, β=98.097(4)°, and V=0.298 3(1) nm3 at 153 K. The structure comprises two-dimensional 2∞[CuS2] layers along [100] separated by the Tb atoms. In the structure, each Tb and Cu atoms are coordinated to seven and four S atoms, respectively. CSD: 415490. 相似文献
996.
AnExplanationontheElectronIonizationMassSpectraofCrownEthersbyMNDOComputationalMethodYUANHu-shan,TANGMing-shengandWUYang-jie(... 相似文献
997.
Chemical Constituents of Ailanthus triphysa 总被引:2,自引:0,他引:2
Two new compounds,8(14),15-isopimaradiene-2α,3α,19-triol(1),and 6α,7β-dihydroxy-17(20)-cis-5α-pregna-16-one(2),together with four known copounds,a oxygenated rare phyllocladane,phyllocladan-16α,19-diol(3),kaempferol-3-0-β-D-galactopyranosied,kaempferol-3-0-α-L-rhamnopyranoside and scopoletin, were isolated from the leaves of Ailanthus tripysa.Structures of 1-3 were elucidated on the basis of spectroscopic data as compared with related compounds. 相似文献
998.
N,N′-双吡咯的合成及其邻位基团效应 总被引:1,自引:0,他引:1
2,2-联吡咯是某些天然存在的活性吡咯化合物中关键组成,关于手性联吡咯的研究己有详细的综述报道。近年发现,某些含N-取代氨基的空间阻碍吡咯有明显的生理活性和可贵的药理性质。N,N′-联吡咯中N-N键,很容易发生均裂反应而生成游离基,后 相似文献
999.
Situated in the Taihu plain between the mouth of the Changjiang River and theHangzhou Bay, the Taihu Lake is a large shallow-water lake in China with a surface area of 2427.8 km~2.The lake bottom mainly consists of loess-like sediment. Some buried and silted up channels and residual depressions can be found at the bottom and a lot of Neolithic cultural relics on the loess-like sediment. This indicated that the Taihu Lake was formed on the alluvial plain charaterized by widely deposited loess-like sediment because of siltation and stagnancy of water, instead of by development from lagoons as reported in the past.Recent deposition including influent-effluent current accumulation, wind-driven current and storm deposition in this lake occurred mainly in the south, the west shore and the midst of the lake.The sedimentary rate in the east Taihu Lake is about 1.7-1.8 mm/a, whereas in the west Taihu Lake it is about 0.41 ram/a, only 23% of that of the former. 相似文献
1000.