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81.
82.
Steinbeck C 《Natural product reports》2004,21(4):512-518
Advancements in the field of Computer-Assisted Structure Elucidation (CASE) of Natural Products achieved in the past five years are discussed. This process starts with a dereplication procedure, supported by structure-spectrum databases. Both commercial and free products are available to support the procedure. A number of new programs,as well as advancements in existing ones, are presented. Finally, the option to validate the result by an independent procedure, a high quality ab initio quantum mechanical calculation, is discussed. 相似文献
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The quantum-mechanical D-dimensional inverse square potential is analyzed using field-theoretic renormalization techniques. A solution is presented for both the bound-state and scattering sectors of the theory using cutoff and dimensional regularization. In the renormalized version of the theory, there is a strong-coupling regime where quantum-mechanical breaking of scale symmetry takes place through dimensional transmutation, with the creation of a single bound state and of an energy-dependent s-wave scattering matrix element. 相似文献
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87.
Martin Steinbeck Wolfgang W. Schoeller Wolfgang A. Herrmann 《Journal of organometallic chemistry》2011,696(25):3945-3954
Different chiral mono-substituted N-heterocyclic carbene complexes of rhodium were prepared, starting from [Rh(COD)Cl]2 (COD = cyclooctadiene) by addition of free N-heterocyclic carbenes (NHC), or an in-situ deprotonation of the corresponding iminium salt. All new complexes were characterized by spectroscopy methods. In addition, the structures of chloro(η4-1,5-cyclooctadiene)(1,3-di-[(1R,2R,3R,5S)-2,6,6-trimethylbicyclo[3.1.1]hept-3-yl] imidazolin-2-ylidene)rhodium(I) (5a), chloro(η4-1,5-cyclooctadiene)(1,3-di-[(1R,2S,5R)-2-isopropyl-5-menthylcyclohex-1-yl]imidazol-2-ylidene)rhodium(I) (5b) and chloro(η4-1,5-cyclooctadiene)(1,3-di-[(2R,4S,5S)-2-methyl-4-phenyl-1,3-dioxacyclohex-5-yl]imidazolin-2-ylidene)rhodium(I) (5i) were analyzed by DFT-calculations. The enantioselective hydrosilylation of acetophenone, ethylpyruvate and n-propylpyruvate with diphenylsilane and hydrolysis was carried out with chiral C2-symmetrical mono-substituted N-heterocyclic carbene rhodium complexes giving for the first time an enantioselective excess of up to 74% ee in the case of the n-propylpyruvate. 相似文献
88.
为了理解化学键的这一结构效应, 本文对具有相同化学键而分子内结构环境不同的系列分子进行了计算研究, 讨论了化学键结构环境对解离能的影响. 相似文献
89.
The Blue Obelisk-interoperability in chemical informatics 总被引:1,自引:0,他引:1
Guha R Howard MT Hutchison GR Murray-Rust P Rzepa H Steinbeck C Wegner J Willighagen EL 《Journal of chemical information and modeling》2006,46(3):991-998
The Blue Obelisk Movement (http://www.blueobelisk.org/) is the name used by a diverse Internet group promoting reusable chemistry via open source software development, consistent and complimentary chemoinformatics research, open data, and open standards. We outline recent examples of cooperation in the Blue Obelisk group: a shared dictionary of algorithms and implementations in chemoinformatics algorithms drawing from our various software projects; a shared repository of chemoinformatics data including elemental properties, atomic radii, isotopes, atom typing rules, and so forth; and Web services for the platform-independent use of chemoinformatics programs. 相似文献
90.
We investigate the statistical properties of two single-mode dye-laser models-the colored-loss-noise model and the colored-gain-noise model. Analytic expressions of the probability,the mean and the variance of the steady-state laser intensity are obtained through the unified expansion theory [Phys. Rev. A43 (1991) 700]. By comparison we find that when the cavity decay rate for the electric field is large and the pump parameter a0 is small, the differences of the results of the two laser models are small. Otherwise, the differences are large. And the correlation time of the noise has very obvious influence on the results of the two models. 相似文献