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71.
《Journal of Coordination Chemistry》2012,65(11):2021-2027
Results of quantum-chemical calculations of MCl4–C6H5COCl (M=Si, Ge, Sn) systems of 1?:?1 composition using RHF/3-21?G* and MP2/3-21?G* levels as well as those of 1?:?2 composition using the RHF/3-21?G* level have been represented. MCl4?←?C6H5COCl complexes of 1?:?1 composition are energetically more advantageous. They are formed in solid state provided that the M···O distance in individual systems is considerably less than the sum of van der Waals radii of M and O and their total energies are appreciably less than the sum of total energies of components. These conditions are realized only for M=Sn. In systems of 1?:?2 compositions, calculated M···O distances are practically equal to the sum of covalent radii of M and O. Nonetheless, complexes with such composition are not formed in solid state. Total energy of the system which is lower than the sum of its components’ energies is not an indispensable condition for complex formation. The 35Cl nuclear quadrupole resonance (NQR) frequencies and asymmetry parameters of the electric field gradient at the 35Cl nuclei have been evaluated using the results of ab initio calculations. 相似文献
72.
《复变函数与椭圆型方程》2012,57(9):753-766
In this article some problems related to the Krzy? conjecture are discussed. In particular, we prove the Krzy? conjecture for the fifth coefficient. 相似文献
73.
CMPO-离子液体萃取分离铀(VI)体系的电化学性质 总被引:1,自引:0,他引:1
研究了辛基(苯基)-N,N-二异丁基胺甲酰基甲基氧化膦(CMPO)-离子液体(IL)从硝酸铀酰水溶液中萃取铀(VI)的电化学行为, 离子液体(IL)为1-丁基-3-甲基咪唑双三氟甲基磺酰亚胺盐(C4mimNTf2). 用等摩尔系列法测得萃取过程中CMPO与U(VI)形成摩尔比为3:1的配合物. 用循环伏安法研究了萃取液中U(VI)-CMPO配合物的电化学性质, 结果表明, 在C4mimNTf2中U(VI)-CMPO 配合物经过准可逆还原生成U(V)-CMPO 配合物, U(VI)/U(V)电对的表观氧化还原电势(EΘ, vs Fc/Fc+)为(?0.885±0.008) V. 对萃取液进行控制电位电解, 发现在铂片上有沉淀析出. X射线光电子能谱(XPS) 测试结果表明, 沉积物中只含有U(VI)、U(IV)和氧, 而CMPO和C4mimNTf2没有被夹带析出. 相似文献
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76.
Patrick Florchinger 《随机分析与应用》2015,33(6):1056-1067
The purpose of this article is to derive finite-dimensional filters for exponential functionals of the state of nonlinear Bene? type filtering systems with correlated noises. These new filters can be applied in the state reconstruction of doubly–stochastic auto–regressive processes. 相似文献
77.
Selberg-type integrals that can be turned into constant term identities for Laurent polynomials arise naturally in conjunction with random matrix models in statistical mechanics. Built on a recent idea of Karasev and Petrov we develop a general interpolation based method that is powerful enough to establish many such identities in a simple manner. The main consequence is the proof of a conjecture of Forrester related to the Calogero–Sutherland model. In fact we prove a more general theorem, which includes Aomoto's constant term identity at the same time. We also demonstrate the relevance of the method in additive combinatorics. 相似文献
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Nuclear magnetization storage in biologically-relevant molecules opens new possibilities for the investigation of metabolic pathways, provided the lifetimes of magnetization are sufficiently long. Dissolution-dynamic nuclear polarization-based spin-order enhancement, sustained by long-lived states can measure the ratios between concentrations of endogenous molecules on a cellular pathway. These ratios can be used as meters of enzyme function. Biological states featuring intracellular amino-acid concentrations that are depleted or replenished in the course of in-cell or in-vivo tests of drugs or radiation treatments can be revealed. Progressing from already-established long-lived states, we investigated related spin order in the case of amino acids and other metabolites featuring networks of coupled spins counting up to eight nuclei. We detail a new integrated theoretical approach between quantum chemistry simulations, chemical shifts, J-couplings information from databanks, and spin dynamics calculations to deduce a priori magnetization lifetimes in biomarkers. The lifetimes of long-lived states for several amino acids were also measured experimentally in order to ascertain the approach. Experimental values were in fair agreement with the computed ones and prior data in the literature. 相似文献
80.