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41.
使用含时密度泛函理论(TDDFT)B3LYP方法计算了IB, IIB, VIIIB过渡金属与8-羟基喹啉络合(MQ)后, 配合物的电子光谱以及二阶非线性光学性质. 结果表明, 掺杂过渡金属后, 形成络合物的能隙值减小100~150 kJ/mol, 最大吸收波长红移150~200 nm左右. 电子从基态到激发态的跃迁主要为p→p*, n→p*跃迁, 属于LLCT, MLCT过程. IB的络合物MQ以及VIIIB的络合物MQ3表现出良好的非线性光学性质. 相似文献
42.
In this paper, we describe a useful class of finite-dimensional variational inequalities which we call partitionable. These variational inequalities are characterized by state functions which can be thought of as nonlinear separable functions added to antisymmetric linear functions. In the case of partitionable variational inequalities, questions of the monotonicity and coercivity of the state function can be addressed by considering the monotonicity and coercivity of a series of lower-dimensional functions. These functions are generally simpler to investigate than the state function. In the applications, these lower-dimensional functions are usually the natural functions to consider. To demonstrate, we conclude the paper by reviewing several models in the recent literature which give rise to partitionable variational inequalities. 相似文献
43.
历代反动派总是宣扬孔老二“上智与下愚不移”的唯心论说教,把它作为“剥削有理”、“压迫有理”的根据。林彪这个地主资产阶级的代理人,为了篡党夺权,复辟资本主义,建立林家法西斯王朝,也鼓吹“上智下愚”的谬论。他把自己吹成“生而知之”的“天才”,以“至贵”、超人自居,污蔑劳动人民“愚昧”、“落后”,只会说“恭喜发财”,只能想“油盐酱醋柴”。 相似文献
44.
The construction and exact quantum mechanical solution of anharmonic potential models is discussed. For low energy eigenvalues the proposed models simulate the usual quadratic-quartic potentials, but for high eigenvalues their properties are essentially those of the harmonic oscillator. 相似文献
45.
Hoogesteger FJ van Walree CA Jenneskens LW Roest MR Verhoeven JW Schuddeboom W Piet JJ Warman JM 《Chemistry (Weinheim an der Bergstrasse, Germany)》2000,6(16):2948-2959
The photophysical properties of a bicyclohexylidene (1DA) and a bicyclohexyl (2DA) substituted with an anilino electron donor and a dicyanoethylene electron acceptor have been studied. Quenching of local donor emission is observed for these compounds as well as quenching of the "pseudo-local" acceptor emission. Transient absorption spectra show dialkylanilino-type radical-cation and dicyanoethylene-type radical-anion absorptions. These results show that intramolecular charge separation takes place in 1DA and 2DA. This was corroborated by time-resolved microwave conductivity measurements from which large excited-state dipole moments were found for both 1DA and 2DA. Time-resolved fluorescence spectroscopy revealed that in the charge-separated state in cyclohexane for 2DA, molecular folding takes place on a nanosecond timescale. For 1DA in cyclohexane, either charge separation takes place in a (fully) folded conformation or very rapid (subnanosecond timescale) folding takes place subsequent to charge separation. In addition to this difference in conformational behavior, the presence of the exocyclic double bond between the cyclohexyl-type rings results in efficient quenching of the anilino donor triplet state and acceleration of the charge recombination rate by a factor of 20. 相似文献
46.
The rotational barriers in dimethyl acetylene (CH3CCCH3), diamino acetylene (H2NCCNH2), dihydroxy acetylene (HOCCOH), methyl trifluoro methyl acetylene (CF3CCCH3), silyl methyl acetylene (SiH3CCH3), propene, cis and trans 2-butene and ethane were studied by ab initio molecular orbital methods using various basis sets. The eclipsed structure for dimethyl acetylene and its CF3 and SiH3 analogs was found to be the most stable, as has been inferred from experimental work, and the barrier height for these compounds has been predicted. The barriers in the OH and NH2 substituted acetylenes, propene, butene and ethane were studied in order to more clearly understand the important influences in determining the barrier mechanism; specifically, the delocalized molecular orbital and Pauling VB model have been compared. 相似文献
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A design of polarization-maintaining retro-reflectors(PMRRs) for folded-path applications is proposed and analyzed.The prism-based scheme enables the output light,which is parallel to the input,to have an identical state of polarization.The principle of the design is theoretically verified,and the related error is analyzed due to possible manufacturing imperfection.The maximum spatial angle error is ±2.75°.The effect on the extinction ratio and insertion loss is also discussed,which further proves the design’s feasibility in practical applications. 相似文献
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