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许雪松 《原子与分子物理学报》2006,23(1):137-142
应用密度泛函B3LYP/6—31+G(d,p)方法对C8H80-(H2O)n(n=1~5)团簇这种弱相互作用体系进行垒自由度能量梯度优化,得到该系列团簇的稳定蛄构.计算结果表明。在该系列二元团簇中,一方面水分子数目的多少对苯基丙酮分子的结构影响很小,另一方面由于苯基丙酮分子的存在,破坏了团簇中水分子的对称性结构,在团簇内部极力形成O—H—O这样弯曲的有方向性的氢键.对苯基丙酮-水这样结构复杂的团簇,指认光谱的难度非常大,本文只讨论了与C=O有关的振动峰和水分子的对称伸缩振动的最强峰. 相似文献
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《ournal of non Newtonian Fluid Mechanics》2007,141(2-3):85-98
Two solutions are presented for fully-developed pipe and planar flows of multimode viscoelastic models. The fluids have a Newtonian solvent contribution and the polymer modes are described by the Phan-Thien—Tanner (PTT), the FENE-P or the Giesekus equation. The first solution is exact and can handle any number of modes, but is only semi-analytical. The second solution, which is presented only for the PTT model with a linear stress coefficient and the FENE-P model, can also handle any number of modes. It is based on a truncated series expansion and is completely analytical, but provides only an approximated solution. The complexity of the multimode solutions is investigated first with the exact semi-analytical method and it is shown that at high Deborah number flows the high-order stresses can become as important as the stress of the first mode. It is also under these conditions that the approximated analytical solution deviates from the exact semi-analytical solution. A criterion for the accurate use of the approximated solution is presented. Fortran codes are provided to obtain these solutions at the internet address at the end. 相似文献
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Siegfried Grossmann Denis Jérome Antonio Paoletti 《The European Physical Journal B - Condensed Matter and Complex Systems》2003,31(4):447
We mourn the death of Professor Dr. Gilbert Grynberg, April 17, 1948 - January 27, 2003. We have lost an excellent and highly esteemed scientist, an outstanding character and a good friend. He has been a very active colleague in the merger of Zeitschrift für Physik and Journal de Physique in the early days. As one of the Co-Editors-in-Chief of The European Physical Journal D, from its start, he has formed the scienti.c standards of EPJ. Untiringly he has served our Journal with greatest dedication. We are grateful that he has been with us. The editorial board and o.ce of EPJ B Siegfried Grossmann, Denis Jérome, Antonio Paoletti 相似文献
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ZHANG Wei-wei CHEN Yu-chun LUO Zhao-feng WANG Ju-ying MA De-yi 《高等学校化学研究》2007,23(4):404-407
In this study, surface plasmon resonance (SPR) for monitoring 17β-eatradiol (E2) was developed. The small molecule E2 was immobilized on a CM5 sensor chip for an indirect competitive immunoassay to detect E2. The SPR response bahed on the antigen-antibody reaction was measured by injecting the sample solution into the flow system. The limitation of detection was 0.445 μg/L. The developed SPE-SPR system was applied to analyze the seawater samples. Recovery of E2 was 91.6%-93. 1%. Relative standard deviations(RSD) for the E2 assay were between 10.9%-15.1% (n = 3). The range of determination of E2 samples from the sewage in the coastal marine environ-ment was between ND(lower than detection limit) and ca. 11.78 ng/L. 相似文献
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碳酸自由基、硝酸自由基、磷酸自由基和硫酸自由基是化学反应的重要中间体,都具有氧化性,对污染物在自然和人为环境中的迁移转化会产生重要的影响.文中较为详细地介绍这几种自由基的电极电位、产生方式、检测方法及与有机物的反应方式.总结四种自由基的特性及与有机物的反应方式可发现,四种自由基和羟自由基电极电位不同,导致它们和有机物反应速率的不同;碳酸自由基并不是羟自由基去除剂,对于一些容易被氧化的化合物,碳酸自由基氧化效果比羟自由基好;四种自由基均可由羟自由基转化而来,并且这四种自由基和羟自由基与有机物反应方式基本一致,都通过电子转移、夺氢和加成的方式进行.可以预测四种自由基和羟自由基降解有机物的机理将非常相似,今后应研究四种自由基与羟自由基相互转化的规律,以及与代表性有机物的反应机理. 相似文献
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Diao Hongyue Deng Ansheng Cui Hui Liu Xin Zou Li 《Fuzzy Optimization and Decision Making》2022,21(1):45-69
Fuzzy Optimization and Decision Making - Linguistic information processing exists in multi-criteria decision making, and linguistic truth-valued lattice implication algebra (LTV-LIA) has definite... 相似文献
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One dimensional nanostructures of cerium doped dysprosium phosphate (DyPO4:Ce3+) were synthesized via hydrothermal route in the presence of different surfactants [sodium dodecyl sulfate (SDS), dodecyl sulfosuccinate (DSS), polyvinyl pyrollidone (PVP)] and solvent [ethylene glycol and water]. The prepared nanostructures were characterized by Powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), Field emission scanning electron microscopy (FE-SEM), Transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), UV-VIS-NIR absorption spectrophotometer and photoluminescence (PL) studies. The PXRD and FTIR results indicate purity, good crystallinity and effective doping of Ce3+ in nanostructures. SEM and TEM micrographs display nanorods, nanowires and nanobundles like morphology of DyPO4:Ce3+. Energy-dispersive X-ray spectra (EDS) of DyPO4:Ce3+nanostructures confirm the presence of dopant. UV-VIS-NIR absorption spectra of prepared compounds are used to calculate band gap and explore their optical properties. Luminescent properties of DyPO4:Ce3+ was studied by using PL emission spectra. The effect of additives and solvents on the uniformity, morphology and optical properties of the nanostructures were studied in detail. 相似文献