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991.
A convex nonsmooth optimization problem is replaced by a sequence of line search problems along recursively updated rays. Convergence of the method is proved, and relations to existing methods are discussed.  相似文献   
992.
Generalized OWA Aggregation Operators   总被引:7,自引:0,他引:7  
We extend the ordered weighted averaging (OWA) operator to a provide a new class of operators called the generalized OWA (GOWA) operators. These operators add to the OWA operator an additional parameter controlling the power to which the argument values are raised. We look at some special cases of these operators. One important case corresponds to the generalized mean and another special case is the ordered weighted geometric operator.  相似文献   
993.
This problem (proposed for the 4th International Symposium on Applied Stochastic Models and Data Analysis) concerns an exploratory study related to the presently accepted hypothesis that temporal curves of the forced pulse luminescence of specialized blood cells, granulocytes, may indicate the level of effectiveness of the immunological system. This paper presents a new set of empirical data and an analysis of its structure.  相似文献   
994.
In this paper, we present a conductivity method for measuring the RBC (red blood cell)aggregation-sedimentation phenomenon and the theoretical analysis of this phenomenon. Atheory describing the RBC aggregation-sedimentation phenomenon with the conductivity meth-od is proposed and the formula of the I-t function which depicts the RBC aggregation-sedimentation process is given. We put forward the aggregation index and sedimentation fac-tot describing the RBC aggregation-sedimentation phenomenon for the first time.  相似文献   
995.
996.
Pyrene-labeled functionalized ethylene-propylene (EP) copolymer was prepared by grafting 1-pyrenebutyrylhydrazine onto EP copolymer through maleic anhydride pendants. The EP copolymer contained 60 mol % ethylene; its weight-average molecular weight (Mw) was 148,000. The pyrene-labeled amide functionalized EP copolymer, PA-EP(60/40), was made to simulate the amine functionalized EP copolymers that are commonly used as dispersant additives in motor oils. UV absorption spectra, fluorescence emission and excitation spectra, and fluorescence decay profiles of the pyrene were studied to determine the copolymer conformation and dynamics in methylcyclohexane and tetrahydrofuran (THF). The pyrene fluorescence characteristics of PA-EP(60/40) were highly dependent on the solvent. The dependence of fluorescence emission intensity on the excitation wavelength was large in methylcyclohexane and moderate in THF. A frequency shift of about 2 nm was observed between the excitation spectrum obtained with the emission line at 377 nm and that at 550 nm in the methylcyclohexane solutions, but no shift was found in the corresponding tetrahydrofuran solutions. The ratios of the preexponential factors (a21/a22) of the excimer decays obtained in both methylcyclohexane and THF solutions were different from ?1.0. However, the deviation of the excimer formation process from the Birks scheme is small in THF but large in methylcyclohexane. In addition, the Huggins constants obtained from intrinsic viscosity measurements of the PA-EP(60/40) copolymer solutions suggest that copolymer aggregation occurs in methylcyclohexane but not in THF. H-bonding between two pyrene-containing pendants is apparently the main driving force for the formation of the ground state pyrene complex. THF is found to be effective in inhibiting the H-bonding formation. © 1995 John Wiley & Sons, Inc.  相似文献   
997.
998.
Asymmetric anionic polymerizations of 2,6-dimethyl-7-phenyl-1,4-benzoquinone methide ( 1 ) were performed with various chiral anionic initiators, and the specific rotations of the obtained polymers were investigated. Optically active poly( 1 )s with configurational chirality were obtained with all the initiators, and a complex of fluorenyllithium (FlLi) with (−)-sparteine [(−)-Sp] produced poly( 1 ) with the largest negative specific rotation ([α]435 = −26.8°). The specific rotations of poly( 1 )s obtained with FlLi/(−)-Sp depended on the initiator concentration and the solvent polarity. The maximum specific rotations were obtained at an almost constant initiator concentration (ca. 0.03 mol/L), regardless of the monomer concentration, in toluene, whereas a higher initiator concentration was required in more polar solvents. These results suggested that the aggregation state of the propagating chain end significantly affected the specific rotation of poly( 1 ). © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 4548–4555, 2004  相似文献   
999.
连季春  林晓  高利  高鸿钧 《物理》2005,34(2):131-137
文章介绍了纳米电子学在自组织生长、器件构造和电学/光学器件应用等方面的最新进展,其中包括:利用流体或极性分子实现了纳米线/管的定向排列;用此方法制成了纳米线逻辑电路和新型纳米线/带薄膜晶体管;研制成功可进行高密度信息存储的单分子层面纳米线交叉电路;进行了半导体CdS纳米线电泵激光和碳纳米管电致发光研究.此外,还对自旋电子学的研究进展进行了简要介绍,对纳米电子学的研究与发展方向提出了建议。  相似文献   
1000.
开环聚合制备高分子量聚二茂铁衍生物及其性能的研究   总被引:4,自引:0,他引:4  
王学杰  王立 《化学进展》2002,14(6):486-493
综述了近年来国内外高分子量聚二茂铁衍生物的研究进展。对热引发、阴离子引发、过渡金属催化等开环聚合方法及机理以及聚合物结构、性能及潜在应用作了介绍。  相似文献   
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