排序方式: 共有96条查询结果,搜索用时 31 毫秒
1.
Equilibrium Problems with Applications to Eigenvalue Problems 总被引:5,自引:0,他引:5
In this paper, we consider equilibrium problems and introduce the concept of (S)+ condition for bifunctions. Existence results for equilibrium problems with the (S)+ condition are derived. As special cases, we obtain several existence results for the generalized nonlinear variational inequality studied by Ding and Tarafdar (Ref. 1) and the generalized variational inequality studied by Cubiotti and Yao (Ref. 2). Finally, applications to a class of eigenvalue problems are given. 相似文献
2.
Top S el Hafa H Vessiéres A Huché M Vaissermann J Jaouen G 《Chemistry (Weinheim an der Bergstrasse, Germany)》2002,8(22):5241-5249
In order to elucidate the extent to which recognition of the estrogen receptor is influenced by addition of an organometallic substituent at the 17 alpha position, modification of 17 beta-estradiol at this position was carried out by using the organometallic groups -C identical to C(eta 5-C5H4)RuCp, CH2-(eta 5-C5H4)RuCp, -C identical to C-(eta 5-C5H4)-W(CO)3(Me), -(C identical to CCHO)Co2(CO)6, and -(C identical to CCH2OH)Co2(CO)6. The relative binding affinity (RBA) values for estradiol receptor alpha showed that recognition was good (RBA between 20 and 13.5%) when the organometallic moiety was attached at the end of a rigid alkyne spacer. However, the affinity of the modified hormone for the receptor was severely reduced (RBA = 1%) for a substituent such as -CH2-(eta 5-C5H4)RuCP, in which the spacer is reduced to a single flexible sp3 carbon atom, allowing the organometallic moiety greater freedom of movement around the attachment point. The RBA values found were in agreement with results obtained from a molecular-modeling study in which 5, an organometallic hormone with a rigid spacer, or 7, a molecule with a flexible spacer, was inserted into the cavity of the recently characterized Ligand-Binding Domain of estrogen receptor alpha. 相似文献
3.
We report the use of a novel pulsed ESR technique for distance measurement, based on the detection of double quantum coherence (DQC), which yields high quality dipolar spectra, to significantly extend the range of measurable distances in proteins using nitroxide spin-labels. Eight T4 lysozyme (T4L) mutants, doubly labeled with methanethiosulfonate spin-label (MTSSL), have been studied using DQC-ESR at 9 and 17 GHz. The distances span the range from 20 A for the 65/76 mutant to 47 A for the 61/135 mutant. The high quality of the dipolar spectra also allows the determination of the distance distributions, the width of which can be used to set upper and lower bounds in future computational strategy. It is also demonstrated that the shape of these distributions can reveal the presence of multiple conformations of the spin-label, an issue of critical relevance to the structural interpretation of the distances. The distances and distributions found in this study are readily rationalized in terms of the known crystal structure, the characteristic conformers of the nitroxide side chains, and molecular modeling. This study sets the stage for the use of DQC-ESR for determining the tertiary structure of large proteins with just a small number of long-distance constraints. 相似文献
4.
5.
Archiv der Mathematik - Let k be a field of characteristic $$ p\not =0 $$. For a (purely) inseparable extension K / k the notion of modularity, defined by M.E. Sweedler in the... 相似文献
6.
A series of 4-spiro-cyclohexadienonyl-β-lactam-3-carbonitriles, 2,7-dioxo-1-azaspiro[3.5]nona-5,8-diene-3-carbonitriles, was synthesized in satisfactory to excellent yields via the intramolecular nucleophilic cyclization of N-(p-hydroxyphenyl)cyanoacetamides with iodobenzene diacetate (IBD) as oxidant and potassium hydroxide as base. Acetic 4-spiro-cyclohexadienonyl-β-lactam-3-carbimidic anhydrides were obtained when organic base triethylamine was applied instead of potassium hydroxide. The mechanisms of the intramolecular nucleophilic cyclization and formation of acetic β-lactam-3-carbimidic anhydrides were proposed. The cyclization is a sequence of nucleophilic ipso addition and oxidative dearomatization. The formation of acetic carbimidic anhydrides is an acid-catalyzed acetate addition to the nitriles. 相似文献
7.
The gas-phase molecular structure of 6,6-dimethyl-1-oxa-spiro[2.5]octane has been investigated by joint analysis of the microwave spectrum and molecular mechanics calculations. Both experimental and theoretical data concur showing the presence of two stable conformational isomers having a chair cyclohexane ring. A set of structural parameters which reproduce the ground state rotational constants has been derived. The influence of 1,4 disubstitution is discussed in terms of deformations of the cyclohexane ring. 相似文献
8.
Fatima El Guezar Hassane Bouzahir Danièle Fournier-Prunaret 《Nonlinear Analysis: Hybrid Systems》2011,5(4):626-638
Many switched circuits are made of linear components switched by a simple logic unit. In this paper, we use a generic planar Piece-wise Affine Hybrid System (PWAHS) to model this kind of circuit. Usually, simulations are run by analytical methods (adapted to a specific simple model) or by numerical simulations that can miss some events’ occurrences. We propose a generic planar method to simulate PWAHSs with periodic and state dependent events. Using analytical expressions, our approach can reach arbitrary accuracy in event detections without any loss. As a result, we have implemented our method in Scilab and Matlab toolboxes. 相似文献
9.
The truncated singular value decomposition is a popular method for the solution of linear ill-posed problems. The method requires the choice of a truncation index, which affects the quality of the computed approximate solution. This paper proposes that an L-curve, which is determined by how well the given data (right-hand side) can be approximated by a linear combination of the first (few) left singular vectors (or functions), be used as an aid for determining the truncation index. 相似文献
10.
We consider the interface between a twisted birefringent mesophase and an isotropic medium. In the selective reflection band, when illuminated at normal incidence, the interface creates a coupling between the located dielectric reflection and the spread selective reflection. This coupling enables experimental measurement of the standing electric field orientation inside the liquid crystal. 相似文献