全文获取类型
收费全文 | 475篇 |
免费 | 5篇 |
国内免费 | 3篇 |
专业分类
化学 | 377篇 |
晶体学 | 1篇 |
力学 | 15篇 |
数学 | 38篇 |
物理学 | 52篇 |
出版年
2022年 | 7篇 |
2021年 | 4篇 |
2020年 | 7篇 |
2019年 | 4篇 |
2018年 | 6篇 |
2017年 | 2篇 |
2016年 | 9篇 |
2015年 | 7篇 |
2014年 | 14篇 |
2013年 | 24篇 |
2012年 | 30篇 |
2011年 | 28篇 |
2010年 | 17篇 |
2009年 | 14篇 |
2008年 | 24篇 |
2007年 | 24篇 |
2006年 | 21篇 |
2005年 | 27篇 |
2004年 | 29篇 |
2003年 | 33篇 |
2002年 | 33篇 |
2001年 | 8篇 |
2000年 | 8篇 |
1999年 | 8篇 |
1998年 | 6篇 |
1997年 | 9篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1994年 | 7篇 |
1993年 | 8篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1988年 | 6篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 6篇 |
1984年 | 6篇 |
1982年 | 5篇 |
1981年 | 6篇 |
1980年 | 5篇 |
1978年 | 2篇 |
1977年 | 3篇 |
1976年 | 2篇 |
1975年 | 3篇 |
1974年 | 2篇 |
1973年 | 1篇 |
排序方式: 共有483条查询结果,搜索用时 15 毫秒
101.
Martine Ben Amar Pasquale Ciarletta 《Journal of the mechanics and physics of solids》2010,58(7):935-562
The purpose of this work is to provide a theoretical analysis of the mechanical behavior of the growth of soft materials under geometrical constraints. In particular, we focus on the swelling of a gel layer clamped to a substrate, which is still the subject of many experimental tests. Because the constrained swelling process induces compressive stresses, all these experiments exhibit surface instabilities, which ultimately lead to cusp formation. Our model is based on fixing a neo-Hookean constitutive energy together with the incompressibility requirement for a volumetric, homogeneous mass addition. Our approach is developed mostly, but not uniquely, in the plane strain configuration. We show how the standard equilibrium equations from continuum mechanics have a similarity with the two-dimensional Stokes flows, and we use a nonlinear stream function for the exact treatment of the incompressibility constraint. A free energy approach allows the extension both to arbitrary hyperelastic strain energies and to additional interactions, such as surface energies. We find that, at constant volumetric growth, the threshold for a wavy instability is completely governed by the amount of growth. Nevertheless, the determination of the wavelength at threshold, which scales with the initial thickness of the gel layer, requires the coupling with a surface effect. Our findings, which are valid in proximity of the threshold, are compared to experimental results. The proposed treatment can be extended to weakly nonlinearities within the aim of the theory of bifurcations. 相似文献
102.
Pierre Thuéry Martine Nierlich Éronique Lamare Jean-François Dozol Zouhair Asfari Jacques Vicens 《Journal of inclusion phenomena and macrocyclic chemistry》2000,36(4):375-408
The association within one molecule ofcalix[4]arene and crown ether moieties leads toligands with new complexing properties. In particular,calix[4]arene bis(crown-6) and some of itsderivatives have been shown to be highly selectiveextractants for caesium ions. This review presents thebackground of the study and the results of crystalstructure determinations and molecular modellingcalculations performed during the investigation of twomolecular families, the bis(crown ether) and theazobenzocrown derivatives of calix[4]arene. 相似文献
103.
Pierre Thuéry Martine Nierlich Jacques Vicens Bernardo Masci 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(1):70-71
The title compound, 7,13,21,27-tetra-tert-butyl-3,17-dioxapentacyclo[23.3.1.15,9.111,15.19,23]ditriaconta-1(29),5,7,9(30),11(31),12,14,19(32),20,22,25,27-dodecaene-29,30,31,32-tetraol, crystallizes as a solvate with one molecule of chloroform and one molecule of tetrahydrofuran, C46H60O6·CHCl3·C4H8O. The calixarene assumes a cone-like conformation stabilized by intramolecular hydrogen bonds involving both phenolic and ether O atoms. The two solvent molecules are located in each of the two half-cone cavities of the calixarene. 相似文献
104.
Daniel Plusquellec Catherine Brenner-Hénaff Pascale Léon-Ruaud Stéphane Duquenoy Martine Lefeuvre Henri Wróblewski 《Journal of carbohydrate chemistry》2013,32(5):737-751
Abstract Treatment of free glycosylamines with 3-acyl-5-methyl-1,3,4-thiadiazole-2 (3H)-thiones 6 or with acids and 5-methyl-2-thioxo-1,3,4-thiadiazole-3(2H)-carbothioic acid S-(5-methyl-1,3,4-thiadiazol-2-yl) ester 7 in hydroorganic media afforded N-acylglycosylamines in high yields and without any competitive deglycosylation. This reaction found applications in the synthesis of N-glycopeptide building blocks and of glycosidic non ionic surfactants. Results concerning surface activities of two N-acylglycosylamines are reported. The new non ionic N-octanoyl-β-D-glucosylamine surfactant exhibited efficacy and selectivity in the extraction of membrane proteins, enhanced the activity of a membrane succinate dehydrogenase and proved thus useful for membrane studies. 相似文献
105.
B. Gawlik Martine Druges Michele Bianchi Angelo Bortoli Antonius Kettrup Herbert Muntau 《Fresenius' Journal of Analytical Chemistry》1997,358(3):441-445
The quality of the aquatic and marine environment can be monitored by the determination of pollutants in organisms living
in this environment. Certified reference materials and well-organised proficiency tests are powerful means of ensuring a constant
level of quality and verifying the correct application of standardised methods. The preparation of a tuna fish proficiency
testing material for the evaluation of quality of As and Hg monitoring in seafood is described. Preparation and characterisation
of the material as well as studies on its homogeneity and stability are described. Concentrations of 3.4 ± 0.2 mg/kg total
arsenic and 2.91 ± 0.09 mg/kg total mercury have been determined as target values. Moreover indicative values for some trace
elements (Cd, Cu, Ni, Pb, Sr) and some major constituents (Al, Br, C, Ca, Cl, Fe, H, K, Mg, N, Na, P, S, Si, Zn) have also
been measured.
Received: 29 November 1996 / Revised: 17 February 1997 / Accepted: 22 February 1997 相似文献
106.
Dimitra Markovitsi Jean-Jacques Andre André Mathis Jacques Simon Pierre Spegt Gilbert Weill Martine Ziliox 《Chemical physics letters》1984,104(1):46-49
The solid—solid phase transition of an annlide type copper complex are described. As the temperature is raised, three different constituents of the complex successively melt. In the temperature range 77–95°C, the polyethylene oxide chains and the paraffinic tail are both in a very mobile state while the copper complex sub-units still form a two-dimensional crystalline array. 相似文献
107.
Jean-Pierre Pulicani Daniel Bzard Jean-Dominique Bourzat Herv Bouchard Martine Zucco Dominique Deprez Alain Commeron 《Tetrahedron letters》1994,35(52):9717-9720
A new route to semisynthetic 2-modified docetaxel analogs is described using electrochemical cleavage of the 2-benzoate as the key reaction. Subsequent reacylation at C-2 followed by sequential deprotections afforded the title analogs. Biological results of selected 2-docetaxel analogs are presented. 相似文献
108.
Martine Labbe 《European Journal of Operational Research》1985,20(3):299-313
For a given set of users located at the vertices of a network N, we consider the location of a single facility. Two different decision making procedures, voting among the users and minimizing total distance travelled by the users, are compared.Provided that a voting solution exists, it is shown that the two solutions sets coincide if N is a so-called cactus. For general networks, the outcomes of the two procedures are compared in terms of the cyclic structure of N and the number of users. 相似文献
109.
110.
Bravo M Lespes G De Gregori I Pinochet H Potin-Gautier M 《Journal of chromatography. A》2004,1046(1-2):217-224
Because of the high toxicity of organotin compounds and the current regulation about their applications, analytical method usable in routine analysis is required. A speciation procedure based on NaBEt4 ethylation and GC-PFPD analysis has shown to be suitable for the organotin determination. Unfortunately, some matrix effects were observed during the analysis of harbour sediments from Chile. These effects were identified as the alkylation of elemental sulfur and the coelution between the organotin compounds and some dialkylsulfides. The re-optimization of GC parameters and application of solid phase microextraction (SPME) were proposed to solve these analytical problems. Certified reference materials and different harbour sediment samples were analysed in order to evaluate the suitability of the methods for organotin control in complex environment samples. 相似文献