全文获取类型
收费全文 | 930篇 |
免费 | 0篇 |
国内免费 | 16篇 |
专业分类
化学 | 524篇 |
晶体学 | 3篇 |
力学 | 50篇 |
数学 | 165篇 |
物理学 | 204篇 |
出版年
2022年 | 11篇 |
2021年 | 13篇 |
2020年 | 7篇 |
2019年 | 8篇 |
2018年 | 14篇 |
2017年 | 7篇 |
2016年 | 12篇 |
2015年 | 12篇 |
2014年 | 22篇 |
2013年 | 52篇 |
2012年 | 50篇 |
2011年 | 64篇 |
2010年 | 42篇 |
2009年 | 34篇 |
2008年 | 50篇 |
2007年 | 59篇 |
2006年 | 53篇 |
2005年 | 46篇 |
2004年 | 59篇 |
2003年 | 36篇 |
2002年 | 38篇 |
2001年 | 12篇 |
2000年 | 17篇 |
1999年 | 8篇 |
1998年 | 9篇 |
1997年 | 15篇 |
1996年 | 9篇 |
1995年 | 13篇 |
1994年 | 19篇 |
1993年 | 10篇 |
1992年 | 11篇 |
1991年 | 10篇 |
1990年 | 6篇 |
1989年 | 6篇 |
1987年 | 7篇 |
1985年 | 7篇 |
1984年 | 6篇 |
1983年 | 8篇 |
1982年 | 12篇 |
1981年 | 5篇 |
1980年 | 8篇 |
1979年 | 5篇 |
1978年 | 5篇 |
1977年 | 3篇 |
1976年 | 5篇 |
1975年 | 3篇 |
1974年 | 3篇 |
1973年 | 3篇 |
1967年 | 3篇 |
1928年 | 3篇 |
排序方式: 共有946条查询结果,搜索用时 140 毫秒
81.
Jean-Marc Jancu Jean-Christophe Harmand Gilles Patriarche Anne Talneau Karine Meunier Frank Glas Paul Voisin 《Comptes Rendus Physique》2007,8(10):1174-1183
A new attempt to solve the phase matching problem for semiconductor-based frequency conversion devices, based on the implementation of intrinsic birefringence in artificial materials, is discussed. The first results concerning the growth and characterization of ultrashort period superlattices are presented. To cite this article: J.-M. Jancu et al., C. R. Physique 8 (2007). 相似文献
82.
Jean-Marc Hrard 《Comptes Rendus Mecanique》2008,336(8):650-655
We introduce an hyperbolic two-fluid two-pressure model to compute unsteady two-phase flows in porous media. The closure laws comply with the entropy inequality, and a unique set of jump conditions holds within each field. To cite this article: J.-M. Hérard, C. R. Mecanique 336 (2008). 相似文献
83.
S. A. Gottlieb J. Kuti D. Toussaint A. D. Kennedy S. Meyer B. J. Pendleton R. L. Sugar 《Journal of statistical physics》1986,43(5-6):1105-1115
We present a large-scale Monte Carlo calculation of the deconfining phase transition temperature in lattice quantum chromodynamics
without fermions. Using the Wilson action, the transition temperature as a function of the lattice couplingg is consistent with scaling behavior dictated by the perturbativeα function for 6/g2>6.15.
Speaker at the conference; on leave from CRIP, Budapest. 相似文献
84.
Jean-Marc Renaud Georges Tsoupras Helen Stoeckli-Evans Raffaele Tabacchi 《Helvetica chimica acta》1989,72(6):1262-1267
The novel allenic epoxycyclohexanes 1 , and related compounds 2 and 3 have been isolated from the culture medium of Eutypa lata. Their structures were established by combination of spectroscopic and chemical techniques. Biogenetic origin and biological activity of these compounds are also discussed. 相似文献
85.
86.
Jean-Marc Vincent 《Journal of fluorine chemistry》2008,129(10):903-909
Perfluorocarbons (PFCs) are emerging as a new type of liquid phase in which molecular recognition processes can effectively take place. The combination of perfluorocarbons (PFCs) and noncovalent associations, mostly hydrogen bonds, ion pairing, halogen bonds or coordination bonds, has already been successfully exploited for applications in organic synthesis (catalyst recycling, by-product removal), electrochemical sensing, selective extraction/titration processes or to prepare gels. Due to the extreme solvophobic effect in PFCs, the least polar existing fluids, noncovalent associations tend to be enhanced. For instance, quantitative data on the increase in association strength occurring in PFCs have recently been reported for ion-pairing interactions or encapsulation processes. Moreover, several examples show that confining a receptor in a fluorous phase leads to recognition processes with improved selectivity. 相似文献
87.
88.
Séverine Humbert Olivier Lame Jean-Marc Chenal Cyrille Rochas Gérard Vigier 《Journal of polymer science. Part A, Polymer chemistry》2010,48(13):1535-1542
Stack lamella deformation depends on their orientation with respect to the loading axis, the intrinsic properties of the lamellae, and the mechanical coupling between crystalline and amorphous phases. The aim of this work is to investigate the influence of the stress transmitter (ST) density and the crystallinity Xc on the local deformation. A wide experimental campaign has been undertaken on several polyethylenes with controlled molecular parameters and subjected to different thermal treatments. The ST density has been evaluated by the natural draw ratio and calculated by the Brown's model. The local deformation was measured by SAXS along a tensile test by using the long period stretching of the equatorial lamella stacks. The ratio εlocal/εmacro was found to be a constant close to 0.5. This surprising low value has highlighted that the equatorial regions could be either the stiffest zone of the spherulite or submitted to a lower stress. It is proposed that the stability of the ratio εlocal/εmacro is the result of two opposite phenomena: On one hand, the increase of Xc leads to unload the equatorial regions due to partial percolation of the crystalline phase and so decreases the stresses. On the other hand, when increasing Xc, the ST density decreases which causes the decrease in the local equatorial modulus. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1535–1542, 2010 相似文献
89.
We present an extension of some popular hindered rotor (HR) models, namely, the one-dimensional HR (1DHR) and the degenerated two-dimensional HR (d2DHR) models, allowing for a simple and accurate treatment of internal rotations. This extension, based on the use of a variable kinetic function in the Hamiltonian instead of a constant reduced moment of inertia, is extremely suitable in the case of rocking/wagging motions involved in dissociation or atom transfer reactions. The variable kinetic function is first introduced in the framework of a classical 1DHR model. Then, an effective temperature and potential dependent constant is proposed in the cases of quantum 1DHR and classical d2DHR models. These methods are finally applied to the atom transfer reaction SiCl(3)+BCl(3)→SiCl(4)+BCl(2). We show, for this particular case, that a proper accounting of internal rotations greatly improves the accuracy of thermodynamic and kinetic predictions. Moreover, our results confirm (i) that using a suitably defined kinetic function appears to be very adapted to such problems; (ii) that the separability assumption of independent rotations seems justified; and (iii) that a quantum mechanical treatment is not a substantial improvement with respect to a classical one. 相似文献
90.
Gomila A Le Poul N Cosquer N Kerbaol JM Noël JM Reddy MT Jabin I Reinaud O Conan F Le Mest Y 《Dalton transactions (Cambridge, England : 2003)》2010,39(48):11516-11518
We report the self-induced "electroclick" immobilization of the [Cu(II)(6-ethynyl-TMPA)(H(2)O)](2+) complex, by its simple electro-reduction, onto a mixed azidoundodecane-/decane-thiol modified gold electrode. The redox response of the grafted [Cu(II/I)(TMPA)] at the modified electrode is fully reversible indicating no Cu coordination change and a fast electron transfer. 相似文献