全文获取类型
收费全文 | 13221篇 |
免费 | 613篇 |
国内免费 | 1135篇 |
专业分类
化学 | 9783篇 |
晶体学 | 145篇 |
力学 | 113篇 |
综合类 | 53篇 |
数学 | 2967篇 |
物理学 | 1908篇 |
出版年
2024年 | 10篇 |
2023年 | 93篇 |
2022年 | 249篇 |
2021年 | 216篇 |
2020年 | 188篇 |
2019年 | 602篇 |
2018年 | 334篇 |
2017年 | 539篇 |
2016年 | 328篇 |
2015年 | 333篇 |
2014年 | 425篇 |
2013年 | 1010篇 |
2012年 | 645篇 |
2011年 | 861篇 |
2010年 | 661篇 |
2009年 | 831篇 |
2008年 | 942篇 |
2007年 | 857篇 |
2006年 | 755篇 |
2005年 | 627篇 |
2004年 | 620篇 |
2003年 | 540篇 |
2002年 | 485篇 |
2001年 | 349篇 |
2000年 | 306篇 |
1999年 | 249篇 |
1998年 | 217篇 |
1997年 | 212篇 |
1996年 | 218篇 |
1995年 | 219篇 |
1994年 | 177篇 |
1993年 | 147篇 |
1992年 | 139篇 |
1991年 | 86篇 |
1990年 | 66篇 |
1989年 | 45篇 |
1988年 | 52篇 |
1987年 | 41篇 |
1986年 | 35篇 |
1985年 | 43篇 |
1984年 | 42篇 |
1983年 | 16篇 |
1982年 | 26篇 |
1981年 | 29篇 |
1980年 | 20篇 |
1979年 | 25篇 |
1978年 | 20篇 |
1976年 | 11篇 |
1974年 | 9篇 |
1973年 | 8篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Jun-ichi Miyachi 《Archiv der Mathematik》2006,86(4):317-320
Let Λ be a left Artinian ring, D+(mod Λ) (resp., D−(mod Λ), D(mod Λ)) the derived category of bounded below complexes (resp., bounded above complexes, unbounded complexes) of
finitely generated left Λ-modules. We show that the Grothendieck groups K0(D+(mod Λ)), K0(D−(mod Λ)) and K0(D(mod Λ)) are trivial.
Received: 7 April 2005 相似文献
62.
We introduce and study Hopf monads on autonomous categories (i.e., monoidal categories with duals). Hopf monads generalize Hopf algebras to a non-braided (and non-linear) setting. In particular, any monoidal adjunction between autonomous categories gives rise to a Hopf monad. We extend many fundamental results of the theory of Hopf algebras (such as the decomposition of Hopf modules, the existence of integrals, Maschke's criterium of semisimplicity, etc.) to Hopf monads. We also introduce and study quasitriangular and ribbon Hopf monads (again defined in a non-braided setting). 相似文献
63.
64.
The category of small covariant functors from simplicial sets to simplicial sets supports the projective model structure [B. Chorny, W.G. Dwyer, Homotopy theory of small diagrams over large categories, preprint, 2005]. In this paper we construct various localizations of the projective model structure and also give a variant for functors from simplicial sets to spectra. We apply these model categories in the study of calculus of functors, namely for a classification of polynomial and homogeneous functors. In the n-homogeneous model structure, the nth derivative is a Quillen functor to the category of spectra with Σn-action. After taking into account only finitary functors—which may be done in two different ways—the above Quillen map becomes a Quillen equivalence. This improves the classification of finitary homogeneous functors by T.G. Goodwillie [T.G. Goodwillie, Calculus. III. Taylor series, Geom. Topol. 7 (2003) 645-711 (electronic)]. 相似文献
65.
We demonstrate that the 3-power torsion points of the Jacobians of the principal modular curves X(3n) are fixed by the kernel of the canonical outer Galois representation of the pro-3 fundamental group of the projective line
minus three points. The proof proceeds by demonstrating the curves in question satisfy a two-part criterion given by Anderson
and Ihara. Two proofs of the second part of the criterion are provided; the first relies on a theorem of Shimura, while the
second uses the moduli interpretation.
Received: 30 September 2005 相似文献
66.
67.
M.A. Batanin 《Advances in Mathematics》2007,211(2):684-725
It is well known that the forgetful functor from symmetric operads to nonsymmetric operads has a left adjoint Sym1 given by product with the symmetric group operad. It is also well known that this functor does not affect the category of algebras of the operad. From the point of view of the author's theory of higher operads, the nonsymmetric operads are 1-operads and Sym1 is the first term of the infinite series of left adjoint functors Symn, called symmetrisation functors, from n-operads to symmetric operads with the property that the category of one object, one arrow, …, one (n−1)-arrow algebras of an n-operad A is isomorphic to the category of algebras of Symn(A).In this paper we consider some geometrical and homotopical aspects of the symmetrisation of n-operads. We follow Getzler and Jones and consider their decomposition of the Fulton-Macpherson operad of compactified real configuration spaces. We construct an n-operadic counterpart of this compactification which we call the Getzler-Jones operad. We study the properties of Getzler-Jones operad and find that it is contractible and cofibrant in an appropriate model category. The symmetrisation of the Getzler-Jones operad turns out to be exactly the operad of Fulton and Macpherson. These results should be considered as an extension of Stasheff's theory of 1-fold loop spaces to n-fold loop spaces n?2. We also show that a space X with an action of a contractible n-operad has a natural structure of an algebra over an operad weakly equivalent to the little n-disks operad. A similar result holds for chain operads. These results generalise the classical Eckman-Hilton argument to arbitrary dimension.Finally, we apply the techniques to the Swiss-Cheese type operads introduced by Voronov and prove analogous results in this case. 相似文献
68.
H. Sakuma T. Taniyama K. Ishii Y. Kitamoto Y. Yamazaki 《Journal of magnetism and magnetic materials》2006,300(2):284-292
The order parameter S of Fe–Pt nanoparticles is estimated from X-ray diffraction (XRD) patterns. The total intensity of a diffraction peak is obtained by Rietveld analysis as well as simply integrating the intensity. The Rietveld analysis is found to provide a plausible value of S even for a sample showing an XRD pattern with broad and overlapped peaks. Another order parameter Q, which is obtained from Mössbauer spectra, is introduced, and it is confirmed that Q is equivalent to the probability of Fe atoms being in the L10-type atomic arrangement. The coercivity of Fe–Pt nanoparticles is directly proportional to Q, while it vanishes at S=0.4, indicating that the magnetic property of Fe–Pt nanoparticles has a closer relationship to Q than S. 相似文献
69.
Shigeru Yamagami 《Journal of Pure and Applied Algebra》2002,167(1):83-128
A duality for orbifolds is presented as an application of group extensions in tensor categories. 相似文献
70.