全文获取类型
收费全文 | 11556篇 |
免费 | 792篇 |
国内免费 | 1518篇 |
专业分类
化学 | 83篇 |
力学 | 232篇 |
综合类 | 186篇 |
数学 | 7993篇 |
物理学 | 1209篇 |
综合类 | 4163篇 |
出版年
2024年 | 21篇 |
2023年 | 96篇 |
2022年 | 111篇 |
2021年 | 158篇 |
2020年 | 206篇 |
2019年 | 268篇 |
2018年 | 263篇 |
2017年 | 273篇 |
2016年 | 294篇 |
2015年 | 244篇 |
2014年 | 506篇 |
2013年 | 709篇 |
2012年 | 493篇 |
2011年 | 651篇 |
2010年 | 620篇 |
2009年 | 827篇 |
2008年 | 807篇 |
2007年 | 901篇 |
2006年 | 793篇 |
2005年 | 693篇 |
2004年 | 573篇 |
2003年 | 599篇 |
2002年 | 555篇 |
2001年 | 376篇 |
2000年 | 408篇 |
1999年 | 401篇 |
1998年 | 342篇 |
1997年 | 332篇 |
1996年 | 227篇 |
1995年 | 162篇 |
1994年 | 151篇 |
1993年 | 141篇 |
1992年 | 120篇 |
1991年 | 96篇 |
1990年 | 89篇 |
1989年 | 81篇 |
1988年 | 70篇 |
1987年 | 37篇 |
1986年 | 9篇 |
1985年 | 15篇 |
1984年 | 28篇 |
1983年 | 15篇 |
1982年 | 25篇 |
1981年 | 17篇 |
1980年 | 23篇 |
1979年 | 11篇 |
1978年 | 8篇 |
1977年 | 6篇 |
1976年 | 3篇 |
1936年 | 4篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
We develop the theory of analytically controlled Poincaré complexes over C
*-algebras. We associate a signature in C
*-algebra K-theory to such a complex, and we show that it is invariant under bordism and homotopy.
The authors were supported in part by NSF Grant DMS-0100464. 相似文献
992.
A weighted estimate with power weights is established for the maximal operator associated with the commutator of the Bochner-Riesz operator. An application of this weighted estimate is also given.
993.
Franz Lehner 《Proceedings of the American Mathematical Society》1997,125(11):3423-3431
Let be a discrete group and denote by its left regular representation on . Denote further by the free group on generators and its left regular representation. In this paper we show that a subset of has the Leinert property if and only if for some real positive coefficients the identity
holds. Using the same method we obtain some metric estimates about abstract unitaries satisfying the similar identity
994.
I.K. Argyros 《Applied Mathematics Letters》1997,10(6):21-28
In this note, we use inexact Newton-like methods to find solutions of nonlinear operator equations on Banach spaces with a convergence structure. Our technique involves the introduction of a generalized norm as an operator from a linear space into a partially ordered Banach space. In this way, the metric properties of the examined problem can be analyzed more precisely. Moreover, this approach allows us to derive from the same theorem, on the one hand, semilocal results of Kantorovich-type, and on the other hand, global results based on monotonicity considerations. By imposing very general Lipschitz-like conditions on the operators involved, on the one hand, we cover a wider range of problems, and on the other hand, by choosing our operators appropriately, we can find sharper error bounds on the distances involved than before. Furthermore, we show that special cases of our results reduce to the corresponding ones already in the literature. Finally, several examples are being provided where our results compare favorably with earlier ones. 相似文献
995.
Miao Changxing 《数学学报(英文版)》1997,13(2):247-268
We consider the scattering problem for the Hartree equation with potential |x|−1 in a space of dimensionn≥2. We prove the existence ofH
m
-modified wave operator for Hartree equation on a dense set of a neighborhood of zero inH
m
(ℝ
n
), meanwhile, we obtain also the global existence for the Cauchy problem of Hartree equation in a space of dimensionn≥2.
This project is supported by the National Natural Science Foundation of China, 19601005 相似文献
996.
L. I. Sukhocheva 《Mathematical Notes》1997,61(3):313-320
Sufficient conditions for the “separation of the spectrum” of a quadratic matrix pencil with self-adjoint coefficients are
found. A criterion for the representability of a positive operator in a finite-dimensional space in the form of a matrix with
dominating main diagonal in each orthonormal basis is obtained.
Translated fromMatematicheskie Zametki, Vol. 61, No. 3, pp. 381–390, March, 1997.
Translated by A. I. Shtern 相似文献
997.
Yu. A. Konyaev 《Mathematical Notes》1997,62(4):414-419
A class of singularly perturbed initial and boundary value problems for systems of linear differential equations with singularities
of various types is studied. The asymptotics of the solutions of these problems is constructed; in contrast to known results,
it involves boundary layers of new types that are dependent not only on the spectrum of the limit operator.
Translated fromMatematicheskie Zametki, Vol. 62, No. 4, pp. 494–501, October, 1997.
Translated by N. K. Kulman 相似文献
998.
1IntroductionInmanyproblemsofmechanicsandphysics,therefrequentlyappeartheellipticequationswiththederivativetermofthehigherordercontainingsmallparameters.Inengineering,thehigherorderellipticequationswithbothboundaryperturbationandoperatorperturbationoccurintheproblemsofcircularorellipticcoluxnnarshell(suchasthehullofasubmarineorthecolumnarshellroofetc.)withstiffeningribinthecirculnferentialdirection.Insuchcasesjthestudyofweldingstresscausedbyexternalpressureorself-weightduetoabnormalweldingposi… 相似文献
999.
本文给出了一类带参数2n阶非对称微分算子Aλ的一些正则性定理,籍此可刻画一类飞行器在其运行过程中的双向平稳行为. 相似文献
1000.
This paper is concerned with the Poincaré-Steklov operator that is widely used in domain decomposition methods. It is proved that the inverse of the Poincaré-Steklov operator can be expressed explicitly by an integral operator with a kernel being the Green's function restricted to the interface. As an application, for the discrete Poincaré-Steklov operator with respect to either a line (edge) or a star-shaped web associated with a single vertex point, a preconditioner can be constructed by first imbedding the line as the diameter of a disk, or the web as a union of radii of a disk, and then using the Green's function on the disk. The proposed technique can be effectively used in conjunction with various existing domain decomposition techniques, especially with the methods based on vertex spaces (from multi-subdomain decomposition). Some numerical results are reported.