全文获取类型
收费全文 | 8763篇 |
免费 | 922篇 |
国内免费 | 1251篇 |
专业分类
化学 | 395篇 |
晶体学 | 1篇 |
力学 | 371篇 |
综合类 | 199篇 |
数学 | 7985篇 |
物理学 | 1985篇 |
出版年
2024年 | 18篇 |
2023年 | 85篇 |
2022年 | 123篇 |
2021年 | 154篇 |
2020年 | 204篇 |
2019年 | 255篇 |
2018年 | 254篇 |
2017年 | 257篇 |
2016年 | 292篇 |
2015年 | 210篇 |
2014年 | 426篇 |
2013年 | 665篇 |
2012年 | 375篇 |
2011年 | 519篇 |
2010年 | 502篇 |
2009年 | 699篇 |
2008年 | 654篇 |
2007年 | 689篇 |
2006年 | 599篇 |
2005年 | 524篇 |
2004年 | 447篇 |
2003年 | 459篇 |
2002年 | 421篇 |
2001年 | 282篇 |
2000年 | 312篇 |
1999年 | 297篇 |
1998年 | 257篇 |
1997年 | 236篇 |
1996年 | 152篇 |
1995年 | 83篇 |
1994年 | 90篇 |
1993年 | 47篇 |
1992年 | 46篇 |
1991年 | 28篇 |
1990年 | 22篇 |
1989年 | 26篇 |
1988年 | 22篇 |
1987年 | 13篇 |
1986年 | 7篇 |
1985年 | 20篇 |
1984年 | 30篇 |
1983年 | 14篇 |
1982年 | 23篇 |
1981年 | 16篇 |
1980年 | 22篇 |
1979年 | 14篇 |
1978年 | 11篇 |
1977年 | 11篇 |
1976年 | 5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.
《佛山科学技术学院》2014,6(4):435-450
In the present paper, self-adjoint operator and completely continuous operator on soft inner product spaces have been introduced and some basic properties of such operators are studied. 相似文献
992.
Let H be a separable Hilbert space and Bsa(H) the set of all bounded linear self-adjoint operators. We say that A,B∈Bsa(H) quasi-commute if there exists a nonzero ξ∈C such that AB=ξBA. Bijective maps on Bsa(H) which preserve quasi-commutativity in both directions are classified. 相似文献
993.
Xianfu Wang 《Journal of Mathematical Analysis and Applications》2010,368(1):293-310
Associated to a lower semicontinuous function, one can define its proximal mapping and farthest mapping. The function is called Chebyshev (Klee) if its proximal mapping (farthest mapping) is single-valued everywhere. We show that the function f is 1/λ-hypoconvex if its proximal mapping Pλf is single-valued. When the function f is bounded below, and Pλf is single-valued for every λ>0, the function must be convex. Similarly, we show that the function f is 1/μ-strongly convex if the farthest mapping Qμf is single-valued. When the function is the indicator function of a set, this recovers the well-known Chebyshev problem and Klee problem in Rn. We also give an example illustrating that a continuous proximal mapping (farthest mapping) needs not be locally Lipschitz, which answers one open question by Hare and Poliquin. 相似文献
994.
Jussi Laitila 《Mathematische Nachrichten》2010,283(11):1646-1653
995.
Symplectic self-adjointness of infinite dimensional Hamiltonian operators is studied, the necessary and sufficient conditions are given. Using the relatively bounded perturbation, the sufficient conditions about symplectic self-adjointness are shown. 相似文献
996.
In this paper, we study some properties of composition operators on Hilbert spaces of Dirichlet series, which include the Fredholmness, Hilbert-Schmidtness, spectra, cyclic and hypercyclic phenomenons, and also answer a norm question raised by Cowen and MacCluer. 相似文献
997.
998.
《Mathematische Nachrichten》2018,291(10):1470-1485
In this paper we study a class of second order coefficient operators differential equation with general (possibly non local) boundary conditions. We obtain new results extending those given in a previous paper 1 . Existence, uniqueness and optimal regularity of the strict solution are proved in UMD spaces, using the well‐known Dore–Venni theorem. 相似文献
999.
在LP(1≤P〈∞)空间上,研究了板几何中一类具抽象边界条件下各向异性、连续能量、非均匀介质的迁移方程,证明了这类方程相应的迁移算子的谱在右半平面中仅由有限个具有限代数重数的离散本征值组成等结果. 相似文献
1000.
YU Tao 《中国科学 数学(英文版)》2011,(9)
In this paper we first prove that a dual Hankel operator R φ on the orthogonal complement of the Dirichlet space is compact for φ∈ W 1,∞(D),and then that a semicommutator of two Toeplitz operators on the Dirichlet space or two dual Toeplitz operators on the orthogonal complement of the Dirichlet space in Sobolev space is compact.We also prove that a dual Hankel operator R φ with φ∈ W 1,∞(D) is of finite rank if and only if B φ is orthogonal to the Dirichlet space for some finite Blaschke product B,and give ... 相似文献