全文获取类型
收费全文 | 10785篇 |
免费 | 279篇 |
国内免费 | 33篇 |
专业分类
化学 | 7968篇 |
晶体学 | 32篇 |
力学 | 162篇 |
综合类 | 3篇 |
数学 | 1799篇 |
物理学 | 1133篇 |
出版年
2020年 | 138篇 |
2019年 | 104篇 |
2018年 | 80篇 |
2017年 | 83篇 |
2016年 | 196篇 |
2015年 | 198篇 |
2014年 | 188篇 |
2013年 | 355篇 |
2012年 | 407篇 |
2011年 | 466篇 |
2010年 | 342篇 |
2009年 | 290篇 |
2008年 | 464篇 |
2007年 | 453篇 |
2006年 | 476篇 |
2005年 | 447篇 |
2004年 | 384篇 |
2003年 | 332篇 |
2002年 | 340篇 |
2001年 | 235篇 |
2000年 | 168篇 |
1999年 | 150篇 |
1998年 | 183篇 |
1997年 | 151篇 |
1996年 | 159篇 |
1995年 | 158篇 |
1994年 | 146篇 |
1993年 | 196篇 |
1992年 | 133篇 |
1991年 | 130篇 |
1990年 | 115篇 |
1989年 | 134篇 |
1988年 | 132篇 |
1987年 | 169篇 |
1986年 | 158篇 |
1985年 | 179篇 |
1984年 | 187篇 |
1983年 | 159篇 |
1982年 | 144篇 |
1981年 | 152篇 |
1980年 | 153篇 |
1979年 | 156篇 |
1978年 | 141篇 |
1977年 | 122篇 |
1976年 | 140篇 |
1975年 | 93篇 |
1974年 | 89篇 |
1973年 | 92篇 |
1971年 | 80篇 |
1970年 | 73篇 |
排序方式: 共有10000条查询结果,搜索用时 21 毫秒
91.
On the theory of collective motion in nuclei. III. From Hamiltonian dynamics to vortex-free fluidity
It is assumed that the Hamiltonian for collective motion in nuclei is invariant under the orthogonal group O(n, ). For degenerate orbits in phase space it is shown that the classical Hamiltonian equations reduce to the equations of a vortex-free fluid with a velocity field determined by independent equations of motion. 相似文献
92.
93.
María Cristina Bustos Freddy Paiva Wolfgang Wendland 《Mathematical Methods in the Applied Sciences》1990,12(6):533-548
We present the control of continuous sedimentation in an ideal thickener as an initial and boundary value problem and construct the entropy solution. 相似文献
94.
Wolfgang R.?BergmannEmail author Roberto?ContiEmail author 《Annali di Matematica Pura ed Applicata》2003,182(3):271-286
Let H be the extended Cuntz algebra over the Hilbert space H. Since its zero grade part H0 is the C*-inductive limit of B(Hr), we look for some family of representations on an inductive limit of Hr as r. When such construction is shaped according to the structure of H0, von Neumanns notion of a reference sequence of unit vectors for Hilbert infinite tensor products emerges; after a further Rieffel induction step, a class IPR[H] of representations of H arises. For any two such representations, we describe explicitly their associated intertwiners. Any two representations in IPR[H] are either disjoint or unitarily equivalent. Actions of the group by translation on sequences of unit vectors are involved, as well as the ideals of . 相似文献
95.
We introduce a new spectral sequence called the p-chain spectral sequence which converges to the (co-)homology of a contravariant C-space with coefficients in a covariant C-spectrum for a small category C. It is different from the corresponding Atiyah–Hirzebruch-type spectral sequence. It can be used in combination with the Isomorphism Conjectures of Baum and Connes and Farrell and Jones to compute algebraic K- and L-groups of group rings and topological K-groups of reduced group C*-algebras. 相似文献
96.
Wolfgang Staubach 《Journal d'Analyse Mathématique》2003,91(1):389-400
In this paper, we present an explicit calculation of the heat kernel, fundamental solution and Schwartz kernel of the resolvent
for the Heisenberg Laplacian using Wiener path integrals and their realizations via the Trotter product formula. This also
gives another derivation of mehler’s formula. 相似文献
97.
Wolfgang Lindner 《ZDM》2003,35(2):36-42
Usually the Gaussian algorithm (GA) is presented at school as a method of solving a given system of linear equations by reducing it to a “triangular form”. In contrast to this technically oriented view, I will demonstrate a CAS-supported learning environment which includes a visual representation of GA and an activity-oriented «Gauss-game». This game stresses the concept of elementary matrices and leads directly to a partial, implementation of GA in the form of a «semi-automatic” functional CAS-program. These multiple representation of GA tries to take into consideration the research results on mental representations, to design rich variations of student activities and thereby to lead leading to webbeb concepts around GA. The CAS MuPAD is used. 相似文献
98.
99.
Wolfgang Adamski 《Mathematische Nachrichten》1992,156(1):87-97
Let P be a Markov kernel defined on a measurable space (X, ??). A P-ergodic probability is an extreme point of the family of all P-invariant probability measures on ??. Several characterizations of P-ergodic probabilities are given. In particular, for the special case of a topological space X both P-ergodic Baire probabilities and P-ergodic Borel probabilities with additional regularity properties are characterized. 相似文献
100.
给出目标信息系统学习的多准则决策方法,建立多准则决策的规则学习模型,讨论该模型的性质。该模型优于Z.Pawlak方法,将规则提取与信息融合为一体。也优于AHP等模型,具有简洁性.通过实例计算,取得了满意结果。 相似文献