全文获取类型
收费全文 | 2975篇 |
免费 | 76篇 |
国内免费 | 12篇 |
专业分类
化学 | 45篇 |
晶体学 | 1篇 |
力学 | 37篇 |
综合类 | 1篇 |
数学 | 2841篇 |
物理学 | 138篇 |
出版年
2022年 | 5篇 |
2021年 | 4篇 |
2020年 | 9篇 |
2019年 | 74篇 |
2018年 | 87篇 |
2017年 | 46篇 |
2016年 | 35篇 |
2015年 | 44篇 |
2014年 | 82篇 |
2013年 | 176篇 |
2012年 | 103篇 |
2011年 | 197篇 |
2010年 | 183篇 |
2009年 | 235篇 |
2008年 | 208篇 |
2007年 | 249篇 |
2006年 | 167篇 |
2005年 | 123篇 |
2004年 | 91篇 |
2003年 | 92篇 |
2002年 | 62篇 |
2001年 | 66篇 |
2000年 | 58篇 |
1999年 | 71篇 |
1998年 | 57篇 |
1997年 | 40篇 |
1996年 | 69篇 |
1995年 | 62篇 |
1994年 | 65篇 |
1993年 | 56篇 |
1992年 | 41篇 |
1991年 | 26篇 |
1990年 | 21篇 |
1989年 | 12篇 |
1988年 | 8篇 |
1987年 | 8篇 |
1986年 | 11篇 |
1985年 | 14篇 |
1984年 | 15篇 |
1983年 | 12篇 |
1982年 | 14篇 |
1981年 | 13篇 |
1980年 | 12篇 |
1979年 | 5篇 |
1978年 | 8篇 |
1977年 | 8篇 |
1976年 | 10篇 |
1975年 | 3篇 |
1974年 | 2篇 |
1973年 | 2篇 |
排序方式: 共有3063条查询结果,搜索用时 78 毫秒
111.
Ewelina Zatorska 《Journal of Differential Equations》2012,253(12):3471-3500
We consider the Cauchy problem for the system of equations governing flow of isothermal reactive mixture of compressible gases. Our main contribution is to prove sequential stability of weak solutions when the state equation essentially depends on the species concentration and the viscosity coefficients vanish on vacuum. Moreover, under additional assumption on the “cold” component of the pressure in the regions of small density, we prove the existence of weak solutions for arbitrary large initial data. 相似文献
112.
Dongsoo Shin 《Journal of Pure and Applied Algebra》2010,214(7):1001-1010
If X is a smooth curve such that the minimal degree of its plane models is not too small compared with its genus, then X has been known to be a double cover of another smooth curve Y under some mild condition on the genera. However there are no results yet for the minimal degrees of plane models of double covers except some special cases. In this paper, we give upper and lower bounds for the minimal degree of plane models of the double cover X in terms of the gonality of the base curve Y and the genera of X and Y. In particular, the upper bound equals to the lower bound in case Y is hyperelliptic. We give an example of a double cover which has plane models of degree equal to the lower bound. 相似文献
113.
《Mathematische Nachrichten》2017,290(2-3):349-366
In this paper, we give a new characterization for the boundedness of weighted differentiation composition operator from logarithmic Bloch spaces to Bloch‐type spaces and calculate its essential norm in terms of the n‐th power of induced analytic self‐map on the unit disk. From which a sufficient and necessary condition of compactness of this operator follows immediately. 相似文献
114.
Fractal differential equations on the Sierpinski gasket 总被引:9,自引:0,他引:9
Kyallee Dalrymple Robert S. Strichartz Jade P. Vinson 《Journal of Fourier Analysis and Applications》1999,5(2-3):203-284
Let denote the symmetric Laplacian on the Sierpinski gasket SG defined by Kigami [11] as a renormalized limit of graph Laplacians on the sequence of pregaskets Gm whose limit is SG. We study the analogs of some of the classical partial differential equations with playing the role of the usual Laplacian. For harmonic functions, biharmonic functions, and Dirichlet eigenfunctions of , we give efficient algorithms to compute the solutions exactly, we display the results of implementing these algorithms, and we prove various properties of the solutions that are suggested by the data. Completing the work of Fukushima and Shima [8] who computed the Dirichlet eigenvalues and their multiplicities, we show how to construct a basis (but not orthonormal) for the eigenspaces, so that we have the analog of Fourier sine series on the unit interval. We also show that certain eigenfunctions have the property that they are a nonzero constant along certain lines contained in SG. For the analogs of the heat and wave equation, we give algorithms for approximating the solution, and display the results of implementing these algorithms. We give strong evidence that the analog of finite propagation for the wave equation does not hold because of inconsistent scaling behavior in space and time.Research supported in part by the National Science Foundation, Grant DMS-9623250.Research supported by the National Science Foundation through the Research Experiences for Undergraduates (REU) Program. 相似文献
115.
Ru-Zong Fan 《Potential Analysis》1996,5(5):417-462
In this paper, we are going to study the capacity theory and exceptionality of hyperfinite Dirichlet forms. We shall introduce positive measures of hyperfinite energy integrals and associated theory. Fukushima's decomposition theorem will be established on the basis of discussing hyperfinite additive functionals and hyperfinite measures. We shall study the properties of internal multiplicative functionals, subordinate semigroups and subprocesses. Moreover, we shall discuss transformation of hyperfinite Dirichlet forms.Research was supported by the National Natural Science Foundation of P.R. China, No. 18901004. The support from the position of Wissenschaftliche Hilfskraft of Ruhr-University Bochum under Prof. Sergio Albeverio is also acknowledged. 相似文献
116.
Yoshihiro Nakamura 《Integral Equations and Operator Theory》1993,17(3):373-403
The structure of isometries on a Hilbert space are well studied. In this paper we study contractions which are one-dimensional perturbations of isometries, in particular, perturbations of the shift operator onH
2. 相似文献
117.
Pavlos Tzermias 《manuscripta mathematica》1998,97(4):483-488
We determine all algebraic points of degree at most five over Q on the Fermat curve of degree seven.
Received: 26 February 1998 / Revised version: 1 June 1998 相似文献
118.
M. Van De Vel 《Topology and its Applications》1983,16(2):181-206
It is shown that two-dimensional convex structures with certain natural properties are join-hull commutative. The main intermediate step is the computation of the so-called exchange number. We also give two examples of three-dimensional convexities which are not join-hull commutative. The second one has certain additional properties showing that the main theorem is sharp in many other respects. These properties are obtained from a study of convex hyperspaces. 相似文献
119.
We reformulate a recent result of Arason and
Elman by giving a very simple presentation of the
powers of the fundamental ideal of the Witt ring of a field
of characteristic 2.
Sur les puissances de lidéal fondamental de lanneau de Witt
Nous reformulons un résultat récent de Arason et Elman en donnant une présentation très simple des puissances de lidéal fondamental de lanneau de Witt dun corps de caractéristique 2.相似文献
120.