全文获取类型
收费全文 | 1974篇 |
免费 | 162篇 |
国内免费 | 171篇 |
专业分类
化学 | 14篇 |
力学 | 58篇 |
综合类 | 25篇 |
数学 | 2132篇 |
物理学 | 78篇 |
出版年
2024年 | 2篇 |
2023年 | 34篇 |
2022年 | 19篇 |
2021年 | 38篇 |
2020年 | 69篇 |
2019年 | 63篇 |
2018年 | 59篇 |
2017年 | 66篇 |
2016年 | 58篇 |
2015年 | 64篇 |
2014年 | 97篇 |
2013年 | 242篇 |
2012年 | 65篇 |
2011年 | 101篇 |
2010年 | 91篇 |
2009年 | 140篇 |
2008年 | 141篇 |
2007年 | 114篇 |
2006年 | 110篇 |
2005年 | 95篇 |
2004年 | 56篇 |
2003年 | 86篇 |
2002年 | 84篇 |
2001年 | 59篇 |
2000年 | 51篇 |
1999年 | 47篇 |
1998年 | 56篇 |
1997年 | 42篇 |
1996年 | 25篇 |
1995年 | 15篇 |
1994年 | 9篇 |
1993年 | 7篇 |
1992年 | 11篇 |
1991年 | 16篇 |
1990年 | 6篇 |
1989年 | 7篇 |
1988年 | 2篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1985年 | 7篇 |
1984年 | 7篇 |
1983年 | 4篇 |
1982年 | 11篇 |
1981年 | 3篇 |
1980年 | 8篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 4篇 |
1974年 | 1篇 |
1973年 | 4篇 |
排序方式: 共有2307条查询结果,搜索用时 15 毫秒
121.
Phan Van Tuoc 《Journal of Mathematical Analysis and Applications》2008,343(2):826-834
We consider a strongly coupled nonlinear parabolic system which arises in population dynamics in n-dimensional domains (n?1). We prove the global existence of classical solutions to the system for n<10. 相似文献
122.
The problem of the boundedness of the Riesz potential I
α
, 0 < α < n, in local Morrey-type spaces is reduced to the boundedness of the Hardy operator in weighted L
p
-spaces on the cone of non-negative non-increasing functions. This allows obtaining sufficient conditions for the boundedness
in local Morrey-type spaces for all admissible values of the parameters. Moreover, for a certain range of the parameters,
these sufficient conditions coincide with the necessary ones.
V. Guliyev’s research was partially supported by the grant of the Azerbaijan-U. S. Bilateral Grants Program II (project ANSF
Award / AZM1-3110-BA-08) and the Turkish Scientific and Technological Research Council (TUBITAK, programme 2221, no. 220.01-619-4889). 相似文献
123.
We give necessary and sufficient conditions for the (bounded) law of the iterated logarithm for U-statistics in Hilbert spaces. As a tool we also develop moment and tail estimates for canonical Hilbert-space valued U-statistics of arbitrary order, which are of independent interest.
R. Adamczak’s research partially supported by MEiN Grant 2 PO3A 019 30.
R. Latała’s research partially supported by MEiN Grant 1 PO3A 012 29. 相似文献
124.
Veli B. Shakhmurov 《中国科学A辑(英文版)》2008,51(7):1215-1231
The unique continuation theorems for the anisotropic partial differential-operator equations with variable coeffcients in Banach-valued Lp-spaces are studied.To obtain the uniform maximal regularity and the Carleman type estimates for parameter depended differential-operator equations,the suffcient conditions are founded.By using these facts,the unique continuation properties are established.In the application part,the unique continuation properties and Carleman estimates for finite or infinite systems of quasielliptic partial differential equations are studied. 相似文献
125.
Didier Bresch Benoît Desjardins Emmanuel Grenier 《Journal of Functional Analysis》2008,254(5):1269-1281
In this paper we consider linear Schrödinger operator with double or resonant eigenvalues. The main result is the bound of the measure (in a suitable space of functions) of the potentials leading to such double or resonant eigenvalues. Namely we present measure type estimates evaluating neighborhoods of the so-called double or resonant set. 相似文献
126.
This paper considers a posteriori error estimates by averaged gradients in second order parabolic problems. Fully discrete
schemes are treated. The theory from the elliptic case as to when such estimates are asymptotically exact, on an element,
is carried over to the error on an element at a given time. The basic principle is that the elliptic theory can be extended
to the parabolic problems provided the time-step error is smaller than the space-discretization error. Numerical illustrations
confirming the theoretical results are given. Our results are not practical in the sense that various constants can not be
estimated realistically. They are conceptual in nature.
AMS subject classification (2000) 65M60, 65M20, 65M15 相似文献
127.
In this paper we study the existence of a first zero and the oscillatory behavior of solutions of the ordinary differential equation ′(vz′)+Avz=0, where A, v are functions arising from geometry. In particular, we introduce a new technique to estimate the distance between two consecutive zeros. These results are applied in the setting of complete Riemannian manifolds: in particular, we prove index bounds for certain Schrödinger operators, and an estimate of the growth of the spectral radius of the Laplacian outside compact sets when the volume growth is faster than exponential. Applications to the geometry of complete minimal hypersurfaces of Euclidean space, to minimal surfaces and to the Yamabe problem are discussed. 相似文献
128.
129.
R. Quintanilla 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2006,57(4):595-603
In this note we investigate the spatial behavior of several nonlinear parabolic equations with nonlinear boundary conditions.
Under suitable conditions on the nonlinear terms we prove that the solutions either cease to exist for a finite value of the
spatial variable or else they decay algebraically. The main tool used is the weighted energy method. Our results can be applied
to several situations concerning heat conduction.
Received: April 4, 2004; revised: September 20, 2004 相似文献
130.
C. Lupoli 《Meccanica》1993,28(4):315-322
We consider a non-prismatic cylinder consisting of an anisotropic, compressible, inhomogeneous thermoelastic material, subject to either null tractions or null displacements on the lateral boundary and loaded by a self-equilibrated force system at one end. We show that the mean square cross-sectional measures of the temperature and the coupled displacement—temperature either grow faster than an exponentially increasing function of axial distance or decrease faster than a decaying exponential function of axial distance. We thus establish a Phragmèn-Lindelöf principle for the thermoelastic cylinder of variable cross-section.
Sommario Viene considerato un cilindro non-prismatico costituito da un materiale termoelastico, anisotropo, comprimibile ed omogeneo. Il cilindro é soggetto a zero trazioni o zero dislocamenti sul limite laterale ed é caricato su uno dei termini con un sistema autoequilibrilata delle forze. Mostriamo che il valore medio quadratico della temperatura e dell'accoppiata della temperatura ed il dislocamento cresce più veloce che una funzione esponenziale crescente della distanza assiale o diminuisce più veloce che una funzione esponenziale declinante della distanza assiale. Viene stabilito un principio di Phragmèn-Lindelöf per il cilindro termoelastico di sezione trasversale variabile.相似文献