全文获取类型
收费全文 | 15235篇 |
免费 | 344篇 |
国内免费 | 255篇 |
专业分类
化学 | 1831篇 |
晶体学 | 74篇 |
力学 | 150篇 |
综合类 | 19篇 |
数学 | 12456篇 |
物理学 | 1304篇 |
出版年
2023年 | 58篇 |
2022年 | 82篇 |
2021年 | 82篇 |
2020年 | 101篇 |
2019年 | 330篇 |
2018年 | 331篇 |
2017年 | 208篇 |
2016年 | 186篇 |
2015年 | 205篇 |
2014年 | 380篇 |
2013年 | 810篇 |
2012年 | 487篇 |
2011年 | 901篇 |
2010年 | 717篇 |
2009年 | 1026篇 |
2008年 | 1081篇 |
2007年 | 1165篇 |
2006年 | 842篇 |
2005年 | 611篇 |
2004年 | 491篇 |
2003年 | 454篇 |
2002年 | 318篇 |
2001年 | 299篇 |
2000年 | 273篇 |
1999年 | 332篇 |
1998年 | 323篇 |
1997年 | 273篇 |
1996年 | 319篇 |
1995年 | 370篇 |
1994年 | 321篇 |
1993年 | 296篇 |
1992年 | 279篇 |
1991年 | 157篇 |
1990年 | 164篇 |
1989年 | 161篇 |
1988年 | 111篇 |
1987年 | 112篇 |
1986年 | 109篇 |
1985年 | 148篇 |
1984年 | 120篇 |
1983年 | 91篇 |
1982年 | 140篇 |
1981年 | 109篇 |
1980年 | 100篇 |
1979年 | 66篇 |
1978年 | 93篇 |
1977年 | 77篇 |
1976年 | 72篇 |
1975年 | 20篇 |
1974年 | 15篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
This paper is based on the M. Sc. thesis written by the third author under the supervision of the first two authors. It was submitted to the University of Baghdad in 1986. 相似文献
72.
Nicola Fusco Michele Gori Francesco Maggi 《NoDEA : Nonlinear Differential Equations and Applications》2006,13(4):425-433
An approximation theorem for families of weakly coercive convex functions by means of countably many smooth families of convex
functions is proved. As a consequence, the classical “three-fold” lower semicontinuity theorem for integral functionals of
the Calculus of Variations by James Serrin is unified in one single statement. 相似文献
73.
Vsevolod K. Malinovskii 《Acta Appl Math》1994,34(1-2):261-281
Edgeworth expansions for the distribution of a sequential least squares estimator in the random coefficient autoregressive (RCA) model are derived. The regenerative approach to second-order asymptotic analysis of Markov-type statistical models is developed. 相似文献
74.
Multiderivations of Coxeter arrangements 总被引:3,自引:0,他引:3
Hiroaki Terao 《Inventiones Mathematicae》2002,148(3):659-674
Let V be an ℓ-dimensional Euclidean space. Let G⊂O(V) be a finite irreducible orthogonal reflection group. Let ? be the corresponding Coxeter arrangement. Let S be the algebra of polynomial functions on V. For H∈? choose α
H
∈V
* such that H=ker(α
H
). For each nonnegative integer m, define the derivation module D
(m)
(?)={θ∈Der
S
|θ(α
H
)∈Sα
m
H
}. The module is known to be a free S-module of rank ℓ by K. Saito (1975) for m=1 and L. Solomon-H. Terao (1998) for m=2. The main result of this paper is that this is the case for all m. Moreover we explicitly construct a basis for D
(m)
(?). Their degrees are all equal to mh/2 (when m is even) or are equal to ((m−1)h/2)+m
i
(1≤i≤ℓ) (when m is odd). Here m
1≤···≤m
ℓ are the exponents of G and h=m
ℓ+1 is the Coxeter number. The construction heavily uses the primitive derivation D which plays a central role in the theory of flat generators by K. Saito (or equivalently the Frobenius manifold structure
for the orbit space of G). Some new results concerning the primitive derivation D are obtained in the course of proof of the main result.
Oblatum 27-XI-2001 & 4-XII-2001?Published online: 18 February 2002 相似文献
75.
Here we prove that every compact differential manifold has a smooth algebraic model defined over Q. In dimension 2 we find an algebraic model (may be singular) defined over Q and birational over Q to the projective plane. 相似文献
76.
Scott McCullough 《Integral Equations and Operator Theory》1992,15(1):43-71
Kernels over the unit disk for which a version of Carathéodory interpolation is true are characterized in a simple computationally verifiable manner. 相似文献
77.
Hideaki Ishikawa 《Archiv der Mathematik》2002,79(6):439-448
In this paper we introduce a certain sum by using Dirichlet characters. We investigate the Riesz mean of the sum using the
analytic properties of the MultipleL-function systematically.
Eine überarbeitete Fassung ging am 6. 8. 2001 ein 相似文献
78.
多目标分数变分问题的对偶性 总被引:1,自引:0,他引:1
本文利用参数逼近在函数广义(F,ρ)-凸的条件下,建立了一类多目标式变分问题关于有效解的对偶理论。 相似文献
79.
Robert J. Daverman 《Topology and its Applications》2007,155(2):105-111
This paper sets forth three mismatch properties, strictly ordered in strength, about sewings of crumpled n-cubes. The strongest is a sufficient but not a necessary condition for a sewing to yield Sn, and the weakest, a necessary but not sufficient one. We show that when both crumpled cubes satisfies the Disjoint Disks Property, then the weakest property implies the sewing yields Sn, and we also show that the intermediate property leads to the same conclusion when just one of the crumpled cubes possesses the Disjoint Disks Property. In addition, we develop examples that confirm sharpness of the relevant Disjoint Disks conditions. 相似文献
80.
We consider the Abelian gauge theory related to the interaction between the solitary waves of the nonlinear Klein-Gordon equation
and the electromagnetic field. We analyze the existence of electromagnetostatic solutions and, in particular, of vortices.
Dedicated to the memory of Professor Aldo Cossu 相似文献