全文获取类型
收费全文 | 13405篇 |
免费 | 307篇 |
国内免费 | 65篇 |
专业分类
化学 | 458篇 |
晶体学 | 13篇 |
力学 | 192篇 |
综合类 | 12篇 |
数学 | 12269篇 |
物理学 | 833篇 |
出版年
2023年 | 19篇 |
2022年 | 33篇 |
2021年 | 26篇 |
2020年 | 63篇 |
2019年 | 399篇 |
2018年 | 480篇 |
2017年 | 220篇 |
2016年 | 150篇 |
2015年 | 162篇 |
2014年 | 434篇 |
2013年 | 761篇 |
2012年 | 477篇 |
2011年 | 818篇 |
2010年 | 763篇 |
2009年 | 1047篇 |
2008年 | 1054篇 |
2007年 | 1031篇 |
2006年 | 810篇 |
2005年 | 494篇 |
2004年 | 425篇 |
2003年 | 392篇 |
2002年 | 268篇 |
2001年 | 273篇 |
2000年 | 257篇 |
1999年 | 306篇 |
1998年 | 264篇 |
1997年 | 203篇 |
1996年 | 291篇 |
1995年 | 305篇 |
1994年 | 291篇 |
1993年 | 225篇 |
1992年 | 143篇 |
1991年 | 89篇 |
1990年 | 64篇 |
1989年 | 83篇 |
1988年 | 55篇 |
1987年 | 42篇 |
1986年 | 49篇 |
1985年 | 67篇 |
1984年 | 70篇 |
1983年 | 51篇 |
1982年 | 79篇 |
1981年 | 57篇 |
1980年 | 34篇 |
1979年 | 29篇 |
1978年 | 34篇 |
1977年 | 30篇 |
1976年 | 24篇 |
1975年 | 12篇 |
1974年 | 11篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Wen-Rong Dai 《Journal of Differential Equations》2007,235(1):127-165
In this paper, we study the global existence and the asymptotic behavior of classical solution of the Cauchy problem for quasilinear hyperbolic system with constant multiple and linearly degenerate characteristic fields. We prove that the global C1 solution exists uniquely if the BV norm of the initial data is sufficiently small. Based on the existence result on the global classical solution, we show that, when the time t tends to the infinity, the solution approaches a combination of C1 traveling wave solutions. Finally, we give an application to the equation for time-like extremal surfaces in the Minkowski space-time R1+n. 相似文献
62.
Jan J. Dijkstra 《Topology and its Applications》2006,153(15):2948-2951
In 1988 A. Gutek proved that there exist one-point connectifications of hereditarily disconnected spaces that do not have the fixed point property. We improve on this result by constructing a one-point connectification of a totally disconnected space without the fixed point property. 相似文献
63.
In this paper, we establish some new nonlinear integral inequalities of the Gronwall–Bellman–Ou-Iang-type in two variables. These on the one hand generalizes and on the other hand furnish a handy tool for the study of qualitative as well as quantitative properties of solutions of differential equations. We illustrate this by applying our new results to certain boundary value problem. 相似文献
64.
Weak vector equilibrium problems with bi-variable mappings from product space of two bounded complete locally convex Hausdorff topological vector spaces to another topological vector space are studied. The existence theorems of solutions are proved by the FKKM fixed point theorem. Viscosity principle of vector equilibrium problems is dealt with. The relations between solutions of the vector equilibrium problem and those of its perturbation problem are presented. 相似文献
65.
Ion synthesis and laser annealing of Cu nanoparticles in Al2O3 总被引:1,自引:0,他引:1
A.L. Stepanov V.N. Popok D.E. Hole I.B. Khaibullin 《Applied Physics A: Materials Science & Processing》2002,74(3):441-446
Al2O3 samples with Cu nanoparticles, synthesised by ion implantation at 40 keV with a dose of 1×1017 ion/cm2 and a current density from 2.5 to 12.5 μA/cm2, were annealed using ten pulses from a KrF excimer laser with a single pulse fluence of 0.3 J/cm2. The copper depth distribution, formation and modification of metal nanoparticles under the ion implantation and laser treatment
were studied by Rutherford backscattering (RBS), energy dispersive X-ray (EDX) analysis, atomic force microscopy (AFM) and
optical spectroscopy. It was found that laser annealing leads to a reduction in the nanoparticle size without diffusion of
metal atoms into the bulk. The change in particle size and the possibility for oxidation of the copper particles are examined
in the framework of Mie theory. Calculations presented show that under excimer laser treatment, Cu nanoparticles are more
likely to be reduced in size than to undergo oxidation.
Received: 19 April 2001 / Accepted: 7 November 2001 / Published online: 23 January 2002 相似文献
66.
The qualitative behavior of buckled states of two different models of elastic beams is studied. It is assumed that random imperfections affect the governing nonlinear equations. It is shown that near the first critical value of the buckling load the stochastic bifurcation is described asymptotically by an algebraic equation whose coeffficients are Gaussian random variables. The corresponding asymptotic expansion for the displacement is to lowest order a Gaussian stochastic process.Work supported by NSF Grant No. DCR81-14726.Work supported by NSF Grant No. DMS87-01895. 相似文献
67.
Cyrille Ospel 《Journal of Pure and Applied Algebra》2002,173(3):315-337
For a commutative algebra the shuffle product is a morphism of complexes. We generalize this result to the quantum shuffle product, associated to a class of non-commutative algebras (for example all the Hopf algebras). As a first application we show that the Hochschild-Serre identity is the dual statement of our result. In particular, we extend this identity to Hopf algebras. Secondly, we clarify the construction of a class of quasi-Hopf algebras. 相似文献
68.
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
69.
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
70.
Kim Dang Phung 《Journal of Differential Equations》2007,240(1):92-124
Using Fourier integral operators with special amplitude functions, we analyze the stabilization of the wave equation in a three-dimensional bounded domain on which exists a trapped ray bouncing up and down infinitely between two parallel parts of the boundary. 相似文献