全文获取类型
收费全文 | 16642篇 |
免费 | 544篇 |
国内免费 | 140篇 |
专业分类
化学 | 10730篇 |
晶体学 | 86篇 |
力学 | 346篇 |
综合类 | 4篇 |
数学 | 3461篇 |
物理学 | 2699篇 |
出版年
2023年 | 101篇 |
2022年 | 199篇 |
2021年 | 373篇 |
2020年 | 326篇 |
2019年 | 303篇 |
2018年 | 669篇 |
2017年 | 485篇 |
2016年 | 532篇 |
2015年 | 423篇 |
2014年 | 484篇 |
2013年 | 942篇 |
2012年 | 949篇 |
2011年 | 1044篇 |
2010年 | 693篇 |
2009年 | 675篇 |
2008年 | 933篇 |
2007年 | 913篇 |
2006年 | 833篇 |
2005年 | 795篇 |
2004年 | 611篇 |
2003年 | 579篇 |
2002年 | 482篇 |
2001年 | 304篇 |
2000年 | 328篇 |
1999年 | 210篇 |
1998年 | 163篇 |
1997年 | 168篇 |
1996年 | 188篇 |
1995年 | 134篇 |
1994年 | 144篇 |
1993年 | 124篇 |
1992年 | 119篇 |
1991年 | 109篇 |
1990年 | 114篇 |
1989年 | 99篇 |
1988年 | 83篇 |
1987年 | 83篇 |
1986年 | 82篇 |
1985年 | 107篇 |
1984年 | 122篇 |
1983年 | 93篇 |
1982年 | 97篇 |
1981年 | 103篇 |
1980年 | 72篇 |
1979年 | 56篇 |
1978年 | 81篇 |
1977年 | 62篇 |
1976年 | 65篇 |
1975年 | 54篇 |
1973年 | 41篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
101.
J. Balogh D. Kaptás L. F. Kiss T. Kemény L. Bujdosó I. Vincze 《Hyperfine Interactions》2006,169(1-3):1343-1347
Magnetic multilayers of 57Fe with nominal thickness, T
nom, between 0.4 and 1.0 nm separated by 3.0 nm Al spacer layers were prepared by alternate deposition of the constituents in
high vacuum. The samples were investigated at 4.2 K in external magnetic field. A fraction of Fe atoms corresponding to about
0.3 nm equivalent Fe-thickness was found to mix into the Al spacer. The extremely strong magnetic anisotropy observed for
T
nom < 0.8 nm is attributed to Fe layers of approximately two atomic planes thick. The anisotropy decreases considerably after
the building up of the third Fe atomic layer starts at T
nom = 0.8 nm, but full saturation was not achieved even for T
nom = 1 nm and 3 T magnetic field applied perpendicularly to the sample plane. 相似文献
102.
The convergence of iterative based domain decomposition methods is linked with the absorbing boundary conditions defined on the interface between the sub-domains. For linear elasticity problems, the optimal absorbing boundary conditions are associated with non-local Dirichlet-to-Neumann maps. Most of the methods to approximate these non-local maps are based on a continuous analysis. In this paper, an original algebraic technique based on the computation of local Dirichlet-to-Neumann maps is investigated. Numerical experiments are presented for linear elasticity problems with extreme contrasts in the coefficients. 相似文献
103.
Roland Omnès 《Foundations of Physics》1995,25(4):605-629
A rather recent interpretation of quantum mechanics, known under the various names of consistent histories, decohering histories, or logical interpretation, has brought interpretation into a standard deductive theory and is now investigated in many places. A key difference with the Copenhagen interpretation is the status of classical physics, now derived completely from quantum principles in both its dynamical and logical aspects. After describing briefly this new interpretation in its essentials, leaving aside technical details, it is shown how its consequences in epistemology differ drastically from the familiar outcomes of the Copenhagen interpretation, leading in particular to a well-defined theory of knowledge. Some more speculative philosophical consequences associated with the unsolved problem of actuality are also mentioned. 相似文献
104.
János Komlós 《Order》1990,7(2):107-113
Using Ramsey theory, we establish the following pigeon-hole type principle: From a large number of random variables (functions, vectors, etc.) one can always select two, X and Y, such that P(X < Y) 1/2. We apply the principle for a poset problem. 相似文献
105.
106.
107.
We give an asymptotically sharp estimate for the error term of the maximum number of unit distances determined byn points in
d, d4. We also give asymptotically tight upper bounds on the total number of occurrences of the favourite distances fromn points in
d, d4. Related results are proved for distances determined byn disjoint compact convex sets in 2.At the time this paper was written, both authors were visiting the Technion — Israel Institute of Technology. 相似文献
108.
109.
In the following note we investigate the second smallest distance between finitely many points on the sphere. Actually we look for the smallest upper bound for the second smallest distance between n points on the unit sphere. We solve this problem for n=9 and also we give a general, non-trivial upper bound for the second smallest distance of n points with n9.Supported by the Hungarian National Foundation for Scientific Research, Number 1238. 相似文献
110.
In this paper the distribution of the zeros of the error function for bestL
1-approximation by rational functions fromR
n,m
is considered. It is shown that the maximal distance between such zeros isO(1/(n–m)), ifn > m.Communicated by Edward B. Saff. 相似文献