全文获取类型
收费全文 | 681篇 |
免费 | 37篇 |
国内免费 | 2篇 |
专业分类
化学 | 445篇 |
晶体学 | 8篇 |
力学 | 11篇 |
数学 | 58篇 |
物理学 | 198篇 |
出版年
2024年 | 3篇 |
2023年 | 6篇 |
2022年 | 12篇 |
2021年 | 13篇 |
2020年 | 20篇 |
2019年 | 24篇 |
2018年 | 22篇 |
2017年 | 23篇 |
2016年 | 27篇 |
2015年 | 25篇 |
2014年 | 25篇 |
2013年 | 65篇 |
2012年 | 46篇 |
2011年 | 49篇 |
2010年 | 34篇 |
2009年 | 33篇 |
2008年 | 38篇 |
2007年 | 38篇 |
2006年 | 29篇 |
2005年 | 22篇 |
2004年 | 21篇 |
2003年 | 12篇 |
2002年 | 14篇 |
2001年 | 6篇 |
2000年 | 5篇 |
1999年 | 7篇 |
1998年 | 3篇 |
1997年 | 4篇 |
1996年 | 2篇 |
1995年 | 5篇 |
1993年 | 5篇 |
1992年 | 4篇 |
1991年 | 2篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1988年 | 7篇 |
1987年 | 2篇 |
1986年 | 8篇 |
1985年 | 2篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1981年 | 5篇 |
1980年 | 8篇 |
1979年 | 5篇 |
1977年 | 6篇 |
1976年 | 3篇 |
1975年 | 9篇 |
1971年 | 2篇 |
1970年 | 2篇 |
排序方式: 共有720条查询结果,搜索用时 312 毫秒
671.
The reaction of tetrafluoro-1,2-diiodobenzene with tellurium yields an oil which, on treatment with bromine yields perfluorotelluranthrene- 9,9,10,10-tetrabromide. The latter is reduced by sodium sulfide to perfluorotelluranthrene. The crystal structure of perfluorotelluranthrene is reported. 相似文献
672.
673.
Let X be a Banach space, let K be a non–empty closed subset of X and let T : K → X be a non–self mapping. The main result of this paper is that if T satisfies the contractive–type condition (1.1) below and maps ?K (?K the boundary of K) into K then T has a unique fixed point in K. 相似文献
674.
The disintegration characteristics of 164mHo and 164gHo have been studied using a high-resolution Ge(Li) spectrometer. Radioactive samples of 164mHo and 164gHo were obtained through the (n, 2n) reaction on spectroscopically pure holmium oxide with 14 MeV neutrons. The isomeric cross-section ratio for the yields of the ground and metastable states has been estimated to be 1.0±0.25. Gamma rays of 37.7 and 56.1 keV energy have been assigned to the decay of 164mHo and 73.4 and 91.5 keV γ-rays are attributed to the decay of 164gHo by electron capture and negaton emission, respectively. The branching ratio for the electron capture decay of 164gHo to the levels in 164Dy has been estimated accurately from the analysis of X-ray intensities. The results have been incorporated into a decay scheme. 相似文献
675.
676.
The solutions of the Jacobi difference heat equation ▽ n v(n, t)=(δ/δt)v (n, t) are considered. The theory of Poisson-Jacobi transform is developed to solve the equation. Convergence and inversion theorems are established.
相似文献677.
H. K. Pathak 《International Journal of Mathematical Education in Science & Technology》2013,44(1):77-82
In this article, we shall discuss some interesting, viable, meaningful, applicable and productive conjectures and methods to deal with some fundamental results in the theory of numbers. 相似文献
678.
679.
H. K. Pathak A. S. Grewal 《International Journal of Mathematical Education in Science & Technology》2013,44(4):575-583
A general cubic equation ax 3 + bx 2 + cx + d = 0 where a, b, c, d ∈R, a ≠ 0 has three roots with two possibilities—either all three roots are real or one root is real and the remaining two roots are imaginary. Dealing with the second possibility this paper attempts to give the geometrical locations of the imaginary roots of the equation under three different sets of conditions. These sets of conditions include: (i) the real root of the given cubic equation is given, (ii) the real part of an imaginary root is given, and (iii) the imaginary part of an imaginary root is given. 相似文献
680.
We will give a new short proof of Bezout's Theorem for complex algebraic curves in P 2 which is local. 相似文献