全文获取类型
收费全文 | 18122篇 |
免费 | 3154篇 |
国内免费 | 2414篇 |
专业分类
化学 | 12977篇 |
晶体学 | 206篇 |
力学 | 1300篇 |
综合类 | 165篇 |
数学 | 1844篇 |
物理学 | 7198篇 |
出版年
2024年 | 63篇 |
2023年 | 384篇 |
2022年 | 654篇 |
2021年 | 705篇 |
2020年 | 771篇 |
2019年 | 685篇 |
2018年 | 596篇 |
2017年 | 532篇 |
2016年 | 848篇 |
2015年 | 839篇 |
2014年 | 1025篇 |
2013年 | 1230篇 |
2012年 | 1627篇 |
2011年 | 1651篇 |
2010年 | 1099篇 |
2009年 | 1029篇 |
2008年 | 1186篇 |
2007年 | 1025篇 |
2006年 | 1057篇 |
2005年 | 869篇 |
2004年 | 685篇 |
2003年 | 570篇 |
2002年 | 566篇 |
2001年 | 470篇 |
2000年 | 391篇 |
1999年 | 452篇 |
1998年 | 316篇 |
1997年 | 294篇 |
1996年 | 338篇 |
1995年 | 286篇 |
1994年 | 272篇 |
1993年 | 201篇 |
1992年 | 190篇 |
1991年 | 155篇 |
1990年 | 134篇 |
1989年 | 112篇 |
1988年 | 107篇 |
1987年 | 66篇 |
1986年 | 60篇 |
1985年 | 43篇 |
1984年 | 31篇 |
1983年 | 26篇 |
1982年 | 13篇 |
1981年 | 18篇 |
1980年 | 7篇 |
1979年 | 3篇 |
1966年 | 1篇 |
1959年 | 1篇 |
1957年 | 5篇 |
1936年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
11.
A hybrid cluster complex, formed by chelating a chromogenic ligand to a [2Fe-2S] cluster, sensitively exhibited differential colorimetric responses towards Hg2+, Cd2+, Cr3+, Pb2, Sn2+, Cu2+, Zn2+, Fe3+ and Co2+ in water at physiological pH. Speciation of some of these metal elements, such as Cr(III) and Sn(IV), was also studied by UV/Vis absorption. 相似文献
12.
13.
Zhao Zheng Zhang Jian-hua Jiang Ya-ling 《International Journal of Theoretical Physics》1997,36(6):1359-1368
The Hawking effect of a nonuniformly rectilinearly accelerating Kinnersley black hole is studied. Its horizons are rotationally
symmetric. Its Hawking temperature depends not only on the time, but also on the polar angle. When a Kinnersley black hole
touches its Rindler horizon, the Hawking temperature at the contact point is reduced to zero. But at the opposite pole of
the black hole, the Hawking temperature increases rapidly. A jet appears as a tail of the accelerating black hole. 相似文献
14.
We present a variational treatment for the E × e pseudo Jahn-Teller system. Through canonical transformation the electron and phonon states are decoupled. An analytical form is obtained for the ground state energy by scaling transformation. Including both the dynamical displacement of phonon modes and the softening of phonon frequency, this approach yields fairly accurate results for the ground state energy. The energy splitting and Ham's reduction factor are calculated, which also generates fairly good results compared with other perturbation results. We argue that our variational wave function is valid for the weak and intermediate coupling range. 相似文献
15.
The distortion theorem for biholomorphic convex mappings in bounded symmetric domains are considered. Especially the distortion theorem for biholomorphic convex mappings in classical domain of type IV and two exceptional domains are given. 相似文献
16.
17.
18.
19.
Jü rgen Herzog Takayuki Hibi Xinxian Zheng 《Transactions of the American Mathematical Society》2006,358(9):4119-4134
Squarefree monomial ideals arising from finite meet-semilattices and their free resolutions are studied. For the squarefree monomial ideals corresponding to poset ideals in a distributive lattice, the Alexander dual is computed.
20.
Precise measurement of magnetic moment of short-lived β-emitting nuclei12B ( I π=1+, T 1/2=20.18 ms)
Zhou Dongmei Zheng Yongnan Du Enpeng Xu Yongjun Zhu Jiazheng Yuan Daqing Wang Zhiqiang Luo Hailong Zuo Yi Ma Ruigang Duan Xiao M. Mihara M. Fukuda K. Matsuta T. Minamisono Zhu Shengyun 《中国科学G辑(英文版)》2004,47(5):531-539
The spin polarized β-emitting nuclei12B (I
π=1+,T
1/2=20.18 ms) were produced by the nuclear reaction11B(d, p)12B and by the selection technique of the incident deuteron energy and the12B recoil angle following the nuclear reaction. The nuclear magnetic moment of the short-lived nuclei12B was measured by β-NMR with the β-NMR and β-NQR setup established for the first time in China. The nuclear magnetic moment
of12B was determined to be μ=0.99993±0.00048 nm org=0.99993±0.00048 after the precise correction of the Knight shift. 相似文献