全文获取类型
收费全文 | 1575篇 |
免费 | 462篇 |
国内免费 | 95篇 |
专业分类
化学 | 515篇 |
晶体学 | 21篇 |
力学 | 185篇 |
综合类 | 10篇 |
数学 | 98篇 |
物理学 | 1303篇 |
出版年
2024年 | 4篇 |
2023年 | 24篇 |
2022年 | 51篇 |
2021年 | 51篇 |
2020年 | 61篇 |
2019年 | 46篇 |
2018年 | 46篇 |
2017年 | 40篇 |
2016年 | 43篇 |
2015年 | 63篇 |
2014年 | 63篇 |
2013年 | 114篇 |
2012年 | 81篇 |
2011年 | 126篇 |
2010年 | 82篇 |
2009年 | 131篇 |
2008年 | 137篇 |
2007年 | 131篇 |
2006年 | 136篇 |
2005年 | 112篇 |
2004年 | 86篇 |
2003年 | 93篇 |
2002年 | 83篇 |
2001年 | 47篇 |
2000年 | 47篇 |
1999年 | 28篇 |
1998年 | 33篇 |
1997年 | 20篇 |
1996年 | 26篇 |
1995年 | 21篇 |
1994年 | 24篇 |
1993年 | 12篇 |
1992年 | 12篇 |
1991年 | 6篇 |
1990年 | 6篇 |
1989年 | 7篇 |
1988年 | 2篇 |
1987年 | 6篇 |
1986年 | 4篇 |
1985年 | 8篇 |
1984年 | 4篇 |
1983年 | 1篇 |
1982年 | 4篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1974年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有2132条查询结果,搜索用时 31 毫秒
1.
文章首先将史瓦西黑洞场中自由下落质点的固有时(诺维科夫坐标时)公式,由自然单位制化成了国际单位制中的形式.然后,根据牛顿第二定律和万有引力定律,推导出了自由下落质点经历的绝对时间公式,进而证明了广义相对论中自由落体经历的固有时,恰好等于牛顿力学给出的绝对时间.最后,对自由下落质点在黑洞内外经历的时间进行了特例计算. 相似文献
2.
In 1976 S. Hawking claimed that “Because part of the information about the state of the system is lost down the hole, the final situation is represented by a density matrix rather than a pure quantum state”. 1 This was the starting point of the popular “black hole (BH) information paradox”. 相似文献
3.
Lubomir Spanhel 《Journal of Sol-Gel Science and Technology》2006,39(1):7-24
The past research work devoted to ZnO nanocolloidal sol-gel route is reviewed. It highlights the cluster chemistry of alcoholic
ZnAc2 solutions and the results of ZnO colloid growth investigations performed worldwide. Moreover, the role of doping and co-doping
in the processing of functional ZnO coatings is discussed. The possibilities of tuning the optical properties are also reported
with a particular attention to luminescence. The last part of this paper deals with electrical and photoelectrochemical properties
of ZnO nanocrystals and their aggregates.
This contribution is dedicated to the 80th birthday of Prof. Arnim Henglein from the Hahn-Meitner-Institut in Berlin and to
the memory of Prof. Jacques Mugnier from the Université Claude-Bernard Lyon 1 in France. 相似文献
4.
5.
沈有根 《中国科学A辑(英文版)》2002,45(3):400-408
Using the membrane model which is based on brick wall model, we calculated the free energy and entropy of Garfinkle-Horne dilatonic black hole due to arbitrary spin fields. The result shows that the entropy of scalar field and the entropy of Fermionic field have similar formulas. There is only a coefficient between them. 相似文献
6.
S. J. Cheng W. Sheng P. Hawrylak S. Raymond S. Studenikin A. Sachrajda Z. Wasilewski A. Babinski M. Potemski G. Ortner M. Bayer 《Physica E: Low-dimensional Systems and Nanostructures》2004,21(2-4):211
We present results of calculations and experiments on electron–hole complexes in InGaAs/GaAs self-assembled quantum dots in high magnetic field (B). Due to hidden symmetries, the chemical potential of an N-exciton system at special B fields becomes insensitive to the exciton number as well as the magnetic field. This results in plateau regions of high intensity in measured magneto-PL spectrum. Theoretical calculations using exact diagonalization techniques successfully explain the measured magneto-photoluminescence spectrum with B fields up to 28 T. 相似文献
7.
Kayll Lake 《General Relativity and Gravitation》2004,36(5):1159-1169
The norms associated with the gradients of the two non-differential invariants of the Kerr vacuum are examined. Whereas both locally single out the horizons, their global behavior is more interesting. Both reflect the background angular momentum as the volume of space allowing a timelike gradient decreases with increasing angular momentum becoming zero in the degenerate and naked cases. These results extend directly to the Kerr-Newman geometry. 相似文献
8.
Understanding the end state of black hole evaporation, the microscopic origin of black hole entropy, the information loss paradox, and the nature of the singularity arising in gravitational collapse - these are outstanding challenges for any candidate quantum theory of gravity. Recently, a midisuperspace model of quantum gravitational collapse has been solved using a lattice regularization scheme. It is shown that the mass of an eternal black hole follows the Bekenstein spectrum, and a related argument provides a fairly accurate estimate of the entropy. The solution also describes a quantized mass-energy distribution around a central black hole, which in the WKB approximation, is precisely Hawking radiation. The leading quantum gravitational correction makes the spectrum non-thermal, thus providing a plausible resolution of the information loss problem. 相似文献
9.
10.
利用brick-wall模型研究了引力场对Vaidya-Bonner-de Sitter黑洞熵的量子修正.当黑洞事 件视界不随超前时间变化时,结果与Reissner-Nordstrm-de Sitter黑洞的量子熵完全相 同. 相似文献