全文获取类型
收费全文 | 97232篇 |
免费 | 17428篇 |
国内免费 | 9986篇 |
专业分类
化学 | 66295篇 |
晶体学 | 979篇 |
力学 | 6184篇 |
综合类 | 554篇 |
数学 | 11037篇 |
物理学 | 39597篇 |
出版年
2024年 | 359篇 |
2023年 | 2188篇 |
2022年 | 3529篇 |
2021年 | 3809篇 |
2020年 | 4253篇 |
2019年 | 3796篇 |
2018年 | 3464篇 |
2017年 | 3085篇 |
2016年 | 4878篇 |
2015年 | 4668篇 |
2014年 | 5704篇 |
2013年 | 7262篇 |
2012年 | 8797篇 |
2011年 | 9018篇 |
2010年 | 5964篇 |
2009年 | 5757篇 |
2008年 | 6167篇 |
2007年 | 5406篇 |
2006年 | 5121篇 |
2005年 | 4107篇 |
2004年 | 3154篇 |
2003年 | 2475篇 |
2002年 | 2353篇 |
2001年 | 1955篇 |
2000年 | 1756篇 |
1999年 | 1985篇 |
1998年 | 1702篇 |
1997年 | 1681篇 |
1996年 | 1683篇 |
1995年 | 1421篇 |
1994年 | 1236篇 |
1993年 | 1049篇 |
1992年 | 920篇 |
1991年 | 830篇 |
1990年 | 683篇 |
1989年 | 538篇 |
1988年 | 403篇 |
1987年 | 324篇 |
1986年 | 343篇 |
1985年 | 281篇 |
1984年 | 159篇 |
1983年 | 119篇 |
1982年 | 101篇 |
1981年 | 62篇 |
1980年 | 43篇 |
1979年 | 15篇 |
1957年 | 33篇 |
1931年 | 1篇 |
1930年 | 3篇 |
1922年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
The main purpose of this paper is to use a mean value theorem of Dirichlet L-functions to study the asymptotic property of a hybrid mean value of a generalized Cochrane sum, and give an interesting mean value formula.2000 Mathematics Subject Classification: Primary—11F20; Secondary—11F99 相似文献
52.
This paper shows that the dimension of internal structure of a component can be measured remotely to a resolution better than 5 μm by use of the combination of high resolution optical microscopy and image processing.A specialised high resolution, long working distance and diffraction limited lens was used to image within the component. A series of digital images were made to map spatially the interior of the component. An edge detector was then used to localise the specific location of features in order that an accurate internal measurement could be made. A visualisation of the internal surface finish was also achieved. 相似文献
53.
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
54.
混合位级正交试验设计的极差分析方法 总被引:3,自引:0,他引:3
本文指出,在混合位级的正交试验设计中,以往的极差分析方法存在着不足。本文给出了极差的修正方法,并用大量实例做了数值验证,说明这个修正确实很有效 相似文献
55.
The thermal and thermo-elastic-plastic response of newly developed ceramic-metalfunctionally graded materials under a thermal shock load is studied.The materials are heated at the ce-ramic surface with a sudden high-intensity heat flux input,and cooled at the metal surface with aflowing liquid nitrogen.Emphasis is placed on two aspects:(1)the influence of the graded composi-tion of the materials on the temperature and stress response;and(2)the optimum design of the gradedcomposition from a unified viewpoint of the heat insulation property and stress relaxation property.Moreover,a comparison between the thermoelastic stress and the thermo-elastic-plastic stress is alsomade to indicate the plasticity effect. 相似文献
56.
L.-Q. Han S.-Y. Zhao Y.-D. Zhou P.-L. Zhang 《Applied physics. B, Lasers and optics》1997,65(3):399-402
Received: 18 June 1996/Revised version: 3 January 1997 相似文献
57.
58.
Gang Tian 《Inventiones Mathematicae》1997,130(1):1-37
In this paper, we prove that the existence of K?hler-Einstein metrics implies the stability of the underlying K?hler manifold
in a suitable sense. In particular, this disproves a long-standing conjecture that a compact K?hler manifold admits K?hler-Einstein
metrics if it has positive first Chern class and no nontrivial holomorphic vector fields. We will also establish an analytic
criterion for the existence of K?hler-Einstein metrics. Our arguments also yield that the analytic criterion is satisfied
on stable K?hler manifolds, provided that the partial C
0-estimate posed in [T6] is true.
Oblatum 12-IV-1996 & 8-XI-1996 相似文献
59.
基于无穷维空间中的生存定理,我们研究了集值映象的不动点,得到了一个新的不动点定理,推广和改进了[1]和[5]中的相应结果。 相似文献
60.
SINGULARBOUNDARYPROPERTIESOFHARMONICFUNCTIONSANDFRACTALANALYSISWENZHIYINGZHANGYIPINGManuscriptreceivedJanuary11,1995.Revi... 相似文献