全文获取类型
收费全文 | 204947篇 |
免费 | 1733篇 |
国内免费 | 604篇 |
专业分类
化学 | 102852篇 |
晶体学 | 3348篇 |
力学 | 9298篇 |
综合类 | 5篇 |
数学 | 22582篇 |
物理学 | 69199篇 |
出版年
2021年 | 1676篇 |
2020年 | 1809篇 |
2019年 | 2013篇 |
2018年 | 2715篇 |
2017年 | 2612篇 |
2016年 | 3797篇 |
2015年 | 2326篇 |
2014年 | 3634篇 |
2013年 | 9127篇 |
2012年 | 7293篇 |
2011年 | 8788篇 |
2010年 | 6073篇 |
2009年 | 5940篇 |
2008年 | 7950篇 |
2007年 | 8114篇 |
2006年 | 7748篇 |
2005年 | 6913篇 |
2004年 | 6447篇 |
2003年 | 5674篇 |
2002年 | 5520篇 |
2001年 | 6450篇 |
2000年 | 4967篇 |
1999年 | 3810篇 |
1998年 | 3046篇 |
1997年 | 3063篇 |
1996年 | 2805篇 |
1995年 | 2617篇 |
1994年 | 2473篇 |
1993年 | 2350篇 |
1992年 | 2707篇 |
1991年 | 2682篇 |
1990年 | 2622篇 |
1989年 | 2405篇 |
1988年 | 2461篇 |
1987年 | 2461篇 |
1986年 | 2287篇 |
1985年 | 2969篇 |
1984年 | 3217篇 |
1983年 | 2640篇 |
1982年 | 2809篇 |
1981年 | 2777篇 |
1980年 | 2642篇 |
1979年 | 2732篇 |
1978年 | 2825篇 |
1977年 | 2821篇 |
1976年 | 2888篇 |
1975年 | 2673篇 |
1974年 | 2647篇 |
1973年 | 2779篇 |
1972年 | 1763篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
141.
142.
Summary It is shown that the outer automorphism group of a Coxeter groupW of finite rank is finite if the Coxeter graph contains no infinite bonds. A key step in the proof is to show that if the
group is irreducible andΠ
1 andΠ
2 any two bases of the root system ofW, thenΠ
2 = ±ωΠ
1 for some ω εW. The proof of this latter fact employs some properties of the dominance order on the root system introduced by Brink and
Howlett.
This article was processed by the author using the Springer-Verlag TEX PJour1g macro package 1991. 相似文献
143.
The magnetic properties of existing amorphous iron based materials, i.e., Fe--metalloid, Fe--early transition metals and Fe--rare
earth alloys, are briefly discussed for some representative alloys. The spin orientation of amorphous Fe--metalloid alloys
has been determined by the angular dependence of hyperfine interactions. It is shown that in iron--early transition metals
ferromagnetic order is not long-ranged, but determined by magnetic clusters. The magnetic hyperfine field distributions of
Fe-rich iron--early transition metals consist of a high and a low field tail. The magnetic structure has been investigated
for two representative Fe--RE (RE = Er, Ce) amorphous alloys. For the first time, the magnetic coupling phenomenon in amorphous/crystalline
multilayers has been discussed.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
144.
T. Engel M. Würtz S. Borneis St. Becker I. Klaft A. Kohl T. Kühl F. Laeri D. Marx K. Meier R. Neumann F. Schmitt P. Seelig L. Völker 《Hyperfine Interactions》1997,108(1-3):251-258
Laser spectroscopy at storage rings often suffers from a limited resolution due to Doppler-broadened resonances. Broadening
is caused by the velocity spread of the ions stored in the beam. In the following, the present status of our work on laser
systems specialized on the specific needs of laser spectroscopy at storage rings is reported.
Two pulsed laser systems were developed. One is a dye laser whose spectral bandwidth can be switched by inserting different
Littrow-prisms into the resonator. An increase in bandwidth up to a factor of 45 was achieved. This laser was used for fast
qualitative scans and high resolution measurements. The other laser system is a Nd : YAG laser pumped optical parametric oscillator.
It is a tunable laser system covering the spectral range from 410 to 4000 nm. Furthermore, a continuous wave laser with a
frequency shifted feedback cavity is described. It shows broadband emission with an adjustable bandwidth of up to 4.5 GHz.
This laser can be advantageous for laser cooling of ion beams.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
145.
146.
147.
E. D. Nursultanov 《Mathematical Notes》1998,63(2):205-214
In this paper we prove theorems on multiplicators of Fourier series inL
p, where the conditions depend on a parameterp. An example illustrating the importance of these conditions is constructed.
Translated fromMatematicheskie Zametki, Vol. 63, No. 2, pp. 235–247, February, 1998. 相似文献
148.
A. Sánchez-Lavega A. Salazar A. Ocariz L. Pottier E. Gomez L.M. Villar E. Macho 《Applied Physics A: Materials Science & Processing》1997,65(1):15-22
Received: 16 September 1996/Accepted: 6 January 1997 相似文献
149.
150.
The plane contact problem of steady thermoelasticity taking heat generation into account 总被引:2,自引:0,他引:2
The plane steady contact problem of thermoelasticity when there is heat generation from friction, which arises when an infinite cylindrical punch moves over the surface of an elastic half-space along its generatrix, is considered. It is assumed that heat exchange between the free boundary of the half-space and the surrounding medium obeys Newton's law, while the condition for ideal thermal contact exists in the region in which the solids interact. The problem is reduced to a system of three integral equations in the heat fluxes and temperature. The effect of the thermal and mechanical properties of the cylinder and the half-space on the main contact characteristics is investigated numerically. 相似文献