全文获取类型
收费全文 | 164439篇 |
免费 | 847篇 |
国内免费 | 323篇 |
专业分类
化学 | 63774篇 |
晶体学 | 2600篇 |
力学 | 10403篇 |
综合类 | 8篇 |
数学 | 29983篇 |
物理学 | 58841篇 |
出版年
2022年 | 535篇 |
2021年 | 478篇 |
2020年 | 447篇 |
2019年 | 427篇 |
2018年 | 10074篇 |
2017年 | 10955篇 |
2016年 | 5244篇 |
2015年 | 1584篇 |
2014年 | 1120篇 |
2013年 | 2625篇 |
2012年 | 6897篇 |
2011年 | 16275篇 |
2010年 | 9842篇 |
2009年 | 9995篇 |
2008年 | 14072篇 |
2007年 | 17736篇 |
2006年 | 2671篇 |
2005年 | 9632篇 |
2004年 | 5747篇 |
2003年 | 5415篇 |
2002年 | 3165篇 |
2001年 | 3181篇 |
2000年 | 2479篇 |
1999年 | 1599篇 |
1998年 | 1129篇 |
1997年 | 1079篇 |
1996年 | 1071篇 |
1995年 | 889篇 |
1994年 | 796篇 |
1993年 | 705篇 |
1992年 | 1024篇 |
1991年 | 1022篇 |
1990年 | 923篇 |
1989年 | 835篇 |
1988年 | 829篇 |
1987年 | 887篇 |
1986年 | 737篇 |
1985年 | 980篇 |
1984年 | 941篇 |
1983年 | 669篇 |
1982年 | 659篇 |
1981年 | 627篇 |
1980年 | 591篇 |
1979年 | 736篇 |
1978年 | 772篇 |
1977年 | 693篇 |
1976年 | 646篇 |
1975年 | 536篇 |
1974年 | 574篇 |
1973年 | 547篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
11.
J. Conrad J. Cohen-Tanugi L. E. Strigari 《Journal of Experimental and Theoretical Physics》2015,121(6):1104-1135
The launch of the gamma-ray telescope Fermi Large Area Telescope (Fermi-LAT) started a pivotal period in indirect detection of dark matter. By outperforming expectations, for the first time a robust and stringent test of the paradigm of weakly interacting massive particles (WIMPs) is within reach. In this paper, we discuss astrophysical targets for WIMP detection and the challenges they present, review the analysis tools which have been employed to tackle these challenges, and summarize the status of constraints on and the claimed detections in the WIMP parameter space. Methods and results will be discussed in comparison to Imaging Air Cherenkov Telescopes. We also provide an outlook on short term and longer term developments. 相似文献
12.
S. V. Panin I. V. Vlasov V. P. Sergeev B. B. Ovechkin P. O. Marushchak Sunder Ramasubbu P. S. Lyubutin V. V. Titkov 《Physical Mesomechanics》2015,18(3):261-272
The structure and properties of 12Cr1MoV steel irradiated with a zirconium ion beam were studied by optical microscopy, scanning electron microscopy, and micro- and nanoindentation. It is shown that the modification covers the entire cross-section of the irradiated specimens to a depth of 1 mm. The data on irradiation-induced structural changes are used to interpret the changes in mechanical properties of the irradiated specimens under static and cyclic loading. Particular attention is given to analysis of strain estimation by the digital image correlation method. 相似文献
13.
14.
Sh. M. Khaliullin V. D. Zhuravlev V. G. Bamburov L. V. Ermakova 《Physics of Atomic Nuclei》2015,78(12):1382-1388
Submicron CaZrO3 powder is obtained in combustion reactions (solution combustion synthesis—SCS) with glycine. It is found that SCS reduces the sintering temperature of CaZrO3 powders. The dielectric properties of calcium zirconate ceramics are studied by the electrochemical impedance method. It is shown that a ceramics of powders obtained by the SCS method has high dielectric characteristics. 相似文献
15.
16.
The structure, chemical composition, and magnetic properties of electrochemically deposited nanocrystalline Co-Ni-Fe films
were investigated using a number of techniques. A high saturation magnetic induction up to B
s
= 21 kG was attained. An enhancement of the saturation magnetization compared to the ideal anticipated one was revealed,
which correlated with the nonlinear behavior of the structural phase composition and lattice parameters with the change of
the composition.
The text was submitted by the authors in English. 相似文献
17.
N. I. Golovina G. N. Nechiporenko G. G. Nemtsev G. P. Dolganova V. P. Roshchupkin D. B. Lempert G. B. Manelis 《Russian Journal of Applied Chemistry》2007,80(1):24-30
Methods for phase stabilization of ammonium nitrate were sought for in order to considerably expand the application area of this oxidizing agent in various-purpose self-combustible formulations, including that in a new generation of gas-generating formulations for automobile air bags. New methods for stabilization of ammonium nitrate were studied and, in particular, a search was made for organic compounds that can stabilize ammonium nitrate even at their low content. The mechanism of phase state stabilization of ammonium nitrate by compounds of this kind was examined. 相似文献
18.
Yu. V. Pokonova 《Russian Journal of Applied Chemistry》2007,80(12):2163-2164
Kinetic, sorption and selectivity properties of commercial adsorbents are improved by adding petroleum residues (tar asphaltene concentrates) 13% of whole mass. Obtained adsorbents can be used for selective extraction of nobel metals from multicomponent polymetallic solutions of heavy metals and fro sewages purification for removing arsenic. 相似文献
19.
G. Panina 《Central European Journal of Mathematics》2003,1(2):157-168
All 3-dimensional convex polytopes are known to be rigid. Still their Minkowski differences (virtual polytopes) can be flexible
with any finite freedom degree. We derive some sufficient rigidity conditions for virtual polytopes and present some examples
of flexible ones. For example, Bricard's first and second flexible octahedra can be supplied by the structure of a virtual
polytope. 相似文献
20.