全文获取类型
收费全文 | 465616篇 |
免费 | 2294篇 |
国内免费 | 928篇 |
专业分类
化学 | 204954篇 |
晶体学 | 6592篇 |
力学 | 28934篇 |
综合类 | 11篇 |
数学 | 87220篇 |
物理学 | 141127篇 |
出版年
2020年 | 4168篇 |
2019年 | 5063篇 |
2018年 | 17523篇 |
2017年 | 17406篇 |
2016年 | 15363篇 |
2015年 | 5232篇 |
2014年 | 8717篇 |
2013年 | 16136篇 |
2012年 | 16474篇 |
2011年 | 25113篇 |
2010年 | 17998篇 |
2009年 | 18618篇 |
2008年 | 20919篇 |
2007年 | 22718篇 |
2006年 | 13072篇 |
2005年 | 12416篇 |
2004年 | 12274篇 |
2003年 | 11926篇 |
2002年 | 11293篇 |
2001年 | 10700篇 |
2000年 | 8397篇 |
1999年 | 6324篇 |
1998年 | 5849篇 |
1997年 | 5616篇 |
1996年 | 5199篇 |
1995年 | 4581篇 |
1994年 | 4580篇 |
1993年 | 4602篇 |
1992年 | 4640篇 |
1991年 | 5137篇 |
1990年 | 5055篇 |
1989年 | 5112篇 |
1988年 | 4752篇 |
1987年 | 4829篇 |
1986年 | 4521篇 |
1985年 | 5401篇 |
1984年 | 5590篇 |
1983年 | 4760篇 |
1982年 | 5015篇 |
1981年 | 4671篇 |
1980年 | 4331篇 |
1979年 | 4968篇 |
1978年 | 5137篇 |
1977年 | 5315篇 |
1976年 | 5467篇 |
1975年 | 5073篇 |
1974年 | 4899篇 |
1973年 | 5158篇 |
1972年 | 4320篇 |
1971年 | 3953篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
161.
Golovchenko A. V. Pil'o S. G. Brovarets V. S. Drach B. S. 《Russian Journal of General Chemistry》2003,73(11):1832-1833
Russian Journal of General Chemistry - 相似文献
162.
163.
I. L. Bataronov A. M. Roshchupkin 《Journal of Applied Mechanics and Technical Physics》1991,32(2):259-265
Translated from Zhurnal Prikladnoi Mekhaniki i Tekhnicheskoi Fiziki, No. 2, pp. 127–134, March–April, 1991. 相似文献
164.
165.
The kinetics of hydrogen peroxide decomposition in a guaiacol solution, catalyzed by potassium hexacyanoferrate(II), were studied. The reaction mainly follows the pathway of guaiacol hydroxylation. The reaction order is 1 with respect to H2O2, 0.5 with respect to hexacyanoferrate, and from 0.4 to 0 with respect to guaiacol (the latter parameter decreases with increasing guaiacol concentration). The apparent activation energy is 105 kJ mol-
1. A kinetic scheme of the process was proposed. An expression consistent with the experiment was obtained for the rate of hydrogen peroxide decomposition in the presence of guaiacol, catalyzed by hexacyanoferrate(II). 相似文献
166.
Nikulin S. S. Akatova I. N. Kondrat'eva N. A. 《Russian Journal of Applied Chemistry》2003,76(4):652-655
The influence of the charge of a metal cation and the nature of a coagulant on the recovery of butadiene-styrene rubber and properties of rubber stocks and vulcanizates was examined. 相似文献
167.
N. B. Voznesensky E. V. Gavrilov A. P. Zhevlakov V. K. Kirillovskiĭ P. V. Orlov 《Technical Physics》2007,52(2):271-275
Methods and schemes to inspect the EUV mirror shape are developed on the basis of a point diffraction interferometer with computer processing of interferograms. A measurement accuracy to within 0.001 of a wavelength in the visual range is achieved. 相似文献
168.
V. V. AntiĆ M. P. AntiĆ M. N. Govedarica P. R. DvorniĆ 《Journal of polymer science. Part A, Polymer chemistry》2007,45(11):2246-2258
The kinetics of the formation of poly(carbosiloxane), as well as of alkyl-substituted poly(siloxane), by Karstedt's catalyst catalyzed hydrosilylation were investigated. Linear poly(carbosiloxane), poly[(1,1,3,3-tetramethyldisiloxanyl)ethylene], (PTMDSE), was obtained by hydrosilylation of 1,3-divinyltetramethyldisiloxane (DVTMDS) and 1,1,3,3-tetramethyldisiloxane (TMDS), while alkyl-substituted poly(siloxane), poly(methyldecylsiloxane), (PMDS), was synthesized by hydrosilylation of poly(methylhydrosiloxane) (PMHS) and 1-decene. To investigate the kinetics of PTMDSE formation, two series of experiments were performed at reaction temperatures ranging from 25 to 56 °C and with catalyst concentrations ranging from 7.0 × 10−6 to 3.1 × 10−5 mol Pt/mol CHCH2. A series of experiments was performed at reaction temperatures ranging from 28 to 48 °C, with catalyst concentrations of 7.0 ×10−6 mol of Pt per mol of CHCH2, when kinetics of PMDS formation was investigated. All reactions were carried out in bulk, with equimolar amounts of the reacting Si H and CHCH2 groups. The course of the reactions was monitored by following the disappearance of the Si H bands using quantitative infrared spectroscopy. The results obtained showed typical first order kinetics for the PTMDSE formation, consistent with the proposed reaction mechanism. In the case of PMDS an induction period occurred at lower reaction temperatures, but disappeared at 44 °C and the rate of Si H conversion also started to follow the first-order kinetics. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2246–2258, 2007 相似文献
169.
170.
A. V. Chashkin 《Moscow University Mathematics Bulletin》2007,62(3):119-123
A realization of graphs with vertices of bounded branching in a subspace of bounded depth is considered. A volume order inside of which an arbitrary graph can be realized is determined. 相似文献