全文获取类型
收费全文 | 1079篇 |
免费 | 9篇 |
国内免费 | 12篇 |
专业分类
化学 | 591篇 |
晶体学 | 5篇 |
力学 | 35篇 |
数学 | 328篇 |
物理学 | 141篇 |
出版年
2019年 | 6篇 |
2016年 | 11篇 |
2015年 | 13篇 |
2014年 | 18篇 |
2013年 | 31篇 |
2012年 | 24篇 |
2011年 | 36篇 |
2010年 | 20篇 |
2009年 | 21篇 |
2008年 | 38篇 |
2007年 | 50篇 |
2006年 | 33篇 |
2005年 | 41篇 |
2004年 | 39篇 |
2003年 | 27篇 |
2002年 | 25篇 |
2001年 | 22篇 |
2000年 | 14篇 |
1999年 | 12篇 |
1998年 | 19篇 |
1997年 | 12篇 |
1996年 | 13篇 |
1995年 | 21篇 |
1994年 | 19篇 |
1993年 | 12篇 |
1992年 | 18篇 |
1991年 | 13篇 |
1990年 | 12篇 |
1989年 | 15篇 |
1988年 | 21篇 |
1987年 | 20篇 |
1986年 | 33篇 |
1985年 | 27篇 |
1984年 | 17篇 |
1983年 | 11篇 |
1982年 | 19篇 |
1981年 | 16篇 |
1980年 | 29篇 |
1979年 | 31篇 |
1978年 | 22篇 |
1977年 | 10篇 |
1976年 | 19篇 |
1975年 | 19篇 |
1974年 | 27篇 |
1973年 | 20篇 |
1972年 | 15篇 |
1971年 | 14篇 |
1970年 | 13篇 |
1969年 | 6篇 |
1968年 | 8篇 |
排序方式: 共有1100条查询结果,搜索用时 15 毫秒
1.
This article deals with Leibniz's reception of Descartes' “geometry.” Leibnizian mathematics was based on five fundamental notions: calculus, characteristic, art of invention, method, and freedom. On the basis of methodological considerations Leibniz criticized Descartes' restriction of geometry to objects that could be given in terms of algebraic (i.e., finite) equations: “Descartes's mind was the limit of science.” The failure of algebra to solve equations of higher degree led Leibniz to develop linear algebra, and the failure of algebra to deal with transcendental problems led him to conceive of a science of the infinite. Hence Leibniz reconstructed the mathematical corpus, created new (transcendental) notions, and redefined known notions (equality, exactness, construction), thus establishing “a veritable complement of algebra for the transcendentals”: infinite equations, i.e., infinite series, became inestimable tools of mathematical research. 相似文献
2.
Using [Cp(Me)5Rh(bipy)C1]C1 (1) as redox catalyst for the continous NADH regeneration it was possible to perform an electrochemically driven enzymatic reduction of pyruvate to D-lactate catalyzed by D-LDH at a rate of 5 turnovers per hour. This is by a factor of 20 faster than the best results obtained until now. Current yields of 50 to 70 % may be obtained. 相似文献
3.
4.
5.
First, the demonstration of Bell's theorem, i.e., of the nonlocal character of quantum theory, is spelled out using the EPR criterion of reality as premises and a gedankenexperiment involving two particles. Then, the EPR criterion is extended to include quantities predicted almostwith certainty, and Bell's theorem is demonstrated on these new premises. The same experiment is used but in conditions that become possible in real life, without the requirements of ideal efficiencies and zero background. Very high efficiencies and low background are needed, but these requirements may be met in the future. 相似文献
6.
Eberhard Breitmaier 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》1973,85(15):676-677
7.
Applied Biochemistry and Biotechnology - The US chemical industry is facing maturing markets, variability in raw materials supply, and stiff competition from emerging chemical industries in other... 相似文献
8.
Hiller W Brüll A Argyropoulos D Hoffmann E Pasch H 《Magnetic resonance in chemistry : MRC》2005,43(9):729-735
The application of HPLC-NMR for the analysis of a mixture of fatty alcohol ethoxylates (FAEs) is described. The use of the new generation, cryogenically cooled probes is investigated in respect of the sensitivity advantage that they provide. The FAE mixture is separated using liquid chromatography at the critical point of adsorption. The ability of the method to differentiate between the different end groups and the degree of polymerization of the mixture constituents is investigated. Both on-flow and stop-flow HPLC-NMR techniques were used together with two-dimensional NMR spectroscopy. The results are compared with those obtained by using an evaporative light scattering detector for the HPLC. 相似文献
9.
10.
Aihara H Alston-Garnjost M Avery RE Barbaro-Galtieri A Barker AR Barnes AV Barnett BA Bauer DA Bengtsson H Bintinger DL Bobbink GJ Bolognese TS Bross AD Buchanan CD Buijs A Cain MP Caldwell DO Clark AR Cowan GD Crane DA Dahl OI Derby KA Eastman JJ Eberhard PH Eisner AM Enomoto R Erné FC Fujii T Gary JW Gorn W Hauptman JM Hofmann W Huth JE Hylen J Kamae T Kaye HS Kees KH Kenney RW Kerth LT Ko W Koda RI Kofler RR Kwong KK Lander RL Langeveld WG Layter JG Linde FL Lindsey CS Loken SC Lu A Lu X 《Physical review letters》1986,57(8):945-948