全文获取类型
收费全文 | 47382篇 |
免费 | 15690篇 |
国内免费 | 68篇 |
专业分类
化学 | 56615篇 |
晶体学 | 68篇 |
力学 | 2073篇 |
数学 | 2728篇 |
物理学 | 1656篇 |
出版年
2024年 | 372篇 |
2023年 | 4086篇 |
2022年 | 1441篇 |
2021年 | 2489篇 |
2020年 | 4631篇 |
2019年 | 2324篇 |
2018年 | 2285篇 |
2017年 | 616篇 |
2016年 | 5590篇 |
2015年 | 5542篇 |
2014年 | 4958篇 |
2013年 | 5186篇 |
2012年 | 3263篇 |
2011年 | 1136篇 |
2010年 | 3453篇 |
2009年 | 3414篇 |
2008年 | 1148篇 |
2007年 | 848篇 |
2006年 | 204篇 |
2005年 | 174篇 |
2004年 | 155篇 |
2003年 | 144篇 |
2002年 | 128篇 |
1996年 | 103篇 |
1995年 | 164篇 |
1994年 | 119篇 |
1993年 | 236篇 |
1992年 | 126篇 |
1988年 | 146篇 |
1987年 | 119篇 |
1985年 | 131篇 |
1984年 | 137篇 |
1983年 | 122篇 |
1982年 | 149篇 |
1981年 | 180篇 |
1980年 | 213篇 |
1979年 | 200篇 |
1978年 | 211篇 |
1977年 | 329篇 |
1976年 | 380篇 |
1975年 | 476篇 |
1974年 | 481篇 |
1973年 | 290篇 |
1972年 | 374篇 |
1971年 | 361篇 |
1970年 | 543篇 |
1969年 | 415篇 |
1968年 | 463篇 |
1967年 | 116篇 |
1963年 | 115篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
21.
Hirofumi Tsumura 《Journal of Number Theory》2004,106(1):155-168
In this paper, we define the multiple Euler numbers and consider some multiple harmonic series of Mordell-Tornheim's type, which is a partial sum of the Mordell-Tornheim zeta series defined by Matsumoto. Indeed, we prove a certain reducibility of these series as well as the multiple zeta values. 相似文献
22.
Günter Graumann Prof. Dr. 《ZDM》2005,37(3):190-198
Problem fields with one or two generating problems and possibilities of varying existing problems give a good chance for self-activities of students and can be used for reaching different general aims. In this paper some topics concerning quadrilaterals will be presented. I hope they will animate teachers for more problem orientation in mathematics education. First we will reflect about different types of convex and non-convex quadrilaterals and possibilities of ordering them. Then we focus on middle-quadrilaterals and types of quadrilaterals with special middle-quadrilaterals as well as their logical ordering. Finally we investigate the analogies in space to the parallelogram and its sub-types and order them in the “house of parallelepipeds”. 相似文献
23.
Hirofumi Tsumura. 《Mathematics of Computation》2004,73(245):251-258
In this paper, we give some evaluation formulas for Tornheim's type of alternating series by an elementary and combinatorial calculation of the uniformly convergent series. Indeed, we list several formulas for them by means of Riemann's zeta values at positive integers.
24.
25.
26.
27.
Dr.-Ing. M. Millies Dipl.-Ing. St. v. Bose Dipl.-Ing. A. Tokarz Univ.-Prof.Dr.-Ing. D. Mewes 《Heat and Mass Transfer》1994,30(1):17-25
The common methods for calculating the mass transfer across liquid-liquid interfaces in technical applications take into account the mass transfer resistances within the bulk phases. The transfer resistance of the interface and a possible coupling between the momentum and the mass transport is not taken into account. In the present paper a survey is given of theoretical approaches which can describe this coupling and the additional mass transfer resistance. A theory is proposed by Hampe which can be used to explain the coupling between momentum and mass transport employing thermodynamics of irreversible processes. On the basis of this work, the influence of the dilatation of a flat interface on the mass transfer is deduced. It is also concluded from this theory that the diffusion coefficients within the bulk phases are coupled near the thermodynamic equilibrium. 相似文献
28.
29.
Prof. Dr. Leszek Stoch 《Journal of Thermal Analysis and Calorimetry》1992,38(9):1947-1948
30.