全文获取类型
收费全文 | 1522篇 |
免费 | 30篇 |
国内免费 | 39篇 |
专业分类
化学 | 104篇 |
力学 | 48篇 |
数学 | 490篇 |
物理学 | 643篇 |
综合类 | 306篇 |
出版年
2024年 | 2篇 |
2023年 | 9篇 |
2022年 | 10篇 |
2021年 | 15篇 |
2020年 | 18篇 |
2019年 | 25篇 |
2018年 | 14篇 |
2017年 | 17篇 |
2016年 | 19篇 |
2015年 | 30篇 |
2014年 | 46篇 |
2013年 | 66篇 |
2012年 | 48篇 |
2011年 | 67篇 |
2010年 | 58篇 |
2009年 | 79篇 |
2008年 | 106篇 |
2007年 | 92篇 |
2006年 | 93篇 |
2005年 | 53篇 |
2004年 | 62篇 |
2003年 | 49篇 |
2002年 | 70篇 |
2001年 | 71篇 |
2000年 | 64篇 |
1999年 | 70篇 |
1998年 | 63篇 |
1997年 | 17篇 |
1996年 | 16篇 |
1995年 | 37篇 |
1994年 | 28篇 |
1993年 | 21篇 |
1992年 | 16篇 |
1991年 | 21篇 |
1990年 | 19篇 |
1989年 | 18篇 |
1988年 | 12篇 |
1987年 | 16篇 |
1986年 | 8篇 |
1985年 | 9篇 |
1984年 | 8篇 |
1983年 | 6篇 |
1982年 | 3篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1979年 | 2篇 |
1978年 | 4篇 |
1977年 | 4篇 |
1974年 | 2篇 |
1948年 | 1篇 |
排序方式: 共有1591条查询结果,搜索用时 8 毫秒
21.
J. Iwaniszewski 《Il Nuovo Cimento D》1995,17(7-8):819-825
Summary The phenomenon of stochastic resonance is predicted in a monostable system displaying transient bimodality during the evolution.
The signal-to-noise ratio as a function of the noise intensity calculated within the rate equation theory with many simplifying
assumptions exhibits a promising peak. The numerical simulations are also reported.
Paper presented at the International Workshop ?Fluctuations in Physics and Biology: Stochastic Resonance, Signal Processing
and Related Phenomena?, Elba, 5–10 June 1994. 相似文献
22.
Dr. Haymo Ross 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(59):13449-13451
23.
24.
Masayuki Kawakita 《Journal of the American Mathematical Society》2003,16(2):331-362
We treat three-fold divisorial contractions whose exceptional divisors contract to Gorenstein points. We prove that a general element in the anti-canonical system around the exceptional divisor has at worst Du Val singularities. As application to classification, we describe divisorial contractions to compound points, and moreover, we deduce that any divisorial contraction to a compound or point has discrepancy .
25.
26.
A core-envelope model for superdense matter distribution with the feature- core consisting of anisotropic fluid distribution
and envelope with isotropic fluid distribution is reported on the background of pseudospheroidal space-time. The physical
plausibility of the model is examined analytically and numerically. 相似文献
27.
Saibal Ray P. C. Ray M. Khlopov P. P. Ghosh U. Mukhopadhyay P. Chowdhury 《International Journal of Theoretical Physics》2009,48(9):2499-2510
Choosing the three phenomenological models of the dynamical cosmological term Λ, viz.,
,
and Λ∼ρ where a is the cosmic scale factor, it has been shown by the method of numerical analysis for the considered non-linear differential
equations that the three models are equivalent for the flat Universe k=0 and for arbitrary non-linear equation of state. The evolution plots for dynamical cosmological term Λ vs. time t and also the cosmic scale factor a vs. t are drawn here for k=0,+1. A qualitative analysis has been made from the plots which supports the idea of inflation and hence expanding Universe. 相似文献
28.
Iva Franjić 《Mathematische Nachrichten》2015,288(17-18):2016-2027
This paper aims to contribute to the exploration of quadrature formulae by proving that the error of a quadrature formula has the Schur‐convexity property. The emphasis is on the quadrature formulae with the maximum degree of precision. The Schur‐convexity of the error has an interesting implication – the monotonicity of the error. Namely, it turns out that the absolute value of the error is always smaller on a smaller interval (of the two which share the same midpoint). 相似文献
29.
K. Vela Velupillai 《Applied mathematics and computation》2009,215(4):1404-1416
Economic theory, game theory and mathematical statistics have all increasingly become algorithmic sciences. Computable Economics, Algorithmic Game Theory[Noam Nisan, Tim Roiughgarden, Éva Tardos, Vijay V. Vazirani (Eds.), Algorithmic Game Theory, Cambridge University Press, Cambridge, 2007] and Algorithmic Statistics[Péter Gács, John T. Tromp, Paul M.B. Vitányi, Algorithmic statistics, IEEE Transactions on Information Theory 47 (6) (2001) 2443-2463] are frontier research subjects. All of them, each in its own way, are underpinned by (classical) recursion theory - and its applied branches, say computational complexity theory or algorithmic information theory - and, occasionally, proof theory. These research paradigms have posed new mathematical and metamathematical questions and, inadvertently, undermined the traditional mathematical foundations of economic theory. A concise, but partial, pathway into these new frontiers is the subject matter of this paper. Interpreting the core of mathematical economic theory to be defined by General Equilibrium Theory and Game Theory, a general - but concise - analysis of the computable and decidable content of the implications of these two areas are discussed. Issues at the frontiers of macroeconomics, now dominated by Recursive Macroeconomic Theory (The qualification ‘recursive’ here has nothing to do with ‘recursion theory’. Instead, this is a reference to the mathematical formalizations of the rational economic agent’s intertemporal optimization problems, in terms of Markov Decision Processes, (Kalman) Filtering and Dynamic Programming, where a kind of ‘recursion’ is invoked in the solution methods. The metaphor of the rational economic agent as a ‘signal processor’ underpins the recursive macroeconomic paradigm.), are also tackled, albeit ultra briefly. The point of view adopted is that of classical recursion theory and varieties of constructive mathematics. 相似文献
30.