全文获取类型
收费全文 | 10674篇 |
免费 | 869篇 |
国内免费 | 1055篇 |
专业分类
化学 | 610篇 |
晶体学 | 12篇 |
力学 | 482篇 |
综合类 | 207篇 |
数学 | 9757篇 |
物理学 | 1530篇 |
出版年
2024年 | 10篇 |
2023年 | 112篇 |
2022年 | 132篇 |
2021年 | 163篇 |
2020年 | 268篇 |
2019年 | 260篇 |
2018年 | 246篇 |
2017年 | 318篇 |
2016年 | 301篇 |
2015年 | 266篇 |
2014年 | 464篇 |
2013年 | 846篇 |
2012年 | 449篇 |
2011年 | 569篇 |
2010年 | 548篇 |
2009年 | 655篇 |
2008年 | 756篇 |
2007年 | 779篇 |
2006年 | 645篇 |
2005年 | 643篇 |
2004年 | 503篇 |
2003年 | 498篇 |
2002年 | 398篇 |
2001年 | 361篇 |
2000年 | 318篇 |
1999年 | 301篇 |
1998年 | 300篇 |
1997年 | 265篇 |
1996年 | 200篇 |
1995年 | 122篇 |
1994年 | 120篇 |
1993年 | 79篇 |
1992年 | 81篇 |
1991年 | 66篇 |
1990年 | 55篇 |
1989年 | 42篇 |
1988年 | 40篇 |
1987年 | 31篇 |
1986年 | 32篇 |
1985年 | 51篇 |
1984年 | 45篇 |
1983年 | 26篇 |
1982年 | 33篇 |
1981年 | 43篇 |
1980年 | 24篇 |
1979年 | 43篇 |
1978年 | 27篇 |
1977年 | 23篇 |
1976年 | 19篇 |
1974年 | 7篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
1.
2.
《Indagationes Mathematicae》2021,32(1):55-85
We show that the differential structure of the orbit space of a proper action of a Lie group on a smooth manifold is weakly reflexive. This implies that the orbit space is a differentiable space in the sense of Smith, which ensures that the orbit space has an exterior algebra of differential forms, that satisfies Smith’s version of de Rham’s theorem. Because the orbit space is a locally closed subcartesian space, it has vector fields and their flows. 相似文献
3.
A finite support product of clones of Jensen's minimal singleton forcing is used to define a model in which any non-empty analytically definable set of reals contains an analytically definable real (the full basis theorem), but there is no analytically definable wellordering of the reals. 相似文献
4.
5.
ABSTRACTThe Coupled-Cluster (CC) theory is one of the most successful high precision methods used to solve the stationary Schrödinger equation. In this article, we address the mathematical foundation of this theory with focus on the advances made in the past decade. Rather than solely relying on spectral gap assumptions (non-degeneracy of the ground state), we highlight the importance of coercivity assumptions – Gårding type inequalities – for the local uniqueness of the CC solution. Based on local strong monotonicity, different sufficient conditions for a local unique solution are suggested. One of the criteria assumes the relative smallness of the total cluster amplitudes (after possibly removing the single amplitudes) compared to the Gårding constants. In the extended CC theory the Lagrange multipliers are wave function parameters and, by means of the bivariational principle, we here derive a connection between the exact cluster amplitudes and the Lagrange multipliers. This relation might prove useful when determining the quality of a CC solution. Furthermore, the use of an Aubin–Nitsche duality type method in different CC approaches is discussed and contrasted with the bivariational principle. 相似文献
6.
Liang Zhao 《Journal of Differential Equations》2019,266(9):5615-5624
In this paper, let be n-dimensional noncompact metric measure space which satisfies Poincaré inequality with some Ricci curvature condition. We obtain a Liouville theorem for positive weak solutions to weighted p-Lichnerowicz equation where are real constants. 相似文献
7.
当前锂离子动力电池电化学模型存在模型复杂、建模难度大、计算效率低、老化评估效果差的问题,本文提出一种考虑电池衰退老化的机理模型(ADME).本文首先通过有限差分法对伪二维(P2D)电化学模型进行离散降阶处理,得到简化伪二维(SP2D)模型.在SP2D模型的基础上,基于阴阳两极发生的副反应导致的衰退老化现象,提出一种考虑电池衰退老化的机理模型.其次,使用多变量偏差补偿最小二乘法实现模型参数辨识.最后通过动力电池衰退老化性能循环实验,对比分析了恒流、脉冲工况下SP2D模型和ADME模型的终端电压输出.结果表明:ADME模型较为简单、计算效率和估算精度高,可以有效评估电池容量老化衰退,得到理想的锂离子动力电池外特性曲线. 相似文献
8.
9.
AbstractRealistic stochastic modeling is increasingly requiring the use of bounded noises. In this work, properties and relationships of commonly employed bounded stochastic processes are investigated within a solid mathematical ground. Four families are object of investigation: the Sine-Wiener (SW), the Doering–Cai–Lin (DCL), the Tsallis–Stariolo–Borland (TSB), and the Kessler–Sørensen (KS) families. We address mathematical questions on existence and uniqueness of the processes defined through Stochastic Differential Equations, which often conceal non-obvious behavior, and we explore the behavior of the solutions near the boundaries of the state space. The expression of the time-dependent probability density of the Sine-Wiener noise is provided in closed form, and a close connection with the Doering–Cai–Lin noise is shown. Further relationships among the different families are explored, pathwise and in distribution. Finally, we illustrate an analogy between the Kessler–Sørensen family and Bessel processes, which allows to relate the respective local times at the boundaries. 相似文献
10.
In this paper, we propose a sufficient and necessary condition for the boundedness of all the solutions for the equation with the critical situation that on g and p, where , is periodic and is bounded. 相似文献