全文获取类型
收费全文 | 37657篇 |
免费 | 4228篇 |
国内免费 | 2524篇 |
专业分类
化学 | 3891篇 |
晶体学 | 74篇 |
力学 | 3954篇 |
综合类 | 678篇 |
数学 | 24401篇 |
物理学 | 11411篇 |
出版年
2024年 | 67篇 |
2023年 | 338篇 |
2022年 | 451篇 |
2021年 | 599篇 |
2020年 | 996篇 |
2019年 | 987篇 |
2018年 | 950篇 |
2017年 | 929篇 |
2016年 | 1076篇 |
2015年 | 860篇 |
2014年 | 1615篇 |
2013年 | 2976篇 |
2012年 | 1743篇 |
2011年 | 2270篇 |
2010年 | 2231篇 |
2009年 | 2544篇 |
2008年 | 2599篇 |
2007年 | 2536篇 |
2006年 | 2245篇 |
2005年 | 2050篇 |
2004年 | 1719篇 |
2003年 | 1682篇 |
2002年 | 1476篇 |
2001年 | 1193篇 |
2000年 | 1080篇 |
1999年 | 1049篇 |
1998年 | 954篇 |
1997年 | 778篇 |
1996年 | 643篇 |
1995年 | 525篇 |
1994年 | 437篇 |
1993年 | 313篇 |
1992年 | 312篇 |
1991年 | 283篇 |
1990年 | 251篇 |
1989年 | 168篇 |
1988年 | 157篇 |
1987年 | 151篇 |
1986年 | 126篇 |
1985年 | 141篇 |
1984年 | 128篇 |
1983年 | 69篇 |
1982年 | 133篇 |
1981年 | 106篇 |
1980年 | 83篇 |
1979年 | 108篇 |
1978年 | 63篇 |
1977年 | 56篇 |
1976年 | 40篇 |
1973年 | 33篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
This paper is concerned with the Cauchy problem on the Boltzmann equation without angular cutoff assumption for hard potential in the whole space. When the initial data is a small perturbation of a global Maxwellian, the global existence of solution to this problem is proved in unweighted Sobolev spaces with . But if we want to obtain the optimal temporal decay estimates, we need to add the velocity weight function, in this case the global existence and the optimal temporal decay estimate of the Boltzmann equation are all established. Meanwhile, we further gain a more accurate energy estimate, which can guarantee the validity of the assumption in Chen et al. (0000). 相似文献
2.
3.
Tomoyuki Nakatsuka 《Mathematische Nachrichten》2021,294(1):98-117
We study the existence of a time‐periodic solution with pointwise decay properties to the Navier–Stokes equation in the whole space. We show that if the time‐periodic external force is sufficiently small in an appropriate sense, then there exists a time‐periodic solution of the Navier–Stokes equation such that and uniformly in as . Our solution decays faster than the time‐periodic Stokes fundamental solution and the faster decay of its spatial derivatives of higher order is also described. 相似文献
4.
《Annales de l'Institut Henri Poincaré (C) Analyse Non Linéaire》2021,38(5):1337-1371
In this paper we consider minimizers of the functional where is a bounded open set and where are the first k eigenvalues on Ω of an operator in divergence form with Dirichlet boundary condition and with Hölder continuous coefficients. We prove that the optimal sets have finite perimeter and that their free boundary is composed of a regular part, which is locally the graph of a -regular function, and a singular part, which is empty if , discrete if and of Hausdorff dimension at most if , for some . 相似文献
5.
6.
Bifurcation analysis of visual angle model with anticipated time and stabilizing driving behavior
下载免费PDF全文
![点击此处可从《中国物理 B》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Xueyi Guan 《中国物理 B》2022,31(7):70507-070507
In the light of the visual angle model (VAM), an improved car-following model considering driver's visual angle, anticipated time and stabilizing driving behavior is proposed so as to investigate how the driver's behavior factors affect the stability of the traffic flow. Based on the model, linear stability analysis is performed together with bifurcation analysis, whose corresponding stability condition is highly fit to the results of the linear analysis. Furthermore, the time-dependent Ginzburg-Landau (TDGL) equation and the modified Korteweg-de Vries (mKdV) equation are derived by nonlinear analysis, and we obtain the relationship of the two equations through the comparison. Finally, parameter calibration and numerical simulation are conducted to verify the validity of the theoretical analysis, whose results are highly consistent with the theoretical analysis. 相似文献
7.
8.
9.
10.