全文获取类型
收费全文 | 3503篇 |
免费 | 409篇 |
国内免费 | 139篇 |
专业分类
化学 | 200篇 |
晶体学 | 1篇 |
力学 | 998篇 |
综合类 | 40篇 |
数学 | 1644篇 |
物理学 | 1168篇 |
出版年
2024年 | 18篇 |
2023年 | 45篇 |
2022年 | 55篇 |
2021年 | 70篇 |
2020年 | 142篇 |
2019年 | 110篇 |
2018年 | 99篇 |
2017年 | 105篇 |
2016年 | 107篇 |
2015年 | 90篇 |
2014年 | 141篇 |
2013年 | 277篇 |
2012年 | 168篇 |
2011年 | 199篇 |
2010年 | 162篇 |
2009年 | 206篇 |
2008年 | 235篇 |
2007年 | 214篇 |
2006年 | 197篇 |
2005年 | 181篇 |
2004年 | 145篇 |
2003年 | 141篇 |
2002年 | 118篇 |
2001年 | 96篇 |
2000年 | 102篇 |
1999年 | 100篇 |
1998年 | 78篇 |
1997年 | 80篇 |
1996年 | 52篇 |
1995年 | 32篇 |
1994年 | 44篇 |
1993年 | 30篇 |
1992年 | 29篇 |
1991年 | 22篇 |
1990年 | 25篇 |
1989年 | 17篇 |
1988年 | 17篇 |
1987年 | 13篇 |
1986年 | 13篇 |
1985年 | 10篇 |
1984年 | 12篇 |
1983年 | 5篇 |
1982年 | 7篇 |
1981年 | 8篇 |
1980年 | 4篇 |
1979年 | 3篇 |
1978年 | 8篇 |
1975年 | 5篇 |
1972年 | 3篇 |
1971年 | 3篇 |
排序方式: 共有4051条查询结果,搜索用时 125 毫秒
1.
2.
3.
4.
5.
Rong Yin Jihui Zhang Xudong Shang 《Mathematical Methods in the Applied Sciences》2020,43(15):8736-8752
This paper is dedicated to studying the following Schrödinger–Poisson system Under some different assumptions on functions V(x), K(x), a(x) and f(u), by using the variational approach, we establish the existence of positive ground state solutions. 相似文献
6.
Recent Progress in the $L_p$ Theory for Elliptic and Parabolic Equations with Discontinuous Coefficients
下载免费PDF全文
![点击此处可从《分析论及其应用》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Hongjie Dong 《分析论及其应用》2020,36(2):161-199
In this paper, we review some results over the last 10-15 years on elliptic and parabolic equations with discontinuous coefficients. We begin with an approach given by N. V. Krylov to parabolic equations in the whole space with $\rm{VMO}_x$ coefficients. We then discuss some subsequent development including elliptic and parabolic equations with coefficients which are allowed to be merely measurable in one or two space directions, weighted $L_p$estimates with Muckenhoupt ($A_p$) weights, non-local elliptic and parabolic equations, as well as fully nonlinear elliptic and parabolic equations. 相似文献
7.
8.
Maria Kordaki Athanasia Balomenou 《International Journal of Computers for Mathematical Learning》2006,11(1):99-135
This study focuses on the constructions in terms of area and perimeter in equivalent triangles developed by students aged 12–15 years-old, using the tools provided by Cabri-Geometry II [Labore (1990). Cabri-Geometry (software), Université de Grenoble]. Twenty-five students participated in a learning experiment where they were asked to construct: (a) pairs of equivalent triangles “in as many ways as possible” and to study their area and their perimeter using any of the tools provided and (b) “any possible sequence of modifications of an original triangle into other equivalent ones”. As regards the concept of area and in contrast to a paper and pencil environment, Cabri provided students with different and potential opportunities in terms of: (a) means of construction, (b) control, (c) variety of representations and (d) linking representations, by exploiting its capability for continuous modifications. By exploiting these opportunities in the context of the given open tasks, students were helped by the tools provided to develop a broader view of the concept of area than the typical view they would construct in a typical paper and pencil environment. 相似文献
9.
The molding processes of polymer melts involve geometrically complex dies. Such dies are usually tapered or streamlined to achieve a maximum output rate under conditions of laminar flow. The model of a generalized second-grade fluid of power-law type is used and the results obtained are illustrated by examples of convergent flows in conical and wedge-shaped dies. 相似文献
10.
介绍了13~18世纪物理学史和科技史上曾名噪一时的第一类永动机的设计方案的破灭.第一类永动机幻梦破灭的历史引起了人们的反思与启示,有力地促进了19世纪中叶能量转化和守恒定律的确立. 相似文献