全文获取类型
收费全文 | 90922篇 |
免费 | 7325篇 |
国内免费 | 6186篇 |
专业分类
化学 | 24659篇 |
晶体学 | 1822篇 |
力学 | 4140篇 |
综合类 | 637篇 |
数学 | 28147篇 |
物理学 | 45028篇 |
出版年
2023年 | 274篇 |
2022年 | 263篇 |
2021年 | 504篇 |
2020年 | 822篇 |
2019年 | 1190篇 |
2018年 | 1130篇 |
2017年 | 892篇 |
2016年 | 763篇 |
2015年 | 659篇 |
2014年 | 1545篇 |
2013年 | 2345篇 |
2012年 | 1626篇 |
2011年 | 2310篇 |
2010年 | 2879篇 |
2009年 | 7600篇 |
2008年 | 8700篇 |
2007年 | 7258篇 |
2006年 | 6537篇 |
2005年 | 4627篇 |
2004年 | 4274篇 |
2003年 | 4530篇 |
2002年 | 5685篇 |
2001年 | 4144篇 |
2000年 | 3979篇 |
1999年 | 3696篇 |
1998年 | 3100篇 |
1997年 | 2200篇 |
1996年 | 1930篇 |
1995年 | 2311篇 |
1994年 | 2256篇 |
1993年 | 1688篇 |
1992年 | 1177篇 |
1991年 | 897篇 |
1990年 | 735篇 |
1989年 | 632篇 |
1988年 | 603篇 |
1987年 | 427篇 |
1985年 | 987篇 |
1984年 | 660篇 |
1983年 | 503篇 |
1982年 | 677篇 |
1981年 | 819篇 |
1980年 | 746篇 |
1979年 | 584篇 |
1978年 | 602篇 |
1977年 | 558篇 |
1976年 | 550篇 |
1975年 | 323篇 |
1974年 | 363篇 |
1973年 | 465篇 |
排序方式: 共有10000条查询结果,搜索用时 515 毫秒
11.
Recent Progress in the $L_p$ Theory for Elliptic and Parabolic Equations with Discontinuous Coefficients 下载免费PDF全文
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
12.
13.
14.
15.
16.
17.
18.
In this work, the variation of the magnetic moments of the Ni/Pt multilayers are studied using the linearized augmented plane waves (LAPW) method in the framework of the density functional theory (DFT) implemented in the version of WIEN2K program. The systems have been modeled by seven layers slab separated in z direction by a vacuum region of four substrate layers. We present the results of the dependence of the magnetic properties with respect to the thickness variation of the different multilayers. The modeling of these systems finds an important empirical support. Experiment and theory show the same trends for the magnetic moments: hybridization effects between Ni and Pt are mostly localized at the interface. 相似文献
19.
Single-crystalline gallium nitride nanobelts have been synthesized through the reaction of gallium vapor with flowing ammonia using nickel as a catalyst. The as-synthesized products were characterized using X-ray powder diffraction (XRD), scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, and selected-area electron diffraction (SAED). XRD and SAED results revealed that the products are pure, single-crystalline GaN with hexagonal structure. The widths and thickness of the nanobelts ranged from 80 to 200 nm, and 10 to 30 nm, respectively. The lengths were up to several tens of micrometers. The nanobelts had smooth surface with no amorphous sheath, and a sharp-tip end. The growth mechanism of nanobelts was discussed. 相似文献
20.