全文获取类型
收费全文 | 115842篇 |
免费 | 9709篇 |
国内免费 | 8229篇 |
专业分类
化学 | 31546篇 |
晶体学 | 1899篇 |
力学 | 5975篇 |
综合类 | 1113篇 |
数学 | 41088篇 |
物理学 | 52159篇 |
出版年
2023年 | 537篇 |
2022年 | 655篇 |
2021年 | 1118篇 |
2020年 | 1411篇 |
2019年 | 1808篇 |
2018年 | 1761篇 |
2017年 | 1638篇 |
2016年 | 1621篇 |
2015年 | 1311篇 |
2014年 | 2793篇 |
2013年 | 4240篇 |
2012年 | 2923篇 |
2011年 | 3772篇 |
2010年 | 4157篇 |
2009年 | 9191篇 |
2008年 | 10293篇 |
2007年 | 8830篇 |
2006年 | 8039篇 |
2005年 | 5915篇 |
2004年 | 5428篇 |
2003年 | 5501篇 |
2002年 | 6515篇 |
2001年 | 4840篇 |
2000年 | 4553篇 |
1999年 | 4267篇 |
1998年 | 3576篇 |
1997年 | 2683篇 |
1996年 | 2296篇 |
1995年 | 2639篇 |
1994年 | 2521篇 |
1993年 | 1945篇 |
1992年 | 1509篇 |
1991年 | 1094篇 |
1990年 | 907篇 |
1989年 | 768篇 |
1988年 | 726篇 |
1987年 | 572篇 |
1986年 | 339篇 |
1985年 | 1111篇 |
1984年 | 777篇 |
1983年 | 584篇 |
1982年 | 786篇 |
1981年 | 933篇 |
1980年 | 847篇 |
1979年 | 684篇 |
1978年 | 671篇 |
1977年 | 595篇 |
1976年 | 599篇 |
1974年 | 379篇 |
1973年 | 496篇 |
排序方式: 共有10000条查询结果,搜索用时 234 毫秒
1.
深挖高职院校公选课“生活中的化学”的育人元素,精心设计教学内容,运用课堂主题辩论、趣味生活实验的设计与展示、探秘生活中的化学等理论知识传授与课内外实践相结合的教学方式,实现全过程育人,充分展现了公选课在立德树人方面的价值。 相似文献
2.
3.
4.
《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
5.
《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
7.
Marcus Carlsson 《Expositiones Mathematicae》2021,39(1):149-157
von Neumann’s inequality in matrix theory refers to the fact that the Frobenius scalar product of two matrices is less than or equal to the scalar product of the respective singular values. Moreover, equality can only happen if the two matrices share a joint set of singular vectors, and this latter part is hard to find in the literature. We extend these facts to the separable Hilbert space setting, and provide a self-contained proof of the “latter part”. 相似文献
8.
Dr. Joaquim Torra Dr. Felipe Viela Dr. Diego Megías Dr. Begoña Sot Prof. Cristina Flors 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(19):e202200026
CRANAD-2 is a fluorogenic curcumin derivative used for near-infrared detection and imaging in vivo of amyloid aggregates, which are involved in neurodegenerative diseases. We explore the performance of CRANAD-2 in two super-resolution imaging techniques, namely stimulated emission depletion (STED) and single-molecule localization microscopy (SMLM), with markedly different fluorophore requirements. By conveniently adapting the concentration of CRANAD-2, which transiently binds to amyloid fibrils, we show that it performs well in both techniques, achieving a resolution in the range of 45–55 nm. Correlation of SMLM with atomic force microscopy (AFM) validates the resolution of fine features in the reconstructed super-resolved image. The good performance and versatility of CRANAD-2 provides a powerful tool for near-infrared nanoscopic imaging of amyloids in vitro and in vivo. 相似文献
9.
10.
Dr. Chenge Li Dr. Alison G. Tebo Marion Thauvin Marie-Aude Plamont Prof. Dr. Michel Volovitch Dr. Xavier Morin Prof. Dr. Sophie Vriz Prof. Dr. Arnaud Gautier 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(41):18073-18079
Far-red emitting fluorescent labels are highly desirable for spectral multiplexing and deep tissue imaging. Here, we describe the generation of frFAST (far-red Fluorescence Activating and absorption Shifting Tag), a 14-kDa monomeric protein that forms a bright far-red fluorescent assembly with (4-hydroxy-3-methoxy-phenyl)allylidene rhodanine (HPAR-3OM). As HPAR-3OM is essentially non-fluorescent in solution and in cells, frFAST can be imaged with high contrast in presence of free HPAR-3OM, which allowed the rapid and efficient imaging of frFAST fusions in live cells, zebrafish embryo/larvae, and chicken embryos. Beyond enabling the genetic encoding of far-red fluorescence, frFAST allowed the design of a far-red chemogenetic reporter of protein–protein interactions, demonstrating its great potential for the design of innovative far-red emitting biosensors. 相似文献