全文获取类型
收费全文 | 1466篇 |
免费 | 56篇 |
国内免费 | 14篇 |
专业分类
化学 | 1187篇 |
晶体学 | 10篇 |
力学 | 12篇 |
数学 | 100篇 |
物理学 | 227篇 |
出版年
2023年 | 6篇 |
2022年 | 11篇 |
2021年 | 18篇 |
2020年 | 4篇 |
2019年 | 34篇 |
2018年 | 20篇 |
2017年 | 7篇 |
2016年 | 21篇 |
2015年 | 43篇 |
2014年 | 34篇 |
2013年 | 100篇 |
2012年 | 99篇 |
2011年 | 96篇 |
2010年 | 60篇 |
2009年 | 57篇 |
2008年 | 95篇 |
2007年 | 105篇 |
2006年 | 110篇 |
2005年 | 94篇 |
2004年 | 91篇 |
2003年 | 59篇 |
2002年 | 67篇 |
2001年 | 21篇 |
2000年 | 25篇 |
1999年 | 14篇 |
1998年 | 14篇 |
1997年 | 13篇 |
1996年 | 24篇 |
1995年 | 7篇 |
1994年 | 7篇 |
1993年 | 13篇 |
1992年 | 9篇 |
1991年 | 13篇 |
1990年 | 14篇 |
1989年 | 10篇 |
1988年 | 5篇 |
1987年 | 3篇 |
1986年 | 5篇 |
1985年 | 17篇 |
1984年 | 11篇 |
1983年 | 7篇 |
1982年 | 11篇 |
1981年 | 9篇 |
1980年 | 13篇 |
1979年 | 3篇 |
1978年 | 6篇 |
1977年 | 9篇 |
1976年 | 5篇 |
1975年 | 5篇 |
1973年 | 9篇 |
排序方式: 共有1536条查询结果,搜索用时 11 毫秒
121.
122.
Tomoyuki Miyazawa Haruka Abe Takayuki Suzuki Yosuke Togashi Kazuhiro Koshiji Yuki Nonaka 《Journal of carbohydrate chemistry》2013,32(5):252-266
We evaluated the potential of a linear β-1,3-glucan (curdlan) as a starting material to access C6-modified glucose derivatives and found that 6-bromo-6-deoxyglucose, 6-azide-6-deoxyglucose, and 6-acetamido-6-deoxyglucose could be readily prepared from curdlan through its C6-selective and quantitative modifications and subsequent acid-catalyzed hydrolysis. 相似文献
123.
124.
125.
This paper studies the Cauchy problem for a doubly nonlinear parabolic equation. The main result shows that if there is a
nonnegative solution of the Cauchy problem, then the initial trace of the solution is uniquely given as a nonnegative Borel
measure satisfying an exponential growth condition. This extends the known result for the heat equation to the nonlinear case. 相似文献
126.
127.
This paper presents an approach to the generation of unstructured surface meshes for Computer‐Aided Design (CAD) surface models represented as lists of polygons with minimum user interventions. Stereolithography (STL) data are adopted as an interface between a CAD system and the surface grid generator. STL files often include problems such as overlapping surfaces, gaps, and intersections. They have to be revised quickly and automatically before the surface models are used for the background grid of the surface grid generation. In this paper, we describe an automatic revision method for use with STL‐defined surface models. The advancing front method using geometric features is adopted directly on the modified STL surfaces. The capability of the method is demonstrated for several 3D surface models. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
128.
129.
An automatic aberration correction method has been implemented in scanning electron microscopes (SEM). Necessity of the automatic aberration correction is discussed. The procedure of the automatic aberration correction is explained in detail, where deconvolution techniques are used in order to extract probe information from SEM images. Due to the precise digitization and the usage of proper combinations of correction fields, linearity has been found between the amplitude of each aberration and the corresponding field strength. Experimental results are shown which demonstrate that the aberrations are corrected automatically by a linear feedback control method. After the automatic aberration correction, the image quality has been improved drastically. 相似文献
130.
A generalized phase-shifting algorithm is implemented in the electron-wave interferometry with a transmission electron microscope, based on simultaneous measurement of the initial phases of the interferograms. The initial phase of each interferogram that has inherent linear carrier fringes is calculated using the Fourier co-efiicients of the interferogram itself corresponding to the carrier-frequency. Taking advantage of this phase-shifting method in both spatial resolution and precision, the phase distribution of a biological weak phase object is successfully measured. This promises to be one of the most spectacular application fields for this new technology. 相似文献