全文获取类型
收费全文 | 1471篇 |
免费 | 51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 0 毫秒
91.
92.
93.
Kazuhiro Kurata Seiichi Nishigaki Satoko Sugano 《Proceedings of the American Mathematical Society》2000,128(4):1125-1134
In this paper, we study boundedness of integral operators on generalized Morrey spaces and its application to estimates in Morrey spaces for the Schrödinger operator with nonnegative (reverse Hölder class) and small perturbed potentials .
94.
A new noise-removal technique is applied to scanning laser microscopic (SLM) images to remove clustered spike noise in the images and to recover the shapes of diamond abrasive grains degraded by the noise. For achievement of this purpose, noise points in the SLM image are accurately detected by taking advantage of their properties in the space and spatial-frequency regions. The noise points are removed by a method of smoothing that is based on linear interpolation; that is, their pixel values are replaced by the interpolated values of their non-noise neighboring points. Noise-point information in the space region is acquired from image segmentation based on pixel classification, while noise-point information in the frequency region is derived from redundant wavelet decomposition for the SLM image. Fisher's linear discriminant method is used to yield the two noise-point images. The degraded grain shapes in the SLM images at different noise levels are satisfactorily recovered with a single iteration of smoothing without losses in sharp edges although a single smoothing needed four interpolations. Thus, the present noise-removal technique is shown to be effective for recovering the original shapes of the grains in every SLM image. 相似文献
95.
Kazuhiro Kato Hideo OmotoTakao Tomioka Atsushi Takamatsu 《Applied Surface Science》2011,257(21):9207-9212
The influence of high-temperature annealing on the electrical properties and microstructure of tin-doped indium oxide (ITO) thin films was investigated as a function of oxygen gas flow ratio to argon gas during the sputtering deposition. The ITO thin films were annealed at 500 °C in air after the deposition. It was found that the ITO thin films, which were deposited in relatively low oxygen gas flow ratio, exhibited high Hall mobility and low-resistivity after the annealing. Furthermore, the X-ray reflectivity and diffraction measurement revealed that the ITO thin film with low-resistivity after annealing exhibited high packing density, smooth surface and low crystallization degree. It can be considered that the carrier electron scattering was suppressed with increasing in the packing density of the ITO thin film; as a result, the Hall mobility and resistivity were improved. 相似文献
96.
97.
[reaction: see text] The Heck reaction is a more efficient and reliable method than previous ones for introducing a C3 unit at the benzyl position for the synthesis of Beraprost. Especially, trialkylated long-chain amines such as (n-C(8)H(17))(3)N and (n-C(12)H(25))(3)N resulted in good yields. This development will be used for the industrial synthesis of Beraprost. 相似文献
98.
Cyclic and acyclic ethers are regioselectively cleaved at less substituted α-carbon-oxygen bond in the absence of Lewis acid by the reagent system of sodium iodide and acyl chlorides. 相似文献
99.
Kazuhiro Higuchi 《Tetrahedron》2010,66(6):1236-6033
A novel preparative method for 2,2-disubstituted 1,2-dihydro-3H-indol-3-ones through the oxidation of 2-arylindoles followed by a Mannich-type reaction with carbon nucleophiles is described. 相似文献
100.