全文获取类型
收费全文 | 472篇 |
免费 | 8篇 |
国内免费 | 2篇 |
专业分类
化学 | 356篇 |
晶体学 | 8篇 |
力学 | 6篇 |
数学 | 27篇 |
物理学 | 85篇 |
出版年
2021年 | 4篇 |
2020年 | 8篇 |
2019年 | 2篇 |
2018年 | 6篇 |
2017年 | 5篇 |
2016年 | 6篇 |
2015年 | 7篇 |
2014年 | 8篇 |
2013年 | 36篇 |
2012年 | 24篇 |
2011年 | 20篇 |
2010年 | 11篇 |
2009年 | 20篇 |
2008年 | 24篇 |
2007年 | 25篇 |
2006年 | 21篇 |
2005年 | 18篇 |
2004年 | 17篇 |
2003年 | 23篇 |
2002年 | 28篇 |
2001年 | 9篇 |
2000年 | 9篇 |
1999年 | 3篇 |
1998年 | 10篇 |
1997年 | 8篇 |
1996年 | 10篇 |
1995年 | 6篇 |
1994年 | 6篇 |
1993年 | 6篇 |
1992年 | 5篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 4篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1986年 | 3篇 |
1985年 | 10篇 |
1984年 | 14篇 |
1983年 | 2篇 |
1982年 | 9篇 |
1981年 | 8篇 |
1980年 | 7篇 |
1979年 | 6篇 |
1978年 | 4篇 |
1977年 | 5篇 |
1975年 | 4篇 |
1974年 | 4篇 |
1973年 | 2篇 |
1968年 | 1篇 |
1958年 | 1篇 |
排序方式: 共有482条查询结果,搜索用时 578 毫秒
141.
Togawa Y Harada K Akashi T Kasai H Matsuda T Nori F Maeda A Tonomura A 《Physical review letters》2005,95(8):087002
Using Lorentz microscopy to directly image vortices, we investigate vortex motion control and rectification in a niobium superconductor. We directly observe a net motion of vortices along microfabricated channels with a spatially asymmetric potential, even though the vortices were driven by an oscillatory field. By observing the individual motion of vortices, we clarify elementary processes involved in this rectification. To further demonstrate the ability to control the motion of vortices, we created a tiny vortex "racetrack" to monitor the motion of vortices in a closed circuit channel. 相似文献
142.
Selective uptake of various dyes into an aggregate of amphiphilic copolymer consisting of a hydrophilic linear polyelectrolyte block and hydrophobic block carrying pendant dendritic moiety has been investigated in water. The copolymer associated into an aggregate with a hydrophobic interior at concentrations above 0.2 mg cm(-3). The uptake (23 and 36 molecules per aggregate, respectively) of pyrene and Oil Yellow in an aggregate was one order higher than that of benzo[a]pyrene and SudanIII. The hydrophobic dyes are always doped in the interior of the aggregate, but the difference in uptake among dyes may depend on their structure. Even if a large number of guest molecules was doped into the interior of an aggregate, the size of the sphere-like aggregate was conserved. It is suggested that guest molecules are encapsulated into the persisting cavity within and between hydrophobic dendron moieties in an aggregate. Structure-selective uptake reported in this investigation is a unique character of an aggregate of copolymer with dendron moiety because the dendron moiety offers a large void for doping. 相似文献
143.
Hisao Urata Hiroharu Suzuki Yoshihiko Moro-Oka Tsuneo Ikawa 《Journal of organometallic chemistry》1982,234(3):367-373
Treatment of α-halogenated carbonyl or cyano compounds with hexamethyldisilane in the presence of catalytic amounts of tetrakis(triphenylphosphine)-palladium gives the corresponding parent carbonyl or cyano compounds in excellent yields via oxy-π-allyl(trimethylsilyl)palladium intermediates. 相似文献
144.
Shosuke Yamamura Seiji Kosemura Shigeru Ohba Masatoki Ito Yoshihiko Saito 《Tetrahedron letters》1981,22(52):5315-5318
Two new toxic substances, euphoscopins A and B, have been isolated from the plant L., and their absolute stereostructures also been elucidated on the basis of their spectral data coupled with an X-ray crystallographic analysis of the -bromobenzoate readily obtained on treatment of euphoscopin A with -bromobenzoyl chloride - pyridine. These antitumor substances belong to a group of jatrophone-type diterpenes. 相似文献
145.
146.
147.
148.
Akitami Ichihara Noriki Nio Yoshihiko Terayama Ryoji Kimura Sadao Sakamura 《Tetrahedron letters》1979,20(39):3731-3734
Various 2-alkyl-2-butenolactones were simply prepared from cyclopentadiene-maleic anhydride adducts through the retro-Diels-Alder reaction. The procedure was applied for the synthesis of dehydrolappaol A dimethyl ether. 相似文献
149.
150.