全文获取类型
收费全文 | 282篇 |
免费 | 12篇 |
国内免费 | 2篇 |
专业分类
化学 | 263篇 |
晶体学 | 1篇 |
力学 | 2篇 |
数学 | 7篇 |
物理学 | 23篇 |
出版年
2022年 | 4篇 |
2021年 | 4篇 |
2020年 | 5篇 |
2019年 | 4篇 |
2016年 | 10篇 |
2015年 | 5篇 |
2014年 | 6篇 |
2013年 | 12篇 |
2012年 | 14篇 |
2011年 | 20篇 |
2010年 | 7篇 |
2009年 | 9篇 |
2008年 | 14篇 |
2007年 | 12篇 |
2006年 | 18篇 |
2005年 | 18篇 |
2004年 | 18篇 |
2003年 | 22篇 |
2002年 | 14篇 |
2001年 | 4篇 |
2000年 | 4篇 |
1999年 | 1篇 |
1998年 | 5篇 |
1997年 | 6篇 |
1996年 | 7篇 |
1995年 | 2篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1987年 | 1篇 |
1986年 | 3篇 |
1985年 | 2篇 |
1984年 | 4篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1981年 | 3篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1976年 | 4篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1972年 | 4篇 |
1968年 | 2篇 |
1967年 | 1篇 |
1965年 | 1篇 |
1961年 | 2篇 |
排序方式: 共有296条查询结果,搜索用时 15 毫秒
271.
The intramolecular ruthenium(II)-catalyzed radical addition of the trichloroacetyl pendant group to the 2-oxazolone skeleton is greatly enhanced in the presence of catalytic Lewis acids including rare earth metal triflates, thus providing a convenient route to a highly potential chiral synthon for vic-amino alcohols. 相似文献
272.
273.
Takahisa Anada Masako Ogawa Hisashi Yokomizo Yoshihisa Ozaki Tohru Takarada Yoshiki Katayama Mizuo Maeda 《Analytical sciences》2003,19(1):73-77
We describe here a method of affinity capillary electrophoresis in which oligodeoxynucleotide (ODN) was immobilized onto the inner surface of the capillary. The immobilized ODN functioned successfully as an affinity ligand for sequence-based DNA separation. Six- or 12-mer ODN with a sequence complementary to one of the c-K-ras gene was used as an immobilized ligand. When the 12-mer ODN was used, the detection peak for the complementary ODN disappeared selectively, while the single-base mutant was detected as usual. In contrast, when the 6-mer ODN was used as the affinity ligand with a mixture of the complementary ODN and its single-base mutant, it was possible to detect both as completely separate peaks. That is, the separation mode was dependent on the base number of the immobilized ODN used as an affinity ligand. 相似文献
274.
275.
276.
Sans résumé
Work supported by the National Science Foundation under NSF-GP780. 相似文献
Work supported by the National Science Foundation under NSF-GP780. 相似文献
277.
Koso Aoki Yuji Kawanishi Takahiro Seki Masako Sakuragi Takashi Tamaki Kunihiro Ichimura 《Liquid crystals》1995,19(1):119-125
In connection with the mechanism of reversible alignment change of nematic liquid crystals induced by photoisomerizable azobenzene molecules attached to a quartz surface, a static contact angle measurement was carried out for azo-modified plates before and after UV irradiation. The results were not in line with the so-called Friedel-Creagh-Kmetz rule which claims that the alignment is governed by a mutual relationship between a substrate surface energy and surface tension of a liquid crystal. On the other hand, electronic absorption spectra of the plate demonstrated that the ratio of an absorbance at around 340 nm to that at around 240 nm of the azo-chromophore on the surface is reduced by wetting the surface with a UV-transparent nematic liquid crystal. This reflects that the surface azobenzene units are induced to stand approximately perpendicular to the surface upon contact with the liquid crystal. Further discussion is made concerning the photo-induced homogeneous alignment triggered by a rubbed and azo-modified quartz plate determined by polarized absorption spectroscopy. 相似文献
278.
279.
Takanori Suzuki Ryuuichi Tamaki Eisuke Ohta Takashi Takeda Hidetoshi Kawai Kenshu Fujiwara Masako Kato 《Tetrahedron letters》2007,48(22):3823-3827
The spiro-acridan/acridinium-based dynamic redox pair (1/22+) transduces the electrochemical input into UV-vis and fluorescence spectra, whereas the 2,2′-bipyridine units in 1 works as a bidentate ligand for metal ions. X-ray structural analyses of this redox pair and the corresponding Zn-complexes [1-ZnI2/22+-Zn2+(OTf−)4] demonstrate drastic structural changes upon electron-transfer, thus metal binding properties are modified by redox reactions. 相似文献
280.
Tao Y Noguchi D Yang CM Kanoh H Tanaka H Yudasaka M Iijima S Kaneko K 《Langmuir : the ACS journal of surfaces and colloids》2007,23(18):9155-9157
Conductive and mesoporous single-wall carbon nanohorn/resorcinol-formaldehyde aerogel composites were fabricated by embedding organic resorcinol-formaldehyde aerogels with single-wall carbon nanohorns. Samples were characterized with transmission electron microscopy, field emission scanning electron microscopy, nitrogen adsorption at 77 K, and direct-current volume electrical conductivity measurement. It was demonstrated that these composites have important properties, such as controllable nanoporosity and high electrical conductivity in the range of 10-4 S m-1, which enables many potential applications. 相似文献