全文获取类型
收费全文 | 252篇 |
免费 | 0篇 |
专业分类
化学 | 214篇 |
数学 | 1篇 |
物理学 | 37篇 |
出版年
2021年 | 2篇 |
2020年 | 3篇 |
2016年 | 3篇 |
2014年 | 2篇 |
2013年 | 3篇 |
2012年 | 2篇 |
2010年 | 2篇 |
2009年 | 4篇 |
2008年 | 2篇 |
2007年 | 2篇 |
2006年 | 1篇 |
2005年 | 1篇 |
2004年 | 5篇 |
2002年 | 1篇 |
2001年 | 2篇 |
2000年 | 4篇 |
1999年 | 4篇 |
1998年 | 1篇 |
1996年 | 11篇 |
1995年 | 10篇 |
1994年 | 3篇 |
1993年 | 7篇 |
1992年 | 10篇 |
1991年 | 7篇 |
1990年 | 7篇 |
1989年 | 9篇 |
1988年 | 9篇 |
1987年 | 9篇 |
1986年 | 6篇 |
1985年 | 3篇 |
1984年 | 5篇 |
1983年 | 5篇 |
1982年 | 4篇 |
1981年 | 4篇 |
1980年 | 5篇 |
1979年 | 8篇 |
1978年 | 6篇 |
1977年 | 12篇 |
1976年 | 12篇 |
1975年 | 5篇 |
1974年 | 11篇 |
1973年 | 4篇 |
1972年 | 7篇 |
1971年 | 7篇 |
1970年 | 5篇 |
1969年 | 4篇 |
1968年 | 5篇 |
1967年 | 2篇 |
1966年 | 1篇 |
1917年 | 1篇 |
排序方式: 共有252条查询结果,搜索用时 109 毫秒
81.
82.
Hetisane - Type Diterpenoid Alkaloids 总被引:1,自引:0,他引:1
Data in the literature up to 1998 on hetisane-type diterpenoid alkaloids isolated from plants of the generaAconitum, Consolida, Delphinium, Thalictrum,andSpireaare reviewed and systematized. Data on the chemistry and physicochemical methods of studying the structures and pharmacology of hetisane alkaloids are generalized. An alphabetical list of 107 hetisane alkaloids with an indication of the plant source, structure, characteristic derivatives, physicochemical data, and references to the original literature is presented 相似文献
83.
The possibility of determining eight adrenocorticotropic steroid hormones (cortisol, cortisone, corticosterone, 11-dehydrocorticosterone, 17-hydroxyprogesterone, 11-deoxycortisol, and progesterone) by micellar electrokinetic chromatography (MEKC) using urea as an organic additive to the working electrolyte (a 25 mM phosphoric acid solution and 10 mM sodium dodecyl sulfate) was demonstrated. The use of online preconcentration (stacking and sweeping) allowed us to lower the detection limit for steroids to ~3 ng/mL. The total analysis time was 15 min. 相似文献
84.
85.
86.
V. I. Akhmedzhanova Kh. A. Rasulova I. A. Bessonova A. S. Shashkov N. D. Abdullaev L. Angenot 《Chemistry of Natural Compounds》2005,41(1):60-64
The new quinoline alkaloid folipidine, the structure of which was established by chemical transformations and spectral data (UV, IR, mass, NMR) using APT, 2D 1H-1H COSY, NOESY, and 1H-13C HSQC, HMBC, was isolated from two plants of the Haplophyllum genus. Folipidine is the first representative of a new type of quinoline alkaloids that contain a heteroaromatic skeleton of [3,4-b] conjugated pyrrole and quinoline fragments. The total alkaloids of these plants exhibit antitumor activity. Folipidine does not possess such activity.__________Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 49–52, January–February, 2005. 相似文献
87.
Institute of the Chemistry of Plant Substances, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 284, March–April, 1990. 相似文献
88.
89.
90.
A. Zunnundzhanov I. A. Bessonova N. D. Abdullaev D. K. Ogai 《Chemistry of Natural Compounds》1987,23(4):461-465
A new optically active phenolic alkaloid with the composition C10H11NO2S, mp 85–88°C, [α]D +28° (c 1.0; chloroform) (I) has been isolated from the microorganismPseudomonas aeruginosa (strain 590) and has been called aerugine. The action of diazomethane gave an O-methyl derivative (II). On the basis of the formation of ortho-cresol by the hydrogenolytic desulfuration reaction, a study of the IR, mass, and PMR spectra and (I) and its acetyl derivative (III), and also the13C NMR spectrum of (I), the structure of 4-hydroxymethyl-2-(o-hydroxyphenyl)-2-thiazoline has been established for aerugine. The spectral characteristics of the compounds mentioned are given. 相似文献