全文获取类型
收费全文 | 335篇 |
免费 | 3篇 |
国内免费 | 6篇 |
专业分类
化学 | 239篇 |
晶体学 | 3篇 |
力学 | 9篇 |
数学 | 32篇 |
物理学 | 61篇 |
出版年
2021年 | 6篇 |
2020年 | 4篇 |
2019年 | 6篇 |
2018年 | 8篇 |
2017年 | 9篇 |
2016年 | 10篇 |
2015年 | 4篇 |
2014年 | 6篇 |
2013年 | 10篇 |
2012年 | 17篇 |
2011年 | 3篇 |
2010年 | 9篇 |
2009年 | 11篇 |
2008年 | 8篇 |
2007年 | 12篇 |
2006年 | 6篇 |
2005年 | 7篇 |
2004年 | 8篇 |
2003年 | 7篇 |
2002年 | 6篇 |
2001年 | 6篇 |
2000年 | 5篇 |
1999年 | 5篇 |
1998年 | 5篇 |
1994年 | 5篇 |
1993年 | 6篇 |
1992年 | 5篇 |
1991年 | 8篇 |
1990年 | 6篇 |
1989年 | 3篇 |
1988年 | 9篇 |
1987年 | 4篇 |
1984年 | 6篇 |
1983年 | 5篇 |
1982年 | 3篇 |
1981年 | 4篇 |
1980年 | 3篇 |
1978年 | 3篇 |
1977年 | 5篇 |
1976年 | 3篇 |
1975年 | 6篇 |
1974年 | 9篇 |
1973年 | 11篇 |
1972年 | 5篇 |
1971年 | 6篇 |
1969年 | 3篇 |
1968年 | 4篇 |
1967年 | 9篇 |
1966年 | 5篇 |
1948年 | 3篇 |
排序方式: 共有344条查询结果,搜索用时 16 毫秒
1.
I. P. Nazarova A. I. Glushenkova N. T. Ul'chenko G. P. Moiseeva 《Chemistry of Natural Compounds》1989,25(1):54-57
A study has been made of the gossypol pigments of the seeds and roots of a cotton plant of the variety Tashkent-1 infected with wilt in comparison with a healthy plant. The amount of gossypol in the infected plant was lower than in the healthy plant. In the diseased plant, gossypurpurin was concentrated in the roots, and in the healthy plant it was concentrated in the seeds. Gossypol possessing optical activity was detected in the seeds and roots of both the healthy and the diseased plants.Institute of the Chemistry of Plant Substances, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 63–66, January–February, 1989. 相似文献
2.
3.
I. P. Nazarova N. T. Ul'chenko A. I. Glushenkova K. K. Babievski I. A. Yamskov 《Chemistry of Natural Compounds》1991,27(6):664-668
It has been shown that the use of chitin (technical), which is a production waste, as adsorbent permits the clarification of black cottonseed oil and the purification of technical gossypol. 相似文献
4.
A simple method for the synthesis of N-substituted 5-aminofurfurals based on the reaction of 5-halogenofurfurals with secondary amines has been developed. The reaction takes place through the formation of quaternary salts of N-substituted 5-aminofurfurals. 5-(Diethylamino)-, 5-(N-methyl-N-phenylamino)-, and 5-piperidinofurfurals have been obtained for the first time. 相似文献
5.
6.
7.
Iron Nanoparticles in Severe-plastic-deformed Copper 总被引:1,自引:0,他引:1
Superparamagnetic iron nanoparticles with a size of a few nanometers were produced in copper by severe plastic deformation. In a isochronal annealing experiment near a temperature of 450K, which corresponds to the temperature of structural relaxation and the first step of grain growth (from 128 to 150nm) of submicrocrystalline copper, an abrupt increase in the magnetic susceptibility is detected. This increase is shown to be due to iron nanoparticles increasing in size from 2.8 to 3.3nm. The vanishing of the ferromagnetic contribution by iron nanoparticles observed at 850K, well below the Curie temperature of iron, is due to the dissolution of nanoparticles in plastically deformed copper. 相似文献
8.
D. A. Davydov S. Z. Nazarova A. A. Valeeva A. A. Rempel 《Bulletin of the Russian Academy of Sciences: Physics》2007,71(5):677-680
The order-disorder phase transition in vanadium monoxide of substoichiometric compositions VOy has been studied for the first time in situ by the Faraday method with a pendulum magnetic balance of the Domenically type. A minimum is found on the temperature dependence of the magnetic susceptibility of vanadium monoxide of different compositions at a temperature of about 700 K. X-ray diffraction analysis performed before and after measuring the magnetic susceptibility confirmed the change in the structure of vanadium monoxide and the possibility of atom-vacancy processes upon cooling and heating of the samples. 相似文献
9.
General Relativity and Gravitation - In previous work, we established theoretical results concerning the effect of matter shells surrounding a gravitational wave (GW) source, and we now apply these... 相似文献
10.
R. M. Islamova O. I. Ishkinina S. V. Nazarova O. N. Chupakhin I. A. Utepova N. M. Andriyashina A. O. Terent’ev 《Russian Chemical Bulletin》2013,62(5):1282-1285
Cyclic peroxides as initiators for the radical polymerization of methyl methacrylate were proposed. The initial rates, initiation rates, and effective activation energies of polymerization initiated by cyclic peroxides and cyclic peroxide-1-pyridyl-2-ferrocene systems were determined. The radical yields to the volume upon the thermal decomposition of cyclic peroxides and their catalytic decomposition in the presence of 1-pyridyl-2-ferrocene were determined. In combination with 1-pyridyl-2-ferrocene cyclic peroxides form efficient initiating systems favoring an increase in the polymerization rate, a decrease in the molecular weights, and an increase in syndiotacticity of the synthesized poly(methyl methacrylate). 相似文献