全文获取类型
收费全文 | 7835篇 |
免费 | 156篇 |
国内免费 | 30篇 |
专业分类
化学 | 4796篇 |
晶体学 | 67篇 |
力学 | 302篇 |
数学 | 1218篇 |
物理学 | 1638篇 |
出版年
2022年 | 74篇 |
2021年 | 103篇 |
2020年 | 132篇 |
2019年 | 123篇 |
2018年 | 184篇 |
2017年 | 203篇 |
2016年 | 232篇 |
2015年 | 123篇 |
2014年 | 197篇 |
2013年 | 377篇 |
2012年 | 345篇 |
2011年 | 411篇 |
2010年 | 271篇 |
2009年 | 280篇 |
2008年 | 330篇 |
2007年 | 350篇 |
2006年 | 282篇 |
2005年 | 215篇 |
2004年 | 237篇 |
2003年 | 204篇 |
2002年 | 191篇 |
2001年 | 123篇 |
2000年 | 99篇 |
1999年 | 72篇 |
1998年 | 74篇 |
1997年 | 70篇 |
1995年 | 106篇 |
1994年 | 112篇 |
1993年 | 99篇 |
1992年 | 69篇 |
1991年 | 87篇 |
1990年 | 94篇 |
1989年 | 88篇 |
1988年 | 74篇 |
1987年 | 84篇 |
1986年 | 71篇 |
1985年 | 100篇 |
1984年 | 125篇 |
1983年 | 82篇 |
1982年 | 99篇 |
1981年 | 83篇 |
1980年 | 85篇 |
1979年 | 121篇 |
1978年 | 110篇 |
1977年 | 118篇 |
1976年 | 123篇 |
1975年 | 99篇 |
1974年 | 70篇 |
1973年 | 91篇 |
1970年 | 70篇 |
排序方式: 共有8021条查询结果,搜索用时 15 毫秒
11.
12.
N. I. Khamidov B. T. Kadyrov N. T. Ul'chenko A. Sh. Isamukhamedov A. I. Glushenkova 《Chemistry of Natural Compounds》1994,30(4):430-433
The phsicochemical indices and the fatty-acid and triacylglycerol compositions of cottonseed and palm oils, of cottonseed
oil hydrogenate, and of compositions based on them have been determined with the aid of IR and UV spectroscopies, GLC analysis,
and chemical transformations. The compositions and amounts of the main classes of lipids in the initial oils and the hydrogenate
have been studied. It has been found that in the process of hydrogenation the amount of oxygenated components falls.
The work was conducted with the financial support of the Uzbek Fund for Fundamental Investigations. 相似文献
13.
14.
N. Sh. Pal'ants R. Sh. Shakirov M. N. Sultankhodzhaev S. T. Akramova 《Chemistry of Natural Compounds》1994,29(5):662-664
The preparation and spectral properties of rhamnose orthoacetates of aconitine and imperialine are described.Tashkent Pharmaceutical Institute. Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 743–746, September–October, 1993. 相似文献
15.
M. S. Tashmukhamedov O. K Zakirova Sh. Ya. Mirzaakhmedov Sh. I. Salikhov I. T. Yakubov M. M. Rakhimov 《Chemistry of Natural Compounds》1994,30(1):97-100
Phospholipase A2 has been isolated fromthe venom of he Central Asian green toad Bufo viridis in the electroophoretically homogeneous state for the first time by biospecific absorption chromatography. The affinity sorbent used was Affi-Gel 10 with covalently bound phosphatidylserine (PDS). The chemical inertness of the bound PDS to the hydrolytic action of phospholipase A2 and its high tendency to form biospecific complexes have been shown. Some biochemical characteristics of the enzyme isolated have been studied: influence of the pH and of the Ca2+ concentration and dependence of activity on substrate concentration.A. S. Sadykov Institute of Bioorganic Chemistry, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax 627071. Tashkent State University, fax 462472. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 105–109, January–February, 1994. 相似文献
16.
R. A. Ganeev A. I. Ryasnyanskii M. K. Kodirov Sh. R. Kamalov V. A. Li R. I. Tugushev T. Usmanov 《Technical Physics》2002,47(8):991-995
Nonlinear optical parameters (nonlinear refractive indices and nonlinear absorption coefficients) of solutions of polyvinylpyrrolidone doped by cobalt to various concentrations are measured at the lasing and second-harmonic wavelengths of a picosecond Nd:YAG laser (λ=1064 and 532 nm, respectively, and τ=35 ps). Data on optical limitation in these solutions are presented. The absence of nonlinear absorption in the IR spectral range and its significant effect in the visible range are demonstrated. Optical limitation at a wavelength of 1064 nm is related to defocusing, whereas at 532 nm, this effect is caused by two-photon absorption and partially by inverse saturated absorption and defocusing. Nonlinear optical parameters of metal-polymer complexes are reported. 相似文献
17.
18.
Yu. V. Vasil’ev R. R. Abzalimov Sh. K. Nasibullaev R. F. Tuktarov F. Hauke U. Reuther A. Hirsch T. Drewello 《Physics of the Solid State》2002,44(3):554-556
The formation and decay of negative molecular ions of azafullerenes and their hydrogenated derivatives are investigated by mass spectrometry. The mechanisms of resonant electron capture and the lifetimes of negative molecular ions with respect to the electron autodetachment in azafullerene molecules are discussed. A comparative analysis of the data obtained for azafullerenes and hydrogenated fullerene derivatives is carried out. 相似文献
19.
A new approach to observing the effect of electromagnetically induced transparency in gamma optics is proposed. The propagation of a resonant photon in a 57Fe magnetic medium in an applied rf field is considered for this purpose. It is shown that, under crossing-anticrossing conditions, a resonant rf field substantially changes the gamma-optical properties of the medium, which become dependent on the parameters of the field. This opens the possibility for exercising a coherent control of the photon group velocity and a controllable filtration of unpolarized gamma radiation in a sample. 相似文献
20.
Sh. M. Aitaliev 《International Applied Mechanics》2004,40(10):1065-1091
Some results on underground structures obtained by Kazakh mechanicians are reviewed. The review covers a period of the last forty years. Also results on the mechanics of special objects are discussed.Translated from Prikladnaya Mekhanika, Vol. 40, No. 10, pp. 3–36, October 2004. 相似文献