全文获取类型
收费全文 | 301篇 |
免费 | 3篇 |
专业分类
化学 | 53篇 |
力学 | 20篇 |
综合类 | 1篇 |
数学 | 83篇 |
物理学 | 147篇 |
出版年
2021年 | 3篇 |
2020年 | 9篇 |
2019年 | 5篇 |
2018年 | 3篇 |
2017年 | 7篇 |
2016年 | 6篇 |
2014年 | 7篇 |
2013年 | 10篇 |
2012年 | 12篇 |
2011年 | 7篇 |
2010年 | 10篇 |
2009年 | 10篇 |
2008年 | 9篇 |
2007年 | 6篇 |
2006年 | 8篇 |
2005年 | 6篇 |
2004年 | 8篇 |
2003年 | 5篇 |
2002年 | 10篇 |
2001年 | 6篇 |
2000年 | 8篇 |
1999年 | 9篇 |
1997年 | 6篇 |
1996年 | 6篇 |
1995年 | 2篇 |
1994年 | 6篇 |
1993年 | 5篇 |
1992年 | 3篇 |
1991年 | 3篇 |
1990年 | 8篇 |
1989年 | 8篇 |
1988年 | 6篇 |
1987年 | 2篇 |
1986年 | 11篇 |
1984年 | 4篇 |
1983年 | 5篇 |
1982年 | 3篇 |
1981年 | 5篇 |
1980年 | 3篇 |
1979年 | 3篇 |
1978年 | 4篇 |
1976年 | 5篇 |
1975年 | 5篇 |
1974年 | 3篇 |
1972年 | 3篇 |
1971年 | 6篇 |
1970年 | 5篇 |
1969年 | 4篇 |
1968年 | 5篇 |
1967年 | 2篇 |
排序方式: 共有304条查询结果,搜索用时 15 毫秒
11.
M. R. DE BACKER-BARILLY A. BARBE S. A. TASHKUN VL. G. TYUTEREV A. CHICHERY 《Molecular physics》2013,111(22):3499-3506
The four 5v 3 bands of 18O enriched ozone have been observed and analysed for the first time. Two species (16O18O16O and 18O16O18O) belong to the C2v symmetry group and two other (18O18O16O and 16O16O18O) to the Cs symmetry group. They have been recorded at a resolution of 0.008 cm?1 with a pathlength of 32.16 m. Despite the very weak absorptions observed, almost 250 energy levels have been derived for each of the 4 species, with J ? 35 and K a ? 13, and suitable sets of Hamiltonian parameters have been determined. For 3 species it has been necessary to account for the resonance between the (005) and (311) states to correctly reproduce the spectra observed. These resonances, anharmonic for C2v, and hybrid (both anhar-monic and Coriolis) for Cs symmetry confirm the accidentally extremely strong coupling between the (005) and (311) states for 16O3, due in that case to the very close distance between unperturbed energy levels. This work also confirms the excellent prediction of band centres of these four species derived from the recently determined isotopically invariant molecular potential function. 相似文献
12.
A. A. Pribylov I. A. Kalinnikova S. M. Kalashnikov G. F. Stoeckli 《Russian Chemical Bulletin》2000,49(4):692-700
The isotherms of excess adsorption of CH4 (atP=0.001–160 MPa), SF6 (atP=0.001–2.4 MPa), and C6H6 (atP=0.0001–0.1 MPa) on carbon adsorbents—microporous carbons CMS and FAS with developed mesoporosity and graphitized soot—were
measured in the 298–408 K temperature region. Calculation of the isotherms of absolute adsorption of the total content of
these substances requires knowledge of the adsorption volume, which was determined by different methods: by the Dubinin—Radushkevich
equation; by the experimental isotherm of excess adsorption and the equation of absolute adsorption; by the method using the
intersection of nonlinear isosteres of excess adsorption and isosteres of absolute adsorption; by the comparative plot of
values of the excess C6H6 adsorption ΓFAS—Γsoor; by the method using the difference of molecular radii of adsorptives and the surface of the specific adsorbent; and by the
calculation of the adsorption layer thickness using the FHH equation for mesoporous systems. The results of determination
of the adsorption volume for microporous systems of these carbons agree well with each other and with the passport data for
the adsorbents. Analysis of the results revealed the peculiarity of the sulfur hexafluoride adsorption related to the formation
of associates on the surface of the carbon adsorbents.
Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 4, pp. 688–696, April, 2000. 相似文献
13.
14.
15.
16.
A macroscopic system which consists of a set of interacting subsystems in an external field is considered. A convenient formula is derived for the mean energy Qj absorbed per unit time by a subsystem. The expression obtained for Qj takes into account that in general the Hamiltonian H of such a system does not coincide with the sum of the Hamiltonians of the subsystems Hj; Qj appears to be the same for various possible definitions of Hj's. 相似文献
17.
Topchieva IN Tonelli AE Panova IG Matuchina EV Kalashnikov FA Gerasimov VI Rusa CC Rusa M Hunt MA 《Langmuir : the ACS journal of surfaces and colloids》2004,20(21):9036-9043
Wide-angle X-ray scattering observations of alpha-cyclodextrin (CD)-poly(ethylene glycol) (PEG) inclusion complexes (ICs) have shown for the first time that two crystalline columnar modifications (forms I and II) are produced in the process of their formation. This was made possible by precise azimuthal X-ray diffraction scanning of oriented IC samples. Form I is characterized by CDs threaded onto PEG chains and arranged along channels in the order head-to-head/tail-to-tail, while form II is formed by unbound CDs also arranged into columns in a head-to-tail and also possibly a head-to-head/tail-to-tail manner, probably as a result of template crystallization on the form I IC crystals. It was shown that similar structural peculiarities are inherent for channel structures based on ICs obtained with PEG with a wide range of molecular weights (MWs). The characteristic feature of ICs based on PEG, especially with MW > 8000, is the presence of unbound polymer in the composition of the complex. The amount of unbound PEG was shown to rise with increasing MW of PEG, resulting in greater imperfections in the IC crystalline structure. The polyblock structure of ICs based on alpha-CD and PEG was therefore proposed. 相似文献
18.
M. Yu. Doladov V. S. Kazakevich I. G. Kalashnikov V. V. Kupaeva V. A. Shcherbakov 《Journal of Applied Spectroscopy》2001,68(4):708-710
The results of an investigation of the reflection spectrum of the human tympanic membrane in the visible and near IR ranges ( = 400–900 nm) are reported. 相似文献
19.
N. G. Basov B. L. Vasin A. A. Galichii A. E. Danilov B. Yu. Ivanov M. P. Kalashnikov B. V. Kruglov Yu. A. Mikhailov V. P. Osetrov V. N. Puzyrev A. V. Rode S. M. Savchenko G. V. Sklizkov V. M. Solodkov S. I. Fedotov V. A. Tsitovich L. I. Shishkina 《Journal of Russian Laser Research》1983,4(3):205-220
The construction principle and the applicable system are considered for the highpower laser amplifier module of the “Del'fin” facility, intended for spherical heating of thermonuclear targets. Results are presented of investigations of the radiation parameters of the amplifier module under various operating regimes. The system for focusing the laser radiation on the target surfaces is described and the results of experiments on plasma heating by radiation of three composite laser beams, at a laser energy level up to 1 kJ at a flux density up to 1014 W/cm2, are analyzed. 相似文献
20.
U. B. Imashev S. M. Kalashnikov G. N. Gordeeva 《Chemistry of Heterocyclic Compounds》1983,19(4):369-373
The Lewis acid-catalyzed addition of cyclic orthoformates to vinyl ethyl ether, which leads to the formation of malonaldehyde acetals, was studied. It is shown that of the linear-cyclic malonaldehyde acetals, 2-(2,2-diethoxyethyl)- and 5,5-dimethyl-2-(2,2-diethoxyethyl)-1,3-dioxanes are stable. The transacetalization of 1,1,3,3-tetraethoxypropane with 1,2- and 1,3-diols, which leads to the formation of cyclic malonaldehyde acetals, was studied. The physicochemical constants of the acetals were determined, and their 1H and 13C NMR spectra are described.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 459–463, April, 1983. 相似文献