全文获取类型
收费全文 | 223篇 |
免费 | 1篇 |
专业分类
化学 | 163篇 |
晶体学 | 6篇 |
力学 | 2篇 |
数学 | 5篇 |
物理学 | 48篇 |
出版年
2022年 | 3篇 |
2021年 | 2篇 |
2020年 | 8篇 |
2019年 | 6篇 |
2018年 | 4篇 |
2017年 | 5篇 |
2016年 | 11篇 |
2015年 | 4篇 |
2014年 | 6篇 |
2013年 | 6篇 |
2012年 | 12篇 |
2011年 | 12篇 |
2010年 | 3篇 |
2009年 | 10篇 |
2008年 | 10篇 |
2007年 | 10篇 |
2006年 | 8篇 |
2005年 | 5篇 |
2004年 | 6篇 |
2003年 | 6篇 |
2002年 | 6篇 |
2001年 | 2篇 |
2000年 | 5篇 |
1999年 | 2篇 |
1998年 | 5篇 |
1997年 | 3篇 |
1996年 | 2篇 |
1994年 | 4篇 |
1990年 | 4篇 |
1988年 | 3篇 |
1987年 | 3篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 3篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1974年 | 3篇 |
1973年 | 4篇 |
1972年 | 3篇 |
1971年 | 1篇 |
1970年 | 3篇 |
1969年 | 6篇 |
1968年 | 4篇 |
1967年 | 6篇 |
1966年 | 1篇 |
1965年 | 1篇 |
1964年 | 1篇 |
排序方式: 共有224条查询结果,搜索用时 0 毫秒
1.
The results of magneto-optical investigations into the Γ2–Γ4 spin reorientation in an Sm0.6Tb0.2Tm0.2FeO3 orthoferrite single crystal are reported. The magneto-optical parameters are determined taking into account the dichroism. The orientation of the antiferromagnetic vector in the canted phase is investigated as a function of the magnetic field and temperature. The magnetic anisotropy field strengths are determined by the processing of the results. The orientation contribution to the birefringence is estimated. 相似文献
2.
S. V. Trukhanov V. V. Fedotova A. V. Trukhanov S. G. Stepin H. Szymczak 《Crystallography Reports》2008,53(7):1177-1180
Nanocrystalline manganite La0.50Ba0.50MnO3 was synthesized by the soft-chemical method. For this purpose, the sol-gel method was modified and improved. A trihydric saturated alcohol, e.g., glycerol, was suggested as a new organic matrix. The crystal structure of the composite was studied by X-ray powder diffraction at room temperature. A La0.50Ba0.50MnO3 powder annealed in air at T = 500°C is characterized by a perovskite-like cubic structure with the unit-cell parameter a = 3.869 Å. The chemical composition of the sample was studied by electron-probe X-ray microanalysis. The La: Ba: Mn cation ratio in the material was 1: 1: 2. The surface topography was examined with a scanning electron microscope. The crystallite size was ~30 nm. The dependence of the crystal structure and the surface topology on the annealing temperature was studied. The high-temperature treatment in air resulted in the growth of larger, micrometer-size, crystallites. 相似文献
3.
O. V. Fedotova E. V. Lipatova V. K. Bel'skii 《Chemistry of Heterocyclic Compounds》1998,34(10):1137-1141
A comparative assessment was made of the reactivity of carbonyl-containing spirohydrochromans in their reaction with hydrogen
sulfide under the conditions of acid catalysis. The special features of the structure of one of the obtained condensed spiro(thia)chromans
are examined on the basis of the results from x-ray crystallographic analysis, the13C NMR spectra, and quantum-chemical calculations.
N. G. Chernyshevskii Saratov State University, Saratov 410026, Russia. Translated from Khimiya Geterotsiklicheskikh Soedinenii,
No. 10, pp. 1340–1345, October, 1998. 相似文献
4.
5.
O. V. Fedotova M. I. Skuratova M. A. Panov S. P. Mushtakova 《Russian Journal of Organic Chemistry》2005,41(11):1661-1665
Reactions were studied of fused spirodihydrofurans originating from 1,3-cyclohexanedione with hydrogen sufide arising in situ. Depending on a substituent at the atom C 3 of the heterocycle the reaction ended by thionation of the conjugated carbonyl group followed by heterocyclization involving the spirodimedonyl fragment. A quantum-chemical forecasting of the protonation stages of substrates and their thionated analogs was performed applying the semiempirical PM3 procedure. A probable mechanism of investigated transformations of the spirodihydrofurans was suggested. 相似文献
6.
Atovmyan E. G. Nikonova L. A. Filipenko O. S. Fedotova T. N. Aldoshin S. M. 《Russian Chemical Bulletin》2002,51(1):99-104
N"-Substituted isonicotinic hydrazides of the general formula Py—C(=O)—N(H)-N"=C(H)—R, where R is o- (1), m- (2), or p-nitrophenyl (3), were studied by IR spectroscopy and X-ray diffraction analysis. The position of the nitro group in these compounds has no effect on the type of the crystal structure. The crystal packings are based on stacks consisting of antiparallel planar molecules. The molecules from the adjacent stacks are linked to each other via the N—H...NPy hydrogen bonds. Depending on the position of the nitro group, the N...NPy distance increases in the series 3 > 1 > 2 and the energy of the hydrogen bonds decreases (according to the IR spectroscopic data) from 3.9 to 3.1 kcal mol–1. Analysis of the IR spectra demonstrated that the intensity of absorption in the (C—H) stretching region of the pyridine ring increases substantially as the the N—H...NPy hydrogen bond is strengthened. Some regularities of the changes, which are observed for the (NO2) bands in the spectra of the nitrophenyl-containing conjugated molecules in solutions, persist in the crystalline state. 相似文献
7.
J. V. Kasiuk J. A. Fedotova M. Marszalek A. Karczmarska M. Mitura-Nowak Yu. E. Kalinin A. V. Sitnikov 《Physics of the Solid State》2012,54(1):178-184
The elemental and phase compositions and the magnetic state of metal particles in FeCoZr-Pb(ZrTi)O3 granular nanocomposites (GNCs) synthesized by ion-beam sputtering of composite targets in oxygen-containing media at different
oxygen partial pressures have been studied. The phase transformations in GNCs have been monitored by the Raman and M?ssbauer
spectroscopy techniques. Correlation between the oxygen pressure during GNC synthesis and the valence state of iron ions in
metal granules has been established. It has been confirmed that (i) the degree of metal oxidation increases with increasing
oxygen pressure and (ii) the degree of crystallinity of oxides increases as a result of annealing. It has been established
that the percolation threshold in GNCs can also be varied by changing the oxygen pressure during GNC synthesis. 相似文献
8.
Alfimov M. V. Chibisov A. K. Zakharova G. V. Fedotova T. V. Plotnikov V. G. 《Russian Physics Journal》2020,63(8):1363-1369
Russian Physics Journal - The results of investigations of the properties of cyanine dye dimers in the triplet state are presented. The formation of dimers is demonstrated as two absorption bands... 相似文献
9.
10.
Atovmyan E. G. Grishchuk A. A. Fedotova T. N. Chirkova Yu. N. Estrin Ya. I. 《Russian Journal of Applied Chemistry》2012,85(1):159-160
The reaction of fullerene with excess 2,2′-azobis(isobutyronitrile) in o-dichlorobenzene at 60°C was studied, and the chemical structure of the reaction product was determined. 相似文献