全文获取类型
收费全文 | 841篇 |
免费 | 3篇 |
专业分类
化学 | 246篇 |
晶体学 | 70篇 |
力学 | 48篇 |
数学 | 56篇 |
物理学 | 424篇 |
出版年
2022年 | 16篇 |
2021年 | 28篇 |
2020年 | 14篇 |
2019年 | 26篇 |
2018年 | 40篇 |
2017年 | 29篇 |
2016年 | 33篇 |
2015年 | 10篇 |
2014年 | 33篇 |
2013年 | 25篇 |
2012年 | 26篇 |
2011年 | 37篇 |
2010年 | 27篇 |
2009年 | 28篇 |
2008年 | 34篇 |
2007年 | 22篇 |
2006年 | 21篇 |
2005年 | 21篇 |
2004年 | 25篇 |
2003年 | 15篇 |
2002年 | 25篇 |
2001年 | 20篇 |
2000年 | 22篇 |
1999年 | 12篇 |
1998年 | 10篇 |
1997年 | 13篇 |
1996年 | 11篇 |
1995年 | 7篇 |
1994年 | 10篇 |
1993年 | 5篇 |
1992年 | 10篇 |
1991年 | 7篇 |
1990年 | 6篇 |
1988年 | 9篇 |
1987年 | 11篇 |
1986年 | 16篇 |
1985年 | 14篇 |
1984年 | 13篇 |
1983年 | 9篇 |
1982年 | 7篇 |
1981年 | 6篇 |
1977年 | 6篇 |
1976年 | 8篇 |
1975年 | 4篇 |
1974年 | 14篇 |
1972年 | 9篇 |
1971年 | 5篇 |
1969年 | 5篇 |
1968年 | 9篇 |
1966年 | 6篇 |
排序方式: 共有844条查询结果,搜索用时 15 毫秒
1.
Crystallography Reports - Nd1 – yEuyF3 – y crystals (y is the molar fraction of EuF2; 0 ≤ y ≤ 0.15) with a tysonite (LaF3) structure have... 相似文献
2.
Yu. K. Voron'ko A. B. Kudryavtsev V. V. Osiko E. V. Sorokin 《Journal of Applied Spectroscopy》1991,55(4):953-957
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 55, No. 4, pp. 535–540, October, 1991. 相似文献
3.
B. P. Sorokin D. A. Glushkov L. N. Bezmaternykh V. L. Temerov I. A. Gudim K. S. Aleksandrov 《Physics of the Solid State》2004,46(3):458-461
Single crystals of lead gallium germanate Pb3Ga2Ge4O14 are grown from their own solution melts. The propagation of bulk acoustic waves is investigated, and the elastic, piezoelectric, and dielectric constants are calculated. The temperature dependences of the dielectric constants of this compound are analyzed. 相似文献
4.
A. P. Tyutnev R. Sh. Ikhsanov E. L. Grin’ G. P. Safonov A. I. Kononenko A. M. Sorokin I. V. Rudenko 《Polymer Science Series A》2006,48(11):1190-1195
A general theory of the phenomenon of recovered voltage in polymers was considered on the basis of representation of an actual poling process by a discrete set of Debye relaxators. Examples of numerical solution of the direct and inverse problems are given. A correlation expression between intentionally aged polymer specimens and recovered-voltage curves was proposed for use in the assessment of the material state of a polymer under actual service conditions. It was shown that it is sufficient to restrict consideration to three relaxation processes in analysis of the phenomenon. 相似文献
5.
Girard V Farrenq R Sorokin E Sorokina IT Guelachvili G Picqué N 《Chemical physics letters》2006,419(4-6):584-588
The spectral dynamics of a mid-infrared multimode Cr(2+):ZnSe laser located in a vacuum sealed chamber containing acetylene at low pressure is analyzed by a stepping-mode high-resolution time-resolved Fourier transform interferometer. Doppler-limited absorption spectra of C(2)H(2) in natural isotopic abundance are recorded around 4000 cm(-1) with kilometric absorption path lengths and sensitivities better than 3 10(-8) cm(-1). Two cold bands are newly identified and assigned to the ν(1)+ν(4) (1) and ν(3)+ν(5) (1) transitions of (12)C(13)CH(2). The ν(1)+ν(5) (1) band of (12)C(2)HD and fourteen (12)C(2)H(2) bands are observed, among which for the first time ν(2)+2ν(4) (2)+ν(5) (-1). 相似文献
6.
L. D. Smirnov S. V. Nikitin A. I. Chernyshev A. A. Sorokin V. P. Lezina V. G. Zabrodnyaya M. M. Kaganskii 《Chemistry of Heterocyclic Compounds》1992,28(12):1425-1431
It has been shown that the alkylation of 2-methyl-9-hydroxy-4H-pyrido[1,2-a]pyrimidin-4-one takes place at the oxygen atom, but electrophilic substitution takes place mainly at position 8 of the molecule (the ortho position relative to the hydroxy group).Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1660–1666, December, 1992. 相似文献
7.
Modified procedures were developed for the detection of -hydroxybutyric acid and 1,4-butanediol (its metabolic precursor) in foods, food additives, and urine using gas chromatography and gas chromatography–mass spectrometry. The analytical range was 0.1–20 wt %. 相似文献
8.
V. K. Turchaninov N. N. Chipanina T. N. Aksamentova M. S. Sorokin V. A. Pestunovich 《Russian Chemical Bulletin》1998,47(2):231-236
Five ionization potentials for thesp,ac andsp, sp conformers of (acetylthiomethyl)trifluorosilane MeC(O)SCH2SiE3 and six ionization potentials for the same conformers of (benzoylthiomethyl)trifluorosilane PhC(O)CH2SiF3 were calculated by the semiempirical AM1 method. The resulting values are in good agreement with the data of photoelectron
spectroscopy only for thesp.ac conformers. The structure of the preferred conformer of (acetylthiomethyl)trifluorosilane was confirmed by measurement of
its dipole moment in the gas phase. The influence of the long-range inductive effect (field effect) on the energy of nonbonding
electrons of the carbonyl oxygen atom in the series of acetic acid derivatives was observed.
For Part 9, see Ref. 1.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 236–241, February, 1998. 相似文献
9.
V. A. Sedavkina I. V. Lizak N. N. Sorokin 《Chemistry of Heterocyclic Compounds》1987,23(10):1129-1132
A group of previously unreported 5-alkyl-1,4-diaza- and 5-alkyl-1-aza-4-oxabicyclo[3.3.0]octan-8-ones have been synthesized from the ethyl esters of -ketocarboxylic acids and ethylenediamine or ethanolamine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1405–1408, October, 1987. 相似文献
10.
N.V. Loginova T.V. Kovalchuk R.A. Zheldakova A.A. Chernyavskaya N.P. Osipovich G.K. Glushonok G.I. Polozov V.N. Povalishev V.L. Sorokin O.I. Shadyro 《Polyhedron》2006,25(18):3603-3610
Cu (II) complexes with 3,5-di(tert-butyl)-1,2-benzenediol (I), 4,6-di(tert-butyl)-1,2,3-benzentriol (II) and sulfur-containing sterically hindered o-diphenol derivatives such as 4,6-di(tert-butyl)-3-(2-hydroxyethylsulfanyl)-1,2-benzenediol (III) and 2-[4,6-di(tert-butyl)-2,3-dihydroxyphenylsulfanyl]acetic acid (IV) have been synthesized and characterized by means of elemental analysis, TG/DTA, FT-IR, ESR, XPS, XPD and conductivity measurements. Antifungal activities of these ligands and their respective Cu (II) complexes have been determined against Aspergillus niger, Fusarium sp., Penicillium lividum, Mucor sp. and Botrytis cinerea. Most of the compounds (both the free ligands and the complexes) exert pronounced antifungal activities (RI 70%), and virtually all of them (apart from the Cu(LII)2 complex) have the highest inhibitory properties (RI = 100%) against B. cinerea. 相似文献