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1.
In this work, on the basis of a semiempirical model of bonding forces that allows for three-particle interaction and uses the pseudopotential method, the mechanical and electrical properties of barium chalcogenides are studied at hydrostatic pressure. Equations of state are formulated from hydrostatic compression, parameters of the type B1–B2 structural phase transitions are calculated, the change in the energy band spectrum under the influence of the pressures is studied, and an estimate is made of the critical amount of compression that induces a dielectric-metal phase transition. The results obtained are in agreement with the available data.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 11, pp. 44–52, November, 1991. 相似文献
2.
I. Yu. Strobykina V. E. Kataev A. N. Vereshchagin I. V. Galyametdinova V. D. Akamsin 《Russian Chemical Bulletin》1987,36(6):1213-1217
Conclusions In the compounds examined, the angle of rotation of the plane of the aromatic ring relative to the unshared electron pair of the nitrogen atom is close to orthogonal, but in the o-fluoro-compound it is smaller.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1317–1321, June, 1987. 相似文献
3.
Kataev V. A. Spirikhin L. V. Khaliullin A. N. Gailyunas I. A. 《Russian Journal of Organic Chemistry》2002,38(10):1507-1509
The alkylation of 2-chloro-5(6)-nitrobenzimidazole with 2-chloromethylthiirane was studied for the first time. Depending on the conditions, isomeric mixtures of nitro-substituted 2-chloro-1-(thietan-3-yl)benzimidazoles and dihydrothiazolo[3,2-a]benzimidazoles were obtained. 相似文献
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6.
The conformational equilibrium of -(aminoethyl)pyridines has been studied by molecular-mechanics using the geometry optimization. It has been determined that the equilibrium is characterized by the nearly statistical distribution of the ap- and sc-conformers about the
bond. Substitution of the dimethylamino-group for the amino-group results in a slight shift of the equilibrium toward the ap-rotamers. The global minimum in -(ammoniumethyl)pyridines corresponds to the conformation with the +sc-orientation about the central C-C bond and the -sc-orientation (in the case of the dimethylammonium derivatives) about the
bond. In the latter conformation, the
bond of the ammonium group is oriented toward the pyridine cycle. For charged compounds, the regular orthogonal conformation of the aromatic-ring plate is distorted (the vicinal C-C bond becomes eclipsed).Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1833–1840, August, 1991.The authors are grateful to P. P. Shagidullin and A. Kh. Plyamovatyi for their interest in this work and for fruitful discussions. 相似文献
7.
I. A. Litvinov O. N. Kataeva V. E. Kataev O. Yu. Butenko 《Russian Chemical Bulletin》1991,40(8):1607-1609
It was established by x-ray crystallographic analysis that the molecular o-nitrobenzyltriethylammonium cation has an orthogonal orientation of the benzene ring and the vicinal C-N+ bond (=93.8°). The nitro group deviates from the plane of the aromatic ring by an angle of 26.9°. One of the ethyl groups at the quaternary nitrogen atom is in an ap-conformation (=176.2°); the other two are in sc-conformations, characterized by torsional angles 65.1 and 69.4°.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1816–1818, August, 1991. 相似文献
8.
Viktoriya V. Skripacheva Ella Kh. Kazakova Nelly A. Markarova Vladimir E. Kataev Ludmila V. Ermolaeva Wolf D. Habicher 《Journal of inclusion phenomena and macrocyclic chemistry》2002,42(1-2):77-81
The binding of different sized and shaped metal complexes [Co(His)2]ClO4(1), [Co(en)2C2O4]Cl (2) and [K18-crown-6]SCN (3)(en-ethylendiamine, His-L-histidynate-anion) with a new tetrasulfonatomethylcalix[4]resorcinarene([H8X]Na4) was investigated in neutral and alkaline aqueous media by NMR and pH-metrictitration methods and compared with those of recently studied NMe4Br (4). The resultsobtained indicate that the outer-sphere coordination of complexes 1–3 by[H8X]4- proceeds via the interaction of hydrophobic fragments of the guestswith both the negatively charged rim and the hydrophobic cavity as a -base. Thenature of binding does not change for cations 1, 2 and 4 on going from[H8X]4- in neutral to [H4X]8- in alkaline media, while the inclusionof 3 decreases on going from [H8X]4- to [H4X]8-. 相似文献
9.
Z. G. Aliev L. O. Atovmyan S. S. Kataev V. V. Zalesov 《Chemistry of Heterocyclic Compounds》2007,43(3):377-381
Reactions between 2-pyridylamides of Z-4-aryl-2-hydroxy-4-oxobut-2-enoic acids with diazomethane have been used to synthesize
3-(2-aryl-2-oxoethyl)-3-methoxy-2-oxo-2,3-dihydroimidazo[1,2-a]pyridines, which form hydrochlorides with hydrochloric acid.
The structure of the latter has been demonstrated by XRD for the hydrochloride of 3-methoxy-2-oxo-3-(2-phenyl-2-oxoethyl)-2,3-dihydroimidazo[1,2-a]pyridine.
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Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 464–468, 2007. 相似文献
10.