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91.
E. K. Alidzhanov Yu. D. Lantukh S. N. Letuta S. N. Pashkevich I. E. Kareev V. P. Bubnov E. B. Yagubskii 《Optics and Spectroscopy》2010,109(4):578-583
The optical properties of solutions of endometallofullerenes with lanthanides (Gd@C82, Ce@C82, La@C82, Y@C82) in dimethylformamide are studied. It is found that these solutions luminesce in the visible region. This luminescence is
accompanied by enhanced Raman scattering. It is suggested that these processes are related to nanoplasmon excitations in clusters
of endometallofullerenes. It is shown that the luminescence spectrum is described by a superposition of three to four Gaussian
spectral profiles, whose energy positions and intensities nonmonotonically depend on the energy of excitation quanta. A detailed
quantitative dependence of the intensity and shape of the Raman scattering signal on the concentration of endometallofullerenes
in the solutions is determined. Comparative measurements are performed for the emission spectra of solutions of simple fullerenes
and chromatographically pure endometallofullerenes. Complex investigations show that the visible luminescence and Raman scattering
enhancement are only observed in the case of the formation of nanosized anionic complexes of endometallofullerenes in the
solution. 相似文献
92.
D. S. Pashkevich P. S. Kambur D. A. Mukhortov V. B. Petrov Yu. I. Alekseev 《Russian Journal of Applied Chemistry》2009,82(9):1565-1569
The saturation of a liquid phase with a gas and the heat exchange in a gas-liquid apparatus with a high-speed agitator in
a flow circuit at various operating modes, constructions of the agitators were investigated and under various physical conditions. 相似文献
93.
O. G. Khomutov V. I. Filyakova A. V. Kuchin K. I. Pashkevich GA. Tolstikov 《Russian Chemical Bulletin》1992,41(10):1834-1835
Unlike nonfluorinated analogs, complex esters of polyfluorinated acids in reactions with trialkylalanes produce only polyfluorinated secondary alcohols.Department of Fine Organic Synthesis, Institute of Organic Chemistry, Urals Branch, Russian Academy of Sciences, 450054 Ufa. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 10, pp. 2339–2341, October, 1992. 相似文献
94.
Polyfluoroalkyl-containing bispyrazoles, bis(5-hydroxy-Δ2-isoxazolines), and bisisoxazoles were synthesized for the first time by reactions of polyfluoroalkyl-containing bis-β-diketones
with hydrazine, phenylhydrazine, and hydroxylamine, respectively.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 762–764, April, 1999. 相似文献
95.
We obtain some elementary formulas for the volume of a symmetric tetrahedron in hyperbolic and spherical spaces. 相似文献
96.
97.
V. I. Filyakova Y. G. Ratner N. S. Karpenko K. I. Pashkevich 《Russian Chemical Bulletin》1996,45(9):2163-2168
The composition of products of the interaction of asymmetric fluoroalkyl-containing -diketones with amines was studied. Mixtures of regioisomeric -aminovinylketones and products of cleavage and secondary condensation are formed, depending on the temperature, the solvent, the nature of the fluorinated and nonfluorinated substituents in the -diketone, and the basicity of the amine. The major product is a -aminovinylketone in which the NH2 group is removed from the fluoroalkyl substituent. No -aminovinylimines, products of condensation involving two electrophilic centers, were observed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 2278–2284, September, 1996. 相似文献
98.
V. A. Tartakovsky I. E. Filatov A. M. Churakov S. L. Ioffe Yu. A. Strelenko V. S. Kuz’min G. L. Rusinov K. I. Pashkevich 《Russian Chemical Bulletin》2004,53(11):2577-2583
Treatment of 2- and 4-amino-3-(tert-butyl-NNO-azoxy)pyridines with nitrating agents (N2O5or NO2BF4) afforded the first representatives of pyridoannelated 1,2,3,4-tetrazine di-N-oxides, viz., pyrido[2,3-e][1,2,3,4]tetrazine 1,3-dioxide (9), 7-nitropyrido[2,3-e][1,2,3,4]tetrazine 1,3-dioxide (10), and pyrido[3,4-e][1,2,3,4]tetrazine 2,4-dioxide (11). These compounds were studied by 1H, 13C, and 14N NMR spectroscopy. The 1:1 complex of compound 10 with benzene was studied by X-ray diffraction analysis.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2471–2477, November, 2004. 相似文献
99.
Ralph-Matthias Schoth Dmitrii Sevenard Kazimir Pashkevich Gerd-Volker Rschenthaler 《Coordination chemistry reviews》2000,210(1):101-134
The role of fluorinated β-diketones, their tautomers (keto–enols) and their derivatives as reagents towards λ3P compounds is reviewed, including 2-trifluoroacetyl phenols, possessing formally a keto–enol system, and their derivatives. In an ‘insertion’ reaction phosphine and the keto–enol tautomers of 1,1,1,5,5,5-hexafluoro- and 1,1,1-trifluoropentan-2,4-dione furnished primary (S) or (R) α-hydroxy phosphines, whose enol functions probably isomerized the corresponding keto compounds. Further addition and isomerisation furnished 1,3α,5,7β-tetrakis(trifluoromethyl)-2-phospha-6-oxa-9-oxabicyclo[3.3.1]-nonan-3β,7α-diol and 1,7-trifluoromethyl-3,5-methyl-2,4,8-trioxa-6-phophaadamantane, exclusively one diastereomer in each case. The main mechanistic feature of these reactions is a consecutive diastereoselective hemiketal cyclization. 1,1,1,5,5,5-Hexafluoro- and 1,1,1-trifluoropentan-2,4-dione, as well as 2-trifluoroacetyl phenol and its imino derivatives reacted diastereospecifically with phosphonous acid dichlorides, RPCl2 to give in a concerted mechanism thermally stable tricyclic λ5σ5P phosphoranes containing two five-membered rings and one six-membered ring. Surprisingly, the two CF3 groups bonded to an sp3-hybridized carbon were in a cisoid arrangement having closest non-bonding FF distances of 301.4 or 273.5 pm. These findings reflect the ‘through space’ F---F coupling constants of the tricyclic phosphoranes (JFF=4.0–7.0 Hz), in solution. 4,4,4-Trifluoro-3-hydroxy-1-phenyl-butan-1-one and methyl or phenyl phosphonous acid dichlorides gave similar tricyclic phosphoranes decomposing at ambient temperature to furnish 1,2λ5σ4-oxaphospholanes and (E)-1,1,1-trifluoro-4-phenyl-but-2-en-4-one. Dialkylphosphites and 1,1,1,5,5,5-hexafluoropentan-2,4-dione reacted to give either the (Z)-enol phosphonates or the respective γ-ketophosphonates from which in two cases four diastereomeric 2-oxo-2,5-dialkoxy-3,5-bis(trifluoromethyl)-3-hydroxy-1,2λ5σ4-oxa-phospholanes were obtained. 2-Trifluoroacetyl cyclohexanone, 4,4,4-trifluoro-3-trimethylsiloxy-1-phenylbutan-1-one, 1-benzoyl-2-trifluormethyloxirane, 1-benzoyl-2-trifluoro-methylaziridine, 2-trifluoroacetyl-1-trimethylsiloxybenzene and (trifluoroacetyl-1-phenyl) diethyl phosphate reacted with tris(trimethylsilyl) phosphite to give functionalized α-trimethylsiloxy phosphonates, which could easily be transferred into the respective phosphonic acids. In the case of an oxirane and an aziridine ketone no ring cleavage was observed. For 1,1′-(2-hydroxy-5-methyl-m-phenylene)-bis-ethanone and 1,1′-(2-trimethylsiloxy-5-methyl-m-phenylene)-bis-ethanone benzoxaphospholanes were obtained. Trialkyl phosphites and 1,1,1,5,5,5-hexafluoropentan-2,4-dione furnished cyclic phosphoranes containing the 3-hydroxy-3,5-bis(trifluoromethyl)-1,2λ5σ5-oxaphospholene structural element, stable at ambient temperature only in the case of one cyclic phosphite precursor. (E)-1,1,1-Trifluoro-4-phenyl-but-2-en-4-one and trimethylphosphite reacted to form 1,2λ5σ5-oxaphosphol-4-ene as the sole product. Results similar to the reaction of 1,1′-(2-hydroxy-5-methyl-m-phenylene)-bis-ethanone with diethyltrimethylsilylphosphite were obtained for trimethylphosphite and 2-trifluoroacetyl phenol where a deoxygenated phosphorane was found, easily hydrolyzed to give the respective phosphonic acid. With dialkylisocyanato phosphites and the keto components, 1,1,1,5,5,5-hexafluoro- and 1,1,1-trifluoropentan-2,4-dione, 4,4,4-trifluoro-1-phenyl-1,3-butandione, 2-trifluoroacetyl cyclohexanone, 2-trifluoroacetyl phenol and 1,1′-(2-hydroxy-5-methyl-m-phenylene)-bis-ethanone reacted in a ‘double’ cycloaddition to form bicyclic phosphoranes containing the 4,8-dioxa-2-aza-1λ5σ5-phosphabicyclo[3.3.0]-oct-6-en-3-one ring system; for the imino derivatives of 2-trifluoroacetyl phenol a corresponding 8-oxa-2,4-diaza- system was generated. For (E)-1,1,1,5,5,5-hexafluoro-4-trimethylsiloxy-3-penten-2-one however, a cyclic spiroimino phosphorane was obtained which underwent a [2+2] cyclodimerization to form a diazadiphosphetidine. Dimethylpropynyl phosphonite and 1,1,1,5,5,5-hexafluoropentan-2,4-dione yielded diastereoselectively a bisphosphorane, namely 1,4-bis(trifluoromethyl)-3,6-dioxa-2,2,7,7-tetramethoxy-2,7-di(1-propynyl)-2,7-diphosphabicyclo[2.2.1] heptane. When trimethylsilanyl–phosphenimidous acid bis-trimethylsilanyl–amide, Me3SiN=PN(SiMe3)2, was allowed to react with 1,1,1,5,5,5-hexafluoro- and 1,1,1-trifluoropentan-2,4-dione, (E)-1,1,1,5,5,5-hexafluoro-4-trimethylsiloxy-3-penten-2-one, 2-trifluoroacetyl cyclopentanone, 2-trifluoroacetyl phenol and its imino derivatives, 2-imino-1,2λ5σ4-oxaphospholenes were found containing two diastereomers in each case, which added hexafluoroacetone across the P=N bond to give 1,3,2λ5σ5-oxazaphosphetanes. 相似文献
100.
Pashkevich D. S. Mukhortov D. A. Alekseev Yu. I. Asovich V. S. Rozhdestvenskaya O. V. 《Russian Journal of Applied Chemistry》2001,74(7):1151-1155
Scientific basis for industrial gas-phase fluorination of fluoroethanes with elemental fluorine allowing production of higher-fluorinated fluoroethanes from lower-fluorinated compounds is developed. 相似文献