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31.
V. A. Izumrudov N. V. Kuchkina A. L. Rusanov Z. B. Shifrina 《Polymer Science Series A》2009,51(3):229-241
Cationic water-soluble dendrimers have been prepared by the alkylation of pyridyl groups in polypyridylphenylene dendrimers of the first four generations, and their interaction with a polymethacrylate anion has been studied. The stability of polyelectrolyte complexes in aqueoussaline solutions has been studied by fluorimetric titration with the use of the pyrenyl-tagged polyanion, and it has been shown that the stability of these complexes significantly increases with the dendrimer generation number and the content of hydrophobic phenylene groups. Based on sedimentation analysis and turbidimetric titration, it is inferred that a significant part of charged groups of dendrimers are inaccessible to interaction with the polyanion and that water-soluble nonstoichiometric polyelectrolyte complexes develop in mixtures of higher generation dendrimers. Modeling results of this study may be useful for designing efficient cationic dendrimer carriers of genetic material and hydrophobic physiologically active compounds. 相似文献
32.
To evaluate the reactivity of new difluroroaromatic compounds in nucleophilic substitution, the positive charges on carbon
atoms of C−F bonds were calculated using the quantum-chemical semiempirical PM3 method. A correlation between the charges
calculated and the chemical shifts in the19F NMR spectra was established.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 623–625, April, 1998. 相似文献
33.
N. N. Smirnova A. V. Markin Yu. A. Zakharova N. V. Kuchkina A. L. Rusanov Z. B. Shifrina 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2010,84(4):548-553
The temperature dependence of heat capacity C p o = f (T) of second generation hard poly(phenylene-pyridyl) dendrimer (G2-24Py) was measured by a adiabatic vacuum calorimeter over the temperature range 6–320 K for the first time. The experimental results were used to calculate the standard thermodynamic functions: heat capacity C p o (T), enthalpy H o(T)–H o(0), entropy S o(T)–S o(0) and Gibbs function G o(T)–H o(0) over the range from T → 0 K to 320 K. The standard entropy of formation at T = 298.15 K of G2-24Py was calculated. The low-temperature heat capacity was analyzed based on Debye’s heat capacity theory of solids. Fractal treatment of the heat capacity was performed and the values of the temperature characteristics and fractal dimension D were determined. Some conclusions regarding structure topology are given. 相似文献
34.
Ganna A. Senchyk Andrey B. Lysenko Eduard B. Rusanov Alexander N. Chernega Konstantin V. Domasevitch 《Acta Crystallographica. Section C, Structural Chemistry》2010,66(7):m180-m183
In the structures of the CdII pseudohalide coordination polymer poly[[diaquabis[μ2‐3,3′‐bis(1,2,4‐triazol‐4‐yl)‐1,1′‐biadamantane‐κ2N1:N1′]cadmium(II)] dithiocyanate dihydrate], {[Cd(C24H32N6)2(H2O)2](NCS)2·2H2O}n, (I), and the isomorphous selenocyanate analogue, {[Cd(C24H32N6)2(H2O)2](NCSe)2·2H2O}n, (II), the CdII cations occupy inversion centres and have octahedral CdN4O2 environments, completed by four N atoms of the organic ligands [Cd—N = 2.316 (2) and 2.361 (2) Å for (I), and 2.313 (3) and 2.372 (3) Å for (II)] and two trans‐coordinated aqua ligands [Cd—O = 2.3189 (15) Å for (I) and 2.323 (2) Å for (II)]. In each compound, the ligand displays a bidentate N1:N1′‐bridging mode, connecting the metal centres at a distance of 14.66 Å into two‐dimensional nets of (4,4)‐topology, while the uncoordinated thio(seleno)cyanate anions reside inside the net cavities. Hydrogen bonding between the water molecules, anions and 1,2,4‐triazole N atoms supports the tight packing, with an interlayer distance of 6.09 Å. 相似文献
35.
Julia A. Rusanova Eduard B. Rusanov Konstantin V. Domasevitch 《Acta Crystallographica. Section C, Structural Chemistry》2010,66(8):m207-m210
The title compound, {[U(C12H14O4)O2(H2O)]·H2O}n, is the first actinide complex featuring adamantanecarboxylate ligands. The metal ion possesses a pentagonal–bipyramidal UO7 coordination involving two axial oxide ligands [U—O = 1.732 (5) and 1.764 (5) Å] and five equatorial O atoms [U—O = 2.259 (5)–2.494 (4) Å] of aqua and carboxylate ligands. The latter display pseudo‐chelating and bridging coordination modes of the carboxylate groups that are responsible for the generation of the centrosymmetric discrete uranium–carboxylate [UO2(μ‐RCOO)2UO2] dimers [U...U = 5.5130 (5) Å] and their connection into one‐dimensional chains. Hydrogen bonding involving two coordinated and two solvent water molecules [O...O = 2.719 (7)–2.872 (7) Å] yields centrosymmetric (H2O)4 ensembles and provides noncovalent linkage between the coordination chains to generate a three‐dimensional network structure. 相似文献
36.
Tobias Rüffer Clemens Bruhn Eduard Rusanov Karsten Nordhoff Dirk Steinborn 《无机化学与普通化学杂志》2002,628(2):421-427
Sulfur‐substituted methylmercury compounds [Hg(CH2SR)2]( 1a, R = Me; 1b, R = Ph ) react with aluminium amalgam in refluxing toluene with transmetallation to give homoleptic tris(thiomethyl)aluminium complexes [Al(CH2SR)3]( 2a, R = Me; 2b, R = Ph ) (degree of conversion: >80%, isolated yields: 2a 63%, 2b 41%). Their identities were confirmed by NMR spectros‐copy (1H, 13C) and X‐ray crystal structure analyses. In crystals of compound 2a the aluminium atoms possess a trigonal‐bipyramidal arrangement with the coordination polyhedron defined by three carbon and two sulfur atoms. Two of the three CH2SMe ligands are bridging ligands (μ‐η2; 1kC:2kS), the third one is terminal bound (η1; kC). The structure is polymeric. Crystals are threaded by helical chains built up of six‐membered Al2C2S2 rings. Crystals of 2b are built up of centrosymmetrical dimers with six‐membered Al2C2S2 rings having bridging CH2SPh ligands (μ‐η2; 1kC:2kS). On each Al atom two terminal (η1; kC)CH2SPh ligands are bound. They exhibit quite different Al‐C‐S angles (116.7(4) and 106.5(3)?). Similar values (114.32115.7? and 109.52109.9?) were found in ab initio calculations of model compounds [{Al(CH2SR)3}2]( 3a, R=H; 3b, R=Me; 3c, R=CH=CH2 ). A conformational energy diagram for rotation of one of the terminal CH2SH ligand in the parent compound 3a around the Al‐C bond is discussed in terms of repulsive interactions of lone electron pairs of sulfur atoms. 相似文献
37.
Lebedev B. V. Kulagina T. G. Smirnova N. N. Shifrina Z. B. Averina M. S. Rusanov A. L. 《Journal of Thermal Analysis and Calorimetry》2003,74(3):735-748
In an adiabatic vacuum calorimeter, the temperature dependence of the heat capacity C
p of phenylated polyphenylene and initial comonomer 1,4-bis(2,4,5-triphenylcyclopentadienone-3-yl)benzene was studied between
6 and 340 K with an uncertainty of about 0.2%. In a calorimeter with a static bomb and an isothermal shield their energies
of combustion DUcomb were measured. From the experimental data, the thermodynamic functions C
p
0 (T), H
0(T)-H
0(0), S
0(T)-S0(0), G
0(T)-H
0(0) were calculated from 0 to 340 K, and standard enthalpies of combustion ΔH
comb
0 and thermodynamic parameters of formation-enthalpies ΔH
f
0, entropies ΔH
f
0, Gibbs functions ΔG
f
0 - of the substances studied were estimated at T=298.15 K at standard pressure. The results were used to calculate the thermodynamic characteristics (ΔH
f
0 ,ΔS
f
0, ΔG
f
0) of phenylated polyphenylene synthesis in the range from 0 to 340 K.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
38.
N. V. Mel’nichenko A. V. Bentya E. B. Rusanov M. V. Vovk 《Russian Journal of General Chemistry》2015,85(6):1440-1446
Reactions of aryl trifluoromethyl ketone imines with 2-sulfanylacetic and 3-sulfanylpropanoic acids afforded 2-aryl-2-trifluoromethyl-1,3-thiazolidin-4-ones and 2-aryl-2-trifluoromethyltetrahydro-4H-1,3-thiazin-4-ones, respectively. Their subsequent oxidation with hydrogen peroxide gave the corresponding 2-aryl-2-trifluoromethyl-1,3-thiazolidin-4-one 1-oxides and 2-aryl-2-trifluoromethyltetrahydro-4H-1,3-thiazin-4-one 1-oxides and 1,1-dioxides. 相似文献
39.
40.
O. V. Shablykin V. S. Brovarets E. B. Rusanov B. S. Drach 《Russian Journal of General Chemistry》2008,78(4):655-661
Substituted 5-(3,5-dimethyl-1H-pyrazol-1-yl)-1,3-oxazole-4-carbonitrile differently react with nitrogen bases having different numbers of labile hydrogen atoms. Treatment of the title compounds with secondary amines or morpholine results in nucleophilic replacement of the pyrazolyl substituent at C5, the ozaxole ring remaining unchanged. Their reactions with primary amines are accompanied by cleavage of the oxazole ring with formation of the corresponding enamino nitriles. Hydrazine hydrate acts in a similar way, but enehydrazino nitriles thus formed undergo fast cyclization to give new 4,5-diaminopyrazole derivatives. The latter can be converted into substituted pyrazolo[1,5-a]pyrimidines whose structure has been proved by X-ray analysis. 相似文献