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251.
Cindy Patinote Kamel Hadj-Kaddour Marjorie Damian Carine Deleuze-Masquéfa Pierre Cuq Pierre-Antoine Bonnet 《Journal of fluorescence》2017,27(5):1607-1611
The fluorescence properties of eleven novel derivatives based on the imidazo[1,2-a]quinoxaline structures have been studied. The absorption and emission spectra of these compounds have been recorded in dimethylsulfoxide solution. The phenyl substituting group on position 1 gives them particular properties thanks to the diverse hydroxy or methoxy decorating moieties, especially when they are multiplied or mixed. The investigated fluorescence auto-quenching revealed that the decreasing fluorescence intensity correlated only with the chemical structures of the aromatic compounds. 相似文献
252.
Delphine Veys-Renaux Richard Drevet Carine Petitjean Lionel Aranda Nicolas David Patrice Berthod 《Journal of Solid State Electrochemistry》2018,22(9):2821-2828
The electrochemical behavior of pure Co, pure Sb, and CoSb3 has been investigated over a large anodic potential range (0 to 40 V) in two acids, i.e., oxalic acid or sulfuric acid at different concentrations (0.01 to 1 M). Potentiodynamic polarizations performed on CoSb3 plates reveal the possible formation of a passive layer between 1 and 3 V (vs SCE), on a passivation plateau. The oxidation of CoSb3 at 2 V in sulfuric and oxalic acids results in the growth of an anodic conversion layer. This coating is mainly made of a porous layer of amorphous antimony oxides due to dealloying of CoSb3. In the specific case of oxalic acid, rods of crystallized oxalates are tangled between the oxide sheets. 相似文献
253.
Besora M Maseras F McGrady JE Oulié P Dinh DH Duhayon C Etienne M 《Dalton transactions (Cambridge, England : 2003)》2006,(19):2362-2367
The synthesis and characterisation of the cyclobutyl complex Tp(Me2)NbCl(c-C4H7)(MeC[triple bond]CMe) completes the family of cycloalkyl complexes Tp(Me2)NbCl(c-C(n)H(2n-1)), n = 3-6. The properties of the cyclobutyl complex are qualitatively similar to those of its cyclopentyl and cyclohexyl analogues, and dramatically different from those of the cyclopropyl derivative. Most conspicuously, the cyclobutyl system has an alpha-C-H agostic interaction in the dominant isomer, with no evidence for the alpha-C-C agostic character found for the smaller ring. C-C agostic character therefore seems to be unique to the cyclopropyl complex, where the acute C-C-C angles destabilise the C-C bonding orbitals. 相似文献
254.
Jean De Dieu Zabsonré Carine Lucas Adama Ouedraogo 《Nonlinear Analysis: Real World Applications》2013,14(2):1216-1224
In this paper, we consider a viscous bilayer shallow water model in one space dimension that represents two superposed immiscible fluids. For this model, we prove the existence of strong solutions in a periodic domain. The initial heights are required to be bounded above and below away from zero and we get the same bounds for every time. Our analysis is based on the construction of approximate systems which satisfy the BD entropy and on the method developed by A. Mellet and A. Vasseur to obtain the existence of global strong solutions for the one dimensional Navier–Stokes equations. 相似文献
255.
256.
Chevolleau S Jacques C Canlet C Tulliez J Debrauwer L 《Journal of chromatography. A》2007,1167(2):125-134
The determination of biomarkers of acrylamide exposure in humans from general French population by measurement of hemoglobin adduct levels of acrylamide (AA) and glycidamide (GA) is presented. The analytical procedure included modified Edman degradation and LC-ESI-MS/MS analysis of the final derivatives using deuterated internal standards. Method performances were evaluated in terms of linearity, precision, accuracy, and sensitivity. The method was firstly assessed on rat blood samples and then applied to the study of background adducts levels of AA and GA in 68 human hemoglobin samples, showing mean levels of 33 and 23 pmol/g globin for AA and GA adducts, respectively. 相似文献
257.
Carta P Puljic N Robert C Dhimane AL Fensterbank L Lacôte E Malacria M 《Organic letters》2007,9(6):1061-1063
A novel radical domino process relying on the homolytic cleavage of P-S bonds allows the preparation of phosphorus-containing molecules through addition of P-centered radicals onto olefins. The key step of this reaction is a homolytic substitution on a sulfur atom. The scope of the reaction is broad. Diaminophosphonyl radicals whose reactivity was unknown react smoothly with olefins. Use of tin hydride can be avoided. A radical thiophosphinoylation of triple bonds has been uncovered. [reaction: see text] 相似文献
258.
259.
The syntheses of a variety of novel angular azaspiro[3.3]heptanes are reported. gem-Difluoro and gem-dimethyl variants of the angular 1,6-diazaspiro[3.3]heptane module were prepared in high yields using efficient sequences. Additionally, a practical one-pot synthesis of 5-oxo-2-azaspiro[3.3]heptanes and subsequent conversions into functionalized derivatives are described. The methods reported are amenable to the synthesis of these building blocks for drug discovery as members of a library or individually on a preparative scale. 相似文献
260.
Conformational landscape of neutral and ionized n-butylbenzene has been examined. Geometries have been optimized at the B3LYP/6-31G(d), B3LYP/6-31+G(d,p), B3LYP-D/6-31+G(d,p), B2PLYP/6-31+G(d,p), B2PLYP-D/6-31+G(d,p), B97-D/6-31+G(d,p), and M06-2X/6-31+G(d,p) levels. This study is complemented by energy computations using 6-311++G(3df,2p) basis set and CBS-QB3 and G3MP2B3 composite methods to obtain accurate relative enthalpies. Five distinguishable conformers have been identified for both the neutral and ionized systems. Comparison with experimentally determined rotational constants shows that the best geometrical parameters are provided by B3LYP-D and M06-2X functionals, which include an explicit treatment of dispersion effects. Composite G3MP2B3 and CBS-QB3 methods, and B2PLYP-D, B3LYP-D, B97-D, and M06-2X functionals, provide comparable relative energies for the two sets of neutral and ionized conformers of butyl benzene. An exception is noted however for conformer V(+) the stability of which being overestimated by the B3LYP-D and B97-D functionals. The better stability of neutral conformers I, III, and IV, and of cation I(+) , demonstrated by our computations, is in perfect agreement with conclusions based on micro wave, fluorescence, and multiphoton ionization experiments. 相似文献