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221.
Dr. Céline Pichon Dr. Nicolas Suaud Valentin Jubault Dr. Carine Duhayon Prof. Nathalie Guihéry Dr. Jean-Pascal Sutter 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(62):15484-15495
Trinuclear systems of formula [{Cr(LN3O2Ph)(CN)2}2M(H2LN3O2R)] (M=MnII and FeII, LN3O2R stands for pentadentate ligands) were prepared in order to assess the influence of the bending of the apical M−N≡C linkages on the magnetic anisotropy of the FeII derivatives and in turn on their Single-Molecule Magnet (SMM) behaviors. The cyanido-bridged [Cr2M] derivatives were obtained by assembling trans-dicyanido CrIII complex [Cr(LN3O2Ph)(CN)2]− and divalent pentagonal bipyramid complexes [MII(H2LN3O2R)]2+ with various R substituents (R=NH2, cyclohexyl, S,S-mandelic) imparting different steric demand to the central moiety of the complexes. A comparative examination of the structural and magnetic properties showed an obvious effect of the deviation from straightness of the M−N≡C alignment on the slow relaxation of the magnetization exhibited by the [Cr2Fe] complexes. Theoretical calculations have highlighted important effects of the bending of the apical C−N−Fe linkages on both the magnetic anisotropy of the FeII center and the exchange interactions with the CrIII units. 相似文献
222.
Dr. Dymytrii Listunov Prof. Ole Hammerich Irving Caballero-Quintana Dr. Albert Poater Cécile Barthes Dr. Carine Duhayon Dr. Mie Højer Larsen Dr. José-Luis Maldonado Dr. Gabriel Ramos-Ortiz Prof. Mogens Brøndsted Nielsen Dr. Valérie Maraval Prof. Remi Chauvin 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(47):10707-10711
carbo-Benzene is an aromatic molecule devised by inserting C2 units within each C−C bond of the benzene molecule. By integrating the corresponding carbo-quinoid core as bridging unit in a π-extended tetrathiafulvalene (exTTF), it is shown that a carbo-benzene ring can be reversibly formed by electrochemical reduction or oxidation. The so-called carbo-exTTF molecule was thus experimentally prepared and studied by UV–visible absorption spectroscopy and cyclic voltammetry, as well as by X-ray crystallography and by scanning tunneling microscopy (STM) on a surface of highly oriented pyrolytic graphite (HOPG). The molecule and its oxidized and reduced forms were subjected to a computational study at the density functional theory (DFT) level, supporting carbo-aromaticity as a driving force for the formation of the dication, radical cation, and radical anion. By allowing co-planarity of the dithiolylidene rings and carbo-quinoidal core, carbo-exTTFs present a promising new class of redox-active systems. 相似文献
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The electronic structures, as well as spectroscopic and thermodynamic properties of the title Pu@M12 clusters, are considered at the density functional theory level. In both cases, a Pu2+ ion is encapsulated in an icosahedral, stanna- or plumbaspherene cage. As suggested before for M = Pb, both systems are reported to follow a 32-electron principle for the central atom. 相似文献
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An efficient nickel-catalyzed method devoted to the direct formation of functionalized 2-arylpyridines is described avoiding the prior preparation of organometallic species. Various functionalized 2-arylpyridines are obtained in moderate to excellent yields by a one-step chemical procedure from corresponding halides. The NiBr2(2,2′-bipyridine) complex appears to be an extremely suitable catalyst for the activation in the presence of manganese dust of aromatic halides and pyridyl halides functionalized by reactive groups. The versatility of this original process represents a simple alternative to most known methods using organometallic reagents. 相似文献
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Two monoterpenols, perillyl alcohol and nerol, have been converted into their γ,δ-unsaturated ester derivatives following a modified process of microwave-assisted ortho ester Claisen rearrangement. The yields obtained (>90%) are better than those previously obtained. The optimized process needs less reaction time (5 min), smaller amount of reagent, and no solvent. 相似文献
230.
Snehangshu Patra Carine Davoisne Stéphanie Bruyère Houssny Bouyanfif Sophie Cassaignon Pierre‐Louis Taberna Frédéric Sauvage 《Particle & Particle Systems Characterization》2013,30(12):1093-1104
The synthesis of highly divided anatase TiO2 nanoparticles displaying 300 m2 g?1 surface area is achieved by following a two‐step synthetic process at room temperature. The particles exhibit a needle‐like morphology composed of self‐assembled 4 nm nanoparticles. The crystallization process from amorphous TiO2.1.6H2O to oriented aggregation of anatase TiO2 proceeds according to a slow solid dehydration process taking place in a large range of pH in deionized water (1 < pH < 12) or alternatively when including a low amount of NH4F(aq) in solution. Driven by their high surface area enhancing the chemical/electrochemical reactivity, it is reported in the case of the anatase TiO2 that a modification in the lithium insertion mechanism is no longer attributable to a two‐phase reaction between the two‐end members LiεTiO2 and Li0.5±αTiO2 when downsizing the particle size, but instead through a complete solid solution all along the composition range. 相似文献