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991.
Nathalie LHermite Jean-Franois Peyrat Moud Alami Jean-Daniel Brion 《Tetrahedron letters》2005,46(52):8987-8991
A rapid convergent synthesis of first- and second-generation halogenated linear poly(arylpropargyl ether) branches 7 and 10 is described. The key step of the sequence studied involves a selective Sonogashira–Linstrumelle (S–L) cross-coupling reaction of aryl iodides with alkynes bearing an sp2-carbon–iodine bond. Application to the synthesis of functionalized first-generation poly(arylpropargylether) stars having a benzene-1,3,5-tricarboxylic acid core has been realized. 相似文献
992.
Nathalie Bellec Frédéric Lerouge Olivier Jeannin Geneviève Cerveau Robert J.P. Corriu Dominique Lorcy 《Journal of organometallic chemistry》2006,691(26):5774-5781
The effect of the interactions generated by the spacer group between the TTF core and the four triethoxysilane groups on the auto-organization of the organic bridging moieties in hybrid materials obtained by sol-gel chemistry has been investigated. The silica-based hybrid solids are highly polycondensed. They present different scales of organization (nanometric and micrometric) that are independent one from each other and are governed by the different parameters which control the kinetics of polycondensation. Their anisotropic organization is function of the interaction forces induced by the spacer, van der Waals, hydrogen bonding or both, during the hydrolytic condensation process. 相似文献
993.
994.
Carbene in Cupredoxin Protein Scaffolds: Replacement of a Histidine Ligand in the Active Site Substantially Alters Copper Redox Properties
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Dr. Matteo Planchestainer Dr. Nathalie Segaud Dr. Muralidharan Shanmugam Prof. Jonathan McMaster Prof. Francesca Paradisi Prof. Martin Albrecht 《Angewandte Chemie (International ed. in English)》2018,57(33):10677-10682
N‐heterocyclic carbene (NHC) ligands have had a major impact in homogeneous catalysis, however, their potential role in biological systems is essentially unexplored. We replaced a copper‐coordinating histidine (His) in the active site of the redox enzyme azurin with exogenous dimethyl imidazolylidene. This NHC rapidly restores the type‐1 Cu center, with spectroscopic properties (EPR, UV/Vis) that are identical to those from N‐coordination of the His in the wild type. However, the introduction of the NHC markedly alters the redox potential of the metal, which is a key functionality of this blue copper protein. These results suggest that C‐bonding for histidine is plausible and a potentially relevant bonding mode of redox‐active metalloenzymes in their (transient) active states. 相似文献
995.
Theoretical and Experimental Study on Boron β‐Diketonate Complexes with Intense Two‐Photon‐Induced Fluorescence in Solution and in the Solid State
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Dr. Pierre‐Henri Lanoë Dr. Bastien Mettra Dr. Yuan Yuan Liao Dr. Nathalie Calin Dr. Anthony D'Aléo Tomotaka Namikawa Prof. Kenji Kamada Prof. Fréderic Fages Dr. Cyrille Monnereau Dr. Chantal Andraud 《Chemphyschem》2016,17(14):2128-2136
Three boron diketonate chromophores with extended π‐conjugated backbone were prepared and their spectroscopic features were investigated through a combined theoretical/experimental study. It was shown that these complexes, which undergo very large electronic reorganization upon photoexcitation, combine large two‐photon absorption cross section with an emission energy and quantum efficiency in solution that is strongly dependent on solvent polarity. The strong positive influence of boron complexation on the magnitude of the two‐photon absorption was clearly established, and it was shown that the two‐photon absorption properties were dominated by the quadrupolar term. For one of the synthesized compounds, intense one‐ and two‐photon‐induced solid‐state emission (fluorescence quantum yield of 0.65 with maximum wavelength of 610 nm) was obtained as a result of antiparallel J‐aggregate crystal packing. 相似文献
996.
Natalia Del Rio Dr. Antoine Baceiredo Dr. Nathalie Saffon‐Merceron Dr. Daisuke Hashizume M. Sc. Dennis Lutters Prof. Dr. Thomas Müller Dr. Tsuyoshi Kato 《Angewandte Chemie (International ed. in English)》2016,55(15):4753-4758
A new stable heterocyclic germylene, in which the divalent germanium atom lies between a nitrogen atom and a phosphanylidene phosphorane group, was synthesized. Experimental and theoretical studies revealed the peculiar effect of phosphanylidene phosphorane substituent, which is a stronger π‐donor towards germanium than an amino group is. Because of the weak phosphorus–germanium π‐bond, this new germylene compound shows an enhanced reactivity compared to classical N‐heterocyclic germylenes. 相似文献
997.
Kévin Cocq Nathalie Saffon‐Merceron Yannick Coppel Corentin Poidevin Valérie Maraval Remi Chauvin 《Angewandte Chemie (International ed. in English)》2016,55(48):15133-15136
A ring carbo‐mer of naphthalene, C32Ar8 (Ar=p‐n‐pentylphenyl), has been obtained as a stable blue chromophore, after a 19‐step synthetic route involving methods inspired from those used in the synthesis of carbo‐benzenes, or specifically devised for the present target, like a double Sonogashira‐type coupling reaction. The last step is a SnCl2/HCl‐mediated reduction of a decaoxy‐carbo‐decalin, which is prepared through successive [8+10] macrocyclization steps. Two carbo‐benzene references are also described, C18Ar6 and o‐C18Ar4(C≡C‐SiiPr3)2. The carbo‐naphthalene bicycle is locally aromatic according to structural and magnetic criteria, as revealed by strong diatropic ring current effects on the deshielding of 1H nuclei of the Ar groups and on the negative value of the DFT‐calculated NICS at the center of the C18 rings (?12.8 ppm). The stability and aromaticity of this smallest fused molecular fragment of α‐graphyne allows prediction of the same properties for the carbon allotrope itself. 相似文献
998.
Donor‐Stabilized 1,3‐Disila‐2,4‐diazacyclobutadiene with a Nonbonded Si⋅⋅⋅Si Distance Compressed to a Si=Si Double Bond Length
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Dr. David Gau Raphael Nougué Dr. Nathalie Saffon‐Merceron Dr. Antoine Baceiredo Dr. Abel De Cózar Prof. Fernando P. Cossío Dr. Daisuke Hashizume Dr. Tsuyoshi Kato 《Angewandte Chemie (International ed. in English)》2016,55(47):14673-14677
A donor‐stabilized 1,3‐disila‐2,4‐diazacyclobutadiene presents an exceptionally short nonbonded Si???Si distance (2.23 Å), which is as short as that of Si=Si bonds (2.15–2.23 Å). Theoretical investigations indicate that there is no bond between the two silicon atoms, and that the unusual geometry can be related to a significant coulomb repulsion between the two ring nitrogen atoms. This chemical pressure phenomenon could provide an alternative and superior way of squeezing out van der Waals space in highly strained structures, as compared to the classical physical methods. 相似文献
999.
Luca Demonti Hana Tabikh Dr. Nathalie Saffon-Merceron Dr. Noel Nebra 《欧洲无机化学杂志》2023,26(19):e202300348
The synthesis of Naumann's AgI/AgIII mixed valence salt [AgI]+[AgIII(CF3)4]− ( Ag-1 ) is revisited. Ag-1 is now safely available in half gram scale upon 2e− oxidation of AgF in presence of CF3SiMe3 and ambient air. In addition to its unprecedented crystallographic characterization, the use of Ag-1 to build the novel AgI/AgIII salts [ Ag (bpy)2] -1 , [ Ag (18-crown-6)2] -1 , [ Ag -crypt-222] -1 and [ Ag (PCy3)2] -1 is herein reported, alongside their characterization by NMR, single crystal X-ray diffraction (Sc-XRD) and elemental analysis (EA). The utility of the currently affordable Ag-1 in gold(I) catalysis was demonstrated by the excellent catalytic activity displayed by [{ Au (PPh3)}2(μ-Cl)] -1 and [ Au (PPh3)] -1 in the 5-exo-dig cyclization of N-propargylbenzamide ( 2 ). These cationic AuI catalysts are accessible from (PPh3)AuCl and Ag-1 , and outperform the activity of the well-known benchmark catalyst (PPh3)AuNTf2. 相似文献
1000.
Dr. Abdelaziz Jouaiti Lavinia Ballerini Hsiang-Ling Shen Ronan Viel Prof. Dr. Federico Polo Nathalie Kyritsakas Prof. Dr. Stefan Haacke Yu-Ting Huang Prof. Dr. Chin-Wei Lu Dr. Christophe Gourlaouen Prof. Dr. Hai-Ching Su Dr. Matteo Mauro 《Angewandte Chemie (International ed. in English)》2023,62(38):e202305569
Two binuclear heteroleptic CuI complexes, namely Cu−NIR1 and Cu−NIR2, bearing rigid chelating diphosphines and π-conjugated 2,5-di(pyridin-2-yl)thiazolo[5,4-d]thiazole as the bis-bidentate ligand are presented. The proposed dinuclearization strategy yields a large bathochromic shift of the emission when compared to the mononuclear counterparts (M1–M2) and enables shifting luminescence into the near-infrared (NIR) region in both solution and solid state, showing emission maximum at ca. 750 and 712 nm, respectively. The radiative process is assigned to an excited state with triplet metal-to-ligand charge transfer (3MLCT) character as demonstrated by in-depth photophysical and computational investigation. Noteworthy, X-ray analysis of the binuclear complexes unravels two interligand π–π-stacking interactions yielding a doubly locked structure that disfavours flattening of the tetrahedral coordination around the CuI centre in the excited state and maintain enhanced NIR luminescence. No such interaction is present in M1–M2. These findings prompt the successful use of Cu−NIR1 and Cu−NIR2 in NIR light-emitting electrochemical cells (LECs), which display electroluminescence maximum up to 756 nm and peak external quantum efficiency (EQE) of 0.43 %. Their suitability for the fabrication of white-emitting LECs is also demonstrated. To the best of our knowledge, these are the first examples of NIR electroluminescent devices based on earth-abundant CuI emitters. 相似文献