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941.
Cover Picture: Dinuclear Ruthenium(II) Complexes as Two‐Photon,Time‐Resolved Emission Microscopy Probes for Cellular DNA (Angew. Chem. Int. Ed. 13/2014) 下载免费PDF全文
942.
Dinuclear Ruthenium(II) Complexes as Two‐Photon,Time‐Resolved Emission Microscopy Probes for Cellular DNA 下载免费PDF全文
Elizabeth Baggaley Martin R. Gill Nicola H. Green David Turton Igor V. Sazanovich Stanley W. Botchway Carl Smythe John W. Haycock Julia A. Weinstein Jim A. Thomas 《Angewandte Chemie (International ed. in English)》2014,53(13):3367-3371
The first transition‐metal complex‐based two‐photon absorbing luminescence lifetime probes for cellular DNA are presented. This allows cell imaging of DNA free from endogenous fluorophores and potentially facilitates deep tissue imaging. In this initial study, ruthenium(II) luminophores are used as phosphorescent lifetime imaging microscopy (PLIM) probes for nuclear DNA in both live and fixed cells. The DNA‐bound probes display characteristic emission lifetimes of more than 160 ns, while shorter‐lived cytoplasmic emission is also observed. These timescales are orders of magnitude longer than conventional FLIM, leading to previously unattainable levels of sensitivity, and autofluorescence‐free imaging. 相似文献
943.
Erdi A. Bleda Ilhan Yavuz Zikri Altun Carl Trindle 《International journal of quantum chemistry》2013,113(8):1147-1154
We use a variant of the focal point analysis to refine estimates of the relative energies of the four low‐energy torsional conformers of glycolaldehyde. The most stable form is the cis‐cis structure which enjoys a degree of H‐bonding from hydroxyl H to carbonyl O; here dihedral angles τ1 (O?C? C? O) and τ2 (C? C? O? H) both are zero. We optimized structures in both CCSD(T)/aug‐cc‐pVDZ and aug‐cc‐pVTZ; the structures agree within 0.01 Å for bond lengths and 1.0 degrees for valence angles, but the larger basis brings the rotational constants closer to experimental values. According to our extrapolation of CCSD(T) energies evaluated in basis sets ranging to aug‐cc‐pVQZ the trans‐trans form (180°, 180°) has a relative energy of 12.6 kJ/mol. The trans‐gauche conformer (160°, ±75°) is situated at 13.9 kJ/mol and the cis‐trans form (0°, 180°) at 18.9 kJ/mol. Values are corrected for zero point vibrational energy by MP2/aug‐cc‐pVTZ frequencies. Modeling the vibrational spectra is best accomplished by MP2/aug‐cc‐pVTZ with anharmonic corrections. We compute the Watsonian parameters that define the theoretical vibrational‐rotational spectra for the four stable conformers, to assist the search for these species in the interstellar medium. Six transition states are located by G4 and CBS‐QB3 methods as well as extrapolation using energies for structures optimized in CCSD(T)/aug‐cc‐pVDZ structures. We use two isodesmic reactions with two well‐established thermochemical computational schemes G4 and CBS‐QB3 to estimate energy enthalpy and Gibbs energy of formation as well as the entropy of the gas phase system. Our extrapolated electronic energies of species appearing in the isodesmic reactions produce independent values of thermodynamic quantities consistent with G4 and CBS‐QB3. © 2013 Wiley Periodicals, Inc. 相似文献
944.
Interactions between ions and itinerant charges govern electronic processes ranging from the redox chemistry of molecules to the conductivity of organic semiconductors, but remain an open frontier in the study of microporous materials. These interactions may strongly influence the electronic behavior of microporous materials that confine ions and charges to length scales comparable to proton-coupled electron transfer. Yet despite mounting evidence that both solvent and electrolyte influence charge transport through ion–charge interactions in metal–organic frameworks, fundamental microscopic insights are only just beginning to emerge. Here, through electrochemical analysis of two open-framework chalcogenides TMA2FeGe4S10 and TMA2ZnGe4S10, we outline the key signatures of ion-coupled charge transport in band-type and hopping-type microporous conductors. Pressed-pellet direct-current and impedance techniques reveal that solvent enhances the conductivity of both materials, but for distinct mechanistic reasons. This analysis required the development of a fitting method that provides a novel quantitative metric of concerted ion–charge motion. Taken together, these results provide chemical parameters for a general understanding of electrochemistry in nanoconfined spaces and for designing microporous conductors and electrochemical methods used to evaluate them.Interactions between ions and itinerant charges govern electronic processes ranging from the redox chemistry of molecules to the conductivity of organic semiconductors, but remain an open frontier in the study of microporous materials. 相似文献
945.
Carl Djrassi 《Nachrichten aus der Chemie》1989,37(4):403-407
Mit dem Namen Carl Djerassi verbindet der Chemiker hauptsächlich Steroidchemie oder die Anwendung von Massenspektroskopie und Rotationsdispersion zur Strukturaufklärung. In letzter Zeit hat sich der gebürtige Wiener aber auch als Schriftsteller hervorgetan. Die folgende Kurzgeschichte um einen Nobelpreis erschien zuerst in englischer Sprache in „Hudson Review”︁ (New York), später auch in Buchform („The Futurist and Other Stories”︁, Macdonald/Futura, London 1988). 相似文献
946.
Carl G. Simon Naomi Eidelman Yan Deng Newell R. Washburn 《Macromolecular rapid communications》2004,25(24):2003-2007
Summary: A method for rapidly determining the modulus of polymer blends was developed. A polymer blend gradient library of poly(L ‐lactic acid) (PLLA) and poly(D ,L ‐lactic acid) (PDLLA) was created in the form of a strip‐shaped film and characterized with FTIR microspectroscopy. Nanoindentation measurements were made along the gradients to obtain modulus data over a wide range of PLLA‐PDLLA blend compositions. This novel, high‐throughput approach to material characterization provides engineers with a technique to accelerate the development of materials.
947.
A new phase in europium‐tin‐chalcogenide chemistry has been prepared using the reactive flux method: Eu8(Sn4Se14)(Se3)2. The compound crystallizes in the orthorhombic space group P21212 with cell parameters a = 11.990(2) Å, b = 16.425(4) Å, c = 8.543(1) Å, and Z = 2. Eu8(Sn4Se14)(Se3)2 is a three dimensional structure with EuII cations linked together with an unusual (Sn4Se14)12– anionic unit and (Se3)2– chains. UV‐VIS‐NIR band‐gap analysis shows that these black metallic crystals are likely semiconductors with an optical band‐gap of 1.07 eV. 相似文献
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