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681.
Fustero S Cuñat AC Flores S Báez C Oliver J Cynamon M Gütschow M Mertens MD Delgado O Tresadern G Trabanco AA 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(52):14772-14784
The preparation of novel fluorinated allylamines and their use as key fragments for the stereoselective synthesis of hydroxyethyl secondary amine (HEA)-type peptidomimetics is described. Our strategy employs chiral sulfinyl imines as synthesis intermediates, by treatment of hemiaminal precursors with two equivalents of vinylmagnesium bromide. The subsequent oxidation of the allylic amines to the corresponding epoxides was achieved by treatment with methyl(trifluoromethyl)dioxirane. Finally, epoxide ring opening with a range of nitrogen nucleophiles provided a library of HEA-derived peptidomimetics with a phenyldifluoromethylene moiety. The biological evaluation of these derivatives revealed compounds with remarkable BACE1 inhibitory activity. Docking studies revealed the influence of the fluorine atoms in the binding mode of the synthesized ligands. Furthermore, the biological evaluation of our final products and synthesis intermediates led to the discovery of compounds with antimicrobial activity against Mycobacterium and Nocardia species. 相似文献
682.
Eduardo V. Flores 《Foundations of Physics》2008,38(8):778-781
We respond to criticism of our paper “Paradox in Wave-Particle Duality for Non-Perturbative Measurements”. We disagree with
Steuernagel’s derivation of the visibility of the Afshar experiment. To calculate the fringe visibility, Steuernagel utilizes
two different experimental situations, i.e. the wire grid in the pattern minima and in the pattern maxima. In our assessment,
this procedure cannot lead to the correct result for the complementarity properties of a wave-particle in one particular experimental
set-up. 相似文献
683.
Betti MG Kanjilal A Mariani C Vázquez H Dappe YJ Ortega J Flores F 《Physical review letters》2008,100(2):027601
The energy level alignment at the metal-organic and organic-organic interfaces of the Cu(100)/benzenethiolate/pentacene heterostructure is studied by photoemission spectroscopy and discussed theoretically using a model that includes, in a consistent way, charge transfer, Pauli repulsion, intrinsic molecular dipoles, and interface screening as a function of coverage. Despite the different nature of the two interfaces, our model provides a unified explanation for the work-function changes at both junctions and enables us to determine the benzenethiolate orientation as a function of coverage. 相似文献
684.
Natalya V. Likhanova Diego Guzmán-Lucero Eugenio A. Flores Paloma García Marco A. Domínguez-Aguilar Jorge Palomeque Rafael Martínez-Palou 《Molecular diversity》2010,14(4):777-787
Seventy five ionic liquids (ILs) were tested as a sequestering agent of sulfured compounds in natural gasoline (NG). Desulphurization
of NG was performed by means of liquid–liquid extraction method at room temperature and atmospheric pressure. Experimental
ILs containing imidazolium, pyridinium, and ammonium cations along with organic and inorganic anions were synthesized conventionally
and under microwave and sonochemical conditions. The effect of the molecular structure of ILs on the desulfurization efficiency
of NG with high sulfur content was evaluated. Analysis indicated that the anion type played a more important role than the
cation on the desulphurization process. ILs based on halogen–ferrates and halogen–aluminates exhibited the highest efficiency
in sulfur removal, and their efficiency is further improved when there is an excess of metallic salt in a ratio of at least
1:1.3 during the synthesis of the corresponding IL. An explanation for the ability of metallic ILs to remove sulfur-containing
compounds from natural gasoline based on the ratio of the ionic charge to the atomic radius is proposed. Furthermore, a method
to recover and reuse water-sensitive to halogenated precursors is described. 相似文献
685.
Izabel Caldeira Andressa Lüdtke Fabiele Tavares Camila Cholant Raphael Balboni Wladimir H. Flores Alexandre Galio Agnieszka Pawlicka César O. Avellaneda 《Ionics》2018,24(2):413-420
Two water-soluble and biodegradable polymers: xanthan gum (XG) and poly(vinyl alcohol) (PVA) were used to synthesize ecologically friendly solid polymer electrolyte (SPE) matrices. While XG is a natural polymer, PVA is a synthetic one, but both are colorless and form transparent membranes. To obtain ionic conductivity properties, the samples were doped with acetic acid and characterized by electrochemical impedance spectroscopy (EIS), X-ray diffraction, UV-Vis spectroscopy, and tensile test. The best results of ionic conductivity of 1.97 × 10?4 and 7.41 × 10?4 S/cm at room temperature and 80 °C, respectively, were obtained for the sample containing 55 wt% of acetic acid. Moreover, this electrolyte was found to be predominantly amorphous with transmittance in the visible region of 80% and absorbance values below 0.5 between 240 and 375 nm. Tensile test of this sample, applied up to 18 N of maximum force, resulted in strain of 2322% and Young’s modulus of 0.02 MPa. The obtained results showed that these new eco-friendly materials are promising for use as electrolytes in electrochemical devices. 相似文献
686.
687.
Dr. Samuel E. Griffin Grant P. Domecus Clarissa E. Flores Dr. R. Eric Sikma Prof. Lauren Benz Prof. Seth M. Cohen 《Angewandte Chemie (International ed. in English)》2023,62(23):e202301611
Low-valent metal–organic frameworks (LVMOFs) and related materials have gained interest due to their potential applications in heterogeneous catalysis. However, of the few LVMOFs that have been reported, none have shown catalytic activity. Herein, a low-valent metal-organic material constructed from phosphine linkers and IrI nodes is reported. This material is effectively a crystalline, insoluble analogue of Vaska's complex. As such, the material reversibly binds O2 and catalyzes the reductive formation of enamines from amides. 相似文献
688.