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431.
We prove a discrete version of the Stam inequality for randomvariables taking values on a finite group. 相似文献
432.
Reineri F Viale A Ellena S Alberti D Boi T Giovenzana GB Gobetto R Premkumar SS Aime S 《Journal of the American Chemical Society》2012,134(27):11146-11152
(15)N-Propargylcholine has been synthesized and hydrogenated with para-H(2). Through the application of a field cycling procedure, parahydrogen spin order is transferred to the (15)N resonance. Among the different isomers formed upon hydrogenation of (15)N-propargylcholine, only the nontransposed derivative contributes to the observed N-15 enhanced emission signal. The parahydrogen-induced polarization factor is about 3000. The precise identification of the isomer responsible for the observed (15)N enhancement has been attained through a retro-INEPT ((15)N-(1)H) experiment. T(1) of the hyperpolarized (15)N resonance has been estimated to be ca. 150 s, i.e., similar to that reported for the parent propargylcholine (144 s). Experimental results are accompanied by theoretical calculations that stress the role of scalar coupling constants (J(HN) and J(HH)) and of the field dependence in the formation of the observed (15)N polarized signal. Insights into the good cellular uptake of the compound have been gained. 相似文献
433.
Tommaso Crisenza Hans‐Jürgen Butt Kaloian Koynov Roberto Simonutti 《Macromolecular rapid communications》2012,33(2):114-119
Blends of chlorinated polyethylene and nylon‐6/‐6,6/‐12 terpolyamide were prepared. The ratio of the two components was systematically varied within the blends. The mechanical behavior of the samples was analyzed with tensile tests and dynamical mechanical analysis showing that, for several ratios, materials with improved mechanical properties typical of thermoplastic elastomers were obtained. In such a mechanical regime, a co‐continuous phase‐separated morphology was clearly evidenced at the microscopic scale by 3D laser scanning confocal fluorescent microscopy (LSCFM). At blend compositions where plastic tensile behavior is observed, LSCFM reveals dispersed spheres of one component in the other. 相似文献
434.
Poli T Chiantore O Giovagnoli A Piccirillo A 《Analytical and bioanalytical chemistry》2012,402(9):2977-2984
The study of polished cross sections is a well-assessed and practical method to investigate the stratigraphy of paintings
and multilayer polychromies on works of art, in general. Analyses on cross sections allow us to characterize, at once, all
the layers in the stratigraphy, giving information about the artists technique, the number of layers and their composition
and sometimes about the conservation history of the artefact. In this paper, the application of an imaging detector focal
plane array (FPA) coupled to an infrared (IR) microscope has been studied, focusing on the characteristics and potential of
the different working methodologies (attenuated total reflectance (ATR) and total reflection). FPA detector coupled with ATR
crystal can “localize” IR information coming from a 30 × 30μm sample area, in a 64 × 64 dot matrix detector. In particular,
an innovative analysis methodology has been tested for the total reflectance measurements in order to obtain maximum information
with single measurements. Micro-infrared total reflection measurements have been carried out in an extended IR range (from
1,000 to 5,266 cm−1) exploiting the broad spectral response of mercury cadmium telluride detector in order to include overtones and combination
bands from near-infrared spectral range without any modification of the standard mid-infrared micro-FT instrumentation. The
potentialities of this new approach have been successfully transferred in the imaging/mapping investigations with a minimal
tuning of the apparatus. Results obtained on a polished cross section coming from a modern painting and on a micro-sample
of a wood polychromy from an undated historic polyptic are shown for demonstration. 相似文献
435.
Mecca T Consoli GM Geraci C La Spina R Cunsolo F 《Organic & biomolecular chemistry》2006,4(20):3763-3768
A mutual induced fit mechanism is responsible for the exceptional complexation performances exhibited by calix[8]arene polycations towards heparin. The recognition process was studied in comparison with two other heparin antagonists: protamine and polylysine. The arrangement of multiple functional groups on the flexible macrocyclic scaffold of calix[8]arene, with respect to the conformationally rigid protamine and low ordered polylysine, allowed a mutual adaptability between calixarene polycations and heparin, significantly enhancing the recognition performances. Fluorescence, NMR titration, and activated partial thromboplastin time (aPTT) experiments confirmed that these calixarene derivatives have a very high specificity and affinity towards heparin neutralization as in aqueous solution as in blood. Analogous results were obtained with low molecular weight heparin (LMWH) whose effect protamine is unable to completely reverse. 相似文献
436.
Marcelli T van Maarseveen JH Hiemstra H 《Angewandte Chemie (International ed. in English)》2006,45(45):7496-7504
In the steadily expanding field of organocatalysis, cinchona alkaloids play a prominent role. Until the late 1990s, bifunctional catalysts based on this scaffold relied exclusively on the C9-hydroxy group as the hydrogen-bond donor. Recently, new cinchona catalysts have been developed that feature a phenolic OH group in the C6' position-a structural feature that allows a diverse set of reactions to be catalyzed in a highly stereoselective fashion. This Minireview describes the scope and modes of action of this new class of asymmetric bifunctional organocatalysts. 相似文献
437.
Stener M Di Tommaso D Fronzoni G Decleva P Powis I 《The Journal of chemical physics》2006,124(2):024326
In the present work the photoelectron circular dichroism of camphor has been theoretically studied using B-spline and continuum multiple scattering-Xalpha methods, and comparisons are made with available experimental data. In general, rather large dichroism effects have been found for both valence and core (O 1s, C 1s) photoionizations. The agreement between the two calculations reported here and previous experimental measurements for core C 1s data is essentially quantitative. For valence ionization satisfactory agreement between theory and experiment has been obtained and the discrepancies have been attributed to both exchange-correlation potential limitations and the absence of response effects in the adopted formalism. The calculations predict, moreover, important features in the cross-section profiles, which have been discussed in terms of dipole-prepared continuum orbitals. 相似文献
438.
439.
Every 1‐rotational solution of a classic or twofold Oberwolfach problem (OP) of order n is generated by a suitable 2‐factor (starter) of or , respectively. It is shown that any starter of a twofold OP of order n gives rise to a starter of a classic OP of order (doubling construction). It is also shown that by suitably modifying the starter of a classic OP, one may obtain starters of some other OPs of the same order but having different parameters. The combination of these two constructions leads to lots of new infinite classes of solvable OPs. Still more classes can be obtained with the help of a third construction making use of the possible gracefulness of a graph whose connected components are cycles and at most one path. As one of the many applications, Hilton and Johnson's [J London Math Soc, 64 (2001) 513–522] bound about the solvability of OP is improved to in the case of r even. © 2012 Wiley Periodicals, Inc. J. Combin. Designs 20: 483‐503, 2012 相似文献
440.