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81.
Castagnola M Zuppi C Rossetti DV Vincenzoni F Lupi A Vitali A Meucci E Messana I 《Electrophoresis》2002,23(12):1769-1778
The general properties of dendrimers and in particular their electrolytic characteristics that are relevant in electrokinetic separations, are described. In order to confirm theoretical considerations on commercial dendrimer charge and hydrodynamic radius, several capillary zone electrophoresis (CZE) experiments were performed. Electrophoretic mobilities measured at different pH values indicated a sensible increase of dendrimer hydrodynamic radius at pH values lower than 2.5. This was probably due to the Coulombic repulsion of charged amine groups of the inner dendrimer shells. The principal reasons that should address the use of dendrimers as pseudostationary phases in micellar electrokinetic chromatography (MEKC) are discussed. Moreover, a survey of different separations performed utilizing dendrimers in MEKC as well as of several future plausible uses of various classes of dendrimers is presented. 相似文献
82.
Various aspects of our communication are well known to havechanged over time (1-3). This article describes a cross-sectional study that examined the acoustic characteristics of two groups of Australian women aged 18–25 years from recordings made in 1945 and 1993 and investigated the possible changes in the voice across generations. Archival recordings from 1945 which had been used in a longitudinal study (4) were compared to recordings made in 1993. The results of this study show that women in 1993 have significantly deeper voices than women of the same age recorded in 1945. The possible factors influencing this change are discussed. 相似文献
83.
84.
Erika Ferrari Romano Grandi Sandra Lazzari Gaetano Marverti Maria Cecilia Rossi Monica Saladini 《Polyhedron》2007
The NMR study on the interaction of Pt(II) with Amadori compounds is performed. The Amadori compounds are derived from the reaction of β-d-glucose with l-cystine leading to N,N′-di-(1-deoxy-β-fructos-1-yl)-l-cystine [FruCyscys], and with l-methionine leading to N-(1-deoxy-β-fructos-1-yl)-l-methionine [FruMet]. 相似文献
85.
Open-framework materials synthesized in the TMA+/TEA+ mixed-template system: the new low Si/Al ratio zeolites UZM-4 and UZM-5. 总被引:1,自引:0,他引:1
C Scott Blackwell Robert W Broach Michael G Gatter Jennifer S Holmgren Deng-Yang Jan Gregory J Lewis Beckay J Mezza Thomas M Mezza Mark A Miller Jaime G Moscoso R Lyle Patton Lisa M Rohde Michael W Schoonover Wharton Sinkler Ben A Wilson Stephen T Wilson 《Angewandte Chemie (International ed. in English)》2003,42(15):1737-1740
86.
R. Stenbacka G. Ekspong S.O. Holmgren S. Nilsson Ch. Walck P. Gregory P. Mason H. Muirhead G. Warren 《Nuclear Physics B》1978,135(1):20-44
Single-pion production in interactions at 9.1 GeV/c is analysed and cross sections are given. The plab dependence of the isospin amplitudes is determined by a fit to the world data. The data are also compared with the predictions of a reggeized Deck model. The results and the amplitudes are compared with the results at other energies and with the corresponding NπN amplitudes. 相似文献
87.
88.
Roccatano D Sbardella G Aschi M Amicosante G Bossa C Di Nola A Mazza F 《Journal of computer-aided molecular design》2005,19(5):329-340
The dynamical aspects of the fully hydrated TEM-1 β-lactamase have been determined by a 5 ns Molecular Dynamics simulation.
Starting from the crystallographic coordinates, the protein shows a relaxation in water with an overall root mean square deviation
from the crystal structure increasing up to 0.17 nm, within the first nanosecond. Then a plateau is reached and the molecule
fluctuates around an equilibrium conformation. The results obtained in the first nanosecond are in agreement with those of
a previous simulation (Diaz et al., J. Am. Chem. Soc., (2003) 125, 672–684). The successive equilibrium conformation in solution
shows an increased mobility characterized by the following aspects. A flap-like translational motion anchores the Ω-loop to
the body of the enzyme. A relevant part of the backbone dynamics implies a rotational motion of one domain relative to the
other. The water molecules in the active site can exchange with different residence times. The H-bonding networks formed by
the catalytic residues are frequently interrupted by water molecules that could favour proton transfer reactions. An additional
simulation, where the aspartyl dyad D214–D233 was considered fully deprotonated, shows that the active site is destabilized. 相似文献
89.
P. Gregory D. Everett P. Grossmann P. Mason H. Muirhead G. Warren R. Carlsson G. Ekspong S.O. Holmgren S. Nilsson R. Stenbacka C. Walck 《Nuclear Physics B》1974,78(2):222-232
Relations have been derived between the invariant cross sections for various inclusive processes by assuming factorisation of the leading (pomeron) and non-leading (meson) trajectories. In this paper predictions for the invariant cross sections have been tested using data from interactions at 4.6 and 9.1 GeV/c.A large discrepancy between experiment and theory is apparent for the π? data: in the π+ case the discrepancy is less marked but still present. 相似文献
90.
S.M. Flatte J.B. Gay R.J. Hemingway S.O. Holmgren M.J. Losty R. Blokzijl J.C. Kluyver G.G.G. Massaro W.J. Metzger J.J.M. Timmermans R.T. Van de Walle P.R. Lamb P. Grossmann 《Physics letters. [Part B]》1976,64(2):225-229
A πω enhancement at 1245 MeV is observed in the reaction K?p → Σ+π?ω. Its properties agree with those of a B meson produced by natural-parity exchange thus establishing a coupling of the B to a system. 相似文献