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31.
Recently, Bauke and Mertens conjectured that the local statistics of energies in random spin systems with discrete spin space
should in most circumstances be the same as in the random energy model. We review some rigorous results confirming the validity
of this conjecture. In the context of the SK models, we analyse the limits of the validity of the conjecture for energy levels
growing with the volume of the system. In the case of the Generalised Random energy model, we give a complete analysis for
the behaviour of the local energy statistics at all energy scales. In particular, we show that, in this case, the REM conjecture
holds exactly up to energies E
N
< β
c
N, where β
c
is the critical temperature. We also explain the more complex behaviour that sets in at higher energies.
Research supported in part by the DFG in the Dutch-German Bilateral Research Group “Mathematics of Random Spatial Models from
Physics and Biology” and by the European Science Foundation in the Programme RDSES. 相似文献
32.
Irina V. Glinkina Vladimir A. Durov Galina A. Mel''nitchenko 《Journal of Molecular Liquids》2004,110(1-3):63-67
Modelling of the biologic solutions has a great importance for basic physicochemical backgrounds of the living processes, mechanism of the diseases and drugs action, etc. The modelling of the chemical equilibria in solution that served as a prototype of the blood plasma with application to calcification of the tissues is performed. The concentrations of molecular–ionic forms containing calcium and hydrogen cations and phosphate anions in the range of ionized-calcium and total phosphorus concentrations from 0.5 to 3.0 mM and at the solution pH of 7.1–7.8 were calculated. The activities of the ionized species were described in approach to Debye–Hückel's theory. The full set of the equilibria taking into consideration dissociation of the water, phosphoric acid, formation of both inert and ionic calcium phosphates was considered. The states of calcium hydrophosphate dihydrate CaHPO4·2H2O (CHPD), calcium phosphate Ca3(PO4)2 (CP), calcium hydrophosphate-phosphate dihydrate Ca4H(PO4)3·2H2O (CHPPD) and hydroxyapatite Ca3OH(PO4)3 (HA) with respect to the boundary of the region in which they crystallise were determined. A criterion has been introduced to characterize the degree of salt supersaturation with respect to crystallisation, which is based on the concentration distance between the states of a salt in solution and at the boundary of its crystallisation. This criterion is used to provide a quantitative characteristic of the supersaturation of the phosphates and their tendency to crystallise in blood's plasma. It was established that the most soluble of the phosphates, CaHPO4·2H2O, is undersaturated and the other phosphates are supersaturated with respect to crystallisation. Thus, this phosphate does not take part in the calcification, and this is the source for ionized calcium in a blood plasma from the soft tissues. The role of the other phosphates in calcification of the soft tissues is decreased in the series HA>CP>CHPPD. The dependencies of the supersaturation of the solution on the pH and on the concentrations of calcium and phosphorus in a mixture are discussed. 相似文献
33.
ABSTRACT Revealing molecular alterations induced on kiwifruit under UV-Vis irradiation requires a discussion of biochemical-cell infrared (IR) fingerprint (900 cm?1–1800 cm?1) bands characteristic of nucleic acids. FTIR-ATR spectroscopy and statistics and nondestructive methods for screening exposure effects induced by irradiation were used. There the irradiation influence on the main molecular bonds (i.e., ν(C-C), νs(PO2?) and νas(PO2?)) can be observed. Regression methods were used for statistical investigations. Two categories of variables were used: the absorbance measured at fixed wavenumber variables and the exposure dose. The bivariate correlations, partial correlations, and polynomial regression methods from SPSS were used for statistical investigations. The obtained results show that FTIR-ATR, in correlation with statistics techniques, might be useful to assess immediate radiation and oxidative-induced damage to nucleic acids. In this case IR spectroscopy can be used successfully to study conformational changes during DNA reversible denaturation especially on the sugar-phosphate vibrations domain. 相似文献
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Anastasia O. Kolodiazhna Irina V. Guliaiko Oleg I. Kolodiazhnyi 《Phosphorus, sulfur, and silicon and the related elements》2013,188(10):2335-2346
Abstract The addition of silylphosphines to chiral aldehydes proceeds with high diastereoselectivity to give optically pure tertiary α -trimethylsiloxyalkylphosphines. The diastereomeric excesses of the addition products were achieved to 90–100%. The reaction of bis(trimethylsilyl)phenylphosphine with the acetonide of (R)-glyceraldehyde provides diastereomerically enriched tertiary bis(glyceryl)phosphines. 相似文献
40.
Aidar T. Gubaidullin Vladimir F. Mironov Gulnara A. Ivkova Igor A. Litvinov Irina V. Konovalova Liliya M. Burnaeva 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1)
Abstract Hexafluoroacetone imine easily interacts with compounds (I, R = OMe, OCH2CF2CHF2, NEt2, Ph) in two directions unlike hexafluoroacttone and gives 1,4,2-oxazaphosphepines (II) (pathway I) or 1,3,2-oxszaphosphepines (III) (pathway 2). The compound (II) (R = NEt2) lightly hydrolyzes to yield the salt (IV). The structure of heterocycles II-IV) has been confirmed by X-ray analysis (see fig. I, II, R = OMe; fig. 2, IV). The detail structural peculiarities of the compounds am discussed. 相似文献