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41.
Chemo-, regio-, and enantioselective Pd-catalyzed allylic alkylation of indolocarbazole pro-aglycons
[reaction: see text] Monosubstituted isomerically pure indolopyrrolocarbazole precursors have been prepared via palladium-catalyzed asymmetric allylic alkylation methodology, employing both achiral cyclopentenyl electrophiles and chiral glycal derivatives. Chemoselective allylation of (bis)indole lactam pro-aglycon 3 allows access to N-distally substituted indolopyrrolocarbazole derivatives; glyoxamide precursor 14 provides entry into N-proximally substituted derivatives. 相似文献
42.
Ellen Kirkman Ian M. Musson D. S. Passman 《Proceedings of the American Mathematical Society》1999,127(11):3161-3167
Down-up algebras were introduced by G. Benkart and T. Roby to better understand the structure of certain posets. In this paper, we prove that is equivalent to being right (or left) Noetherian, and also to being a domain. Furthermore, when this occurs, we show that is Auslander-regular and has global dimension 3.
43.
A.K. Kerman 《Nuclear Physics A》1981,361(1):179-191
A general nuclear rotation including precession and wobbling motion is studied by the time-dependent variational method and a classical equation of motion is derived. The intrinsic wave function associated with the general rotational motion is constructed by making use of the constrained Hartree-Fock method and variables necessary in solving the equation are calculated. The method developed here is applied to a schematic extension of the Nilsson model. 相似文献
44.
Wilfried Heller Ellen Shirley E. Schwartz 《Journal of Polymer Science.Polymer Physics》1972,10(10):1903-1915
The theory of an interferometric method for determining partial specific volumes of macromolecules is briefly reviewed. The experimental technique developed in this laboratory is described. Detailed results are given on the partial specific volume of ovalbumin in aqueous solution and its dependence on pH and KCl concentration. The results are compared, as far as possible, with dilatometric results obtained in another laboratory. The contribution of a change in partial specific volume of the macromolecules and in the partial specific volume of the water associated with them to the results is analyzed, and the scope of a possible complication due to changes in molecular polarizability is pointed out. 相似文献
45.
46.
We present a careful analysis of the auxiliary field functional integral formalism for many fermion systems. We examine the limiting procedure used in construction of such integrals and show that a wide flexibility exists with respect to the choice of the one-body field representation upon which mean field expansions are made. We demonstrate the utility of this flexibility in the context of the evaluation of the grand canonical partition function. We examine the zero order. RPA and certain higher-order terms. The above-mentioned flexibility is reflected in the dependence of the results on a trial two-body interaction, different choices of which produce Hartree, Fock, HartreeFock or other forms of the mean field expansions. A standard variational procedure selects the Hartree-Fock as the optimal choice. With this choice we find certain corrections to previously reported RPA contribution for the Hartree mean field. We also indicate the relevance of our formulation for the recent applications of the functional integral mean field approach to nuclear dynamical problems. 相似文献
47.
We present a new technique for measuring ultrashort optical pulses by use of spectral phase interferometry for direct electric-field reconstruction that is suitable for large bandwidth pulses. The method does not require generation of a replica of the pulse to be measured and encodes the spectral phase information in a spatial interference pattern. A major advantage of this method is that the spectral sampling saturates the Whittaker-Shannon bound. Moreover, the technique allows for the characterization of some types of space-time coupling. An experimental demonstration of the technique is presented. 相似文献
48.
We demonstrate that the crystallization of thin, supported amorphous solid water layers is initiated at the water surface. This is concluded from the observation of sequential crystallization of amorphous water at the surface, in the bulk, and at the water-support interface. A surface nucleation model quantitatively reproduces the observed transformation kinetics at the three sites. 相似文献
49.
T.?BergemanEmail author A.?J.?Kerman J.?Sage S.?Sainis D.?DeMille 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2004,31(2):179-188
Recently, we have reported photoassociation of laser-cooled Rb and Cs atoms, decay of the RbCs photoassociation resonances
to high levels of the
state, and reexcitation to vibronic levels of the
state [Kerman et al. , Phys. Rev. Lett. 92, 033004; 153001 (2004)]. Considering the reexcitation spectrum, we report here a preliminary analysis of perturbations in
the c state by high levels of the
and low levels of the
state. Mixing with the B state provides the singlet character needed to stimulate decay to v = 0 of the
ground state. We conclude that an experimental procedure that involves photoassociation of laser-cooled atoms, radiative
decay, and stimulated Raman transfer to the ground electronic state is a feasible method for producing translationally, rotationally,
vibrationally and electronically cold RbCs molecules.
Electronic supplementary material to this article is available at and is accessible for authorized users.
Received: 1 September 2004, Published online: 23 November 2004
PACS:
33.80.Ps Optical cooling of molecules; trapping - 34.50.Gb Electronic excitation and ionization of molecules; intermediate
molecular states (including lifetimes, state mixing, etc.) - 33.20.Kf Visible spectra - 34.20.-b Interatomic and intermolecular
potentials and forces, potential energy surfaces for collisions - 33.15.Pw Fine and hyperfine structure
A supplementary table (Tab. I) is only available in electronic form at http: //www.eurphysj.org 相似文献
50.
Stokvis E Rosing H López-Lázaro L Schellens JH Beijnen JH 《Biomedical chromatography : BMC》2004,18(6):403-407
In this paper the transfer of an existing method for the quantitative determination of the anticancer agent ES-285 in human plasma using liquid chromatography tandem mass spectrometry on an API 365 to an API 3000 mass spectrometer is described. The transfer appeared not to be straightforward. Problems arose resulting from carry-over and interferences. In addition, due to the expansion of the calibration range, data ought to be weighted with a different factor to increase the accuracy of the lower concentrations. After finding appropriate solutions for these problems, the lower limit of quantitation could be lowered from 10 to 1 ng/mL for ES-285 in human plasma. The usefulness and necessity of the modified assay was demonstrated by analysis of plasma samples from a patient receiving a low dosage of the drug. 相似文献