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991.
Subject Index
Subject Index to Volume 31 相似文献992.
993.
The question of the effect of the structure of the anisotropic quasi-two-dimensional electron spectrum of high-T
c
superconductors on the character of the screening of the Coulomb interaction and the symmetry of the superconducting order
parameter is studied. Calculations of the polarization operator of electrons are performed on the basis of the single-particle
band spectrum extracted from angle-resolved photoemission spectroscopy data. It is shown that the static screened Coulomb
repulsion has a minimum at small momentum transfers. This corresponds to an effective electron-electron attraction in the
-wave channel of Cooper pairing of the charge carriers on account of their interaction with the long-wavelength charge-density
fluctuations. This attraction together with the anisotropic electron-phonon interaction increase the critical superconducting
transition temperature T
c
with increasing hole density and can give quite high values of T
c
while at the same time suppressing the isotope effect, in qualitative agreement with the experimental data for underdoped
hole-type cuprate metal-oxide compounds.
Pis’ma Zh. éksp. Teor. Fiz. 69, No. 10, 703–710 (25 May 1999) 相似文献
994.
Jack E. Baldwin Bulbul Chakravarti Leslie D. Field John A. Murphy Kathy R. Whitten Sir Edward P. Abraham Gamini Jayatilake 《Tetrahedron》1982,38(18):2773-2776
The title peptide () has been synthesized and incubated with an active cell-free extract of , no conversion to active antibiotics was observed; however on co-incubation with the Arnstein tripeptide (ACV) (), strong inhibition of the conversion of ACV to isopenicillin N was observed. 相似文献
995.
We construct a class of intrinsic or trial states to generate the ground state band of a rotating nucleus in a highly schematized shell model possessing R(5) symmetry. This model is described in the preceding paper. The exponential form of the state links this work to a line of recent developments tracing back ultimately to the work of Jancovici and Schiff on the generator coordinate method. For the present case the state is a product of BCS states and is seen to contain more general (four-particle) correlations than a single deformed BCS state. A technique for the construction of the states is described. The major result of this paper is the proof that the cranking variational principle associated with the trial state is essentially equivalent (exactly equivalent in the thermodynamic or large system limit) to the algebraic-variational method described in the preceding paper, when the latter is restricted to the oneband approximation. The existence of sharp phase transitions in the model is then investigated analytically. A spherical to deformed transition is thus confirmed, as well as an anti-pairing transition. As explained, this is unrelated to the Coriolis anti-pairing phenomena. 相似文献
996.
Abraham Klein 《Nuclear Physics A》1984,431(1):90-124
The equations-of-motion approach to large-amplitude collective motion is implemented both for systems of coupled bosons, also studied in a previous paper, and for systems of coupled fermions. For the fermion case, the underlying formulation is that provided by the generalized Hartree-Fock approximation (or generalized density matrix method). To obtain results valid in the semi-classical limit, as in most previous work, we compute the Wigner transform of quantum matrices in the representation in which collective coordinates are diagonal and keep only the leading contributions. Higher-order contributions can be retained, however, and, in any case, there is no ambiguity of requantization. The semi-classical limit is seen to comprise the dynamics of time-dependent Hartree-Fock theory (TDHF) and a classical canonicity condition. By utilizing a well-known parametrization of the manifold of Slater determinants in terms of classical canonical variables, we are able to derive and understand the equations of the adiabatic limit in full parallelism with the boson case. As in the previous paper, we can thus show: (i) to zero and first order in the adiabatic limit the physics is contained in Villars' equations; (ii) to second order there is consistency and no new conditions. The structure of the solution space (discussed thoroughly in the previous paper) is summarized. A discussion of associated variational principles is given. A form of the theory equivalent to self-consistent cranking is described. A method of solution is illustrated by working out several elementary examples. The relationship to previous work, especially that of Zeievinsky and Marumori and coworkers is discussed briefly. Three appendices deal respectively with the equations-of-motion method, with useful properties of Slater determinants, and with some technical details associated with the fermion equations of motion. 相似文献
997.
Adam Vincze Leon Gefen Abraham Fisher Adam Shatkay Ruth Saranga 《Fresenius' Journal of Analytical Chemistry》1981,305(3):193-195
Summary A method was developed for the determination of the lindane content of commercial household insecticide spray aerosols. After the propellant is removed from the chilled contents of the spray packages the hydrocarbon solution is analysed for its lindane content by electron-capture gas chromatography. Pure -isomer of hexachlorocyclohexane serves as the internal standard. Experimental error is ± 5%.
Gas-chromatographische Bestimmung von Lindan in Haushalts-Spraydosen
Zusammenfassung Das Treibmittel wird durch Ausfrieren abgetrennt und die Insecticidlösung gas-chromatographisch mit Electron-capture Detektor analysiert. Das reine -Isomere dient als innerer Standard. Der Fehler beträgt ± 5%.相似文献
998.
999.
A 96-capillary array electrophoresis (CAE) instrument has been adapted for large-scale mono- and oligosaccharide analysis and characterization. Operational protocols and data processing tools have been developed to optimize the CAE system for this application. Effects of different additives to the running buffer on efficiency and capillary-to-capillary performance reproducibility have been studied. 相似文献
1000.
Automated 96-capillary array electrophoresis (CAE) methodology described in the first part of the present work offered large-scale high-performance profiling of oligo- and monosaccharides to fulfill the needs of bioindustrial laboratories. Sensitivity at low nanomolar concentration, good resolving power and reliability achieved in the experiments is invaluable for monitoring reaction products from enzymatic polysaccharide digestion with numerous applications in agricultural, chemical and food industries. In addition to optimization of mono- and oligosaccharide separations in CAE system and necessary operational protocol modifications, capillary-to-capillary and run-to-run variation in migration time and signal intensity necessitated development of data normalization tools. Internal fluorescent standards have been incorporated into the analysis aiding migration time normalization and CAE trace alignment. Data processing, visualization, and programming tools have been developed along with quantification approaches. 相似文献