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181.
We have studied antimony and selenium atomization processes including a chemical matrix modifier (palladium-containing activated
carbon) during their determination by electrothermal atomic absorption spectrometry. We have developed and fine-tuned an experimental
setup for determining the kinetic characteristics (activation energy and frequency factor) for element atomization processes
from measurements in the initial section of the analytical signal. We provide a rationale for the most likely mechanism for
the interactions that occur. The results of the kinetic studies of the atomization processes showed that the modifier we developed
was highly effective, as a result of formation of a thermally stable condensed system C-Pd-A (where A is the analyte).
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 4, pp. 530–534, July–August, 2006. 相似文献
182.
C. Zălinescu 《Mathematical Methods of Operations Research》1991,35(4):291-298
In this paper there is stated a result on sets in ordered linear spaces which can be used to show that some properties of the sets are inherited by their convex hulls under suitable conditions. As applications one gives a characterization of weakly efficient points and a duality result for nonconvex vector optimization problems. 相似文献
183.
SiC films doped with aluminum (Al) were prepared by the rf-magnetron sputtering technique on p-Si substrates with a composite target of a single crystalline SiC containing several Al pieces on the surface. The as-deposited films were annealed in the temperature range of 400-800 °C under nitrogen ambient. The thin films have been characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The results show that the introduction of Al into films hinders crystalline formation process. And with the increase of annealing temperature, more Si particles are formed in the films, which strongly affect the optical absorption properties. The photoluminescence (PL) spectra of the samples show two peaks at 370 nm and 412 nm. The intensities of the PL peaks are evidently improved after Al doped. We attribute the origin of the two PL peaks to a kind of Si-related defect centres. The obtained results are expected to have important applications in modern optoelectronic devices. 相似文献
184.
This work is supported in part by the fund OTKA (No. 5-134). 相似文献
185.
We report a method to grow thin strain-released InAs layer on GaAs (1 0 0) substrates by molecular beam epitaxy. We have shown that by controlling the growth parameters, a thin 2D InAs layer can be grown during initial stages, which eventually serves as a buffer layer to trap dislocations and epitaxial regrowth of InAs on this buffer results in high crystal quality. The size dependence of the InAs islands formed during initial stages with growth time has been studied by atomic force microscopy. With continuous short-time epitaxial growth during various stages, the InAs growth mode transfers from 3D to 2D. The introduction of dislocations into InAs epitaxial islands and their behavior during initial growth stage has been theoretically studied. The theoretical results are in remarkable agreement with the experimental results and shows that once the film is formed, the film strain is totally relaxed. The 200 nm thick InAs epilayer grown on this buffer shows a narrow X-ray diffraction peak. Such InAs strain-released buffer layer would be useful for regrowth of high In content based materials on top of it for electronics and optoelectronics device applications. 相似文献
186.
The low-temperature reaction of magnesium with fluorobenzene has been investigated. Joint condensation of magnesium and fluorobenzene vapours at low temperatures quantitatively gave phenylmagnesium fluoride in one stage. 相似文献
187.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 50, No. 1, pp. 158–162, January, 1989. 相似文献
188.
Z. B. Alfassi F. Groppi M. L. Bonardi O. Presler U. German 《Journal of Radioanalytical and Nuclear Chemistry》2006,268(3):639-640
Summary The paper deals with the common mistake of interpolating calculation of the efficiency of gamma-detectors by the inverse square
law of the distance of the source from the detector cap and suggests the use of the distance from the virtual point detector
instead. 相似文献
189.
This paper summarizes a set of novel techniques for obtaining optical transformations, which are useful tools for signal processing. Then the paper focuses on deriving several interesting discrete transformations. The discussed transforms include continuous fractional transformations, hybrid transforms and discrete transform kernels. 相似文献
190.
Z. Sebestyén 《Periodica Mathematica Hungarica》1989,20(1):85-87
We prove, as an application of our positive extension argument, a theorem of Parrott concerning the quotient norm with respect to spaces of Hilbert space operators. 相似文献