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981.
982.
Two-photon optogalvanic transitions in Ar glow discharge with Nd: YAG laser pumped dye laser excitation in the frequency range
13520–16520 cm−1 has been studied using linear and circular polarization. The intensities of two-photon optogalvanic transitions are very
sensitive to changes in the incident laser power which is not the case with one-photon transitions. Intensity ratio for circular
and linear polarized light for two photon transitions 6s′[1/2]°1←4s[3/2]°2, 6s′[1/2]°0←4s[3/2]°2, and 5d[1/2]°0←4s[3/2]°2, 5d[1/2]°1←4s[3/2]°2 are quite different from the other two-photon transitions. This has been explained as due to near one photon resonance
of 4p′[3/2]1 level for the first pair and 4p′[1/2]1 for the second pair of transitions. The ratio of optogalvanic intensity for circular to linear polarized light has
been theoretically estimated and compared with the observed results. 相似文献
983.
M. Kundu K. Niyogi A. K. Ray B. Talukdar 《Zeitschrift fur Physik C Particles and Fields》1982,15(1):61-66
The predictions ofSU(2)×U(1)×U′(1) andSO(10) gauge models for the asymmetry parametersA-,B-,C L andC R in the deep inelastic scattering of polarized electrons and positrons by unpolarized protons and deuterons are compared with those calculated in the Weinberg Salam model for different values ofy. The model based on,SU(2)×U(1)×U′(1) group has been found almost indistinguishable from the Weinberg Salam model with regard to the parametersA-,B- andC L (except forB- in the region 0≦y≦0.2) althoughC R exhibits marked distinguishability. TheSO(10) model, for certain choice of its model parameters, can be distinguished from the Weinberg Salam model through measurement of the asymmetry parameters for different values ofy. 相似文献
984.
985.
986.
Multilayered solid structures made of isotropic, transversely isotropic, or general anisotropic materials are frequently used in aerospace, mechanical, and civil structures. Ultrasonic fields developed in such structures by finite size transducers simulating actual experiments in laboratories or in the field have not been rigorously studied. Several attempts to compute the ultrasonic field inside solid media have been made based on approximate paraxial methods like the classical ray tracing and multi-Gaussian beam models. These approximate methods have several limitations. A new semianalytical method is adopted in this article to model elastic wave field in multilayered solid structures with planar or nonplanar interfaces generated by finite size transducers. A general formulation good for both isotropic and anisotropic solids is presented in this article. A variety of conditions have been incorporated in the formulation including irregularities at the interfaces. The method presented here requires frequency domain displacement and stress Green's functions. Due to the presence of different materials in the problem geometry various elastodynamic Green's functions for different materials are used in the formulation. Expressions of displacement and stress Green's functions for isotropic and anisotropic solids as well as for the fluid media are presented. Computed results are verified by checking the stress and displacement continuity conditions across the interface of two different solids of a bimetal plate and investigating if the results for a corrugated plate with very small corrugation match with the flat plate results. 相似文献
987.
Abhijit Kar Gupta 《Physica A》2008,387(27):6819-6824
We examine the concept of relaxation in the wealth exchange models that are recently proposed in econophysics to interpret wealth distributions. To quantify and characterize the process of relaxation, we define an appropriate quantity and evaluate that numerically for the systems of many agents. Also, heuristic arguments are provided in support of some numerical results. 相似文献
988.
989.
Development of chemical and biochemical sensors is the current need of the society. In this report, we present our investigation
on the development of a label-free fibre-optic biosensor based on evanescent wave absorbance to detect the presence of analytes
such as bacteria, virus and some clinically important proteins. A simple UV-LED (280 nm) and photodetector combination along
with a fibre probe was used for developing cost-effective, user-friendly and field applicable device. To improve the sensitivity
of the detection technique, the probe design was modified and the U-bent probe was fabricated by simple procedure. Further,
to overcome the problems for using UV light source in the fibre, the localized surface plasmon resonance of noble metal nanoparticles
at visible wavelength was exploited as a sensing medium for the biochemical reactions. Our systematic studies in this regard
presented in this communication may bring the excitement for developing the waterborne pathogen detection device for house-hold
as well as field applications. 相似文献
990.
Abhijit Mitra Pamela J. Seaton Kraig A. Wheeler 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(9):o581-o582
The title new diquinaldine derivative, C27H24N4, forms molecular assemblies organized by intermolecular quinoline π–π stacking [3.356 (3) and 3.440 (3) Å] and both inter‐ and intramolecular N—H⋯N hydrogen bonds [3.039 (3)–3.104 (3) Å and 129 (2)–172 (2)°]. The combination of such interactions provides readily definable contacts that propagate along each crystallographic axis. 相似文献