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81.
《Mathematical Methods in the Applied Sciences》2018,41(9):3282-3293
This paper investigates the problem of exponential H∞ synchronization of discrete‐time chaotic neural networks with time delays and stochastic perturbations. First, by using the Lyapunov‐Krasovskii (Lyapunov) functional and output feedback controller, we establish the H∞ performance of exponential synchronization in the mean square of master‐slave systems, which is analyzed using a matrix inequality approach. Second, the parameters of a desired output feedback controller can be achieved by solving a linear matrix inequality. Finally, 2 simulated examples are presented to show the effectiveness of the theoretical results. 相似文献
82.
A percolation study of RTS noise in deep sub-micron MOSFET by Monte Carlo simulation 总被引:2,自引:0,他引:2 下载免费PDF全文
Based on percolation theory and random telegraph signal (RTS) noise generation mechanism, a numerical model for RTS in deep submicron metal-oxide-semiconductor field-effect transistor (MOSFET) was presented, with which the dependence of Tc/Te (where Tc=capture time, Te=emission period ) on energy levels and trap depth with respect to the interface of traps can be simulated. Compared with experimental results, the simulated ones showed a good qualitative agreement. 相似文献
83.
Xu Xiaoyong Zheng Guoguang Wang Qing-an 《Journal of Quantitative Spectroscopy & Radiative Transfer》2005,92(1):61-72
This paper experimentally and theoretically examines the scattering properties of simulated non-spherical hydrometeors including water oblates, ice oblates and ice sphere-cone-oblates, in terms of the backscattering cross-section and the differential reflectivity. The experimental measurements of the backscattering cross-sections of non-spherical hydrometeor samples were performed in the Electromagnetic Scattering Laboratory of China National Space Industrial Corporation. Meanwhile, the backscattering cross-sections have been computed with the transition (<em>Tem>) matrix method. The theoretical results are compared with the experimental data, showing that the calculations are consistent with the observations in general. Experimental and theoretical analyses indicate that the backscattering cross-section of non-spherical particles increases as the particle size parameter increases, and fluctuates when the sizes are larger under the effect of resonance scattering. Differential reflectivity <em>Zem><em>DRem> of water oblates in natural rainfall is always greater than 0 dB whereas <em>Zem><em>DRem> of hailstones may be negative. There is a good linear relationship between differential reflectivity and aspect ratio of a particle. These derivations agree with the literature and can be used to identify the presence of hail particles and distinguish between plate-type and columnar-type hydrometeors. In this study, the measuring experiment and the <em>Tem>-matrix method calculations for the scattering of simulated raindrop and ice particles are also briefly described. 相似文献
84.
Thin films of Ti1−<em>xem>Co<em>xem>O2 (<em>xem>=0 and 0.03) have been prepared on sapphire substrates by spin-on technique starting from metalorganic precursors. When heat treated in air at 550 and 700 °C, respectively, these films present pure anatase and rutile structures as shown both by X-ray diffraction and Raman spectroscopy. Optical absorption indicate a high degree of transparency in the visible region. Such films show a very small magnetic moment at 300 K. However, when the anatase and the rutile films are annealed in a vacuum of 1×10−5 Torr at 500 and 600 °C, respectively, the magnetic moment, at 300 K, is strongly enhanced reaching 0.36<em>μem>B/Co for the anatase sample and 0.68<em>μem>B/Co for the rutile one. The ferromagnetic Curie temperature of these samples is above 350 K. 相似文献
85.
Neodymium doped bismuth layer structure ferroelectrics (BLSFs) ceramics CaBi4−<em>xem>Nd<em>xem>Ti4O15 (<em>xem>=0, 0.25, 0.50, 0.75) were prepared by solid-state reaction method. X-ray diffraction pattern showed that single phase was formed when <em>xem>=0-0.75. The refined lattice parameters showed that <em>aem> (<em>bem>) axes decrease at <em>xem>=0.25 and increase with more Nd3+ dopant. The effects of Nd3+ doping on the dielectric and ferroelectric properties of CaBi4Ti4O15 ceramics are studied. Nd3+ dopant decreased the Curie temperature linearly, and the dielectric loss, tan <em>δem>, as well. The remnant polarization of Nd3+ doped CaBi4Ti4O15 ceramics was increased by 80% at <em>xem>=0.25, while more Nd3+ dopant decreased the remnant polarization. CaBi3.75Nd0.25Ti4O15 ceramics had the largest piezoelectric constant <em>dem>33. The structure and properties of CaBi4−<em>xem>Nd<em>xem>Ti4O15 ceramics showed that Nd3+ may occupy different crystal locations when Nd3+ content <em>xem> is less than 0.25 and more than 0.50. 相似文献
86.
Hongtao Sun Liyan Zhang Junjie Zhang Chunlei Yu Shixun Dai Zhonghong Jiang 《Solid State Communications》2005,133(12):781-784
Infrared-to-visible upconversion fluorescence property of Er3+/Yb3+-codoped novel bismuth-germanium glass under 975 nm LD excitation has been studied. Intense green and red emissions centered at 525, 546 and 657 nm, corresponding to the transitions 2H11/2→4I15/2, 4S3/2→4I15/2, and 4F9/2→4I15/2, respectively, were observed at room temperature. The quadratic dependence of the 525, 546 and 657 nm emissions on excitation power indicates that a two-photon absorption process occurs. The structure of the bismuth-germanium glass has been investigated by peak-deconvolution of FT-Raman spectrum, and the structural information was obtained from the peak wavenumbers. This novel bismuth-germanium glass with low maximum phonon energy (∼750 cm−1) can be used as potential host material for upconversion lasers. 相似文献
87.
We present how enlarging the size of a telescope from the current 10 meter telescope to the future 100 meter Extremely Large Telescopes increases the complexity of a classical or multiconjugate adaptive optics instrument. We point out elements or parameters of the system for which it is critical to propose new ideas as solutions and we study the effect of the increase of the diameter on the point spread function of an MCAO and a Ground Layer AO system. To cite this article: R. Ragazzoni et al., C. R. Physique 6 (2005). 相似文献
88.
We study the complexity of the problem of deciding the existence of a spanning subgraph of a given graph, and of that of finding a maximum (weight) such subgraph. We establish some general relations between these problems, and we use these relations to obtain new NP-completeness results for maximum (weight) spanning subgraph problems from analogous results for existence problems and from results in extremal graph theory. On the positive side, we provide a decomposition method for the maximum (weight) spanning chordal subgraph problem that can be used, e.g., to obtain a linear (or O(nlogn)) time algorithm for such problems in graphs with vertex degree bounded by 3. 相似文献
89.
In this paper, we introduce the notion of T*-extension of a Lie triple system. Then we show that T*-extension is compatible with nilpotency, solvability, and it preserves in certain sense the decomposition properties. In addition, we investigate the equivalence of T*-extensions using cohomology. Finally, we show that every finite-dimensional nilpotent metrised Lie triple system over an algebraically closed field is the T*-extension of an appropriate quotient system. 相似文献
90.
We analyze matrix-valued transfer operators. We prove that the fixed points of transfer operators form a finite-dimensional <em>Cem>∗-algebra. For matrix weights satisfying a low-pass condition we identify the minimal projections in this algebra as correlations of scaling functions, i.e., limits of cascade algorithms. 相似文献