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41.
42.
Jong Seong Bae Kyoo Sung Shim Soung-soo Yi Young Soo Kim 《Applied Surface Science》2006,252(13):4564-4568
The influence of lithium doping on the crystallization, the surface morphology, and the luminescent properties of pulsed laser deposited Y2−xGdxO3:Eu3+ thin film phosphors was investigated. The crystallinity, the surface morphology, and the photoluminescence (PL) of films depended highly on the Li-doping and the Gd content. The relationship between the crystalline and morphological structures and the luminescent properties was studied, and Li+ doping was found to effectively enhance not only the crystallinity but also the luminescent brightness of Y2−xGdxO3:Eu3+ thin films. In particular, the incorporation of Li and Gd into the Y2O3 lattice could induce remarkable increase in the PL. The highest emission intensity was observed Li-doped Y1.35Gd0.6O3:Eu3+ thin films whose brightness was increased by a factor of 4.6 in comparison with that of Li-doped Y2O3:Eu3+ thin films. 相似文献
43.
We investigate the connection between the entanglement system in Minkowski spacetime and the black hole using the scaling analysis. Here we show that the entanglement system satisfies the Bekenstein entropy bound. Even though the entropies of two systems are the same form, the entanglement energy is different from the black hole energy. Introducing the Casimir energy of the vacuum energy fluctuations rather than the entanglement energy, it shows a feature of the black hole energy. Hence the Casimir energy is more close to the black hole than the entanglement energy. Finally, we find that the entanglement system behaves like the black hole if the gravitational effects are included properly. 相似文献
44.
C.-B. Moon T. Komatsubara Y. Sasaki T. Jumatsu K. Yamada K. Satou K. Furuno 《The European Physical Journal A - Hadrons and Nuclei》2002,14(1):13-16
Excited states of the 119Xe nucleus have been studied by using in-beam γ-ray spectroscopy with the 107Ag ( 16O, p3n) 119Xe fusion-evaporation reaction at a beam energy of 85 MeV. The level scheme of 119Xe has been derived from γ-γ coincidence and γ-γ angular correlation analyses. We have, for the first time, established the
second negative-parity favored and unfavored states built on the 11/2- state, namely the yrare rotational bands in 119Xe. In contrast to the behavior of the yrast bands where the favored states are lying lower in energy, the yrare favored states
were observed to lie above the unfavored band. Such a signature inversion in 119Xe is changed to be normal at I = 12?.
Received: 8 January 2002 / Accepted: 18 April 2002 相似文献
45.
We investigated the film-thickness and ambient oxygen-pressure dependence of the electric field, EF, required to initiate unipolar resistance switching (URS) in Ta2O5?x thin films. We measured the dependence of EF by applying a triangular-waveform voltage signal to the film over a wide sweep-rate range (v = 20 mV s?1 to 5 MV s?1). Our results showed that the URS-EF was not influenced by the Ta2O5?x film thickness nor ambient oxygen-pressure. This suggested that the URS-forming process in Ta2O5?x thin films should be governed by thermally assisted dielectric breakdown in our measurement range. 相似文献
46.
Filevich J Rocca JJ Marconi MC Moon SJ Nilsen J Scofield JH Dunn J Smith RF Keenan R Hunter JR Shlyaptsev VN 《Physical review letters》2005,94(3):035005
We present clear experimental evidence showing that the contribution of bound electrons can dominate the index of refraction of laser-created plasmas at soft x-ray wavelengths. We report anomalous fringe shifts in soft x-ray laser interferograms of Al laser-created plasmas. The comparison of measured and simulated interferograms shows that this results from the dominant contribution of low charge ions to the index of refraction. This usually neglected bound electron contribution can affect the propagation of soft x-ray radiation in plasmas and the interferometric diagnostics of plasmas for many elements. 相似文献
47.
The frequency-dependent attenuation and backscatter coefficients were measured in 25 bovine femoral trabecular bone samples from 0.2 to 1.2 MHz. When the average attenuation coefficient was fitted to a nonlinear power law α(f)=α(0)+α(1)f(n), the exponent n was found to be 1.65. In contrast, the average backscatter coefficient was fitted to a power law η(f)=η(1)f(n) and the exponent n was measured as 3.25. The apparent bone density was significantly correlated with the parameter α(1) (0.2-0.7 MHz: r = 0.852, 0.6-1.2 MHz: r = 0.832) as well as the backscatter coefficient (0.5 MHz: r = 0.751, 1.0 MHz: r = 0.808). 相似文献
48.
This paper deals with the vibration characteristics of a piezoelectric open-shell transducer which was made by dividing a cylindrical piezoelectric transducer longitudinally into two segments. Two-dimensional governing equations were derived by using the cylindrical membrane theory. Applying mechanical and electrical boundary conditions yielded a characteristic equation for the resonance frequencies of the piezoelectric open-shell transducer. The fundamental frequency and the electromechanical coupling factor were calculated and compared with the results of the finite element analysis and experiment. The fundamental mode shape obtained theoretically was compared with the result of the finite element analysis. The theoretical analysis was verified to provide the vibration characteristics of an open-shell transducer. 相似文献
49.
The free flexural vibration of a hanged clamped-free cylindrical shell with various boundary conditions partially submerged in a fluid is investigated. Specifically, the effects of the boundary conditions such as the existence of the external wall, internal shaft, and bottom on the natural vibration characteristics of the partially submerged cylindrical shell are investigated both theoretically and experimentally. The fluid is assumed to be inviscid and irrotational. The cylindrical shell is modeled by using the Rayleigh–Ritz method based on the Sanders shell theory. The kinetic energy of the fluid is derived by solving a boundary-value problem related to the fluid motion. The theoretical predictions were in good agreement with the experimental results validating the theoretical approach developed in this study. The effects of the external wall, internal shaft, and bottom on the natural vibration characteristics can be neglected when its boundaries are not very close to the shell structure. 相似文献
50.
We have examined the surface characteristics of Ag‐doped Au nanoparticles (below 5 mol% of Ag) by means of the surface‐enhanced Raman scattering (SERS) of 2,6‐dimethylphenylisocyanide (2,6‐DMPI) and 4‐nitrobenzenethiol (4‐NBT). When Ag was added to Au to form ∼35‐nm‐sized alloy nanoparticles, the surface plasmon resonance band was blue‐shifted linearly from 523 to 517 nm in proportion to the content of Ag up to 5%. In the SERS spectra of 2,6‐DMPI, the N‐C stretching peak also shifted almost linearly from 2184 to 2174 cm−1 when the Ag content was 5 mol% or less; the peak then remained the same as that of the pure Ag film. The potential variation of the SERS spectrum of 2,6‐DMPI in an electrochemical environment, as well as the effect of organic vapor, also showed a similar tendency. From the SERS of 4‐NBT, we confirmed the occurrence of a surface‐induced photoreaction converting 4‐NBT to 4‐aminobenzenethiol, when Ag was added to Au to form alloy nanoparticles. The photoreaction induction ability also increased linearly with the Ag content, reaching a plateau level at 5 mol% of Ag. All these observations suggest that the surface content of Ag should increase almost linearly as a function of the overall mole fraction of Ag and, once the Au/Ag nanoparticles reach 5 mol% of Ag, their surfaces are fully covered with Ag, showing the same surface characteristics of pure Ag nanoparticles. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献