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311.
312.
《Liquid crystals》2012,39(12):1852-1860
ABSTRACTIn this paper, we use multicomponent mutual diffusion method to derive a one-dimensional non-local diffusion dynamic model to describe the diffusion kinetics of a dynamic holographic polymer dispersed liquid crystal grating (H-PDLC) doped with nano-silver. The physical mechanism of diffusion between monomer and liquid crystal, monomer and nano-silver particles is analysed using this model. Using coupled-wave theory, the H-PDLC’s diffraction efficiency curve with the expose time are simulated due to the vivid changing of effective refractive index modulation caused by the movement of concentration of each component with the expose time. Correspondingly, in the experiment, the diffraction efficiency of the grating is measured in real time, which shows the improvement for the holographic properties because of nano-silver doped H-PDLC. The simulation results have a good agreement with experimental data by fitting the corresponding parameters of the model. In addition, through comparing with simulation and experimental results with doping different concentrations of nano-silver particles, the recipe and diffraction characteristics of H-PDLC grating can be improved. Thus, the diffusion Kinetics model can be used to optimise the phase separation of the PDLC grating, and finally to improve the opto-electrical properties of H-PDLC gratings. 相似文献
313.
Hoyong Park Wonho Choe S.J. Yoo 《Spectrochimica Acta Part B: Atomic Spectroscopy》2010,65(12):1029-1032
As typical emission spectroscopy involves chord integration along the line of sight, a local measurement with high spatial resolution is attempted using simple lens optics in this work. In the experiment, chord integrated optical plasma emission profile was measured by moving a scanning lens located outside the plasma. The measured emission intensities were spatially reconstructed by employing a geometry-dependent system function, and the local (i.e., only from the lens focal point) emission intensities were obtained with all out-focused emissions subtracted. The 34 different Ar I emission lines spatially reconstructed in this way were used to determine excitation temperature (Texc) of the argon plasma by the Boltzmann plot method. Being different from the plasma driven at 13.56 MHz where a rather uniform profile was obtained, the spatial profile of Texc from the plasma driven at 90 MHz showed a hollow profile, which is similar to that of the electron temperature (Te) measured by a Langmuir probe. This hollow profile is attributed from the electromagnetic phenomena such as skin effect and standing wave effect. The similar spatial tendency of Texc and Te implies that Texc can be a representative of Te. This is particularly useful for the cases in which conventional Langmuir probe measurements are limited, such as in large size plasmas. 相似文献
314.
We study the spontaneously induced general relativity (GR) from the scalar-tensor gravity. We demonstrate by numerical methods that a novel inner core can be connected to the Schwarzschild exterior with cosmological constants and any sectional curvature. Deriving an analytic core metric for a general exterior, we show that all the nontrivial features of the core, including the locally holographic entropy packing, are universal for the general exterior in static spacetimes. We also investigate whether the f(R) gravity can accommodate the nontrivial core. 相似文献
315.
A computational method based on pure-phase look-up-table (LUT) is proposed for generating kinoforms of full-color real-existing three-dimensional (3D) objects. The principle of the pure-phase LUT method is described. 3D depth as well as color information of a full-color 3D object is obtained by the full-color 3D profile measurement approach based on binocular vision. The obtained full-color 3D data is decomposed into red (R), green (G), and blue (B) channels, and kinoforms of each channel are calculated from the depth map and color information of the corresponding channel using the pure-phase LUT method. In order to reduce the speckle noise of reconstructed full-color 3D image, sequential kinoforms of each color channel are generated by adding dynamic-pseudorandom phase factor into the object domain. Numerical reconstruction and optical reconstruction with a phase-only spatial light modulator (SLM) show that, with the proposed method, full-color holographic 3D display of real-existing full-color 3D objects is available. 相似文献
316.
Simulation of simultaneous measurement for red blood cell thickness and refractive index 总被引:1,自引:0,他引:1
Weifeng JinYawei Wang Naifei RenMin Bu Xuefu ShangYuanyuan Xu Yujiao Chen 《Optics and Lasers in Engineering》2012,50(2):154-158
Red blood cell (RBC) parameters are of great importance for diagnostic purposes. Using the simulation method, the variations of both the thickness and the refractive index of a RBC were investigated in a dual-medium quantitative measurement (DMQ), which is realized via phase-shifting digital holography with two types of cell media. Results show that both the calculated thickness and the calculated refractive index agree well with the original ones with an average relative deviation of 2.13% and of 0.12% in valid regions, respectively. The simulation for RBC will provide some guidance for experimental parameter setting and data processing in DMQ. 相似文献
317.
制备了一种对整个可见光波段都敏感的光全息存储材料,并研究了该材料的透过率、衍射效率、灵敏度等全息特性.用He-Ne激光器633 nm和Ar+ 激光器514 nm,488 nm,476 nm四种波长的光曝光,材料的饱和衍射效率最大为66%,最小为48%;最高灵敏度为8.06×10-3 cm2/mJ.最高折射率调制度为4.22×10-4.用多波长存储时,不同波长的光可存储多幅全息图,且再现图像清晰.结果表明,该材料是较好的高密度数字全息存储材料. 相似文献
318.