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31.
A direct detection Doppler wind lidar with the dual Fabry–Perot technique has been built in Hefei, China, and the system is
described in this paper. A dual, air-spaced Fabry–Perot etalon is designed as the frequency discriminator and the transmission
characteristics are measured with a stabilized cw laser and a pulse laser. The experimental data are found to be in agreement
with the designed parameters. The Doppler shift is measured by taking the ratio of the transmitted intensities from the dual
etalon. Analysis of the accuracy of Doppler measurement is made by considering the factors of the number of iterations in
converting the measured ratio to the Doppler shift, the laser intensity fluctuation and the signal-to-noise ratio. In the
sufficient signal-to-noise ratio the velocity accuracy of the Doppler lidar system is estimated to be better than 0.5 m/s. 相似文献
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V. S. Airapetyan 《Journal of Applied Spectroscopy》2009,76(2):268-272
We have developed, built, and tested an automated differential lidar system for measuring low concentrations of atmospheric
gases, based on an optical parametric oscillator tunable in the near IR region. We have calculated the spectral shift of the
relative intensities of the individual lines in the ν3 absorption band of methane. In comparing the measured and calculated spectra, we did not observe any shifts in the ν3 absorption band of methane. At the same time, in the experimental spectra we observe broadening of the Q branch and the individual lines of the P branch.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 76, No. 2, pp. 285–290, March–April, 2009. 相似文献
34.
薄膜多腔滤光片型梳状滤波器的设计 总被引:11,自引:5,他引:6
介绍了一种通过使用多个薄膜法布里—珀罗滤光片的叠加来实现密集波分复用中使用的梳状滤波器的设计的新方法。采用间隔层为熔融石英的薄膜法布里—珀罗滤光片作为基本结构的光学梳状滤波器可以比较容易地控制各腔的厚度,因而能精确地达到波分复用系统中波长间隔非常窄的要求。分析了如何确定间隔层厚度和各法布里—珀罗腔的反射镜的反射率以及它们之间的匹配问题,最后给出了与设计吻合较好的实验结果,制作的梳状滤波器在C波段的信道间隔为100GHz,相邻通道窜音小于-24dB,最小插入损耗约-0.4dB。 相似文献
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通常情况下该实验用以对电子的荷质比进行测量。笔者发现,如果进行逆向构思,把电子的荷质比作为已知量时,可重新进行理论推导从而得到真空中的光速值。基于该理论基础重新设计塞曼效应试验,就可以得到测量光速的一种新方法。本文主要就采用这一方法测光速时,对影响测量精度的主要因素进行了分析。 相似文献
37.
Au nanoparticle (AuNP) core particles coated with a poly(N‐isopropylacrylamide) (pNIPAm) shell (Au@pNIPAm) are synthesized by seed mediated free radical polymerization. Subsequently, a temperature–light‐responsive photonic device is fabricated by sandwiching the Au@pNIPAm particles between two thin layers of Au. The optical device exhibits visual color and characteristic multipeak reflectance spectra, where peak position is primarily determined by the distance between two Au layers. Dual responsivities of the photonic device are achieved by combining the photothermal effect of AuNPs core (localized surface plasmon resonance (LSPR) effect) and the temperature responsivity of the pNIPAm shell. That is, the pNIPAm shell collapses as the temperature is increased above pNIPAm's lower critical solution temperature, either by direct heat input or heat generated by AuNPs' LSPR effect. To investigate the effect of AuNPs distribution in the microgels on the devices' photothermal responsivity, the Au@pNIPAm microgel‐based etalon devices are compared with that fabricated by AuNP‐doped pNIPAm‐based microgels; in terms of response kinetics and optical spectrum homogeneity. The uniform Au@pNIPAm microgel‐based devices show a fast response and exhibit a comparatively homogeneous spectrum over the whole slide. These materials can potentially find use in drug delivery systems, active optics, and soft robotics. 相似文献
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把一个由GaAs光电导开关和激光腔中的普克尔盒组成的正反馈回路,用于YAG激光器中,选单纵模和调Q,获得了稳定可靠的单纵模调Q脉冲. 相似文献