共查询到20条相似文献,搜索用时 171 毫秒
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《电力标准化与计量》2009,(11):80-80
日前,国内首个第三代聚光式太阳能电池并网发电示范项目在宜兴经济开发区宜兴创业园投入使用。聚光式太阳能电池,就是通过聚光设备将一定面积内的太阳光汇聚到一个狭小范围内的太阳能电池上再进行发电的系统。据介绍,该太阳能电池发电站示范项目总装机容量为30kw,采用了太阳能转化率可达42%的砷化镓多节半导体电池、聚光倍数达500倍的透镜组,并且配套了双轴太阳跟踪器。 相似文献
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《中国照明电器光源灯具文摘》2007,27(1):4-5
0700025光纤采光系统[刊]/张文进(南京春辉科技实业有限公司),/照明,-2006年第4期。20~23页。基本方法是将自然光经聚光采光器高效汇聚后,直接由光纤传输到使用场所照明。光纤采光系统采用灵敏性高、无探测盲区的四方位光纤光敏传感器作为太阳跟踪传感器, 相似文献
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Ilev I.K. Waynant R.W. Byrnes K.R. Anders J.J. 《IEEE journal of selected topics in quantum electronics》2003,9(2):331-336
A novel and simple concept for on-off switching laser radiation delivery into a precise tissue area using tissue-activated optical fiber probes is demonstrated. The authors present the operating principle and general optical features of the fiber-optic-based delivery technique. The basic idea includes the use of a single delivery fiber with a specially shaped angled tip. Because of the frustrated-total-internal reflectance caused by the refractive-index change of the surrounding medium, the angled fiber tip acts as a smart tissue-activated probe. It provides a safe way for laser delivery that includes only two states of tissue illumination: 1) off-state (no tissue illumination), when the fiber tip is out of the tissue area and the laser emission is backreflected due to total-internal-reflection and 2) on-state (maximum tissue illumination), when the fiber tip is on the absorbing tissue area and becomes "transparent" because of the frustrated-total-internal reflectance. Here, optical properties of tissue-activated fiber probes used for precise laser delivery are investigated both experimentally and theoretically by analyzing the backreflectance signal power. Optical fibers working in the visible and mid-infrared spectral regions with various geometrical parameters are used and a spatial resolution of 2 /spl mu/m is achieved when the fiber tip is moved toward the absorption tissue surface. 相似文献
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汽车照明系统的设计及超精密自由曲面加工技术 总被引:3,自引:0,他引:3
随着汽车产业的高速发展和市场的激烈竞争,现代汽车照明系统对发光效率、安全性能、以及美观的要求也越来越高。汽车照明中的自由曲面反射镜及LED照明系统的设计和加工是至关重要的。有别于传统光学系统的设计,汽车照明系统的非成像光学的设计是个多学科、复杂的过程。设计结果的好坏直接影响到照明系统的发光效率、能耗、以及汽车的安全性能。随着光学系统设计和超精密加工技术的进步,越来越多的光学元件采用了非球面以及自由曲面,汽车照明系统的效率以及性能得以极大的提高。本文阐述了汽车照明的非成像光学系统的设计和超精密加工技术。 相似文献
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Sized-fiber spectroscopy describes a device and method for measuring absorption and reduced scattering properties of tissue using optical fibers with different diameters. The device used in this paper consists of two fibers with diameters of 200 and 600 μm. Each fiber emits and collects its own backscattered light. Backscattered light measurements for solutions with absorption coefficients of 0.1-2.0 cm -1 and reduced scattering coefficients of 5-50 cm-1 demonstrate that the device is most sensitive for the highest scattering materials. Monte Carlo simulations suggest the device is insensitive to the fiber illumination characteristics and that the light returning to the fiber is nearly uniform over all directions. Finally, experiments and Monte Carlo simulations of the sized-fiber device indicate that 50% of the signal arises from roughly 1.2 and 1.9 reduced mean-free paths for the 200- and 600-μm fibers, respectively 相似文献
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微机电系统(MEMS)的动态表征是为可动MEMS器件的设计和加工过程提供可靠的实验数据反馈.文中构建了一个MEMS动态测试系统,它采用了光学检测方法,具有非接触、快速、高精度等优点.系统分别采用光流技术和显微干涉技术,结合频闪照明的方法,对MEMS器件的面内和离面运动特性进行了测量.通过对一个微加工水平谐振器的运动特性测量实验说明了系统具有的功能. 相似文献
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Jiyama K. Maeda T. Takamiya S. 《IEEE journal of selected topics in quantum electronics》2001,7(3):484-489
We describe the experimental results on the chromatic dispersion measurement of long optical fibers by means of optical ranging system using a wavelength-tunable frequency-shifted feedback (FSF) laser. The optical ranging system using an FSF laser has high spatial resolution of several centimeter over 10-km measurement range, and then the dependence of the group delay time of the lightwave in the optical fibers on the wavelength can be directly measured. The chromatic dispersion and the zero-dispersion wavelength of an 80-km-long dispersion shifted fiber was estimated, which is in good agreement with the result obtained by the phase method 相似文献
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Jackson D.K. Buffaloe T.K. Leeb S.B. 《Industry Applications, IEEE Transactions on》1998,34(3):625-630
The prevalence of electric discharge illumination has led the authors to consider ways to use discharge lamps for communication. This paper describes an optical transceiver system which transmits by modulating the lamp arc. The prototype power electronic lamp ballast uses a pulse-frequency modulation scheme which ensures no perceptible flicker 相似文献
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Kishi N. Sano T. Yamashita E. 《IEEE journal of selected topics in quantum electronics》1997,3(4):1045-1048
The paper describes the characterization of an improved fiber-optic transceiver for optical time-domain reflectometers (OTDR). The transceiver employs an active fiber ring which has both transmitter and receiver functions of OTDR. An optical circulator takes the place of the combination of a 3-dB coupler and an optical isolator in the previously reported system. Reflections from several lengths of cascaded fibers are measured to characterize the transceiver. Compared with the previous system, performance improvement of the transceiver with the optical circulator is achieved 相似文献