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临边昏暗在恒星角直径测量中的影响
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作者 赵定烽 杭恒荣 陈子栋 《空间科学学报》 CAS CSCD 北大核心 2000年第4期303-309,共7页
讨论了恒星临边昏暗在恒星角直径测量中的影响.研究表明,相对于二项式近似而言,UD模型和线性模型均对恒星角直径测量有所低估,在线性临边昏暗系数较小时,这种影响最大, UD和线性近似与二项式近似的差别最多分别达 25.5%... 讨论了恒星临边昏暗在恒星角直径测量中的影响.研究表明,相对于二项式近似而言,UD模型和线性模型均对恒星角直径测量有所低估,在线性临边昏暗系数较小时,这种影响最大, UD和线性近似与二项式近似的差别最多分别达 25.5%和 12.6%;而在线性系数值趋近于1时,其相互差别随之可以忽略.而新旧线性临边近似之间对于恒星角直径测量的影响似乎并不很大.最后我们认为非线性临边昏暗效应的影响不可忽略. 展开更多
关键词 恒星大气 恒星 角直径测量 临边昏暗
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Measurement of the applanated diameter of ocular cornea using a novel optical probe
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作者 张学勇 卢荣胜 +1 位作者 李平 马建国 《Optoelectronics Letters》 EI 2011年第4期294-297,共4页
A precise measurement of the applanated diameter of the ocular cornea with the optical probe is very important in applanation tonometry.A novel optical probe with a common path configuration is presented.The optical p... A precise measurement of the applanated diameter of the ocular cornea with the optical probe is very important in applanation tonometry.A novel optical probe with a common path configuration is presented.The optical probe mainly consists of a cone-shaped prism and a photodetector.The former serves as a measuring body touching the ocular cornea to shape the area to be measured,and the latter converts the quantity of the luminous flux returning from the cone-shaped prism into one electronic current signal.Laboratory experiments are carried out on a simulated eyeball,followed by an enucleated porcine eyeball specimen.Experimental results show that there is a significant rise of the normalized variational current with increasing the applanation diameter of the ocular cornea,and the sensitivity is 0.2111/mm with an error of 0.00263/mm.Measurements of the normalized variational current on the porcine eyeball have good agreement with those on the simulated eyeball. 展开更多
关键词 Optoelectronic devices PRISMS
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