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光学面型指标ΔN和PV值的关系及验收方法
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作者 姚曹阳 何开远 +4 位作者 刘卫明 许红 宋海涛 杨壮 张昊 《云光技术》 2022年第2期97-100,共4页
光学零件面型偏差是检验产品中较为重要的项目,ΔN和PV值是描述面型的两种主要评价指标。在日常检验产品时,可能遇到面型指标要求和检验结论分别使用上述两种评价标准的情况,给检验人员对产品的合格判定带来了困难。本文研究了ΔN和PV... 光学零件面型偏差是检验产品中较为重要的项目,ΔN和PV值是描述面型的两种主要评价指标。在日常检验产品时,可能遇到面型指标要求和检验结论分别使用上述两种评价标准的情况,给检验人员对产品的合格判定带来了困难。本文研究了ΔN和PV值两种评价指标的测量原理,并给出了ΔN和PV值不等式的关系,即ΔNλ≥PV值≥ΔNλ/2。对于要求和检验结论使用的不同评价指标,检验人员可以利用此不等式关系加严检验,从而判定产品合格与否。 展开更多
关键词 面型偏差 干涉条纹 放大原理 ΔN和PV
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光圈识别的数字化实现
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作者 王鑫 高玫 王群 《科技视界》 2015年第28期66-66,69,共2页
本文介绍了一种光圈识别的数字化评价方法。运用数字图像处理技术,通过Matlab软件编程实现了对光圈的计算和评价,并将该方法的结果与传统测量方法的结果进行比较,证明了该评价方法的有效性。
关键词 面型偏差 数字图像处理
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Development of a 50-year daily surface solar radiation dataset over China 被引量:9
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作者 TANG WenJun YANG Kun +1 位作者 QIN Jun MIN Min 《Science China Earth Sciences》 SCIE EI CAS 2013年第9期1555-1565,共11页
Although solar radiation is a crucial parameter in designing solar power devices and studying land surface processes,long-term and densely distributed observations of surface solar radiation are usually not available.... Although solar radiation is a crucial parameter in designing solar power devices and studying land surface processes,long-term and densely distributed observations of surface solar radiation are usually not available.This paper describes the development of a 50-year dataset of daily surface solar radiation at 716 China Meteorological Administration(CMA) stations.First,a physical model,without any local calibration,is applied to estimate the daily radiation at all 716 CMA routine stations.Then,an ANN-based(Artificial Neural Network) model is applied to extend radiation estimates to earlier periods at each of all 96 CMA radiation stations.The ANN-based model is trained with recent reliable radiation data and thus its estimate is more reliable than the physical model.Therefore,the ANN-based model is used to correct the physical model dynamically at a monthly scale.The correction generally improves the accuracy of the radiation dataset estimated by the physical model:the mean bias error(MBE) averaged over all the 96 radiation stations during 1994-2002 is reduced from 0.68 to 0.11 MJ m-2 and the root mean square error(RMSE) from 2.01 to 1.80 MJ m-2.The new radiation dataset shows superior performance over previous estimates by locally calibrated ngstr m-Prescott models.Based on the new radiation dataset,the annual mean daily solar radiation over China is 14.3 MJ m-2.The maximal seasonal mean daily solar radiation occurs in the Tibetan Plateau during summer with a value of 27.1 MJ m-2,whereas the minimal seasonal mean daily solar radiation occurs in the Sichuan Basin during winter with a value of 4.7 MJ m-2. 展开更多
关键词 Development of a 50-year daily surface solar radiation dataset over China
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