简介:提出了一种基于楔形平板等厚干涉原理测量光学玻璃非线性折射率变化的方法。在理论分析的基础上,建立了变形的等厚干涉条纹变化△e/e与待测玻璃平片(K9玻璃)折射率变化量△nb之间的数学模型;在选取一定的实验条件下,获得等厚干涉实验测量干涉图样,并利用MATLAB对实验所得的干涉图进行图像数据处理分析计算,恢复出非线性变化光学玻璃材料的折射率变化量△nb该方法的测量精度可达10^-6。
简介:AIM:Toevaluatetheaccuracyofsphericalequivalent(SE)estimatesofadouble-passsystemandtocompareitwithretinoscopy,subjectiverefractionandatablemountedautorefractor.METHODS:Non-cycloplegicrefractionwasperformedon125eyesof65healthyadults(age23.5±3.0years)fromOctober2010toJanuary2011usingretinoscopy,subjectiverefraction,autorefraction(AutokeratorefractometerTOPCONKR-8100,Japan)andadoublepasssystem(OpticalQualityAnalysisSystem,OQAS,VisiometricsS.L.,Spain).Nineconsecutivemeasurementswiththedouble-passsystemwereperformedonasubgroupof22eyestoassessrepeatability.ToevaluatethetruenessoftheOQASinstrument,theSElaboratorybiasbetweenthedoublepasssystemandtheothertechniqueswascalculated.RESULTS:TheSEmeancoefficientofrepeatabilityobtainedwas0.22D.SignificantcorrelationscouldbeestablishedbetweentheOQASandtheSEobtainedwithretinoscopy(r=0.956,P<0.001),subjectiverefraction(r=0.955,P<0.001)andautorefraction(r=0.957,P<0.001).ThedifferencesinSEbetweenthedouble-passsystemandtheothertechniquesweresignificant(P<0.001),butlackedclinicalrelevanceexceptforretinoscopy;Retinoscopygavemorehyperopicvaluesthanthedouble-passsystem-0.51±0.50Daswellasthesubjectiverefraction-0.23±0.50D;Moremyopicvalueswereachievedbymeansofautorefraction0.24±0.49D.CONCLUSION:Thedouble-passsystemprovidesaccurateandreliableestimatesoftheSEthatcanbeusedforclinicalstudies.Thistechniquecandeterminethecorrectfocuspositiontoassesstheocularopticalquality.However,ithasarelativelysmallmeasuringrangeincomparisonwithautorefractors(-8.00to+5.00D),andrequirespriorinformationontherefractivestateofthepatient.
简介:摘要随着科技产品不断地深入日常生活,科技产品在使用过程中带来了对教育的反思以及如何让每一个民众都能享有科技成果。本文以中国电信的“e家169”套餐为例,围绕科技产品在使用中产生的问题,以及如何以小区教育的模式解决相关问题而进行了分析。