学科分类
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4 个结果
  • 简介:一曲动人的《美丽的亚美利加》给我们带到了美国雄伟壮丽的落基山脉,那里的一座海拔4300米气势奇特的山峰,它就是冬天里山上雪花纷飞,峰顶白雪皑皑的“美丽之山”——派克峰。

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  • 简介:Graycrosscorrelationmatchingtechniqueisadoptedtoextractcandidatematcheswithgraycrosscorrela-tioncoefficientslessthansomecertainrangeofmaximalcorrelationcoefficientcalledmulti-peakcandidatematches.Multi-peakcandidatesareextractedcorrespondingtothreeclosestfeaturepointsatfirst.Thecorrespondingmulti-peakcandidatematchesareusedtoconstructthemodelpolygon.Correspondenceisdeterminedbasedonthelocalgeometricrelationsbetweenthethreefeaturepointsandthemulti-peakcandidates.Thedisparitytestandtheglobalconsistencycheckoutareappliedtoeliminatetheremainingambiguousmatchesthatarenotremovedbythelocalgeometricrelationaltest.Experimentalresultsshowthattheproposedalgorithmisfeasibleandaccurate.

  • 标签: 匹配算法 约束方法 电镀技术 机械设备
  • 简介:TransientthermalimpedanceofGaN-basedhigh-powerwhitelightemittingdiodes(LEDs)iscreatedusingathermaltransienttester.Anelectro-thermalsimulationshowsthatLEDjunctiontemperature(JT)risestoaverylowdegreeunderlowdutycyclepulsedcurrent.AtthesameJT,emissionpeaksareequivalentatpulsedandcontinuouscurrents.Moreover,thediferenceinpeakwavelengthwhenaLEDisdrivenbypulsedandcontinuouscurrentsinitiallydecreasesthenincreaseswithincreasingpulsewidth.Thus,selectinganappropriatepulsewidthdecreaseserrorsinJTmeasurement.

  • 标签: 白光LED 结温测量 大功率 GaN 白光发光二极管 瞬态热阻抗
  • 简介:ThestimulatedBrillouinscattering(SBS)thresholdaffectedbyrepetitionrateandpulsedurationinasinglefrequencynanosecondpulsedfiberamplifierisstudied.TheexperimentalresultsdemonstratethattheSBSthresholdcanbeimprovedeitherbyreducingtherepetitionrateorbynarrowingthepulseduration;however,theaveragepowermaybelimitedinsomecases.Otherwise,twoevaluationmethodsfortheSBSthresholdinthefiberamplifierarecomparedanddiscussed,aimingtoobtainamoreaccuratedescriptionfortheSBSthresholdinoursingle-frequencyamplifiersystem.

  • 标签: 受激布里渊散射 光纤放大器 纳秒脉冲 阈值 峰值功率 单频