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用于皮秒激光切割的贝塞尔镜头研究 被引量:2
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作者 魏张帆 孙川 +4 位作者 郭凯 陈明 黄立华 曾爱军 黄惠杰 《光子学报》 EI CAS CSCD 北大核心 2020年第10期1-11,共11页
设计并研制了一套用于激光切割的贝塞尔镜头及光束检测系统.此外,采用设计的贝塞尔镜头与中心波长为1064 nm的皮秒脉冲激光器产生皮秒贝塞尔光束,对厚度为1 mm的硅酸盐玻璃进行了切割实验.结果表明,一定直径的高斯光束入射到此贝塞尔镜... 设计并研制了一套用于激光切割的贝塞尔镜头及光束检测系统.此外,采用设计的贝塞尔镜头与中心波长为1064 nm的皮秒脉冲激光器产生皮秒贝塞尔光束,对厚度为1 mm的硅酸盐玻璃进行了切割实验.结果表明,一定直径的高斯光束入射到此贝塞尔镜头上,产生的贝塞尔光束中心主瓣直径和无衍射传输距离分别达到3.4μm和2.46 mm;切割实验中,玻璃分离前的表面微孔直径不超过设计的贝塞尔光束中心主瓣直径.本文设计的贝塞尔镜头及光束检测系统能够满足激光切割应用要求. 展开更多
关键词 激光光学 贝塞尔光束 激光材料加工 玻璃切割 光束检测
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Utilization of Thermal Infrared Image for Inversion of Winter Wheat Yield and Biomass 被引量:3
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作者 DU Wen-yong ZHANG Lu-da +7 位作者 HU Zhen-fang Shamaila Z zeng ai-jun SONG Jian-li LIU Ya-jia Wolfram S Joachim M HE Xiong-kui 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2011年第6期1476-1480,共5页
The present paper utilizes thermal infrared image for inversion of winter wheat yield and biomass with different technology of irrigation(drip irrigation,sprinkler irrigation,flood irrigation).It is the first time tha... The present paper utilizes thermal infrared image for inversion of winter wheat yield and biomass with different technology of irrigation(drip irrigation,sprinkler irrigation,flood irrigation).It is the first time that thermal infrared image is used for predicting the winter wheat yield and biomass.The temperature of crop and background was measured by thermal infrared image.It is necessary to get the crop background separation index(CBSIL,CBSIH),which can be used for distinguishing the crop value from the image.CBSIL and CBSIH(the temperature when the leaves are wet adequately;the temperature when the stomata of leaf is closed completely) are the threshold values.The temperature of crop ranged from CBSIL to CBSIH.Then the ICWSI was calculated based on relevant theoretical method.The value of stomata leaf has strong negative correlation with ICWSI proving the reliable value of ICWSI.In order to construct the high accuracy simulation model,the samples were divided into two parts.One was used for constructing the simulation model,the other for checking the accuracy of the model.Such result of the model was concluded as:(1) As for the simulation model of soil moisture,the correlation coefficient(R2) is larger than 0.887 6,the average of relative error(Er) ranges from 13.33% to 16.88%;(2) As for the simulation model of winter wheat yield,drip irrigation(0.887 6,16.89%,-0.12),sprinkler irrigation(0.970 0,14.85%,-0.12),flood irrigation(0.969 0,18.87%,0.18),with the values of R2,Er and CRM listed in the parentheses followed by the individual term.(3) As for winter wheat biomass,drip irrigation(0.980 0,13.70%,0.13),sprinkler irrigation(0.95,13.15%,-0.14),flood irrigation(0.970 0,14.48%,-0.13),and the values in the parentheses are demonstrated the same as above.Both the CRM and Er are shown to be very low values,which points to the accuracy and reliability of the model investigated.The accuracy of model is high and reliable.The results indicated that thermal infrared image can be used potentially for inversion of winter wheat yield and biomass. 展开更多
关键词 Thermal infrared image Infrared index ICWSI Technology of irrigation
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