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单束激光-连续超声波空气流动速度测量方法
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作者 张彬乾 王磊 +1 位作者 李建英 宋宙模 《西北工业大学学报》 EI CAS CSCD 北大核心 2009年第5期669-673,共5页
文章提出了一种新型单束激光-连续超声波空气流动速度测量方法。该方法利用连续超声波在运动空气流场中传播时,超声波传播速度音速与空气运动速度叠加的物理现象,采用激光-超声干涉原理,通过测量波长变化,实现对空气流动速度的测量。建... 文章提出了一种新型单束激光-连续超声波空气流动速度测量方法。该方法利用连续超声波在运动空气流场中传播时,超声波传播速度音速与空气运动速度叠加的物理现象,采用激光-超声干涉原理,通过测量波长变化,实现对空气流动速度的测量。建立了试验验证系统,通过测量静止流场中的音速与均匀流场的速度,验证了该方法原理的正确性和技术可行性。该方法对流动现象不产生任何干扰与改变;不存在流动速度方向判别以及信号失真、丢失与辨别等复杂测量技术问题;可直接测量流场中任意一点瞬时速度;具有测量精度高、数据处理简单、成本小、造价低、操作简便等优点;易于实现"阵排列激光-超声测量技术",有望进行多个截面的速度测量以及非定常流场测量,适用于研究集中涡、二次涡、不规则分离等多种复杂流动现象。 展开更多
关键词 单束激光 超声波 声-光干涉 流动测量
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TX06A单束激光控制组件
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作者 马荣军 《电子世界》 2001年第4期36-37,共2页
TX06A单束激光控制组件是利用激光束能量集中:空气媒介中衰减小、传输距离远、装调容易等特点,制成的遥控系统电路。它可广泛用于:    同步计数器、入侵监测系统、激光制导装置、水平测量仪器、远距离遥控装置、战争游戏机、铁道... TX06A单束激光控制组件是利用激光束能量集中:空气媒介中衰减小、传输距离远、装调容易等特点,制成的遥控系统电路。它可广泛用于:    同步计数器、入侵监测系统、激光制导装置、水平测量仪器、远距离遥控装置、战争游戏机、铁道路口预警等系统。    组件简介    TX06A内部结构复杂,发射出的单束激光并非简单的激光束,而是被内部电路驱动的连续点段,示意图如图1所示,其光束内含有复杂的密码程序。在接收电路内含有解码器,只有它才能破解出光束内的密码。采用其它外部手段是无能为力的,这就保证了TX06A的高度可靠性和很强的防外部非法干涉能力,而每一套TX06A内含密码均不同,这样在同一场合中,允许多套TX06A同时工作,而不出现干扰现象。 展开更多
关键词 TX06A 单束激光控制组件 专用集成电路
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基于机载LiDAR单束激光穿透指数的白桦林LAI估测 被引量:11
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作者 邢艳秋 霍达 +4 位作者 尤号田 田昕 焦义涛 谢杰 姚松涛 《应用生态学报》 CAS CSCD 北大核心 2016年第11期3469-3478,共10页
森林叶面积指数(LAI)是描述森林冠层结构和树木生长状况的一个重要指标.本研究以内蒙古依根地区为研究区,在充分考虑机载激光雷达不同回波脉冲之间差异的基础上,对LiDAR点云数据进行分束处理,同时利用传感器与目标之间的距离对LiDAR点... 森林叶面积指数(LAI)是描述森林冠层结构和树木生长状况的一个重要指标.本研究以内蒙古依根地区为研究区,在充分考虑机载激光雷达不同回波脉冲之间差异的基础上,对LiDAR点云数据进行分束处理,同时利用传感器与目标之间的距离对LiDAR点云强度进行校正,在由点云校正强度计算传统激光穿透指数(LPI)的同时提出了一个新的激光穿透指数,即单束激光穿透指数(LPI_s),并分别采用LPI和LPI_s两种激光穿透指数在4种不同LiDAR数据采样尺度(直径分别为5、10、15和20 m)下分别应用理论模型和经验模型两种不同的建模方法对森林LAI进行估测,以期通过激光分束来提高森林LAI的估测精度.结果表明:分束激光穿透指数均值(LPI_(mean))估测LAI的效果明显好于未分束LPI的估测效果,且当LiDAR数据采样尺度为15 m时,LPI_(mean)的经验模型(R2=0.80,平均绝对偏差MAD为0.11)和理论模型(R^2=0.77,MAD=0.16)的估测结果均达到最佳.最后综合应用最佳经验模型与理论模型各自的优点绘制了研究区的白桦林LAI分布图. 展开更多
关键词 叶面积指数 机载激光雷达 强度校正 激光分束 单束激光穿透指数
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脉冲准分子激光沉积Mg/Ag掺杂薄膜 被引量:1
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作者 胡少六 江超 王又青 《激光杂志》 CAS CSCD 北大核心 2004年第2期68-69,共2页
基于梯度掺杂功能薄膜材料在工业应用中的需要、通过金属掺杂对新材料改性研究的需要 ,用单束激光交替作用于两相异靶材 ,制备了Mg Ag组分比为 0 .
关键词 梯度掺杂功能薄膜 金属掺杂 Mg/Ag掺杂 单束激光交替沉积
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Calibration of laser beam direction based on monocular vision 被引量:2
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作者 WANG Zhong YANG Tong-yu +2 位作者 WANG Lei FU Lu-hua LIU Chang-jie 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2017年第4期354-363,共10页
In the laser displacement sensors measurement system,the laser beam direction is an important parameter.Particularly,the azimuth and pitch angles are the most important parameters to a laser beam.In this paper,based o... In the laser displacement sensors measurement system,the laser beam direction is an important parameter.Particularly,the azimuth and pitch angles are the most important parameters to a laser beam.In this paper,based on monocular vision,a laser beam direction measurement method is proposed.First,place the charge coupled device(CCD)camera above the base plane,and adjust and fix the camera position so that the optical axis is nearly perpendicular to the base plane.The monocular vision localization model is established by using circular aperture calibration board.Then the laser beam generating device is placed and maintained on the base plane at fixed position.At the same time a special target block is placed on the base plane so that the laser beam can project to the special target and form a laser spot.The CCD camera placed above the base plane can acquire the laser spot and the image of the target block clearly,so the two-dimensional(2D)image coordinate of the centroid of the laser spot can be extracted by correlation algorithm.The target is moved at an equal distance along the laser beam direction,and the spots and target images of each moving under the current position are collected by the CCD camera.By using the relevant transformation formula and combining the intrinsic parameters of the target block,the2D coordinates of the gravity center of the spot are converted to the three-dimensional(3D)coordinate in the base plane.Because of the moving of the target,the3D coordinates of the gravity center of the laser spot at different positions are obtained,and these3D coordinates are synthesized into a space straight line to represent the laser beam to be measured.In the experiment,the target parameters are measured by high-precision instruments,and the calibration parameters of the camera are calibrated by a high-precision calibration board to establish the corresponding positioning model.The measurement accuracy is mainly guaranteed by the monocular vision positioning accuracy and the gravity center extraction accuracy.The experimental results show the maximum error of the angle between laser beams reaches to0.04°and the maximum error of beam pitch angle reaches to0.02°. 展开更多
关键词 monocular vision laser beam direction coordinate transformation laser displacement sensor
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Influence of positioning errors of optical shaping components for single emitter laser diode on beam shaping effects 被引量:2
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作者 YAN Yi-xiong ZHENG Yu DUAN Ji-an 《Journal of Central South University》 SCIE EI CAS CSCD 2019年第10期2814-2821,共8页
Beam shaping is required for semiconductor lasers to achieve high optical fiber coupling efficiency in many applications.But the positioning errors on optics may reduce beam shaping effects,and then lead to low optica... Beam shaping is required for semiconductor lasers to achieve high optical fiber coupling efficiency in many applications.But the positioning errors on optics may reduce beam shaping effects,and then lead to low optical fiber coupling efficiency.In this work,the positioning errors models for the single emitter laser diode beam shaping system are established.Moreover,the relationships between the errors and the beam shaping effect of each shapers are analysed.Subsequently,the relationship between the errors and the optical fiber coupling efficiency is analysed.The result shows that position errors in the Z axis direction on the fast axis collimator have the greatest influence on the shaping effect,followed by the position errors in the Z axis direction on the converging lens,which should be strictly suppressed in actual operation.Besides,the position errors have a significant influence on the optical fiber coupling efficiency and need to be avoided. 展开更多
关键词 single emitter laser diode beam shaping positioning error coupling efficiency
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Generation of Entangled Displacement Fock State of Trapped Ion Manipulated by a Laser Beam
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作者 WANG Zhong-Jie ZHANG Ke-Fu 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第5期1315-1318,共4页
The interaction of a single two-level two-mode trapped ion with a laser beam has been studied theoretically. With application of a unitary transformation, an analytical solution to this quantum system has been obtaine... The interaction of a single two-level two-mode trapped ion with a laser beam has been studied theoretically. With application of a unitary transformation, an analytical solution to this quantum system has been obtained without performing the Lamb-Dicke approximation. In this system the entangled displacement Fock state is produced. 展开更多
关键词 trapped ion unitary transformation Lamb-Dicke limit
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