针对非球形降水粒子测量和雨滴体积重建的问题,首先讨论雨滴形状模型,认为BC模型(the model of Beard and Chuang)能准确地反应雨滴形状,并将雨滴按照等效尺度大小建模。然后结合降水粒子的图像扫描探测技术,分析线阵CCD对非球形降水粒...针对非球形降水粒子测量和雨滴体积重建的问题,首先讨论雨滴形状模型,认为BC模型(the model of Beard and Chuang)能准确地反应雨滴形状,并将雨滴按照等效尺度大小建模。然后结合降水粒子的图像扫描探测技术,分析线阵CCD对非球形降水粒子的扫描过程和粒子尺度、下落末速度的测量计算模型,并提出一种新的雨滴体积计算方法;为验证体积计算模型的有效性,选择CCD扫描频率30 k Hz、像元数1024×1024,采样区域面积100 mm×100 mm对3 mm雨滴进行扫描仿真,体积仿真结果与BC模型积分体积对比,其误差约为0.2%左右。结果表明,当粒子产生倾斜角时,需要对正、侧面投影分情况进行讨论。在此基础上,对测量模型中可能存在的误差进行探讨,并讨论了相关减小误差的方法,以期对下一步进行雨滴体积计算模型实验室实测数据的验证及其他相关研究做指导。展开更多
Scanning near-field acoustic microscope （SNAM） combines the ultrasonic detection technology with scanning near-field microscopy. The main characteristic of such microscope is that the acoustic wave is produced or de...Scanning near-field acoustic microscope （SNAM） combines the ultrasonic detection technology with scanning near-field microscopy. The main characteristic of such microscope is that the acoustic wave is produced or detected in near-field area whether ultrasonic transducer acts as generator or detector. The resolution of SNAM can reach to nanometer scale. First, two typical SNAMs, scanning electron acoustic Inicroscope and scanning probe acoustic microscope, will be introduced in this paper. The working principle of our homemade SNAM based on a commercial scanning probe microscope will be reported, together with some recent results from this homemade SNAM.展开更多
文摘针对非球形降水粒子测量和雨滴体积重建的问题,首先讨论雨滴形状模型,认为BC模型(the model of Beard and Chuang)能准确地反应雨滴形状,并将雨滴按照等效尺度大小建模。然后结合降水粒子的图像扫描探测技术,分析线阵CCD对非球形降水粒子的扫描过程和粒子尺度、下落末速度的测量计算模型,并提出一种新的雨滴体积计算方法;为验证体积计算模型的有效性,选择CCD扫描频率30 k Hz、像元数1024×1024,采样区域面积100 mm×100 mm对3 mm雨滴进行扫描仿真,体积仿真结果与BC模型积分体积对比,其误差约为0.2%左右。结果表明,当粒子产生倾斜角时,需要对正、侧面投影分情况进行讨论。在此基础上,对测量模型中可能存在的误差进行探讨,并讨论了相关减小误差的方法,以期对下一步进行雨滴体积计算模型实验室实测数据的验证及其他相关研究做指导。
基金supported by the National Natural Science Foundation of China (Grant Nos.50971011 and 10874006)Beijing Natural Science Foundation (Grant No.1102025)Research Fund for the Doctoral Program of Higher Education of China (Grant No.20091102110038)
文摘Scanning near-field acoustic microscope （SNAM） combines the ultrasonic detection technology with scanning near-field microscopy. The main characteristic of such microscope is that the acoustic wave is produced or detected in near-field area whether ultrasonic transducer acts as generator or detector. The resolution of SNAM can reach to nanometer scale. First, two typical SNAMs, scanning electron acoustic Inicroscope and scanning probe acoustic microscope, will be introduced in this paper. The working principle of our homemade SNAM based on a commercial scanning probe microscope will be reported, together with some recent results from this homemade SNAM.
