It could particularly improve the health of the elderly and impoverished , people who often do n ' t have access to routine health care , bright said . as well , doctors could use it to filter out possible diagnoses and cut down on costly medical tests 它还能改善人们，特别是老年人和贫困人口的健康状况，因为这部分人一般不可能定期去做体检，而利用这种仪器滤出病因还可以省去昂贵的检查费用。
The following is the main works and conclusions of this thesis . the novel upfc needs high power rate because it is generally used in high voltage transmission lines . after studied high - power converters and the literatures of upfc , the main circuit topology of novel upfc base on diode - clamping multilevel inverter is presented and the principle of using novel upfc to eliminate zero sequence and negative sequence currents is analyzed 本文所做的主要工作及得出的主要结论如下：由于upfc一般用于高压输电线，其功率等级要求很高，在综合研究大功率变换器和upfc现有文献的基础上，提出了基于二极管箝位多电平变换器的新型upfc的主电路拓扑，分析了用其来滤出高压输电线非全相运行时所产生的零序和负序电流的原理。
First , a new method of ultrasound - modulated optical tomography with real - time fast fourier transformation ( fft ) is reported to improve the detection sensitivity and snr . by discriminating ultrasound modulated information carried by scattering photons , the tomographic images of the biological tissue simulating media and a buried object are reconstructed with fft spectral intensity 1 、用实时快速fourier变换( fft )和聚焦超声调制的光学层析术以增加探测灵敏度和信噪比，用fft实时地将调制光光信号滤出，用其谱强度重建图像。
