爆电换能脉冲大电流输出研究

 基于爆电换能原理,使用掺铌的PZT 95/5陶瓷组装换能器件,在垂直工作模式下,对爆电电源LRC电路响应进行了理论分析,并开展了脉冲大电流输出实验研究。实验采用多组PZT 95/5铁电陶瓷并联,利用平面波发生器作为冲击加载手段,获得了峰值5 kA以上的脉冲大电流,初始电流上升速率可达10~20 GA/s。实验结果与理论设计符合较好。     

镶嵌型宽波束换能器

本文描述了一种用于水下运载体上的宽波束换能器的设计方法和实验结果。分析了影响波束开角的因素及变化趋势。所建立的模型可以设计不同工作频率的宽波束换能器。     

The Hamming weight of the non-adjacent-form under various input statistics

The Hamming weight of the non-adjacent form is studied in relation to the Hamming weight of the standard binary expansion. In particular, we investigate the expected Hamming weight of the NAF of an n-digit binary expansion with k ones where k is either fixed or proportional to n. The expected Hamming weight of NAFs of binary expansions with large (≥ n/2) Hamming weight is studied. Finally, the covariance of the Hamming weights of the binary expansion and the NAF is computed. Asymptotically, these Hamming weights become independent and normally distributed. Communicated by Attila Pethő     

以有效值计算的热声键合PZT换能器阻抗分析

在热超声芯片键合过程中,PZT换能器阻抗是键合系统的一个重要的研究参数。本文在提取PZT换能器驱动电信号实部数据的前提下,采用连续加窗的有效统计值计算的广义阻抗表征整个键合周期内的PZT换能器阻抗变化,由此获得键合过程PZT换能器阻抗的动态变化规律。文中详细介绍了PZT换能器阻抗的试验方法,并分析了试验结果。     

一种用于应力测量的复合型超声波探头

为了在应力测量中更好地测量超声波的纵波声速和横波声速，提高测量的精度和准确性，本文研究了一种由两种不同频率的纵波晶片和两处偏振方向相互垂直的横波晶片组成的复合型超声波探头，研究了它的几种组合的发射与接怍ＭＡＳＯＮ等效电路图，并报道了它的一些实验结果。     

适用于计算机控制的一种新型铂电阻温度变送器电路

改造铂电阻温度变送器使之适用于计算机的采集与控制,进一步提高控温和显示精度,这是目前我国测温控温领域中的迫切任务。本文不仅给出了该变送器的电路,而且给出了具体的测量数据。     

Light Amplification in a New Light Transducer Combining an Organic Electroluminescent Diode with Photoresponsive Organic Pigment Film

Light amplification was successfully demonstrated in an all-organic light transducer based on hybridization of an organic electroluminescent diode and a perylene pigment film as an electron photoinjecting electrode. Amplification gain of photon conversion from red to red light reached 25 with the assistance of effective electron photoinjection due to large photocurrent multiplication in a perylene film. Optical switching behavior caused by feedback of output-light to the photoconductive layer was observed.     

测量冲击温度的六通道瞬态光学高温计

 研制了一台测量冲击载荷下材料光谱辐射的瞬态光学高温计。在可见光和近红外光谱范围内，把光源的热辐射取出六个波段进行测量。每个波段信号通过各自的光线传输，光电倍增管探测和示波器记录。系统的时间分辨率约为20 ns。冲击温度测量范围为2 400~9 000 K，测量误差小于3%。给出了以空气和NaI警惕为样品的若干爆轰实验结果。     

Ultrasonic imaging of solid surfaces using a focussed air-coupled capacitance transducer

A variety of small solid objects have been imaged in atmospheric air using a focussed, micromachined air-coupled capacitance transducer. The transducer, which was capable of generating and receiving ultrasound in air over a large frequency bandwidth (< 100 kHz 1.5 MHz) was employed in a pulse-echo arrangement such that generated waves reflected off the surface of the object before returning to the same transducer for detection. By raster scanning the transducer in a plane and recording the detected ultrasonic echo amplitude as a function of transducer position, images of object surfaces were obtained. As the transducer had been fitted with a micromachined Fresnel zone-plate, the ultrasonic waves could be focussed to a spot-size of 680 μm so as to provide images of high lateral resolution. One of the key factors in making the Fresnel zone-plate function effectively in these imaging applications involved the inclusion of a second aperture in front of the zone-plate. This additional aperture blocked the zone-plate's side-lobes and reduced the appearance of multiple (diffracted) images.     

螺栓紧固型纵振换能器设计考虑

本语文采用网络传输法分析了螺栓螺固型纵振换能器的设计方法，并考虑了换能器结构件的内部机械损耗和压电元件的电损耗，数值计算了换能器谐振特性及节面位置，结果与实验情况一致。