SJTU-1型医用超声诊断设备声输出测量系统的研制

本系统地研究了医用超声诊断设各声输出公布要求的国家标准GB16846—1997(idt.IEC61157—1992)中规定的主要指标的定义和测量方法，给出了相关的计算公式。介绍了为实施国标而研制的专用测量设备SJTU-1型医用超声设备声输出测量系统的工作原理、系统构成和技术性能。     

A Novel Method to Measure Acoustic Power of Focusing Transducer with Spherical Surface Based on Self-Reciprocity Theorem

A novel method to measure acoustic power of focusing transducer based on the self-reciprocity theorem of convergent spherical acoustic wave is proposed. The performance of this reciprocity method is compared with that of the radiation force balance (RFB) method and the admittance circle method. The average deviations of the reciprocity method from RFB in measurements of the acoustic power and the radiation conductance for a focusing transducer of 1.525 MHz are 7.5% and 3.6% respectively, and for another focusing transducer of 5.27 MHz,they are 1.7% and 1.1%. The measured radiation conductance deviation by the reciprocity method from the admittance circle method for the focusing transducer of 1.525 MHz is 7.9%. It presents encouraging results even in measuring low acoustic power level. The overall uncertainty of acoustic power measurement using the method is evaluated below 10%, and it has many advantages such as high signal-to-noise ratio, good stability and less interference of bubbles and environment.     

医用超声测量用PVDF探针形高频微型水听器的研制

本文叙述了用于医学超声测量的两种ＰＶＤＦ探针形高频微型水听器的设计特点，结构和它们的性能测量结果，最后介绍在非线性声学研究中的应用实例。     

薄壁压电陶瓷圆管机电参数的测定

依据导出的切向极化和径向极化压电陶瓷薄壁圆管无负载电导纳方程,给出由压电陶瓷圆管测量数据,计算出机电参数的方法、公式和步骤。实验测知压电陶瓷薄壁圆管的尺寸、密度、低频电容、最大导纳频率与最小导纳频率以及其它若干频率上的电导纳等,然后用给出的公式计算杨氏模量、泊松比、机电耦合系数、介电常数和压电常数等。运用这一方法,对若干实际圆管样品作出了测量和计算。     

MEASUREMENT AND CALCULATION OF ELECTROMECHANICAL PARAMETERS OF PIEZOCERAMIC THIN CYLINDRICAL TUBE TRANSDUCERS

On the basis of the electrical admittance equation for the unloaded tangentially and radiallypolarized piezoceramic thin circular cylindrical tube,the method and formulas,and the prognm forcalculating the electromechanical parameters from the measured data are presented.If the size,density,capcitance at low frequency,frequencies at maximum and minimum admittances near theradial resonant frequency and the longitudinal resonant frequency,etc.are known from themeasurement,then the Young's modulus,Poisson's ratio,electromechanical coupling coefficents,permitivity and piezoelectric constants can be calculated with the formulas given here.Practicalmeasurements and calculations for several samples have been carried out with this method.