Abstract: An ultrasonic probe includes a first group of one or more piezoelectric elements extending concentrically, and a second group of one or more piezoelectric elements extending concentrically and extending outward of the elements in the first group. The elements in the first and second groups form a front surface via which ultrasonic wave is transmitted and received. The elements in the first and second groups are separated by predetermined gaps. Areas of the respective elements in the second group over the front surface are substantially equal to each other within an accuracy corresponding to areas of the gaps over the front surfaces. Areas of the respective elements in the first group over the front surface are substantially equal to half the areas of the respective elements in the second group within an accuracy corresponding to the areas of the gaps.

Abstract: An ultrasonic wave diagnostic apparatus having an array of electro-acoustic transducer elements and respective channels for supplying drive signals to the electro-acoustic transducer elements and amplifying received echo signals from these elements, with the respective overall gains of the channels being controlled by corresponding values of weighting data. A set of mutually independent D/A converters, smaller in number than the number of electro-acoustic transducer elements, produce weighting data for respective ones of the channels that are spaced apart by a fixed number of channels. Respective interpolated values of weighting data for the remaining channels are derived by analog operations executed upon each of successive pairs of D/A converter outputs.

Abstract: A magnetic amorphous alloy having a compositional formula(Co.sub.100-y Fe.sub.y).sub.100-x Zr.sub.100-w Nb.sub.w).sub.xin which 5.ltoreq.x.ltoreq.10, 0.5.ltoreq.y.ltoreq.4, and 20.ltoreq.w.ltoreq.90.