Abstract: An ink-jet recording head comprises a plurality of liquid flow paths having discharge openings for discharging an ink, and a plurality of thermoelectric transducers provided for each liquid flow path in order to discharge the ink, wherein, a frontward thermoelectric transducer located on the discharge opening side is so provided that, when the ink is discharged by the frontward thermoelectric transducer alone, a value of (discharge velocity v/discharge quantity Vd) with respect to a distance OH extending from an end of its discharge opening side to the discharge opening is at a distance OH of the first region in a regional classification into a first region in which the value of v/Vd increases with a decrease in the distance OH and a second region in which it comes to be substantially constant with an increase in the distance OH.

Abstract: A high-toughness ZrO.sub.2 sintered body having a stress-induced transformation ratio of 25% or more, which consists essentially of 40-90 volume % of ZrO.sub.2 containing 0.1-3 mol % of Nd.sub.2 O.sub.3 and 0.5-3.5 mol % of Y.sub.2 O.sub.3 as stabilizers of the crystal structure of ZrO.sub.2, and 10-60 volume % of at least one of Al.sub.2 O.sub.3, SiC, TiC, B.sub.4 C and TiB.sub.2.

Abstract: A superfinishing machine using lapping film applied in superfinishing of the surface to be polished of the work which is rotated or turned reciprocally. The rotating direction of a pair of take-up reels for lapping film is changed over and controlled by the driving changeover means, and in cooperation with this changeover control, the follower friction wheels becoming the driven side are controlled by braking means. As a result, the whole grain surface of the lapping film can be used effectively. Besides, excessive withdrawal of the lapping film can be effectively prevented. There is also pressing means for pressing the lapping film against the surface to be polished of the work, so that high-precision polishing along the contour of the surface is realized.

Abstract: A connection apparatus mainly comprises a gas-tight container one surface of which is made of a film, a gas supply source for filling the container with a gas at a predetermined pressure, and a heat source. Two substrates, at least one of which is flexible, are tightly supported on the film surface of the container in such a manner that electrodes or terminals formed on the both substrates confront with each other. The gas pressure in the container is increased to the predetermined value, thereby to tightly contact the electrodes formed on the both substrates with each other. Thereafter, the heat source is enabled to melt the electrodes and to electrically connect the two substrates with each other.