Optical-beam deflection was used to probe a focused sound field in water. A laser beam was deflected by ultrasonic waves radiating from a concave transducer at 2.1 MHz under conditions in which that the sound wavelength is larger than the laser beam width. The deflected signal was detected with a position-sensitive photodiode, yielding a waveform that was the time derivative of the sound pressure. Scanning the laser beam in the propagation and radial directions, we obtained a map of the focused sound field. The results were compared with those from hydrophone measurements and theoretical calculations. The comparison showed qualitative agreement, and the observed difference was explained by the optical integrated effect over a range of interaction between the laser light and ultrasound. The amplitude of the maximum pressure estimated from the deflection angle was roughly in agreement with that obtained from the hydrophone method.

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The pericyclic reactions of 2,5-bis(methoxycarbonyl)-3,4-diphenylcyclopentadienone (1a) with both allylic and propargylic amines have been investigated. The reaction proceeded via initial formation of the 1,4 adducts followed by the ene cyclization and/or sequential pericyclic reactions depending upon the structures of the amines. The reaction of 1a with diallylamine (2a) gave the tetracyclic compound (3a). On the other hand, the reaction of 1a with 2-propynylamine (2c) gave exclusively the bicyclic compound (5c). In the reactions with the secondary 2-propynylamines (2d,e), the tetracyclic compounds (3d,e) were exclusively formed. The reactions of 1a with alpha-branched primary 1,1-dialkyl-2-propynylamines (2f,g) gave mixtures of 3- and 5-type compounds. The tetracyclic compounds 3 were formed from the intramolecular [4+2]pi cycloadditions of the [1,5]-sigmatropic rearrangement products of the 1,4 adducts of 1a and 2, followed by the [1,5]-sigmatropic rearrangement of hydrogen and dehydrogenation. The bicyclic compounds 5 were derived from the [2pi+2pi+2sigma] reaction of the 1,4 adducts of 1a and 2. The one-pot multistage sequential pericyclic reactions were discussed on the basis of the X-ray crystallographic structures and the MO calculation data.

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In pulse ECM, it has been found that the low-level voltage of the applied pulse influences the tool electrode wear and the machining accuracy. To attain a higher machining accuracy, the relationship between the low-level voltage and the machining accuracy was experimentally investigated in this study. It was found that a low-level voltage higher than 0V not only prevents tool electrode wear, but also improves the machining accuracy. In addition to the low-level voltage, the influence of the tool materials on the machining speed was also investigated. It was found that the different optimal low-level voltage depends on the tool material.