This paper describes a new positioning control system with one degree of freedom. The system consists of positioning feedback and pneumatic pressure control. We report on the experimental results of the system and analysis of it. Obtained conclusions are as follows ; (1) The model of the system is approximated by third-order system. (2) This experimental device enables 1(μm) order's control of within 1(%) error. (3) The static stiffness of the device is about 70(kg/μm). (4) The bandwidte which is characteristic of the frequency response becomes about 20(Hz). (5) The natural frequency of the controlled object is 500(Hz) and the damping ratio is 0.03.

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We made the fabrication of a now mixer using thin film Josephson-junction which is called the quaisi planner type. The junction was developed by Dr.OTA at the Institute of Physical and Chemical Research. We designed the mixermount that was able to be changed with many matching section in order to match RF and IF coupling for the junction. At the experiment, the signal frequency of 112.0GHz and the local frequency of 110.7GHz were used through a ringfilter. From this result, a loss of the convertion for the mixer was poor but we got many sujestions to upgrade the sensitivity for the mixer of milimeter wave.

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[in Japanese]

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The purposes of this research are to make a cooled receiver at 230GHz, to examine its efficiency and to obtain a key for the realization of low noise receiver at submillimeter wavelength. Thus the most significant point of this research is a trial which enables the application at submillimeter range. (1) Since it is difficult at submillimeter range to obtain high local oscillator power, we used a diode with epitaxial layer of less than 1000A for the mixer. As a result, we got the conversion loss of 9dB at the low input power of -5dBm, and this value is good enough for the utility. (2) We used the gaussian beam mode as the transmission system to decrease the transmission loss. And the frequency mixing by beamsplitter was also tried. The residuary loss of less than 2.4dB is enough for utility. (3) The multiplier which we tried to make as a source of local oscillator shows the conversion loss of 12dB, and we can tell the realization in the near future. (4) The cryostat that we made has an ability to be cooled down to 25K even if we settle two mixers in it. The problem that it is a little unstable for heat cycles. But the stabilization is possible by the improvement of the FET amplifier etc. In conclusion, we could obtain a good prospect for the realization of submillimeter low noise receiver.

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[in Japanese]

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The distribution of chlorophyll a involved in leaves of spinach, camellia and hibiscus is investigated by studing the fluorescence (685nm) intensity of in vivo chlorophyll a. In vivo chlorophyll a is excited by T. E. nitrogen laser radiation at 337.1 nm and organic dye laser radiation at 420nm. The intensity of the fluorescence is proportional to the amount of chlorophyll a (50μg/l〜10mg/l). The fluorescence intensity increases with the growth of plants and the back of the leaf has an excess of chlorophyll a compared with the surface. Experimental technique and result are discussed in detail.

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It is imperative that the hurdler sprint between hurdles. With the hurdles spaced 8.5m apart, the hurdler covers about 3.1m in clearing the hurdle and about 5.4m in the three strides between hurdles. The average of 1.8m per stride presents no problem to a mature athlete who is an experienced hurdler. But to many beginners this is a major problem. One of the most difficult tasks for the beginner is to develop a correct and consistent step pattern between hurdles. Some beginners have to use a loping rhythm between hurdles in order to cover the distance in three strides. This action is often helpful during the learning period but it must be replaced by an even three step sprint before the hurdler can perform well. A point to be emphasized is that the trail leg, as it clears the hurdle, must be whipped forward into a full running stride.

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[in Japanese]

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[in Japanese]

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