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A multi-layered nanoparticles optical disk has been developed for a jitter-free high-density data storage system. The disk has nano structures composed of 300-nm-diameter photosensitive particles and 30-nm-width non-photosensitive buffer rings around them. With the buffer rings into the nanoparticles disk, a conventional confocal microscope equipped with a low numerical aperture (NA) objective picked up a particle’s shape signal to generate a synchronous signal on its own. In the three-dimensional structured disk proposed, no electronically-produced reference signal is necessary for clock data recover (CDR); no jitter occurs in data decoding.

An optical disk storage composed of nanospheres with buffer rings is proposed for high density recording without jitter. Nonlinear organic dyes were doped in the nanospheres as recordable bits. A new process has been devised.

We succeeded in growing a single crystal of YbPd 5 Al 2 with the tetragonal structure. The temperature dependence of electrical resistivity and a small value of the coefficient A in the Fermi liquid relation ρ=ρ 0 + A T 2 suggest that the 4 f -electrons are well localized. A magnetic ordering was found at T o =0.19 K in the specific heat measurement. On the other hand, the magnetic entropy exhibits only 0.5 R ln 2 at T o , and the specific heat shows a long tail above T o .

We synthesized a new compound of CeRhGe 2 with the orthorhombic CeNiSi 2 -type structure. By measuring the electrical resistivity, magnetic susceptibility, magnetization, specific heat, and neutron scattering for single crystals, CeRhGe 2 was found to order antiferromagnetically below T N = 7.6 K with an ordered moment of 1.3 µ B /Ce oriented along the magnetic easy-axis of the c -axis. Similar measurements were also carried out for CePtSi 2 single crystals. From the experimental results of anisotropic magnetic susceptibility and magnetization, the crystalline electric field (CEF) scheme was obtained for CeRhGe 2 and CePtSi 2 , together with the similar compound CeNiGe 2 . Furthermore, we carried out pressure experiments by measuring the electrical resistivity of CePtSi 2 and CeRhGe 2 . In the quantum critical region where the Neel temperature becomes zero, we observed superconductivity in CePtSi 2 and most likely CeRhGe 2 , at 1.5 and 7.1 GPa, respectively. The upper critical field of CePtSi 2 was found ...

We succeeded in growing single crystals of cage-structure compounds RCd11 (R: La, Ce, and Pr) and precisely studied their low-temperature magnetic and electronic properties by measuring electrical resistivity, magnetic susceptibility, magnetization, specific heat, and the de Haas–van Alphen (dHvA) effect. We found antiferromagnetic ordering at 0.44 and 0.39 K in CeCd11 and PrCd11, respectively, and clarified the magnetic phase diagrams of the compounds. In addition, low-lying crystalline electric field (CEF) schemes were proposed from the specific heat results of both compounds. From the present study, the antiferromagnetic ordering in PrCd11 is found to be of the exchange-induced type with a singlet ground state. From the dHvA experiment, we detected small dHvA branches ranging from 7 � 10 5 to 2 � 10 7 Oe, which correspond to small Fermi surfaces. This is mainly due to a small Brillouin zone based on a large unit cell. Moreover, the dHvA frequencies and cyclotron masses are approximately the same among RCd11, revealing a localized character of 4f electrons in CeCd11 and PrCd11.

In this research, a jitter-free optical storage media with high density is realized by using nano-spheres as digital recording bits. The media has an arranged structure composed of 300 nm diameter polystyrene spheres on the thin PMMA film. The optical shape signal reflected from nano-spheres is scanned with a confocal laser scanning microscope. A pickup reconstruction signal including a clocksignal is measured from the optical shape signal. This storage device is expected as a jitter-free media because no electrically-produced clocksignal is necessary for the pickup procedure.

The investigation was performed to search the polluted materials in the street tree leaves between heavy and light traffic parts. The results obtained are as follows;1. There were no differences of the polluted materilas per day (dry weight) among the tree species in one month. As a general trends, they were more accumulated in July and August than the others. In comphor trees, materials per day (dry weight) were more accumulated in summer.2. In heavy traffic parts, materials were more accumulated than the others. Espesially, in August, acacia trees situated in naka-jincho (heavy traffic part) had the highest concentration of the polluted materials.3. From the loss of the organic materials by theburning method and the lead content in ash part of the polluted materilas, these were confirmed as a originated materials in motor-car gas.4. Almost of these materials (80-90%) were streamed out by the precipitation (20mm). But some ash parts (mineral materials) was remained in the leaves at the heavy traffic parts (naka-jincho, gobancho).5. In the individuals of the polluted meterials, the burning materials except of the tar had a higher content at the heavy traffic parts.6. From the lead contents in the street tree leaves, it was assumed that the air in the dense traffic of a main street were polluted by the motor-car gas.

Recent studies have demonstrated that Sox2-expressing stem/progenitor cells play roles in the pituitary cell turnover. Two types of niches have been proposed for stem/progenitor cells, the marginal cell layer (MCL) and the dense cell clusters in the parenchyma. Among them, the appearance of the parenchymal-niche only after birth indicates that this niche is involved in the cell turnover required for the postnatal pituitary. However, little is known about the roles of the parenchymal-niche and its regulation. The present study aimed to isolate pituitary stem/progenitor cells from the parenchymal-niche in the adult rat pituitary. Cell dispersion by stepwise treatment with proteases allowed the isolation of dense cell clusters. Immunocytochemistry demonstrated that clusters are universally composed of SOX2-positive cells, and most of them are positive for PROP1. Taken together with the anatomical analysis, we concluded that the isolated clusters are the parenchymal stem/progenitor cell (PS)-clusters, not the MCL-one. PS-clusters cultivated by serum-free overlay 3-dimensional culture maintained their stemness, and treatment with bFGF and EGF induced cyst-formation. Moreover, PS-clusters demonstrated some differentiation capacity with GSK3β-inhibitor treatment. Collectively, the present study demonstrates a simple method for isolating stem/progenitor cells from the parenchymal-niche, and provides tools to analyze the factors for regulating the pituitary niches.

本論文は、1923年9月に発生した関東大震災における朝鮮人虐殺事件を経験し生き延びた朝鮮人にとって、関東大震災朝鮮人虐殺がどのような出来事だったのかについて実証的に明らかにしようとしたものである。本論文の課題は、第一に、関東大震災朝鮮人虐殺を経験し生き延びた朝鮮人の生と記憶について。第二に、日朝間にまたがる関東大震災に対する日本の治安当局の対応。そして第三に、朝鮮人虐殺事件後、朝鮮社会にどのような影響を及ぼしたのか。以上の三点を明らかにすることである。, Doctor of Philosophy in Contemporary Asian Studies, Doshisha University