Supersymmetry of Hexabenzocoronene Torus

Hexabenzocoronene torus (HBCT) is a hypothetical torus-shaped network derived by properly connecting the nine pairs of peripheral carbon atoms of the hexabenzocoronene skeleton. The π-electronic structure of this hypothetical conjugated carbon network has an exceedingly high symmetry (supersymmetry) and is closely related to that of the graphite network. By using the group-theoretic technique developed by the authors it is shown that this 42 × 42 secular determinant of HBCT can be factorized into the product of 21 quadratic equations. A number of interesting mathematical properties of the supersymmetry of HBCT are introduced

EFFECTS OF ALUMINUM OVER-LAYER THICKNESS ON CHARACTERISTICS OF NIOBIUM TUNNEL-JUNCTIONS FABRICATED BY DC MAGNETRON SPUTTERING

We have fabricated Nb/AlOX/Nb Josephson tunnel junctions using a sputtering apparatus with a load-lock system. The junctions that had 50 mu m x 50 mu m area showed a V-m value (the product of the critical current and the subgap resistance at 2 mV) as high as 50 mV at a current density of 160 A/cm(2). Moreover, junctions having different thicknesses of the Al over-layer were concurrently fabricated on one wafer to study the dependence of the current-voltage characteristics on this Al over-layer. The I-V characteristics were also calculated by McMillan\u27s tunneling model and were compared with the measured I-V characteristics

シマネケン イワミ チホウ ニ サンスル テイヒンイ ネンド ゲンリョウ ノ セイシツ ト ゴウセイガワラ ハイド エノ リヨウ

The traditional Sekishu roofing-tiles have been made from the raw clays occurring in the Tsunodu formation of the Neogene age. These clays consist mainly of disordered kaolinite, quartz and feldspar, accompanied by a small quantity of mica clay minerals and halloysite. The properties of three types of low quality clays, two are of sediment origin and the one is red color altered granite, were investigated in order to utilize them as potential raw materials for the preparation of compound roofing-tile bodies, since the raw clays of good quality tend to be steeply exhausted. As a result, it was found that these clays have functional uses for making compound bodies, although they are lack in shaping ability, individually. The one of sedimentary clays, characterized by dark brown color owing to the accumulation of humic substances, is advantage to improve the plasticity of compound bodies, because it is rich in the finer particle-size fractions and contains a small quantity of smectite. The other one, abundant in quartz and feldspar with coarser particle size, found the uses as non-plastic material and fluxing material. The red color clay, in which gibbsite and halloysite form dominantly, resembles the existent raw clays in chemical composition and is characterized by remarkably small size-changes in firing. The compound body blended by the red color clay with the black color clay at the rate of 1:3 showed the thermal property about equal to that of the raw clays in present use for the roofing tiles

EFFECTS OF ALUMINUM OVER-LAYER THICKNESS ON CHARACTERISTICS OF NIOBIUM TUNNEL-JUNCTIONS FABRICATED BY DC MAGNETRON SPUTTERING

We have fabricated Nb/AlOX/Nb Josephson tunnel junctions using a sputtering apparatus with a load-lock system. The junctions that had 50 mu m x 50 mu m area showed a V-m value (the product of the critical current and the subgap resistance at 2 mV) as high as 50 mV at a current density of 160 A/cm(2). Moreover, junctions having different thicknesses of the Al over-layer were concurrently fabricated on one wafer to study the dependence of the current-voltage characteristics on this Al over-layer. The I-V characteristics were also calculated by McMillan's tunneling model and were compared with the measured I-V characteristics

Positron annihilation - ICPA-13

Proceedings of the 13th International Conference on Positron Annihilation, September, 2003