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Nagasaki, Japan

Nagasaki Institute of Applied Science is a Japanese university located in the city of Nagasaki, Nagasaki Prefecture, Japan. Its nickname is Sōkadai and its public abbreviation is Chōsōdai. Wikipedia.

Nakata K.,Nagasaki Institute of Applied Science | Nakata K.,Tokyo Keizai University | Zschokke S.,University of Basel
Proceedings of the Royal Society B: Biological Sciences | Year: 2010

Almost all spiders building vertical orb webs face downwards when sitting on the hubs of their webs, and their webs exhibit an up-down size asymmetry, with the lower part of the capture area being larger than the upper. However, spiders of the genus Cyclosa, which all build vertical orb webs, exhibit inter-and intraspecific variation in orientation. In particular, Cyclosa ginnaga and C. argenteoalba always face upwards, and C. octotuberculata always face downwards, whereas some C. confusa face upwards and others face downwards or even sideways. These spiders provide a unique opportunity to examine why most spiders face downwards and have asymmetrical webs. We found that upward-facing spiders had upside-down webs with larger upper parts, downward-facing spiders had normal webs with larger lower parts and sideways-facing spiders had more symmetrical webs. Downward-facing C. confusa spiders were larger than upward-and sideways-facing individuals. We also found that during prey attacks, downward-facing spiders ran significantly faster downwards than upwards, which was not the case in upwardfacing spiders. These results suggest that the spider's orientation at the hub and web asymmetry enhance its foraging efficiency by minimizing the time to reach prey trapped in the web. © 2010 The Royal Society.

Kato T.,Nagasaki Institute of Applied Science
Synthetic Metals | Year: 2011

The essential role of the phonon- and photon-coupled interactions in the electron pairing in the macroscopic sized conventional superconductivity is investigated by comparing the conventional superconductivity in the macroscopic sized materials with the nondissipative diamagnetic currents in the negatively charged small sized molecules such as cyclopentadiene monoanion (5an -) and cyclobutadiene dianion (4an 2-). The nondissipative diamagnetic currents in the negatively charged small sized molecules such as 5an - and 4an 2- cannot be explained by the Bardeen-Cooper-Schrieffer (BCS) theory because attractive phonon-coupled interactions between two electrons (V 6π,N,BCS,phonon,e-e) are zero and direct electron-electron repulsion (V 6π,N,BCS,repulsive,e-e) becomes very large. However, these phenomena in 5an - and 4an 2- can be well explained by the photon-coupled interactions between all nuclei and electrons. The phonon-coupled interactions (V phonon,e-e) play an essential role in the forming of the closed-shell electronic structures with finite valence-conduction band gaps, in which two electrons occupying the same orbitals with opposite momentum and spins become stable, and the photon-coupled interactions (V macro,photon,N,j,σ) play an essential role in attractive interactions between these two electrons. Because of the photon-coupled interactions as well as the phonon-coupled interactions, electron pairs can be formed in the macroscopic sized materials, and the conventional superconducting states can appear below the superconducting critical temperature (T c). Our molecular perspective suggested in this article is compared with the BCS theory, and the reason why the conventional superconductivity has been excellently explained by the BCS theory is also discussed. © 2011 Published by Elsevier B.V.

Kato T.,Nagasaki Institute of Applied Science
Journal of Physical Chemistry C | Year: 2011

The dependence of dimensionless electron-phonon coupling constants (λx), which play an important role in electrical conductivity and spectroscopy, on doped carriers are systematically discussed in the fractionally charged (-3.00 ≤ x ≤ -2.00) polyacene molecular crystals. The λx values for x (-2.86 ≤ x ≤ -2.71) are much larger than the λ-3.00 value. This is because the density of states at the Fermi level (NNM,intra (εF)x) values of 8 (states per molecule) for x (-2.86 ≤ x ≤ -2.71) are estimated to be much larger than the NNM,intra (εF) -3.00 value of 2 (states per molecule). In general, the λx value becomes very large if 0.50-1.00 charge of carrier with respect to the closed-shell electronic states can be doped. © 2011 American Chemical Society.

Kato T.,Nagasaki Institute of Applied Science
Journal of Physical Chemistry C | Year: 2013

We investigate the vibronic stabilization energy (Δvib,-x) in aromatic 1,2:8,9-dibenzopentacene (Kx30dba) by comparison with electronic properties of aromatic hydrocarbons such as picene (K 322ph). Approximately twice larger value of the density of states at the Fermi level (N(εF)-x) for K3.1730dba than that for K330dba is the main reason why the experimental Δvib,-x value of 28.2 K for K3.1730dba is much larger than that of 7.4 K for K330dba. Approximately 5.1-5.6 and 4.3-4.8 times larger N(εF)-x values reproducing the Δvib,-3.45 values of 33.1 and 21.3 K, respectively, for K 3.4530dba than that reproducing the Δvib,-3.00 value of 7.4 K for K330dba are the main reasons why the Δvib,-3.45 values of 33.1 and 21.3 K for K3.4530dba are much larger than the Δvib,-3.00 value of 7.4 K for K 330dba. The molecular crystals of possible minimum sized molecules, with small charges, in which the stable fractionally charged (±0.50∼ ± 1.00 (in particular, ±0.57∼ ±0.86)) states with respect to the closed-shell electronic states can be realized, are the best candidates for large vibronic stabilization energies. © 2013 American Chemical Society.

Kato T.,Nagasaki Institute of Applied Science | Kambe T.,Okayama University | Kubozono Y.,Okayama University
Physical Review Letters | Year: 2011

Superconductivity was recently discovered in solid potassium-intercalated picene (K322ph), in which the picene molecule becomes trianionic (22ph3-). In this Letter, we conduct a theory-based study of the superconductivity of 22ph3- within the framework of BCS theory. We estimate the density of states N(εF) on the Fermi level to be 2.2 states per (eVmoleculespin) by using the theoretical intramolecular electron-phonon coupling lx and the experimental superconducting transition temperature Tc of 18 K. The theoretical value is consistent with the 1.2 states per (eVmoleculespin) determined experimentally for K322ph with Tc=18K, indicating the validity of our theoretical treatment and the electron-phonon mechanism for superconductivity. The predicted lx, 0.206 eV, for 22ph3- is larger than any value reported for organic superconductors, so picene may have the largest lx among the superconductors reported so far. © 2011 American Physical Society.

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