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Tokyo Denki University is a private university in Adachi, Tokyo, Japan. The predecessor of the school was founded in 1907. It was chartered as a university in 1949 with Yasujiro Niwa as first president. Wikipedia.

Yabuuchi N.,Tokyo University of Science | Yabuuchi N.,Kyoto University | Yabuuchi N.,Tokyo Denki University | Kubota K.,Tokyo University of Science | And 5 more authors.
Chemical Reviews | Year: 2014

The material's abundance is a simple and clear reason as to why sodium ions are attractive as charge carriers for rechargeable batteries. It is also expected that potassium ions have a further smaller desolvation energy compared with the Li and Na systems in aprotic solvents. However, further energy sacrifice is also unavoidable for the potassium system due to heavy atomic weight. In addition to the oxides, a wide variety of crystal structures is known for polyanionic compounds and the structural chemistry of the Na system is much more complicated in comparison to the Li system. Na ions are apparently coordinated by four fluoride ions at bottleneck sites when the Na ions migrate across the perovskite-type framework structure.

Otsuka N.,Tokyo Denki University
Systems and Control Letters | Year: 2010

In this paper, disturbance decoupling problems without stability and with quadratic stability for switched linear systems are formulated in the framework of the so-called geometric approach. Firstly, necessary and sufficient conditions for the problem without stability to be solvable are given. Secondly, sufficient conditions for the problem with quadratic stability to be solvable are given. Further, for switched linear systems composed of two subsystems necessary and sufficient conditions for the problem with quadratic stability to be solvable are also investigated. Finally, an illustrative example is shown. © 2010 Elsevier B.V. All rights reserved.

Hatanaka M.,Tokyo Denki University
Bulletin of the Chemical Society of Japan | Year: 2011

Reaction profiles for catalytic urethanation are analyzed by DFT calculations. A well-known basic catalyst 1,4-diazabicyclo[2.2.2]octane (DABCO) activates alcohol molecules and accelerates the direct addition toward isocyanates. Self-catalysis by alcohols is also characterized as an accelerated direct addition. © 2011 The Chemical Society of Japan.

Hatanaka M.,Tokyo Denki University
Tetrahedron Letters | Year: 2013

Unusual instability of keto tautomers in polyphenols is theoretically analyzed. Apart from ordinary resonance energy and bond energy, it is shown that there should be additional keto instability originated from through-bond interactions between the true and pseudo π orbitals. The interactions are characteristic of non-bonding like amplitude pattern in the frontier π orbitals. The magnitude of instability is estimated to be 4 kcal/mol per carbonyl group by modern DFT calculations and experimental results. Copyright © 2012 Published by Elsevier Ltd.

Hatanaka M.,Tokyo Denki University
Theoretical Chemistry Accounts | Year: 2011

Stability criterion for organic ferromagnetism is derived from crystal orbital method. For a given flat-band system, there exists a unique set of Wannier functions localized near each unit cell, which should be symmetric with respect to the lattice vector. The set of Wannier functions minimizes the exchange integral of the system within the freedom of degeneracy. When each Wannier function spans common atoms between the adjacent cells, the system becomes ferromagnetic. On the other hand, when each Wannier function spreads only at one unit cell, the system becomes antiferromagnetic. The proof of this rule is given by variational principle. © 2011 Springer-Verlag.

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