Production of Ultrahigh Magnetic Fields by Explosive-Driven Flux Compression

Magnetic fields exceeding 1 MOe are reproducibly generated by a flux compression method using a cylindrical metal liner and high explosives. Some new devices are employed for simultaneous initiation of the cylindrical explosive on its outer surface. Detailed measurements are made on the dependence of the liner velocity on the mass ratio of liner and explosive. The results are consistent with an analysis based on the theory of detonation

Shock Compression Experiments in Solids using High Explosives

Small-scale explosive plane wave generators, 40-78 mm in diameter, are developed to perform solid state experiments at shock pressures up to 1 Mbar. Techniques for determining the shock compression curve are described in detail, especially in the case where a phase transformation occurs at a high pressure

Shock Compression of Titanium Monoxide up to 600 kbar(Physics)

Hugoniot data were obtained for titanium monoxide TiO_x (x=0.84, 1.06, and 1.28), up to about 600 kbar by shock wave compression. A small explosive lens system was used for the purpose of generating plane shock waves. Shock velocities and free surface velocities were measured by means of an electric pin-contactor method ; the shock state was computed on the basis of free surface approximation. Regardless of the values of x, the compounds TiO_x were shown to be extremely incompressible even in this ultrahigh pressure region ; no evidence was found for significant filling of vacancies

Modifed Minimum Classification Error Learning and Its Application to Neural Networks

A novel method to improve the generalization performance of the Minimum Classification Error (MCE) / Generalized Probabilistic Descent (GPD) learning is proposed. The MCE/GPD learning proposed by Juang and Katagiri in 1992 results in better recognition performance than the maximum-likelihood (ML) based learning in various areas of pattern recognition. Despite its superiority in recognition performance, as well as other learning algorithms, it still suffers from the problem of "over-fitting" to the training samples. In the present study, a regularization technique has been employed to the MCE learning to overcome this problem. Feed-forward neural networks are employed as a recognition platform to evaluate the recognition performance of the proposed method. Recognition experiments are conducted on several sorts of data sets

Reports of studies supported by Grant-in-Aid for Research from the Graduate School of Biosphere Science, Hiroshima University

基盤研究サポート Grant-in-Aid for Fundamental Research ・環境ウイルスのキャラクタリゼーションに関する基礎研究…中井敏博 ・ウシの行動反応と気質関連遺伝子多型との関係…豊後貴嗣 ・クラスター構造の根を形成する植物の低リン適応特性の解明…和崎

Vortex Imaging in the pi-Band of Magnesium Diboride

We report scanning tunneling spectroscopy imaging of the vortex lattice in single crystalline MgB2. By tunneling parallel to the c-axis, a single superconducting gap (Delta = 2.2 meV) associated with the pi-band is observed. The vortices in the pi-band have a large core size compared to estimates based on Hc2, and show an absence of localized states in the core. Furthermore, superconductivity between the vortices is rapidly suppressed by an applied field. These results suggest that superconductivity in the pi-band is, at least partially, induced by the intrinsically superconducting sigma-band.Comment: 4 pages, 3 figure

Semi-dynamic traffic assignment model with mode and route choices under stochastic travel times

Transportation network conditions vary significantly during the course of a day. In many urban areas, public transit and (private) automobiles constitute the actual forms of transportation that use such networks. Public transportation by rail is more reliable than by automobiles or buses; therefore, ordinary static and deterministic traffic assignment models with combined mode and route choices may not be suitable to assess a transportation network that includes public railways. Moreover, within-day dynamics and reliability need to be incorporated in such a model. In this paper, we use a semi-dynamic traffic assignment model that considers within-day dynamics by improving the static traffic assignment model. In addition, stochastic travel times are incorporated into the model. Thus, we propose a semi-dynamic traffic assignment model with mode choice between public transit and automobiles, route choice with stochastic travel times, and an accompanying computing algorithm. This model enables us to assess within-day dynamics of transportation networks and travel time reliability of public railways. Copyright © 2012 John Wiley & Sons, Ltd

Comparison of Bacterial Flora in a Methane Fermentation Plant in Field Science Center at Tohoku University and Bovine Rumen Used as the Plant Microbial Resource by 16S rRNA Gene Sequencing

Poster Sessio

Scanning Tunneling Spectroscopy on Single Crystal MgB2

We report on the results of scanning tunneling spectroscopy measurements on single crystals of Mg2. Tunneling was performed both parallel and perpendicular to the crystalline c-axis. In the first case, a single superconducting gap (Delta_pi = 2.2 meV) associated with the pi-band is observed. Tunneling parallel to the ab-plane reveals an additional, larger gap (Delta_sigma ~ 7 meV) originating in the highly two-dimensional sigma-band. Vortex imaging in the pi-band was performed with the field and tunnel current parallel to the c-axis. The vortices have a large core size compared to estimates based on Hc2, and show an absence of localized states in the core. Furthermore, superconductivity between the vortices is rapidly suppressed by an applied field. A comparison to specific heat measurements is performed.Comment: 12 pages, 7 figs. Submitted to Physica