Binding Energy between a Vacancy and an Atom of Third Element and their Effects on the Initial Aging of Aluminium Binary Alloys

Al-Zn, Al-Ag and Al-Cu base ternary alloys were studied by measurement of electrical resistivity. An approximate methods to estimate the binding energy between an atom of a third element and a vacancy was derived. The binding energy between a vacancy and an atom of Cu, Ag, Au, Be, Ca, Cd, In, Si, Ti, Ge, Zr, Sn, Pb or Mn was estimated to be 0.35, 0.28, 0.27, 0.32, 0.39, 0.28, 0.30, 0.33, 0.33, 0.43, >0.38 or <0.23 (±0.05) eV, respectively. The results may be summarized as follows: (I) The ratio of the time required to reach the maximum electrical resistivity in isothermal aging curves of the Al-Zn-X or Al-Ag-X ternary alloy to that in the Al-Zn or Al-Ag binary alloy may be inversely proportional to the ratio of the concentration of vacancies bound to Zn or Ag atoms immediately after quenching in the ternary alloy to that in the binary alloy. And also the ratio of initial rate of clustering for AI-Cu-X ternary alloy to that in the binary alloy may be inversely proportional to the ratio of the concentration of vacancies bound to Cu atoms immediately after quenching in the ternary alloy to that in the binary alloy. It is possible to deduce the binding energy between an atom of X element and a vacancy using this relations. (2) The effect of the valence of the solute element on the binding energy between an atom of a third element and a vacancy was remarkable. (3) The effect of the radius of an atom of the solute element on the binding energy is also observed, but this effect is smaller than that of the valence

Binding Energies between a Vacancy and a Cadmium, Indium or Tin Atom in Al-10wt % Zn, Al-3.0wt % Ag and Al-3.0wt % Cu Alloys

The changes of electrical resistivity of several alloys, that is, Al-10wt % Zn, Al-10wt % Zn-0.01wt % Cd, Al-10wt % Zn-0.01wt % In, Al-10wt % Zn-0.01wt % Sn, Al-3.0wt % Ag, Al-3.0wt % Ag-0.01wt % Cd, Al-3.0wt % Ag-0.01wt % In, Al3.0wt % Ag-0.0lwt % Sn, Al-3.0wt % Cu, Al-3.0wt % Cu-0.0lwt % Cd and Al-3.0wt % Cu-0.01wt % In, during isothermal aging after quenching were measured. The interactions between a vacancy and a cadmium, indium or tin atom in Al-10wt % Zn, Al-3.0wt % Ag and Al-3.0wt % Cu alloys were estimated. Binding energies obtained for Al-Zn, Al-Ag and Al-Cu base ternary alloys agree within experimental accuracy with each other

Binding Energies between a Vacancy and an Atom of Lead or Gold in Al-10wt % Zn Alloys

Binding energies between a vacancy and an atom of lead or gold were measured with the same method as those previously reported. The solid solubility of lead or gold in aluminium is very small, and the small quantity of precipitates are found along grain boundaries in this experiment. Therefore, it was not possible to determine the value of binding energy, but the lower limit of binding energy was estimated. The values of lower limit for Pb-Vacancy and Au-Vacancy binding energy were 0.38 eV and 0.35 eV, respectively

A corrigendum to "Games with imperfectly observable actions in continuous time"

Sannikov (2007) investigates properties of perfect public equilibria in continuous time repeated games. This note points out that the proof of the main theorem (Theorem 2) needs some corrections. I show that the main theorem holds as it is with suitable modifications of Lemmata 5 and 6

A corrigendum to "Games with imperfectly observable actions in continuous time"

Sannikov (2007) investigates properties of perfect public equilibria in continuous time repeated games. This note points out that the proof of the main theorem (Theorem 2) needs some corrections. I show that the main theorem holds as it is with suitable modifications of Lemmata 5 and 6

Specificity of cultured anterior pituitary cells in detecting corticotropin releasing factor(s): the effect of biologically active peptides and neurotransmitter substances on ACTH release in pituitary cell cultures.

Biologically active peptides and neurotransmitter substances were added to anterior pituitary cell cultures to examine the presence of corticotropin releasing factor (CRF)-like activity. Hypothalamic extract (HE) induced significant dose-related increase of ACTH, and the lowest effective dose was 0.01 HE/ml. Other tested substances including luteinizing hormone-releasing hormone, thyrotropin releasing hormone, melanocyte stimulating hormone release inhibiting factor, somatostatin, substance P, neurotensin, beta-endorphin. leu-enkephalin, met-enkephalin, bradykinin, norepinephrine, dopamine, serotonin, acetylcholine, histamine, gamma-amino butyric acid or gamma-hydroxy butyric acid showed no CRF-like activity. Relatively high doses of lysine vasopressin, arginine vasopressin and angiotensin II increased the release of ACTH in pituitary cell cultures, but the maximal ACTH response was markedly less than with HE. These results indicate that cultured anterior pituitary cells are sensitive and fairly specific in detecting CRF(s) comparing with other detecting procedures.</p

Effects of Quantum-Well Inversion Asymmetry on Electron-Nuclear Spin Coupling in the Fractional Quantum Hall Regime

We examine effects of inversion asymmetry of a GaAs/Al0.3Ga0.7As quantum well (QW) on electron-nuclear spin coupling in the fractional quantum Hall (QH) regime. Increasing the QW potential asymmetry at a fixed Landau-level filling factor (nu) with gate voltages suppresses the current-induced nuclear spin polarization in the nu = 2/3 Ising QH ferromagnet, while it significantly enhances the nuclear spin relaxation at general nu. These findings suggest that mixing of different spin states due to the Rashba spin-orbit interaction strongly affects the electron-nuclear spin coupling.Comment: 15 pages, 4 figure

PK- = 1 GeV/c での3He( K-,n )反応による K-pp束縛状態の探索

学位の種別:課程博士University of Tokyo(東京大学

A randomised, double-blind, placebo-controlled trial of tropisetron in patients with schizophrenia

<p>Abstract</p> <p>Background</p> <p>Cognitive deficits in schizophrenia are associated with psychosocial deficits that are primarily responsible for the poor long-term outcome of this disease. Auditory sensory gating P50 deficits are correlated with neuropsychological deficits in attention, one of the principal cognitive disturbances in schizophrenia. Our studies suggest that the α7 nicotinic acetylcholine receptor (α7 nAChR) agonist tropisetron might be a potential therapeutic drug for cognitive deficits in schizophrenia. Therefore, it is of particular interest to investigate the effects of tropisetron on the cognitive deficits in patients with schizophrenia.</p> <p>Methods</p> <p>A randomised, placebo-controlled trial of tropisetron in patients with schizophrenia was performed. A total of 40 patients with chronic schizophrenia who had taken risperidone (2 to 6 mg/day) were enrolled. Subjects were randomly assigned to a fixed titration of tropisetron (n = 20, 10 mg/day) or placebo (n = 20) in an 8-week double-blind trial. Auditory sensory gating P50 deficits and Quality of Life Scale (QLS), Cambridge Neuropsychological Test Automated Battery (CANTAB), and Positive and Negative Syndrome Scale (PANSS) scores were measured.</p> <p>Results</p> <p>In all, 33 patients completed the trial. Tropisetron was well tolerated. Administration of tropisetron, but not placebo, significantly improved auditory sensory gating P50 deficits in non-smoking patients with schizophrenia. The score on the rapid visual information processing (sustained visual attention) task of CANTAB was significantly improved by tropisetron treatment. Total and subscale scores of PANSS were not changed by this trial. QLS scores in the all patients, but not non-smoking patients, were significantly improved by tropisetron trial.</p> <p>Conclusions</p> <p>This first randomised, double-blind, placebo-controlled trial supports the safety and efficacy of adjunctive tropisetron for treatment of cognitive deficits in schizophrenia.</p