Минералого-геохимические особенности почв в зоне воздействия хвостохранилищ Алтайского и Джидинского ГОКов

Выявление минералого-геохимических особенностей почв в зоне влияния хвостохранилищ горнодобывающих предприятий.Identification of the mineralogical and geochemical features of soils in the zone of influence of tailings of mining and refining plants

敗血症や癌悪液質で誘導される炎症性サイトカインに対する好中球枯渇化療法

平成9年度-平成11年度年度科学研究費補助金 (基盤研究(C)(2)　課題番号09671220) 研究成果報告

Bericht des Präsidiums 2000 - 2001

The measurement of grain boundary migration in pure Al bicrystals by X-ray continuous interface tracking is introduced. This method provides information on the mobility of specific grain boundaries without interfering with the process of migration. Moreover, the effect of hydrostatic pressure on grain boundary migration was investigated. Several topics of grain boundary motion relevant to microstructure and texture evolution by recrystallization and grain growth were addressed. It was found that the maximum growth rate misorientation changes with temperature from the exact ∑7 orientation relationship to a 40.50°<111> rotation. This behavior is of concern for recrystallization texture evolution. The effect of material purity on grain boundary migration is shown not to be confined to drag effects but also to involve changes of grain boundary structure. From the activation volume of grain boundary mobility it has to be concluded that at least <110> tilt boundaries move by cooperative motion (group mechanism) of atoms in the boundary

Grain boundary migration: misorientation dependence

Abstract The ability of grain boundaries (GB) to move has been found to be strongly dependent on crystallography, i.e. misorientation of the adjacent grains and orientation (inclination) of the GB in a crystal. Boundary mobility is rate-controlling in recrystallization and grain growth and thus, affects microstructure evolution and texture formation. This paper deals with recent advances in our understanding of misorientation and inclination dependence of grain boundary migration. © 2001 Elsevier Science Ltd. All rights reserved. A most important peculiarity of grain boundaries is their capillary driven motion technique, in which a curved GB ability to move. This grain boundary (GB) property has moves under the action of GB curvature, and the driving been found to be strongly dependent on grain boundary force p is provided by the GB surface tension g. Since the crystallography, i.e. misorientation of the adjacent grains true value of g is commonly not known, a reduced GB and orientation (inclination) of the GB in a crystal. Boundary mobility is rate-controlling in recrystallization [m / s], i.e. the same as the diffusion coefficient. An and grain growth and thus, affects microstructure evolution inherent feature of GB mobility is that it depends, apart and texture formation. Recent achievements in our underfrom the conventional thermodynamic variables (temperastanding of misorientation and inclination dependence of ture, pressure, etc.), on the misorientation of the adjacent grain boundary migration constitute the subject of this grains and GB orientation. A precise measurement and paper. thus, examination of the misorientation dependence of GB The mobility m is a quantitative measure of the kinetic mobility was made possible by tracking techniques of GB b properties of a grain boundary and thus, the principal migration in bicrystals. The distinctive properties of such parameter of the process of GB migration. It is defined as techniques are: controlled driving force, continuous track-GB velocity v per unit of driving force p: ing of GB displacement, accuracy and reproducibility of GB crystallography [**1]. As a first milestone, from v ] m 5 measurements with these techniques materials scientists b p became aware that properties of GBs with different A driving force for GB migration arises when a boundary misorientation can be essentially different. In particular, it displacement leads to a reduction of the total energy of the was established that GB mobility and its parameters are system. It is necessary to stress that the system need not be changing in a non-motonic way with the angle of mislimited to adjacent grains and a GB only, but may include orientation. external elastic, electrical or magnetic fields as well. There For special misorientations (low-S boundaries) the are two ways by which this driving force arises. The first activation enthalpy H of GB migration assumes a minim uses the free energy of a GB itself, the other utilizes a free mum. An example is shown i