ISSN:0950-0839    

DOI:10.1080/09500838708205241

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The problem of the interaction between a superficial inhomogeneity and an elastic matrix subjected to both tractions and displacements is considered. It is shown that configurational force and torque act on the inhomogeneity due to the interfacial discontinuity of the elastostatic energy-momentum tensor. These force and torque can result in effective displacements of the inhomogeneity.

ISSN:0950-0839    

DOI:10.1080/09500838708205242

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Nous analysons en détail la propagation d'une micromacle dans l'alliage Cu 6,5 at.%Si à basse énergie de faute (γ∼8 mJ m−2) déformé ‘in situ’ a la température de 480 K dans un microscope électronique. Nous montrons que c'est le mécanisme d'intersection de micromacles qui contrôle la déformation et que cette intersection se produit par l'ouverture d'une fenětre sur la micromacle obstacle par les premières partielles de la micromacle incidente.

ISSN:0950-0839    

DOI:10.1080/09500838708205243

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

This Letter describes the cyclic behaviour and saturated dislocation structures of [011] copper single crystals, the main features of which are compared with those found in [122] crystals. A dislocation labyrinth structure has been observed. The results fall in line with the predictions of the dislocation interaction model of cyclic deformation.

ISSN:0950-0839    

DOI:10.1080/09500838708205244

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The perovskites, Y0.75La0.25Ba2Cu3O7and Y0.75Lu0.25Ba2Cu3O7, show high-Tcsuperconductivity (with zero resistance at or above 80 K), just as the parent compound YBa2Cu3O7. The Lu-substituted oxide, with the smallest unit-cell parameters, shows the highestTcbesides exhibiting a 100% Meissner effect.Hc1, in these oxides is around 25 mT, but theHc2, is large. The thermopower of YBa2Cu3O7shows a sharp transition to zero at the superconducting transition, reinforcing the bulk nature of the superconductivity. Preliminary studies show that ErBa2Cu3O7and Er0.5Y0.5Ba2Cu3O7are both high-temperature superconductors with zero resistance in the 82–90 K range.

ISSN:0950-0839    

DOI:10.1080/09500838708205245

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Surface-energy calculations have, in the past, been undertaken for a wide range of silicon surfaces with a degree of success that remains unclear. They suggest, for example, that the {113} face has a particularly high energy, but this is in direct conflict with the results of thermal etching. Simulated profile images of the theoretically derived silicon {113} surface and of a reconstruction based upon ‘rebonding at steps’ are here compared with recent observations. It is concluded that the former model may be discounted, while the latter, hitherto dismissed on theoretical energy grounds, gives good qualitative agreement with experiment. The practical implications of this are discussed briefly.

ISSN:0950-0839    

DOI:10.1080/09500838708205246

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

We extend our previous quantum-chemical calculations of the incorporation and motion of interstitial molecular oxygen in silica. Our results based on CNDO calculations for an α-quartz cluster show how the key energies vary with strainezzalong thecaxis and normal to it (exxyeyy). The results show the overall Arrhenius energy varies as (1·18 − 12·16[exx+eyy] − 5·14exx)eV, with the larger component (0·79−3·13[exx, +eyy] − 1·96ezz) eV being the activation energy for motion. We compare the predictions with experiment and discuss implications for silicon oxidation.

ISSN:0950-0839    

DOI:10.1080/09500838708205247

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

A small correction of the Lekner and Bishop (1973) model of electron mobility in simple fluids near the critical point brings it into agreement with the observations that electron localization does not occur in the critical region of argon, xenon or neopentane.

ISSN:0950-0839    

DOI:10.1080/09500838708205248

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor