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Béla Joós

Bio: Béla Joós is an academic researcher from University of Ottawa. The author has contributed to research in topics: Ion homeostasis & Vacancy defect. The author has an hindex of 20, co-authored 77 publications receiving 1636 citations. Previous affiliations of Béla Joós include Simon Fraser University & University of Maryland, College Park.


Papers
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Journal ArticleDOI
TL;DR: In this paper, a simple and rigorous analytic formula for the Peierls stress of a dislocation within the Peiers-Nabarro model was derived, which is both a generalization and a correction of the previously known formula valid only for wide dislocations.
Abstract: A simple and rigorous analytic formula is derived for the Peierls stress of a dislocation within the Peierls-Nabarro model. This is both a generalization and a correction of the previously known formula valid only for wide dislocations. Our formula is shown to have quantitative predictive capabilities, and to permit estimation of the Peierls stress directly from the generalized stacking fault energy surface, for both narrow and wide dislocations.

255 citations

Journal ArticleDOI
TL;DR: Using generalized stacking-fault energies obtained from first-principles density-functional calculations, a zero-temperature model for dislocations in silicon is constructed within the framework of a Peierls-Nabarro (PN) model.
Abstract: Using generalized stacking-fault (gsf) energies obtained from first-principles density-functional calculations, a zero-temperature model for dislocations in silicon is constructed within the framework of a Peierls-Nabarro (PN) model. Core widths, core energies, PN pinning energies, and stresses are calculated for various possible perfect and imperfect dislocations. Both shuffle and glide sets are considered. 90\ifmmode^\circ\else\textdegree\fi{} partials are shown to have a lower Peierls stress than the 30\ifmmode^\circ\else\textdegree\fi{} partials in accord with experiment.

226 citations

Journal ArticleDOI
TL;DR: A l'aide de cette propriete d'echelle, on construit les approximants analytiques et on discute du role des correlations.
Abstract: Calcul de la distribution P(L) des largeurs des terrasses L a basse temperature, pour le modele du decrochement des marches des terrasses (TSK) d'une surface a marches, en appliquant ce probleme au modele des fermions libres unidimensionnel. Dans cette approximation, la seule interaction energetique entre les marches est une repulsion des cœurs durs. On trouve une distribution hyperbolaidale avec une montee parabolique et une trainee (queue) gaussienne dont les formes asymptotiques sont representees. En representant P(L) en fonction de L/ , on obtient une courbe «universelle» presque independante de la largeur moyenne des terrasses . A l'aide de cette propriete d'echelle, on construit les approximants analytiques et on discute du role des correlations

82 citations

Journal ArticleDOI
TL;DR: From the general formalism simple fluctuation formulas for the stability criteria are deduced for systems in the canonical ensemble, for arbitrary stress, and it is shown that stability conditions in the Constant pressure ensemble are stronger than in the constant volume ensemble.
Abstract: Second-order elastic constants cannot be applied directly to the study of the mechanical stability of a stressed material. We derive general expressions for stability criteria by constructing appropriate thermodynamic potentials. For a system under isotropic initial stress, elastic stiffness coefficients which govern stress-strain relations can be used as stability criteria. However, for a system under anisotropic initial stress, stability criteria are different from either elastic constants or elastic stiffness coefficients. We show that stability conditions in the constant pressure ensemble are stronger than in the constant volume ensemble, i.e., a state can be stable in the constant volume ensemble but unstable in the constant pressure ensemble. From the general formalism simple fluctuation formulas for the stability criteria are deduced for systems in the canonical ensemble, for arbitrary stress. \textcopyright{} 1996 The American Physical Society.

79 citations

Journal ArticleDOI
TL;DR: Haller, B. Joos and L. M. Falicov Engineering and Technical Services as mentioned in this paper, Berkeley, California, USA 1979 Two-WEEK LOAN COP This is a L Prepar~d for the U.S. Department of Energy under Contract W-7405-ENG-48
Abstract: LBL -1 0144(!J Preprint SITY 0 CALIFO Submitted to Physical Review !3 ACCEPTOR COMPLEXES IN GERMANIUM: SYSTEMS WIT!l 7UNNELING HYDROGEN E. E. Haller, B. Joos and L. M. Falicov Engineering and Technical Services. Materials and Molecular Research Oi vision, Lawrence Berke 1 ey Laboratory, and Department of Physics. University of California, Berkeley November 1979 TWO-WEEK LOAN COP This is a L Prepar~d for the U.S. Department of Energy under Contract W-7405-ENG-48

76 citations


Cited by
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28 Jul 2005
TL;DR: PfPMP1)与感染红细胞、树突状组胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作�ly.
Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1(PfPMP1)与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员,通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

18,940 citations

Journal Article
TL;DR: In this article, a nucleosome-DNA interaction model was proposed to predict the genome-wide organization of nucleosomes, and it was shown that genomes encode an intrinsic nucleosomal organization and that this intrinsic organization can explain ∼50% of the in-vivo positions.
Abstract: Eukaryotic genomes are packaged into nucleosome particles that occlude the DNA from interacting with most DNA binding proteins. Nucleosomes have higher affinity for particular DNA sequences, reflecting the ability of the sequence to bend sharply, as required by the nucleosome structure. However, it is not known whether these sequence preferences have a significant influence on nucleosome position in vivo, and thus regulate the access of other proteins to DNA. Here we isolated nucleosome-bound sequences at high resolution from yeast and used these sequences in a new computational approach to construct and validate experimentally a nucleosome–DNA interaction model, and to predict the genome-wide organization of nucleosomes. Our results demonstrate that genomes encode an intrinsic nucleosome organization and that this intrinsic organization can explain ∼50% of the in vivo nucleosome positions. This nucleosome positioning code may facilitate specific chromosome functions including transcription factor binding, transcription initiation, and even remodelling of the nucleosomes themselves.

1,399 citations

Journal ArticleDOI
TL;DR: In this paper, a review of deformation twinning in nanocrystalline materials is presented, including deformation twins observed by molecular dynamics simulations and experiments, twinning mechanisms, factors affecting the twinning, analytical models on the nucleation and growth of deformations, interactions between twins and dislocations, and the effects of twins on mechanical and other properties.

1,015 citations

Book
01 Jan 2002
TL;DR: The cell is studied as a model for three-dimensional networks, and the role of Membrane undulations in these networks is examined.
Abstract: 1. Introduction to the cell Part I. Rods and Ropes: 2. Polymers 3. Two-dimensional networks 4. Three-dimensional networks Part II. Membranes: 5. Biomembranes 6. Membrane undulations Part III. The Whole Cell: 7. The simplest cells 8. Intermembrane forces 9. Dynamic filaments 10. Mechanical designs Appendix A. Animal cells and tissues Appendix B. The cell's molecular building blocks Appendix C. Elementary statistical mechanics Appendix D. Elasticity References Index.

880 citations

Journal ArticleDOI
TL;DR: The role of surface stress at solid surfaces in a vacuum environment and in contact with a liquid electrolyte in reconstruction, epitaxial growth and self-organization or stabilization of mesoscopic structures is critically reviewed in this paper.

705 citations