scholarly journals Formation mechanisms of magnetic bubbles in an M -type hexaferrite: Role of chirality reversal at domain walls

2016 ◽  
Vol 94 (22) ◽  
Author(s):  
H. Nakajima ◽  
A. Kotani ◽  
K. Harada ◽  
Y. Ishii ◽  
S. Mori
Keyword(s):  
Domain Walls ◽  
Formation Mechanisms

Regeneration and pattern formation in planarians. II. and role of cell movements in blastema formation

Development ◽  
1989 ◽  
Vol 107 (1) ◽  
pp. 69-76 ◽  
Author(s):  
E. Salo ◽  
J. Baguna
Keyword(s):  
Pattern Formation ◽  
Cell Movement ◽  
Formation Mechanisms ◽  
Blastema Formation ◽  
Chromosomal Markers ◽  
Undifferentiated Cells ◽  
Local Cell ◽  
Number Of Cells ◽  
Wound Epithelium

In planarians, blastema cells do not divide, and growth blastema is thought to result from the steady wound epithelium, of undifferentiated cells produced in the stump. However, whether these cells come only sources or whether cells placed far from the wound can participate, after long-range migrations, in the still uncertain. To study this problem, we have parameters of the process of regeneration: cell growth; number of cells produced by mitosis in the wound (postblastema); and rates of movement undifferentiated cells using grafting procedures with chromosomal markers. The results show that: (1) cells area spread (move) at higher rates than cells placed (90–140_mday-1 versus 40–50_mday-1); (2) cells than 500_m from the wound boundary are hardly 5-day-old blastemata; and (3) the number of cells within a 200–300_m postblastema area around the wound explain, provided their rates of movement are taken increasing number of blastema cells. From this, it is blastema cells in planarians originate from local mitotic activity jointly with local cell movement postblastema area around the wound match the blastema cells during regeneration. The implications for blastema growth and pattern formation mechanisms

scholarly journals A Molecular Candle Where Few Molecules Shine: HeHHe+

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2183
Author(s):  
Ryan C. Fortenberry ◽  
Laurent Wiesenfeld
Keyword(s):  
Mass Spectrometry ◽  
Hydrogen Atom ◽  
Photon Emission ◽  
Decisive Role ◽  
Zero Point ◽  
Formation Mechanisms ◽  
Cold Plasmas ◽  
The Universe ◽  
Marked Stability

HeHHe + is the only potential molecule comprised of atoms present in the early universe that is also easily observable in the infrared. This molecule has been known to exist in mass spectrometry experiments for nearly half-a-century and is likely present, but as-of-yet unconfirmed, in cold plasmas. There can exist only a handful of plausible primordial molecules in the epochs before metals (elements with nuclei heavier than 4 He as astronomers call them) were synthesized in the universe, and most of these are both rotationally and vibrationally dark. The current work brings HeHHe + into the discussion as a possible (and potentially only) molecular candle for probing high-z and any metal-deprived regions due to its exceptionally bright infrared feature previously predicted to lie at 7.43 μ m. Furthermore, the present study provides new insights into its possible formation mechanisms as well as marked stability, along with the decisive role of anharmonic zero-point energies. A new entrance pathway is proposed through the triplet state ( 3 B 1 ) of the He 2 H + molecule complexed with a hydrogen atom and a subsequent 10.90 eV charge transfer/photon emission into the linear and vibrationally-bright 1 Σ g + HeHHe + form.

X-Ray Diffraction Applied to the Study of Defects in Surfaces

1984 ◽  
Vol 41 ◽  
Author(s):  
I. K. Robinson ◽  
K. L. D'amico
Keyword(s):  
Long Range ◽  
Domain Walls ◽  
Surface Structures ◽  
Long Range Order ◽  
X Ray Diffraction ◽  
X Ray ◽  
Line Defects ◽  
Reconstructed Surface ◽  
Regular Arrays

AbstractThe role of x-ray diffraction in characterising defects in crystals is reviewed briefly. It is most sensitive to the presence of plane defects which destroy the long-range order. The same argument is shown to apply to line defects in surface structures. Two recent glancing incidence x-ray diffraction experiments provide contrasting examples: randomly distributed steps are found in the Au(110) reconstructed surface, while regular arrays of domain walls modify certain phases of krypton monolayers physisorbed on graphite substrates.

Formation Mechanisms of ZnO Nanowires: The Crucial Role of Crystal Orientation and Polarity

2013 ◽  
Vol 117 (40) ◽  
pp. 20738-20745 ◽  
Author(s):  
Sophie Guillemin ◽  
Laetitia Rapenne ◽  
Hervé Roussel ◽  
Eirini Sarigiannidou ◽  
Georges Brémond ◽  
...  
Keyword(s):  
Crucial Role ◽  
Crystal Orientation ◽  
Zno Nanowires ◽  
Formation Mechanisms

METAL ATOMS IN CARBON NANOTUBES AND RELATED NANOPARTICLES

2001 ◽  
Vol 15 (31) ◽  
pp. 4037-4069 ◽  
Author(s):  
F. BANHART ◽  
N. GROBERT ◽  
M. TERRONES ◽  
J.-C. CHARLIER ◽  
P. M. AJAYAN
Keyword(s):  
Carbon Nanotubes ◽  
Tight Binding ◽  
Formation Mechanisms ◽  
Production Methods ◽  
Metal Atoms ◽  
In Situ Electron Microscopy ◽  
State Of Research ◽  
Walled Carbon Nanotubes

The paper reviews the present state of research in the field of metal-carbon nanocomposites and the interaction of metal atoms with graphitic structures. Metal crystals can be encapsulated within graphitic shells of cylindrical, spherical, or other geometry. Various chemical and physical production methods to generate metal containing carbon nanotubes and possible microscopic formation mechanisms are presented. In this context, the role of metals as catalysts in the formation of single-walled carbon nanotubes is discussed. The interaction of metal atoms with the graphitic lattice is of particular interest. In situ electron microscopy is used to study the behaviour of individual metal atoms in a graphitic lattice. Furthermore, novel nanostructures can be generated under electron irradiation. Finally, an overview of theoretical studies using molecular dynamics and tight binding calculations of the carbon-metal interaction is given.

scholarly journals Mechanisms of Formation of Human Culture in Education

2017 ◽  
Vol 52 (1) ◽  
pp. 9-20
Author(s):  
Helen B. Baboshina
Keyword(s):  
Research Problem ◽  
Formation Mechanisms ◽  
Positive Role ◽  
Experimental Realization ◽  
Human Culture ◽  
Cultural Concepts ◽  
Culture Formation ◽  
Mechanisms Of Formation ◽  
The Ideal

Abstract The relevance of the research problem lies in the necessity of an axiological approach to the formation of the personality in education and the task of strengthening the ideal image of the function. The aim of this article is studying and understanding the culture of personality formation mechanisms in relation to future specialists. The leading method of research was the theoretical analysis of philosophical and cultural approaches to the cultural formation of the personality and to the content of human culture. Content analysis was based on the philosophical and cultural concepts of V. S. Bibler, M. Buber, J. G. Herder, I. Kant, L. N. Kogan, D. S. Likhachev, A. Schweitzer, M. Scheler, and others. The experiment method was the experimental realization of formation stages of the future specialist as a person of culture, which allowed revealing the positive role of cultural mechanisms in this process. The result is the stages of human culture formation as well as mechanisms for their implementation. The article may be useful for specialists of the educational sphere, social philosophers, and culturologists.

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