670 research outputs found
On the evolution of Lyman alpha clouds based upon the Minihalo model
Intergalactic clouds confined by the gravity of cold dark matter (CDM), the so called mini-halo, is considered. Assuming a simplified evolution law of UV flux and mass function of gas clouds, number density evolution and H1 column density distribution can be reproduced by mini-halo model. Considering interaction between supersonic flow and a mini-halo, spatial correlation and the proximity effect of Ly-alpha forest can be investigated
Electrides as a New Platform of Topological Materials
Recent discoveries of topological phases realized in electronic states in
solids have revealed an important role of topology, which ubiquitously appears
in various materials in nature. Many well-known materials have turned out to be
topological materials, and this new viewpoint of topology has opened a new
horizon in material science. In this paper we find that electrides are suitable
for achieving various topological phases, including topological insulating and
topological semimetal phases. In the electrides, in which electrons serve as
anions, the bands occupied by the anionic electrons lie near the Fermi level,
because the anionic electrons are weakly bound by the lattice. This property of
the electrides is favorable for achieving band inversions needed for
topological phases, and thus the electrides are prone to topological phases.
From such a point of view, we find many topological electrides, YC
(nodal-line semimetal (NLS)), ScC (insulator with Zak phase),
SrBi (NLS), HfBr (quantum spin Hall system), and LaBr (quantum anomalous
Hall insulator), by using ab initio calculation. The close relationship between
the electrides and the topological materials is useful in material science in
both fields.Comment: 12 pages, 9 figure
Almost periodic processes and the existence of almost periodic solutions
Some property which is equivalent to the concept of an asymptotically almost periodic integral for almost periodic processes is introduced. By using this property, it is shown that a precompact integral of almost periodic processes which is uniformly asymptotically stable is an asymptotically almost periodic integral. Results are applied to the existence of almost periodic solutions of some evolution equation
A sequencing protocol of some DNA regions in nuclear, chloroplastic and mitochondrial genomes with an individual colony of Thalassiosira nordenskioeldii Cleve (Bacillariophyceae)
From cultured cells of micro algal species of Thalassiosira nordenskioeldii Cleve, total DNA was extracted with a buffer containing a chelating agent, Chelex 100. Each DNA fragment for 18s rDNA, 16s rDNA and coxI in nuclear, chloroplastic and mitochondrial genomes, respectively, were amplified from the DNA extracts by polymerase chain reactions, and their sequences were determined. This protocol for determining DNA sequences, was scaled down for the DNA extracts from small amounts of cells. Finally, DNA sequences in genomes were determined with 10 cells collected by a micromanipulation technique. The quantity of cells corresponded to an individual colony of this species. With this protocol, DNA sequences in various regions in genomes of each individual micro algal species living in natural environments can be determined directly, without isolation of strains and cultures
RELATION BETWEEN RELEASE PARAMETERS AND THROWING DISTANCE OF THE JAVELIN THROW
The present study was clarified a three-dimensional examination of the relation between the release parameters and throwing distances, in order to understand the initial flight characteristics of javelins. The subjects were 57 right-handed javelin throwers. The measured throwing distances ranged from 45.25 m to 87.17 m. The elite throwers had tendency to significant positive correlation between theoretical distance and initial velocity of javelin release. Throwers who achieved throwing distances of over 70m were observed to have throwing distances that were shorter than their theoretical distances, while those whose throwing distances were under 70 m group had throwing distances that were longer than their theoretical distances. When the data were applied to initial velocity of javelin release, it was equivalent to 26 m/s
- …