We present two-dimensional temperature map of the Perseus cluster based on multi-pointing observations with the ASCA GIS, covering a region with a diameter of ∼ 2. By correcting for the effect of the X-ray telescope response, the temperatures were estimated from hardness ratios and the complete temperature structure of the cluster with a spatial resolution of about 100 kpc was obtained for the ...

The molecular dynamics method, based on an empirical potential energy surface, was used to study the effect of catalyst particle size on the growth mechanism and structure of single-walled carbon nanotubes (SWNTs). The temperature for nanotube nucleation (800-1100 K), which occurs on the surface of the cluster, is similar to that used in catalyst chemical vapor deposition experiments, and the g...

Stress shadowing affects the simultaneous propagation of fractures from multiple perforation clusters. Employing uniform parameters for all clusters cause unbalanced growth fractures, which arouses demand optimizing non-uniform parameters. An optimization workflow combining a fracture model and particle swarm method (PSO) is proposed multi-cluster fracturing in this study. The considers couplin...

The Sloan Digital Sky Survey provides colors for more than 100,000 moving objects, among which a significant fraction has albedos determined. Here we combined and albedo in order to perform cluster analysis on the main-belt asteroid population, identify C-cluster, group of related C-type as defined earlier work. Members this C-cluster are fair agreement with color boundaries B DeMeo Carry (2013...

We study epidemic threshold properties in a scale-free random graph model. We show via a branching process approximation that the divergence of the second moment of the degree distribution is equivalent to the absence of an epidemic threshold. We study further the relation between diameter and epidemic threshold. Absence of an epidemic threshold happens precisely when a positive fraction of the...

seventeen iranian shallot genotypes from ashtian, arak, boroujerd, dashtearjan, doshmanziari, divandareh, khomein, khansar, sepidan, siakhdarengoon, sahne, kangavar, koohrang, koohmaresorkhi, nahavand, harsin and yasouj areas were evaluated for their morphological traits. corms were collected from the mentioned regions and planted based on a complete block design. quantitative and qualitative t...

one of the most visible aspects of a forest stand structure is the spatial patterns of trees. competition affects on forest structure and its understanding is important, when the purpose of forest management is to imitate the dynamic of natural ecosystems. for this purpose, an unmanaged intact forest was selected with 26 hectares area. all chestnut leaf oak (quercus castaneifolia) trees with a ...

The probability that the cluster of the origin in critical site percolation on the triangular grid has diameter larger than R is proved to decay like R−5/48 as R→ ∞.

We study a percolation model on the square lattice, where clusters “freeze” (stop growing) as soon as their volume (i.e. the number of sites they contain) gets larger than N , the parameter of the model. A model where clusters freeze when they reach diameter at least N was studied in [14, 6]. Using volume as a way to measure the size of a cluster – instead of diameter – leads, for large N , to ...

A red luminescent silver cluster was synthesized in milligram quantities by the direct core reduction of the most widely studied class of large silver nanoparticles, namely silver@citrate of tens of nanometres diameter. No byproducts such as thiolates were detected, unlike in the case of typical methods of making such clusters. The route provides nearly pure clusters. The possibility to make di...