1,210 research outputs found
An XMM-Newton study of the mixed-morphology supernova remnant W28 (G6.4-0.1)
We have performed an XMM-Newton imaging and spectroscopic study of supernova
remnant (SNR) W28, a prototype mixed-morphology or thermal composite SNR,
believed to be interacting with a molecular cloud. The observed hot X-ray
emitting plasma is characterized by low metal abundances, showing no evidence
of ejecta. The X-rays arising from the deformed northeast shell consist of a
thermal component with a temperature of keV plus a hard component of
either thermal (temperature keV) or non-thermal (photon index
-2.4) origin. The X-ray emission in the SNR interior is blobby and the
corresponding spectra are best described as the emission from a cold
( keV) plasma in non-equilibrium ionization with an ionization
timescale of cm s plus a hot ( keV)
gas in collisional ionization equilibrium. Applying the two-temperature model
to the smaller central regions, we find non-uniform interstellar absorption,
temperature and density distribution, which indicates that the remnant is
evolving in a non-uniform environment with denser material in the east and
north. The cloudlet evaporation mechanism can essentially explain the
properties of the X-ray emission in the center and thermal conduction may also
play a role for length scales comparable to the remnant radius. A recombining
plasma model with an electron temperature of keV is also feasible
for describing the hot central gas with the recombination age of the gas
estimated at yr.Comment: 16 pages, 7 figures, 5 tables, ApJ in pres
Empirical Study on Employee Job Satisfaction in Retail Industries
Enterprises are constituted by a number of employees, Employee Satisfaction directly determine their level of enthusiasm, which affecting the basic conditions of human resources. In this area, the research about retail industries is weak. In view of this paper is to make my own explorations. So I explore the characteristics and features of investigation upon the research of Employee Satisfaction people did before. Then the evaluation criteria of Employee Satisfaction is determined. The evaluation criteria is determined quantitative by AHP, The article use the AHP and Fuzzy Comprehensive Assessment Model to find the way to assess the Employee Satisfaction effectively
HexaaquaÂcobalt(II) bisÂ{[N-(4-methÂoxy-2-oxidobenzylÂidene)glycylÂglycinato]copper(II)} hexaÂhydrate
In the crystal structure of the title compound, [Co(H2O)6][Cu(C12H11N2O5)]2·6H2O, the CoII atom is located on an inversion center and coordinated by six water molÂecules in a slightly distorted octaÂhedral geometry. The CuII atom is chelated by the Schiff base ligand in a distorted CuN2O2 square-planar geometry. An extensive O—H⋯O hydrogen-bonding network is present in the crystal structure
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Convenient and General Zinc-Catalyzed Borylation of Aryl Diazonium Salts and Aryltriazenes under Mild Conditions
A convenient and general zinc-catalyzed borylation of aryl diazonium salts and aryltriazenes has been developed. With bis- (pinacolato)diboron as the borylation reagent, aryldiazonium tetrafluoroborate salts and aryltriazenes were transformed into the corresponding arylboronates in moderate to excellent yields under mild conditions. As a convenient and practical methodology, no additional ligands, base, or any other additives are required here
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