2,607 research outputs found
Bottom Baryons
Recently CDF and D0 collaborations observed several bottom baryons. In this
work we perform a systematic study of the masses of bottom baryons up to
in the framework of heavy quark effective field theory (HQET) using the
QCD sum rule approach. The extracted chromo-magnetic splitting between the
bottom baryon heavy doublet agrees well with the experimental data.Comment: 8 pages, 5 figures, 3 tables. More discussions and references adde
A review of the open charm and open bottom systems
Since the discovery of the first charmed meson in 1976, many open-charm and
open-bottom hadrons were observed. In 2003 two narrow charm-strange states
and were discovered by the BaBar and CLEO
Collaborations, respectively. After that, more excited heavy hadrons were
reported. In this work, we review the experimental and theoretical progress in
this field.Comment: Review accepted by Reports on Progress in Physics, 161 pages, 53
figures, 23 tables, more references added and review on heavy baryons adde
Clinical study of retinal detachment associated with choroidal detachment
AIM: To analyze the clinical characteristics of retinal detachment associated with choroidal detachment and to evaluate the surgical techniques, the efficacy and operation time for treatment.<p>METHODS: We reviewed and analyzed the operative effects of vitreoretinal surgeries in 45 patients(45 eyes)with retinal and choroidal detachment in our hospital from January, 2010 to January, 2012. In these 45 patients, there were 38 patients of rhegmatogenous retinal detachment associated with choroidal detachment, 7 patients of retinal redetachment associated with choroidal detachment. The surgical techniques include scleral encircling operation, epichoroidal space drainage by sclerocentesis intraocular photocoagulation, gas-fluid exchange, perfluoropropane(C<sub>3</sub>F<sub>8</sub>)or silicone oil intraocular tamponade and vitreoretinal surgery.<p>RESULTS: The drainage of the suprachoroidal space liquid and blood was successful in 45 eyes. Silicone oil tamponade was performed for 39 eyes and C<sub>3</sub>F<sub>8</sub> tamponade for 6 eyes. Retinas and choroids were all reattached and retinal holes were closed. Visual acuities were improved, ≥0.1 in 23 eyes.<p>CONCLUSION: The vitreoretinal surgery and external drainage by sclerocentesis and scleral encircling operation is an effective operating method for rhegmatogenous retinal detachment associated with choroidal detachment
Diaquabis(5-carboxy-2-propyl-1H-imidazole-4-carboxylato-κ2 N 3,O 4)magnesium(II) 3.5-hydrate
In the title complex, [Mg(C8H9N2O4)2(H2O)2]·3.5H2O, the MgII atom is six-coordinated by two N,O-bidentate 5-carboxy-2-propyl-1H-imidazole-4-carboxylate ligands and two water molecules, forming a distorted octahedral environment. The complex molecules are linked into a three-dimensional network by N—H⋯O and O—H⋯O hydrogen-bonding interactions. The propyl groups are disordered over two sites, with site occupancies of 0.755 (7):0.245 (7) and 0.556 (13):0.444 (13)
Latest data constraint of some parameterized dark energy models
Using various latest cosmological datasets including Type-Ia supernovae,
cosmic microwave background radiation, baryon acoustic oscillations, and
estimations of the Hubble parameter, we test some dark energy models with
parameterized equations of state and try to distinguish or select
observation-preferred models. We obtain the best fitting results of the six
models and calculate their values of the Akaike Information Criteria and Bayes
Information Criterion. And we can distinguish these dark energy models from
each other by using these two information criterions. However, the CDM model remains the best fit model. Furthermore, we perform geometric
diagnostics including statefinder and Om diagnostics to understand the
geometric behaviour of the dark energy models. We find that the six DE models
can be distinguished from each other and from CDM, Chaplygin gas,
quintessence models after the statefinder and Om diagnostics were performed.
Finally, we consider the growth factor of the dark energy models with
comparison to CDM model. Still, we find the models can be
distinguished from each other and from CDM model through the growth
factor approximation.Comment: 23 pages, 6 figures, to be published in CP
Determining the Toll and Capacity of a Highway to Be Constructed in Parallel with Subway
This paper considers the problem of toll and capacity choice of a new highway with a bottleneck added onto an existing transit network under four ownership/tolling regimes: public fine toll, public flat toll, private fine toll, and private flat toll. Whenever fine toll and flat toll are imposed, in a competitive highway/transit network with constant returns to scale in road construction, an optimally designed and priced privately owned highway would produce positive net benefit justly equal to the total markup with respect to all autocommuters, whereas an optimally designed and priced publicly owned highway would lead to a deficit; that is, the toll revenues are insufficient to cover its all costs. The economic conditions to invest a new road are investigated under different ownership/tolling regimes
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