550 research outputs found
Structure of mitochondrial DNA control region of Argyrosomus amoyensis and molecular phylogenetic relationship among six species of Sciaenidae
The structure of the mitochondrial DNA (mtDNA) control region of Argyrosomus amoyensis was examined in this study. TAS, cTAS, CSB-D to CSB-F and CSB-1 to CSB-3 segments were detected in the species. The results indicated that the structures of these parts were different from that of most fishes. All the mtDNA control region sequences examined had missing tandem repeat sequences downstream of CSB-3, which were the same as most fishes’. In addition, part of the COI gene was used to analyze the phylogenetic relationships of six Sciaenids species. The phylogenetic tree results supported the classification by traditional morphology, and COI barcodes were useful for identifying these six species of Sciaenids.Key words: Control region, structure, Argyrosomus amoyensis, COI, phylogenetic relationship, Sciaenidae
Excitonic quantum confinement modified optical conductivity of monolayer and few-layered MoS2
2016-2017 > Academic research: refereed > Publication in refereed journal201804_a bcmaVersion of RecordPublishe
Compensation ratio-dependent concentration of a V InH 4 complex in n-type liquid encapsulated Czochralski InP
The concentration of hydrogen-indium vacancy complex V InH 4 in liquid encapsulated Czochralski undoped and Fe-doped n-type InP has been studied by low-temperature infrared absorption spectroscopy. The V InH 4 complex is found to be a dominant intrinsic shallow donor defect with concentrations up to ∼10 16 cm -3 in as-grown liquid encapsulated Czochralski InP. The concentration of the V InH 4 complex is found to increase with the compensation ratio in good agreement with the proposed defect formation model of Walukiewicz [W. Walukiewicz, Phys. Rev. B 37, 4760 (1998); Appl. Phys. Lett. 54, 2094 (1989)], which predicts a Fermi-level-dependent concentration of amphoteric defects. © 1998 American Institute of Physics.published_or_final_versio
Formation of P In defect in annealed liquid-encapsulated Czochralski InP
Fourier transform infrared spectroscopy measurements have been carried out on liquid-encapsulated Czochralski-grown undoped InP wafers, which reproducibly become semi-insulating upon annealing in an ambient of phosphorus at 800-900°C. The measurements reveal a high concentration of hydrogen complexes in the form V InH 4 existing in the material before annealing in agreement with recent experimental studies. It is argued that the dominant and essential process producing the semi-insulating behavior is the compensation produced by an EL 2-like deep donor phosphorus antisite defect, which is formed by the dissociation of the hydrogen complexes during the process of annealing. The deep donor compensates acceptors, the majority of which are shallow residual acceptor impurities and deep hydrogen associated V In and isolated V In levels, produced at the first stage of the dissociation of the V InH 4 complex. The high concentration of indium vacancies produced by the dissociation are the precursor of the EL 2-like phosphorus antisite. These results show the importance of hydrogen on the electrical properties of InP and indicate that this largely results from low formation energy of the complex V InH 4 in comparison with that of an isolated V In. © 1998 American Institute of Physics.published_or_final_versio
Inclusive Dielectron Cross Sections in p+p and p+d Interactions at Beam Energies from 1.04 to 4.88 GeV
Measurements of dielectron production in p+p and p+d collisions with beam
kinetic energies from 1.04 to 4.88 GeV are presented. The differential cross
section is presented as a function of invariant pair mass, transverse momentum,
and rapidity. The shapes of the mass spectra and their evolution with beam
energy provide information about the relative importance of the various
dielectron production mechanisms in this energy regime. The p+d to p+p ratio of
the dielectron yield is also presented as a function of invariant pair mass,
transverse momentum, and rapidity. The shapes of the transverse momentum and
rapidity spectra from the p+d and p+p systems are found to be similar to one
another for each of the beam energies studied. The beam energy dependence of
the integrated cross sections is also presented.Comment: 15 pages and 16 figure
Search for Charged Higgs Bosons in e+e- Collisions at \sqrt{s} = 189 GeV
A search for pair-produced charged Higgs bosons is performed with the L3
detector at LEP using data collected at a centre-of-mass energy of 188.6 GeV,
corresponding to an integrated luminosity of 176.4 pb^-1. Higgs decays into a
charm and a strange quark or into a tau lepton and its associated neutrino are
considered. The observed events are consistent with the expectations from
Standard Model background processes. A lower limit of 65.5 GeV on the charged
Higgs mass is derived at 95 % confidence level, independent of the decay
branching ratio Br(H^{+/-} -> tau nu)
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