719 research outputs found
Thomson backscattering in combined two laser and magnetic field
The Thomson backscattering of an electron moving in combined fields is
studied by a dynamically assisted mechanism. The combined fields are composed
of two co-propagating laser fields and a magnetic field, where the first laser
field is strong and low-frequency while the second is weak and high-frequency,
relatively. The dependence of fundamental frequency of emission on the ratio of
incident laser high-to-low frequency is presented and the spectrum of
backscattering is obtained. It is found that, with a magnetic field, the peak
of the spectrum and the corresponding radiation frequency are significantly
larger in case of two-laser than that in case of only one laser. They are also
improved obviously as the frequency of the weak laser field. Another finding is
the nonlinear correlation between the emission intensity of the backscattering
and the intensity of the weak laser field. These results provide a new
possibility to adjust and control the spectrum by changing the ratios of
frequency and intensity of the two laser fields.Comment: 13 pages, 4 figure
Tensor coupling effects on spin symmetry in anti-Lambda spectrum of hypernuclei
The effects of -tensor coupling on the spin
symmetry of spectra in -nucleus systems have
been studied with the relativistic mean-field theory. Taking
C+ as an example, it is found that the tensor coupling
enlarges the spin-orbit splittings of by an order of magnitude
although its effects on the wave functions of are negligible.
Similar conclusions has been observed in -nucleus of different
mass regions, including O+, Ca+ and
Pb+. It indicates that the spin symmetry in
anti-lambda-nucleus systems is still good irrespective of the tensor coupling.Comment: 12 pages, 3 figures
The significance of Notch ligand expression in the peripheral blood of children with hand, foot and mouth disease (HFMD)
BACKGROUND: Hand, foot and mouth disease (HFMD), a virus-induced infectious disease that usually affects infants and children, has an increased incidence in China in recent years. This study attempted to investigate the role of the Notch signaling pathway in the pathogenesis of HFMD. METHODS: Eighty-two children diagnosed with HFMD were enrolled into this study. The HFMD group was further divided into the uncomplicated HFMD and HFMD with encephalitis groups. The control group included 40 children who underwent elective surgery for treatment of inguinal hernias. RESULTS: Children with HFMD displayed significantly reduced CD3+, CD3+CD4+ and CD3+CD8+ cell subsets, but substantially enhanced CD3−CD19+ cell subset (p < 0.05 versus control subjects). The expression levels of Notch ligands Dll1 and Dll4 in the peripheral blood of the HFMD group were significantly higher than those in the control group (p < 0.05). There were statistically significant differences in CD3+, CD3+CD4+ and CD3−CD19+ cell subsets, but not in Notch ligand expression, between the uncomplicated HFMD and HFMD with encephalitis groups. Dll4 expression in HFMD subjects correlated negatively with the CD3+ and CD3+CD8+ cell subsets (p < 0.05), but positively with the CD3−CD19+ cell subset (p < 0.05). Furthermore, Dll4 expression in HFMD with encephalitis subjects correlated positively with total white blood cell (WBC) counts and total protein contents in cerebrospinal fluid (CSF) (p < 0.05). CONCLUSIONS: The Notch ligand Dll4 exhibits a strong correlation with the CD3+, CD3+CD8+ and CD3−CD19+ cell subsets in children with HFMD, indicating that the Notch signaling may be involved in the development of HFMD by affecting the number and status of peripheral lymphocytes
M dwarf Stars - The By-Product of X-Ray Selected AGN Candidates
X-ray loud M dwarfs are a major source of by-product (contamination) in the
X-ray band of the multiwavelength quasar survey (MWQS). As a by-product, the
low dispersion spectra of 22 M dwarfs are obtained in which the spectra of 16
sources are taken for the first time. The spectral types and distance of the
sample are given based on spectral indices CaH2, CaH3, and TiO5. The parameter
{\zeta}TiO/CaH is calculated to make the metallicity class separation among
dwarfs, subdwarfs and extreme subdwarfs. We also discuss the distributions in
the diagrams of Log(Lx/Lbol) versus spectral type and infrared colors.Comment: 10 pages, 26 figures, accepted for publication in Research in
Astronomy and Astrophysics (RAA
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