7,707 research outputs found
Production rates for hadrons, pentaquarks and , and di-baryon in relativistic heavy ion collisions by a quark combination model
The hadron production in relativistic heavy ion collisions is well described
by the quark combination model. The mixed ratios for various hadrons and the
transverse momentum spectra for long-life hadrons are predicted and agree with
recent RHIC data. The production rates for the pentaquarks , and the di-baryon are estimated, neglecting
the effect from the transition amplitude for constituent quarks to form an
exotic state.Comment: The difference between our model and other combination models is
clarified. The scaled transverse momentum spectra for pions, kaons and
protoms at both 130 AGeV and 200 AGeV are given, replacing the previous
results in transverse momentum spectr
The instability of diffusive convection and its implication for the thermohaline staircases in the deep Arctic Ocean
In the present study, the classical description of diffusive convection is
updated to interpret the instability of diffusive interfaces and the
dynamical evolution of the bottom layer in the deep Arctic Ocean. In the new
consideration of convective instability, both the background salinity
stratification and rotation are involved. The critical Rayleigh number of
diffusive convection is found to vary from 10<sup>3</sup> to 10<sup>11</sup> in the deep
Arctic Ocean as well as in other oceans and lakes. In such a wide range of
conditions, the interface-induced thermal Rayleigh number is shown to be
consistent with the critical Rayleigh number of diffusive convection. In most
regions, background salinity stratification is found to be the main hindrance
to the occurrence of convecting layers. With the new parameterization, it is
predicted that the maximum thickness of the bottom layer is 1051 m in the
deep Arctic Ocean, which is close to the observed value of 929 m. The evolution time of
the bottom layer is predicted to be ~ 100 yr, which is on the same
order as that based on <sup>14</sup>C isolation age estimation
Deformation monitoring of high-latitude permafrost region of northeastern China with time series inSAR technique
Abstract. Permafrost distributed in northeast China is the only high-altitude permafrost in China. The deformation monitoring over this permafrost region is of great importance to local climate change and ecological environments. This study focuses on the deformation monitoring of high-latitude permafrost in northeast China with time series InSAR technique. The spatial distribution characteristics, the annual deformation rates and the temporal deformation evolutions of permafrost could be retrieved from multi-temporal InSAR processing with Sentinel-1 TOPS datasets. This work concludes that time series InSAR technique could help to retrieve a comprehensive and reliable permafrost deformation, while a long time-series of displacements facilitated to better understand permafrost kinematics.</p
Mass movement susceptibility mapping using satellite optical imagery compared with InSAR monitoring: Zigui County, Three Gorges region, China
Mass movements on steep slopes are a major hazard to
communities and infrastructure in the Three Gorges
region, China. Developing susceptibility maps of mass
movements is therefore very important in both current
and future land use planning. This study employed
satellite optical imagery and an ASTER GDEM (15 m)
to derive various parameters (namely geology; slope
gradient; proximity to drainage networks and proximity
to lineaments) in order to create a GIS-based map of
mass movement susceptibility. This map was then
evaluated using highly accurate deformation signals
processed using the Persistent Scatterer (PS) InSAR
technique. Areas of high susceptibility correspond well
to points of high subsidence, which provides a strong
support of our susceptibility map
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