160 research outputs found
Blue rubber bleb nevus syndrome coexisted with intestinal intussusception: a case report
Blue Rubber Bleb Nevus Syndrome (BRBNS) is an uncommon congenital disorder characterized by sporadic venous malformation which mainly occurs in skin and alimentary canal. Here, we report a BRBNS patient with concomitant intestinal intussusception who diagnosed by intraoperative endoscopy and ultimately managed using surgical resection. A 19-year-old boy was referred to urgent surgery for acute melena and stomachache. He had used to be a long-term iron user for undiagnosed chronic anemia and papules. Abdominal CT on admission demonstrated the presence of intestinal intussusception. The following exploratory laparotomy and intraoperative endoscopy revealed multiple gastrointestinal hemangiomas. The postoperative course was uneventful and pathological examination certified multiple cavernous hemangiomas in the resected gastrointestines.Key words: Blue rubber bleb nevus syndrome, gastrointestinal bleeding, jejunojejunal intussusception, intraoperative endoscopy, papul
Global Hilbert expansion for some non-relativistic kinetic equations
The Vlasov-Maxwell-Landau (VML) system and the Vlasov-Maxwell-Boltzmann (VMB)
system are fundamental models in dilute collisional plasmas. In this paper, we
are concerned with the hydrodynamic limits of both the VML and the non-cutoff
VMB systems in the entire space. Our primary objective is to rigorously prove
that, within the framework of Hilbert expansion, the unique classical solution
of the VML or non-cutoff VMB system converges globally over time to the smooth
global solution of the Euler-Maxwell system as the Knudsen number approaches
zero.
The core of our analysis hinges on deriving novel interplay energy estimates
for the solutions of these two systems, concerning both a local Maxwellian and
a global Maxwellian, respectively. Our findings address a problem in the
hydrodynamic limit for Landau-type equations and non-cutoff Boltzmann-type
equations with a magnetic field. Furthermore, the approach developed in this
paper can be seamlessly extended to assess the validity of the Hilbert
expansion for other types of kinetic equations.Comment: 61 pages;Some statements of main theorems are adjusted;Partial
results about the VML system was annouced in arxiv:2209.1520
Hilbert expansion for kinetic equations with non-relativistic Coulomb collision
In this paper, we study the hydrodynamic limits of both the Landau equation
and the Vlasov-Maxwell-Landau system in the whole space. Our main purpose is
two-fold: the first one is to give a rigorous derivation of the compressible
Euler equations from the Landau equation via the Hilbert expansion; while the
second one is to prove, still in the setting of Hilbert expansion, that the
unique classical solution of the Vlasov-Maxwell-Landau system converges, which
is shown to be globally in time, to the resulting global smooth solution of the
Euler-Maxwell system, as the Knudsen number goes to zero. The main ingredient
of our analysis is to derive some novel interplay energy estimates on the
solutions of the Landau equation and the Vlasov-Maxwell-Landau system which are
small perturbations of both a local Maxwellian and a global Maxwellian,
respectively. Our result solves an open problem in the hydrodynamic limit for
the Landau-type equations with Coulomb potential and the approach developed in
this paper can seamlessly be used to deal with the problem on the validity of
the Hilbert expansion for other types of kinetic equations
Gate defined quantum dot realized in a single crystalline InSb nanosheet
Single crystalline InSb nanosheet is an emerging planar semiconductor
material with potential applications in electronics, infrared optoelectronics,
spintronics and topological quantum computing. Here we report on realization of
a quantum dot device from a single crystalline InSb nanosheet grown by
molecular-beam epitaxy. The device is fabricated from the nanosheet on a
Si/SiO2 substrate and the quantum dot confinement is achieved by top gate
technique. Transport measurements show a series of Coulomb diamonds,
demonstrating that the quantum dot is well defined and highly tunable. Tunable,
gate-defined, planar InSb quantum dots offer a renewed platform for developing
semiconductor-based quantum computation technology.Comment: 12 pages, 4 figure
Spatio-temporal Fluctuation of Temperature Using Specific Climate Indices in South Xinjiang, China
Temperature and precipitation are significant variables that can be used to determine the climatic variability in a region. This research study has focused on temperature, which is significant for the study of climatic variability over a long period in an area. The temperature has been assessed spatially and temporally in South Xinjiang, China using various climate indices. The temporal data about the temperature of seventeen meteorological stations were acquired from the Chinese Meteorology Administration (CMA) from 1980 to 2018. The Mann-Kendall (MK) trend test and Sen’s Slope (SS) statistical models were used to quantify the magnitude and temporal trend. The monthly and seasonal analysis of temperature reveals a significant increasing trend in mean maximum, mean minimum and average temperatures in the study area. The Sen’s Slope test results indicate an increasing monthly and seasonal temperature trend in almost all meteorological stations. The increasing trend in temperature is mainly due to the desert type of climate of the region that is gradually further aggravating with every passing year. This increasing temperature trend will smoothen the way for perpetual drought in the region in the future. Therefore, this research would be beneficial for future planning and management of water resources in the region and for making preventive measures to mitigate the impacts of climate change in the study area
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