1,219 research outputs found
Time-dependent global simulations of a thin accretion disc: the effects of magnetically-driven winds on thermal instability
According to the standard thin disc theory, it is predicted that the
radiation-pressure-dominated inner region of a thin disc is thermally unstable,
while observations suggest that it is common for a thin disc of more than 0.01
Eddington luminosity to be in a thermally stable state. Previous studies have
suggested that magnetically driven winds have the potential to suppress
instability. In this work, we implement one-dimensional global simulations of
the thin accretion disc to study the effects of magnetically driven winds on
thermal instability. The winds play a role in transferring the angular momentum
of the disc and cooling the disc. When the mass outflow rate of winds is low,
the important role of winds is to transfer the angular momentum and then
shorten the outburst period. When the winds have a high mass outflow rate, they
can calm down the thermal instability. We also explore the parameter space of
the magnetic field strength and the mass loading parameter.Comment: 9 pages, 6 figures, accepted for publication in MNRA
Ultrafast Relaxation Dynamics of Photoexcited Dirac Fermion in The Three Dimensional Dirac Semimetal Cadmium Arsenide
Three dimensional (3D) Dirac semimetals which can be seen as 3D analogues of
graphene have attracted enormous interests in research recently. In order to
apply these ultrahigh-mobility materials in future electronic/optoelectronic
devices, it is crucial to understand the relaxation dynamics of photoexcited
carriers and their coupling with lattice. In this work, we report ultrafast
transient reflection measurements of the photoexcited carrier dynamics in
cadmium arsenide (Cd3As2), which is one of the most stable Dirac semimetals
that have been confirmed experimentally. By using low energy probe photon of
0.3 eV, we probed the dynamics of the photoexcited carriers that are
Dirac-Fermi-like approaching the Dirac point. We systematically studied the
transient reflection on bulk and nanoplate samples that have different doping
intensities by tuning the probe wavelength, pump power and lattice temperature,
and find that the dynamical evolution of carrier distributions can be retrieved
qualitatively by using a two-temperature model. This result is very similar to
that of graphene, but the carrier cooling through the optical phonon couplings
is slower and lasts over larger electron temperature range because the optical
phonon energies in Cd3As2 are much lower than those in graphene
The Efficacy and Tolerability of the Clonidine Transdermal Patch in the Treatment for Children with Tic Disorders: A Prospective, Open, Single-Group, Self-Controlled Study
A cell cycle–related lncRNA signature predicts the progression-free interval in papillary thyroid carcinoma
The cell cycle plays a vital role in tumorigenesis and progression. Long non-coding RNAs (lncRNAs) are key regulators of cell cycle processes. Therefore, understanding cell cycle–related lncRNAs (CCR-lncRNAs) is crucial for determining the prognosis of papillary thyroid carcinoma (PTC). RNA-seq and clinical data of PTC were acquired from The Cancer Genome Atlas, and CCR-lncRNAs were selected based on Pearson’s correlation coefficients. According to univariate Cox regression, least absolute shrinkage and selection operator (LASSO), and multivariate Cox regression analyses, a five-CCR-lncRNA signature (FOXD2-AS1, LOC100507156, BSG-AS1, EGOT, and TMEM105) was established to predict the progression-free interval (PFI) in PTC. Kaplan–Meier survival, time-dependent receiver operating characteristic curve, and multivariate Cox regression analyses proved that the signature had a reliable prognostic capability. A nomogram consisting of the risk signature and clinical characteristics was constructed that effectively predicted the PFI in PTC. Functional enrichment analyses indicted that the signature was involved in cell cycle– and immune-related pathways. Furthermore, we also analyzed the correlation between the signature and immune cell infiltration. Finally, we verified the differential expression of CCR-lncRNAs in vitro using quantitative real-time polymerase chain reaction. Overall, the newly developed prognostic risk signature based on five CCR-lncRNAs may become a marker for predicting the PFI in PTC
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