583 research outputs found
Assessing the effect of lens mass model in cosmological application with updated galaxy-scale strong gravitational lensing sample
By comparing the dynamical and lensing masses of early-type lens galaxies,
one can constrain both the cosmological parameters and the density profiles of
galaxies. We explore the constraining power on cosmological parameters and the
effect of the lens mass model in this method with 161 galaxy-scale strong
lensing systems, which is currently the largest sample with both high
resolution imaging and stellar dynamical data. We assume a power-law mass model
for the lenses, and consider three different parameterizations for
(i.e., the slope of the total mass density profile) to include the effect of
the dependence of on redshift and surface mass density. When treating
(i.e., the slope of the luminosity density profile) as a universal
parameter for all lens galaxies, we find the limits on the cosmological
parameter are quite weak and biased, and also heavily dependent on
the lens mass model in the scenarios of parameterizing with three
different forms. When treating as an observable for each lens, the
unbiased estimate of can be obtained only in the scenario of
including the dependence of on both the redshift and the surface mass
density, that is at 68\% confidence level
in the framework of a flat CDM model. We conclude that the significant
dependencies of on both the redshift and the surface mass density, as
well as the intrinsic scatter of among the lenses, need to be properly
taken into account in this method.Comment: Accepted for publication in MNRAS; 17 pages, 5 figures, 2 table
The appearance of a merging binary black hole very close to a spinning supermassive black hole
The mass and distance of a binary black hole (BBH) are fundamental parameters
to measure in gravitational-wave (GW) astronomy. It is well-known that the
measurement is affected by cosmological redshift, and recent works also showed
that Doppler and gravitational redshifts could further affect the result if the
BBH coalesces close to a supermassive black hole (SMBH). Here we consider the
additional lensing effect induced by the nearby SMBH on the measurement. We
compute the null geodesics originating within gravitational radii of a
Kerr SMBH to determine the redshift and magnification of the GWs emitted by the
BBH. We find a positive correlation between redshift and demagnification, which
results in a positive correlation between the mass and distance of the BBH in
the detector frame. More importantly, we find a higher probability for the
signal to appear redshifted and demagnified to a distant observer, rather than
blueshifted and magnified. Based on these results, we show that a binary at a
cosmological redshift of and composed of BHs of
could masquerade as a BBH at a redshift of
and containing BHs as large as . In the case of extreme
demagnification, we also find that the same BBH could appear to be at and contain subsolar-mass BHs. Such an effect, if not accounted for,
could bias our understanding of the origin of the BHs detected via GWs
Basic Public Cultural Services Problems and Countermeasure Analysis in Rural
Overall balanced development of urban and rural culture is an important part of the current public cultural service system, it is one of the basic means of promoting social development. This article from the perspective of the outstanding problems of the rural public cultural service, analyses the basic reasons which restrict the development of the rural public culture, then proposed to strengthen and improve the countermeasure thinking of rural public cultural services
Existentially Understanding Tourism in Locale : A Dwelling Perspective
Peer reviewedPostprin
Improving immunogenicity and safety of flagellin as vaccine carrier by high-density display on virus-like particle surface
Flagellin is a protein-based adjuvant that activates toll-like receptor (TLR) 5. Flagellin has been actively explored as vaccine adjuvants and carriers. Preclinical and clinical studies find flagellin-based vaccines have a risk to induce systemic adverse reactions potentially due to its overt activation of TLR5. To improve safety and immunogenicity of flagellin as vaccine carriers, FljB was displayed at high densities on hepatitis b core (HBc) virus-like particle (VLP) surface upon c/e1 loop insertion. FljB-HBc (FH) VLPs showed significantly reduced ability to activate TLR5 or induce systemic interleukin-6 release as compared to FljB. FH VLPs also failed to significantly increase rectal temperature of mice, while FljB could significantly increase rectal temperature of mice. These data indicated systemic safety of FljB could be significantly improved by high-density display on HBc VLP surface. Besides improved safety, FH VLPs and FljB similarly boosted co-administered ovalbumin immunization and FH VLPs were found to induce two-fold higher anti-FljB antibody titer than FljB. These data indicated preserved adjuvant potency and improved immunogenicity after high-density display of FljB on HBc VLP surface. Consistent with the high immunogenicity, FH VLPs were found to be more efficiently taken up by bone marrow-derived dendritic cells and stimulate more potent dendritic cell maturation than FljB. Lastly, FH VLPs were found to be a more immunogenic carrier than FljB, HBc VLPs, or the widely used keyhole limpet hemocyanin for nicotine vaccine development with a good local and systemic safety. Our data support FH VLPs to be a potentially safer and more immunogenic carrier than FljB for vaccine development
Evidence for Dirac Fermions in a honeycomb lattice based on silicon
Silicene, a sheet of silicon atoms in a honeycomb lattice, was proposed to be
a new Dirac-type electron system similar as graphene. We performed scanning
tunneling microscopy and spectroscopy studies on the atomic and electronic
properties of silicene on Ag(111). An unexpected
reconstruction was found, which is explained by an extra-buckling model.
Pronounced quasi-particle interferences (QPI) patterns, originating from both
the intervalley and intravalley scattering, were observed. From the QPI
patterns we derived a linear energy-momentum dispersion and a large Fermi
velocity, which prove the existence of Dirac Fermions in silicene.Comment: 6 pages, 4 figure
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