1,127 research outputs found
Effects of hadronic potentials on elliptic flows in relativistic heavy ion collisions
Within the framework of a multiphase transport (AMPT) model that includes
both initial partonic and final hadronic interactions, we show that including
mean-field potentials in the hadronic phase leads to a splitting of the
elliptic flows of particles and their antiparticles, providing thus a plausible
explanation of the different elliptic flows between and ,
and , and and observed in recent Beam Energy Scan (BES)
program at the Relativistic Heavy-Ion Collider (RHIC).Comment: 5 pages, 7 figure
Research on Effects of Incidence to Turbine Guide Cascade Aerodynamic Performance
When steam turbine set runs, the changes of incidence angle could cause the change of the flow loss in the cascade passages. It was necessary to research the flow performance in steam turbine passages by changing incidence angle. With the help of hydrodynamic software CFX, we could conduct numerical simulations at three incidence angles of 20°, 0°, and -20°, respectively. The computation results indicated that the blades with aft-loading profile had a good adaptation to the incidence angle. After changing incidence angle, the incidence angle affected the distribution of static surface pressure less within most of the scope of pressure surface and suction surface than other location. However, incidence angle −20° would decrease pressure loss within a narrow range, and incidence angle 20° would increase pressure loss
QED effects on phase transition and Ruppeiner geometry of Euler-Heisenberg-AdS black holes
Taking the quantum electrodynamics (QED) effect into account, we study the
black hole phase transition and Ruppeiner geometry for the Euler-Heisenberg
anti-de Sitter black hole in the extended phase space. For negative and small
positive QED parameter, we observe a small/large black hole phase transition
and reentrant phase transition, respectively. While a large positive value of
the QED parameter ruins the phase transition. The phase diagrams for each case
are explicitly exhibited. Then we construct the Ruppeiner geometry in the
thermodynamic parameter space. Different features of the corresponding scalar
curvature are shown for both the small/large black hole phase transition and
reentrant phase transition cases. Of particular interest is that an additional
region of positive scalar curvature indicating dominated repulsive interaction
among black hole microstructure is present for the black hole with a small
positive QED parameter. Furthermore, the universal critical phenomena are also
observed for the scalar curvature of the Ruppeiner geometry. These results
indicate that the QED parameter has a crucial influence on the black hole phase
transition and microstructure.Comment: 19 pages, 14 figure
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Water-Soluble Flexible Organic Frameworks That Include and Deliver Proteins.
Four water-soluble hydrazone-based three-dimensional (3D) flexible organic frameworks FOF-1-4 have been synthesized from a semirigid tetracationic tetraaldehyde and four flexible dihydrazides. 1H NMR spectroscopy indicated the quantitative formation of FOF-1-4 in D2O, while dynamic light scattering experiments revealed that, depending on the concentration, these porous frameworks display hydrodynamic diameters ranging from 50 to 120 nm. The porosity of the frameworks is confirmed by ethanol vapor adsorption experiments of the solid samples as well as the high loading capacity for a 2.3 nm porphyrin guest in water. The new water-soluble frameworks exhibit low cytotoxicity and form inherent pores with diameters of 5.3 or 6.7 nm, allowing rapid inclusion of proteins such as bovine serum albumin and green and orange fluorescent proteins, and efficient delivery of the proteins into normal and cancer cells. Flow cytometric analysis reveals percentages of the delivered cells up to 99.8%
Functional maturation of immature β cells: A roadblock for stem cell therapy for type 1 diabetes
Type 1 diabetes mellitus (T1DM) is a chronic autoimmune disease caused by the specific destruction of pancreatic islet β cells and is characterized as the absolute insufficiency of insulin secretion. Current insulin replacement therapy supplies insulin in a non-physiological way and is associated with devastating complications. Experimental islet transplantation therapy has been proven to restore glucose homeostasis in people with severe T1DM. However, it is restricted by many factors such as severe shortage of donor sources, progressive loss of donor cells, high cost, etc. As pluripotent stem cells have the potential to give rise to all cells including islet β cells in the body, stem cell therapy for diabetes has attracted great attention in the academic community and the general public. Transplantation of islet β-like cells differentiated from human pluripotent stem cells (hPSCs) has the potential to be an excellent alternative to islet transplantation. In stem cell therapy, obtaining β cells with complete insulin secretion in vitro is crucial. However, after much research, it has been found that the β-like cells obtained by in vitro differentiation still have many defects, including lack of adult-type glucose stimulated insulin secretion, and multi-hormonal secretion, suggesting that in vitro culture does not allows for obtaining fully mature β-like cells for transplantation. A large number of studies have found that many transcription factors play important roles in the process of transforming immature to mature human islet β cells. Furthermore, PDX1, NKX6.1, SOX9, NGN3, PAX4, etc., are important in inducing hPSC differentiation in vitro. The absent or deficient expression of any of these key factors may lead to the islet development defect in vivo and the failure of stem cells to differentiate into genuine functional β-like cells in vitro. This article reviews β cell maturation in vivo and in vitro and the vital roles of key molecules in this process, in order to explore the current problems in stem cell therapy for diabetes
Energy Dependence Study of Directed Flow in Au + Au Collisions Using an Improved Coalescence in a Multiphase Transport Model
The rapidity-odd component of directed flow () of identified hardons
(, , , , , , ,
, , ) and partons (, , ,
, , ) in Au+Au collisions at various beam energies
( = 7.7, 11.5, 14.5, 19.6, 27, 39, 54.4, 62.4, 200 GeV)
using a multi-phase transport model is analyzed. A data driven approach
(inspired from the experimental analysis) is performed here to distinguish the
transported and produced quarks which are found to have different directed flow
values at various collision beam energies. The coalescence sum rule (Number of
Constituent Quark scaling) violation is observed at lower energies where
hadronic matters dominate. The strange quark () and meson slope
(d/d) show a double sign change around 14.5 GeV, unlike other partons
and hadrons. It suggests that strange quark is more sensitive to the softening
of Equation of State (EoS).Comment: 9 pages, 8 figures, submitted to Phys. Rev.
Re-examining the premise of isobaric collisions and a novel method to measure the chiral magnetic effect
In these proceedings we show that the premise of the isobaric and collisions to search for the chiral magnetic effect (CME) may not hold as originally anticipated due to large uncertainties in the isobaric nuclear structures. We demonstrate this using Woods-Saxon densities and the proton and neutron densities calculated by the density functional theory. Furthermore, a novel method is proposed to gauge background and possible CME contributions in the same system, intrinsically better than the isobaric collisions of two different systems. We illustrate the method with Monte Carlo Glauber and AMPT (A Multi-Phase Transport) simulations
Determination of geopotential difference by hydrogen masers based on precise point positioning time-frequency transfer
According to the general relativity theory, the geopotential difference can
be determined by gravity frequency shift between two clocks. Here we report on
the experiments to determine the geopotential difference between two remote
sites by hydrogen masers based on precise point positioning time-frequency
transfer technique. The experiments include the remote clock comparison and the
local clock comparison using two CH1-95 active hydrogen masers linked with
global navigation satellite system time-frequency receivers. The frequency
difference between two hydrogen masers at two sites is derived from the time
difference series resolved by the above-mentioned technique. Considering the
local clock comparison as calibration, the determined geopotential difference
by our experiments is 12,142.3 (112.4) m^2/s^2, quite close to the value
12,153.3 (2.3) m^2/s^2 computed by the EIGEN-6C4 model. Results show that the
proposed approach here for determining geopotential difference is feasible,
operable, and promising for applications in various fields.Comment: 12 pages, 4 figure
Upstream therapeutic strategies of Valsartan and Fluvastatin on Hypertensive patients with non-permanent Atrial Fibrillation (VF-HT-AF): study protocol for a randomized controlled trial
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