1,812 research outputs found
Deconfinement Phase Transition Heating and Thermal Evolution of Neutron Stars
The deconfinement phase transition will lead to the release of latent heat
during spins down of neutron stars if the transition is the first-order one.We
have investigated the thermal evolution of neutron stars undergoing such
deconfinement phase transition. The results show that neutron stars may be
heated to higher temperature.This feature could be particularly interesting for
high temperature of low-magnetic field millisecond pulsar at late stage.Comment: 4 pages, to be published by American Institute of Physics, ed. D.Lai,
X.D.Li and Y.F.Yuan, as the Proceedings of the conference Astrophysics of
Compact Object
Neuroprotective Effect of Phosphocreatine on Focal Cerebral Ischemia-Reperfusion Injury
Phosphocreatine (PCr) is a natural compound, which can donate high-energy phosphate group to ADP to synthesize ATP, even in the absence of oxygen and glucose. At present, it is widely used in cardiac and renal ischemia-reperfusion (IR) disease. In this study, to examine the protective efficacy of PCr against cerebral IR, disodium creatine phosphate was injected intravenously into rats before focal cerebral IR. Intracranial pressure (ICP), neurological score, cerebral infarction volume, and apoptotic neurons were observed. Expression of caspase-3 and aquaporin-4 (AQP4) was analyzed. Compared with IR group, rats pretreated with PCr had better neurologic score, less infarction volume, fewer ultrastructural histopathologic changes, reduced apoptosis, and lower aquaporin-4 level. In conclusion, PCr is neuroprotective after transient focal cerebral IR injury. Such a protection might be associated with apoptosis regulating proteins
A Short Overview of 6G V2X Communication Standards
We are on the verge of a new age of linked autonomous cars with unheard-of
user experiences, dramatically improved air quality and road safety, extremely
varied transportation settings, and a plethora of cutting-edge apps. A
substantially improved Vehicle-to-Everything (V2X) communication network that
can simultaneously support massive hyper-fast, ultra-reliable, and low-latency
information exchange is necessary to achieve this ambitious goal. These needs
of the upcoming V2X are expected to be satisfied by the Sixth Generation (6G)
communication system. In this article, we start by introducing the history of
V2X communications by giving details on the current, developing, and future
developments. We compare the applications of communication technologies such as
Wi-Fi, LTE, 5G, and 6G. we focus on the new technologies for 6G V2X which are
brain-vehicle interface, blocked-based V2X, and Machine Learning (ML). To
achieve this, we provide a summary of the most recent ML developments in 6G
vehicle networks. we discuss the security challenges of 6G V2X. We address the
strengths, open challenges, development, and improving areas of further study
in this field.Comment: 7 pages, 2 figures, IEEE ICN 202
Quantum algorithms for matrix geometric means
Matrix geometric means between two positive definite matrices can be defined
equivalently from distinct perspectives - as solutions to certain nonlinear
systems of equations, as points along geodesics in Riemannian geometry, and as
solutions to certain optimisation problems. This diversity already suggests the
potential for varied applications, as well as acting as a bridge between
different domains. Here we devise new quantum subroutines to efficiently
prepare quantum unitary operators that embed the standard matrix geometric mean
and its generalisations called the weighted matrix geometric mean. This enables
the construction of solutions to the algebraic Riccati equation, which is an
important class of nonlinear systems of equations that appears in machine
learning, optimal control, estimation, and filtering. Using these subroutines,
we present a new class of quantum learning algorithms called quantum geometric
mean metric learning. This has applications in efficiently finding the best
distance measure and solving classification problems in the weakly supervised
limit and for anomaly detection, for both classical and quantum problems. We
also show how our method can be generalised to a particular p^th-order system
of nonlinear equations. These quantum subroutines for matrix geometric means
are also useful in other areas of quantum information. For example, we show how
to use them in the estimation of geometric Renyi relative entropies and the
Uhlmann fidelity by means of the Fuchs-Caves observable. In particular, our
quantum algorithms for estimating the Uhlmann and Matsumoto fidelities have
optimal dependence on the precision. Finally, we provide a BQP-complete problem
based on matrix geometric means that can be solved by our subroutines, thus
characterising their computational capability
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