2,449 research outputs found
Effect of interaction with neutrons in matter on flavor conversion of super-light sterile neutrino with active neutrino
A super-light sterile neutrino was proposed to explain the absence of the
expected upturn of the survival probability of low energy solar boron
neutrinos. This is because this super-light sterile neutrino can oscillate
efficiently with electron neutrino through a MSW resonance happened in Sun. One
may naturally expect that a similar resonance should happen for neutrinos
propagating in Earth matter. We study the flavor conversion of this super-light
sterile neutrino with active neutrinos in Earth matter. We find that the
scenario of the super-light sterile neutrino can easily pass through possible
constraints from experiments which can test the Earth matter effect in
oscillation of neutrinos. Interestinlgy, we find that this is because the
naively expected resonant conversion disappears or is significantly suppressed
due to the presence of a potential which arises from neutral current
interaction of neutrino with neutrons in matter. In contrast, the neutron
number density in the Sun is negligible and the effect of is effectively
switched off. This enables the MSW resonance in Sun needed in oscillation of
the super-light sterile neutrino with solar electron neutrinos. It's
interesting to note that it is the different situation in the Sun and in the
Earth that makes effectively turned off and turned on respectively. This
observation makes the scenario of the super-light sterile neutrino quite
interesting.Comment: 22 pages, 10 figure
1D van der Waals Material Tellurium: Raman Spectroscopy under Strain and Magneto-transport
Experimental demonstrations of 1D van der Waals material tellurium have been
presented by Raman spectroscopy under strain and magneto-transport. Raman
spectroscopy measurements have been performed under strains along different
principle axes. Pronounced strain response along c-axis is observed due to the
strong intra-chain covalent bonds, while no strain response is obtained along
a-axis due to the weak inter-chain van der Waals interaction. Magneto-transport
results further verify its anisotropic property, resulting in dramatically
distinct magneto-resistance behaviors in terms of three different magnetic
field directions. Specifically, phase coherence length extracted from weak
antilocalization effect, L ~ T, claims its 2D transport
characteristics when an applied magnetic field is perpendicular to the thin
film. In contrast, L ~ T is obtained from universal
conductance fluctuations once the magnetic field is along c-axis of Te,
indicating its nature of 1D transport along the helical atomic chains. Our
studies, which are obtained on high quality single crystal tellurium thin film,
appear to serve as strong evidences of its 1D van der Waals structure from
experimental perspectives. It is the aim of this paper to address this special
concept that differs from the previous well-studied 1D nanowires or 2D van der
Waals materials
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Establishment and verification of solar radiation calculation model of glass daylighting roof in hot summer and warm winter zone in China
In this paper, solar heat gain through glass daylighting roof is deeply studied by theoretical calculation method, taking Guangzhou in the Hot Summer and Warm Winter (HSWW) zone as an example. The direct solar radiation is calculated by Bouguer formula whereas the diffuse solar radiation is calculated by Berlage formula, representing the basis for the calculation method of the solar radiation intensity through the glass daylighting roof. Through the establishment of solar radiation calculation
model, the solar heat gain of the commonly used glass types has been calculated and analyzed, especially comparatively analyzing of Low-E cored-glass with double-coated silver and 6+12A+6 insulating glass. Then, comparison between solar heat
gain as calculated and measured by field measurement tested the indoor solar radiation heat gain distribution by using adjacent rooms with different glass types in a hot summer area, with the aim of demonstrating the effectiveness of the model. The research in this paper is expected to further improve the calculation accuracy of both thermal load and indoor temperature
Vitamin D Signaling through Induction of Paneth Cell Defensins Maintains Gut Microbiota and Improves Metabolic Disorders and Hepatic Steatosis in Animal Models.
Metabolic syndrome (MetS), characterized as obesity, insulin resistance, and non-alcoholic fatty liver diseases (NAFLD), is associated with vitamin D insufficiency/deficiency in epidemiological studies, while the underlying mechanism is poorly addressed. On the other hand, disorder of gut microbiota, namely dysbiosis, is known to cause MetS and NAFLD. It is also known that systemic inflammation blocks insulin signaling pathways, leading to insulin resistance and glucose intolerance, which are the driving force for hepatic steatosis. Vitamin D receptor (VDR) is highly expressed in the ileum of the small intestine, which prompted us to test a hypothesis that vitamin D signaling may determine the enterotype of gut microbiota through regulating the intestinal interface. Here, we demonstrate that high-fat-diet feeding (HFD) is necessary but not sufficient, while additional vitamin D deficiency (VDD) as a second hit is needed, to induce robust insulin resistance and fatty liver. Under the two hits (HFD+VDD), the Paneth cell-specific alpha-defensins including α-defensin 5 (DEFA5), MMP7 which activates the pro-defensins, as well as tight junction genes, and MUC2 are all suppressed in the ileum, resulting in mucosal collapse, increased gut permeability, dysbiosis, endotoxemia, systemic inflammation which underlie insulin resistance and hepatic steatosis. Moreover, under the vitamin D deficient high fat feeding (HFD+VDD), Helicobacter hepaticus, a known murine hepatic-pathogen, is substantially amplified in the ileum, while Akkermansia muciniphila, a beneficial symbiotic, is diminished. Likewise, the VD receptor (VDR) knockout mice exhibit similar phenotypes, showing down regulation of alpha-defensins and MMP7 in the ileum, increased Helicobacter hepaticus and suppressed Akkermansia muciniphila. Remarkably, oral administration of DEFA5 restored eubiosys, showing suppression of Helicobacter hepaticus and increase of Akkermansia muciniphila in association with resolving metabolic disorders and fatty liver in the HFD+VDD mice. An in vitro analysis showed that DEFA5 peptide could directly suppress Helicobacter hepaticus. Thus, the results of this study reveal critical roles of a vitamin D/VDR axis in optimal expression of defensins and tight junction genes in support of intestinal integrity and eubiosis to suppress NAFLD and metabolic disorders
High-Reliability Wireless Communication for High-Speed Railway Empowered by OTFS
早稲田大学修士(工学)master thesi
MLPerf Inference Benchmark
Machine-learning (ML) hardware and software system demand is burgeoning.
Driven by ML applications, the number of different ML inference systems has
exploded. Over 100 organizations are building ML inference chips, and the
systems that incorporate existing models span at least three orders of
magnitude in power consumption and five orders of magnitude in performance;
they range from embedded devices to data-center solutions. Fueling the hardware
are a dozen or more software frameworks and libraries. The myriad combinations
of ML hardware and ML software make assessing ML-system performance in an
architecture-neutral, representative, and reproducible manner challenging.
There is a clear need for industry-wide standard ML benchmarking and evaluation
criteria. MLPerf Inference answers that call. In this paper, we present our
benchmarking method for evaluating ML inference systems. Driven by more than 30
organizations as well as more than 200 ML engineers and practitioners, MLPerf
prescribes a set of rules and best practices to ensure comparability across
systems with wildly differing architectures. The first call for submissions
garnered more than 600 reproducible inference-performance measurements from 14
organizations, representing over 30 systems that showcase a wide range of
capabilities. The submissions attest to the benchmark's flexibility and
adaptability.Comment: ISCA 202
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