2,589 research outputs found
Gravitating tensor monopole in a Lorentz-violating field theory
We present a solution of the coupled Einstein and rank-two antisymmetric
tensor field equations where Lorentz symmetry is spontaneously broken, and we
discuss its observational signatures. Especially, the deflection angles have
important qualitative differences between tensor and scalar monopoles. If a
monopole were to be detected, it would be discriminated whether or not to
correspond to a tensor one. This phenomenon might open up new direction in the
search of Lorentz violation with future astrophysical observations.Comment: 5 pages, 4 figure
Effect Equilibrium Approach in Calculating the Economic Range of a Freeway Industrial Zone
This research aims to develop a valid method to examine the relationship between transportation infrastructure and economic growth through the measurement of the economic boundary of a freeway industrial zone in developing countries. By comparing the similarities of a freeway industrial zone with an electromagnetic field, the Boit-Schwander law in electromagnetism is applied to create an electromagnetic model, which can calculate the attractive effect caused by a freeway on its influential area. When the attractive effect is equal to the traffic impedance, the economic range of the industrial zone can be determined by the effective equilibrium approach. An empirical analysis of the Ha-Shuang freeway demonstrates this approach is valid and practical
Pricing Knowledge Services Based on Meta-knowledge: From the Perspective of Knowledge Payment Platform
IPS Observation System for Miyun 50m Radio Telescope and Its Acceptance Observation
Ground-based observation of Interplanetary Scintillation(IPS) is an important
approach of monitoring solar wind. A ground-based IPS observation system is
newly implemented on 50m radio telescope, Miyun station, National Astronomical
Observatories, Chinese Academy of Sciences(NAOC). This observation system is
constructed for purpose of observing the solar wind speed and scintillation
index by using the normalized cross-spectrum of simultaneous dual-frequency IPS
measurement. The system consists of a universal dual-frequency front-end and a
dual-channel multi-function back-end specially designed for IPS. After careful
calibration and testing, IPS observations on source 3C273B and 3C279 are
successfully carried out. The preliminary observation results show that this
newly developed observation system is capable of doing IPS observation.The
system sensitivity for IPS observation can reach over 0.3Jy in terms of IPS
polarization correlator with 4MHz bandwidth and 2s integration time.Comment: 8 pages, 7 figure
Towards Realistic Low-resource Relation Extraction: A Benchmark with Empirical Baseline Study
This paper presents an empirical study to build relation extraction systems
in low-resource settings. Based upon recent pre-trained language models, we
comprehensively investigate three schemes to evaluate the performance in
low-resource settings: (i) different types of prompt-based methods with
few-shot labeled data; (ii) diverse balancing methods to address the
long-tailed distribution issue; (iii) data augmentation technologies and
self-training to generate more labeled in-domain data. We create a benchmark
with 8 relation extraction (RE) datasets covering different languages, domains
and contexts and perform extensive comparisons over the proposed schemes with
combinations. Our experiments illustrate: (i) Though prompt-based tuning is
beneficial in low-resource RE, there is still much potential for improvement,
especially in extracting relations from cross-sentence contexts with multiple
relational triples; (ii) Balancing methods are not always helpful for RE with
long-tailed distribution; (iii) Data augmentation complements existing
baselines and can bring much performance gain, while self-training may not
consistently achieve advancement to low-resource RE. Code and datasets are in
https://github.com/zjunlp/LREBench.Comment: Accepted to EMNLP 2022 (Findings) and the project website is
https://zjunlp.github.io/project/LREBench
Kosterlitz-Thouless phase transition and reentrance in an anisotropic 3-state Potts model on the generalized Kagome lattice
The unusual reentrant phenomenon is observed in the anisotropic 3-state Potts
model on a gen- eralized Kagome lattice. By employing the linearized tensor
renormalization group method, we find that the reentrance can appear in the
region not only under a partial ordered phase as commonly known but also a
phase without a local order parameter, which is uncovered to fall into the uni-
versality of the Kosterlitz-Thouless (KT) type. The region of the reentrance
depends strongly on the ratios of the next nearest couplings {\alpha} = J2 /|J1
| and {\beta} = J3 /|J1 |. The phase diagrams in the plane of temperature
versus {\beta} for different {\alpha} are obtained. Through massive
calculations, it is also revealed that the quasi-entanglement entropy can be
used to accurately detect the KT transition temperature
Determination and pharmacokinetic study of catechin in rat plasma by HPLC
AbstractA high performance liquid chromatographic method was developed and validated for the quantitative determination of catechin in rat plasma and its pharmacokinetic study after intragastric administration of Catechu and Xiongdanjiangre Wan into SD rats. Plasma samples were prepared by protein precipitation using methanol–5% aqueous zinc sulfate (70:30, v/v) as precipitant. Chromatographic separation was achieved on Hypersil C18 column (250mm×4.6mm, 10μm) with acetonitrile–water–triethylamine (6:94:0.3, v/v/v, pH 4.0±0.1, adjusted with phosphoric acid) as mobile phase, followed by a UV detection at 207nm. Good linearity was obtained over the range of 0.143–7.15mg/L of catechin, with correlation coefficient of 0.9992. The method was simple, sensitive, accurate and reproducible and has been successfully applied to the pharmacokinetic study of catechin in rat plasma
Progress on two-dimensional ferrovalley materials
The electron's charge and spin degrees of freedom are at the core of modern
electronic devices. With the in-depth investigation of two-dimensional
materials, another degree of freedom, valley, has also attracted tremendous
research interest. The intrinsic spontaneous valley polarization in
two-dimensional magnetic systems, ferrovalley material, provides convenience
for detecting and modulating the valley. In this review, we first introduce the
development of valleytronics. Then, the valley polarization forms by the p, d,
and f-orbit that are discussed. Following, we discuss the investigation
progress of modulating the valley polarization of two-dimensional ferrovalley
materials by multiple physical fields, such as electric, stacking mode, strain,
and interface. Finally, we look forward to the future developments of
valleytronics.Comment: 13 pages, 12 figures Accepted Chinese Physics B (2023) [Invited
review
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