266 research outputs found
The Inspiration through World Skills Competition on Tourism & Hotel Management Curriculum Construction and Student Cultivating
In this paper, we emplys the real case and feelings of tourism and hotel management students to participate in the "World Competition", which reflects how the hotel industry has implemented the "banquet service standard", and also lays a solid foundation for future student’s learning and corporate practicing. With the continuous improvement of "Chinese Services" and the application of practical teaching, the training goals of tourism management personnel in vocational colleges have changed. The launch of the World Skills Competition fits this trend and promotes the reform and development of the hotel management talent training model.. The World Skills Competition is hailed as the "World Skills Olympics". China participated in this project for the first time in 2015 (43th), and won consecutive gold awards in 2017 (44th) and 2019 (45th). Awards and restaurant service excellence awards have achieved zero breakthroughs in medals. The four majors covering cooking, baking, restaurant service, and hospitality of the hotel management major are all competitions in the personal and social service areas of the World Skills Competition. From August 22-27, 2019, the 45th World Skills Competition was held in Kazan, Russia. The Chinese delegation won a total of 16 gold medals, 14 silver medals, 5 bronze medals and 17 winning prizes in this competition. The gold medal list, medal list, and group total score are the first. China will host the 46th Shanghai World Skills Competition in 2021. In the future, we should focus on increasing international cooperation with members of the World Skills Organization, and closely follow hotel professional skills projects. It is hoped that the World Skills Competition will become the vane of the hotel management professional training and the level of colleges and universities
Friedmann cosmology on codimension 2 brane with time dependent tension
A solution of codimension 2 brane is found for which 4 dimensional Friedmann
cosmology is recovered on the brane with time dependent tension, in the
Einstein frame. The effective parameter of equation of state on the
brane can be quintessence like, de Sitter like or phantom like, depending on
integration constants of the solution.Comment: 6 pages, 4 figure
New test on the Einstein equivalence principle through the photon ring of black holes
Funding: This work is supported in part by the NSFC (Nos. 11653002, 11961131007, 11722327,1201101448, 11421303), by the CAST (2016QNRC001), by the National Thousand Talents Program of China, by the Fundamental Research Funds for Central Universities, and by the USTC Fellowship for international cooperation.Einstein equivalence principle (EEP), as one of the foundations of general relativity, is a fundamental test of gravity theories. In this paper, we propose a new method to test the EEP of electromagnetic interactions through observations of black hole photon rings, which naturally extends the scale of Newtonian and post-Newtonian gravity where the EEP violation through a variable fine structure constant has been well constrained to that of stronger gravity. We start from a general form of Lagrangian that violates EEP, where a specific EEP violation model could be regarded as one of the cases of this Lagrangian. Within the geometrical optical approximation, we find that the dispersion relation of photons is modified: for photons moving in circular orbit, the dispersion relation simplifies, and behaves such that photons with different linear polarizations perceive different gravitational potentials. This makes the size of black hole photon ring depend on polarization. Further assuming that the EEP violation is small, we derive an approximate analytic expression for spherical black holes showing that the change in size of the photon ring is proportional to the violation parameters. We also discuss several cases of this analytic expression for specific models. Finally, we explore the effects of black hole rotation and derive a modified proportionality relation between the change in size of photon ring and the violation parameters. The numerical and analytic results show that the influence of black hole rotation on the constraints of EEP violation is relatively weak for small magnitude of EEP violation and small rotation speed of black holes.Publisher PDFPeer reviewe
Critical comments on the paper "Crossing by a single scalar field on a Dvali-Gabadadze-Porrati brane" by H Zhang and Z-H Zhu [Phys.Rev.D75,023510(2007)]
It is demonstrated that the claim in the paper "Crossing by a
single scalar field on a Dvali-Gabadadze-Porrati brane" by H Zhang and Z-H Zhu
[Phys.Rev.D75,023510(2007)], about a prove that there do not exist scaling
solutions in a universe with dust in a Dvali-Gabadadze-Porrati (DGP) braneworld
scenario, is incorrect.Comment: 5 pages, 8 eps figure
Divergence Behavior of Thermodynamic Curvature Scalar at Critical Point in the Extended Phase Space of Generic Black Holes
The - phase transition and critical behavior in the extended phase
space of asymptotic Anti-de Sitter (AdS) black holes have been widely
investigated, in which four critical exponents around critical point are found
to be consistent with values in the mean field theory. Recently, another
critical exponent related to divergent correlation length at critical
point is proposed by using thermodynamic curvature scalar in the charged
AdS black hole. In this paper, we develop a method to investigate the divergent
behavior of at critical point, and find that the divergent behavior of
around the critical point expresses a universal property in generic black
holes. We further directly apply this method to investigate black holes in de
Rham-Gabadadze-Tolley (dRGT) massive gravity to check this universality. Those
results shed new lights on the microscopic properties of black holes.Comment: 10 pages, no figure, version accepted by PL
Monocular 3D Object Detection with Decoupled Structured Polygon Estimation and Height-Guided Depth Estimation
Monocular 3D object detection task aims to predict the 3D bounding boxes of
objects based on monocular RGB images. Since the location recovery in 3D space
is quite difficult on account of absence of depth information, this paper
proposes a novel unified framework which decomposes the detection problem into
a structured polygon prediction task and a depth recovery task. Different from
the widely studied 2D bounding boxes, the proposed novel structured polygon in
the 2D image consists of several projected surfaces of the target object.
Compared to the widely-used 3D bounding box proposals, it is shown to be a
better representation for 3D detection. In order to inversely project the
predicted 2D structured polygon to a cuboid in the 3D physical world, the
following depth recovery task uses the object height prior to complete the
inverse projection transformation with the given camera projection matrix.
Moreover, a fine-grained 3D box refinement scheme is proposed to further
rectify the 3D detection results. Experiments are conducted on the challenging
KITTI benchmark, in which our method achieves state-of-the-art detection
accuracy.Comment: 11 pages, 8 figures, AAAI202
Mechanism underlying synergic activation of Tyrosinase promoter by MITF and IRF4
Background: The transcription factor interferon regulatory factor 4 (IRF4) was identified to be involved in human pigmentation by genome-wide association studies (GWASs). The rs12203592-[T/C], which is located in intron 4 of IRF4, shows the strongest link to these pigmentation phenotypes including freckling, sun sensitivity, eye and hair color. Previous studies indicated a functional cooperation of IRF4 with Microphthalmia-associated transcription factor (MITF), a causing gene of Waardenburg syndrome (WS), to synergistically trans-activate Tyrosinase (TYR). However, the underlying mechanism is still unknown. Methods: To investigate the importance of DNA binding in the synergic effect of IRF4. Reporter plasmids with mutant TYR promoters was generated to locate the IRF4 DNA binding sites in the Tyrosinase minimal promoter. By building MITF and IRF4 truncated mutations plasmids, the necessary regions of the synergy functions of these two proteins were also located. Results: The cooperative effect between MITF and IRF4 was specific for TYR promoter. The DNA-binding of IRF4 was critical for the synergic function. IRF4 DNA binding sites in TYR promoter were identified. The Trans-activation domains in IRF4 (aa134-207, aa300-420) were both important for the synergic function, whereas the auto-mask domain (aa207-300) appeared to mask the synergic effect. Mutational analysis in MITF indicated that both DNA-binding and transcriptional activation domains were both required for this synergic effect. Conclusions: Here we showed that IRF4 potently synergized with MITF to activate the TYR promoter, which was dependent on DNA binding of IRF4. The synergic domains in both IRF4 and MITF were identified by mutational analysis. This identification of IRF4 as a partner for MITF in regulation of TYR may provide an important molecular function for IRF4 in the genesis of melanocytes and the pathogenic mechanism in WS
A perspective on meta-boundaries
The judicious design of electromagnetic boundary provides a crucial route to
control light-matter interactions, and it is thus fundamental to basic science
and practical applications. General design approaches rely on the manipulation
of bulk properties of superstrate or substrate and on the modification of
boundary geometries. Due to the recent advent of metasurfaces and
low-dimensional materials, the boundary can be flexibly featured with a surface
conductivity, which can be rather complex but provide an extra degree of
freedom to regulate the propagation of light. In this perspective, we denote
the boundary with a non-zero surface conductivity as the meta-boundary. The
meta-boundaries are categorized into four types, namely isotropic, anisotropic,
biisotropic and bianisotropic meta-boundaries, according to the electromagnetic
boundary conditions. Accordingly, the latest development for these four kinds
of meta-boundaries are reviewed. Finally, an outlook on the research tendency
of meta-boundaries is provided, particularly on the manipulation of
light-matter interactions by simultaneously exploiting meta-boundaries and
metamaterials
Curvaton reheating mechanism in inflation on warped Dvali-Gabadadze-Porrati brane
An impressed feature of inflation on warped Dvali-Gabadadze-Porrati (DGP)
brane is that the inflationary phase exits spontaneously for a scalar inflaton
field with exponential potential, which presents a graceful exit mechanism for
the inflation. But its reheating mechanism leaves open. We investigate the
curvaton reheating in inflation on warped DGP brane model. The reheating may
occur in effctively 5 dimensional or 4 dimensional stage. We study the
permitted parameter space of the curvaton field in detail. We demonstrate how
the inflation model of the warped DGP brane is improved by the curvaton
mechanism.Comment: 10 pages, 7 figures, references adde
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