A5100624238- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Particle physics theoretical and experimental studies
- Astrophysics and Star Formation Studies
- High-Energy Particle Collisions Research
- Particle Detector Development and Performance
- Gamma-ray bursts and supernovae
- Astro and Planetary Science
- Quantum Chromodynamics and Particle Interactions
- Manufacturing Process and Optimization
- Advanced machining processes and optimization
- Astronomical Observations and Instrumentation
- Computational Physics and Python Applications
- Advanced Neural Network Applications
- Solar and Space Plasma Dynamics
- Advanced Surface Polishing Techniques
- Engineering Technology and Methodologies
- Advanced Image and Video Retrieval Techniques
- Image Enhancement Techniques
- Color Science and Applications
- Adaptive optics and wavefront sensing
- Nuclear Physics and Applications
- Phase Change Materials Research
- Image Retrieval and Classification Techniques
- Atmospheric Ozone and Climate
Wuzhou University
2024
Australian National University
2024
Heidelberg Institute for Theoretical Studies
2024
Max Planck Institute for Solar System Research
2019-2024
National University of Defense Technology
2023-2024
Wuhan Institute of Technology
2023-2024
Shanghai University of Electric Power
2024
Chinese Academy of Medical Sciences & Peking Union Medical College
2024
Capital Normal University
2024
Tianjin University
2023-2024
The Kepler mission has provided exquisite data to perform an ensemble asteroseismic analysis on evolved stars. In this work we systematically characterize solar-like oscillations and granulation for 16,094 oscillating red giants, using end-of-mission long-cadence data. We produced a homogeneous catalog of the frequency maximum power (typical uncertainty $\sigma_{\nu_{\rm max}}$=1.6\%), mean large separation ($\sigma_{\Delta\nu}$=0.6\%), oscillation amplitude ($\sigma_{\rm A}$=4.7\%),...
Abstract Study Analysis Group 21 (SAG21) of NASA’s Exoplanet Exploration Program was organized to study the effect stellar contamination on space-based transmission spectroscopy, a method for studying exoplanetary atmospheres by measuring wavelength-dependent radius planet as it transits its star. Transmission spectroscopy relies precise understanding spectrum star being occulted. However, stars are not homogeneous, constant light sources but have temporally evolving photospheres and...
Investigations of the origin and evolution Milky Way disk have long relied on chemical kinematic identification its components to reconstruct our Galactic past. Difficulties in determining precise stellar ages restricted most studies small samples, normally confined solar neighbourhood. Here we break this impasse with help asteroseismic inference perform a chronology throughout age Galaxy. We chemically dissect population using sample red giant stars spanning out 2~kpc annulus observed by...
Abstract Asteroseismology has become widely accepted as a benchmark for accurate and precise fundamental stellar properties. It can therefore be used to validate calibrate parameters derived from other approaches. Meanwhile, one leverage large-volume surveys in photometry, spectroscopy, astrometry infer over wide range of evolutionary stages, independently asteroseismology. Our pipeline, SEDEX ( https://github.com/Jieyu126/SEDEX ), compares the spectral energy distribution predicted by MARCS...
Underwater target detection is widely used in various applications such as underwater search and rescue, environment monitoring, marine resource surveying. However, the complex environment, including factors light changes background noise, poses a significant challenge to detection. We propose an improved algorithm based on YOLOv8n overcome these problems. Our focuses three aspects. Firstly, we replace original C2f module with Deformable Convnets v2 enhance adaptive ability of region...
Model editing techniques modify a minor proportion of knowledge in Large Language Models (LLMs) at relatively low cost, which have demonstrated notable success. Existing methods assume Transformer Layer (TL) hidden states are values key-value memories the Feed-Forward Network (FFN). They usually optimize TL to memorize target and use it update weights FFN LLMs. However, information flow comes from three parts: Multi-Head Self-Attention (MHSA), FFN, residual connections. neglect fact that...
In the power spectra of oscillating red giants, there are visually distinct features defining stars ascending giant branch from those that have commenced helium core burning. We train a one-dimensional convolutional neural network by supervised learning to automatically learn these visual images folded oscillation spectra. By training and testing on \textit{Kepler} we achieve an accuracy up 99\% in separating helium-burning giants branch. The additionally shows capability accurately...
Deep learning in the form of 1D convolutional neural networks have previously been shown to be capable efficiently classifying evolutionary state oscillating red giants into giant branch stars and helium-core burning by recognizing visual features their asteroseismic frequency spectra. We elaborate further on deep method developing an improved network classifier. To make our useful for current future space missions such as K2, TESS PLATO, we train classifiers that are able classify states...
The multitube design in the shell-and-tube type latent heat thermal energy storage (LHTES) system has received intensive attention due to its promising benefits enhancing efficiency. In this paper, single and multi-tube shell LHTES systems were experimentally investigated. First, study compared characteristics between a multiple-tube exchanger (MTHX) single-tube (STHX). STHX's geometrical parameters coincided with virtual cylindrical domain MTHX, being similar model formulated by simplifying...
Abstract Based on all 2 minute cadence TESS light curves from Sector 1 to 60, we provide a catalog of 8651 solar-like oscillators, including frequency at maximum power ( <?CDATA ${\nu }_{\max }$?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>ν</mml:mi> </mml:mrow> <mml:mi>max</mml:mi> </mml:msub> </mml:math> , with its median precision σ = 5.39%), large separation (Δ ν 6.22%), and seismically derived masses, radii, surface gravity...
Obtaining accurate and precise masses ages for large numbers of giant stars is great importance unraveling the assemblage history Galaxy. In this paper, we estimate 6940 red branch (RGB) with asteroseismic parameters deduced from Kepler photometry stellar atmospheric derived LAMOST spectra. The typical uncertainties mass a few per cent, that age ∼20 cent. sample reveal two separate sequences in age–[α/Fe] relation – high-α sequence older than ∼8 Gyr low-α composed ranging younger 1 to 11...
Low stiffness and positioning problems are difficulties challenges in the precise machining of near-net-shaped blades. This paper aims to achieve high accuracy manufacturing by fixture- deformation-control adaptive CNC process. Adaptive technology is first analyzed, new fixture-evaluation criteria methods evaluate process fixture design built. Second, a designed manufactured after analyzing its scheme, clamping materials (PEEK-GF30), structure characteristics. Finally, analyzed FEA...
While long period variables (LPVs) have been extensively investigated, especially with MACHO and OGLE data for the Magellanic Clouds, there still exist open questions in their pulsations regarding excitation mechanisms, radial order angular degree assignment. Here, we perform asteroseismic analyses on LPVs observed by 4-year Kepler mission. Using a cross-correlation method, detect unambiguous pulsation ridges associated fundamental modes ($n=1$) overtones ($n\geqslant2$), where assignment is...
ABSTRACT Stellar light curves contain valuable information about oscillations and granulation, offering insights into stars’ internal structures evolutionary states. Traditional asteroseismic techniques, primarily focused on power spectral analysis, often overlook the crucial phase in these curves. Addressing this gap, recent machine learning applications, particularly those using Convolutional Neural Networks (CNNs), have made strides inferring stellar properties from However, CNNs are...
The importance of numax (the frequency maximum oscillation power) for asteroseismology has been demonstrated widely in the previous decade, especially red giants. With large amount photometric data from CoRoT, Kepler and TESS, several automated algorithms to retrieve values have introduced. Most these correct granulation background power spectrum by fitting a model subtracting it before measuring numax. We developed method that does not require background. Instead, we simply divide function...
Despite more than 20 years since the discovery of first gas giant planet with an anomalously large radius, mechanism for inflation remains unknown. Here, we report EPIC228754001.01, inflated found NASA K2 Mission, and a revised mass another planet, K2-97b. These planets reside on ~9 day orbits around host stars which recently evolved into red giants. We constrain irradiation history these using models constrained by asteroseismology Keck/HIRES spectroscopy radial velocity measurements....
ABSTRACT The Milky Way was shaped by the mergers with several galaxies in past. We search for remnant stars that were born these foreign and assess their ages an effort to put upper limits on merger times thereby better understand evolutionary history of our Galaxy. Using 5D-phase space information from Gaia eDR3, radial velocities DR2 chemical apogee DR16, we kinematically chemically select 21 red giant belonging former dwarf merged Way. With added asteroseismology Kepler K2 , determine ex...
Abstract The Sun is depleted in refractory elements compared to nearby solar twins, which may be linked the formation of giant or terrestrial planets. Here we present high-resolution, high signal-to-noise spectroscopic data for 17 solar-like stars hosting planets, obtained with Magellan II/MIKE, investigate whether this depletion related planet formation. We derive stellar parameters, including atmosphere, age, radius, mass, and chemical abundances 22 from carbon europium through...
Abstract Long-period variables (LPVs) are high-luminosity red giants or supergiants with pulsation periods ranging from days to years. Many LPVs in the Large Magellanic Cloud (LMC) and Galactic bulge (BLG) have been continuously observed over a time span of 26 yr by Optical Gravitational Lensing Experiment (OGLE) survey. Using OGLE-IV data, we applied Gaussian processes kernels tailored for solar-like oscillations extract two global asteroseismic parameters—the frequency maximum power (...
ABSTRACT When low- and intermediate-mass stars evolve off the main sequence, they expand cool into red giant stages of evolution, which include those associated with shell H burning (the branch), core He clump), asymptotic branch). The majority giants have masses &lt;2 M⊙, more massive than this are often excluded from major studies. Here, we present a study highest mass (M &gt; 3.0 M⊙) in Kepler sample 16 000 giants. We begin by re-estimating their global seismic properties new...
ABSTRACT Young α-rich (YAR) stars within the old Galactic thick disc exhibit a dual characteristic of relative youth determined with asteroseismology and abundance enhancement in α elements measured from high-resolution spectroscopy. The origin YAR has been proposed to be binary evolution via mass transfer or stellar mergers. If that is case, should spin rapidly thus magnetically active, because they are angular momentum gainers. In this study, seek footprint, we select on main-sequence...
Radial-velocity (RV) jitter due to intrinsic stellar variability introduces challenges when characterizing exoplanet systems, particularly studying small (sub-Neptune-sized) planets orbiting solar-type stars. In this Letter we predicted for dwarfs and giants the oscillations, which in velocity have much larger amplitudes than noise introduced by granulation. We then fitted terms of following sets parameters: (1) Luminosity, mass, effective temperature: fit returns precisions (i.e., standard...
We analysed solar-like oscillations in 1523 $\textit{Kepler}$ red giants which have previously been misclassified as subgiants, with predicted $\nu_{\rm max}$ values (based on the Kepler Input Catalogue) between 280$\mu$Hz to 700$\mu$Hz. report discovery of 626 new oscillating our sample, addition 897 oscillators that were characterized by Hekker et al. (2011) from one quarter data. Our sample increases known number low-luminosity $26\%$ (up $\sim$ 1900 stars). About three quarters are...
Obtaining measurements of chromospheric and photometric activity stars with near-solar fundamental parameters rotation periods is important for a better understanding solar-stellar connection. We select sample 2603 from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST)-Kepler field use LAMOST spectra to measure their Kepler light curves photospheric (i.e., amplitude variability). While 1556 these could not be measured due low variability highly irregular temporal profile...