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您选择的条件: Ming Yang
  • Construction of nursing HRM model based on manpower supermarket resource bank

    分类: 护理学 >> 护理学 提交时间: 2023-04-22

    摘要: Objective: To explore the effect of implementing manpower supermarket resourcebank management in the nursing human resource management of Jiangsu ProvinceAcademy of Traditional Chinese medicine. Methods: The concept of supermarket management was first developed and appliedto the administration of manpower services. Next, the structure of nursing nursinghuman resource management was established. By developing the commodity bankof the manpower supermarket, comprising ① general nurse bank, ②special post mobile bank ③ post ability refueling bank. The quality of goods is ensuredbycombining job training and recruitment unit criteria. In parallel, a standardizedselection path is created, including the standardization of the order-sending reviewprocess, the implementation of the commodity maintenance regulations, andthescreening of the conditions of the selection units, ensuring the streamlined operationof the manpower supermarket. Results: A total of 1,284 nurses were dynamically deployed in the hospital fromOctober 2021 to October 2022 in 31 different batches. In addition to boostingthequality of nursing human resource management and the quality of specialized nursingcare, the high frequency of staff deployment and orderly and innovative management decreased the rate of patient complaints and the turnover rate of nurses. Conclusion: It is worth learning from the manpower supermarket management which combines diversified staffing needs, the need for flexible nursing staff management inthe management of routine epidemic prevention and control, as well as nursing staff capacity development to meet the needs of nursing human resource management inthe current state of medical services.

  • Correcting Stellar Flare Frequency Distributions Detected by TESS and Kepler

    分类: 天文学 >> 天文学 提交时间: 2023-02-19

    摘要: The habitability of planets is closely connected with the stellar activity, mainly the frequency of flares and the distribution of flare energy. Kepler and TESS find many flaring stars are detected via precise time-domain photometric data, and the frequency and energy distribution of stellar flares on different types of stars are studied statistically. However, the completeness and observational bias of detected flare events from different missions (e.g. Kepler and TESS) vary a lot. We use a unified data processing and detection method for flares events based on the light curve from Kepler and TESS. Then we perform injection and recovery tests in the original light curve of each star for each flare event to correct the completeness and energy of flares. Three samples of flaring stars are selected from Kepler and TESS, with rotating periods from 1 to $\sim$ 5 days. Adopting a hot-blackbody assumption, our results show that the cumulative flare frequency distributions (FFDs) of the same stars in Kepler and TESS bands tend to be consistent after correction, revealing a more natural flaring frequency and energy distribution. Our results also extend the low-energy limit in cumulative FFD fitting to $10^{31.5-33}$ erg on different types of stars. For solar-type stars, the average power-law index of cumulative FFD ($\alpha_{\rm cum}$) is $-0.84$, which indicates that low-energy flares contribute less to the total flare energy. With a piecewise correlation between $\alpha_{\rm cum}$ and $T_{\rm eff}$, $\alpha_{\rm cum}$ first rises with $T_{\rm eff}$ from M2 to K1 stars, then slightly decreases for stars hotter than K1.

  • The Sample of Red Supergiants in Twelve Low-Mass Galaxies of the Local Group

    分类: 天文学 >> 天文学 提交时间: 2023-02-19

    摘要: This work establishes the most complete sample of red supergiants (RSGs) in twelve low-mass galaxies (WLM, IC 10, NGC 147, NGC 185, IC 1613, Leo A, Sextans B, Sextans A, NGC 6822, Pegasus Dwarf, SMC and LMC) of the Local Group, which forms the solid basis to study the properties of RSGs as well as the star formation rate (SFR) and initial mass function (IMF) of the galaxies. After removing the foreground dwarf stars by their obvious branch in the near-infrared color-color diagram ($(J-H)_0/(H-K)_0$) with the UKIRT/WFCAM and 2MASS photometry as well as the Gaia/EDR3 measurements of proper motion and parallax, RSGs are identified from their location in the color-magnitude diagram $(J-K)_{0}/K_{0}$ of the member stars of the specific galaxy. A total of 2,190 RSGs are found in ten dwarf galaxies, and additionally 4,823 and 2,138 RSGs in the LMC and SMC respectively. The locations of the tip of the red giant branch in the $(J-K)_{0}/K_{0}$ diagram are determined to serve as an indicator of the metallicity and distance modulus of the galaxies.

  • Correcting Stellar Flare Frequency Distributions Detected by TESS and Kepler

    分类: 天文学 >> 天文学 提交时间: 2023-02-19

    摘要: The habitability of planets is closely connected with the stellar activity, mainly the frequency of flares and the distribution of flare energy. Kepler and TESS find many flaring stars are detected via precise time-domain photometric data, and the frequency and energy distribution of stellar flares on different types of stars are studied statistically. However, the completeness and observational bias of detected flare events from different missions (e.g. Kepler and TESS) vary a lot. We use a unified data processing and detection method for flares events based on the light curve from Kepler and TESS. Then we perform injection and recovery tests in the original light curve of each star for each flare event to correct the completeness and energy of flares. Three samples of flaring stars are selected from Kepler and TESS, with rotating periods from 1 to $\sim$ 5 days. Adopting a hot-blackbody assumption, our results show that the cumulative flare frequency distributions (FFDs) of the same stars in Kepler and TESS bands tend to be consistent after correction, revealing a more natural flaring frequency and energy distribution. Our results also extend the low-energy limit in cumulative FFD fitting to $10^{31.5-33}$ erg on different types of stars. For solar-type stars, the average power-law index of cumulative FFD ($\alpha_{\rm cum}$) is $-0.84$, which indicates that low-energy flares contribute less to the total flare energy. With a piecewise correlation between $\alpha_{\rm cum}$ and $T_{\rm eff}$, $\alpha_{\rm cum}$ first rises with $T_{\rm eff}$ from M2 to K1 stars, then slightly decreases for stars hotter than K1.

  • Searching for orbital decay in a heartbeat star system KIC 3766353

    分类: 天文学 >> 天文学 提交时间: 2023-02-19

    摘要: Theory suggests that the orbits of a large fraction of binary systems, including planet-star binary systems, shrink by few orders of magnitude after formation. But so far, only one hot Jupiter with tidally-driven orbital decay has been found by transit timing variations. We propose to search for orbital decay companions in heartbeat star systems because the orbital angular momentum is effectively transferred to the host star causing tidal dissipation. KIC 3766353 is one of the heartbeat stars with tidally excited oscillations. We acquired the primary and the secondary eclipse time variations from the \textit{Kepler} photometric light curves. Timing analysis shows that KIC 3766353 is a hierarchical triple system with a hidden third body and a red dwarf (mass $0.35\ M_{\odot}$, radius $0.34\ R_{\odot}$) in its inner orbit. The minimum mass of the third body is $\sim 0.26 \ M_{\odot}$, and the distance from the inner orbital is $\sim 111.4 \ R_{\odot}$. The period decay rate of the red dwarf is approximately 358 ms yr$^{-1}$. The combined effects of the light-travel time and the orbital decay lead to the observed timing variations. Future monitoring with a long time base-line observations is required to delve into the contributions of these two effects.

  • The Measurement of Dynamic Tidal Contribution to Apsidal Motion in Heartbeat Star KIC 4544587

    分类: 天文学 >> 天文学 提交时间: 2023-02-19

    摘要: Apsidal motion is a gradual shift in the position of periastron. The impact of dynamic tides on apsidal motion has long been debated, because the contribution could not be quantified due to the lack of high quality observations. KIC 4544587 with tidally excited oscillations has been observed by \textit{Kepler} high-precision photometric data based on long time baseline and short-cadence schema. In this paper, we compute the rate of apsidal motion that arises from the dynamic tides as $19.05\pm 1.70$ mrad yr$^{-1}$ via tracking the orbital phase shifts of tidally excited oscillations. We also calculate the procession rate of the orbit due to the Newtonian and general relativistic contribution as $21.49 \pm 2.8$ and $2.4 \pm 0.06$ mrad yr$^{-1}$, respectively. The sum of these three factors is in excellent agreement with the total observational rate of apsidal motion $42.97 \pm 0.18$ mrad yr$^{-1}$ measured by eclipse timing variations. The tidal effect accounts for about 44\% of the overall observed apsidal motion and is comparable to that of the Newtonian term. Dynamic tides have a significant contribution to the apsidal motion. The analysis method mentioned in this paper presents an alternative approach to measuring the contribution of the dynamic tides quantitatively.

  • The C/M Ratio of AGB Stars in the Local Group Galaxies

    分类: 天文学 >> 天文学 提交时间: 2023-02-19

    摘要: The number ratio of carbon-rich to oxygen-rich asymptotic giant branch (AGB) stars (the so-called C/M ratio) is closely related to the evolution environment of the host galaxy. This work studies the C/M ratio in 14 galaxies within the Local Group with the most complete and clean sample of member stars identified in our previous works. The borderlines between carbon-rich AGB and oxygen-rich AGB stars as well as red supergiants are defined by Gaussian mixture model fitting to the number density in the $(J - K)/K$ diagram for the member stars of the LMC and M33, and then applied to the other galaxies by shifting the difference in the position of tip red giant branch (TRGB). The C/M ratios are obtained after precise and consistent categorization. Although for galaxies with larger distance modulo there is greater uncertainty, the C/M ratio is clearly found to decrease with the color index $(J - K)_0$ of TRGB as the indicator of metallicity, which agrees with previous studies and can be explained by the fact that carbon stars are more easily formed in a metal-poor environment. Furthermore, the C/M ratio within M33 is found to increase with galactocentric distance, which coincides with this scenario and the galactic chemical evolution model. On the other hand, the C/M ratio within M31 is found to decrease with galactocentric radius, which deserves further study.

  • Detecting and Monitoring Tidal Dissipation of Hot Jupiters in the Era of SiTian

    分类: 天文学 >> 天文学 提交时间: 2023-02-19

    摘要: Transit Timing Variation (TTV) of hot Jupiters provides direct observational evidence of planet tidal dissipation. Detecting tidal dissipation through TTV needs high precision transit timings and long timing baselines. In this work, we predict and discuss the potential scientific contribution of SiTian Survey in detecting and analyzing exoplanet TTV. We develop a tidal dissipation detection pipeline for SiTian Survey that aims at time-domain astronomy with 72 1-meter optical telescopes. The pipeline includes the modules of light curve deblending, transit timing obtaining, and TTV modeling. SiTian is capable to detect more than 25,000 exoplanets among which we expect $\sim$50 sources showing evidence of tidal dissipation. We present detection and analysis of tidal dissipating targets, based on simulated SiTian light curves of XO-3b and WASP-161b. The transit light curve modeling gives consistent results within 1$\sigma$ to input values of simulated light curves. Also, the parameter uncertainties predicted by Monte-Carlo Markov Chain are consistent with the distribution obtained from simulating and modeling the light curve 1000 times. The timing precision of SiTian observations is $\sim$ 0.5 minutes with one transit visit. We show that differences between TTV origins, e.g., tidal dissipation, apsidal precession, multiple planets, would be significant, considering the timing precision and baseline. The detection rate of tidal dissipating hot Jupiters would answer a crucial question of whether the planet migrates at an early formation stage or random stages due to perturbations, e.g., planet scattering, secular interaction. SiTian identified targets would be constructive given that the sample would extend tenfold.

  • ET White Paper: To Find the First Earth 2.0

    分类: 天文学 >> 天文学 提交时间: 2023-02-19

    摘要: We propose to develop a wide-field and ultra-high-precision photometric survey mission, temporarily named "Earth 2.0 (ET)". This mission is designed to measure, for the first time, the occurrence rate and the orbital distributions of Earth-sized planets. ET consists of seven 30cm telescopes, to be launched to the Earth-Sun's L2 point. Six of these are transit telescopes with a field of view of 500 square degrees. Staring in the direction that encompasses the original Kepler field for four continuous years, this monitoring will return tens of thousands of transiting planets, including the elusive Earth twins orbiting solar-type stars. The seventh telescope is a 30cm microlensing telescope that will monitor an area of 4 square degrees toward the galactic bulge. This, combined with simultaneous ground-based KMTNet observations, will measure masses for hundreds of long-period and free-floating planets. Together, the transit and the microlensing telescopes will revolutionize our understandings of terrestrial planets across a large swath of orbital distances and free space. In addition, the survey data will also facilitate studies in the fields of asteroseismology, Galactic archeology, time-domain sciences, and black holes in binaries.