A5100456763- Pulsars and Gravitational Waves Research
- Geophysics and Gravity Measurements
- Radio Astronomy Observations and Technology
- Astrophysical Phenomena and Observations
- Astrophysics and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Cosmology and Gravitation Theories
- GNSS positioning and interference
- Aluminum Alloys Composites Properties
- Advanced Frequency and Time Standards
- High-pressure geophysics and materials
- Advanced materials and composites
- Bee Products Chemical Analysis
- MXene and MAX Phase Materials
- Phytochemicals and Antioxidant Activities
- Advanced ceramic materials synthesis
- Black Holes and Theoretical Physics
- Superconducting Materials and Applications
- Geophysics and Sensor Technology
- Aluminum Alloy Microstructure Properties
- Metal and Thin Film Mechanics
- Superconducting and THz Device Technology
- Metallurgy and Material Science
- Statistical and numerical algorithms
- Nuclear reactor physics and engineering
Lishui University
2022-2025
Xinjiang Astronomical Observatory
2014-2024
Shenyang Institute of Computing Technology (China)
2024
Chinese Academy of Sciences
2012-2024
Zhejiang Chinese Medical University
2024
Lanzhou Institute of Chemical Physics
2001-2021
National Health and Family Planning Commission
2020-2021
Nanjing Institute of Geography and Limnology
2021
Xinyang Normal University
2020
Chinese Center For Disease Control and Prevention
2018-2019
Abstract We describe 14 yr of public data from the Parkes Pulsar Timing Array (PPTA), an ongoing project that is producing precise measurements pulse times arrival 26 millisecond pulsars using 64-m radio telescope with a cadence approximately 3 weeks in three observing bands. A comprehensive description pulsar systems employed at since 2004 provided, including calibration methodology and analysis stability system components. attempt to provide full accounting reduction raw measured Stokes...
A cosmological first-order phase transition is expected to produce a stochastic gravitational wave background. If the temperature on MeV scale, power spectrum of induced waves peaks around nanohertz frequencies, and can thus be probed with high-precision pulsar timing observations. We search for such background latest data set Parkes Pulsar Timing Array. find no evidence Hellings-Downs spatial correlation as Therefore, we present constraints model parameters. Our analysis shows that...
ABSTRACT The main goal of pulsar timing array experiments is to detect correlated signals such as nanohertz-frequency gravitational waves. Pulsar data collected in dense monitoring campaigns can also be used study the stars themselves, their binary companions, and intervening ionized interstellar medium. Timing observations are extraordinarily sensitive changes path-length between Earth, enabling precise measurements positions, distances velocities, shapes orbits. Here we present a analysis...
ABSTRACT We have constructed a new time-scale, TT(IPTA16), based on observations of radio pulsars presented in the first data release from International Pulsar Timing Array (IPTA). used two analysis techniques with independent estimates noise models for pulsar and different algorithms obtaining time-scale. The analyses agree within estimated uncertainties both TT(BIPM17), post-corrected time-scale produced by Bureau des Poids et Mesures (BIPM). show that methods could detect significant...
The nature of dark matter remains obscure in spite decades experimental efforts. mass candidates can span a wide range, and its coupling with the Standard Model sector uncertain. All these unknowns make detection extremely challenging. Ultralight matter, m∼10−22 eV, is proposed to reconcile disagreements between observations predictions from simulations small-scale structures cold paradigm while remaining consistent other observations. Because large de Broglie wavelength local occupation...
Abstract A nanohertz-frequency stochastic gravitational-wave background can potentially be detected through the precise timing of an array millisecond pulsars. This produces low-frequency noise in pulse arrival times that would have a characteristic spectrum common to all pulsars and well-defined spatial correlation. Recently North American Nanohertz Observatory for Gravitational Waves collaboration (NANOGrav) found evidence common-spectrum component their 12.5 yr data set. Here we report on...
Abstract We report the timing analysis of PSR J1846−0513, a pulsar discovered by Five-hundred-meter Aperture Spherical radio Telescope (FAST) in Commensal Radio Astronomy FAST Survey. The possesses spin period 23.36 ms and spin-down rate ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mover accent="true"> <mml:mrow> <mml:mi>P</mml:mi> </mml:mrow> <mml:mo>̇</mml:mo> </mml:mover> </mml:math> ) 1.0106(3) × 10 −18 s −1 , it is located an eccentric orbit e...
The stable rotation of young pulsars is often interrupted by two non-deterministic phenomena: glitches and red timing noise, glitches, noise. Timing noise provides insights into plasma nuclear physics under extreme conditions. framework leverages rotational symmetry in pulsar spin-down models temporal processes to achieve computational efficiency, aligning with the journal’s focus on principles physical systems. In this paper, we apply a novel frequentist developed within PINT software...
Pulsar timing arrays (PTAs) are designed to detect nanohertz-frequency gravitational waves (GWs). Since GWs anticipated from cosmic strings, PTAs offer a viable approach testing their existence. We present the results of first Bayesian search for gravitational-wave bursts string cusps (GWCSs) using third PPTA data release 30 ms pulsars. In this collection, we find no evidence GWCS signals. compare model with signal one only noise, including common spatially uncorrelated red noise (CURN), and...
Phenolics and flavonoids in honey are considered as the main phytonutrients which not only act natural antioxidants, but can also be used floral markers for identification. In this study, chemical profiles of phenolics flavonoids, antioxidant competences including total phenolic content, DPPH ABTS assays discrimination using chemometric analysis various Chinese monofloral honeys from six botanical origins (acacia, Vitex, linden, rapeseed, Astragalus Codonopsis) were examined. A reproducible...
We present timing solutions and analyses of 11 pulsars discovered by the Five-hundred-meter Aperture Spherical radio Telescope (FAST). These were using an ultra-wide bandwidth receiver in drift-scan observations made during commissioning phase FAST, then confirmed timed 64-m Parkes Radio Telescope. Each pulsar has been observed over a span at least one year. Highlighted discoveries include PSR J0344-0901, which displays mode-changing behaviour may belong to class so-called `swooshing'...
Abstract The Parkes 20 cm multibeam pulsar surveys have discovered nearly half of the known pulsars and revealed many distant with high dispersion measures. Using a sample 1301 from these surveys, we explored spatial distribution birth rate normal pulsars. distances used to calculate surface density are estimated YMW16 electron-density model. When estimating impact Galactic background radiation on our survey, projected in galaxy onto plane, assuming that flux is uniform all directions,...
Abstract Understanding the jitter noise resulting from single-pulse phase and shape variations is important for detection of gravitational waves using pulsar timing arrays. We present measurements variability 12 millisecond pulsars that are part International Pulsar Timing Array sample Five-hundred-meter Aperture Spherical radio Telescope. find levels can vary dramatically among pulsars. A moderate correlation with a coefficient 0.57 between pulse width detected. To mitigate noise, we...
Cu-xNi-5Sn (wt %) alloys with a different Ni content were prepared by powder metallurgy method. The effect of on the hardness and yield strength was investigated. microstructure, composition, morphology observed X-ray diffraction (XRD), scanning electron microscopy (SEM) energy dispersive spectroscopy (EDS), cold field emission microscope (FESEM), respectively. Results indicate that firstly increase then decrease reach up to maximum when is 12.5 wt %. Furthermore, formation sandwich...
Pulsar positions can be measured with high precision using both pulsar timing methods and very-long-baseline interferometry (VLBI). are referenced to a solar-system ephemeris, whereas VLBI distant quasars. Here we compare from published measurements those obtained data the Nanshan Parkes radio telescopes in order relate two reference frames. We find that differ significantly (and also between different ephemerides). A statistically significant change obliquity of ecliptic $2.16\pm0.33$\,mas...
ABSTRACT Detailed structures of the Vela pulsar (PSR B0833-45, with a period 89.33 ms) are predicted by adopting recently constructed unified treatment all parts neutron stars: outer crust, inner and core based on modern microscopic Brueckner–Hartree–Fock calculations. Taking mass in range from 1.0 to 2.0 M ⊙ , we calculate central density, core/crust radii, core/crustal mass, thickness, moment inertia, crustal inertia. Among them, inertia could be effectively constrained accumulated glitch...
Abstract Black widows are millisecond pulsars ablating their companions. The material blown from the companion blocks radio emission, resulting in eclipses. properties of eclipse medium poorly understood. Here, we present direct evidence existence magnetic fields black widow PSR J2051−0827 using observations made with Five-hundred-meter Aperture Spherical Telescope. We detect a regular decrease rotation measure (RM) egress eclipse, changing 60 to −28.7 rad m −2 . RM gradually changes back...