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On the moment of inertia of a proto neutron star

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Chinese Physics C 2010年第10期34卷 1587-1592页

作者：赵先锋张华贾焕玉 Department of Electronics Engineering Chuzhou University Institute of Applied Physics and Computational Mathematics Institute for Modern Physics Southwest Jiaotong University

The influences of σ^＊ and Ф mesons, temperature and coupling constants of nucleons on the moment of inertia of the proto neutron star （PNS） are examined in the framework of relativistic mean field theory for the baryon octet {n, p, A, ∑^-, ∑^,∑^＋,^-, ^0} system. It is found that, compared with that without considering σ^＊ and Ф mesons, the moment of inertia decreases. It is also found that the higher the temperature, the larger the incompressibility and symmetry energy coefficient, and the larger the moment of inertia of a PNS. The influence of temperature and coupling constants of the nucleons on the moment of inertia of a PNS is larger than that of the σ^＊ and Ф mesons.

关键词： neutron star moment of inertia relativistic mean field theory

On-orbit Identification of Time-varying moment of inertia for Spacecraft Based on a Recursive Subspace Method 36

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On-orbit Identification of Time-varying Moment of Inertia fo...

Analysis of High Precision moment of inertia Measurement Method Based on Torsion Pendulum Method

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作者： Zhiyu Ni Zhigang Wu Jinguo Liu Xinhui Shen Shenyang Institute of Automation Chinese Academy of Sciences Dalian University of Technology School of Aeronautics and Astronautics

ISBN: (纸本)9781538629185

In this paper, a novel recursive method to identify the moment of inertia parameters of on-orbit spacecraft is proposed. Different from the frequently-used momentum conservation and least squares approach, the presented method is implemented based on the Projection Approximation Subspace Tracking（PAST）, and the moment of inertia parameters can be determined recursively from the system state-space model by coordinate transformation. For a spacecraft with flexible appendages, three on-orbit cases that may cause the moment of inertia parameters to vary with time are investigated. In numerical simulations, comparing with the classical subspace method based on the singular value decomposition（SVD）, the results illustrate that the proposed recursive algorithm can identify the time-varying moment of inertia parameters effectively. Moreover, the computational efficiency is also higher than that of the SVD-based method without the decomposition of the Hankel matrix.

关键词： Recursive subspace method time-varying system moment of inertia on-orbit identification state space model

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Analysis of High Precision Moment of Inertia Measurement Met...

Comparison between formulas of rotational band for axially symmetric deformed nuclei

第40届中国控制会议

作者： Haoyue Li Yong Xu Jiuhui Ding Kangrui Zhai School of Aerospace Engineering Beijing Institute of Technology

The accuracy of parameters such as the moment of inertia will directly affect the accuracy of the missile’s orbit and attitude control,at present,the measurement of the moment of inertia mainly relies on experimental methods. The instrument for measuring moment of inertia by Torsional-pendulum method discussed in this article is aimed at calculating the damping coefficient and stiffness *** only needs to measure the angle,angular velocity and angular acceleration during the torsion pendulum to calculate the moment of *** accelerometer and gyroscope to measure angle and angular velocity respectively,and extract angular acceleration from *** methods have the disadvantages of amplifying noise and large overshoot when extracting or restoring the original signal from noisy signal,so it will use differential The tracker obtains the best approximation of the original signal to extract the more accurate angular acceleration,use the least square method to calculate the damping coefficient and stiffness coefficient,and then find the moment of inertia,which improves the calculation accuracy.

关键词： Torsional-pendulum method moment of inertia Differential tracker Recursive least square method

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Chinese Physics C 2008年第2期32卷 112-119页

作者：吴熙雷奕安 Department of Physics Peking University Beijing 100871China

The experimental rotational spectra of the deformed nuclei available in even-even and odd-A nuclei in the rare-earth and actinide regions are systematically analyzed with several rotational spectra formulas, including Bohr-Mottelson＇s I（I＋ 1）-expansion, Harris＇ ω^2-expansion, ab and abc formulas. It is shown that the simple 2-parameter ab formula is much better than the widely used 2-parameter Bohr-Mottelson＇s AB formula and Harris＇ αβ formula. The available data of the rotational spectra of both ground-state band in even-even nuclei and one-quasiparticle band in odd-A nuclei can be conveniently and rather accurately reproduced by ab formula and abc formula. The moment of inertia and the variation with rotational frequency of angular momentum can be satisfactorily reproduced by ab and abc formulas.

关键词： rotational band moment of inertia ab formula abc formula

moments of inertia of neutron stars in relativistic mean field theory:The role of the isovector scalar channel

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Science China(Physics,Mechanics & Astronomy) 2018年第8期61卷 54-60页

作者： Zhuang Qian RuoYu Xing BaoYuan Sun School of Nuclear Science and Technology Lanzhou University

With the inclusion of the isovector scalar channel in the meson-nucleon couplings, taking DD-MEδ as an effective interaction, the moments of inertia of neutron stars possessing various stellar masses are studied within the density dependent relativistic mean field （RMF） theory. The isovector scalar channel contributes to the softening of the neutron-star matter equation of state （EOS） and therefore the reduction of the maximum mass and radius of neutron stars. Smaller values of the total moment of inertia 1 and the crustal moment of inertia AI are then obtained in DD-ME~ via numerical procedure in comparison with those in other selected RMF functionals. In addition, the involvement of the isovector scalar channel lowers the thickness of the neutron star crust and its mass fi＇action as well. The sensitivity to both the crustal mass and stellar radius causes the crustal moment of inertia to be more obviously reduced than the total one, eventually leading to a suppression on the fraction of crustal moment of inertia △I/I in DD-MFδ. The results indicate the crustal moment of inertia as a more sensitive probe of the neutron-star matter EOS than the total one, and demonstrate that the isovector scalar meson-nucleon couplings in the RMF theory could exert influence over the physics of pulsar glitches.

关键词： neutron star moment of inertia relativistic mean field theory isovector scalar channel

Investigation of the two-quasiparticle bands in the doubly-odd nucleus ^(166)Ta using a particle-number conserving cranked shell model

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Science China(Physics,Mechanics & Astronomy) 2016年第7期59卷 33-39页

作者： ZhenHua Zhang Mathematics and Physics Department North China Electric Power University

The high-spin rotational properties of two-quasiparticle bands in the doubly-odd 166Ta are analyzed using the cranked shell model with pairing correlations treated by a particle-number conserving method, in which the blocking effects are taken into account exactly. The experimental moments of inertia and alignments and their variations with the rotational frequency hw are reproduced very well by the particle-number conserving calculations, which provides a reliable support to the configuration assignments in previous works for these bands. The backbendings in these two-quasiparticle bands are analyzed by the calculated occupation probabilities and the contributions of each orbital to the total angular momentum alignments. The moments of inertia and alignments for the Gallagher-Moszkowski partners of these observed two-quasiparticle rotational bands are also predicted.

关键词： particle-number conserving method pairing correlations moment of inertia

Properties of hyperon stars rotating at Keplerian frequency

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Chinese Physics B 2011年第2期20卷 592-600页

作者：文德华陈伟 Department of Physics South China University of Technology Department of Physics Jinan University

The structure and properties of a Keplerian rotating hyperon star with an equation of state （EOS） investigated using the relativistic σ-ω-p model are examined by employing an accurate numerical scheme. It is shown that there is a clear rotating effect on the structure and properties, and that hyperon star matter cannot support a star with a mass larger than 1.9 M~, even a star rotating at the fastest allowed frequency. The constraints of the two known fastest rotating frequencies （716 Hz and 1122 Hz） on the mass and radius of a hyperon star are also explored. ~rthermore, our results indicate that the imprint of the rapid rotation of a hyperon star on the moment of inertia is clear; the backward equatorial redshift, the forward equatorial redshift and the polar redshift can be distinguished clearly, the forward equatorial redshift is always negative; and its figuration is far from a spherical symmetric shape.

关键词： equation of state hyperon star moment of inertia redshift

moments of inertia of triaxial nuclei in covariant density functional theory

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Nuclear Science and Techniques 2024年第10期35卷 197-207页

作者： Yu-Meng Wang Qi-Bo Chen Department of Physics East China Normal UniversityShanghai 200241China

The covariant density functional theory(CDFT)and five-dimensional collective Hamiltonian(5DCH)are used to analyze the experimental deformation parameters and moments of inertia(MoIs)of 12 triaxial nuclei as extracted by Allmond and Wood[*** and ***,***.B 767,226(2017)].We find that the CDFT MoIs are generally smaller than the experimental values but exhibit qualitative consistency with the irrotational flow and experimental data for the relative MoIs,indicating that the intermediate axis exhibites the largest ***,it is found that the pairing interaction collapse could result in nuclei behaving as a rigid-body flow,as exhibited in the^(186-192)Os ***,by incorporating enhanced CDFT MoIs(factor of f≈1.55)into the 5DCH,the experimental low-lying energy spectra and deformation parameters are reproduced *** with both CDFT and the triaxial rotor model,the 5DCH demonstrates superior agreement with the experimental deformation parameters and low-lying energy spectra,respectively,emphasizing the importance of considering shape fluctuations.

关键词： moment of inertia Trixial nucleus Covariant density functional theory Five-dimensional collective Hamiltonian Low-lying energy spectrum

Particle-number-conserving analysis of multiquasiparticle bands in ^(177)Lu

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Chinese Physics C 2010年第1期34卷 39-44页

作者：张振华齐寿涛孙宝玺雷奕安曾谨言 State Key Lab of Nuclear Physics and Technology School of Physics Peking University Institute of Theoretical Physics College of Applied Sciences Beijing University of Technology

The experimental one-, three-, and five-quasiparticle bands in 177Lu are analyzed by the particle-number conserving （PNC） method for treating the cranked shell model with pairing interaction, in which the blocking effects are taken into account exactly. The experimental moments of inertia are reproduced very well by PNC calculations with us free parameter.

关键词： multiquasiparticle band blocking effect moment of inertia particle-number-conserving method