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Spin-1/2 Fermion Gas in One-Dimensional Harmonic Trap with Attractive Delta Function Interaction

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Chinese Physics Letters 2017年第2期34卷 11-14页

作者： ya-hui wang Zhong-Qi Ma School of Physics and Telecommunication Engineering Shaanxi Sci-Tech University Hanzhong 723000 Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049

In terms of the Thomas Fermi method, we solve the ground state energy of the iv-body 1D harmonically trapped spin-l/2 fermion gas with the attractive ^-function interaction in the limit N→∞.

关键词： Delta functions

Lattice Boltzmann method for simulation of time-dependent neutral particle transport

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Nuclear Science and Techniques 2017年第3期28卷 74-84页

作者： ya-hui wang Li-Ming yan Bang-yang Xia Yu Ma School of Energy Science and Engineering Harbin Institute of Technology Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China

In this paper, a novel model is proposed to investigate the neutron transport in scattering and absorbing medium. This solution to the linear Boltzmann equation is expanded from the idea of lattice Boltzmann method(LBM) with the collision and streaming process. The theoretical derivation of lattice Boltzmann model for transient neutron transport problem is proposed for the first *** fully implicit backward difference scheme is used to ensure the numerical stability, and relaxation time and equilibrium particle distribution function are obtained. To validate the new lattice Boltzmann model, the LBM formulation is tested for a homogenous media with different sources, and both transient and steady-state LBM results get a good agreement with the benchmark solutions.

关键词： Transient neutron transport Lattice Boltzmann method Linear Boltzmann equation

Simulation of internal nitrogen release from bottom sediments in an urban lake using a nitrogen flux model

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Water Science and Engineering 2023年第3期16卷 252-260页

作者： Ran Gong hui-ya wang Zhi-xin Hu Yi-ping Li School of Environmental Engineering Nanjing Institute of TechnologyNanjing 211167China College of Environment Hohai UniversityNanjing 210098China

Nutrient release from sediment is considered a significant source for overlying water. Given that nutrient release mechanisms in sediment are complex and difficult to simulate, traditional approaches commonly use assigned parameter values to simulate these processes. In this study, a nitrogen flux model was developed and coupled with the water quality model of an urban lake. After parameter sensitivity analyses and model calibration and validation, this model was used to simulate nitrogen exchange at the sediment–water interface in eight scenarios. The results showed that sediment acted as a buffer in the sediment–water system. It could store or release nitrogen at any time, regulate the distribution of nitrogen between sediment and the water column, and provide algae with nitrogen. The most effective way to reduce nitrogen levels in urban lakes within a short time is to reduce external nitrogen loadings. However, sediment release might continue to contribute to the water column until a new balance is achieved. Therefore, effective measures for reducing sediment nitrogen should be developed as supplementary measures. Furthermore, model parameter sensitivity should be individually examined for different research subjects.

关键词： Diagenesis Nitrogen flux model EFDC Urban lake Modeling Latin hypercube sampling

Ultrathin self-assembly MXene/Co-based bimetallic oxide heterostructures as superior and modulated microwave absorber

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Journal of Materials Science & Technology 2023年第3期134卷 132-141页

作者： hui-ya wang Xiao-Bo Sun Yue Xin Shu-Hao yang Peng-Fei Hu Guang-Sheng wang School of Chemistry Beihang UniversityBeijing 102206China Research Institute of Aero-Engine Beihang UniversityBeijing 102206China

Lightweight and high-efficiency absorbing materials equipped with tunable electromagnetic properties are the foremost important factors for driving applications of 5 G smart era and military ***-ulated by the remarkable merits of heterogeneous interface engineering,a series of unique flower-like Co-based multiphases nanostructures were successfully synthesized through identical hydrothermal method,and subsequently anchored on the Ti_(3)C_(2)T_(x)*** suitable metal ion modulation is feasible to regulate the components,heterogeneous interfaces and defects for tailoring the electromag-netic parameters and microwave absorption(MA)***,the permittivity decreases of CMOT(CoO/MCo_(2)O_(4)/Ti_(3)C_(2)T_(x),M=Fe,Cu,Zn)composites proceed gradually in the order of Fe^(2+),Cu^(2+),Zn^(2+),while the MA performance with tunable absorption peak could be modulated *** asobtained CFOT-12(10 wt%),CCOT-15(10 wt%)and CZOT-15(15 wt%)exhibit excellent MA capacity with a minimum reflection loss(RL_(min))of-41.06,-52.67,-52.52 dB and corresponding effective absorption bandwidth(EAB)of 3.68,4.48,3.92 GHz at 2.10,1.90,1.80 mm,*** work expands a novel approach to construct multicomponent heterostructure for tuning the EM parameters and absorbing property,as well as realize the high efficient and light weight.

关键词： Heterogeneous interface Modulation MXene High-efficiency absorbing materials Lightweight

Reduced-order method for nuclear reactor primary circuit calculation

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Nuclear Science and Techniques 2024年第11期35卷 28-45页

作者： Ze-Long Zhao ya-hui wang Zhe-Xian Liu Hong-Hang Chi Yu Ma Sino‑French Institute of Nuclear Engineering and Technology Sun Yat-sen UniversityZhuhai 519082China

Accurate real-time simulations of nuclear reactor circuit systems are particularly important for system safety analysis and *** effectively improve computational efficiency without reducing accuracy,this study establishes a thermal-hydraulics reduced-order model(ROM)for nuclear reactor circuit *** full-order circuit system calculation model is first established and verified and then used to calculate the thermal-hydraulic properties of the circuit system under different states as *** proper orthogonal decomposition method is used to extract the basis functions from snapshots,and the ROM is constructed using the least-squares method,effectively reducing the difficulty in constructing the ROM.A comparison between the full-order simulation and ROM prediction results of the AP1000 circuit system shows that the proposed ROM can improve computational efficiency by 1500 times while achieving a maximum relative error of 0.223%.This research develops a new direction and perspective for the digital twin modeling of nuclear reactor system circuits.

关键词： Reactor system model Primary circuit Reduced-order Proper orthogonal decomposition Least-squares method

A method for estimating masses of W Ursae Majoris-type binaries

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Research in Astronomy and Astrophysics 2020年第12期20卷 243-253页

作者： Li-Na Lu Jin-Zhong Liu Deng-Kai Jiang ya-hui wang Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China University of Chinese Academy of Sciences Beijing 100049China Yunnan Observatories Chinese Academy of SciencesKunming 650216China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of SciencesKunming 650216China Laboratory of New Energy and Materials Xinjiang Institute of EngineeringUrumqi 830091China

Masses of W Ursae Majoris-type(W UMa) binaries play a critical role in investigating stellar dynamical evolutionary status. In this paper, we combine the PARSEC(PAdova and TRieste Stellar Evolution Code) with the Roche geometric model to provide a method to determine the masses of W UMa systems. To verify the validity of this method, we compile a sample of 140 spectrum binaries from the literature, which includes 76 W-and 64 A-subtype systems with reliable physical parameters. We find that the average fractional difference and the standard deviation(σM) of the residuals for W-subtype and Asubtype approximately amount to 15.66% and 0.1218, 16.03% and 0.2094, respectively. Meanwhile, we also perform detailed analyses in accordance with the orbital period, the effective temperatures and the mass ratio. We find that the method is more applicable to determine masses for W UMa systems with low effective temperature and short period.

关键词： stars:binaries:eclipsing W Ursae Majoris(W UMa)binaries masses

From multicolor-photometric observations to a guaranteed mass of AL Cas

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Research in Astronomy and Astrophysics 2019年第8期19卷 19-30页

作者： ya-hui wang Jin-Zhong Liu Li-Na Lu Guo-Liang Lü School of Physical Science and Technology Xinjiang UniversityUrumqi830046China Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi830011China University of Chinese Academy of Sciences Beijing100049China

We utilize the PAdova and TRieste Stellar Evolution Code(PARSEC) combined with photometric observations to determine a guaranteed mass of AL Cas and re-examine its related physical ***-photometric observations of AL Cas have been performed in 2016 and 2017. We use the WilsonDevinney(W-D) code to analyze the light curves and find that AL Cas is probably an A-subtype contact binary(f = 35.7±0.9%) with a mass ratio q = 0.6399±0.0230 and an effective temperature difference?T = 78 K. The mass-radius relation of a higher luminosity component for AL Cas is obtained by two methods: depending on calculation of the Roche lobe(DCRL method) and depending on calculation of the W-D code(DCWD method). Using this relationship with the PARSEC model, we investigate the component masses of AL Cas as M1 = 1.19±0.23 M⊙ with M2 = 0.76±0.18 M⊙ by the DCRL method and M1 = 1.22±0.26 M⊙ with M2 = 0.78±0.20 M ⊙ by the DCWD method. By means of the photometric studies, we examine the related physical properties of AL Cas with the latest findings. We update the orbital period(Porb = 0.50055593 d) of AL Cas according to six new times of light minimum together with those collected from the literature. Meanwhile, the(O-C)2 curve analysis suggests that the orbital period of AL Cas has a cyclic variation with a period of 81.25 yr and an amplitude of 0.01415 d. This cyclic change would be caused by the light-travel time effect from a third body. A similar mass of the third body(M3 sin i′= 0.279 M⊙) is derived from our two methods.

关键词： stars:binaries:close stars:binaries:eclipsing stars:individual:AL Cassiopeiae

C/2015 O1: A long-period comet with photometric observations

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Research in Astronomy and Astrophysics 2019年第5期19卷 27-30页

作者： Xuan Zhang Jin-Zhong Liu ya-hui wang Li-Na Lu Xinjiang Astronomical Observatory Chinese Academy of Sciences School of Physical Science and Technology Xinjiang University University of Chinese Academy of Sciences

In this work, we report the observations of the long-period comet C/2015 O1 performed on2018 January 29–30 and April 13 with the Nanshan 1-meter wide-field telescope operated by Xinjiang Astronomical Observatory. We obtain the morphological features of C/2015 O1 using an image enhancement method, and calculate the dust-activity parameter Afρ and the coma color based on photometric analysis. An obvious fan-shaped structure was observed at different observation times. We find that the activity of C/2015 O1 gradually decreases as the comet advances toward perihelion and the observed B-V and V-R colors are consistent with those of other comets.

关键词： comets general-comets individual(C/2015 O1)

Metasurface-assisted low-frequency performance enhancement of ultra-broadband honeycomb absorber based on carbon nanotubes

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Nano Research 2024年第9期17卷 8542-8551页

作者： Cai-Liang wang Shuang Bai Pei-yan Zhao Tao Zhou hui-ya wang Jun-Peng wang Luo-Xin wang Guang-Sheng wang School of Chemistry Beihang UniversityBeijing 100191China Aerospace Science and Industry Corporation of Wuhan Magnetoelectricity Co. Ltd.Wuhan 430070China College of Materials Science and Engineering Key Laboratory for New Textile Materials and Applications of Hubei ProvinceWuhan Textile UniversityWuhan 430200China School of Chemistry and Chemical Engineering Lingnan Normal UniversityZhanjiang 524048China School of Materials Science and Engineering Zhejiang Sci-Tech UniversityHangzhou 310018China

Here,we present a unique method to enhance the low-frequency absorption performance of a honeycomb absorber by integrating a *** geometrical dimensions of the proposed metasurface have been numerically *** introduction of the metasurface allows exploitation of its robust resonance and superior impedance matching in low-frequency bands,thereby improving microwave absorption *** incorporation of the metasurface does not impact the wave transmission performance of the honeycomb core absorber at high-frequency band,thus preserving its high-frequency *** broadens the absorption range,leading to an expanded *** results reveal that the composite absorber(CA)exhibits strong absorption performance with an incident angle stability up to 45°for both transverse electric(TE)and transverse magnetic(TM)*** absorption mechanism of the CA has been investigated by using an equivalent circuit model and electromagnetic field analysis.A prototype was designed,fabricated,and tested to validate the proposed *** simulation and measurement results demonstrate that the prototype can achieve an average absorption rate exceeding 90%across a 1.0-18.0 GHz *** study introduces an innovative technique for creating microwave absorbers for low-frequency wideband applications.

关键词： low frequency metasurface radar absorption impedance matching