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An investigation on the wind profiles and gravity wave dynamics in MLT region based on the meteor radars from the Meridian Project

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Earth and Planetary physics 2025年第1期9卷 29-38页

作者： Tai Liu Zhe Wang MengXi Shi Willie Soon ShiCan Qiu department of Geophysics College of the Geology Engineering and GeomaticsChang’an UniversityXi’an 710054China Center for Environmental Research and Earth Sciences(CERES) SalemMA 01970USA institute of Earth physics and Space Science(ELKH EPSS) 9400SopronHungary

The meteor radar can detect the zenith angle,azimuth,radial velocity,and altitude of meteor trails so that one can invert the wind profiles in the mesosphere and low thermosphere(MLT)region,based on the Interferometric and Doppler *** this paper,the horizontal wind field,gravity wave(GW)disturbance variance,and GW fluxes are analyzed through the meteor radar observation from 2012−2022,at Mohe(53.5°N,122.4°E)and Zuoling(30.5°N,114.6°E)stations of the(Chinese)Meridian *** Lomb−Scargle periodogram method has been utilized to analyze the periodic variations for time series with observational data *** results show that the zonal winds at both stations are eastward dominated,while the meridional winds are southward *** variance of GW disturbances in the zonal and meridional directions increases gradually with height,and there is a strong pattern of annual *** zonal momentum flux of GW changes little with height,showing weak annual *** meridional GW flux varies gradually from northward to southward with height,and the annual periodicity is *** both stations,the maximum values of zonal and meridional wind occur close to the peak heights of GW flux,with opposite *** observational evidence is consistent with the filtering *** horizontal wind velocity,GW flux,and disturbance variance of the GW at Mohe are overall smaller than those at Zuoling,indicating weaker activities in the MLT at *** power spectral density(PSD)calculated by the Lomb−Scargle periodogram shows that there are 12-month period and 6-month period in horizontal wind field,GW disturbance variance and GW flux at both stations,and especially there is also a 4-month cycle in the disturbance *** PSD of the 12-month and 6-month cycles exhibits maximum values below 88 km and above 94 km.

关键词： meteor radar wind field gravity wave Lomb−Scargle method

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Study of the cavity-magnon-polariton transmission line shape

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Science China(physics,Mechanics & astronomy) 2016年第11期59卷 70-80页

作者： Michael Harder LiHui Bai Christophe Match Jesko Sirker CanMing Hu department of physics and astronomy University of Manitoba

We experimentally and theoretically investigate the microwave transmission line shape of the cavity-magnon-polariton(CMP)created by inserting a low damping magnetic insulator into a high quality 3D microwave cavity. While fixed field measurements are found to have the expected Lorentzian characteristic, at fixed frequencies the field swept line shape is in general asymmetric. Such fixed frequency measurements demonstrate that microwave transmission can be used to access magnetic characteristics of the CMP,such as the field line width H. By developing an effective oscillator model of the microwave transmission we show that these line shape features are general characteristics of harmonic coupling. At the same time, at the classical level the underlying physical mechanism of the CMP is electrodynamic phase correlation and a second model based on this principle also accurately reproduces the experimental line shape features. In order to understand the microscopic origin of the effective coupled oscillator model and to allow for future studies of CMP phenomena to extend into the quantum regime, we develop a third, microscopic description,based on a Green's function formalism. Using this method we calculate the transmission spectra and find good agreement with the experimental results.

关键词： cavity-magnon-polariton strong-coupling microwave cavity ferromagnetic resonance

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Research in astronomy and Astrophysics 2010年第12期10卷 1275-1286页

作者： Mohsen Nejad-Asghar department of physics University of Mazandaran Research institute for astronomy and Astrophysics of Maragha department of physics Damghan University

Theoretically, stars formed from the collapse of cores in molecular clouds. Historically, the core had been assumed to be a singular isothermal sphere （SIS）, and the collapse had been investigated in a self-similar manner. When the rotation and magnetic fields lead to non-symmetric collapse, a spheroidal shape may occur. Here, the result of the centrifugal force and magnetic field gradient is assumed to be in the normal direction to the rotational axis, and its components are supposed to be a fraction β of the local gravitational force. In this research, a collapsing SIS core is considered to find the importance that the parameter β plays in the oblateness of the mass shells, which are the crests of the expansion waves. We apply the Adomian decomposition method to solve the system of nonlinear partial differential equations because the collapse does not occur in a spherically symmetric and self-similar man- ner. In this way, we obtain a semi-analytical relation for the mass infall rate M of the shells in the envelope. Near the rotational axis, M˙ decreases with the increase of the non-dimensional radius ξ, while a direct relation is observed between M˙ and ξ in the equatorial regions. Also, the values of M˙ in the polar regions are greater than their equatorial values, and this difference occurs more often at smaller values of ξ. Overall, the results show that before reaching the crest of the expansion wave, the visible shape of the molecular cloud cores can evolve into oblate spheroids. The ratio of major to minor axes of oblate cores increases when increasing the parameter β, and its value can approach the observed elongated shapes of cores in the maps of molecular clouds, such as those in Taurus and Perseus.

关键词： ISM: clouds -- ISM: evolution -- stars: formation - methods: analytical

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Computation of the structure of a magnetized strange quark star

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Research in astronomy and Astrophysics 2011年第7期11卷 851-862页

作者： Gholam Hossein Bordbar Ali Reza Peivand department of physics Shiraz University Research institute for astronomy and Astrophysics of Maragha department of physics Tafresh University

We have calculated some properties of spin polarized strange quark matter（SQM） in a strong magnetic field at zero temperature using the MIT bag *** showed that the equation of state of spin polarized SQM is stiffer than that for unpolarized *** have also computed the structural properties of a spin polarized strange quark star（SQS） and found that the presence of a magnetic field leads to a more stable SQS when compared to the structural properties of an unpolarized SQS.

关键词： dense matter—equation of state—magnetic field

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Modulation of the octahedral structure and potential superconductivity of La3Ni2O7 through strain engineering

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Science China(physics,Mechanics & astronomy) 2025年

作者： Zihao Huo Zhihui Luo Peng Zhang Aiqin Yang Zhengtao Liu Xiangru Tao Zihan Zhang Shumin Guo Qiwen Jiang Wenxuan Chen Dao-Xin Yao Defang Duan Tian Cui Key Laboratory of Material Simulation Methods & Software of Ministry of Education State Key Laboratory of Superhard Materials College of Physics Jilin University Center for Neutron Science and Technology Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices State Key Laboratory of Optoelectronic Materials and Technologies School of Physics Sun Yat-sen University MOE Key Laboratory for Non-equilibrium Synthesis and Modulation of Condensed Matter Shaanxi Province Key Laboratory of Advanced Functional Materials and Mesoscopic Physics School of Physics Xi'an Jiaotong University institute of High Pressure physics School of Physical Science and Technology Ningbo University

The recent transport measurements of La3Ni2O7uncovered a“right-triangle”shape of the superconducting dome in the pressure-temperature （P-T） phase *** by this,we perform theoretical first-principles studies of La3Ni2O7with the pressure ranging from 0 to 100 ***,we reveal a pressure dependence of the Ni-d2zelectron density at the Fermi energy (nE Fz) that highly coincides with such *** this basis,we further explore the electronic structure under uniaxial *** tracking the stress response of nE Fz,we propose that superconductivity can be achieved by applying only～2 GPa of compression along the c *** idea is further exemplified from the perspectives of lattice distortion,band structure,Fermi surface and superconducting phase *** also discuss the possible charge modulation under the stress and provide an insight into the relation between nE Fzand the superconducting Tcin *** study provides new routes to the search of high-Tcsuperconductors in future experiments.

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Symplectic integrators with potential derivatives to third order

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Research in astronomy and Astrophysics 2011年第3期11卷 353-368页

作者： Wei Sun Xin Wu Guo-Qing Huang institute of astronomy ＆ department of physics Nanchang University Nanchang 330031 China

An operator associated with third-order potential derivatives and a force gradient operator corresponding to second-order potential derivatives are used together to design a number of new fourth-order explicit symplectic integrators for the natural splitting of a Hamiltonian into both the kinetic energy with a quadratic form of momenta and the potential energy as a function of position *** simulations show that some new optimal symplectic algorithms are much better than their non-optimal counterparts in terms of accuracy of energy and position calculations.

关键词： celestial mechanics—methods:numerical

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Ca2+ cation-mediated microenvironment for electrochemical hydrodimerization of furfural

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Science China Chemistry 2025年

作者： Wei Du Shuangshuang Cha Can Lei Mengxin Qu Zhongqiang Deng Ming Gong Xinhe Bao department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials Fudan University State Key Laboratory of Catalysis National Laboratory for Clean Energy Collaborative Innovation Center of Chemistry for Energy Materials Dalian Institute of Chemical Physics Chinese Academy of Sciences

Furfural is one of the most important biomass-based platform molecules as sustainable precursors for chemicals and fuels. The electrochemical hydrodimerization of furfural can generate hydrofuroin, which is a promising precursor for gasoline or jet ***, steering the selectivity toward hydrodimerization under near-neutral conditions that suppress polymerization and disproportionation of furfural remains challenging. Herein, we discovered that tuning the electrolyte cations could be an effective and alternative strategy for modulating furfural reduction to the traditional electrocatalyst design. Under the optimal Ca2+cations,hydrofuroin yield could be much improved from other cations with hydrofuroin selectivity of 95.5%. The systematic characterization of the ion-centered double layer reflected the suitable sizes and charges of hydrated Ca2+for suppressing the hydrogen evolution reaction from activation of surrounding water molecules as well as encouraging furfural accumulation via non-covalent interaction for directing the electron transfer to furfurals. Ions with smaller or larger sizes can either activate local water molecules or form a crowded ionic interface that casts an adverse effect on furfural enrichment. This work not only presents an effective strategy for facilitating biomass valorization via hydrodimerization but also emphasizes the essential role of the ion-centered microenvironment for steering the electrocatalytic pathways.

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Density fluctuations in baryon-rich quark matter

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Nuclear Science and Techniques 2016年第6期27卷 17-24页

作者： Che Ming Ko Feng Li Cyclotron institute and department of physics and astronomy Texas A&M UniversityCollege Station

At finite baryon chemical potential,the density of a quark matter develops large fluctuations when it undergoes a first-order phase *** on the transport equation derived from the Nambu–Jona-Lasinio(NJL) model,we have studied the density fluctuations in a baryon-rich quark matter that is confined in a finite *** the expansion of the quark matter using initial conditions from either a blast wave model or a multiphase transport(AMPT) model,we have further studied the survivability of the density fluctuations as the density and temperature of the quark matter *** experimental signatures of the density fluctuations are suggested.

关键词：密度涨落夸克物质重子输运方程一级相变体积密度 AMPT 可生存性

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Insights into structural and spectroscopic characterization of Sm^(3+)doped orange rich red emitting CsMgPO_(4)phosphors

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Journal of Rare Earths 2022年第12期40卷 1837-1848,I0001页

作者： M.K.Pradhan S.Dash department of physics and astronomy National Institute of Technology RourkelaRourkela769008OdishaIndia

In the present study,Sm^(3+)activated inorganic orthophosphate CsMgPO_(4)(CSMP)phosphors were prepared by adopting a solid-state reaction *** structural phase purity and morphological features were studied by X-ray powder diffraction(XRD)and scanning electron microscopy(SEM),*** molecular structure and vibrational modes were substantiated with the Fourier transform infrared spectroscopy(FTIR)and Raman spectroscopy *** optical bandgap of the host and Sm^(3+)doped phosphors was deduced from the diffused reflectance(DR)spectra with a typical value of 5.72 eV and a small variation is observed with increasing concentrations.A systematic study of photoluminescence(PL)properties of Sm^(3+)doped CSMP phosphors was carried *** the room temperature excitation and emission spectra,it is found that the phosphor emits in the orange rich red light under the suitable excitation of 402 nm in the UV region and concentration quenching occurs at x=0.02 doping *** emission peaks observed at around 562,598 and 644 nm confirm the characteristic Sm^(3+)4 f-4 f *** temperature-dependent photoluminescence(TD-PL)of the x=0.02(optimum doping)is recorded from 30 to 210℃,showing good thermal stability even at 150℃.The thermal quenching mechanisms are discussed based on the configuration coordinate model of excitation and *** prepared phosphors are found to exhibit near thermal stability compared to the commercially available red *** decay time and quantum efficiency were *** colour coordinates are found to lie in the orangish-red region of the colour *** the prepared phosphors CSMP:x Sm^(3+)can be useful as a red component in designing UV excitable chip-based phosphor-converted white LED applications.

关键词： Charge compensation Red phosphors Thermal stability Configuration coordinate model Luminescence Rare earths

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Calculation of the structural properties of asymmetrical nuclear matter

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Research in astronomy and Astrophysics 2012年第3期12卷 345-358页

作者： Gholam Hossein Bordbar Hamideh Nadgaran department of physics Shiraz University Research institute for astronomy and Astrophysics of Maragha

The structural properties of asymmetrical nuclear matter have been calculated,employing the AV 18 potential for different values of proton to neutron *** calculations have also been made for the case of symmetrical nuclear matter with the UV14,AV14 and AV 18 *** our calculations,we used the lowest order constrained variational method to compute the correlation function of the system.

关键词： stars:neutron—dense matter—equation of state

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