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A Spectral Element Method to Compute Earth’s Free Core Nutation

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Research in Astronomy and Astrophysics 2023年第9期23卷 171-179页

作者： mian zhang Cheng-Li Huang CAS Key Laboratory of Planetary Sciences Shanghai Astronomical ObservatoryChinese Academy of SciencesShanghai 200030China School of Astronomy and Space Sciences University of Chinese Academy of SciencesBeijing 100049China

The Free Core Nutation(FCN)is a rotational mode caused by non-alignment of the rotation axis of the core and of the *** period observed by VLBI and superconducting gravimetry is around 430 sidereal days(Sd)with precision of better than 1 Sd,while its“theoretical”period calculated by traditional approaches and a given Earth model ranges from 450 to 470 *** gap of about 30 Sd is significant compared with its observation *** propose a spectral element method to compute the period of FCN and obtain a period of 434 Sd which is very close to the observed value.

关键词： Earth-planets and satellites interiors-methods numerical

A Linear Operator Method to Compute the Normal Modes with Rotation of any Asymmetric 3D Planet with Pure Vector Spherical Harmonics

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Research in Astronomy and Astrophysics 2023年第10期23卷 224-254页

In order to compute the free core nutation of the terrestrial planets, such as Earth and Mars, the Moon and lower degree normal modes of the Jovian planets, we propose a linear operator method(LOM). Generalized surface spherical harmonics(GSSHs) are usually applied to the elliptical models with a stress tensor, which cannot be expressed in vector spherical harmonics explicitly. However, GSSHs involve complicated math. LOM is an alternative to GSSHs,whereas it only deals with the coupling fields of the same azimuthal order m, as is the case when a planet model is axially symmetric and rotates about that symmetry axis. We extend LOM to any asymmetric 3D model. The lower degree spheroidal modes of the Earth are computed to validate our method, and the results agree very well with what is observed. We also compute the normal modes of a two-layer Saturn model as a simple application.

关键词： planets and satellites:interiors Earth planets and satellites:gaseous planets

Influence of Megaregolith on the Thermal Evolution of Mercury's Silicate Shell

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Research in Astronomy and Astrophysics 2022年第3期22卷 271-284页

作者： Jing-Chun Xie mian zhang Cheng-Li Huang Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030China School of Physical Science and Technology ShanghaiTech UniversityShanghai 201210China CAS Key Laboratory of Planetary Sciences Shanghai Astronomical ObservatoryChinese Academy of SciencesShanghai 200030China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China

A so-called megaregolith layer that is considered to be produced by continuous impacts in Mercury’s early stages is integrated into the thermal evolution models of Mercury to study its influence on the thermal evolution of Mercury’s silicate *** research first implements a one-dimensional parametric global thermal evolution *** results indicate that megaregolith directly affects the thermal evolution of Mercury’s silicate shell by virtue of its good insulation *** way megaregolith exerts its influence is by prolonging the process of partial melting and reducing the heat loss,resulting in a thicker crust and thinner stagnant *** for the deep parts of the silicate shell,it is suggested that more energy is taken away from the mantle due to the longer partial melting,leading to lower temperatures below the crust compared with the case in the absence of megaregolith,which further helps to advance the formation time of the inner core and promote its final *** addition,we also carry out a simplified two-dimensional mantle convection simulation as a supplement to the one-dimensional *** two-dimensional simulation depicts a typical mantle plume fractional melting *** calculations indicate that megaregolith may be key to the long-term volcanic activities on *** far as the megaregolith itself is concerned,the thermal structure of this particular layer is more sensitive to thermal conductivity,suggesting that for such a highly fragmented structure,the thermal conductivity coefficient plays a key role in its *** work emphasizes the importance of megaregolith to the evolution of Mercury.

关键词： planets and satellites:terrestrial planets planets and satellites:physical evolution planets and satellites:interiors

Monoterpene and tetrahydronaphthene derivatives from Senecio argunensis

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Chinese Chemical Letters 2009年第5期20卷 598-600页

作者： Chao Feng zhang Ning Li Lin Li mian zhang Research Department of Pharmacognosy China Pharmaceutical University Nanjing 210038 China

Two new compounds, senarguines A and B, were isolated from Senecio argunensis. They were respectively identified as （Z）-3- ethylidene-9-hydroxyl-9-methyl-6,7-dioxaspiro [4.4] nonane-5,8-dione （1） and 3,6,6-trimeth... 详细信息

关键词： Compositae Senecio argunensis Senarguine A Senarguine B

Assembly of SPS/MgSi assisted by dopamine with excellent removal performance for ciprofloxacin

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Journal of Environmental Sciences 2020年第8期32卷 111-118页

作者： Yonghao Wang Wenqi Wei Yuzhi Lin mian zhang Yongjing Wang Minghua Liu Fujian Provincial Engineering Research Center of Rural Waste Recycling Technology College of Environment and ResourcesFuzhou UniversityFuzhou 350108China

In this work,magnesium silicate-based sulfonated polystyrene sphere composites(SPS/MgSi)were synthesized by one-step(SMD1)and two-step(SMD2)*** SMD1,MgSi particles were densely assembled on the surface of SPS,assisted by complexation between Fe^3+and hydroxyl *** SMD2,SPS/SiO2 was firstly obtained by the same method as SMD1,and then SPS/SiO2 was transformed directly to SPS/MgSi under hydrothermal ***,MgSi obtained by the two-step method had an interwoven *** to SPS,MgSi and SMD1,SMD2 presented a larger specific surface area and more negative surface ***,SMD2 showed superior adsorption performance toward CIP with concentrations of 5,10 and 50 mg/L,and for 50 mg/L,the equilibrium adsorption capacity could reach 329.7 mg/*** adsorption process is fast and can be described by the pseudo-second-order kinetic *** relationship between pH value and Zeta potential demonstrated that electrostatic interaction dominated the adsorption *** addition,competitive adsorption showed that the effect of Na^+was negligible but the effect of Ca^2+was dependent on its *** acid(HA)could slightly promote the absorption of CIP by *** five rounds of adsorption-desorption,the equilibrium adsorption capacity of SMD2 still remained at 288.6 mg/L for 50 mg/L ***,SMD2 presented likewise superior adsorption capacity for CIP with concentrations of 10 and 50 mg/L in Minjiang source *** the results indicated that this synthesis method is universal and that SMD2 has potential as an adsorbent for CIP removal from aquatic environments.

关键词： Sulfonated polystyrene sphere/Magnesium silicate Complexation Antibiotic Competitive adsorption Regenerable

Two New Compounds from Lindera chunii Merr.

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Chinese Chemical Letters 2006年第10期17卷 1325-1327页

作者： mian zhang Chao Feng zhang Qi Shi SUN Zheng Tao WANG College of Traditional Chinese Pharmacy China Pharmaceutical University Nanjing 210038 College of Traditional Chinese Pharmacy Shenyang Pharmaceutical University Shenyang 110016

Two new compounds, linderafurane A and linchuniinone, were isolated from the root of Lindera chunii Merr.. The structures were elucidated by spectroscopic methods, and their activities against HIV-1 integrase were eva... 详细信息

关键词： Lauraceae Lindera chunii linderafurane A linchuniinone HIV- 1 integrase.

The effect of the differential rotation of the earth inner core on the free core nutation

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Geodesy and Geodynamics 2019年第2期10卷 146-149页

作者： mian zhang Chengli Huang Key Laboratory of Planetary Sciences Shanghai Astronomical ObservatoryChinese Academy of Sciences School of Astronomy and Space Sciences University of Chinese Academy of Sciences

Seismic observations shows that the inner core rotates faster than the mantle and the rotation axis of the inner core may not align with the rotation axis of the mantle. Free core nutation reflects core's information. We discuss the effect of the inner core's differential rotation on free core nutation from two aspects: rotation speed and deflection angle. Our result shows it is in accordance with the observations when the inner core's rotation speed doesn't exceed 10° faster than mantle's per year, and the deflection angle is less than 1°,if the rotation speed and the deflection angle are respectively considered separately.

关键词： Inner core Differential rotation Free core nutation

Two new limonoids from Melia toosendan

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Chinese Chemical Letters 2008年第2期19卷 183-186页

作者： Fan Xie Chao Feng zhang mian zhang Zheng Tao Wang Bo Yang Yu Key Laboratory of Modern Chinese Medicines （China Pharmaceutical University） Ministry of Education Nanjing 210038 PR China Research Department of Pharmacognosy China Pharmaceutical University Nanjing 210038 PR China

Two new limonoid-type triterpenoids, named 12-o-ethyl-l-deacetylnimbolinin B and 1-o-tigloyl-1-o-debenzoylohchinal, have been isolated from the fruit of Melia toosendan Sieb. et Zucc. Their structures were elucidated ... 详细信息

关键词： Melia toosendan Limonoids 12-o-Ethyl-1-deacetylnimbolinin B 1-o-Tigloyl-1-o-debenzoylohchinal

Three New Anthraquinones from Polygonum cillinerve

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Chinese Chemical Letters 2005年第8期16卷 1050-1052页

作者： Huan Yang QI Chao Feng zhang mian zhang Jian Qun LIU Zheng Tao WANG Department of Pharmacognosy China Pharmaceutical University Nanjing 210038

Three new anthraquinones, emodin-8-β-D-（2＂-O-coumarate）glucoside 1, emodin-8-β-D-（6＇-O-acetyl）glucoside 2 and physicon-8-β-D-（6＇-O-acetyl）glucoside 3, were isolated from the roots of Polygonum cillinerve and their structures were established by spectroscopic methods. The biological activity indicated that compound 1 had the scavenging activity on 1,1-diphenyl-2-picrylhydrazyl （DPPH） radicals （the IC50 = 8.5 μmol/L）, and compound 1-3 showed no activities against HL-60 and BCJC-823 cells by MTT method in vitro.

关键词： Polygonum cillinerve anthraquinone antioxidant activity cytotoxic activity.