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Development of a Front End Array for Broadband Phased Array Receiver

Research in Astronomy and Astrophysics 2024年第4期24卷 60-70页

作者： Kai Wang Liang Cao Jun Ma Xue-Feng Duan Hao Yan Mao-Zheng Chen Yun-Wei Ning Xinjiang Astronomical observatory Chinese Academy of SciencesUrumqi 8300lChina University of the Chinese Academy of Sciences Beijing 100049China Xinjiang Key Laboratory of Microwave Technology Urumqi 830011China

The receiver is a signal receiving device placed at the focus of the *** order to improve the observation efficiency,the concept of phased array receiver has been proposed in recent years,which places a small phased array at the focal plane of the reflector,and flexible pattern and beam scanning functions can be achieved through a beamforming *** combined with the element multiplexing,all beams within the entire field of view can be observed simultaneously to achieve continuous sky *** article focuses on the front-end array of phased array receiver at 0.7-1.8 GHz for QiTai Telescope,and designs a Vivaldi antenna array of PCB structure with dual line *** polarization antenna is designed to arrange in a rectangle manner by 11×*** on the simulation results of the focal field,32,18,and eight elements were selected to form one beam at 0.7,1.25,and1.8 *** analog beamforming network was constructed,and the measured gains of axial beam under uniform weighting were 19.32,13.72,and 15.22 *** the beam scanning method of reflector antenna,the pattern test of different position element sets required for PAF beam scanning was carried out under independent *** pattern optimization at 1.25 GHz was carried out by weighting method of conjugate field *** with uniform weighting,the gain,sidelobe level,and main beam direction under conjugate field matching have been *** the above test and simulation results are slightly different,which is related to the passive array and laboratory testing condition,the relevant work has accumulated experience in the development of the front-end array for the phased array receiver,and has good guiding significance for future performance verification after the array is installed on the telescope.

关键词： telescopes instrumentation:detectors techniques:radar astronomy

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Statistical study of magnetic holes in the upstream region of Mercury’s bow shock

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Earth and Planetary Physics 2024年第2期8卷 326-337页

作者： GuoQiang Wang SuDong Xiao MingYu Wu YuanQiang Chen TieLong Zhang Institute of Space Science and Applied Technology Harbin Institute of TechnologyShenzhen 518055China Shenzhen Key Laboratory of Numerical Prediction for Space Storm Harbin Institute of TechnologyShenzhen 518055China Mengcheng national Geophysical observatory University of Science and Technology of ChinaHefei 230026China Chinese Academy of Sciences Center for Excellence in Comparative Planetology Hefei 230026China Space Research Institute Austrian Academy of SciencesGrazAustria

Magnetic holes are magnetic depression structures that exist widely in many plasma *** magnetic holes with durations of>1 s in the solar wind at Mercury’s orbit have drawn much attention,but the properties of the magnetic holes with shorter durations are still ***,we investigate the magnetic holes with durations of 0.1-100 s in the upstream region of Mercury’s bow shock based on observations by the MESSENGER(MErcury Surface,Space ENvironment,GEochemistry,and Ranging)*** can be divided into two groups according to the distribution of their duration:small-duration magnetic holes(SDMHs,0.6 s).The duration of each group approximately obeys a log-normal distribution with a median of~0.25 s and 3 s,*** 1.7%(32.6%)of the SDMHs(LDMHs)reduce the magnetic field strength by more than 50%.For both groups,some structures have a linear or quasi-linear polarization,whereas others have an elliptical *** magnetic hole events in both groups tend to have a higher rate of occurrence when the interplanetary magnetic field strength is *** occurrence rates are also affected by Mercury’s foreshock,which can increase(decrease)the occurrence rate of the SDMHs(LDMHs).This finding suggests that Mercury’s foreshock might be one source of the SDMHs and that the foreshock can destroy some *** observations suggest that a new group of magnetic holes with durations of<0.6 s exist in the upstream region of Mercury’s bow shock.

关键词： magnetic hole solar wind Mercury foreshock

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Confirmation of a Sub-Saturn-size Transiting Exoplanet Orbiting a G Dwarf:TOI-1194 b and a Very Low Mass Companion Star: TOI-1251 B from TESS

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Research in Astronomy and Astrophysics 2024年第3期24卷 129-143页

作者： Jia-Qi Wang Xiao-Jun Jiang Jie Zheng Hanna Kellermann Arno Riffeser Liang Wang Karen A.Collins Allyson Bieryla Lars A.Buchhave Steve B.Howell Elise Furlan Eric Girardin Joao Gregorio Eric Jensen Felipe Murgas Mesut Yilmaz Sam Quinn Xing Gao Ruo-Yu Zhou Frank Grupp Hui-Juan Wang CAS Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy Of SciencesBeijing 10010China University of Chinese Academy of Sciences Beijing 100049China University observatory Munich Scheinertrsse 1.D-81679 MunichGemany Max Planck Institute for Extraterrestrial Physics Giessenbachstr.1D-85748 GarchingGermany national Astronomical Observatories/Nanjing Institute of Astronomical Optics&Technology Chinese Academy of SciencesNanjing210042China CAS Key Laboratory of Astronomical Optics&Technology Nanjing Institute of Astronomical Optics&TechnologyNanjing 210042China Center for Astrophysics Harvard&Smithsonian60 Garden Street.CambridgeMA 02138USA national Space Institute Technical University of DenmarkElektrovejDK-2800 KgsLyngbyDenmark NASA Ames Research Center Moffett FieldCA 94035USA NASA Exoplanet Science Institute Caltech/IPACMail Code 100-221200 E.California Blvd.PasadenaCA91125USA Grand Pra observatory Switzerland Department of Physics Washington UniversitySt.LouisMO 63130.USA Department of Physics and Astronomy Swarthmore CollegeSwarthmorePA 19081USA Instituto de Astrofísica de Canarias(IAC) E-38205 La Laguna.TenerifeSpain Departamento de Astrofísica Universidad de La LagunaSpain Dept.of Astronomy and Space Sciences Ankara UniversityTandogan 06100AnkaraTurkey Xinjiang Astronomical observatory Chinese Academy of SciencesUrumqi 830011China Urumqi No.1 Senior High School Urumqi 830002China Lijiang Gemini observatory Lijiang 674199China

We report the confirmation of a sub-Saturn-size exoplanet,TOI-1194 b,with a mass of about 0.456+0.055-0.051M_(J),and a very low mass companion star with a mass of about 96.5±1.5 MJ,TOI-1251 *** candidates provided by the Transiting Exoplanet Survey Satellite(TESS)are suitable for further follow-up observations by ground-based telescopes with small and medium *** analysis is performed based on data from several telescopes worldwide,including telescopes in the Sino-German multiband photometric campaign,which aimed at confirming TESS Objects of Interest(TOIs)using ground-based small-aperture and medium-aperture telescopes,especially for long-period ***-1194 b is confirmed based on the consistent periodic transit depths from the multiband photometric *** measure an orbital period of 2.310644±0.000001 days,the radius is 0.767+0.045-0.041RJ and the amplitude of the RV curve is 69.4_(-7.3)^(+7.9)m s^(-1).TOI-1251 B is confirmed based on the multiband photometric and high-resolution spectroscopic data,whose orbital period is 5.963054+0.000002-0.000001days,radius is 0.947+0.035-0.033 R_(J) and amplitude of the RV curve is 9849_(-40)^(+42)ms^(-1).

关键词： planets and satellites fundamental parameters-planets and satellites gaseous planets-stars fundamental parameters-stars low-mass-methods data analysis-techniques photometric-techniques spectroscopic

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Evolution of High-energy Electron Distribution in Pulsar Wind Nebulae

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Research in Astronomy and Astrophysics 2024年第7期24卷 201-217页

作者： Yi-Ming Liu Hou-Dun Zeng Yu-Liang Xin Si-Ming Liu Yi Zhang Key Laboratory of Dark Matter and Space Astronomy Purple Mountain ObservatoryChinese Academy of Sciences School of Astronomy and Space Science University of Science and Technology of China School of Physical Science and Technology Southwest Jiaotong University

In this paper,we analyze the spectral energy distributions of 17 powerful (with a spin-down luminosity greater than1035erg s-1) young （with an age less than 15,000 yr） pulsar wind nebulae （PWNe） using a simple timein-dependent one-zone emission *** aim is to investigate correlations between model parameters and the ages of the corresponding PWNe,thereby revealing the evolution of high-energy electron distributions within *** findings are as follows:（1） The electron distributions in PWNe can be characterized by a double power-law with a super-exponential cutoff.（2） As PWNe evolve,the high-energy end of the electron distribution spectrum becomes harder with the index decreasing from approximately 3.5 to 2.5,while the low-energy end spectrum index remains constant near 1.5.（3） There is no apparent correlation between the break energy or cutoff energy and the age of PWNe.（4） The average magnetic field within PWNe decreases with age,leading to a positive correlation between the energy loss timescale of electrons at the break energy or the high-energy cutoff and the age of the PWN.（5） The total electron energy within PWNe remains constant near 2×1048erg,while the total magnetic energy decreases with age.

关键词： gamma-rays: general ISM: general ISM: supernova remnants radiation mechanisms: non-thermal

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Reverse metabolomics as a novel strategy to annotate the human metabolome

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Chinese Journal of Natural Medicines 2024年第4期22卷 289-290页

作者： YAN Tingting NIE Liangliang HAO Haiping State Key Laboratory of Natural Medicines China Pharmaceutical UniversityNanjing 211198China Laboratory of Metabolic Regulation and Drug Target discovery School of PharmacyChina Pharmaceutical UniversityNanjing 210009China

Identifying chemical structures inhuman-derived samples presents significant challenges due to limited structural data obtained from untargeted metabolomics *** the chemical structures of molecules are closely related to the phenotypic status of human ecosystems,it becomes invaluable to devise a method for efficiently and systematically determining structures that correlate with the pathophysiological status of humans in a high-throughput approach.

关键词： Reverse metabolomics Human metabolome Combinational synthesis Bile amidates

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How to Coadd Images.Ⅱ.Anti-aliasing and PSF Deconvolution

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Research in Astronomy and Astrophysics 2024年第4期24卷 103-113页

作者： Lei Wang Huanyuan Shan Lin Nie Dezi Liu Zhaojun Yan Guoliang Li Cheng Cheng Yushan Xie Han Qu Wenwen Zheng Xi Kang Purple Mountain observatory Chinese Academy of SciencesNanjing 210023China national Basic Science Data Center Beijing 100190China Zhejiang University-Purple Mountain observatory Joint Research Center for Astronomy Zhejiang UniversityHangzhou 310030China Shanghai Astronomical observatory Shanghai 200030China Key Laboratory of Radio Astronomy and Technology Chinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China Department of Information Engineering Wuhan Institute of CityWuhan 430083China South-Westem Institute for Astronomy Research Yunnan UniversityKunming 650500China The Shanghai Key Lab for Astrophysics.Shanghai Normal University Shanghai200234China Chinese Academy of Sciences South America Center for Astronomy National Astronomical ObservatoriesCASBeijing 100101China CAS Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China

We have developed a novel method for co-adding multiple under-sampled images that combines the iteratively reweighted least squares and divide-and-conquer *** approach not only allows for the anti-aliasing of the images but also enables Point-Spread Function(PSF)deconvolution,resulting in enhanced restoration of extended sources,the highest peak signal-to-noise ratio,and reduced ringing *** test our method,we conducted numerical simulations that replicated observation runs of the China Space Station Telescope/the VLT Survey Telescope(VST)and compared our results to those obtained using previous *** simulation showed that our method outperforms previous approaches in several ways,such as restoring the profile of extended sources and minimizing ringing ***,because our method relies on the inherent advantages of least squares fitting,it is more versatile and does not depend on the local uniformity hypothesis for the ***,the new method consumes much more computation than the other approaches.

关键词： methods:analytical techniques:image processing gravitational lensing:weak (ISM:)cosmic rays

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Total synthesis of a putative yuzurimine-type Daphniphyllum alkaloid C_(14)–epi-deoxycalyciphylline H

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Chinese Chemical Letters 2024年第4期35卷 336-339页

作者： Jingping Hu Jing Xu Shenzhen Grubbs Institute and Department of Chemistry and Guangdong Provincial Key Laboratory of Catalysis and Shenzhen Key Laboratory of Small Molecule Drug discovery and Synthesis Southern University of Science and TechnologyShenzhen 518055China

One of the largest subfamilies within the famous Daphniphyllum alkaloid family is made up of the yuzurimine-type(or macrodaphniphyllamine-type) alkaloids. Their complex aza-polycyclic caged structures, several contiguous stereogenic centers, and vicinal all-carbon quaternary centers make these alkaloids formidable challenge for synthetic chemists. Recently, synthesis of these alkaloids has received extensive attention from our community. Herein, we wish to report the total synthesis of C_(14)–epideoxycalyciphylline H, a putative member of yuzurimine-type alkaloid subfamily. Key transformations employed in our approach include an intramolecular Prins reaction and a Pd-catalyzed enyne cycloisomerization. In addition, synthesis of a daphnezomine L-type alkaloid, paxdaphnidine A, was also studied.

关键词： Total synthesis Daphniphyllum alkaloids Yuzurimine-type alkaloids Prins reaction Enyne cycloisomerization

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Comparative Analysis of Energy Characteristics of Two Southwest Vortices in Sichuan Under Similar Circulation Backgrounds

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Journal of Tropical Meteorology 2024年第2期30卷 168-179页

作者：周春花张驹肖红茹 Sichuan Meteorological Disaster Prevention Technology Center Chengdu 610072 China Chengdu Meteorological Bureau Chengdu 610072 China Sichuan Meteorological observatory Chengdu 610072 China

Based on ERA5 reanalysis data,the present study analyzed the thermal energy development mechanism and kinetic energy conversion characteristics of two extreme rainstorm processes in relation to the shallow southwest vortex in the warm-sector during a“rain-generated vortex”process and the deep southwest vortex in a“vortex-generated rain”*** findings were as follows:(1)During the extreme rainstorm on August 11,2020(hereinafter referred to as the“8·11”process),intense surface heating and a high-energy unstable environment were *** mesoscale convergence system triggered convection to produce heavy rainfall,and the release of latent condensation heat generated by the rainfall promoted the formation of a southwest *** significant increase(decrease)in atmospheric diabatic heating and kinetic energy preceded the increase(decrease)in *** contrast,the extreme rainstorm on August 16,2020(hereinafter referred to as the“8·16”process)involved the generation of southwest vortex in a low-energy and highhumidity *** dynamic uplift of the southwest vortex triggered rainfall,and the release of condensation latent heat from rainfall further strengthened the development of the southwest *** significant increase(decrease)in atmospheric diabatic heating and kinetic energy exhibited a delayed progression compared to the increase(decrease)in vorticity.(2)The heating effect around the southwest vortex region was non-uniform,and the heating intensity varied in different *** the“8·11”process,the heating effect was the strongest in the initial stage,but weakened during the vortex's *** the contrary,the heating effect was initially weak in the“8·16”process,and intensified during the development stage.(3)The available potential energy of the“8·11”process significantly increased in kinetic energy converted from rotational and divergent winds through baroclinic action,and the divergent wind energy continued to convert into rotatio

关键词： southwest vortex similar circulation background diabatic heating kinetic energy spatial non-uniform heating effect

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Measurement of atmospheric non-reciprocity effects for satellite-based two-way time-frequency transfer

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Photonics Research 2024年第6期12卷 1274-1282页

作者： TING ZENG QI SHEN YUAN CAO JIAN-YU GUAN MENG-ZHE LIAN JIN-JIAN HAN LEI HOU JIAN LU XIN-XIN PENG MIN LI WEI-YUE LIU JIN-CAI WU YONG WANG JUAN YIN JI-GANG REN HAI-FENG JIANG QIANG ZHANG CHENG-ZHI PENG JIAN-WEI PAN Hefei national Research Center for Physical Sciences at the Microscale and School of Physical Sciences University of Science and Technology of ChinaHefei 230026China Shanghai Research Center for Quantum Science and CAS Center for Excellence in Quantum Information and Quantum Physics University of Science and Technology of ChinaShanghai 201315China Hefei national Laboratory University of Science and Technology of ChinaHefei 230094China Faculty of Information Science and Engineering Ningbo UniversityNingbo 315211China Key Laboratory of Space Active Opto-Electronic Technology Shanghai Institute of Technical PhysicsChinese Academy of SciencesShanghai 200083China Xinjiang Astronomical observatory Chinese Academy of SciencesUrumqi 830011China

Future optical clock networks will require high-precision optical time-frequency transfer between satellites and ground ***,due to atmospheric turbulence,satellite motion and time delay between the satellite–ground transmission links will cause spatial and temporal variations,respectively,resulting in the breakdown of the time-of-flight reciprocity on which optical two-way time-frequency transfer is ***,we experimentally simulate the atmospheric effects by two-way spatio-temporally separated links between two stationary terminals located 113 km apart and measure the effects for optical two-way time-frequency *** experiment shows that the effect on the link instability is less than 2.3×10^(−19) at 10,000 *** indicates that when the link instability of satellite-ground optical time-frequency transfer is on the order of 10^(−19),it is not necessary to consider the atmospheric non-reciprocity effects.

关键词： breakdown transfer satellite

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Click chemistry and natural products

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Chinese Journal of Natural Medicines 2024年第2期22卷 97-99页

作者： ZHANG Chen WU Jianbing ZHANG Yihua HUANG Zhangjian State Key Laboratory of Natural Medicines Jiangsu Key Laboratory of Drug Discovery for Metabolic DiseasesCenter of Drug DiscoveryChina Pharmaceutical UniversityNanjing 210009China State Key Laboratory of Pathogenesis Prevention and Treatment of High Incidence Diseases in Central AsiaXinjiang Key Laboratory of Natural Medicines Active Components and Drug Release TechnologySchool of PharmacyXinjiang Medical UniversityUrumqi 830054China

The 2022 Nobel Prize in Chemistry was awarded to American scientists Carolyn Bertozzi,*** Sharpless,and Danish scientist Morten *** for their contributions to the development of click chemistry and bioorthogonal chemi... 详细信息

关键词： Click chemistry Natural product Target identification Drug discovery

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