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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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Exploring Sulfur Chemistry in TMC-1 with NSRT

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Chinese Physics Letters 2024年第2期41卷 129-132页

作者： Wasim Iqbal Xiaohu Li Juan Tuo Ryszard Szczerba Yanan Feng Zhenzhen Miao Jiangchao Yang Jixing Ge Gleb Fedoseev Donghui Quan Qiang Chang Chuan-Lu Yang Tao Yang Gao-Lei Hou Yong Zhang Xuan Fang Xia Zhang Fangfang Li Rong Ma Xiaomin Song Zhiping Kou Yuxuan Sun Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China Xinjiang Key Laboratory of Radio Astrophysics Urumqi 830011China Key Laboratory of Radio Astronomy Chinese Academy of SciencesNanjing 210008China University of Chinese Academy of Sciences Beijing 100049China Nicolaus Copernicus Astronomical Center Rabia´nska 887-100 Toru´nPoland Research Laboratory for Astrochemistry Ural Federal UniversityKuibysheva St.48620026 EkaterinburgRussia Astronomical Computing Research Center Zhejiang LaboratoryHangzhou 311100China School of Physics and Optoelectronic Engineering Shandong University of TechnologyZibo 255000China School of Physics and Optoelectronic Engineering Ludong UniversityYantai 264025China State Key Laboratory of Precision Spectroscopy East China Normal UniversityShanghai 200062China MOE Key Laboratory for Non-Equilibrium Synthesis and Modulation of Condensed Matter School of PhysicsXi’an Jiaotong UniversityXi’an 710049China School of Physics and Astronomy Sun Yat-sen UniversityGuangzhou 510275China Laboratory for Space Research Faculty of ScienceThe University of Hong KongHong KongChina National Astronomical Observatories Chinese Academy of SciencesBeijing 100012China

There have been several studies on sulfur depletion in dense cores like TMC-1(Taurus Molecular Cloud 1),employing updated reaction networks for sulfur species to explain the missing sulfur in the gas within dense *** of these studies used a C/O ratio of 0.7 or *** present NSRT(NanShan 26m Radio Telescope)observations of TMC-1 alongside results from time-dependent chemical simulations using an updated chemical *** findings highlight the impact of the C/O ratio on the gas-phase evolution of C2S and *** simulation results show that the C/O ratio is an important parameter,playing a fundamental role in determining the gas-phase abundances of sulfur species in dense cores.

关键词： sulfur Sulfur depletion

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A Search for Radio Pulsars in Supernova Remnants Using FAST with One Pulsar Discovered

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Chinese Physics Letters 2024年第2期41卷 133-136页

作者：张振闫文明袁建平王娜白俊涛温志刚李保达解进涛赵德王榆斌翟楠楠 Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Radio Astronomy and Technology(Chinese Academy of Sciences) Beijing 100101China Xinjiang Key Laboratory of Radio Astrophysics Urumqi 830011China College of Physics GuiZhou UniversityGuizhou 550025China Research Center for Intelligent Computing Platforms Zhejiang LaboratoryHangzhou 311100China School of Physical Science and Technology Xinjiang UniversityUrumqi 830046China School of Physics and Electronic Engineering Sichuan University of Science&EngineeringZigong 643000China

We report the results of a search for radio pulsars in five supernova remnants(SNRs)with the FAST *** observations were made using the 19-beam receiver in“snapshot”*** integration time for each pointing was 10 *** discovered a new pulsar,PSR J1845–0306,which has a spin period of 983.6 ms and a dispersion measure of 444.6±2.0 cm^(−3)·pc,in observations of SNR G29.6+*** judge the association between the pulsar and the SNR,further verification is *** also re-detected some known pulsars in the data from SNRs G29.6+0.1 and G29.7–*** pulsars were detected in the observations of the other three SNRs.

关键词： observations Pulsar pulsar

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Successful immunological treatment of gallbladder cancer in India―Case report

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2006年第9期7卷 719-724页

作者： KHAN Jamal A. YAQIN Sharmin Microbiology Research Lab C-38/Sector 20 Noida Zip 201301 India

Gallbladder cancer has a poor outcome because of its anatomy and location. Often, the diagnosis is made very late due to its silent course. Post-operated cases do respond to chemotherapy but the survival is counted in months and the quality of life is further hampered due to toxicity of drugs. Immunotherapy holds good promise in non-responding cancers treated by conventional chemotherapeutic agents. Among various therapies, dendritic cell therapy is growing at rapid pace due to its acceptable rationale. It has been utilized in treating successfully resected stage III (T2, N1, M0) gallbladder cancer in one of our patients. A 48 years old lady treated with this therapy is free of metastasis with ten doses of autologous dendritic cell vaccine constructed by utilizing resected tumor lysate antigen. She has received ten doses of therapy in 14 months of her treatment. This therapy has proven to be safe and without apparent side effects. The positive clinical response obtained supports that autologous dendritic cell-based immunotherapy is a promising therapeutic approach for refractory gallbladder cancers.

关键词：胆囊癌树突细胞免疫疗法印度

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Design of RFSoC-based Digital Phased Array Feed(PAF)and Hybrid Architecture Beamforming System

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Research in Astronomy and Astrophysics 2022年第4期22卷 169-184页

作者： Xin Pei Na Wang Dan Werthimer Xue-Feng Duan Jian Li Toktonur Ergesh Qi Liu Ming-Hui Cai Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China University of Chinese Academy of Sciences Beijing 100049China Xinjiang Key Laboratory of Microwave Technology Urumqi 830011China Department of Astronomy University of CaliforniaBerkeleyCA 94720USA

As the number of array elements and bandwidth increase,the design challenges of the Phased Array Feed(PAF)front-end and its signal processing system *** at the ng-PAF of the 110 m radio telescope,this article introduces the concept of fully digital receivers and attempts to use Radio Frequency System-on-Chip(RFSo C)technology to digitize close to the feed array,reduce the complexity and analog components of the front-end,and improve the fidelity of the *** article discusses the digital beamforming topology and designs a PAF signal processing experimental system based on RFSo C+GPU hybrid *** system adopts a ZCU111board to design RF-direct digitization and preprocessing front-end,which can sample eight signals up to 2.048GSPS,12 bit,channelize the signals into 1024 chunks,then reorder into four data streams and select one of the 256MHz frequency bands to output through four 10 Gb links.A GPU server is equipped with four RTX 3090 GPUs running four HRBF_HASHPIPE instances,each receiving a 64 MHz bandwidth signal for high-throughput realtime *** experimental system uses a signal generator to emulate Sa-like signals and propagates through rod antennas,which verifies the effectiveness of the beamforming *** tests show that after algorithm optimization,the average processing time for a given 4 ms data is less than 3 ms in the four-GPU parallel processing *** RFSo C integrated design shows significant advantages in power consumption and electromagnetic radiation compared with discrete circuits according to the measurement results.

关键词： instrumentation:miscellaneous techniques:miscellaneous telescopes

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Observation of solar coronal heating powered by magneto-acoustic oscillations in a moss region

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Research in Astronomy and Astrophysics 2021年第4期21卷 325-330页

作者： Panda Hashim Zhen-Xiang Hong Hai-Sheng Ji Jin-Hua Shen Kai-Fan Ji Wen-Da Cao Graduate School of the Chinese Academy of Sciences Beijing 100871China Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China Purple Mountain Observatory DMSA/CASNanjing 210023China CfASS China Three Gorges UniversityYichang 443002China Yunnan Astronomical Observatory Chinese Academy of SciencesKunming 830011China Big Bear Solar Observatory 40386 North Shore LaneBig Bear CityCA 922314USA

In this paper,we report the observed temporal correlation between extreme-ultraviolet(EUV)emission and magneto-acoustic oscillations in an EUV moss region,which is the footpoint region only connected by magnetic loops with million-degree *** result is obtained from a detailed multiwavelength data analysis of the region with the purpose of resolving fine-scale mass and energy flows that come from the photosphere,pass through the chromosphere and finally heat the solar transition region or the *** data set covers three atmospheric levels on the Sun,consisting of high-resolution broad-band imaging at TiO 7057 A and the line of sight magnetograms for the photosphere,high-resolution narrowband images at helium 110830 A for the chromosphere and EUV images at 171 A for the ***10830 A narrow-band images and the TiO 7057 A broad-band images are from a much earlier observation on 2012 July 22 with the 1.6 meter aperture Goode Solar Telescope(GST)at Big Bear Solar Observatory(BBSO)and the EUV 171 A images and the magnetograms are from observations made by Atmospheric Imaging Assembly(AIA)or Helioseismic and Magnetic Imager(HMI)onboard the Solar Dynamics Observatory(SDO).We report the following new phenomena:(1)Repeated injections of chromospheric material appearing as 10830 A absorption are squirted out from inter-granular lanes with a period of~5 minutes.(2)EUV emissions are found to be periodically modulated with similar periods of~5 minutes.(3)Around the injection area where 10830 A absorption is enhanced,both EUV emissions and strength of the magnetic field are remarkably stronger.(4)The peaks on the time profile of the EUV emissions are found to be in sync with oscillatory peaks of the stronger magnetic field in the *** findings may give a series of strong evidences supporting the scenario that coronal heating is powered by magneto-acoustic waves.

关键词： Sun:corona Sun:chromosphere Sun:magnetic field

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Long-term analysis of clear nights using satellite data considering astronomical sites in western China

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Research in Astronomy and Astrophysics 2020年第6期20卷 96-108页

作者： Zi-Huang Cao Li-Yong Liu Yong-Heng Zhao Lu Feng Hugh RAJones Huang Shen Jin-Xin Hao Yan-Jie Xue Yong-Qiang Yao Jing Xu Ali Esamdin Zhao-Xiang Qi Jian-Rong Shi Jian Li Yuan Tian Zheng Wang Tai-Sheng Yan Xia Wang Jian-Ping Xiong Si-Cheng Yu Jun-Bo Zhang Zhi-Xia Shen Yun-Ying Jiang Jia Yin Guang-Xin Pu Peng Wei Chun-Hai Bai Guo-Jie Feng Lu Ma Teng-Fei Song Jian-Feng Wang Jian-Feng Tian Xian-Qun Zeng Zhi-Gang Hou Shi-Long Liao Zhi-Song Cao Dong-Wei Fan Yun-Fei Xu Chang-Hua Li Yi-Han Tao National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030China Centre for Astrophysics University of HertfordshireHatfieldUK School of Journalism.Communication University of China Beijing 100024China Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China Yunnan Observatories Chinese Academy of SciencesKunming 650216China

A large ground-based optical/infrared telescope is being planned for a world-class astronomical site in *** cloud-free night percentage is the primary meteorological consideration for evaluating candidate *** data from GMS and NOAA satellites and the MODIS instrument were utilized in this research,covering the period from 1996 to *** data analysis benefits from overlapping results from different independent teams as well as a uniform analysis of selected sites using GMS+NOAA *** significant ground-based monitoring is needed to validate these findings,we identify three different geographical regions with a high percentage of cloud-free conditions(~83%on average),which is slightly lower than at Mauna Kea and Cerro Armazones(~85%on average)and were chosen for the large international projects TMT and ELT *** study finds evidence that cloud distributions and the seasonal changes affected by the prevailing westerly winds and summer monsoons reduce the cloud cover in areas influenced by the *** is consistent with the expectations from climate change models and is suggestive that most of the identified sites will have reduced cloud cover in the future.

关键词： methods statistical-site testing-atmospheric effects-MODIS

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Design of a multi-function high-speed digital baseband data acquisition system

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Research in Astronomy and Astrophysics 2021年第10期21卷 61-72页

作者： Xin Pei Jian Li Na Wang Toktonur Ergesh Xue-Feng Duan Jun Ma Mao-Zheng Chen Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Radio Astronomy Chinese Academy of SciencesNanjing 210008China Xinjiang Key Laboratory of Microwave Technology Urumqi 830011China

A multi-function digital baseband data acquisition system is designed for the sampling,distribution and recording of wide-band multi-channel astronomical *** system hires a SNAP2board as a digital baseband converter to digitize,channelize and packetize the received *** can be configured dynamically from a single channel to eight channels with a maximum bandwidth of 4096 *** parallel HASHPIPE instances run on four servers,each carrying two NVMe SSD cards,achieving a total continuous write rate of 8 GB s^(-1).Data are recorded in the standard VDIF file *** system is deployed on a 25-meter radio telescope to verify its functionality based on pulsar *** results indicate that during the 30-minute observation period,the system achieved zero data loss at a data recording rate of 1 GB s^(-1) on a single *** system will serve as a verification platform for testing the functions of the QTT(Qi Tai radio Telescope)digital backend *** addition,it can be used as a baseband/VLBI(Very Long Baseline Interferometry)recorder or D-F-engine of correlator/beamformer as well.

关键词： instrumentation:miscellaneous techniques:miscellaneous site testing

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Data processing and data products from 2017 to 2019 campaign of astronomical site testing at Ali,Daocheng and Muztagh-ata

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Research in Astronomy and Astrophysics 2020年第6期20卷 109-130页

作者： Zi-Huang Cao Jin-Xin Hao Lu Feng Hugh RAJones Jian Li Jing Xu Li-Yong Liu Teng-Fei Song Jian-Feng Wang Hua-Lin Chen Yan-Jie Xue Huang Shen Yong-Heng Zhao Zhao-Xiang Qi Jian-Rong Shi Yuan Tian Zheng Wang Xia Wang Jin-Liang Hou Jin-Ming Bai Ji Yang Xu Zhou Yong-Qiang Yao Jia Yin Ali Esamdin Guang-Xin Pu Peng Wei Chun-Hai Bai Guo-Jie Feng Lu Ma Xuan Zhang Yu Liu Chong Pei Zhi-Xia Shen Yun-Ying Jiang Jian-Feng Tian Xian-Qun Zeng Zhi-Gang Hou Xu Yang Jun-Bo Zhang Shi-Long Liao Dong-Wei Fan Yun-Fei Xu Jian-Ping Xiong Tai-Sheng Yan Xi Zhang Chang-Hua Li Yi-Han Tao Si-Cheng Yu Zhi-Song Cao Hong-Shuai Wang National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030China Centre for Astrophysics University of HertfordshireHatfieldUK School of Journalism Communication University of ChinaBeijing 100024China Nanjing Institute of Astronomical Optics&Technology Chinese Academy of SciencesNanjing 210042China Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China Yunnan Observatories Chinese Academy of SciencesKunming 650216China Purple Mountain Observatory Chinese Academy of SciencesNanjing 210033China Beijing Kaiyang Space Technology Co. LtdBeijing 100085China

Based on previous site testing and satellite cloud data,Ali,Daocheng and Muztagh-ata have been selected as candidate sites for the Large Optical/Infrared Telescope(LOT) in *** present the data collection,processing,management and quality analysis for our site testing based on using similar *** analyze meteorological data,seeing,background light,cloud and precipitable water vapor data from 2017 March 10 to 2019 March *** also investigated the relative usefulness of our all-sky camera data in comparison to that from the meteorological TERRA satellite data based on a night-by-night comparison of the correlation and consistency between *** find a 6% discrepancy arising from a wide range of factors.

关键词： LOT Site-selection-data processing

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Magneto-acoustic oscillations observed in a solar plage region

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Research in Astronomy and Astrophysics 2021年第7期21卷 241-253页

作者： Haisheng Ji Parida Hashim Zhenxiang Hong Zhe Xu Jinhua Shen Kaifan Ji Wenda Cao University of the Chinese Academy of Sciences Beijing 100871China Purple Mountain Observatory DMSA/CASNanjing 210023China Xinjiang Astronomical Observatory CASUrumqi 830011China Yunnan Observatories CASKunming 650216China Big Bear Solar Observatory 40386 North Shore LaneBig Bear CityCA 922314USA

We gave an extensive study for the quasi-periodic perturbations on the time profiles of the line of sight(LOS) magnetic field in 10 × 10 sub-areas in a solar plage region(corresponds to a facula on the photosphere).The perturbations are found to be associated with the enhancement of He I 10830 A absorption in a moss region,which is connected to loops with million-degree *** analysis to the perturbations gives a kind of spectrum similar to that of Doppler velocity:a number of discrete periods around 5 *** amplitudes of the magnetic perturbations are found to be proportional to magnetic field strength over these *** addition,magnetic perturbations lag behind a quarter of the cycle in the phase with respect to the p-mode Doppler *** show that the relationships can be well explained with an MHD solution for the magneto-acoustic oscillations in high-β *** analysis also shows that,for the two regions with the stronger and weaker magnetic field,the perturbations are always *** findings show that the magnetic perturbations are actually magneto-acoustic oscillations on the solar surface,the photosphere,powered by p-mode *** findings may provide a new diagnostic tool for exploring the relationship between magneto-acoustic oscillations and the heating of the solar upper atmosphere,as well as their role in helioseismology.

关键词： Sun:photosphere Sun:magnetic field Sun:helioseismology

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