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Superconducting hot-electron bolometer mixers and their applications

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Superconductivity 2022年第2期2卷 7-16页

作者： Wen Zhang Wei Miao Yuan Ren Kang-Ming zhou Sheng-Cai Shi purple mountain observatory(PMO) Chinese Academy of Sciences10 Yuanhua RoadNanjingJiangsu 210023China

Superconducting hot electron bolometer(HEB)mixers are the most sensitive heterodyne detectors at frequencies beyond 1 THz,and are used for many astronomical ***,consisting of a narrow and short superconducting thin film patch connected to an antenna via contact pads,is brought into a highly sensitive operating regime by applying a DC current and a certain amount of local-oscillator ***,superconducting HEB mixers are capable of exhibiting high sensitivity for frequencies up to several tens of THz,as their output noise and conversion gain are nearly frequency independent according to the mixing ***,the understanding of mixing mechanism has evolved over time from lumped-element model to distributed hot-spot *** this review,we provide an overview of theoretical and experimental studies on HEBs and their applications,especially in astronomical observations on ground,airborne and space telescopes.

关键词： Hot electron bolometer Non-equilibrium superconductivity Phonon cooling Diffusion cooling

Chapter 7 Solar and Heliospheric Physics and Interdisciplinary Research with LHAASO

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chinese Physics C 2022年第3期46卷 153-165页

作者： Huan-Yu Jia Li Feng D.Ruffolo Yu.V.Stenkin Xun-Xiu zhou School of Physical Science and Technology Southwest Jiaotong UniversityChengduChina Key Laboratory of Dark Matter and Space Astronomy Purple Mountain ObservatoryChinese Academy of SciencesNanjingChina Department of Physics Faculty of ScienceMahidol UniversityBangkokThailand Institute for Nuclear Research of Russian academy of sciences MoscowRussia Moscow Institute of Physics and Technology MoscowRussia

In the following sub-sections,studies of solar-heliospheric effects on cosmic rays,investigating a possible link between cosmic ray flux and Earth’s climate,and detection of MeV-rangeγ-rays from thunderstorms with the data from LHAASO will be discussed;geophysical research with environmental neutrons will be introduced,and some Monte Carlo simulation results about effects of thunderstorm electric fields on LHAASO observations of cosmic rays will be given.

关键词： solar-heliospheric effects cosmic rays geophysical research thunderstorm electric field LHAASO

Noise temperature distribution of superconducting hot electron bolometer mixers

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chinese Physics B 2020年第5期29卷 41-46页

作者： Kang-Min zhou Wei Miao Yue Geng Yan Delorme Wen Zhang (任远)[y,u,1,14,18,5,14] Kun Zhang Sheng-Cai Shi purple mountain observatory Chinese Academy of SciencesNanjing 210023China Key Laboratory of Radio Astronomy Chinese Academy of SciencesNanjing 210023China Observatoire de Paris 75014 ParisFrance University of Science and Technology of china Hefei 230026China

We report on the investigation of optimal bias region of a wide-band superconducting hot electron bolometer(HEB)mixer in terms of noise temperature performance for multi-pixel heterodyne receiver application in the 5-meter Dome A Terahertz Explorer(DATE5)*** evaluating the double sideband(DSB)receiver noise temperature(Trec)across a wide frequency range from 0.2 THz to 1.34 THz and with a large number of bias points,a broad optimal bias region has been observed,illustrating a good bias applicability for multipixel application since the performance of the HEB mixer is uniquely determined by each bias *** noise temperature of the HEB mixer has been analyzed by calibrating the noise contribution of all RF components,whose transmissions have been measured by a time-domain *** corrected noise temperature distribution shows a frequency independence *** dependence of the optimal bias region on the bath temperature of the HEB mixer has also been investigated,the bath temperature has limited effect on the lowest receiver noise temperature until 7 K,however the optimal bias region deteriorates obviously with increasing bath temperature.

关键词： superconducting hot electron bolometer(HEB)mixer noise temperature distribution bath temperature dependence frequency dependence

Photonics-aided THz-wireless transmission over 400 m at 335 GHz

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Science china(Technological sciences) 2022年第12期65卷 3082-3084页

作者： LI WeiPing YU JianJun ZHU BoWen WANG Feng TAN YuXuan WANG YanYi ZHU Min ZHANG Jiao zhou Wen ZHAO Feng YU JianGuo Key Laboratory for Information Science of Electromagnetic Waves(MoE) Fudan UniversityShanghai 200433China purple mountain Laboratories Nanjing 211111China School of Electronic Engineering Xi’an University of Posts and TelecommunicationsXi’an 710121China School of Electronic Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China

The terahertz(THz)band(0.3–10 THz),with abundant bandwidth,can satisfy the need for large-capacity transmission of fiber-wireless integration communication systems,which has attracted more and more attention[1–3].

关键词： wireless fiber communication

Person video alignment with human pose registration

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Frontiers of Computer Science 2023年第4期17卷 229-231页

作者： Yu ZHANG Zihua WANG Jingyang zhou Siya MI School of Computer Science and Engineering and the Key Lab of Computer Network and Information Integration(Ministry of Education)Southeast UniversityNanjing 211189China School of Cyber Science and Engineering Southeast UniversityNanjing 211189China purple mountain Laboratories Nanjing 211111China

1 Introduction and main *** alignment,especially human action alignment,is a challenging *** purpose is to develop an algorithm to match the same process so that videos can be *** the progress that has been made in image recognition,it is still a difficult problem for distinguishing from similar frames for alignment without context information.

关键词： alignment video frames

Conceptual design studies of the 5 m terahertz antenna for Dome A, Antarctica

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Research in Astronomy and Astrophysics 2013年第12期13卷 1493-1508页

作者： Ji Yang Ying-Xi Zuo Zheng Lou Jing-Quan Cheng Qi-zhou Zhang Sheng-Cai Shi Jia-Sheng Huang Qi-Jun Yao Zhong Wang purple mountain observatory Chinese Academy of Sciences Key Laboratory for Radio Astronomy Chinese Academy of Sciences Harvard-Smithsonian Center for Astrophysics

As the highest, coldest and driest place in Antarctica, Dome A provides exceptionally good observing conditions for ground-based observations over terahertz wavebands. The 5 m Dome A Terahertz Explorer （DATES） has been proposed to explore new terahertz windows, primarily over wavelengths between 350 and 200 pm. DATE5 will be an open-air, fully-steerable telescope that can function by unmanned operation with remote control. The telescope will be able to endure the harsh polar environment, including high altitude, very low temperature and very low air pressure. The unique specifications, including high accuracies for surface shape and pointing and fully automatic year-around remote operation, along with a stringent limit on the periods of on-site assembly, testing and maintenance, bring a number of challenges to the design, construction, assembly and operation of this telescope. This paper intro- duces general concepts related to the design of the DATE5 antenna. Beginning from an overview of the environmental and operational limitations, the design specifications and requirements of the DATE5 antenna are listed. From these, major aspects on the conceptual design studies, including the antenna optics, the backup structure, the pan- els, the subreflector, the mounting and the antenna base structure, are explained. Some critical issues of performance are justified through analyses that use computational fluid dynamics, thermal analysis and de-icing studies, and the proposed approaches for test operation and on-site assembly. Based on these studies, we conclude that the specifications of the DATE5 antenna can generally be met by using enhanced technological approaches.

关键词： Dome A Antarctica -- antennas -- astronomy -- telescopes -- terahertz

Performance analysis and power allocation of mixed-ADC multi-cell millimeter-wave massive MIMO systems with antenna selection

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Frontiers of Information Technology & Electronic Engineering 2021年第4期22卷 571-585页

作者： Tao zhou Guichao CHEN Cheng-xiang WANG Jiayi ZHANG Liu LIU Yiqun LIANG School of Electronics and Information Engineering Beijing Jiaotong UniversityBeijing 100044China Center of National Railway Intelligent Transportation System Engineering and Technology China Academy of Railway SciencesBeijing 100081China National Mobile Communications Research Laboratory School of Information Science and EngineeringSoutheast UniversityNanjing 210096China purple mountain Laboratories Nanjing 211111China

In this study,we consider a multi-cell millimeter-wave(mmWave)massive multiple-input multiple-output(MIMO)system with a mixed analog-to-digital converter(mixed-ADC)and hybrid beamforming architecture,in which antenna selection is applied to achieve intelligent assignment of high-and low-resolution *** exact and approximate closed-form expressions for the uplink achievable rate are derived in the case of maximum-ratio combining *** impacts on the achievable rate of user transmit power,number of radio frequency chains at a base station,ratio of high-resolution ADCs,number of propagation paths,and number of quantization bits are *** is shown that the user transmit power can be scaled down inversely proportional to the number of antennas at the base *** propose an efficient power allocation scheme by solving a complementary geometric programming *** addition,the energy efficiency is investigated,and an optimal tradeoff between the achievable rate and power consumption is *** results will provide a useful reference for the study of mixed-ADC multi-cell mmWave massive MIMO systems with antenna selection.

关键词： Millimeter-wave Massive multiple-input multiple-output(MIMO) Mixed analog-to-digital converter Performance analysis Antenna selection

The calibration and initial results of the HeI D3 line flash spectrum obtained during the 2008 total solar eclipse

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Science china(Physics,Mechanics & Astronomy) 2009年第11期52卷 1799-1805页

作者： LI Hui JI HaiSheng NI HouKun ZHANG HaiYing ZHANG YaNan LIU HongRui DENG YuanYong WANG DongGuang DU QiuSheng zhou TuanHui LI JingWei SHEN JinHua purple mountain observatory 2 Nanjing 210008China nanjing Institute of Astronomical Optics&Technology Nanjing 210042China National Astronomical Observatories of china Beijing 100012China

The flash spectra in the HeI D3 line were obtained during the 2008 total solar eclipse. This paper describes the instrument and the calibration of the obtained flash spectrum, and presents our initial results. The average integrated intensity is Eave = 8.13×1013 erg·cm-1· s-1·ster-1 at h = 1100 km, which confirms that the HeI D3 emission is negatively correlated with the solar activity. The surface brightness reaches a maximum of F ave = 8.25×105 erg·cm-2·s-1·ster-1 at about h ≈ (1290 ± 75) km and then decreases exponentially with height when h >1800 km with an exponential index β = 1.63×10-8 cm-1.

关键词： total solar eclipse flash spectrum spectral line

内蒙古西部杭乌拉地区寒武—奥陶系分界及有关三叶虫

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西北地质科学 1981年第1期 1-22页

作者：卢衍豪周志毅周志强中国科学院南京地质古生物研究所西安地质矿产研究所

为地质界所俗称的巴丹吉林地区,位于内蒙古自治区西部,其名称来源于南部的巴丹吉林沙漠,其西界是弱水,东界是黄河河套平原.由于地域偏僻、荒芜,地质上一直属于研究程度很低的地区,以往从未有过关于寒武系及奥陶系的报导.1977-1978年宁... 详细信息

为地质界所俗称的巴丹吉林地区,位于内蒙古自治区西部,其名称来源于南部的巴丹吉林沙漠,其西界是弱水,东界是黄河河套平原.由于地域偏僻、荒芜,地质上一直属于研究程度很低的地区,以往从未有过关于寒武系及奥陶系的报导.1977-1978年宁夏地质局综合研究队和西安地质矿产研究所在这一地区开展了详细的地质调查,在珠斯楞海尔罕、

关键词：三叶虫背沟奥陶系头鞍沟间肋沟边缘沟面线前支固定颊眼脊分界内蒙古