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Influences of mass flow rate on heat and mass transfer performances of water sublimator combined with fluid loop

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Chinese Journal of Aeronautics 2019年第4期32卷 888-894页

作者： Yuying WANG Jindong LI Xianwen NING Qi ZHONG Jianyin MIAO Lu WANG Wei LYU Chang LIU Beijing Key Laboratory of space Thermal Control Technology Institute of Spacecraft System EngineeringChina Academy of Space Technology

For spacecraft working in vacuum environment, sublimator is an effective heat rejection approach to reject system's peak heat load, and supplement spacecraft radiation heat rejection. For a spacecraft active fluid loop thermal control system combined with sublimator, waste heat generated from multi-point distributed heat sources could be collected by the fluid loop efficiently. However, the heat and mass transfer performances of the sublimator combined with fluid loop have not been adequately studied in previous research, especially for the influences of the heat load. Since work fluid mass flow rate is the main factor affecting heat load of the fluid loop, this context experimentally studied influences of the fluid loop mass flow rate on sublimator start-up transient characteristics, including heat transfer performances, response time, and work stability. Results indicated that the fluid loop mass flow rate affected the sublimator heat and mass transfer performances obviously, but the heat rejection ability is not always increase with the increasing of the fluid loop mass flow rate. In addition, we obtained the condition to judge whether there is a positive correlation between heat rejection ability and fluid loop mass flow rate.

关键词： Fluid loop Mass flow rate Sublimator spacecraft Thermal control

Direct measurement of the linear energy transfer of ions in silicon for space application

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Science China(Technological Sciences) 2016年第1期59卷 128-134页

作者： CHEN HongFei YU XiangQian SHAO SiPei SHI WeiHong CUI ZhanGuo XIANG HongWen HAO ZhiHua ZOU JiQing ZHONG WeiYing ZOU Hong institute of space Physics and Applied Technology School of Earth and Space SciencesPeking UniversityBeijing 100871China institute of Shandong Aerospace Technology Yantai 264003China China Academy of space Technology Beijing 100094 China

The single event effect(SEE) is an important consideration in electronic devices used in space environments because it can lead to spacecraft anomalies and failures. The linear energy transfer(LET) of ions is commonly investigated in studies of SEE. The use of a thin detector is an economical way of directly measuring the LET in space. An LET telescope consists of a thin detector as the front detector(D1), along with a back detector that indicates whether D1 was penetrated. The particle radiation effect monitor(PREM) introduced in this paper is designed to categorize the LET into four bins of 0.2–0.4, 0.4–1.0, 1.0–2.0 and 2.0–20 Me V·cm^2/mg, and one integral bin of LET>20 Me V·cm^2/mg. After calibration with heavy ions and Geant4 analysis, the LET boundaries of the first four bins are determined to be 0.236, 0.479, 1.196, 2.254, and 17.551 Me V·cm^2/mg, whereas that of the integral bin is determined to be LET>14.790 Me V·cm^2/mg. The acceptances are calculated by Geant4 analysis as 0.452, 0.451, 0.476, 0.446, and 1.334, respectively. The LET accuracy is shown to depend on the thickness of D1; as D1 is made thinner, the accuracy of the measured values increases.

关键词： linear energy transfer measurement LET single event effect space radiation

Performance of bifacial HIT solar cells on n-type silicon substrates

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Optoelectronics Letters 2010年第2期6卷 108-111页

作者：柳琴叶晓军刘成陈鸣波 institute of space Power Sources

The performance of amorphous silicon(a-Si:H) /crystalline silicon(c-Si) heterojunction is studied,and the effects of the emitter layer thickness,doping concentration,intrinsic layer thickness,back heavily-doped n layer,interface state and band offset on the optical and electrical performance of bifacial heterojunction with intrinsic thin-layer(HIT) solar cells on ntype silicon substrates are *** is found that the HIT solar cells on n-type substrates can obtain a higher conversion efficiency than those on p-type substrates by calculating the band diagrams and parameters of HIT solar cells.

关键词：双面太阳能电池电气性能 n型硅基板发光层厚度掺杂浓度无定形硅界面状态

Effects of mesoscale gravity waves on sporadic E simulated by a one-dimensional dynamic model

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Earth and Planetary Physics 2025年第1期9卷 1-9页

作者： Xu Zhou ZeZhong Li XinAn Yue LiBo Liu Key Laboratory of Earth and Planetary Physics/Heilongjiang Mohe National Geophysical Observatory/Beijing National Observatory of space Environment Institute of Geology and GeophysicsChinese Academy of Sciences(CAS)Beijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China CAS Center for Excellence in Comparative Planetology/CAS Key Laboratory of Geospace Environment/Mengcheng National Geophysical Observatory University of Science and Technology of ChinaHefei 230026China

In addition to being driven by tidal winds,the sporadic E(Es)layers are modulated by gravity waves(GWs),although the effects are not yet comprehensively *** this article,we discuss the effects of mesoscale GWs on the Es layers determined by using a newly developed model,MISE-1D(one-dimensional Model of Ionospheric Sporadic E),with low numerical dissipation and high *** by the wind fields resolved by the high-resolution version of the Whole Atmosphere Community Climate Model with thermosphere and ionosphere extension(WACCM-X),the MISE-1D simulation revealed that GWs significantly influence the evolution of the Es layer above 100 km but have a very limited effect at lower *** effects of GWs are diverse and complex,generally including the generation of fluctuating wavelike structures on the Es layer with frequencies similar to those of the *** mesoscale GWs can also cause increases in the density of Es layers,or they can disperse or diffuse the Es layers and increase their *** addition,the presence of GWs is a key factor in sustaining the Es layers in some cases.

关键词： sporadic E ion tidal layer gravity waves numerical simulation

High energy neutron and pion-decay gamma-ray emissions from solar flares

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Chinese Journal of Astronomy and Astrophysics 2009年第1期9卷 11-40页

作者： Edward L.Chupp James M.Ryan Physics Department and space Science Center in the institute for the Study of Earth Oceans and space University of New Hampshire

Solar flare gamma-ray emissions from energetic ions and electrons have been detected and measured to GeV energies since 1980. In addition, neutrons produced in solar flares with 100 MeV to GeV energies have been observed at the Earth. These emissions are produced by the highest energy ions and electrons accelerated at the Sun and they provide our only direct （albeit secondary） knowledge about the properties of the accelerator（s） acting in a solar flare. The solar flares, which have direct evidence for pion-decay gamma-rays, are unique and are the focus of this paper. We review our current knowledge of the highest energy solar emissions, and how the characteristics of the acceleration process are deduced from the observations. Results from the RHESSI, INTEGRAL and CORONAS missions will also be covered. The review will also cover the solar flare capabilities of the new mission, FERMI GAMMA RAY space TELESCOPE, launched on 2008 June II. Finally, we discuss the requirements for future missions to advance this vital area of solar flare physics.

关键词： Sun -- Flares -- Particle Acceleration-Meson Production

Flux emergence in the solar active region NOAA 11158: the evolution of net current

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Research in Astronomy and Astrophysics 2015年第9期15卷 1547-1558页

作者： Panditi Vemareddy Parameswaran Venkatakrishnan Solipuram Karthikreddy Indian institute of Astrophysics Udaipur Solar Observatory Physical Research Laboratory Department of Earth and space Sciences Indian Institute of Space Science and Technology

We present a detailed investigation of the evolution of observed net vertical current using a time series of vector magnetograms of the active region （AR） NOAA 11158 obtained from the Helioseismic and Magnetic Imager. We also discuss the relation of net current to the observed eruptive events. The AR evolved from the βγ to βγδ3 configuration over a period of six days. The AR had two sub-regions of activity with opposite chirality： one dominated by sunspot rotation producing a strong CME, and the other showing large shear motions producing a strong flare. The net current in each polarity over the CME producing sub-region increased to a maximum and then decreased when the sunspots were separated. The time profile of net current in this sub-region followed the time profile of the rotation rate of the south-polarity sunspot in the same sub-region. The net current in the flaring sub-region showed a sudden increase at the time of the strong flare and remained unchanged until the end of the observation, while the sunspots maintained their close proximity. The systematic evo- lution of the observed net current is seen to follow the time evolution of total length of strongly sheared polarity inversion lines in both of the sub-regions. The observed photospheric net current could be explained as an inevitable product of the emergence of a twisted flux rope, from a higher pressure confinement below the photosphere into the lower pressure environment of the photosphere.

关键词： Sun:active regions -- magnetic fields -- activity -- coronal mass ejec-tions -- non-potentiality -- electric current

Anomalous quality factor evolution of induced transparency in a virtualized coupled-oscillator system

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 148-155页

作者： Yunhan Yang Han Jia Tuo Liu Yuzhen Yang Jun Yang Key Laboratory of Noise and Vibration Research Institute of Acoustics Chinese Academy of Sciences University of Chinese Academy of Sciences State Key Laboratory of Acoustics Institute of Acoustics Chinese Academy of Sciences

The phenomenon of induced transparency, characterized by a high quality(Q) factor, holds significant importance in the fields of high-precision sensing, energy storage and wave manipulation. Conventional transparency systems are often constrained by the limited experimentally accessible parameter space and the lack of independent control over intrinsic parameters, thereby hindering advanced research on high-Q effects. Here we propose a virtualized coupled-oscillator system that enables reconfigurable induced transparency in the reflection spectrum. By virtually incorporating a pair of coupled oscillators into an individual acoustic meta-atom, we achieve the manipulation of induced transparency in a decoupled, wide-ranging, and elaborate manner. Exploiting the diverse evolutions across the intrinsic parameter space, we show experimentally a counter-intuitive increase in the Q-factor of the transparency window, which is attributed to the enhanced dissipation of the bright ***, a constant group delay at the center frequency is observed accompanying this evolution. Our work demonstrates an intriguing platform as well as a novel strategy to engineer high-Q induced transparency phenomenon, and paves the way towards applications in programmable acoustic sensors, filters and slow-wave devices.

关键词： induced transparency acoustic meta-atom high quality-factor scattering programmable intrinsic parameter

GEOID: GRID Services for Earth Observation Image Data Processing

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International Journal of Digital Earth 2013年第2期6卷 185-195页

作者： Nitant Dube R.Ramakrishnan K.S.Dasgupta space Applications Centre ISROAhmedabadIndia Indian institute of space Science and Technology ThiruvananthapuramIndia

Recent developments in space technology and exponential increase in demand of earth observation data from space have generated a requirement of a data processing environment,where users can discover the data and process,based on their *** Services for Earth Observation Image Data Processing(GEOID)is proposed with a motivation to cater to future earth observation applications requirements of digital *** paper discusses the overview of the GEOID architecture,its deployment scenario,use-cases and simulation *** technologies used for implementation include Grid computing and Service Oriented *** provides capability to address require-ments of applications such as real-time monitoring,time series data processing and processing with user required quality to meet the requirements of end user *** allows users to access the archive products or the raw satellite data stream and process their area of *** show that applications such as time series analysis show considerable improvement in processing time by using GEOID.

关键词： earth observation digital earth GRID GEOID service oriented architecture GridSIM

Time-resolved spectroscopy for 5s^('4)D_(7/2) state transitions undergoing electron–ion recombination in femtosecond laser-produced copper plasma

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Chinese Physics B 2017年第12期26卷 290-294页

作者：宋海英李辉张艳杰谷鹏刘海云李维刘勋刘世炳 Strong-field and Ultrafast Photonics Laboratory Institute of Laser Engineering Beijing University of Technology Beijing institute of space Mechanics and Electricity China Academy of Space Technology

In the femtosecond laser-produced Cu-plasma, the transient transition dynamics that the excited state 5s4D7/2 via electron-ion recombination transfers to 4p4F9/20 （465.11 nm, Λ1 line） and 4p4D7/20 （529.25 nm, Λ2 line） states are investigated by using the time-resolved spectroscopy. The occupation number and relevant lifetime of the excited state 5s4D7/2, the temporal evolutions of spectral intensities for Λ1 line and Λ2 line emissions are demonstrated to be in direct proportion to the employed laser intensity, which reveals the transient features of transition dynamics clearly differing from that resulted in the traditional collision excitation. Furthermore, some unique characteristics for Λ1 and Λ2 transitions stemming from electron-ion recombination are examined in detail.

关键词： time-resolved spectroscopy recombination transition laser-produced plasma