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| 1 | Dynamic variation and the fast acceleration of particles in Earth's radiation belt显示文摘We have quantitatively investigated the radiation belt's dynamic variations of 1.5-6.0 MeV electrons during 54 CME (coronal mass ejection)-driven storms from 1993 to 2003 and 26 CIR (corotating interaction region)-driven recurrent storms in 1995 by utilizing case and statistical studies based on the data from the SAMPEX satellite. It is found that the boundaries determined by fitting an exponential to the flux as a function of L shell obtained in this study agree with the observed outer and inner boundaries of the outer radiation belt. Furthermore, we have constructed the Radiation Belt Content (RBC) index by integrating the number density of electrons between those inner and outer boundaries. According to the ratio of the maximum RBC index during the recovery phase to the pre-storm average RBC index, we conclude that CME-driven storms produce more relativistic electrons than CIR-driven storms in the entire outer radiation belt, although the relativistic electron fluxes during CIR-related storms are much higher than those during CME-related storms at geosynchronous orbit. The physical radiation belt model STEERB is based on the three-dimensional Fokker-Planck equation and includes the physical processes of local wave-particle interactions, radial diffusion, and adiabatic transport. Due to the limitation of numerical schemes, formal radiation belt models do not include the cross diffusion term of local wave-particle interactions. The numerical experiments of STEERB have shown that the energetic electron fluxes can be overestimated by a factor of 5 or even several orders (depending on the pitch angle) if the cross diffusion term is ignored. This implies that the cross diffusion term is indispensable for the evaluation of radiation belt electron fluxes. Formal radiation belt models often adopt dipole magnetic field; the time varying Hilmer-Voigt geomagnetic field was adopted by the STEERB model, which self-consistently included the adiabatic transport process. The test simulations clearly indicate that the adiabatic process can significantly affect the evolution of radiation belt electrons. The interactions between interplanetary shocks and magnetosphere can excite ULF waves in the inner magnetosphere; the excited polodial mode ULF wave can cause the fast acceleration of 'killer electrons'. The acceleration mechanism of energetic electrons by poloidal and toroidal mode ULF wave is different at different L shells. The acceleration of energetic electrons by the toroidal mode ULF waves becomes important in the region with a larger L shell (the outer magnetosphere); in smaller L shell regions (the inner magnetosphere), the poloidal mode ULF becomes responsible for the acceleration of energetic electrons. | ZONG QiuGang YUAN ChongJing WANG YongFu SU ZhenPeng | 2013 | Science China Earth Sciences2013，56，7： | 5 |
| 2 | Exohiss wave enhancement following substorm electron injection in the dayside magnetosphere显示文摘Exohiss is a low-frequency structureless whistler-mode emission potentially contributing to the precipitation loss of radiation belt electrons outside the plasmasphere. Exohiss is usually considered the plasmaspheric hiss leaked out of the dayside plasmapause.However, the evolution of exohiss after the leakage has not been fully understood. Here we report the prompt enhancements of exohiss waves following substorm injections observed by Van Allen Probes. Within several minutes, the energetic electron fluxes around 100 keV were enhanced by up to 5 times, accompanied by an up to 10-time increase of the exohiss wave power. These substorm-injected electrons are shown to produce a new peak of linear growth rate in the exohiss band(< 0.1 f_(ce)). The corresponding path-integrated growth rate of wave power within 10° latitude of the magnetic equatorial plane can reach 13.4, approximately explaining the observed enhancement of exohiss waves. These observations and simulations suggest that the substorm-injected energetic electrons could amplify the preexisting exohiss waves. | ZhongLei Gao ZhenPeng Su FuLiang Xiao HuiNan Zheng YuMing Wang Shui Wang H. E. Spence G.D. Reeves D. N. Baker J. B. Blake H.O. Funsten | 2018 | Earth and Planetary Physics2018，2，5： | 2 |
| 3 | A low-energy ion spectrometer with half-space entrance for three-axis stabilized spacecraft显示文摘A low-energy ion spectrometer(LEIS) for use aboard three-axis stabilized spacecraft has been developed to measure ion energy per charge distribution in three-dimensional space with good energy-, angular-and temporal-resolutions. For the standard top-hat electrostatic analyzer used widely in space plasma detection, three-axis stabilized spacecraft makes it difficult to obtain complete coverage of all possible ion arrival directions. We have designed angular scanning deflectors supplementing to a cylindrically symmetric top-hat electrostatic analyzer to provide a half-space field of view as 360°×90°(–45°–+45°), and fabricated the LEIS flight model for detecting magnetospheric ions in geosynchronous orbit. The performance of this payload has been evaluated in detail by a series of simulation and environmental tests, and the payload has also been calibrated through laboratory experiments using a low-energy ion source. The results show that capabilities of the LEIS payload are in accordance with the requirements of a magnetospheric mission. | HU RenXiang SHAN Xu YUAN GuangYuan WANG ShuWen ZHANG WeiHang QI Wei CAO Zhe LI YiRen CHEN ManMing YANG XiaoPing WANG Bo SHAO SiPei LI Feng ZHONG XiaoQing FAN Dan HAO XinJun FENG ChangQing SU ZhenPeng SHEN ChengLong LI Xin DAI GuYue QIU BingLin PAN ZongHao LIU Kai XU ChunKai LIU ShuBin AN Qi ZHANG TieLong WANG YuMing CHEN XiangJun | 2019 | Science China(Technological Sciences)2019，62，6： | 1 |
| 4 | A New Type of Li Deposit:Hydrothermal Crypto-Explosive Breccia Pipe Type显示文摘Lithium is one of the important strategic energy metals,which is in short supply in China.There are three major types of lithium deposits:brine and salt lake type,highly differentiated granite or pegmatite type,and carbonate-clay type.In recent years,some new types of lithium deposits have also begun to receive great attention and subject recent research.There are many crypto-explosive breccia pipe type deposits in the world,including copper,gold,lead,zinc,tungsten and tin deposits,but little is known about this type of lithium deposit.This paper introduces the latest research results of the Weilasituo Sn-Li-Rb polymetallic deposit in Inner Mongolia(NE China),which occurs in the middlesouthern section of the Great Xing’an Range metallogenic belt.A remarkable feature of this deposit is the coexistence of various mineralization types,including granite type Rb and Sn-Zn,hydrothermal crypto-explosive breccia pipe type Li-Rb,quartz vein type Sn-Zn and sulfide vein type Pb-Zn-Ag mineralization.Among them,hydrothermal crypto-explosive breccia pipe type Li-Rb deposit is currently very rare at home and abroad,which is likely a new type of rare metal deposit that worthy of our attention.This paper systematically summarizes the geology,alteration and mineralization,geochemistry,isotopes and geochronology of the Weilasituo deposit,and establishes a new petrogenic and metallogenic model. | Shao-Yong Jiang Huimin Su Xinyou Zhu Kangyu Zhu Zhenpeng Duan | 2022 | Journal of Earth Science2022，33，5： | 1 |
| 5 | Three-dimensional ray-tracing simulation of fast magnetoacoustic waves in a stratified solar atmosphere显示文摘In the solar atmosphere, there exist two frequently-observed phenomena, Moreton waves and EIT(extreme-ultraviolet imaging telescope) waves, whose physical nature is still under debate. In this work, we perform a three-dimensional ray-tracing simulation for the propagation of fast magnetoacoustic waves. We build a stratified solar atmosphere model and take partial ionization into consideration to give an exact description of chromosphere and transition region. The calculated result is compared with a flare event observation in which both Moreton waves and EIT waves were present. In agreement with observations, the calculated wavefront show different kinematical characteristics in different propagation directions during different times.Moreton waves and EIT waves have higher propagation speeds near the active region where the magnetic field strength is strong. The result suggests that both Moreton waves and EIT waves of this event can be interpreted as the fast magnetoacoustic waves propagating at different heights in the solar atmosphere. | LIU NiGang ZHENG HuiNan SU ZhenPeng | 2017 | Science China(Technological Sciences)2017，60，10： | 1 |
| 6 | First results of the low energy ion spectrometer onboard a Chinese geosynchronous satellite显示文摘A Chinese geosynchronous satellite was launched on June 23,2020.It carried a plasma detection package to monitor the space environment around the orbit.Here we report the inflight performance of a low energy ion spectrometer(LEIS),one of the primary instruments in the plasma detection package,and its initial observations in flight.Benefiting from the state-of-the-art design of a top-hat electrostatic analyzer cooperated with angular scanning deflectors,three-dimensional measurement of ions in space with a large field of view of 360°×90°and a wide energy range from 50 eV to 25 keV per charge has been achieved.The differential energy flux spectra of ions around the orbit have shown clear signatures of surface charging and storm/substorm ion injections.The occurrence of surface charging could be caused by the lack of photoemission at the Earth's eclipse(near the midnight)or the storm energetic electron injection at the dawn sector.The present results demonstrated a good performance of the LEIS payload in flight for monitoring the space ion environment around the orbit.In situ measurements of the LEIS payload provide us an opportunity to understand the magnetospheric ion dynamics and forecast the associate space weather impacts. | SHAN Xu MIAO Bin CAO Zhe SUN ZhenYu LI YiRen LIU Kai GUO XingYu QU SanBiao SU ZhenPeng SHEN ChengLong PAN ZongHao LI Xin HAO XinJun YANG XiaoPing TIAN Chao JIANG Yu LIU ShuBin AN Qi CHEN XiangJun WANG YuMing | 2023 | Science China(Technological Sciences)2023，66，5： | 0 |
| 7 | In-flight calibration of the magnetometer on the Mars orbiter of Tianwen-1显示文摘Mars orbiter magnetometer(MOMAG)is one of seven science payloads onboard Tianwen-1’s orbiter.Unlike most of the satellites,Tianwen-1’s orbiter is not magnetically cleaned,and the boom where placed the magnetometer’s sensors is not long enough.These pose many challenges to the magnetic field data processing.In this study,we introduce the in-flight calibration process of the Tianwen-1/MOMAG.The magnetic interference including spacecraft generated dynamic field and the slowlychanging zero offsets are cleaned in sequence.Then the calibrated magnetic field data are compared with the data from the Mars atmosphere and volatile Evolutio N(MAVEN).We find that some physical structures in the solar wind are consistent between the two data sets,and the distributions of the magnetic field strength in the solar wind are very similar.These results suggest that the in-flight calibration of the MOMAG is successful and the MOMAG provides reliable data for scientific research. | ZOU ZhuXuan WANG YuMing ZHANG TieLong WANG GuoQiang XIAO SuDong PAN ZongHao ZHANG ZhouBin YAN Wei DU Yang CHI YuTian CHENG Long WU ZhiYong HAO XinJun LI YiRen LIU Kai CHEN ManMing SU ZhenPeng SHEN ChengLong XU MengJiao GUO JingNan | 2023 | Science China(Technological Sciences)2023，66，8： | 0 |
| 8 | Doping of group IVB elements for nickel-rich cobalt-free cathodes显示文摘Hetero-element doping is a promising strategy to improve the cycling stability of nickel-rich cobalt-free cathodes for the next-generation high energy-density Li ion batteries.To make doping effective,it is important to understand the mechanism of how the dopants regulate the electronic band,lattice parameter adjusting,or hetero-phase formation to achieve high stability.In this study,we investigate LiNi_(0.9)Mn_(0.1)O_(2)cathodes doped with IVB grouping elements via multiple characterization techniques.By utilizing in situ XRD and TEM methods,we found that the stronger Ti-O bond effectively improves the cathode stability via a dual protection mechanism.Specifically,the bulk lattice of cathode is wellpreserved during cycling as a result of the suppressed H_(2)-H_(3)phase transition,while a in situ formed Ti-rich surface layer can prevent continuous surface degradation.As a result,the 5%Ti doped LiNi_(0.9)Mn_(0.1)O_(2)cathode exhibits a high capacity retention of 96%after 100 cycles.Whereas,despite IVB group elements Zr and Hf have stronger bonding energy with oxygen,their larger ionic radii actually impede their diffusion into the cathode,thereby they can not improve the cycling stability.Our findings uncover the functional origin of doped elements with their dynamic modification on cathode structure,providing mechanistic insights into the design of nickel-rich cobalt-free cathodes. | Shengnan Guo Xincheng Lei Jiayi Wang Jie Su Yingying Wang Xiaozhi Liu Pengxiang Ji Kangning Zhao Xuefeng Wang Lin Gu Zhenpeng Yao Dong Su | 2023 | Journal of Energy Chemistry2023，，11： | 0 |
| 9 | The Mars orbiter magnetometer of Tianwen-1:in-flight performance and first science results显示文摘The Mars Orbiter MAGnetometer(MOMAG)is a scientific instrument onboard the orbiter of China’s first mission for Mars—Tianwen-1.Since November 13,2021,it has been recording magnetic field data from the solar wind to the magnetic pile-up region surrounding Mars.Here we present its in-flight performance and first science results,based on its first one and one-half months’data.Comparing these early MOMAG observations to the magnetic field data in the solar wind from NASA’s Mars Atmosphere and Volatile EvolutioN(MAVEN)mission,we report that the MOMAG magnetic field data are at the same level in magnitude,and describe the same magnetic structures with similar variations in three components.We recognize 158 clear bow shock(BS)crossings in these MOMAG data;their locations match well statistically with the modeled average BS.We also identify and compare five pairs of datasets collected when Tianwen-1’s orbiter and the MAVEN probe made simultaneous BS crossings.These BS crossings confirm the global shape of modeled BS,as well as the south-north asymmetry of the Martian BS.Two cases presented in this paper suggest that the BS is probably more dynamic at flank than near the nose.So far,MOMAG performs well,and provides accurate magnetic field vectors.MOMAG is continuously scanning the magnetic field surrounding Mars.Data from MOMAG’s measurements complement data from MAVEN and will undoubt edly advance our understanding of the plasma environment of Mars. | YuMing Wang TieLong Zhang GuoQiang Wang SuDong Xiao ZhuXuan Zou Long Cheng ZongHao Pan Kai Liu XinJun Hao YiRen Li ManMing Chen ZhouBin Zhang Wei Yan ZhenPeng Su ZhiYong Wu ChengLong Shen YuTian Chi MengJiao Xu JingNan Guo Yang Du | 2023 | Earth and Planetary Physics2023，7，2： | 0 |
| 10 | Studies of the Anomaly of Hall Coefficient in High T_(c) Superconducting Thin Films显示文摘Measurements of the Hall coefficient(RH)were carried out for a polycrystalline YBa_(2)Cu_(3)O_(7-y) film,a well oriented YBa_(2)Cu_(3)O_(7-y) film and an oriented GdBa_(2)Cu_(3)O_(7-y) film.Sign change of RH was observed for the two YBa_(2)Cu_(3)O_(7-y) films near Tc,but not for the GdBa_(2)Cu_(3)O_(7-y) film which contains partly the component of(110)orientation.The RH anisotropy model proposed previously turns out to be incorrect.Why the YBa_(2)Cu_(3)O_(7-y) films experience sign change of RH while the GdBa_(2)Cu_(3)O_(7-y) film does not is tentatively investigated. | HE Zhenhui SHA Jian SU Zhenpeng CHENG Xiang ai WANG Shunxi FANG Minghu ZHANG Qirui ZHOU Xianyi YAO Weiguo QI Zhenzhong YI Huairen LI Hongcheng | 1991 | Chinese Physics Letters1991，8，6： | 0 |
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