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21篇 您的检索式:作者名="Hongfei Zou"
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1Angular response of ‘pin-hole' imaging structure measured by collimated β source显示文摘The pitch-angle distribution of energetic particles is important for space physics studies on magnetic storm and particle acceleration.A‘pin-hole’imaging structure is built with the‘pin-hole’technique and a position sensitive detector,which can be used to measure the pitch angle distribution of energetic particles.To calibrate the angular response of the‘pin-hole’imaging structure,special experiment facilities are needed,such as the particle accelerator with special design.The features of this kind of particle accelerator are:1)The energy range of the outgoing particles should be mid-energy particles(tens keV to several hundred keV);2)the particle flux should be consistent in time-scale;3)the directions of the outgoing particles should be the same and 4)the particle number within the spot should be low enough.In this paper,a method to calibrate the angular response of the‘pin-hole’imaging structure by the90Sr/90Y β source with a collimator is introduced and simulated by Geant4 software.The result of the calibration with the collimated β source is in accord with the Geant4 simulations,which verifies the validity of this method.ZOU Hong LUO Lin LI ChenFang JIA XiangHong XU Feng CHEN HongFei CHEN Jiang SHI WeiHong YU XiangQian ZOU JiQing 2013Science China(Technological Sciences)2013,56,11:10
2Anti-proton contamination design of the imaging energetic electron spectrometer based on Geant4 simulation显示文摘The measurement of energetic particles plays an important role in the space environment monitoring and space weather forecasting.The accuracy of the energetic electron measurement is seriously influenced by the proton contamination.An anti-proton contamination design for the sensor of imaging energetic electron spectrometer is introduced in this paper.According to the electron and proton spectrum on the typical satellite orbits calculated by the radiation belt models,the efficiency of the anti-proton contamination design is estimated by the Geant4 simulation and the design is optimized based on the simulation results.LUO Lin ZOU Hong ZONG QiuGang WANG LingHua CHEN HongFei SHI WeiHong YU XiangQian 2015Science China(Technological Sciences)2015,58,8:7
3Investigation of electrons inside the satellite by the Geant4 simulation显示文摘The measurement of the electron radiation inside the satellite is important for engineering and space environment researches.The particle radiation detectors (PRD) on board CBERS-1 and CBERS-2 made great contribution to understanding of the space environment.Then,what is the radiation relationship between inside and outside the satellite? The Monte Carlo simula-tion with Geant4 was implemented to study the problem.The boundaries of the energy bins of 0.5 and 2 MeV were precisely corresponding to outside energies of 0.99 and 2.52 MeV,respectively.Besides the changes of the energy bins,the fluxes inside were smaller than those of the corresponding bins outside.The spectrum inside the satellite was harder than that outside.An indicator was that the flux ratio of the high energy bin to the low energy bin increased more than 20% from outside to inside.The geometric factor (GF) relates to the incident energy of electrons.By using the AE-8 model to derive the incident spec-trum,the GFs of the low and high energy bins were 1.15 and 0.70 cm2 sr,respectively.GF of the low energy bin was larger than that of the high energy bin.But they were both smaller than the previous results.It was due to the scattering,straggle and shielding effects.LI XiaoCan CHEN HongFei HAO YongQiang ZOU Hong SHI WeiHong 2011Science China(Technological Sciences)2011,54,9:6
4Imaging energetic electron spectrometer onboard a Chinese navigation satellite in the inclined GEO orbit显示文摘The energetic electron measurement is one of the most important issues to understand dynamics in space physics and the applications for space weather. In this study, the principle and functional components of the imaging energetic electron spectrometer(IES) onboard a Chinese navigation satellite in the inclined GEO orbit(IGSO) was introduced. The IES instrument is developed by the team in Peking University(BeiDa), thus it is named as BD-IES. Based on the pin-hole technique, the instrument can measure 50–600 keV electrons incident from 9 directions over a range of 180° in polar angle. With pulse height analysis(PHA), the spectrum can be determined for each direction. The energy and angular calibrations were performed, which show the good energy and angular characteristics of BD-IES. Monte Carlo simulations show that the anti-proton design of BDIES can effectively decrease the proton contamination on the electron measurements in the inclined GEO orbit. The primary results of BD-IES verify the successful design of this instrument.ZOU Hong YE YuGuang ZONG QiuGang CHEN HongFei ZOU JiQing CHEN Jiang SHI WeiHong YU XiangQian ZHONG WeiYing WANG YongFu ZHOU XuZhi HAO YiXin CHEN XingRan JIA XiangHong XU Feng SHAO SiPei WANG Bo HAO XiaoYun ZHANG XiaoXin 2018Science China(Technological Sciences)2018,61,12:5
5Effects of Martian crustal magnetic field on its ionosphere显示文摘The effect of the Martian crustal magnetic field is one of the hot topics of the study of Martian ionosphere.The studies on this topic are summarized in this paper.Main data of the Martian ionosphere were resulted from radio occultation experiments.According to the observations,the electron density scale height and the peak electron density of the Martian ionosphere are influenced by its crustal magnetic field.The strong horizontal magnetic field prevents the vertical diffusion of the plasma and makes the electron density scale height in the topside ionosphere close to that in the photo equilibrium region.In the cusp-like regions with strong vertical magnetic field,the enhanced vertical diffusion leads to a larger electron density scale height in the diffusion equilibrium region.The observation of radio occultation experiment onboard Mars Global Surveyor (MGS) showed that the averaged peak electron density observed in the southern hemisphere with strong crustal magnetic field was slightly larger than that in the northern hemisphere with weak crustal magnetic field.The Mars advanced radar for subsurface and ionosphere sounding (MARSIS) onboard Mars Express (MEX) was the first topside sounder to be used to observe Martian ionosphere.The MARSIS results confirmed that the enhancement of the peak electron density occurred in cusp-like regions with open field lines,and the amount of the enhancement was much larger than that observed by the radio occultation experiment.There are two possible mechanisms for the peak electron density enhancement in the cusp-like crustal magnetic field regions:One is the precipitation of the energetic particles and the other is the heating by the waves excited by plasma instabilities.It's difficult to determine which one is the key mechanism for the peak electron density enhancement.Based on these studies,several interesting problems on the Martian ionosphere and plasma environment are presented.ZOU Hong,CHEN HongFei,YU Ning,SHI WeiHong,YU XiangQian,ZOU JiQing & ZHONG WeiYing Institute of Space Physics and Applied Technology,Peking University,Beijing 100871,China 2010Science China(Technological Sciences)2010,53,6:4
6Evaluating spatial structure of a mixed broad-leaved/Korean pine forest based on neighborhood relationships in Mudanfeng National Nature Reserve,China显示文摘China’s 13 th 5-year forestry plan explicitly requires the end of commercial harvesting and the improved management of natural forests by means of adjusting and optimizing forest structure and developing high-quality forest production.This requires the quantification of stand structure and species diversity.In this study,species distribution,association and size differentiation in a mixed broad-leaved/Korean pine(Pinus koraiensis Siebold&Zucc.)forest in Mudanfeng National Nature Reserve were analyzed using three spatial structure indices:uniform angle index,complete mingling index,and size differentiation index.The results show that the species were randomly distributed,with a moderate size differentiation and high mixed structure.Three dominant species exhibited different patterns in terms of the three indices and their bivariate distribution.Overall,Korean pine showed an opposite trend to Manchurian maple(Acer mandshuricum Maxim.),whereas the distribution pattern of Manchurian linden(Tilia mandshurica Rupr.&Maxim.)was similar to that of the entire stand.Our work contributes to further the knowledge of population structure in order to optimize the structure of secondary forests and plantations.Miao Yang Tijiu Cai Cunyong Ju Hongfei Zou 2019Journal of Forestry Research2019,30,4:4
7Discussion on the geometric factor in the detection of high energy electrons in geospace显示文摘High energy electron is a kind of sources to be detected in the geospace environ- ment. Generally, the particle telescope with much thick semiconductor detector is used as the sensor for energetic electrons because they can penetrate deeply into the detector. The more energy of the electrons is, the deeper they can penetrate into, so that the geometric factor varies with energy of the incident electrons. We discuss the geometric factor of particle radiation detector (PRD), which is a payload on ZY-1 (CBERS-1 and CBERS-2) satellites to monitor the high energy particle ra- diation inside the satellites. According to the NASA’s AE8 model, the geometric factors of electrons for the low energy bin (0.5―1.0 MeV) and the high energy bin (> 2.0 MeV) are 2.468 and 1.736 cm2·sr, respectively. These results are much differ- ent from the traditional calculation of the geometric factor that is 1.18 cm2·sr. The angle-response function of the telescope is also derived, which can be useful for design of the telescope and analysis of the directional distribution.CHEN HongFei SHI WeiHong ZOU Hong ZOU JiQing 2008Science China(Technological Sciences)2008,51,1:3
8Monte Carlo simulations of the sensor head of imaging energetic electron spectrometer onboard a Chinese IGSO navigation satellite显示文摘An imaging energetic electron spectrometer built by the Peking University team(BD-IES) onboard a Chinese navigation satellite in an inclined GEO orbit has been launched successfully in September 2015, which measures the spectra of the energetic electrons with the energy range of 50–600 keV in nine directions. In this study, Monte Carlo simulations of the BD-IES sensor head were performed using Geant4 and the corresponding characteristic responses to the isotropic energetic particles were derived. The effective geometric factors were estimated using the typical electron and proton spectra in the GEO orbit and the corresponding simulated sensor head responses. It was found that the average effective geometric factors of nine directions are close to the nominal geometric factors calculated with the traditional method, but the effective geometric factor decreases as the center energy of the energy channel decreases. The BD-IES sensor head also responses to the energetic protons, but the average contamination rate of all 72 channels is about 2%, which means that the proton contamination is acceptable. The spectra of the energetic electrons measured by BD-IES are derived using the effective geometric factors of the sensor head and are comparable with the spectra measured by the magnetic electron ion spectrometer(MagEIS) instrument onboard Van Allen Probes.ZOU Hong YE YuGuang ZONG QiuGang CHEN HongFei LUO Lin ZHOU XuZhi CHEN XingRan HAO YiXin REN Jie WANG YongFu SHI WeiHong YU XiangQian JIA XiangHong XU Feng ZHANG XiaoXin 2019Science China(Technological Sciences)2019,62,7:3
9Direct measurement of the linear energy transfer of ions in silicon for space application显示文摘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.CHEN HongFei YU XiangQian SHAO SiPei SHI WeiHong CUI ZhanGuo XIANG HongWen HAO ZhiHua ZOU JiQing ZHONG WeiYing ZOU Hong 2016Science China(Technological Sciences)2016,59,1:2
10An analysis of the correlation between the fluxes of high-energy electrons and low-middle-energy electrons in the magnetosphere显示文摘The variation of the flux of energetic electrons in the magnetosphere has been proven to be strongly related to the solar wind speed. Observations of GEO orbit show that the flux of low-energy electrons is not only modulated by the solar wind speed, but, if a time delay is added, is also positively correlated to the flux of high-energy electrons. This feature provides a possible method to forecast the flux of high-energy electrons in GEO orbit. In this study, the correlations of the fluxes between the high-energy electrons and low-middle-energy electrons obtained at different L values and in different orbits are investigated to develop the application of this feature. Based on the analysis of long–term data observed by NOAA POES and GOES, the correlations between the fluxes of high-energy electrons and low–middle–energy electrons are good enough at different L values and in different orbits in quiet time, but this correlation is strongly affected by CME–driven geomagnetic storms.LI ChenFang ZOU Hong ZONG QiuGang JIA XiangHong CHEN HongFei SHI WeiHong YU XiangQian 2016Science China(Technological Sciences)2016,59,7:2
11Variations of the relativistic electron flux after a magnetospheric compression event显示文摘On January 21, 2015, a sharp increase of the solar wind dynamic pressure impacted the magnetosphere. The magnetopause moved inward to the region L< 8 without causing a geomagnetic storm. The flux of the relativistic electrons in the outer radiation belt decreased by half during this event based on the observations of the particle radiation monitor(PRM) of the fourth of the China-Brazil Earth Resource Satellites(CBERS-4). The flux remained low for approximately 11 d; it did not recover after a small magnetic storm on January 26 but after a small magnetic storm on February 2. The loss and recovery of the relativistic electrons during this event are investigated using the PRM data, medium-and high-energy electron observations of NOAA-15 and the Van Allen Probes, medium-energy electron observations of GOES-13, and wave observations of the Van Allen Probes. This study shows that the loss of energetic electrons in this event is related to magnetospheric compression. The chorus waves accelerate the medium-energy electrons, which causes the recovery of relativistic electrons. The Van Allen Probes detected strong chorus waves in the region L =3–6 from January 21 to February 2. However, the flux of medium-energy electrons was low in the region. This implies that the long-lasting lack of recovery of the relativistic electrons after this event is due to the lack of the medium-energy'seed' electrons. The medium-energy electrons in the outer radiation belt may be a clue to predict the recovery of relativistic electrons.CHEN Zhe CHEN HongFei LI YiFan XIANG HongWen YU XiangQian SHI WeiHong HAO ZhiHua ZOU Hong ZOU JiQing ZHONG WeiYing 2017Science China(Technological Sciences)2017,60,4:1
12Energetic electron detection packages on board Chinese navigation satellites in MEO显示文摘Energetic electron measurements and spacecraft charging are of great significance for theoretical research in space physics and space weather applications.In this paper,the energetic electron detection package(EEDP)deployed on three Chinese navigation satellites in medium Earth orbit(MEO)is reviewed.The instrument was developed by the space science payload team led by Peking University.The EEDP includes a pinhole medium-energy electron spectrometer(MES),a high-energy electron detector(HED)based onΔE-E telescope technology,and a deep dielectric charging monitor(DDCM).The MES measures the energy spectra of 50−600 keV electrons from nine directions with a 180°×30°field of view(FOV).The HED measures the energy spectrum of 0.5−3.0 MeV electrons from one direction with a 30°cone-angle FOV.The ground test and calibration results indicate that these three sensors exhibit excellent performance.Preliminary observations show that the electron spectra measured by the MES and HED are in good agreement with the results from the magnetic electron-ion spectrometer(MagEIS)of the Van Allen Probes spacecraft,with an average relative deviation of 27.3%for the energy spectra.The charging currents and voltages measured by the DDCM during storms are consistent with the highenergy electron observations of the HED,demonstrating the effectiveness of the DDCM.The observations of the EEDP on board the three MEO satellites can provide important support for theoretical research on the radiation belts and the applications related to space weather.YuGuang Ye Hong Zou Qiu-Gang Zong HongFei Chen JiQing Zou WeiHong Shi XiangQian Yu WeiYing Zhong YongFu Wang YiXin Hao ZhiYang Liu XiangHong Jia Bo Wang XiaoPing Yang XiaoYun Hao 2021Earth and Planetary Physics2021,5,2:1
13Characterization of 18 polymorphie microsatellite loci in the red - crowned crane ( Grus japonensis), an endangered bird 显示文摘Hongfei Zou Haiyan Dong Weiyao kong 2010Animal Science Journal2010,81,4:1
14Practicable method to identify ferromagnetic objects显示文摘Ferromagnetic objects are ubiquitous in the world and the identification of ferromagnetic objects is important in many applications.Determining the position and magnetic parameters of the ferromagnetic object from its magnetic signature is challenging and can be used in several fields[1,2].YU XiangQian WANG YongFu XIAO ChiJie LIU Si ZONG QiuGang CHEN HongFei ZOU Hong SHI WeiHong CHEN Ao 2022Science China(Technological Sciences)2022,65,12:1
15The underlying mechanism of variety–water–nitrogen–stubble damage interactions on yield formation in ratoon rice with low stubble height under mechanized harvesting显示文摘Agronomic measures are the key to promote the sustainable development of ratoon rice by reducing the damage from mechanical crushing to the residual stubble of the main crop, thereby mitigating the impact on axillary bud sprouting and yield formation in ratoon rice. This study used widely recommended conventional rice Jiafuzhan and hybrid rice Yongyou 2640 as the test materials to conduct a four-factor block design field experiment in a greenhouse of the experimental farm of Fujian Agricultural and Forestry University, China from 2018 to 2019.The treatments included fertilization and no fertilization, alternate wetting and drying irrigation and continuous water flooding irrigation, and plots with and without artificial crushing damage on the rice stubble. At the same time, a 13C stable isotope in-situ detection technology was used to fertilize the pot experiment. The results showed significant interactions among varieties, water management, nitrogen application and stubble status.Relative to the long-term water flooding treatment, the treatment with sequential application of nitrogen fertilizer coupled with moderate field drought for root-vigor and tiller promotion before and after harvesting of the main crop, significantly improved the effective tillers from low position nodes. This in turn increased the effective panicles per plant and grains per panicle by reducing the influence of artificial crushing damage on rice stubble and achieving a high yield of the regenerated rice. Furthermore, the partitioning of 13C assimilates to the residual stubble and its axillary buds were significantly improved at the mature stage of the main crop, while the translocation rate to roots and rhizosphere soil was reduced at the later growth stage of ratooning season rice. This was triggered by the metabolism of hormones and polyamines at the stem base regulated by the interaction of water and fertilizer at this time. We therefore suggest that to achieve a high yield of ratoon rice with low stubble height under mechanized harvesting, the timely application of nitrogen fertilizer is fundamental,coupled with moderate field drying for root-vigor preservation and tiller promotion before and after the mechanical harvesting of the main crop.Jingnan Zou Ziqin Pang Zhou Li Chunlin Guo Hongmei Lin Zheng Li Hongfei Chen Jinwen Huang Ting Chen Hailong Xu Bin Qin Puleng Letuma Weiwei Lin Wenxiong Lin 2024Journal of Integrative Agriculture2024,23,3:0
16In-flight vector magnetometer calibration for FY-3E satellite显示文摘The FY-3E meteorological satellite was launched by China on July 5,2021.The orbit of the satellite is sun-synchronous with an orbit altitude 836 km and orbit period 102 min.The satellite is equipped with a triaxial anisotropic magnetore-sistance magnetometer to detect ultra-low frequency waves in the magnetosphere.The magnetometer sensor is situated on the satellite truss.It is approximately 1 m away from the satellite body to reduce the effect of spacecraft fields.WANG YongFu YU XiangQian ZONG QiuGang XIAO ChiJie LIU Si CHEN HongFei ZOU Hong SHI WeiHong 2023Science China(Technological Sciences)2023,66,6:0
17Analysis of the internal charging data in medium earth orbit with numerical simulation and ground experiment显示文摘The deep dielectric charging effect monitor(DDCEM)has been designed to study the internal charging effect by measuring the charging currents and potentials inside the spacecraft.It is equipped on three Chinese navigation satellites in a circular medium earth orbit(MEO)with 22000 km average height and 55°inclinations.Numerical simulation based on the Geant4-RIC method was used to evaluate the data of DDCEM.The data during May to November 2019 on one of the three satellites show that the charging currents of DDCEM were negatively enhanced when the satellite moved into the outer radiation belt.The currents reached the negative maximum during a significant electron enhancement in September 2019.Positive currents were also detected besides negative currents that were caused by the deposition of electrons in the sensor.The causation of positive currents in the space environment may be that the low-energy electrons cannot penetrate the satellite skin and make it charging to negative potential,the reference ground of DDCEM that is connected to the satellite skin drops below zero by the low-energy electrons so that the output currents turn to positive.Ground experiment was used to simulate the causation of positive currents and the result verified our theory.SONG SiYu CHEN HongFei YU XiangQian ZOU Hong ZONG QiuGang CHEN Ao SHI WeiHong YE YuGuang 2022Science China(Technological Sciences)2022,65,4:0
18AC vector magnetometer for space-based applications using low-resource magneto-impedance sensor显示文摘This study proposes a novel AC vector magnetometer developed using a low-resource magneto-impedance sensor for China’s Feng-Yun meteorological satellite(FY-3E).It was calibrated and characterized to determine its performance parameters.The total weight of the AC vector magnetometer is 51 g(the aluminum box excluded),while the total power consumption is 310 m W.The proposed AC vector magnetometer can detect magnetic field variations in the range of±1000 nT and noise power spectral density of≤50 pT/Hz^(1/2)@1 Hz.Furthermore,the proposed device has a maximum nonlinearity of≤0.71‰over the entire range and a nonorthogonality error of 3.07 nT or 0.15%(root mean square).The total dose hardness of the sensor is≥30 krad(Si).Furthermore,we propose the first survey results of a magnetometer equipped aboard a Chinese FY-3E satellite in a Sunsynchronous orbit.The data revealed that the AC vector magnetometer can detect transient physical signals such as quasistatic field-aligned currents(~50 nT)and waves at the auroral latitudes.These features render the proposed AC vector magnetometer suitable for space-based applications,particularly those involving the study of geomagnetic activity.YU XiangQian HUANG Cong XIAO ChiJie LI JiaWei LIU Si WANG JingDong LI YunPeng QU YaNan WANG YongFu CHEN HongFei ZOU Hong SHI WeiHong ZONG QiuGang CHEN XiaoFei ZHANG XiaoXin ZONG WeiGuo WANG JingSong 2023Science China(Technological Sciences)2023,66,12:0
19Effects of Modular Threshing and Redrying on Color Difference and Polyphenols of Tobacco Leaves显示文摘[Objectives]This study was conducted to analyze changes of color difference and polyphenols and their relationship in the process of threshing and redrying.[Methods]The change trends of color difference parameters L,a,b,H^(0),C and polyphenol contents in tobacco leaves in the middle leaf module and the Pearson correlation between them were analyzed.[Results]During threshing and redrying,L and H^(0)of tobacco showed a decreasing trend,but H^(0)changed slightly;the values of a and C showed an inverted'S'change trend,and the differences between various processes were significant;and the value of b decreased first and then increased.The content of chlorogenic acid and scopoletin decreased first,then increased,and then decreased during threshing and redrying;rutin content showed a significant decreasing trend.The value of L was in an extremely significant positive correlation with rutin content;the value of a was in an extremely significant negative correlation with chlorogenic acid content;b value was also significantly correlated with rutin;and H^(0)was in significant correlation and extremely significant correlation with rutin and total polyphenols,respectively.[Conclusions]This study provides technical support for online detection of tobacco leaf components by the color difference method and for the homogenization of threshing and redrying.Haitao LUO Jingxin LI Zhouying REN Huaiqi LI Hongfei YIN Bing ZENG Dong CHEN Jiafeng QUAN Yanqiu JING Enkai ZOU Chaoqi RAO 2022Agricultural Biotechnology2022,11,6:0
20ROLLING MILL SYSTEM DYNAMIC DESIGN显示文摘It is studied how the aluminum foil chatter mark is produced and controlled The stableness of hydraulic AGC system,fluid vibration of capsule system,and electromechanical coupling of AC/AC VVVF system and de coupling are also studied It is shown that rolling mill design should go to system dynamic design from traditional design The framed drawing of system dynamic design program is presented.Li Mouwei, Liu Hongfei, Zhang Yang, Zhao Yongzhong (College of Mechanical Engineering,University of Science and Technology Beijing) Wany Yide, Li Aiqun, Pei Quanren (Taiyuan Iron and Steel(Group)Ltd.) Zhao Liangmo, Zou Lihe, Zhou Binsheng (Northeast Light 2001Chinese Journal of Mechanical Engineering2001,14,4:0
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