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Inverse Calculation and Regularization Process for the Solar Aspect System(SAS) of HXI Payload on ASO-S spacecraft

Research in Astronomy and Astrophysics 2024年第4期24卷 13-34页

作者： Ji-Rui Yu Ping Ruan Yang Su Ying-Hong He Jin-You Tao Zhe Zhang Song Guo Bin Xue Jian-Feng Yang Xi'an institute of Optics and Precision Mechanics of Chinese Academy of sciences Xi'an 710119China University of Chinese Academy of sciences Beijing 100049China Key Laboratory of Dark Matter and space Astronomy Purple Mountain ObservatoryChinese Academy of SciencesNanjing 20034China School ofAstronomy and space Science Universityof Science and Technology of ChinaHefei 230026China

For the ASO-S/HXI payload, the accuracy of the flare reconstruction is reliant on important factors such as the alignment of the dual grating and the precise measurement of observation orientation. To guarantee optimal functionality of the instrument throughout its life cycle, the Solar Aspect System (SAS) is imperative to ensure that measurements are accurate and reliable. This is achieved by capturing the target motion and utilizing a physical model-based inversion algorithm. However, the SAS optical system’s inversion model is a typical ill-posed inverse problem due to its optical parameters, which results in small target sampling errors triggering unacceptable shifts in the solution. To enhance inversion accuracy and make it more robust against observation errors, we suggest dividing the inversion operation into two stages based on the SAS spot motion model. First, the as-rigid-aspossible (ARAP) transformation algorithm calculates the relative rotations and an intermediate variable between the substrates. Second, we solve an inversion linear equation for the relative translation of the substrates, the offset of the optical axes, and the observation orientation. To address the ill-posed challenge, the Tikhonov method grounded on the discrepancy criterion and the maximum a posteriori (MAP) method founded on the Bayesian framework are utilized. The simulation results exhibit that the ARAP method achieves a solution with a rotational error of roughly±3 5 (1/2-quantile);both regularization techniques are successful in enhancing the stability of the solution, the variance of error in the MAP method is even smaller—it achieves a translational error of approximately±18μm (1/2-quantile) in comparison to the Tikhonov method’s error of around±24μm (1/2-quantile). Furthermore, the SAS practical application data indicates the method’s usability in this study. Lastly, this paper discusses the intrinsic interconnections between the regularization methods.

关键词： methods:data analysis Sun:flares Sun:X-rays gamma rays

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Effects of coal-fired power plants on soil microbial diversity and community structures

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Journal of Environmental sciences 2024年第3期137卷 206-223页

作者： Bowen Sun Renbin Zhu Yu Shi Wanying Zhang Zeming Zhou Dawei Ma Runfang Wang Haitao Dai Chenshuai Che institute of Polar Environment&Anhui Key Laboratory of Polar Environment and Global Change School of Earth and Space SciencesUniversity of Science and Technology of ChinaHefei 230026China State Key Laboratory of Crop Stress Adaptation and Improvement School of Life SciencesHenan UniversityKaifeng 450046China State Grid Anhui Electric Power Research institute Hefei 230601China

Long-term deposition of atmospheric pollutants emitted from coal combustion and their effects on the eco-environment have been extensively studied around coal-fired power plants.However,the effects of coal-fired power plants on soil microbial communities have received little attention through atmospheric pollutant deposition and coal-stacking.Here,we collected the samples of power plant soils(PS),coal-stacking soils(CSS)and agricultural soils(AS)around three coal-fired power plants and background control soils(BG)in Huainan,a typical mineral resource-based city in East China,and investigated the microbial diversity and community structures through a high-throughput sequencing technique.Coal-stacking significantly increased(p<0.05)the contents of total carbon,total nitrogen,total sulfur and Mo in the soils,whereas the deposition of atmospheric pollutants enhanced the levels of V,Cu,Zn and Pb.Proteobacteria,Actinobacteria,Thaumarchaeota,Thermoplasmata,Ascomycota and Basidiomycota were the dominant taxa in all soils.The bacterial community showed significant differences(p<0.05)among PS,CSS,AS and BG,whereas archaeal and fungal communities showed significant differences(p<0.01)according to soil samples around three coal-fired power plants.The predominant environmental variables affecting soil bacterial,archaeal and fungal communities were Mo-TN-TS,Cu-V-Mo,and organic matter(OM)-Mo,respectively.Certain soil microbial genera were closely related to multiple key factors associated with stacking coal and heavy metal deposition from power plants.This study provided useful insight into better understanding of the relationships between soil microbial communities and long-term disturbances from coal-fired power plants.

关键词： Coal-fired power plants Soil microbial communities Coal-stacking Heavy metals Environmental variables

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QARF: A Novel Malicious Traffic Detection Approach via Online Active Learning for Evolving Traffic Streams

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Chinese Journal of Electronics 2024年第3期33卷 645-656页

作者： Zequn NIU Jingfeng XUE Yong WANG Tianwei LEI Weijie HAN Xianwei GAO School of Computer Science and Technology Beijing Institute of Technology School of space Information Space Engineering University

In practical abnormal traffic detection scenarios,traffic often appears as drift,imbalanced and rare labeled streams,and how to effectively identify malicious traffic in such complex situations has become a challenge for malicious traffic detection.Researchers have extensive studies on malicious traffic detection with single challenge,but the detection of complex traffic has not been widely noticed.Queried adaptive random forests(QARF) is proposed to detect traffic streams with concept drift,imbalance and lack of labeled instances.QARF is an online active learning based approach which combines adaptive random forests method and adaptive margin sampling strategy.QARF achieves querying a small number of instances from unlabeled traffic streams to obtain effective training.We conduct experiments using the NSL-KDD dataset to evaluate the performance of QARF.QARF is compared with other state-of-the-art methods.The experimental results show that QARF obtains 98.20% accuracy on the NSL-KDD dataset.QARF performs better than other state-of-the-art methods in comparisons.

关键词： Training Streams Random forests

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Mulberry leaf supplementation inhibits skatole deposition by regulating gut microbiota and upregulating liver cytochrome P4501A1 expression in finishing pigs

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Animal Nutrition 2024年第1期16卷 34-44页

作者： Yuqing Sun Xiaoming Men Tianbao Lin Bo Deng Shi Zhong Jinxi Huo Kaipeng Qin Zhiqiang Lv Ziwei Xu Yougui Li institute of Sericulture and Tea Zhejiang Academy of Agricultural Sciences institute of Animal Husbandry and Veterinary Science Zhejiang Academy of Agricultural Sciences

Skatole, a strong fecal odor substance, is generated through microbial degradation of tryptophan in the animal hindgut. It easily accumulates in adipose tissue and affects meat quality. In this study, the effect of mulberry leaf supplementation on skatole in finishing pigs was studied. In a 35-day trial, 20 finishing pigs (barrows and gilts) were fed with a basal diet or basal diet with 6% mulberry leaves. Growth performance of the pigs (n=10) was automatically recorded by a performance-testing feeder system and 8 pigs in each treatment were slaughtered and sampled for the remaining tests. Skatole and short-chain fatty acids were detected using HPLC and gas chromatography, respectively. Fecal microbiota were analyzed using 16S r RNA gene sequencing. The metabolomics analysis of feces and serum was performed with UHPLC-MS/MS. The major cytochrome P450 (CYP) enzymes that catalyze skatole degradation in the liver were tested by using RT-PCR and Western blot. Effects of major bioactive compounds in mulberry leaves on the CYP genes were verified in the hepatic cell line Hep G2 in an in vitro test (n=3). In finishing pigs, mulberry leaf supplementation had no significant effect on the average daily gain, average daily feed intake, and feed conversion ratio (P>0.05), but reduced skatole levels in feces, serum, and backfat (P<0.05), and increased acetic acid levels in feces (P=0.027). Mulberry leaf supplementation decreased the relative abundance of the skatole-producing bacteria Megasphaera and Olsenella (P<0.05). Indole-3acetic acid, the intermediate that is essential for skatole production, was significantly reduced in feces by mulberry leaf supplementation (P<0.05) and was positively correlated with skatole content in feces (P=0.004). In pigs treated with mulberry leaves, liver CYP1A1 expression was increased (P<0.05) and was negatively correlated with skatole content in backfat (P=0.045). The in vitro test demonstrated that mulberry leaf polyphenols and polysaccharides could directly stimulate CYP1A1 expression in h

关键词： Pig Skatole Mulberry leaf Microbiota Cytochrome P450

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Influence of low-energy supersymmetric vector-like quirk particles on W mass increment and muon g–2 anomaly

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Chinese Physics C 2024年第3期48卷 39-45页

作者：周平 National space Science Center Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of sciences Beijing 100140China Beijing Key Laboratory of space Environment Exploration Beijing 100140China

In the low energy realization of the quirk assisted Standard Model,the couplings between the exotic particles"quirks"and gauge bosons may contribute to the W mass and muon g−2 anomaly reported by FermiLab.We calculate the contributions from supersymmetric quirk particles as an example.By imposing the theoretical constraints,we determined that the CDF II W-boson mass increment strictly constrains the mixing and coupling parameters and the quirk mass mF,while the muon g−2 anomaly cannot be solely attributed to the involvement of exotic particles,considering their significantly large masses.

关键词： low-energy supersymmetric vector-like quirk models W mass increment muon g-2 anomaly

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Thermosphere joint observations by TM-1 constellations and Swarm-B during the April 2023 geomagnetic storm

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Earth and Planetary Physics 2024年第2期8卷 307-316页

作者： YongPing Li YueQiang Sun XianGuo Zhang JiangZhao Ai XiaoLiang Zheng Jia Li YuJie Wang BiBo Guo Feng Yan ShiLong Wei XinChun Tang YuanYuan Cao National space Science Center Chinese Academy of SciencesBeijing 100190China Beijing Key Laboratory of space Environment Exploration Beijing 100190China Key Laboratory of Science and Technology on space Environment Situational Awareness Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of sciences Beijing 100049China Shenzhen Aerospace Dongfanghong Satellite LtdShenzhen 518057China

The response of thermosphere density to geomagnetic storms is a complicated physical process.Multi-satellite joint observations at the same altitude but different local times(LTs)are important for understanding this process;however,until now such studies have hardly been done.In this report,we analyze in detail the thermosphere mass density response at 510 km during the April 23−24,2023 geomagnetic storm using data derived from the TM-1(TianMu-1)satellite constellation and Swarm-B satellites.The observations show that there were significant LT differences in the hemispheric asymmetry of the thermosphere mass density during the geomagnetic storm.Densities observed by satellite TM02 at nearly 11.3 and 23.3 LTs were larger in the northern hemisphere than in the southern.The TM04 dayside density observations appear to be almost symmetrical with respect to the equator,though southern hemisphere densities on the nightside were higher.Swarm-B data exhibit near-symmetry between the hemispheres.In addition,the mass density ratio results show that TM04 nightside observations,TM02 data,and Swarm-B data all clearly show stronger effects in the southern hemisphere,except for TM04 on the dayside,which suggest hemispheric near-symmetry.The South-North density enhancement differences in TM02 and TM04 on dayside can reach 130%,and Swarm-B data even achieve 180%difference.From the observations of all three satellites,large-scale traveling atmospheric disturbances(TADs)first appear at high latitudes and propagate to low latitudes,thereby disturbing the atmosphere above the equator and even into the opposite hemisphere.NRLMSISE00 model simulations were also performed on this geomagnetic storm.TADs are absent in the NRLMSISE00 simulations.The satellite data suggest that NRLMSISE00 significantly underestimates the magnitude of the density response of the thermosphere during geomagnetic storms,especially at high latitudes in both hemispheres.Therefore,use of the density simulation of NRLMSISE00 may lead to large errors in satellite dra

关键词： TM-1 constellation Swarm-B joint observations geomagnetic storm Local Times

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Basic Survey Scheduling for the Wide Field Survey Telescope(WFST)

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Research in Astronomy and Astrophysics 2024年第1期24卷 59-69页

作者： Yan-Peng Chen Ji-An Jiang Wen-Tao Luo Xian-Zhong Zheng Min Fang Chao Yang Yuan-Yu Hong Zong-Fei Lü Purple Mountain Observatory Chinese Academy of SciencesNanjing 210023China School of Astronomy and space Science University of Science and Technology of ChinaHefei 230026China Department of Astronomy University of Science and Technology of ChinaHefei 230026China National Astronomical Observatory of Japan National Institutes of Natural Sciences2-21-1 OsawaMitakaTokyo 181-8588Japan institute of Deep space sciences Deep Space Exploration LaboratoryHefei 230026China

Aiming at improving the survey efficiency of the Wide Field Survey Telescope, we have developed a basic scheduling strategy that takes into account the telescope characteristics, observing conditions, and weather conditions at the Lenghu site. The sky area is divided into rectangular regions, referred to as “tiles,” with a size of2°. 577 × 2°. 634 slightly smaller than the focal area of the mosaic CCDs. These tiles are continuously filled in annulars parallel to the equator. The brightness of the sky background, which varies with the moon phase and distance from the moon, plays a significant role in determining the accessible survey fields. Approximately 50connected tiles are grouped into one block for observation. To optimize the survey schedule, we perform simulations by taking into account the length of exposures, data readout, telescope slewing, and all relevant observing conditions. We utilize the Greedy Algorithm for scheduling optimization. Additionally, we propose a dedicated dithering pattern to cover the gaps between CCDs and the four corners of the mosaic CCD array, which are located outside of the 3° field of view. This dithering pattern helps to achieve relatively uniform exposure maps for the final survey outputs.

关键词： telescopes surveys Moon

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Two methods for separating the magnetospheric solar wind charge exchange soft X-ray emission from the diffuse X-ray background

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Earth and Planetary Physics 2024年第1期8卷 119-132页

作者： YingJie Zhang TianRan Sun JenniferACarter WenHao Liu Steve Sembay ShuiNai Zhang Li Ji Chi Wang State Key Laboratory of space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190China College of Earth and Planetary sciences The University of Chinese Academy of SciencesBeijing 100190China School of Physics and Astronomy The University of LeicesterLeicesterUK Purple Mountain Observatory Chinese Academy of SciencesNanjing 210008China

Solar wind charge exchange(SWCX)is the process of solar wind high-valence ions exchanging charges with neutral components and generating soft X-rays.Recently,detecting the SWCX emission from the magnetosphere is proposed as a new technique to study the magnetosphere using panoramic soft X-ray imaging.To better prepare for the data analysis of upcoming magnetospheric soft X-ray imaging missions,this paper compares the magnetospheric SWCX emission obtained by two methods in an XMM-Newton observation,during which the solar wind changed dramatically.The two methods differ in the data used to fit the diffuse X-ray background(DXB)parameters in spectral analysis.The method adding data from the ROSAT All-Sky Survey(RASS)is called the RASS method.The method using the quiet observation data is called the Quiet method,where quiet observations usually refer to observations made by the same satellite with the same target but under weaker solar wind conditions.Results show that the spectral compositions of magnetospheric SWCX emission obtained by the two methods are very similar,and the changes in intensity over time are highly consistent,although the intensity obtained by the RASS method is about 2.68±0.56 keV cm^(-2)s^(-1)sr^(-1)higher than that obtained by the Quiet method.Since the DXB intensity obtained by the RASS method is about 2.84±0.74 keV cm^(-2)s^(-1)sr^(-1)lower than that obtained by the Quiet method,and the linear correlation coefficient between the difference of SWCX and DXB obtained by the two methods in diffe rent energy band is close to-1,the diffe rences in magnetospheric SWCX can be fully attributed to the diffe rences in the fitted DXB.The difference between the two methods is most significant when the energy is less than 0.7 keV,which is also the main energy band of SWCX emission.In addition,the difference between the two methods is not related to the SWCX intensity and,to some extent,to solar wind conditions,because SWCX intensity typically va ries with the solar wind.In summary,both methods are robust a

关键词： solar wind charge exchange(SWCX) ROSAT All-Sky Survey(RASS) soft X-ray X-ray imaging magnetosphere

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A Confined Two-peaked Solar Flare Observed by EAST and SDO

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Research in Astronomy and Astrophysics 2024年第4期24卷 71-83页

作者： Liang Zhang Ruisheng Zheng Zhike Xue Changhui Rao Qing Lin Zhimao Du Jiawen Yao Libo Zhong Yao Chen institute of space sciences Shandong UniversityWeihai 264209China Yunnan Key Laboratory of the Solar physics and space Science Kunming 650011China institute of Frontier and Interdisciplinary Science.Shandong University Qingdao266237China institute of Optics and Electronics Chinese Academy of SciencesChengdu 610209China National Laboratory on Adaptive Optics Chengdu610209China University of Chinese Academy of sciences Beijing 100049China Shanghai Astronomy Museum Shanghai201306China

The solar flare is one of the most violent explosions,and can disturb the near-Earth space weather.Except for commonly single-peaked solar flares in soft X-ray,some special flares show intriguing a two-peak feature that is deserved much more attentions.Here,we reported a confined two-peaked solar flare and analyzed the associated eruptions using high-quality observations from Educational Adaptive-optics Solar Telescope and Solar Dynamics Observatory.Before the flare,a magnetic flux rope(MFR)formed through partially tether-cutting reconnection between two sheared arches.The flare occurred after the MFR eruption that was confined by the overlying strong field.Interestingly,a small underlying filament immediately erupted,which was possibly destabilized by the flare ribbon.The successive eruptions were confirmed by the analysis of the emission measure and the reconnection fluxes.Therefore,we suggest that the two peaks of the confined solar flare are corresponding to two episodes of magnetic reconnection during the successive eruptions of the MFR and the underlying filament.

关键词： Sun:activity Sun:corona Sun:flares Sun:magnetic fields Sun:filaments prominences Online material:animations

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Autonomous relative optical navigation based on unified modeling of external systematic errors

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Chinese Journal of Aeronautics 2024年第3期37卷 282-289页

作者： Dayi WANG Bowen SUN Maodeng LI Jiaxing LI Haiyin ZHOU Beijing institute of spacecraft System Engineering Beijing 100191China College of sciences National University of Defense TechnologyChangsha 410073China National Key Laboratory of space Intelligent Control Beijing Institute of Control EngineeringBeijing 100191China

To solve the problem that external systematic errors of the optical camera cannot be fully estimated due to limited computing resources,a unified dimensionality reduction representation method for the external systematic errors of the optical camera is proposed,and autonomous relative optical navigation is realized.The camera translational and misalignment errors are converted into a three-dimensional rotation error,whose differential model can be established through specific attitude control and appropriate assumption.Then,the rotation error and the relative motion state are jointly estimated in an augmented Kalman filter framework.Compared with the traditional method that estimates the camera translational and misalignment errors,the proposed method reduces the computational complexity in that the estimated state dimension is reduced.Furthermore,as demonstrated by numerical simulation,the estimation accuracy is improved significantly.

关键词： Unified model Systematic errors Optical navigation Observability analysis Calibration

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