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Scientific objectives and payload configuration of the Chang'E-7 mission

National Science Review 2024年第2期11卷 285-300页

作者： Chi Wang Yingzhuo Jia Changbin Xue Yangting Lin Jianzhong Liu Xiaohui Fu Lin Xu Yun Huang Yufen Zhao Yigang Xu Rui Gao Yong Wei Yuhua Tang Dengyun Yu Yongliao Zou State key Laboratory of Space Weather National Space Science Center Chinese Academy of Sciences National Space Science Center Chinese Academy of Sciences Institute of Geology and Geophysics Chinese Academy of Sciences Institute of Geochemistry Chinese Academy of Sciences Shandong Provincial key Laboratory of Optical Astronomy and Solar-Terrestrial Environment School of Space Science and Physics Institute of Space SciencesShandong University Institute of Drug Discovery Technology Ningbo University State key Laboratory of Isotope Geochemistry Guangzhou Institute of Geochemistry Chinese Academy of Sciences School of Earth Science and Engineering Sun Yat-sen University Lunar Exploration and Space Engineering Center China Aerospace Science and Technology Corporation

As the cornerstone mission of the fourth phase of the chinese Lunar Exploration program, Chang'E-7(CE-7) was officially approved, and implementation started in 2022, including a main probe and a communication relay satellite. The main probe, consisting of an orbiter, a lander, a rover and a mini-flying probe, is scheduled to be launched in 2026. The lander will land on Shackleton crater's illuminated rim near the lunar south pole, along with the rover and mini-flying probe. The relay satellite(named Queqiao-2) will be launched in February 2024 as an independent mission to support relay communication during scientific exploration undertaken by Chang'E-4, the upcoming Chang'E-6 in 2024 and subsequent lunar *** CE-7 mission is mainly aimed at scientific and resource exploration of the lunar south pole. We present CE-7's scientific objectives, the scientific payloads configuration and the main functions for each scientific payload with its key technical specifications.

关键词： Chang’ E-7 scientific objectives scientific payloads

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Along-track Calibration of the Zhurong Rover Magnetometer

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Science China Earth sciences 2024年第2期67卷 552-565页

作者： Hao LUO Aimin DU Yasong GE Ying ZHANG Haiying LI Lin TIAN Kuixiang ZHANG Shuquan SUN Lin ZHAO Zhi LI Xiao FENG CAS Engineering Laboratory for Deep Resources Equipment and Technology Institute of Geology and GeophysicsChinese Academy of SciencesBeijing100029China College of Earth Science University of Chinese Academy of SciencesBeijing100049China National Astronomical Observatories Chinese Academy of SciencesBeijing100101China

As part of the chinese Tianwen-1 mission,the Zhurong Rover began its scientific investigation in the southern Utopia Planitia after its successful landing in 15 May,*** Zhurong Rover magnetometer(RoMAG),one of the six payloads onboard the rover,includes two identical high-sensitivity triaxial fluxgate magnetometers and can implement mobile magnetic measurements on the surface of *** a rover magnetic compensation procedure was conducted to remove the magnetic interferences pre-launch,due to the different state of the payloads and electric power system such as the solar panel,an along-track calibration of the magnetometer is necessary to obtain a more accurate Martian magnetic *** methods,mast yaw rotations and Rover yaw rotations were utilized separately to determine the Martian horizontal magnetic *** show that the Martian horizontal magnetic components determined by the two methods are in good agreement,with the root mean square deviation less than 2.0 *** vertical component was also constrained through the pitch movements of the mast by assuming the interferences field distributes like a dipole field.A linear correlation between magnetic field measurements and the solar array currents was derived to calibrate the body field during the regular *** conclude that more accurate measurements could be made when applying the calibration results in the magnetic survey on the surface of Mars.

关键词： The Zhurong Rover Magnetometer Along-track calibration Remnant magnetization

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Automatic Generation of Artificial Space Weather Forecast Product Based on Sequence-to-sequence Model

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空间科学学报 2024年第1期44卷 80-94页

作者：罗冠霆 ZOU Yenan CAI Yanxia State key Laboratory of Space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190 University of chinese academy of sciences Beijing 100049 key Laboratory of Science and Technology on Environment Space Situation Awareness Chinese Academy of SciencesBeijing 100190

Both analyzing a large amount of space weather observed data and alleviating personal experience bias are significant challenges in generating artificial space weather forecast *** the use of natural language generation methods based on the sequence-to-sequence model,space weather forecast texts can be automatically *** conduct our generation tasks at a fine-grained level,a taxonomy of space weather phenomena based on descriptions is ***,our MDH(Multi-Domain Hybrid)model is proposed for generating space weather summaries in two *** model is composed of three sequence-to-sequence-based deep neural network sub-models(one Bidirectional Auto-Regressive Transformers pre-trained model and two Transformer models).Then,to evaluate how well MDH performs,quality evaluation metrics based on two prevalent automatic metrics and our innovative human metric are *** comprehensive scores of the three summaries generating tasks on testing datasets are 70.87,93.50,and 92.69,*** results suggest that MDH can generate space weather summaries with high accuracy and coherence,as well as suitable length,which can assist forecasters in generating high-quality space weather forecast products,despite the data being starved.

关键词： Space weather Deep learning Data-to-text Natural language generation

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Impact of Co^(2+)substitution on structure and magnetic properties of M-type strontium ferrite with different Fe/Sr ratios

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chinese Physics B 2024年第10期33卷 427-433页

作者： Yang Sun Ruoshui Liu Huayang Gong Baogen Shen School of Rare Earths University of Science and Technology of ChinaHefei 230026China Ganjiang Innovation academy Chinese Academy of SciencesGanzhou 341119China Ningbo Institute of Materials Technology&Engineering Chinese Academy of SciencesNingbo 315201China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China

Ion substitution has significantly improved the performance of ferrite magnets,and cobalt remains a key area of *** on the mechanism of Co^(2+)in strontium ferrite,especially SrFe_(2n-x)Co_(x)O_(19-d)(n=6.1-5.4;x=0.05-0.20)synthesized using the ceramic method,showed that Co^(2+)preferentially enters the lattice as the Fe/Sr ratio *** results in a decrease in the lattice constants a and c due to oxygen vacancies and iron ion *** impact of Co substitution on morphology is minor compared to the effect of the Fe/Sr *** the Fe/Sr ratio decreases and the Co content increases,the saturation magnetization *** magnetic anisotropy field exhibits a nonlinear change,generally increasing with higher Fe/Sr ratios and Co *** changes in the performance of permanent magnets are attributed to the absence of Fe^(3+)ions at the 12k+2a and 2b sites and the substitution of Co^(2+)at the 2b *** suggests that by adjusting the Fe/Sr ratio and appropriate Co substitution,the magnetic anisotropy field of M-type strontium ferrite can be effectively optimized.

关键词： hexaferrite Co substitution Raman spectra magnetic properties

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The influence of boundary conditions on the distribution of energetic electrons during collisionless magnetic reconnection

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Plasma Science and Technology 2024年第4期26卷 79-84页

作者：王磊黄灿陈冬可杨忠炜杜爱民葛亚松 CAS Engineering Laboratory for Deep Resources Equipment and Technology Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029People’s Republic of China College of Earth and Planetary sciences University of Chinese Academy of SciencesBeijing 100029People’s Republic of China State key Laboratory of Space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190People’s Republic of China

We conducted 2-D particle-in-cell simulations to investigate the impact of boundary conditions on the evolution of magnetic reconnection. The results demonstrate that the boundary conditions are crucial to this evolution. Specifically, in the cases of traditional periodic boundary(PB) and fully-opened boundary(OB) conditions, the evolutions are quite similar before the system achieves the fastest reconnection rate. However, differences emerge between the two cases afterward. In the PB case, the reconnection electric field experiences a rapid decline and even becomes negative, indicating a reversal of the reconnection process. In contrast, the system maintains a fast reconnection stage in the OB case. Suprathermal electrons are generated near the separatrix and in the exhaust region of both simulation cases. In the electron density depletion layer and the dipolarization front region, a larger proportion of suprathermal electrons are produced in the OB case. Medium-energy electrons are mainly located in the vicinity of the X-line and downstream of the reconnection site in both cases. However, in the OB case, they can also be generated in the electron holes along the separatrix. Before the reverse reconnection stage, no high-energy electrons are present in the PB case. In contrast, about 20% of the electrons in the thin and elongated electron current layer are high-energy in the OB case.

关键词： magnetic reconnection electron energization particle-in-cell simulation

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Sugarcane leaves-derived polyphenols alleviate metabolic syndrome and modulate gut microbiota of ob/ob mice

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Food Science and Human Wellness 2024年第2期13卷 633-648页

作者： Li Sun Tao Wang Baosong Chen Cui Guo Shanshan Qiao Jinghan Lin Huan Liao Huanqin Dai Bin Wang Jingzu Sun Hongwei Liu State key Laboratory of Mycology Institute of MicrobiologyChinese Academy of SciencesBeijing 100101China Savaid Medicine School University of Chinese Academy of SciencesBeijing 100101China Guangxi academy of sciences Nanning 530007China

Sugarcane leaves-derived polyphenols(SLP)have been demonstrated to have diverse health-promoting benefits,but the mechanism of action has not been fully *** study aimed to investigate the anti-metabolic disease effects of SLP and the underlying mechanisms in *** the current study,we prepared the SLP mainly consisting of three flavonoid glycosides,three phenol derivatives,and two lignans including one new compound,and further demonstrated that SLP reduced body weight gain and fat accumulation,improved glucose and lipid metabolism disorders,ameliorated hepatic steatosis,and regulated short-chain fatty acids(SCFAs)production and secondary bile acids metabolism in ob/ob ***,SLP largely altered the gut microbiota composition,especially enriching the commensal bacteria Akkermansia muciniphila and Bacteroides *** gavage with the above two strains ameliorated metabolic syndrome(MetS),regulated secondary bile acid metabolism,and increased the production of SCFAs in high-fat diet(HFD)-induced obese *** results demonstrated that SLP could be used as a prebiotic to attenuate MetS via regulating gut microbiota composition and further activating the secondary bile acids-mediated gut-adipose axis.

关键词： Sugarcane leaves-derived polyphenols Metabolic syndrome Bacteroides acidifaciens Akkermansia muciniphila Secondary bile acids metabolism

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Modification of Melting Combustion Kinetic Model of Fine Ash from Entrained-Flow Gasifier

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Journal of Thermal Science 2024年第1期33卷 300-310页

作者： WANG Wenyu LI Wei LU Yu REN Qiangqiang LYU Qinggang Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China University of chinese academy of sciences Beijing 100049China Dalian National Laboratory for Clean Energy Chinese Academy of SciencesDalian 116023China

Coal gasification technology is a prominent technology in the coal chemical industry and serves as the fundamental basis for various process industries,including coal-based chemicals,coal-based liquid fuels,Integrated Gasification Combined Cycle(IGCC) power generation,multi-generation systems,hydrogen production,and fuel *** gasification process generates significant quantities of ash residue,with annual emissions exceeding tens of millions of tons and accumulation reaching hundreds of millions of ***,there is an urgent need to investigate methods for its *** combustion of gasified fine ash(GFA) was conducted in a tube furnace,and the conventional shrinking core model was modified to accurately predict the combustion behaviors at different temperatures(900℃-1500℃).We divided the reaction temperatures into three ranges,which is defined as unmelted combustion(TFT) and mixed combustion(DTFT),the surface ash of GFA grains fell off,and the residual carbon and gas-phase reactants were nearly no longer affected by the diffusion resistance,thus significantly accelerated the reaction of internal residual *** order to predict the melt combustion process more accurately,the time term of the shrinkage core model(SCM) is modified,and the effective diffusion coefficient of T>FT is defined.

关键词： fine ash melting combustion kinetic model combustion characteristics

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MRm-DLDet:a memory-resident malware detection framework based on memory forensics and deep neural network

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Cybersecurity 2024年第1期7卷 88-109页

作者： Jiaxi Liu Yun Feng Xinyu Liu Jianjun Zhao Qixu Liu Institute of Information Engineering Chinese Academy of SciencesBeijing 100085China School of Cyber Security University of Chinese Academy of SciencesBeijing 100049China

Cyber attackers have constantly updated their attack techniques to evade antivirus software detection in recent *** popular evasion method is to execute malicious code and perform malicious actions only in ***-cious programs that use this attack method are called memory-resident malware,with excellent evasion capability,and have posed huge threats to cyber *** static and dynamic methods are not effective in detect-ing memory-resident *** addition,existing memory forensics detection solutions perform unsatisfactorily in detection rate and depend on massive expert knowledge in memory *** paper proposes MRm-DLDet,a state-of-the-art memory-resident malware detection framework,to overcome these ***-DLDet first builds a virtual machine environment and captures memory dumps,then creatively processes the memory dumps into RGB images using a pre-processing technique that combines deduplication and ultra-high resolution image cropping,followed by our neural network MRmNet in MRm-DLDet to fully extract high-dimensional features from memory dump files and detect *** receives the labeled sub-images of the cropped high-resolution RGB images as input of ResNet-18,which extracts the features of the *** trains a network of gated recurrent units with an attention ***,it determines whether a program is memory-resident malware based on the detection results of each sub-image through a specially designed voting *** created a high-quality dataset consisting of 2,060 benign and memory-resident *** other words,the dataset contains 1,287,500 labeled sub-images cut from the MRm-DLDet transformed ultra-high resolution RGB *** implement MRm-DLDet for Windows 10,and it performs better than the latest methods,with a detection accuracy of up to 98.34%.Moreover,we measured the effects of mimicry and adversarial attacks on MRm-DLDet,and the experimental results demonstrated the robustness

关键词： Memory-resident malware Memory forensics Malware detection Deep learning Ultra-high resolution image

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Flow instability of supercritical hydrocarbon fuel in a multi-channel cooling system

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chinese Journal of Aeronautics 2024年第2期37卷 283-295页

作者： Yichao JIN Kun WU Xuejun FAN Institute of Applied Physics and Computational Mathematics Beijing 100094China Institute of Mechanics Chinese Academy of SciencesBeijing 100190China School of Engineering Science University of Chinese Academy of SciencesBeijing 100049China

Thermally-induced flow instabilities are a critical issue in multi-channel regenerative cooling *** particular,the interactions between Density-Wave Oscillations(DWO)and Flow Maldistribution(FMD)can result in complex and disastrous instability *** study investigates the instability behaviors of hydrocarbon fluid in a four-channel system with a constant heat flux ratio using both frequency-and time-domain *** the heat flux increases,the in-tube flow sequentially destabilizes in each channel and converges to new equilibrium states,leading to the emergence of FMD *** also causes the system eigenvalue to change repeatedly from negative to positive rather than increasing ***,the system eigenvalues are between those of the two most unstable channels,indicating that the stability behavior of the entire system is dictated by the most unstable *** FMD occurs,flow oscillations are activated in channels with weak stability,and the in-tube flow is observed to evolve into various flow patterns,including stable flow,self-sustained oscillation,oscillation divergence,quasiperiodic oscillation,and oscillation *** novel instability mode of oscillation excursion involves a spontaneous transition of operating *** oscillates from an equilibrium state and then stabilizes at a new operational state after oscillation-induced ***,the newfound stable state may also be only temporary,with the in-tube flow regressing to the initial state,resulting in quasi-periodic oscillation.

关键词： Cooling Supercritical fluids Hydrocarbons Flow instability Flow maldistribution Density-wave oscillations

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Detecting compromised email accounts via login behavior characterization

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Cybersecurity 2024年第1期7卷 16-36页

作者： Jianjun Zhao Can Yang Di Wu Yaqin Cao Yuling Liu Xiang Cui Qixu Liu Institute of Information Engineering Chinese Academy of SciencesBeijing100085China School of Cyber Security University of Chinese Academy of SciencesBeijing100049China China Cybersecurity Review Technology and Certification Center Beijing100013China Zhongguancun Laboratory Beijing100089China

The illegal use of compromised email accounts by adversaries can have severe consequences for enterprises and *** compromised email accounts is more challenging than in the social network field,where email accounts have only a few interaction events(sending and receiving).To address the issue of insufficient features,we propose a novel approach to detecting compromised accounts by combining time zone differences and alternate logins to identify abnormal *** on this approach,we propose a compromised email account detection framework that relies on widely available and less sensitive login logs and does not require *** framework characterizes login behaviors to identify logins that do not belong to the account owner and outputs a list of account-subnet pairs ranked by their likelihood of having abnormal login *** approach reduces the number of account-subnet pairs that need to be investigated and provides a reference for investigation *** evaluation demonstrates that our method can detect most email accounts that have been accessed by disclosed malicious IP addresses and outperforms similar ***,our framework has the capability to uncover undisclosed malicious IP addresses.

关键词： Compromised account detection Mixture model Login log analysis Attribution and forensic

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