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Plutonium utilization in a small modular molten-salt reactor based on a batch fuel reprocessing scheme

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Nuclear Science and Techniques 2024年第4期35卷 15-28页

作者： Xue-Chao Zhao Rui Yan Gui-Feng Zhu Ya-Fen Liu Jian Guo Xiang-Zhou Cai Yang Zou Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China CAS Innovative Academies in TMSR Energy System Chinese Academy of SciencesShanghai 201800China University of chinese academy of sciences Beijing 100049China

A molten salt reactor(MSR)has outstanding features considering the application of thorium fuel,inherent safety,sustainability,and resistance to ***,fissile material^(233)U is significantly rare at the current stage,thus it is difficult for MSR to achieve a pure thorium-uranium fuel ***,using plutonium or enriched uranium as the initial fuel for MSR is more *** this study,we aim to verify the feasibility of a small modular MSR that utilizes plutonium as the starting fuel(SM-MSR-Pu),and highlight its advantages and ***,the structural design and fuel management scheme of the SM-MSR-Pu were ***,the neutronic characteristics,such as the graphite-irradiation lifetime,burn-up performance,and coefficient of temperature reactivity were calculated to analyze the physical characteristics of the *** results indicate that plutonium is a feasible and advantageous starting fuel for a SM-MSR;however,there are certain shortcomings that need to be *** a 250 MWth SM-MSR-Pu,approximately 288.64 kg^(233)U of plutonium with a purity of greater than 90% is produced while 978.00 kg is burned every ten *** temperature reactivity coefficient decreases from -4.0 to -6.5 pcm K^(-1) over the 50-year operating time,which ensures a long-term safe ***,the amount of plutonium and accumulation of minor actinides(MAs)would increase as the burn-up time increases,and the annual production and purity of^(233)U will *** achieve an optimal burn-up performance,setting the entire operation time to 30 years is ***,more than 3600 kg of plutonium eventually accumulate in the *** research is required to effectively utilize this accumulated plutonium.

关键词： Molten salt fuel Plutonium utilization ^(233)U TRUs mole fraction Temperature feedback coefficient

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

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

Regulating the non-effective carriers transport for high-performance lithium metal batteries

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Journal of Energy Chemistry 2024年第5期92卷 132-141页

作者： Simeng Wang Youchun Yu Shaotong Fu Hongtao Li Jiajia Huang Institute of Process Engineering Chinese Academy of SciencesBeijing 100190China School of Chemical Engineering University of Chinese Academy of SciencesBeijing 100049China Haike Group Research Institute of Innovation&technology Dongying 257000ShangdongChina

The absence of control over carriers transport during electrochemical cycling,accompanied by the deterioration of the solid electrolyte interphase(SEI)and the growth of lithium dendrites,has hindered the development of lithium metal ***,a separator complexion consisting of polyacrylonitrile(PAN)nanofiber and MIL-101(Cr)particles prepared by electrospinning is proposed to bind the anions from the electrolyte utilizing abundant effective open metal sites in the MIL-101(Cr)particles to modulate the transport of non-effective *** binding effect of the PANM separator promotes uniform lithium metal deposition and enhances the stability of the SEI layer and long cycling stability of ultra-high nickel layered oxide *** PANM as the Li||NCM96 separator enables high-voltage cycling stability,maintaining 72%capacity retention after 800 cycles at a charging and discharging rate of 0.2 C at a cut-off voltage of 4.5 V and 0°***,the excellent high-rate performance delivers a specific capacity of 156.3 mA h g^(-1) at 10 *** addition,outstanding cycling performance is realized from−20 to 60°*** separator engineering facilitates the electrochemical performance of lithium metal batteries and enlightens a facile and promising strategy to develop fast charge/discharge over a wide range of temperatures.

关键词： Functional separators Metal-organic frameworks 3D continuous ion transport networks Electrospinning Lithium metal batteries

Comparative analyses of mitogenomes in the social bees with insights into evolution of long inverted repeats in the Meliponini

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Zoological Research 2024年第1期45卷 160-175页

作者： Yu-Ran Li Zheng-Wei Wang Richard T.Corlett Wen-Bin Yu Yunnan key Laboratory for the Conservation of Tropical Rainforests and Asian Elephants&Center for Integrative Conservation Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesMenglaYunnan 666303China CAS key Laboratory of Tropical Forest Ecology Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesMenglaYunnan 666303China Southeast Asia Biodiversity Research Institute Chinese Academy of SciencesMenglaYunnan 666303China University of chinese academy of sciences Shijingshan DistrictBeijing 100049China

The insect mitogenome is typically a compact circular molecule with highly conserved gene ***,mitogenome structural variations have been reported in specific taxa,and gene rearrangements,usually the tRNAs,occur in different *** synapomorphies of mitogenome organizations can provide information for phylogenetic inferences,comparative analyses of mitogenomes have been given increasing ***,most studies use a very few species to represent the whole genus,tribe,family,or even order,overlooking potential variations at lower taxonomic levels,which might lead to some incorrect *** provide new insights into mitogenome organizations and their implications for phylogenetic inference,this study conducted comparative analyses for mitogenomes of three social bee tribes(Meliponini,Bombini,and Apini)based on the phylogenetic framework with denser taxonomic sampling at the species and population *** analyses revealed that mitogenomes of Apini and Bombini are the typical type,while those of Meliponini show diverse variations in mitogenome sizes and *** inverted repeats(IRs)cause significant gene rearrangements of protein coding genes(PCGs)and rRNAs in Indo-Malay/Australian stingless bee *** evolution analyses showed that the lineage with IRs have lower dN/dS ratios for PCGs than lineages without IRs,indicating potential effects of IRs on the evolution of mitochondrial *** finding of IRs and different patterns of gene rearrangements suggested that Meliponini is a hotspot in mitogenome *** conserved PCGs and rRNAs whose rearrangements were found only in the mentioned lineages within Meliponini,tRNA rearrangements are common across all three tribes of social bees,and are significant even at the species level,indicating that comprehensive sampling is needed to fully understand the patterns of tRNA rearrangements,and their implications for phylogenetic inference.

关键词： Social bees Phylogeny Mitogenome structure Gene rearrangement Inverted repeats

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

Tribological properties of PTFE-based fabric composites at cryogenic temperature

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Friction 2024年第2期12卷 245-257页

作者： Mingkun XU Zidan WANG Lihe GUO Liming TAO Tianbao MA Tingmei WANG Qihua WANG key Laboratory of Science and technology on Wear and Protection of Materials Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China State key Laboratory of Tribology Tsinghua UniversityBeijing 100084China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China

Fabric composites are widely employed in self-lubricating bearing liners as solid lubrication *** the tribological behaviors of fabric composites have been extensively studied,the cryogenic tribological properties and mechanisms have been scarcely reported and are largely unclear to instruct material design for aerospace and other high-tech ***,the tribological properties of polytetrafluoroethylene(PTFE)-based hybrid-fabric composites were investigated at cryogenic and ambient temperatures in the form of pin-on-disk friction under heavy *** results suggest that the friction coefficients of the hybrid-fabric composites obviously increase with a decrease in wear when the temperature drops from 25 to−150°***,thermoplastic polyetherimide(PEI),as an adhesive for fabric composites,has better cryogenic lubrication performance than thermosetting phenol formaldehyde(PF)resin,which can be attributed to the flexible chemical structure of *** excellent lubrication performance of hybrid-fabric composites is attributed to the transfer film formed by PTFE fibers on the surface of fabrics.

关键词： cryogenic temperatures fabric composites friction and wear transfer film

Plastid phylogenomics provides new insights into the systematics,diversification,and biogeography of Cymbidium(Orchidaceae)

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Plant Diversity 2024年第4期46卷 448-461页

作者： Hai-Yao Chen Zhi-Rong Zhang Xin Yao Ji-Dong Ya Xiao-Hua Jin Lin Wang Lu Lu De-Zhu Li Jun-Bo Yang Wen-Bin Yu Center for Integrative Conservation&Yunnan key Laboratory for the Conservation of Tropical Rainforests and Asian Elephants Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesMenglaYunnan 666303China University of chinese academy of sciences Huairou DistrictBeijing 101408China Plant Germplasm and Genomics Center Germplasm Bank of Wild SpeciesKunming Institute of BotanyChinese Academy of SciencesKunmingYunnan 650201China State key Laboratory of Plant Diversity and Specility Crops Institute of BotanyChinese Academy of SciencesHaidian DistrictBeijing 100093China School of Pharmaceutical sciences Yunnan Key Laboratory of Pharmacology for Natural Productsand Yunnan College of Modern Biomedical IndustryKunming Medical UniversityKunmingYunnan 650500China Southeast Asia Biodiversity Research Institute Chinese Academy of SciencesYezinNay Pyi Taw 05282Myanmar

Cymbidium(Orchidaceae:Epidendroideae),with around 60 species,is widely-distributed across Southeast Asia,providing a nice system for studying the processes that underlie patterns of biodiversity in the ***,phylogenetic relationships of Cymbidium have not been well resolved,hampering investigations of species diversification and the biogeographical history of this *** this study,we construct a plastome phylogeny of 56 Cymbidium species,with four well-resolved major clades,which provides a framework for biogeographical and diversification rate *** dating and biogeographical analyses show that Cymbidium likely originated in the region spanning northern IndoBurma to the eastern Himalayas during the early Miocene(~21.10 Ma).It then rapidly diversified into four major clades in East Asia within approximately a million years during the middle *** *** to the adjacent regions(Borneo,Philippines,and Sulawesi)primarily occurred during the Pliocene-Pleistocene *** analyses indicate that the net diversification rate of Cymbidium has decreased since its origin,and is positively associated with changes in temperature and monsoon *** hydrothermal conditions brought by monsoon intensification in the early Miocene possibly contributed to the initial rapid diversification,after which the net diversification rate was reduced with the cooling climate after the middle *** transition from epiphytic to terrestrial habits may have enabled adaptation to cooler environments and colonization of northern niches,yet without a significant effect on diversification *** study provides new insights into how monsoon activity and temperature changes affected the diversification dynamics of plants in Southeast Asia.

关键词： Cymbidium East Asia Asian monsoons Climate change Biogeographical patterns

Remote sensing and its applications using GNSS reflected signals:advances and prospects

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Satellite Navigation 2024年第1期5卷 10-51页

作者： Shuanggen Jin Adriano Camps Yan Jia Feng Wang Manuel Martin-Neira Feixiong Huang Qingyun Yan Shuangcheng Zhang Zhongyu Li Komi Edokossi Dongkai Yang Zhiyu Xiao Zhongmin Ma Weihua Bai Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai200030China School of Surveying and Land Information Engineering Henan Polytechnic UniversityJiaozuo454003China Department of Signal Theory and Communications Technical University of CataloniaBarcelona08034Spain Department of Surveying and Geoinformatics Nanjing University of Posts and TelecommunicationsNanjing210023China School of Electronics and Information Engineering Beihang UniversityBeijing100191China European Space Research and technology Centre(ESTEC) European Space Agency2200-AGNoordwijkThe Netherlands National Space Science Center Chinese Academy of SciencesBeijing100190China School of Remote Sensing and Geomatics Engineering Nanjing University of Information Science and TechnologyNanjing210044China College of Geological Engineering and Geomatics Chang’an UniversityXi’an710054China University of Electronic Science and technology of China Chengdu611731China

The Global Navigation Satellite Systems(GNSS),including the US’s GPS,China’s BDS,the European Union’s Galileo,and Russia’s GLONASS,offer real-time,all-weather,any-time,anywhere and high precision observations by transmitting L band signals continuously,which have been widely used for positioning,navigation and *** the development of GNSS technology,it has been found that GNSS-reflected signals can be used to detect Earth’s surface characteristics together with other signals of *** this paper,the current status and latest advances are presented on Global Navigation Satellite System-Reflectometry(GNSS-R)in theory,methods,techniques and *** developments and progresses in GNSS-R instruments,theoretical modeling,and signal processing,ground and space-/air-borne experiments,parameters retrieval(*** speed,sea surface height,soil moisture,ice thickness),sea surface altimetry and applications in the atmosphere,oceans,land,vegetation,and cryosphere are given and reviewed in ***,the challenges in the GNSS-R development of each field are also ***,the future applications and prospects of GNSS-R are discussed,including multi-GNSS reflectometry,new GNSS-R receivers,GNSS-R missions,and emerging applications,such as mesoscale ocean eddies,ocean phytoplankton blooms,microplastics detection,target recognition,river flow,desert studies,natural hazards and landslides monitoring.

关键词： GNSS Reflectometry Remote sensing Environmental change