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Evaluation of infrared camouflage effectiveness via a multi-fractal method

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Defence Technology（防务技术） 2021年第3期17卷 748-754页

作者： xiao-peng Cheng Bo-wang Shu Ya-jing Chang Xin li Da-bin Yu State Key Laboratory of Pulsed Power Laser Technology College of Electronic EngineeringNational University of Defense TechnologyHefei230037PR China

This paper reports an alternative approach to the evaluation of infrared camouflage effectiveness via a multi-fractal method. By calculating multi-fractal spectra of the target region and the background regions in an infrared image, the spectrum shape features and the discrete Frechet distances among these spectra were used to analyze the camouflage effectiveness of the target qualitatively and quantitatively,and the correlation coefficients of the spectra were further used as the index of camouflage *** was found that the camouflaged target had better camouflage effectiveness than the target without camouflage in the same one background, and the same one camouflaged target had different camouflage effectiveness in different backgrounds. On the whole, the target matching well with its background had high camouflage effectiveness value. This approach can expand the application of multi-fractal theory in infrared camouflage technology, which should be useful for the research of infrared camouflage materials, the design of camouflage patterns as well as the deployment of military equipment in battlefield.

关键词： Infrared Camouflage effectiveness Multi-fractal Similarity

End-to-end encrypted network traffic classification method based on deep learning

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The Journal of China Universities of Posts and Telecommunications 2020年第3期27卷 21-30页

作者： Tian Shiming Gong Feixiang Mo Shuang li Meng Wu Wenrui xiao Ding Department of Power Consumption and Energy Efficiency China Electric Power Research Institute Co.Ltd.Beijing 100192China School of Com puter Science Beijing University of Posts and Telecom municationsBeijing 100876China State Grid Corporation of China Beijing 100031China

Network traffic classification,which matches network traffic for a specific class of different granularities,plays a vital role in the domain of network administration and cyber *** the rapid development of network communication techniques,more and more network applications adopt encryption techniques during communication,which brings significant challenges to traditional network traffic classification *** the one hand,traditional methods mainly depend on matching features on the application layer of the ISO/OSI reference model,which leads to the failure of classifying encrypted *** the other hand,machine learning-based methods require human-made features from network traffic data by human experts,which renders it difficult for them to deal with complex network *** this paper,the convolution attention network(CAT)is proposed to overcom those *** an end-to-end model,CAT takes raw data as input and returns classification results automatically,with engineering by human *** CAT,firstly,the importance of different bytes with an attention mechanism of network traffic is ***,convolution neural network(CNN)is used to learn features automatically and feed the output into a softmax function to get classification *** enables CAT to learn enough information from network traffic data and ensure the classified *** experiments on the public encrypted network traffic dataset ISCX2016 demonstrate the effectiveness of the proposed model.

关键词： network traffic classification convolution neural network attention mechanism network management cyber security

High molecular weight guar gum assisted settling of fine solids in diluted bitumen:Effect of solvents

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Petroleum Science 2021年第6期18卷 1877-1886页

作者： Camila Santander Jing liu xiao-li Tan Qi liu Hong-Bo Zeng Department of Chemical and Materials Engineering University of AlbertaEdmontonAB T6G 1H9Canada

As water-based extraction technologies for producing bitumen from oil sands have received increasing environmental concerns,developing non-aqueous extraction(NAE)technique is of both fundamental and practical ***,the relatively high concentration of fine solids trapped in the extracted bitumen presents an obstacle for pipeline transport as well as upgrading and refining *** research attempts to provide a solution to fine solids removal without using synthetic additives or affecting bitumen recovery from NAE ***,naturally hydrophilic additives(i.e.,water and high molecular weight guar gum(HGG)produced from Cyamopsiste tragonolobuosr ***.)were introduced to promote the settling of fine solids suspended in bitumen-solvent solution,and the effects of solvents(i.e.,toluene,cyclohexane and their mixtures)were systematically *** size distribution analyzed by the focused beam reflectance measurements confirmed that the addition of water and HGG could promote the agglomeration and settling of fine solids in all solvents ***,the size range and quantity of the agglomerates vary significantly with the solvent's aromatic *** mixtures demonstrate a superior performance on removing fine solids from bitumen over single ***,in a 3:2 toluene/cyclohexane mixture,the solid content was lowered from 0.66 wt%to 0.09 wt%.

关键词： Non-aquoues extraction Fine solids Guar gum Agglomeration Settling

Stability analysis of surrounding rock mass in underground powerhouse considering damage effect of microfractures

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Journal of Rock Mechanics and Geotechnical Engineering 2022年第4期14卷 1115-1130页

作者： Peiwei xiao Haoyu Mao Bo Qian Biao li Xingguo Yang Nuwen Xu State Key Laboratory of Hydraulics and Mountain River Engineering College of Water Resource and HydropowerSichuan UniversityChengdu610065China Guodian Jinshajiang Xulong Hydropower Development Co. LtdChengdu610041China School of Geoscience and Technology Southwest Petroleum UniversityChengdu610500China

A high-precision microseismic(MS)monitoring system was built to monitor surrounding rock microfractures in the underground powerhouse on the left bank of Shuangjiangkou Hydropower *** surrounding rock damage area with spatiotemporal clustering of MS activities was studied for qualitative analysis of the damage mechanism of surrounding rock microfractures,based on the source parameters of MS *** surrounding rock microfracture scale characterized by the source radius of MS events was considered to establish the constitutive *** information was imported into the model for numerical analysis using fast Lagrangian analysis of continuain 3 dimensions(FLAC^(3D)).The results indicated that the numerical simulation results considering MS damage can better reflect the actual situation of the *** surrounding rock microfractures mainly showed mixed failure *** failures appeared in localized areas while the fracture scale of sections from K0e33 m to K0e15 m on the vault was *** deformation increment caused by microfracture damage in the shallow surrounding rock of the top arch accounted for 10%e13%,and the stress decrement in the surrounding rock caused by microfracture damage accounted for about 10%.

关键词： Underground powerhouse Microseismic(MS)monitoring Numerical modeling Microfracture damage Constitutive relation

Defect engineering in Co-doped Ni_(3)S_(2) nanosheets as cathode for high-performance aqueous zinc ion battery

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Journal of Materials Science & Technology 2022年第23期118卷 199-207页

作者： xiaojuan li Shunshun Zhao Guangmeng Qu xiao Wang Peiyu Hou Gang Zhao Xijin Xu School of Physics and Technology University of JinanJinan 250022China School of Electronic and Information Engineering(Department of Physics) Qilu University of Technology(Shandong Academy of Sciences)Jinan 250353China

With the merits of low cost,environmental benignity,and high safety,aqueous zinc ion batteries(AZIBs)have great potential in the field of energy *** this paper,we craft a Co-doped Ni3 S2 with abundant sulfur vacancies as effective cathode materials(Co-Ni_(3) S_(2-x)) for AZIBs by hydrothermal and chemical reduction ***,cobalt doping and abundant sulfur vacancies can effectively increase the conductivity and the number of active sites for electrochemical reactions,which gives the Co-Ni_(3) S_(2-x) electrode the outstanding capability to energy *** coupling Co-Ni_(3) S_(2-x) cathode with Zn anodes to assemble alkaline AZIBs,the Co-Ni_(3) S_(2-x)//Zn full battery exhibits excellent specific capacity(183.9 mAh g^(-1) at 1 A g^(-1),based on cathode mass) and extraordinary cycling durability(72.9% capacity retention after 6000 cycles).First-principles calculations based on density functional theory(DFT) confirm that the Co-Ni_(3) S_(2-x) electrode has strong energy storage capacity and electrochemical *** results provide an extremely significant reference in designs of self-supported bimetallic sulfide nanosheets,which have promising applications in high-performance energy storage devices.

关键词： Zinc ion battery Metal doping Sulfur vacancy Ni_(3)S_(2)

Microscopic study on the key process and influence of efficient synthesis of natural gas hydrate by in situ Raman analysis of water microstructure in different systems with temperature drop

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Journal of Energy Chemistry 2023年第7期82卷 317-333,I0008页

作者： Wei Zhang Chun-Gang Xu xiao-Sen li Zhuo-Yi Huang Zhao-Yang Chen School of Engineering Science University of Science and Technology of ChinaHefei 230023AnhuiChina Guangzhou Institute of Energy Conversion Chinese Academy of SciencesGuangzhou 510640GuangdongChina CAS Key Laboratory of Gas Hydrate Guangzhou 510640GuangdongChina Guangdong Provincial Key Laboratory of New and Renewable Energy Research and Development Guangzhou 510640GuangdongChina School of Energy Science and Engineering University of Science and Technology of ChinaHefei 230023AnhuiChina

Gas hydrate technology has considerable potential in many ***,due to the lack of understanding of the micro mechanism of hydrate formation,it has not been commercially applied so *** hydrate formation is essentially a gas-liquid-solid phase transition of water and gas molecules at a certain temperature and *** key to the hydrate formation is the transformation of water molecule from disordered arrangement to ordered *** this process,weakly hydrogen bonded water will be correspondingly converted to strongly hydrogen bonded *** in situ Raman analysis and experiments,the position change of the corresponding peaks of the strongly hydrogen bonded water and the weakly hydrogen bonded water was compared in this work,and the key microscopic process and influence of gas hydrate formation in different systems were comprehensively studied and *** is found that,with the decrease of temperature,the OAH of the weakly hydrogen bonded water remains unchanged when the temperature drops to a certain value,which is the key to the transformation of water into cage hydrate rather than *** conversion from the weakly hydrogen bonded water to the strongly hydrogen bonded water is closely related to the gas-liquid interface force,the hydrophilicity/hydrophobicity of the promoter,the ionization degree of liquid,and the electrostatic field of the *** the four most common promoters,tetrahydrofuran(THF)has the highest efficiency in promoting methane(CH4)hydrate ***,this study provides a scientific direction and basis for the development of high efficient hydrate formation promoters,which can effectively weaken the hydrogen bond of weakly hydrogen bonded water and promote the conversion of weakly hydrogen bonded water to strongly hydrogen bonded water.

关键词： Hydrate Conversion Hydrogen bonded water Promoter Micro mechanism

Boron:A key functional component for designing high-performance heterogeneous catalysts

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Chinese Chemical Letters 2023年第1期34卷 45-58页

作者： Meihong Fan xiao liang Qiuju li lili Cui Xingquan He xiaoxin Zou School of Chemistry and Environmental Engineering Changchun University of Science and TechnologyChangchun 130022China State Key Laboratory of Inorganic Synthesis and Preparative Chemistry College of ChemistryJilin UniversityChangchun 130012China Department of Chemistry College of Basic MedicineThird Military Medical University(Army Medical University)Chongqing 400038China

Heterogeneous catalysis is a vivid branch of traditional catalysis field,with the advantage of high efficiency and being easily separated from reactants and products after reaction,and have received widespread attentions in large-scale industrial production,especially in the field of energy *** has been found to be a key functional component for designing high-performance heterogeneous *** this review,we cover and categorize the past and recent progress in boron-containing materials and their applications in heterogeneous catalysis particularly in energy-related *** fundamental roles of boron components in the emerging heterogeneous catalysis of construction,regulation and stabilization of active phases/sites are highlighted,with the emphasis on how they regulating structural and electronic properties of host *** then categorize boron-containing catalysts into six kinds mainly including intermetallic boride catalysts,metal boride-derived catalysts,boron-doped catalysts,metal boride-decorated catalysts,boron-containing compounds as catalyst supports,and singleboron-site catalysts,as well as try to establish structure-catalytic activity *** catalytic applications of these six boron-containing catalysts are discussed separately,focusing on the energy-related reactions such as hydrogen evolution reaction(HER),oxygen evolution reaction(OER),oxygen reduction reaction(ORR),carbon dioxide reduction reaction(CO_(2)RR)and nitrogen reduction reaction(NRR).Finally,the opportunities and challenges related to boron-containing compounds in the field of catalysis are prospected.

关键词： Boron Heterogeneous catalysis Active site Electronic structure Structure-activity relationship

Intestinal microbiota and juvenile idiopathic arthritis:current understanding and future prospective

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World Journal of Pediatrics 2021年第1期17卷 40-51页

作者： Le Xin Feng He Sen li Zhi-Xuan Zhou xiao-lin Ma Gynecological Minimal Invasive Center Beijing Obstetrics and Gynecology HospitalCapital Medical UniversityBeijingChina Department of Biochemistry and Immunology Capital Institute of PediatricsYabao Road No.2Chaoyang DistrictBeijingChina Department of Rheumatology Capital Institute of PediatricsBeijingChina

Background Juvenile idiopathic arthritis(JIA)characterized by arthritis of unknown origin is the most common childhood chronic rheumatic disease,caused by both host genetic factors and environmental *** evidence has mounted to focus on the intestinal microbiota,a potentially recognized set of environmental triggers affecting JIA *** we offer an overview of recently published animal and human studies that support the impact of intestinal microbiota in *** sources We searched PubMed for animal and human studies publications with the search terms"intestinal microbiota or gut microbiota"and"juvenile idiopathic arthritis or juvenile chronic arthritis or juvenile rheumatoid arthritis or childhood rheumatoid arthritis or pediatric rheumatoid arthritis".Results Several comparative studies have demonstrated that intestinal microbial alterations might be triggers in disease ***,a slice of studies has suggested environmental triggers in early life might disrupt intestinal microbial colonization,including cesarean section,formula feeding,and antibiotic *** intestinal microbiota may influence the development of JIA by mediating host immune programming and by altering mucosal *** Specific microbial factors may contribute to the pathogenesis of *** studies,however,are warranted to investigate the causality between intestinal dysbiosis and JIA and the mechanisms behind these epidemiologic *** are also needed to design the best interventional administrations to restore balanced intestinal microbial communities.

关键词： Antibiotic exposure Cesarean section Immune system reprogramming Intestinal microbiota Juvenile idiopathic arthritis

Temporal effect of local hyperthermia on murine contact hypersensitivity

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Chinese Medical Journal 2013年第8期126卷 1555-1559页

作者： ZHANG lan WANG Yi-ru HONG Yu-xiao XU Ya-qin ZHANG li li xiao-dong xiao Ting LU Dong-qing CHEN Hong-duo GAO Xing-hua Department of Dermatology No. 1 Hospital of China MedicalUniversity Shenyang Liaoning 110001 Zhina Department of Dermatology Fifth Affiliated Hospital ofSunYat-sen University Zhuhai Guangdong 519000 China

Background The sensitization and elicitation phases are involved in the immunopathogenesis of contact hypersensitivity （CHS）. langerhans cells （LCs） are believed to play pivotal roles in the sensitization stage of CHS. Local hyperthermia on skin induces the migration as well as maturation of epidermal LCs. Although fever-range whole body hyperthermia and local hyperthermia at 43℃ prior to sensitization were reported to suppress CHS, the effects of different temperatures and the timing sequence of local hyperthermia on CHS have not been tackled. Methods Local hyperthermia was applied to murine dorsal skin 3 days prior to, concurrent with, or 2 days post sensitization with fluorescein isothiocyanate （FITC） in BALB/c mice. Local hyperthermia temperatures at 37℃, 39℃, 41℃ and 43℃ were applied to mouse dorsal skin and the severity of CHS was calculated by measuring the swelling response of the challenged ears. Results Local hyperthermia at 39℃, 41℃ and 43℃ prior to sensitization reduced the severity of CHS, as compared with that at 37℃. The suppression of CHS was temperature dependant in that higher temperature had a stronger effect. On the contrary, the hyperthermia treatments, either concurrent with or post-sensitization, resulted in an enhanced temperature-dependant ear swelling response. Conclusions The severity of murine CHS could be influenced by local hyperthermia at the sensitization stage in a temperature dependant manner. The temporal effect of local hyperthermia suggested a novel factor in interpreting the severity of allergic contact dermatitis.

关键词： fever dermatitis contact langerhans cells immunization