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FusionNN:A Semantic Feature Fusion Model Based on Multimodal for Web Anomaly Detection

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Computers, Materials & Continua 2024年第5期79卷 2991-3006页

作者： Li Wang Mingshan Xia Hao Hu Jianfang Li Fengyao hou Gang Chen Institute of High Energy Physics Chinese Academy of SciencesBeijing100049China Spallation Neutron Source Science Center(SNSSC) Dongguan523803China School of Nuclear Technology University of Chinese Academy of SciencesBeijing100049Chin

With the rapid development of the mobile communication and the Internet,the previous web anomaly detectionand identificationmodels were built relying on security experts’empirical knowledge and attack *** approach can achieve higher detection performance,it requires huge human labor and resources to maintainthe feature *** contrast,semantic feature engineering can dynamically discover new semantic featuresand optimize feature selection by automatically analyzing the semantic information contained in the data itself,thus reducing dependence on prior ***,current semantic features still have the problem ofsemantic expression singularity,as they are extracted from a single semantic mode such as word segmentation,character segmentation,or arbitrary semantic feature *** paper extracts features of web requestsfrom dual semantic granularity,and proposes a semantic feature fusion method to solve the above *** first preprocesses web requests,and extracts word-level and character-level semantic features of URLs viaconvolutional neural network(CNN),*** constructing three loss functions to reduce losses betweenfeatures,labels and *** on the HTTP CSIC 2010,Malicious URLs and HttpParams datasetsverify the *** show that compared withmachine learning,deep learningmethods and BERTmodel,the proposed method has better detection *** it achieved the best detection rate of 99.16%in the dataset HttpParams.

关键词： Feature fusion web anomaly detection multimodal convolutional neural network(CNN) semantic feature extraction

Regulating photothermal properties of near-infrared croconaine dyes by supramolecular assembly

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Nano Research 2024年第9期17卷 8560-8570页

作者： Yangge Ren Yue Lu Juanjuan Gao Yi Ding Bo Zhu Xinyu hou Lin Jia Department of Polymer Materials School of Materials Science and EngineeringShanghai UniversityShanghai 200444China Department of Electronic Information Materials School of Materials Science and EngineeringShanghai UniversityShanghai 200444China

The photochemical and photophysical properties of near-infrared(NIR)dyes are significantly influenced by their aggregation state and mesoscopic ***,beyond chemical synthesis,the regulation mechanisms for the properties of NIR dyes,particularly with respect to photothermal properties of the aggregates,are not yet fully ***,we investigate the photothermal behaviors of croconaine-based(CroA)NIR dyes containing dipeptide or amino acids *** introduction of hydrogen bonding promotesπ-πstacking of croconaine center,which can efficiently regulate aggregation states and assembly structures in *** laser irradiation,CroA aggregates undergo aggregation-dissociation transition,the in-situ monomer generation process regulates two parameters of photothermal performance:heating rates and plateau photothermal *** study reveals the regulation effect of non-covalent bonding interactions on CroA aggregates,highlighting supramolecular assembly strategy not only facilitates to construct of photothermal nanomaterials with well-defined structures,but also provides an alternative and effective method for regulating photothermal performance of NIR dyes.

关键词： croconaine dye hydrogen bonding photothermal performance supramolecular assembly chirality

Extended light absorption and accelerated charge migration in ultrathin twisted carbon nitride nanoplates for efficient solar hydrogen production

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Science China Chemistry 2024年第7期67卷 2215-2223页

作者： Yanmin Zou Shiyao Li Dandan Zheng Jianyong Feng Sibo Wang Yidong hou Guigang Zhang State Key Laboratory of Photocatalysis on Energy and Environment College of ChemistryFuzhou UniversityFuzhou 350108China College of Environment and Safety Engineering Fuzhou UniversityFuzhou 350108China Collaborative Innovation Center of Advanced Microstructures National Laboratory of Solid State MicrostructuresCollege of Engineering and Applied SciencesNanjing UniversityNanjing 210093China

Polymeric carbon nitride has been widely developed as a promising photocatalyst for solar hydrogen production via photocatalytic water ***,pristine carbon nitride prepared by traditional solid-state polymerization usually encounters issues such as rapid carrier recombination and insufficient absorption of visible light below 460 ***,poly(heptazine imide)with a distinctive nanoplate structure was synthesized in a binary molten salt of NaCl–CaCl_(2).The salt template allows the formation of the thin nanoplate structure,which promotes the charge separation and ***,the intercalation of Ca^(2+)ions between the conjugated layers endows the activation of n–π*electron transition due to the distortion of in-plane heptazine ***,the optimized poly(heptazine imide)nanoplates achieve an apparent quantum efficiency of up to 17.3%at 500 nm for photocatalytic hydrogen production from *** work shares new idea for rational control of the optical absorption and charge carrier dynamics of poly(heptazine imide).

关键词： photocatalysis poly heptazine imide nanoplates ion intercalation hydrogen production

Thermal Property Enhancement of a Novel Shape-Stabilized Sodium Acetate Trihydrate-Acetamide/Expanded Graphite-Based Composite Phase Change Material

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Journal of Thermal Science 2024年第4期33卷 1564-1576页

作者： AN Zhoujian hou Wenjie DU Xiaoze HUANG Zhongzheng MOMBEKI PEA Hamir Johan ZHANG Dong LIU Xiaomin College of Energy and Power Engineering Lanzhou University of TechnologyLanzhou730050China Key Laboratory of Multi-supply System with Solar Energy and Biomass of Gansu Province Lanzhou730050China Gansu Natural Energy Research Institute Lanzhou730046China

Phase change materials(PCMs)are a kind of highly efficient thermal storage materials which have a bright application prospect in many fields such as energy conservation in buildings,waste heat recovery,battery thermal management and so *** inorganic hydrated salt PCMs have received increasing attention from researchers due to their advantages of being inexpensive and ***,inorganic hydrated salt PCMs are still limited by the aspects of inappropriate phase change temperature,liquid phase leakage,large supercooling and severe phase separation in the application *** this work,sodium acetate trihydrate was selected as the basic inorganic PCM,and a novel shape-stabilized composite phase change material(CPCM)with good thermal properties was prepared by adding various functional *** first,the sodium acetate trihydrate-acetamide binary mixture was prepared and the melting point was adjusted using *** the binary mixture was incorporated into expanded graphite to synthesize a novel shape-stabilized *** thermophysical properties of the resultant shape-stabilized CPCM were systematically *** microscopic morphology and chemical structure of the obtained shape-stabilized CPCM were characterized and *** experiment results pointed out that acetamide could effectively lower the melting point of sodium acetate *** obtained shape-stabilized CPCM modified with additional 18%(mass fraction)acetamide and 12%(mass fraction)expanded graphite exhibited good shape stability and thermophysical characteristics:a low supercooling degree of 1.75℃and an appropriate melting temperature of 40.77℃were obtained;the latent heat of 151.64 kJ/kg and thermal conductivity of 1.411 W/(m·K)were also ***,after 50accelerated melting-freezing cycles,the obtained shape-stabilized CPCM represented good thermal reliability.

关键词： sodium acetate trihydrate melting point modification agent expanded graphite shape stability thermal conductivity enhancement

Strategies for flame-retardant polymer electrolytes for safe lithiumbased batteries

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Nano Research 2024年第10期17卷 8754-8771页

作者： Xiao Ma Yang Lu Yu Ou Shuaishuai Yan Wenhui hou Pan Zhou Kai Liu Department of Chemical Engineering Tsinghua UniversityBeijing 100084China

The advancement of lithium-based batteries has spurred anticipation for enhanced energy density,extended cycle life and reduced capacity ***,these benefits are accompanied by potential risks,such as thermal runaway and explosions due to higher energy ***,liquid organic electrolytes are the predominant choice for lithium batteries,despite their limitations in terms of mechanical strength and vulnerability to *** development of polymer electrolytes,with their high Young’s modulus and enhanced safety features,offers a potential solution to the drawbacks of traditional liquid *** these advantages,polymer electrolytes are still susceptible to burning and *** address this issue,researchers have conducted extensive studies to improve their flame-retardant properties from various *** review provides a concise overview of the thermal runaway mechanisms,flame-retardant mechanisms and electrochemical performance of polymer *** also outlines the advancements in flame-retardant polymer electrolytes through the incorporation of various additives and the selection of inherently flame-retardant *** review aims to offer a comprehensive understanding of flame-retardant polymer electrolytes and serve as a guide for future research in this field.

关键词： lithium batteries polymer electrolyte thermal runaway flame-retardant additives energy storage materials

Single-step-etched ultra-compact metamaterial grating coupler enabled by a hierarchical inverse design approach

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Science China(Physics,Mechanics & Astronomy) 2024年第2期67卷 119-126页

作者： Qiao Wang Ruiqi Luo Nan Liu Maojing hou Bo Xiong Guandong Liu Wei Ma Intelligent Network Research Institute Zhejiang LabHangzhou 311100China State Key Laboratory of Modern Optical Instrumentation College of Information Science and Electronic EngineeringZhejiang UniversityHangzhou 310027China

With the concept of metamaterials introduced into integrated photonics,subwavelength structures have gained popularity for their ability to create devices with ultra-compact size,high performance,and versatile ***,traditional metamaterial design methods are usually based on empirical templates and physical approximations,lacking the ability to design free-form metamaterial structures and optimize entire devices *** this work,we propose a hierarchical inverse design approach that combines a conventional effective refractive index based metamaterial structures design with a follow-up global topology *** empirical metamaterial grating coupler design based on effective refractive index engineering faces inaccurate index extraction and insufficient approximation of wavevector matching conditions,which deteriorates coupling efficiency,especially for fully-etched devices with the decreased tapering ***,a subsequent overall topology optimization step can well compensate for the negative effect of the shrinking device footprint to increase the efficiency of the metamaterial grating *** demonstrate a 23μm×10μm ultra-compact metamaterial grating coupler with single-stepetched to couple light between a fiber and a 500 nm single-mode silicon waveguide in the *** measurement shows an insertion loss of 3.17 dB and a 3 dB bandwidth of 77 nm,making it the smallest footprint device ever reported.

关键词： waveguide hierarchical inverse

Improved forecasting via physics-guided machine learning as exemplified using“21·7”extreme rainfall event in Henan

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Science China Earth Sciences 2024年第5期67卷 1652-1674页

作者： Qi ZHONG Zhicha ZHANG Xiuping YAO Shaoyu hou Shenming FU Yong CAO Linguo JING China Meteorological Administration Training Center Beijing 100081China State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesBeijing 100081China Zhejiang Meteorological Observatory Hangzhou 310017China Hebei Provincial Weather Modification Center Shijiazhuang 050020China Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029China National Meteorological Center Beijing 100081China School of Computer Science Chengdu University of Information TechnologyChengdu 610225China

As a natural disaster,extreme precipitation is among the most destructive and influential,but predicting its occurrence and evolution accurately is very challenging because of its rarity and *** the example of the“21·7”extreme precipitation event(17–21 July 2021)in Henan Province,this study explores the potential of using physics-guided machine learning to improve the accuracy of forecasting the intensity and location of extreme *** physics-guided ways of embedding physical features,fusing physical model forecasts and revised loss function are used,i.e.,(1)analyzing the anomalous circulation and thermodynamical factors,(2)analyzing the multi-model forecast bias and the associated underlying reasons for it,and(3)using professional forecasting knowledge to design the loss function,and the corresponding results are used as input for machine learning to improve the forecasting *** results indicate that by learning the relationship between anomalous physical features and heavy precipitation,the forecasting of precipitation intensity is improved significantly,but the location is rarely adjusted and more false alarms *** reasons for this are as *** anomalous features used here mainly contain information about large-scale systems and factors which are consistent with the model precipitation deviation;moreover,the samples of extreme precipitation are sparse and so the algorithm used here is ***,by combining“good and different”multi models with machine learning,the advantages of each model are extracted and then the location of the precipitation center in the forecast is improved ***,by combining the appropriate anomalous features with multi-model fusion,an integrated improvement of the forecast of the rainfall intensity and location is ***,this study is a novel exploration to improve the refined forecasting of heavy precipitation with extreme intensity and high variability,

关键词： Extreme precipitation event Refined assessment Anomalous physical features Multi-model fusion Machine learning

Effectively improving the extreme-pressure capacity of a class of intercalated zirconium phosphate materials

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Science China(Technological Sciences) 2024年第3期67卷 753-764页

作者： NIU WenXing ZHAO XinRui YUAN Min hou ZhiGuo LIU Lei XU Hong DONG JinXiang Shanxi Key Laboratory of Chemical Product Engineering Cllege of Chemical Engineering and TechnologyTaiyuan University of TechnologyTaiyuan 030024China School of Chemical and Environmental Engineering Pingdingshan UniversityPingdingshan 467000China

We studied different long-chain ammonium ions intercalated zirconium phosphate α-ZrP, methylamine intercalated ZrP(MAZrP), tetramethylammonium hydroxide intercalated ZrP(TMAH-ZrP), dodecyltrimethylammonium bromide intercalated ZrP(DTAB-ZrP), and stearyl trimethyl ammonium bromide intercalated ZrP(STAB-ZrP) as grease co-additives in combination with isobutylene sulfide(SIB). The grease with co-additives displayed excellent extreme-pressure and anti-wear ***, the combination of the longest chain ammonium ion intercalated zirconium phosphate, STAB-ZrP/SIB, had the best tribological properties. In comparison to α-ZrP, the advantage of STAB-ZrP was that it did not form a large area of the dense physical film like α-ZrP on the worn surface, but rather gave the SIB a chance to contact with the fresh metal surface to generate a chemical film. Therefore, the sub-micron physical film and nanoscale chemical film always exist side by side on the contact surface during the friction process. This intercalated α-ZrP/SIB additive has great potential for use in harsh operating conditions.

关键词： intercalatedα-ZrP/SIB physical film chemical film tribological properties

Multicolor Ramsey Number of Stars Versus a Path

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Journal of Mathematical Research with Applications 2024年第4期44卷 465-469页

作者： Xuejun ZHANG Xinmin hou School of Data Science University of Science and Technology of China School of Mathematical Sciences University of Science and Technology of China CAS Key Laboratory of Wu Wen-Tsun Mathematics University of Science and Technology of China Hefei National Laboratory University of Science and Technology of China

For given simple graphs H1,H2,...,Hc,the multicolor Ramsey number R（H1,H2,...,Hc） is defined as the smallest positive integer n such that for an arbitrary edge-decomposition{Gi}ci=1of the complete graph K_n,at least one Gihas a subgraph isomorphic to *** m,n1,n2,...,nc be positive integers andΣ=Σci=1（ni-1）.Some bounds and exact values of R(K1,n1,...,K1,nc,Pm) have been obtained in *** （Graphs Combin.,2020） conjectured that ifΣ?≡0 （mod m-1） andΣ+1≥（m-3）2,then R(K1,n1,...,K1,nc,Pm)=Σ+*** this note,we give a new lower bound and some exact values of R(K1,n1,...,K1,nc,Pm) provided m≤Σ,Σ≡k （mod m-1）,and 2≤k≤*** results partially confirm Wang’s conjecture.

关键词： Ramsey number star path