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BLS-identification:A device fingerprint classification mechanism based on broad learning for Internet of Things

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Digital Communications and Networks 2024年第3期10卷 728-739页

作者： Yu Zhang bei Gong Qian wang Faculty of Information Technology Beijing University of TechnologyBeijing100124China School of Information Science and Technology Zhengzhou Normal UniversityHenan450044China

The popularity of the Internet of Things(IoT)has enabled a large number of vulnerable devices to connect to the Internet,bringing huge security *** a network-level security authentication method,device fingerprint based on machine learning has attracted considerable attention because it can detect vulnerable devices in complex and heterogeneous access ***,flexible and diversified IoT devices with limited resources increase dif-ficulty of the device fingerprint authentication method executed in IoT,because it needs to retrain the model network to deal with incremental features or *** address this problem,a device fingerprinting mechanism based on a Broad Learning System(BLS)is proposed in this *** mechanism firstly characterizes IoT devices by traffic analysis based on the identifiable differences of the traffic data of IoT devices,and extracts feature parameters of the traffic packets.A hierarchical hybrid sampling method is designed at the preprocessing phase to improve the imbalanced data distribution and reconstruct the fingerprint *** complexity of the dataset is reduced using Principal Component Analysis(PCA)and the device type is identified by training weights using *** experimental results show that the proposed method can achieve state-of-the-art accuracy and spend less training time than other existing methods.

关键词： Device fingerprint Traffic analysis Class imbalance Broad learning system Access authentication

Function-reversible facets enabling SrTiO_(3)nanocrystals for improved photocatalytic hydrogen evolution

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Frontiers in Energy 2024年第1期18卷 101-109页

作者： Bin wang bei AN Xiaoqian LI Shaohua SHEN School of Physics Key Laboratory for Non-equilibrium Synthesis and Modulation of Condensed Matter(Ministry of Education)Key Laboratory of Shaanxi for Advanced Materials and Mesoscopic PhysicsXi’an Jiaotong UniversityXi’an 710049China International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power EngineeringXi’an Jiaotong UniversityXi’an 710049China

It has been widely reported that,for faceted nanocrystals,the two adjacent facets with different band levels contribute to promoted charge separation,and provide active sites for photocatalytic reduction and oxidation reaction,*** such cases,only one family of facets can be used for photocatalytic hydrogen ***,by using SrTiO_(3)nanocrystals enclosed by{023}and{001}facets as a model photocatalyst,this paper proposed a strategy to achieve the full-facets-utilization of the nanocrystals for photocatalytic hydrogen via chemically depositing Pt nanoparticles on all *** photo-deposition experiment of CdS provided direct evidence to demonstrate that the{023}facets which were responsible for photooxidation reaction can be function-reversed for photocatalytic hydrogen evolution after depositing Pt nanoparticles,together with the{001}***,the full-facets-utilization led to a much-improved activity for photocatalytic hydrogen,in contrast to those SrTiO_(3)nanocrystals with only{001}facets deposited by Pt nanoparticles via a photo-deposition method.

关键词： SrTiO_(3)nanocrystals crystal facets photocatalysis hydrogen evolution

Recent progress in carbene-catalyzed fluoroalkylation

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Science China Chemistry 2024年第8期67卷 2448-2460页

作者： bei Zhang Xuan Zhang Jian wang Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control Collaborative Innovation Center of Atmospheric Environment and Equipment TechnologySchool of Environmental Science and EngineeringNanjing University of Information Science and TechnologyNanjing 210044China School of Pharmaceutical Sciences Tsinghua UniversityBeijing 100084China

The fluoroalkyl fragment plays a vital role in various fields such as pharmaceuticals and materials science, and has a significant impact on human life not only on the present but also in the future. The insertion of fluoroalkyl groups into the chemical skeletons can cause considerable alternations in the chemical, physical and biological properties of molecules, which has attracted numerous scientists from different fields. This review focuses on N-heterocyclic carbene(NHC)-catalyzed fluoroalkylation reactions, providing a detailed analysis and summary of the achievements in the past two decades. Many successful examples clearly indicate that NHCs can catalyze the tranformation of fluoroalkylation reagents with various electronic characteristics, whether electrophilic, nucleophilic, or radical precursors. Herein, the fluoroalkylation reactions are classified based on different catalytic modes of NHCs: Lewis base catalysis, Umploung catalysis, radical catalysis and others. Meanwhile, by refining and systematically studying the contribution of NHC catalysis in fluoroalkylation reactions, this review is expected to provide valuable insights and enlightenment for related fields.

关键词： N-heterocyclic carbene fluoroalkylation radical catalysis

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Risk Factors Asscociated with Hypokalemia during Postanesthesia Recovery and Its Impact on Outcomes in Gynecological Patients:A Propensity Score Matching Study

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Current Medical Science 2024年第2期44卷 441-449页

作者： bei-bei wang Li HU Xin-yue HU Dong HAN Jing WU Department of Anesthesiology Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan430022China Institute of Anesthesia and Critical Care Medicine Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan430022China Key Laboratory of Anesthesiology and Resuscitation(Huazhong University of Science and Technology) Ministry of EducationWuhan430022China

Objective:This study aimed to explore the risk factors and outcomes of hypokalemia during the recovery period from anesthesia in the gynecological ***:This retrospective cohort study included 208 patients who underwent gynecological surgery at our institution between January 2021 and March *** were collected for each patient,including demographics,disease status,surgical data,and clinical *** bowel preparation,postoperative gastrointestinal function,and electrolyte levels were compared between the two groups using propensity score matching(PSM).Results:The incidence of hypokalemia(serum potassium level<3.5 mmol/L)during the recovery period from anesthesia was approximately 43.75%.After PSM,oral laxative use(96.4%vs.82.4%,P=0.005),the number of general enemas(P=0.014),and the rate of≥2 general enemas(92.9%vs.77.8%,P=0.004)were identified as risk factors for hypokalemia,which was accompanied by decreased PaCO_(2) and *** were no significant differences in postoperative gastrointestinal outcomes,such as the time to first flatus or feces,the I-FEED score(a scoring system was created to evaluate impaired postoperative gastrointestinal function),or postoperative recovery outcomes,between the hypokalemia group and the normal serum potassium ***:Hypokalemia during postanesthesia recovery period occurred in 43.75%of gynecological patients,which resulted from preoperative mechanical bowel preparation;however,it did not directly affect clinical outcomes,including postoperative gastrointestinal function,postoperative complications,and length of hospital stay.

关键词： hypokalemia gynecological surgery postanesthesia recovery perioperative electrolyte disturbances postoperative recovery

Efficient overall photosynthesis of H_(2)O_(2) by the BTz@Mn_(0.2)Cd_(0.8)S S-scheme heterojunction

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Science China Chemistry 2024年第6期67卷 1953-1960页

作者： Zhongyue Chen Sijie Wan bei Cheng wang wang Yao Xiang Jiaguo Yu Shaowen Cao State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan430070China Hubei Technology Innovation Center for Advanced Composites Wuhan University of TechnologyWuhan430070China Hospital of Wuhan University of Technology Wuhan University of TechnologyWuhan430070China Laboratory of Solar Fuel Faculty of Materials Science and ChemistryChina University of GeosciencesWuhan430074China

The photosynthesis of hydrogen peroxide(H_(2)O_(2))through the selective 2e^(-)oxygen reduction reaction(ORR)from O_(2)and H_(2)O stands out as an environmentally sustainable and cost-effective method for generating this essential ***,the widespread application of most photocatalysts is impeded by their reliance on sacrificial *** this context,we present a noteworthy advancement in the form of a step-scheme(S-scheme)heterojunction involving a donor-acceptor(D-A)-conjugated polymer and manganese cadmium sulfide(BTz@MCS).This innovative configuration enables efficient photocatalytic H_(2)O_(2)production within a non-sacrificial system,showcasing an impressive H_(2)O_(2)yield of 5,368μmol g^(-1)h^(-1)and an apparent quantum yield of 4.5%at 420 *** insights gained from in-situ irradiated X-ray photoelectron spectroscopy(ISIXPS),in-situ diffuse reflectance infrared Fourier transformations spectroscopy(DRIFTS),and density function calculations(DFT),it is revealed that the sp^(2)C between thiazole-thiazole rings at the BTz and the concentrated holes at the MCS function as spatially separated redox *** centers catalyze the selective 2e^(-)ORR and 4e^(-)water oxidation reaction(WOR)*** O_(2)generated from the WOR is subsequently utilized by the ORR cycle,enabling the overall photosynthesis of H_(2)O_(2)with accelerated total reaction ***,the high photocatalytic performance of the developed catalyst is attributed to well-designed S-scheme heterojunctions with tuned band *** spatially separated redox centers and effective transfer of photogenerated charge carriers facilitated by the internal electric field significantly enhance reaction *** study introduces a promising avenue for photocatalytic H_(2)O_(2)production without sacrificial agents,providing valuable insights into the underlying mechanisms in S-scheme heterojunctions.

关键词： hydrogen peroxide non-sacrificial redox centers S-scheme heterojunction

Improved Twin Support Vector Machine Algorithm and Applications in Classification Problems

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China Communications 2024年第5期21卷 261-279页

作者： Sun yi wang Zhouyang beijing University of Posts and Telecommunications School of Computer Science(National Pilot Software Engineering School) beijing University of Posts and Telecommunications International School

The distribution of data has a significant impact on the results of *** the distribution of one class is insignificant compared to the distribution of another class,data imbalance *** will result in rising outlier values and ***,the speed and performance of classification could be greatly *** the above problems,this paper starts with the motivation and mathematical representing of classification,puts forward a new classification method based on the relationship between different classification *** with the vector characteristics of the actual problem and the choice of matrix characteristics,we firstly analyze the orderly regression to introduce slack variables to solve the constraint problem of the lone *** we introduce the fuzzy factors to solve the problem of the gap between the isolated points on the basis of the support vector *** introduce the cost control to solve the problem of sample ***,based on the bi-boundary support vector machine,a twostep weight setting twin classifier is *** can help to identify multitasks with feature-selected patterns without the need for additional optimizers,which solves the problem of large-scale classification that can’t deal effectively with the very low category distribution gap.

关键词： fuzzy ordered regression(OR) relaxing variables twin support vector machine

Experimental study of solid-liquid origami composite structures with improved impact resistance

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Theoretical & Applied Mechanics Letters 2024年第2期14卷 118-123页

作者： Shuheng wang Zhanyu wang bei wang Zhi Liu Yunzhu Ni Wuxing Lai Shan Jiang Yong An Huang AML Department of Engineering MechanicsLaboratory of Flexible Electronics TechnologyTsinghua UniversityBeijing 100084China Institute of Advanced Structure Technology Beijing Key Laboratory of Lightweight Multi-functional Composite Materials and StructuresBeijing Institute of TechnologyBeijing 100081China Hangzhou Institute of Technology Xidian UniversityHangzhou 311200China Nanjing Research Institude of Electronics Technology Nanjing 210039China The Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China State Key Laboratory of Intelligent Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China

In this paper,a liquid-solid origami composite design is proposed for the improvement of impact *** this design strategy,Kresling origami composite structures with different fillings were designed and fabricated,namely air,water,and shear thickening fluid(STF).Quasi-static compression and drop-weight impact experiments were carried out to compare and reveal the static and dynamic mechanical behavior of these *** results from drop-weight impact experiments demonstrated that the solid-liquid Kresling origami composite structures exhibited superior yield strength and reduced peak force when compared to their empty ***,the Kresling origami structures filled with STF exhibited significantly heightened yield strength and reduced peak *** example,at an impact velocity of 3 m/s,the yield strength of single-layer STF-filled Kresling origami structures increased by 772.7%and the peak force decreased by 68.6%.This liquid-solid origami composite design holds the potential to advance the application of origami structures in critical areas such as aerospace,intelligent protection and other important *** demonstrated improvements in impact resistance underscore the practical viability of this approach in enhancing structural performance for a range of applications.

关键词： Solid-liquid design Origami structure Impact resistance Shear thickening fluid

Testing method of rock structural plane using digital drilling

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第7期16卷 2563-2578页

作者： Qi wang Yuncai wang bei Jiang Hongke Gao Fenglin Ma Dahu Zhai Songlin Cai State Key Laboratory for Tunnel Engineering China University of Mining and Technology(Beijing)Beijing100083China

The rock mass consists of rock blocks and structural planes,which can reduce its integrity and ***,accurately obtaining the characteristics of the rock mass structural plane is a prerequisite for evaluating stability and designing supports in underground ***,there are no effective testing methods for the characteristic parameters of the rock mass structural plane in underground *** paper presents the digital drilling technology as a new testing method of rock mass structural *** rock specimens with cracks of varying widths and angles were used to simulate the rock mass structural planes,and the multifunctional rock mass digital drilling test system was employed to carry out the digital drilling *** analysis focuses on the variation laws of drilling parameters,such as drilling pressure and drilling torque,affected by the characteristics of prefabricated cracks,and clarifies the degradation mechanism of rock equivalent compressive ***,an identification model for the characteristic parameters of rock mass structural planes during drilling is *** test results indicate that the average difference of the characteristics of prefabricated cracks identified by the equivalent compressive strength is 2.45and 0.82 mm,*** identification model while drilling is verified to be correct due to the high identification *** on this,a method for testing the characteristic parameters of the surrounding rock structural plane while drilling is *** research offers a theoretical and methodological foundation for precise in situ identification of structural planes of the surrounding rock in underground engineering.

关键词： Structural planes in the rock mass Digital drilling Drilling parameters Equivalent compressive strength Testing method

Unconditionally stable Crank-Nicolson algorithm with enhanced absorption for rotationally symmetric multi-scale problems in anisotropic magnetized plasma

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Journal of Systems Engineering and Electronics 2024年第1期35卷 65-73页

作者： WEN yi wang Junxiang XU Hongbing School of Automatic Engineering University of Electronic Science and Technology of ChinaChengdu 611731China beijing Institute of Aerospace Systems Engineering Beijing 100076China

Large calculation error can be formed by directly employing the conventional Yee’s grid to curve *** order to alleviate such condition,unconditionally stable CrankNicolson Douglas-Gunn(CNDG)algorithm with is proposed for rotationally symmetric multi-scale problems in anisotropic magnetized *** the CNDG algorithm,an alternative scheme for the simulation of anisotropic plasma is proposed in body-of-revolution *** perfectly matched layer(CPML)formulation is proposed to efficiently solve the open region *** example is carried out for the illustration of effectiveness including the efficiency,resources,and *** the results,it can be concluded that the proposed scheme shows considerable performance during the simulation.

关键词： anisotropic magnetized plasma body-of-revolution(BOR) Crank-Nicolson Douglas-Gunn(CNDG) finite-difference time-domain(FDTD) perfectly matched layer(PML) rotationally symmetric multi-scale problems