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Limit Theorems for Critical Galton-Watson Processes with Immigration Stopped at Zero

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Acta Mathematica Sinica,English Series 2024年第2期40卷 435-450页

作者： dou dou LI Mei zhang Xian Yu zhang College of Statistics and Data Science Faculty of ScienceBeijing University of TechnologyBeijing 100124P.R.China Laboratory of Mathematics and Complex Systems(Ministry of Education) School of Mathematical SciencesBeijing Normal UniversityBeijing 100875P.R.China

In this paper,we consider a critical Galton-Watson branching process with immigration stopped at zero *** precise estimation on the probability generating function of the n-th population are obtained,and the tail prob... 详细信息

关键词： Branching immigration critical life period limit theorems

Nuciferine alleviates collagen-induced arthritic in rats by inhibiting the proliferation and invasion of human arthritis-derived fibroblast-like synoviocytes and rectifying Th17/Treg imbalance

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Chinese Journal of Natural Medicines 2024年第4期22卷 341-355页

作者： WANG Hao GENG Xiaolong AI Fangbin YU Zhilun zhang Yan zhang beibei LV Cheng GAO Ruiyang YUE bei dou Wei The MOE Key Laboratory of Standardization of Chinese Medicines Shanghai Key Laboratory of Compound Chinese Medicinesand the SATCM Key Laboratory of New Resources and Quality Evaluation of Chinese MedicineInstitute of Chinese Materia MedicaSchool of Traditional Chinese Materia MedicaShanghai University of Traditional Chinese Medicine(SHUTCM)Shanghai 201203China

Rheumatoid arthritis(RA)is a chronic autoimmune disorder marked by persistent synovial inflammation and joint degradation,posing challenges in the development of effective ***,an alkaloid found in lotus leaf,has shown promising anti-inflammatory and anti-tumor effects,yet its efficacy in RA treatment remains *** study investigated the antiproliferative effects of nuciferine on the MH7A cell line,a human RA-derived fibroblast-like synoviocyte,revealing its ability to inhibit cell proliferation,promote apoptosis,induce apoptosis,and cause G1/S phase ***,nuciferine significantly reduced the migration and invasion capabilities of MH7A *** therapeutic potential of nuciferine was further evaluated in a collagen-induced arthritis(CIA)rat model,where it markedly alleviated joint swelling,synovial hyperplasia,cartilage injury,and inflammatory *** also improved collagen-induced bone erosion,decreased pro-inflammatory cytokines and serum immunoglobulins(IgG,IgG1,IgG2a),and restored the balance between T helper(Th)17 and regulatory T cells in the spleen of CIA *** results indicate that nuciferine may offer therapeutic advantages for RA by decreasing the proliferation and invasiveness of FLS cells and correcting the Th17/Treg cell imbalance in CIA rats.

关键词： Rheumatoid arthritis Collagen-induced arthritis Fibroblast-like synoviocyte Immune imbalance Nuciferine

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

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

Co-aromatization of methane and hexane over Pt encapsulated in ZSM-5 zeolite and the electronic effect of K promoters

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Science China Chemistry 2024年第3期67卷 1017-1027页

作者： bei Liu Fan Wang Xiaomeng dou Pengfei Li Hongwei Xiang Yong Yang Peng He State Key Laboratory of Coal Conversion Institute of Coal ChemistryChinese Academy of SciencesTaiyuan 030001China Department of Chemistry Tsinghua UniversityBeijing 100084China National Energy R&D Center for Coal to Liquid Fuels Synfuels China Technology Co.Ltd.Beijing 101407China University of Chinese Academy of Sciences Beijing 101408China Leibniz-Institut für Katalyse e.V.an der Universitat Rostock Rostock 18059Germany

The co-aromatization of methane with higher hydrocarbons represents a promising route to valorize methane, an abundant but underexploited carbon resource. In this study, we elucidate a novel approach to enhance the catalytic co-aromatization of hexane and methane by confining Pt within zeolite catalysts and modulating its electron density. Our findings show that encapsulating Pt within MFI structure is pivotal for activating the feedstock and fostering the formation of aromatic products. Interaction between K atoms and the silanol nest forms siloxy groups which are critical for the stabilization of Pt species. Tuning the K content in PtSn@MFI catalysts adeptly alters the electronic configuration of Pt clusters. This modification is corroborated by infrared and X-ray photoelectron spectroscopy analysis, and density functional theory calculations. Remarkably, the catalyst with 0.8 wt% K exhibits an optimal Pt electron density, driving its superior efficacy in the co-aromatization reaction, converting 0.78 mol of methane for each mole of hexane processed. By employing ~(13)C isotopic labeling and solid-state NMR studies, we demonstrate the participation of methane in the adsorbed species inside the zeolite channel and its incorporation to the benzyl site of the substitute group and phenyl rings in aromatic compounds, underscoring the importance of Pt encapsulation.

关键词： Pt encapsulation MFI zeolite methane activation co-aromatization ^(13)C solid-state NMR

A novel three-inflection-point sliding mode control framework for forward-tilting morphing aerospace vehicle with performance constraints and actuator faults

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Chinese Journal of Aeronautics 2024年第8期37卷 293-310页

作者： Xinkai LI Lei dou Hongli zhang Yue MENG School of Electrical Engineering Xinjiang UniversityUrumqi 830047China

A prescribed performance control scheme based on the three-inflection-point hyperbolic function and predefined time performance function is proposed to solve the trajectory tracking problem of the forward-tilting morphing aerospace vehicle with time-varying actuator *** accurately estimate the loss degree of actuator faults,an immersion and invariance observer based on the predefined time dynamic scale factor is designed to estimate and compensate it.A composite dynamic sliding mode surface is designed using a three-inflection-point hyperbolic function,and a novel three-inflection-point sliding mode control framework is *** convergent domain of the sliding manifold is adjusted by parameters,and the system error convergence is controllable.A transfer function is designed to eliminate the sensitivity of the three-inflection-point hyperbolic sliding mode to the unknown initial state,and combined with the barrier Lyapunov function,and the performance constraint of the system is *** global asymptotic stability of the system is demonstrated using a strict mathematical *** effectiveness and superiority of the proposed control scheme are proven by simulation experiments.

关键词： Morphing aerospace vehicle Actuator faults Immersion and invariance Three-inflection-point sliding mode control Prescribed performance control

Introducing electrolytic electrochemical polymerization for constructing protective layers on Ni-rich cathodes of Li-ion batteries

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Rare Metals 2024年第6期43卷 2536-2545页

作者： Lin-Tao dou bei Li Hao-Long Nie Dong-Dong Xiao Chao-Qun Shang Xiao-Min Wang Zhan-Hui zhang Katerina E.Aifantis Pu Hu School of Materials Science and Engineering Wuhan Institute of TechnologyWuhan 430205China Huairou Division Institute of PhysicsChinese Academy of SciencesBeijing 101400China Department of Mechanical and Aerospace Engineering University of FloridaGainesvilleFL 32603USA

LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)is the most promising cathode for high-energy Li-ion batteries,despite its poor cycling stability that originates from the reactions that occur with the ***,to solve this interfacial issue,a facile electrolytic electrochemical polymerization process was introduced in this paper,and a uniform conductive electrolyte interface(polyaniline)was successfully constructed on the surface of the NCM811 porous electrode(PANI-NCM),which facilitated the charge transfer during charge/*** side reactions at the interface between the cathode and the electrolyte are suppressed,and thereby,the cycling performance and rate capability are considerably ***-NCM delivers an initial capacity of 157.2 mAh·g^(-1)as well as excellent cyclability(capacity retention of 88%after 500 cycles at 2C),whereas the capacity of the bare NCM811 has dropped to 31.3 mAh·g^(-1).In addition,polypyrrole and polythiophene also can be formed through electrolytic electrochemical polymerization process,which provides a practicable tactic to modify the interfacial stability of cathodes for high-energy Li-ion batteries.

关键词： Lithium-ion battery Ni-rich cathode In-situ polymerization Conductive polymer Electrochemical performance

Enrichment and reconfiguration of titanium-bearing phase in vortex smelting reduction process of vanadium-titanium magnetite

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Journal of Iron and Steel Research International 2024年第7期31卷 1582-1589页

作者： Yong-chao Han Zhi-he dou Rui zhang Ting-an zhang Shuai Fang Key Laboratory for Ecological Metallurgy of Multimetallic Ores(Ministry of Education) Shenyang 110819LiaoningChina School of Metallurgy Northeastern UniversityShenyang 110819LiaoningChina

To comprehensively utilize the low-iron high-vanadium-titanium magnetite,a new method of vortex smelting reduction of vanadium-titanium magnetite was proposed,and the enrichment and reconstitution regularity of Ti-bearing phases in the slag was investigated through X-ray fluorescence spectrometry,X-ray photoelectron spectroscopy,X-ray diffraction analysis,and optical *** phase diagram revealed that the preferential crystallization of MgTi_(2)O_(5) can be achieved by adjusting the CaO,MgO,and TiO_(2) contents of *** predominant Ti-bearing phases in the slag obtained from the reduction process are MgxTi_(3_x)O_(5)(0≤x≤1)and CaTiO_(3).FeTiO_(3) is present at carbon-iron ratio(CR)=1.3,while MgTi_(2)O4 and TiC are formed at CR=*** enrichment of TiO_(2) in the slag increases first and then decreases as the CR increases,and at CR=1.1,the enrichment of TiO_(2) in the slag reaches 51.3 wt.%.Additionally,the concentrations of MgxTi_(3_x)O_(5)(0≤x≤1)and CaTiO_(3) in the slag,along with the grain width of MgxTi_(3_x)O_(5)(0≤x≤1),decrease with the increase in CR.

关键词： Vanadium-titanium magnetite Vortex smelting reduction Phase reconfiguration TiO_(2)enrichment

Optimizing extractants selection for efficient separation of phenols and nitrogen-containing heteroaromatics using hydrogen bond interaction strategies

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Chinese Journal of Chemical Engineering 2024年第4期68卷 43-52页

作者： Pengzhi bei Rui zhang Jie Feng Antony Rajendran Wenying Li State Key Laboratory of Clean and Efficient Coal Utilization Taiyuan University of TechnologyTaiyuan 030024China Department of Chemistry Mepco Schlenk Engineering College(Autonomous)Sivakasi 626005India

Focusing on the use of imidazolium ionic liquids and quaternary ammonium salts-based deep eutectic solvents for the separation of phenols and nitrogen-containing heteroaromatics,the role of heteroaromatics as specific sites for hydrogen bond-based separation has been *** environmentally friendly solvents are known for their ability to form hydrogen bonds with heteroatoms,a key aspect in separation *** quantified the hydrogen bond interaction energy to reach the threshold energy for efficient O-and N-heteroaromatics *** article provides an in-depth study of the structural nuances of different hydrogen bonding sites and their affinity properties while conducting a comparative evaluation of the separation efficiency of ionic liquids and deep eutectic solvents from a thermodynamic *** showed that phenols with dual hydrogen bonding recognition sites were easier to separate than nitrogen-containing *** ionic liquids were more suitable for the extraction of nonbasic nitrogen-containing heteroaromatics,and quaternary ammonium salts-based deep eutectic solvents are more effective for phenols and basic nitrogen-containing heteroaromatics,which was confirmed by Fourier transform infrared spectroscopy and empirical ***,this study provides a theoretical basis for the strategy design and selection of extractants for the efficient separation of O-and N-containing aromatic compounds.

关键词： Deep eutectic solvents Hydrogen bond Ionic liquids Separation Solvents Structural characteristics