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Science China(Information Sciences) 2025年第2期68卷 151-169页

作者： Fenglan SUN Zhonghua xu Wei ZHU ■ KURTHS Key Lab of Intelligent Analysis and Decision on Complex Systems School of ScienceChongqing University of Posts and Telecommunications Key Lab of Intelligent Air-Ground Cooperative Control for Universities in Chongqing College of AutomationChongqing University of Posts and Telecommunications Department of Complexity Science Potsdam Institute for Climate Impact Research Institute of Physics Humboldt University of Berlin

In this paper, an event-triggered time-varying formation tracking control for a class of second-order nonlinear multiagent systems(MAS) operating within a constrained region is investigated. To mitigate the negative effects of external unknown disturbance, a novel disturbance observer with performance guarantees is proposed, enabling precise disturbance *** the artificial potential field(APF) method, a repulsive potential function is introduced to prevent inter-agent collisions as well as collisions with environmental obstacles. To reduce continuous communication and frequent system updates, a sliding mode technique is incorporated into the formation tracking controller, utilizing an event-triggered mechanism. The controller is also applicable to the formation control of MAS in switching-constrained regions. The achievement of the specified timevarying geometric formation is rigorously demonstrated through the Lyapunov framework. Numerical simulations are presented to validate the effectiveness of the theoretical results.

关键词： formation tracking control region constraints repulsive potential function event-triggered mechanism

Atomic cerium-doped CuO_(x) catalysts for efficient electrocatalytic CO_(2) reduction to CH_(4)

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Chinese Chemical Letters 2025年第1期36卷 326-331页

作者： Xiangyu Chen Aihao xu Dong Wei Fang Huang Junjie Ma Huibing He Jing xu Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology School of Chemistry and Chemical EngineeringGuangxi UniversityNanning 530004China State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures Guangxi UniversityNanning 530004China State Key Laboratory of Green Chemical Engineering and Industrial Catalysis School of Chemical EngineeringEast China University of Science and TechnologyShanghai 200237China

Copper(Cu)is widely used in the electrochemical carbon dioxide reduction reaction(ECO_(2)RR)for efficient methane(CH_(4))***,the morphology and valence of Cu-based catalysts are usually unstable under reaction *** this work,we prepared Ce-doped MOF-199 precursor(Ce/HKUST-1)and further obtained nanoparticle electrocatalyst Ce/CuO_(x)-NPs by cyclic voltammetry(CV)*** Faradic efficiency of methane(FE_(CH_(4)))maintains above 62%within a broad potential window of 350 mV and the maximum FE_(CH_(4))reaches 67.4%with a partial current density of 293 mA/cm^(2)at-1.6 V vs.a reversible hydrogen *** characterization and theoretical calculations revealed that the unique electronic structure and large ionic radius of Cerium(Ce)not only promoted the generation of key intermediate*CO but also lowered energy barrier of the*CO to*CHO *** study provides a novel and efficient catalyst for methane production in ECO_(2)RR and offers profound insights into constructing high performance Cu-based catalysts.

关键词： ECO_(2)RR Cu-based catalyst Structure evolution DFT calculation

Co-doped cryptomelane-type manganese oxide in situ grown on a nickel foam substrate for high humidity ozone decomposition

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Journal of Environmental Sciences 2025年第2期148卷 529-540页

作者： Haoyuan Liang xu Wang Hui Wang Zhenping Qu Key Laboratory of Industrial Ecology and Environmental Engineering School of Environmental Science and TechnologyDalian University of TechnologyDalian 116024China

Monolithic catalysts with excellent O_(3)catalytic decomposition performance were prepared by in situ loading of Co-doped KMn_(8)O_(16)on the surface of nickel *** triple-layer structure with Co-doped KMn_(8)O_(16)/Ni6MnO_(8)/Ni foam was grown spontaneously on the surface of nickel foam by tuning the molar ratio of KMnO_(4)to Co(NO_(3))_(2)·6H_(2)O ***,the formed Ni6MnO_(8)structure between KMn_(8)O_(16)and nickel foam during in situ synthesis process effectively protected nickel foam from further etching,which significantly enhanced the reaction stability of *** optimum amount of Co doping in KMn_(8)O_(16)was available when the molar ratio of Mn to Co species in the precursor solution was 2:*** the Mn2Co1 catalyst had abundant oxygen vacancies and excellent hydrophobicity,thus creating outstanding O_(3)decomposition *** O_(3)conversion under dry conditions and relative humidity of 65%,90%over a period of 5 hr was 100%,94%and 80%with the space velocity of 28,000 hr^(−1),*** in situ constructed Co-doped KMn_(8)O_(16)/Ni foam catalyst showed the advantages of low price and gradual applicability of the preparation process,which provided an opportunity for the design of monolithic catalyst for O_(3)catalytic decomposition.

关键词： Co-doped cryptomelane-type manganese O3 decomposition High humidity Nickel foam Monolithic catalyst

Evaluating the affecting factors of glacier mass balance in Tanggula Mountains using explainable machine learning and the open global glacier model

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Journal of Mountain Science 2025年第2期22卷 466-488页

作者： xu Qiangqiang KANG Shichang HE Xiaobo xu Min Key Laboratory of Cryospheric Science and Frozen Soil Engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China Tanggula Mountain Cryosphere and Environment Observation and Research Station of Tibet Autonomous Region Lanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China

Glacier mass balance is a key indicator of glacier health and climate change *** factors include both climatic and nonclimatic elements,forming a complex set of *** is a lack of quantitative analysis of these composite factors,particularly in climate-typical regions like the Tanggula Mountains on the central Tibetan *** collected data on various factors affecting glacier mass balance from 2000 to 2020,including climate variables,topographic variables,geometric parameters,and glacier *** utilized linear regression models,ensemble learning models,and Open Global Glacier Model(OGGM)to analyze glacier mass balance changes in the Tanggula *** indicate that linear models explain 58%of the variance in glacier mass balance,with seasonal temperature and precipitation having significant *** findings show that ensemble learning models made the explanations 5.2%more accurate by including the impact of topographic and geometric factors such as the average glacier height,the slope of the glacier tongue,the speed of the ice flow,and the area of the *** machine learning identified the spatial distribution of positive and negative impacts of these characteristics and the interaction between glacier topography and ice ***,we predicted the responses of glaciers of different sizes to future climate change based on the results of interpretable machine *** was found that relatively large glaciers(>1 km~2)are likely to persist until the end of this century under low emission scenarios,whereas small glaciers(<1 km~2)are expected to nearly disappear by 2080 under any emission *** research provides technical support for improving glacier change modeling and protection on the Tibetan Plateau.

关键词： Glacier mass balance Tanggula Mountains Explainable Machine Learning Open Global Glacier Model Climate change

Profiles,exposure assessment and expanded screening of PAHs and their derivatives in one petroleum refinery facility of China

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Journal of Environmental Sciences 2025年第1期147卷 550-560页

作者： Ning Wang Fengjiao Jiang Lin xu Yaqi Cai School of Municipal and Environmental Engineering Shandong Jianzhu UniversityJinan 250101China Resource and Environmental Innovation Institute Shandong Jianzhu UniversityJinan 250101China State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China School of Environment Hangzhou Institute for Advanced StudyUCASHangzhou 330106China Hubei Key Laboratory of Environmental and Health Effects of Persistence Toxic Substances Institute of Environment and HealthJianghan UniversityWuhan 430056China

This study investigated environmental distribution and human exposure of polycyclic aromatic hydrocarbons(PAHs)and their derivatives in one Chinese petroleum refinery *** was found that,following with high concentrations of 16 EPA PAHs(∑Parent-PAHs)in smelting subarea of studied petroleum refinery facility,total derivatives of PAHs[named as XPAHs,including nitro PAHs(NPAHs),chlorinated PAHs(Cl-PAHs),and brominated PAHs(Br-PAHs)]in gas(mean=1.57×10^(4)ng/m^(3)),total suspended particulate(TSP)(mean=4.33×10^(3) ng/m^(3))and soil(mean=4.37×10^(3) ng/g)in this subarea had 1.76-6.19 times higher levels than those from other subareas of this facility,surrounding residential areas and reference areas,indicating that petroleum refining processes would lead apparent derivation of ***,compared with those in residential and reference areas,gas samples in the petrochemical areas had higher∑NPAH/∑PAHs(mean=2.18),but lower∑Cl-PAH/∑PAHs(mean=1.43×10^(-1))and∑Br-PAH/∑PAHs ratios(mean=7.49×10^(-2)),indicating the richer nitrification of PAHs than chlorination during petrochemical *** occupational exposure to PAHs and XPAHs in this petroleum refinery facility were 24-343 times higher than non-occupational exposure,and the ILCR(1.04×10^(-4))for petrochemical workers was considered to be potential high ***,one expanded high-resolution screening through GC Orbitrap/MS was performed for soils from petrochemical area,and another 35 PAHs were found,including alkyl-PAHs,phenyl-PAHs and other species,indicat-ing that profiles and risks of PAHs analogs in petrochemical areas deserve further expanded investigation.

关键词： Polycyclic aromatic hydrocarbons(PAHs) Derivatives Petroleum refinery Human exposure Non-targeted screening

Construction of attapulgite-based one-dimensional nanonetwork composites with corrosion resistance for high-efficiency microwave absorption

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International Journal of Minerals,Metallurgy and Materials 2025年第3期32卷 689-698页

作者： Kai xu Qingqing Gao Shaoqi Shi Pei Liu Yinxu Ni Zhilei Hao Gaojie xu Yan Fu Fenghua Liu School of Materials Science and Chemical Engineering Ningbo UniversityNingbo 315211China Zhejiang Key Laboratory of Additive Manufacturing Materials Ningbo Institute of Materials Technology&EngineeringChinese Academy of SciencesNingbo 315201China Northwest Yongxin Coatings Limited Company Lanzhou 730046China

Exploring high-efficiency and broadband microwave absorption(MA)materials with corrosion resistance and low cost is ur-gently needed for wide practical ***,the natural porous attapulgite(ATP)nanorods embedded with TiO_(2)and polyaniline(PANI)nanoparticles are synthesized via heterogeneous precipitation and in-situ *** obtained PANI-TiO_(2)-ATP one-di-mensional(1D)nanostructures can intertwine into three-dimensional(3D)conductive network,which favors energy *** min-imum reflection loss(RL_(min))of the PANI-TiO_(2)-ATP coating(20wt%)reaches-49.36 dB at 9.53 GHz,and the effective absorption band-width(EAB)can reach 6.53 GHz with a thickness of 2.1 *** excellent MA properties are attributed to interfacial polarization,mul-tiple loss mechanisms,and good impedance matching induced by the synergistic effect of PANI-TiO_(2)nanoparticle shells and ATP *** addition,salt spray and Tafel polarization curve tests reveal that the PANI-TiO_(2)-ATP coating shows outstanding corrosion resist-ance *** study provides a low-cost and high-efficiency strategy for constructing 1D nanonetwork composites for MA and corrosion resistance applications using natural porous ATP nanorods as carriers.

关键词： microwave absorption corrosion resistance attapulgite TiO_(2) polyaniline

Organic solvent nanofiltration membranes for separation in non-polar solvent system

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Green Energy & Environment 2025年第2期10卷 244-267页

作者： Shuyun Gu Siyao Li Zhi xu State Key Laboratory of Chemical Engineering School of Chemical EngineeringEast China University of Science and Technology130 Meilong RoadShanghai200237China

Membrane technology holds significant potential for augmenting or partially substituting conventional separation techniques,such as heatdriven distillation,thereby reducing energy *** solvent nanofiltration represents an advanced membrane separation technology capable of discerning molecules within a molecular weight range of approximately 100-1000 Da in organic solvents,offering low energy requirements and minimal carbon *** separation in non-polar solvent system,such as toluene,n-hexane,and n-heptane,has gained paramount importance due to their extensive use in the pharmaceutical,biochemical,and petrochemical *** this review,we presented recent advancements in membrane materials,membrane fabrication techniques and their promising applications for separation in nonpolar solvent system,encompassing hydrocarbon separation,bioactive molecule purification and organic solvent ***,this review highlighted the challenges and opportunities associated with membrane scale-up strategies and the direct translation of this promising technology into industrial applications.

关键词： Organic solvent nanofiltration Membranes Membrane separation Non-polar solvent system Petrochemical and pharmaceutical application

Permutation orbifolds of vertex operator superalgebras and associative algebras

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Science China Mathematics 2025年第1期68卷 19-38页

作者： Chongying Dong Feng xu Nina Yu Department of Mathematics University of California at Santa CruzSanta CruzCA 95064USA Department of Mathematics Huzhou UniversityHuzhou 313000 China Department of Mathematics University of California at RiversideRiversideCA 92521USA School of Mathematical Sciences Xiamen UniversityXiamen 361005China

Let V be a vertex operator superalgebra and g=(12···k)be a k-cycle which is viewed as an automorphism of the tensor product vertex operator superalgebra V^(■k).In this paper,we construct an explicit isomorphism from A_(g)(V^(■k))to A(V)if k is odd and to Aσ(V)if k is even whereσis the canonical automorphism of V of order 2 determined by the superspace structure of *** recover previous results by Barron(2016)and Barron and Vander Werf(2014)that there is a one-to-one correspondence between irreducible g-twisted V^(■k)-modules and irreducible V-modules(***σ-twisted V-modules)when k is odd(***).This explicit isomorphism is expected to be useful in our further study on the Zhu algebra of the fixed point subalgebra.

关键词： permutation orbifold vertex operator superalgebra Zhu algebra

A polynomial resultant approach to algebraic constructions of extremal graphs

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Science China Mathematics 2025年第2期68卷 485-506页

作者： Tao Zhang Zixiang xu Gennian Ge Institute of Mathematics and Interdisciplinary Sciences Xidian UniversityXi’an 710071China School of Mathematical Sciences Capital Normal UniversityBeijing 100048China

The Turán problem asks for the largest number of edges ex(n,H)in an n-vertex graph not containing a fixed forbidden subgraph H,which is one of the most important problems in extremal graph ***,the order of magnitude of ex(n,H)for bipartite graphs is known only in a handful of *** particular,giving explicit constructions of extremal graphs is very challenging in this *** this paper,we develop a polynomial resultant approach to the algebraic construction of explicit extremal graphs,which can efficiently decide whether a specified structure exists.A key insight in our approach is the multipolynomial resultant,which is a fundamental tool of computational algebraic *** main results include the matched lower bounds on the Turán number of 1-subdivision of K3,t1and the linear Turán number of the Berge theta hypergraph■_(3,t_(2))^(B).where t_(1)=25 and t_(2)=***,the constant t1improves the random algebraic construction of Bukh and Conlon(2018)and makes the known estimation better on the smallest value of t1concerning a problem posed by Conlon et al.(2021)by reducing the value from a magnitude of 10^(56)to the number 25,while the constant t_(2)improves a result of He and Tait(2019).

关键词： Turan number resultant algebraic construction subdivision Berge theta hypergraph

Quantile-based optimization under uncertainties for complex engineering structures using an active learning basis-adaptive PC-Kriging model

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Chinese Journal of Aeronautics 2025年第1期38卷 340-352页

作者： Yulian GONG Jianguo ZHANG Dan xu Ying HUANG School of Reliability and Systems Engineering Beihang UniversityBeijing 100191China

The Reliability-Based Design Optimization(RBDO)of complex engineering structures considering uncertainties has problems of being high-dimensional,highly nonlinear,and timeconsuming,which requires a significant amount of sampling simulation *** this paper,a basis-adaptive Polynomial Chaos(PC)-Kriging surrogate model is proposed,in order to relieve the computational burden and enhance the predictive accuracy of a *** active learning basis-adaptive PC-Kriging model is combined with a quantile-based RBDO ***,five engineering cases have been implemented,including a benchmark RBDO problem,three high-dimensional explicit problems,and a high-dimensional implicit *** with Support Vector Regression(SVR),Kriging,and polynomial chaos expansion models,results show that the proposed basis-adaptive PC-Kriging model is more accurate and efficient for RBDO problems of complex engineering structures.

关键词： Reliability-based design optimization Quantile-based Basis-adaptive PC-Kriging Complex engineering structures Active learning Uncertainty