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Seasonal Variation of the Sea Surface Temperature Growth Rate of ENSO

Advances in Atmospheric Sciences 2024年第3期41卷 465-477页

作者： Xinyi XING Xianghui FANG Da PANG Chaopeng ji Department of Atmospheric and Oceanic Sciences and Institute of Atmospheric Sciences Fudan UniversityShanghai 200438China Shanghai Frontiers Science Center of Atmosphere-Ocean Interaction Shanghai 200438China Shanghai Key Laboratory of Ocean-land-atmosphere Boundary Dynamics and Climate Change Fudan UniversityShanghai 200438China

El Ni?o–Southern Oscillation(ENSO) exhibits a distinctive phase-locking characteristic, first expressed during its onset in boreal spring, developing during summer and autumn, reaching its peak towards winter, and decaying over the next spring. Several studies have demonstrated that this feature arises as a result of seasonal variation in the growth rate of ENSO as expressed by the sea surface temperature(SST). The bias towards simulating the phase locking of ENSO by many state-of-the-art climate models is also attributed to the unrealistic depiction of the growth rate. In this study, the seasonal variation of SST growth rate in the Ni?o-3.4 region(5°S–5°N, 120°–170°W) is estimated in detail based on the mixed layer heat budget equation and recharge oscillator model during 1981–2020. It is suggested that the consideration of a variable mixed layer depth is essential to its diagnostic process. The estimated growth rate has a remarkable seasonal cycle with minimum rates occurring in spring and maximum rates evident in autumn. More specifically, the growth rate derived from the meridional advection(surface heat flux) is positive(negative) throughout the year. Vertical diffusion generally makes a negative contribution to the evolution of growth rate and the magnitude of vertical entrainment represents the smallest contributor. Analysis indicates that the zonal advective feedback is regulated by the meridional immigration of the intertropical convergence zone, which approaches its southernmost extent in February and progresses to its northernmost location in September, and dominates the seasonal variation of the SST growth rate.

关键词： SST growth rate intertropical convergence zone zonal advective feedback mixed layer depth ENSO seasonal variation

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Catalytically generated noncovalent ammonium dienolate:a versatile platform for the development of organocatalytic asymmetric cascade reactions

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Science China Chemistry 2024年第8期67卷 2524-2546页

作者： Jun-Bing Lin Dong-Sheng ji Peng-Fei Xu State Key Laboratory of Applied Organic Chemistry College of Chemistry and Chemical EngineeringLanzhou UniversityLanzhou 730000China Shaanxi Key Laboratory of Chemical Reaction Engineering College of Chemistry and Chemical EngineeringYan’an UniversityYan’an 716000China

Organocatalytic cascade reactions represent a powerful strategy for the rapid construction of complex chiral molecules with multiple stereocenters from simple substrates under mild conditions. The intriguing structural feature and diverse reactivity of catalytically generated dienolate species render them competent and versatile intermediates for the development of practical and valuable cascade reactions. Over the past years, a plethora of innovative and pioneering noncovalent ammonium dienolatemediated cascade reactions have been designed and implemented under the catalysis of chiral organocatalysts, making dienolate activation a general, robust, and complementary method for the functionalization of unsaturated carbonyl compounds and related substances. This review illustrates the recent advances in organocatalytic noncovalent ammonium dienolate-mediated cascade reactions(mainly from 2010 to 2023), including the cascade transformations of ammonium dienolates directly generated from unsaturated ketone/aldehyde, ester/lactone/azlactone, amide/lactam/pyrazolone/oxindole, and alkylidene nitrile compounds. The contents are arranged based on the reaction types of the ammonium dienolates, with an emphasis on cascade 2,5-, 3,5-, and 4,5-difunctionalizations of these intermediates. Furthermore, other cascade reactions involving the 1,3-, 2,3-, and even more complex 3,4,5-reactivities of ammonium dienolates were also discussed. The reaction pathway, reaction stereoinduction, and synthetic applications of the ammonium dienolate-mediated cascade reactions were highlighted throughout the article. As a stimulating and ever-growing research area, the organocatalytic noncovalent ammonium dienolate-mediated cascade reactions are expected to continue demonstrating their magic power for constructing chiral targets in the future and further expanding the boundaries of asymmetric catalysis.

关键词： organocatalysis asymmetric catalysis ammonium dienolate cascade reaction difunctionalization

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Nuclearity and Finite-Representability in the System of Completely Integral Mapping Spaces

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Acta Mathematica Sinica,English Series 2024年第5期40卷 1197-1214页

作者： Zhe DONG ji Cheng TAO Ya Fei ZHAO Department of Mathematics Zhejiang UniversityHangzhou 310027P.R.China Department of Mathematics China Jiliang UniversityHangzhou 310018P.R.China Department of Mathematics Zhejiang International Studies UniversityHangzhou 310023P.R.China

In this paper,we investigate local properties in the system of completely integral mapping *** introduce notions of injectivity,local reflexivity,exactness,nuclearity,finite-represent ability and WEP in the system of completely integral mapping *** we obtain that any finite-dimensional operator space is injective in the system of completely integral mapping *** we prove that C is the unique nuclear operator space and the unique exact operator space in this *** also show that C is the unique operator space which is finitely representable in{T_(n)}n∈Nin this *** corollaries,Kirchberg’s conjecture and QWEP conjecture in the system of completely integral mapping spaces are false.

关键词： Completely integral mapping space injectivity exactness nuclearity finite-representability WEP

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Event-triggered adaptive output feedback control for hyperbolic PDEs: swapping-based design

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Science China(Information Sciences) 2024年第5期67卷 327-328页

作者： Chunting ji Zhengqiang ZHANG Xue-Jun XIE School of Engineering Qufu Normal University Institute of Automation Qufu Normal University

Partial differential equations(PDEs) characterize transport phenomena and fluid flow, and common cases include heat exchangers and road traffic [1]. Recently, scholars have become enthusiastic about event-triggered control(ETC) of hyperbolic PDEs, primarily because it can help conserve computing and communication resources. For example,Ref. [2] presented an output feedback ETC scheme for 2 × 2hyperbolic PDEs.

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Sedimentary and Heavy Mineral Records for the Oligocene-Miocene Exhumation of the Easternmost Tianshan

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Journal of Earth Science 2024年第2期35卷 449-461页

作者： Yan Ding Tianyi Shen Guocan Wang Junliang ji School of Earth Sciences Center for Global TectonicsChina University of GeosciencesWuhan430074China State Key Laboratory of Geological Processes and Mineral Resources China University of GeosciencesWuhan430078China Hubei Key Laboratory of Critical Zone Evolution School of Geography and Information EngineeringChina University of GeosciencesWuhan430074China

The topography of the Harlik Mountain has a strong impact on the formation of current arid climate in the Turpan-Hami ***,it is still controversial if Harlik Mountain experienced significant exhumation during the Middle to Late Cenozoic according to the previous thermochronology *** features of the Oligocene to Miocene sediments in the foreland basin could provide productive information for resolving the *** peak ages of detrital apatite fission track analysis of the Oligocene–Miocene sandstone in the Turpan-Hami Basin are well comparable with the cooling age records of the Harlik Mountain rocks,indicating that the Oligocene–Miocene Taoshuyuanzi Formation in the basin was mostly derived from the Harlik *** stratigraphic sequence exhibits coarsening upward,reflecting that the source area was in a tectonically active period during the deposition *** mineral assemblages also suggest that the unstable minerals in the sediment increased significantly at the end of the ***,the proportion of apatite increased up-section,while the garnet content decreased significantly,indicating that the Carboniferous metamorphic rocks have been gradually eroded out and more intrusive rocks have been exposed to the *** observations suggest that the Harlik Mountain experienced exhumation during the Oligocene to Miocene,and the denudation depth afterward was probably less than 2.5 km according to the previously apatite(U-Th)/He *** Oligocene–Miocene exhumation probably acted as one of the triggers for the heavy drought of the Turpan-Hami Basin during the Middle–Late Neogene.

关键词： Turpan-Hami Basin Harlik Mountain Taoshuyuanzi Formation Oligocene–Miocene uplift sedimentology structural geology

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Cyclic Beam Direction of Arrival Estimation Method for Ship Propeller Noise

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Journal of Ocean University of China 2024年第4期23卷 883-896页

作者： ZHANG Xiaowei NIE Weihang XU ji YAN Yonghong The Key Laboratory of Speech Acoustics and Content Understanding Institute of AcousticsChinese Academy of SciencesBeijing 100190China The Key Laboratory of Speech Acoustics and Content Understanding Institute of AcousticsUniversity of Chinese Academy of SciencesBeijing 100049China The State Key Laboratory of Acoustics Institute of AcousticsChinese Academy of SciencesBeijing 100190China

In underwater acoustic applications,the conventional cyclic direction of arrival algorithm faces challenges,including a low signal-to-noise ratio and high bandwidth when compared with modulated *** response to these issues,this paper introduces a novel,robust,and broadband cyclic beamforming *** proposed method substitutes the conventional cyclic covariance matrix with the variance of the cyclic covariance matrix as its primary *** that the same frequency band shares a common steering vector,the new algorithm achieves superior detection performance for targets with specific modulation frequencies while suppressing interference signals and background *** results demonstrate a significant enhancement in the directibity index by 81%and 181%when compared with the traditional Capon beamforming algorithm and the traditional extended wideband spectral cyclic MUSIC(EWSCM)algorithm,***,the proposed algorithm substantially reduces computational complexity to 1/40th of that of the EWSCM algorithm,employing frequency band statistical averaging and covariance matrix variance.

关键词： cyclostationarity direction of arrival extended wideband spectral cyclic music cyclic covariance matrix

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Regulating Anderson localization with structural defect disorder

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Chinese Physics B 2024年第10期33卷 102-107页

作者： Mouyang Cheng Haoxiang Chen ji Chen School of Physics Peking UniversityBeijing 100871China Interdisciplinary Institute of Light-Element Quantum Materials and Research Center for Light-Element Advanced Materials Peking UniversityBeijing 100871China Frontiers Science Center for Nano-Optoelectronics Peking UniversityBeijing 100871China Collaborative Innovation Center of Quantum Matter Beijing 100871China

Localization due to disorder has been one of the most intriguing theoretical concepts that evolved in condensed matter ***,we expand the theory of localization by considering two types of disorders at the same time,namely,the original Anderson’s disorder and the structural defect disorder,which has been suggested to be a key component in recently discovered two-dimensional amorphous *** increasing the degree of both disorders could induce localization of wavefunction in real space,we find that a small degree of structural defect disorder can significantly enhance the *** the degree of structural defect disorder increases,localized states quickly appear within the extended phase to enter a broad crossover region with mixed *** establish two-dimensional diagrams for the wavefunction localization and conductivity to highlight the interplay between the two types of *** theoretical model provides a comprehensive understanding of localization in two-dimensional amorphous materials and highlights the promising tunability of their transport properties.

关键词： Anderson localization structural defect disorder electronic transport properties

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Controlled Synthesis of Metal-Nanoparticles Decorated Block Copolymer Hybrid Particles via Emulsion Confined Self-assembly and Their Catalytic Applications

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Chinese Journal of Chemistry 2024年第8期42卷 835-840页

作者： Xiaohua Chang Qunli Yu Dan ji Yutian Zhu College of Material Chemistry and Chemical EngineeringKey Laboratory of Organosilicon Chemistry and Material TechnologyMinistry of EducationHangzhou Normal UniversityHangzhouZhejiang311121 China

Comprehensive Summary Metal nanoparticles(NPs)decorated block copolymer(BCP)hybrid nanoparticles have attracted enormous attention for their actual value in catalysis,medical therapy,and *** confined assembly of BCPs within evaporative emulsion droplet is verified as an effective method to provide polymeric scaffolds to load metal ***,to date,it remains challenging to generate different types of metal NPs decorated BCP hybrid ***,we employed the emulsion confined self-assembly of poly(styrene-b-2-vinylpyridine)(PS-b-P2VP)and the followed seed-mediated growth of Au and palladium(Pd)NPs onto well-defined BCP particles to design a series of Au/Pd decorated BCP hybrid nanoparticles,which exhibited excellent catalytic activity for the reduction of 4-nitrophenol to 4-aminophenol with the reductant of *** work may inspire more researchers to investigate the selective decoration of different metal NPs onto the polymeric scaffolds,broadening the potential applications of the inorganic/organic hybrid nanoparticles.

关键词： Block copolymers Emulsion confined self-assembly Hybrid nanoparticles Catalytic activity Recyclability

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Reduced-order modeling and vibration transfer analysis of a fluid-delivering branch pipeline that consider fluid–solid interactions

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Frontiers of Mechanical Engineering 2024年第2期19卷 75-97页

作者： Wenhao ji Hongwei MA Wei SUN Yinhang CAO School of Mechanical Engineering and Automation Northeastern UniversityShenyang 110819China Key Laboratory of Vibration and Control of Aero-Propulsion Systems(Ministry of Education) Northeastern UniversityShenyang 110819China College of Power and Energy Engineering Harbin Engineering UniversityHarbin 150001China

The efficient dynamic modeling and vibration transfer analysis of a fluid-delivering branch pipeline(FDBP)are essential for analyzing vibration coupling effects and implementing vibration reduction ***,this study proposes a reduced-order dynamic modeling method suitable for FDBPs and then analyzes the vibration transfer *** the modeling method,the finite element method and absorbing transfer matrix method(ATMM)are integrated,considering the fluid–structure coupling effect and fluid *** dual-domain dynamic substructure method is developed to perform the reduced-order modeling of FDBP,and ATMM is adopted to reduce the matrix order when solving fluid ***,the modeling method is validated by experiments on an H-shaped branch ***,transient and steady-state vibration transfer analyses of FDBP are performed,and the effects of branch locations on natural characteristics and vibration transfer behavior are *** show that transient vibration transfer represents the transfer and conversion of the kinematic,strain,and damping energies,while steady-state vibration transfer characteristics are related to the vibration *** addition,multiple-order mode exchanges are triggered when branch locations vary in frequency-shift regions,and the mode-exchange regions are also the transformation ones for vibration transfer patterns.

关键词： fluid-delivering branch pipeline vibration transfer analysis reduced-order modeling fluid-solid interactions finite element method absorbing transfer matrix method

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Benchmarking visual SLAM methods in mirror environments

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Computational Visual Media 2024年第2期10卷 215-241页

作者： Peter Herbert jing Wu Ze ji Yu-Kun Lai School of Computer Science and Informatics Cardiff UniversityAbacws BuildingSenghennydd RdCardiff CF244AGUK School of Engineering Cardiff UniversityQueen’s BuildingsThe ParadeCardiff CF243AAUK

Visual simultaneous localisation and mapping(vSLAM)finds applications for indoor and outdoor navigation that routinely subjects it to visual complexities,particularly mirror *** effect of mirror presence(time visible and its average size in the frame)was hypothesised to impact localisation and mapping performance,with systems using direct techniques expected to perform ***,a dataset,MirrEnv,of image sequences recorded in mirror environments,was collected,and used to evaluate the performance of existing representative *** ORB-SLAM3 and BundleFusion appear to show moderate degradation of absolute trajectory error with increasing mirror duration,whilst the remaining results did not show significantly degraded localisation *** mesh maps generated proved to be very inaccurate,with real and virtual reflections colliding in the reconstructions.A discussion is given of the likely sources of error and robustness in mirror environments,outlining future directions for validating and improving vSLAM performance in the presence of planar *** MirrEnv dataset is available at https://***/10.17035/d.2023.0292477898.

关键词： visual simultaneous localisation and mapping(vSLAM) mirror localisation mapping reflection datase

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