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Divergent responses of runoff to climate change in the upper basins of the Third Pole dominated by westerlies and monsoon

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Science China Earth Sciences 2024年第8期67卷 2592-2614页

作者： Qikai suN Fengge su He suN State Key Laboratory of Tibetan Plateau Earth System Environment and Resources(TPESER)Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100101China

The diverse climates,distribution of snow and glaciers,and geographic locations directly affect the runoff response to climate change in the upper basins of the Third *** present,a comprehensive analysis of runoff variations and their distinct responses to climate change in the westerlies-and monsoon-dominated upper basins is still *** study comprehensively analyzed annual runoff variations in westerlies-dominated basins(the upper basins of the Aksu(UAKS),Syr Darya(USRD),Yarkant(UYK),Hotan(UHT),Amu Darya(UAMD),and Indus(UI))and monsoon-dominated basins(the upper basins of the Yangtze(UYA),Yellow(UYE),Lancang(ULC),Nujiang(UNJ),and Yarlung Zangbo(UYZ))of the Third Pole from 1961 *** multi-source meteorological data and large-scale circulation factors,this study investigated the divergent responses of runoff in the upper basins to climate change,and explored the large-scale circulation mechanisms underlying runoff variations in these upper *** results showed that:(1)The annual runoff in the majority of upper basins(except for the UYE and UYZ)exhibited an increasing trend,and the annual runoff in the UAKS,UYK,and UI showed a significant increasing trend from1961 to *** annual runoff in the upper basins of the Third Pole changed abruptly from decreasing to increasing between the 1980s and 2000s,with the exception of the UYE.(2)The runoff in the monsoon-dominated upper basins has been controlled primarily by changes in precipitation over the past 55 *** contrast,the runoff in the westerlies-dominated upper basins exhibited three distinct long-term responses to climate change:temperature-dominated(UYK and UHT),precipitation-dominated(USRD and UAMD),and the combined influence of precipitation and temperature(UAKS and UI).Since the 1960s,the sensitivity of runoff to warm season temperature changes in the most westerlies-dominated upper basins has decreased,while the response of runoff to precipitation changes has intensified.(3)The stud

关键词： Upper basins of the Third Pole Climate change Westerlies and monsoon Runoff variations Large-scale circulation factors

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An improved bound on accelerated light dark matter

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Science China(Physics,Mechanics & Astronomy) 2024年第2期67卷 105-118页

作者： Liangliang su Lei Wu Bin Zhu Department of Physics and Institute of Theoretical Physics Nanjing Normal UniversityNanjing 210023China School of Physics Yantai UniversityYantai 264005China

Light(sub-GeV)dark matter has gained increasing interest in terms of direct *** dark matter is a promising candidate that can generate detectable nuclear recoil energy within the sub-GeV *** of the large kinetic energy,its interactions with the nucleus are predominantly governed by inelastic scattering,including quasi-elastic and deep inelastic *** this work,we calculated the inelastic effects in dark matter-Earth scattering mediated by a vector *** analysis revealed that the impact of inelastic scattering relies on the mediator mass and the kinetic energy spectrum of dark *** results exhibited considerable disparity:the upper bounds of the exclusion limit for the spin-independent cross-section between accelerated dark matter and nuclei via a heavy mediator differ by several tens of times when inelastic scattering is considered.

关键词： accelerated dark matter inelastic scattering direct detection experiment

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Multiscale observation in wide-spatial radar surveillance based on coherent FDA design

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Science China(Information Sciences) 2024年第2期67卷 232-252页

作者： Lei YU Feng HE Yi su College of Electronics Science National University of Defense Technology

Wide-spatial radar surveillance missions are challenging tasks, requiring an increased power budget and agility in transmission aimed at extracting information from multiple targets in different environments. These requirements necessitate high transmitting degrees of freedom(DOF) to achieve the objective of multiscale observation for specific tasks in specialized regions of interest. Herein, we exploit the multiscale observation ability in wide-spatial radar surveillance based on frequency diverse array(FDA)radar. The proposed method facilitates spatial anisotropic control of multiple radar resources, including the transmitting waveforms, beampattern, and bandwidth. By utilizing a coherent FDA radar, we offer principles for the selection of baseband waveforms, in addition to the quantitative design of the beampattern gain and optimal bandwidth from the perspective of detection. The feasibility of the proposed method is validated through numerical experiments, thus indicating the potential in wide-spatial radar surveillance. Moreover,this work can be regarded as a preliminary attempt to gauge the efficacy of the computational array, a novel academic concept.

关键词： multi-scale observation wide-spatial surveillance frequency diverse array (FDA) beampattern synthesis frequency diversity gain computational array

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Multiresponsive,easy-reversible,and dual-visual Pt(Ⅱ)salt nanostructures for advanced anti-counterfeiting application

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Nano Research 2024年第1期17卷 372-381页

作者： Zhen su§ Depeng Li§ Lixin Zhang Si Tian Yuhong su Xiaoyun Hu Duan Xiong Qingqing Guan Key Laboratory of Oil and Gas Fine Chemicals Ministry of Education College of Chemical EngineeringXinjiang UniversityUrumqi 830017China

Smart materials that integrate multi-stimuli response,full reversibility,and dual-visual read-out channel are highly desired for anticounterfeiting and information encryption ***,we developed a multiresponsive perchlorate terpyridyl Pt(Ⅱ)nano complex which could undergo fully reversible conversion between three forms stimulated by water or formaldehyde molecule due to the extent of Pt–Pt ***,a dual-visual channel,i.e.,the colorimetric channel changed from yellow to orange or red and the corresponding luminescent channel from orange to orange-red or red,has also been *** weak and equivalent strength of ion-dipole interaction and hydrogen bond that generated between formaldehyde/water and Pt(II)salt result in the easy-control reversibility between the three ***,by introducing different polymer matrices,1Cl·ClO_(4)@PMMA(1Cl·ClO_(4):[Pt(tpy)Cl]·ClO4,tpy:2,2':6',2''-terpyridine),PMMA:poly(methyl methacrylate))and 1Cl·ClO4@PVA(PVA:polyvinyl alcohol)are successfully constructed,which exhibit different reversible behaviors since the PMMA and PVA matrix exert different influences on the strength of *** smart Pt(II)salt nanostructures present great potential for high-security-level anticounterfeiting application.

关键词： Pt(II)complex multiresponse reversibility anticounterfeiting information encryption

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A Geometric Based Connection between Fractional Calculus and Fractal Functions

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Acta Mathematica Sinica,English Series 2024年第2期40卷 537-567页

作者： Yong Shun LIANG Wei Yi su School of Mathematics and Statistic Nanjing University of Science and TechnologyNanjing 210094P.R.China Department of Mathematics Nanjing UniversityNanjing 210023P.R.China

Establishing the accurate relationship between fractional calculus and fractals is an important research content of fractional calculus *** the present paper,we investigate the relationship between fractional calculus and fractal functions,based only on fractal dimension *** dimension of the Riemann-Liouville fractional integral of continuous functions seems no more than fractal dimension of functions *** fractal dimension of the Riemann-Liouville fractional differential of continuous functions seems no less than fractal dimension of functions themselves when they *** further discussion,fractal dimension of the Riemann-Liouville fractional integral is at least linearly decreasing and fractal dimension of the Riemann-Liouville fractional differential is at most linearly increasing for the Holder continuous *** about other fractional calculus,such as the Weyl-Marchaud fractional derivative and the Weyl fractional integral has also been given *** work is helpful to reveal the mechanism of fractional calculus on continuous *** the same time,it provides some theoretical basis for the rationality of the definition of fractional *** is also helpful to reveal and explain the internal relationship between fractional calculus and fractals from the perspective of geometry.

关键词： Fractional calculus fractal functions fractal dimension fractional calculus equation relationship

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A microphysical investigation of different convective cells during the precipitation event with sustained high-resolution observations

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Frontiers of Earth Science 2024年第2期18卷 279-295页

作者： Ziheng HUANG Zheng RUAN Debin su State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesBeijing 100081China College of Electronic Engineering Chengdu University of Information TechnologyChengdu 610225China Key Laboratory of Atmospheric Sounding China Meteorological AdministrationChengdu 610225China

The growth and breakup processes of raindrops within a cloud influence the rain intensity and the sizes of raindrops on the *** Doppler velocity spectrum acquired by a vertically pointing radar(VPR)contains information on atmospheric turbulence and the size classification of falling *** this study,the four types of Convective Cells(CC)during precipitation events with more than 700 mm of precipitation in southern China are *** characteristics of four types of CCs correspond to the isolated convection,the early stage,the mature stage,and the decline stage of organizational convection,in that *** analysis using retrieval of vertical air motion(Vair)and raindrop evolution in clouds from Doppler velocity spectra collected by C-band VPR revealed the growth and breakup of falling raindrops with dynamic *** raindrops appear in the early stages and are accompanied by ice particles,which are impacted by the falling path᾽s *** aggregation,which is primarily related to the alternation of updraft and downdraft,accounts for the mature stage᾽s high efficiency of surface *** CCs in the decline stage originate from the shallow uplift in the weak and broad downdraft under conditions of enough water *** updraft dominates the stage of isolated *** of convective cells could be more accurately represented in model evaluations.

关键词： cloud microphysics convective systems convective cell vertically pointing radar observations Doppler velocity spectrum

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Spatio-temporal Evolution Characteristics and Driving Forces of Winter Urban Heat Island:A Case Study of Rapid Urbanization Area of Fuzhou City,China

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Chinese Geographical Science 2024年第1期34卷 135-148页

作者： WANG Zili LU Chunyan su Yanlin su Yue YU Qianru LI Wenzhe YANG Nuocheng College of Computer and Information Sciences Fujian Agriculture and Forestry UniversityFuzhou350002China Key Laboratory of Smart Agriculture and Forestry(Fujian Agriculture and Forestry University) Fujian Province UniversityFuzhou350002China College of Forestry Fujian Agriculture and Forestry UniversityFuzhou350002China

Under the influence of anthropogenic and climate change,the problems caused by urban heat island(UHI)has become increasingly *** order to promote urban sustainable development and improve the quality of human settlements,it is significant for exploring the evolution characteristics of urban thermal environment and analyzing its driving *** the Landsat series images as the basic data sources,the winter land surface temperature(LST)of the rapid urbanization area of Fuzhou City in China was quantitatively retrieved from 2001 to *** comprehensively the standard deviation ellipse model,profile analysis and GeoDetector model,the spatio-temporal evolution characteristics and influencing factors of the winter urban thermal environment were systematically *** results showed that the winter LST presented an increasing trend in the study area during 2001–2021,and the winter LST of the central urban regions was significantly higher than the *** was a strong UHI effect from 2001 to 2021with an expansion trend from the central urban regions to the suburbs and coastal areas in space *** LST of green lands and wetlands are significantly lower than croplands,artificial surface and unvegetated *** and water bodies had a significant mitigation effect on UHI,especially in the *** winter UHI had been jointly driven by the underlying surface and socio-economic factors in a nonlinear or two-factor interactive enhancement mode,and socio-economic factors had played a leading *** research could provide data support and decision-making references for rationally planning urban layout and promoting sustainable urban development.

关键词： winter urban heat island(UHI) rapid urbanization area land surface temperature(LST)retrieval profile analysis GeoDetector model Fuzhou City,China

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Performance evaluation for multi-target tracking with temporal dimension specifics

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Chinese Journal of Aeronautics 2024年第2期37卷 446-458页

作者： Zhenzhen su Hongbing JI Cong TIAN Yongquan ZHANG School of Computer Science and Technology Xidian UniversityXi’an 710071China School of Electronic Engineering Xidian UniversityXi’an 710071China

With the great development of Multi-Target Tracking(MTT)technologies,many MTT algorithms have been proposed with their own advantages and *** to the fact that requirements to MTT algorithms vary from the application scenarios,performance evaluation is significant to select an appropriate MTT algorithm for the specific application *** this paper,we propose a performance evaluation method on the sets of trajectories with temporal dimension specifics to compare the estimated trajectories with the true *** proposed method evaluates the estimate results of an MTT algorithm in terms of tracking accuracy,continuity and ***,its computation is based on a multi-dimensional assignment problem,which is formulated as a computable form using linear *** enhance the influence of recent estimated states of the trajectories in the evaluation,an attention function is used to reweight the trajectory errors at different time ***,simulation results show that the proposed performance evaluation method is able to evaluate many aspects of the MTT *** evaluations are worthy for selecting suitable MTT algorithms in different application scenarios.

关键词： Multi-target tracking Temporal dimension specifics Performance evaluation Random finite sets Linear programming

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Role of catalyst surface-active sites in the hydrogenation ofα,β-unsaturated aldehyde

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Frontiers of Chemical Science and Engineering 2024年第6期18卷 41-69页

作者： Haixiang Shi Tongming su Zuzeng Qin Hongbing Ji School of Chemistry and Chemical Engineering Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification TechnologyGuangxi UniversityNanning 530004China Zhejiang Green Petrochemical and Light Hydrocarbon Transformation Research Institute Zhejiang University of TechnologyHangzhou 310014China

As an important technology in fine chemical production,the selective hydrogenation ofα,β-unsaturated aldehydes has attracted much attention in recent *** the process ofα,β-unsaturated aldehyde hydrogenation,a conjugated system is formed between>C=CC=O,leading to hydrogenation at both ends of the conjugated system,which competes with each other and results in more complex ***,improving the reaction selectivity is also difficult in industrial ***,many researchers have reported that surface-active sites on catalysts play a crucial role inα,β-unsaturated aldehyde *** review attempts to summarize recent advances in understanding the effects of surface-active sites(SASs)over metal catalysts for enhancing the process of *** construction strategies and roles of SASs for hydrogenation catalysts are *** attention has been given to the adsorption configuration and transformation mechanism ofα,β-unsaturated aldehydes on catalysts,which contributes to understanding the relationship between SASs and hydrogenation *** addition,recent advances in metal-supported catalysts for the selective hydrogenation ofα,β-unsaturated aldehydes to understand the role of SASs in hydrogenation are briefly ***,the opportunities and challenges will be highlighted for the future development of the precise construction of SASs.

关键词： α,β-unsaturatedd aldehydes hydrogenation active site cinnamaldehyde

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A multi-agent collaboration scheme for energy-efficient task scheduling in a 3D UAV-MEC space

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Frontiers of Information Technology & Electronic Engineering 2024年第6期25卷 824-838页

作者： Yang LI Ziling WEI Jinshu su Baokang ZHAO College of Computer National University of Defense TechnologyChangsha 410073China Academy of Military Sciences Beijing 100091China

Multi-access edge computing(MEC)presents computing services at the edge of networks to address the enormous processing requirements of intelligent *** to the maneuverability of unmanned aerial vehicles(UAVs),they can be used as temporal aerial edge nodes for providing edge services to ground users in ***,MEC environment is usually dynamic and *** is a challenge for multiple UAVs to select appropriate service ***,most of existing works study UAV-MEC with the assumption that the flight heights of UAVs are fixed;i.e.,the flying is considered to occur with reference to a two-dimensional plane,which neglects the importance of the *** this paper,with consideration of the co-channel interference,an optimization problem of energy efficiency is investigated to maximize the number of fulfilled tasks,where multiple UAVs in a threedimensional space collaboratively fulfill the task computation of ground *** the formulated problem,we try to obtain the optimal flight and sub-channel selection strategies for UAVs and schedule strategies for *** on the multi-agent deep deterministic policy gradient(MADDPG)algorithm,we propose a curiosity-driven and twin-networks-structured MADDPG(CTMADDPG)algorithm to solve the formulated *** uses the inner reward to facilitate the state exploration of agents,avoiding convergence at the sub-optimal ***,we adopt the twin critic networks for update stabilization to reduce the probability of Q value *** simulation results show that CTMADDPG is outstanding in maximizing the energy efficiency of the whole system and outperforms the other benchmarks.

关键词： Multi-access edge computing Multi-agent reinforcement learning Unmanned aerial vehicles Task scheduling

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