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Evaluation and Projection of Population Exposure to Temperature Extremes over the Beijing−Tianjin−Hebei Region Using a High-Resolution Regional Climate Model RegCM4 Ensemble

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Advances in Atmospheric Sciences 2024年第6期41卷 1132-1146页

作者： Peihua QIN Zhenghui xie Rui HAN Buchun LIU State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics(LASG) Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Institute of Environment and Sustainable Development in Agriculture Chinese Academy of Agricultural Sciences(CAAS)Beijing 100081China

Temperature extremes over rapidly urbanizing regions with high population densities have been scrutinized due to their severe impacts on human safety and *** of all,the performance of the regional climate model RegCM4 with a hydrostatic or non-hydrostatic dynamic core in simulating seasonal temperature and temperature extremes was evaluated over the historical period of 1991–99 at a 12.km spatial resolution over China and a 3-km resolution over the Beijing−Tianjin−Hebei(JJJ)region,a typical urban agglomeration of *** of spatial distributions of temperature extremes over the JJJ region using RegCM4 with hydrostatic and non-hydrostatic cores showed high spatial correlations of more than 0.8 with the *** a warming climate,temperature extremes of annual maximum daily temperature(TXx)and summer days(SU)in China and the JJJ region showed obvious increases by the end of the 2.st century while there was a general reduction in frost days(FD).The ensemble of RegCM4 with different land surface components was used to examine population exposure to temperature extremes over the JJJ *** exposure to temperature extremes was found to decrease in 2.91−99 relative to 1991−99 over the majority of the JJJ region due to the joint impacts of increases in temperature extremes over the JJJ and population decreases over the JJJ region,except for downtown ***,changes in population exposure to temperature extremes were mainly dominated by future population ***,we quantified changes in exposure to temperature extremes with temperature increase over the JJJ *** study helps to provide relevant policies to respond future climate risks over the JJJ region.

关键词： CMIP6 convection-permitting population exposure RegCM4 temperature extremes

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Solvent effects on Diels-Alder reaction in ionic liquids:A reaction density functional study

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Chinese Journal of Chemical Engineering 2024年第2期66卷 180-188页

作者： Zijiang Dou Weiqiang Tang Peng xie Shuangliang Zhao Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology and School of Chemistry and Chemical Engineering Guangxi UniversityNanning 530004China State Key Laboratory of Chemical Engineering and School of Chemical Engineering East China University of Science and TechnologyShanghai 200237China

Extensive experimental studies have been performed on the Diels-Alder(DA)reactions in ionic liquids(ILs),which demonstrate that the IL environment can significantly influence the reaction rates and ***,the underlying microscopic mechanism remains *** this work,the multiscale reaction density functional theory is applied to explore the effect of 1-butyl-3-methylimidazolium hexafluorophosphate([BMIM][PF_(6)])solvent on the reaction of cyclopentadiene(CP)with acrolein,methyl acrylate,or *** analyzing the free energy landscape during the reaction,it is found that the polarization effect has a relatively small influence,while the solvation effect makes both the activation free energy and reaction free energy *** addition,the rearrangement of local solvent structure shows that the cation spatial distribution responds more evidently to the reaction than the anion,and this indicates that the cation plays a dominant role in the solvation effect and so as to affect the reaction rates and selectivity of the DA reactions.

关键词： Solvent effect Ionic liquids Diels-Alder reaction Reaction density functional theory

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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.× 2.yperbolic PDEs.

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Understanding Surface Water-Groundwater Conversion Relationship and Associated Hydrogeochemistry Evolution in the Upper Reaches of Luan River Basin, North China

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Journal of Earth Science 2024年第3期35卷 1010-1023页

作者： Le Zhao Chunli Su Wenbo Liu Xianjun xie School of Environmental Studies China University of GeosciencesWuhan 430078China State Environmental Protection Key Laboratory of Source Apportionment and Control of Aquatic Pollution Ministry of Ecology and EnvironmentWuhan 430078China China Geological Environmental Monitoring Institute Beijing 100081China

Luan River is the main water source in Beijing-Tianjin-Hebei region,northern China,where the groundwater system is vulnerable and pollution issue is *** is significant for regional groundwater resources protection to identify the hydrogeochemistry evolution and affecting factors along flow direction occurred in the upper reaches,especially the surface water-groundwater(SWGW)conversion *** this study,recharge,conversion and geochemistry evolution of SW and GW were elucidated based on physical-hydrochemical indicators and stable isotopes in 36 GW samples and 2. SW samples,which were collected in July 2.19 and July *** factor analysis was further utilized to determine the main factors responsible for regional hydrogeochemical *** indicate that GW recharged SW in plateau area,and SW and GW recharged each other in typical Alpine valley *** hydrochemical types are HCO3-Ca·Mg and HCO3-Ca,and the hydrochemical evolution is dominated by weathering of silicate and carbonate *** cation exchange adsorption has minor impact on groundwater *** rise of SO42.and NO3-contents in groundwater is related to industrial and agricultural *** main controlling factors of SW hydrochemical components included recharge from groundwater,industrial and mining activities,explaining 90.04%of data ***,water-rock interaction,agricultural and domestic sewage are responsible for GW quality,accounting for 83.38%.

关键词： groundwater water sources conversion relationship hydrogeochemical characteristics evolutional processes water-rock interaction factor analysis Luan River Basin.

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Compressed Least Squares Algorithm of Continuous-Time Linear Stochastic Regression Model Using Sampling Data

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Journal of Systems Science & Complexity 2024年第4期37卷 1488-1506页

作者： xie Siyu ZHANG Shujun WANG Ziming GAN Die School of Aeronautics and Astronautics University of Electronic Science and Technology of ChinaChengdu 611731China China Academy of Aerospace Science and Innovation Beijing 100176China Zhongguancun Laboratory Beijing 100094China

In this paper,the authors consider a sparse parameter estimation problem in continuoustime linear stochastic regression models using sampling *** on the compressed sensing(CS)method,the authors propose a compressed least squares(LS) algorithm to deal with the challenges of parameter *** each sampling time instant,the proposed compressed LS algorithm first compresses the original high-dimensional regressor using a sensing matrix and obtains a low-dimensional LS estimate for the compressed unknown ***,the original high-dimensional sparse unknown parameter is recovered by a reconstruction *** introducing a compressed excitation assumption and employing stochastic Lyapunov function and martingale estimate methods,the authors establish the performance analysis of the compressed LS algorithm under the condition on the sampling time interval without using independence or stationarity conditions on the system *** last,a simulation example is provided to verify the theoretical results by comparing the standard and the compressed LS algorithms for estimating a high-dimensional sparse unknown parameter.

关键词： Compressed excitation condition compressed sensing continuous-time model least squares linear stochastic regression parameter identification sampling data

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A Deep Model for Partial Multi-label Image Classification with Curriculum-based Disambiguation

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Machine Intelligence Research 2024年第4期21卷 801-814页

作者： Feng Sun Ming-Kun xie Sheng-Jun Huang MIIT Key Laboratory of Pattern Analysis and Machine Intelligence College of Computer Science and TechnologyNanjing University of AeronauticsandAstronauticsNanjing211106China

In this paper,we study the partial multi-label(PML)image classification problem,where each image is annotated with a candidate label set consisting of multiple relevant labels and other noisy *** PML methods typically design a disambiguation strategy to filter out noisy labels by utilizing prior knowledge with extra assumptions,which unfortunately is unavailable in many real ***,because the objective function for disambiguation is usually elaborately designed on the whole training set,it can hardly be optimized in a deep model with stochastic gradient descent(SGD)on *** this paper,for the first time,we propose a deep model for PML to enhance the representation and discrimination *** the one hand,we propose a novel curriculum-based disambiguation strategy to progressively identify ground-truth labels by incorporating the varied difficulties of different *** the other hand,consistency regularization is introduced for model training to balance fitting identified easy labels and exploiting potential relevant *** experimental results on the commonly used benchmark datasets show that the proposed method significantlyoutperforms the SOTA methods.

关键词： Partial multi-label image classification curriculum-based disambiguation consistency regularization label difficulty candidatelabel set.

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Joint Optimization of Resource Allocation and Trajectory Based on User Trajectory for UAV-Assisted Backscatter Communication System

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China Communications 2024年第2期21卷 197-209页

作者： Peizhong xie Junjie Jiang Ting Li Yin Lu School of Communication and Information Engineering Nanjing University of Posts and TelecommunicationsNanjing 210003China Key Lab of Broadband Wireless Communication and Sensor Network Technology(Nanjing University of Posts and Telecommunications) Ministry of EducationNanjing 210003China

The Backscatter communication has gained widespread attention from academia and industry in recent years. In this paper, A method of resource allocation and trajectory optimization is proposed for UAV-assisted backscatter communication based on user trajectory. This paper will establish an optimization problem of jointly optimizing the UAV trajectories, UAV transmission power and BD scheduling based on the large-scale channel state signals estimated in advance of the known user trajectories, taking into account the constraints of BD data and working energy consumption, to maximize the energy efficiency of the system. The problem is a non-convex optimization problem in fractional form, and there is nonlinear coupling between optimization *** iterative algorithm is proposed based on Dinkelbach algorithm, block coordinate descent method and continuous convex optimization technology. First, the objective function is converted into a non-fractional programming problem based on Dinkelbach method,and then the block coordinate descent method is used to decompose the original complex problem into three independent sub-problems. Finally, the successive convex approximation method is used to solve the trajectory optimization sub-problem. The simulation results show that the proposed scheme and algorithm have obvious energy efficiency gains compared with the comparison scheme.

关键词： energy efficiency joint optimization UAV-assisted backscatter communication user trajectory

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Development of porphyrin-based fluorescent sensors and sensor arrays for saccharide recognition

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Chinese Chemical Letters 2024年第2期35卷 16-23页

作者： Yubin Ding Jiaxin Wang Ruinan Wang Yongshu xie Department of Chemistry College of SciencesNanjing Agricultural UniversityNanjing 210095China Shanghai Key Laboratory of Functional Materials Chemistry Key Laboratory for Advanced Materials and Institute of Fine ChemicalsSchool of Chemistry and Molecular EngineeringEast China University of Science & TechnologyShanghai 200237China

Saccharide sensing is a very meaningful research topic as saccharides are involved in many biological ***,it is challenging to design molecular sensors for saccharides because this family of compounds is hydromimetic in aqueous solutions and shares a similar chemical *** this review,research progress in the development of porphyrin-based saccharide sensors is described with representative *** focus on using porphyrin as the signal reporter because porphyrins exhibit unique advantages in high chemical stability,long emission wavelength,and multiple structural modification *** literature results have been classified into mainly two sections according to the general working principles of the porphyrin sensor *** the first section,recognition unit,design strategy and sensing performance of traditional porphyrin-based selective saccharide sensors are *** in the second section,development of porphyrin-based sensor arrays for pattern recognition of saccharides has been *** through the design strategy and sensing performance of reported achievements,it is reasonable to anticipate a bright future for designing practical porphyrin-based saccharide sensors.

关键词： Porphyrin Saccharide Fluorescent sensing Selective sensing Pattern recognition

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An NMOS output-capacitorless low-dropout regulator with dynamic-strength event-driven charge pump

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Journal of Semiconductors 2024年第6期45卷 23-34页

作者： Yiling xie Baochuang Wang Dihu Chen Jianping Guo School of Electronics and Information Technology Sun Yat-sen UniversityGuangzhou 510006China School of Microelectronics University of Science and Technology of ChinaHefei 230000China

In this paper,an NMOS output-capacitorless low-dropout regulator(OCL-LDO)featuring dual-loop regulation has been proposed,achieving fast transient response with low power *** event-driven charge pump(CP)loop with the dynamic strength control(DSC),is proposed in this paper,which overcomes trade-offs inherent in conventional *** presented design addresses and resolves the large signal stability issue,which has been previously overlooked in the event-driven charge pump *** breakthrough allows for the full exploitation of the charge-pump structure's poten-tial,particularly in enhancing transient ***,a dynamic error amplifier is utilized to attain precise regulation of the steady-state output voltage,leading to favorable static characteristics.A prototype chip has been fabricated in 65 nm CMOS *** measurement results show that the proposed OCL-LDO achieves a 410 nA low quiescent current(IQ)and can recover within 30 ns under 2.0 mA/10 ns loading change.

关键词： output-capacitorless low-dropout regulator fast transient low quiescent current event-driven charge pump

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Alignment of Track Oscillations during Tropical Cyclone Rapid Intensification

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Advances in Atmospheric Sciences 2024年第4期41卷 655-670页

作者： Tong xie Liguang WU Yecheng FENG Jinghua YU Key Laboratory of Meteorological Disaster of Ministry of Education Nanjing University of Information Science and TechnologyNanjing 210044China Dept.of Atmospheric and Oceanic Sciences and Institute of Atmospheric Sciences Fudan UniversityShanghai 200438China CMA-FDU Joint Laboratory of Marine Meteorology Shanghai 200438China

Recent studies on tropical cyclone(TC)intensity change indicate that the development of a vertically aligned TC circulation is a key feature of its rapid intensification(RI),however,understanding how vortex alignment occurs remains a challenging topic in TC intensity change *** on the simulation outputs of North Atlantic Hurricane Wilma(2.05)and western North Pacific Typhoon Rammasun(2.14),vortex track oscillations at different vertical levels and their associated role in vortex alignment are examined to improve our understanding of the vortex alignment during RI of TCs with initial hurricane *** is found that vortex tracks at different vertical levels oscillate consistently in speed and direction during the RI of the two simulated *** the consistent track oscillation reduces the oscillation tilt during RI,the reduction of vortex tilt results mainly from the mean track before *** is also found that the vortex tilt is primarily due to the mean vortex track before and after *** track oscillations are closely associated with wavenumber-1 vortex Rossby waves that are dominant wavenumber-1 circulations in the TC inner-core *** study suggests that the dynamics of the wavenumber-1 vortex Rossby waves play an important role in the regulation of the physical processes associated with the track oscillation and vertical alignment of TCs.

关键词： tropical cyclone rapid intensification vortex tilt Rossby wave

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