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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

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

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

surrogate modeling for unsaturated infiltration via the physics and equality-constrained artificial neural networks

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Journal of Rock Mechanics and geotechnical Engineering 2024年第6期16卷 2282-2295页

作者： Peng Lan Jingjing su Sheng Zhang School of Civil Engineering Central South UniversityChangsha410075China Discipline of Civil Surveying and Environmental EngineeringPriority Research Centre for Geotechnical Science and EngineeringThe University of NewcastleCallaghanNSW2308Australia Qinghai University Qinghai810016China

Machine learning(ML)provides a new surrogate method for investigating groundwater flow dynamics in unsaturated *** pure data-driven methods(*** neural network,DNN)can provide rapid predictions,but they do require sufficient on-site data for accurate training,and lack interpretability to the physical processes within the *** this paper,we provide a physics and equalityconstrained artificial neural network(PECANN),to derive unsaturated infiltration solutions with a small amount of initial and boundary *** takes the physics-informed neural network(PINN)as a foundation,encodes the unsaturated infiltration physical laws(*** equation,RE)into the loss function,and uses the augmented Lagrangian method to constrain the learning process of the solutions of RE by adding stronger penalty for the initial and boundary *** unsaturated infiltration cases are designed to test the training performance of PECANN,***-dimensional(1D)steady-state unsaturated infiltration,1D transient-state infiltration,two-dimensional(2D)transient-state infiltration,and 1D coupled unsaturated infiltration and *** predicted results of PECANN are compared with the finite difference solutions or analytical *** results indicate that PECANN can accurately capture the variations of pressure head during the unsaturated infiltration,and present higher precision and robustness than DNN and *** is also revealed that PECANN can achieve the same accuracy as the finite difference method with fewer initial and boundary training ***,we investigate the effect of the hyperparameters of PECANN on solving RE *** provides an effective tool for simulating unsaturated infiltration.

关键词： Richards equation(RE) Unsaturated infiltration Data-driven solutions Numerical modeling Machine learning(ML)

High-performance grinding of ceramic matrix composites

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Nanotechnology and Precision Engineering 2024年第3期7卷 45-55页

作者： Jingfei Yin Jiuhua Xu Honghua su College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China Department of Technology Center AECC Shenyang Liming Aero-engine Co.Ltd.Shenyang 110043China

Ceramic matrix composites(CMCs)are highly promising materials for the next generation of ***,machining of CMCs suffers from low efﬁciency and poor surfaceﬁnish,which presents an obstacle to their wider *** overcome these problems,this study investigates high-efﬁciency deep grinding of CMCs,focusing on the effects of grinding *** results show that both the sur-face roughness and the depth of subsurface damage(SSD)are insensitive to grinding *** material removal rate can be increased sixfold by increasing the grinding depth,while the surface roughness and SSD depth increase by only about 10%.Moreover,it is found that the behavior of material removal is strongly dependent on grinding *** the grinding depth is increased,ﬁbers are removed in smaller sizes,with theﬁber length in chips being reduced by about 34%.However,too large a grinding depth will result in blockage by chip powder,which leads to a dramatic increase in the ratio of tangential to normal grinding *** study demonstrates that increasing the depth of cut is an effective approach to improve the machining efﬁciency of CMCs,while maintaining a good surfaceﬁ*** provides the basis for the further development of high-performance grinding methods for CMCs,which should facilitate their wider application.

关键词： Ceramic matrix composite grinding surfaceﬁnish subsurface damage Fiber breakage

Hollow Multi-shelled Structure Photoelectric Materials: Multiple Shells Bring Novel Properties

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Chemical Research in Chinese Universities 2024年第3期40卷 413-427页

作者： su Fengmei WAN Jiawei WANg Dan State Key Laboratory of Biochemical Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing 100190P.R.China University of Chinese Academy of Sciences Beijing 100049P.R.China Key Laboratory of Biopharmaceutical Preparation and Delivery Chinese AcademyofSciencesBeijing 100049P.R.China

Hollow multi-shelled structures(HoMSs)have made significant strides across a wide spectrum of scientific investigations since the inception of the sequential templating approach(STA)in 2009,revealing distinctive temporal-spatial ordering *** recent establishment of a mathematical model for STA has not only demystified the formation of concentration waves within the STA process but also extended its relevance to gentler solutionbased systems,thereby broadening the HoMs ***,focusing on photoelectric applications,this review first summarizes the unique temporal-spatial ordering features of ***,the greatly enhanced properties of light capture and absorption,exciton separation,and transfer are deeply ***,we conclude with a perspective on the potential challenges and burgeoning opportunities that lie ahead in the advancement of HoMs development.

关键词： Hollow multi-shelled structure Photoelectric conversion Sequential templating approach Light absorption Chargetransfer

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

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

Unveiling oscillatory nature for sustainable fuel production

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National Science Review 2024年第05期11卷 90-91页

作者： Ning Han Ye Wang Bao-Lian su Department of Materials Engineering State Key Laboratory of Physical Chemistry of Solid surfaces Collaborative Innovation Center of Chemistry for Energy Materials National Engineering Laboratory for Green Chemical Productions of Alcohols Ethers and Esters College of Chemistry and Chemical Engineering Xiamen University Laboratory of Inorganic Materials Chemistry(CMI) University of Namur State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology

A century ago, in 1923, Franz Fischer and Hans Tropsch introduced the groundbreaking Fischer–Tropsch (FT) synthesis, a heterogeneous catalytic process used to convert synthesis gas (syngas,CO+H2) into multi-carbon hydrocarbons [1]. Over the past 100 years, FT synthesis has emerged as a pivotal method for converting non-petroleum resources into exceptionally clean fuels or valuable chemicals via syngas [2–4].

关键词： CO HYDROgENATION CATALYSTS BEHAVIOR KINETICS