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Improved forecasting via physics-guided machine learning as exemplified using“21·7”extreme rainfall event in Henan

Science China Earth Sciences 2024年第5期67卷 1652-1674页

作者： Qi ZHONG Zhicha ZHANG Xiuping YAO Shaoyu HOU Shenming FU Yong CAO Linguo JING China Meteorological Administration Training Center Beijing 100081China State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesBeijing 100081China Zhejiang Meteorological Observatory Hangzhou 310017China Hebei Provincial Weather Modification Center Shijiazhuang 050020China institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029China National Meteorological Center Beijing 100081China School of Computer Science Chengdu University of Information TechnologyChengdu 610225China

As a natural disaster,extreme precipitation is among the most destructive and influential,but predicting its occurrence and evolution accurately is very challenging because of its rarity and *** the example of the“21·7”extreme precipitation event(17–21 July 2021)in Henan Province,this study explores the potential of using physics-guided machine learning to improve the accuracy of forecasting the intensity and location of extreme *** physics-guided ways of embedding physical features,fusing physical model forecasts and revised loss function are used,i.e.,(1)analyzing the anomalous circulation and thermodynamical factors,(2)analyzing the multi-model forecast bias and the associated underlying reasons for it,and(3)using professional forecasting knowledge to design the loss function,and the corresponding results are used as input for machine learning to improve the forecasting *** results indicate that by learning the relationship between anomalous physical features and heavy precipitation,the forecasting of precipitation intensity is improved significantly,but the location is rarely adjusted and more false alarms *** reasons for this are as *** anomalous features used here mainly contain information about large-scale systems and factors which are consistent with the model precipitation deviation;moreover,the samples of extreme precipitation are sparse and so the algorithm used here is ***,by combining“good and different”multi models with machine learning,the advantages of each model are extracted and then the location of the precipitation center in the forecast is improved ***,by combining the appropriate anomalous features with multi-model fusion,an integrated improvement of the forecast of the rainfall intensity and location is ***,this study is a novel exploration to improve the refined forecasting of heavy precipitation with extreme intensity and high variability,

关键词： Extreme precipitation event Refined assessment Anomalous physical features Multi-model fusion Machine learning

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Validation of EMMS-based drag model using lattice Boltzmann simulations on GPUs

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Particuology 2011年第4期9卷 365-373页

作者： Yun Zhang Wei Ge Xiaowei Wang Chaohe Yang State Key Laboratory of Heavy Oil Processing China University of Petroleum Qingdao 266555 China The EMMS Croup State Key Laboratory of Multi-phase Complex Systems Institute of Process Engineering Chinese Academy of Sciences Beijing 100190 China

lnterphase momentum transport in heterogeneous gas-solid systems with multi-scale structure is of great importance in process engineering. In this article, lattice Boltzmann simulations are performed on graphics processing units （GPUs）, the computational power of which exceeds that of CPUs by more than one order of magnitude, to investigate incompressible Newtonian flow in idealized multi-scale particle-fluid systems. The structure consists of a periodic array of clusters, each constructed by a bundle of cylinders. Fixed pressure boundary condition is implemented by applying a constant body force to the flow through the medium. The bounce-back scheme is adopted on the fluid-solid interfaces, which ensures the no-slip boundary condition. The structure is studied under a wide range of particle diameters and packing fractions, and the drag coefficient of the structure is found to be a function of voidages and fractions of the clusters, besides the traditional Reynolds number and the solid volume fractions. Parameters reflecting multi-scale characters are, therefore, demonstrated to be necessary in quantifying the drag force of heterogeneous gas-solid system. The numerical results in the range 0.1 〈 Re 〈 10 and 0 〈 Ф 〈 0.25 are compared with Wen and Yu＇s correlation, Gibilaro equation, EMMS-based drag model, the Beetstra correlation and the Benyahia correlation, and good agreement is found between the simulations and the EMMS-based drag model for heterogeneous systems.

关键词： EMMS Drag model Lattice Boltzmann method GPU

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Structural and chemical transformations of CuZn alloy nanoparticles under reactive redox atmospheres:An in situ TEM study

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Nano Research 2024年第7期17卷 6265-6273页

作者： Shengnan Yue Qian Li Chaobin Zeng Alexander Klyushin Ramzi Farra Marc-Georg Willinger Xing Huang College of Chemistry Fuzhou UniversityFuzhou 350108China Qingyuan Innovation Laboratory Quanzhou 362801China Hitachi High-Tech Scientific Solutions(Beijing)Co. Ltd.Beijing 100015China MAX IV Laboratory Lund UniversityBox 11822100 LundSweden Department of Inorganic Chemistry Fritz-Haber Institute of Max Planck SocietyBerlin 14195Germany Department of Chemistry Technical University of MunichGarching 85748Germany

Alloying metals to form intermetallics has been proven effective in tuning the chemical properties of metal-based ***,intermetallic alloys can undergo structural and chemical transformations under reactive conditions,leading to changes in their catalytic *** and understanding these transformations are crucial for establishing relevant structureperformance relationships and for the rational design of alloy-based *** this work,we used CuZn alloy nanoparticles(NPs)as a model material system and employed in situ transmission electron microscopy(TEM)to investigate the structural and chemical changes of CuZn NPs under H_(2),O_(2)and their *** results show how CuZn NPs undergo sequential transformations in the gas mixture at elevated temperatures,starting with gradual leaching and segregation of Zn,followed by oxidation at the NP *** remaining copper at the core of particles can then engage in dynamic behavior,eventually freeing itself from the zinc oxide *** structural dynamics arises from an oscillatory phase transition between Cu and Cu_(2)O and is correlated with the catalytic water formation,as confirmed by in situ mass spectrometry(MS).Under pure H_(2)or O_(2)atmosphere,we observe different structural evolution pathways and final chemical states of CuZn NPs compared to those in the gas *** results clearly demonstrate that the chemical state of alloy NPs can vary considerably under reactive redox atmospheres,particularly for those containing elements with distinct redox properties,necessitating the use of in situ or detailed ex situ characterizations to gain relevant insights into the states of intermetallic alloy-based catalysts and structure-activity relationships.

关键词： In situ transmission electron microscopy(TEM) CuZn alloy structural and chemical transformations redox atmosphere

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distributed best response dynamics for Nash equilibrium seeking in potential games

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Control Theory and Technology 2020年第3期18卷 324-332页

作者： Shijie HUANG Peng YI Key Lab of systems and Control Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China School of Mathematical Sciences University of Chinese Academy of SciencesBeijing 100190China Department of Control Science&Engineering Tongji UniversityShanghai 201804China Shanghai institute of Intelligent Science and Technology Tongji UniversityShanghai 201804China

In this paper,we consider distributed Nash equilibrium(NE)seeking in potential games over a multi-agent network,where each agent can not observe the actions of all its *** on the best response dynamics,we design a distributed NE seeking algorithm by incorporating the non-smooth finite-time average tracking dynamics,where each agent only needs to know its own action and exchange information with its neighbours through a communication *** give a sufficient condition for the Lipschitz continuity of the best response mapping for potential games,and then prove the convergence of the proposed algorithm based on the Lyapunov *** simulations are given to verify the resultandillustrate the effectiveness of the algorithm.

关键词： distributed algorithms Nash equilibrium seeking best response dynamics non-smooth finite-time tracking dynamics potential games

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Large-scale fabrication of highly ordered sub-20 nm noble metal nanoparticles on silica substrates without metallic adhesion layers

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Microsystems & Nanoengineering 2018年第1期4卷 380-389页

作者： Hai Le-The Erwin Berenschot Roald M.Tiggelaar Niels R.Tas Albert van den Berg Jan C.T.Eijkel BIOS Lab-on-a-Chip Group MESA+Institute for NanotechnologyMIRA Institute for Biomedical Technology and Technical MedicineMax Planck Center for Complex Fluid DynamicsUniversity of TwenteEnschede 7522 NBThe Netherlands Mesoscale Chemical systems Group MESA+Institute for NanotechnologyUniversity of TwenteEnschede 7522 NBThe Netherlands NanoLab Cleanroom MESA+Institute for NanotechnologyUniversity of TwenteEnschede 7522 NBThe Netherlands

Periodic noble metal nanoparticles offer a wide spectrum of applications including chemical and biological sensors,optical devices,and model catalysts due to their extraordinary *** sensing purposes and catalytic studies,substrates made of glass or fused-silica are normally required as supports,without the use of metallic adhesion ***,precise patterning of such uniform arrays of silica-supported noble metal nanoparticles,especially at sub-100 nm in diameter,is challenging without adhesion *** this paper,we report a robust method to large-scale fabricate highly ordered sub-20 nm noble metal nanoparticles,i.e.,gold and platinum,supported on silica substrates without adhesion layers,combining displacement Talbot lithography(DTL)with dry-etching *** photoresist nanocolumns at diameters of~110 nm are patterned on metal-coated oxidized silicon wafers using DTL,and subsequently transferred at a 1:1 ratio into anti-reflection layer coating(BARC)nanocolumns with the formation of nano-sharp tips,using nitrogen plasma *** BARC nanocolumns are then used as a mask for etching the deposited metal layer using inclined argon ion-beam *** find that increasing the etching time results in coneshaped silica features with metal nanoparticles on the tips at diameters ranging from 100 nm to sub-30 nm,over large areas of 3×3 cm^(2).Moreover,subsequent annealing these sub-30 nm metal nanoparticle arrays at high-temperature results in sub-20 nm metal nanoparticle arrays with~10^(10) uniform particles.

关键词： metallic ordered columns

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Flame-retardant ammonium polyphosphate/MXene decorated carbon foam materials as polysulfide traps for fire-safe and stable lithium-sulfur batteries

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Journal of Energy Chemistry 2024年第2期89卷 313-323,I0008页

作者： Yang Li Yong-Cheng Zhu Sowjanya Vallem Man Li Seunghyun Song Tao Chen Long-Cheng Tang Joonho Bae Department of Physics Gachon UniversitySeongnam-siGyeonggi-do 13120South Korea Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education College of MaterialChemistry and Chemical EngineeringHangzhou Normal UniversityHangzhou 311121ZhejiangChina Key laboratory of Advanced Energy Materials Chemistry(Ministry of Education) College of ChemistryNankai UniversityTianjin 300071China School of Materials Engineering Changzhou Vocational Institute of Industry TechnologyChangzhou 213164JiangsuChina

Lithium-sulfur(Li-S)batteries are one of the most promising modern-day energy supply systems because of their high theoretical energy density and low ***,the development of high-energy density Li-S batteries with high loading of flammable sulfur faces the challenges of electrochemical performance degradation owing to the shuttle effect and safety issues related to fire or explosion *** this work,we report a three-dimensional(3D)conductive nitrogen-doped carbon foam supported electrostatic self-assembled MXene-ammonium polyphosphate(NCF-MXene-APP)layer as a heat-resistant,thermally-insulated,flame-retardant,and freestanding host for Li-S batteries with a facile and costeffective synthesis ***,through the use of NCF-MXene-APP hosts that strongly anchor polysulfides,the Li-S batteries demonstrate outstanding electrochemical properties,including a high initial discharge capacity of 1191.6 mA h g^(-1),excellent rate capacity of 755.0 mA h g^(-1)at 1 C,and long-term cycling stability with an extremely low-capacity decay rate of 0.12%per cycle at 2 *** importantly,these batteries can continue to operate reliably under high temperature or flame attack ***,this study provides valuable insights into the design of safe high-performance Li-S batteries.

关键词： Flame-retardant MXene Ammonium polyphosphate Safety Lithium-sulfur battery

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Current status and challenges in the application of microbial PHA particles

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Particuology 2024年第4期87卷 286-302页

作者： Jiaxuan Liu Ziqi Zhou Haoru Li Xinyu Yang Zeyu Wang jian Xiao Dai-Xu Wei Key Laboratory of Resource Biology and Biotechnology in Western China Ministry of EducationSchool of MedicineDepartment of Life Sciences and MedicineNorthwest UniversityXi'an710069China School of Clinical Medicine Qujing Medical CollegeQujing655000China School of Physics and Electronic Information Shangrao Normal UniversityShangrao334001China Zigong Affiliated Hospital of Southwest Medical University Zigong Psychiatric Research CenterZigong Institute of Brain ScienceZigong643002China

Polyhydroxyalkanoates(PHAs)are diversiform biopolyesters with a similar structure and different side chain groups,synthesized by a variety of *** to their excellent biodegradability and biocompatibility,PHAs have been used for many applications,including medical implants,antibacterial agents and ***-architecture is an emerging area for the use of *** review summarizes the current status and challenges of PHAs-based particles on the micro-and nano-scale,including their production,degradation,biological safety,and surface *** also focus on the applications of PHA particles in drug delivery systems,environment protection,tissue engi-neering,vaccine engineering,food science,biotechnology and ***,the future development trends of PHAs-based particles are prospected.

关键词： Polyhydroxyalkanoates(PHAs) Particles Synthetic biology Tissue engineering

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A New Method for the Aging Evaluation of Oil-Paper Insulation Using η-Butanol and Methanol

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CSEE Journal of Power and Energy systems 2024年第2期10卷 717-726页

作者： Jianyi Wang Yuanxiang Zhou Jun Liu Zhaowei Wang Song Bai Jiayu Lu Department of High Voltage China Electric Power Research InstituteBeijing 100192China State Key Laboratory of Power Grid Environmental Protection Beijing 100192China Electrical Engineering Department Tsinghua UniversityBeijing 100084China Solar Storage Division of State Key Lab of Power System and Generation Equipment School of Electrical EngineeringXinjiang UniversityUrumqi 830047China State Grid Wuwei Electric Power Supply Company Wuwei 733000China

To improve the accuracy and efficiency of the aging life prediction and assessment of transformer oil-paper insulation,and to make up for the deficiencies of traditional characterizers,such as 2-furfural,carbon monoxide,and carbon dioxide,a method for the simultaneous determination of methanol,ethanol,n−propanol,and η-butanol in oil with a single injection is established by headspace-gas chromatography-mass *** measured results show that the determination limits of the four alcohol characterizers can be controlled to 10μg/kg *** on this method,the change patterns of the above four alcohols with thermal aging time and degree of polymerization are obtained through thermal aging experimental ***,η-propanol,and η-butanol in oil indicate nearly linear correlations with thermal aging time and degree of polymerization,similar to that of *** analyzing 52 sets of measured data of 500 kV EHV transformers in operation,η-butanol is found to have excellent performance,and a new method to evaluate the aging state of oil-paper insulation employing η-butanol and methanol is proposed along with the aging attention value *** measured data of 500 kV EHV transformers in operation indicate that the combination of η-butanol and methanol as the preferred characterizers can effectively compensate for the shortcoming of traditional characterizers in the early stages of aging,and the feasibility of the method is *** possible pathways for the generation of η-butanol by cellulose cleavage during the aging of oil-paper are proposed from the chemical structure of cellulose.

关键词： Aging characterization determination method methanol η-butanol oil-paper insulation 500 kV transformers

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Bifunctional noble-metal-free cocatalyst coating enabling better coupling of photocatalytic CO_(2)reduction and H_(2)O oxidation on direct Z-scheme heterojunction

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Nano Research 2024年第6期17卷 5022-5030页

作者： Wei Zhao Weihao Mo Yan Zhang Lingxuan Hu Yiyi Zheng Zhulei Chen Xiangyue Niu Yuling Zhao Lichun Liu Shuxian Zhong Song Bai Key Laboratory of the Ministry of Education for Advanced Catalysis Materials College of Chemistry and Materials ScienceZhejiang Normal UniversityJinhua 321004China College of Biological Chemical Sciences and Engineering and Nanotechnology Research InstituteJiaxing UniversityJiaxing 314001China College of Geography and Environmental Sciences Zhejiang Normal UniversityJinhua 321004China College of Chemical and Biological Engineering Zhejiang UniversityHangzhou 310058China School of Biological and Chemical Engineering Panzhihua UniversityPanzhihua 617000China

Selective loading of spatially separated redox cocatalysts on direct Z-scheme heterojunctions holds great promise for advancing the efficiency of artificial photosynthesis,which however is limited to the photodeposition of noble metal cocatalysts and the fabrication of hollow double-shelled semiconductor ***,the co-exposure of discrete cocatalyst and semiconductor increases the product diversity when both the exposed sites of which participate in CO_(2)***,we present a facile and versatile protocol to overcome these limitations via surface coating of Z-scheme heterojunctions with bifunctional noble-metal-free *** Cu_(2)O/Fe_(2)O_(3)(CF)as a model heterojunction and layered Ni(OH)_(2)as a model cocatalyst,it is found that Ni(OH)_(2)lying on the surfaces of Cu_(2)O and Fe_(2)O_(3)separately co-catalyzes the CO_(2)reduction and H_(2)O *** experimental and theoretical investigation reveals that the Ni(OH)_(2)outer layer:(i)mitigates the charge recombination in CF and balances their transfer and consumption;(ii)reduces the rate-determining barriers for CO_(2)-to-CO and H_(2)O-to-O_(2)conversion,(iii)suppresses the side proton reduction occurring on CF,and(iv)protects the CF from component *** expected,the redox reactions stoichiometrically proceed,and significantly enhanced photocatalytic activity,selectivity,and stability in CO generation are achieved by the stacked Cu_(2)O/Fe_(2)O_(3)@Ni(OH)_(2)in contrast to *** study demonstrates the significance of the synergy between bifunctional cocatalysts and Z-scheme heterojunctions for improving the efficacy of overall redox reactions,opening a fresh avenue for the rational design of artificial photosynthetic systems.

关键词： Z-scheme heterojunction bifunctional cocatalyst CO_(2)reduction H_(2)O oxidation stoichiometric redox reaction

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Toward Greener and Smarter Process Industries

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Engineering 2017年第2期3卷 152-153页

作者： Wei Ge State Key Laboratory of Multiphase Complex systems. institute of Process Engineering. Chinese Academy of Sciences Beijing 100190. China University of Chinese Academy of Sdences Beifing 100049 China

The main mission of the process industries is to process resourc-es and energies into a form that can be utilized in other industriesand throughout society. In this sense, process industries cover a vastterritory, encompassing the chemical/biochemical, material, mining,metallurgical, power, food, and even pharmaceutical industries; inaddition, they are closely related to mechanical, civil, electrical, andelectronic industries, as well as to emerging fields such as biotech-nology, nanotechnology, and information technologies.

关键词：期刊编辑工作规范写作方法

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