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CCS Chemistry 2024年第10期6卷 2549-2559页

作者： jian-Xiong Yang jia-qing hu Qi Wen Jie Xu Yan Zhang Heng jiang School of Chemistry and Chemical Engineering Chemistry and Biomedicine Innovation Center(Chem BIC)Nanjing UniversityNanjing 210023 Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs Shanghai Frontiers Science Center of Drug Target Identification and DeliverySchool of Pharmaceutical SciencesShanghai Jiao Tong UniversityShanghai 200240

The direct excitation of dihydroquinazolinone(DHQ)anions by visible light has been demonstrated by photophysical *** excited-state DHQ anion serves as both a potent reductant and a radical precursor in a redox neutral radical cascade,circumventing the use of an external photoredox *** gem-difluoroalkyl radicals(CF_(2)H and CF_(2)R)are produced from the excited-state DHQ anions,leading to the first example of intermolecular 1,2-difluoroalkylarylation(CF_(2)H-and CF_(2)R-arylation)of alkenes in overall redox-neutral ***,1,2-difluoroalkylamination of styrenes has also been realized,offering a practical pathway for the preparation of diverseβ-CF_(2)H *** general and efficient strategy for the generation of CF_(2)H and CF_(2)R radicals exhibits great potential for applications in drug discovery.

关键词： excited state anion difluoromethyl radical difluoromethylation photochemistry radical chemistry

One new bufadienolide biotransformed from cinobufagin by Cunninghamella elegans

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Chinese Chemical Letters 2008年第3期19卷 299-301页

作者： Li Qiao Yu Zhi Zhou huan Chen jia qing Cao Yue hu Pei School of Traditional Chinese Materia Medica Shenyang Pharmaceutical University Shenyang 110016 China

Cunninghamella elegans has been employed for the biotransformation of cinobufagin （1） to afford one metabolites. The structure of the transformation product has been characterized as 7β,12β-dihydroxylcinobufagin （2）. Product 2 is a new compound. In vitro cytotoxic activities of the biotransformation product and the substrate-cinobufagin have been assayed against HeLa; they all showed cytotoxic activities.

关键词： Biotransformation Cinobufagin 7β,12β-Dihydroxylcinobufagin Cunninghamella elegans

Physics of cavitation near particles

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Journal of Hydrodynamics 2024年第1期36卷 102-118页

作者： jia-xin Yu Xiao-yu Wang Jun-wei Shen Jin-sen hu Xiang-qing Zhang Da-qing He Yu-ning Zhang Key Laboratory of Power Station Energy Transfer Conversion and System(Ministry of Education) School of Energy Power and Mechanical EngineeringNorth China Electric Power UniversityBeijing102206China

The combined effect of cavitation and silt abrasion presents a great challenge and threat to secure the operation and the efficiency of hydraulic machineries working in sediment-laden *** present paper critically reviews the current research progress on the interaction mechanisms of the bubbles and the ***,the analytical models including boundary treatment methods for predicting the jet dynamics of the bubble collapse near particles are ***,the bubble collapsing dynamics,jet dynamics and shock wave characteristics near particles are revealed both experimentally and ***,the bubble-particle-wall system is investigated with a focus on microjets.

关键词： Cavitation bubble particle jet shock wave

Electricity-Heat-Based Integrated Demand Response Considering Double Auction Energy Market with Multi-Energy Storage for Interconnected Areas

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CSEE Journal of Power and Energy Systems 2024年第4期10卷 1688-1700页

作者： Dan Wang Deyu huang qing'e hu Hongjie jia Bo Liu Yang Lei Key Laboratory of Smart Grid of Ministry of Education Tianjin UniversityTianjin 300072China Key Laboratory of Smart Energy&Information Technology of Tianjin Municipality Tianjin 30072China

With development of integrated energy systems and energy markets,transactive energy has received increasing attention from society and academia,and realization of energy distribution and integrated demand response through market transactions has become a current research *** on optimized operation of a distributed energy station as a regional energy supply center is of great significance for improving flexibility and reliability of the *** on retail-side energy trading market,this study first establishes a framework of combined electric and heating energy markets and analyses a double auction market mechanism model of interconnected distributed energy *** study establishes a mechanism model of energy market participants,and establishes the electric heating combined market-clearing model to maximize global surplus considering multi-energy ***,in the case study,a typical user energy consumption scenario in winter is selected,showing market-clearing results and demand response effects on a typical *** of transmission line constraints,energy supply equipment capacity,and other factors on clearing results and global surplus are compared and analyzed,verifying the effects of the proposed method on improving global surplus,enhancing interests of market participants and realizing coordination and optimal allocation of both supply and demand resources through energy complementarity between regions.

关键词： Double auction energy market integrated energy system interconnected energy stations multi-energy storage

A compact X-band backward traveling-wave accelerating structure

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Nuclear Science and Techniques 2024年第5期35卷 13-29页

作者： Xian-Cai Lin Hao Zha jia-Ru Shi Qiang Gao Fang-Jun hu qing-Zhu Li huai-Bi Chen Department of Engineering Physics Tsinghua UniversityBeijing 100084China Key Laboratory of Particle and Radiation Imaging(Tsinghua University) Ministry of EducationBeijing 100084China

Very high-energy electrons(VHEEs)are potential candidates for FLASH radiotherapy for deep-seated *** proposed a compact VHEE facility based on an X-band high-gradient high-power *** this study,we investigated and realized the first X-band backward traveling-wave(BTW)accelerating structure as the buncher for a VHEE facility.A method for calculating the parameters of single cell from the field distribution was introduced to simplify the design of the BTW ***-domain circuit equations were applied to calculate the transient beam parameters of the buncher in the unsteady state.A prototype of the BTW structure with a thermionic cathode-diode electron gun was designed,fabricated,and tested at high power at the Tsinghua X-band high-power test *** structure successfully operated with 5-MW microwave pulses from the pulse compressor and outputted electron bunches with an energy of 8 MeV and a pulsed current of 108 mA.

关键词： Backward traveling-wave accelerating structure Equivalent circuit model High-power test Very high-energy electron radiotherapy

The New Methods for Characterization of Molecular Weight of Supramolecular Polymers

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Chinese Journal of Polymer Science 2024年第10期42卷 1403-1413,I0006页

作者： hui Liu Rui hu Zi-qing hu Xiao-Fan Ji Key Laboratory of Materials Chemistry for Energy Conversion and Storage Ministry of EducationHubei Key Laboratory of Materials Chemistry and Service FailureHubei Engineering Research Center for Biomaterials and Medical Protective MaterialsSchool of Chemistry and Chemical EngineeringHuazhong University of Science and TechnologyWuhan430074China

Supramolecular polymers,as a type of dynamic polymers,are subordinate to the interdisciplinary field of polymer chemistry and supramolecular chemistry,whose development has greatly promoted the prosperity of new ***,molecular weight is one of the most important parameters of supramolecular polymers,which affects the physical/chemical properties and processing applications of *** new methods for characterizing the molecular weight of supramolecular polymers is crucial for advancing the development of supramolecular *** this review,we elaborate and summarize three strategies for characterizing the molecular weight of supramolecular polymers that recently reported by our research group according to the characteristics of supramolecular polymers,including(1)the molecular weight distinction corresponding to variable fluorescence colors,(2)matching different molecular weights with different fluorescence lifetime,(3)transforming supramolecular polymers into mechanically interlocked polymers or covalent ***,we also discuss the limitations of current methods for characterizing supramolecular *** hope that this review can promote the development of supramolecular polymers and significantly inspire to exploit new methods to characterizing molecular weight of supramolecular polymers.

关键词： Supramolecular polymers Molecular weight Self-assembly Mechanically interlocked polymers Dynamic polymers

Improving the Short-Range Precipitation Forecast of Numerical Weather Prediction through a Deep Learning-Based Mask Approach

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Advances in Atmospheric Sciences 2024年第8期41卷 1601-1613页

作者： jiaqi ZHENG qing LING jia LI Yerong FENG School of Computer Science and Engineering/Guangdong Provincial Key Laboratory of Computational Science Sun Yat-Sen UniversityGuangzhou 510006China School of Mathematics Sun Yat-Sen UniversityGuangzhou 510275China Guangzhou Institute of Tropical and Marine Meteorology/Guangdong Provincial Key Laboratory of Regional Numerical Weather Prediction Guangzhou 510641China Shenzhen Institute of Meteorological Innovation Shenzhen 518038China

Due to various technical issues,existing numerical weather prediction(NWP)models often perform poorly at forecasting rainfall in the first several *** correct the bias of an NWP model and improve the accuracy of short-range precipitation forecasting,we propose a deep learning-based approach called UNet Mask,which combines NWP forecasts with the output of a convolutional neural network called *** UNet Mask involves training the UNet on historical data from the NWP model and gridded rainfall observations for 6-hour precipitation *** overlap of the UNet output and the NWP forecasts at the same rainfall threshold yields a *** UNet Mask blends the UNet output and the NWP forecasts by taking the maximum between them and passing through the mask,which provides the corrected 6-hour rainfall *** evaluated UNet Mask on a test set and in real-time *** results showed that UNet Mask outperforms the NWP model in 6-hour precipitation prediction by reducing the FAR and improving CSI *** tests also showed that different small rainfall thresholds applied to the UNet and the NWP model have different effects on UNet Mask's forecast *** study shows that UNet Mask is a promising approach for improving rainfall forecasting of NWP models.

关键词： deep learning numerical weather prediction(NWP) 6-hour quantitative precipitation forecast

Noise-induced phase transition in the Vicsek model through eigen microstate methodology

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Chinese Physics B 2024年第9期33卷 327-338页

作者： Yongnan jia jiali Han qing Li School of Automation and Electrical Engineering University of Science and Technology BeijingBeijing 100083China

This paper presents a comprehensive framework for analyzing phase transitions in collective models such as theVicsek model under various noise types. The Vicsek model, focusing on understanding the collective behaviors of socialanimals, is known due to its discontinuous phase transitions under vector noise. However, its behavior under scalar noiseremains less conclusive. Renowned for its efficacy in the analysis of complex systems under both equilibrium and nonequilibriumstates, the eigen microstate method is employed here for a quantitative examination of the phase transitions inthe Vicsek model under both vector and scalar noises. The study finds that the Vicsek model exhibits discontinuous phasetransitions regardless of noise type. Furthermore, the dichotomy method is utilized to identify the critical points for thesephase transitions. A significant finding is the observed increase in the critical point for discontinuous phase transitions withescalation of population density.

关键词： Vicsek model phase transitions eigen microstate method noise

Relationship between hydrogenation degree and pyrolysis performance of jet fuel

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Chinese Journal of Chemical Engineering 2024年第4期68卷 35-42页

作者： qing Liu Tinghao jia Lun Pan Jijun Zou Xiangwen Zhang Key Laboratory for Green Chemical and Technology School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China Haihe Laboratory of Sustainable Chemical Transformations Tianjin 300192China Zhejiang Institute of Tianjin University Ningbo 315201China Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture Technology College of Chemical and Biological EngineeringZhejiang UniversityHangzhou 310027China

Understanding the relationship between the chemical composition and pyrolysis performance of endothermic hydrocarbon fuel(EHF) is of great significance for the design and optimization of advanced EHFs. In this work, the effect of deep hydrogenation on the pyrolysis of commercial RP-3 is *** with different hydrogenation degrees were obtained by the partially and completely catalytic hydrogenation and their pyrolysis performances were investigated using an apparatus equipped with an electrically heated tubular reactor. The results show that with the increase of hydrogenation degree, fuel conversion almost remains constant during the pyrolysis process(500-650°C, 4 MPa);however, the heat sink increases slightly, and the anti-coking performance significantly improves, which are highly related to their H/C ratios. Detailed characterisations reveal that the difference of the pyrolysis performance can be ascribed to the content of aromatics and cycloalkanes: the former are prone to initiate secondary reactions to form coking precursors, while the latter could act as the hydrogen donor and release hydrogen, which will terminate the radical propagation reactions and suppress the coke deposition. This work should provide the guidance for upgrading EHFs by modulating the composition of EHFs.

关键词： RP-3 Fuel Pyrolysis Hydrogenation Deposition

Vertically grown MoS_(2)nanosheets on graphene with defect-rich structure for efficient sodium storage

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Rare Metals 2024年第3期43卷 1062-1071页

作者： Ying Wang jia-Peng He Han-qing Pan qing-Peng Wang Lei Zhang Yong-Chang Liu qing-Hong Wang School of Chemistry&Materials Science Jiangsu Key Laboratory of Green Synthetic Chemistry for Functional MaterialsJiangsu Normal UniversityXuzhou221116China Institute of Biopharmaceutical Research Liaocheng UniversityLiaocheng252059China Beijing Advanced Innovation Center for Materials Genome Engineering Institute for Advanced Materials and TechnologyState Key Laboratory for Advanced Metals and MaterialsUniversity of Science and Technology BeijingBeijing100083China Centre for Catalysis and Clean Energy Gold Coast CampusGriffith UniversityGold CoastQLD4222Australia

The synthesis of a perpendicular growth structure of MoS_(2)nanosheets on graphene for efficient sodium storage is challenging yet ideal due to the benefits of open ion diffusion channels and high electronic *** this study,we have successfully fabricated a novel structure of vertical MoS_(2)nanosheets on graphene,with ZnS nanoparticles serving as bonding points(MoS_(2)/ZnS/G),through a facile hydrothermal *** the synthesis process,Zn^(2+)not only acts as a landing site for the vertical growth of MoS_(2)nanosheets but also triggers the formation of a defect-rich structure in the final *** unique architecture of MoS_(2)/ZnS/G effectively combines the advantages of a vertically aligned geometry and a defectrich structure for energy *** resulting structure displays shortened transport paths for electrons/ions,enhanced conductivity,improved structural integrity,and an increased number of active sites for promising electrochemical *** expected,when used as anode for sodium-ion batteries,the as-synthesize d MoS_(2)/ZnS/G exhibits excellent rate capability(high capacity of 298 mAh·g^(-1)at 5 A·g^(-1))and good cycling stability(a capacity decay of 0.056%per cycle after 500 cycles at 1 A·g^(-1)).According to the kinetic investigations,the electrochemical process of the MoS_(2)/ZnS/G sample is primarily governe d by a pseudocapacitive behavior,which enhances the charge/discharge kinetics and allows the MoS_(2)/ZnS/G structure to remain intact during cycling.

关键词： MoS_(2) Perpendicular growth Graphene Sodium storage Electrochemical performance