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Characteristics and Preliminary Causes of Tropical Cyclone Remote Precipitation over China

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Journal of Ocean University of China 2024年第4期23卷 845-858页

作者： jia li REN Fumin MCBRIDE John Leonard CONG Chunhua School of Atmospheric Science Nanjing University of Information Science and TechnologyNanjing 210044China State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesBeijing 100081China School of Earth Science University of MelbourneMelbourne 3052Australia Research and Development Division Bureau of MeteorologyMelbourne 3052Australia Shandong Meteorological Bureau Jinan 250031China

In this study,the characteristics and preliminary causes of tropical cyclone remote precipitation(TRP)over China during the period from 1979 to 2020 are *** indicated that approximately 72.42%of tropical cyclones(TCs)in the Western Pacific produce TRP over *** peak months for TRP are July and *** four key regions of TRP are the adjacent areas between the Sichuan and Shaanxi Provinces,the northern coast of the Bohai Sea,the coast of the Yellow Sea,and the southern coast *** typical distance between the station with TRP and the TC center ranges from 1500 to 2500 *** of these stations are situated north to 60°west of north of the *** south–west water vapor transportation on the west side of the TC is crucial to *** has a decreasing trend because of the decrease in the number of TCs that generate *** the perspective of large-scale environmental conditions,a decrease in the integrated horizontal water vapor transport in China' Mainland,the weakening of upward motion at approximately 25°–35°N,which is inconducive to convection,and an increase in low-level vertical wind shear,which is unfavorable for the development of TC in areas with high frequencies of TRP-related TCs,are the factors that result in the decreasing trend of TRP.

关键词： tropical cyclone remote precipitation characteristics causes

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

同方期刊数据库

Collaborative multi-lane on-ramp merging strategy for connected and automated vehicles using dynamic conflict graph

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Journal of Intelligent and Connected Vehicles

Journal of Intelligent and Connected Vehicles 2024年第1期7卷 38-51页

作者： jia Shi Yugong Luo Pengfei li jiawei Wang Keqiang li School of Vehicle and Mobility Tsinghua UniversityBeijing 100084China Department of Civil and Environmental Engineering University of MichiganAnn ArborMI 48109USA

The on-ramp merging in multi-lane highway scenarios presents challenges due to the complexity of coordinating vehicles’merging and lane-changing behaviors,while ensuring safety and optimizing traffic ***,there are few studies that have addressed the merging problem of ramp vehicles and the cooperative lane-change problem of mainline vehicles within a unified framework and proposed corresponding optimization *** tackle this issue,this study adopts a cyber-physical integration perspective and proposes a graph-based solution ***,the information of vehicle groups in the physical plane is mapped to the cyber plane,and a dynamic conflict graph is introduced in the cyber space to describe the conflict relationships among vehicle ***,graph decomposition and search strategies are employed to obtain the optimal solution,including the set of mainline vehicles changing lanes,passing sequences for each route,and corresponding ***,the proposed dynamic conflict graph-based algorithm is validated through simulations in continuous traffic with various densities,and its performance is compared with the default algorithm in *** results demonstrate the effectiveness of the proposed approach in improving vehicle safety and traffic efficiency,particularly in high traffic density scenarios,providing valuable insights for future research in multi-lane merging strategies.

关键词： cooperative merging multi-lane graph theory cyber-physical integration system

A study of novel real-time power balance strategy with virtual asynchronous machine control for regional integrated electric-thermal energy systems

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Science China(Technological Sciences) 2024年第7期67卷 2074-2086页

作者： WANG Rui li Ming-jia WANG YiBo SUN QiuYe ZHANG Pinjia College of Information Science and Engineering Northeastern UniversityShenyang 110819China School of Mechanical Engineering Beijing Institute of TechnologyBeijing 100081China Department of Electrical Engineering Tsinghua UniversityBeijing 100084China

The development of regional integrated electric-thermal energy systems(RIETES) is considered a promising direction for modern energy supply systems. These systems provide a significant potential to enhance the comprehensive utilization and efficient management of energy resources. Therein, the real-time power balance between supply and demand has emerged as one pressing concern for system stability operation. However, current methods focus more on minute-level and hour-level power optimal scheduling methods applied in RIETES. To achieve real-time power balance, this paper proposes one virtual asynchronous machine(VAM) control using heat with large inertia and electricity with fast response speed. First, the coupling timescale model is developed that considers the dynamic response time scales of both electric and thermal energy systems. Second, a real-time power balance strategy based on VAM control can be adopted to the load power variation and enhance the dynamic frequency response. Then, an adaptive inertia control method based on temperature variation is proposed, and the unified expression is further established. In addition, the small-signal stability of the proposed control strategy is validated. Finally, the effectiveness of this control strategy is confirmed through MATLAB/Simulink and HIL(Hardware-in-the-Loop) experiments.

关键词： regional integrated electric-thermal energy systems real-time power balance virtual asynchronous machine adaptive inertia small-signal stability

Demonstration of safety characteristics and effects on gut microbiota of Lactobacillus gasseri HMV18

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Food Science and Human Wellness 2024年第2期13卷 611-620页

作者： Xianxian jia Miaomiao jia Xiang Gao Xiang li Mengyuan Wang Shengqiang Du Rui Huang Xiaotong li Jun Zhang Shujin li Chunling Ma Yan Zhang Bin Cong Department of Pathogen Biology Institute of basic MedicineHebei Medical UniversityShijiazhuang 050017China Research Unit of Digestive Tract Microecosystem Pharmacology and Toxicology Chinese Academy of Medical SciencesShijiazhuang 050017China Institute of Basic Medicine Hebei Medical UniversityShijiazhuang 050017China College of Forensic Medicine Hebei Key Laboratory of Forensic MedicineCollaborative Innovation Center of Forensic Medical Molecular IdentificationHebei Medical UniversityShijiazhuang 050017China Hebei Food Safety Key Laboratory Hebei Food Inspection and Research InstituteShijiazhuang 050227China

Human normal flora is a source of *** safety characteristics of a specific isolate determine its application in foods or *** food-borne-pathogen antagonist strain Lactobacillus gasseri HMV18 is one of the isolates from normal human *** this work,we assessed the in vitro pH tolerance,bile tolerance,biogenic amine production,mucin utilization,and safety of in vivo administration to mice to evaluate general health,organ-body weight index,organ histopathological change,whether *** HMV18 can colonize in the gut or modulate the gut microbiota after oral *** results suggest that *** HMV18 can tolerate pH 3 for 2 h,3%bile for 3 h,biogenic amine negative,mucin usage negative,does not encode verified toxins,and cause no visible change in mice's *** HMV18 might not colonize in mice's gut,but can significantly affect the structure of gut microbiota.A bibliographical survey suggested that there were as few as 8 opportunistic infection cases from 1984 to 2022 and that the possibility for *** to cause infection is relatively ***,this work provides a basis for the foods or drugs application of *** HMV18 and gives a map of experiments for the safety assessment of probiotics.

关键词： Probiotics Lactobacillus gasseri Safety assessment Gut microbiota

High-rate lithium-ion battery performance of a ternary sea urchin-shaped CoNiO_(2)@NiP_(6)Mo_(18)/CNTs composites

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Journal of Energy Chemistry 2024年第9期96卷 516-525页

作者： li-ping Cui Shuang Sun Kai Yu Shu Zhang Mei-lin Wang jia-jia Chen Bai-bin Zhou Key Laboratory for Photonic and Electronic Bandgap Materials Ministry of EducationSchool of Chemistry and Chemical EngineeringHarbin Normal UniversityHarbin 150025HeilongjiangChina State Key Laboratory of Physical Chemistry of Solid Surfaces Department of ChemistryCollege of Chemistry and Chemical EngineeringCollaborative Innovation Centre of Chemistry for Energy MaterialsXiamen UniversityXiamen 361005FujianChina

Bimetallic oxides are attractive anode materials for lithium-ion batteries(liBs)due to their large theoretical ***,the low conductivity,short cycle life,and poor rate capability are the bottlenecks for their further *** overcome above issues,the basket-like polymolybdate(NiP_(6)Mo_(18))and carbon nanotubes(CNTs)were uniformly embedded on the urchin-shaped CoNiO_(2)nanospheres to yield a ternary composites CoNiO_(2)@NiP_(6)Mo_(18)/CNTs via electrostatic *** multi-level morphology of urchin spinules accelerates the diffusion rate of li^(+);CNT improves the conductivity and enhances cycle stability of the material;and heteropoly acid contributes more redox activity ***,CoNiO_(2)@NiP_(6)Mo_(18)/CNTs as an anode of liBs exhibits a high initial capacity(1396.7 mA h g^(−1)at 0.1 A g^(−1)),long-term cycling stability(750.2 mA h g^(−1)after 300 cycles),and rate performance(450.3 mA h g^(−1)at 2 A g^(−1)),which are superior to reported metallic oxides anode of *** density functional theory(DFT)and kinetic mechanism suggest that CoNiO_(2)@NiP_(6)Mo_(18)/CNTs delivers an outstanding pseudocapacitance and rapid li^(+)diffusion behaviors,which is due to the rich surface area of the urchin-like CoNiO_(2)with the uniform embeddedness of NiP_(6)Mo_(18)and *** study provides a new idea for optimizing the performance of bimetallic oxides and developing high-rate lithium-ion battery composites.

关键词： Bi-metal oxides Transition metal oxides Polyoxometalates nanocomposite liBs

Effect of Sc on Al_(3)Fe phase and mechanical properties of as-cast AA5052 aluminum alloy

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China Foundry 2024年第3期21卷 257-264页

作者： Yang li Qing Yu Feng-feng Chen jia-wen He Hong-mei Yang Meng-nie li Faculty of Materials Science and Engineering Kunming University of Science and TechnologyKunming 650093China

The AA5052 aluminum alloy is widely used in automobile and aerospace manufacturing,and with the development of light-weight alloys,it is required that these materials exhibit better mechanical *** studies have demonstrated that the addition of Sc to aluminum alloys can improve both the microstructure and properties of the *** this study,the effect of Sc on the Fe-rich phase and properties of the AA5052 aluminum alloy was studied by adding 0%,0.05%,0.2%,and 0.3%*** results show that with the increase of Sc,the coarse needle-like Fe-rich phase gradually transforms into Chinese-script and then nearly spherical particles,reduce the size of Fe-rich phase,and refine the grain with increase of high angle grain boundaries(HAGBs).These microstructure changes enhance the strength of the AA5052 alloy through Sc *** ductility of the alloy is obviously improved because the addition of a lower amount of Sc changes the morphology of Fe-rich phase from needle-like into a Chinese-script,and it is subsequently reduced as a result of significant increase in HAGBs with increasing Sc content.

关键词： AA5052 aluminum alloy Al3Fe phase mechanical properties grain boundary

Stress-assisted corrosion mechanism of 3Ni steel by using gradient boosting decision tree machining learning method

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International Journal of Minerals,Metallurgy and Materials 2024年第6期31卷 1311-1321页

作者： Xiaojia Yang Jinghuan jia Qing li Renzheng Zhu Jike Yang Zhiyong liu Xuequn Cheng Xiaogang li Institute of Advanced Materials and Technology University of Science and Technology BeijingBeijing 100083China AECC Key Laboratory of Advanced Corrosion and Protection of Aeronautical Materials AECC Beijing Institute of Aeronautical MaterialsBeijing 100095China Shunde Innovation School University of Science and Technology BeijingFoshan 528399China

Traditional 3Ni weathering steel cannot completely meet the requirements for offshore engineering development,resulting in the design of novel 3Ni steel with the addition of microalloy elements such as Mn or Nb for strength enhancement becoming a *** stress-assisted corrosion behavior of a novel designed high-strength 3Ni steel was investigated in the current study using the corrosion big data *** information on the corrosion process was recorded using the galvanic corrosion current monitoring *** gradi-ent boosting decision tree(GBDT)machine learning method was used to mine the corrosion mechanism,and the importance of the struc-ture factor was *** exposure tests were conducted to verify the calculated results using the GBDT *** indic-ated that the GBDT method can be effectively used to study the influence of structural factors on the corrosion process of 3Ni ***-ferent mechanisms for the addition of Mn and Cu to the stress-assisted corrosion of 3Ni steel suggested that Mn and Cu have no obvious effect on the corrosion rate of non-stressed 3Ni steel during the early stage of *** the corrosion reached a stable state,the in-crease in Mn element content increased the corrosion rate of 3Ni steel,while Cu reduced this *** the presence of stress,the increase in Mn element content and Cu addition can inhibit the corrosion *** corrosion law of outdoor-exposed 3Ni steel is consistent with the law based on corrosion big data technology,verifying the reliability of the big data evaluation method and data prediction model selection.

关键词： weathering steel stress-assisted corrosion gradient boosting decision tree machining learning

Wireless Power Supply Based on MNG-MNZ Metamaterial for Cardiac Pacemakers

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CES Transactions on Electrical Machines and Systems 2024年第1期8卷 103-112页

作者： Weihua Chen Jingtao jia Xiaoheng Yan Yuhang Song jiayi li Faculty of Electrical and Control Engineering Liaoning Technical UniversityNo.188Longwan South StreetXingchengHuludao 125105China CES

To solve the low power transfer efficiency and magnetic field leakage problems of cardiac pacemaker wireless powering, we proposed a wireless power supply system suitable for implanted cardiac pacemaker based on mu-negative(MNG) and mu-nearzero(MNZ) metamaterials. First, a hybrid metamaterial consisted of central MNG unit for magnetic field concentration and surrounding MNZ units for magnetic leakage shielding was established by theoretical calculation. Afterwards, the magnetic field distribution of wireless power supply system with MNG-MNZ metamaterial slab was acquired via finite element simulation and verified to be better than the distribution with conventional MNG slab deployed. Finally, an experimental platform of wireless power supply system was established with which power transfer experiment and system temperature rise experiment were *** and experimental results showed that the power transfer efficiency was improved from 44.44%,19.42%, 8.63% and 6.19% to 55.77%, 62.39%, 20.81%and 14.52% at 9.6 mm, 20 mm, 30 mm and 50 mm,respectively. The maximum SAR acquired by SAR simulation under human body environment was-7.14 dbm and maximum reduction of the magnetic field strength around the receiving coil was 2.82 A/m. The maximum temperature rise during 30min charging test was 3.85℃,and the safety requirements of human bodies were met.

关键词： Cardiac pacemaker MNG metamaterial MNZ metamaterial Wireless power supply system