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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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A modified Johnson–Cook model for 7N01 aluminum alloy under dynamic condition

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Journal of Central South University 2017年第11期24卷 2550-2555页

作者： zhang Yi-ben yao Song HONG Xiang WANG zhong-gang Key Laboratory of Traffic Safety on Track of Ministry of Education School of Traffic and Transportation EngineeringCentral South UniversityChangsha 410075China

Tensile tests at different strain rates(0.0002, 0.002, 0.02, 1000 and 3000 s^(-1)) were carried out for 7N01 aluminum alloy. Low strain rate experiments(0.0002, 0.002 and 0.02 s^(-1)) were conducted using an electronic mechanical universal testing machine, while high strain rate experiments(1000, 3000 s^(-1)) were carried out through a split Hopkinson tensile bar. The experimental results showed that 7N01 aluminum alloy is strain rate sensitive. By introducing a correction scheme of the strain rate hardening coefficient, a modified Johnson–Cook model was proposed to describe the flow behaviors of 7N01 aluminum alloy. The proposed model fitted the experimental data better than the original Johnson–Cook model in plastic flow under dynamic condition. Numerical simulations of the dynamic tensile tests were performed using ABAQUS with the modified Johnson–Cook model. Digital image correlation was used together with high-speed photography to study the mechanical characters of specimen at high strain rate. Good correlations between the experiments results, numerical predictions and DIC results are achieved. High accuracy of the modified Johnson-Cook model was validated.

关键词： aluminum alloy constitutive relation modified Johnson–Cook model high strain rate digital image correlation finite element analysis

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Selective flotation separation of andalusite and quartz and its mechanism

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International Journal of Minerals,Metallurgy and Materials 2019年第9期26卷 1059-1068页

作者： Yan-ping Niu Chuan-yao Sun Wan-zhong Yin Xing-rong zhang Hong-feng Xu Xu zhang College of Resources and Civil Engineering Northeastern UniversityShenyang 110000China State Key Laboratory of Mineral Processing BGRIMM Technology GroupBeijing 100160China The Research Center of Experimental Testing for Geology and Minerals in Heilongjiang Province Harbin 150000China Heilongjiang Mining Group Co. Ltd. Harbin 150000China

The separation of andalusite and quartz was investigated in the sodium oleate flotation system, and its mechanism was studied by solution chemical calculation, zeta-potential tests, Fourier transform infrared spectroscopic(FTIR), and X-ray photoelectron spectroscopic(XPS). The flotation tests results show that FeCl3·6H2O has a strong activation effect on andalusite and quartz and citric acid has a strong inhibitory effect on activated quartz, thus increasing the floatability difference between quartz and andalusite when the pulp p H is approximately 8. The FTIR, Zeta potential, and XPS analyses combined with the chemical calculation of flotation reagent solutions demonstrate that Fe forms hydroxide precipitates on the surface of andalusite and quartz and that oleate anions and metal ions adsorb onto the surface of the minerals. The elements Al and Fe can be chemically reacted. The anions in citric acid have different degrees of dissolution of Fe on the andalusite and quartz surfaces, thereby selectively eliminating the activation of the elemental Fe on andalusite and quartz and increasing the floatability of andalusite, leading to a better separation effect between andalusite and quartz.

关键词： andalusite quartz flotation mechanism zeta potential Fourier infrared spectrum analysis X-ray photoelectron energy spectrum analysis

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Novel Spectrum Allocation Algorithm Based on the Activities of Primary Users for Cognitive Radio Networks

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Journal of Harbin Institute of Technology(New Series) 2013年第1期20卷 57-62页

作者： yao Wang zhong-Zhao zhang Lin Ma Jia-Mei Chen Communication Research Center Harbin Institute of Technology Science and Technology on Information Transmission and Dissemination in Communication Networks Laboratory Shenyang Artillery Academy

In traditional cognitive radio (CR) network, most existing graph-based spectrum allocation schemes don't take on-off behavior of primary users (PUs) into consideration. In this paper, a novel spectrum allocation algorithm based on the activities of the PUs is proposed. The proposed algorithm mainly focuses on the vacant probability of licensed spectrums. And it allocates the vacant spectrums considering the interference to the neighbor cognitive nodes and the probability fairness of different cognitive nodes during the allocation. Based on the definition of the obtained benefit of cognitive node, new utility functions are formulated to characterize the system total spectrum utilization and fairness performance from the perspective of available probability. The simulation results validate that the proposed algorithm with low system communication cost is more effective than the traditional schemes when the available licensed spectrums are not sufficient, which is effective and meaningful to a real CR system with bad network condition.

关键词： cognitive radio resource allocation activities of primary users fairness.

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A new protoberberine alkaloid from Corydalis yanhusuo ***

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Chinese Chemical Letters 2009年第8期20卷 955-957页

作者： Tian Tian Hu Xue zhang Shi zhong Ma Xin Sheng yao School of Traditional Chinese Materia Medica Shenyang Pharmaceutical University Shenyang 110016 China

A new protoberberine alkaloid, named 5,6-dihydro- 10-hydroxy-2,3,9-trimethoxy- 13-methyldibenzo[α,g]quinoliziniurn （1） was isolated from the 60% ethanol extract of the tubers of Corydalis yanhusuo W. T. Wang, together with a new natural product, 13methylpalmatrubine （2）. Their structures were established by spectroscopic methods. 2009 Xin Sheng yao. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All fights reserved.

关键词： Corydalis yanhusuo W. T. Wang Protoberberine alkaloid 13-Methylpalmatrubine

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Targeting Epac2 and GluA3-containing AMPARs:a novel therapeutic strategy for Alzheimer's disease

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Neural Regeneration Research 2025年第11期20卷 3223-3224页

作者： Tong zhang Martina Schmidt Department of Molecular Pharmacology Groningen Research Institute of PharmacyUniversity of GroningenGroningenThe Netherlands School of Pharmacy Tianjin Medical UniversityTianjinChina

Alzheimer's disease(AD)is a neurodegenerative disease that manifests progressive decline in memory and *** the early stage of AD,memory retrieval is impaired preceding memory acquisition and consolidation(Roy et al.,2016).Prior to the onset of symptoms,pathological amyloid-β(Aβ)plagues and tau protein tangles accumulate in extracellular and intracellular spaces,respectively,leading to *** these hallmark pathologies,Aβ is proposed to be the primary etiology by triggering a cascade of pathogenic events,including neuroinflammation,oxidative stress,tau hyperphosphorylation,synaptic/neuronal dysfunction,and neuronal death(zhang et al.,2023b).

关键词： Alzheimer impaired Aβ

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Thermal-flow-electric coupling performance analysis of a liquid-immersed battery thermal management system

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Science China Technological Sciences 2025年第1期 157-176页

作者： Qiang GAO Jun TIAN Chujin BAO Yangfan zhong Chengbin zhang Yongping CHEN School of Energy and Environment Southeast University Battery Testing Center China North Vehicle Research Institute Zhejiang Immertech Co. Ltd. Alibaba Cloud Computing Co. Ltd.

Ensuring the safety and performance of lithium-ion batteries(LIBs) is a significant challenge for electric *** tackle this issue, an innovative liquid-immersed battery thermal management system(LIBTMS) using bionic baffles with fish-like perforations is developed. The thermal-flow-electric coupling characteristics of LIBTMSs with different baffle structures(no baffle, conventional baffle, baffle with circular perforations and baffle with fish-like perforations) are systematically investigated using experimental and numerical methods. The results indicate that the forced flow scheme exhibits better thermal management performance and voltage equalization than static flow. Moreover, the LIB temperatures and voltage deviations of different LIBTMSs increase quickly with increasing discharge rates. More importantly, the innovative LIBTMS exhibits the best thermoelectric performance due to its excellent thermoelectric equilibrium behavior caused by high electrical and temperature consistency, as well as the best overall performance involving the balance between the pressure loss and heat transfer capacity of the system. Compared with other structures, the innovative LIBTMS using baffles with fish-like perforations exhibits a maximum reduction of 10.1%, 15.2%, 25.8% and 9.0% in LIB maximum temperature, maximum temperature difference, system pressure drop and voltage deviation, respectively, under the same operating ***, for the LIBTMS using baffles with fish-like perforations, the bottom inlet and top outlet configuration and coolant precooling are suggested to enhance cooling performance.

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不同热处理蛋黄脂质对小鼠学习认知能力下降的缓解能力

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食品工业科技 2025年第1期46卷 367-376页

作者：吴瑶刘铭坤方冰张明合肥工业大学食品与生物工程学院安徽合肥230061 中国农业大学营养与健康系北京100083 北京工商大学食品与健康学院北京100048

为探讨不同温度处理下蛋黄脂质对小鼠学习认知能力下降的缓解能力的差异。本研究利用小鼠认知障碍模型,比较95℃(水浴30 min)和121℃(灭菌锅加热30 min)热处理蛋黄脂质组分改善小鼠学习认知能力的差异。研究结果表明,相较于121℃热处理... 详细信息

为探讨不同温度处理下蛋黄脂质对小鼠学习认知能力下降的缓解能力的差异。本研究利用小鼠认知障碍模型,比较95℃(水浴30 min)和121℃(灭菌锅加热30 min)热处理蛋黄脂质组分改善小鼠学习认知能力的差异。研究结果表明,相较于121℃热处理的蛋黄脂质,95℃热处理的蛋黄脂质更有效地降低了Tau蛋白的磷酸化和Aβ1-40、GSK-3β表达,下调了促炎因子的表达,其提升小鼠的学习记忆能力的效果更好。95℃热处理蛋黄脂质中的多不饱和脂肪酸以及DHA较121℃热处理的蛋黄脂质显著增加(P<0.05)。因此,过度的加热条件,会破坏蛋品中DHA等多不饱和脂肪酸,削弱蛋黄脂质的改善认知的生物活性。本研究为蛋制品的热加工工艺的优化提供参考依据。

关键词：蛋黄脂质热处理学习和记忆

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Multi-depots distribution problem study based on rich network road model

Multi-depots distribution problem study based on rich networ...

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第25届中国控制与决策会议

作者： Chunlong yao Guijun zhang Beijin zhang Siheng zhong College of Information Engineering Zhejiang University of Technology

ISBN: (纸本)9781467355339

The multi-depots distribution logistic is a particular combination of transportation and routing problems, in which items that have to be loaded into different customers within vehicles, and then delivered with minimum cost. In this paper, a model is built firstly and the weights between the target nodes are acquired based on actual network road by branch-and-cut and Dijkstra algorithms;Next, the idea of the evolutionary tree classification is used to solve the nonlinear cost variables in the distribution model. Extensive computational results show that the proposed algorithm are capable of solving to optimality for a large number of small-size instances, and consistently outperform previous algorithms from the literature on large-size and real-world instances.

关键词： rich network model dijkstra algorithm linear programming path optimal time optimal

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Ammonia pyrolysis oxidation excited by nanosecond pulsed discharge:Global/fluid models hybrid solution

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Journal of Energy Chemistry 2025年第1期100卷 385-396页

作者： Mingming zhang Hanyu Wu Qi Chen Jiaxin Yang Bonan Liu School of Mechanical Electronic and Control Engineering Beijing Jiaotong University China University of Petroleum

The kinetic characteristics of plasma-assisted oxidative pyrolysis of ammonia are studied by using the global/fluid models hybrid solution ***,the stable products of plasma-assisted oxidative pyrolysis of ammonia are *** results show that the consumption of NH3/O2and the production of N2/H2change linearly with the increase of voltage,which indicates the decoupling of nonequilibrium molecular excitation and oxidative pyrolysis of ammonia at low ***,the detailed reaction kinetics mechanism of ammonia oxidative pyrolysis stimulated by a nanosecond pulse voltage at low pressure and room temperature is *** on the reaction path analysis,the simplified mechanism is *** detailed and simplified mechanism simulation results are compared with experimental data to verify the accuracy of the simplified ***,based on the simplified mechanism,the fluid model of ammonia oxidative pyrolysis stimulated by the nanosecond pulse plasma is established to study the pre-sheath/sheath behavior and the resultant consumption and formation of key *** results show that the generation,development,and propagation of the pre-sheath have a great influence on the formation and consumption of *** consumption of NH3by the cathode pre-sheath is greater than that by the anode pre-sheath,but the opposite is true for OH and O（1S）.However,within the sheath,almost all reactions do not ***,by changing the parameters of nanosecond pulse power supply voltage,it is found that the electron number density,electron current density,and applied peak voltages are not the direct reasons for the structural changes of the sheath and ***,the discharge interval has little effect on the sheath structure and gas mixture *** research results of this paper not only help to understand the kinetic promotion of non-equilibrium excitation in the process of oxidative pyrolysis but also help to explore th

关键词： Nanosecond pulsed discharge Ammonia Oxidative pyrolysis Fluid model Global model

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