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Record-breaking summer-autumn drought in southern China in 2022:Roles of tropical sea surface temperature and Eurasian warming

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Science China Earth Sciences 2024年第2期67卷 420-431页

作者： Yuepeng HU Botao ZHOU Huijun WANG dapeng zhang Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters/Key Laboratory of Meteorological Disaster Ministry of Education/Joint International Research Laboratory of Climate and Environment ChangeNanjing University of Information Science and TechnologyNanjing210044China School of Atmospheric Sciences Nanjing University of Information Science and TechnologyNanjing210044China

From summer to autumn in 2022,a severe drought lasted in southern China,posing serious effects on economic growth and ecological *** study explored the atmospheric circulations accounting for this persistent drought *** shows that the drought in southern China during the summer of 2022 was strongly linked to the divergence of water vapor flux and descending motions,which were respectively caused by the anomalous anticyclone over the western North Pacific and the northward movement of the East Asian subtropical jet(EASJ).Differently,the atmospheric background responsible for the sustained drought in autumn is manly featured by a cyclonic circulation anomaly over the region from the Bay of Bengal to the South China Sea,which led to decreased moisture and descending motions in southern *** investigation suggests that the rarely strong surface warming over northern Eurasia and the extreme La Nina-like pattern over the tropical Pacific jointly resulted in the anomalous anticyclone over the western North Pacific and the northward shift of the EASJ in the summer of 2022,while the cyclonic circulation anomaly prevailing over the region from the Bay of Bengal to the South China Sea in autumn was largely attributed to the extremely negative anomalies of the tropical Indian Ocean sea surface temperature.

关键词： Summer-autumn drought Southern China Tropical sea surface temperature Eurasian warming

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Reconstruction of particle distribution for tomographic particle image velocimetry based on unsupervised learning method

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PARTICUOLOGY 2024年第10期93卷 349-363页

作者： zhang, Duanyu Huang, Haoqin Zhou, Wu Feng, Mingjun zhang, dapeng Gao, Limin Univ Shanghai Sci & Technol Sch Energy & Power Engn Shanghai 200093 Peoples R China Univ Shanghai Sci & Technol Shanghai Key Lab Multiphase Flow & Heat Transfer P Shanghai 200093 Peoples R China Northwestern Polytech Univ Natl Key Lab Aerodynam Design & Res Xian 710072 Peoples R China

The development of deep learning has inspired some new methods to solve the 3D reconstruction problem for Tomographic Particle Image Velocimetry (Tomo-PIV). However, the supervised learning method requires a large number of data with ground truth as training information, which is very difficult to gather from experiments. Although synthetic datasets can be used as alternatives, they are still not exactly the same with the real-world experimental data. In this paper, an Unsupervised Reconstruction Technique based on U-net (UnRTU) is proposed to reconstruct volume particle distribution explicitly. Instead of using ground truth data, a projection function is used as an unsupervised loss function for network training to reconstruct particle distribution. The UnRTU was compared with some traditional algebraic reconstruction algorithms and supervised learning method using synthetic data under different particle density and noise level. The results indicate that UnRTU outperforms these traditional approaches in both reconstruction quality and noise robustness, and is comparable to the supervised learning methods AI-PR. For experimental tests, particles dispersed in cured epoxy resin are moved by an electric rail with a certain speed to obtain the ground truth data of particle velocity. Compared with other algorithms, the reconstructed particle distribution by UnRTU has the best reconstruction fidelity. And the accuracy of the 3D velocity field estimated by UnRTU is 12.9% higher than that from the traditional MLOS-MART algorithm. It demonstrates significant potential and advantages for UnRTU in 3D reconstruction of particle distribution. Finally, UnRTU was successfully applied to the high-speed planar cascade airflow field, demonstrating its applicability for measuring complex fluid flow fields at higher particle density. (c) 2024 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V. This is an open acc

关键词： Tomographic particle image velocimetry 3D reconstruction Unsupervised learning Convolutional neural network FLOWS

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Monitoring Surface Water Change in Northeast China in 1999–2020:Evidence from Satellite Observation and Refined Classification

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Chinese Geographical Science 2024年第1期34卷 106-117页

作者： LIU Kai zhang dapeng CHEN Tan CUI Peipei FAN Chenyu SONG Chunqiao Key Laboratory of Watershed Geographic Sciences Nanjing Institute of Geography and LimnologyChinese Academy of SciencesNanjing210008China University of Chinese Academy of Sciences Nanjing(UCASNJ)Nanjing211135China Geographic Information and Tourism College Chuzhou UniversityChuzhou239000China

As a typical region with high water demand for agricultural production,understanding the spatiotemporal surface water changes in Northeast China is critical for water resources management and sustainable ***,the long-term variation characteristics of surface water of different water body types in Northeast China remain rarely *** study investigated how surface water bodies of different types(e.g.,lake,reservoir,river,coastal aquaculture,marsh wetland,ephemeral water) changed during1999–2020 in Northeast China based on various remote sensing-based *** results showed that surface water in Northeast China grew dramatically in the past two decades,with an equivalent area increasing from 24 394 km^(2) in 1999 to 34 595 km^(2) in *** surge of ephemeral water is the primary driver of surface water expansion,which could ascribe to shifted precipitation *** wetlands,rivers,and reservoirs experienced a similar trend,with an approximate 20% increase at the interdecadal *** contrast,coastal aquacultures and natural lakes remain relatively *** study is expected to provide a more comprehensive investigation of the surface water variability in Northeast China and has important practical significance for the scientific management of different types of surface water.

关键词： surface water spatiotemporal variation water body classification remote sensing Northeast China

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Enhanced Beta2-band Oscillations Denote Auditory Hallucination in Schizophrenia Patients and a Monkey Model of Psychosis

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Neuroscience Bulletin 2024年第3期40卷 325-338页

作者： Shuo Ma Tianzhen Chen Wenjun Jia Jie Liu Shihan Ding Puzhe Li Hong Gan dapeng zhang Shuxin Shao Mu-Ming Poo Min Zhao Bomin Sun Jian Jiang Department of Neurosurgery Ruijin HospitalSchool of MedicineShanghai Jiao Tong UniversityShanghai200020China Shanghai Mental Health Center Shanghai Jiao Tong University School of MedicineShanghai200030China Shanghai Center for Brain Science and Brain-inspired Technology Lingang LaboratoryShanghai201602China University of California at Berkeley BerkeleyCA94720USA School of Life Science and Technology ShanghaiTech UniversityShanghai201210China Institute of Neuroscience CAS Center for Excellence in Brain Science and Intelligence TechnologyCAS Key Laboratory of Primate NeurobiologyState Key Laboratory of NeuroscienceChinese Academy of SciencesShanghai200031China Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology Lingang LaboratoryShanghai201210China Fuyang Third People’s Hospital Fuyang Mental Health CenterFuyang236052China Shanghai Key Laboratory of Psychotic Disorders Shanghai200030China Institute of Psychological and Behavioral Science Shanghai Jiao Tong UniversityShanghai200030China Shanghai Quanlan Technology Co. LtdShanghai201602China

An electroencephalographic(EEG)signature of auditory hallucinations(AHs)is important for facilitating the diagnosis and treatment of AHs in *** recorded EEG from 25 schizophrenia patients with recurrent *** the period of AHs,EEG recordings exhibited significantly elevated beta2-band power in the temporal region,as compared to those recorded in the absence of AHs or during stimulation with verbal *** further generated methamphetamine-treated rhesus monkeys exhibiting psychosis-like behaviors,including repetitive sudden searching actions in the absence of external intrusion,suggesting the occurrence of *** EEG beta2-band power in the temporal region of these monkeys was enhanced immediately after methamphetamine treatment and positively correlated with the frequency of sudden searching ***,the enhancement of temporal beta2-band oscillations represents a signature for AHs in both patients and a monkey model of psychosis,and this monkey model can be used for developing closed-loop neuromodulation approaches for the treatment of refractory AHs in schizophrenia.

关键词： Schizophrenia Auditory hallucinations Non-human primate Methamphetamine Electroencephalography

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The Epidemiological Characteristics of Mpox Cases-China,2023

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China CDC weekly 2024年第26期6卷 619-623页

作者： Ruiqi Ren Chao Li Wenqing Bai Yali Wang Dan Li Fan Ding Niu Yan Qi Wang Nijuan Xiang Lianmei Jin Lei Zhou Wenling Wang Fan Lyu Peilong Li dapeng zhang Yan Li Quanyi Wang Qun Li Guoqing Shi National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases Chinese Center for Disease Control and PreventionBeijingChina Chinese Center for Disease Control and Prevention BeijingChina National Institute for Viral Disease Control and Prevention Chinese Center for Disease Control and PreventionBeijingChina National Center for AIDS/STD Control and Prevention Chinese Center for Disease Control and PreventionBeijingChina Guangdong Provincial Center for Disease Control and Prevention Guangzhou CityGuangdong ProvinceChina Beijing Municipal Center for Disease Prevention and Control BeijingChina

Summary What is already known about this topic?Since May 2022,a global outbreak of mpox has emerged in more than 100 non-endemic *** of December 2023,over 90,000 cases had been *** outbreak has predominantly affected men who have sex with men(MSM),with sexual contact identified as the principal mode of *** is added by this report?Since June 2023,China has faced an occurrence of mpox,predominantly affecting the MSM *** 90%of those affected reported engaging in homosexual behavior within 21 days prior to symptom onset,a trend that aligns with the global outbreak *** prompt identification of cases,diligent tracing of close contacts,and the implementation of appropriate management strategies have successfully mitigated the spread of mpox virus in *** are the implications for public health practice?We propose that mpox is transmitted locally within *** from our experiences in controlling the virus spread,it is crucial to investigate and formulate effective surveillance and educational ***,we must encourage high-risk populations to promptly seek medical care upon the onset of symptoms.

关键词： prompt Drawing spread

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考虑分离特性的包带式星箭连接结构优化设计

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宇航学报 2024年第5期45卷 680-691页

作者：于宝石张大鹏唐雨张文沁雷勇军国防科技大学空天科学学院长沙410073 空天任务智能规划与仿真湖南省重点实验室长沙410073 火箭军工程大学西安710025

针对高鲁棒性包带式星箭连接结构(CBJ)优化设计问题,提出一种兼顾结构的连接承载性能与分离冲击响应的包带式星箭连接结构轻量化设计方法。优化设计基于包带结构三维非线性有限元参数化模型,以连接框与夹块径向截面尺寸参数为设计变量,... 详细信息

针对高鲁棒性包带式星箭连接结构(CBJ)优化设计问题,提出一种兼顾结构的连接承载性能与分离冲击响应的包带式星箭连接结构轻量化设计方法。优化设计基于包带结构三维非线性有限元参数化模型,以连接框与夹块径向截面尺寸参数为设计变量,以结构静力学承载性能与动力学分离冲击为约束,以轻量化为目标。针对优化中设计空间高维度、非规则导致的算法收敛困难问题,提出了基于近似模型与序列采样策略的约束序列近似优化(CSAO)算法。结果表明:算法可实现在复杂设计域内迅速收敛至最优解,相较于初始设计,优化结构的质量降低了5.62%,同时,结构连接刚度提升了19.27%,卫星下裙解锁冲击降低了18.52%,在满足性能约束的条件下减重效果明显,验证了提出方法的有效性。设计的优化构型兼顾了连接与分离特性,具有一定的工程应用价值。

关键词：包带式星箭连接结构轻量化设计连接刚度冲击响应序列近似优化

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碳纳米管增强复合材料Timoshenko梁弯曲和屈曲行为分析

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国防科技大学学报 2024年第3期46卷 70-78页

作者：吴栋张大鹏于宝石雷勇军国防科技大学空天科学学院湖南长沙410073 空天任务智能规划与仿真湖南省重点实验室湖南长沙410073 火箭军工程大学陕西西安710025

考虑碳纳米管(carbon nanotubes,CNTs)的尺度效应,研究宏观尺度下碳纳米管增强复合材料(carbon nanotubes reinforced composites,CNTRCs)梁的弯曲和屈曲行为。在EMT(Eshelby-Mori-Tanaka)方法的基础上,利用非局部理论提出了可表征CNTs尺度效应的非局部EMT本构模型。根据Timoshenko梁理论,采用哈密顿原理得到CNTRCs梁的静力学微分方程和边界条件。求解简支边界条件下CNTRCs梁的弯曲响应和极限屈曲载荷,并与文献进行对比验证所建模型和求解方法的正确性。分析了CNTs的尺度效应参数和体积分数以及复合材料梁的长细比等因素对简支CNTRCs梁弯曲响应和极限屈曲载荷的影响规律。结果表明,考虑CNTs的尺度效应会削弱结构等效刚度,且CNTs体积分数和尺度效应参数对大长细比CNTRCs梁的弯曲响应和极限屈曲载荷的影响幅度较大。

关键词：非局部理论 Eshelby-Mori-Tanaka方法弯曲屈曲碳纳米管增强复合材料

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线黏弹性材料数字图像相关实验教学探索

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力学与实践 2024年第1期46卷 201-207页

作者：苏昂张大鹏张文沁关棒磊李璋国防科技大学空天科学学院长沙410073 图像测量与视觉导航湖南省重点实验室长沙410073

线黏弹性理论是固体力学原理课程的重要内容,目前实验教学一般采用电子万能试验机对线黏弹性材料进行单轴拉伸实验,实验结果不够直观。数字图像相关方法是一种高精度全场应变测量方法,近年来在实验力学领域应用广泛。本文以固体推进剂... 详细信息

线黏弹性理论是固体力学原理课程的重要内容,目前实验教学一般采用电子万能试验机对线黏弹性材料进行单轴拉伸实验,实验结果不够直观。数字图像相关方法是一种高精度全场应变测量方法,近年来在实验力学领域应用广泛。本文以固体推进剂这种线黏弹性材料为例,采用数字图像相关方法设计了线黏弹性材料单轴拉伸实验,实现了全场变形测量并且实验结果可视化更直观,有助于调动学生积极性。实验发现,数字图像相关方法与国标规定的固体推进剂单向拉伸法测量的材料应变有明显差异,针对该问题设计了实验教学研讨环节,引导学生深入分析,有助于加深对线黏弹性理论的理解。

关键词：数字图像相关线黏弹性单轴拉伸全场测量实验教学

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三温模型和基于阻抗蒸散发模型的整合与模拟分析

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北京林业大学学报 2024年第4期46卷 115-126页

作者：邢宇华张大鹏李思颖王佩北京师范大学地理科学学部北京100875 北京师范大学地表过程与资源生态国家重点实验室北京100875

【目的】整合消除阻抗的三温模型和基于阻抗的双源模型,开展蒸散发(ET)和蒸腾(T)的模拟及对比分析,实现不同模型的融合与蒸散发的动态模拟。【方法】本研究基于已有的双源阻抗模型框架、干土壤和干叶片能量平衡,结合数值模拟技术模拟了... 详细信息

【目的】整合消除阻抗的三温模型和基于阻抗的双源模型,开展蒸散发(ET)和蒸腾(T)的模拟及对比分析,实现不同模型的融合与蒸散发的动态模拟。【方法】本研究基于已有的双源阻抗模型框架、干土壤和干叶片能量平衡,结合数值模拟技术模拟了参考温度的季节动态,并将其与三温模型整合开展蒸腾和土壤蒸发的模拟。【结果】与涡动实测值相比,三温模型和双源模型对大满站日尺度ET模拟,R^(2)分别为0.85和0.72,对温带草地站小时尺度ET模拟,R^(2)均为0.89。在小时尺度模拟效果更好。并且,三温模型和双源模型对植被蒸腾的估算结果较为一致(R^(2)分别为0.67、0.68)。以上研究表明该研究框架对三温模型中参考温度的估算,提供了理论方法支撑,较好地量化了参考温度的时空动态。(2)模型情景试验分析表明:两个模型对2个站点的ET和T的预测结果相似,前提是冠层可利用能量(如净辐射)和地面土壤可利用能量(如净辐射和地热通量)受到能量平衡的限制。相反,由于输入驱动因子(温度和辐射)在干湿情景下的系统不匹配,三温模型对T和ET的模拟精度显著下降。因此,在能量平衡的框架内,干湿土地条件下输入的温度和辐射系统匹配时,三温模型的效果更好。(3)参考温度具有一定的日变化与季节变动。【结论】在白天,叶片和土壤参考温度普遍高于实际温度,而在夜晚低于实际温度,呈现出较大的日变幅。就日均值而言,参考温度普遍高于实际模拟温度。本研究的结果提供了一种新的温度梯度计算方法,可用来监测冠层水分胁迫及动态。

关键词：数值模拟参考温度三温模型双源模型蒸散发植物水压力能量平衡

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基于高速公路客流数据的重庆与毗邻地区联系网络空间结构研究

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热带地理 2024年第5期44卷 794-803页

作者：宗会明刘绘敏陈易林张大鹏张嘉敏西南大学地理科学院重庆400715 自然资源部国土空间规划监测评估预警重点实验室重庆401147 重庆市交通规划研究院重庆401147 山东省建筑设计研究院有限公司济南250001

基于高速公路交通客流数据,采用社会网络与GIS空间分析法,以客流联系视角探讨重庆市与毗邻地区的城镇网络空间结构。结果表明:1)重庆中心城区为网络的绝对核心,长寿、江津、璧山为网络中的重要节点城市,涪陵、璧山、长寿在网络中通达性... 详细信息

基于高速公路交通客流数据,采用社会网络与GIS空间分析法,以客流联系视角探讨重庆市与毗邻地区的城镇网络空间结构。结果表明:1)重庆中心城区为网络的绝对核心,长寿、江津、璧山为网络中的重要节点城市,涪陵、璧山、长寿在网络中通达性明显,涪陵、黔江、江津、万州的中介作用突出;2)重庆与毗邻地区的客流网络呈现三级轴线联系,整体网络呈现明显的放射性特征,部分地区联系突破省级行政边界,网络层级按照“4+15+18”分布;3)重庆与毗邻地区的凝聚子群表现出高度的地理邻近性,形成“核心―边缘”结构。未来重庆中心城区需进一步加强与四川东部地级市的辐射能力与交通联系,进一步培育与成都双城联系的发展轴,在远期发展中考虑纳入遵义市等地区更好融入重庆都市圈。

关键词：网络结构公路客流都市圈联系毗邻地区重庆

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