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Summer extreme precipitation patterns and synoptic-scale circulation precursors over the Tibetan Plateau

Science China Earth Sciences 2024年第5期67卷 1625-1638页

作者： Zhiyuan ding Yao HA Zhong ZHONG College of Meteorology and Oceanography National University of Defense TechnologyChangsha 410073China Key Laboratory for Virtual Geographic Environment School of Geography ScienceNanjing Normal UniversityNanjing 210023China Jiangsu Collaborative Innovation Center for Climate Change School of Atmospheric SciencesNanjing UniversityNanjing 210023China

In the context of global warming,the extreme summer precipitation over the Tibetan Plateau(TP)has changed *** this study,the summer(June–August)extreme precipitation on the TP was classified into three spatial types by applying the K-means clustering method to the Third Pole Region long time-series high-resolution(1/30°)precipitation dataset(TPHi Pr,1979–2020).The characteristics of the circulation anomalies and precursors corresponding to the extreme precipitation on the TP in summer during 1979–2020 were *** results showed that the summer extreme precipitation of the TP can be categorized into northwestern(NW),southeastern(SE),and southern Himalayan(HS)types based on extreme precipitation *** NW and SE types are mainly influenced by anomalous signals in the mid-to-high latitude regions upstream of them,whereas the HS type is controlled by the localized subtropical anomalous *** the 8th day before the onset of the NW type,an anomalous cyclone was observed in the western Atlantic Ocean(60°W,50°N),which triggered the west-to-east quasi-latitudinal propagation of Rossby *** the onset day of the NW type,the upper troposphere showed positive-negative-positive geopotential height anomalies along the latitudinal 40°N from the Caspian Sea,the western part of Xinjiang,to the northeastern *** entered from the Arabian Sea along the southeastern edge of the anomalous cyclone on the southwestern TP and converged in the northwestern *** to the NW type,the precursors of the SE type appeared at higher latitudes and were more *** the 8th day before the onset of the SE type,an anomalous cyclone occurred near Greenland(60°W,70°N)and excited Rossby waves propagating *** the onset day of the SE type,the upper troposphere showed negative-positive-negative geopotential height anomalies across Eurasia from the Ural Mountains and the Iranian Plateau to the northern TP in the northwest-southeast directi

关键词： Tibetan Plateau Summer extreme precipitation Atmospheric circulation anomaly Precursor Teleconnection wave train

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De novo Synthesis of Chiral 3,4-Dihydroquinazolines via One-Pot Enantioselective Ugi-Azide/Cyclization Sequences

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Chinese Journal of Chemistry 2024年第18期42卷 2140-2146页

作者： Zu-Kui Xie Jun-Jun ding yi-Ming Ou Jun-Xiu Shi Meng-Lan Shen Chuan-Zhi Yao Hua-Jie Jiang Jie Yu Department of Applied Chemistry Anhui Province Engineering Laboratory for Green Pesticide Development and Applicationand Anhui Province Key Laboratory of Crop Integrated Pest ManagementAnhui Agricultural UniversityHefeiAnhui 230036China

Background and Originality Content,3,4-Dihydroquinazoline frameworks have frequently been encountered in natural products and bioactive *** the past decades,these key structures prompted the development of creative pharmaceuticals owing to their prominent biological properties,including trypanothione reductase(TryR)inhibitor,Hepatitis B virus(HBV)inhibitive activities,anticancer activities,etc.(Scheme 1A).[1]Notably,the chirality of the C4 atom is crucial for drug *** example,the DPC-083 is a potent reverse transcriptase inhibitor for the treatment of HIV infection but the undesired enantiomers exhibit virtually no activity.[ia]Therefore,developing synthetic methods for innovative chiral 4-substituted 3,4-dihydroquinazolines is significant and essential for drug discovery.

关键词： Anionic stereogenic-at-cobalt(ll)complex De novo synthesis post-Ugi transformation One-pot sequence Asymmetric synthesis Multicomponentreactions

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Advances and prospects in SAR microwave vision three-dimensional imaging

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National Science Open 2024年第5期3卷 53-83页

作者： Xiaolan Qiu Zekun Jiao zhe Zhang Qiancheng Yan Chibiao ding National Key Laboratory of Microwave Imaging Aerospace Information Research InstituteChinese Academy of SciencesBeijing 100190China School of Electronic Electrical and Communication EngineeringUniversity of Chinese Academy of SciencesBeijing 100094China Key Laboratory of Intelligent Aerospace Big Data Application Technology Suzhou 215123China

Synthetic Aperture Radar three-dimensional(3D)imaging enables the acquisition of more comprehensive information,making it a recent hotspot in radar *** 3D imaging methods have evolved from 2D and interferometric imaging,combining elevation aperture extension with signal processing *** such as long acquisition or complex system from its imaging mechanism restrict its *** recent years,rapid development of artificial intelligence has led to a swift advancement in radar,injecting new vitality into SAR 3D *** microwave vision 3D imaging theory,which is built upon advanced technologies,has emerged as a new interdisciplinary field for radar *** paper reviews SAR 3D imaging’s history and present situation,and introduces SAR microwave *** establish a theoretical framework covering representation models,computational models,processing paradigms and evaluation ***,our research progress in this area is discussed,along with future prospects for SAR microwave vision 3D imaging.

关键词： SAR microwave vision 3D imaging visual semantics scattering mechanism

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Large magnetostriction of Nd_(0.2)Tb_(0.3)Dy_(0.5)Fe_(1.93)/epoxy composites in a wide temperature range

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Journal of Rare Earths 2024年第4期42卷 705-709页

作者： Hehe ding Yangguang Shi Shaolong Tang MIIT Key Laboratory of Aerospace Information Materials and Physics Department of Applied PhysicsNanjing University of Aeronautics and AstronauticsNanjing210016China National Laboratory of Solid State Microstructures Nanjing UniversityNanjing210093China

We report the magnetostrictive performance of the Nd_(0.2)Tb_(0.3)Dy_(0.5)Fe_(1.93)/epoxy *** of M?ssbauer spectra and the XRD results indicate that the easy magnetic direction of the Nd_(0.2)Tb_(0.3)Dy_(0.5)Fe_(1.93)compound is alongdirection with spontaneous magnetostrictionλ111 of1900 ***-oriented Nd_(0.2)Tb_(0.3)Dy_(0.5)Fe_(1.93)/epoxy composites with particle volume fractions of20 vol%-55 vol%were *** measurements demonstrate that the composite is highly *** raw material cost of Nd_(0.2)Tb_(0.3)Dy_(0.5)Fe_(1.93)is about 85%of that of the Terfenol-D(Tb_(0.3)Dy_(0.7)Fe_(2))***_(0.2)Tb_(0.3)Dy_(0.5)Fe_(1.93)/epoxy composites possess comparable magnetostriction with those composites made of Tb_(0.3)Dy_(0.7)Fe_(2)*** room temperature,the magnetostrictionλ_Ⅱof the Nd_(0.2)Tb_(0.3)Dy_(0.5)Fe_(1.93)/epoxy composite reaches 420 ppm at a low field of 80 kA/m and about1000 ppm at 239 kA/*** addition,the composite exhibits a large saturation magnetostrictionλ_Ⅱover1200 ppm from 300 to 100 K,suggesting its potential applications as a low-cost magnetostrictive material in a wide temperature ***,the current study offers an opportunity to widen the operating temperature range of the magnetostrictive composite.

关键词： Magnetostrictive composite Nd_(0.2)Tb_(0.3)Dy_(0.5)Fe_(1.93) Wide temperaturerange Laves phase Rare earths

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Analysis on the causes of massive stranding of Yellow Sea green tide on Lianyungang and Rizhao coasts in 2022

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Journal of Oceanology and Limnology 2024年第3期42卷 816-830页

作者： Lingjuan WU Juan HUANG yi ding Guiyan LIU Shuai HUANG Song GAO Chao YUAN Jiangling XU Ping WU Rui HUANG Ruobing WEN Jie MEI North China Sea Marine Forecasting and Hazard Mitigation Center Ministry of Natural ResourcesQingdao 266061China Shandong Key Laboratory of Marine Ecological Environment and Disaster Prevention and Mitigation Qingdao 266061China National Engineering Laboratory for Integrated Aero-Space-Ground-Ocean Big Data Application Technology Xi’an 710129China East China Sea Marine Forecasting and Hazard Mitigation Center Ministry of Natural ResourcesShanghai 200136China North China Sea Ecological Center Ministry of Natural ResourcesQingdao 266033China

In 2022,Yellow Sea green tide caused by Ulva prolifera reached a historic minimum and the coastal areas of Shandong Peninsula were less ***,the largest amount of seaweed biomass has been washed ashore on Lianyungang and Rizhao coasts since *** studied the development pattern of Yellow Sea green tide in 2022,and analyzed the key environmental factors on the growth and drifting,then discussed the possible reasons that resulted in the massive stranding of green tide biomass in Lianyungang and *** show under the combined influence of the east to southeast winds and currents with shoreward anomalies,green tide drifted to the coastal waters between Shandong and Jiangsu provinces and the distribution areas located westward compared with previous years(2008–2021).Floating *** rafts from the coastal waters of Binhai and Sheyang drifted continuously into the coastal waters of Lianyungang and Rizhao,providing important supplements for Yellow Sea green *** green tide in 2022 distributed close to the coastal waters,the abundant nutrients might support their continuous high growth *** addition,the amount of rainfall around Shandong Peninsula from late June to early July were significantly higher than in previous years,which might promote the development of green tide to some extent.

关键词： Yellow Sea green tide stranding biomass development pattern environmental factor

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Application of texture signatures based on multiparameter-magnetic resonance imaging for predicting microvascular invasion in hepatocellular carcinoma:Retrospective study

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World Journal of Gastrointestinal Oncology 2024年第4期16卷 1309-1318页

作者： Hai-Yang Nong Yong-yi Cen Mi Qin Wen-Qi Qin You-Xiang Xie Lin Li Man-Rong Liu Ke ding Department of Radiology The Third Affiliated Hospital of Guangxi Medical UniversityNanning 530031Guangxi Zhuang Autonomous RegionChina Department of Radiology The Affiliated Hospital of Youjiang Medical University for NationalitiesBaise 533000Guangxi Zhuang Autonomous RegionChina Department of Radiology The First Affiliated Hospital of Guangxi University of Traditional Chinese MedicineNanning 530031Guangxi Zhuang Autonomous RegionChina Department of Hepatobiliary Surgery The Third Affiliated Hospital of Guangxi Medical UniversityNanning 530031Guangxi Zhuang Autonomous RegionChina Department of Ultrasound The Third Affiliated Hospital of Guangxi Medical UniversityNanning 530031Guangxi Zhuang Autonomous RegionChina

BACKGROUND Despite continuous changes in treatment methods,the survival rate for advanced hepatocellular carcinoma(HCC)patients remains low,highlighting the importance of diagnostic methods for *** To explore the efficacy of texture analysis based on multi-parametric magnetic resonance(MR)imaging(MRI)in predicting microvascular invasion(MVI)in preoperative *** This study included 105 patients with pathologically confirmed HCC,categorized into MVI-positive and MVI-negative *** employed Original Data Analysis,Principal Component Analysis,Linear Discriminant Analysis(LDA),and Non-LDA(NDA)for texture analysis using multi-parametric MR images to predict preoperative *** effectiveness of texture analysis was determined using the B11 program of the MaZda4.6 software,with results expressed as the misjudgment rate(MCR).RESULTS Texture analysis using multi-parametric MRI,particularly the MI+PA+F dimensionality reduction method combined with NDA discrimination,demonstrated the most effective prediction of MVI in *** accuracy in the pulse and equilibrium phases was 83.81%.MCRs for the combination of T2-weighted imaging(T2WI),arterial phase,portal venous phase,and equilibrium phase were 22.86%,16.19%,20.95%,and 20.95%,*** area under the curve for predicting MVI positivity was 0.844,with a sensitivity of 77.19%and specificity of 91.67%.CONCLUSION Texture analysis of arterial phase images demonstrated superior predictive efficacy for MVI in HCC compared to T2WI,portal venous,and equilibrium *** study provides an objective,non-invasive method for preoperative prediction of MVI,offering a theoretical foundation for the selection of clinical therapy.

关键词： Magnetic resonance imaging Hepatocellular carcinoma Texture analysis Microvascular invasion

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基于负压吸附爬壁机器人和Transformer的混凝土桥塔裂缝识别检测

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中国公路学报 2024年第2期37卷 53-64页

作者：丁威夏哲舒江鹏叶建龙项贻强浙江大学建筑工程学院浙江杭州310058 浙江省交通集团检测科技有限公司浙江杭州310058

为了解决大型桥梁混凝土桥塔结构裂缝难以高效、安全、精准量化识别的问题,提出了基于爬壁机器人和Transformer的桥塔裂缝识别检测方法。该方法以基于负压吸附机制的爬壁机器人为装备载体,其可在混凝土桥塔上快速移动并近距离采集表观... 详细信息

为了解决大型桥梁混凝土桥塔结构裂缝难以高效、安全、精准量化识别的问题,提出了基于爬壁机器人和Transformer的桥塔裂缝识别检测方法。该方法以基于负压吸附机制的爬壁机器人为装备载体,其可在混凝土桥塔上快速移动并近距离采集表观病害高清数据。通过建立包含图像拼接、特征金字塔Transformer(Feature Pyramid Transformer,FPT)裂缝分割网络、尺度量化计算的裂缝识别方法,得到裂缝关键位置的宽度数据,并输出裂缝全局分布可视化结果,有效提升了微小裂缝的分割和边缘定位精度。基于试验验证了该方法的可行性与识别检测精度,并成功将其应用于中国东部某跨海大桥主塔裂缝检测工程。检测结果表明:该法对实际桥塔表面分布在0.1~3.3 mm宽度范围内的多尺度裂缝进行检测,宽度量化的最大误差小于10%。研究成果具有较好的应用前景,有望进一步推进现有混凝土桥梁结构检测技术与装备的智能化发展。

关键词：桥梁工程桥塔裂缝检测爬壁机器人特征金字塔Transformer 多尺度裂缝

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2D black arsenic phosphorous

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Journal of Semiconductors 2024年第3期45卷 1-3页

作者： Junchuan Liang yi Hu Liming ding Zhong Jin Key Laboratory of Mesoscopic Chemistry(MoE) School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023China Center for Excellence in Nanoscience(CAS) Key Laboratory of Nanosystem and Hierarchical Fabrication(CAS)National Center for Nanoscience and TechnologyBeijing 100190China

Since the successful exfoliation of graphene in 2014,twodimensional(2D)materials have explosively increased in the past few years[1].2D pnictogen materials with intriguing properties beyond graphene are gradually coming into eyesight,such as black phosphorous(BP)[2],arsenene[3],antimonene[4],bismuthine[5],*** is a star material in 2D materials.

关键词： materials graphene bismuth

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A human-sensitive frequency band vibration isolator for heavy-duty truck seats

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Applied Mathematics and Mechanics(English Edition) 2024年第10期45卷 1733-1748页

作者： Qingqing LIU Shenlong WANG Ge YAN Hu ding Haihua WANG Qiang SHI Xiaohong ding Huijie YU School of Mechanical Engineering University of Shanghai for Science and TechnologyShanghai 200093China State Key Laboratory of Mechanical System and Vibration School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai Frontier Science Center of MechnoinformaticsShanghai Institute of Applied Mathematics and MechanicsSchool of Mechanics and Engineering ScienceShanghai UniversityShanghai 200072China State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body College of Mechanical and Vehicle EngineeringHunan UniversityChangsha 410082China Yanfeng Adient Seating Co. Ltd.Shanghai 201315China College of Mechanical and Electrical Engineering Jiaxing Nanhu UniversityJiaxing 314001Zhejiang ProvinceChina

In this study,a human-sensitive frequency band vibration isolator(HFBVI)with quasi-zero stiffness(QZS)characteristics for heavy-duty truck seats is designed to improve the comfort of heavy-duty truck drivers on uneven ***,the analytical expressions for the force and displacement of the HFBVI are derived with the Lagrange equation and d'Alembert's principle,and are validated through the prototype restoring force ***,the harmonic balance method(HBM)is used to obtain the dynamic responses under harmonic excitation,and further the influence of pre-stretching on the dynamic characteristics and transmissibility is ***,the experimental prototype of the HFBVI is fabricated,and vibration experiments are conducted under harmonic excitation to verify the vibration isolation performance(VIP)of the proposed vibration *** experimental results indicate that the HFBVI can effectively suppress the frequency band(4-8 Hz)to which the human body is sensitive to vertical *** addition,under real random road spectrum excitation,the HFBVI can achieve low-frequency vibration isolation close to 2 Hz,providing new prospects for ensuring the health of heavy-duty truck drivers.

关键词： human-sensitive frequency band quasi-zero stiffness(QZS) heavy-duty truck seat real random road spectrum low-frequency vibration isolation

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Does the continuous wetting of the Tibetan Plateau contribute to the accelerated degradation of permafrost?

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Science China Earth Sciences 2024年第5期67卷 1714-1718页

作者： Yuyang WANG Jinzhi ding Shilong PIAO Sino-French Institute for Earth System Science College of Urban and Environmental SciencesPeking UniversityBeijing 100871China State Key Laboratory of Tibetan Plateau Earth System Environment and ResourcesInstitute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China

Global warming is causing the Tibetan permafrost to degrade, as evidenced by rising ground temperatures, thicker active layer thickness, thinner permafrost layer, and melting underground ice, etc.(Ran et al., 2018;Wang et al., 2020).The degradation of permafrost not only profoundly alters the carbon cycling processes in high-altitude ecosystems,thereby influencing the regional climate system, but also affects landscape hydrological connectivity。

关键词： Tibetan landscape altitude

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