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Character of Convective Systems Producing Short-Term Heavy Precipitation in Central China Revealed by Kilometer and Minute Interval Observations

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Journal of Meteorological Research 2024年第3期38卷 530-541页

作者： zitong CHEN Yunying LI Zhiwei ZHANG Jing SUN Chengzhi YE Anyuan XIONG College of Meteorology and Oceanography National University of Defense TechnologyChangsha410073China High Impact Weather Key Laboratory of China Meteorological Administration Changsha410073China Unit No.92192 of Chinese People’s Liberation Army Ningbo315000China Hubei Key Research Laboratory for Heavy Rain Monitoring and Warning Institute of Heavy RainChina Meteorological AdministrationWuhan430223China Institute of Meteorological Sciences of Hunan Province Hunan Meteorological BureauChangsha410118China National Meteorological Information Centre China Meteorological AdministrationBeijing100081China

Accurate forecasting of heavy precipitation in central China is still a challenge,within which a key issue is our still incomplete understanding of the convective systems(CSs)responsible for such *** this study,through use of an iterative rain-cell tracking algorithm,the macroscale characteristics(scale,intensity,duration,etc.)of the CSs that produced 595 short-term heavy precipitation events in Hunan Province,central China,are quantitatively analyzed,based on radar reflectivity,echo top,and rainfall observations at 1-km and 6-min intervals in April-September of *** results show that CSs present significant seasonal and diurnal *** CSs usually cover a larger echo area with stronger convective cores and thus generate more precipitation than summer CSs,though summer CSs develop more vigorously and *** initiated at 1400-1600 local time are characterized by the strongest convection and a smaller spatiotemporal scale,causing violent and transient showers with typical areal precipitation of 0.5-1 mm km^(−2),but less total *** analyses of the relationships among the scale,intensity,duration,and total precipitation of CSs reveal that the convective intensity is linearly correlated to the spatiotemporal scale of CSs,with the duration increasing on average by 0.0372 h dBZ^(−1);the echo area is significantly correlated to the total precipitation,and the duration and rainfall amount are connected with the area expansion rate(AER)of CSs:when the AER exceeds 50%,CSs expand rapidly with increasing total precipitation,but the duration is *** findings provide a helpful reference for the forecasting of short-term heavy precipitation induced by CSs in central China.

关键词： convective system radar reflectivity factor total precipitation iterative rain-cell tracking

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Dynamic adaptive spatio-temporal graph network for COVID-19 forecasting

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CAAI Transactions on Intelligence Technology 2024年第3期9卷 769-786页

作者： Xiaojun Pu Jiaqi Zhu Yunkun Wu Chang Leng zitong Bo Hongan Wang Institute of Software Chinese Academy of Sciences BeijingChina Ecovacs Robotics Co. Ltd.SuzhouJiangsuChina Automotive Software Innovation Center ChongqingChina

Appropriately characterising the mixed space-time relations of the contagion process caused by hybrid space and time factors remains the primary challenge in COVID-19 ***,in previous deep learning models for epidemic forecasting,spatial and temporal variations are captured separately.A unified model is developed to cover all spatio-temporal ***,this measure is insufficient for modelling the complex spatio-temporal relations of infectious disease transmission.A dynamic adaptive spatio-temporal graph network(DASTGN)is proposed based on attention mechanisms to improve prediction *** DASTGN,complex spatio-temporal relations are depicted by adaptively fusing the mixed space-time effects and dynamic space-time dependency *** dual-scale model considers the time-specific,space-specific,and direct effects of the propagation process at the fine-grained ***,the model characterises impacts from various space-time neighbour blocks under time-varying interventions at the coarse-grained *** performance comparisons on the three COVID-19 datasets reveal that DASTGN achieves state-of-the-art results with a maximum improvement of 17.092%in the root mean-square error and 11.563%in the mean absolute *** results indicate that the mechanisms of designing DASTGN can effectively detect some spreading characteristics of *** spatio-temporal weight matrices learned in each proposed module reveal diffusion patterns in various *** conclusion,DASTGN has successfully captured the dynamic spatio-temporal variations of COVID-19,and considering multiple dynamic space-time relationships is essential in epidemic forecasting.

关键词： adaptive COVID-19 forecasting dynamic intervention spatio-temporal graph neural networks

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Selenophene-Flanked Diketopyrrolopyrrole Based Conjugated Polymers for Ambipolar Field-Effect Transistors

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Chinese Journal of Chemistry 2020年第10期38卷 1075-1080页

作者： Dandan Shi Xiaobo Yu Liangliang Chen Daoliang Chen zitong liu Xisha Zhang Guanxin Zhang Deqing Zhang Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Organic SolidsCAS Center of Excellence in Molecular SciencesInstitute of ChemistryChinese Academy of SciencesBeijing 100190China School of Chemical Sciences University of Chinese Academy of SciencesBejjing 100049China

Summary of main observation and conclusion The development of selenophene-flanked DPP(SeDPP)based copolymers,especially for the ambipolar ones,lags behind other aromatic group flanked DPP-based ***,we report two new ambipolar SeDPP-based conjugated *** is the alternating polymer PSeDPPFT with normal SeDPP and 3,4-difluorothiophene *** other is PSeFDFT,in which the electron acceptor unit is replaced by a new SeDPP derivative,referred as to half-fused *** more planar structure of half fused SeDPP endows the backbone of PSeFDFT with good rigidity and *** polymers exhibit ambipolar transporting properties in *** PSeFDFT based fleld-effect transistors(FETs)display higher and more balanced ambipolar properties with μnave of 0.27 cm2·V-1·s-1,μe ave of 0.18 cm2·V-1·s-1,and μh ave/μeave of 1.5 than those of PSeDPPFT(μhave=0.11cm2·V-1·s-1,μeave=0.042cm2·V-1·s-1,and μh/μe=2.6).This is attributed to the more planar structure,lower LUMO level,higher HOMO level,and better interchain packing orientations of PSeFDFT by comparing with ***,a new molecular design strategy to modulate the hole and electron transporting properties is proposed for conjugated D-A polymers.

关键词： planar conjugated fused

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Tumor budding is a meaningful prognostic marker in patients with hepatocellular carcinoma after curative hepatectomy

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Portal Hypertension & Cirrhosis 2024年第2期3卷 86-95页

作者： Kaibo Yang Kunjin Wu zitong Lei Tong liu Xing Zhang Jing Li Kun Yang Qiuting Peng Ting Lin Chang liu Kai Qu Department of Hepatobiliary Surgery and Liver Transplantation The Second Affiliated Hospital of Xi'an Jiaotong UniversityXi'anShaanxiChina Key Laboratory of Surgical Critical Care and Life Support(Xi'an Jiaotong University) Ministry of EducationXi'anShaanxiChina Department of Critical Care Nephrology and Blood Purification The First Affiliated Hospital of Xi'an Jiaotong UniversityXi'anShaanxiChina Hangzhou Institute of National Extremelyweak Magnetic Field Infrastructure HangzhouZhejiangChina Department of Surgical Intensive Care Units The First Affiliated Hospital of Xi'an Jiaotong UniversityXi'anShaanxiChina

Aim:Tumor budding(TB)has excellent prognostic value in many solid tumors,but there is little research on it in hepatocellular carcinoma(HCC).This study assessed the prognostic value of TB in patients with HCC who received ***:This retrospective study included 210 patients with HCC who received curative hepatectomy at the First Affiliated Hospital of Xi'an Jiaotong University,between 2016 and *** was evaluated on hematoxylin-and eosin-stained slides according to the criteria established by the 2016 International Tumor Budding Consensus Conference.t-tests,Chi-squared tests,and rank-sum tests were used to correlate the extent of TB with clinicopathological *** analysis was performed using Cox regression models and the Kaplan–Meier ***:The positive detection rate of TB was 45.2%(95/210)in 210 patients with *** positive for TB always exhibit lower tumor differentiation,higher hepatitis B virus DNA levels,and more severe liver *** Cox analysis identified TB(hazard ratio[HR]:2.232,95%confidence interval[CI]:1.479–3.368,p<0.001)as an independent prognostic factor for patients'recurrence-free survival(RFS),similar to tumor size(HR:1.070,95%CI:1.070–1.142,p=0.042)and satellite nodule(HR:2.266,95%CI:1.298–3.956,p=0.004).Kaplan–Meier analysis also demonstrated that TB-positive patients had a significantly worse ***,subgroup analysis revealed that among HCC patients with negative microvascular invasion(MVI),TB was also strongly associated with RFS(HR:3.206,95%CI:1.667–6.168,p<0.001).These findings suggest that TB may serve as a supplemental prognostic biomarker for HCC-negative ***:TB is an adverse prognostic biomarker for HCC,particularly in patients negative for *** evaluation should be considered in the postoperative pathological examination of HCC in clinical practice.

关键词： hepatocellular carcinoma microvascular invasion prognosis tumor budding

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Generating barcodes for nanopore sequencing data with PRO

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Fundamental Research 2024年第4期4卷 785-794页

作者： Ting Yu zitong Ren Xin Gao Guojun Li Renmin Han Research Center for Mathematics and Interdisciplinary Sciences Frontiers Science Center for Nonlinear Expectations(Ministry of Education)Shandong UniversityShandong 266000China Computer Electrical and Mathematical Sciences and Engineering Division&Computational Bioscience Research CenterKing Abdullah University of Science and TechnologyThuwal 23955Saudi Arabia

DNA barcodes,short and unique DNA sequences,play a crucial role in sample identification when processing many samples simultaneously,which helps reduce experimental ***,the low quality of long-read sequencing makes it difficult to identify barcodes accurately,which poses significant challenges for the design of barcodes for large numbers of samples in a single sequencing ***,we present a comprehensive study of the generation of barcodes and develop a tool,PRO,that can be used for selecting optimal barcode sets and *** formulate the barcode design problem as a combinatorial problem and prove that finding the optimal largest barcode set in a given DNA sequence space in which all sequences have the same length is theoretically *** practical applications,we developed the novel method PRO by introducing the probability divergence between two DNA sequences to expand the capacity of barcode kits while ensuring demultiplexing ***,the maximum size of the barcode kits designed by PRO is 2,292,which keeps the length of barcodes the same as that of the official ones used by Oxford Nanopore Technologies(ONT).We validated the performance of PRO on a simulated nanopore dataset with high error *** demultiplexing accuracy of PRO reached 98.29%for a barcode kit of size 2,922,4.31%higher than that of Guppy,the official demultiplexing *** the size of the barcode kit generated by PRO is the same as the official size provided by ONT,both tools show superior and comparable demultiplexing accuracy.

关键词： Third-generation sequencing Nanopore sequencing DNA barcode Farthest point sampling algorithm High throughput

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轴式对大功率电力机车车轮第3类滚动接触疲劳的影响

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机械工程学报 2022年第12期58卷 159-167页

作者：刘永锋陶功权刘子通赵鑫温泽峰西南交通大学牵引动力国家重点实验室成都610031 株洲中车时代电气股份有限公司轨交技术中心株洲412001 中国铁路太原局集团有限公司太原机务段太原030045

六轴(Co-Co)和八轴(2(Bo-Bo))和谐型大功率电力机车在诸如小曲线和大坡度等线路上运行时,车轮名义滚动圆附近频繁发生沿车轮一周连续分布且近似横向的第3类滚动接触疲劳(简称RCF3),严重影响列车的安全运营。为了分析轴式对机车车轮RCF3... 详细信息

六轴(Co-Co)和八轴(2(Bo-Bo))和谐型大功率电力机车在诸如小曲线和大坡度等线路上运行时,车轮名义滚动圆附近频繁发生沿车轮一周连续分布且近似横向的第3类滚动接触疲劳(简称RCF3),严重影响列车的安全运营。为了分析轴式对机车车轮RCF3的影响,基于SIMPACK多体动力学软件建立六轴和八轴机车的动力学模型,结合损伤函数预测车轮的RCF3。结果表明,曲线通过时,六轴和八轴机车仅在转向架端轴非导向轮对的高轨侧车轮发生RCF3,考虑左、右曲线和机车换向运行,曲线可导致RCF3发生在六轴机车的1、3、4和6轴以及八轴机车的所有车轮。轨面干态下通过平面曲线或曲线下坡时六轴机车车轮的裂纹萌生速率约为八轴机车的1.2~2.5倍,而轨面湿态下通过曲线上坡时八轴机车的磨耗速率约为六轴机车的1~1.5倍,因而六轴机车更易发生RCF3。其原因是六轴机车转向架固定轴距更大,导致曲线引起的负纵向蠕滑力幅值更大。在直线轨道运行时,轴式对车轮RCF3无影响;直线下坡运行时,RCF3在所有车轮发生。轨面干态下RCF3的生长速率随着曲线半径的减小或下坡坡度的增加而增大,轨面湿态下RCF3的生长速率随下坡坡度的增加先增大后减小,其原因是湿态下车轮纵向蠕滑率显著增大而引起磨耗,可磨掉萌生的RCF3。

关键词：大功率电力机车轴式滚动接触疲劳损伤函数曲线坡道

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Effects of forsythin extract in Forsythia leaves on intestinal microbiota and short-chain fatty acids in rats fed a high-fat diet

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Food Science and Human Wellness 2024年第2期13卷 659-667页

作者： Lanlan Gui Shaokang Wang Jing Wang Wang Liao zitong Chen Da Pan Hui Xia Guiju Sun Su Tian Department of Nutrition and Food Hygiene School of Public HealthSoutheast UniversityNanjing 210009China Nanjing Municipal Center for Disease Control and Prevention Nanjing 210003China Department of Nutrition and Food Hygiene School of Public HealthHebei Medical UniversityShijiazhuang 050017China

Forsythia suspensa,belonging to the deciduous shrubs of the Luteaceae family,a traditional Chinese medicine,has effects of alleviating swelling,clearing heat,detoxification and promoting blood *** leaves of *** contain multiple chemical components and have a long history of use in folk medicines and health *** purpose of this study was to explore the effects of forsythin extract from *** leaves on intestinal microbiota and short-chain fatty acid(SCFA)content in rats with obesity induced by a high-fat *** extract in *** leaves increased the abundance of the intestinal microbiota,ameliorated intestinal microbiota disorders and inhibited the increase in total SCFA content in the intestinal tract in rats with obesity induced by a high-fat *** results suggested that forsythin extract in *** leaves may slow the development of obesity induced by a high-fat diet;thus,its active components and efficacy are worthy of further study.

关键词： Forsythin High-fat diet Intestinal microbiota Short-chain fatty acid(SCFA)

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A high precision two-axis GMR angular sensor manufactured by post-annealing

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Science China(Information Sciences) 2024年第6期67卷 465-466页

作者： zitong ZHOU Zhiqiang CAO Shaohua YAN Xiaolong WANG Libo XIE Shiyang LU Dapeng ZHU Qunwen LENG Weisheng ZHAO School of Integrated Circuit Science and Engineering Beihang University Beihang Qingdao Microelectronics Research Institute Beihang University National Key Lab of Spintronics Institute of International InnovationBeihang University

Angle sensors are widely used in numerous fields such as industry,military,medical care,and the Internet of Things(IoT)[1].Magnetoresistance angle sensors have become a mainstream approach for angle measurement becaus... 详细信息

关键词： Annealing

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Multi-Stimuli-Responsive Field-Effect Transistor with Conjugated Polymer Entailing Spiropyran in the Side Chains

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CCS Chemistry 2020年第2期2卷 632-641页

作者： Jing Ma Jianwu Tian zitong liu Dandan Shi Xisha Zhang Guanxin Zhang Deqing Zhang Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Organic SolidsCAS Center of Excellence in Molecular SciencesInstitute of ChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

Multi-stimuli-responsive field-effect transistors(FETs)with organic/polymeric semiconductors have received increasing ***,we report a novel strategy for fabricating multi-stimuliresponsive polymeric semiconductors through the incorporation of spiropyran(SP)groups in the polymer side *** semiconducting performances of resultant FETs with a diketopyrrolopyrroles(DPP)-based conjugated donor–acceptor(D–A)polymer,that entails SP units in the side chains(pDSP-1),could be modulated reversibly through UV and visible light irradiations,or UV light irradiation and heating,or acid treatment and *** studies reveal that during the reversible transformations of closed,open,and the protonated forms of spiropyran,achieved by light irradiations,heating,and under acidic conditions,a large dipole moment changes occur,which triggers the reversible variation of semiconducting performance of the FETs.

关键词： conjugated semiconducting polymer polymeric field-effect transistor side-chain modification spiropyran multi-stimuli responsiveness

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等离子处理对医用镁合金表面聚合物防护涂层的影响

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材料研究学报 2023年第4期37卷 271-280页

作者：李鹏宇刘子童亢淑梅陈姗姗辽宁科技大学材料与冶金学院鞍山114051 中国科学院金属研究所沈阳110016 沈阳理工大学材料科学与工程学院沈阳110159

用匀速提拉法在氟化处理的AZ31镁合金表面制备PBA防护涂层,然后再进行等离子处理。使用扫描电子显微镜(SEM)、X射线光电子能谱(XPS)、傅里叶红外测试(FT-IR)和接触角测量仪等手段对其表征,研究了等离子处理对PBA防护涂层表面的微观形貌... 详细信息

用匀速提拉法在氟化处理的AZ31镁合金表面制备PBA防护涂层,然后再进行等离子处理。使用扫描电子显微镜(SEM)、X射线光电子能谱(XPS)、傅里叶红外测试(FT-IR)和接触角测量仪等手段对其表征,研究了等离子处理对PBA防护涂层表面的微观形貌、物相组成以及表面润湿性的影响;用动电位极化曲线(PD)和电化学阻抗谱(EIS)表征防护涂层处理镁合金的耐蚀性;对在等离子处理前后样品表面细胞的铺展进行比较,以验证防护涂层的生物活性。结果表明,等离子处理使PBA防护涂层表面粗糙化提高了氧原子的占比,从而显著提高了防护涂层表面的浸润性;等离子处理在一定程度上降低了防护涂层处理镁合金的耐蚀性,但是与未经防护处理的AZ31镁合金和氟化处理的镁合金相比其电流密度仍高2~3个数量级,表明防护涂层能有效防护镁合金基体;等离子处理,使样品表面黏附的细胞显著增多。

关键词：金属材料镁合金防护涂层等离子处理润湿性耐蚀性

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