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Transient-Spatial Pattern Mining of Eddy Current Pulsed Thermography Using Wavelet Transform

Chinese Journal of Mechanical Engineering 2014年第4期27卷 768-778页

作者： YANG Hailong GAO Bin TIAN Guiyun ren wenwei WOO Wai Lok School of Automation Engineering University of Electronic Science and Technology of China School of Electrical and Electronic Engineering Newcastle University

Eddy current pulsed thermography（ECPT） is an emerging Non-destructive testing and evaluation（NDT E） technique, which uses hybrid eddy current and thermography NDT E techniques that enhances the detectability from their compensation. Currently, this technique is limited by the manual selection of proper contrast frames and the issue of improving the efficiency of defect detection of complex structure samples remains a challenge. In order to select a specific frame from transient thermal image sequences to maximize the contrast of thermal variation and defect pattern from complex structure samples, an energy driven approach to compute the coefficient energy of wavelet transform is proposed which has the potential of automatically selecting both optimal transient frame and spatial scale for defect detection using ECPT. According to analysis of the variation of different frequency component and the comparison study of the detection performance of different scale and wavelets, the frame at the end of heating phase is automatically selected as an optimal transient frame for defect detection. In addition, the detection capabilities of the complex structure samples can be enhanced through proper spatial scale and wavelet selection. The proposed method has successfully been applied to low speed impact damage detection of carbon fibre reinforced polymer（CFRP） composite as well as providing the guidance to improve the detectability of ECPT technique.

关键词： non-destructive testing and evaluation composite impact damage detection wavelet transform energy driven approach transient-spatial analysis

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基于环境DNA宏条形码的青岚湖自然保护区鱼类组成及分布特征

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中国环境监测 2024年第3期40卷 235-246页

作者：史艳萍屈婵娟许旺周春花梁璐王宇翔任文伟戴年华徐晓娟黎栩霞计勇吴小平金斌松南昌工程学院水利与生态工程学院江西南昌330099 江西鄱阳湖湿地保护与恢复国家长期科研基地江西鄱阳湖湿地生态系统国家定位观测研究站江西省流域生态演变与生物多样性重点实验室南昌大学生命科学学院和研究院江西南昌330031 同济大学环境科学与工程学院上海200092 嘉兴同济环境研究院浙江嘉兴314051 广东省深圳生态环境监测中心站广东深圳518049 Department of Biology Queen's UniversityOntario Kingston K7L 3N6 江西科学院江西南昌330029 赣江上游水文水资源监测中心江西赣州341000 杭州师范大学生命与环境科学学院浙江杭州310018

为探究在不同引物、不同参考数据库下环境DNA技术检测结果的差异,于2021年4月,采用环境DNA宏条形码技术分析了青岚湖鱼类多样性。选取16S rRNA及Cytb 2种引物,NCBI及本地数据库2种数据库,分别进行比对注释。结果表明:在青岚湖29个采样点... 详细信息

为探究在不同引物、不同参考数据库下环境DNA技术检测结果的差异,于2021年4月,采用环境DNA宏条形码技术分析了青岚湖鱼类多样性。选取16S rRNA及Cytb 2种引物,NCBI及本地数据库2种数据库,分别进行比对注释。结果表明:在青岚湖29个采样点中,共检测到7目15科43属64种鱼类,其中在16S-NCBI情形下获得4目9科19属20种鱼类,在16S-本地数据库情形下获得6目13科27属38种鱼类,在Cytb-NCBI情形下获得4目6科16属19种鱼类,在Cytb-本地数据库情形下获得2目5科15属20种鱼类。在青岚湖29个采样点中,鱼类更多地分布于湖面宽阔的中间地带(如S31附近),且南部较北部更少,鱼种的分布呈现一定的空间相似性。就研究区域而言,选择16S rRNA引物及本地数据库可以获得更全面的鱼类物种。通过与青岚湖鱼类历史数据比对发现,环境DNA技术在研究区域具有较强的适用性,如能选择适当的引物和本地数据库,可以更全面地反映研究区域的物种组成情况。

关键词：环境DNA宏条形码鄱阳湖鱼类多样性引物参考数据库

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Modern pollen-vegetation relationships along altitudinal vegetation belts in the Leigong Mountain of southwestern China

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Journal of Mountain Science 2024年第7期21卷 2249-2262页

作者： LI Shuming ZHAO wenwei WEI Lisi ren Weihe GU Qinran WU Siqi JI Yang YANG Ziteng ZHUANG Rui CHEN Chunzhu College of Geography and Tourism Hengyang Normal UniversityHengyang 421002China School of Geographical Science Nantong UniversityNantong 226019China State Key Laboratory of Modern Palaeobiology and Stratigraphy Nanjing Institute of Geology and PalaeontologyChinese Academy of Sciences Nanjing 210008China 4 University of Chinese Academy of SciencesBeijing 100049China

Understanding the distribution,dispersal,and correlation of modern pollen with vegetation in mountainous regions is essential for establishing accurate modern analogs for fossil pollen *** study,conducted in Leigong Mountain on the YunnanGuizhou Plateau of southwestern China,involved the collection of 35 surface soil samples from diverse vegetation communities along an elevational gradient ranging from 1210 to 1875 *** results reveal a close correspondence between modern pollen assemblages and vegetation *** Component Analysis(PCA)results indicate that pollen assemblages can effectively distinguish between subtropical montane evergreen broad-leaved forest(SEBF)and subtropical montane deciduous broadleaved forest(SDBF).However,both SEBF and SDBF show significant overlap with subtropical montane evergreen-deciduous broad-leaved mixed forest(SEMF).Detrended Correspondence Analysis(DCA)results clearly distinguish the three vegetation zones,and the first axis of DCA shows a significant positive correlation with elevation(prence for reconstructing ancient environments from fossil pollen retrieved in this region.

关键词： Modern pollen assemblages Pollenvegetation relationship Pollen diversity and richness Leigong Mountain Southwestern China

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A FAS approach for stabilization of generalized chained forms: part 1. Discontinuous control laws

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Science China(Information Sciences) 2024年第2期67卷 118-143页

作者： Guang-ren DUAN Center for Control Theory and Guidance Technology Harbin Institute of Technology Center for Control Science and Technology Southern University of Science and Technology

In this paper, a type of general nonholonomic systems is proposed, which contains both the Brockett’s two example systems, and their extended n-dimensional chained forms, as special cases. For the stabilization of such systems, a stabilizing controller is proposed based on the fully actuated system(FAS)approach, which is discontinuous at the origin but time-invariant when the open-loop system is time-invariant,and drives the feasible trajectories of the system to the origin exponentially. Furthermore, the proposed FAS approach is also extended to the sub-normal system case and the time-delay system case.

关键词： nonholonomic systems feedback stabilization exponential convergence sub-fully actuated systems time-delay systems

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A FAS approach for stabilization of generalized chained forms: part 2. Continuous control laws

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Science China(Information Sciences) 2024年第3期67卷 114-135页

作者： Guang-ren DUAN Center for Control Theory and Guidance Technology Harbin Institute of Technology Shenzhen Key Laboratory of Control Theory and Intelligent Systems Southern University of Science and Technology

In this paper, continuous time-varying stabilizing controllers for the type of general nonholonomic systems proposed and treated in part 1 are designed using the fully actuated system(FAS) approach. The key step is to differentiate the first scalar equation, and by control of the obtained second-order scalar system, a proportional plus integral feedback form for the first control variable is obtained. With the solution to this designed second-order scalar system, the rest equations in the nonholonomic system form an independent time-varying subsystem which is then handled by the FAS approach. The overall designed controller contains an almost arbitrarily chosen design parameter, and is proven to guarantee the uniformly and globally exponential stability of the closed-loop system. The proposed approach is simple and effective,and is demonstrated with a practical example of ship control.

关键词： nonholonomic systems feedback stabilization fully actuated systems Lyapunov stability continuous controllers

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Resilient control of flexible hypersonic vehicles against unmatched distributed faults

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Chinese Journal of Aeronautics 2024年第5期37卷 60-70页

作者： Dong ZHAO Wenjing ren School of Artificial Intelligence Anhui UniversityHefei 230601China Key Laboratory of System Control and Information Processing Ministry of EducationShanghai Jiao Tong UniversityShanghai 200240China School of Electrical Engineering and Automation Hefei University of TechnologyHefei 230009China

This paper studies a robust fault compensation and vibration suppression problem of flexible hypersonic *** controlled plant is represented by a cascade system composed of a nonlinear Ordinary Differential Equation(ODE)and an Euler-Bernoulli Beam Equation(EBBE),in which the vibration dynamics is coupled with the rigid dynamics and suffers from distributed faults.A state differential transformation is introduced to transfer distributed faults to an EBBE boundary and a longitudinal dynamics is refined by utilizing T-S fuzzy IF-THEN rules.A novel T-S fuzzy based fault-tolerant control algorithm is developed and related stability conditions are *** robust exponential stability and well-posedness are proved by using the modified l_(0)-semigroup based Lyapunov direct approach.A simulation study on the longitudinal dynamics of flexible hypersonic vehicles effectively verifies the validity of the developed theoretical results.

关键词： Flexible hypersonic vehicles ODE-EBBE cascade Robust exponential stability Unmatched distributed fault compensation Vibration suppression

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Global Solvability for a Predator-Prey Model with Prey-Taxis and Rotational Flux Terms

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Chinese Annals of Mathematics,Series B 2024年第2期45卷 297-318页

作者： Guoqiang ren Bin LIU School of Mathematics and Statistics Huazhong University of Science and Technology Hubei Key Laboratory of Engineering Modeling and Scientific Computing Huazhong Universityof Science and Technology

In this paper the author investigates the following predator-prey model with prey-taxis and rotational?ux terms■in a bounded domain with smooth *** presents the global existence of generalized solutions to the model... 详细信息

关键词： Predator-prey Prey-taxis Giopal existence Kotational flnux

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Progress in modeling and control of probe-and-drogue autonomous aerial refueling

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Chinese Journal of Aeronautics 2024年第5期37卷 6-26,I0001页

作者： Jinrui ren Quan QUAN School of Automation Xi’an University of Posts&TelecommunicationsXi'an 710072China School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China

By refueling aircraft while they are in flight,aerial refueling is an efficient technique to extend their endurance and *** Aerial Refueling(AAR)is anticipated to be used to complete aerial refueling for unmanned *** are three aerial refueling methods:the Probe-and-Drogue Refueling(PDR)refueling method,the flying-boom refueling method,and the boom-drogue-adapter refueling *** paper considers the PDR approach,the most challenging of the three,because the flexible hose-drogue assembly has fast dynamics and is susceptible to various kinds of winds,which makes the probe docking with the drogue *** is divided into four phases,namely the rendezvous phase,joining phase,refueling phase,and reform phase,with the refueling phase being the most *** controller design faces the greatest challenge during the docking control of the refueling phase since it calls for a high level of safety,precision,and *** a result,the modeling and control issues encountered during the refueling phase are typical and *** fundamental idea of AAR is presented in the paper first,after which the characteristics and requirements of AAR are *** progress in modeling and control techniques for the AAR’s refueling phase is then systematically ***,potential future work for high safety,precision,and efficiency requirements is examined and suggested.

关键词： Aerial refueling Probe-and-drogue refueling Docking Flight controlsystems Unmanned Aerial Vehicles

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The effect of cigarette smoking on vitamin D level and depression in male patients with acute ischemic stroke

The effect of cigarette smoking on vitamin D level and depre...

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2015年浙江省神经病学学术年会

作者： wenwei ren Jincai He 温州医科大学附属第一医院

Objective:The purposes of this study were to compare vitamin D levels in smokers to nonsmokers with acute ischemic stroke and examine the association between vitamin D levels and depression *** and methods:Serum levels of 25-hydroxyvitamin D[25(OH)D]were measured in 194 male within 24 h after admission:116 smokers and 78 *** symptoms were assessed with the 17-item Hamilton Depression Scale(HAMD-17),Patients with the HAMD-17 score >7 were identified to have depression ***:The percent of patients with depression symptoms in the smoker group was significantly higher than that in the nonsmoker group(23.3%vs 11.56%;p=0.039).Vitamin D levels were significantly lower in smokers than in nonsmokers(52.4 ± 20.8 nmol/L vs 61.7 ± 19.2 nmol/L;p=0.002).Patients with depression symptoms showed lower vitamin D levels than those with no depression symptoms(49.2 ± 19.6 vs 57.7 ± 20.6;p=0.03).Conclusion:Smoking was associated with more depression symptoms and with lower vitamin D levels,smoking may increase the risk of depression in stroke patients through reducing the vitamin D levels.

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Scientific and technological innovations of wastewater treatment in China

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Frontiers of Environmental Science & Engineering 2024年第6期18卷 43-48页

作者： Hui Huang Rui Ma Hongqiang ren State Key Laboratory of Pollution Control and Resource Reuse School of the EnvironmentNanjing UniversityNanjing 210023China

The“dual-carbon”strategy promotes the development of the wastewater treatment sector and is an important tool for leading science and technology *** on the global climate change and the new policies introduced by China,this paper described the new needs for the development of wastewater treatment science and *** offered a retrospective analysis of the historical trajectory of scientific and technological advancements in this *** bibliometrics,it delineated the research hotspots within wastewater treatment,notably highlighting materials genomics,artificial intelligence,and synthetic ***,it posited that,in the future,the field of wastewater treatment should follow the paths of technological innovations with multi-dimensional needs,such as carbon reduction,pollution reduction,health,standardisation,and *** purpose of this paper was to provide references and suggestions for scientific and technological innovations in the field of wastewater treatment,and to contribute to the common endeavor of moving toward a Pollution-Free Planet.

关键词： Wastewater treatment Dual-carbon strategy Technological innovation Carbon reduction

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