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Dynamic of a stochastic delayed one-predator two-prey model with Lévy jumps in polluted environments

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International Journal of Biomathematics 2021年第1期14卷 125-150页

作者： Yongxin Gao Nana Wang shiquan tian College of Science Civil Aviation University of ChinaTianjin 300300P.R.China

This paper is concerned with a stochastic delayed one-predator two-prey model with Lévy jumps in polluted ***,under some simple assumptions,we prove that there exists a unique global nonnegative solution which is permanent in time ***,sufficient criteria for the extinction of each species are ***,we carry out some numerical simulations to verify the theoretical results.

关键词： One-predator two-prey model delay white noise Levy noise toxicant

基于ANSYS Workbench的冷敲机花键轴模态分析

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锻压技术 2017年第11期42卷 109-114页

作者：田世权杜诗文李永堂牛婷太原科技大学材料科学与工程学院山西太原030024 太原科技大学山西省金属材料成形理论与技术重点实验室山西太原030024

花键轴是花键冷敲机分度机构与滚打机构的连接轴,是冷敲机微量进给系统的重要部件。以花键冷敲机的花键轴作为研究对象,采用SolidWorks对其进行建模,并利用ANSYS Workbench对其进行模态分析。提取前5阶固有频率以及与之相对应的振型,通... 详细信息

花键轴是花键冷敲机分度机构与滚打机构的连接轴,是冷敲机微量进给系统的重要部件。以花键冷敲机的花键轴作为研究对象,采用SolidWorks对其进行建模,并利用ANSYS Workbench对其进行模态分析。提取前5阶固有频率以及与之相对应的振型,通过对振型图进行分析,发现了花键轴振幅较大的问题,并设计出减小花键轴振幅的装置。对花键轴的不同位置施加约束,并进行模拟分析,得出其固有频率的变化规律,说明采用浮动的约束装置对花键轴有振动补偿控制作用,改善了花键轴的刚性和设备运转的稳定性,大大提高了生产效率和花键的机械性能。

关键词： ANSYS Workbench 花键轴花键冷敲机模态分析固有频率振型

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高等教育融入终身教育体系的策略研究

通化师范学院学报 2024年第6期45卷 99-104页

作者：孙子淇田世全通化师范学院吉林通化134001 通化市外国语学校

高等教育作为终身教育体系中的重要一环,要在贯彻终身教育政策理念的要求下,以终身教育理念为指导,满足更多学习者的教育需求.可以通过开放教育资源、改革教学模式和教学内容、推进远程教育等方法,促进高等教育积极融入终身教育体系,进... 详细信息

高等教育作为终身教育体系中的重要一环,要在贯彻终身教育政策理念的要求下,以终身教育理念为指导,满足更多学习者的教育需求.可以通过开放教育资源、改革教学模式和教学内容、推进远程教育等方法,促进高等教育积极融入终身教育体系,进而推动自身的转型和发展.

关键词：终身教育体系高等教育终身学习教学改革

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基于林产品贸易Web信息增量爬虫的研究

农业网络信息 2016年第2期 18-21页

作者：许美田世全陈钊北京林业大学北京100083

随着互联网信息的快速增长和大数据掀起的热潮,如何保证主题数量的增量爬取再次成为获取信息的必要手段,增量爬虫能够以较少的资源实现信息的快速更新,从而提高信息检索的准确率。文章结合林产品贸易Web信息的特点,提出了一种适用于林... 详细信息

随着互联网信息的快速增长和大数据掀起的热潮,如何保证主题数量的增量爬取再次成为获取信息的必要手段,增量爬虫能够以较少的资源实现信息的快速更新,从而提高信息检索的准确率。文章结合林产品贸易Web信息的特点,提出了一种适用于林产品贸易Web信息的基于优先级增量爬取方法,网页更新的优先级伴随着抓取而动态改变。最后通过实验证明随着抓取信息的增加该方法在保证网页质量的同时能有效的降低系统的资源使用,在海量信息爬取的过程中具有很好的应用价值。

关键词：增量爬虫林产品动态模型

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花键冷敲成形设备分度机构分析与优化

锻压装备与制造技术 2019年第1期54卷 13-16页

作者：宋建军田世权杜诗文李永堂太原科技大学金属材料成形理论与技术山西省重点实验室太原山西030024

对花键冷敲成形设备分度机构进行了分析。通过对传统的直线槽轮机构进行运动学和动力学分析,发现直线槽轮分度机构在拨销进入和离开轮槽的时候发生柔性冲击,引起了分度机构的振动。在此基础上,设计了两种减小冲击的分度机构:新型曲线槽... 详细信息

对花键冷敲成形设备分度机构进行了分析。通过对传统的直线槽轮机构进行运动学和动力学分析,发现直线槽轮分度机构在拨销进入和离开轮槽的时候发生柔性冲击,引起了分度机构的振动。在此基础上,设计了两种减小冲击的分度机构:新型曲线槽轮机构及弧面凸轮分度机构。对这两种分度机构进行了设计计算,建立了几何模型,并进行了运动学及动力学特性分析。结果表明:改进之后的分度机构可以减少冲击,分度精确,运行平稳。

关键词：冷敲成形分度机构弧面凸轮运动分析

Motion-copying method with symbol sequence-based phase switch control for intelligent optical manufacturing

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Light(Advanced Manufacturing) 2024年第2期5卷 1-13页

作者： Yutang Wang Dapeng tian Haixiang Hu Yan Li shiquan Ni The Key Laboratory of Airborne Optical Imaging and Measurement Changchun Institute of OpticsFine Mechanics and PhysicsChinese Academy of SciencesChangchunJilin130033 China Changchun Institute of Optics Fine Mechanics and PhysicsChinese Academy of SciencesChangchunJilin130033 China State Key Laboratory of Dynamic Optical Imaging and Measurement ChangchunJilin130033 China University of Chinese Academy of Sciences 100049BeijingChina

Implementation of robot-based motion control in optical machining demonstrably enhances the machining *** introduction of motion-copying method enables learning and replicating manipulation from experienced ***,the location uncertainties of objects and frequent switching of manipulated spaces in practical applications impose constraints on their further *** address this issue,a motion-copying system with a symbol-sequence-based phase switch control(SSPSC)scheme was developed by transferring the operating skills and intelligence of technicians to *** manipulation process is decomposed,symbolised,rearranged,and reproduced according to the manufacturing characteristics regardless of the change in object location.A force-sensorless adaptive sliding-mode-assisted reaction force observer(ASMARFOB),wherein a novel dual-layer adaptive law was designed for high-performance fine force sensing,was *** uniformly ultimate boundedness(UUB)of the ASMARFOB is guaranteed based on the Lyapunov stability theory,and the switching stability of the SSPSC was *** simulations and experiments demonstrated that the proposed method enables better motion reproduction with high consistency and *** findings of this study can provide effective theoretical and practical guidance for high-precision intelligent optical manufacturing.

关键词： Intelligent optical manufacturing Motion copy Uncertain environments Phase switch control Reaction force observer

Microstructure observation of multilayers separated from wheat bran

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Grain & Oil Science and Technology 2021年第4期4卷 165-173页

作者： Xiaoling tian Zhen Wang Shukai Yang Xiaoxi Wang Li Li Binghua Sun Sen Ma shiquan Zheng College of Food Science and Engineering Henan University of TechnologyZhengzhou 450001China Henan University of Technology Design and Research Academy Zhengzhou 450001China

In order to understand more clearly the morphology of the structural layers of the soft and hard wheat bran to understand the effect of mechanical force on the wheat grain,we observed the microstructure of each layer of the wheat bran from soft and hard mature *** on the differences in mechanical properties and water permeability of each wheat bran layer,the mature wheat grains were alternately treated under cold and heat conditions and separated by manual *** microstructure of each layer of wheat bran from soft and hard mature wheat was determined by optical and fluorescence *** different structure layers were observed by optical microscopy,named them as epidermis,epicarp,cross cells,tube cells,testa,nucellar layer,and aleurone *** the layers of the outer bran of wheat grains were separated,except for the tube cells *** autofluorescence imagings of five layers were *** was found that the morphology of the structural layers of the soft and hard wheat bran did not differ much,except for the aleurone *** aleurone layer of soft wheat bran was significantly different from that of the hard wheat bran,which is fuller and denser compared to soft *** this study,more aleurone grains were lost in the aleurone layer obtained by the outsidein peeling *** mastery of the morphology of each structural layer of the bran helps us to quickly quantify the degree of peeling of wheat milling,and to make immediate adjustments to the *** the same time,we understand that the contents of the aleurone cells have different binding strengths with the nucellar layer and the starchy *** paper is instructive to deep investigation of wheat milling mechanism and product process refinement.

关键词： Wheat bran Microstructure Morphology Mechanical property

Grazing by microzooplankton and copepods on the microbial food web in spring in the southern Yellow Sea,China

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Marine Life Science & Technology 2020年第4期2卷 442-455页

作者： Yuan Zhao Yi Dong Haibo Li shiquan Lin Lingfeng Huang tian Xiao Gerald Gregori Li Zhao Wuchang Zhang CAS Key Laboratory of Marine Ecology and Environmental Sciences Institute of OceanologyChinese Academy of SciencesQingdao 266071China Laboratory for Marine Ecology and Environmental Science Pilot National Laboratory for Marine Science and Technology(Qingdao)Qingdao 266071China Key Laboratory of Marine Ecosystem Dynamics Second Institute of OceanographyMinistry of Natural ResourcesHangzhou 310012China Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems College of the Environment and EcologyXiamen UniversityXiamen 361005China Fujian Provincial Key Laboratory of Coastal Ecology and Environmental Studies Xiamen UniversityXiamen 361102China Aix-Marseille University Toulon UniversityCNRSIRDMediterranean Institute of Oceanography UM 11013288 MarseilleFrance Center for Ocean Mega-Science Chinese Academy of SciencesQingdao 266071China

Assessment of microzooplankton and copepods grazing pressure on picoplankton is a key requirement for resolving the microbial food web *** microzooplankton grazing on picoplankton has been extensively studied,the impact of microzooplankton on different groups of picoplankton,i.e.,heterotrophic bacteria,Synechococcus and picoeukaryotes have rarely been ***,in the very few existing studies there is no consistent evidence of an enhancing or restraining effect of copepods on *** studies are needed to improve our understanding of the influence of microzooplankton and copepod on *** incubations and copepod addition incubations were performed during a cruise to the southern Yellow Sea on May 16-29,*** bulk grazing of microzooplankton and the calanoid copepod Cal anus sinicus on phytoplankton,flagellates and picoplankton was *** were divided into either eutrophic or oligotrophic according to the nutrient and biological *** comprised a large part of the diet of microzooplankton in the central oligotrophic area,while phytoplankton was the main food of microzooplankton in the coastal eutrophic *** the central oligotrophic area,microzooplankton preferred grazing on *** copepod addition,ciliate abundance decreased while Synechococcus abundance increased(382%,64%and 64%at three experimental stations,respectively),indicating strong grazing pressure of microzooplankton on *** results suggest that Synechococcus might be an essential carbon source the planktonic food web in the oligotrophic waters of southern Yellow Sea.

关键词： Microzooplankton Dilution incubations Copepod addition incubations Ciliate-Picoplankton Yellow Sea

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高应变率下新型纤维砂浆动态劈拉特性

建筑材料学报 2018年第2期21卷 189-195页

作者：田正宏江桂林吴军罗时权河海大学水利水电学院江苏南京210098 中国水利水电第七工程局有限公司四川成都610081

采用分离式霍普金森压杆(SHPB)冲击试验,研究了超高分子聚乙烯(UHMWPE)纤维砂浆、聚乙烯醇(PVA)纤维砂浆试件的动态劈拉特性,阐述了纤维砂浆动态劈拉强度和动态增长因子的应变率效应;提出了静动态统一的纤维砂浆劈拉强度拟合公式;结合... 详细信息

采用分离式霍普金森压杆(SHPB)冲击试验,研究了超高分子聚乙烯(UHMWPE)纤维砂浆、聚乙烯醇(PVA)纤维砂浆试件的动态劈拉特性,阐述了纤维砂浆动态劈拉强度和动态增长因子的应变率效应;提出了静动态统一的纤维砂浆劈拉强度拟合公式;结合试件破坏形态和能量耗散,分析了纤维砂浆劈拉性能的优劣.结果表明:相对于PVA纤维砂浆,UHMWPE纤维砂浆抗拉增强效应更加突出;不同类型的PVA纤维砂浆动态力学性能存在明显差异;纤维砂浆动态劈拉强度、动态增长因子和能量耗散均随加载应变率增大而增长;相比素砂浆,掺1.8kg/m^3的UHMWPE纤维砂浆最大动力耗散能Ws,max大约提高15%.

关键词：超高分子聚乙烯纤维高应变率动态增长因子破坏形态能量耗散