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Local resonance metamaterial-based integrated design for suppressing longitudinal and transverse waves in fluid-conveying pipes

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Applied Mathematics and Mechanics(English Edition) 2024年第10期45卷 1821-1840页

作者： donghai han Qi JIA Yuanyu GAO Qiduo JIN Xin FANG Jihong WEN Dianlong YU Laboratory of Science and Technology on Integrated Logistics Support National University of Defense TechnologyChangsha 410073China College of Intelligence Science and Technology National University of Defense TechnologyChangsha 410073China

To solve the problem of low broadband multi-directional vibration control of fluid-conveying pipes,a novel metamaterial periodic structure with multi-directional wide bandgaps is ***,an integrated design method is proposed for the longitudinal and transverse wave control of fluid-conveying pipes,and a novel periodic structure unit model is constructed for vibration *** on the bandgap vibration reduction mechanism of the acoustic metamaterial periodic structure,the material parameters,structural parameters,and the arrangement interval of the periodic structure unit are *** finite element method(FEM)is used to predict the vibration transmission characteristics of the fluid-conveying pipe installed with the vibration reduction periodic ***,the wave/spectrum element method(WSEM)and experimental test are used to verify the calculated results ***,the vibration attenuation characteristics of the structure under different conditions,such as rubber material parameters,mass ring material,and fluid-structure coupling effect,are *** results show that the structure can produce a complete bandgap of 46 Hz-75 Hz in the low-frequency band below 100 Hz,which can effectively suppress the low broadband vibration of the fluidconveying *** addition,a high damping rubber material is used in the design of the periodic structure unit,which realizes the effective suppression of each formant peak of the pipe,and improves the vibration reduction effect of the fluid-conveying ***,the structure has the effect of suppressing both bending vibration and longitudinal vibration,and effectively inhibits the transmission of transverse waves and longitudinal waves in the *** research results provide a reference for the application of acoustic metamaterials in the multi-directional vibration control of fluid-conveying pipes.

关键词： fluid-conveying pipe acoustic metamaterial multi-directional vibration reduction local resonance

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河北省大学生总体国家安全观教育实践调查研究

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石家庄铁路职业技术学院学报 2024年第1期23卷 79-83页

作者：赵军华韩东海王康石家庄铁道大学河北石家庄050019

将习近平总书记关于国家安全的重要讲话精神贯彻落实到位、全面增强大学生人群的国家安全观意识是2023年我国高校安全教育工作的重中之重。为全面了解河北省大学生对总体国家安全观的认知现状,促进河北省高校国家安全观教育进一步发展,... 详细信息

将习近平总书记关于国家安全的重要讲话精神贯彻落实到位、全面增强大学生人群的国家安全观意识是2023年我国高校安全教育工作的重中之重。为全面了解河北省大学生对总体国家安全观的认知现状,促进河北省高校国家安全观教育进一步发展,研究团队对河北省内多所高校的大学生进行了调查,调查发现部分大学生对国家安全的重要性和紧迫性认知不足,部分高校在国家安全教育方面存在缺乏组织保障和监督考核机制、课程设置和教学内容不够全面、学生缺乏实践机会、宣传力度不够等问题,并对导致安全观教育成效不理想的主要因素进行了深入分析,最后提出了加强大学生总体国家安全观教育的相关建议,希望能够为政府决策和高校完善与落实国家安全教育相关政策提供有益的帮助。

关键词：总体国家安全观高校教育

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Establishment of a comprehensive indicator to nondestructively analyze watermelon quality at different ripening stages

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Journal of Innovative Optical Health Sciences 2014年第4期7卷 1-11页

作者： Shuye Qi Shuhui Song Shengnan Jiang Yingrui Chen Wu Li donghai han College of Food Science and Nutritional Engineering China Agricultural University 17 Qinghua East Road Haidian District BeijingP.R.China National Engineering Research Center for Vegetables 50 Zhanghua Street Haidian District BeijingP.R.China

Two nondestructive methods based on visible and near-infrared(VIS-NIR)spectroscopy and X-ray image have been used for the evaluation of watermelon *** prediction perform-ance based on partial least squares(PLS)by diffuse transmittance measurement(500-1010 nm)was evaluated for_chemical quality attributes SSC(Rc=0.903;RMSEC=0.572%Brix;Rp=0.862;RMSEP=0.717%Brix;RPD=1.83),lycopene(Rc=0.845;RMSEC=0.266 mg/100 gFW;Rp=0.751;RMSEP=0.439 mg/100 gFW;RPD=1.13)and moisture(Rc=0.917;RMSEC=0.280%;Rp=0.937;RMSEP=0.276%;RPD=2.79).The X-ray calibration linearequations developed by extracting the appropriate gray threshold were sufficiently precise forvolume(R?=0.986)and weight(R?=0.993).In order to optimize prediction model of water-melon quality in growth period,multivariate multi-block technique factor analysis enabled in-tegration of these traits:chemical information is related to physical *** component analysis to extract common factors and varimax with Kaiser normalizationto improve explanatory,the comprehensive indicator based on variances was established *** with Rc=0.94,RMSEC=0.244,Rp=0.93,RMSEP=0.344 and RPD=*** of these models indicates that the comprehensive indicator determined only by portable VIS-NIR spectrometer appears as a suitable method for appraising watermelon qualitynondestructively on the plant at diferent ripen *** method contributes to infer the picking date of watermelon with higher accuracy and bigger economic benefits than that byexperience.

关键词： Visible and near-infrared spectroscopy X-ray imaging maturity process factoranalysis comprehensive indicator.

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Nondestructive determination of soluble solids and firmness in mix-cultivar melon using near-infrared CCD spectroscopy

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Journal of Innovative Optical Health Sciences 2015年第6期8卷 17-24页

作者： Jie Lu Shuye Qi Ran Liu Enyang Zhou Wu Li Shuhui Song donghai han College of Food Science and Nutritional Engineering China Agricultural University Beijing 100083P.R.China National Engineering Research Center for Vegetables(NERCV)Beijing 100097 P.R.China

Nondestructive evaluation of melon quality is in great need of comprehensive *** solids content(SSC)and firmness are the two indicators of melon internal quality that mostly a®ect consumer *** provide guidance for fruit classification,internal quality standards was preliminarily established through sensory test,as:Melon with SSC over 12Brix,firmness 4–5.5 kgf·cm^(-2)2 were considered as satisfactory class sample;and SSC over 10Brix,¯rmness 3.5–6.5 kgf·cm^(-2) as average class *** near infrared(NIR)nondestructive detection program was set as spectra collected from the stylar-end,Brix expressed by the average SSC of inner and outer mesocarp,each cultivar of melon was detected with its own optimum integration time,and the second derivative algorithm was used to equalize *** wavelength selected by genetic algorithms(GA),a robust SSC model of mix-cultivar melon was established,the root mean standard error of cross-validation(RMSECV)was 0.99 and the ratio performance deviation(RPD)nearly reached 3.0,which almost could meet the accuracy requirement of 1.5*** model of mix-cultivar melon was acceptable but inferior.

关键词： Melon nondestructive detection near-infrared fruit quality soluble solids content firmness

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胆宁片联合甘露醇在肠镜检查前肠道准备的效果评估

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中国当代医药 2024年第19期31卷 30-33页

作者：王军生王屹然许琳韩东海孙晴晴李祥佩江苏省徐州市肿瘤医院消化内科江苏徐州221000

目的探讨胆宁片与甘露醇联合用药在肠镜检查前肠道准备的临床应用效果。方法根据《城市癌症早诊早治项目》技术方案,选取2019年1月至2022年12月的525例高危居民作为研究对象,至徐州市肿瘤医院消化内镜中心进行结肠镜筛查。采用随机数字... 详细信息

目的探讨胆宁片与甘露醇联合用药在肠镜检查前肠道准备的临床应用效果。方法根据《城市癌症早诊早治项目》技术方案,选取2019年1月至2022年12月的525例高危居民作为研究对象,至徐州市肿瘤医院消化内镜中心进行结肠镜筛查。采用随机数字表法将其分为和对照组(262例)和试验组(263例)。对照组仅使用甘露醇进行结肠镜前肠道准备,试验组应用胆宁片联合甘露醇进行结肠镜前肠道准备。采用波士顿量表清洁评分比较两组不同部位的肠道清洁效果,同时比较两组不良反应发生率。结果试验组不同肠道部位清洁评分均高于对照组,差异有统计学意义(P0.05)。结论胆宁片联合甘露醇的肠镜前肠道准备方法是可行、安全且有效的,值得临床进一步推广应用。

关键词：胆宁片甘露醇肠道准备肠镜检查

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Peroxidase-like active Cu-ZIF-8 with rich copper(I)-nitrogen sites for excellent antibacterial performances toward drug-resistant bacteria

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Nano Research 2024年第8期17卷 7427-7435页

作者： Xiaoze Wang Hui Wang Jingkun Zhang Ning han Wenjun Ma donghai Zhang Mingshui Yao Xianliang Wang Yunfa Chen State Key Laboratory of Mesoscience and Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China University of the Chinese Academy of Sciences Beijing 100049China Laboratory of Theoretical and Computational Nanoscience CAS Key Laboratory of Nanosystem and Hierarchial FabricationCAS Center for Excellence in NanoscienceNational Center for Nanoscience and TechnologyBeijing 100190China China CDC Key Laboratory of Environment and Population Health National Institute of Environmental HealthChinese Center for Disease Control and PreventionBeijing 100021China

Bacterial pathogens pose a serious threat to human health,and there is an urgent need to develop highly effective antibacterial materials to eliminate the increasingly serious contamination of drug-resistant ***,a Cu-doped ZIF-8 particle with unsaturated copper exhibits high peroxidase-like activity.99.998%antibacterial efficiency against *** can be achieved for 30 min at a low concentration of 50μg·mL^(−1),as well as complete sterilization against ***(up to 8 log).99.999%antibacterial efficiency against Methicillin-resistant Staphylococcus aureus can be achieved,performing orders of magnitude higher than *** mechanism shows that the unsaturated Cu-Nx sites are enzyme-like active centers,which could promote the consumption of bacteria reducing substances by H_(2)O_(2),and the generated*OH further aggravates bacterial oxidative stress and membrane *** importantly,the oxidation activity of adsorbed oxygen species on Cu-ZIF-8 is enhanced by charge transfer and structural changes between the ligand and copper center like natural ***-doped ZIF-8 with peroxidase-like activity shows great potential in antibacterial application and the revealed catalytic mechanism is helpful for understanding the high antibacterial activity of nanoparticles with Cu-Nx sites.

关键词： Cu-doped ZIF-8 peroxidase-like reactive oxygen species(ROS) catalytic mechanism antibacterial activity

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水果内部品质近红外光谱无损检测研究进展

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中国激光 2008年第8期35卷 1123-1131页

作者：韩东海王加华中国农业大学食品科学与营养工程学院北京100083

近红外(NIR)光谱分级技术正越来越广泛地应用于水果的产后加工和质量评判中.介绍了水果内部品质光学特性检测原理;分析了规则反射、透射和漫反射3种光特性测量方法在水果内部品质不同需求检测中的适用性;化学计量学方法是近红外光谱分... 详细信息

近红外(NIR)光谱分级技术正越来越广泛地应用于水果的产后加工和质量评判中.介绍了水果内部品质光学特性检测原理;分析了规则反射、透射和漫反射3种光特性测量方法在水果内部品质不同需求检测中的适用性;化学计量学方法是近红外光谱分析技术的一个重要部分,对一些新的预处理方法和回归算法作了介绍;探讨了水果状态对光谱影响及修正方法,如温度补偿、大小修正等;并阐述了水果的糖度、酸度、硬度等定量检测和褐变、黑心、水心、损伤等定性判别的国内外最新研究进展;分析了近红外技术在水果品质检测和控制方面的应用前景.

关键词：应用光学近红外光谱无损检测化学计量学光谱预处理水果内部品质

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2D-to-3D buckling transformability enabled reconfigurable metamaterials for tunable chirality and focusing effect

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Photonics Research 2023年第10期11卷 1770-1780页

作者： donghai han WENKANG LI TAO SUN MIN LIU XIAOMING CHEN HONGYU SHI ZHENGJIE FAN FANQI MENG LIUYANG ZhanG XUEFENG CHEN State Key Laboratory for Manufacturing Systems Engineering Xi’an Jiaotong UniversityXi’an 710049China School of Information and Communications Engineering Xi’an Jiaotong UniversityXi’an 710049China Physikalisches Institut Goethe-Universität60438 Frankfurt am MainGermany

Recently,multifarious deformation approaches in nature have promoted dynamic manipulation for electromagnetic(EM)waves in metamaterials,and those representative strategies are mainly focused on the modulation of spectral *** works have also achieved tunable phase-gradient ***,to broaden the modulation freedom of mechanical deformation,we initially propose two reconfigurable metamaterials consisting of mirrored S-shaped meta-atoms selectively bonded on biaxially pre-stretched *** meta-atoms with spin-insensitive transmittance are buckled into 3D morphologies to break residual symmetries by releasing the stress and to facilitate spin-dependent transmittance under circularly polarized *** to the geometric anisotropy of S-shaped meta-atoms along the x and y axes,3D chiral meta-atoms exhibit discriminate circularly cross-polarized transmittance under opposite *** underlying physical mechanism reveals that EM resonance originates from the excitation of electric dipoles and magnetic dipoles,and their cross coupling finally triggers the chiral effects of 3D *** introducing the gradient-phase design that keeps unchanged under various strains,two types of meta-atoms with specified orientations are interleaved to design a double-foci metalens,and its 2D-to-3D morphology transformation shortens the focusing length and facilitates the intensity change of two *** approach in designing reconfigurable EM metamaterials with 2D-to-3D buckling transformability can be further extended toward terahertz even optical wavebands,and it may assist with deriving more applicable multi-functionalities in the aspects of imaging,sensing,and holograms.

关键词： buckling polarized circular

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苹果糖度在线检测降低杂散光影响研究

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农业机械学报 2015年第11期46卷 260-265页

作者：韩东海周恩洋戚淑叶中国农业大学食品科学与营养工程学院北京100083 中国农业大学工学院北京100083

基于光谱学原理设计了智能苹果糖度在线分级设备,研究了上置式检测器在线检测中的杂散光问题,通过光路图分析了富士苹果3种摆放方式对杂散光的影响,并提出了遮光降噪方案。利用偏最小二乘(PLS)回归分别建立了3种摆放方式的富士苹果可溶... 详细信息

基于光谱学原理设计了智能苹果糖度在线分级设备,研究了上置式检测器在线检测中的杂散光问题,通过光路图分析了富士苹果3种摆放方式对杂散光的影响,并提出了遮光降噪方案。利用偏最小二乘(PLS)回归分别建立了3种摆放方式的富士苹果可溶性固形物含量(SSC)在线预测模型。研究结果表明,对于上置式检测器而言,摆放方式和遮光处理尤为重要。其中果柄朝上遮光为最佳降噪措施,所建立的模型校正集均方差(RMSEC)为0.60,校正集相关系数(RC)为0.94,预测集均方差(RMSEP)为0.67,预测集相关系数(RP)为0.87,可以满足实际生产中的在线分级要求。

关键词：苹果糖度光谱学在线检测杂散光上置式检测器

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Ultrafast dynamics of femtosecond laser-induced high spatial frequency periodic structures on silicon surfaces

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Opto-Electronic Science 2024年第3期3卷 33-46页

作者： Ruozhong han Yuchan Zhang Qilin Jiang Long Chen Kaiqiang Cao Shian Zhang donghai Feng Zhenrong Sun Tianqing Jia State Key Laboratory of Precision Spectroscopy School of Physics and Electronic ScienceEast China Normal UniversityShanghai 200241China Institute of Laser Manufacturing Henan Academy of SciencesZhengzhou 450046China Institute of Physics Chinese Acadamy of SciencesBeijing 100190China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006China

Femtosecond laser-induced periodic surface structures(LIPSS)have been extensively studied over the past few *** particular,the period and groove width of high-spatial-frequency LIPSS(HSFL)is much smaller than the diffraction limit,making it a useful method for efficient ***,compared with the low-spatial-frequency LIPSS(LSFL),the structure size of the HSFL is smaller,and it is more easily ***,the formation mechanism of HSFL is complex and has always been a research hotspot in this *** this study,regular LSFL with a period of 760 nm was fabricated in advance on a silicon surface with two-beam interference using an 800 nm,50 fs femtosecond *** ultrafast dynamics of HSFL formation on the silicon surface of prefabricated LSFL under single femtosecond laser pulse irradiation were observed and analyzed for the first time using collinear pump-probe imaging *** general,the evolution of the surface structure undergoes five sequential stages:the LSFL begins to split,becomes uniform HSFL,degenerates into an irregular LSFL,undergoes secondary splitting into a weakly uniform HSFL,and evolves into an irregular LSFL or is *** results indicate that the local enhancement of the submerged nanocavity,or the nanoplasma,in the prefabricated LSFL ridge led to the splitting of the LSFL,and the thermodynamic effect drove the homogenization of the splitting LSFL,which evolved into HSFL.

关键词： laser-induced periodic surface structures(LIPSS) local field enhancement collinear pump-probe imaging silicon high spatial frequency periodic structures

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