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渐变附着式起重机风致响应及疲劳分析

山东建筑大学学报 2024年第4期39卷 25-31,38页

作者：刘金樟王有志周磊烟台黄金职业学院资源与土木工程系山东烟台265401 山东大学土建与水利学院山东济南250061 杭州市钱江新城开发集团有限公司浙江杭州310016

起重机风载特性的研究有助于确定起重机的薄弱环节、制定附着杆的附着方案,从而提高其安全性。文章以SP7525型平头式起重机为原型,建立ABAQUS有限元模型,通过自回归Auto Regressive改进模型模拟了风速时程,采用雨流计数法并引入应力-寿... 详细信息

起重机风载特性的研究有助于确定起重机的薄弱环节、制定附着杆的附着方案,从而提高其安全性。文章以SP7525型平头式起重机为原型,建立ABAQUS有限元模型,通过自回归Auto Regressive改进模型模拟了风速时程,采用雨流计数法并引入应力-寿命曲线处理应力时程,探索了渐变附着式起重机的风致动力响应及疲劳损伤规律。结果表明:塔吊附着杆的风致应力数值随塔吊高度的增加而增大,不等长附着状态下,FZG7-1、FZG7-2、FZG7-3的风致应力值分别降低了5.70%、5.17%、7.78%;平衡臂、起重臂以及接近塔顶处塔身的疲劳损伤度量级为10^(-9)~10^(-8);FZG n-1、FZG n-3相对FZG n-2的风致应力值分别增大了10.10%、23.15%,且疲劳损伤度增加了1~2个数量级;塔吊采用不等长附着形式具有更高的安全性。

关键词：渐变附着式起重机 Auto Regressive模型风致响应疲劳分析

Two-dimensional materials： Emerging toolkit for construction of ultrathin high-efficiency microwave shield and absorber

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Frontiers of physics 2018年第4期13卷 53-91页

作者： Mingjun Hu Naibo Zhang Guangcun Shan Jiefeng Gao jinzhang liu Robert K. Y. Li School of Materials Science and Engineering Beihang University Beijing 100191 China Beijing Research and Development Center the 54th Research Institute Electronics Technology Group Corporation Beijing 100070 China School of Instrumentation Science and Opto-electronics Engineering Beihang University Beijing 100191 China School of Chemistry and Chemical Engineering Yangzhou University Yangzhou 225002 China Department of Materials Science and Engineering City University of Hong Kong Hong Kong China

Two-dimensional （2D） materials generally have unusual confined electro-strong interaction in a plane and can physical and chemical properties owing to the exhibit obvious anisotropy and a significant quantum-confinement effect, thus showing great promise in many fields. Some 2D materials, such as graphene and MXenes, have recently exhibited extraordinary electromagnetic-wave shielding and absorbing performance, which is attributed to their special electrical behavior, large specific surface area, and low mass density. Compared with traditional microwave attenuating materials, 2D materials have several obvious inherent advantages. First, similar to other nanomaterials, 2D materials have a very large specific surface area and can provide numerous interfaces for the enhanced interfacial polarization as well as the reflection and scattering of electromagnetic waves. Second, 2D materials have a particular 2D morphology with ultrasmall thickness, which is not only beneficial for the penetration and dissipation of electromagnetic waves through the 2D nanosheets, giving rise to multiple reflections and the dissipation of electromagnetic energy, but is also conducive to the design and fabrication of various well-defined structures, such as layer-by-layer assemblies, core-shell particles, and porous foam, for broadband attenuation of electromagnetic waves. Third, owing to their good processability, 2D materials can be integrated into various multifunctional composites for multimode attenuation of electromagnetic energy. In addition to behaving as microwave reflectors and absorbers, 2D materials can act as impedance regulators and provide structural support for good impedance matching and setup of the optimal structure. Numerous studies indicate that 2D materials are among the most promising microwave attenuation materials. In view of the rapid development and enormous advancement of 2D materials in shielding and absorbing electromagnetic wave, there is a strong need to summar

关键词： electromagnetic interference shielding microwave absorber graphene MXenes polymernanocomposites

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基于AT89C51的新型垃圾处理器设计

机械管理开发 2024年第8期39卷 100-102,105页

作者：张雨婷章盼梅劳宇鹏刘金璋蔡文鑫林展涛广州城市理工学院广东广州510800

厨余垃圾处理器的刀片及处理流程对垃圾处理效果影响较大,基于此,提出增加4Cr材质的啮齿式双齿辊粉碎结构,并基于AT89C51设计了二次研磨及脱水干燥流程,能有效改善研磨不充分的问题并且实现自动化处理,为家用厨余垃圾处理器的创新设计... 详细信息

厨余垃圾处理器的刀片及处理流程对垃圾处理效果影响较大,基于此,提出增加4Cr材质的啮齿式双齿辊粉碎结构,并基于AT89C51设计了二次研磨及脱水干燥流程,能有效改善研磨不充分的问题并且实现自动化处理,为家用厨余垃圾处理器的创新设计提供了参考。

关键词：厨余垃圾处理技术单片机

A new strategy for the fabrication of a flexible and highly sensitive capacitive pressure sensor

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Microsystems & Nanoengineering 2021年第6期7卷 173-184页

作者： Ruzhan Qin Mingjun Hu Xin Li Te Liang Haoyi Tan jinzhang liu Guangcun Shan School of Instrumentation Science and Opto-electronics Engineering Beihang UniversityBeijing 100191China School of Materials Science and Engineering Beihang UniversityBeijing 100191China

The development of flexible capacitive pressure sensors has wide application prospects in the fields of electronic skin and intelligent wearable electronic devices,but it is still a great challenge to fabricate capacitive sensors with high *** reports have considered the use of interdigital electrode structures to improve the sensitivity of capacitive pressure *** this work,a new strategy for the fabrication of a high-performance capacitive flexible pressure sensor based on MXene/polyvinylpyrrolidone(PVP)by an interdigital electrode is *** increasing the number of interdigital electrodes and selecting the appropriate dielectric layer,the sensitivity of the capacitive sensor can be *** capacitive sensor based on MXene/PVP here has a high sensitivity(~1.25 kPa^(−1)),low detection limit(~0.6 Pa),wide sensing range(up to 294 kPa),fast response and recovery times(~30/15 ms)and mechanical stability of 10000 *** presented sensor here can be used for various pressure detection applications,such as finger pressing,wrist pulse measuring,breathing,swallowing and speech *** work provides a new method of using interdigital electrodes to fabricate a highly sensitive capacitive sensor with very promising application prospects in flexible sensors and wearable electronics.

关键词： electrode capacitive sensor

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城市投资建设的新模式——城市投资社会化

施工技术 2011年第6期40卷 90-92页

作者：刘锦章中国科学院研究生院北京100080

当前地方政府城市投资(简称城投)公司的过度负债等问题已经引起了国家的高度关注,其发展的可持续性受到了广泛的质疑。社会化城投可以提供公共物品、准公共物品和私人物品,从业务上讲可以替代政府城投,从经济学和管理学理论上讲符合城... 详细信息

当前地方政府城市投资(简称城投)公司的过度负债等问题已经引起了国家的高度关注,其发展的可持续性受到了广泛的质疑。社会化城投可以提供公共物品、准公共物品和私人物品,从业务上讲可以替代政府城投,从经济学和管理学理论上讲符合城市公共事业市场化、社会化的规律,从政策上讲符合国家的投资体制改革决定。城投社会化是我国城市基础设施投资建设市场化改革的最终目标。

关键词：城市投资融资平台城投公司城市运营公共管理