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凝灰岩机制砂混凝土工作性的流变学分析

硅酸盐通报 2024年第1期43卷 71-83页

作者：温宏平宋鹏飞汪愿甘珑王旭昊山西工程科技职业大学工程管理学院太原030619 长安大学公路学院西安710064 中国电建集团西北勘测设计研究院有限公司西安710061

机制砂的生产与应用是我国混凝土行业走向低碳发展的良好契机,但机制砂的复杂特性导致混凝土工作性较差且难以预测。为研究基于流变学特性的机制砂混凝土工作性的影响因素及变化规律,从机制砂特性及混凝土配合比参数两个角度展开,建立... 详细信息

机制砂的生产与应用是我国混凝土行业走向低碳发展的良好契机,但机制砂的复杂特性导致混凝土工作性较差且难以预测。为研究基于流变学特性的机制砂混凝土工作性的影响因素及变化规律,从机制砂特性及混凝土配合比参数两个角度展开,建立了流变学特性与工作性的二维、三维关系模型,并采用灰色关联度分析法,对基于流变学分析的凝灰岩机制砂混凝土工作性影响机制进行因素显著性分析。结果表明,动态屈服应力和塑性黏度与混凝土的工作性关系密切,随着石粉含量、机制砂取代率和砂率的增加,动态屈服应力呈先减小后增大的趋势,机制砂特性与混凝土各项流变性能之间的关联度在强相关的区间内,通过合理调配各因素的水平可以达到实际工程所需要的最佳工作性。

关键词：凝灰岩机制砂混凝土流变学工作性灰色关联度分析石粉含量机制砂取代率

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一种复合驱动并联机构的设计与运动学分析

机械设计 2024年第5期41卷 121-130页

作者：吴孟丽吕东洋林玉飞王旭浩陈莫中国民航大学航空工程学院天津300300

提出了一种新型的5自由度复合驱动并联机构,并对其进行了运动学分析。首先,根据复合驱动并联机构的构型特点,开展了伴随运动分析,推导得到了位置逆解计算公式;其次,通过分析动平台上一组点的线速度分量与驱动速度间的映射,推导出5×5齐... 详细信息

提出了一种新型的5自由度复合驱动并联机构,并对其进行了运动学分析。首先,根据复合驱动并联机构的构型特点,开展了伴随运动分析,推导得到了位置逆解计算公式;其次,通过分析动平台上一组点的线速度分量与驱动速度间的映射,推导出5×5齐次量纲的雅可比矩阵;采用离散法计算机构的可达工作空间,根据灵活度指标,即条件数的倒数在可达工作空间的分布情况,确定了许用工作空间位置;然后,通过分析最大压力角在机构许用工作空间中的分布情况和驱动力与机构末端受力之间的映射关系,完成了并联机构的奇异性分析;最后,基于MATLAB和ADAMS软件进行了运动学仿真验证。所述工作为下一代样机的优化设计提供了理论基础。

关键词：复合驱动并联机构运动学分析奇异性分析

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高寒区混凝土多场耦合损伤劣化机制研究进展

硅酸盐通报 2024年第7期43卷 2317-2334页

作者：张维东汪愿宋鹏飞王亚坤刘倩倩王旭昊甘肃路桥第三公路工程有限责任公司兰州730000 长安大学公路学院西安710064 海南省交通规划勘察设计研究院有限公司海口570100

高寒区混凝土结构在实际服役过程中不仅受到车辆荷载的作用,同时还受到盐蚀和冻融等环境因素的作用。在荷载、盐蚀及冻融等多场耦合的作用下,高寒区混凝土的劣化涉及到化学、物理和力学等多种作用的交互影响。氯盐与混凝土之间发生复杂... 详细信息

高寒区混凝土结构在实际服役过程中不仅受到车辆荷载的作用,同时还受到盐蚀和冻融等环境因素的作用。在荷载、盐蚀及冻融等多场耦合的作用下,高寒区混凝土的劣化涉及到化学、物理和力学等多种作用的交互影响。氯盐与混凝土之间发生复杂的化学反应生成膨胀性复盐,导致混凝土内部体积膨胀,产生化学损伤。与此同时,冻融循环和动态荷载会造成混凝土物理损伤,在化学损伤和物理损伤的耦合作用下混凝土会迅速劣化。本文综述了盐蚀、冻融循环和动态荷载多场耦合对混凝土性能影响的研究现状,并总结了本领域最先进的材料无损表征技术和建模手段,从宏、细、微观多尺度建立兼具物理、化学损伤特性参数的预测模型,形成混凝土在多场耦合下的损伤劣化机制和劣化行为预测模型,最后提出了目前研究的不足之处。

关键词：高寒区混凝土路面劣化机制耦合作用预测模型耐久性力学性能

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复合驱动并联机构的动力学建模与仿真分析

机械设计 2024年第3期41卷 112-121页

作者：吴孟丽陈莫李德祚王旭浩李明宇林玉飞中国民航大学航空工程学院天津300300

针对一种PUU-2PRRS 5自由度复合驱动并联机构的刚体动力学建模问题,采用拉格朗日法结合虚功原理建立刚体动力学模型并进行仿真分析。首先,在考虑存在次闭环的情况下,采用闭环矢量法对并联机构进行运动学分析,推导出机构各构件质心的线... 详细信息

针对一种PUU-2PRRS 5自由度复合驱动并联机构的刚体动力学建模问题,采用拉格朗日法结合虚功原理建立刚体动力学模型并进行仿真分析。首先,在考虑存在次闭环的情况下,采用闭环矢量法对并联机构进行运动学分析,推导出机构各构件质心的线速度和角速度;其次,采用拉格朗日法结合虚功原理建立复合驱动并联机构的刚体动力学模型,为复合驱动并联机构驱动力的求解及后续动力学仿真分析奠定了基础;最后,基于MATLAB软件和ADAMS软件对该并联机构进行动力学仿真分析,在给定相同末端轨迹的情况下,对比两种软件得到的驱动力变化曲线,仿真结果验证了所建动力学模型的正确性。文中不仅为PUU-2PRRS 5自由度复合驱动并联机构控制系统的搭建打下了基础,也为其他复合驱动并联机构的动力学建模分析提供了理论依据。

关键词：复合驱动并联机构次闭环结构刚体动力学建模拉格朗日法虚功原理

SDDNet:Infrared small and dim target detection network

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CAAI Transactions on Intelligence Technology 2023年第4期8卷 1226-1236页

作者： Ma Long Shu Cong Huang Shanshan Wei Zoujian wang xuhao Wei Yanxi School of Computer Science and Engineering Xi'an Technological UniversityXi'anShaanxiChina State and Local Joint Laboratory of Advanced Network and Monitoring Xi'anShaanxiChina School of Computing University of Kent CanterburyUK

This study focuses on developing deep learning methods for small and dim target *** model infrared images as the union of the target region and background *** on this model,the target detection problem is considered a two‐class segmentation problem that divides an image into the target and ***,a neural network called SDDNet for single‐frame images is *** network yields target extraction results according to the original *** multiframe images,a network called IC‐SDDNet,a combination of SDDNet and an interframe correlation network module is *** and IC‐SDDNet achieve target detection rates close to 1 on typical datasets with very low false positives,thereby performing significantly better than current *** models can be executed end to end,so both are very convenient to use,and their implementation efficiency is very *** speeds of 540+/230+FPS and 170+/60+FPS are achieved with SDDNet and IC‐SDDNet on a single Tesla V100 graphics processing unit and a single Jetson TX2 embedded module ***,neither network needs to use future information,so both networks can be directly used in real‐time *** well‐trained models and codes used in this study are available at https://***/LittlePieces/ObjectDetection.

关键词： deep learning detection of moving objects

Design and Testing of a Novel Piezoelectric-Driven Microvibration Hammerhead

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Nanomanufacturing and Metrology 2023年第1期6卷 79-87页

作者： Zhiyong Guo Zhemin Shen Weidong Liu Zhiqiang Zhang Lifeng Zhang xuhao wang College of Aeronautical Engineering Civil Aviation University of ChinaTianjin 300300China

A novel microvibration hammerhead consists of a piezoelectric actuator and a double cross-shape compliant mechanism(DCCM)is presented in this *** output force of the piezoelectric actuator can be detected in real time by an insideinstalled pressure sensor.A theoretical model including the stiffness,first natural frequency,and stress of the DCCM and the displacement output of the piezoelectric actuator are established,and then they are further analyzed using the finite element analysis *** effects of the beam thickness on the static and dynamic properties are deeply analyzed and compared.A prototype micro hammering system is constructed by integrating the microvibration hammerhead assembly and controlling *** experiments are also carried out to verify the basic performance of the micro hammering system.

关键词： Piezoelectric Flexure hinge Micro hammering

Heterogeneous data-driven aerodynamic modeling based on physical feature embedding

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Chinese Journal of Aeronautics 2024年第3期37卷 1-6页

作者： Weiwei ZHANG xuhao PENG Jiaqing KOU Xu wang School of Aeronautics Northwestern Polytechnical UniversityXi’an 710072China Institute of Aerodynamics RWTH Aachen UniversityAachen 52062Germany

Aerodynamic surrogate modeling mostly relies only on integrated loads data obtained from simulation or experiment,while neglecting and wasting the valuable distributed physical information on the *** make full use of both integrated and distributed loads,a modeling paradigm,called the heterogeneous data-driven aerodynamic modeling,is *** essential concept is to incorporate the physical information of distributed loads as additional constraints within the end-to-end aerodynamic *** heterogenous data,a novel and easily applicable physical feature embedding modeling framework is *** framework extracts lowdimensional physical features from pressure distribution and then effectively enhances the modeling of the integrated loads via feature *** proposed framework can be coupled with multiple feature extraction methods,and the well-performed generalization capabilities over different airfoils are verified through a transonic *** with traditional direct modeling,the proposed framework can reduce testing errors by almost 50%.Given the same prediction accuracy,it can save more than half of the training ***,the visualization analysis has revealed a significant correlation between the discovered low-dimensional physical features and the heterogeneous aerodynamic loads,which shows the interpretability and credibility of the superior performance offered by the proposed deep learning framework.

关键词： Transonic flow Data-driven modeling Feature embedding Heterogenous data Feature visualization

Dynamic interactive bitwise meta-holography with ultra-high computational and display frame rates

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Opto-Electronic Advances 2024年第1期7卷 36-46页

作者： Yuncheng Liu Ke Xu xuhao Fan Xinger wang Xuan Yu Wei Xiong Hui Gao Wuhan National Laboratory for Optoelectronics and School of Optical and Electronic Information Huazhong University of Science and TechnologyWuhan 430074China Optics Valley Laboratory Wuhan 430074China

Interactive holography offers unmatched levels of immersion and user engagement in the field of future *** of the substantial progress has been made in dynamic meta-holography,the realization of real-time,highly smooth interactive holography remains a significant challenge due to the computational and display frame rate *** this study,we introduced a dynamic interactive bitwise meta-holography with ultra-high computational and display frame *** our knowledge,this is the first reported practical dynamic interactive metasurface holographic *** spa-tially divided the metasurface device into multiple distinct channels,each projecting a reconstructed *** switching states of these channels were mapped to bitwise operations on a set of bit values,which avoids complex holo-gram computations,enabling an ultra-high computational frame *** approach achieves a computational frame rate of 800 kHz and a display frame rate of 23 kHz on a low-power Raspberry Pi computational *** to this methodology,we demonstrated an interactive dynamic holographic Tetris game system that allows interactive gameplay,color display,and on-the-fly hologram *** technology presents an inspiration for advanced dynamic meta-holography,which is promising for a broad range of applications including advanced human-computer interaction,real-time 3D visualization,and next-generation virtual and augmented reality systems.

关键词： interactive display meta-holography bitwise operation ultra-high frame rate

Carbon dots-enhanced pH-responsive lubricating hydrogel based on reversible dynamic covalent bondings

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Chinese Chemical Letters 2024年第5期35卷 232-237页

作者： Jianye Kang Xinyu Yang xuhao Yang Jiahui Sun Yuhang Liu Shutao wang Wenlong Song State Key Laboratory of Supramolecular Structure and Materials College of ChemistryJilin UniversityChangchun 130012China CAS Key Laboratory of Bio-inspired Materials and Interfacial Science CAS Center for Excellence in NanoscienceTechnical Institute of Physics and ChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

Due to the various pH liquid environment in nature,the pH-responsive lubricating hydrogel is widely investigated and developed for tissue interface ***,the applied liquid environment will lead to poor mechanical property and weaken the pH-responsive *** this work,a carbon dotsenhanced pH-responsive lubricating hydrogel is developed by combining a pH-responsive section of dynamic PVA-borax network into a PAAm covalent polymer *** formed hydrogel presents a partial gel-sol transition under controlled pH *** low pH environments(<6.0),the formed lubricating layer originated from dynamic disassembly of PVA-borax hydrogel,and brings the lubricating properties on the hydrogel ***,the mechanical strength and lubrication properties are well promoted by introducing the carbon dots into the hydrogel,the blue sol layer can be observed more visually under the fluorescence *** pH-response also exhibits well *** prepared hydrogel broadens the idea for designing pH-responsive soft materials for soft lubricating actuator or robot.

关键词： pH-responsive Carbon dots Dynamic covalent bonding Lubrication