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FLEXOELECTRICITY:THEORY, EXPERIMENTS AND APPLICATIONS

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FLEXOELECTRICITY:THEORY, EXPERIMENTS AND APPLICATIONS

2016年全国压电和声波理论及器件应用研讨会

作者： Liang xu ming-long xu Sheng-ping SHEN State Key Laboratory for Strength and Vibration of Structures School of Aerospace Xi’an Jiaotong University

Flexoelectric effect describes the coupling between the electric polarization and the elastic strain/stress gradients in dielectric solids and in liquid crystals. In contrast to piezoelectricity which is invalid in materials with inversion symmetry, flexoelectricity exists, commonly, in all solid dielectrics. Flexoelectricity still have many open questions and unresolved issues in the developing field, although it has attracted a surge of attention recently. This talk will present our recent work on flexoelectricity from the basic theory, experiment measurements to applications including sensors and energy harvesters.

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膨胀土的二维膨胀各向异性试验研究

中国公路学报 2022年第10期35卷 65-74页

作者：张锐龙明旭刘昭京郑健龙刘正楠长沙理工大学交通运输工程学院湖南长沙410114 中国铁路南宁局集团有限公司广西南宁530029

为给膨胀土地区结构物设计计算提供关键参数,研制了二维膨胀仪,选取广西百色中膨胀土和湖北枝江弱膨胀土,制备不同干密度状态的试样,分别开展了恒体积膨胀力、单向膨胀和二维膨胀试验,分析和表征了竖向和侧向膨胀的规律,并比较了两向膨... 详细信息

为给膨胀土地区结构物设计计算提供关键参数,研制了二维膨胀仪,选取广西百色中膨胀土和湖北枝江弱膨胀土,制备不同干密度状态的试样,分别开展了恒体积膨胀力、单向膨胀和二维膨胀试验,分析和表征了竖向和侧向膨胀的规律,并比较了两向膨胀的差异性;通过扫描电镜观察,分析了产生膨胀各向异性的原因。结果表明:恒体积条件下最终侧向与竖向膨胀力之比,以及单向膨胀条件下最终侧向与竖向膨胀率的比值,均会随压实度发生变化,干密度越大两向膨胀力(或膨胀率)的差异性越大;两向膨胀力随膨胀应变的变化均表现出前期快速衰减、后期缓慢衰减的趋势,可用幂函数表征,但拟合参数不同;在二维膨胀条件下,竖向膨胀会影响侧向膨胀,不同程度竖向膨胀后的侧向膨胀规律同样可用幂函数表征,拟合结果表明竖向膨胀会改变拟合参数导致曲线形态的改变,继而影响侧向膨胀力随侧向应变的衰减幅度。干密度增大致使黏土矿物片状颗粒整体更趋向于水平定向排列,这是造成膨胀各向异性的主要原因。膨胀过程中土颗粒的重分布会导致各向异性不断变化,故难以通过竖向膨胀力预测侧向膨胀力,在进行相关计算时建议实测侧向膨胀规律。

关键词：道路工程膨胀土二维膨胀仪各向异性干密度

Real-Time Discrete Adaptive Control of Robot Arm Based on Digital Signal Processing

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Journal of Southwest Jiaotong University(English Edition) 2008年第1期16卷 24-29页

作者：龙绪明 School of Electrical Engineering Southwest Jiatong University

A discrete model reference adaptive controller of robot arm is obtained by integrating the reduced dynamic model of robot, model reference adaptive control （MRAC） and digital signal processing （DSP） computer system into an electromechanical system. With the DSP computer system, the control signal of each joint of the robot arm can be processed in real time and independently. The simulation and experiment results show that with the control strategy, the robot achieved a good trajectory following precision, a good decoupling performance and a high real-time adaptivity.

关键词： Robot Model reference adaptive control (MRAC) Digital signal processing (DSP) Real-time control

MoS_(2)Lubricate‑Toughened MXene/ANF Composites for Multifunctional Electromagnetic Interference Shielding

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Nano-Micro Letters 2025年第2期17卷 358-371页

作者： Jiaen Wang Wei ming longfu Chen Tianliang Song Moxi Yele Hao Zhang long Yang Gegen Sarula Benliang Liang Luting Yan Guangsheng Wang School of Physical Science and Engineering Beijing Jiaotong UniversityBeijing 100044People’s Republic of China Key Laboratory of Bio‑Inspired Smart Interfacial Science and Technology of Ministry of Education School of ChemistryBeihang UniversityBeijing 100191People’s Republic of China

The design and fabrication of high toughness electromagnetic interference(EMI)shielding composite films with diminished reflection are an imperative task to solve electromagnetic pollution *** MXene/ANF(aramid nanofibers)–MoS_(2)composite films with nacre-like layered structure here are fabricated after the introduction of MoS_(2)into binary MXene/ANF composite *** introduction of MoS_(2)fulfills an impressive“kill three birds with one stone”improvement effect:lubrication toughening mechanical performance,reduction in secondary reflection pollution of electromagnetic wave,and improvement in the performance of photothermal *** the introduction of MoS_(2)into binary MXene/ANF(mass ratio of 50:50),the strain to failure and tensile strength increase from 22.1±1.7%and 105.7±6.4 MPa and to 25.8±0.7%and 167.3±9.1 MPa,*** toughness elevates from 13.0±4.1 to 26.3±0.8 MJ m^(−3)(~102.3%)*** the reflection shielding effectiveness(SE_(R))of MXene/ANF(mass ratio of 50:50)decreases~10.8%.EMI shielding effectiveness(EMI SE)elevates to 41.0 dB(8.2–12.4 GHz);After the introduction of MoS_(2)into binary MXene/ANF(mass ratio of 60:40),the strain to failure increases from 18.3±1.9%to 28.1±0.7%(~53.5%),the SE_(R)decreases~22.2%,and the corresponding EMI SE is 43.9 *** MoS_(2)also leads to a more efficient photothermal conversion performance(~45 to~55℃).Additionally,MXene/ANF–MoS_(2)composite films exhibit excellent electric heating performance,quick temperature elevation(15 s),excellent cycle stability(2,2.5,and 3 V),and long-term stability(2520 s).Combining with excellent mechanical performance with high MXene content,electric heating performance,and photothermal conversion performance,EMI shielding ternary MXene/ANF–MoS_(2)composite films could be applied in many industrial *** work broadens how to achieve a balance between mechanical properties and versatility of composites in the case of high-function fillers.

关键词： MXene-MoS_(2) Lubrication toughening EMI shielding Photothermal conversion Electric heating performance

（2D）2LDA和支持向量机在PCB焊点检测中的应用

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现代电子技术 2015年第2期38卷 100-103页

作者：贺海浪龙绪明刘明晓罗爱玲西南交通大学电气工程学院四川成都610031

在现代印刷电路板生产过程中,焊点质量检测是其中的一个重要组成部分。然而随着电子元器件封装的不断小型化,焊点质量检测也变得越来越具有挑战性,传统的依靠人工检测的方式已经越来越不能满足实际生产的需要,同时,基于图像处理与人工... 详细信息

在现代印刷电路板生产过程中,焊点质量检测是其中的一个重要组成部分。然而随着电子元器件封装的不断小型化,焊点质量检测也变得越来越具有挑战性,传统的依靠人工检测的方式已经越来越不能满足实际生产的需要,同时,基于图像处理与人工智能的自动光学检测技术在焊点质量检测中得到越来越广泛的应用。在此提出一种将双方向二维线性判别分析和支持向量机相结合的焊点质量自动光学检测方法。实验结果表明,该方法能够取得良好的识别效果。

关键词：焊点检测双方向二维线性判别分析支持向量机印刷电路板生产

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高速贴片机的非线性自适应逆控制

自动化技术与应用 2007年第2期26卷 36-39页

作者：胡勇龙绪明西南交通大学电气工程学院四川成都610031

对SMT生产线的关键设备贴片机提出了自适应逆控制方案。该方案用一个非线性滤波器作为贴片机的建模和逆建模的辨识器和自适应逆控制器,在MATLAB/SIMULINK平台下进行了算法仿真检验。结果表明该方案收敛快．能有效控制该非线性对象。此... 详细信息

对SMT生产线的关键设备贴片机提出了自适应逆控制方案。该方案用一个非线性滤波器作为贴片机的建模和逆建模的辨识器和自适应逆控制器,在MATLAB/SIMULINK平台下进行了算法仿真检验。结果表明该方案收敛快．能有效控制该非线性对象。此方案首次为贴片机的控制提供了一个先进的、全新的思路。

关键词：贴片机建模与逆建模非线性自适应逆控制滤波LMS算法模型辨识

Small extracellular vesicles derived from human induced pluripotent stem cell-differentiated neural progenitor cells mitigate retinal ganglion cell degeneration in a mouse model of optic nerve injury

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Neural Regeneration Research 2025年第2期20卷 587-597页

作者： Tong Li Hui-Min Xing Hai-Dong Qian Qiao Gao Sheng-Lan xu Hua Ma Zai-long Chi State Key Laboratory of Ophthalmology Optometry and Visual ScienceEye HospitalWenzhou Medical UniversityWenzhouZhejiang ProvinceChina National Clinical Research Center for Ocular Diseases Eye HospitalWenzhou Medical UniversityWenzhouZhejiang ProvinceChina

Several studies have found that transplantation of neural progenitor cells(NPCs)promotes the survival of injured ***,a poor integration rate and high risk of tumorigenicity after cell transplantation limits their clinical *** extracellular vesicles(sEVs)contain bioactive molecules for neuronal protection and *** studies have shown that stem/progenitor cell-derived sEVs can promote neuronal survival and recovery of neurological function in neurodegenerative eye diseases and other eye *** this study,we intravitreally transplanted sEVs derived from human induced pluripotent stem cells(hiPSCs)and hiPSCs-differentiated NPCs(hiPSC-NPC)in a mouse model of optic nerve *** results show that these intravitreally injected sEVs were ingested by retinal cells,especially those localized in the ganglion cell *** with hiPSC-NPC-derived sEVs mitigated optic nerve crush-induced retinal ganglion cell degeneration,and regulated the retinal microenvironment by inhibiting excessive activation of *** analysis further revealed that hiPSC-NPC derived sEVs transported neuroprotective and anti-inflammatory miRNA cargos to target cells,which had protective effects on RGCs after optic nerve *** findings suggest that sEVs derived from hiPSC-NPC are a promising cell-free therapeutic strategy for optic neuropathy.

关键词： exosome miRNA neural progenitor cell neurodegeneration neuroinflammation neuroprotection optic nerve crush optic neuropathy retinal ganglion cell small extracellular vesicles

MODELING AND SIMULATION OF A NEW PIEZOELECTRIC STACK ACTUATOR WITH BI-DIRECTION OUTPUTS

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MODELING AND SIMULATION OF A NEW PIEZOELECTRIC STACK ACTUATO...

应用于贴片机贴装顺序优化的遗传算法的比较和改进

2010全国压电和声波理论及器件技术研讨会

作者： Ya-jun LUO,ming-long xu,Xi-nong ZHANG MOE Key Laboratory for Strength and Vibration/School of Airspace,Xi'an Jiaotong University, 28 West Xianning Road 28,Xi'an,Shaanxi 710049,China

In this paper,a new piezoelectric stack actuator is proposed,and the modeling and simulation are completed. Generally,piezoelectric stack can take significant compressive loads but cannot tolerate tension,so this new actuator is designed that can obtain obvious bilateral actuated *** actuator is made of two piezoelectric stacks and a bilateral output *** controlling the voltage polarity of two piezoelectric stacks,one is always under compressive loads in ***,the actuated principle of the new actuator is analyzed and a simplified drive model is ***,a linear model and a nonlinear model are built up, *** nonlinear model is mainly in order to analyze the hysteresis of piezoelectric material. Moreover,the effect of the preload on the actuator is considered in the two ***,the models are simulated by MATLAB *** corresponding results indicate the actuated characteristics and the effect of some *** simulated results of two models are also compared,and it is shown that the hysteresis is not neglected.

关键词： Piezoelectric stack bilateral hysteresis preload

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现代电子技术 2014年第6期37卷 129-131,135页

作者：罗爱玲龙绪明西南交通大学四川成都610031

元件贴装顺序优化是决定贴片机生产效率的关键问题,传统的解决贴装顺序优化问题的方法有遗传算法,蚁群算法,SS(伞布搜索法)等。使用较多的还是遗传算法。遗传算法中包含选择算子、交叉算子、变异算子,且编程思想简单,但容易出现局部最优... 详细信息

元件贴装顺序优化是决定贴片机生产效率的关键问题,传统的解决贴装顺序优化问题的方法有遗传算法,蚁群算法,SS(伞布搜索法)等。使用较多的还是遗传算法。遗传算法中包含选择算子、交叉算子、变异算子,且编程思想简单,但容易出现局部最优,过早收敛等情况。在此,通过对遗传算法在贴装顺序优化应用的结果比较找到一种更适合的遗传算法,使之拥有较快的收敛速度和全局优化性。

关键词：元件贴装顺序优化贴片机遗传算法交叉算子