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Preparation of Self-limiting Heating Cables with Excellent Processability, Mechanical Properties and PTC Effect via Thermal and Electrical Treatments

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Chinese Journal of Polymer Science 2024年第4期42卷 511-520页

作者： tian-Hao Yang Tong Wu Qiang Fu State Key Laboratory of Polymer Materials Engineering College of Polymer Science and EngineeringSichuan UniversityChengdu610065China State Key Laboratory of Polymer Materials Engineering Polymer Research Institute of Sichuan UniversityChengdu610065China

Polymer/conductive filler composites have been widely used for the preparation of self-limiting heating cables with the positive temperature coefficient (PTC) effect. The control of conductive filler distribution and network in polymer matrix is the most critical for performance of PTC materials. In order to compensate for the destruction of the filler network structure caused by strong shearing during processing, an excessive conductive filler content is usually added into the polymer matrix, which in turn sacrifices its processability and mechanical properties. In this work, a facile post-treatment of the as-extruded cable, including thermal and electrical treatment to produce high-density polyethylene (HDPE)/carbon black (CB) cable with excellent PTC effect, is developed. It is found for the as-extruded sample, the strong shearing makes the CB particles disperse uniformly in HDPE matrix, and 25 wt% CB is needed for the formation of conductive paths. For the thermal-treated sample, a gradually aggregated CB filler structure is observed, which leads to the improvement of PTC effect and the notable reduction of CB content to 20 wt%. It is very interesting to see that for the sample with combined thermal and electrical treatment, CB particles are agglomerated and oriented along the electric field direction to create substantial conductive paths, which leads to a further decrease of CB content down to 15 wt%. In this way, self-limiting heating cables with excellent processability, mechanical properties and PTC effect have simultaneously been achieved.

关键词： Self-limiting heating cables Positive temperature coefficient Thermal treatment Electrical treatment

Electrochemical anodic oxidation assisted fabrication of memristors

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International Journal of Extreme Manufacturing 2024年第3期6卷 250-272页

作者： Shuai-Bin Hua tian Jin Xin Guo School of Materials Science and Engineering State Key Laboratory of Material Processing and Die&Mould TechnologyHuazhong University of Science and TechnologyWuhan 430074People’s Republic of China

Owing to the advantages of simple structure,low power consumption and high-density integration,memristors or memristive devices are attracting increasing attention in the fields such as next generation non-volatile memories,neuromorphic computation and data ***,the deposition of memristive films often requires expensive equipment,strict vacuum conditions,high energy consumption,and extended processing *** contrast,electrochemical anodizing can produce metal oxide films quickly(e.g.10 s) under ambient *** means of the anodizing technique,oxide films,oxide nanotubes,nanowires and nanodots can be fabricated to prepare *** film thickness,nanostructures,defect concentrations,etc,can be varied to regulate device performances by adjusting oxidation parameters such as voltage,current and *** memristors fabricated by the anodic oxidation technique can achieve high device consistency,low variation,and ultrahigh yield *** article provides a comprehensive review of the research progress in the field of anodic oxidation assisted fabrication of ***,the principle of anodic oxidation is introduced;then,different types of memristors produced by anodic oxidation and their applications are presented;finally,features and challenges of anodic oxidation for memristor production are elaborated.

关键词： anodic oxidation anodized aluminium oxide memristor resistive switching electrical properties

Friendship Inference Based on Interest Trajectory Similarity and Co-occurrence

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Chinese Journal of Electronics 2024年第3期33卷 708-720页

作者： Junfeng tian Zhengqi HOU School of Cyber Security and Computer Hebei University Hebei Key Laboratory of High Confidence Information Systems Hebei University

Most of the current research on user friendship speculation in location-based social networks is based on the co-occurrence characteristics of users,however,statistics find that co-occurrence is not common among all users;meanwhile,most of the existing work focuses on mining more features to improve the accuracy but ignoring the time complexity in practical *** this basis,a friendship inference model named ITSIC is proposed based on the similarity of user interest tracks and joint user location *** utilizing MeanShift clustering algorithm,ITSIC clustered and filtered user check-ins and divided the dataset into interesting,abnormal,and noise *** interest trajectories were constructed from user interest check-in data,which allows ITSIC to work efficiently even for users without *** the same time,by application of clustering,the single-moment multi-interest trajectory was further proposed,which increased the richness of the meaning of the trajectory *** extensive experiments on two real online social network datasets show that ITSIC outperforms existing methods in terms of AUC score and time efficiency compared to existing methods.

关键词： Data privacy Social networking (online) Noise Clustering algorithms Prediction algorithms Inference algorithms Data models

XLPE电力电缆典型缺陷局部放电测量与分析

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高压电器 2015年第2期51卷 44-50页

作者：刘蓉李继胜田维坚樊养余西北工业大学电子信息学院西安710072 陕西师范大学物理学与信息技术学院西安710062

为了研究XLPE电力电缆典型缺陷的放电特征,在试验室条件下设计了3种放电物理模型,采用脉冲电流法对其局部放电信号进行测量。对比研究了3种典型缺陷模型的局部放电特征,分析了电压幅值对放电谱图、放电波形、放电频率和中心相位分布的... 详细信息

为了研究XLPE电力电缆典型缺陷的放电特征,在试验室条件下设计了3种放电物理模型,采用脉冲电流法对其局部放电信号进行测量。对比研究了3种典型缺陷模型的局部放电特征,分析了电压幅值对放电谱图、放电波形、放电频率和中心相位分布的影响关系。试验结果表明,相同条件下同一缺陷模型放电稳定、重复性好;不同缺陷类型其放电发展过程不尽相同,呈现的PRPD谱图、单个脉冲波形及相位分布趋势图区别明显。这些特征为进一步进行放电类型的模式识别及局部放电机理研究提供了试验依据。

关键词： XLPE 缺陷模型局部放电 PRPD谱图脉冲波形特征分析

Model-driven path planning for robotic plasma cutting of branch pipe with single Y-groove based on pipe-rotating scheme

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Advances in Manufacturing 2024年第1期12卷 94-107页

作者： Yan Liu Qiu Tang Xin-Cheng tian School of Control Science and Engineering Shandong UniversityJinan250061People’s Republic of China Engineering Research Center of Intelligent Unmanned System Ministry of EducationJinan250061People’s Republic of China School of Mechanical and Electronic Engineering Shandong Jianzhu UniversityJinan250101People’s Republic of China

The automatic cutting of intersecting pipes is a challenging task in *** improved automation and accuracy,this paper proposes a model-driven path planning approach for the robotic plasma cutting of a branch pipe with a single ***,it summarizes the intersection forms and introduces a dual-pipe intersection *** on this model,the moving three-plane structure(a description unit of the geometric characteristics of the intersecting curve)is constructed,and a geometric model of the branch pipe with a single Y-groove is ***,a novel mathematical model for plasma radius and taper compensation is ***,the compensation model and groove model are integrated by establishing movable ***,to prevent collisions between the plasma torch and workpiece,the torch height is planned and a branch pipe-rotating scheme is *** the established models and moving frames,the planned path description of cutting robot is provided in this novel *** accuracy of the proposed method is verified by simulations and robotic cutting experiments.

关键词： Automatic groove cutting of intersecting pipes Model-driven robot path planning Plasma beam radius and taper compensation

Response of InSight resonance modes to environmental factors on Mars

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Earth and Planetary Physics 2024年第4期8卷 579-588页

作者： LiFei tian HuaJian Yao Laboratory of Seismology and Physics of Earth’s Interior School of Earth and Space SciencesUniversity of Science and Technology of ChinaHefei 230026China Chinese Academy of Sciences Center for Excellence in Comparative Planetology University of Science and Technology of ChinaHefei 230026China Mengcheng National Geophysical Observatory University of Science and Technology of ChinaMengcheng 230026China

The InSight(Interior Exploration using Seismic Investigations,Geodesy,and Heat Transport)mission has recorded continuous ambient noise signals with many spectral peaks since its landing in *** majority of these peaks are modes produced by instrumental vibrations and are associated with environmental factors,such as temperature and wind energy *** how these modes react under various conditions is crucial because it aids in identifying their *** this study,we analyzed the three-component spectra of InSight recordings from sols 184–738 and obtained the horizontal-to-vertical spectral ratio(HVSR,also known as H/V)curves for different time *** primary modes,such as those at 3.3 and 4.1 Hz,exhibited different behaviors,suggesting diverse *** modes were sensitive to low temperature and some were sensitive to high ***,we investigated the influence of wind and temperature on the H/V *** peak frequency was mainly affected by temperature,whereas the H/V value was not associated with the temperature or wind *** these modes and elucidating their origins are significant for processing signals from InSight and can provide valuable guidance for designing future planetary seismometers.

关键词： Mars InSight spectral peaks H/V curve

Mechanical properties and microstructure of Mg-treated and Catreated industrial H13 steel after quenching and tempering

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Journal of Iron and Steel Research International 2024年第8期31卷 1987-2001页

作者： Jun-ying Yue Dong Hou De-yong Wang tian-peng Qu Xiang-long Li Jun tian School of Iron and Steel Soochow UniversitySuzhou 215021JiangsuChina

The effect of magnesium treatment and calcium treatment on the microstructure and mechanical properties of industrial H13 steel after quenching and tempering was *** impact toughness and tensile tests were mainly carried out,and the microstructure was observed by scanning electron microscopy,electron backscattered diffraction,and X-ray *** results show that magnesium treatment is still feasible in industrial *** is mainly manifested in the refinement of lath martensite and *** with calcium treatment,the prior austenite grains and carbides size of industrial H13 steel treated with magnesium decreased by 3.17μm after *** quenching and tempering,the carbides(especially V-rich carbides)in Mg treatment obviously spheroidized and distributed uniformly and increased in quantity *** lath martensite size is reduced from 2.45 to 2.31μ*** suggests that magnesium treatment was able to yield smaller grains and more evenly distributed ***,the impact toughness,yield strength,and ultimate tensile strength of industrial H13 steel with magnesium treatment increased by 28%,65.5 MPa and 123.7 MPa,*** increment of strength mainly comes from dislocation strengthening,grain refinement strengthening,and precipitation strengthening,among which precipitation strengthening accounts for the largest proportion.

关键词： Industrial H13 steel Mg treatment Heat treatment Carbide-Mechanical property

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使用亚波长光栅器件产生圆柱型矢量光束

红外与激光工程 2019年第3期48卷 169-177页

作者：周国尊田维坚西北工业大学电子信息学院陕西西安710072 浙江清华长三角研究院杭州分院浙江杭州310000

基于严格矢量衍射理论,分析了亚波长光栅将圆偏光转化为线偏光的机理。根据分析的结果提出了一种利用光栅空间分布控制出射光偏振态分布的方法,并使用该方法规设计了一类光栅区域呈多带环形分布的偏振器件。通过改变该型器件的环形光栅... 详细信息

基于严格矢量衍射理论,分析了亚波长光栅将圆偏光转化为线偏光的机理。根据分析的结果提出了一种利用光栅空间分布控制出射光偏振态分布的方法,并使用该方法规设计了一类光栅区域呈多带环形分布的偏振器件。通过改变该型器件的环形光栅区域数量,可以得到不同的偏振光束。通过对出射光束使用Richards-Wolf矢量衍射法进行数值分析,得到了在大数值孔径条件下,聚焦光束在焦点附近的归一化光强分布。其中大多数出射光束的焦点光强分布为平顶光斑,光斑的最大径向半高全宽达到了1.541λ。与同数值孔径下线偏光、径向偏振光及角向偏振光的聚焦光强分布具有明显区别。

关键词：亚波长光栅器件圆柱型矢量光束矢量衍射分析平顶聚焦光强分布

光锥与TDI-CCD耦合监控中测试目标的一种实现方法

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光子学报 2006年第7期35卷 1090-1094页

作者：刘蔚张伯珩边川平翟学锋田维坚卜江萍中国科学院西安光学精密机械研究所瞬态光学技术国家重点实验室信息光子学研究室

为了给光锥与时间延迟积分电荷耦合器件耦合监控装置提供有效的被测运动条纹,分析了传统推扫成像实验装置的不足之处,设计了电子显示目标滚屏运动装置·采用光学相机对印刷条纹静止成像,并用TDI-CCD数字相机对监视器屏幕上的运动条纹动... 详细信息

为了给光锥与时间延迟积分电荷耦合器件耦合监控装置提供有效的被测运动条纹,分析了传统推扫成像实验装置的不足之处,设计了电子显示目标滚屏运动装置·采用光学相机对印刷条纹静止成像,并用TDI-CCD数字相机对监视器屏幕上的运动条纹动态成像·实验结果表明,该方案解决了高分辨率的鉴别率图样无法在监视器或投影仪上精确显示的困难·与传统的实验室模拟装置相比,该方案提高了鉴别率条纹的运动稳定性,减小了条纹运动速率与TDI-CCD扫描行频间的失配误差,不仅能够对耦合过程实施监控,而且还能用于耦合系统的像质评价·

关键词： TDI-CCD 耦合监控电子显示目标