用于柔性可穿戴设备的薄膜式曲率传感器（英文）

Flexible and wearable electronics integrated with various sensors have great potential for applications in monitoring human activities and personal health.Bending and tension/compression dominate the deformation modes yielded by flexure of joints and diverse body gestures.A key challenge now is to sense the curvature/bending angle,while much research has been focused on the strain sensors for tension/compression.Alternative approaches by strain sensors or non-contact optical methods for curvature sensing are not practical for wearable electronics,because the former demands perfect adhesion of the sensors to target surfaces(e.g.,the human skin) and the latter requires complicated and bulky measurement systems that hinder their portability.Here,a novel adhesion-free thin-film-like curvature sensor that can monitor bending activities is introduced for flexible and wearable electronics.We present comprehensive design,fabrication,mechanism,structural analysis,performance characterization,and device-level demonstrations for bending of joints,gesture recognition,and real-time sitting posture correction.The most prominent advantage of the present sensor is that the measurement is independent of the strain of the target surface and the interfacial slippage,thus the perfect adhesion between the sensor and the surface is unnecessary.The features of adhesion-free,simple mechanical principle,low cost,and satisfactory monitoring results highlight the superiority of the present curvature sensors for practical applications to flexible and wearable electronics

北京首都国际机场鸟击物种鉴定及防控建议

鸟击是威胁航空安全的重要因素之一，鸟击物种的准确鉴定对机场鸟击防范工作具有重要意义。收集2020年5月—2021年4月北京首都国际机场的鸟击残留物，使用DNA条形码技术对138份鸟击残留物进行鉴定，共鉴定出61个物种。分析发现：鸟击物种以云雀（Alauda arvensis）、金腰燕（Cecropis daurica）和红胁蓝尾鸲（Tarsiger cyanurus）等小型鸟为主；雀形目（Passeriformes）发生鸟击的次数最多，占鸟击总次数的74.64%。此外，鸟击具有季节和时间相关性，首都机场白天（06：00—18：00）和夜间（18：00—次日06：00）的鸟击高峰均发生在10月，且夜间鸟击次数高于白天，这与机场附近的鸟类活动具有一致性。基于研究结果建议：（1）机场要做好鸟击残留物的收集和信息记录，为及时准确鉴定物种提供基础信息。（2）鸟击防范以小型鸟为主，尤其注重秋季鸟类迁徙季的防范工作。（3）加强鸟情监测与生境调查

Industrial Edge Computing: Vision and Challenge

随着工业互联网技术的发展,工业设备生成的数据量以指数形式增长,给云计算带来了巨大的数据压力.边缘计算由于低时延、低流量、隐私性等特点在工业领域中有了越来越多的应用研究.本文针对近几年的工业云计算和边缘计算技术进行了综述.首先介绍了工业互联网背景下云计算和边缘计算的发展历史,分析了边缘计算的定义和边缘计算的几种计算典型形式与工业边缘计算的关系.其次分析了工业边缘计算的几种典型应用,针对当前的研究现状,讨论了工业场景中影响边缘计算应用的几种关键技术,并对工业场景下的研究挑战做了总结与展望.</p

非均匀折射率分布少模光纤光学特性研究

以实现柱矢量光横向选模为目标,研究了非均匀折射率分布的少模光纤的光学特性。利用有限元法分析了U型折射率分布和弯曲少模光纤的模场特性:前者结合1 550nm泵浦光可支持LP11模式并抑制LP01模式;后者包括二模光纤和四模光纤,当二者弯曲半径分别为4和2cm时,仅支持LP01和LP11模式。结合理论和实验研究了四模和二模FBG（光纤布拉格光栅）,对于二模FBG,当透射波长位于1 549.79nm附近时,可获得呈两瓣分布的LP11模式;对于四模FBG,其反射谱峰值波长个数随尾纤弯曲半径的减小而减少。相关结果对于柱矢量光的产生和应用具有重要的理论和实践意义