Ultrasensitive and Highly Stretchable Multifunctional Strain Sensors with Timbre‐Recognition Ability Based on Vertical Graphene

Stretchable/wearable strain sensors are attracting growing interest due to their broad applications in physical and physiological measurements. However, the development of a multifunctional highly stretchable sensor satisfying the requirements of ultrahigh sensitivity (able to distinguish sound frequency) remains a challenge. An ultrasensitive and highly stretchable multifunctional strain sensor with timbre‐recognition ability based on high‐crack‐density vertical graphene (VGr) is fabricated using an ultrasonic peeling (UP) method. It can distinguish frequencies of sounds higher than 2500 Hz. Detailed microscopic examinations reveal that their ultrahigh sensitivity stems from the formation of high‐density nanocracks in the graphitic base layer, which is bridged by the top branched VGr nanowalls. These nanocracks cut the VGr film into a large number of nanopieces, which increase the natural frequency of the sensors, enabling the sensors to distinguish the sound frequency. Demonstrations are presented to highlight the sensors' potential as wearable devices for human physiological signal and timbre detections. This is the first multifunctional highly stretchable strain sensor with timbre‐recognition ability.     

基于BMP架构的多核差异化运行技术研究

随着高速网络及多核处理器技术的快速发展,业务应用的复杂度也在日益增加。为了保证复杂业务的吞吐量及实时性,基于BMP架构提出了多核环境下操作系统任务差异化运行方案,将多核处理器分为数据面与控制面,数据面核的处理能力提供给高性能要求的循环任务使用,控制面核的任务处理不影响数据面核的性能。方案在Linux内核上进行了改造实现,实验结果表明,可有效提升复杂业务实时响应及业务吞吐能力。     

基于图模型的小尺寸飞行器地面试验中位姿估计方法

在多飞行器地面试验位姿估计中,由于跟踪算法导致的跟踪轨迹不连续会使得位姿估计产生累积误差,为了实现位姿的精确估计,提出了一种基于图模型的全局位姿估计非线性优化方法。首先,建立了一个飞行器地面视觉位姿估计系统。然后根据飞行器上特征点的数目提出了一种向量交叉式的飞行器位姿解算方法,求解得到数据已关联飞行器位姿估计值。利用中介坐标系法求解得到轨迹段初始位姿节点在测量坐标系下的值,最后,在图模型基础上下,对整个量测过程中飞行器的位姿估计结果进行非线性全局优化减小线性算法的累积误差,并通过仿真与实际实验对飞行器位姿估计算法的可行性与精度进行验证。实验结果表明:在测量范围为6 000 mm×6 000 mm×3 000 mm的范围内,飞行器尺寸约为400 mm,特征点三维定位精度为2.9 mm的条件下,基于非线性优化的飞行器位姿估计算法的理论精度分别可达0.5°(3σ)与3 mm (3σ),实际绝对测量精度分别可达1.3°(3σ)与4 mm (3σ),基本满足地面试验对多飞行器编队算法开发以及制导控制系统性能长时间评估稳定可靠、精度高、抗干扰能力强等要求。     

Algorithm of locating the sphere center imaging point based on novel edge model and Zernike moments for vision measurement

High accuracy of locating the sphere center imaging points is crucial for the vision measurement system. This paper investigates the effect of projection projective model on extraction of the sphere center, upon which the sub-pixel edge-location algorithm based on the sphere projection model is proposed. The sphere center projection model is established by analysing the process of sphere imaging, and the sub-pixel edge-location algorithm consisted of the novel edge model and the improved Zernike moment computing is studied. The novel edge model based on the Erf (error function) is adopted for modelling the practical edge part, which obtains the edge distribution points with high precision. Then a closed-form solution of edge locating error compensation is calculated based on Zernike moments. Finally, the proposed method is verified via simulations and experiments. The relevant results show that the proposed method can accurately locate the sphere center imaging point, which further improves the precision and robustness of the vision measurement system.     

一种正前视宽扇区高分辨雷达扫描成像方法

合成孔径雷达（Synthetic Aperture Radar,SAR）只有照射到飞行方向左、右两侧的感兴趣成像区域时才能处理出高分辨率SAR图像,飞行方向正前方的成像区域就成为了SAR成像的固有盲区。三通道（和、方位差、俯仰差）毫米波单脉冲成像雷达能够实现对正前视场景的二维成像,获取单脉冲图像。提出对SAR/单脉冲图像进行图像配准和融合拼接的方法：首先利用多尺度多方向二维Gabor滤波器组分别对SAR/单脉冲图像进行特征提取,然后对两组特征矩阵进行归一化互相关匹配,对匹配好的图像进行像素级融合处理,得到完整的正前视宽扇区高分辨雷达图像。试验数据成像处理结果表明,所提复合成像算法能够对飞行正前方宽扇区范围内进行高分辨成像,有效解决了工程实际中碰到的正前视高分辨成像盲区的难题,对于前视雷达成像侦察、弹载雷达目标区域景象匹配、飞行器夜航、盲降等具有一定的工程实际意义。     

A low-complexity and efficient encoder rate control solution for distributed residual video coding

Multimedia Tools and Applications - Existing encoder rate control (ERC) solutions have two technical limitations that prevent them from being widely used in real-world applications. One is that...     

基于红外光传感器的泥沙在线监测方法应用研究

悬移质泥沙在线测量一直是一个难以解决的问题,红外光的测量技术是一种快速、有效和简便的悬沙在线观测方法,对于低含沙量河流应用前景广阔。设计基于红外光传感器的泥沙在线监测系统,介绍系统的测量原理、安装位置选择、防雷设计措施等。从黄桥水文站的大断面和泥沙整编资料对其含沙量横向分布进行分析,确定在线监测位置的代表性,实现悬移质泥沙在线监测。通过 1 个汛期的数据采集,结合人工实测含沙量结果进行统计分析,探索出该方法在实际水域中应用的可行性。从 2019 年 8 月—2020 年 4 月率定和运行结果看,在一定边界条件下,该方法所测数据基本符合测验有关规范要求,且数据畅通率达到 98.79%,在新仪器新设备推广方面有一定指导意义。     

Ultrathin Conductive Interlayer with High-Density Antisite Defects for Advanced Lithium–Sulfur Batteries

Lithium–sulfur (Li–S) batteries are promising next-generation rechargeable batteries due to thier high energy density, low cost, and environmental friendliness. However, the extremely low electrical conductivity of sulfur and the dissolution of polysulfides limit their actual electrochemical performances, especially in the case of high sulfur mass loading. Here, a new strategy based on intrinsic point defects of materials is proposed to simultaneously enhance the electrical conductivity of active material and regulate the migration of polysulfides. Taking advantage of ultrathin and lightweight Bi₂Te_2.7Se_0.3 (BTS) interlayers with high-density antisite defects on the separator surface, the Li–S battery with BTS interlayer shows a capacity of 756 mAh g⁻¹ at 2C and a low capacity decay rate of 0.1% over 300 cycles. The BTS interlayer can not only enhance the active material utilization but also improve capacity retention. The defect engineering strategy accompanied with facile method is promising for the development of advanced Li–S batteries for practical application.     

一种家庭自动控制系统的知识发现算法研究

针对依据用户兴趣对家电的状态数据进行信息获取的问题,提出了一种应用于家庭自动控制的知识发现算法.分析了家电功能、家电状态数据与家庭事件的关系,利用模糊理论把家电状态数值转化成语言变量,通过脚本的知识表达方法把用户感兴趣的家庭事件和语言变量关联起来,在此基础上实现家庭事件的推理.仿真实验表明该算法能够从家电状态数值获取相关信息,并实现依据用户兴趣对获取信息的再加工,能够解决从家电状态量到家庭事件及其影响推理的问题.