基于K-means和SOM的水下传感器数据采集方法

随着海洋资源勘探和海洋污染物监控工作的开展，水文数据的监测和采集等已经成为重要的研究方向。其中，水下无线传感器网络在水文数据采集过程中起着举足轻重的作用。本文研究的是水下无线传感器二维监测网络模型中，传感器节点数据采集的问题，其设计方法是通过自组织映射（Self-organizing mapping，SOM）对传感器节点进行路径最优化处理，结合优化的路径图形和K-means算法找到路径内部聚合点，利用聚合点和传感器的节点得到传感器通信半径内的数据采集点，最后通过SOM得到水下机器人（Autonomous underwater vehicle，AUV）到各个数据采集点采集数据的最优路径。经过实验验证，在水下1 200 m×1 750 m范围内布置52个传感器节点的情景下，数据采集点相比于传感器节点路径规划采用相同的采集顺序得到的路径优化了6.7%；对数据采集点重新进行自组织路径规划得到的路径比传感器结点路径的最优解提高了12.2%。增加传感器节点的数量，其结果也大致相同，因此采用该方法可以提高水下机器人采集数据的效率。     

Effect of microwave heating time on the gel properties of chicken myofibrillar proteins and their formation mechanism

The present work was conducted to illustrate the mechanism of gel formation of myofibrillar proteins (MPs) under different microwave heating times. The results showed that the denaturation enthalpy (ΔH) of the MPs significantly decreased when the heating time increased from 3 to 9 s and then completely disappeared as the heating time progressed, indicating that the MPs gradually denatured and subsequently aggregated with increasing heating time, which was further verified by the changes in the secondary structure, electrophoretic bands, and gel properties (e.g., water holding capacity and textural profiles) of the MPs. Microstructural images indicated that the MP gel formed under 12 s had the most compact network, indicating that extended microwave heating time could induce quality deterioration of MP gels. Moreover, the hydrophobic forces, electrostatic forces, and disulphide bonds of the MPs gradually intensified with increasing microwave heating time, suggesting that both non-covalent and covalent bonds could promote molecular denaturation and subsequent aggregation of MPs. In addition, correlation analysis revealed that the changes in the molecular conformation of MPs induced by different microwave heating times could effectively regulate the formation of MP gels and their related properties.     

一种模拟量模块的应用

模拟量模块采用RS485通讯网路,将分散的现场数据点的模拟量经AD变换传输到主机或由PC控制远程主站点。模拟量模块具有计量数据采集、测量数据采集、设备开关状态采集和对外逻辑控制等多项功能,主要用作各种测控终端的数据采集、控制和显示设备,适用于各行业的自动化、信息化系统。本文介绍了一种模拟量模块的应用。     

全电动注塑机研究进展及在汽配电子行业中的应用

介绍了全电动注塑机的特色，综述了国内外全电动注塑机在精密注塑、智能注塑、高效注塑和绿色注塑方面的研究进展，并对全电动注塑机在汽配电子行业中的应用作了简单介绍。对双电机同步控制技术的逐渐成熟为全电动注塑机实现大型化提供了助力，全电动注塑机高效、精密、智能、节能、环保的优势在汽配电子行业显示了很好的应用前景。     

轨道式垃圾回收机器人设计与分析

针对高速公路高峰期拥挤产生的垃圾等问题,设计一种轨道式垃圾回收机器人,由光伏发电装置、机器人壳体、末端手爪、关节臂以及控制系统等组成,主体结构采用双臂三关节结构,采用西门子PLC控制系统,通过控制关节臂的旋转以及偏转、末端手爪的旋转及开合等动作来实现工作的目的。结合外场作业的特殊性,采用光伏能源装置,对其结构及控制系统进行设计,通过对机器人进行三维建模、运动和控制仿真分析,验证系统的可行性及有效性。     

超高性能混凝土国内外研究与应用进展*

介绍了超高性能混凝土（UHPC）的制备原理和性能特点，对UHPC国内外研究和应用情况进行了综述，指出了我国UHPC研究和应用中存在的问题。结果表明：UHPC是一种具有优异的力学性能、耐久性能和环保效益的新型水泥基复合材料。国外在UHPC理论研究和应用研究方面都取得了大量成果，在实际工程中已经获得了广泛的应用；近年来我国在理论研究和应用方面也得到了快速发展；如何简化UHPC制备工艺、降低生产成本、补偿自收缩是今后的主要研究方向，完善相关规范标准以更好地指导UHPC现浇工程应用是目前首要解决的问题。随着环保和可持续发展理念的日益重视，UHPC这种低碳环保材料将有广阔的发展前景。     

继电保护中多路模拟量采集系统的设计

介绍了一种基于高性能浮点DSP芯片TMS320C32、CPLD芯片XC95288和A/D采样芯片AD976组成的多路采集系统的工作原理以及设计方法。通过对第一路施加特殊的电压量,在CCS开发环境下读取采样缓冲区的值,并利用Matlab对采样数据进行了全波傅氏变换。此外,该系统已在继电保护中得到广泛应用,实践表明,该系统能较好地解决多路模拟量的采集,并确保了采样数据的安全可靠性。     

Collection efficiency of liquid‐based samplers for fungi in indoor air

This study assessed the collection efficiency (CE) of two popularly used sampling devices (BioSampler and Coriolis sampler) for fungal aerosols. Phosphate‐buffered saline (PBS) supplemented with or without surfactant (Tween‐20, Tween‐80, or Triton X‐100) and antifoam agent was prepared and used as collection liquids. The agar impactor (BioStage) was simultaneously operated with liquid‐based samplers to collect fungi from seven sites located at a university building, public library, and animal farming. Fungal concentrations determined by liquid samplers were divided by those by BioStage, and the ratio values represented CE. Results indicate that the CE of BioSampler was superior to that of Coriolis (P = 0.0001) and the PBS containing surfactant collected fungi better than that without surfactant (P < 0.0001), whereas antifoam agent showed no influence (P = 0.8). Moreover, fungal concentrations determined by BioSampler with surfactant‐added PBS were statistically indifferent from those by BioStage (P > 0.05) with a Spearman correlation coefficient of 0.81‐0.83 (P < 0.01). In addition to sampler and collection liquid, sampling location was also identified as a significant CE factor (P = 0.006), implying potential influences by fungal genera in the studied fields. Overall, BioSampler with surfactant‐supplemented PBS (eg, Triton X‐100) is recommended considering the great CE and compatibility with a variety of analytical assays.     

粉末渗锌钢渗层的形成机理及影响因素研究进展

粉末渗锌工艺是一种热扩散表面改性技术，将渗锌剂与钢构件在高温条件下接触，利用原子扩散作用，在构件表面形成一层合金保护层。作为一种工艺简单、环境友好的高效表面防腐处理工艺，粉末渗锌技术可有效改善金属材料的耐磨、耐蚀和耐氧化等性能，具有广泛的应用前景而备受研究者的关注。首先分析了粉末渗锌层的形成机理，并重点讨论了渗层的组织结构;然后，综述了保温温度、保温时间以及合金元素等因素对渗层形成的影响。研究者发现，升高温度和延长时间有益于渗层厚度的增加，但要合理控制，温度过高或时间过长不仅使渗层性能变差，还会增加能耗和降低生产率。此外，通过调整渗剂中合金元素的添加量以及种类，能够改善渗锌层的性能，但各类元素的最佳添加量以及其对渗层的改性机理还有待于进一步探究。目前，粉末渗锌生产中存在效率低的问题，在渗锌工艺中应用机械能助渗技术和纳米技术，可有效提高渗锌效率、改善渗层性能。最后，结合当前的研究现状，对粉末渗锌工艺的研究方向进行了探讨。