基于单片机和GM8125的多路串口收发器设计

介绍了串口扩展芯片GM8125的特性,设计了基于该芯片和8051单片机的多路串口收发器,程序算法及硬件电路实现了多达4台子设备(电子天平)到主设备(打印机)数据标号传输,并有效地解决了GM8125芯片多路并行工作时的出现的乱码和数据混乱的问题。系统使用方便,实时性好,扩展方便,取得了良好的实际应用效果。     

任意阶PDE降噪特性分析

通过对分数阶微积分原理的研究,提出了任意阶偏微分方程(partial differential equations,简称PDE)降噪的统一模型,实现了基于任意阶PDE降噪的数值化方法,并分析了任意阶PDE降噪特性。该数值化方法能够快速实现信号降噪,耗时少。通过仿真实验,分析了PDE降噪性能的影响因素,与其他去噪方法进行了对比分析,并对现场实测信号进行了降噪分析。结果表明,PDE数值求解降噪方法性能优良,算法简单。     

Effect of copolymer composition on the miscibility of blends of styrene-acrylonitrile copolymers with poly (methyl methacrylate)

The phase behaviour for blends of various polymethacrylates with styrene-acrylonitrile (SAN) copolymers has been examined as a function of the acrylonitrile content of the copolymer. Poly(methyl methacrylate), poly(ethyl methacrylate) and poly(n-propyl methacrylate) were found to be miscible with SANs over a limited window of acrylonitrile contents while no SANs appear to be miscible with poly(isopropyl methacrylate) or poly(n-butyl methacrylate). These conclusions were reached on the basis of lower critical solution temperature (LCST) and glass transition temperature behaviour. All miscible blends exhibited phase separation on heating, LCST behaviour, at temperatures which varied greatly with copolymer composition. An optimum acrylonitrile (AN) level ranging from about 10 to 14% by weight resulted in the highest temperatures for phase separation which has important implications for selection of SANs to produce homogeneous mixtures by melt processing. The basis for miscibility in these systems is evidently repulsion between styrene and acrylonitrile units in the copolymer as explained by recent models. The excess volumes for all blends are zero within experimental accuracy which suggests that the interactions for miscibility are relatively weak even for the optimum AN level. This interaction becomes smaller the larger or more bulky is the alkyl side group of the polymethacrylate.     

基于谐波特征分析的时间调制阵列测向研究进展

针对近年来发展起来的基于谐波特征分析的时间调制阵列(time modulated array,TMA)测向这一新型无线电测向技术体制,全面总结了其目前的发展现状以及与传统阵列测向体制相比较的优缺点.首先分析了TMA的起源、发展与数学基础;其次总结了基于TMA的测向方法的研究现状;然后对二单元TMA测向、多单元TMA测向...     

质量法压缩天然气加气机在线检测装置

研制了一套基于质量法的压缩天然气加气机在线检测装置,系统集成了数据采集和自动控制系统。利用计算机控制工作流程,实时采集瞬时流量、累计流量、密度、温度等信号,实现在线检测。对系统的不确定度分量进行了分析,给出了测量结果的不确定度。基于使用该标准装置进行检测的经验,给出了保证检测结果准确可靠应采取的一些措施。     

Present state of corrosion inhibitors in Japan

In this report, the utilization, research and development of corrosion inhibitors in Japan and the action mechanism of corrosion inhibitors are explained, and their effects and future utilization are also described. In Japan, corrosion inhibitor was commercialized in the 1970s, and the use of these showed the rapid elongation as a countermeasure of the use of sea sand as an aggregate for the period 1975–1977 and the use of corrosion inhibitors decreased after 1979 because of the regulation for the total amounts of chloride in concrete in the standards. Then, amounts of concretes with corrosion inhibitors decreased in 1990s. However, in the civil engineering and construction industry fields, they seem to have to deal with the problem of increase of chloride content in concrete by the deregulation and the utilization of various industrial waste materials. We should consider the utilization of corrosion inhibitor from the new viewpoint.     

惯性导航设备升沉数据测试系统研究

研制了一套基于STM32单片机与单轴摇摆台的测试系统,利用固定圆心、固定半径条件下的圆内三角形关系,通过拉线传感器采集单轴摇摆台复合运动中的升沉数据;同时,对惯性导航设备输出的升沉数据进行采集与处理。对测试系统输出的升沉数据进行了验证,实验结果表明:该测试系统的测试数据准确合理,可实现对惯性导航设备升沉参数的动态测试,弥补了现有同类测试系统的结构复杂、量程小等不足。     

Optimal Design and Economic Evaluation of Dividing‐Wall Columns

In an effort to reduce costs, a systematic optimization approach is proposed to address the energy consumption of dividing‐wall columns (DWCs). This iterative optimization procedure begins by minimizing the overall heat duty using an innovative objective function within a constrained design space. A sensitivity analysis is then carried out on the manipulated variables to obtain their optimal ranges. Optimal operating parameters are obtained through the evaluation of the total annualized cost (TAC). For the separation process of benzene/toluene/o‐xylene, the optimal DWC flow sheet exhibits a significant decrease in TAC when compared to conventional flow sheet optimum designs. The applied optimization method and sensitivity analysis have proven to produce results at the global optimum. This method is both practical and easily applied to other systems, even to systems with more than three components.     

Knowledge-enhanced graph convolutional network for recommendation

Multimedia Tools and Applications - Recommendation systems based on collaborative filtering (CF) are often accompanied by cold start and sparsity issues, which can be alleviated by using user...