基于PC的电机云母槽自动下刻机测控系统的设计

采用工业用计算机实现自动下刻电机云母槽测控系统的设计方法.在加工工艺允许的情况下,系统采用接触式的检测方法能降低成本,提高可靠性,并提高其自动化的水平.在软件设计上,系统由找槽控制算法和下刻深度算法双闭环控制组成,槽控制算法与下刻深度算法之间相互切换直到加工完电机的所有槽.     

室内环境的污染物

室内的环境质量与人体健康的关系很大，所以应从设计、施工、材料运用、验收等诸多方面对室内环境质量进行全面控制。     

偏心因子数据的计算方法研究进展

从偏心因子(acentric factor)的定义出发，分析了ω数据的确定方法和获取数据的手段，评述了国内外ω计算方法的近期进展，包括对应态蒸气压关联方程法、对应态基团贡献法(CSGC)、图论法及拓扑法等，指出了各种方法的优缺点及最新的计算发展方向。     

An ERP study for the degrees of the difficulty in visual search

The present study mainly probed the relationships between ERP components and the degrees of difficulty in visual search. Three experimental and one controlled conditions were randomly selected. Results showed that the P1, N1, and P2 amplitudes and latencies had no significant differences among the three experimental and one controlled conditions, and the ERP waveforms of low perceptual load of visual search were different from that of high perceptual load. These results might indicate that the latencies and amplitudes of initial P1, N1 and P2 in high and low perceptual load conditions were almost the same. The ERP waveforms of parallel search were very different from that of serial search, and the ERP waveforms of serial search were very similar. The P3 amplitudes increased as the degrees of the difficulty in visual search decreased.     

普通高校大学生英语学习焦虑和学习策略的调查研究

学习焦虑和学习策略是英语学习的两个重要因素,它们不仅影响学习者的英语学习,而且内部之间也相互影响。本研究以普通高校大学生为研究对象,调查了大学生的英语学习焦虑和英语学习策略使用情况,并分析了影响英语学习焦虑和英语学习策略使用的因素,以及英语学习焦虑和英语学习策略之间的关系。该研究结果对普通高校的大学英语教学具有实践指导意义。     

远程学习材料中的活动设计

本文对远程学习材料中活动设计的重要性、类型和形式、结构、数量安排、与学习者之间的关系等内容进行了全面的介绍，指出良好的活动设计是远程学习材料开发的关键要素，只有符合远程学习特征的学习材料才能真正适合远程学习者的需要，才能保证远程教育的质量。     

基于二分法迭代的频谱感知节能优化策略

针对认知无线电(CR)系统中频谱感知技术能量效率低的问题,提出了一种基于二分法迭代寻优的联合优化算法。该算法通过联合传输功率与感知时隙进行优化,最大化地提高了CR系统的能量效率,并且在针对优化参数ξ的寻优过程中,使用了二分法与迭代算法结合的寻优方法。通过理论分析,与其他类似算法相比,该算法的寻优速度更快,算法复杂度更低,函数收敛速度更快,实际应用的可扩展性更强。数值仿真分析结果表明,在保证检测性能的前提下,提出的算法能够很好地解决能效的最优化问题,在恒定检测概率Pd=0.9和Pd=0.7条件下,所提出算法的能耗开销均低于其他算法,在系统吞吐量中所提出算法均优于其他算法,为CR系统的发展提供了理论支撑,更加符合未来CR系统的节能发展方向。     

Picturing the moon: Hevelius’s and Riccioli’s visual debate

This article investigates the maps of the moon produced in the mid-seventeenth century by Jesuit Giambattista Riccioli (1598-1671) and Johannes Hevelius (1611-1687), whose cartographic projects competed for widespread acceptance. Although Hevelius’s Selenographia (1647) was applauded for its many detailed, self-engraved pictures of the moon, his cartography and proposed nomenclature were supplanted by Riccioli’s as offered in Almagestum novum (1651), in spite of the latter’s simplistic pictures and promotion of geocentric cosmology. Exploring this paradox through pictorial analysis, three types of images common to both Selenographia and Almagestum novum are compared, employing an analytical tool developed by Svetlana Alpers in The art of describing (1983). A focus on this debate exposes the tensions evoked by new technologies of vision and competing cultures of visual epistemology in seventeenth-century astronomy. As both selenographers grappled with questions about the role of representation and what kinds of knowledge could be generated visually, the successes and failures of their competing projects present implications for the course of visual astronomy, as well as for our understanding of the use of ‘visual technologies’ in a period of controversy.     

基于PLC的温度控制在电镀生产线中的应用

介绍了以三菱FX0NPLC为核心的温度控制系统在电镀生产线中的应用。简述了温度控制原理,论述了控制系统的设计方案及其软硬件的实现方法。实践表明该方法简单易行,适应性好,可靠性高。     

PowerBuilder在C/S模式下的并发控制

并发控制是多用户环境下实现数据共享非常重要的机制,介绍了并发控制的理论及方法,在此基础上讨论了PowerBuilder在多用户时实现并发控制的方法和途径.