单片机控制的超声波测距仪汽车倒车系统的设计

本文设计一种基于单片机STC89C52的超声波测距仪汽车倒车系统,介绍了超声波测距的基本原理,阐述了倒车雷达系统的结构组成、硬件电路设计,并在数据处理部分采用温度补偿消除温度对声速的影响,提高了测距精度.倒车距离采用LCD进行实时显示,并通过语音报警电路对不同距离段做出不同的语音提示.实验表明该倒车雷达系统在30～ 5...     

Urban Agriculture: Coping with Urbanization Problems and Promoting Sustainable Urban Development

This paper analyzes the theoretical connotation of urban agriculture and sustainable urban development, and their interactions. Based on the analysis, this paper proposes a series of policy optimization approaches and engineering optimization measures in coping with the urbanization problems and promoting the sustainable urban development.     

Unicase炉有效加热区的测定

本文介绍了Unicase炉有效加热区的测定方法，阐述了空炉测温的必要性，并对测量结果不理想时提出了改进措施。     

工程建设中大体积混凝土温度裂缝控制初探

对大体积混凝土的温度裂缝成因和影响因素进行了探讨,并提出了相应的控制措施,为大体积混凝土工程施工中温度裂缝控制提供了思路和方法,以达到减少温度裂缝产生的目的。     

关于对自贡盐化产业集群发展的思考

通过对自贡盐化产业集群现状的分析，探讨了影响集群发展的制约因素，从理论上提出了集群发展的具体对策和措施。     

Chance measure for hybrid events with fuzziness and randomness

In many cases, fuzziness and randomness simultaneously appear in a system. Hybrid variable is a tool to describe this phenomena. Fuzzy random variable and random fuzzy variable are instances of hybrid variable. In order to measure hybrid event, a concept of chance measure is proposed in this paper. Furthermore, several useful properties about this measure are proved such as self-duality, subadditivity and semicontinuity. Some concepts are also presented such as chance distribution, expected value, variance, moments, critical values, entropy, distance and sequence convergences.     

电液锤液压系统泄漏的原因分析及防治措施

在介绍电液锤工作原理的基础上，分析了造成电液锤液压系统泄漏的原因，并提出了相应的防治措施，以消除电液锤液压系统可能产生的泄漏。     

广州电视台新址工程基坑雨季排水措施

雨季排水对于地下结构施工是非常重要的,会直接影响到桩基础、地下室等的施工质量。本文叙述了广州电视台新址工程基坑雨季排水能力设计与排水措施,通过计算,提出了基坑的排水方案,并对雨季施工措施进行了总结,对类似工程起到一定的借鉴作用。     

保证管道输送油品质量的几项措施

就如何确保管道输送油品质量，防止质量事故的发生，提出要做好输油管道系统的清洗，合理安排输油顺序，做好混油的处理和把好油料接收关等项措施。     

Pseudo-optimal measures

Based on a pseudo-addition ⊕ on [0, ∞], pseudo-optimal measures related to non-negative set functions vanishing at the empty set (non-negative games) are introduced. For a fixed pseudo-addition ⊕, an equivalence ∼_⊕ on non-negative set functions is studied. A special stress is given to pure pseudo-optimal measures, admitting no other ∼_⊕ equivalent set function.