数字集群移动通信系统基站子系统

本文主要讨论欧洲数字集群移动通信系统基站子系统（ＴＥＴＲＡ系统）的构成,各功能模块的功能及其工作原理。     

应用最小余能原理确定变截面杆的固有频率（I）——棱柱形悬臂杆

本应用最小余能原理的理论和方法,对棱柱形悬臂杆进行动力分析。具体地计算了楔体及平头楔体悬臂杆的固有频率,并讨论了变截面深梁中剪力及挤压应力对固有频率的影响。     

气液两相流体润滑技术在滚动轴承中的试验研究

介绍了一种新型的润滑技术———气液两相流体润滑,对该润滑技术在滚动轴承中的应用进行了试验研究,证明气液两相流体润滑在高速、超高速滚动轴承的应用中具有良好的性能,并将油气润滑与油雾润滑作了对比.     

Control-oriented dynamic fuzzy model and predictive control for proton exchange membrane fuel cell stack

Proton exchange membrane fuel cell （PEMFC） stack temperature and cathode stoichiometric oxygen are very important control parameters. The performance and lifespan of PEMFC stack are greatly dependent on the parameters. So, in order to improve the performance index, tight control of two parameters within a given range and reducing their fluctuation are indispensable, However, control-oriented models and control strategies are very weak junctures in the PEMFC development. A predictive control algorithm was presented based on their model established by input-output data and operating experiences. It adjusts the operating temperature to 80℃. At the same time, the optimized region of stoichiometric oxygen is kept between 1.8-2.2. Furthermore, the control algorithm adjusts the variants quickly to the destination value and makes the fluctuation of the variants the least. According to the test results, compared with traditional fuzzy and PID controllers, the designed controller shows much better performance.     

Research on the stability, controllability and observability for fractional order LTI systems

Fractional calculus has a history of300years.Itoccurred at almost the same time as classical integer or-der calculus,but it is different from the latter.It is asubject studying the derivatives and integrals with arbi-trary order.Since the computation of fractional calculusis much more complicated than that of integer order cal-culus,the development of the theory of fractional calcu-lus mainly focused on the pure mathematical domain formany years,and it is interesting mainly to mathemati-cians.…     

高职学生社会主义核心价值体系教育方法和途径探析

社会主义核心价值体系教育是新时期高职院校思想政治教育的一项重要内容,也是开展好高职院校思想政治教育工作的方向指南和主线依托。本文就如何加强高职学生社会主义核心价值体系教育的方法和途径进行探析。     

考虑外送通道极限的水电站联合优化调度研究

云南部分地区水电资源丰富,但电网中负荷一般相对较轻,电力能源以外送为主.然而,电网建设的速度往往滞后于电源建设,电力外送受阻严重.充分挖掘现有电网输送能力的潜力,是增强此类电网外送能力的有效方法.首先提出了水电站联合优化的调度思想,考虑外送通道极限对水电站发电量的限制,对地区电网水电站进行联合调度;其次建立了水电站联合优化调度模型,考虑外送通道极限不等式约束条件以及水库水量等式约束条件建立了以地区电网水电站发电量最大的目标函数,然后运用SOA人群搜索算法对水电站联合优化调度模型进行优化计算,SOA算法优化多峰函数收敛速度快;最后以典型的水电送出型怒江电网作为实例进行仿真.仿真效果表明在水电站联合优化调度的策略下,考虑怒江水电外送通道极限约束,怒江电网水电站发电量得到提升,增强了怒江水电外送能力,验证了SOA优化算法的有效性.     

电子布氏硬度计在电池锌饼检测中的应用

锌饼的硬度与铅、镉、铁等金属杂质含量有关。采用金属布氏硬度法检测锌饼硬度,能快速间接地判定杂质以及添加的金属含量是否异常。介绍了电子布氏硬度计的工作原理和使用条件;对常见的故障及排除方法进行了探讨。     

预应力管桩施工中常见质量问题的分析与处理

介绍打(压)桩施工中常见质量问题的类别、原因分析、常用处理方法。