埋入混凝土中PZT声场指向性和声能研究

将PZT作为声源埋入混凝土中构成的混凝土压电机敏模块具有超声检测功能。对埋入该模块中的PZT圆片模态分析发现,在各阶振动模态下PZT声辐射面存在分布不同的振幅极大值区域。基于混凝土压电机敏模块的声场指向性和声能实验表明:将PZT声辐射面等效为振幅相等的单一点声源的叠加,忽略振动模态对声场指向性影响,使得PZT圆片的声场指向性随频率变化规律偏离实际较大,而且在相同频率下声场指向性理论结果比实验结果发散;在各阶固有频率激励下,PZT圆片的声场指向性集中,但在一阶固有频率下声能最高,更适用于超声检测。     

一种具有提高覆盖性能的传感器网络节能分簇算法

通过分析不同类型节点的失效对于网络覆盖效率的影响,提出一种具有能量和覆盖意识的无线传感器网络分簇算法.该算法不依赖节点的物理位置信息,优先选取部署密度较高区域的节点担任簇首,当簇首的剩余能量低于设定阈值时实施簇首迁移,以均衡网络能耗,降低节点的死亡率.进一步分析了算法复杂度和节点最优广播半径的选取.仿真结果表明,所提出的算法可有效改善网络运行中的覆盖性能,延长网络寿命.     

Fuzzy parametric programming model for multi-objective integrated solid waste management under uncertainty

Solid waste management is increasingly becoming a challenging task for the municipal authorities due to increasing waste quantities, changing waste composition, decreasing land availability for waste disposal sites and increasing awareness about the environmental risk associated with the waste management facilities. The present study focuses on the optimum selection of the treatment and disposal facilities, their capacity planning and waste allocation under uncertainty associated with the long-term planning for solid waste management. The fuzzy parametric programming model is based on a multi-objective, multi-period system for integrated planning for solid waste management. The model dynamically locates the facilities and allocates the waste considering fuzzy waste quantity and capacity of waste management facility. The model addresses uncertainty in waste quantity as well as uncertainties in the operating capacities of waste management facilities simultaneously. It was observed that uncertainty in waste quantity is likely to affect the planning for waste treatment/disposal facilities more as compared with the uncertainty in the capacities of the waste management facilities. The relationship between increase in waste quantity and increase in the total cost/risk involved in waste management is found to be nonlinear. Therefore, it is possible that a marginal change in waste quantity could increase the total cost/risk substantially. The information obtained from the analysis of modeling results can be effectively used for understanding the effect of changing the priorities and objectives of planning decisions on facility selections and waste diversions.     

无线传感器网络在风力发电中的应用研究

为解决风力发电场中现有测控方法存在的成本高、维护难等问题,通过对无线传感器网络和风力发电场特点进行研究,设计了一种基于无线传感器网络的传输平台.该平台使用基于ZigBee技术的CC2420芯片进行数据传输,并利用OPNET软件对其网络传输特性进行网络仿真.仿真结果有力地证明了无线传感器网络应用于风力发电场的可行性,该网络平台能够很好地完成风力发电场的数据检测和数据传输任务.     

WSN中基于分簇的改进路由协议

LEACH协议的非均匀分簇会造成网络节点能耗分布不均衡。为此,提出一种基于分簇的改进LEACH路由协议。根据节点剩余能量以及节点到基站的距离选举簇首,依据接收信号强度确定簇成员节点,并且成簇规模不得超过最大成员数。采用在簇首与基站之间建立多跳路由树的方法,向基站发送数据。仿真结果证明,改进协议能均衡网络负载,提高网络运行周期。     

智能电网中双寡头的电价竞争策略

在竞争性市场条件下,灵活电价机制成为电能提供商调节电力市场需求的手段。如何保证电力投资的适时性和充足性成为电能提供商投资决策问题的关键。在此背景下研究了电能供应商竞争购买闲置电能并进行交易,并建立了相应的数学模型。通过分析电能质量,供电成本对投资利益的影响,并将投资收益最大化作为投资决策的基本原则,利用博弈论理论得到电能交易价格的纳什均衡解及其存在条件。最后通过算例仿真验证了所述结果的有效性。有利于节省用户的电费支出并降低供电公司的购电费,实现多方共赢。     

数字式三相智能电能表的研制

介绍了一款基于单片机Atmega128的三相数字式智能电能表的研制,从电路硬件选型、电路设计及制作进行论述。所设计的智能电能表与同类产品相比具有集成度高、功能强、成本更低廉、抗干扰能力强、功耗低等优点。随着未来电能智能化管理及电能表集抄需求,该款表具有很大的应用前景。     

太原理工大学能源管理平台建设研究

随着能源问题日益突出,高校为了响应国家建设节约型社会的号召,加强了节约型校园的建设。围绕太原理工大学能源管理的实际需求,制定了一套适合太原理工大学能源管理平台的解决方案,为太原理工大学建设节约型校园提供一定的参考依据,使学校在节约型校园建设方面不断深化和改进。     

电能质量智能在线监测系统设计

论述了电能质量问题的内容及其对电力系统的影响,设计了一种基于嵌入式技术的电能质量在线监控系统,给出了系统的硬件结构图和软件结构图及流程图,进行了样机的功能性验证试验,证明该系统对于构成具有智能化的监控及通信系统具有一定的应用价值。     

Force Curve Measurements with the AFM: Application to the In Situ Determination of Grafted Silicon-Wafer Surface Energies

The atomic force microscope (AFM) can be used to perform surface force measurements in the quasi-static mode (cantilever is not oscillating) to investigate nanoscale surface properties. Nevertheless, there is still a lack of literature proposing a complete systematic and rigorous experimental procedure that enables one to obtain reproducible and significant quantitative data. This article focuses on the fundamental experimental difficulties arising when making force curve measurements with the AFM in air. On the basis of this AFM calibration procedure, quantitative assessment values were used to determine, in situ, SAM (or Self Assembled Monolayer)-tip thermodynamic work of adhesion at a local scale, which have been found to be in good agreement with quoted values. Finally, determination of surface energies of functionalised silicon wafers (as received, CH₃, OH functionalised silicon wafers) with the AFM (at a local scale) is also proposed and compared with the values obtained by wettability (at a macroscopic scale). In particular, the effect of the capillary forces is discussed.