低成本教育型机器人控制器的设计与实现

论述了一种低成本机器人控制器的设计与实现 .采用AT89C2 0 5 1作为主芯片 ,提供两路独立的电机驱动和最多 7个外围扩展口 .软件采用汇编语言编写 ,能下载并运行上位机程序 ,配合外围红外传感器 ,实现了追踪和安全漫游 .     

基于集对分析的模糊逻辑研究

介绍了一种新的解决模糊问题的途径 ,提出了一种模糊逻辑表示新形式 ,论证了其较之于传统模糊逻辑表示法的优点 .     

基于PowerBuilder的电子邮件应用设计与实现

阐述了在PowerBuilder的应用程序中 ,实现嵌入电子邮件的一般原理、方法及具体的程序实现 ,使PowerBuilder应用程序能够访问与MAPI兼容的电子邮件系统 .该邮件应用的特点在于能在应用软件系统中自动发送和接收电子邮件 ,同时还能获得地址薄的信息 .该邮件应用模块可挂接在任意PowerBuilder应用软件中 ,具有一定实用价值 .     

国际单项体育联合会善治评价体系构建及其实证研究

基于治理理论和委托—代理模型,本研究以35 个国际单项体育联合会善治 评价为对象,设计了以透明度、程序民主、制衡、团结等维度作为关键维度的指标体系, 并使用文献资料法、问卷调查法和访谈法等方法,对数据进行搜集整理。研究发现,国 际单项体育联合会平均得分为45.5（满分100）,善治状况评价为“一般”,决策和工作 机制不透明、选举和工作程序失范、利益相关者参与不足等,导致组织内部投机主义盛 行,国际单项体育联合会合法性面临危机。研究建议：1）严格执行选举程序,健全主席 和高管资格审查机制;2）完善信息公开制度,提升组织透明度;3）规范工作流程,充 实组织行政程序正当性;4）多元主体参与,健全组织内外部审查制度;5）明确最长任 期,保证组织官员积极性。     

Nanoengineering of amino - functionalized mesoporous silica nanospheres as nanoreactors

Selective functionalization of mesoporous silica nanospheres (MSNs) is crucial for nanoengineering of MSNs. Herein, we have combined “surface-protected etching strategy” and “cationic surfactant assisted etching strategy” to prepare functionalized MSNs with externally attached amino groups. The externally attached NH2 groups endow the catalysts with excellent catalytic performance for nitroaldol reaction between nitromethane and benzaldehyde. In addition, those NH2-MSNs can also be used to support gold nanoparticles, which display very good catalytic performance for reduction of 4-nitrophenol. It can be envisioned that the synthesis protocol developed in this work could also be extended to nanoengineered MSNs, which provides opportunities for nanoreactors design.     

The influence of anthropogenic climate change on wet and dry summers in Europe

Understanding the role of anthropogenic forcings in regional hydrological changes can help communities plan their adaptation in an informed manner.Here we apply...     

Towards Disaggregate Dynamic Travel Forecasting Models

The authors argue that travel forecasting models should be dynamic and disaggregate in their representation of demand, supply, and supply-demand interactions, and propose a framework for such models. The proposed framework consists of disaggregate activity-based representation of travel choices of individual motorists on the demand side integrated with disaggregate dynamic modeling of network performance, through vehicle-based traffic simulation models on the supply side. The demand model generates individual members of the population and assigns to them socioeconomic characteristics. The generated motorists maintain these characteristics when they are loaded on the network by the supply model. In an equilibrium setting, the framework lends itself to a fixed-point formulation to represent and resolve demand-supply interactions. The paper discusses some of the remaining development challenges and presents an example of an existing travel forecasting model system that incorporates many of the proposed elements.     

BEM Analysis of Wave Propagation in a Water-Filled Borehole in an Anisotropic Solid

This paper describes a time-domain boundary element method developed to analyze the interactions of acoustic and elastic waves near the interfaces between water and an anisotropic elastic solid. Two models are analyzed with one being the interface between two half spaces of fluid and solid and the other being a fluid region sandwiched by half space domains of anisotropic elastic solids. Both monopole and dipole point sources are used to generate an initial pressure wave in the fluid. Some snapshots of the transient wave behavior near the fluid-solid interfaces are given. The effect of the anisotropy in the solid on the pressure waveforms in the fluid is discussed. The numerical results allow detailed arrival identification and interpretation of acoustic and elastic waves propagating along the fluid-solid interfaces.     

Growth mechanisms of Ag and Cu nanodendrites via Galvanic replacement reactions

Dendritic silver and copper crystals were produced via Galvanic replacement reactions on zinc and aluminum plates, respectively. The growth orientations of these metals were determined using electron microscopy. The results showed that a fast crystal growth associated with a high concentration of metal cations led to kinetically controlled growth along the <112> axes of the cubic close-packed structures. However, a slow growth rate resulted in thermodynamically controlled growth along the ...     

实验测得的C2-C6二元羧酸溶液的冻结温度:冰核核化过程中的重要指标

由于大气气溶胶影响着地球辐射总量的平衡与能量的估算, 有机化合物作为气溶胶和云凝结核(cloud condensation nuclei, CCN)的重要组成成分, 其重要性已经越来越引起科学家们的重视. 而低分子量二元羧酸(low molecular weight dicarboxylic acids, LMWDCA)作为大气(包括云和雾)中气溶胶的重要成分,其在大气中的传输与转化过程中的作用尤其是对冰核(ice nuclei, IN)核化过程的影响已经成为当前的一个重要的前沿科学研究领域. 本研究利用麦吉尔大学的冻结核记数仪分别测量了不同pH的水溶液(超纯净水与自来水)中单纯态的与混合态的低分子量二元羧酸(C2-C6)液滴的冻结温度. 结果显示, 低分子量二元羧酸(C2-C6)自来水溶液的冻结温度明显的高于其相应的超纯净水溶液. 不同混合态的二元羧酸(C2-C6)的纯净水和自来水溶液液滴的平均冻结温度范围分别是: (-24.1±2.8)~(-21.3±3.9)℃和(-10.2±2.2)~(-9.5±2.2)℃, 而所测对照水(超纯净水与自来水)溶液液滴的平均冻结温度则分别是(-22.6±3.5)和(-11.2±2.4)℃. C2-C6二元羧酸的加入对于水溶液液滴的冻结温度增高的促进作用并不显著.