污泥热干燥粘结的特征和影响因素

污泥热干燥过程中在干燥设备内部表面的粘结是影响干燥设备性能的重要因素。通过热干燥模拟实验,分析了污泥含水率、加热温度、加热方式、加热界面性质等因素对污泥粘结的影响。结果表明,含水率是影响污泥粘结最主要的因素,污泥含水率较高时,粘结量较少,随着污泥干燥程度增加,含水率降低,粘结量逐渐增加,当含水率达到60%左右时粘结量达到最大,之后转而减少;加热温度不超过120℃时,温度对污泥粘结的影响不明显,加热温度高于120℃时,污泥粘结量随温度升高而显著增加;传导加热方式比对流加热方式更易导致污泥粘结;加热接触界面的表面粗糙度越大则污泥粘结量越大。     

利用臭氧控制VOCs生物过滤塔生物量

生物过滤塔在挥发性有机物和恶臭气体处理方面具有良好的应用前景,但生物量过度累积是影响其运行稳定性的主要问题。为了探讨利用臭氧控制生物量过度累积的可行性,该研究系统考察了连续投加臭氧对于生物过滤塔甲苯去除性能、填料层压降及空隙率、生物量增长以及碳平衡的影响。研究结果表明,臭氧浓度为0～220mg/m3时,投加臭氧不会降低生物过滤塔的甲苯去除性能;臭氧浓度为100～220mg/m3时,投加臭氧可以显著控制生物量过度累积、优化填料层结构和控制压降快速升高。进一步研究表明,提高甲苯的矿化率是臭氧控制生物量快速累积的主要途径。     

LRB曲线桥震致碰撞效应的非线性分析方法

发展了一种适用于体元模拟联间轴向正面碰撞效应的束缚面型碰撞单元（Constraint-sur-face Impact Element,CIE）;基于柔度法给出了不同以往文献中碰撞单元刚度的计算取值,该取值不仅理论合理且在物理角度可解释其合理性。将该方法应用于广州潮汕机场航站楼高架桥的震致碰撞分析。箱梁采用壳单元模拟,伸缩缝位置设有CIE,桥墩与箱梁间设置隔震单元模拟铅芯橡胶隔振支座（Lead-rubber Bearing,LRB）,采用通过试验得到的双线性刚度模型模拟其物理行为。采用非线性直接积分法进行时程分析,主要考察联间的碰撞力、LRB滞回耗能、LRB位移量、基底弯矩、剪力以及碰撞力分别对这些因素的影响。     

阿拉山口供水工程运行监控 管理系统研究

本文介绍了阿拉山口供水工程运行监控管理系统的建设。该系统通过监测数据判断系统运行状况及对设备的控制,完成了工程运行过程的自动化。在硬件上,采用了中控室、分控室、监测节点的分级结构,使用光纤和无线模式进行数据传输,以采集压力计、水位计、流量计、测沙仪、阀门开度等传感器数据;在软件上,开发了服务器端、客户端的监控程序,实现了数据采集传输、设备控制和信息报警等功能。系统已应用于阿拉山口供水工程实际的运行管理工作中。     

A Comparative Study of the Performance of Public Water Rights Allocation in China

Pubic water rights allocation, in which water resources are allocated to users administratively as shared public property, is an effective and powerful policy for water resource management. Dozens of public water right allocation systems have been established in China since 1998 without any unified standard across the country. An indicator-based assessment approach, based on equity, efficiency and sustainability, is proposed in this study to evaluate the performance of public water rights allocation systems in China in a quantitative way. The approach was applied in 11 river basins of China in which water rights have been defined. The results show that the performance of the allocation systems depends on the spatial density and exploitation ratio of the water resources. The performance of allocated water rights systems is better in river basins with greater resource densities and smaller water exploitation ratios. This assessment approach is very useful for evaluating policy options for public water rights allocation with appropriate consideration of the local conditions of the river basins.     

An integrated urban drainage system model for assessing renovation scheme

Due to sustained economic growth in China over the last three decades, urbanization has been on a rapidly expanding track. In recent years, regional industrial relocations were also accelerated across the country from the east coast to the west inland. These changes have led to a large-scale redesign of urban infrastructures, including the drainage system. To help the reconstructed infrastructures towards a better sustainability, a tool is required for assessing the efficiency and environmental performance of different renovation schemes. This paper developed an integrated dynamic modeling tool, which consisted of three models for describing the sewer, the wastewater treatment plant (WWTP) and the receiving water body respectively. Three auxiliary modules were also incorporated to conceptualize the model, calibrate the simulations, and analyze the results. The developed integrated modeling tool was applied to a case study in Shenzhen City, which is one of the most dynamic cities and facing considerable challenges for environmental degradation. The renovation scheme proposed to improve the environmental performance of Shenzhen City's urban drainage system was modeled and evaluated. The simulation results supplied some suggestions for the further improvement of the renovation scheme.     

基于物理过程的分布式流域水沙预报模型

将分布式水文模型与土壤侵蚀产沙模型相互嵌套,构建了一个分布式流域水沙预报模型。模型基于DEM,将流域离散为“坡面+ 沟道”系统,采用“+ 1 ”分级方法将沟道组织为河网,实现了流域水沙预报的并行计算。坡面单元划分为植被层、地表层、非饱和带和地下水层,模拟了降雨、截留、蒸散发、入渗、地表径流、壤中流和地下水、各种形式的侵蚀产沙及泥沙输移;沟道进行汇流演算以及泥沙输移。模型在李子溪流域对长系列降雨的模拟结果表明,模型的水文模块模拟精度良好,侵蚀产沙模块模拟效果基本令人满意。     

用改进扩展有限元法研究重力坝强震断裂过程

采用改进的扩展有限元法(Extended Finite Element Method,XFEM),即引入虚结点的XFEM,在静力功能基础上实现了动力断裂分析功能,并用于强震中结构多条裂缝的同时扩展分析。采用混凝土Ⅰ型和Ⅰ-Ⅱ混合型动力断裂试验进行了精度验证,然后将该方法应用于Koyna坝的地震开裂分析。结果表明,这一方法在求解混凝土Ⅰ型和Ⅰ-Ⅱ混合型动力断裂问题方面具有良好精度,其避免了网格不断重剖分的问题,也无需采用开裂单元的子域积分来描述非连续位移场,即可实现单元内连续断裂过程的模拟。     

鉴别式多核手跟踪

快速运动、背景混杂及手的特殊性为传统的核目标跟踪技术提出了挑战.文中提出一种鉴别式颜色子空间选择和多核校正机制的核跟踪方法.首先基于前景背景建模,通过鉴别函数选取最优鉴别式颜色子空间集,再基于训练的肤色模型保留高置信子空间表征目标.其次,为适应尺度变化和快速运动,基于多核快速估计相似度表面以校正初始核位置,迭代定位目标.实验表明,融合二者的跟踪器在有效性和速度上都实现了满意的性能,满足实时性需要.     

On trajectory tracking control for nonholonomic mobile manipulators with dynamic uncertainties and external torque disturbances

This paper studies the trajectory tracking control problem of mobile manipulators subject to nonholonomic constraints, operating in task space, with the presence of external torque disturbances and dynamic uncertainties. The proposed controls are robust to external torque disturbances and can overcome the effects of the unknown dynamic parameters. The stability of the closed-loop system and the asymptotic convergences of tracking errors are proved using Lyapunov synthesis. The proposed control strategies have been designed to drive the system motion converges to the desired manifold and, at the same time, guarantees the boundedness of all the closed-loop signals. Simulation results validate that the system trajectory converge to the desired one.