石灰石和石膏浆液密度计的选型与工程设计探讨

石灰石和石膏浆液的密度是湿法烟气脱硫工程中的重要过程检测参数,也是重要的控制对象。由于浆液中含有固体颗粒,对测量仪表提出了抗腐蚀、抗磨损、防止堵塞等要求。文中分析了五种型武的浆液密度计的结构和测量原理,比较了这些密度计在浆液测量上的性能和特点。结合工程设计经验,总结和提出了浆液密度计的安装和配管设计要求。     

基于Fluent的恒温箱温度场仿真分析

在线密度计检定规程指出试验过程中液体温度稳定性应小于0.05℃,采用恒温箱为在线密度计提供可控温场,因此恒温箱的温度偏差不得高于2℃。基于Fluent强制对流传热模型对选取的温度点下恒温箱以及在线密度计温度场分布进行分析。为进一步分析恒温箱的恒温性能,改变在线密度计流体入口的温度、速度2个参数对于在线密度计稳定后温差的影响。结果表明,在选取的温度点下恒温箱性能均满足要求;当在线密度计流体入口温度与当前设置温度点的差值小于0.9℃,液体温差在0.05℃以内;当在线密度计与恒温箱温度差值一定,在线密度计流体速度越快,流体温差越小。     

用于疏浚工程泥浆密度测量的电阻层析成像技术

江河湖海疏浚工程对于拓展和保障航运安全、促进生态恢复、维护/改善远海岛礁环境具有不可或缺的作用.目前,在绞吸和耙吸疏浚船上,多采用射线密度计及电磁流量计对输泥密度、产量等进行在线计量,并作为实现疏浚系统自动控制的重要参量.由于射线密度计潜在的人员健康、公共安全和环保风险,在一些国家和地区已建立了放射源的有序退出机制.电阻层析成像使用安装于管壁的电极阵列获得管道内流体的电导率分布,进而推导出管道内的泥浆密度,具有无辐射、全场测量及实时可视化的优点.电阻层析成像测量系统经过特殊设计,可适应从内陆淡水到海水的巨大电导率变化.初步测试表明,电阻层析成像测量数据与射线密度计具有良好一致性,具备了作为在线泥浆密度测量的可行性.此外,ERT可提供实时的流动成像,对于提高对疏浚管道监测能力和降低堵管概率具有重要意义.     

振动管式液体密度传感器数学模型研究

本文介绍了振动管式液体密度计的数学模型,推导了其在出厂标定与发生系统漂移后一对重要参数的比例关系,优化了被测液体密度与振动管谐振周期的对应关系,结果证明,本方法所得曲线不仅拟合精确,还能有效消除系统漂移对测量结果带来的影响.     

γ射线密度传感器

γ射线密度计的特点是，非接触测量，被测对象不限，无需担心腐蚀，可靠性高，测量精度高等特点，广泛适用于腐蚀性液体，高粘度液体，高温、高压下的液体等的测量。     

某火电机组石灰石-石膏脱硫工艺吸收塔设计

据统计,目前已投运或正在建设的脱硫系统中,湿法烟气脱硫技术占80%左右.在湿法烟气脱硫技术中,石灰石-石膏法是最主要的脱硫技术,本文以某火电厂石灰石——石膏法脱硫工艺为对象,对比各种吸收工艺,针对主要设备吸收塔进行设计.     

新型泥浆池差压式密度计的设计与实现

石油勘探中需要在线测量泥浆密度的变化,再通过取样分析来判断地下是否含有石油.传统的泥浆池差压式密度计可靠性差,精度不高.文中设计的差压式密度计以微处理器为核心,采用双陶瓷电容压力传感器作为敏感元件,具有响应快,精度高的特点.文章介绍了差压式密度计的工作原理以及软、硬件设计,并且针对应用场合的特殊性提出了提高精度的一些方法.     

基于模糊控制的火电厂湿法烟气脱硫系统

火电厂湿法脱硫为多变量、强耦合的连续控制过程,具有控制系统复杂、控制精度不高以及工艺过程复杂和难以建立准确数学模型的特点,因此提出了利用可编程控制器(PLC)对系统进行模糊控制的方法,建立了湿法脱硫系统主参数pH值的模糊自适应PID控制器.通过在张庄电厂湿法烟气脱硫上的应用证明,该方法实现的脱硫效率达到96％以上,将设计脱硫率提高了4个百分点.系统运行稳定、可靠,响应速度快,抗干扰能力强,有较高的推广、应用价值.     

石灰石/石膏湿法烟气脱硫系统物料平衡计算软件的设计与开发

物料平衡计算为湿法烟气脱硫工艺设计的基础,并为预测工艺系统的调试和运行提供相关参数.本文在分析石灰石/石膏湿法烟气脱硫系统的数学模型基础上,依据工艺原理和反应方程式,确定输入数据与输出数据的等量关系,用VB 6.0设计开发有关石灰石/石膏湿法烟气脱硫的物料平衡计算软件,具有界面友好、操作方便、功能齐全等特点.运行结果通过实际工程数据验收,为烟气脱硫装置参数、工艺系统设计和设备选型提供可靠的技术资料.     

DCS系统在火电厂烟气脱硫控制系统的实现

设计用于工业控制DCS系统,以实现烟气脱硫的自动化控制.该文介绍了湿法烟气脱硫的工艺概况和系统配置,详细说明了烟气脱硫过程控制的实现方法.     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.