在线自调整高压差模糊控制系统研究

针对羰基合成反应中气液分离器压力难以实现自动控制的问题,提出了一种基于模糊控制思想,构成参数在线自调整智能控制系统的设计方法。将该系统应用于气液分离器压力控制中,鲁棒性较好,满足了生产工艺对压力的控制要求。     

带尾冷回收的精馏塔真空系统建模及参数估计

真空系统是减压精馏塔的重要组成部分。当真空系统运行时,会有部分塔顶工艺物料通过真空系统抽出,需要回收处理,增加操作成本。针对真空系统设计参数不易核算的情况,首先对精馏塔真空系统进行建模,然后采用现场的压力和回收工艺物料量数据回归出尾冷器的压降参数和精馏系统泄漏空气量。将估计的泄漏空气量与经验公式进行对比,预测不同压力下的冷凝液量并将其与现场数据对比。结果表明,所回归出的参数可以很好地预测不同压力下的真空系统工艺物料回收量。     

二氧化碳与2-丁醇二元体系在高压下的亨利系数和偏摩尔体积性质计算

利用固定体积可视高压釜测量出的在323K~353K温度范围内的CO2与2-丁醇二元体系在高压下的汽液相平衡数据,根据Krichevsky-Kasarnovsky方程建立了CO2在液相中的溶解度模型,得到了该二元体系在高压下的亨利系数和CO2在无限稀释溶液中的偏摩尔体积等性质。同时根据偏摩尔体积性质和Peng-Robinson状态方程及Van der Waals-2混合规则来计算该体系在平衡状态下的气、液相的偏摩尔体积。结果表明CO2在2-丁醇中的亨利系数和CO2在无限稀释溶液中的偏摩尔体积均为温度的函数,CO2在2-丁醇中的亨利系数随温度的升高而降低。CO2在无限稀释溶液中的偏摩尔体积∞1V在研究温度下均为负值,其中随温度升高,其绝对值下降。在平衡状态下的气、液相的偏摩尔体积计算结果表明:平衡状态下,液相中CO2与2-丁醇的偏摩尔体积均为正值。气相中不同温度下CO2的偏摩尔体积均为负值,且其绝对值随着压力的增加而越来越大,2-丁醇的偏摩尔体积均为正值。此研究为该体系超临界萃取条件的确立和指导工业化生产提供了理论依据。     

聚碳酸酯液液分离器进料构件的流体力学模拟

测定了聚碳酸酯(PC)物料电导率随水油相体积比的变化,确定生产中物料为水包油型乳液,即分散相为PC胶液,连续相为水。采用F1uent商用软件对液液分离器内部流场进行了数值模拟,通过得到的分离器内部流线分布和轴向速度标准偏差分布,考察了不同进料口位置、挡板位置以及不同整流构件尺寸对液液分离器内部流场的影响。研究发现,进料口位置为中部,挡板位置距离进料口为50mm,整流构件开孔率为40%,长度为150mm时,分离器内的流场质量最佳,为液液分离器进料构件的进一步优化研究提供了参考。     

煤焦油中低含量组分气液平衡模拟计算

利用Aspen Plus模拟软件,采用合适的物性方法,建立煤焦油蒸馏模型。研究了温度、压力对低含量组分气液相平衡数据的影响。模拟数据表明随着温度的升高,低含量组分在气相中质量分数都在200℃~300℃左右出现峰值,在液相中质量分数随着温度的升高而降低;吡啶、2-甲基萘、1-甲基萘、二甲基萘、吲哚和芴分别在200℃~210℃、260℃~270℃、240℃~250℃、250℃~260℃、260℃~270℃和270℃~280℃馏分段富集,降低压力对组分在气液相中分布影响不大。模拟结果为煤焦油的精细化分离提供了理论依据。     

气液分离器的结构优化

常规气液分离器一般采用重力沉降罐的结构形式,具有结构简单等特点,但设备体积庞大,占地面积大,处理时间长。基于计算流体动力学方法,采用Gambit建模,利用Fluent软件进行分析,对常规立罐式离心气液分离器进行了仿真。通过流场分析可以看出,流场对称性很差,底流出口附近气体含量较多,说明气液分离效果不好。通过结构优化,包括将底流出口改为正下方排液,单入口改为双入口结构,罐体直径减小,溢流管伸入分离器内部入口管之下,以及将分离器下端改为锥型结构等,经优化后改善了分离器内部流场的轴对称性及气相浓度分布情况,使分离效果有了明显改善,锥段的壁面和底流出口附近的含气量很低,提高了分离器的净化程度。通过实验研究说明优化后分离器的分离性能较好,而且通过实验也验证了仿真模型选取的正确性和准确性。     

新型气液旋流分离器的模拟研究

为了分离气液喷射反应器的产物,开发了一种新型气液旋流分离器。分别采用Muschelknautz模型、改进的Muschelknautz模型和计算流体力学(CFD)离散相模型对新型气液旋流分离器进行了模拟计算,对新型气液旋流分离器的压力场、分离效率、液滴运行轨迹进行了考察。结果表明:相对于传统Muschelknautz模型,改进的Muschelknautz模型与CFD的模拟结果更为接近,能更加准确地对旋流分离器的分离性能和压降进行预测:在设计条件下,液滴直径越小,颗粒在旋流分离器中的运动轨迹就越紊乱,>3μm的液滴颗粒的分离效率超过80%:颗粒的入口位置会影响颗粒的运动轨迹。     

基于流量与温度信号的变频油气回收系统设计与参数优化

本文详细研究了温度以及流量对汽油加注过程中油气挥发的影响。在剖析传统油气回收系统存在不足的基础上,设计了基于温度及流量信号的新型油气回收系统,并对气液比参数进行了优化。新型油气回收系统可以根据温度的变化确定相应的气液比,实现了油气回收过程自适应调节。本文还对温控油气回收系统回收效果进行了测试。     

两相分离计量系统的应用研究

油田进入高含水期后,由于高含水和气相的存在,传统的计量方式已经不能满足计量精度的要求.通过工艺计算,为计量系统选择了合适的计量分离器.分别对分离器内部构件和流量计进行选型,并设计了详细的气液相计量流程.同时,根据数值模拟结果,对气液相计量进行了误差分析和预测,并针对各不确定性因素对分离效率的影响进行了敏感性分析.分析结果为两相分离计量系统的现场应用提供了理论依据.     

管式油井气液两相流量计的研制与应用

通过分析胜利油田现有单井计量技术的优缺点,基于传统立式分离器玻璃管液位计油井计量装置测量原理,设计研制了一种价格低廉、稳定可靠、可直接安装在油井井口的管式油井气液两相流量计。现场试验证明,该流量计适用于低产、波动、间歇、低气液比、稠油等各种类型的油井,液相计量误差小于±3%,气相计量误差小于±5%,造价低于2万元。该流量计计量性能优良,在油田开发中具有十分广阔的应用前景。     

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.