含离子液体体系的二元液液相平衡的计算

离子液体是许多领域中逐渐推广的绿色溶剂。鉴于离子液体在双相化学和工业萃取过程中的应用,对含离子液体体系的液液相平衡的研究,将有利于科研和生产。本文以文献中提供的未进行过数据关联的含[Et3NH][Al2Cl7]、[Emim] [NTf2]、[Bmim][PF6]、[Penmim][PF6]、[Hxmim][PF6]、[Hptmim][PF6]、[Omim][PF6]等7种离子液体与苯(C6C6),三氯化磷(PCl3),正丙醇(C3H7OH),正丁醇(C4H9OH),正戊醇(C5H11OH)等组成的10个二元系的溶解度数据为基础,应用NRTL和UNIQUAC活度系数模型进行了关联计算,得到了相应的模型参数。通过比较计算值与实验值,结果令人满意,NRTL和UNIQUAC方程计算得到的10个体系的全体平均误差(AAD,Overall-average deviation)的平均值分别为3．228％和2．691％。同时,在应用NRTL和UNIQUAC活度系数模型对含离子液体的二元体系作相平衡数据的关联的时候,首次将相互作用参数由常用的对温度的线性函数关系改进为对温度的双曲线型函数关系,从而显著地提高了对上部会溶点计算的准确性。     

超临界二氧化碳与异丁醇二元体系气液相互溶解度模型的研究

采用可变体积可视观察法测量装置,测定CO_2与异丁醇在40℃-80℃温度范围和不同压力下的平衡数据。研究高压状态下CO_2在液相中的溶解度和异丁醇在气相中的溶解度模型,以改进亨利定律和Chrastil半经验溶解度方程,提出适合于高压下CO_2与异丁醇二元体系的相互溶解度模型,其中CO_2在液相中的溶解度可用4次多项式模型关联,其形式为:P_(CO_2)=A+B_1·x~(CO_2)+B_2·x_(CO_2)~2+B_3·x_(CO_2)~3+B_4·x_(CO_2)~4。异丁醇在CO_2中的溶解度可用改进的Chrastil半经验溶解度方程模拟,其形式为C=p~k·exp(α/T)+b。结果:所提出的气相溶解度方程和液相溶解度方程与试验数据非常吻合,拟合相关系数和精度较高。     

利用ASPENPLUS计算高温高压下硫酸铵的溶解度

利用ASPEN PLUS软件中的Mixer,Herter和Sensitivity模块,计算得到硫酸铵固体在(0~100)℃下的溶解度,计算值与文献值之间的最大相对偏差为0.4%,平均相对偏差为0.26%。使用同样方法得到0.4Mpa G,(100~150)℃下硫酸铵的溶解度,并通过Apelblat方程进行了关联计算。该方法及方程能够为工业生产提供科学可靠的溶解度数据。     

UNIFAC法估算甲烷在常三柴油中的高压溶解度

为满足富氢气氛下,煤直接液化基础数据的需要,选择大港常三柴油做溶剂,用自建的循环法测定气体高压溶解度试验装置,测定甲烷在柴油中的高压溶解度数据(273.45 K-293.75 K,1.79 MPa-8.06 MPa)。根据柴油特点假设其基团构成,用n-d-M-LP法计算柴油的平均结构。用UNIFAC方程估算同条件下的溶解度值,结果估算值与实验值比较,当芳香环和环烷环上有2个取代基时,平均相对误差为3.36%,满足数据缺乏下的估算要求。     

通过改进物性参数估计提高1,10-癸二酰在超临界CO_2流体中溶解度的计算精度

关于1,10-癸二酰在超临界CO_2流体中溶解度计算精度的改进,是在利用Aspen Plus对其物性参数进行模拟的基础上,采用PR方程对其溶解度数据进行关联和计算。溶解度的计算值与实验值符合很好,最大相对偏差为2.53%,最大计算方差为8.83×10~(-5)。该方法为改进固体在超临界流体中溶解度数据计算关联精度提供了一种新的途径。     

计算液液平衡的基团溶解度参数模型研究

为得到一种简便可靠的计算液液平衡的新方法,利用Delphi语言构建了液液平衡数据库,以此为基础对基团溶解度参数模型(GSP模型)进行了研究。采用的基团溶解度参数具有4维,分别表征基团间4种主要的相互作用。通过建立液液平衡算法,并采用非线性优化方法SIMPLEX作为优化方法,对548个三元体系液液平衡数据进行回归得到模型参数的具体数值。对于这些体系,GSP模型计算的平均R．M．S．为0．07446(mol),计算总体摩尔浓度分数的绝对误差为0．05305(mol)。采用改进的UNIFAC模型进行了同样的关联计算以进行比较。结果表明,对应所收集的平衡数据,GSP模型可以达到与改进的UNIFAC模型同样的关联计算精度,而所需要的参数更少,参数值也更容易得到。     

共溶剂-SC CO_2中固体溶解度的小波神经网络关联与预测

为了更好地关联和预测共溶剂-超临界(SC)CO2中固体的溶解度,本文采用经局部动量法和自适应理论优化的小波神经网络模型(WNN),分别以共溶剂的溶剂参数α、β、π*和溶解度参数δd、δp、δh为影响因素,关联了4种共溶剂-SC CO2体系中萘普生的溶解度,以预测其在乙醇-SC CO2中的溶解度.其关联误差AARD分别为1.94%和2.12%;其预测误差AARD分别为8.14%和30.32%.以上结果表明共溶剂的溶剂参数α、β、π*是共溶剂-SC CO2中固体溶解度的主要影响因素;优化的WNN模型能较好地关联和预测共溶剂-SC CO2中固体的溶解度.     

利用Aspen Plus计算和预测物质的溶解度

利用Aspen Plus计算和预测固体、液体和气体物质的溶解度。固体物质溶解度计算利用Mixer+Heater模块,液体溶解度计算利用Decanter模块,气体溶解度计算利用Flash2模块,并利用Sensitivity模块进行灵敏度分析,可得到固体和液体在不同温度下以及气体在不同温度和不同压力下的溶解度。以KCl、NaNO_3和NH_4Cl为例,计算不同温度下固体物质在水中的溶解度,计算值与文献值的平均相对偏差分别为0.47%、0.65%和0.26%:液体物质以苯为例,计算其不同温度下在水中的溶解度,计算值与文献值吻合良好:气体物质以CO_2为例,计算其在不同温度和不同压力下水中溶解度,计算结果均与文献值吻合较好。案例研究的结果表明本文建立的固体、液体和气体物质的溶解度计算方法均是可靠的,对于物性手册和文献中查不到的溶解度数值,可以通过本文提出的方法进行计算和预测,计算结果可为工业生产提供科学可靠的数据。     

基于Aspen Plus软件模拟计算水盐体系溶解度

利用Aspen Plus软件模拟计算水盐体系的溶解度,建立包括混合器Mixer、RGibbs反应器的模拟流程,选择ELECNRTL物性方法,并利用Sensitivity模块对RGibbs反应器进行灵敏度分析,计算水盐体系在不同温度下的溶解度。对于二元体系,分别计算了Na Cl、KCl、KNO3、Na NO3、Mg Cl2、Mg SO4六种物质在1 atm、0℃~100℃范围内不同温度下的溶解度,计算值和文献值吻合较好,平均相对偏差均小于5%。对于三元体系,分别计算了4种三元体系Na Cl-KCl-H2O、Na Cl-Mg Cl2-H2O、Na Cl-Na NO3-H2O、KCl-K2SO4-H2O在25℃时的溶解度,共饱点处其相对偏差都很大,但Na Cl-Mg Cl2-H2O、KCl-K2SO4-H2O的计算值落在不同作者所测得共饱点之间。结果表明:本文建立的计算方法可以较为准确地预测二元体系和部分三元水盐体系的溶解度。     

乙醇、异丙醇在超临界二氧化碳中的溶解度及其模型

采用固定体积可视观察法,测定温度313 K～393 K范围内,不同压力下乙醇和异丙醇在超临界CO2中的的溶解度,并应用Chrastil半经验溶解度模型关联这些溶解度.实验结果表明,在相同温度下,随着CO2密度的升高,溶质在气相中的溶解度也升高.且得到了相应于该系统的溶解度方程参数,与实验数据几乎一致.     

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.