也论汉代画像石图像的构图方式

在当代,对汉代画像石图像的构图方式的研究,不同学者有着"平面散点布局的方式""分层方式""散点透视法"和"焦点透视法"等阐释。这些构图方式体现的是民间美术的构图法则与思想,汉代民间画师、民间石刻艺人们的思维方式、对事物的认知、习惯、信仰等应该是汉代画像石图像构图的内在思想方式。研究现出土的汉代画像石图像的构图方式不能仅从现代中西方绘画的构图理论、法则与方法入手。从民间美术的构图法则与思想角度深入研究汉代画像石图像的构图方式,应该更有意义。     

Experimental implementation of automatic ‘cycle to cycle’ control to a nonlinear chiral simulated moving bed separation

In order to better exploit the economic potential of the simulated moving bed chromatography a ‘cycle to cycle’ controller which only requires the information about the linear adsorption behavior and the overall average porosity of the columns has been proposed. Recently, an automated on-line HPLC monitoring system which determines the concentrations in the two product streams averaged over one cycle, and returns them as feedback information to the controller was implemented. The new system allows for an accurate determination of the average concentration of the product streams even if the plant is operated at high concentrations. This paper presents the experimental implementation of the ‘cycle to cycle’ control concept to the separation of guaifenesin enantiomers under nonlinear chromatographic conditions, i.e. at high feed concentrations. Different case studies have been carried out to challenge the controller under realistic operation conditions, e.g. introducing pump disturbances and changing the feed concentration during the operation. The experimental results clearly demonstrate that the controller can indeed deliver the specified purities and improve the process performance.     

基于流的可伸缩性网页布局的最高效设计方法

曾经横行以往的标准即基于table+css的网页设计技术已经不再流行,目前更多的网站更愿意使用div+css的网页结构。[1]利用现在主流的div+css布局技术能使网页呈现很多梦幻效果,特别是在网页后期的更新与维护中省时省力,只需略做调整便可适应不同风格或不同浏览器。尤其是在设计可伸缩性页面布局方面,div+css技术是最高效的不二选择。     

Gossip: The Architecture of SpreadPlots

A spreadplot is a visualization that simultaneously shows several different views of a dataset or model. The individual views can be dynamic, can support high-interaction direct manipulation, and can be algebraically linked with each other, possibly via an underlying statistical model. Thus, when a data analyst changes the information shown in one view of a statistical model, the changes can be processed by the model and instantly represented in the other views. Spreadplots simplify the analyst's task when many different plots are relevant to the analysis at hand, as is the case in regression analysis, where there are many plots that can be used for model building and diagnosis. On the other hand, the development of a visualization involving many dynamic, highly interactive, directly manipulable graphics is not a trivial task. This article discusses a software architecture which simplifies the spreadplot developer's task. The architecture addresses the two main problems in constructing a spreadplot, simplifying the layout of the plots and structuring the communication between them.     

On spanning tree congestion

We prove that every connected graph G of order n has a spanning tree T such that for every edge e of T the edge cut defined in G by the vertex sets of the two components of T−e contains at most edges. This result solves a problem posed by Ostrovskii (M.I. Ostrovskii, Minimal congestion trees, Discrete Math. 285 (2004) 219-226).     

环形翅片的分析模拟与优化设计

强化效率是评价翅片的最基本参数之一,翅片的结构参数直接影响着翅片传热的强化效率。对翅片结构进行优化设计的目的在于找到翅片的最佳结构,使得用最小换热面积满足换热的设计要求。可为进一步的对空冷器的结构优化提供参考。     

最优血管分支构造

本文介绍了一个数学模型，以表明利用数学解决实际问题时的方式和效果，体现了数学在实际应用中的重要作用。     

基于混合粒子群算法的通用导弹固定平台布局优化

为实现导弹运输的通用化保障,提高导弹运输装备的运输能力,设计了一种可以加装在越野车副车架上的新型通用导弹固定平台,满足固定机构布局面积达到最小的要求,从而减小对底盘上装空间的需求,降低底盘选型的难度.针对这一问题,在对基本粒子群算法中的惯性权重取值进行改进的基础上,利用模拟退火原理对粒子群算法每次迭代产生的全局最优解进行优化.经仿真实验验证,与基本粒子群算法相比,该混合算法搜索能力强、搜索精度高、收敛性好、优化效果明显,很好的解决了通用导弹固定平台的布局优化问题.     

优化二次函数与共轭梯度算法

本文提出构造二次函数作为目标函数。无约束条件下优化这个函数,导出本征方程 AX=λX,一般矩阵方程 AX=Y 和齐次方程 AX=0的自适应和递推解。计算机模拟表明这种算法稳定,能获得精确解和具有快速收敛特性。