Optimum performance of capillary GC columns as a function of tube diameter and film thickness under various operating conditions. Computer program for calculation of H-ū curves and minimum analysis times

The Golay-Giddings and Poiseuille equations are used to derive equations for the calculation of the maximum plate number and minimum time conditions for given columns at fixed, but selectable, outlet pressures. In addition, expressions are presented for the determination of minimum analysis times for separation problems requiring given plate numbers. In this instance, the optimum column length can be calculated as a function of outlet pressure. A Basic computer program, incorporating the equations for the various optima, together with the H-ū curves, is described. Input variables are either column length or desired plate number, column diameter, film thickness, capacity ratio of the solute, column outlet pressure, seperation temperature, and carrier gas. The carrier gas viscosity is automatically calculated in the case of hydrogen, helium, or nitrogen. For these gases, and if the solute is a n-alkane, the diffusivity of the solute in the mobile phase is calculated. In this case, the carbon number of the solute is needed in the computation. For high molecular weight polydimethylsilicone phases (e.g. SE-30), the program can approximate the diffusivity of n-alkanes in the stationary phase at the given temperature as a function of the carbon number. Of course, manually entered values of viscosity and diffusion coefficients can be included in the calculations.     

On the convergence of the affine-scaling algorithm

The affine-scaling algorithm, first proposed by Dikin, is presently enjoying great popularity as a potentially effective means of solving linear programs. An outstanding question about this algorithm concerns its convergence in the presence of degeneracy. In this paper, we give new convergence results for this algorithm that do not require any non-degeneracy assumption on the problem. In particular, we show that if the stepsize choice of either Dikin or Barnes or Vanderbei, et al. is used, then the algorithm generates iterates that converge at least linearly with a convergence ratio of , wheren is the number of variables and (0,1] is a certain stepsize ratio. For one particular stepsize choice which is an extension of that of Barnes, we show that the cost of the limit point is within O(/(1–)) of the optimal cost and, for sufficiently small (roughly, proportional to how close the cost of the nonoptimal vertices are to the optimal cost), is exactly optimal. We prove the latter result by using an unusual proof technique, that of analyzing the ergodic convergence of the corresponding dual vectors. For the special case of network flow problems with integer data, we show that it suffices to take = 1/(6mC), wherem is the number of constraints andC is the sum of the cost coefficients, to attain exact optimality.This research is partially supported by the U.S. Army Research Office, contract DAAL03-86-K-0171 (Center for Intelligent Control Systems), by the National Science Foundation, grant NSF-ECS-8519058, and by the Science and Engineering Research Board of McMaster University.     

Important unanswered questions—1970

This paper was given as the opening address at the 1970 Albany International Conference on Radiation Effects in Semiconductors, and it attempts to establish a general overview of the field by concentrating on recent research developments and important unanswered questions. The continuing importance of impurity-defect interactions, of microscopic defect identification, and of the necessity for more theoretical calculations are emphasized. The rapid development of the field of ion implantation and its close relationship with radiation effects studies are pointed out. It is predicted that research in compound semiconductors will increase rapidly with close beneficial interaction with ion implantation studies.     

影视节目中酸碱指示剂的应用与评价

将影视节目中酸碱指示剂的应用引入到化学教学中，让学生在娱乐中学习化学知识，创造一个有趣的学习情境，提高学生的学习兴趣。     

Stable local trace formula

Langlands program is the central concern of modern number theory. In general, we think that the main tool for studying this program is the trace formula. Arthur-Selberg’s trace formula is successful in solving the endoscopic case of Langlands program. Arthur stabilized the geometric side of the local trace formula in the general case, but did not stabilize the general spectral. This paper aims to solve the general case by different method in the Archimedean case, by directly stabilizing the spectral side of the local trace formula, and obtains the stable local trace formula.     

A mathematical model for the 3d location estimation of 2D echocardiography data

The recovery of 3D left ventricle(LV) shape using 2D echocardiography is very attractable topic in the field of ultrasound imaging. In this paper, we propose a mathematical model to determine the 3D position of LV contours extracted from multiple 2D echocardiography images. We formulate the proposed model as a non-convex constrained minimization problem. To solve it, we propose a proximal alternating minimization algorithm with a solver OPTI for quadratically constrained quadratic program. For validating the proposed model, numerical experiments are performed with real ultrasound data. The experimental results show that the proposed model is promising and available for real echocardiography data.     

类氖氩离子能级及碰撞强度的计算

利用扭曲波波恩近似方法及AUTOSTRUCTURE (AS)程序，快速精确地计算了类氖Ar8+离子2s22p6、2s22p53s、2s22p53p、2s22p53d、2s2p63s、2s2p63p和2s2p63d组态的能级以及当电子碰撞能量为75.0、125.0、175.0、250.0 (Ry)时，从j能态到i能态的碰撞强度.并且与已有的研究成果进行了对比.结果表明，采用扭曲波波恩近似并结合AUTOSTRUCTURE (AS)程序的研究方法，可以成为研究原子或离子碰撞强度的有效途径。     

基于CAN总线的码头岸电监控系统实时性分析

随着我国"节能减排"的势在必行,船舶靠港期间使用码头岸电以及岸电供给的智能监控已经成为当前的趋势,并正在大力推广。CAN总线在智能监控领域具有广阔的应用前景,在大型网络监控系统中,监控系统的实时性具有重要的意义。文章分析了CAN总线的实时性问题,针对CAN协议提出了仿真模型,实验测出延时数据,总结比较了当前几种基于TTCAN的算法优化问题。对于开发大型网络监控系统具有一定的现实参考意义。     

基于对象引用关系的Java程序内存行为分析方法

本文提出一种基于对象引用关系的Java程序内存行为分析方法.与传统的通过内存消耗的大小来确定程序中数据结构的重要性并分析相关内存行为的方法不同,本文方法同时考虑内存消耗和内存支配两个因素来确定一个数据结构在程序内存行为中的重要性,通过研究数据结构之间在内存使用上的支配关系和对数据结构进行引用分析,得到程序中重要的内存行为.实验结果表明该方法能有效地分析程序的内存行为,且对比其它方法能提供更加准确的内存行为分析结果.     

基于物联网的煤矿检测监控系统研究

为了解决传统的煤矿监控系统存在的信息孤岛和被动监视的问题,本文提出了一种基于物联网的煤矿检测监控系统。系统主要由基于嵌入式平台的井下人员终端、环境检测设备、ZigBee路由器和ZigBee协调器、服务器、监控中心组成。在通讯协议上,采用Zigbee协议和高层自定义协议,使各组成部分之间实现了互联互通。本系统具有结构简单、工作可靠、便于维护等特点,对于我国矿井安全监测监控系统的现代化改造,提高矿井生产效率和经济效益具有重要意义。