高等学校文科数学教学改革与实践

本文结合南京工业大学十多年来文科数学课程的教学实践,围绕大学文科专业开设数学课程的必要性和重要性以及文科数学的课程体系、教学内容、教学方法、教学手段等方面,作了初步的探讨和研究。     

一种基于滤波特征和不变矩的混合指纹识别算法

滤波特征匹配和不变矩匹配是常用的指纹识别算法,是将两种识别算法以一定的权值进行结合而提出的一种混合识别算法.通过采用来自不同手指采集的多幅指纹图像作为样本集并两两匹配,得到相应的滤波特征和不变矩匹配分数样本.而算法中权值的确定可以转换成一个匹配分数样本的分类器设计问题,用这些样本对权值进行分类学习估计.以100对指纹图像对混合识别算法进行测试,结果证明该算法具有较好的识别效果.     

Relationship Between Embedding Depth and Residual Stress in the cBN Grain of Monolayer Brazed Abrasive Tools

The relationship between the embedding depth and the residual stress in the brazed cBN grains is analyzed experimentally in order to optimize the embedding depth of grains in the monolayer brazed abrasive tools. It is found that the residual stress is stable without remarkable gradient in the core zones of the brazed grains. However, the stress distribution gradient is rather great in the regions such as both ends of the central axis, the margin region of the central plane in the cBN grains, and the margin region of the section plane between the grains and the filler top. The maximum tensile stress in the margin zone of the brazed cBN grains has the most important influence on the mechanical property of the grains. The embedding depth is accordingly optimized at 30-40% of the total height of cBN grain.     

J4不锈钢热轧板冷轧横裂原因分析

分析发现了J4不锈钢热轧板冷轧横裂形成的主要原因是:钢中有大量显微气泡破坏基体的连续性,降低材料的塑性,导致裂纹形成。加大脱氧、脱气力度,可减少显微气泡,预防裂纹形成。     

Desorption kinetics of trichloroethylene and perchloroethylene from aged dense nonaqueous phase liquid-contaminated soil

Batch experiments were conducted to investigate the desorption kinetics of a contaminated soil collected from a field site at Hill Air Force Base (AFB), Utah. The site has been contaminated with many dense nonaqueous phase liquids (DNAPLs), primarily trichloroethylene (TCE) and perchloroethylene (PCE), for more than 60 years. Similar desorptive behaviour of both TCE and PCE was observed: a stage of fast release of the contaminant at the start followed by a very slow stage. Moreover, it is suggested that not all the contaminant in the solid phase may be released to the aqueous phase, apparently due to the age factor. Local variations were observed in the effective diffusivity and other sorption-related parameters across the site due to aquifer heterogeneity. Experimental results were then simulated using a numerical code based on the intraparticle diffusion model. Good agreement was found between both results.     

高层建筑外整饰工程排栅脚手架施工方案及其安全管理

通过广州市区某临近内环路的高层建筑外整饰工程实例,介绍脚手架搭设的施工技术方案及其安全技术管理措施,为同类施工提供参考。     

楼宇自动化系统(BAS)在现代建筑工程中的进化与应用

概述了构成智能建筑的基本框架,根据涉外工程实施的经验,介绍了其中楼宇自动系统的分类、特性,基本功能及系统结构,基于目前技术和经济水平下的成本限制,大多数检测设备和执行装置不具备网络通信功能,而是以模拟信号与现场DDC系统直接连接的,是数字技术与模拟技术共用的混合结构。并展望了楼宇自动化系统的发展趋势。     

总体城市设计产生背景、实施障碍与实施路径

改革开放以来我国城市建设在城市形态和空间方面所存在的城市整体面貌趋同、城市公共空间不足及封闭社区蔓延等问题成为总体城市设计产生的现实背景和动力。在市场经济条件下总体城市设计的目标实现存在着矛盾与障碍,形成独立系统、融入现有规划体系、调整开发与管理模式成为总体城市设计可能的实施路径。     

建筑工程管理中的问题分析和措施探讨

文章分析了建筑工程管理中存在的问题及其原因,阐述了建筑工程管理中的控制因素,针对如何提高建筑工程管理效益提出了改进建议。建筑行业要健康发展,必须按照法制化、市场化的精髓逐步深入改革,探索出一条可持续发展之路。     

后张预应力混凝土箱形梁施工中的质量问题分析与解决措施探讨

本文结合工程实例,分析了后张预应力混凝土了箱梁施工过程中存在诸多质量问题及产生的原因,并针对性地阐述了具体的解决措施方案,实践证明,这些措施方案是行之有效的。