基于颜色特征的智能焊点定位算法

针对现有自动光学检测系统焊点定位自动化程度低的问题,提出了一种基于颜色特征的智能焊点定位算法.对样本焊点区域的灰度直方图进行统计分析,获得焊点分割的初始颜色阈值,并以最小像素损失为目标对阈值进行修正,得到最优分割阈值,实现了焊点颜色的自动抽取;定位过程中,使用阈值对焊点图像进行二值化,并使用优化后的面积最大法来搜索焊点位置,实现了焊点的快速定位.实验结果表明:文中算法对焊点图像的分割效果理想,定位误差小,定位速度可以满足实际应用的要求.     

Spatiotemporal dynamics of impervious surface areas across China during the early 21st century

China has experienced an unprecedented urbanization and industrialization in the past decades. In this research, we examined the dynamics of construction lands and impervious surface areas (ISA) based on land use/cover change and ISA datasets between 2000 and 2008, which were provided by the national resources and environmental remote sensing information platform. The results indicated that the construction areas and ISA increased by 3468.30 and 2212.24 km 2 /a in this period primarily due to the implementation of national macro-development strategies and fast-growing economy. In 2008, ISA accounted for 0.86% of the total land area in China. Urban land areas increased by 43.46% between 2000 and 2008. The annual growth rate of 1788.22 km 2 /a in this period was 2.18 times that in the 1990s. In particular, urban ISA increased by 53.30% between 2000 and 2008 with an annual growth rate of 1348.85 km 2 /a. During the 8 years, the ISA in China increased rapidly, especially in the Beijing-Tianjin-Tangshan Metropolitan Region, Pearl River Delta, Yangtze River Delta, and the western China region. The increasing ISA may influence potentially water environmental quality in the major basins. In particular, the number of subbasins having ISA of greater than 10% increased considerably, which were primarily distributed in the Haihe River, Yangtze River and Pearl River basins. In 2008, 14.42% of the basin areas were affected by the increased ISA.     

暴涨宇宙的一个可能解

证明了在非均匀球对称的Tolman-Bondi时空中，应用Brans-Dicke理论，当作为外场的B-D标量场是非均匀的，且将其视为时空挠率的挠率势时，选取合适的拉氏作用量，则极早期宇宙将以指数幂律倍增的形式发生暴涨。     

关于边际函数与时间最优控制的一些注记

本文在较弱的假设下，研究了边际函数的可测性，其结果被应用于时间最优控制问题。     

家兔模拟直肠癌手术损伤盆腔植物性神经后的性机能观察

为了验证损伤盆腔植物性神经后会导致术后性机能障碍，以及进一步了解神经的走行和解剖关系，对雄性家兔进行了模拟直肠癌根治性手术的实验：即损伤其低前神经盆内脏神经及盆丛后再与雌性家兔配对，继续喂养６个月，看有无生育能力，以观察性机能。观察结果：生育者只占１０％，而对照组全部有生育，这与临床上直肠癌振治性手术后所发生的排尿、性机能障碍基本一致。这项研究为实施保存植物性神经的直肠癌手术提供了可靠依据；对维持直肠癌术后的排尿和性机能，提高生存质量有重要意义。     

Effects of overaging temperature on the microstructure and properties of 600 MPa cold-rolled dual-phase steel

C–Mn steels prepared by annealing at 800°C for 120 s and overaging at 250–400°C were subjected to pre-straining (2%) and baking treatments (170°C for 20 min) to measure their bake-hardening (BH2) values. The effects of overaging temperature on the microstructure, mechanical properties, and BH2 behavior of 600 MPa cold-rolled dual-phase (DP) steel were investigated by optical microscopy, scanning electron microscopy, and tensile tests. The results indicated that the martensite morphology exhibited less variation when the DP steel was overaged at 250–350°C. However, when the DP steel was overaged at 400°C, numerous non-martensite and carbide particles formed and yield-point elongation was observed in the tensile curve. When the overaging temperature was increased from 250 to 400°C, the yield strength increased from 272 to 317 MPa, the tensile strength decreased from 643 to 574 MPa, and the elongation increased from 27.8% to 30.6%. Furthermore, with an increase in overaging temperature from 250 to 400°C, the BH2 value initially increases and then decreases. The maximum BH2 value of 83 MPa was observed for the specimen overaged at 350°C.     

试论点支式玻璃幕墙系统施工技术及质量控制

笔者结合工程实例,分析了点支式玻璃幕墙系统设计与施工技术,并对点支式玻璃幕墙系统施工过程中的质量控制要点进行了阐述及总结。     

框架网络研究综观

Fillmore等学者创建的框架网络不仅给句法研究带来新研究思路,而且在自然语言处理方面也显示出了它的巨大潜力.文章首先介绍了框架网络的缘起、工作原理、优点及影响,之后重点讨论框架网络在句法研究上存在的问题,如义项的归属、框架之间关系的确定、语料标注、核心元素的省略处理等方面,并进一步指出这些问题可以从理论和语料标注两方面作出改进.     

Nb微合金化冷轧双相钢DP980的试制研究

采用C-Si-Mn-Cr-Nb合金系,采取两种热轧、退火工艺,在实验室试制Nb微合金化冷轧双相钢DP980. 结果表明,两种试制钢的抗拉强度分别为1 034 MPa和1 048 MPa,屈服强度分别为534 MPa和499 MPa,伸长率分别为11.2%和11.3%,n值分别为0.28和0.27,屈强比分别为0.52和0.48;试制钢的热轧组织为F+P,连续退火后的组织为F+M,退火后的应力应变曲线表现出连续屈服的特点.     

基于神经网络的装备维修保障系统研究与应用

随着计算机应用技术的发展,神经网络及以数据库技术和数据库管理系统为基础的数据挖掘技术广泛地应用在现代高科技领域中,成为处理以信息化为主体的装备维修保障系统中大量信息的主要技术手段.文章通过对神经网络的概念、过程以及装备维修保障系统中涉及的数据挖掘方法及系统的实现对上述问题进行了论述.