双级套管螺纹连接有限元分析

应用ANSYS对双级套管螺纹连接进行性能仿真，建立双级套管螺纹有限元模型，利用接触分析模块，分析螺纹各扣牙受力情况，最后总结了双级套管螺纹连接受力分布规律，并与普通套管螺纹接头作了比较，结果显示双级套管螺纹接头各扣牙受力分布要比普通套管螺纹均匀。研究结果提高了对双级套管接头应力水平的认识，对改进套管连接螺纹设计，提高套管接头的连接质量，促进特殊套管螺纹接头的发展具有一定的参考价值。     

油管螺纹图像处理方法研究

油管螺纹图像主要用于对螺纹形貌的观察和测量。对螺纹图像采用了低通滤波、对比度变换、高通滤波等处理方法,有效地改善了图像的质量。用于尺寸测量的螺纹牙型图像根据其直方图的特征,首先采用灰度阈值分割法分离牙型轮廓,生成二值图像,然后利用跨度最小的Roberts算子提取二值图中螺纹轮廓线,得到的轮廓边缘细致、准确,可以用于尺寸测量。     

基于红外成像的埋地热油管道定位方法

对埋地输油管道进行了传热分析,建立了埋地输油管道三维物理模型。通过简化物理模型,建立了埋地输油管道三维数学模型,并通过CFD软件进行了模拟计算。输油管道热影响区域在地面红外成像分布比较明显,输油管道在地面投影区域温度明显偏高。进行了红外成像管道定位实验测试,由于土壤热物性不同,在输油管道地面热影响区域温度场分布并不非常均匀。模拟计算和实验研究表明:输油管道热影响区域在地面模拟红外成像分布情况和实际情况吻合。     

X射线数字成像技术在长输管道中的应用

针对目前长输管道X射线胶片成像技术劳动强度大、效率低、成本高的缺点,开展了X射线数字成像技术的研究,通过研究以及现场试验确定了该技术在长输管道中应用的可行性。文中通过对该技术原理、现行标准以及现场工程实践应用的分析,表明X射线数字成像技术在长输管道环焊缝检测中结果直观、效率高、成本低。     

埋地蒸汽管道保温失效传热的数值计算

文中对埋地蒸汽管道进行了传热分析,建立了埋地蒸汽管道三维温度场物理模型。通过简化物理模型建立了大地温度场的三维数学模型,利用CFD计算软件进行了温度场模拟计算并进行了客观地分析,分析的结果对红外成像检测埋地蒸汽管道保温失效具有指导意义。     

高压输送管道中高固多相黏稠物料流动显示方法

在分析输送管道中高固多相黏稠物料流动测量特点和难点的基础上,结合现阶段数字式射线辐射成像的性能和特点,提出了适合于高压输送管道中高固多相黏稠物料流动显示的具体方案———射线实时数字成像系统,并由射线成像系统的性能指标论证了射线成像系统方案的可行性。     

管道环焊缝数字射线检测技术研究

在管道环焊缝检测技术领域,X射线检测技术和超声检测技术并存可以取长补短。随着数字化X射线成像技术的推广应用,管道环焊缝X射线检测正向数字射线技术方向发展。由于射线探测器的图像质量和包含的信息远远超过普通胶片成像,数字射线技术代表了管道环焊缝检测的发展方向。管道科学研究院通过对面阵探测器成像技术的研究,开发出了管道环焊缝数字射线成像设备,实现了管道环焊缝射线检测的实时显示和电子存储。     

可膨胀套管螺纹连接上扣状态仿真分析

膨胀套管多为直连型螺纹连接,套管螺纹的膨胀性能仿真分析对膨胀管的现场应用具有较大的指导意义,而套管螺纹连接上扣状态的仿真是螺纹连接膨胀性能仿真的前提。文中用螺纹三维实体模型得到轴向与径向过盈量的关系,用过盈量来模拟上扣扭矩,并用此种方法得出了Φ146×8套管API偏梯形锥螺纹（锥度为1∶24）上扣过程中轴向过盈量与径向过盈量的关系为δl/δr=1/17.8,并通过对上扣扭矩的等效处理得出了此种型号螺纹连接的最佳上扣扭矩为2 207.9～2 750.6 N.m.     

在用压力管道检测中红外热成像技术的应用

根据红外热成像技术的工作原理,模拟设计了在用压力管道管壁存在局部减薄的缺陷条件下及不同工况条件下应用红外热成像技术进行检测的试验装置,并根据试验中所得到的有关数据,分析了影响检测灵敏度的相关因素.     

近距平行跑道机场平面布局与运行特点分析

采用近距平行跑道构型是大型机场提升容量的重要方式，在近距平行跑道机场占比逐年升高的背景下，首先对我国近距平行跑道机场的跑道间距、入口错开情况和绕行滑行道设置进行了统计，并对比了美国部分近距平行跑道机场平面布局形式；其次依据布局特点对布局形式进行归纳和分类，然后对三种典型的布局形式展开研究；最后根据布局特点和运行模式，分析并提出提升近距平行跑道机场运行效率的策略，为提高近距平行跑道机场地面运行安全水平、提升地面运行效率提供理论支持。     

基于机器视觉的非接触式螺纹参数测量系统

文中采用光机电一体化的思想,将光源、CCD、计算机等有机结合,开发了一种基于面阵CCD技术的石油管螺纹参数智能化测量系统。生产现场测量结果表明：该系统具有重复性好、精度高、检测速度快等优点,此外,此系统具有抗环境光及振动干扰,可操作性强等特点,适用于各种规格钢管外螺纹参数的在线测量。     

数字图像处理技术在隧道围岩收敛量测中应用的初步研究

文章系统地总结了国内外图像处理技术在隧道工程中的应用现状和隧道变形收敛量测的各种方法,并对各种方法的优缺点进行了详细分析;尝试了应用数字图像处理技术对隧道围岩收敛进行量测的新方法(二次比较法);编制了一套隧道图像处理系统(TUNNEL IMAGE PROCESSING SYSTEM,简称TIPS)。室内试验证明,本系统对距离的量测结果是可靠的,灵敏度和精度达到了相关要求。本研究成果可供有关人员在现场实用研究中参考。     

Development of an integrated system based vehicle tracking algorithm with shadow removal and occlusion handling methods

Video image processing system (VIPS) is more efficient than other detecting systems. However, VIPS involves outdoor images and is very sensitive to the external environment, which could greatly decrease its accuracy according to rapid environmental changes. To obtain accurate traffic data accordingly, VIPS must address the problems such as growing shadows in transition; distortion of images due to the headlights at night; noises caused by the rain, snow or fog; and occlusions. This study intends to accurately calculate traffic data while addressing the shadow and occlusion problems, which are the most difficult tasks for the image‐detector‐based traffic data system. In this study, an algorithm for the individual vehicle tracking collection was developed to address the occlusion problem and to eliminate the noises or shadows caused by external environmental factors. A traffic data collection system was also proposed in order to accurately track individual vehicles that pass through the detection region. In addition, establishing an integrated system with shadow removal and occlusion handling using an image processing was also proposed. Copyright © 2010 John Wiley & Sons, Ltd.     

剥肋滚压直螺纹套筒钢筋机械现场质量控制方法

文章介绍剥肋滚压直螺纹套筒钢筋机械连接技术,通过实验发现引起钢筋机械接头不合规范的四种因素,并提出通过检验每个套筒尺寸、控制每个钢筋丝头尺寸、检验拧紧力矩、成品检验的四因素检验控制方法来保障该技术现场施工质量。     

Is the intention to use public transport for different travel purposes determined by different factors?

The objective of this study was to examine the psychological predictors of the intention to use public transport for three travel purposes: work or study, shopping, and leisure. An expanded version of the theory of planned behaviour (TPB) which contains overall image and past behaviour is used. Data were gathered through the survey of 392 residents living in the central parts of Kuala Lumpur in Malaysia. These data were analysed using the partial least squares technique. The results indicate that attitude and perceived behavioural control are significant predictors of the intention to use public transportation for various purposes. Further, they explain between 34.6% and 49.8% of the intention variance. By adding the overall image and past behaviour to the original predictors in the TPB, the explained variance, with regard to work or study, shopping, and leisure purposes, increased by 5.6%, 5.1%, and 6.8%, respectively.     

P110长圆螺纹套管粘扣原因分析

某厂生产的规格为Φ139.70 mm×9.17 mm LC P110套管在进行上/卸扣试验过程中发生严重粘扣现象。根据套管螺纹粘扣形貌、螺纹参数、表面处理工艺等,对其粘扣原因进行分析。分析可知,该批套管外螺纹锥度偏大、内螺纹锥度偏小、内外螺纹的紧密距均偏小、螺纹参数配合不当是发生粘扣现象的原因之一;经过上卸扣后,套管内螺纹磷化层大部分脱落,这说明套管磷化层厚度不够,表面处理工艺差。     

基于VB和PC-6319的等温输油管路实验数据采集系统

介绍了以VB为软件开发平台,利用PC-6319的丰富资源,构建等温输油管路实验数据采集系统的方法。详细阐述了利用DLL实现对I/O端口的读写得到测量值,给出了PC-6319各通道A/D值的标度变换通用公式,分析和解决了现场变送器的零点迁移问题,提供了对VB编写的系统软件的调试方法。     

The future mobility of the world population

On average a person spends 1.1 h per day traveling and devotes a predictable fraction of income to travel. We show that these time and money budgets are stable over space and time and can be used for projecting future levels of mobility and transport mode. The fixed travel money budget requires that mobility rises nearly in proportion with income. Covering greater distances within the same fixed travel time budget requires that travelers shift to faster modes of transport. The choice of future transport modes is also constrained by path dependence because transport infrastructures change only slowly. In addition, demand for low-speed public transport is partially determined by urban population densities and land-use characteristics. We present a model that incorporates these constraints, which we use for projecting traffic volume and the share of the major motorized modes of transport—automobiles, buses, trains and high speed transport (mainly aircraft)—for 11 regions and the world through 2050. We project that by 2050 the average world citizen will travel as many kilometers as the average West European in 1990. The average American's mobility will rise by a factor of 2.6 by 2050, to 58,000 km/year. The average Indian travels 6000 km/year by 2050, comparable with West European levels in the early 1970s. Today, world citizens move 23 billion km in total; by 2050 that figure grows to 105 billion.