运行管道在线焊接工艺研究之评述

介绍了运行管道的国内外维护焊接技术的现状及研究状况，着重京维护焊接过程中的有关问题进行了评述，指出目前世界各国在运行管道维护焊接工艺研究及应用上各有千秋，水平浊一。了解现代管线维护焊接的最新工艺及发展趋势对我国管线业的发展具有积极意义。     

光纤通信系统在输油管道工程中的设计与应用

靖—惠输油管道工程沿线山峰起伏,沟壑纵横,约有30km的无人区,冬春两季多沙尘暴,故该线路对通信系统的实时性和误码率要求很高。通过对卫星通信和光纤通信的经济技术指标对比,并考虑管道沿线通信发展的趋势,选用了光纤通信方案。文章介绍了靖—惠输油管道工程通信系统设计方案,讨论了该通信系统的经济合理性、先进性与实用性,并介绍了该通信系统投入运行后的技术特点。     

An algorithm for computing the distance to uncontrollability

In this paper, we present an algorithm to compute the distance to uncontrollability. The problem of computing the distance is an optimization problem of minimizing σ(x,y) over the complete plane. This new approach is based on finding zero points of grad σ(x,y ). We obtain the explicit expression of the derivative matrix of grad σ(x,y). The Newton's method and the bisection method are applied to approach these zero points. Numerical results show that these methods work well.     

应用圆柱螺线法计算邻井最近距离点的新算法

在邻井井段曲线类型为圆柱螺线时,通过数学变换,将邻井间最近距离点的约束方程转化为一个形式更简单的约束方程;使用二分法,得到了一个计算量最小且收敛性好的新的迭代算法。新算法可应用于钻井轨道设计、井眼轨迹监控等实际问题中。     

Perceptions of academic quality among students with a hearing loss in distance education.

There has been little research on the experiences of students with a hearing loss in mainstream higher education. This investigation compared perceptions of academic quality in 265 students with a hearing loss who were taking courses by distance learning and 178 students taking the same courses who had no declared form of disability. Students who were classified as hard of hearing (rather than deaf) produced significantly lower ratings of the appropriateness of their academic workload than did the students with no declared disability, but the ratings produced by students who were classified as deaf were not significantly different from those produced by the comparison group, In other respects, the students with a hearing loss were remarkably similar to the students with no declared disability in their perceptions of academic quality and their overall satisfaction with their courses, (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Bundle adjustment of multi-position measurements using the Mahalanobis distance

Precision three-dimensional metrology frequently involves the measurement of common points by several three-dimensional measurement systems. These can be laser tracking interferometers, electronic theodolites, etc. A new analysis technique has been developed that fully takes into account the uncertainty ellipsoid for each measurement point. This technique solves for the positions and orientations of the measurement systems while determining the optimal fit to each physical point. No a priori knowledge of the location and orientation of the measurement systems is required. An initial estimate for the location and orientation of the measurement systems is derived from the measurement data by assuming equal uncertainties for each data point. Then a merit function is minimized to determine the optimized location and orientation of the measurement systems and the weighted mean for the position estimates of the physical points. This merit function is based on the Mahalanobis distance from multivariate statistics and takes into account the particular shape and orientation of the three-dimensional uncertainty ellipsoid of each data point from each measurement system. This technique can utilize data from differing types of three-dimensional measurement systems including distance only and angle only measurements, evaluate the “strength” of a measurement configuration and accommodate missing data points from some of the measurement systems.     

超距离声波透射法在大直径桩无损检测中的应用

在分析声波检测技术应用现状和局限性问题的基础上,使用不同频率换能器和设置不同的仪器工作参数的试验,解决声测管(钻孔)超距离2 000 mm以上结构体声波检测的应用问题,并验证此情况下缺陷分析判别的准确性。实现超距离声波透射检测,将进一步拓展该检测方法的应用领域,增强其实用性并提高其技术水平,为工程施工提供可靠的质量监控评价依据,具有重要的现实意义。     

灰土挤密桩适用桩间距的工程分析

结合铜川地区的地基处理实践,在保证相同技术效果的条件下,考虑经济效益、施工难易等因素,给出了不同类别湿陷性黄土的灰土挤密桩适用桩间距的推荐值,为类似地区湿陷性黄土的处理提供了参考依据和技术支持。     

对规范中机械送风进风口位置某条文的修改建议

对GB 50019-2003《采暖通风与空气调节设计规范》第5.3.4条第3款进行了分析,提出当机械送风系统进风口风速降至1 m/s以下时,其下缘与室外地坪的距离可小于1 m.建议将此款修改为:进风口的下缘距室外地坪不宜小于2 m,当设在绿化地带时,不宜小于1 m;当进风口风速低于1 m/s时,可不受此限.以某商业建筑为例,根据修改后的条文进行了设计.     

Assessing disharmony and disaffection in intimate relationships: Revision of the Marital Satisfaction Inventory factor scales.

Previous research has identified 2 broad components of distress in intimate relationships: overt conflict, or disharmony, and emotional distance, or disaffection. Using confirmatory factor analysis, the authors derived 2 broadband scales of disharmony and disaffection from the Marital Satisfaction Inventory-Revised (D. K. Snyder, 1997), building upon previous measures of these constructs (D. K. Snyder & Regts, 1982) derived from the original instrument. The new scales demonstrated high internal consistency and test-retest reliability, as well as discriminative validity and convergent validity with independent criteria of relationship functioning. Distinct distributions of these scales in community and clinical samples suggested their complementary role in research on intimate relationships and assessment of couples in treatment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)