菱形式风电运维生活平台锚泊系统设计研究

海洋平台需要通过锚泊系统长期锚泊于使用固定地点,来削弱外部环境载荷的作用。针对菱形式风电运维生活平台特点及黄海海域特定的海洋环境,根据设计要求,对菱形平台锚泊系统选型,分析环境载荷,提出四种系泊布置方案,给出四种系泊布置方案导缆孔位置坐标,运用静力分析的方法确定锚泊参数,得出四种方案锚固点位置,初步确定两种锚泊系统方案,对初定的两种方案锚泊线张力进行研究,最后统计分析校核锚泊线张力以得到最终的锚泊方案。并提出锚泊系统设计进一步的优化方法,为今后相关平台锚泊系统的设计提供理论依据。     

The role of chemical signals in copepod reproduction

Because the reproductive fitness of a copepod is influenced by its ability to discriminate between conspecific and heterospecific mates, it is important to understand the mechanisms involved in these complex mate-recognition systems. Several lines of evidence suggest that chemical communication plays a role in mate location, recognition and reproduction in copepods. However, the relative importance of chemosensory cues, as well as other factors, including hydromechanical and morphological cues, remains unclear. Some studies show that mating ‘mistakes' occasionally occur in nature, which for species that mate only once, would have considerable effects on fitness. By reducing the likelihood of heterospecific matings, species-specific mate location and recognition chemicals have high adaptive value. The relative importance and molecular characteristics of these chemicals, whether diffusible or contact signals, may explain differences in premating and copulatory behavior observed among different copepod taxa. Current research suggests that both forms of chemical communication significantly influence the reproductive success of copepods. In this review, we summarize examples from the literature that may serve as a means to critically analyze postulated ideas and offer new questions for future study.     

利用加速度计实现管道缺陷定位的研究

介绍了一种利用高分辩率加速度计实现管道缺陷定位的方法,通过加速度值对时间进行二次积分运算并进行适当的误差修正,可以得到智能清管器行走的精确距离,依据时标与距离的线性关系,达到较高的缺陷定位精度.室内实验研究表明,定位精度可以达到定标长度的0.2%.     

沥青拌和楼燃烧系统火焰调整

介绍了玛连尼MAP系列沥青拌和楼燃烧系统火焰好坏的判断依据及成因,针对着火点位置、鼓风量、引风量、风油比、雾化质量5个方面的调整方法进行分析,最终达到良好的燃烧效果。     

基于法线偏差的旧路平面线形拟合精度评估方法

在论述拟合法线偏差定义、构成及性质的基础上,提出以拟合法线偏差表征旧路平面线形拟合偏差;建立了基于法线偏差的旧路平面线形拟合精度指标;提出了采用步长压缩摆动趋近法计算拟合法线偏差的算法,并就拟合法线偏差的符号判定准则及方法进行了讨论。最后对321国道某路段旧路改造设计中的平面线形拟合精度进行评估。结果表明:按照外业、内业2个阶段,采用拟合精度指标控制旧路平面线形拟合质量是可行的。     

汽车侧围外板回弹补偿及尺寸精度控制

为提高汽车侧围外板成形质量及其尺寸精度,以某车型侧围外板为研究对象,通过冲压工艺稳健性分析,在前期准确模拟评估回弹量,以保证CAE分析结果的可靠性和稳定性;采用优化后的补偿策略进行全工序回弹补偿,有效控制汽车侧围外板回弹;最终通过实际生产验证了尺寸精度控制方法的有效性,提高制件成形质量和尺寸精度,减少了后期因回弹造成的模具调试工作量,缩短开发周期。     

跨声速射流冲击对挡板作用特性的模拟分析

为了得到跨声速理想膨胀射流冲击对于挡板的压力、驻点位置等规律,对射流角度为45°,60°和90°,射流距离与喷口直径比H/D为4,6,8的模型进行了数值模拟．结果表明：当H/D从4增加到8时,作用力增加约10％,改变的幅度较小;当射流角度从45°增加到90°时,作用力提高大约40％,作用力大小跟射流角度关系较大．射流角度从45°增加到90°时,驻点距离射流中心由0.07～0.10 m减小到0;射流距离变化对驻点的距离影响很小,变化幅度在10％左右．     

Extending the Scope of Highway Planning: Accessibility,Negative Externalities and the Residential Context

The objectives of this review-based paper were twofold. Firstly, we aimed to explore the need and possibilities for broadening the scope of highway planning by taking account of the residential context, including residential satisfaction. Satisfaction appears to be an interesting, and in our opinion, valuable mediating planning concept between road infrastructure planning and the accompanying external effects on the one hand and household coping strategies on the other. Households living near highway infrastructure are influenced by both positive (i.e. accessibility gains) and negative road-related factors (e.g. noise nuisance and air pollution). Changes in these factors may trigger people to accept the new situation, adjust preferences, try to influence plans and/or even relocate. The second aim was to gain a greater understanding of the influence of both accessibility characteristics and negative externalities on the residential context of households. With respect to context, we make a distinction between residential satisfaction, housing prices and residential relocation. We see changes in residential satisfaction as a potential early predictor of opposition to plans, not only from active opposers but also from the more ‘silent majority’, and as a predictor of housing price changes and residential migration. Insights into residential satisfaction around highways may help transportation planners to relieve locational stress and may also prevent protests and relocations. Our literature review indicated that households prefer to live close to highways to benefit from high regional accessibility, but do not want to contend with the nuisances. This is also reflected in property values. However, the literature appears to put more emphasis on studying the impact of (regional) accessibility and externalities on location behaviour than on residential satisfaction. Because of the added value that the concept of residential satisfaction may provide in road planning, and the limited scientific insights, it is important to gain greater insight into how residential satisfaction is influenced by negative and positive externalities and into how residential satisfaction changes over time—from the stage when new road projects are discussed through to concrete planning, realization and the period after completion. Moreover, it would be worthwhile to gain a deeper understanding of the extent to which house prices, location behaviour and residential satisfaction near highways interrelate.     

新疆盐渍土易溶盐试验的准确性控制探讨

通过现有的研究资料详细论述了碳酸根离子、碳酸氢根离子、氯离子、硫酸根离子、钙镁离子合量、纳离子和钾离子等的测定过程,并阐述测定过程中应注意的一些问题,以期能够对施工单位提供一些经验借鉴。     

Estimating arterial link speed using conventional road detectors

Abstract

In response to an initiative to develop an advanced traffic information system in Bangkok, this paper explores practical guidelines for the optimal location of road sensors, such that the data collected on spot speeds reflect an entire link's average speed. In particular, the authors use microsimulation software to investigate optimal detector locations, using the sum of squared errors and root mean squared errors. The analysis hypothesizes that road segments are 0.4, 0.6, 0.8, 1.0, 2.0 and 3.0 km in length and are specially designed to replicate typical arterial streets in Bangkok. The results show that a single detector location can produce good estimates of link speed only for segments that are shorter than 1.0 km. For distances of 1.0 km or more, the results suggest that two detectors be used for good link speed estimates under all traffic conditions.