风沙活动区工程线路走向与风沙危害程度的关系--以塔里木沙漠公路为例

在风沙活动区,公路或铁路等工程线路的走向无疑会对其本身及防护体系所受的风沙危害程度产生影响。本文以塔里木沙漠公路为例,提出在将风况与公路走向结合起来考虑的同时,以风沙活动强度垂直分量的转化率作为评价公路走向的一种数学方法,并用该方法对沙漠公路不同路段走向进行评价与说明。     

Use of species-specific PCR for the identification of 10 sea cucumber species

We developed a species-specific PCR method to identify species among dehydrated products of 10 sea cucumber species. Ten reverse species-specific primers designed from the 16S rRNA gene, in combination with one forward universal primer, generated PCR fragments of ca. 270 bp length for each species. The specificity of the PCR assay was tested with DNA of samples of 21 sea cucumber species. Amplification was observed in specific species only. The species-specific PCR method we developed was successfully applied to authenticate species of commercial products of dehydrated sea cucumber, and was proven to be a useful, rapid, and low-cost technique to identify the origin of the sea cucumber product.     

Excel在单一线法定线中的应用

应用Excel强大的绘图和函数功能,处理水文资料整编中单一线法图形的绘制和水位～流量关系曲线的拟合,具有很多优势:可以减少整编定线中因徒手绘制而导致的任意性,减小整编的工作量,提高工作效率和整编精度;并且拟合后的曲线用函数表达更便于计算机处理。以河边水文站2009年实测流量资料为例,说明Excel在单一线法整编定线中的应用。     

Braking index diagnostics of pulsars. I. alignment,Counteralignment and slowing-down noise

We show that the strong correlation observed between the braking indices (n) and the slowing-down ages (Τ) of pulsars is inconsistent with counteralignment between their rotation and magnetic axes, but that the data on pulsars with positive braking indices is consistent with alignment. Alternatively, slowing-down noise can quantitatively account for the data on all pulsars except the Crab and the Vela, and so for the apparent|n| ∼ Τ² correlation observed for the older pulsars.     

清河曲线斜拉桥施工测量控制技术研究

依据设计要求与工程特点,开展曲线斜拉桥施工测量控制网、施工测量技术、施工测量最佳时段的研究。研究与施工测量实际相结合,保证了清河曲线斜拉桥安全施工。     

SA综合测量软件在兰州重离子加速器准直测量中的应用

本文介绍了SA图形化测量平台软件在加速器准直方面的应用.目前兰州重离子加速器冷却储存环采用SA软件协作下的激光跟踪仪测量三维控制网,快速地完成了设备的标定、准直安装、监测等准直测量任务,最终安装误差达到0.135mm.     

3维激光扫描技术在地铁调线调坡测量中的应用

主要对3维激光扫描技术应用于地铁调线调坡的关键技术进行了研究,探讨了基于此技术的点云数据获取的流程和断面数据提取的方法。以天津地铁三号线的一段区间调线调坡测量为例,同时使用3维激光扫描技术和传统技术进行调线调坡测量,并对实测数据进行了对比。结果表明,3维激光扫描技术应用于地铁调线调坡测量方法具有作业效率高、可靠性大、实用性强等特点,可以应用于地铁调线调坡测量。     

黄茅海内治导线对潮汐要素影响的试验研究

通过物理模型试验 ,研究了黄茅海内不同治导线对潮汐要素的影响 ,得出治导线对河口湾内的潮位变化随着上游径流量的增加而逐渐减弱的结论。中水大潮时 ,湾顶与湾腰处高潮位降低 ,低潮位抬高 ,其幅度与治导线进占的海域面积成正比。洪水大潮时 ,高潮位一般也降低。低潮位则有时降低 ,有时有所抬高。河口湾治导线实施后 ,涨潮最大流速、平均流速和落潮平均流速均有所减小 ,但落潮最大流速不减反增。涨、落潮潮量有不同程度的减少 ,其减幅与治导线的进占规模成正比。各站的高、低潮位发生时间都有前移趋势 ,治导线越往外推 ,潮时前移量就越大。本文对这些现象的成因进行了分析 ,并就潮位、潮流速及潮流量的变化对防洪水位和交通航运水深的影响作了阐述。     

A metaheuristic approach for efficient and effective sketch-to-metric map alignment

Sketching as a natural mode for human communication and creative processes presents opportunities for improving human–computer interaction in geospatial information systems. However, to use a sketch map as user input, it must be localized within the underlying spatial data set of the information system, the base metric map. This can be achieved by a matching process called qualitative map alignment in which qualitative spatial representations of the two input maps are used to establish correspondences between each sketched object and one or more objects in the metric map. The challenge is that, to the best of our knowledge, no method for matching qualitative spatial representations suggested so far is applicable in realistic scenarios due to excessively long runtimes, incorrect algorithm design or the inability to use more than one spatial aspect at a time. We address these challenges with a metaheuristic algorithm which uses novel data structures to match qualitative spatial representations of a pair of maps. We present the design, data structures and performance evaluation of the algorithm using real-world sketch and metric maps as well as on synthetic data. Our algorithm is novel in two main aspects. Firstly, it employs a novel system of matrices known as local compatibility matrices, which facilitate the computation of estimates for the future size of a partial alignment and allow several types of constraints to be used at the same time. Secondly, the heuristic it computes has a higher accuracy than the state-of-the-art heuristic for this task, yet requires less computation. Our algorithm is also a general method for matching labelled graphs, a special case of which is the one involving complete graphs whose edges are labelled with spatial relations. The results of our evaluation demonstrate practical runtime performance and high solution quality.     

惯性系统/激光测距仪组合定位技术研究

本文针对捷联惯性系统定位精度随误差积累而降低的情况,提出了一种基于惯性系统和激光测距仪的组合定位技术,并加以调平转位机构辅之。主要研究了捷联惯导系统静基座初始对准,分析了初始对准的精度,推导了激光测距仪载体坐标系到导航坐标系的坐标转换关系。最后,通过仿真和实施相关实验验证该定位技术。结果表明,此方法的测量误差较为稳定,误差大小在允许范围内,定位精度较高,具有一定的可行性。