南北地震带强震复发间隔的估计   总被引：1，自引：0，他引：1  

任雪梅  赵卫明  柴炽章  刘秀景 《内陆地震》2002,16(1):69-75

通过对南北地震带各主要断裂带历史强震的时空特点研究 ,试图寻找出带内各主要构造带强震的复发和填充特征 ,并在此基础上研究其差异性 ,对未来各带发生强震的危险性作出估计  相似文献   

中国地图藏南地名的表示   总被引：2，自引：1，他引：1  

郝晓光  廖小韵  王阳  李奇楠  索朗仁青 《测绘科学》2017,42(5)

该文针对1958年之后,中国地图上西藏南部有一片地区只标志寥寥无几地名的历史状况,以中国地图上藏南地区编制方法的历史状况为纽带,搜索相关历史事实,重现1958年针对藏南地区地图问题引发的两国交流,认清地图对于国家领土主权确认的重要性,推动标注藏南地区地名标注工作的进行。  相似文献   

一种基于Voronoi图的人防警报器空间选址算法     

王峰  王惠  赵耀强  夏飞 《测绘软科学研究》2012,(2):81-84

首先通过声学传播原理研究了警报器覆盖范嗣模型。结合Voronoi图影像范围、最大空心圆策略和平面完全刮分等特性,提出了基于Voronoi图的警报器空间选址算法。文章详细阐述了算法基本思想和流程,最后进行了算法组件设计和系统开发实践。实践表明采用该算法能满足城市警报器合理选址和适当重叠覆盖的要求,并具有其优越性。  相似文献   

一种基于Voronoi图的人防警报器空间选址算法     

王峰  王惠  赵耀强  夏飞 《地理信息世界》2012,10(2):81-84

首先通过声学传播原理研究了警报器覆盖范围模型,结合Voronoi图影像范围、最大空心圆策略和平面完全剖分等特性,提出了基于Voronoi图的警报器空间选址算法。文章详细阐述了算法基本思想和流程,最后进行了算法组件设计和系统开发实践。实践表明采用该算法能满足城市警报器合理选址和适当重叠覆盖的要求,并具有其优越性。  相似文献   

A protocol for preparing subfossil chironomid head capsules (Diptera: Chironomidae) for stable isotope analysis in paleoclimate reconstruction and considerations of contamination sources     

Y. Wang  D. R. Francis  D. M. O’Brien  M. J. Wooller 《Journal of Paleolimnology》2008,40(3):771-781

Several techniques are available to examine the isotopic composition of historic lake waters, providing data that can subsequently be used to examine environmental changes. A recently-developed technique is the stable oxygen isotope analysis of subfossil chironomid (Diptera: Chironomidae) head capsules (mostly chitin) preserved in lake sediments. This technique involves a high Temperature Conversion Elemental Analyzer (TC/EA), which has been a relatively recent addition to the suite of online peripherals for analyzing the stable isotopic composition of organic samples. The highly precise and accurate ¹⁸O/¹⁶O and D/H measurements obtainable using the TC/EA with samples in the microgram range make this instrumentation suitable for studying geochemical and biological processes. Preparation of organic samples for isotopic analysis typically requires first weighing each sample into silver/tin capsules. These capsules can introduce oxygen and hydrogen contamination (a “blank effect”), which is especially problematic for analysis of small organic samples (e.g. less than 100 μg). Here we tested tin and silver capsules from two manufacturers and a range of sizes to assess contamination to small organic samples on the TC/EA. We also assessed how a method for cleaning silver capsules affected our analysis of commercial chitin. In general, capsules made of silver have less detectible oxygen than those made of tin, and capsules from the two manufacturers varied in their detectible oxygen. There was no detectable H contamination from silver capsules. In addition to our empirical findings, we present a model demonstrating the influence that contaminant oxygen can have on the δ¹⁸O of small organic samples. Sample mass becomes an important issue for such analyses. In light of our findings, we recommend a minimum sample mass ≥50 μg (approximately 120 whole chironomid head capsules) on a TC/EA-IRMS (Delta^plus XP system). Finally, we present a detailed protocol for preparing and transferring chironomid head capsules into silver capsules that minimizes the influence of contaminant oxygen. This protocol provides the paleo-community with another potential method for reconstructing paleoenvironments.  相似文献