Measurements of 460 GHz Atmospheric Opacity at Yangbajing Observational Station†     

Zhou Ming-feng  Yao Qi-junLi Sheng  Luo Zhi-quanYang Ji 《Chinese Astronomy and Astrophysics》2011,35(3):327

In order to assess the submillimeter wave observational conditions of Yangbajin, a Portable Submillimeter Telescope (POST) is used to measure the zenith atmospheric opacity at 460 GHz from November 2008 to December 2008. The results show that the quartiles of atmospheric opacity during the observing time at 460 GHz at Yangbajin Observatory is 1.25, 1.42 and 1.63, and the time proportion of atmospheric opacity less than 1 is about 3.4%. At last, the submillimeter wave site conditions of Yangbajin with those of other submillimeter observatories in the world are compared, and the possible causes that may influence the submillimeter atmospheric opacity are explored.  相似文献   

Grubbs revisited: a statistical technique to differentiate measurement methods of the degree of exposure of raingauges in a network     

《水文科学杂志》2013,58(6):891-897

Abstract

Precipitation measurement by raingauges is biased by the systematic error resulting from deformation of the local wind field due to the presence of the gauge itself. To correct for this error, it is necessary to know the degree of site exposure. Four measurement methods are dealt with to determine site exposure. It is shown how statistical techniques developed by Grubbs can be used to select the most precise measurement method.  相似文献   

喀什场地土剪切波速与土层深度经验关系          下载免费PDF全文

李帅  赵纯青  葛鸣 《地震工程学报》2013,35(3):702-708

在喀什市城区地震小区划工作的基础上,通过对喀什城区地貌单元划分,描述了不同地貌单元内的地层岩性,将实测剪切波速钻孔资料统计分析,运用较为常用的三种统计回归分析方法给出喀什市城区不同地貌单元不同土类剪切波速与土层深度的经验关系。结果可为喀什市城区防震减灾规划土层地震反应分析提供依据。  相似文献   

岷县漳县6.6级地震黄土场地放大效应地脉动测试研究          下载免费PDF全文

严武建  吴志坚  车爱兰  钟鹏飞  陈豫津 《地震工程学报》2013,35(3):477-482

2013年7月22日甘肃岷县漳县MS6.6级地震在极震区出现了黄土场地放大效应,为了从理论上解释黄土场地放大效应的原理,本文利用地脉动测试了极震区2个典型的黄土场地进行研究。结果发现:在黄土覆盖地区场地卓越频率特征显著,即在同一区域内山顶卓越频率较低,集中在1～2Hz,山沟卓越频率较高,集中在3～6Hz;同时,黄土场地随着高程的增加表现为厚黄土分布特征,其场地卓越频率在1.3～1.8Hz,与地震观测波的卓越频率1.0Hz接近,呈现出较明显的场地放大效应。结果与实际受灾情况相符。  相似文献   

基于能量耗散的重力坝地震响应时频特征分析     

张社荣  王超  孙博 《地震工程与工程振动》2013,33(4)

为了从能量角度研究重力坝地震响应的时频特征,在重力坝非线性动力分析基础上,探讨了重力坝地震过程中振动能量的时域耗散机制;采用小波频域多层次分解技术研究了其动响应的分频段能量特征,得到了坝体典型位置动响应分频段振动能量随高程的变化规律.通过分析发现:结构地震能量耗散为时域上不可逆的增加,坝体损伤集中出现在地震过程的某个时间段,地震动峰值后坝体损伤状态基本稳定;小波分解可以较全面地描述结构动响应能量的分频段特征.对于本文算例,在坝踵和上游折坡附近,重力坝地震响应的振动能量以4～8 Hz频段为主,这与输入的地震信号分频段特征一致;而坝顶附近则以1 ～4 Hz的振动能量为主,高频能量分量的比重随高程增大而逐渐减小.  相似文献   

山东数字地震台站场地响应估算   总被引：1，自引：0，他引：1  

蔡寅  林秀娜  穆娟  曲保安 《地震地磁观测与研究》2013,(5):98-103

为了建立山东省数字地震台站场地响应数据库,选取山东区域数字地震台网自2009年4月至2012年1月记录的ML≥2.5地震事件,通过信噪比方法挑选出质量较高的86次地震,采用互相衔接的三段几何衰减模型,基于遗传算法,利用Moya等方法对山东省36个地震台站进行场地响应测算.其中35个台站未显示明显的放大作用,聊城台场地响应变化起伏较大,高频部分放大明显,烟台、招远、即墨、五连、菏泽台场地响应总体表现出一定衰减作用.  相似文献   

The retail site location decision process using GIS and the analytical hierarchy process     

《Applied geography (Sevenoaks, England)》2013

The opening of a new establishment is a critical factor for firms in the retail sector because the decision carries with it a series of very serious financial and corporate image risks. This paper presents the development of a methodology for the process of selecting a retail site location that combines geographic information systems (GIS) and the analytical hierarchy process (AHP). The AHP methodology shows that the success factors for a supermarket are related to its location and competition. The proposed retail site location decision process was applied to the opening of a new supermarket in the Spanish city of Murcia.  相似文献   

A grid-based collaborative virtual geographic environment for the planning of silt dam systems     

Lin Hui  Gong Jianhua  Xu Bingli  Qi Hua 《International journal of geographical information science》2013,27(4):607-621

To improve the efficiency of planning and designing silt dam systems, this article employs theories and technologies of collaboration and distributed virtual geographic environments (VGEs) to construct a collaborative virtual geographic environment (CVGE) system. The CVGE system provides geographically distributed users with a shared virtual space and a collaborative platform to implement collaborative planning. Many difficulties have been found in integrating data resources and model procedures for the planning of silt dam systems because of their diversity in heterogeneous environments. Unlike most of the current distributed system applications, the proposed CVGE system not only supports multi-platform and multi-program-language interoperability in the dynamically changing network environment, but also shares programs, data and software in the collaborative environment. Based on creating a shared 3D space by virtual reality technology, agent and grid technologies were tightly coupled to develop the CVGE system. A grid-based multi-agent system service framework was designed to implement this new paradigm for the CVGE system, which efficiently integrates and shares geographically distributed resources as well as having the ability to build modelling procedures on different platforms. At the same time, mobile agent computing services were implemented to reduce the network load, process parallel tasks, enhance communication efficiency and adapt dynamically to the changing network environment. Using Java, JMF (Java Media Framework API), Globus Toolkits (GT) core, Voyager, C++, and the OpenGL development package, a prototype system was developed to support silt dam systems planning in the case study area, the Jiu-Yuan-Gou watershed of the Loess Plateau, China. Compared with the traditional workflow, the CVGE system can reduce the workload by between one third and a half.  相似文献   

A Review of “Business Site Selection,Location Analysis and GIS”     

Grant Ian Thrall 《The Professional geographer》2013,65(3):446-447

This study seeks to examine the relationship between childhood exposure to air pollution and long-term respiratory health and to identify significant predictors of respiratory health in adulthood. Logistic regression modeling was undertaken using health and exposure data for 395 participants who resided during childhood in four distinct neighborhoods in Hamilton, Ontario, Canada. Significant predictors include exposure to SO₂ in childhood, location of residence in childhood, sex, residential and occupational histories, stressful life events, and respiratory health in childhood. This study suggests that the health impacts of childhood exposure to air pollution are located beyond the short-term period that most research addresses.  相似文献   

格栅坝（桩林）混凝土施工质量及温度控制          下载免费PDF全文

白革学  盛宏文  林广乾  杨维信 《甘肃地质》2012,(4):73-76

结合舟曲县罗家峪沟泥石流灾害治理工程格栅坝钢筋混凝土施工实例,介绍在受限条件下大体积混凝土在施工中采用质量控制技术措施及控制温度裂缝,为类似格栅坝混凝土施工提供借鉴。  相似文献