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191.
抚边河断裂距大渡河干流大型水利工程金川水电站仅35km,因其近期较强的地震活动性成为电站区域稳定性评价的重要考虑因素。研究从地球物理、地震、地质、地貌等方面分析了断层存在的证据和活动性,首次发现断层切割第四系的直接证据。分析了断层活动性对大坝建设的影响。 相似文献
192.
Alternatives to current GPS-RTK services and some implications for CORS infrastructure and operations 总被引:1,自引:1,他引:1
Chris Rizos 《GPS Solutions》2007,11(3):151-158
The justification for the establishment of CORS networks was initially in support of geodesy and other geoscientific applications at the global and regional level. However, increasingly GPS CORS network operators have sought ways of making their network infrastructure the basis of a profitable business. This has arisen with the introduction of real-time centimeter-level accuracy services, carrier phase-based modes of operation generally referred to as GPS-RTK (real-time kinematic). One approach is to try to recruit a core group of users who are prepared to pay for the GPS-RTK services. But this is only feasible if the number of users, and the fees that are charged, are sufficient to generate a reasonable return-on-investment (ROI). This ROI (or at the very least “cost-recovery”) is important for many network operators in order that they may provide for the maintenance and upgrade of the CORS infrastructure. On the other hand, there are those who advocate that there is no need to recoup CORS investment, that the installed GPS receivers should be seen as public infrastructure in a similar manner to roads, bridges, etc. This paper discusses some new business and operational models for GPS-RTK services. These include models for the establishment and operation of CORS infrastructure, service provision, business cases, and options for value-added services beyond the standard GPS-RTK service. One concept is based on a “client–server” model. Currently GPS-RTK service providers have no control over the quality of the results computed by users. This makes it difficult for them to justify charging for their services. What if instead of broadcasting RTK corrections and placing the onus of obtaining a final solution on the user and his equipment, the user’s coordinates are determined by the service provider? Putting the computational effort on the server side will justify more easily the charging of users for a value-added product: an accurate and quality assured coordinate in the local reference frame. This paper describes the client–server concept as well as possible business models that may underpin such a service model. These models include some derived from mobile telephony and service/hospitality businesses. Furthermore, with the projected proliferation of independent, competitive GPS-RTK services, the concept of a GPS data or service “broker” is worth exploring. 相似文献
193.
利用19种不同型号的自动雨量站2005年6—9月在北京 (54511)、宜昌 (57461) 和南京 (58238) 3站的实测对比观测资料, 进行降雨资料质量评估, 不同的评估方法将会导致评估结果的差异。结果表明:采用自动气象站降雨资料和雨量筒人工定时观测记录作为降雨量参考标准对自动雨量站进行评估时, 由于降雨量参考标准本身存在的不确定性, 或多或少影响了评估结果的准确性。在广泛试验的基础上, 提出了采用基于各自动雨量站观测结果的拟合降雨量作为降雨量参考标准的新思路, 并对拟合降雨量的可行性、适用性以及计算方法进行了详细论述。 相似文献
194.
The attenuation factor QP at the top of the inner core is evaluated by using the amplitude spectral ratio of PKPdf and PKPbc phases observed at African
stations (BGCA mostly), from strong deep earthquakes in the Pacific Ocean area. The maximum depth of penetration of the PKPdf
phase into the inner core (IC) is roughly 377 km, and the sampled region of IC is centered beneath the Southern Indian Ocean.
The derived mean value of QP is 249 ± 31 (95% confidence level) in the frequency range 0.2–2 Hz, where no frequency dependence of attenuation has been
reliably observed. By using Student’s t-test, we show that the value is statistically significantly different (with a probability
greater than 95%) from other mean values of Q derived by using the same method, for both the western (180 °W to 40 °E) and
eastern (40 °E to 180 °E) hemispheres of the IC. The decrease of Q with the radius of the turning point (denoted by rTP), according to QP = 840 − 0.62 rTP, has a moderate statistical support (the R-squared value is 38%). A slightly increase of Q as a function of the angle of
the PKPdf path within the inner core with respect to the Earth’s spin axis is observed, in agreement with various investigations
performed in the time domain. However, the value of the anisotropy, if any, is suggested to be around 3%. 相似文献
195.
清江水布垭水电站地下厂房岩体质量评价及反馈设计研究 总被引:17,自引:2,他引:15
考虑地下水 ,地应力及结构面产状和岩溶、剪切带发育的特点修正 ,确定了水布垭水电站地下工程洞室工程岩体质量 ,进行了地下工程的 RMR分类研究 ,讨论了与水布垭地下工程反馈设计及信息法施工的有关问题。 相似文献
196.
A series of spatial ~feding for traVeler's retUrn from the starting place of touriSt source conshtUtes thewhole process of tourist flow ti]. The tourist flow is the bilatelal directions of touristS in the whole processby going to tile tourist destinations from the place of tourist souxces and returning to that source. ThetouriSt flow is tile main and core body that has the decisive and restricted funchons for touriSt matter flowand energy flow [21. There are few researches on the fiXing amo… 相似文献
197.
应用3D-? 软件对西南某大型水电站左岸边坡开挖过程进行三维数值模拟,模拟结果表明:开挖坡面产生不同程度的张拉应力区域;缆机平台和拱肩槽槽坡底部产生一些竖直方向的回弹变形和水平向坡外的变形;5#梁山脊在拱肩槽开挖后将产生进一步的卸荷松弛,表层岩体稳定性将可能恶化,f42-9断层以上的大块岩体将是一个潜在的威胁;根据以上分析对开挖边坡制定了分层开挖、分层加固的方案,支护方案采用预应力锚索及排水系统的组合形式进行加固,支护后的稳定性计算表明,采用的支护措施是有效的,达到了工程设计的要求。 相似文献
198.
水电站安全监测部位众多,监测难度大,它要求在恶劣的环境持续稳定地检测出水电站微小的物理变化.本文提出采用智能测量机器人、GNSS天线阵列技术、测斜仪以及温度传感器等,设计多传感器集成的水电站一体化自动安全监测系统,并通过数据库实现监测数据的管理查询. 相似文献
199.
200.
在对澜沧江中上游干流规划电站(苗尾水电站以上)开发影响区实地调查、文献收集整理的基础上,通过确定影响区内4个县16个乡镇范围内关键人文生态对象,利用ARCGIS和Googleearth软件分析技术,并用线性加权综合法分析关键人文生态对象的重要性和地域分布特征,就其对水电开发的敏感度进行5级评估,得出主要结果:(1)关键人文生态对象包括6类:文物保护单位、传统村落、特色小镇、非物质文化遗产、风景名胜区和A级景区、历史文化名镇名村;(2)康普乡和石登乡的敏感度最高,兔峨乡和功果桥镇次之,而巴迪乡、维登乡、攀天阁乡、中路乡、营盘镇和苗尾乡的敏感度最低。 相似文献