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91.
92.
兰州CAWS600-R自动站与人工观测资料对比分析 总被引:7,自引:10,他引:7
利用2002年11月到2003年2月兰州CAWS600-R型自动站与人工观测的温度、本站气压、水汽压、相对湿度、5~320cm地温等资料,分析了对比观测资料的差值。结果表明:对气温、本站气压、水汽压、相对湿度及320cm地温等要素观测误差较小,5~160cm地温的观测误差较大。自动观测仪器的系统性偏差、测量元件的精度及对气象要素变化响应的灵敏度、观测时间的差异和人为因素的影响是造成对比观测误差的原因。 相似文献
93.
94.
沙尘暴常规观测资料主要来自地面气象观测系统,是揭示沙尘暴的时空分布特征和变化规律的重要基础,其内在属性明显地受到地面气象观测规范和统计规范的制约,而且同样明显地受到两个规范变革的影响,但是这些问题在以往的沙尘暴研究中没有引起足够的重视,常常被忽视掉了,因此最终形成了一些似是而非的认识.该文从中国沙尘暴的观测规范和统计规范入手,探讨了其变革对沙尘暴内在统计特征的影响.另外,文章还分析了沙尘暴与其它沙尘天气的同日出现问题,以及沙尘暴资料时间序列的统计分布特征. 相似文献
95.
结合西部地区某深埋长大公路隧道信息化施工 ,对深埋长隧地应力演化及围岩应力位移进行了弹塑性有限元数值模拟研究。研究结果表明 ,隧道轴线现代地应力状况与隧道埋深、地层岩性及构造发育程度有关 ,最大地应力为40 0MPa左右 ;隧道周边围岩应力在曲边墙底部最大 ,约 3 8 0MPa ,隧道开挖引起的围岩应力影响范围约 2 5 0m ;隧道水平收敛和拱顶下沉位移与隧道埋深近于成直线关系。这些研究结果为深埋长隧信息化设计和施工以及围岩稳定性分析提供了科学依据。 相似文献
96.
关于数字化记录中前兆信号的分析 总被引:1,自引:0,他引:1
王亮 《地震地磁观测与研究》2005,(Z1)
介绍了如何用MATLAB工具软件—小波分析的基本理论对数字信号进行数字滤波,着重分析和研究了呼和浩特地震台形变观测资料出现各种信号,提出了小波分析理论对台站实际工作的重要性。 相似文献
97.
On the basis of about 300 earthquake wave forms observed in the Shidian M
S=5.9 sequences on April 12, 2001 recorded in Kunming Digital Seismic Network, the spectra of shear wave have been used to
estimate the focal parameters of these earthquake sequences. The results show that within the magnitude range of 1.5–5.3,
the seismic moments are 1010–1016 N·m, the corner frequencies are 0.2–0.8 Hz, radii of the focal rupture are 200–2 500 m and the stress drops are 0.1×105–20×105Pa. Through the statistical analyses of variation of corner frequency f
c and stress drop Δσ with time, it is discovered that the average corner frequency of the foreshock sequences is obviously
lower than that of the aftershock sequences. Contrarily, the average stress drops Δσ of the foreshock sequences are clearly
higher than that of the aftershocks. It is considered that these variation characteristics of average corner frequency and
stress drops before and after the main shock have index significance to the precursory information before a strong earthquake.
The higher stress drops for the foreshock sequences show that the higher shear stresses have been stored in the area of main
shock. After the main shock, most of the stresses have been released, so the aftershock sequences show a rupture process of
lower stresses.
Foundation item: Scientific and Technological Key Project of Yunnan Province (2001NG46) 相似文献
98.
The effect of fluids on recrystallization behaviour is well known; however, the detailed microscale distribution of fluid in grain boundaries and the influence of fluid on grain boundary migration are still unresolved. In this study, in‐situ deformation experiments in transmitted light microscopy were undertaken, as this allows continuous and direct observation of the whole range of processes involved in fluid‐assisted grain boundary migration. A new see‐through deformation apparatus was developed to enable the control of fluid pressure. Bischofite containing small amounts of aqueous fluid was deformed at temperatures between 50 and 90 °C, over a range of fluid pressure from 0.5 to 1 MPa, and strain rates of 5 × 10?6 to 1 × 10?4 s?1. The rates of grain boundary migration were measured at different temperatures and strain rates. Detailed observations during and after the deformation illustrate the evolution of migrating fluid‐filled grain boundaries and show that the incorporation of fluids from inclusions as well as their pinch‐off is dependent on the grain boundary velocity, the thickness of the grain boundary and the size and shape of the inclusions. Direct evidence is presented for the contraction of the grain boundary fluids into isolated inclusions after equilibrium conditions are attained. 相似文献
99.
试图从台站产出的原始地形变前兆数据出发,提出一些实际操作性较强的预处理方法,从已编制好的软件中给出处理实例,从而达到提高台站观测人员的科研能力,填补资料预处理方面的某些空白的目的,这对于台站人员集观测、科研于一体有着十分重要的意义。从95-01-02项目厦门地震台前兆数据预处理的实践表明:这些方法取得了明显的实效,直到今天仍然具有很大的使用价值。 相似文献
100.
Comparison of runoff characteristics of two adjacent basins in a tropical rainforest using a modified hydrologic cycle model with outflow 下载免费PDF全文
We propose a new runoff model including an outflow process that was applied to two adjacent basins (CL, TL) located in Lambir Hills National Park in north‐central Sarawak, Malaysia. Rainfall, runoff, topography, and soil layer thickness were observed. About 19% of annual runoff was observed in the CL basin (21.97 ha), whereas about 46% was observed in the TL basin (23.25 ha). It was inferred that the CL basin has an outflow because of low base flow, small runoff peak, and excessive water loss. By incorporating the outflow process into the HYdrological CYcle MODEL, good agreement between the data generated by the model and that observed was shown, with the exception of the data from the rainless period. Then, the fitting parameters for each basin were exchanged, except for the outflow parameter, and the characteristics of each basin were compared by calculating virtual runoff. As a result, the low base flow of the CL basin was estimated by the movement of the rainwater that escaped from the basin as deep percolation or lateral flow (11% of rainfall). The potential of the CL basin for mitigating flood and drought appeared to be higher than that of the TL basin. This is consistent with the topographic characteristics of the CL basin, which has a gentler slope than the TL basin. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献