漾濞地震震源位置分析     

李桂华  何家斌 《地震研究》2002,25(2):163-165

采用一致的地震震相和台网布局，应用昆明数字地震台网资料，对2002年月1月4日－1月7日的漾濞地震及序列作进一步核定，得出了更精确的地震震源位置，并作出三维空间图。  相似文献   

青藏高原土壤水热分布特征及冻融过程在季节转换中的作用   总被引：21，自引：0，他引：21  

杨梅学  姚檀栋  何元庆 《山地学报》2002,20(5):553-558

利用GAME-Tibet期间所取得的高分辩率土壤温度和含水量资料，对青藏高原（主要是藏北高原）土壤水热分布特征及冻融过程在季节转换中的作用进行了分析。指出藏北高原4cm学深处土壤在10月份开始冻结，次年4-5月份开始消融，冻结持续时间长达5-7个月。冻结过程有利于土壤维持其水分，因此，在刚刚开始消融时土壤含水量仍然很高。从而为夏季风爆发前土壤通过蒸发向大气提供水分打下了基础。指出土壤冻融过程可能在高原季节转换中起着重要作用。  相似文献   

Cyclic tests on large‐scale models of existing bridge piers with rectangular hollow cross‐section     

A. V. Pinto  J. Molina  G. Tsionis 《地震工程与结构动力学》2003,32(13):1995-2012

Cyclic tests on two large‐scale models of existing bridge piers with rectangular hollow cross‐section were performed in the ELSA laboratory. The prototype structure is an existing reinforced concrete highway bridge constructed in Austria in 1975. The piers presented several seismic deficiencies and consequently they showed poor hysteretic behaviour and limited deformation capacity as well as undesirable failure modes that do not comply with the requirements of modern codes for seismic‐resistant structures. Experimental data are compared to numerical and empirical predictions. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   

Longitudinal Displacement of the Subtropical High in the Western Pacific in Summer and its Influence   总被引：17，自引：0，他引：17  

YANG Hui  SUN Shuqing 《大气科学进展》2003,20(6):921-933

Using the relative vorticity averaged over a certain area, a new index for measuring the longitudinal position of the subtropical high (SH) in the western Pacific is proposed to avoid the increasing trend of heights in the previous indices based on geopotential height. The years of extreme westward and eastward extension of SH using the new index are in good agreement with those defined by height index. There exists a distinct difference in large-scale circulation between the eastward and westward extension of SH under the new definition, which includes not only the circulation in the middle latitudes but also the flow in the lower latitudes. It seems that when the SH extends far to the east (west), the summer monsoon in the South China Sea is stronger (weaker) and established earlier (later). In addition, there exists a good relationship between the longitudinal position of SH and the summer rainfall in China. A remarkable negative correlation area appears in the Changjiang River valley, indicating that when the SH extends westward (eastward), the precipitation in that region increases (decreases). A positive correlation region is found in South China, showing the decrease of rainfall when the SH extends westward. On the other hand, the rainfall is heavier when the SH retreats eastward. However, the anomalous longitudinal position of SH is not significantly related to the precipitation in North China. The calculation of correlation coefficients between the index of longitudinal position of SH and surface temperature in China shows that a large area of positive values, higher than 0.6 in the center, covers the whole of North China, even extending eastward to the Korean Peninsula and Japan Islands when using NCEP/NCAR reanalysis data to do the correlation calculation. This means that when the longitudinal position of the SH withdraws eastward in summer, the temperature over North China is higher. On the other hand, when it moves westward, the temperature there is lower. This could explain the phenomenon of the seriously high temperatures over North China during recent summers, because the longitudinal position of SH in recent summers was located far away from the Asian continent. Another region with large negative correlation coefficients is found in South China.  相似文献   

The Northward Shift of Climatic Belts in China During the Last 50 Years and the Corresponding Seasonal Responses   总被引：29，自引：0，他引：29  

YE Duzheng  JIANG Yundi  DONG Wenjie 《大气科学进展》2003,20(6):959-967

Along the meridian of 105°E, the Chinese region are divided into two parts, east and west. The results show that in the east part of China the temperate extratropical belt, the warm extratropical belt,and the northern subtropical belt shift northward significantly, whereas the middle subtropical belt and the southern subtropical belt have less or no change. As for the northern subtropical belt, the maximal northward shift can reach 3.7 degrees of latitude. As for the warm extratropical belt, along the meridian of 120°-125°E, the maximal northward shift can reach 3-4 degrees. In the west part of China, each climatic belt changes little. Only in the Xinjiang area are the significant northward shifts. Correspondingly, it is found that in the last 50 years the traditional seasons have changed. For Beijing, Hailar, and Lanzhou, in general, summer becomes longer and winter shorter over the last 50 years. Summer begins early and ends late with respect to early 1950s. Contrary to the summer, winter begins la  相似文献   

2002年5月河南省多雨成因分析     

梁钰  王蕊 《河南气象》2003,(1):14-16

分析了2002年5月多雨期的环流形势演变特征以及河南省出现大范围降水过程时的影响系统、物理量资料等，揭示了2002年5月河南省多雨的天气学成因，得出了5月份强降水预报的一些有意义的结论。  相似文献   

云南省卫星监测火点三级定位系统   总被引：1，自引：1，他引：1       下载免费PDF全文

赵红旭 《气象》1997,23(7):10-12

云南省卫星监测火点三级定位系统，是根据云南护林防火需求，按照地理信息系统设计思想，研制出的一套将火情快速定位到地、县、乡的计算机定位系统，实践表明，该系统可以充分发挥卫星监测林火的快速优势，特别适合山区护林防火的需求。  相似文献   

高岭土深加工产品开发     

杨玉枝  赵风 《内蒙古地质》1997,(2)

当前世界上煅烧高岭土产品已瞄准高档化、专用化、精细化和功能化，深加工系列产品已应用于高档汽车、船舶、乳胶、颜料、化工、造纸、涂料等方面。内蒙古自治区有丰富的高岭土资源，我们应依托优势资源，尽快掌握高新技术，开发高岭土系列产品，争取在较短的时间内在国内外激烈的市场竞争中立于不败之地，为自治区的经济繁荣起到积极的推动作用。  相似文献   

基于拉格朗日插值法修正地形影响的分布式降水模型研究   总被引：1，自引：0，他引：1  

张升堂  康绍忠 《水文》2004,24(6):6-9

降水量一直是进行水文分析计算的输入项，对其分布状况的模拟直接影响水文分析成果精度。降水中心位置及其中心降水量对暴雨分析尤为重要，而目前尚未见对降水中心位置方面的模型研究。在对目前国内外降水模型分析的基础上，根据天气系统降水如不受地形影响其降水量等值线在平面上的分布近似为一组同心椭圆这一原理，建立了一种能够模拟次降水过程的降水中心位置及其中心降水量的新型分布式降水数学模型，并对其进行地形影响因素修正。由于模型建立原理简单，易于实现对流域未设站研究点的实时降水量估计，同时由于模型能够指明降水中心位置及其中心降水量，因此在流域暴雨分析和洪水预报中具有实用价值。模型经实践检验具有较高精度。  相似文献   

Entropy Analysis of Multiple Scale Causality and Qualitative Causal Shifts in Spatial Systems*     

Jonathan D. Phillips 《The Professional geographer》2005,57(1):83-93

Spatial systems are typically characterized by multiple controlling factors and processes operating at different spatial and temporal scales (multiple scale causality [MSC]). An entropy decomposition‐based approach to MSC is presented here in two contexts. First, given maps or distributions of an observed phenomenon at two or more scales, the contribution at more local or global (relative to the primary scale of observation) controls to the observed entropy can be estimated. Second, a theoretical treatment of the entropy decomposition equations shows that as the range of scale is increased by broadening or narrowing resolutions or by incorporating more controls, the influence of larger or smaller‐scale influences not only changes, but may change qualitatively, e.g., in terms of having positive (entropy‐increasing) or negative (information‐increasing) effects. Such qualitative causal shifts have implications for efforts to use any single causal explanation across the molecular to planetary spatial and instantaneous to geological range of scales relevant to physical geography. The entropy decomposition method is illustrated with an application to soil landscapes in the Ouachita Mountains, Arkansas.  相似文献