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主要介绍在北京地区开展气球携带碘化银焰弹雨雪作业的作业技术,经济效益等问题。通过各种增雨雪技术比较,认敢球携带碘化银焰弹增雨雪作业在北方干旱地区的抗旱工作中或作为收音机增雨雪作业的补充手段具有应用价值 相似文献
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深基坑边坡滑塌锚拉钢管桩补救技术 总被引:1,自引:0,他引:1
汪发文 《水文地质工程地质》1997,24(6):51-52
通过对某大厦深基坑边坡失稳事故原因的分析,介绍了粉喷桩,锚拉钢管桩补救设计施工技术及效果。 相似文献
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露天矿边坡实用型专家系统PESOPS V1.0的设计与应用 总被引:3,自引:0,他引:3
结合边坡工程和岩质边坡普遍存在的问题,建造了一个露天矿边坡实用型专家系统PESOPS V1.0。介绍了滑坡预报子系统的原理和方法,通过应用实例表明该子系统适用性强,预报可靠、使用方便。 相似文献
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A Modeling Study of the Effects of Anomalous Snow Cover over the Tibetan Plateau upon the South Asian Summer Monsoon 总被引:1,自引:0,他引:1
The effect of anomalous snow cover over the Tibetan Plateau upon the South Asian summer monsoon is investigated by numerical simulations using the NCAR regional climate model (RegCM2) into which gravity wave drag has been introduced. The simulations adopt relatively realistic snow mass forcings based on Scanning Multi-channel Microwave Radiometer (SNINIR) pentad snow depth data. The physical mechanism and spatial structure of the sensitivity of the South Asian early summer monsoon to snow cover anomaly over the Tibetan Plateau are revealed. The main results are summarized as follows. The heavier than normal snow cover over the Plateau can obviously reduce the shortwave radiation absorbed by surface through the albedo effect, which is compensated by weaker upward sensible heat flux associated with colder surface temperature, whereas the effects of snow melting and evaporation are relatively smaller.The anomalies of surface heat fluxes can last until June and become unobvious in July. The decrease of the Plateau surface temperature caused by heavier snow cover reaches its maximum value from late April to early May. The atmospheric cooling in the mid-upper troposphere over the Plateau and its surrounding areas is most obvious in May and can keep a fairly strong intensity in June. In contrast, there is warming to the south of the Plateau in the mid-lower troposphere from April to June with a maximum value in May.The heavier snow cover over the Plateau can reduce the intensity of the South Asian summer monsoon and rainfall to some extent, but this influence is only obvious in early summer and almost disappears in later stages. 相似文献
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低空急流与阿勒泰暖区大--暴雪 总被引:2,自引:0,他引:2
分析了冬季产生新疆低空急流的大型环流特征及低空急流与阿勒泰暖区大-暴雪的关系。结果表明,在中高纬度欧亚范围内呈现“双阻型”,中亚中纬度高空维持纬向强急流锋区的情况下,若有巴尔喀什湖以南的暖湿气流向北输送,则有利于造成阿勒泰暖区大-暴雪的新疆低空急流产生。高低空急流的位置及强度可作为降雪量和大-暴雪落区的短期预报指标。 相似文献
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Claude Boutron Kevin Rosman Carlo Barbante Michael Bolshov Freddy Adams Sungmin Hong Christophe Ferrari 《Comptes Rendus Geoscience》2004,336(10):847-867
The investigation of the occurrence of lead in dated snow and ice from Greenland and Antarctica has played a major role in our understanding of the history of the pollution of the atmosphere of our planet by this metal. Such studies have however proved to be very demanding, mainly because of the extreme purity of polar snow and ice. Reliable measurements can be obtained only if ultra-clean and highly sensitive procedures are used, as pioneered by Clair Patterson. The Greenland data show evidence of large-scale pollution of the atmosphere of the Northern Hemisphere for lead as early as two millennia ago during Greco–Roman times, especially because of mining and smelting activities in southern Spain. It peaked at the end of the 1960s, with lead concentrations in snow about 200 times higher than natural values, before declining during recent times because of the fall in the use of leaded gasoline. Lead pollution in Antarctica was already significant at the end of the 19th century as a consequence of whaling activities, the traffic of coal-powered ships crossing the Cape Horn, and mining activities in South America, South Africa and Australia. After declining because of the opening of the Panama Canal, the great economic depression and World War II, it reached a maximum during the 1980s, with lead concentrations 20 times higher than natural values. Other studies focus on past natural variations of lead in ancient ice dated from the last climatic cycles. To cite this article: C. Boutron et al., C. R. Geoscience 336 (2004). 相似文献
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