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951.
鄂西超细重碳酸钙产品开发应用研究   总被引:6,自引:0,他引:6  
鄂西超细重碳酸钙产品开发应用研究沈上越潘铁虹张德李珍周明张汉凯(中国地质大学,武汉430074)关键词方解石矿工艺流程超细重碳酸钙鄂西1鄂西方解石矿质量概述鄂西方解石矿有数个矿区,每个矿区的矿体厚为几米至几十米,长几百米至上千米,储量巨大。经系统化学...  相似文献   
952.
强夯加插板加固软基的试验研究   总被引:1,自引:1,他引:0  
采用强夯法加固地基上部吹,回填土,打设塑料排水板排水固结地基下部软土的联合施工工艺,对我国北方某地的软土地基处理进行了试验研究,通过分析试验小区的监测资料得知,该地基处理方法在技术上可靠,工艺上合理。  相似文献   
953.
Geochemical analysis of six radiometrically dated short cores of recent sediment from Lake Baikal shows clear evidence of enhanced Pb supply. However, the sediment concentration increases are very small; the average Pb concentration rises from a baseline value of 10.9 g g-1 to a peak value of only 14.8 g g-1. In contrast to the more polluted lakes commonly studied in Europe and North America, variation in Pb concentration is far more strongly influenced by natural variation than by pollution. In sediment deposited over the last 150–200 years 73% of the variance in the sediment Pb concentration can be accounted for by variation in bulk composition of the sediment, and by atmospheric pollution. Factors influencing Pb concentrations over this time period are, in order of decreasing average importance (fraction of total variance explained), catchment supply (indicated by 226Ra activity variation) (43%), anthropogenic Pb emissions (24%), and dilution by ferromanganese hydroxides (6%). On longer (1000s of years) time scales dilution by biogenic silica is probably more important.The recent enhanced supply of catchment Pb correlates with accelerating accumulation rates, indicating a link with enhanced erosion. Anthropogenic sources dominate only in the southern basin, where local fossil-fuel burning industry is situated. The evidence for a local industrial source for the Pb pollution is strengthened by the high correlation between the inventories for Pb and for spheroidal carbonaceous particles. The absence of detectable anthropogenic Pb enrichment in the northern part of the lake suggests that long-distance Pb pollution is small compared with the local natural supply.  相似文献   
954.
该文介绍了陕西地方暴雨增数值预业务系统,并对1995年6-8月进行的降水准业务预报试验结果作了分析及Ts评分检验。结果表明:模式系统运行48h以上性能稳定,对陕西区域暴雨的预报效果较好,对日常业务预报有参考价值。  相似文献   
955.
An experimental work on the transplant of high resolution limited area model(HIRLAM) isfirstly introduced into China.For the implementation,first of all is to adjust a new geographicalcoordination and to remove the instability caused by the Tibetan Plateau,the roof of the world.Then,we have applied this model to simulate a flood-making torrential rain process which occurredin the Changjiang-Huaihe River Valley in July 1991.That revealed the formation,development andmovement of a mesoseale heavy rain system which had made a disastrous flood event in the middleand lower reaches of Changjiang River Valley.The result encourages us to use the HIRLAM for the researches on the Meiyu belt,the salientfeature of precipitation of East Asia,and the numerical prediction of heavy rains in China.  相似文献   
956.
毕春盛  李强 《气象》1996,22(3):37-39
中期暴雨预报系统实现了从信息采集、预报制作到服务全过程自动化。中期暴雨预报方法主要有:环流分型相似预报、暴雨个例相似预报和中期暴雨预报专家系统,采用层次分析动态决策方法进行预报集成。该系统在业务预报中取得显著效果。  相似文献   
957.
华南地区MCC云图特征和成因分析   总被引:3,自引:2,他引:3  
伍星赞  纪英惠 《气象》1996,22(4):32-36
利用伪彩色数字化卫星云图资料,对1994年6月中旬造成华南地区特大洪涝的5次中尺度对流复合体的活动规律、形态特征进行了分析,对其在该地区不断衍生的原因作了初步探讨,得出它们的云图特征和成因。  相似文献   
958.
The paper studied the distribution law of Xinjiang's heavy rain in time-area-depth bytheoretical expression deduced from the entropy maximum principle and found some regularities ofheavy rainfall in Xinjiang based on analyzing 32-year observational data from about 400hydrological and meteorological stations.It has practical significance for studying Xinjiang's heavyrainfall,designing water conservancy and reducing flood catastrophe caused by heavy rain.  相似文献   
959.
The impacts of the enhanced model's moist physics and horizontal resolution upon the QPFs(quantitative precipitation forecasts)are investigated by applying the HIRLAM(high resolutionlimited area model)to the summer heavy-rain cases in China.The performance of the control run,for which a 0.5°×0.5°grid spacing and a traditional“grid-box supersaturation removal+Kuo typeconvective paramerization”are used as the moist physics,is compared with that of the sensitivityruns with an enhanced model's moist physics(Sundqvist scheme)and an increased horizontalresolution(0.25°×0.25°),respectively.The results show:(1)The enhanced moist physics scheme(Sundqvist scheme),by introducing the cloud watercontent as an additional prognostic variable and taking into account briefly of the microphysicsinvolved in the cloud-rain conversion,does bring improvements in the model's QPFs.Althoughthe deteriorated QPFs also occur occasionally,the improvements are found in the majority of thecases,indicating the great potential for the improvement of QPFs by enhancing the model's moistphysics.(2)By increasing the model's horizontal resolution from 0.5°×0.5°,which is already quitehigh compared with that of the conventional atmospheric soundings,to 0.25°×0.25°without thesimultaneous enhancement in model physics and objective analysis,the improvements in QPFs arevery limited.With higher resolution,although slight amelioration in locating the rainfall centersand in resolving some finer structures of precipitation pattern are made,the number of the mis-predicted fine structures in rainfall field increases with the enhanced model resolution as well.  相似文献   
960.
一种卫星和雷达资料结合的强降水临近预报方法   总被引:1,自引:1,他引:1       下载免费PDF全文
蔡晓云  伏建国  朱革 《气象》1997,23(1):46-49
在短期和短时天气预报的基础上,通过对气象卫星红外数字资料的定量处理和统计分析,作出降水云系的实时降雨量估计,并根据降水云系生命史的演变和移动、传播等特征,结合天气系统分型和雷达回波资料,提出一种北京密云水库上游潮河,白河流域区域性0-3小时强降水临近预报方法。  相似文献   
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