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61.
<海洋与湖沼>编辑部 《海洋与湖沼》2000,31(2)
Professor Zhang Guofan, born in Haicheng, Liaoning Province, China in April 1954, graduatedfrom Xiamen University majoring in marine biology, gained his MS degree in South China SeaInstitute, the Chinese Academy of Sciences in 1982 and his Ph. D. in Institute of Oceanology, theChinese Academy of Sciences in 1992. Now he is professor of shellfish mariculture at DalianFisheries University and director of Key Laboratory of Mariculture Ecology, Ministry of Agriculture.Dr. Zhang has e… 相似文献
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Based on the HEIFE 1988 and 1990 pilot observations,an analysis on the turbulence structure of Gobi surfacelayer,mainly on the similarity formulations of wind and temperature variances,the spectra and cospectracharacteristics,is presented.The phenomenon of downward water vapor flux over Gobi desert in daytime is confirmedin both observations,this and the well-known‘oasis effect’are two sides of a local mesoscale circulation. 相似文献
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OBSERVATION AND MODEL ANALYSES OF POSITIVE CLOUD-TO-GROUND LIGHTNING IN MESOSCALE CONVECTIVE SYSTEMS 总被引:1,自引:0,他引:1 下载免费PDF全文
Yan Muhong Guo Changming Qie Xiushu Ge Zhengmo Zhang Guangshu Lanzhou Institute of Plateau Atmospheric Physics Academia Sinica Lanzhou 《Acta Meteorologica Sinica》1992,(4)
The analyses of spatial and temporal characteristics of positive cloud-to-ground(CG)lightning for four mesoscaleconvective systems and two severe local convective systems in 1989 and 1990 show that positive CG flash rate usuallyhas two peak values.The major peak occurs during the developing stage of the storm and most of the positive CGflashes originate at the lower part of the storm.The minor occurs during the dissipative stage of the storm and most ofthe positive CG flashes originate at the upper part of the storm,especially in the region of the wind divergence in thestorm anvil.The positive CG flash rate is almost an order of magnitude larger in the developing stage than in thedissipative stage.The appearing time of the peak of negative CG flash rate is in accordance with that of the valley of pos-itive CG flash rate.The higher the intensity of the radar echo,the higher the positive CG flash rate.Most of the positive CG flashes oc-cur when the weak echo area is larger,and mostly originate in the region where the radar echo intensity is about 10dBzand in the back region of the moving storms.The spatial distribution of the positive CG flashes is much more dispersivethan that of the negative.The mesoscale analysis reveals a bipolar lightning pattern.The mean bipole--length reaches itsminimum during the mature stage of the storm and reaches the maximum during the developing stage of the storm.The vertical distribution of the charge density is calculated by a one-dimensional charging model.Then,we discussthe producing condition of the positive CG lightning and forming cause of charge structure mentioned above. 相似文献
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用声发射波形采集分析系统记录的完整花岗岩在固体围压下破裂及粘滑过程中产生的声发射波形,研究了声发射和粘滑时间序列与天然地震序列的关系,讨论了粘滑过程的时间分布,发现粘滑事件的累积频度曲线随时间的变化受围压和应变率影响,大致呈现指数函数和线性关系两种形式。总事件(包括粘滑和声发射)的累积频度随时间的变化在不同的实验条件下呈现出对数函数形式,粘滑序列中的声发射随时间减少。本文的结果对于研究不同应变速率及不同震源深度的地区的地震活动时间分布特征,以及在判别地震活跃期内不同阶段强震序列类型和前兆特征有一定参考作用。 相似文献
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STUDY ON APPLICATIONS OF C-BAND DUAL LINEAR POLARIZATION RADAR IN METEOROLOGY 总被引:4,自引:0,他引:4 下载免费PDF全文
Theoretical study and development of a dual linear polarization weather radar in China are briefly presented.Also discussed are the potential uses of the new radar system in improving the accuracy of areal rainfall measure-ments and analysing the spacial structure of storms and distribution of hydrometecrs in clouds based on theradar observational data from the field experimcnts during the summers of 1987—1989. The results indicatethat a C-band dual polarization weather radar, after considering the microwave attenuation correction, may beemployed to quantitatively measure rainfall and to monitor heavy rain and flood events and becomes an impor-rant means to study storm structure. 相似文献
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作者在研究中发现水系的展布集中于区域内主要的活动断裂带方向及其正交方向上,并且断裂带活动程度越高,这种集中越明显,在文中,运用岩石破裂试验结果及水系展布受构造活动影响的观点对此进行讨论。 相似文献
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等性块段指数法是中国地质大学(武汉)詹才高等于1985年创立的,用构造指数和煤层指数定量划分井田勘探类型。本文阐述等性块段指数法的计算方法;较划分煤田勘探类型的其它方法,具有突出的优点及实际应用效果。并提出在我省煤田地质勘探中推广应用的建议。 相似文献