上海浦东地区“梅雨期”降水及其多尺度时频特征          下载免费PDF全文

陈敏  张国琏 《大气科学学报》2007,30(3):305-311

提出了浦东地区“梅雨期”降水的概念。在此基础上,利用小波变换分析了浦东地区“梅雨期”降水的多尺度时频特征及其突变现象。结果表明:浦东地区6月1日—7月10日期间的降水序列能更加客观地反映该地区春末夏初这一特殊的“梅雨期”降水量的实际状况;浦东地区“梅雨期”降水存在准2 a和10～20 a的主要振荡周期;利用小波逆变换重构的不同振荡周期的时间序列能更好地反映原序列的主要周期振荡特征及其趋势信息。  相似文献   

建筑工程沉降监测若干问题的探讨     

胡珂  熊春宝 《测绘与空间地理信息》2007,30(2):119-121

根据多年沉降监测的实际经验,结合国家及行业的有关规范标准,对建筑工程沉降监测的方法、监测点的布设、周期的安排等问题进行了探讨,提出了一些新的见解。  相似文献   

Power Laws Governing Historical Earthquakes in the Apennine Chain (Southern Italy)     

E.?Cubellis  G.?luongo  A.?Marturano  A.?MazzarellaEmail author  F.?Obrizzo 《Natural Hazards》2005,34(3):263-278

Rank-ordering analysis is applied to the intertimes between seismic events recorded in the Apennine belt between 40–42° N and 14–16° E from the 15th century onwards. It shows a power law capable of governing the intertimes between 1529 and 368 months and another power law which approximates a random simulation, for the intertimes shorter than 368 months. Only the first power law allows the computation of the return period of major events. Earthquakes with the same energy that are aligned according to different power laws imply the presence of two different populations, indicating, in turn, that the physics of seismic phenomena in the region examined is not straightforward, that the stress is probably not unidirectional and that it acts on a non-isotropic medium. The most probable estimated intertime value for the next event is found to be equal to 60 ± 20 years.  相似文献   

兰坪盆地水泄铜(钴)矿床石英的⁴⁰Ar-³⁹Ar快中子活化年龄   总被引：2，自引：2，他引：0  

黄震  徐晓春  谢巧勤  陈天虎  岳书仓 《地质科学》2005,40(1):125-128

选取水泄铜(钴)矿床主成矿阶段的石英样品进行⁴⁰Ar-³⁹快中子活化法同位素地质年龄测定,获得坪年龄59.2±0.8Ma,对应的等时年龄为59.8±0.5Ma,反等时线年龄为59.9±0.1Ma,三者在误差范围内完全一致,都可代表矿石的形成年龄。该年龄与兰坪盆地铜多金属矿集区的矿床形成时代一致,反映包括水泄铜(钴)矿床在内的区域矿床形成于喜马拉雅造山运动早期统一的构造地质背景之下,受同一期构造—热演化事件的制约。  相似文献   

U-Pb dating of zircon fromthe bed parallel anatectic granitic intrusion in the Baoban group in Hainan Island and the tectonic implication     

DING Shijiang  HU Jianmin  SONG Biao    CHEN Mulun  XIE Shengzhou & FAN Yuan . Geological Surveying Institute of Hainan  Haikou  China  . Institute of Geomechanics  Chinese Academy of Geological Sciences  Beijing  China  . Beijing Center of SHRIMP  Beijing  China  . Institute of Geology  Chinese Academy of Geological Sciences  Beijing  China 《中国科学D辑(英文版)》2005,48(12):2092-2103

1 Geological setting Hainan Island is situated in the conjunction region between the Euro-Asian plate, the Indian-Australian plate and the Pacific plate, its tectonic setting and evolution is implicated in understanding the continen-tal margin accretion and evolution of East Asia and the formation of the South China sea. The Jiusuo-Lingshui fault zone divides Hainan Island into the Yaxian Pa-leozoic massif in the south and the Qiongzhong Pa-leozoic massif in the north (Fig. 1), they con…  相似文献   

Pollution au plomb dans la Savoie antique (II–IIIe s. apr. J.-C.) en relation avec une installation métallurgique de la cité de Vienne     

Fabien Arnaud  Joël Serralongue  Thierry Winiarski  Marc Desmet  Martine Paterne 《Comptes Rendus Geoscience》2006,338(4):244-252

In Lake Anterne (NW French Alps), the Roman period is characterised by a lead contamination more important than that of the 1970s, due to the use of leaded gasoline. The maximum of this contamination period has been varve-dated 220 AD, i.e., during the optimum of Roman civilization in the Alps. Crossing palaeoenvironmental and archaeological evidences points out the economic importance of the town of Passy for the City of Vienne and yields a new example of lead contamination due to local metallurgical activity rather than distant impact of the exploitation of the Spanish Rio Tinto mine. To cite this article: F. Arnaud et al., C. R. Geoscience 338 (2005).  相似文献   

鲁西地区中元古代四堡期辉绿岩基本特征——以蒙阴野店及费县高家围子地区为例          下载免费PDF全文

甘延景  张荣隋 《山东国土资源》2002,18(2):20-23

蒙阴野店—费县高家围子一带辉绿岩广泛发育 ,多呈NNW向及近SN向岩墙分布 ,常成群产出。该辉绿岩是幔源基性岩浆沿区域性张裂隙 (刚性陆块伸展作用的结果 )上侵形成的 ,它标志着鲁西乃至整个华北地区早前寒武纪基底第三次克拉通化的完成 ,陆块从此进入稳定发展阶段。  相似文献   

Representation of near-fault pulse-type ground motions   总被引：7，自引：3，他引：4  

谢礼立  徐龙军Adrian Rodriguez-Marek 《地震工程与工程振动(英文版)》2005,4(2):191-199

Near-fault ground motions with long-period pulses have been identified as critical in the design of structures. To aid in the representation of this special type of motion, eight simple pulses that characterize the effects of either the fling-step or forward-directivity are considered. Relationships between pulse amplitudes and velocity pulse period for different pulses are discussed. Representative ratios and peak acceleration amplification can exhibit distinctive features depending on variations in pulse duration, amplitude and the selected acceleration pulse shape. Additionally, response spectral characteristics for the equivalent pulses are identified and compared in terms of fixed PGA and PGV, respectively. Response spectra are strongly affected by the duration of pulses and the shape of the basic pulses. Finally, dynamic time history response features of a damped SDOF system subjected to pulse excitations are examined. These special aspects of pulse waveforms and their response spectra should be taken into account in the estimation of ground motions for a project site close to a fault.  相似文献   

河南省小麦青枯发生规律的EOF分析   总被引：3，自引：0，他引：3  

陈怀亮  张雪芬  邹春辉  祝新建 《气象科技》2005,(Z1)

通过对河南省30个台站1967~1996年30年的气象资料统计,得出全省小麦青枯发生日数,对其进行EOF分析,发现全省小麦青枯发生日数主要呈“中部多南北部少”空间分布型,另外还有其它几种空间分布型;小麦青枯发生日数随时间推移呈减少趋势;对各模态时间系数进行功率谱分析,发现小麦青枯发生日数具有较明显的准3年周期;第一、第二模态时间系数与全省小麦单产存在显著负相关关系,为防御和减轻小麦青枯灾害提供了理论依据。  相似文献   

从历史唯物主义角度透视跨越式发展     

于新 《吉林地质》2001,20(4):46-49,97

社会发展是决定性和选择性的统一,跨越式发展与历史规律性是一致的,体现了发展主体的选择性;人的创造活动具有超越性,“世界历史”造成的国家间的相互联系,以及科学技术的迅猛发展是跨越式发展的主要成因;跨越式发展理论启发广大后发国家不失时机地把握历史机遇,走创新发展之路。  相似文献