隋唐五代日月食记录     

刘次沅  马莉萍 《时间频率学报》2013,36(2)

对隋唐五代时期的日食、月食记录进行了全面的搜集、勘误和统计分析.研究了这些记录的文献来源、时间分布、覆盖率和记录特征.这一时期记载了实际可见日食的65％和月食的28％.  相似文献   

中国古代月与行星掩犯恒星记录及其用于传统星名考证     

马莉萍  孙晓宇  王晓晗 《时间频率学报》2013,(4)

月与行星掩犯恒星的记录是中国古代天象记录中数量最多的门类,此类记录的可靠性比较高,自北宋开始,月与五星掩犯恒星的错误率平均为10%,而之前的平均错误率也仅有20%。统计分析了这些记录在历代正史中的分布。在用现代天文学计算方法检验的基础上,考证了中西黄道区星名的对应关系。  相似文献   

祁连山老虎沟冰芯记录的高山区大气降水变化     

秦 翔崔晓庆  杜文涛等 《地理学报》2014,(5):681-689

冰芯所记录的积累量是恢复高山区过去降水变化最可靠的指标。2006年在青藏高原东北缘祁连山老虎沟12号冰川粒雪盆海拔5040 m处钻取了的一支20.12 m的冰芯,利用其年积累量估算了1960-2006年期间的冰川区降水量,结合2010年实测资料,分析了这一时期降水变化特征并研究其与周边其他地区降水变化的关系。结果表明,在过去50年中,高山冰川区降水量表现出先增加后减少的趋势。在1960-1980年,降水量表现出明显增加趋势,1980-2006年表现出明显减小趋势。重建的冰川区降水量变化与临近低海拔区的肃北气象站降水变化有很好的一致性,二者相关系数为0.619(P0.001),而量级上高山区是低山区的约3倍。祁连山老虎沟冰川区降水与周边的敦德冰芯同期的累积量、树轮重建降水、青藏高原东北部多个气象站点的实测降水,以及临近区域格点PDSI干旱指数变化对应较好。此外,近50年来祁连山老虎沟冰川区及毗邻的青藏高原东北部地区降水变化与ENSO呈正相关关系明显,反映了该地区高海拔大气降水变化很可能受ENSO的影响。  相似文献   

High resolution records of flood deposition in the mud area off the Changjiang River mouth during the past century     

胡刚  李安春  刘健  徐刚  梅西  孔祥淮 《中国海洋湖沼学报》2014,32(4):909-920

This paper presents a paleoflood study to determine the flood frequency of the Changjiang River, based on core cj0702, taken from the Changjiang River subaqueous delta. We identified flood deposits by means of high-resolution grain-size variation, sensitive population, geochemical indexes and magnetic susceptibility. The core covers a time span of 120 years by 210 Pb dating and was sampled at 1–2 cm intervals. Grain size, geochemical elements, and physical parameters were analyzed. The results indicate that the sediment of the core is mainly composed of silt and clay, as well as groups of interbedded silt, clay silt, and clay. Vertically, the grain size pattern was controlled by seasonal variations in water discharge and by the sediment input in winter from the abandoned Huanghe River delta. River flooding caused extreme values in all our measured parameters. We identified more than 20 flood events that occurred since 1887 using the physical parameter analysis method. The environmentally sensitive component of sediment grain size(14.32–96.39 μm) contribution30%, Zr/Rb ratio1.5, and magnetic susceptibility16 were selected as the criteria for flood identification generally. We also found that floods that had taken place in the upstream, midstream, or downstream parts of the river were clearly identified by these indexes while the large-scale floods that covered the whole drainage area did not leave clear indications in the sediment record. This study for identification of flood events is of great significance for understanding hyperpycnal current sedimentation as well as for forecasting of floods.  相似文献   

自动气象站草面温度、地面温度异常记录处理分析     

张梅  秦莉  李元华 《内蒙古气象》2014,(3):44-46

针对自动气象站在数据采集过程中,由于受仪器故障、维护不当或自动站仪器校准漂移等因素的影响,容易造成草面温度、地面温度数据的异常,文章根据具体实例分析了各种异常记录出现的原因,提出相关处理方法,以保证数据序列完整、准确。  相似文献   

新县矿产资源 管理成效显著     

黄成高 《河南国土资源》2014,(4)

正自2013年以来,新县采取有效措施,强化矿产资源管理,全面规范矿产资源开发利用秩序。一是抓好矿山企业年检工作。该局开展矿山企业年度审查工作,采取网上审查录入、实地检查和上报材料、图纸及野外记录相结合的方式,对全县22个采矿权和15个探矿权进行年度审查,合格率达100%。  相似文献   

基于Windows Mobile的水准测量记录软件的开发与应用     

张振军  杨建  胡祖平  涂进 《地理空间信息》2014,(5):140-141

阐述了在嵌入式操作系统上开发功能完备的电子记录软件的依据和方法 ,以及如何解决水准测量外业信息、测量数据记录以及观测质量的检核。实践证明,此软件促进了水准数据采集的数字化和自动化,保证了测绘成果的质量,提高了生产效率。  相似文献   

检查记录信息质量控制系统的设计与实现     

黄琛  邓国庆  王建明 《测绘标准化》2014,(3):37-39

针对DLG质量检查记录信息,利用质量管理理论、数据库技术和软件技术,提出一种基于数据库方式管理和质量管理工具分析质量信息的模式,并基于.NET平台开发检查记录信息质量控制系统。实践证明,该系统能充分挖掘质量检查记录中的丰富信息,对DLG成果质量管理体系建设具有一定的现实意义。  相似文献   

鸭绿江口主汊道常量元素沉积记录的特征及其意义     

刘月  程岩  李红军  李富祥 《海洋科学》2022,46(3):36-47

本文依据鸭绿江口主汊道采集的K1和K12柱状样,进行了常量元素的富集特征、相关系数、主成分分析及含量与特征参数垂向分布的讨论。研究表明:鸭绿江口属于涨潮三角洲,纳潮海湾泥质堆积区快速沉积的时间始于1960年。主汊道的沉积物具有多源性,K12柱状样受粒度控制显著,陆源碎屑为主;K1柱状样受粒度控制不显著,受海洋作用的影响较大。主汊道的沉积记录以1978年为界,分为上下2个沉积单元。主汊道的沉积物受到河口区水动力的强烈改造,与物源区的沉积物相比已经产生了很多的分异和变化。该研究通过对鸭绿江口主汊道常量元素沉积记录的分析,发现了近百年来该区域地貌演变和发育的规律,有效补充了鸭绿江口新生陆地形成过程的全貌。  相似文献   

Site effects by generalized inversion technique using strong motion recordings of the 2008 Wenchuan earthquake   总被引：3，自引：1，他引：2  

Yefei Ren  Ruizhi Wen  Hiroaki Yamanaka  Toshihide Kashima 《地震工程与工程振动(英文版)》2013,12(2):165-184

The generalized inversion of S-wave amplitude spectra from the free-field strong motion recordings of the China National Strong Motion Observation Network System (NSMONS) are used to evaluate the site effects in the Wenchuan area. In this regard, a total of 602 recordings from 96 aftershocks of the Wenchuan earthquake with magnitudes of M3.7-M6.5 were selected as a dataset. These recordings were obtained from 28 stations at a hypocenter distance ranging from 30 km to 150 km. The inversion results have been verified as reliable by comparing the site response at station 62WUD using the Generalized Inversion Technique (GIT) and the Standard Spectral Ratio method (SSR). For all 28 stations, the site predominant frequency F _p and the average site amplification in different frequency bands of 1.0–5.0 Hz, 5.0–10.0 Hz and 1.0–10.0 Hz have been calculated based on the inversion results. Compared with the results from the horizontal-to-vertical spectral ratio (HVSR) method, it shows that the HVSR method can reasonably estimate the site predominant frequency but underestimates the site amplification. The linear fitting between the average site amplification for each frequency band and the V _s20 (the average uppermost-20 m shear wave velocity) shows good correlation. A distance measurement called the asperity distance D _Aspt is proposed to reasonably characterize the source-to-site distance for large earthquakes. Finally, the inversed site response is used to identify the soil nonlinearity in the main shock and aftershocks of Wenchuan earthquake. In ten of the 28 stations analyzed in the main shock, the soil behaved nonlinearly, where the ground motion level is apparently beyond a threshold of PGA > 300 cm/s² or PGV > 20 cm/s, and only one station coded 51SFB has evidence of soil nonlinear behavior in the aftershocks.  相似文献