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通过对2013年红山地震台地磁GM4磁通门磁力仪与FHD-2B质子矢量磁力仪产出的观测资料进行对比,系统分析两套仪器分均值、日均值和基线值的变化趋势,并对仪器背景噪声做相应对比,认为观测数据变化趋势一致,而GM4仪观测精度较大。 相似文献
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红山地震台数字地磁观测质量控制与分析 总被引：1，自引：0，他引：1
利用红山基准地震台地磁相对和绝对观测资料,采用单台绝对差值检测法、多台相对差值检测法、F-P检测法和地磁绝对观测改进措施,研究分析了红山地磁观测资料质量及其控制。结果表明:红山基准地震台相对记录仪GM4-1、FHD-2B和绝对观测仪Mingeo-DIM工作正常,运行稳定;因仪器故障,FHD-2B仪D分量在2015年3月24日出现台阶错误数据;2015年4月23日GM4-1和FHD-2B仪分钟值数据预处理错误;GM4-1仪各分量基线值稳定,同日及相邻2日观测基线值之差D_B≤0.1',H_B≤1.0 nT,Z_B≤1.0 nT,精度较高。 相似文献
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选取红山地震台2009—2013年磁通门磁力仪GM4-1和GM4-2的参考背景噪声数据进行分析。结果显示:两套仪器背景噪声年变化趋势一致,其中D分量背景噪声随季节变化明显,H分量、Z分量不明显。另外,GM4-2仪各分量背景噪声值较高,认为是其自身原因引起的。 相似文献
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红山台地磁日变化记录准确度标定分析 总被引：1，自引：0，他引：1
《华北地震科学》2016,(1)
为了正确评价相对记录仪器记录到的地磁日变化的准确度,分析了红山台2套GM4磁通门磁力仪2009—2012年4年来的地磁日变化记录准确度标定基线值的精度和稳定性,同时对地磁日变化记录准确度标定基线值与地磁日变化的相关性进行了研究,得出以下结论:在标定时段2套GM4磁通门磁力仪D、H、Z3个分量基线值的变化幅度和测量误差都很小;1号GM4磁通门磁力仪比2号运行更加稳定,且日变化记录准确度标定基线值和地磁日变化之间相关性并不显著,这与2套仪器的自身老化和所处的观测环境等因素有关;红山台在上午10:30—12:30和下午15:30之后的时间段地磁日变化记录准确度标定基线值稳定,适宜进行地磁绝对观测。 相似文献
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对2007年红山地磁台GM4磁通门磁力仪、FHD质子旋进磁力仪及CZM-2核旋仪的总强度F观测数据,进行了趋势变化、均值、差值以及基线值的对比分析,认为两台数字化仪器F的观测数据具有较高的观测精度和一致的变化趋势,仅均值存在较小的差别,已达到了国内高精度地磁观测的水平.CZM-2核旋仪受人为因素影响较大,仪器精度低. 相似文献
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使用肇庆地磁台2005年dldD矢量磁力仪与GM3磁通门磁力仪的观测数据，系统地分析了两套仪器分钟值、日均值、基线值的变化趋势。根据均值和方差检验以及基线值的变化趋势，认为两套仪器有相同的观测精度，除了均值有较小的差异外。两套仪器的观测数据无系统偏差，仪器的稳定性和数据的一致性较好。 相似文献
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肇庆地磁台磁通门磁力仪对比分析 总被引：1，自引：0，他引：1
对2003年肇庆地磁台GM3和Flare-plus磁通门磁力仪的H、D、Z分量观测数据.进行了趋势变化、均值、方差一致性检验以及基线值分析,认为两台磁力仪的观测数据具有同等观测精度和一致的变化趋势,仅均值存在较小的差别,已达到了国内高精度地磁观测的水平.与英国产的Flare-plus磁力仪相比,国产GM3磁力仪的观测精度和稳定性部分性能已达到世界上高精度数字地磁观测仪器的水平,但仪器的总体稳定性,传感器探头受温度影响的程度、仪器零漂等指标还需进一步提高. 相似文献
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《中国科学:地球科学(英文版)》2014,(12)
正SCIENCE CHINA Earth Sciences,an academic journal cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China,and published by Science China Press and Springer,is committed to publishing high-quality,original results in both basic and applied research. 相似文献
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《中国科学:地球科学(英文版)》2014,(9)
正SCIENCE CHINA Earth Sciences,an academic journal cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China,and published by Science China Press and Springer,is committed to publishing high-quality,original results in 相似文献
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In natural waters arsenic concentrations up to a few milligrams per litre were measured. The natural content of arsenic found in soils varies between 0.01 mg/kg and a few hundred milligrams per kilogram. Anthropogenic sources of arsenic in the environment are the smelting of ores, the burning of coal, and the use of arsenic compounds in many products and production processes in the past. A lot of arsenic compounds are toxic and cause acute and chronic poisoning. In aqueous environment the inorganic arsenic species arsenite (As(III)) and arsenate (As(V)) are the most abundant species. The mobility of these species is influenced by the pH value, the redox potential, and the presence of adsorbents such as oxides and hydroxides of Fe(III), Al(III), Mn(III/IV), humic substances, and clay minerals. 相似文献
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《中国科学:地球科学(英文版)》2014,(3)
正SCIENCE CHINA Earth Sciences,an academic journal cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China,and published by Science China Press and Springer,is committed to publishing high-quality,original results in both basic and applied research. 相似文献
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《国际泥沙研究》2014,(4)
正Director:Shangfu Kuang,China Vice-directors:Chunhong Hu,China Duihu Ning,China Guangquan Liu,China The International Research and Training Center on Erosion and Sedimentation(IRTCES)was jointly set up by the Government of China and UNESCO on July 21,1984.It aims at the promotion of international exchange of knowledge and cooperation in the studies of erosion and 相似文献
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Richard D. Hey 《地球表面变化过程与地形》1979,4(1):59-72
Feedback mechanisms, which operate upstream through drawdown and backwater effects and downstream through sediment discharge are responsible for channel evolution. By combining these mechanisms with channel processes it euables a dynamic process-response model to be developed to simulate the initial evolution of straight gravel-bed channels. When erosion commences on a land surface, sediment entrained in the headwater reach by hydraulic action is selectively transported, deposited and reworked. This produces a damped oscillation between degradation and aggradation as the channel and valley respond to spatial and temporal variations in sediment calibre and hydraulic conditions. The initial cut and fill phases are responsible for valley incision and floodplain development while secondary and subsequent activity can produce river terraces. Eventually sediment entrainment in the headwaters declines as slopes are reduced. Subsequent channel evolution is relatively insignificant because it is dependent on local weathering activity producing material that can be transported on declining slopes. Therefore landforms produced during the initial phase of development, when local weathering was non-limiting, dominate the landscape. 相似文献