排序方式： 共有15条查询结果，搜索用时 46 毫秒
1.
Under the artificial condition the 59Fe morphology in sea water, its concentration in sediment and phytoplankton, its distribution and metabolism in tissue organs of marine animals were studied. The results showed that the morphology of 59Fe was in a particulate state in sea water. The adsorption rule of 59Fe by three kinds of sediments was similar. The concentration ability of 59Fe by phytoplankton was very strong. The critical concentration organs of S9Fe by marine animals were viscera. The gross radioactivity of 59Fe was mainly concentrated in protein. The concentration factor of 59Fe by DNA was the highest one. After excretion experiment, 59Fe of all the tissue organs was not detected. Small part of59Fe remained in the organic acid and protein state. There was a redistribution process in sediment for59Fe. 相似文献
2.
本文采用大森公式ｎ（ｔ）＝Ｋ／（ｔ＋ｃ）＾ｐ求解Ｋ、ｃ、ｐ三个参数，对云南１９６５年以来７１个地震序列进行研究。确定Ｐ＝０．８为前兆震群和正常震群的判定指标。利用Ｋ、ｃ、ｐ三参数计算序列理论曲线得到晚期强余震前差残曲线超出两倍均方差的结果。 相似文献
3.
Two NE-SW trending wide-angle seismic profiles were surveyed across the Chinese side Two NE-SW trending wide-angle seismic profiles were surveyed across the Chinese side of the Yinggehai (莺歌海) basin (YGHB) with ocean bottom hydrophones (OBHs) and piggyback recorded by onshore stations located on the Hainan (海南)Island.Detailed velocity-depth models were obtained through traveltime modeling and partially constrained by amplitude calculations.More than 15 km Tertiary sedimentary infill within the YGHB can be divided in to three layers with distinct velocity-depth distribution.Overall,the upper layer has a high velocity gradient with 3.8-4.1 km/s at its bottom,consistent with progressive compaction and diagenesls.Its thickness increases gradually towards the basin center,reaching 4.5 km along the southern profile.The middle layer is characterized in its most part as a pronounced low velocity zone (LVZ) with average velocity as low as 3.0 km/s.Its thickness increases from 3.0 to over 4.5 km from NW towards SE.The primary causes of the velocity inversion are high accumulation rate and subsequent under-compaction of sediments.The velocity at the top of the lower layer is estimated at about 4.5 km/s.Despite strong energy source used (4 x 12L airgun array),no reflections can be observed from deeper levels within the basin.Towards NE the basin is bounded sharply by a clear and deep basement fault (Fault No.1),which seems to cut through the entire crust.A typical continental crust with low-velocity middle crust is found beneath the coast of the western Hainan Island.Its thickness is determined to be 28 km and shows no sign of crustal thinning towards the basin.The sharp change in crustal structure across Fault No.1 indicates that the fault is a strike-slip fault.The crustal structure obtained in this study clearly favors the hypothesis that the YGHB is a narrow pull-apart basin formed by strike-slip faulting of the Red River fault zone. 相似文献
4.
5.
本文将地震系统作为开放系统进行研究,认为系统和外界有物质和能量的交流,导致孕震区滑向不稳定的非平衡态,然后在各种涨落扰动下发生地震。本文研究1988年澜沧——耿马地震、1976年龙陵、宁蒗地震、1974年昭通地震、1970年通海地震孕震区,得到大震孕育调整模型,大震前地震开放系统熵值曲线变化特征,可作为大震预报指标应用于日常监测工作中。 相似文献
6.
7.
本文采用极值理论、线性预测和最大熵谱分析三种不同的概率统计预报方法，从不同的角度对滇西南地区地震活动进行研究，得到滇西南５年内将有１次６．５－６．９级地震活动，１９９２年有６．０－６．４级发震可能的中短期预报结果。 相似文献
8.
山东五莲七宝山金矿床成矿物理化学条件及矿床成因 总被引：4，自引：0，他引：4
七宝山金铜矿床流体包裹体的研究表明：成矿流体具有较高的Ｋ￣＋、Ｎａ￣＋、及Ｃｌ￣－含量，并富含ＣＯ＿２等挥发组分。成矿温度主要变化于２００～３５０℃，成矿体系具有中等偏高的及较高的。同位素的研究表明：成矿流体以岩浆水为主导，成矿热液及成矿物质主要来自岩浆。成矿体系由封闭型向开放型演变，导致物化条件的突变是促使金、铜矿质沉淀的关键所在。 相似文献
9.
10.