环境植物样品中铜铅锌铁锰的测定

将环境植物样品在４００─５００℃灰化，用硝酸、氢氟酸和高氯酸分解，用盐酸（１＋１）提取，控制２％─３％的盐酸介质，用火焰原子吸收分光光度法测定环境植物样品中的微量铜、铅、锌、铁、锰。该方法简单、快速、可靠。对环境植物标准样品的测定结果理想。     

Type III Bursts Associated with Millisecond Spikes Which Occurred Within the Frequency Range from 230 to 300 MHz

The metric spectral data obtained at the Yunnan Observatory from July 1990 to December 1991 are analysed and some type III bursts associated with millisecond spikes are found. Their different morphologies reveal the relation between the type III bursts and the millisecond spikes. Based on the occurrence time and the characteristics of continuity and changes of the morphologies in the spikes and the type III bursts of two typical events, we verify that the acceleration region of the coronal electrons is located above the emitting region of the millisecond spikes and the type III bursts. The observations show that the interface frequency of a pair of type III bursts lies near 250 MHz. Finally the authors attempt to explain qualitatively the generating mechanism of the metric millisecond spike-type III bursts by means of the plasma hypothesis.     

MD数字化断层形变测量仪资料的应用分析

分析了“九五”期间安装在“山东数字化地震前兆台网”的MD跨断层形变测量仪资料的干扰因素、变化特点及其与水准、基线观测的一致性 ,探讨了其映震能力及断层运动的表现方式     

Influence of underground space development mode on the groundwater flow field in Xiong’an new area

The degree and scale of underground space development are growing with the continuous advancement of urbanization in China. The lack of research on the change of the groundwater flow field before and after the development of underground space has led to various problems in the process of underground space development and operation. This paper took the key development zone of the Xiong’an New Area as the study area, and used the Groundwater modeling system software (GMS) to analyse the influence on the groundwater flow field under the point, line, and surface development modes. The main results showed that the underground space development would lead to the expansion and deepening of the cone of depression in the aquifer. The groundwater level on the upstream face of the underground structure would rise, while the water level on the downstream face would drop. The “line” concurrent development has the least impact on the groundwater flow field, and the maximum rise of water level on the upstream side of the underground structure is expected to be approximately 3.05 m. The “surface” development has the greatest impact on the groundwater flow field, and the maximum rise of water level is expected to be 7.17 m.     

西昆仑山前柯深—柯东地区断裂传递型超压的识别与计算

西昆仑山前柯深—柯东地区断裂构造活动剧烈,在浅部地层中存在压力系数高达2.1的极高超压,对于这种超压分布特征和形成机制的研究和认识对钻井工程和油气运移研究具有十分重要的意义。综合储层实测压力、间接估算的泥岩地层压力以及超压地层岩石力学与物性的关系等资料,并结合研究区断裂发育条件和油气运移史,分析了地层压力分布特征和主控机制。结果表明,西昆仑山前柯深和柯东两地区在古近系—白垩系储层中各自形成了相对统一的异常压力系统,系统内地层压力向深部以静水压力梯度增加,储层压力大于附近泥岩压力。研究区储层压力分布特征与深部流体沿开启性断裂的向上传递密切相关。在此基础上,估算了压力传递量,并探讨了影响压力传递量的地质因素。柯深和柯东地区断裂传递增压量分别为15.0～34.0 MPa和8.1～16.5 MPa,与实测总剩余压力的比值分别为24.2%～67.2%和23.4%～53.7%。两个地区断裂传递增压量的差异主要受断裂发育及其与地层的空间配置关系的影响。     

Fourier Coefficients Variation with Angle for Fracture Detection and Fluid Discrimination in Tilted Transversely Isotropic Media

Surveys in Geophysics - Fracture detection and fluid discrimination play significant roles in the field of geothermics, hydrogeology, and exploration geophysics. However, it is still a challenging...     

2021年9月16日四川泸县MS6.0地震强地面运动特征分析

2021年9月16日4时33分在四川省泸州市泸县发生M_S6.0地震,震中附近的强震动观测台网获取了1 320组三分向加速度记录,对有效记录进行常规处理后计算出地震动相关参数,并利用克里金插值方法得到峰值加速度PGA、峰值速度PGV和拟加速度反应谱的空间分布图。结果显示,极震区与中远场的长轴方向有较大差异,地震动表现出沿断裂走向衰减较慢的特性。通过与常用衰减关系预测值进行对比,分析了PGA和多个周期的拟加速度反应谱随距离的衰减特性,结果显示此次地震的PGA相比衰减关系预测值偏小,拟加速度反应谱相比各经验预测值呈现周期越大衰减变慢的特点,体现出川东南地区特有的衰减规律。最后分析了本次地震获得的最大加速度记录,进一步验证了局部地形和场地对地震动有显著影响。      

Dating of multi-period earthquake-triggered rockfalls: a method for revealing paleo-seismic events that occurred along the Yushu fault in the eastern Tibetan Plateau

Landslides - The quantitative study of earthquake-triggered rockfall debris along seismogenic fault zones has proven to be a valid approach for use in identifying paleo-earthquakes and faulting...     

Deep-seated toppling deformations of rock slopes in western China

Toppling is the foremost failure pattern of anaclinal rock slopes, and deep-seated toppling deformations (DSTDs) are common on high anaclinal slopes on the sides of gorges in western China. The DSTDs can develop to depths of more than 200 m, and may show distinct signs of zonal failure. Many DSTDs undergo transformation to large landslides involving rock volumes of more than 10⁶ m³. However, the conditions for the formation and the basic evolving processes of DSTDs remain unclear. This study seeks to develop an inventory to classify the distribution, and the conditioning factors which govern the formation and deformation modes of DSTDs in western China and to analyze the effect of the geological and geomorphological variables on the toppling intensities. To this end, forty-nine DSTDs were analyzed. The results indicate that DSTDs in western China are commonly distributed along large deeply incised rivers in the southeastern margin of the Qinghai-Tibet plateau. The steep-dip anaclinal metamorphic soft or soft-hard-interbedded strata with near parallel strikes in the river channel, V-shaped deeply incised river channels, and convex slopes are favorable conditions for the formation of DSTDs in these settings. The dip angle, the gradient, and the height of most slopes which develop DSTDs are 60–90°, 30–50°, and 200–800 m, respectively. There is a highly positive relationship between the depth of toppling and the height of the slope. The toppled rock masses can be classed as extremely intense, intense, moderate, and weak toppling zones characterized by complete block detachment, tensile-shear fracture, tensile fracture, and reverse slip along foliations, respectively. Each zone corresponds to a specific range of the dip angle of the toppled strata, the aperture of the tensile cracks, the P-wave velocity, the state of rock weathering, and the degree of unloading. The extremely intense and the intense toppling zones tend to evolve into sliding failures. Overall, 94% of the DSTDs were derived from flexural toppling and 33% have developed into large landslides.