用深地震反射方法研究邢台地震区地壳细结构

为了取得邢台地震区的地壳细结构,1990年冬,国家地震局地球物理研究所等实施了一条穿过华北平原中部束鹿断陷盆地的深地震反射剖面.经过叠加和偏移后的剖面显示出清晰的地壳细结构图像.剖面图上1—4s之间的强反射对应于由一组正断层产生的沉积层变形,其中新河断裂为束鹿盆地和新河凸起之间的边界主断裂,它伸展到8km以下深处.在5s左右显示出一组较强的反射界面,它可能对应于脆性上地壳的下界面.10—11s之间的壳-幔过渡带包含一组振幅大、连续性好的强反射,在震源下方的Moho界面上似乎被间断.岩浆从上地幔顶部侵入到地壳中,使得地壳可能出现部分熔融,这一过程是产生扩张盆地和发生邢台地震的主要原因.     

井间层析成像的最大熵方法

本文研究最大熵图像重建用于地球物理学中井间观测问题,着重研究了剑桥算法.对算法中拉格朗日乘子的确定给出了新方法;解决了算法的收敛条件和收敛范围;提出了减少算法计算量和内存量的方法,并编制了实用程序MECT.通过数值模型的研究,最后重建出了某矿区的剖图,与BPT和ART方法的结果进行了比较.证明最大熵图像重建法的优越性在于能有效地抑制噪声,分辨率高,边界影响程度小.若改善观测条件,将提高最大熵成像法的分辨率.     

200-kg large explosive detonation facing 50-km thick crust beneath west Qinling,northeastern Tibetan plateau

It is difficult to acquire deep seismic reflection profiles on land using the standard oil-industry acquisition parameters. This is especially true over much of Tibetan plateau not only because of severe topography and rapid variation of both velocity and thickness of near-surface layer, but also strong attenuation of seismic wave through the thickest crust of the Earth. Large explosive sources had been successfully detonated in US, but its application in Tibetan plateau rarely has an example of good quality. Presented herein is the data of a 200-kg single shot we recorded in west Qinling, northeastern Tibetan plateau. The shot gather data with phenomenal signal-to-noise ratios illustrate the energy of the PmP phase. Although the observations are only limited to the northeastern Tibetan plateau and thus cannot comprise an exhaustive study, they nevertheless suggest that large explosions may be a useful exploration tool in Tibetan Plateau where standard seismic sources and profiling methods fail to produce adequate data of low crust.     

北京地区臭氧垂直分布的演变趋势与特征的研究——卫星SBUV资料与地面遥感对比分析

利用地面遥感O3垂直分布的逆转方法〈C〉测量出的北京上空O3剖面资料,对雨云7号卫星的SBUV系统测量的同地区的O3垂直分布数据进行了订正.对订正后的长达8年（1979—1986年）的完整的SBUV资料进行了较为仔细的分析,得出了这一时期内的O3垂直分布长期演变呈下降趋势.并在上层O3含量的季节变化特征和周期振荡等方面,有新的发现,得出一些有意义的结果.     

中国南极第三次内陆冰盖考察剖面的雪貌及气象特征

给出了中国第三次南极考察的线路图、纵断面图及距离中山站 68~4 64km路段的表面年积雪状况图,分析了海拔高度的测定精度。同时,就考察剖面的雪貌及常规气象 (包括大气温度、湿度、气压和风速等)特征进行了描述。     

地气测量在叶县—邓县—南漳地学剖面研究中的应用

本剖面横跨华北地台南缘,秦岭造山带和杨子地台北缘。在剖面上系统地采集了壤中气、土壤和气溶胶样品,分别测定Ｃｒ、Ｃｏ、Ｎｉ、Ｃｕ、Ｐｈ、Ｚｎ等微量元素以及Ｈｇ气、Ｈｇ土、Ｒｎ、ＣＨ４、ＣＯ２等气体组分,研究了它们的空间分布特征,并结合剖面沿线的地质和地震资料,讨论了异常与岩性分布、地质构造和找矿靶区之间的关系。研究结果表明,宽坪群和二郎坪群是找寻多金属矿的有利层位;龙王集至龙门集一带是找油气的有利地段;潦河附近的Ｆ（１４）断裂带是一条规模较大的含金破碎带。这次试验的结果还表明,地气测量用于研究厚层的松散层覆盖下的地质构造具有良好的前景。     

国际参考电离层用于中国地区时的修正计算方法

在充分利用中国电离层台站长期观测资料的基础上,阐述了国际参考电离层用于中国地区时的一种修正计算方法．它采用“亚大地区Ｆ２电离层预测方法”计算ｆ０Ｆ２和Ｍ（３０００）Ｆ２,合理地描述Ｆ１层的出现和提高Ｅ层的峰值高度．与实测的电离层数据的系统比较说明,该方法在中国地区使用时,其精度比国际参考电离层有明显提高．     

ICP－AES 法测定地质样品中微量锆、 铪的研究

摘 要　 在2％酒石酸介质中‚用阳离子交换树脂吸附干扰元素‚以 ICP-AES 法分别在 343∙823nm 和264∙141nm 直接测定地质样品中的微量锆和铪。锆的检出限为0∙5×10 －6 ‚铪 为0∙4×10 －6 。此方法简单、快速‚应用于地球化学标准样品中锆和铪的分析‚取得了满意 的结果。     

Particle velocity and concentration profiles in bedload experiments on a steep slope

Depth profiles of particle streamwise velocity, concentration and bedload sediment transport rate were measured in a turbulent and supercritical water flow. One‐size 6 mm diameter spherical glass beads were transported at equilibrium in a two‐dimensional 10% steep channel with a mobile bed. Flows were filmed from the side by a high‐speed camera. Particle tracking algorithms made it possible to determine the position, velocity and trajectory of a very large number of particles. Approximately half of the sediment transport rate was composed by rolling grains, and the other half by saltation. This revealed a complex structure, with several concentration and flux peaks due to rolling, and one peak due to saltation. With an increase of the sediment transport rate, the depth structure remained the same at the water/granular interface, with peak value increases but with no shift in elevations. The saltation region expanded towards higher elevations with an increase of the particle velocity commensurate to the water velocity. The proportion of the sediment transport rate in saltation did not vary significantly. The particle streamwise velocity profiles exhibited three segments: an exponential decay in the bed, a linear increase where rolling and saltation co‐existed, and above this, a logarithmic‐like shape due to saltating particles. These results are comparable to profiles measured and modelled in dry granular free surface flows and in more intense bedload such as sheet flows. Copyright © 2014 John Wiley & Sons, Ltd.     

过渡区动床明渠流的流速分布

利用激光流速仪测量了随水流强度加大松散床面,从定床到具有一定输沙强度的动床流动,试验水流条件均处于过渡区。试验资料分析表明,动床过渡区明渠流的卡门常数小于通常所采用的0.4;水流强度逐渐增大,随着推移质运动量增加,阻力系数有减小再增大的趋势;雷诺应力分布和紊动强度分布规律同光滑明渠流类似。