n维广义Radon变换

本文提出了一种在任意变换曲线族情况下的广义Ｒａｄｏｎ变换及反投影公式，研究了在何种变换曲线情况下，其反变换能唯一恢复原出数。事实上，并非任意变换曲线簇作广义Ｒａｄｏｎ变换都能由象函数唯一恢复原出数，同时探讨了广义Ｒａｄｏｎ变换比常规Ｒａｄｏｎ变换地震数据处理中具有更广泛的应用。     

水氡异常的水动力学机制

在水氡异常机制研究中，人们以往都强调岩石力学机制，即孕震过程中岩石微破裂产生氡射气。然而，大量的震例表明，水氡异常可出现在孕震早期，可见于距震中较远的井中，那里的与那时的含水层岩石很难处在微破裂状态。因此，笔者提出水氡异常的水动力学机制，即在较低的应力水平下含水岩体的变形与其水动力状态的变化引起水氡异常的机制     

地形表面反射强度的数学层析成像方法

若二维ＲＦ窄波反射函数是定义在地面一圆形区域内部的，并假定该圆域表面介质是弱反射介质，那么在给定时刻，接收发射器（如机载合成孔径雷达）所接收到的近回数据可视 过该圆域的一圆弧上的线积分值，Ｍｕｍｓｏｎ，ｅｔ，ａｌ。在假定圆域半径与接收发射器运动路径到该圆域中心的距离相比很小的情况，用直线上的线积分值来代替圆弧线上的线积分值，利用古典的Ｒａｄｏｎ变换方法，给出了该圆域反射函数的成像模式。本文将克服这     

Mapping radon-prone areas - a geophysical approach

 Radon-prone areas in Israel were mapped on the basis of direct measurements of radon (²²²Rn) in the soil/rock gas of all exposed geological units, supported by the accumulated knowledge of local stratigraphy and sub-surface geology. Measurements were carried out by a modified alpha-track detection system, resulting in high radon levels mainly in rocks of the Senonian-Paleocene-aged Mount Scopus Group, comprised of chert-bearing marly chalks, rich in phosphorite which acts as the major uranium source. Issues of source depth, seasonal variations and comparison with indoor radon levels are addressed as well. This approach could be applied to other similar terrains, especially the Mediterranean Phosphate Belt.     

Radon modelling and the heat transfer surface area of the British hot dry rock geothermal reservoir

A simple thermal model is developed to evaluate the heat exchange surface area of a hot dry rock geothermal reservoir. This model, in conjunction with the Rn model of Andrews and coworkers, is applied to RH12/RH15 system of the British HDR reservoir. Results suggest that although the estimated Rn transfer surface area represents the actual swept surface area, it is between 25 and 45 times larger than the heat transfer surface area. The difference is explained as due to clustering of several fractures within a range of thermal interaction, over the duration of the circulation. It is also shown that the decline in the measured temperatures of circulation fluids since 1985 to the present is consistent with the heat exchange surface area going through a maximum in 1987.     

用气体地球化学方法探讨活断层的有关问题

探讨了以氡为主的断层气测量结果与断层活动性的关系;并讨论了土质、土壤、含水量、取样深度等对断层气氡测量的影响。     

Radon variation in groundwaters in the Campi Flegrei Caldera (southern Italy) during and after the 1982–1984 bradyseismic crisis

Groundwater Rn concentration has been monitored at several sites in the Campi Flegrei Caldera since the time of the last episode of bradyseismic activity. The results concerning the period 1983–88 indicate that the Rn concentration is spatially variable due to the different chemico-physical characteristics of the waters or structural features. Rn concentration is generally influenced by the long-term changes of meteorological factors. Rainfalls appear to affect the Rn content of the most superficial aquifers. Several short-term spike-like Rn anomalies have been detected both during and after the period of the bradyseismic crisis. They do not show correlation with temporal changes of the pH and/or temperature of waters. A systematic correlation between Rn anomalies and episodic strong rainfall events is also absent. Furthermore, a clear relationship between Rn spikes and both uplift velocity changes and seismic activity has not been found.The overall evidence makes it very difficult to understand the temporal changes of groundwater Rn concentration that have occurred during and after the 1982–84 bradyseismic crisis. Nevertheless, a clear causal relationship between Rn concentration and the dynamics of the bradyseism is observed in some monitored sites. Its appearance may have been favoured by the low Rn concentration in the groundwaters during periods of quiescent activity.     

Hard X-ray all-sky imaging with BATSE/CGRO

The large Area Detectors (LADs) of the BATSE experiment aboard the Compton Gamma-ray Observatory have been used recently as the first hard X-ray all-sky imager at energies between 20 keV and 300 keV. The Earth occultation process is formulated in terms of a curved Radon transform convoluted by a step transform in a selected field of view (FOV) ranging from 5°×5° to 40°×40°. The Maximum Entropy Method is then used to reconstruct an image in the hard X-ray sky. Multiple images of different regions of the sky can be produced simultaneously. A source location accuracy of 0.1° for strong sources and a sensitivity limit of 100 mCrab have been achieved in an one-day integration period.Invited Paper on Imaging in High Energy Astronomy, Sept., 1994, Capri, Italyalso Universities Space Research Association     

Radioelement (U,Th, Rn) concentrations in Norwegian bedrock groundwaters

Twenty-eight samples of groundwater from bedrock boreholes in three distinct Norwegian geological provinces have been taken and analyzed for content of Rn, U, and Th, together with a wide variety of minor and major species. Median values of 290 Bq/1, 7.6 g/1, and 0.02 g/1 were obtained for Rn, U, and Th respectively, while maximum values were 8500 Bq/1, 170 g/1, and 2.2 g/1. Commonly suggested drinking water limits range from 8 to 1000 Bq/1 for radon and 14 to 160 g/1 for uranium. Radioelement content was closely related to lithology, the lowest concentrations being derived from the largely Caledonian rocks of the Trøndelag area, and the highest from the Precambrian Iddefjord Granite of southeast Norway (11 boreholes) where median values of 2500 Bq/1, 15 g/1 and 0.38 g/1, respectively, were obtained. The Iddefjord Granite is not believed to be unique in Norway in yielding high dissolved radionuclide contents in groundwaters, and several other granitic aquifers warrant further investigation in this respect.     

应用断层气氡进行地震监测预报

概述了断层气氡观测点的地理位置,地质环境和观测条件,用最优周期谱持和多元逐步回归分析方法对观测资料进行了详细分析,分析结果表明观测曲线具有“冬高夏低”的年动态变化和固体潮变化特征。其中固体潮变化是断层气氡进行地震监测预报的力不基础。