利用Radon变换进行三度体重磁异常反演

从Ｒａｄｏｎ变换角度分析解释了重磁三度体异常和二度体异常之间的等价关系，提出了利用Ｒａｄｏｎ正变换将三度体异常转化为二度体异常，对二度体异常做一维反演，然后将反演结果通过反Ｒａｄｏｎ变换实现三维场源图象重建的思想，并付诸实施，在微机上通过模型检验，证明该方法实用、可行。     

Radon变换提取P波剖面及去噪

介绍一种既能提取有效反射信号同相轴，又能提取Ｐ波剖面的方法。先将动校正后的共中心点道集记录沿反射同相轴方向的“时间－空间”域数据模型，变换到“序率一空间”域数据模型，并加以简化，使信号部分构成一个特殊的数据模型。然后引入Ｒａｄｏｎ变换，使信号和噪音在Ｒａｄｏｎ域中有根本的区别，噪音变得更加高斯化。在Ｒａｄｏｎ域中通过平滑处理，就可以消除噪音而又不损害信号。最后经过Ｒａｄｏｎ逆变换及Ｗａｌｓｈ逆变换，获得“时间－空间”域中高信噪比的ＣＭＰ记录、叠加剖面及零炮检距地震剖面。     

用二维付氏变换及希氏变换作倾斜滤波

本文讨论了文献中提出的利用付氏变换和希氏变换在频率波数域中对垂直地震剖面中的上行波与下行波进行分解的基本原理,并将该方法推广到作倾斜滤波,本文还在文献所提多维快速付氏变换算法的基础上,研制了二维及多维快变程序,使得倾斜滤波更加简便快捷。最后通过对人工合成地震记录和野外实际资料的处理结果,说明了该滤波方法的可靠性及有效性。     

二维小波分析程序(Ⅰ)—方法与设计

小波变换是地球物理数据分析的有力工具 ,研制小波分析应用程序系统并将其广泛地应用于实际的资料处理和分析 ,尤其重要。在对二维小波多尺度分析理论方法、算法研究的基础上 ,设计了“二维小波分析”程序系统的基本框架 ,将利用这一设计研制“二维小波分析”应用程序。     

实序列FFT程序

本文提供了一个计算实序列富里叶变换的复谱及其复谱的逆变换程序。此程序所用算法速度高,内存省,无需倒序和分离计算结果。它的计算精度与Cooley—Tukey算法一致,程序长度也与其基本相当。     

一种等值线连通区域填充算法与程序设计

提出了一种等值线连通区域填充算法,该算法是依据事的等值线曲线端点与区域,边界的拓扑关系,程序自动建立一种适应于等值线连通区域搜寻的数据结构,在该数据结构信息的关联下,实现了用表达不同意义的颜色填充区域。由于该区是一个由矢量化线段组成的区域,从而可以实现不比例,不同方向的变换。     

二维小波分析程度（Ⅰ）—方法与设计

小波变换是地球物理数据分析的有力工具，研制小波分析应用程序系统并将其广泛地应用于实际处理和分析，尤其重要。在对二维小波多尺度分析理论方法、算法研究的基础上，设计了“二维小波分析”程序系统的基本框架，将利用这一设计研制“二维小波分析”应用程序。     

二维电阻率法有限元模拟的改进方法

根据电测深装置的实际供电电极数目,本文讨论了双点源情况下二维构造电阻率法有限元模拟中边界条件的建立和反傅氏变换算法两个主要问题,提出了双点源同步处理方法,并给出了相应的程序框图及应用该程序的部分计算实例。     

MT二维正演的混合剖分算法及其在线源CSAMT正演计算中的应用

在矩形有限元和三角形有限元方法大地电磁测深（ＭＴ）二维正演计算的基础上，设计了矩形单元粗剖分、程序自动进行三角形单元细剖分的混合剖分算法程序，使得ＭＴ二维模型正演的计算速度大为提高。该方法同时被应用于线电流源变频电磁测深（ＣＳＡＭＴ）ＴＥ极化方式的二维正演计算。文章给出了在不同模型上计算的ＭＴ和线源ＣＳＡＭＴ的响应，分析了计算ＣＳＡＭＴ响应时，计算点离源的距离对视电阻率和相位值计算的影响，比较了ＭＴ和ＣＳＡＭＴ网格剖分的特点，提出了计算ＣＳＡＭＴ响应的改进的边界条件设计     

利用磁盘实现大数据量二维快速付里叶变换的方法

本文对Eklundb快速矩阵转置算法作了进一步推广,将它用于通过磁盘实现大数据量二維快速付里叶变换获得成功。在地矿部北京计算中心的国产150机上调通了能对52万人数据量的航磁数据进行快速付里叶变换的程序,已用于生产。     

介质中氡运移的模拟

氡的运移是一个复杂的过程，前人作了许多模型实验，探讨氡的运移问题，作者在前人工作基础上设计了一氡运移模型，并用氡运移的扩散、对流理论检验实验结果，证明近地表岩石、土壤和空气中氡的运移，可用扩散与对流理论描述。     

Radon migration into different building types at medium and low south-eastern flank of Mt Etna (Sicily): connection with the volcanic activity

Indoor Radon concentrations have been carried out simultaneously at the villages of S. Venerina and Acireale, which are located on the south-eastern flank of Mt. Etna volcano. Both investigation sites are partially affected by the same fault system, which plays an important role in the dynamics of the volcano, especially before and during eruptive periods. Measurements were performed in the period from January 2006 until April 2006, just prior to an eruption which took place on 14th July 2006. Indoor Radon monitoring at S. Venerina, was carried out at two buildings located nearby, characterized by a different type of construction. These buildings were chosen because they can be considered as representative of both the historical centre and the new neighbourhoods of the village. At the same time, a Radon active monitor was operating in-soil near the two aforesaid edifices. Cross-correlation analysis between the in-soil one with both the indoor S. Venerina Radon series indicated different temporal correlation, probably due to the different types of building foundations and constructive materials of their walls, both causing the different indoor accumulation. S. Venerina’s indoor Radon values taken at the new building showed similar trends and the same anomalies as the ones recorded at Acireale. The simultaneous increase in indoor Radon concentration was observed at both sites from the last ten days of March, when a significant increase in the CO₂ efflux was recorded. Increases in volcanogenic gases occurred very probably throughout an inflating state of the volcano during the pre-eruptive period, which caused the wide opening of the fractures. Lastly, variations in indoor Radon concentrations observed before an eruption, indicate the suitability of the investigated sites for in-soil Radon monitoring at a low altitude of the south-eastern flank of Mt. Etna. Moreover, in this place repeated and long period Radon indoor measurements should be carried out due to high potential indoor accumulation which depends from the volcanic activity, as this could constitute a serious danger to public health.     

峨眉山柿子坪热田地表氡气异常特征

本文通过柿子坪地区地表氡气测量,对热田地表氡气异常特征作了初步分析。该区地表氡气高值异常呈环状产出,并严格受构造控制。同时指出地表氡气测量是热田勘查的有效途径。     

基于迭代阈值收缩的高分辨率Radon变换方法效果对比

提高Radon变换分辨率的研究一直是地震数据处理方法研究的热点之一。常用的提高分辨率的算法是在频率域进行的,然而此方法在频域中计算的模型权重是偶然耦合的,会对所有同相轴施加相同的权重,导致高能量同相轴地震道生成假像。此文给出了3种时间域提高Radon变换分辨率的方法,IST(iterative shrinkage thresholding)、FIST(fast iterative shrinkage thresholding)和SRTIS(sparse radon transform iterative shrinkage),并对3种算法的收敛效率和计算效果进行了对比分析。理论和实际数据的测试表明,SRTIS方法在效率和效果的对比上均优于其他两种,并且具有较好的去除多次波能力。     

Radon and tilt measurements in a seismic area: Temperature effects

Since 1977 five tilt-strainmeter stations have been installed in the Friuli seismic area for the detection of tectonic deformations and pre co and post-seismic effects. In 1994 a station for Radon concentration measurements was installed with the aim to detect possible precursors. The noise effect due to rainfalls and atmospheric pressure variations was already stressed in previous papers. In this work the effect of temperature on both tilt measurements and Radon emanation is examined. A significant correlation between tilt and temperature is present on the annual behaviour, mainly due to thermoelastic effects although annual water table level variations can greatly influence the done results. On shorter periods (10–20 days) significant correlations also exist. Regarding the Radon measurements, an interpretative model has been reported. It relates the variation of the correlation coefficient sign with the temperature. Indeed Radon and temperature are positively correlated in winter and inversely correlated during the summer.     

串联去噪技术在金属矿地震勘探中的应用

金属矿地震勘探中原始数据的信噪比很低,多种干扰混杂在记录中,常规去噪手段难以达到理想效果。针对金属矿地震数据中强线性干扰,设计了f-k 滤波、Radon 变换方法二级衰减; 针对强随机噪声,设计Radon 变换以及Curvelet 域组合变换法二级衰减,组成了f-k 滤波法、Radon 变换及Curvelet 域组合变换法串联去噪方法。应用于金昌金属矿多类混杂强噪声的地震实际数据中,大幅提高了数据的信噪比,经验证本文方法实用、有效。     

Presence of radon in groundwater in parts of Bangalore

Presence of high levels of Radon (²²²Rn) gas was reported from groundwater in Bangalore. To ascertain the ground reality and the nature of the hazards, if any, a study was conducted by the Central Ground Water Board, Bangalore in and around Bangalore city. Groundwater samples from borewells and a dug well were collected and analysed. Available data on Radon gas from both groundwater and surface water sources were also compared. The presence of Radon gas and its concentration in groundwater were examined with respect to geology and well depths. The results are discussed in the paper.     

基于低频约束的高分辨率Radon变换多次波压制方法研究

抛物线Radon变换是地震资料处理中常用的一种多次波压制方法,常规Radon变换由于采用最小二乘算法的原因,对不同的曲率值采用相同的加权值进行求解,分辨率较低。为提高Radon域数据的分辨率,应采用对不同曲率值应用不同的加权值的方法。一般的思路是利用前一次迭代的结果得到加权矩阵,该算法需要迭代进行,运算量较大。这里拟采用低频约束的方式提高Radon变换的分辨率,即利用前一个频率的运算结果对下一个频率的计算进行约束,该算法分辨率高,计算速度快。模拟数据和实际数据的测试表明,本文方法在多次波压制处理中,可以快速有效地完成多次波去除。     

时间域拉东变换的实现及其改进

介绍了时间域拉东正反变换的基本原理及该项技术在地震数据处理中的应用。以Ng和Perz的算法为基础,以开发地震勘探处理与解释系统为实例,解决了实验中遇到的拉东正变换时收敛精度、反变换数据无损还原和截断信号引起的能量扩散、低信噪比情况下的滤波等问题,进一步研究了改进算法在其他地形下应用问题。     

Estimation of radon as an earthquake precursor: A neural network approach

An artificial neural networks (ANN) approach combined with Fourier Transform based selection of time period in the time series Radon Emission Data has been presented and shown to improve event prediction rates and reduce false alarms in Earthquake Event Identification over the traditional multiple linear regression techniques. The paper presents a neural networks system using radial basis function (RBF) network as an alternative to traditional statistical regression technique in isolating Radon Emission Anomaly caused by seismic activities. The RBF model has been developed to accept and predict earthquakes events based on a known data set of Radon Emanation, Metrological parameters and actual earthquake events. Subsequently, the model was tested and evaluated on a future data set and a prediction rate of 87.8%, if a reduced false alarm was achieved, the results obtained are better than the traditional techniques.