综合地球物理方法对南海西北部-印支半岛地区中生界分布的研究

南海西北部是我国海洋油气的重要基地.为了研究该区前新生代尤其是中生代油气资源潜力,本文以岩石物性的差异为基础,建立地质界面与物性界面的联系,利用综合地球物理方法来分析目标物性界面的分布特征.在地震资料控制浅层沉积结构的约束下,根据重力资料,通过小波分析位场剥离等方法得到剩余场,由Parker界面反演法反演计算了研究区的重力基底,结合新生代沉积分布得出中生界分布特征并给出了中生代残留盆地的可能分布范围,为分析研究区中生代油气资源潜力提供参考.     

土体动力一维非线性本构关系剖析与评价

土体动力一维非线性本构关系是场地及地基动力响应、土工数值分析的关键。回顾和总结了国内外的发展状况及研究进展,对其分析方法、等幅循环荷载到不规则荷载的扩展及应用规则、试验阻尼比的等效、滞回曲线形状等核心问题进行剖析、评价和探讨,并对各种模型的优缺点进行了比较和讨论,着重介绍了最近研究结果。最后指出未来发展方向及有待进一步研究的问题。     

犯罪热点时空分布研究方法综述

犯罪在地理时空内并不是均匀分布的,而是表现出明显的时空聚集特性,这种聚集性常用“犯罪热点”表述.基于对犯罪热点的理解,从犯罪热点时空分布模式、犯罪热点成因分析以及犯罪热点时空转移及预测等3 个方面总结了当前国内外犯罪热点时空分布相关研究方法的进展.最后,对该领域研究进行了总结与展望.总体上,国内相关研究较少,尚需进一步结合中国国情,提出适用方法.另外,也需要通过相关犯罪理论的深入研究以及其他领域研究方法的借鉴,实现犯罪热点时空分布研究方法的突破与创新.     

地铁施工对济南白泉泉群流量的影响

为研究地铁建设对济南白泉泉群的影响，在综合分析白泉泉域地质、水文地质条件的基础上，假定研究区岩溶强径流带位置及水力性质，利用FEFLOW软件建立地下水流数值模型。以规划地铁M1号线为研究对象，分析了济南东站、梁王站、梁王东站分别施工及3个站同时施工4种情景下，采用施工降水或施工降水+人工回灌两种施工方式对白泉泉群流量的影响。结果表明：单独采用施工降水的施工方式使得白泉泉群流量衰减，其中3个站同时施工对泉流量的影响最大，泉流量最大衰减达5.48%；各站分别施工时，济南东站对泉流量影响最大，泉流量较未施工时减少了0.043×10⁴ m³/d。采用施工降水+人工回灌的施工方式，能够有效缓解泉流量的衰减，各车站施工时的泉流量衰减由仅施工降水时的2.26%~5.48%降低至0.08%~1.21%。岩溶强径流带有利于地下水形成优势径流，促进白泉泉群补给，一定程度上缓解因地铁施工引起的泉流量衰减。     

Application of kriging with external drift to estimate hydraulic conductivity from electrical-resistivity data in unconsolidated deposits near Montalto Uffugo, Italy

In the framework of various studies to characterize the aquifer at the groundwater experimental field near Montalto Uffugo, Italy, the present work estimates the spatial distribution of hydraulic conductivity of the unconsolidated deposits that underlie the area, by applying the geostatistical technique of kriging with external drift to electrical-resistivity and hydraulic-conductivity data. The reliability of the estimation method was tested by implementing a model, based on the method of cells, that simulates groundwater flow, with the estimated values of hydraulic conductivity. The results obtained indicate that the estimation method used has an acceptable degree of reliability.     

Calculating the two-dimensional magnetotelluric Jacobian in finite elements using reciprocity

To speed up the calculation of the field Jacobian for 2-D magnetoteliuric inversion using finite elements, the principle of electromagnetic reciprocity is applied. The governing relationship for the Jacobian of the field along strike is obtained by differentiating the Helmholtz equation with respect to the resistivity of each region in the finite-element mesh. The result is a similar Helmholtz equation for the Jacobian, with new sources distributed over all nodes within the parameter medium. However, according to the principle of electromagnetic reciprocity, the roles of sources and receivers are interchangeable. Utilizing reciprocity, the field values obtained from the original forward problem and for new unit sources imposed at the receivers are then utilized in the calculation of the Jacobian by simple multiplication and summation with finite-element terms at each rectangle in the mesh. For the auxiliary (across-strike) fields, the Jacobian terms are obtained by solving source vectors loaded with parabola coefficients used in the approximation to Maxwell's equations. Jacobian terms for the apparent resistivity ( p _a), the impedance phase (φ) and the vertical magnetic field ( K _zy) are then calculated utilizing the parallel- and auxiliary-field Jacobians. Comparison of Jacobian values obtained from reciprocity calculations and by differencing two forward solutions show that the reciprocity method is accurate and can be used to decrease the number of calculations required to obtain sensitivities by one to two orders of magnitude.     

遥感技术在腾冲西南地区地热资源研究预测中的应用

利用TM数据,对滇西腾冲西南地区进行地质构造解译,阐明了该区多地热活动的原因.通过对TM6波段热红外异常信息的提取,经构造解译与地热异常分布区的叠加分析,发现了该区地热富集的规律性,提出了地热田的遥感影像模式.据此,预测出腾冲西南地区62处水热活动Ⅰ级异常区.     

东天山戈壁荒漠景观区地球化学勘查中某些工作方法的研究

通过东天山地区地球化学勘查中某些方法的试验,研究了一套适宜于戈壁荒漠景观中地球化学勘查的工作方法.（1）查明了盛行风对岩屑异常特征的影响程度;（2）推荐消除风成沙影响的合理采样粒级;（3）利用水溶态铜、金异常指示被运积物掩盖的铜、金矿体;（4）明确了荒漠区盐磐层不会阻碍在残积物覆盖区发现矿致岩屑异常和在运积物覆盖区发现后生晕.     

The analysis of indexed astronomical time series – VI. Covariances of amplitude ratios and phase differences estimated from multicolour photometry of a pulsating star

One of the tools used to identify the pulsation modes of stars is a comparison of the amplitudes and phases as observed photometrically at different wavelengths. Proper application of the method requires that the errors on the measured quantities, and the correlations between them, be known (or at least estimated). It is assumed that contemporaneous measurements of the light intensity of a pulsating star are obtained in several wavebands. It is also assumed that the measurements are regularly spaced in time, although there may be missing observations. The amplitude and phase of the pulsation are estimated separately for each of the wavebands, and amplitude ratios and phase differences are calculated. A general scheme for estimating the covariance matrix of the amplitude ratios and phase differences is described. The first step is to fit a time series to the residuals after pre-whitening the observations by the best-fitting sinusoid. The residuals are then cross-correlated to study the interdependence between the errors in the different wavebands. Once the multivariate time-series structure can be modelled, the covariance matrix can be found by bootstrapping. An illustrative application is described in detail.