麦兹地区火山沉积岩型铅-锌矿床地质特征与找矿方向

阿尔泰山南缘的铅-锌矿床主要分布于麦兹地区,为了在其找矿空间和找矿类型上有所突破,详细地阐明了麦兹地区铅-锌矿床的主要地质特征、成因类型及其控矿因素,并结合区域构造演化背景,总结了麦兹地区铅-锌矿床的成矿规律,指明了铅-锌矿床的找矿方向。     

阿勒泰复向斜的成矿环境及其矿产

在阿勒泰复向斜内,分布有众多矿产,是阿尔泰山南缘重要的铜、铅、锌及多金属成矿区之一。文章详细介绍了这些重要矿床即铁木尔特铜-锌矿床、大东沟铅-锌矿床、乌拉斯沟铜-铅-锌矿床、阿巴宫铁矿床、红墩铅-锌矿床的地质特征,并从现代成矿理论角度全面分析了这些矿床形成的区域成矿环境及其找矿前景。     

广西大瑶山古里脑和龙头山金矿岩浆期后断裂成矿作用及找矿意义

通过对大瑶山区古里脑和龙头山金矿床地层、岩浆岩含矿性的分析,并进行断裂构造作用多期性的分析和岩浆期后断裂成矿作用的讨论,认为该区深部地层和岩体中的金元素在次火山—斑岩期后断裂构造热液的作用下逐步向上叠加、富集成矿;矿体与岩浆岩体在空间上具有密切的关系;构造-热液作用导致次火山岩、斑岩体或周围地层产生破碎,并使成矿热液沿裂隙充填和再充填而形成金矿体,区内凡构成工业富集的富矿体和含金石英脉或破碎带都与多期次活动的构造-热液作用有关。因此,多期活动的构造-热液作用在大瑶山区具有非常重要的找矿意义。     

含铍条纹状蚀变岩在发现界牌岭锡多金属隐伏矿床中的找矿意义

界牌岭锡多金属矿床是一个大型隐伏矿床，找矿工作采用了化探次生晕、原生晕、地质调查等多种方法和手段。含敛条纹状蚀变岩的发现在找矿预测中起到了致关重要的作用，为找矿工作开拓了新的思路．     

Multi-year drought frequency analysis at multiple sites by operational hydrology - A comparison of methods

This paper compares two generators of yearly water availabilities from sources located at multiple sites with regard to their ability to reproduce the characteristics of historical critical periods and to provide reliable results in terms of the return period of critical sequences of different length. The two models are a novel multi-site Markov mixture model explicitly accounting for drought occurrences and a multivariate ARMA. In the case of the multisite Markov mixture model parameter estimation is limited to a search in the parameter space guided by the value of parameter λ to show the sensitivity of the model to this parameter. Application to two of the longest time series of streamflows available in Sicily (Italy) shows that the models can provide quite different results in terms of estimated return periods of historic droughts, although they seem to perform more uniformly when it comes to simulate drought-related statistics such as drought length, severity and intensity. The role of parameter selection for the multisite Markov mixture model and of the marginal probability of generated flows in providing results consistent with the characteristics of the observed series is discussed. Both models are applied to the system of sources supplying the city of Palermo (Sicily) and its environs showing the applicability of the newly developed multisite Markov mixture model to medium-to-large scale water resources systems.     

Short and long memory unobserved components in hydrological time series

In this paper a semiparametric approach is introduced to decompose an ARFIMA model in the long memory and short memory unobserved components. The procedure is based on the DECOMEL method which produces a statistical decomposition by minimizing the Euclidean distance between the spectrum of the aggregated series and the sum of the parametric spectra of the components. The extension to long memory stationary models is achieved defining an approximate model where the fractional operator is replaced by the ratio of two polynomials of order one. The feasibility and performance of the proposed procedure are discussed through a case study.     

Selection of ground motion time series and limits on scaling

A procedure to select time series for use in non-linear analyses that are intended to result in an average response of the non-linear system is proposed that is not based simply on magnitude, distance, and spectral shape. A simple model of a yielding system is used as a proxy for the non-linear behavior of a more complicated yielding system. As an example, Newmark displacements are used as a proxy for more complex slope-stability models. The candidate scaled time series are evaluated to find those that yield a response of the simple non-linear system that is near the expected response for the design event. Those scaled time series with responses near the expected value are selected as the optimum time series for defining average response even if the scale factors are larger than commonly accepted (e.g. scale factors >factor of 2).     

基于? -SVR算法的隧道围岩位移演化规律预测

针对目前广泛应用的灰色理论、遗传算法(GA)和人工神经网络(ANN)等方法预测隧道稳定性的缺陷，提出应用稳健性能较好的? -SVR（support vector machine）算法对非对称连拱隧道围岩位移演化规律进行预测研究。应用加速混合遗传算法搜索? -SVR最优参数，以提高? -SVR的预测能力。将预测结果与灰色理论、BP神经网络预测结果进行比较，显示? -SVR算法学习和预测精度高。     

利用岩石质量指标和岩体块度指数进行岩体质量评价研究——以高放废物地质处置库预选场址甘肃北山1号钻孔为例

岩体质量的评价对于各类大型建筑物特别是地下工程建筑物的安全性具有十分重要的作用。文章基于岩石质量指标（RQD）和岩体块度指数（RBI）的理论，通过对甘肃北山1号钻孔的岩心实测资料证明，岩体块度指数在一定程度上能反映岩体的完整性与相应力学性质的变化特点，同时给出钻孔附近岩体质量分类，进而与岩石质量指标所获得的钻孔附近岩体质量评价分级进行对比。对比结果表明：岩体块度指数在岩石质量评价中能更准确地反映其优越性，具有更为显著的工程意义。     

天山地区新元古代-早寒武世火山岩地球化学和岩石成因

天山地区新元古代-早寒武世玄武质熔岩包括拉斑玄武质和碱性玄武质两个主要岩浆系列，前者是早期（早南华世贝义西组、早震旦世扎摩克提组）喷发的火山岩系的主要组成，后者是晚期（早震旦世苏盖特布拉克组、晚震旦世水泉组、早寒武世西山布拉克组）喷发的火山岩系的主要组成。稀土、微量元素和Sr、Nd同位素特征揭示，这些火山岩均形成于大陆裂谷环境，其源区可能是源于一种似洋岛玄武岩源的软流圈地幔源，并且在岩浆上侵喷发过程中发生了岩石圈的混染。