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1.
航空重力局部异常地质成因分类及找矿意义 总被引：2，自引：0，他引：2
以我国首次试验的航空重力数据为基础,通过局部重力异常的突出方法处理和反演拟合,结合航磁、地震、钻井等资料,按照引起局部异常的地质体性质,将研究区的局部重力异常划分为6类,即与基岩凸起有关的局部异常、与基岩凹陷有关的局部异常、与侵入岩有关的局部异常、与喷出岩有关的局部异常、与中酸性岩浆岩中老地层有关的局部异常、与深部地幔柱有关的局部异常.每类局部异常又可根据具体的地质体属性划分为若干种局部异常,并构成某种矿产资源的反映.其中,基岩凸起异常、基岩凹陷异常、岩浆岩体异常分别构成油气田、煤田、金属矿床的重要找矿标志.正确认识局部重力异常及其成因,是航空重力地质资源调查的目标之一,具有重要的找矿意义. 相似文献
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通过激电测深对内蒙古义盛店银多金属矿区进行了物探测量,并对所取得的数据进行了正反演处理,消除了地形对有用异常的影响,压制了局部干扰异常,突出了矿化异常,找到了深部矿化体的空间赋存状态及中心位置.经过钻探初步验证,见矿效果良好,显示出乐观的找矿前景.该方法对类似地区的找矿工作提供了可借鉴的找矿经验. 相似文献
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位场场源边界识别是位场数据分析解释中的重点内容之一。相邻异常源由于场的叠加而难以区分,尤其是对于叠加异常中不同深度的场源边界的识别。倾斜角法是位场数据处理中常用的边界增强方法之一,能有效突出低振幅、短波长的异常特征。本文基于倾斜角法定义了新的位场边界探测方法,该方法利用倾斜角方程中位场二阶垂直导数与垂向导数水平导数之比进行计算,能有效区分相邻异常源产生的叠加异常,突出叠加异常中不同深度场源的边界特征。通过综合模型和实测数据,并与现有的基于导数的位场边界探测方法进行比较,评价了该方法的应用效果。结果表明,该方法对场源深度的变化不太敏感,它可以更准确地确定场源边界,区分相邻异常源的叠加异常,尤其对密集型组合地质构造的识别有较好的效果,即使是在场源埋深较大情况下,也能突出叠加异常中不太明显的微弱变化的线性异常特征,以及弱异常源的形态特征,可为精细研究局部地质构造提供技术支持。 相似文献
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重力勘探在金属矿区的应用虽然愈来愈多,但对局部异常的解释目前仍停留在对异常的简单描述上,还没有建立起象磁法勘探那样完整、系统的定性和定量解释方法,因而妨碍了重力勘探效力的发挥.本文想通过几种简单规则形体重力异常的g_z-g_x参量曲线(即以水平线上的局部重力异常g_z为纵坐标,相应的重力异常的水平分量 相似文献
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小波多尺度分析是重磁异常分离的一个重要方法,它不同于如窗口滑动平均法、趋势分析法、匹配滤波等常用方法,因这些方法分离出的局部异常是地质体从某个深度往上直到地表的综合反应,由于近地表地质体及干扰源的作用使得被分离出的局部异常成分复杂、形态较为凌乱、不规整;而用小波多尺度分析分解出的N(N1)阶细节异常划分的局部异常则为地质体从深度A往上到深度B这一空间段的综合反应,由于其不包含以一阶细节异常为代表的浅层地质体及干扰源异常,异常成分简单、形态规整、为深部地质体的自然反应,适用于研究隐伏岩体与隐伏矿床。通过二次开发解释20世纪80年代采集的月山地区1∶1万地面磁测数据,并最终提交由小波多尺度分析法分解的局部异常成果,其中3个异常与朱冲铁矿的3个矿段相吻合,而这些局部异常却是在未知朱冲铁矿的前提下提取的,可预见其它几个有类似地质条件的局部异常也具找矿前景。 相似文献
7.
李景朝 《吉林大学学报(地球科学版)》1998,(3)
介绍了几种油气化探多参数异常评价方法,包括以多元正态分布理论为基础的多元背景与异常下限划分方法——ＭＡＡ方法;以突出油气信息、压抑不利影响的ＭＰＶ方法;Ｄ函数方法——ＭＡＤ和ＭＡＶ方法。通过在华北某油区的应用,异常对油气藏指示成功率达５０％以上。并提出了油气藏的套合异常模式。 相似文献
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根据小子域滤波原理,小子域滤波产生异常边界扭曲主要表现为高频干扰,提出小子域滤波与非局部均值滤波联合的方法以克服小子域滤波存在的异常边界扭曲问题。利用小子域滤波良好的边界增强能力和非局部均值滤波高频细节保护能力,在压制小子域滤波缺陷的同时尽可能保护小子域滤波的边界增强效果。通过模拟计算和莱州湾海域实测重力数据处理表明,本文方法在增强异常边界的同时压制小子域滤波产生的边界扭曲效应,获得了更好的重力异常处理效果。与单一小子域滤波相比,本文方法不需要考虑异常边界形态,具有更强的稳定性和普适性。 相似文献
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划分重力局部异常和区域异常的常用方法有平行直线法、圆周法、平滑曲线法和多项式拟合法(或趋势分析法).前两种方法适用于区域场为平面特征的情况;第三种方法的效果受人为经验因素的影响很大;最后一种方法由于测区内局部异常数据参与区域场多项式的拟合,所以分离效果往往不太理想. 本文推荐的方法称为九点差分格式异步迭代法,简称差分迭代法.它不仅适用于平面特征的区域场,还能逼近二次曲面特征的区域场,并可靠地从复杂背景上提取局部异常.运算过程借助电子计算机(或可编程序的电子计算器)即可实现. 相似文献
11.
Günther R. Drevin 《Mathematical Geology》2006,38(7):871-890
A number of subjective and objective methods have been proposed to determine the roundness of rock particles, roundness being
one of three properties describing the shape of a particle.
Methods that make use of the Fourier transform of the polar coordinates of particles’ edge elements are proposed in this paper.
Lowpass filters are used to smooth the profiles of rock particle, roundness is then determined from the differences between
the original and smooth profiles. Further methods that are proposed make use of different measures of inequality to quantify
the distribution of the energy among the transform coefficients of the profiles of rock particles. These values are then used
to determine the roundness of the particles. Entropy and Emlen’s modified entropy are the measures of inequality that are
used. Different methods of determining the centre point of a particle and different methods to interpolate the edge elements
are compared. The sensitivity of the methods to different resolutions is also investigated.
The results obtained with the proposed methods are comparable to those obtained with an existing Fourier transform based method,
however it is shown that the proposed methods are computationally less demanding. It is also shown that the proposed methods
are better than the existing method when the comparison is based on the correlation between the mean roundness of samples
of particles and the actual roundness of the particles. 相似文献
12.
纳米碳管分离提纯技术 总被引：2，自引：0，他引：2
较详细地介绍了当前国内外纳米碳管分离提纯的最新技术 ,并分别对各种可能具有应用价值的分离方法进行了评述。在综合分析目前国际上研究纳米碳管两大类截然不同的分离技术———化学提纯法和物理提纯法———的基础上 ,提出这方面研究应该综合利用物理分离和化学分离方法 ,达到既能得到高纯度纳米碳管 ,又能减少对纳米碳管的结构破坏的最终目的。最后 ,对各国的纳米碳管分离研究现状进行了进一步的讨论。 相似文献
13.
Evaluation of hydrophilic cotton processing wastewater treatment methods and giving the optimum method for it 总被引：1，自引：1，他引：0
We studied the methods of wastewater treatment of hydrophilic cotton producing industries. Several major cotton producing countries, such as India, have provided very stringent environmental standards for these industries, and it is expected that these standards are becoming more stringent day by day. This is necessary for monitoring and control facilities, in order to minimize problems and difficulties associated with treated wastewater disposal. Unit processes of these industries are: pretreatment, dyeing, printing and other complementary processes. In this industry, aside from considerable amounts of energy and water consumption, considerable quantity of wastewater is also produced. This article discusses all types of waste producing hydrophilic cotton processes; we have also advanced wastewater treatment methods, such as electrical oxidation, membrane processes, biological and photochemical treatments. Results showed that traditional methods of wastewater treatment are compound methods including physical–chemical and biological methods, and requires substantial investment and operational costs. Compared to traditional methods, membrane systems are very effective methods and are a good substitute. Investigation showed that hybrid treatment methods that include absorption and absorption by nano-filtration can play an effective role in improving treated wastewater quality. Moreover, advanced treatments such as ion exchange systems can improve wastewater quality to the extent that it can be recycled to the production processes for second usage. 相似文献
14.
In this paper, we study newly developed methods for linear elasticity on polyhedral meshes. Our emphasis is on applications of the methods to geological models. Models of subsurface, and in particular sedimentary rocks, naturally lead to general polyhedral meshes. Numerical methods which can directly handle such representation are highly desirable. Many of the numerical challenges in simulation of subsurface applications come from the lack of robustness and accuracy of numerical methods in the case of highly distorted grids. In this paper, we investigate and compare the Multi-Point Stress Approximation (MPSA) and the Virtual Element Method (VEM) with regard to grid features that are frequently seen in geological models and likely to lead to a lack of accuracy of the methods. In particular, we look at how the methods perform near the incompressible limit. This work shows that both methods are promising for flexible modeling of subsurface mechanics. 相似文献
15.
Groundwater recharge in semi-arid carbonate aquifers under intensive use: the Estepa Range aquifers (Seville, southern Spain) 总被引：2，自引：1，他引：1
Sergio Martos-Rosillo Miguel Rodríguez-Rodríguez Antonio Pedrera J. Javier Cruz-SanJulián J. Carlos Rubio 《Environmental Earth Sciences》2013,70(6):2453-2468
Quantifying groundwater recharge in carbonate aquifers located in semi-arid regions and subjected to intensive groundwater use is no easy task. One reason is that there are very few available methods suitable for application under such climatic conditions, and moreover, some of the methods that might be applied were originally designed with reference to non-carbonate aquifers. In addition, it is necessary to take into account the fact that, in any given aquifer, groundwater recharge is modified by the groundwater exploitation. Here we focus on four methods selected to assess their suitability for estimating groundwater recharge in carbonate aquifers affected by intensive exploitation. The methods were applied to the Estepa Range aquifers of Seville, southern Spain, which are subjected to different degrees of exploitation. Two conventional methods were used: chloride mass balance and daily soil–water balance. These results were compared with the results obtained by means of two non-conventional methods, designed for application to the carbonate aquifers of southern Spain: the APLIS and ERAS methods. The results of the different methods are analogous, comparable to those obtained in nearby non-exploited carbonate aquifers, confirming their suitability for use with carbonate aquifers in either natural or exploited regimes in a semi-arid climate. 相似文献
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湖泊沉积物中三种磷提取方法比较 总被引：3，自引：1，他引：2
水体沉积物中磷的分级提取没有统一的方法,大多数的提取方法只对沉积物中无机磷(IP)进行了研究,有机磷(OP)是作为一个整体被研究,OP的形态尚不清楚。文章探讨了SMT法、Ivanoff法和Golterman法三种方法对湖泊沉积物中磷形态提取的特征,分析了各方法应用于IP和OP形态提取的联系和差别。结果表明SMT法提取的钙磷(Ca-P)是Golterman法提取Ca-P的16倍,Golerman法提取的铁铝结合态磷(Fe/Al-P)是SMT法提取的近3倍。从OP提取结果来看,Goterlman法>Ivanoff法>SMT法,Golterman法和Ivanoff法提取的酸可提取有机磷相差较大,其他形态OP含量则相当。研究结果对于沉积物磷形态分析提取方法的合理选择具有指导意义。 相似文献
18.
物探方法在研究三峡库区滑坡中的应用前景 总被引：4，自引：0，他引：4
介绍了滑坡的地质－地球物理特征，指出了滑坡中的物性参数分布和滑坡产生的地球物理异常都和稳定边坡有明显的不同，为用物探方法研究滑坡提供了良好的地质－地球物理前提；对物探方法在滑坡时的应用进行了介绍，用实例说明了物探方法可以成功地用来研究滑坡地段的工程地质条件和预测滑直过程；对三峡为哎应用物探方法研究滑坡的必要性和可能性进行了探讨。 相似文献
19.
打入桩承载力确定方法对安全系数的影响 总被引：1，自引：0，他引：1
在传统的容许应力设计方法中桩基承载力安全系数取决于桩基承载力的确定方法,然而,基于经验选择的承载力安全系数缺少理论依据,为此,基于贝叶斯理论和线性回归方法提出了评价桩基承载力确定方法对承载力安全系数影响的方法,给出了现行规范对于不同承载力确定方法采用不同安全系数的理论依据,阐明了桩基动力测试降低安全系数的理论依据,并以7种桩基设计方法为例,分析了承载力确定方法对安全系数的影响。结果表明,采用所提出的方法计算的安全系数基本上与现行的经验值相一致,表明精确的承载力确定方法可以有效地降低承载力安全系数,设计方法、承载力确定方法和水平都对安全系数有影响,但当承载力试验桩的数目足够多时,安全系数对于设计方法的精确性不敏感。 相似文献