再谈黎平敖市金刚石异常——贵州省当前最佳金刚石找矿靶区分析     

盛学庸 《贵州地质》2011,28(1):2-8

诸多迹象表明,敖市金刚石异常为一浓集异常,且叠加在一辉石重砂异常之上,显示出强烈的近源补给特征,其补给源极有可能是具工业价值的金刚石原生矿.鉴于湘黔金刚石成矿区内已知的含金刚石钾镁煌斑岩及其相关岩体的同位素年龄值均在375～475 Ma范围,其成矿期显然属加里东晚期,而紧邻敖市异常尚有后加里东盖层残留,作为幔源火山作用...  相似文献   

城市近地层湍流特征分析   总被引：3，自引：3，他引：0  

邹钧  孙鉴泞  刘罡 《气象科学》2011,31(4):525-533

利用中国科学院大气物理研究所在北京的325 m铁塔观测资料,本文分析了47、140和280 m三个高度的湍流统计特征.结果表明,城市近地层的湍流速度方差和湍流温度方差都较好地满足局地相似关系,140 m和280 m的湍流特征非常接近,而47 m的湍流特征与之相比表现出明显的差异,说明由于城市冠层动力和热力非均匀性的影响...  相似文献   

气枪激发信号传播的谱元法数值模拟研究          下载免费PDF全文

唐杰 《地球物理学报》2011,54(9):2348-2356

为了研究气枪激发信号的波场,本文利用谱元法对双相介质中波的传播做了数值模拟,分析了波的传播特征.本文主要做了以下工作:(1)研究了使用谱无法(SEM)模拟孔隙弹性介质中波的传播,模拟结果表明,采用谱元法能有效解决双相介质的波场传播模拟问题.(2)验证了Biot理论中慢纵波的存在.双相介质中存在明显的慢纵波,流相波场的慢...  相似文献   

Artificial neural network forward modelling and inversion of electrokinetic logging data     

N. Ardjmandpour  C. Pain  J. Singer  J. Saunders  E. Aristodemou  J. Carter 《Geophysical Prospecting》2011,59(4):721-748

An artificial neural network method is proposed as a computationally economic alternative to numerical simulation by the Biot theory for predicting borehole seismoelectric measurements given a set of formation properties. Borehole seismoelectric measurements are simulated using a finite element forward model, which solves the Biot equations together with an equation for the streaming potential. The results show that the neural network method successfully predicts the streaming potentials at each detector, even when the input pressures are contaminated with 10% Gaussian noise. A fast inversion methodology is subsequently developed in order to predict subsurface material properties such as porosity and permeability from streaming potential measurements. The predicted permeability and porosity results indicate that the method predictions are more accurate for the permeability predictions, with the inverted permeabilities being in excellent agreement with the actual permeabilities. This approach was finally verified by using data from a field experiment. The predicted permeability results seem to predict the basic trends in permeabilities from a packer test. As expected from synthetic results, the predicted porosity is less accurate. Investigations are also carried out to predict the zeta potential. The predicted zeta potentials are in agreement with values obtained through experimental self potential measurements.  相似文献   

Hydropower licensing and climate change: Insights from cooperative game theory   总被引：3，自引：0，他引：3  

Kaveh Madani 《Advances in water resources》2011,34(2):174-183

Cooperative game theory solutions can provide useful insights into how parties may use water and environmental resources and share any benefits of cooperation. Here, a method based on Nash and Nash-Harsanyi bargaining solutions is developed to explore the Federal Energy Regulatory Commission (FERC) relicensing process, in which owners of non-federal hydropower projects in the United States have to negotiate their allowable operations, with other interest groups (mainly environmental). Linkage of games to expand the feasible solution range and the “strategic loss” concept are discussed and a FERC relicensing bargaining model is developed for studying the bargaining stage (third stage) of the relicensing process. Based on the suggested solution method, how the lack of incentive for cooperation results in long delay in FERC relicensing in practice is explained. Further, potential effects of climate change on the FERC relicensing are presented and how climate change may provide an incentive for cooperation among the parties to hasten the relicensing is discussed. An “adaptive FERC license” framework is proposed, based on cooperative game theory, to improve the performance and adaptability of the system to future changes with no cost to the FERC, in face of uncertainty about future hydrological and ecological conditions.  相似文献   

平面不对称结构非弹性地震反应分析的平扭耦联Bouc-Wen模型     

余波  杨绿峰 《地震工程与工程振动》2011,31(6):78-87

综合考虑强度退化、刚度退化、捏拢效应等典型滞回特性的影响,建立了双向地震作用下平面不对称结构非弹性地震动力响应分析的平扭耦联Bouc-Wen模型.该模型采用圆形屈服面来描述双向抗侧恢复力之间的耦合效应,而采用锥体或球体屈服面来描述双向抗侧和抗扭恢复力之间的耦合效应,并结合69条强震记录,定量地分析了平扭耦联效应对平面不...  相似文献   

安徽铜陵狮子山矿田铜、金共生与分离的热力学研究   总被引：4，自引：0，他引：4       下载免费PDF全文

徐晓春  楼金伟  谢巧勤  肖秋香  梁建锋  褚平利 《地质学报》2011,85(5):731-743

狮子山矿田是安徽铜陵矿集区内最具代表性的大型铜金多金属矿田.矿田内铜、金矿床或矿体既各自独立产出,义相互共生或伴生,铜矿化和金矿化在时间上和空间上存在既共生又分离的现象.本文选择矿田内代表性铜矿床和金矿床开展系统的流体包裹体地球化学研究,并进行成矿流体中铜、金溶解度的热力学理论计算和1分析,探索铜、金共生与分离的机制和...  相似文献   

基于极化相干矩阵的河流水质污染监测初探   总被引：1，自引：0，他引：1  

陈炯  贾海峰  杨健  陈玉荣 《遥感学报》2011,15(5):1065-1078

利用遥感手段监测水质污染具有监测范围广、实时性强的优点。本研究选择中国南方地区水质变化明显的河流区域作为研究对象,利用C波段星载极化合成孔径雷达(极化SAR)卫星RADARSAT-2提供的数据,对基于极化SAR的河流水质污染监测技术进行了初步研究。首先介绍了电磁波的极化现象以及极化SAR的基本原理;其次结合一次同步测量实验,提取河流区域,并对极化SAR数据与水质常见监测指标的监测数据进行对比分析,通过对10个采样点18组数据的分析发现,极化相干矩阵中的T 22元素与部分水质指标(如五日生化需氧量BOD₅等)具有较强的相关性,从而反映水质的污染状况;并通过实测数据和最小二乘法,拟合得到了利用[T]矩阵元素反演BOD₅的经验公式,拟合系数达到0.82。最后通过对地表散射模型和菲涅尔系数的分析,从理论上探讨了极化相干矩阵中部分元素与水体物理性质存在相关性的原因。初步理论分析和实验数据表明,T 22元素能够反映水体的污染状况。  相似文献   

基于模糊理论和典型线路的地质灾害评价的GIS方法研究   总被引：1，自引：0，他引：1  

胡圣武 《测绘科学》2011,36(4):86-88,65

根据影响区域地质灾害发生的地质因素、地形因素、诱发因素和人为因素,建立区域地质灾害评价指标体系,对典型线路穿越的评价试验区进行地质灾害区域评价.由于地质灾害数据不仅含有不确定性而且还有复杂的模糊性,因而选用模糊评价方法.本文主要通过选取典型线路,采用模糊综合评判,利用GIS来进行,该研究结果表明是科学的、合理的和客观的...  相似文献   

基于力学思想的空间聚类有效性评价     

刘启亮  邓敏  彭东亮  王佳璆 《武汉大学学报(信息科学版)》2011,(8):982-986,990

从力学的角度来考虑空间聚类问题,并结合地理学基本规律提出了一种基于力学思想的空间聚类有效性评价指标(简称SCV)。实验分析表明,本文提出的评价指标能够更准确、高效地对二维地理空间数据的硬聚类结果进行有效性评价。  相似文献