城市环境下的水土作用对土强度的影响   总被引：11，自引：1，他引：10  

吴恒  张信贵  易念平  代志宏  龚琦 《岩土力学》1999,20(4):25-30

在对南宁市水化学场进行历史分析的基础上,对南宁市天然水化学场进行模拟,以模拟溶液作为土体的浸渍液,研究变异后的水化学场对土体强度的影响。  相似文献   

江西金山矿床地质特征及矿床成因探讨   总被引：4，自引：0，他引：4  

王可勇 《地质与勘探》1999,35(2):17-20

金山金矿为赣东北地区－大型独立金矿床,其产出受金山顺层剪切控制,主要矿化类型有硅化岩及含金石英脉型两种,金的大量淀积晚于石英脉的形成。矿区岩,矿石稀土元素地球化学特征及铅,硫同位素分析表明,成矿物质主要来自元古界双桥山群浅变质地层,氢,氧同位素资料证明成矿溶液为变质水,成矿温度为２３０℃～４００℃矿床属剪刀带型中温变化变质诚因。  相似文献   

1998年泾阳4.8级地震的一些特征   总被引：4，自引：0，他引：4       下载免费PDF全文

吴富春  段锋  柯昌安  张春生  董星宏 《地震工程学报》2000,22(1):54-58

分析了 1 998年泾阳MS4.8地震的一些特征 .该次地震序列类型属孤立型 ,与陕西关中地区历史强震多以主 余震型为主的特征不同 .震源机制解显示 ,该次地震的断层错动以左旋走滑为主 ,主压应力方向为NE～SW ,与大华北区域应力场的方向吻合  相似文献   

基于偏最小二乘法的巢湖悬浮物浓度反演   总被引：6，自引：1，他引：5  

刘忠华  李云梅  吕恒  徐祎凡  徐昕  黄家柱  檀静  郭宇龙 《湖泊科学》2011,23(3):357-365

悬浮物浓度是水质评价的重要参数.对2009年6月巢湖实测的高光谱数据进行小波变换以去除数据冗余,减少建模时间.考虑到不同的小波基函数和分解尺度对数据压缩的影响,采用3个指标作为评价标准,最终选择小波基函数为Db4,分解尺度为4的小波变换,经小波变换后,原来的451个波段的光谱数据压缩为34个特征变量.利用小波变换后的光...  相似文献   

Reconsidering Schwarzschild's original solution     

S. Antoci  D.‐E. Liebscher 《Astronomische Nachrichten》2001,322(3):137-142

We analyse the Schwarzschild solution in the context of the historical development of its present use, and explain the invariant definition of the Schwarzschild's radius as a singular surface, that can be applied to the Kerr‐Newman solution too.  相似文献   

Effective KEM solutions for the limit load and the slope stability problem     

Peter Gussmann 《国际地质力学数值与分析法杂志》2000,24(14):1061-1077

The matrix formulation for the limit‐load problem in soil mechanics can be solved by the KEM effectively. The solution of the slope stability problem is more complicated in principle, but together with an effective iteration technique the solution of the implicit equation system can be simplified to the recursive solution of just a quadratic equation. Copyright © 2000 John Wiley & Sons, Ltd.  相似文献   

Explanation of locking of four‐node plane element by considering it as elastic Dirichlet‐type boundary value problem     

F. Molenkamp  J. B. Sellmeijer  C. B. Sharma  E. B. Lewis 《国际地质力学数值与分析法杂志》2000,24(13):1013-1048

The aim of this study is to arrive at a better understanding of the phenomenon of locking of low‐order compatible displacement type of finite elements in particular for the hour‐glass mode of the plane four‐node element and dilative materials. To this end the properties of finite elements are investigated in an analytical way, where a finite element is considered as a plane boundary value problem with prescribed boundary displacement (Dirichlet problem). In this paper for the sake of simplicity the simplest possible linear comparison solid, namely isotropic linear elasticity, is applied, although recognizing fully that for a dilative material elasto‐plasticity would be more realistic. From the study described in this paper it is concluded that locking of the four‐node element is not due to any particular numerical formulation of this compatible finite element since, even the analytical solution suffers from this problem. The locking of this element is not related to incompressibility of the material either as the analytical solution shows locking to occur at a parameter set which differs significantly from the one in case of incompressibility. It is shown that locking is a consequence of the combination of the dilative material behaviour and the compatible displacement type of boundary conditions, which leads to infinite isotropic stresses in the element. These infinite isotropic stresses occur at the limit of uniqueness of the solution, which for this element is shown to occur outside the parameter range of the sufficiency of uniqueness. Copyright © 2000 John Wiley & Sons, Ltd.  相似文献   

胶东台上金矿成矿机制模拟实验研究   总被引：2，自引：0，他引：2  

周凤英  李兆麟 《地质论评》1994,40(5):456-465

模拟实验研究表明，台上金矿床的成矿机制为：胶东群地层重熔形成滦家河花岗岩岩浆时，初始浆为几乎均匀的熔体相；随着结晶成岩作用的进行，由于局部岩浆结晶分异作用，产生富Ｋ＾＋，Ｎａ＾２＾＋，Ｃａ＾２＾＋，Ｍｇ＾２＾＋，Ｆ＾－，Ｃｌ＾－，Ｓ＾２＾－，ＣＯ３＾２＾－及挥发份ＣＯ２，ＣＯ，Ｈ２Ｏ等的流体相，并不断从已结晶矿物及残熔体中，以［Ａｕ（ＨＳ）２］＾－，［Ａｕ（ＨＳ）Ｓ］＾２＾－，ＡｕＣｌ４］＾－等络  相似文献   

基于除镉作用机理探讨的碳羟磷灰石溶解特性研究     

胥焕岩  王鹏  刘羽  彭明生 《矿物岩石》2005,25(4):6-10

碳羟磷灰石（CHap）在含镉溶液和空白溶液中溶解特性的对比实验结果表明：介质pH值是影响CHap溶解的重要因素,强酸务件下,溶解度最大;溶钙量和溶磷量的摩尔比均不是1、67;溶解初期阶段反应速度快,动力学过程复杂,后期阶段符合一级反应动力学特征,说明CHap溶解机理符合氢催化模型、非化学计量比溶解模型、多核模型,在含镉溶液中溶解时,还包括离子交换模型,即溶液中的镉离子与CHap中的钙离子发生交换作用。从溶解特性的角度推测：CHap除镉过程中存在有离子交换作用机理。  相似文献   

Relocation of the MS5.7 Earthquake Sequence in Songyuan, Jilin Province, 2018 and the Analysis of Its Seismogenic Structure     

An Yanru  Zhang Yingying  Yang Zhigao  Bai Lanshu  Liu Jie 《中国地震研究》2018,32(4):491-500

The 2018,Songyuan,Jilin M_S5. 7 earthquake occurred at the intersection of the FuyuZhaodong fault and the Second Songhua River fault. The moment magnitude of this earthquake is M_W5. 3,the centroid depth by the waveform fitting is 12 km,and it is a strike-slip type event. In this paper,with the seismic phase data provided by the China Earthquake Network, the double-difference location method is used to relocate the earthquake sequence,finally the relocation results of 60 earthquakes are obtained. The results show that the aftershock zone is about 4. 3km long and 3. 1km wide,which is distributed in the NE direction. The depth distribution of the seismic sequence is 9km-10 km. 1-2 days after the main shock,the aftershocks were scattered throughout the aftershock zone,and the largest aftershock occurred in the northeastern part of the aftershock zone. After 3-8 days,the aftershocks mainly occurred in the southwestern part of the aftershock zone. The profile distribution of the earthquake sequence shows that the fault plane dips to the southeast with the dip angle of about 75°. Combined with the regional tectonic setting,focal mechanism solution and intensity distribution,we conclude that the concealed fault of the Fuyu-Zhaodong fault is the seismogenic fault of the Songyuan M_S5. 7 earthquake. This paper also relocates the earthquake sequence of the previous magnitude 5. 0 earthquake in 2017. Combined with the results of the focal mechanism solution,we believe that the two earthquakes have the same seismogenic structure,and the earthquake sequence generally develops to the southwest. The historical seismic activity since 2009 shows that after the magnitude 5. 0 earthquake in 2017,the frequency and intensity of earthquakes in the earthquake zone are obviously enhanced,and attention should be paid to the development of seismic activity in the southwest direction of the earthquake zone.  相似文献