大青山伸展拆离断层运动学涡度研究及构造指示意义

在华北北缘的大青山伸展拆离断裂带叠加在中生代逆冲断层之上,其韧性剪切带在变质核杂岩南北两侧出露,运动学指向为上盘向南东向拆离.运动学涡度分析表明,大青山拆离断层剪切带早期(较高温)简单剪切分量不断增加直至简单剪切;拆离断层总体平均涡度Wm简单剪切分量沿拆离断层上盘运动方向增大,与韧性剪切带先垂向颈缩、后水平伸展的被动式...     

基于三点击实法的压实度评估方法

基于三点击实法的基本原理,提出了压实度的评估方法。该方法考虑了击实试样初始含水率与碾压现场含水率的误差,得到不同误差组合下的真实压实度,并由此得到真实压实度的取值范围、真实压实度大于某个临界值或设计指标的概率及近似压实度相比于真实压实度偏大或偏小的概率。该方法可获得压实度更加详细的信息,有利于对施工质量作出准确判断。     

集对分析径向基函数神经网络预测模型

将集对分析与径向基函数神经网络结合,提出了集对分析径向基函数神经网络预测模型。模型思路是将研究对象t-1时和t时的影响因子集构造为集对并计算联系度,由联系度的同一度、差异度、对立度及研究对象t-1时的值为输入,研究对象t时的值为输出,构建径向基函数神经网络。以年径流预测为例研究表明,模型结构清晰、步骤明确、预测精度较高,为集对分析应用于水文预测提供了新思路。     

Stratigraphic Division and Correlation of the Nihewan Beds by Multivariate Statistical Analysis

Described in paper is the principle of optimal partitioning method for stratigraphic division and correlation.The Nihewan Beds are taken for example to show how to apply this approach in stratigraphic division and correlation.The semiquantitative spectral analysis data on aggregate trace elements in 324 samples taken from the nine sections in the Nihewan Basin are treated with multivariate statistical method for stratigraphic division and correlation.First ,the data from all the sections are respectively calculated by the optimal partitioning method to establish the stratigraphic boundaries.The optimal partitioning method has proved itself to be applicable to stratigraphic division and correlation. In our practice the Nihewan Beds are divided into five zones (I-V).Zone I includes subzones Ia and Ib,Zones Ia,Ib,II and III are considered to be corresponding to the Pliocene(N2),the early Early Pleistocene,the late Early Pleistocene,and the Middle Pleistocene,respectively .Zones IV and V are probably Late Pleistocene in age.This indicated that sediments deposited con-temporaneous in the sections of the same basin are similar in geochemical characteristics,although dif-ferent in geographical location.However,the sediments also show some variations ,with a transitional relationship from one section to another .For example ,in Zone II,the sediments of the Xiaodukou section show not only the characteristics of the Nangou-Hongya and Hutouliang sections,but also those of the Xiashagou,Shixiaxi,Shixiadong and Wulitai sections.It can be seen from the above that the zones can be characteristically correlated with one another.In addition the feasibility of the optimal partitioning method is also described in the present paper.     

福建数字地震台网试运行期间编目工作的若干问题

本文对福建数字地震台网试运行期间在测定地震参数、编辑地震目录和台网观测报告等方面存在的问题及其解决过程作简短回顾。     

内蒙古苏尼特左旗二叠系的重新厘定及大地构造演化分析

探讨了苏尼特左旗地区二叠系地层单元的划分与时代归属,认为该区二叠系地层应包含大石寨组,哲斯组与林西组底部,重新厘定了该区二叠系剖面序列。通过对大石寨组火山岩岩石化学、稀土元素的分析,认为大石寨组所处的大地构造环境为活动大陆边缘,中朝板块与西伯利亚板块的最终汇聚时期应为早二叠世中期。     

Fractal Analysis of the Complexity of United States Coastlines

Coastlines have long been used as a principal example of a natural feature that exhibits fractal structure. With the advent of large digitized databases, it has become possible to examine in detail large regions of coast and to examine differences in complexity, as measured by the fractal dimension, among regions. In this study, we have determined the fractal dimension of the Atlantic and Pacific coastlines of the conterminous United States. The traditional divider method was used in obtaining the fractal dimension of each coastline arc from the NOAA Medium-Resolution Shoreline Data Set. On average, the Atlantic coast has much higher fractal dimension than the Pacific coast. The results also indicate that the complexity of the Atlantic coast increases toward low latitudes. These results have implications for the interpretation of species distributions and diversity patterns along the coast and for the understanding of the dynamics of biotic recovery from mass extinctions.     

应用嵌套模式研究梅梁湖区风生流

应用数值嵌套模式,研究不同风向情况下,梅梁湖与竺山湖之间的马山区围垦对梅梁湖风生流的影响。结果表明:风场作用初期,偏Ｓ风使得太湖湖水流入梅梁湖;偏Ｎ风使得梅梁湖湖水流入太湖。梅梁湖稳定风生流流态表现为:在S、E风作用下形成逆时针环流;在N、W风作用下形成顺时针环流。马山区围垦阻隔了梅梁湖与竺山湖之间的湖水交换,进而影响梅梁湖的风生流流态,导致其湖水更新速度减慢。     

青海祁连两类火山成因硫化物矿化蚀变带地球化学特征及找矿标志

研究区发育火山成因块状黄铁矿矿床和铅锌铜多金属硫化物矿床及其相应的两类矿化蚀变带．黄铁矿矿化蚀变带以亏损Ｐｂ,Ｚｎ,Ｃｕ,Ａｇ,Ｓｒ,Ｂａ,Ｍｎ及Ｋ,Ｎａ,Ｍｇ等元素,且多为负异常,元素无明显共生组合规律为特点;多金属矿化蚀变带则以富集多金属元素及伴生元素,富Ｋ,Ｍｇ,贫Ｎａ为特征,而且多元素共生组合好,异常强度高而宽度窄,下盘晕强于上盘晕．同时,总结了两类矿化蚀变带地球化学找矿标志,对区内主要蚀变带进行了含矿远景评价