Mapping the Dyke Swarms Emplaced within the Different Archean Cratons of the Indian Shield Using Google^(TM) Earth Images and Arc GIS^(TM) Techniques

The Indian shield comprises a number of Archean–Paleoproterozoic cratonic blocks and predominantly Meso–Neoproterozoic mobile belts with Archean protoliths.All these ancient cratons were thought to be integral parts of

Research on the Activity Characteristics of Small Earthquake Swarms in the Muli Area of Sichuan Province

In this article,we relocated the seismic source location of the earthquakes in the Muli area of Sichuan,inverted the focal mechanism of the larger earthquakes and analyzed the relationship between the water level of the Jinping reservoir and the frequency of the earthquake swarm. The results show that:( 1) The epicenters of the relocated small earthquake swarms are distributed in a seismic zone,and the earthquake focal depths were in the range of 0- 12 km.( 2) By analyzing the earthquake swarm spatial distribution,we found that the swarms were generated by one branch fault on the west of Xiaojinhe fault.( 3) The focal mechanism of the three earthquakes with magnitude greater than 4. 0 is significantly different,with the shallow source thrust events affected by vertical stress,and the strike-slip events are related to regional stress tectonic activity.

集中供热系统热网流量的优化神经网络控制

传统集中供热系统存在一个缺点,就是现有的集中供热系统对供热量的控制都是选取一次网供水温度和二次网回水温度为控制量来实现。但是考虑到热量传递的时滞性和管网结构的复杂性以及热量控制的非线性变化,为了优化这一缺陷,提出按需供热这一控制理念。在整个热网满足水力平衡的前提下,选取整个热网内的流量为控制量,即控制整个管网的热媒总量。热媒流入管网进行循环供热。系统通过热媒的传输量直接确定整个供热系统获取的热量,再通过检测一次网供回水流量、一次网供回水温度,以及二次网供回水流量、二次网供回水温度作为监测系统供热量的参照。采用改进的粒子群优化(PSO)算法优化反向传播(BP)神经网络比例积分微分(PID)控制器的权值,对整个热网的流量进行优化控制。结果显示,提出的新供热理念和优化后的神经网络PID控制器能够解决供热系统难以进行精确系统建模的缺点,提高系统的控制精度和减少能耗,具有较高的实用和推广价值。