从中国东部若干重要矿区看花岗岩类的成矿专属性     

张师 《地球科学》1985,(2)

本文着重讨论中国东部与铁、铜、钨、相及锡矿床有关的花岗岩类的岩石化学特征:铁矿成矿母岩通常为SiO_2 52—63%,Fe_2O_3 FeO 5.2—10%,K_2O Na_2O 5—10%。正常系列。S=62—72,b=10—20,σ=3—5。当PH_2O=500～1000巴时,初始结晶温度≥820°C。铜矿成矿母岩通常为SiO_2 61—70%,Fe_2O_3 FeO 2—5.2%,K_2O Na_2O5—7％。正常或铝过饱和系列。S=70—80.5,b=6—12,σ≤3。当PH_2O=500—1000巴时,初始结晶温度为780—820°C。钨、钼和锡矿成矿母岩SiO_2 70—77%,Fe_2O_3 FeO<5％,K_2O Na_2O 7—10%。铝过饱和系列。S=77—83,b=1—9,σ≤3。当PH_2O=300—1000巴时,初始结晶温度<780°C。  相似文献   

The two-component extreme value distribution for flood frequency analysis: Derivation of a new estimation method   总被引：1，自引：0，他引：1  

M. Fiorentino  K. Arora  V. P. Singh 《Stochastic Environmental Research and Risk Assessment (SERRA)》1987,1(3):199-208

The two component extreme value (TCEV) distribution has recently been shown to account for most of the characteristics of the real flood experience. A new method of parameter estimation for this distribution is derived using the principle of maximum entropy (POME). This method of parameter estimation is suitable for application in both the site-specific and regional cases and appears simpler than the maximum likelihood estimation method. Statistical properties of the regionalized estimation were evaluated using a Monte Carlo approach and compared with those of the maximum likelihood regional estimators.  相似文献   

Least squares parameter estimation in chaotic differential equations     

Josef Kallrath  Johannes P. Schlöder  Hans Georg Bock 《Celestial Mechanics and Dynamical Astronomy》1993,56(1-2):353-371

A recent least squares algorithm, which is designed to adapt implicit models to given sets of data, especially models given by differential equations or dynamical systems, is reviewed and used to fit the Hénon-Heiles differential equations to chaotic data sets.This numerical approach for estimating parameters in differential equation models, called theboundary value problem approach, is based on discretizing the differential equations like a boundary value problem,e.g. by a multiple shooting or collocation method, and solving the resulting constrained least squares problem with a structure exploiting generalized Gauss-Newton-Method (Bock, 1981).Dynamical systems like the Hénon-Heiles system which can have initial values and parameters that lead to positive Lyapunov exponents or phase space filling Poincaré maps give rise to chaotic time series. Various scenarios representing ideal and noisy data generated from the Hénon-Heiles system in the chaotic region are analyzedw.r.t. initial conditions, parameters and Lyapunov exponents. The original initial conditions and parameters are recovered with a given accuracy. The Lyapunov spectrum is then computed directly from the identified differential equations and compared to the spectrum of the true dynamics.presently at IWR, Universität Heidelberg, Im Neuenheimer Feld 368, D-6900 Heidelberg, Germany  相似文献   

Correlation between the seismicity parameters     

王林瑛  吴忠良  陈佩燕 《地震学报(英文版)》2004,17(Z1)

Though the forecast and prediction of earthquakes is a commonly accepted difficult problem in science, the step towards the exploration and knowledge of the generation and occurrence of earthquakes has never stopped. It has strong scientific exploration nature and great social efficacy in disaster reduction. For this reason, it has always been the object and motivation pursued assiduously by earthquake researchers. It is beyond doubt that the study of seismicity is still one of the important information sources that have historical records of the longest time and most abundant earthquake cases that can be testified. For many years, with the progress of study in this aspect and the unceasing increase of study methods, there have been not less than tens of methods that can be used to describe theseismicity characteristics from different angles. It is of great importance to determine from the numerous methods those ones that are relatively independent and to understand how many dimensions are there to restrict the complexsystem of earthquake generation and occurrence. Taking these as a referential basis, we would be able to identify the quantities that restrict the study of the seismogenic system, to raise the scientific value and rigorousness of prediction and forecast, and to get rid of the trouble of repeated information superposition.  相似文献   

中国黄淮海地区冬小麦光合作用特征参数   总被引：5，自引：1，他引：5       下载免费PDF全文

刘建栋  周秀骥于强 《应用气象学报》2003,14(3):257-265

利用Licor-6200便携式光合作用测定仪，对1949年以来不同历史年代的冬小麦叶片光合作用进行了大量测定，拟合了不同年代12个典型品种的叶片光合作用光响应曲线，首次揭示了黄淮海地区冬小麦叶片光合特征参数随时间演变规律，并利用数值模式分析了特征参数对光合日总量的影响。该研究为我国气候生态数值模型提供了基础数据，并为模式的区域应用提供了重要前提条件。  相似文献   

GPS导航仪在测绘工程中的应用     

高占峰  杨国良  周朝义  吴妍 《全球定位系统》2003,28(6):26-28,34

通过以GARMIN GPS导航仪为例，介绍了导航仪的主要功能特点、参数设置等，并对其在测绘工程中的应用进行了探讨。  相似文献   

Adaptive bang–bang control for the vibration control of structures under earthquakes     

C. W. Lim  T. Y. Chung  S. J. Moon 《地震工程与结构动力学》2003,32(13):1977-1994

An adaptive method based on the modified bang–bang control algorithm is proposed for the vibration control of structures subjected to unexpected severe seismic loads greater than the design loads. A hydraulic‐type active mass damper was made and experiments were carried out in the laboratory using a one‐story test structure and a five‐story test structure with the active mass damper. Through numerical simulations and experiments it was confirmed that the proposed method works well to suppress the vibration of structures subjected to unexpected severe seismic loads greater than the design loads without causing any unstable situations. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   

支撑刚度对磁摩擦耗能减振体系的影响   总被引：1，自引：0，他引：1  

王伟  刘振鹏  李庆祥 《地震工程与工程振动》2003,23(3):170-176

本文在已有磁摩擦耗能减振体系振动台试验基础上，讨论了两类磁摩擦耗能减振体系支撑刚度的影响，揭示了支撑刚度对磁摩擦耗能装置减振效果的影响规律，给出了两类磁摩擦耗能装置在结构中发挥最佳减振效果时支撑刚度的取值范围。  相似文献   

一种新型软钢阻尼器力学性能和减震效果的研究   总被引：11，自引：0，他引：11  

邢书涛  郭迅 《地震工程与工程振动》2003,23(6):179-186

本文研究了一种新型软钢阻尼器。首先分析了这种阻尼器的力学性能和减震机理，依据试验结果给出了它的恢复力模型，并推导得出了特征参数的表达式和疲劳验算式；研究了阻尼器参数对减震效果的影响，给出了最佳的参数取值范围；算例分析表明该种阻尼器具有很好的减震效果。  相似文献   

地震活动性参数分类及其相关性初步研究   总被引：9，自引：0，他引：9  

韩渭宾 《四川地震》2003,(3):1-5

从各地震活动性参数的原始定义及其计算过程所反映出的物理本质出发，并为研究不同参数间相关性方便，将已有的30多种地震活动性参数分为五类：频度类、能量类、分布类、综合类和非线性类。在过去工作的基础上，进一步研究了同一类别中各参数间的相关性，取得了一些初步看法。  相似文献