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排序方式: 共有198条查询结果,搜索用时 15 毫秒
1.
北京时间2017年6月16日19时48分, 湖北省秭归县发生MS4.3地震(震中位置31.06°N, 110.48°E)。 此次地震导致当地160多间建筑物出现不同程度损坏, 100多人生活受到影响, 震区中危岩体出现一定程度破坏。 分析此次地震的震源参数将有助于了解其震源特征和发震机制。 本文首先获取了震中距在3°以内的40个宽频带固定台站的三分量数据, 然后利用FK(Frequency wavenumber)方法计算了在不同深度下Crust2.0模型和改进的1-D模型的格林函数, 分别使用Cut And Paste(CAP)方法反演得到本次地震的震源机制解和深度; 并采用基阶Rayleigh波振幅谱进一步约束了质心深度。 结果表明此次地震的最佳震源机制解的节面Ⅰ: 68°/59°/163°; 节面Ⅱ: 166°/75°/32°, 最佳矩震级为MW4.3, 最佳深度约为5 km。 对比2013年巴东地震、 2014年秭归地震以及2011年湖北阳新—江西瑞昌地震的震源参数和余震信息, 此次地震有可能是水库诱发地震, 但要判断成因还需进一步研究。 相似文献
2.
云南腾冲新期火山岩矿物及其熔体包裹体研究 总被引:1,自引:1,他引:0
腾冲火山群位于我国云南省西部和缅甸的交界处,由黑空山、大空山、小空山、打鹰山、马鞍山等一系列火山组成,是我国著名的第四纪火山群,从喷发活动时间上可分为老期火山和新期火山.前人研究证实,打鹰山、马鞍山和黑空山为新期火山,它们在全新世都有过喷发活动.这些新期火山岩的主要斑晶矿物为辉石、橄榄石和长石,主要的斑晶矿物中都含有熔体包裹体,它们形态多样,分布不规则,且部分显示后期有变化.探针分析表明,新期火山岩矿物中熔体包裹体成分的变化范围大于其基质玻璃成分的变化范围,它们的化学成分分布范围涵盖了玄武粗安岩、粗面安山岩、粗面岩和流纹岩等岩石类型,与腾冲火山区晚更新世以来火山岩的成分分布范围基本一致.根据对新期火山岩斑晶和微晶矿物中熔体包裹体及基质玻璃成分的测试研究,其中挥发分Cl的含量在包裹体和基质中变化不大,但F、SO3在熔体包裹体中的含量高于基质,总体上腾冲新期火山喷发时岩浆的脱气率较低,喷发时并未向空中喷出大量气体,推测对当时的气候环境影响不大,但未来喷发的灾害效应不容忽视. 相似文献
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简要介绍了三种不同旋转角下的坐标转换模型,并通过Visual C++6.0编制相应的坐标转换程序,对三种坐标转换模型的精度做对比分析,结果表明根据旋转角的大小选择不同的坐标转换模型对坐标转换精度有直接影响. 相似文献
5.
Determination of total sulfur in geothermal water by inductively coupled plasma-atomic emission spectrometry 下载免费PDF全文
Sulfur speciation and concentration in geothermal water are of great significance for the research and utilization of the water resources. In most situations, it is necessary to determine the total sulfur in geothermal water. In this study, the method was established for the determination of determining total sulfur content — the inductively coupled plasma-atomic emission spectrometry (ICP-AES), with the wavelength of 182.034 nm selected in spectral line of sulfur. It was identified that the optimal working conditions of the ICP-AES instrument were 1 200 W for high frequency generator power 9 mm for vertical observation height, 0.30 MPa atomizer pressure, and 50 r/min analytical pump speed. The matrix interference of the method was eliminated by the matrix matching method. Using this method, sulfur detection limit and minimum quantitative detection limit were 0.028 mg/L and 0.110 mg/L, respectively, whilst the linear range was 0.0–100.0 mg/L. The recovery rate of sample was between 90.67% and 108.7%, and the relative standard deviation (RSD) was between 0.36% and 2.14%. The method was used to analyze the actual samples and the results were basically consistent with the industry standard method. With high analysis efficiency, the method has low detection limit and minimum quantitative detection limit, wide linear range, good precision and accuracy, and provides an important detection method for the determination of total sulfur in geothermal water. 相似文献
6.
MATLAB语言在非线性最小二乘估计中的应用 总被引:1,自引:0,他引:1
张庆 《测绘与空间地理信息》2004,27(3):35-38
伴随着测量事业的发展,要编制测量参数估计的矩阵运算程序越来越复杂,难度也越来越大。MATLAB与其他编程语言相比,具有简单直观、速度快等特点。本文将MATLAB语言运用于非线性模型参数估计,并给出了单纯形法进行非线性参数估计的函数程序。 相似文献
7.
YOSHIKATSU MIYASHITA TOSHIAKI ITOZAWA HIROYUKI KATSUMI SHIN-ICHI SASAKI Department of Knowledge-Based Information Engineering Toyohashi University of Technology Tempaku.Toyohashi Japan 《地理学报(英文版)》1990,(1)
The Non-linear lterative Partial Least Squares(NIPALS)algorithm is used in principal componentanalysis to decompose a data matrix into score vectors and eigenvectors(loading vectors)plus a residualmatrix.N1PALS starts with some guessed starting vector.The principal components obtained by NIPALSdepends on the starting vector;the first principal component could not always be computed.Wold hassuggested a starting vector for NIPALS,but we have found that even if this starting vector is used,thefirst principal component cannot be obtained in all cases.The reason why such a situation occurs isexplained by the power method.A simple modification of the original NIPALS procedure to avoid gettingsmaller eigenvalues is presented. 相似文献
8.
A. M. Mickaelian 《Astrophysics》2004,47(3):361-377
Results of spectral observations of 66 objects from the BIG (Byurakan IRAS Galaxies) sample made with the 1.93 m telescope at the Observatoire de Haute Provence (OHP, France) are presented. Emission lines are observed from 64 of the galaxies. The red shifts are determined, the radial velocities, distances, and absolute stellar magnitudes are calculated, the spectrum line parameters are determined, diagnostic diagrams are constructed, the objects are classified according to activity type, and their IR and far-IR luminosities are calculated. Of the 66 objects (corresponding to 61 IRAS sources), 6 are Sy2, 2 are LINERs, 8 are AGN (Sy2 or LINER), 10 are composite, 34 are HII, and 4 are Em of undetermined type. It is calculated that IRAS 07479+7832= BIG d141a is a ultraluminous IR galaxy (ULIG), and 21 are LIG. Spectra of several of the galaxies being studied are presented. 相似文献
9.
An ecological economics framework for assessing environmental flows: the case of inter-basin water transfers in Lesotho 总被引:3,自引:1,他引:2
This paper used the Lesotho Highlands Water Project (LHWP) that transfers water from the Orange River Basin in Lesotho to the Vaal River Basin in South Africa as a case study to show how environmental sustainability aspects can be integrated into economic development planning. Using the Ecological Social Accounting Matrix (ESAM) for Lesotho that integrates ecological implications of the LHWP with economic benefits of the project, the paper analysed the impact of lost ecological services downstream the LHWP dams in Lesotho on the well-being of households directly affected by the project (riparians) and the general economy of the country. The results revealed that despite significant economic benefits, the project has unintended impacts on ecological resources and services with resultant deleterious well-being implications for riparians. The results from the ESAM analysis indicated that not only the income of riparians is likely to suffer, but also that of other households and social groups, as well as the general economy of Lesotho. While results of the ESAM analysis did not indicate large income impacts on the economy at large, they were significant for riparians. The importance of integrating ecological consequences into impact assessment of IBWT before such transfers can be implemented to ensure sustainable development and considering economy-wide impacts associated with IBWT was proven necessary for a holistic impact assessment of IBWT. 相似文献
10.
An in situ method of estimating the effective diffusion coefficient for a chemical constituent that diffuses into the primary porosity of a rock is developed by abruptly changing the concentration of the dissolved constituent in a borehole in contact with the rock matrix and monitoring the time-varying concentration. The experiment was conducted in a borehole completed in mudstone on the campus of the University of the Free State in Bloemfontein, South Africa. Numerous tracer tests were conducted at this site, which left a residual concentration of sodium chloride in boreholes that diffused into the rock matrix over a period of years. Fresh water was introduced into a borehole in contact with the mudstone, and the time-varying increase of chloride was observed by monitoring the electrical conductivity (EC) at various depths in the borehole. Estimates of the effective diffusion coefficient were obtained by interpreting measurements of EC over 34 d. The effective diffusion coefficient at a depth of 36 m was approximately 7.8×10?6 m2/d, but was sensitive to the assumed matrix porosity. The formation factor and mass flux for the mudstone were also estimated from the experiment. 相似文献