云南省雷灾特征分析及灾情评估     

殷娴  尹丽云  许迎杰  刘平英 《气象科技》2013,41(1):184-190

根据云南省2007 2008年的雷电灾害资料以及地闪资料,分析了云南省16个地级市的雷电灾害分布特征,讨论了雷灾分布与地闪分布的关系,并从雷灾记录中提取了6个灾度指标,通过AHP法(层次分析法)建立灾情评估层次模型和灾度评估方程,计算了云南省522次雷灾的灾度值,用SAS中聚类分析过程将灾度值分为4级,并统计分析了各级雷灾在各地区的分布情况,得出云南雷电灾害中小型雷灾分布较广、出现几率较大,而大型和特大型雷灾发生几率较低、主要集中在昆明和德宏地区.该文结论为区域防雷减灾规划提供了科学依据.  相似文献   

影响鸢乌贼手钓上钩率的因子探讨     

吴国峰  陈新军 《广东海洋大学学报》2006,26(6):35-38

根据印度洋西北部鸢乌贼(Symplectoteuthis oualaniensis)作业渔场的现场调查数据,分析了作业水深、作业时段、摄食等级和月相等因子对手钓上钩率的影响。统计表明,晚上、午夜和凌晨3个不同时段和不同作业水深对手钓上钩率均有显著性影响。3个时段中,其摄食等级呈先低后高再低的现象。午夜和凌晨,上钩率的变化趋势与摄食等级的变化趋势呈显著的负相关。在月相的影响下,离朔日三四天之前,手钓产量呈上升趋势;离望日五六天之前,手钓产量呈明显的下降趋势。  相似文献   

Static Spheroidal Deformation of Degree 1 - Consistency Relation, Stress Solution and Partials     

Shuhei Okubo  Takeshi Endo 《Geophysical Journal International》1986,86(1):91-102

This paper treats the static spheroidal deformation of degree 1 in detail. We give a physical interpretation of the consistency relation imposed on it. the relation serves as a guiding principle to find out all of its members. Following Okubo & Saito, we derive the partial derivatives of the degree 1 Love numbers with respect to density, bulk modulus and rigidity.  相似文献   

Are Arc Basalts Dry, Wet, or Both? Evidence from the Sumisu Caldera Volcano, Izu-Bonin Arc, Japan   总被引：2，自引：0，他引：2  

TAMURA  Y.; TANI  K.; ISHIZUKA  O.; CHANG  Q.; SHUKUNO  H.; FISKE  R. S. 《Journal of Petrology》2005,46(9):1769-1803

Basalt–basaltic andesite (<55 wt % SiO₂) and dacite–rhyolite(66–74 wt % SiO₂) are the predominant eruptive productsin the Sumisu caldera volcano, Izu–Bonin arc, Japan. Themost magnesian basalt (8·5% MgO), as well as some ofthe other basalts, has a low Zr content (20–25 ppm), andcannot yield basalts with higher Zr contents (29–40 ppm)through fractionation and/or assimilation. The high- and low-Zrbasalts have different phenocryst assemblages, olivine, plagioclaseand pyroxene phenocryst chemistries, REE (rare earth element)patterns, and fluid-mobile element/immobile element ratios.Estimated primary olivine compositions are more magnesian (>Fo₉₁)in the low-Zr basalts compared with those in high-Zr basalts(<Fo₈₉). The low-Zr basalts contain up to 11 vol. % augite,but many high-Zr basalts are free of augite, which appears onlyin their more differentiated products. The low-Zr basalts areconsidered to be hydrous magmas in which olivine crystallizesfirst followed by augite and plagioclase, whereas the high-Zrbasalts are dry. The low-Zr basalts have higher U/Th ratiosthan the high-Zr basalts. We suggest that both dry and wet primarybasalts existed in the Sumisu magmatic system, each having differenttrace element concentrations, mineral assemblages and mineralchemistry. The lower contents of Zr and light REE and magnesianprimary olivines in the wet basalts could have resulted froma higher degree of partial melting (20%) of a hydrous sourcemantle compared with 10% melting of a dry source mantle. TheSr, Nd and Pb isotope compositions of the wet and dry basaltsare similar and are limited in range. These lines of evidenceindicate that a mantle diapir model might be applicable to satisfythe configuration of such a mantle source region beneath a singlevolcanic system such as Sumisu. KEY WORDS: degree of melting; hot fingers; isotopes; mantle diapir; mantle wedge  相似文献   

锆石红外光谱在地质研究中的应用     

闫秋实  尹观 《物探与化探》2004,28(2):142-146

以甘肃白银厂地区的7件锆石同位素年龄样品为例,根据其红外光谱中615cm-1吸收峰的高和半高宽度的比值,将锆石样品的变生程度量化,并将其分为晶质锆石、半变生锆石和变生锆石3类。参考相关资料,利用7件锆石样品的红外光谱特征对其铀钍含量和"红外年龄"做了估测,并将估测年龄与其U Th年龄和全岩Rb Sr年龄进行了比较和分析。  相似文献   

Global Bifurcations of Periodic Solutions of the Restricted Three Body Problem     

A. J. Maciejewski  S. M. Rybicki 《Celestial Mechanics and Dynamical Astronomy》2004,88(3):293-324

We describe global bifurcations from the libration points of non-stationary periodic solutions of the restricted three body problem. We show that the only admissible continua of non-stationary periodic solutions of the planar restricted three body problem, bifurcating from the libration points, can be the short-period families bifurcating from the Lagrange equilibria L ₄, L ₅. We classify admissible continua and show that there are possible exactly six admissible continua of non-stationary periodic solutions of the planar restricted three body problem. We also characterize admissible continua of non-stationary periodic solutions of the spatial restricted three body problem. Moreover, we combine our results with the Déprit and Henrard conjectures (see [8]), concerning families of periodic solutions of the planar restricted three body problem, and show that they can be formulated in a stronger way. As the main tool we use degree theory for SO(2)-equivariant gradient maps defined by the second author in [25].This revised version was published online in October 2005 with corrections to the Cover Date.  相似文献   

基于物元分析的地下水质量综合评判     

邹叶锋  陈锁忠 《安徽地质》2006,16(2):116-119

由于地下水中含有多种离子,若仅通过单项离子来评判水质等级,势必有很大的缺陷,因此采用一种基于物元分析理论的综合评判方法,建立多种指标的评判模型,运用关联函数来进行地下水质量等级的评判。  相似文献   

大跨径高桥墩垂直度观测方法和精度分析     

许娅娅  王月莉 《测绘工程》2006,15(1):38-40

介绍了高桥墩的垂直度观测方法和精度分析,推导出一系列实用公式,观测方法简单,结果精确可靠。利用这种方法能快速有效地判断出桥墩的倾斜量,及时采取相应调整措施,以保证桥墩的垂直性。  相似文献   

河南省境内淮河南北气候变化的小麦适应度比较   总被引：3，自引：0，他引：3  

苏坤慧  延军平  白晶  张立伟  王晓喆  李建山  田青霞 《地理科学进展》2012,31(1):63-71

适应度是气候变化下适应性研究的关键环节,本文提出气候变化适应度的概念及其定量评价方法,并对淮河南北的小麦适应度进行比较分析。结果表明,目前河南省境内的南北气候分界线并非淮河干流区,而是由原位置北移约300 km处的最大支流地带,冬小麦的适应度空间变化大致围绕该分界线呈经向分布。淮河分界线以南地域适应度为62.57%,高于以北地域的56.81%,研究结果表明,欲达到河南农业可持续发展,距离完全适应仍有较大空间需要人为调控,且北部相比较南部其调控压力更大。在年际变化上,随着20世纪80年代气候的突变,各地小麦温度适应度骤增,水分适应度骤减,之后随着气候的日趋稳定,各气候要素的适应度不断上升,但在21世纪初上升速度下降,甚至有降低趋势,表明气候变暖的环境对小麦的负面影响日渐突出。  相似文献   

基于GIS和遥感的中国城市分布与自然环境关系的定量研究     

刘沁萍  田洪阵  杨永春 《地理科学》2012,(6):686-693

利用ArcGIS10、ENVI4.5、Visual FoxPro6.0等软件,采用空间分析技术手段,定量分析了中国655个建制城市的空间分布与河流、植被、地形起伏度、高程4种自然环境因素的关系,结论如下:①城市对水的依赖程度高,城市等级越高,依赖程度越强;②总体趋势上,植被状况越好,城市分布数目越多;城市对植被的依赖程度高,城市等级越高,依赖程度越强;③总体趋势上,地形起伏度越大,城市分布数目越少;地形起伏度对城市分布有较大影响,城市等级越高,影响程度越大;④高程对城市分布有较大影响,城市等级越高,影响程度越大。综合评价全国不同区域的城市发展适宜度,分析了适合城市发展的区域。  相似文献