Relationship of Arctic sea ice and Northern Hemispheric 500 hPa Polar vortices     

References： 《极地研究(英文版)》2007,18(1):73-83

Using the NCEP/NCAR reanalysis monthly 500 hPa height data on a 2.5 latitude-longitude grid and 1°×1° sea ice data,the polar vortex area,intensity index and arctic sea ice area index are calculated respectively,and the meridional distribution,period variation and the abrupts in the long range trend are analyzed to study their relationship.The results show that the meridional distribution of sea ice and polar vortex h-ave distinctive difference,the relative positions of them are different in the eastern and western hemispheres,and exept they have periods of 4 months,quasi half year,quasi year,4-5 years and 10 years commonly,and each of them has its own respective variation as well.The sea ice area is decreasing apparently since 1980's,so is the polar vortex area,but their abrupt changge time are different totally.The area of sea ice and polar vortex has prominent positive correlation,but the relationship of sea ice intensity,polar vortex intensity,polar vortex area is complicated.  相似文献   

用正行列式解瓶颈指派问题     

由雷  岳中亮 《广东海洋大学学报》2007,27(6):67-70

用正行列式作为工具，给出了瓶颈指派问题新的解法，并利用正行列式的值求出了瓶颈指派问题的全部最优解。最后通过一个实例说明该算法的实用和有效性。  相似文献   

用正行列式解瓶颈指派问题     

由雷  岳中亮 《广东海洋大学学报》2007,27(6):67-70

用正行列式作为工具,给出了瓶颈指派问题新的解法,并利用正行列式的值求出了瓶颈指派问题的全部最优解。最后通过一个实例说明该算法的实用和有效性。  相似文献   

广西上泥盆统F-F界线碳同位素的变化特征   总被引：3，自引：0，他引：3  

许冰  顾兆炎  胡滨  李镇梁 《沉积学报》2004,22(4):603-608

发生在晚泥盆世弗拉期(Frasnian)-法门期(Famennian)之交的生物灭绝事件(简称F-F事件)是古生代以来五大生物集群灭绝事件之一,其原因仍含糊不清。碳同位素研究显示,伴随F-F事件全球碳循环发生了显著的变化。但对中国南方F-F事件地层碳同位素变化特征的认识不够,缺乏系统的研究。对广西桂林杨堤上泥盆统灰岩剖面的碳同位素的分析结果表明,在上泥盆统存在两次碳同位素正偏移,分别出现在下rhenana带和F-F的界线,其中,出现在F-F界线的碳同位素正偏移与广西垌村以及欧美和非洲等地的上泥盆统F-F界线附近的碳同位素记录一致,且具有相近的变化幅度。进一步对广西桂林附近的杨堤和垌村剖面F-F界线的碳同位素组成变化模式的分析发现,这次正偏移可能是由多次次级变化组成,与F-F事件中生物的灭绝步骤相似。  相似文献   

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孟庆筱  王太松  吕健  董彦知  郭宝震 《大地测量与地球动力学》2014,34(1):38-42

????????????????????????????棬??????????????????????????????????????????GPS???????????????????????????M≥5.0????????????????????????????????????????????????Ч???????XY?????????????????????????????????????????????????????????????????????????ο???????????  相似文献   

高频表面波对定常Ekman流解的影响     

徐俊丽  宋金宝 《海洋与湖沼》2014,45(1):197-205

基于Jenkins(1989)建立的包含Stokes漂流、风输入和波耗散影响的修正Ekman模型,采用Paskyabi等(2012)使用的推广的Donelan等(1987)中的谱和波耗散函数,并利用Paskyabi等(2012)中修正方法给出的包含高频波的风输入函数,在粘性不依赖于水深及粘性随深度线性变化的条件下,研究了包含高频毛细重力波的随机表面波对Stokes漂流和Song(2009)导出的波浪修正定常Ekman流解的影响。结果表明高频表面波使Stokes漂流在海表面剪切加强,对定常Ekamn流解的影响通常不能忽略,但对Ekman流场的角度偏转影响很小。最后,将考虑高频表面波尾谱影响所估算的定常Ekman流解与已有观测结果以及经典Ekman解进行了比对分析。  相似文献   

Conflicting goals in fisheries management—A study of the Norwegian cod fisheries     

《Marine Policy》2014

A multi-objective programming model has been applied to investigate conflicting goals of the Norwegian cod fisheries. The goals included in this article are economic rent and employment. Fisheries managers are confronted with the problem of how best to allocate the total allowable catch (TAC) of cod among eight vessel groups. Compromise solutions taking into account both objectives by giving them equal weights in the multi-objective programming model are calculated and discussed. This article is an extension of an earlier article in which the trade-off analysis was performed using data only for North Norway and one particular year. The present analysis includes the entire Norwegian cod fisheries and is carried out using time series data for 2003–2007, examining the annual variations of key economic and technological parameters of the cod fisheries. Based on the results from compromise programming, the article discusses management and policy implications of reallocation of the TAC by vessel groups.  相似文献   

基于VB的测量坐标正算与反算研究     

王家帮  邓晓斌 《北京测绘》2014,(4):87-88

坐标正反算在测量实际工作中经常用到,本文介绍了测量坐标正算与反算的数学模型,采用VB开发语言,设计了测量坐标正算与反算程序,为测绘工作中坐标转换提供了思路。  相似文献   

Cosmological Scalar in the Jordan-Brans-Dicke Theory. I     

R. M. Avagian  G. H. Harutyunyan  V. V. Papoyan 《Astrophysics》2005,48(3):381-388

A variant of the Jordan-Brans-Dicke (JBD) theory is examined which contains a cosmological scalar that is written so that on going to the Einstein representation it becomes the ordinary cosmological constant of general relativity theory. This paper is divided into two parts. In Part I we examine the cosmological solutions for the Einstein representation of the JBD theory, i.e., in the presence of a minimally coupled scalar field. In Part II we shall study the cosmological solutions in the proper representation of the JBD theory with a self consistent scalar field. The analysis of these solutions is of interest in connection with modern concepts of the evolution of the universe, in particular, with the observed acceleration of cosmological expansion and estimates of the density of dark matter and dark energy.__________Translated from Astrofizika, Vol. 48, No. 3, pp. 455–462 (August 2005).  相似文献   

一阶可变号非线性奇异初值问题     

杨光崇 《成都信息工程学院学报》2005,20(2):213-218

获得了一类一阶可变号非线性奇异初值问题的新结果。  相似文献