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1.
孙力  安刚 《应用气象学报》2002,13(6):650-661
利用1951~2000年共50年的北半球500 hPa月平均高度距平场资料和奇异值分解技术(SVD),重点对东亚地区季节间大气环流异常的相互关系进行了初步探讨。结果表明,东亚地区季节间大气环流异常存在着较为密切的关联,并且这种明显的非同步联系具有时空相关显著的特点,尤其是夏季大气环流异常与其前冬和前春大气环流异常的联系更为密切。当前冬和前春北半球东亚大槽和北美大槽及蒙古高压偏强(或偏弱),极涡偏弱(或偏强),中高纬度盛行经向环流(或纬向环流),以及低纬和热带地区高度正距平(或负距平)明显时,则对应于夏季东亚地区西太平洋副高和鄂霍次克海阻高强度偏强(或偏弱),位置偏南(或偏北),贝加尔湖阻高强度也偏强(或偏弱),但位置偏西(或偏东)的大尺度环流形势出现。当春季北半球大气环流具有上述特点以及夏季鄂霍次克海阻高和西太平洋副高强度偏强(或偏弱),位置偏南(或偏北),且极涡较弱(较强)时,则东亚地区秋季大气环流对应于蒙古高压加强(或较弱),西太平洋副高减弱(或加强),并向南和向东移动(或移动较慢),极涡向南扩散(或扩散减弱),大气环流向冬季过渡加快(或减慢)。另外,大气环流异常还具有一定的持续性特征。  相似文献   
2.
The mangrove crab Aratus pisonii was considered to have an amphi‐American distribution; however, a recent study revealed that the Eastern Tropical Pacific populations were genetically distinct, thus representing a new species: Aratus pacificus. These species separated by the Isthmus of Panama have diverged under different environmental conditions that may have influenced their reproductive biology. As the available information about this genus concerns almost exclusively the Caribbean species, the aim of the present study was to analyse and compare reproductive aspects of Apacificus and A. pisonii obtained from both the Pacific and Caribbean coasts of Costa Rica. Females were collected from April 2011 to April 2012, and reproductive features such as breeding season, size distribution of ovigerous females, fecundity, reproductive output, embryo volume and embryo water content were assessed. Both species produced embryos during the entire sampled period. Most females of A. pacificus carrying embryos close to hatching were found during the rainy season. Ovigerous females of A. pisonii were substantially larger and reached sexual maturity at a larger size than females of A. pacificus. Embryo production started in A. pacificus at a smaller female size than in A. pisonii. As fecundity increased with female size, the average fecundity was lower in A. pacificus. Females of A. pisonii produced larger embryos, which might be related to lower food availability: higher energy content in the embryo enhances the chances of larval survival. These data regarding reproductive features of the Pacific and Caribbean species support the conclusion to separate A. pacificus from A. pisonii.  相似文献   
3.
为了解象山近岸海域水质污染状况,文章根据2012—2016年象山县近岸海域的水质监测结果,分析象山近岸海域水质现状及年际变化。应用灰色预测的模型来对象山近岸海域水质主要污染物的相关数据进行处理,得出主要污染物的预测结果。分析结果表明:象山近岸海域主要污染物为无机氮。用预测结果和实际数值通过残差验证,最后模拟出今后几年的监测值,为象山县近岸海域生态环境相关管理部门提供数据支撑和决策依据。  相似文献   
4.
本文介绍了TMS320C25高速接口电路的设计方法,并以高速A/D接口为例,说明接口电路设计中的一些技巧。这对充分利用TMS320C25的硬件资源有非常重要的意义。  相似文献   
5.
国外关于年代际气候变率的研究   总被引:28,自引:2,他引:26  
王绍武  朱锦红 《气象学报》1999,57(3):376-384
文中指出在气候变率与可预报性研究计划中,列出年代际气候变率及可预报性研究子计划充分显示出这个问题的重要性,回顾并总结了近年来年代际气候变率的研究成果,特别对全球气候变暖、海气相互作用、温盐环流、自然气候变率和ENSO的年代际变率的研究几个重点问题进行了讨论,最后对年代际气候变率研究今后的发展方向提出了看法。  相似文献   
6.
Studies of interactions among bioactive compounds are often difficult to interpret unambiguously.A priori assumptions about the nature of such interactions can seriously distort analysis of the data.Byapplying a rank order analysis appropriate to the naturally ordinal scale of response to xenobiotic insult,several co-herbicides were successfully identified from among numerous candidates in an experimentinvolving multiple blocks,rates and species.Moreover,underlying herbicide interactions weresubstantiated and identified which were not apparent by more traditional parametric analysis.  相似文献   
7.
A number of previous studies have identified changes in the climate occurring on decadal to multi‐decadal time‐scales. Recent studies also have revealed multi‐decadal variability in the modulation of the magnitude of El Niño–Southern Oscillation (ENSO) impacts on rainfall and stream flow in Australia and other areas. This study investigates multi‐decadal variability of drought risk by analysing the performance of a water storage reservoir in New South Wales, Australia, during different climate epochs defined using the Inter‐decadal Pacific Oscillation (IPO) index. The performance of the reservoir is also analysed under three adaptive management techniques and these are compared with the reservoir performance using the current ‘reactive’ management practices. The results indicate that IPO modulation of both the magnitude and frequency of ENSO events has the effect of reducing and elevating drought risk on multi‐decadal time‐scales. The results also confirm that adaptive reservoir management techniques, based on ENSO forecasts, can improve drought security and become significantly more important during dry climate epochs. These results have marked implications for improving drought security for water storage reservoirs. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   
8.
一种特殊的实时图象处理—图环图象展开   总被引:1,自引:0,他引:1  
作者在文中给出了一种将圆环域图象展开成矩形图象的方法,这种方法主要采用八分之一圆扫描方法,快速找出某个圆的所有象素,然后通过双线性插值或抽值将其变为展开图中对应的象素。  相似文献   
9.
江西修水地区中元古界双桥山群修水组内波内潮汐沉积   总被引:9,自引:0,他引:9  
详细论述了江西修水地区中元古界双桥山群修水组中的深水牵引流内波内潮汐的沉积特征及形成环境。深水牵引流内波内潮汐沉积具双向递变、单向递变和对偶层递变层序;其岩相可划分为双向交错层理砂岩相,单向交错层理砂岩相,砂岩、板岩薄互层相,波状、脉状、透镜状细砂岩、粉砂岩、板岩相;发育双向和单向交错层理、曲线型和干涉波痕及波状、脉状、透镜状层理;在综合分析的基础上,进一步建立了该区水道型和非水道型内波内潮汐沉积模式。  相似文献   
10.
本文对扰动量方程引进了相应的简单的非绝热作用,分析了二维界面流的稳定性。结果发现:非绝热加热作用是影响稳定性的重要因子,尤为下行波急流的左侧,加热作用与切变均能导致不稳定。  相似文献   
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