Year aridity index patterns in northwest China and the relationship to summer North Atlantic sea surface temperature

Aim to linking the variability of drought in northwest China to the oceanic influence of North Atlantic SSTs at the background of global warming and at the regional climate change shifting stages, year aridity index variations in northwest China and summer North Atlantic sea surface temperature （SST） variations are examined for the 44 a period of 1961-2004 using singular value decomposition （SVD） analysis. Results show that the SST anomalies （SSTA）in the North Atlantic in summer reflected three basic models. The first SVD mode of SST pattern shows a dipole - like variation with the positive center located at southwest and negative center at northeast of extratropical North Atlantic. And it strongly relates to the positive trend in AI variation in northwest China. The second coupled modes display the coherent positive anomalies in extratropical North Atlantic SST and the marked opposite trend of AI variability between north and south of Xinjiang. In addition, the lag correlation analysis of the first mode of SSTA and geopotential heights at 500 hPa variations also shows that the indication of the former influencing the latter configuration, which result in higher air temperature and less precipitation when the SSTA in the North Atlantic Ocean in summer motivated Eurasian circulation of EA pattern, further to influence the wet - dry variations in northwest China by the ocean-to - atmosphere forcing.     

海洋微型和小型底栖生物相互作用研究综述

The microscopic organisms from sediments are classified into microbenthos and meiobenthos. The former groups are usually referred to protozoa, microalgae and bacteria, whereas the latter comprise micrometazoa defined by mesh-size. Micro- and meiobenthos have been suggested as being one complex and are characterized by their small size, relative short life spans, high turnover rate, and complicated trophic structure. The quantification of the exchange rate of carbon seems a prerequisite for understanding the processes regulating the trophic structure in this complex, where the basic interactions of micro- and meiobenthos include nutrition, competition, synergy and inhibition, etc. The ecological processes mediating the interactions between these groups are poorly understood and invite our attention to more detailed studies. In this paper, we summarize literature data to outline the interactions of the two major assemblages and discuss the main progress in benthic microbial food web.     

东海和黄海表层沉积物生物标志物的分布特征及古生态重建潜力

多参数生物标志物法已被广泛用于重建浮游植物生产力和种群结构.但目前还缺乏这一应用的现代证据,尤其是西太平洋边缘海地区.文中作者对东/黄海的表层沉积物中的浮游植物生物标志物的分布进行研究,发现东海表层沉积物中菜子甾醇、甲藻甾醇、长链烯酮的总含量变化范围为357～3 115 ng/g,黄海的总含量变化范围为2 898 ～6 714 ng/g,硅藻、甲藻和颗石藻生物标志物总量基本具有近岸高、离岸低的趋势,与现场调查资料所得到的趋势基本一致.生物标志物比例结果显示在东海的长江口方向离岸越远硅藻相对比例下降,而在长江口以南则是离岸越远硅藻比例升高.在东海和黄海颗石藻所占比例都很低,但是有离岸越远比例升高的趋势.用生物标志物所重建的种群结构的变化趋势与现场调查资料相符,但其绝对值却与现场资料存在差异.本研究为生物标志物重建种群结构提供了现代数据,但是此方法的定量应用还需做进一步的研究.     

Web服务驱动的地理信息系统研究

Web服务具有松散耦合、高度集成、基于标准规范等优点。将Web服务的这些特性应用到地理信息系统的开发中，提出了Web服务驱动的地理信息系统架构。该架构对现有的Web服务技术进行了改进，引入了服务语义化描述、动态服务组合以及主动服务等概念。最后，对Web服务驱动的地理信息系统进行了测试（以服务发现为例），验证了系统架构的可行性和合理性。     

Causes of rockfalls in Al-Huwayshah area,Yemen

According to topography of Yemen,most areas and villages are located at obligated crest,toe of mountain and under cliffs.Therefore Al-Huwayshah consisting of Tawilah sandstone group is characterized by steep slope reach to 90° in some areas.This area is affected by strong tectonic movements and faults that occurred during the geological epochs.This effect enhances to find out fractures and joints as well as the rocks become brittle and ready to slide depending on the position of area.And there are some frac...     

f-3项与投影函数对电离层延迟的影响

依据Chapman正常电离层理论,构造Chapman剖面函数加权投影函数,给出VTEC三角多项式模型,并以武汉站2005年1月1日观测数据进行实例解算,分析电离层延迟f-3项、电离层单层高度、电离层投影函数形式等对电离层延迟的影响.     

Slope stability FEM analysis and retaining wall design: a case study of clinker in Benxi of Liaoning

Stability is always the most important problem after high slope was excavated. The study analyzed the stress and strain inside the slope by Finite Element Method (FEM) and carried through stress distribution and failure zone, then analyzed the stability of the slope using three different methods and came to the conclusion that it is in unstable condition, so the designed retaining wall was put forward which makes the slope stable.     

罗布泊“大耳朵”地区多源遥感影像数据库的设计与实现

目前,由空间数据引擎管理遥感影像数据的技术已经非常成熟,但在对多源遥感影像数据的合理组织和有效管理以及数据共享方面,还需要寻求更有效的方法。本文在分析不同遥感影像类型的基础上,结合罗布泊“大耳朵”地区研究的需要,设计实现了该区多源遥感影像数据库。讨论了逻辑上设计相同空间分辨率和不同空间分辨率的多源遥感影像数据存储的方法。即根据遥感影像数据的空间分辨率进行分类,并通过遥感影像元数据表建立多源遥感影像数据之间的逻辑关联来组织和管理影像数据的设计方法。该方法的成功运用,为多源遥感影像数据库的设计与建设提供了参考。     

末次冰盛期以来日本海浮游植物生产力和群落结构变化

生物标志物法已经被广泛应用于重建海洋浮游植物生产力和群落结构变化。本文利用这种方法重建了日本海末次冰盛期以来浮游植物生产力和群落结构变化。结果显示,生物标志物含量在末次冰期最盛期21～19 ka和14～4 ka时有高值,而在19～14 ka、4～0 ka有低值。末次冰期最盛期时生物标志物的高含量是由于分层导致的底层水缺氧,生物标志物得到较好保存的结果,而此时日本海盐度很低,使颗石藻相对含量很低;19～14 ka陆源输入减少,日本海生产力水平较低,不断增加的盐度使浮游植物群落结构由硅藻、甲藻占优转变为颗石藻占优;14～4 ka对马暖流流量的加大提高了日本海的初级生产力,同时高营养盐利于硅藻、甲藻的生长,使颗石藻的相对比例减小;4 ka以后随冬季风的增强和黑潮减弱,对马暖流减弱,供应的营养盐减少,日本海生产力水平降低,使颗石藻的相对比例增大,硅藻、甲藻的相对比例减小。     

近岸波浪破碎区不规则波浪的数值模拟

基于近岸不规则波浪传播的抛物型缓坡方程和两类波浪破碎能量损耗因子,对近岸波浪破碎区不规则波浪的波高分布进行了数值模拟,并结合实验结果对数值模拟结果进行了验证分析,结果表明采用两类波浪破碎能量损耗因子所模拟的破碎区波高与实测值均吻合良好,波浪破碎能量损耗因子及波浪破碎指标对破碎区波浪波高分布影响较明显。