2010年上海世博会选址研究   总被引：1，自引：0，他引：1  

石忆邵 《地域研究与开发》2005,24(4):83-86,91

根据2010年上海世博会对快捷高效的综合交通运输体系、优美的亲水环境、有效的危机管理系统、高标准的防灾体系等运营环境的基本要求,结合该市中心城区高昂的土地置换成本、高强度的交通流量压力、较弱的承灾能力等客观实际条件,文章提出了将世博会选址于上海临港新城的建议,认为这将有利于发挥临港新城的综合交通网络优势,彰显国际性港口城市的会展功能,形成城市化发展的多重社会经济效应,推动上海加快实施海洋开发战略等。  相似文献   

用X射线荧光光谱法测定Cl、S等31个元素     

杨剑  万飞  王佳丽  杨婷 《吉林地质》2009,28(2):116-119

采用硼酸镶边垫底的粉末样品压片制样,用ARL ADVANT′XP＋型X射线荧光光谱仪对土壤和水系沉积物样品中Na、Mg、Al、Si、P、S、Cl等31个组分进行测定。重点研究了Cl和S等元素的测定条件、痕量元素的背景选择和谱线重叠校正问题。使用经验系数法和康普敦散射作内标校正基体效应。经标准物质校验,结果与标准值吻合。方法的检出限、精密度和准确度能满足多目标地球化学调查样品的分析要求。  相似文献   

A System for Fast Cartographic Sounding Selection     

Haigang Sui  Xinyan Zhu  Anming Zhang 《Marine Geodesy》2013,36(2):159-165

Soundings on nautical charts provide information about the shape of the ocean bottom between chart depth curves. A single chart may have thousands of soundings posted on it. This article describes a system for automatic cartographic sounding selection. In this system, a new algorithm for automated selecting soundings is developed. The algorithm is employed in such a way that it can guarantee (a) fast and accurate selecting sounding, (b) processing the circular depth curves, (c) solving the overplotting problems between depth curves and soundings, and (d) keeping selected soundings “prettier.” The system was intensively tested using real data sets, and its superiority has been revealed by the testing results.  相似文献   

Population dynamics of cryptogenic calcarean sponges (Porifera,Calcarea) in Southeastern Brazil     

Fernanda F. Cavalcanti  Luís Felipe Skinner  Michelle Klautau 《Marine Ecology》2013,34(3):280-288

The calcarean sponge Paraleucilla magna is classified as being an invasive species on the Mediterranean Sea, where it causes economic damages to mollusc farms. On the Brazilian coast, this species is considered to be cryptogenic, and information on its ecology is scarce. The same is true for Sycettusa hastifera, another calcarean sponge with a worldwide distribution. Data on the ecology of these species could help in elucidating their potential to become a threat if they are found to be exotic species in Brazil. In the present work, we studied habitat selection, growth and mortality of early juveniles of P. magna and habitat selection of S. hastifera in a Marine Reserve from Southeastern Brazil, where these species are abundant in the benthic community. Granite plates were used for habitat selection analysis, varying in substrate inclination (vertical and horizontal) and exposure to light and hydrodynamism (exposed and sheltered). To analyse the growth and mortality rates, sponges were mapped and then measured once a week for 10 weeks. If a monitored sponge was not found in the following week, it was considered to be dead. Our results showed that, although P. magna and S. hastifera are capable of inhabiting substrates exposed to different environmental conditions, they showed habitat preferences. Growth of the juveniles of P. magna seemed not to have damaged any neighbouring invertebrates. The mortality of juveniles of this species was higher during the first 2 weeks of life but its causes could not be elucidated.  相似文献   

Since turtles cannot talk: what beak movement sensors can tell us about the feeding ecology of neritic loggerhead turtles,Caretta caretta     

Sandra Hochscheid  Andrea Travaglini  Fulvio Maffucci  Graeme C. Hays  Flegra Bentivegna 《Marine Ecology》2013,34(3):321-333

Understanding the role that consumers play in an ecosystem requires knowledge about food selection and intake rates. However, such basic data are often difficult to obtain, particularly for marine animals that are not easy to observe. To overcome this problem, a beak movement sensor was employed on a free‐ranging loggerhead turtle in a neritic foraging habitat at the Domitian littoral (SW Italy). In combination with gastrointestinal content analysis from six turtles found dead in the same area we sought to identify which beak movement patterns were associated with which prey type, and to quantify the ingestion of the various prey types. Brachyuran crabs (100% occurrence), in particular Liocarcinus vernalis, and small molluscs (66% occurrence) were found most frequently in the stomach and intestine of the turtles. Beak movements revealed average ingestion rates of (mean ± SE) 0.27 ± 0.13 food items per minute and that feeding occurred predominantly during dives >4 m and during early morning and evening. Interestingly, the time spent feeding amounted to only 2.2% of the total observation time, whereas feeding‐associated dives added up to just above 10% of the total time. We thus established that loggerhead turtles in this area are specialised on brachyuran crabs, on which they prey with high success during the short time dedicated to foraging. This information strengthens our knowledge about turtle–prey and turtle–habitat interactions, which are essential data to delineate the role that turtles play in this and similar marine ecosystems. Moreover, since the same area is also intensively used by the regional bottom trawl fishery, our results have important conservation implications, because they clearly show the time of day and water depths for which fishing activity should be regulated to reduce the number of turtles that are currently being incidentally caught in this area.  相似文献   

深部咸水层CO2地质储存工程场地选址技术方法   总被引：4，自引：0，他引：4  

郭建强  张森琦  刁玉杰  李旭峰  张徽  范基姣 《吉林大学学报(地球科学版)》2011,41(4):1084-1091

CO₂地质储存作为环保型工程项目,其合理的工程场址是实现长期、安全封存CO₂的首要前提。我国CO₂地质储存工作刚刚起步,尚未形成成熟的选址技术方法体系。CO₂地质储存工程场地选址应遵循目标储层有效储存量大、安全、经济、符合一般建设项目环境保护选址条件、不受外部不良地质因素影响的原则,选址技术宜采用多尺度目标逼近法,选址程序包括规划选址和工程选址两大阶段。规划选址包括国家级、盆地级和目标区级潜力评价3个阶段;工程选址旨在通过目标靶区确定、综合地质调查、钻探及灌注试验和选定场地多因子排序综合评价,最终选出良好的工程场址。深部咸水层CO₂地质储存工程场地多尺度目标逼近选址技术方法对我国批量开展CO₂地质储存工程场地选址具有一定的指导意义。  相似文献   

基于遗传神经网络的入侵特征选择模型     

李享梅  张仕斌 《成都信息工程学院学报》2013,(6):598-603

针对高维数据包含的不相关和冗余特征影响检测方法性能的问题,提出了基于遗传神经网络入侵特征选择模型.该模型在传统的遗传神经网的输入层和隐含层之间增加特征选择层,并在特征选择层与输入层间设置连接开关,如果开关合上,则该特征被选中;否则为放弃.实验结果表明,该模型在保持原有信息完整性的同时,能有效减少冗余特性;在保证检测准确率的前提下,有效提高系统的检测速度.  相似文献   

A procedure on ground motion selection and scaling for nonlinear response of simple structural systems     

Bekir Özer Ay  Sinan Akkar 《地震工程与结构动力学》2012,41(12):1693-1707

This study presents a ground-motion selection and scaling methodology that preserves the basic seismological features of the scaled records with reduced scatter in the nonlinear structural response. The methodology modifies each strong-motion recording with known fundamental seismological parameters using the estimations of ground-motion prediction equations for a given target hazard level. It provides robust estimations on target building response through scaled ground motions and calculates the dispersion about this target. This alternative procedure is not only useful for record scaling and selection but, upon its further refinement, can also be advantageous for the probabilistic methods that assess the engineering demand parameters for a given target hazard level. Case studies that compare the performance of the proposed procedure with some other record selection and scaling methods suggest its usefulness for building performance assessment and loss models. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

农田景观空间异质性分析及遥感监测最优尺度选择——以三江平原为例   总被引：4，自引：0，他引：4  

温兆飞  张树清  白静  丁长虹  张策 《地理学报》2012,67(3):346-356

农情遥感监测需要高时间分辨率的遥感数据,目前这些数据大都为中低空间分辨率影像。在这些尺度下,像元内部往往是异质的,从而影响农情参数反演精度。因此分析和表达农田景观空间异质性和最优尺度选择对遥感农情监测质量的提高具有重要的应用价值。选取建三江农垦区四种典型农田景观为研究点,Landsat/TM NDVI为实验数据,利用实验变异函数对四种景观类型的各向空间异质性进行了分析, 而后通过变异函数模型拟合,定量分析了各个研究点的整体空间异质性,并在此基础上进行了研究区遥感监测最优尺度选择。研究表明:(1) 基于实验变异函数的结构分析方法,可定性地认识空间异质性的大小和方向,进而挖掘出其背后的自然和人为驱动因素。(2) 对实验变异函数进行拟合分析,可定量地刻画不同景观格局各自的空间异质性特性。此外,基于变异函数对空间异质性的定量表达,讨论了利用积分变程A结合Nyquist-Shannon采样定理进行最优尺度选择的方法。  相似文献   

国家自然科学基金人文地理学项目研究特征简析   总被引：3，自引：0，他引：3  

冷疏影 《地理学报》2013,68(10):1307-1315

以2007-2011 年国家自然科学基金人文地理学代码(D0102) 的申请书作为样本,对申请代码、重点研究领域以及研究内容进行梳理,分析中国人文地理学近期发展特征。分析认为,科学问题综合与学科间交叉研究的增加使人文地理学学科边界呈现模糊化的趋势;研究方向体现了时代特点且各研究方向之间申请数量比较均衡;研究关键词大量涌现但共识性表述相对较少;选题颇具本土应用特点但学科体系建设意识逐步增强。  相似文献