Relative pollen productivities of the major plant taxa of subtropical evergreen–deciduous mixed woodland in China

Quantifying the relationship between pollen and vegetation is an essential step in the pollen-based quantitative reconstruction of past vegetation cover. In this study, we use the Extended R-Value (ERV) model and a modern dataset of pollen (collected from moss polsters) and related vegetation from 50 sites in the Daba Mountains (subtropical China) to (i) estimate the relevant source area of pollen (RSAP) of the moss samples and the relative pollen productivities (RPPs) of nine major plant taxa-characteristic of the region, and (ii) evaluate the obtained RPPs. The RSAP estimates of moss polsters vary between 225 and 610 m depending on the ERV submodels and models of pollen dispersal and deposition used. The RPP estimates are different from values published in previous studies from temperate and subtropical China. This may be explained by differences in methodology, climate and vegetation (species composition and spatial distribution), of which vegetation is probably the most important factor. The ranking of the RPP estimates for the nine taxa is Pinus > Juglandaceae > D − Quercus (deciduous Quercus) > Poaceae > Rosaceae > Cyperaceae > Anacardiaceae > Castanea > Fabaceae. We use a ‘leave-one-out’ cross-validation strategy and the Landscape Reconstruction Algorithm (LRA) for pollen-based reconstruction of regional and local plant cover to evaluate the ERV model-based RPP estimates. Both the REVEALS (Regional Estimates of VEgetation Abundance from Large Sites)-based and the LOVE (LOcal Vegetation Estimates)-based plant cover using the RPP estimates are closer to the modern vegetation composition than pollen percentages, thus confirming the applicability of the ERV model and the LRA approach in subtropical China.     

面向服务的南京市电子地图编制及应用

近年来政府部门和社会公众对城市电子地图的内容、现势性、服务方式等多个方面提出了越来越高的要求,面对迫切的应用需求,南京市规划局组织开展了面向服务的南京市电子地图编制工作,并积累了一定的成果和经验。本文主要阐述面向服务的南京市电子地图的分类与特点、标准建设、编制技术要点,并介绍其应用情况。     

加拿大拉布拉多地区主要金属矿床地质特征及其时空分布

拉布拉多是加拿大大西洋成矿域中具地质多样性的最大的成矿省,区域成矿地质条件优越,产有Superior型含铁建造、岩浆硫化物、铂族元素、火山成因块状硫化物、铀、稀有稀土等多种金属矿床。文章介绍了拉布拉多铁、铀、稀有稀土、镍多金属等优势金属矿床的成矿背景、成矿特征、矿床(点)分布、典型矿床地质特征及最新勘探成果,分析了区域地质演化作用与区域内主要金属矿床的时空分布。     

Study of fate and transport of chromium in unsaturated zone- saturated zone

<正>Effluent irrigation can ease the water shortage area agricultural water shortage,and waste-water recycling,as well as bring a series of scientific and socio-economic issues,such as environmentalissues,food safety,sustainable development and so on,which has attracted the attention of people.So,paper to Kaifeng city several important dirt irrigation district for     

广东官田含铜碲黄铁矿矿床中的硫盐矿物及矿床成因

对广东官田黄铁矿矿床研究过程中，在该区首次发现多种硫盐矿物，文章对硫盐矿物进行了系统阐述，对矿石组构、主、微量元素特征，矿化期，次进行了研究。通过硫、氢氧同位素、流体包裹体成分等几方面的研究，进而探讨矿床成因，研究认为，矿床的形成以火山－岩浆期后气液为主，并有大气降水混合中－低温热液交代脉状矿床。     

应用瑞雷波等方法对公路质量进行无损检测

针对水泥混凝土公路质量检测的内容和目前常规检验方法的不足,本文叙述了采用瑞雷波法、超声波法和音频共振法的结合,测试路基路面强度和路面厚度的基本原理,并对几个工程测试实例进行了分析。     

碲砷黝铜矿在我国的首次发现及其找矿意义

碲砷黝铜矿产于广东陆丰中低温热液蚀变岩型硫矿床中，该矿物呈浑圆状、不规则状嵌布在黄铁矿内，粒径０．０２－０．２０ｍｍ，铅灰色，硬度Ｈｖ＝２６９．３ｋｇ／ｍｍ＾２，反射色呈灰色微带棕色色调，均质性。     

论潜蚀和块体运动在河流袭夺中的主导作用─—河流袭夺作用机制与实例剖析

区域地壳隆升或地槽回返褶皱成山后,斜坡上出现平行状水系.随着河流的溯源侵蚀,分水岭后退,水系适应内外力条件演变成不同型式,并发生河流袭夺.导致河流发生袭夺的决定性原因,一是袭夺河的快速溯源侵蚀,二是位于分水岭反面的高位被袭夺河的河床下与古分水岭下潜蚀作用和块体运动.湔江支流之一海子河在早更新世末依次袭夺了古花园沟河(已消失)和古银厂沟河(原石亭江右支流)等河.     

高分辨率遥感影像城中村提取的景观语义指数方法

城中村是中国一类特殊的非正式居民区。本文从城中村的物理特点出发,采用景观语义指数描述复杂的城中村场景,提出基于景观语义指数的高分辨率遥感影像城中村提取方法,并采用“分类置信度-反馈”机制进行实际可操作的大范围城中村制图。以广州市核心城区为例,城中村检测的总体精度达到了90%以上。试验结果表明相对于传统的光谱、纹理特征,景观语义指数能够更好地描述城中村的根本形态特点,更准确的城中村提取。此外,“分类置信度-反馈”机制能够充分参考机器学习的分类概率,以有限的人工干预生产更加准确的城中村制图产品。因此,本文方法能够有效应用于大范围的城中村提取与制图。