热带人工林SAR散射组成及对遥感估测叶面积指数的影响     

高帅  牛铮 《地球科学进展》2008,23(9):982-989

基于RADARSAT SAR数据,利用MIMICS（ Michigan Microwave Canopy Scattering）模型模拟森林组分（冠层、树干层、地表）雷达后向散射,模拟研究表明在稀疏的人工林地区,地表层与森林冠层的直接散射是影响森林总的后向散射中最重要的两个因素。在同样的地表条件与森林环境假设下,阔叶林的模拟结果与影像的一致性要优于针叶林,针叶林由于受到地形起伏的影响,难以利用模型模拟森林的散射情况。同时,研究发现,利用森林郁闭度可以定量的表示森林冠层直接散射与总散射的相关关系,因而在一定的条件下得到冠层直接散射。最后,对该方法进行了简单的验证。、  相似文献   

南京市“一张图”的数据管理机制研究及实现     

钮晨  李梅香  于燕 《国土资源信息化》2017,(1)

本文基于对南京市“一张图”数据管理方式研究,概述了通过确定数据标准,实行数据汇交和更新制度,建立数据应用机制,开发相配套的数据管理应用与监督考核系统等多种手段,实现市级国土资源数据统一、集中、高效的管理,为深化《国土资源数据管理暂行办法》在基层数据管理工作中的应用,加快国土资源基础数据应用共享提供借鉴.  相似文献   

Experimental and Numerical Study on Stress Relaxation of Sandstones Disturbed by Dynamic Loading     

Wancheng Zhu  Shuai Li  Leilei Niu  Kai Liu  Tao Xu 《Rock Mechanics and Rock Engineering》2016,49(10):3963-3982

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Temperature sensitivity thresholds to warming and cooling in phenophases of alpine plants     

Fandong Meng  Yang Zhou  Shiping Wang  Jichuang Duan  Zhenhua Zhang  Haishan Niu  Lili Jiang  Shujuan Cui  Xin’e Li  Caiyun Luo  Lrirong Zhang  Qi Wang  Xiaoying Bao  Tsechoe Dorji  Yingnian Li  Mingyuan Du  Xinquan Zhao  Liang Zhao  Guojie Wang  David W. Inouye 《Climatic change》2016,139(3-4):579-590

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毛乌素沙漠东南缘滴哨沟湾剖面DGS1层段粒度特征及其指示的全新世气候变化   总被引：4，自引：2，他引：2  

舒培仙  李保生  牛东风  王丰年  温小浩  司月君  陈琼 《地理科学》2016,36(3):448-457

分析滴哨沟湾剖面全新统DGS1段的粒度数据,认为流动沙丘砂、泥炭、砂质古土壤、古固定-半固定沙丘砂到湖沼相和次生黄土的颗粒总体上变细,分选变差。结合腹足类动物化石和湖沼相地层中石英砂粒表面电镜扫描,认为DGS1粒度结果实际上是全新世以来多次冬夏季风的交互演替过程的气候-地质记录。据此,将DGS1粒度信号记录的全新世气候分为4个阶段——全新世早期好转期、全新世鼎盛期、大暖期向寒冷期转变波动期和降温不稳定的沙漠化频繁变化时期。  相似文献   

Migratory Waterbirds Response to Coastal Habitat Changes: Conservation Implications from Long-term Detection in the Chongming Dongtan Wetlands,China     

Ye-Ai Zou  Chen-Dong Tang  Jun-Ying Niu  Tian-Hou Wang  Yong-Hong Xie  Hao Guo 《Estuaries and Coasts》2016,39(1):273-286

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Landslide susceptibility mapping based on global and local logistic regression models in Three Gorges Reservoir area,China     

Miao Zhang  Xuelian Cao  Ling Peng  Ruiqing Niu 《Environmental Earth Sciences》2016,75(11):958

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Lithospheric foundering and underthrusting imaged beneath Tibet     

Min Chen  Fenglin Niu  Jeroen Tromp  Adrian Lenardi  Cin-Ty A. Lee  Wenrong Cao  Julia Ribeiro 《《地质学报》英文版》2018,92(Z1):48-48

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Effect of multifactors interaction on competitive adsorption of Zn<Superscript>2+</Superscript> and Cd<Superscript>2+</Superscript> by response surface methodology     

Zhenru Niu  Qiang Xue  Shuo Qi  Ying Guo  Honghan Chen 《Environmental Earth Sciences》2018,77(6):244

The problem associated with multi-metals contaminated soils has generated increasingly more attention. Thus, it is necessary within the field to study the mutual influence of environmental factors on competitive adsorption. The majority of studies carried out to date have concentrated on the variation of adsorption capacity or the removal efficiency, with only a single factor changed (including pH, ionic strength, and metal concentration). However, the interaction effect among various environmental factors was ignored in these studies. The purpose of this study was mainly aimed toward the investigation of the interaction of two influential factors, as well as the influential degree of each factor (such as the initial pH, ionic strength, initial metal concentration, and the competitive metal concentration) on competitive adsorption using the response surface method. These results demonstrated that the influential degree of each factor studied on the competitive adsorption of Zn²⁺ and Cd²⁺ followed the trend of having the initial concentration of the target metal?>?initial pH?>?concentration of competitive metal?>?ionic strength. When the metal concentration was held constant, we found that the competitive adsorption of Zn²⁺ initially increased, followed by a decrease with increasing initial pH. However, this was found to change minimally with increasing ionic strength. When the initial pH or ionic strength was held constant, the competitive ability was observed to increase with increasing Zn²⁺ concentration. However, with increasing Zn²⁺ or Cd²⁺ concentrations, the variation degree of the competitive adsorption was found to become smaller. These results provide novel information toward a better understanding of the effect of multifactors on the competitive adsorption of Zn²⁺ and Cd²⁺.  相似文献   

Frontiers in geoscience: A tribute to Prof. Xuanxue Mo-Preface     

Zengqian Hou  M.Santosh  Wenjiao Xiao  Yaoling Niu  Victor Mocanu 《地学前缘(英文版)》2018,9(5):1261-1264

正1.Introduction In response to the proposal by the Earth Science community of China,we are delighted to organize this special issue of Geoscience Frontiers(GSF)in honor of the work by Xuanxue Mo,Professor of Petrology and Geochemistry of China University of Geosciences(Beijing)and Academician of the Chinese Academy of Sciences,as a tribute to him on his 80th birthday.In his over 50 years of profes-  相似文献