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微地域搬运——碳酸盐岩红色风化壳形成过程的一种方式 被引量:17
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作者 冯志刚 王世杰 +1 位作者 刘秀明 罗维均 《地质学报》 EI CAS CSCD 北大核心 2007年第1期127-138,共12页
由于差异溶蚀作用,由碳酸盐岩强烈风化形成的红色风化壳通常表现出独特的剖面构型:风化壳发育深厚、下伏基岩面强烈起伏波动、溶沟和石牙相间展布。以黔中岩溶台地之上发育的红色风化壳——平坝剖面为例,通过宏观地质、地球化学、粒度... 由于差异溶蚀作用,由碳酸盐岩强烈风化形成的红色风化壳通常表现出独特的剖面构型:风化壳发育深厚、下伏基岩面强烈起伏波动、溶沟和石牙相间展布。以黔中岩溶台地之上发育的红色风化壳——平坝剖面为例,通过宏观地质、地球化学、粒度分析以及矿物学等方法,并以邻近的两个石灰土剖面(罗吏剖面和龙洞堡剖面)作对比,对碳酸盐岩红色风化壳的形成过程进行了讨论,论证了微地域搬运是碳酸盐岩红色风化壳尤其是厚层红色风化壳形成过程的一种方式。溶沟部位的风化壳,从风化前锋向上的一定深度范围内,为原位残积风化的产物(残积层);在此深度以上的部分,为地势较高的相邻石牙部位不同风化程度的残积物的搬运堆积(堆积层),也是导致风化指标随深度呈锯齿状波动的直接原因。后者一般组成剖面的主体。风化壳的年代地层学表现为,在残积层,从风化前锋向上,风化年龄由新到老;在堆积层,从下到上,风化年龄由老到新。风化前锋是一个重要的地球化学作用场所,在这一狭窄的界面上,伴随碳酸盐矿物的快速淋失,残余酸不溶物开始了明显分解。而风化壳的后期演化是一个缓慢而长期的过程。达到重力平衡的剖面(即风化壳表面平缓、不发生微地域搬运的剖面),在由表及里的风化作用下,从地表向下的一定深度范围内,逐渐改造为常态风化壳的发育特征。 展开更多
关键词 微地域搬运 红色风化壳 碳酸盐岩 风化前锋 贵州
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渔塘坝微地域中玉米硒的分布及其与土壤硒的关系 被引量:6
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作者 朱建明 郑宝山 +3 位作者 王中良 肖化云 毛大均 苏宏灿 《环境科学》 EI CAS CSCD 北大核心 1999年第4期38-41,共4页
在渔塘坝0.01km2的微域内,玉米硒含量达到较高水平,其根、茎、叶、籽中的平均硒含量分别是4.36±3.27mg/kg、3.08±2.24mg/kg、9.74±7.62mg/kg和8.07±5.02... 在渔塘坝0.01km2的微域内,玉米硒含量达到较高水平,其根、茎、叶、籽中的平均硒含量分别是4.36±3.27mg/kg、3.08±2.24mg/kg、9.74±7.62mg/kg和8.07±5.02mg/kg.渔塘坝中玉米硒分布类似土壤硒分布,也可划分出相对低、中、高硒的分布区.土壤硒含量基本决定了玉米硒含量,但土壤硒含量的微小变化即可导致玉米硒含量的较大变化.因此推测。 展开更多
关键词 玉米硒 分布 敏感指标 微地域 环境硒水平
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四湖地区涝渍微地域分类及梯级农业模式试验
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作者 刘章勇 李必华 《湖北农学院学报》 2003年第4期241-244,共4页
分析了四湖地区涝渍灾害形成的原因;根据涝渍地域微地貌的差异和涝渍灾害发生特点,将四湖地区的涝溃微地域分为6种主要类型;选择其中广泛分布的典型碟形洼地,根据其高程不同按水体圈、涝地圈、渍地圈、旱地圈和庭院圈分别进行了高效生... 分析了四湖地区涝渍灾害形成的原因;根据涝渍地域微地貌的差异和涝渍灾害发生特点,将四湖地区的涝溃微地域分为6种主要类型;选择其中广泛分布的典型碟形洼地,根据其高程不同按水体圈、涝地圈、渍地圈、旱地圈和庭院圈分别进行了高效生态农业模式的开发,取得了较好的综合效益。 展开更多
关键词 四湖地区 涝渍微地域 地域分类 梯级农业模式 试验 灾害特点 碟形洼地
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不同微地域上长白落叶松土壤含水率的分布状况 被引量:1
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作者 张迎新 刘滨辉 +2 位作者 师丽华 朱世龙 于文波 《东北林业大学学报》 CAS CSCD 北大核心 2002年第3期72-75,共4页
为探索土壤含水率在微地域上的分布,采用根系与非根系定点取样和方差分析的方法,分析了长白落叶松幼林林地土壤的含水率微地域分布情况。结果表明:含水率在微地域上有显著性差异;在沟底部根际水分与非根际水分有显著差异;土壤容重在微... 为探索土壤含水率在微地域上的分布,采用根系与非根系定点取样和方差分析的方法,分析了长白落叶松幼林林地土壤的含水率微地域分布情况。结果表明:含水率在微地域上有显著性差异;在沟底部根际水分与非根际水分有显著差异;土壤容重在微地域上无显著差异;适宜幼林生长的微地域水分环境有台地、阴坡沟首部、沟中部、阳坡沟中部和汇水部。 展开更多
关键词 微地域 长白落叶松 土壤 含水率 区域分布
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微地域对长白落叶松幼林生长的影响 被引量:1
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作者 张迎新 唐立君 +1 位作者 孟繁福 唐立彬 《东北林业大学学报》 CAS CSCD 北大核心 2002年第4期88-90,共3页
为探索微地域对幼林生长的影响 ,采用定位测树和方差分析方法分析了长白落叶松幼林期间的地径、树高和树冠的生长量。结果表明 :微地域的地形因子对幼林地径和树冠的影响最明显 ,对树高的影响较明显 ,这种影响突出表现在阳坡上部和下部... 为探索微地域对幼林生长的影响 ,采用定位测树和方差分析方法分析了长白落叶松幼林期间的地径、树高和树冠的生长量。结果表明 :微地域的地形因子对幼林地径和树冠的影响最明显 ,对树高的影响较明显 ,这种影响突出表现在阳坡上部和下部之间 ;不利于幼林生长的微地域部位有阴坡汇水区、阳坡下部汇水区。 展开更多
关键词 微地域 长白落叶松 幼林生长 影响
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微地域土壤含水率对长白落叶松幼林生长的影响
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作者 王军 郭宏锐 《黑龙江林业》 2003年第8期38-38,共1页
关键词 微地域 土壤含水率 长白落叶松 幼林 生长
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数量化理论I在土地分级中的应用 被引量:7
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作者 黄永平 田小海 《湖北农学院学报》 2000年第3期236-240,共5页
阐述了数量化理论I应用于农业综合开发示范小区土地分级的基本原理 ,并运用这一理论对一个村级水平的示范小区的土地资源进行了实际分级。结果表明 ,应用这一方法在微地域上能客观。
关键词 数量化理论Ⅰ 土地分级 微地域 土地质量评价
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The Determination of Geographical Origin of Foodstuffs by Using Innovative Biological Bar-Code
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作者 Aly E1 Sheikha Didier Montet 《Journal of Life Sciences》 2012年第12期1334-1342,共9页
Abstract: One of the great concerns of the customers is the traceability of the products. The authors proposed to link microbial ecology to geographical origin of foodstuffs by a molecular technique joined to an imag... Abstract: One of the great concerns of the customers is the traceability of the products. The authors proposed to link microbial ecology to geographical origin of foodstuffs by a molecular technique joined to an image analysis. Molecular techniques employing 16S and 28S rDNA profiles generated by PCR-DGGE were used to detect the variation in microbial community (bacteria, fungi) of Pangasius fish from Viet Nam harvested in different aquaculture farms and during different seasons and Shea tree fruits from five different districts in Mali. The bacterial DNA profiles from Pangasius fish and the fungal DNA profile from Shea tree fruits were specific to each place of production and could be used as a biological bar code certifying the origin of fish and fruit. To follow the product during processing, the authors proposed to identify and validate some pertinent biological markers which come from the environment of the food to assure their traceability during international trade. It is new analytical method which permits to determine the origin of food or to follow them during international trade. 展开更多
关键词 Geographical origin FOODSTUFF PCR-DGGE microbial community DNA profile biological bar-code.
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Change Numbers of Microorganisms under Vegetable Cultures of Irrigated Soils of Subtropical Zone of Azerbaijan
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作者 N. H. Orujova 《Journal of Agricultural Science and Technology(A)》 2011年第3X期394-400,共7页
Number of microorganisms of soils of subtropic zones in a vegetable-fodder and vegetable-bean crop rotations compared with permanent cultivation of these cultures has been studied. The results of the analyses have sho... Number of microorganisms of soils of subtropic zones in a vegetable-fodder and vegetable-bean crop rotations compared with permanent cultivation of these cultures has been studied. The results of the analyses have shown that character of change of number of the basic physiological groups of microorganisms (a bacteria, sporeforming bacteria, actinomysetes and microscopic fungies) depends not only on soil-ecological conditions but also on the kind and biological features of cultivated cultures. In soils of subtropical zones the greatest number of organisms using organic nitrogen in food was observed on alluvial meadow-forestry soils and yellowish-gley soils. Gray-brown soils are rich in actinomycetes in comparison with alluvial meadow-forestry soils, but meadow-serozem is rich in spore-forming bacteria forms. A number of microscopic fungi of the studied soils were the least. High intensity of processes of mineralization was marked in meadow-serozem soils, the least in alluvial meadow-forestry and yellowish-gley soils. Under permanent cultures the quantity of microorganisms was less, and factor of mineralization is higher above, than in crop rotation. 展开更多
关键词 Rotation vegetable cultures permanent cultivation irrigated soils numbers of microorganisms the coefficient ofmineralization.
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Progress in the micro-perspective studies of economic geography in China since 1980s 被引量:3
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作者 李小建 罗庆 +1 位作者 海贝贝 李立 《Journal of Geographical Sciences》 SCIE CSCD 2016年第8期1041-1056,共16页
Micro-perspective studies on economic geography in China can be classified into geography of the enterprise, geography of the rural household, and small-scale studies on economic activities. Literature on geography of... Micro-perspective studies on economic geography in China can be classified into geography of the enterprise, geography of the rural household, and small-scale studies on economic activities. Literature on geography of the enterprise includes spatial expansion of the enterprise, industrial location, firm's networks, industrial relocation, industrial clusters, and the relationship between industrial organizations and the environment. Studies on geography of the rural household(GRH) include the theoretical framework of GRH, the locations of rural economic activities, and the interrelation between rural households and geographical environment. Small-scale studies focus on human-land interaction from a land plot perspective, relations between specialized villages and the environment, and regional sustainable development research at site-specific scale. Micro-perspective studies on economic geography attempt to search for the basic unit of economic-geographical landscape, exploring the geographical process and the formation mechanism of geographical phenomena. The exploration of these three perspectives anticipates new approaches to economic-geographical studies with China's special background. 展开更多
关键词 economic geography geography of the enterprise geography of the rural household small-scale studies
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