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L波段对不同盐类土壤的微波介电特性分析 总被引：1，自引：0，他引：1
土壤盐碱化是世界面临的一大难题。微波遥感探测土壤具有优势,L波段对土壤含水量和含盐量较为敏感。为了分析不同盐类对土壤介电特性的影响,本文利用L波段(1.43 GHz)微波谐振腔测量了我国盐碱土中普遍存在的3种盐类(NaCl,Na2SO4,NaHCO3)土壤样品的介电常数,研究了土壤介电常数与含水量、含盐量和盐种类的关系。得出结论:实部主要由土壤的含水量决定,含盐量对实部的影响无明显规律;虚部值随含水量和含盐量的增加而增大;3种盐类土壤介电常数虚部随含盐量变化呈现不同的递增趋势,在含盐浓度一定的条件下,虚部值是ε″ NaCI>ε″ NaHCO3>ε″ Na2SO4;在某一含盐量点3种盐类土壤虚部随含水量变化的斜率不同,以此能将3种盐类区分。该研究为建立含不同盐类土壤介电常数模型和微波遥感监测土壤盐碱化提供了实验的依据。 相似文献
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柴达木盆地北缘土壤积盐特点及对公路工程建设的影响 总被引：2，自引：0，他引：2
本文在分析研究柴达木盆地土壤积盐类型分布特点及成因的基础上，客观地阐述了柴达木盆地土壤成盐环境及盐胀溶陷灾害形成演化对工程建设的影响，进而提出了相应有效的防护治理对策。 相似文献
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比较研究了水浸提、盐液浸提及超声辅助盐液浸提的近江牡蛎糖蛋白粗提物对羟自由基、DPPH自由基、超氧阴离子自由基的清除效果。结果表明:水浸提、盐液浸提及超声辅助盐液浸提的糖蛋白中可溶性蛋白与总糖含量之比分别为1.83∶1、4.49∶1和2.51∶1;3种糖蛋白粗提物均具有一定的清除羟自由基、DPPH自由基和超氧阴离子自由基的能力;它们对羟自由基的清除能力高于对DPPH自由基和超氧阴离子自由基;盐液浸提物清除超氧阴离子的能力最弱;超声辅助盐液浸提的糖蛋白粗提物清除羟自由基、超氧阴离子自由基及DPPH自由基的能力比水浸提和盐液浸提的糖蛋白的能力强。 相似文献
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河南登封大金店乡大贾沟下寒武统辛集组、馒头组中的次生岩石——盐溶角砾岩、次生灰岩、石膏硅化岩是盐类沉积物的地表露头。这些次生岩石中角砾的成因是盐类沉积物(主要是石膏)在地表条件下吸水膨胀,在地层的重压下塑性流动使夹层岩石碎裂而成的;次生灰岩则是石膏与大气水反应的产物;石膏硅化岩则是瘤状石膏受次生方解石化后再硅化的结果。沿这些次生岩石倾向在地下深处可找到原生盐类沉积矿床。以这种认识为指导,在华北其它地区有望找到一定规模的盐类沉积矿床。 相似文献
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１微生物浸出的简单历史回顾早在１７６２年西班牙人就在Ｒｉｏｔｉｔｏ矿利用矿坑水浸出含铜黄铁矿中的铜,我国人民也早在北宋时期就知道用酸性水浸铜（胆水浸铜）。但人们对微生物浸出的真正认识和深入研究却是从１９４７年美国人柯尔麦（Ｃｏｌｍｅｒ）发现细菌的氧化... 相似文献
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正Rapid changes of Arctic sea ice cover have been in the focus of the international climate research community in recent years.Quite a few of nations have completed a large number of related surveys and research projects in the Arctic Ocean.Up to now,China has performed six research cruises to the Arctic Ocean resulting in a significant volume of research output.Improved knowledge on the atmospheree-sea ice-ocean interactions in the Arctic is a 相似文献
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The GRV 024516 and GRV 024517 meteorite samples collected from Grove Montains,Antactica are ureilite and H5 ordinary chondrite,respectively.Based on the study of mineralogy-petrology,the cosmic-ray exposure ages and gas retention ages of these two meteorites were determinated and calculated.Their cosmic-ray exposure ages are 33.3 Ma,51.7 Ma,and gas retention ages are 1936.8 Ma and 3720 Ma,respectively.The ureilite contains diamond,graphite and amorphous C,which are mainly carrier of noble gases indicating obviously shock metamorphism effects,which induced 40Ar partial loss.The H5 chondrite indicates thermal metamorphism of parent body,its gas retention age fall the range between 3220 Ma and 4510 Ma of the least shocked H5 chondrites 相似文献
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<正>Although a crucial objective of ecosystem management should be the avoidance of degradation at the beginning,an unfortunate truth is that ecosystems have been substantially exploited,degraded and destroyed in the last century as a result of the global increase in economic and societal prosperity(Suding,2011).More than 60%of ecosystems have been converted for human use or degraded through unsustainable harvest,pollution, 相似文献
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《东北亚地学研究》2014,(3)
正The journal of Global Geology(English Edition)is sponsored by the International Center of Geoscience Research and Education in Northeast Asia,Jilin University of China(ISSN 1673-9736,CN22-1371/P).The former name of the journal was the Journal of International Geoscientific Research in Northeast Asia.It was launched in 1998 and served the scientists and teachers in 相似文献
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《山地科学学报》2014,(5)
<正>The Journal of Mountain Science(JMS),founded in2004,is an international English-language journal on mountain sciences.JMS is supervised by the Chinese Academy of Sciences(CAS),sponsored by the Chengdu Institute of Mountain Hazards and Environment,CAS,published by Science Press 相似文献
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The vertical temperature profiles of snow and sea ice have been measured in the Arctic during the 2nd Chinese National Arctic Research Expedition in 2003(CHINARE2003).The high-resolution temperature profile in snow is solved by one-dimensional heat transfer equation.The effective heat diffusivity,internal heat sources are identified.The internal heat source refers to the penetrated solar radiation which usually warms the lower part of the snow layer in summer.By temperature gradient analysis,the zero level can be clarified quantitatively as the boundary of the dry and wet snow.According to the in situ time series of vertical temperature profile,the time series of water content in snow is obtained based on an evaluation method of snow water content associated with the snow and ice physical parameters.The relationship of snow water content and snow temperature and temporal-spatial distribution of snow water content are presented 相似文献
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The present paper reports 7 species of pontoniine shrimps collected from Hainan Island,South China Sea,by the Joint Chinese-German Marine Biology Expeditions,in which,Conchodytes nipponensis(De Haan,1844)and Coralliocaris brevirostris Borradaile,1898 are new records from Chinese waters. 相似文献