二维薄板体自电异常的定量解释

薄板体自电异常的解释方法,经罗伊、乔德赫里、迈泽和保罗等人的不断研究,得到进一步发展.对于走向无限延伸、斜倾或直立薄板的自电异常,作者在这里提出另一种解释方法.     

Detecting genotoxicity using the Comet assay following chronic exposure of Manila clam Tapes semidecussatus to polluted estuarine sediments

Sediments frequently cause damage to biota due to the accumulation of toxic compounds and the bioavailability of sediment-bound contaminants. Damage can be assessed using biomarkers, such as the degree of genotoxic impact following in vivo exposure to pollutants. Genotoxic damage, expressed as single-strand DNA breaks, was measured in cells isolated from haemolymph, gill and digestive gland from the clam Tapes semidecussatus, using the single cell gel electrophoresis (Comet assay). Clams were exposed for three weeks to sediment samples collected from a polluted site and a ‘clean’ reference site.

The level of DNA damage was assessed using an image analysis package and expressed as Tail Moment. Throughout the study, significant differences in DNA damage were recorded for each tissue type between clams exposed to the two sediment samples. We conclude that the Comet assay is a useful tool for the detection of DNA damage in clams chronically exposed to polluted sediments.     

From Physical Space to Visual Image Space

1　IntroductionVirtualreality (VR)isaformofhuman computerinterface(HCI) [1 ] .Andnowitisamajorbranchofcomputing ,cover ingabroadspectrumofhumaninteractionwithcomputers .Itrangesfromtheinteractionwithrealenvironmentstothatwithsyntheticallygeneratedworlds[2 ] .Usually ,intheinterac tiveprocess ,oneofthemainoutputsofcomputerisgraphicsonthescreen .Thegraphicsarethemaininformationsourcereceivedbyhumanfromthecomputers .Tohuman ,visionisthemostimportantorgantogaininformationfromthenaturalworld .S…     

地磁学千年（一）

地磁学的历史可以追溯到公元1000年左右磁罗盘在中国的发现。对地球磁场的系统研究始于1600年吉尔伯特(William Gilbert)的De Magnete一书(Gilbert，1600)。此后，哈雷(Edmond Halley)、厍伦(Charles Augustin de Coulomb)、高斯(Carl Fdedrich Gauss)和赛宾(Edward SabinO相继进行了该方面的研究工作。奥斯特(Hans Christian Oersted)和安培(Andre-Made Ampere)磁理论的发现为法拉第(MichaleFaraday)的流体发电机理论奠定了基础。基于赫尔(George Ellery Hale)对太阳黑子磁学的观测，拉莫尔（Joseph Larmor)于1919年提出了通过导电流体对流来维持自身运转的发电机理论，由此形成了日地磁场的现代发电机理论。古地磁研究表明，在遥远的过去，地球的磁极曾经历过数次倒转，这为板块构造理论的创立提供了重要的依据。近代科学太空飞船的观测表明了地球远磁场的复杂性以及太阳系中其他行星、卫星的伴生磁场的存在。     

PROPOSAL TO ORGANIZE A WORLD ASSOCIATION FOR SEDIMENT RESEARCH

Sediment Problems·Matter of Global Concern In the twenty-first eentury,humanity will be confronted with three major Problems,namely raPid inerease in PoPulation,shortage of natural resources and Proteetion of the     

NUTRIENT LOAD ESTIMATION METHODS FOR RIVERS

Pollutant load estimation is essential for watershed management and water pollution control. For most watersheds, only sparse water quality measurements (e.g. monthly data) are available. The influence of input data on the accuracy of non-point source pollution load estimation is studied using the water quality and stream flow data from a small watershed in Hong Kong. Comparison and analysis of the results using 8 different methods show that the accuracy of stream-flow runoff is the single most important factor for the calculation of pollutant load. Based on the results, the stream flow correction coefficient is advanced to provide a more reliable load estimation. The improved method of pollutant load estimation can be easily applied in practice since the stream-flow runoff can be measured by hydrological station or estimated with various hydrological methods.     

2014年地籍——论瑞士地籍的可持续发展

1.前言 在瑞士,地籍具有悠久而成功的传统。自从1848年制定联邦宪法之后,瑞士各州就开始实施州级土地登记。随着瑞士民法典     

南秦岭横丹浊积岩系—晚古生代发育于扬子板块被动陆缘上的弧前盆地充填物

南秦岭横丹浊积岩系是一套巨厚的浊流沉积，以向南或南东倾的单斜构造产出。由下而上，该沉积层序包括深水盆地、深水浊积扇和斜坡水道3个相序。相应地，沉积物粒度变粗，厚度变大，火山质组分含量增加，凝灰层大量发育，表明横丹浊积岩系为活动型浊积岩；其古水流方向为NNW－NNE向，物源区为南侧的碧口火山岩系。另外，横丹浊积岩系内还见石英岩、重结晶大理岩成分的砾石，说明其物源还包括被动陆缘环境的沉积物。相序、组构、沉积特征和物源区综合分析表明，横丹浊积岩系为弧前盆地充填物。构筑这一弧前盆地的动力学机制是洋壳板块向南俯冲于扬子板块被动陆缘之下，时代可能晚于中晚泥盆世。