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401.
The village of Collebrincioni is located right at the center of the most damaged area of the April 6th 2009 L’Aquila earthquake.
It is known from historical data that this site had been heavily affected by the 1461 and 1703 seismic events and for that
reason remained abandoned for a long time; the area has been settled again at the end of the 18th century with the rebuilding
of the present conurbation in a new safer location. After the April 6th 2009 earthquake many evidences of coseismic effects
have been found around the Collebrincioni surroundings, even though the macroseismic intensity calculated in the new settlement
was found to be moderate (6 MCS). The aim of this work is to verify whether the cause of the migration from the old location
can be linked to site effects; for this purpose, several measurements of horizontal to vertical spectral ratio (HVSR) have
been carried out at various locations to obtain information on amplification phenomena. To allow a quick evaluation of site
seismic response, without requesting any information about stratigraphical and geotechnical properties of the foundation soils,
the Nakamura’s technique was adopted in this paper. Measurements of HV spectral ratio carried out in the area show relevant
differences between the new and the ancient settlements confirming the hypothesis that the abandonment of the old Collebrincioni
settlement can be related to the site effects which have amplified the destructive effects of the earthquakes. 相似文献
402.
Kica Worrilow Todd King Raymond Walker Mark E. Rose William Moore Steven Joy 《Earth Science Informatics》2010,3(1-2):51-57
From a scientist’s viewpoint a web site is one tool used to conduct research. From an artist’s viewpoint web sites are a form of visual composition. From a developer’s point of view a web site is a type of application. While web sites are a relatively new medium with a particular set of constraints, they do adhere to the same basic design principles that apply to other art forms. These design principles are the basic assumptions that affect the arrangement of elements within a composition. A successful design uses the principles and elements to achieve a visual goal in the composition. A web site designed for scientists has unique properties which are not shared by many other types of web sites. These properties influence the overall visual design of the web sites. Recently at the Institute of Geophysics and Planetary Physics at UCLA undertook a re-design of a number of its websites. In the effort, the use of visual design principles combined with the properties of a science web site were put to the test. In all, six different web sites were designed each with a difference science focus. We describe the process used to design the web sites which involve forming teams of designers, scientists and developers. We present example pages from each design and conclude with a discussion of what was learned during the process. 相似文献
403.
The effect of silica and natural organic matter on the Fe(II)-catalysed transformation and reactivity of Fe(III) minerals 总被引:3,自引:0,他引:3
The Fe(II)-catalysed transformation of synthetic schwertmannite, ferrihydrite, jarosite and lepidocrocite to more stable, crystalline Fe(III) oxyhydroxides is prevented by high, natural concentrations of Si and natural organic matter (NOM). Adsorption isotherms demonstrate that Si adsorbs to the iron minerals investigated and that increasing amounts of adsorbed Si results in a decrease in isotope exchange between aqueous Fe(II) and the Fe(III) mineral. This suggests that the adsorption of Si inhibits the direct adsorption of Fe(II) onto the mineral surface, providing an explanation for the inhibitory effect of Si on the Fe(II)-catalysed transformation of Fe(III) minerals. During the synthesis of lepidocrocite and ferrihydrite, the presence of equimolar concentrations of Si and Fe resulted in the formation of 2-line ferrihydrite containing co-precipitated Si in both cases. Isotope exchange experiments conducted with this freeze-dried Si co-precipitated ferrihydrite species (Si-ferrihydrite) demonstrated that the rate and extent of isotope exchange between aqueous Fe(II) and solid 55Fe(III) was very similar to that of 2-line ferrihydrite formed in the absence of Si and which had not been allowed to dry. In contrast to un-dried ferrihydrite formed in the absence of Si, Si-ferrihydrite did not transform into a more crystalline Fe(III) mineral phase over the 7-day period of investigation. Reductive dissolution studies using ascorbic acid demonstrated that both dried Si-ferrihydrite and un-dried 2-line ferrihydrite were very reactive, suggesting these species may be major contributors to the rapid release of dissolved iron following flooding and the onset of conditions conducive to reductive dissolution in acid sulphate soil environments. 相似文献
404.
东坪金矿“芥末金”及其类型 总被引:4,自引:1,他引:4
对中国河北东坪金 -碲化物型金矿的成分及性质复杂多样的金矿物的研究表明 ,东坪金矿产有由不同尺寸微粒金与碲酸盐 /亚碲酸盐 /含水氧化物组成的一些特殊的混合相 ,具芥末状或胶状结构 ,沿用“芥末金”之称。研究所获众多的分析数据得以对这些成分复杂的物质进行鉴别和分类。并按碲金矿蚀变模式 ,利用孔隙中充填的针铁矿、水硫碲铅石、绿碲铁矿、黄碲矿、黄碲铁石、碲酸等 (或一些未知混合相 )对铁芥末金、碲铅芥末金、碲铁芥末金、锰铅芥末金等各类型的化学组成及性质进行模式化。与前人资料进行了对比 ,对蔡长金、田澍章等描述过的金的碲酸盐或氧化物矿物做出了新的解释 ,提出其中某些未定名的新矿物应解释为芥末金的变种。根据电子能谱学数据推测 ,芥末金中可能存在金的纳米级团簇。 相似文献