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141.
Babu Nallusamy 《Marine Georesources & Geotechnology》2013,31(5):437-446
Detrital zircon crystals from beach and were subjected to morphology and Inductively coupled plasma mass spectrometry (ICPMS) analysis to assess the efficacy of the zircon composition as a provenance indicator. The inclusions of rutile and sillimanite in the lattice of the zircon support metamorphic growth. Zircon grains from relatively dry alkalic and igneous rocks tend to be dominated by {100} and {101} forms, whereas those from aluminous to calc-alkaline rocks exhibit various combinations of forms, with a predominance of {211}, and those from water-rich granites and pegmatites tend to have {110} and {101} as their dominant forms. Prismatic faces develop from zircon mainly due to the temperature of the crystallisation, but the pyramidal faces were linked to chemical factors. Light group Rare Earth Element (LREE) is enriched relative to Heavy group Rare Earth Element (HREE) in zircon. It shows significant negative anomalies in Eu, Co, Rb, and Cs and positive anomalies in V, Zn, Sr, Y, Nb, and Ba. The negative anomaly of Eu is maybe due to the redox condition operative at the time of zircon crystallisation from magma, where most of the Eu could be in Eu2+ state. The ratio of the Zr/Hf in detrital zircon shows a range of values between 6.56 and 6.25%. This supports the idea of the role ascribed to mafic rocks for the parentage of southwest coastal placer deposits. 相似文献
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Nephroselmis gaoae sp.nov.is described on the basis of light and electron microscope observations ofcultured material originally collected and isolated from seawater of Jiaozhou Bay,Qingdao,China.Theperiplasts on the cell body and flagella are covered by five types of scales,two types on the flagella andthree on the body.Among these,the morphology and the number of spines of large stellate body scalesdiffer remarkably from those of previously described species of Nephroselmis.Apart from these,the unusualfine structure of the eyespot(stigma)is very characteristic.As in the other species of Nephroselmis,theeyespot lies immediately under the two-membraned chloroplast envelope;unlike the others,however,it isnot composed of a number of osmiophilic globules,but consists of about 14 curved rod-shapedosmiophilic bodies arranged loosely and randomly.This feature distinguishes the present new species notonly from the other species of Nephroselmis but also from the other motile algal species,the eyespots struc-ture 相似文献
145.
For more than a century, studies of sedimentology and sediment transport have measured bed-sediment grain size by collecting samples and transporting them back to the laboratory for grain-size analysis. This process is slow and expensive. Moreover, most sampling systems are not selective enough to sample only the surficial grains that interact with the flow; samples typically include sediment from at least a few centimeters beneath the bed surface. New hardware and software are available for in situ measurement of grain size. The new technology permits rapid measurement of surficial bed sediment. Here we describe several systems we have deployed by boat, by hand, and by tripod in rivers, oceans, and on beaches. 相似文献
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本文利用扫描电镜对黄土湿陷变形机理及古风化花岗岩成生环境机理进行了研究, 分析了扫描电镜在工程岩土的变形与强度问题机理研究中的重要作用。 相似文献
149.
利用高分辨透射电子显微镜,结合能谱仪观察了20nm左右的胶态Au,在黄铁矿的[001]方向析出。固体原子象显示出Au的附近由于晶格畸变而空隙度较大。 相似文献
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运用扫描电镜和透射电镜对马氏珠母贝(Pinctada martensii D0外套膜组织培养过程中各种细胞的生长变化和活动状况的研究,重点是对上皮细胞分泌活动的观察。最初从外套膜组织迁出的上皮细胞为圆球形,细胞表面近似光滑,但有走向规则细而浅的花纹;培养到第4天,上皮细胞形态上发生了较大的变化,分成A型和B型两种细胞,A型上皮细胞内颗粒物少,是处于合成分泌物的早期阶段或尚未开始合成分泌物,B型上皮细胞处于旺盛的分泌物合成阶段,细胞内粗面内质网和线粒体丰富。培养到15-16天的B型上皮细胞体积明显变大,细胞合成并聚集了大量单层膜包裹的颗粒物,培养到第31天的B型上皮细胞分泌活动减弱,上皮细胞逐渐失去分泌功能,进入衰老,死亡,胞体明显萎缩变小,整个培养过程持续了65d。 相似文献