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~(210)Pb法测定东海大陆架现代沉积速率 总被引：4，自引：0，他引：4
一、前言自从七十年代初期(Krishnaswami等,Koide等)。~(210)Pb法首次用于测定湖泊和海洋沉积速率以来,它已成功地用于湖泊、河口、峡湾、潮间带、大陆架和大陆斜坡等不同环境的沉积作用研究(Bruland,Robbins,)。在实际应用中,~(210)Pb法与纹泥法,树木年轮法,孢粉法及某些放射胜同位素法一样,已被证实是一种较可靠的测年方法。这种方法尤其适用于近百年内现代沉积速率的测定。测定沉积物年龄的~(210)Pb法不仅在近代沉积作用的研究方面,而且在解释工业革命以来人类活动对近代地球化学过程的影响方面均有显著的进展。应用~(210)Pb并结合化学 相似文献
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本文以翡翠贻贝(Mytilus viridis Linnaeus)为材料,研究它在含有不同浓度60Co、137Cs的海水中培养一个月,不同组织器官对单核素和双核素的积累与浓度之间的线性关系,以及再经过一个月的排放实验,对这种线性关系的影响,结果表明,翡翠贻贝的足丝、软组织、外壳、体液等组织器官能高水平地积60Co累,而以很慢的速率排出体外,其积累量与各浓度之间存在一定线性关系,排出实验对线性关系没有影响,这种贻贝可以用作污染海区60Co的指示物。 相似文献
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本文根据单细胞植物利用太阳光和CO2进行光合作用,为海洋生物提供能量和食物,而底质中的细菌又把海洋动物排泄的含氮化合物转化为可供单细胞植物利用的氮源之原理,建立一个人工密闭小生境,综合地考察137Cs、134Cs、65Zn、60Co、59Fe、54Mn在小生境中各组成部分(海水、底质及五种生物)的分配关系.结果表明,137Cs,134Cs有78%是以离子态存在于天然海水中,其中28%几乎均匀地参与悬浮物和生物过程的交换,59Fe、54Mn,65Zn、60Co则均约80%被固相物质所浓集,它们的运动主要受生物过程和物理化学过程所控制,文中还讨论了影响核素在各组成部分分配的因素,本文也是目前国内外正在进行的各种受控生态系研究的另一种类型,它对于定量地研究污染物质在海洋中的转移规律有一定的参考价值. 相似文献
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本文研究了人工小生境中59Fe在海水,底质与海洋生物间的转移以及在藻类,罗非鱼、对虾、毛蚶等生物体内的积累、分布和代谢.结果表明,59Fe在海水中主要是以颗粒形式存在,悬浮物对它有高的浓集系数,底质、藻类对59Fe的浓集作用,24 h内达到动态平衡.罗非鱼和毛蚶的肠道、消化腺及对虾的内脏等组织器官对59Fe的浓集系数很高,但排出也很快,是59Fe在这些生物体中代谢的紧要器官.59Fe在生化物质里的分布就总量看,主要集中在蛋白质,其次是DNA,就结合能力而言,DNA大于蛋白质,而有机酸均为最少. 相似文献
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The concentration of 65Zn under artificial conditions in suspended matter, sediment, algae, and excretion as well as its distribution in the organs of fish (Tilapia mossambia), prawn (Penaeus peni-cillatus), clam (Area granosa), clam (Cyclina sinensis) are studied. The results show a high concentration factor of suspended matter, with a dynamic equilibrium of concentration by lagea arrived after two days. The concentration factor of 85Zn in the intestines of fish, prawn, clam and gills of clam are very high, and their excretive rate is rapid. It shows that the intestines and gills are critical organs of 65Zn concentration. The content of 65Zn in nucleic acid is highest, and is higher in RNA than in DNA, while that in organic acid is lowest. 相似文献
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The mussel (Mytilus virids Linnaeus) were cultured in seawater containing ~(60)Co, ~(137)Csand ~(60)Co plus ~(137)Cs respectively with different concentrations (10~(10)--10~(-6) Ci/ 1) for one month.Then, the loss experiments were carried on for another month. It was studied that therelation between the accumulation amount of radioactivity in every parts of mussel bodyand pollution amount of radioactivity in seawater. The results showed that ~(60)Co can be 相似文献
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The pathway by which "Co and 137C3 got into Area, and the type of uptake in animal were studied. The results showed that 60Co was taken up by gill and was transferred quickly to other organs through blood. There are more uptake pathways for 137Cs. The uptake of 60Co by Arca was mainly active transfer and the energy comes mainly from the process of biotic oxidation. On the contrary, the uptake of 137C3 by Arca was mainly a passive transfer, and for most organs the exchange through body-wall was a significant factor. 相似文献
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According to the principle of photosythesis with sunlight and CO2 by phytoplankton supplying food for marine organisms, while the nitrogenous compounds excreted by marine animals are transferred by bacteria into the nitrate for the use of phytoplankton, an artificial microhabitat is built to investigate comprehensively distributive relationship of 127Cs, 134Cs, 65Zn, 60Co, 50Fe, 54Mn In the parts of the microhabitat. The results show that 78% of the 134Cs and 137Cs in ion state are present in sea water, with 28 % of them nearly homogenous envolved in the exchanging processes of the suspensates and organisms, and that 80% of 59Fe, 54Mn, 65Zn, 60Co were concentrated by solid substance, whose motion was mainly controlled by biological processes. The factors affecting the distribution of nuclides in each composition are discussed. As another type of research on the controlled ecological system which is a subject currently studied in the world, the present paper is of reference value for studying quantitativ 相似文献