湘黔地区下寒武统黑色岩系型镍钼矿床中磷结核的成分特征初步研究          下载免费PDF全文

江永宏 《地质找矿论丛》2010,25(1):12-17

对湘黔地区下寒武统黑色岩系底部镍钼矿床中磷结核的成分进行了电子探针分析。根据20个磷灰石成分的测定结果,得出Ca/P变化范围为1.36~1.710,平均值为1.605,认为磷结核中磷灰石类型为羟磷灰石,成因类型为生物化学沉积型。磷结核中Na+,Fe2+,Al3+,La3+,Sm3+,Ce+,Cr3+,Ti4+的含量较高,并且均显示了异常丰富的组合类型,如Na+和LREE。在1/4大小的磷结核横剖面上,存在着单核或双核沉积中心,结核的内部构造类型为不规则纹层状。磷结核从边部到中心的贵金属元素,其活性元素相对惰性元素的参数(Pd/Pt,Ag/Au,TD/SUHR)呈现同样的变化趋势。磷结核的外层是相对活性的元素,核部则为相对惰性的元素,部分相对活性的元素(如Pt,Pd,Ag)向外层发生初步迁移。铂族元素的超常富集归因于携带海底岩石物质的热水作用。  相似文献   

赤潮生物的毒害机理与毒素生物化学研究   总被引：2，自引：0，他引：2  

周成旭  严小军 《海洋科学》2000,24(5):23-26

对赤潮毒素的研究已成为当前国际上的一个研究热点。本文仅对赤潮生物的毒害机理与毒素生物化学的研究进展进行综述。１亚历山大藻（Ａｌｅｘａｎｄｒｉｕｍｓｐｐ．）的毒害机理亚历山大藻的毒害机理是在代谢过程中产生麻痹性贝毒。１９７５年,当第一个麻痹性贝毒石房蛤毒素(ＳＴＸ)的化学结构用Ｘ射线结晶学方法鉴定成功时,发现这个分子属于生物碱类型,其基本骨架单元是全氢化嘌呤。通过同位素分子对Ａｌｅｘａｎｄｒｉｕｍｔａｍａｒｅｎｓｅ和Ａｐｈａｎｉｚｏｍｅｎｏｆｌｏｓａｑｕａｅ的培养试验发现,该毒素是由精氨酸和乙酸通过一种…  相似文献   

Studies on the pathogenic bacterium of ulcer disease in Epinephelus awoara   总被引：2，自引：0，他引：2  

QIN Yingxue  WANG Jun  SU Yongquan  WANG Dexiang  CHEN Xinzhong 《海洋学报(英文版)》2006,25(1):154-159

1 Introduction Groupers are commercially valuable species which attract considerable mariculture interest in Southeast Asia, especially in China’s Mainland, Tai- wan Province, Hong Kong District, and Singapore. In the recent years, groupers have become t…  相似文献   

影响海水中二甲基硫（DMS）浓度的若干生物化学过程研究     

崔贞  张曼平 《海洋湖沼通报》1998,(2):17-22

影响海水中ＤＭＳ浓度大小的因素很多。本文综述了目前国仙外有关ＤＭＳ的生物和化学过程的研究进展。  相似文献   

Non-specific immune response of bullfrog Rana catesbeiana to intraperitoneal injection of bacterium Aeromonas hydrophila     

张俊杰  邹文政  鄢庆枇 《中国海洋湖沼学报》2008,26(3)

Non-specific immune response of bullfrog Rana catesbeiana to pathogenic Aeromonas hydrophila was studied to 60 individuals in two groups.Each bullfrog in bacterium-injected group was injected intraperitoneally(i.p.) with 0.2 ml bacterial suspension at a density of 5.2 × 106 CFU/ml,while each one in control group injected i.p.with 0.2 ml sterile saline solution(0.85%,w/v).Three bullfrogs in both groups were sampled at 0,1,3,7,11,15 and 20 days post-injection(dpi) for the evaluation of non-specific immune parameters.It was observed that intraperitoneal injection of A.hydrophila significantly increased the number of leucocytes and that of NBT-positive cells in peripheral blood.Significant increases in serum bactericidal activity and serum acid phosphatase activity were also observed in the bacterium-injected frogs when compared with those in the control group.However,a significant reduction was detected in vitro in phagocytosis activity of peripheral blood phagocytes.No significant difference in changes in the number of peripheral erythrocytes,serum superoxide dismutase(SOD) activity,and lysozyme activity was detected between the two groups.It is suggested that bullfrogs may produce a series of non-specific immune reactions in response to the A.hydrophila infection.  相似文献