西北太平洋多金属结核铂族元素地球化学特征

Polymetallic nodules and cobalt (Co)-rich crusts are enriched in platinum-group elements (PGEs),especially platinum (Pt) and may be important sinks of PGEs.At present,little information is available on PGEs in polymetallic nodules,and their geochemical characteristics and the causes of PGEs enrichment are unclear.Here PGEs of polymetallic nodules from abyssal basin in the Marcus-Wake Seamount area of the Northwest Pacific Ocean are reported and compared with the published PGEs data of polymetallic nodules and Co-rich crusts in the Pacific.The total PGEs (ΣPGE) content of polymetallic nodules in study area is 258×10~(–9) in average,markedly higher than that of Clarion-Clipperton Zone (CCZ) nodules (ΣPGE=127×10~(–9)) and lower than that of Co-rich crusts in the Marcus-Wake Seamount (ΣPGE=653×10~(–9)),similar to that of Co-rich crusts in the South China Sea(ΣPGE=252×10~(–9)).The CI chondrite-normalized PGEs patterns in different regions of polymetallic nodules and cobalt-rich crusts are highly consistent,with all being characterized by positive Pt and negative Pd anomalies These results,together with those of previous studies,indicate that PGEs in polymetallic nodules and Co-rich crusts are mainly derived directly from seawater.Pt contents of polymetallic nodules from the study area are negatively correlated with water depth,and Pt/ΣPGE ratios in nodules there are also lower than those of the Corich crusts in the adjacent area,indicating that sedimentary water depth and oxygen fugacity of ambient seawater are the possible important controlling factors for Pt accumulation in crusts and nodules.     

A STUDY OF THE WAVE FORCE UPON A VERTICAL BREAKWATER

Field measurement of waves and wave pressure in a given harbour were carried out in the years 1973 and 1977 and then the statistical analysis was made. Based on this analysis and the linear wave theory some problems concerning the total pressure spectrum and the total pressure crest value and trough value are discussed, and the method of calculating these quantities is given.     

无线电长波传播时延的测量

为了在长波授时与导航系统中,进行传播时延的修正,研究电波传播时延修正的理论及方法,及通过传播时延的测量测定土地等效导电率等,必须对电波传播的时延进行精确的测量。利用飞机搬运原子钟方法就是一种高精度的测量长波传播时延的方法。一九七八年十月至十一月进行的3262工程电波传播搬运钟试验,采用飞机搬运铷原子钟测量了我国不同传播路径上许多地点长波天、地波传播的时延,测量的精度为±0.14μs。下面我们就这次实验中传播时延的测量问题进行分析讨论。     

某铜镍矿区物化探工作的初步经验

为了积极地寻找国家急需的镍矿资源,通过综合物化探工作方法,发现了脉状含矿岩体,经过验证该矿体比盆状含矿岩体质量好,储量大,现将物化探工作初步体会介绍出来供大家参考。一、地质、地球物理、地球化学概况:本区位于两种性质不同的大地构造单元的衔接处,其间为一深大断裂所隔开。区域地层主要由前震     

迎接知识经济挑战落实科教兴国战略

本文首先分析了知识经济时代高学院校面临的新的机遇与挑战,并总结了测绘科技大学在科技创新与成果转化方面的实践经验,为高校落实科教兴国战略提出了有益的建议。     

新疆喀喇昆仑地区甜水海岩群发现青白口纪叠层石

2003年在对新疆喀喇昆仑地区原划长城系甜水海岩群进行地质填图及实测剖面的工作中,采集到了大量叠层石化石,时代为新元古代青白口纪。该群岩石变形非常强烈,变质达绿片岩相。本次区调依据其岩石变形变质特征,结合叠层石化石资料,对其形成时代进行了重新厘定。     

遥感制图技术在洪涝灾害监测,评估,治理中的应用

人类活动正大规模地改变着环境,人类赖以生存的环境处于急剧变化之中,导致自然灾害加剧,全球可持续发展问题已引起各国政府、各学科领域和社会公众的广泛关注和重视。中国是世界上灾害最频繁、损失最严重的少数国家之一。每年由各种灾害所造成的经济损失达到数千亿元,其中洪涝灾害位居第一。今年入夏以来的长江全流域、松嫩平原特大洪水,水位高,持续时间长,洪水量大。如何增强人类抵御和减轻灾害的能力,实施“可持续发展”战略,成为当前全国人民关心的焦点之一。从当前对洪涝灾害的防范和处理手段来看,虽然建立了一些相对独立的系…     

青黄(仿河湟野曲“花儿”)

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