浅部侵入环境中的,铀,钍再分配     

G.  WD  Jr 夏斯高 《国外地质(北京)》1991,(3):26-29

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蛇绿岩成矿作用的熔融、结晶和构造控制—来自菲律宾吕宋岛Zambles蛇绿杂岩的例子   总被引：1，自引：0，他引：1  

Gractano P.Yumul Jr.  洪景鹏 《世界地质》1993,(1)

比较特提斯、加里东和菲律宾西部盆地中外消减带(SSZ)蛇绿岩与洋中脊(MOR)蛇绿岩,可得出前者比后者含有更多的铬铁矿及块状硫化物矿床。铂族元素矿物(PGMs)在SSZ蛇绿岩中比在MOR蛇绿岩中也更加富集。菲律宾吕宋岛的Zambales蛇绿杂岩是SSZ蛇绿岩,其中也含有这些类型的矿床。  相似文献   

中纬度中尺度对流系统多普勒天气雷达显示的解释（续完）     

RobertA.Houze.Jr周一鹤  吴竞成裴巨才 王书治 《山西气象》1991,(4):26-30

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Late Mesozoic crustal extension along the southern Eurasian margin: evidence from volcanic rocks of the Bangong-Nujiang Suture zone, Tibet     

Decibel FAUSTINO-ESLAVA  Jonathan A. AITCHISON  Rodolfo A. TAMAYO  Jr.Graciano P. YUMUL  Jr.Carla B. DIMALANTA 《地球学报》2009,30(Z1):8-8

The Mesozoic was a period of marginal basin formations, closures and reactivations along segments of the southern Eurasian margin. Remnants of some of these events are now preserved as exposures of Juras-sic-Cretaceous ophiolites and ophiolitic mélanges, thick sequences of Jurassic flysch deposits and Middle Cretaceous sedimentary and volcanic formations along the Bangong-Nujiang Suture Zone (BNS).  相似文献   

SEDIMENT RETENTION AND WATER QUALITY ENHANCEMENT IN DISTURBED WATERSHEDS     

C. M. Cooper 《国际泥沙研究》2000,(1)

lPRoBLEMSTATEMENTANDOVERVIEWQualitywateriswithoutdoubtalimitingsubstance,notonlyforhumansbutforalllife.Yet,ashumanpopulation,activity,andpollutioncontinuetoincrease,naturalsourcesofreadilyuseablewateraredecliningatanalarmingfate.Humanscurrentlydiveftorregulatemorethanhalfofgloballyavailablefreshwaterrunofffortheirownpurposes(Posteletal.,l996),includingtheuseoflargedamsordiversionsonriversandthewidespreadcreationofotherartificialcatchments.Additionally,groundwatersourcesarebecomingin…  相似文献   

全球气候变化对水利政策的影响     

Warren Viessman  邹芙林 《地理科学进展》1991,10(4):61-62

目前在科学权威人士中间有一个共同的认识,即大气中二氧化碳及其他痕量气体如甲烷、一氧化氮、二氧化硫及氯氟碳化合物的浓度不断增加,正在导致一个全球性变暖的趋势。这样一个变暖模式将使降水、土壤温度和径流的分布发生变化。这些变化在全世界范围内将对水利政策产生意义深远的影响。大多数气候变化模型表明,北半球高纬地区变暖幅度更大,而变暖趋势在冬季比夏季显著。不幸的是,仅仅了解天气将逐渐变暖,对水资源规划和决策人员并没有多大帮助。他们希望了解的是,在他们的地区,将产生怎样的效应。  相似文献   

科迪勒拉和岛弧环境的浸染型金一银矿特征     

B.  HF  Jr 李友良 《国外铀金地质》1991,(2):23-26

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Cytogenetic mechanism for the aneuploidy and mosaicism found in tetraploid Pacific oyster Crassostrea gigas (Thunberg)     

ZHANG Zhengrui  WANG Xinglian  ZHANG Quanqi  and Standish Allen Jr. 《中国海洋大学学报(英文版)》2014,13(1):125-131

Chromosome constitution was investigated in adult tetraploid Pacific oyster produced by blocking the first polar body of triploid eggs which were fertilized with haploid sperms. A high incidence of aneuploid and heteroploid mosaics were found among the offspring. Of 20 individuals identified, only 9 (45%) were eutetraploid which contained 40 chromosomes; 2 (10%) were aneuploid (hypotetraploid), which contained 39 and 38 chromosomes, respectively; and 9 (45%) were heteroploid mosaics. One mosaic was consisted of cells containing 40 and 39 chromosomes, respectiovely (1:1 in cell number), while the other 8 were consisted of cells containing chromosomes varying between tetraploid and triploid. It was also interesting to note that 3 mosaics even contained some diploid cells with 20 chromosomes. A certain number of cells of 2 tetraploids and 8 mosaics spread with 32–37 well-scattered and some clumped chromosomes at metaphase. The percentage of aneuploid cells with chromosomes varying between triploid and tetraploid correlated significantly with that of heteroploid mosaics cells with clumping chromosomes (P<0.05). Our findings suggested that reversion existed in both tetraploid and triploid oyster and chromosome clumping may underline the chromosome elimination in tetraploid oyster. It seems that the reversing cells, at least some of them, continuously eliminate their chromosomes until the most stable diploid state is established.  相似文献