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1.
MEN Wu ) WEI Hao ) and LIU Guangshan ) * ) College of Oceanography Environmental Science Xiamen University State Key Laboratory of Marine Environmental Science 《中国海洋大学学报(英文版)》2006,5(3):228-234
1Introduction Therearefourradiumisotopesinnature,ofwhich224Ra,226Raand228Rahavebeenwidelyinvestigated inmarineresearch,butthespecificactivityof223Rais toolowtobemeasured,therefore,itsapplicationsarelimited(Moore,1969;Broeckeretal.,1976;KuandLin,1976;Nozak… 相似文献
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南海中部和冲绳海槽沉积物中的氨基酸物质 总被引:2,自引:0,他引:2
本文通过对南海中部和冲绳海槽三个深海沉积物柱状样腐植物质水解氨基酸的研究,试图阐述南海和冲绳海槽沉积物的演化与沉积环境。 相似文献
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本文主要叙述了在开发煤矿地质信息系统(CMGIS)中的几种主要地质图件的数据存贮与处理技术。地质图件作为一种专业图件,有它特有的属性,如岩性花纹符号的大量出现,各种构造、地物等特殊线条的出现,地质曲线与文字标注的大量出现等。实践表明,采用商品化通用软件包(Auto CAD)已满足不了用户的要求,因为它缺乏地质上所需要的特殊性线型。用它编辑后的图形数据难以二次利用,图素的地质含义不再表现在图形数据库中,况且,如果图形编辑量过大,还必须考虑是否要对原始数据进行调整或增加辅助数据,为此,用户必须在不同的软件环境下运行不同的软件和数据,造成用户学习掌握和使用上的困难。 相似文献
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本文记述了发现于辽南复州湾上石炭统太原组的燕海扇类,计5属17种。讨论了Annuliconcha与Paradoxipecten的属征及有关问题。上述发现在东北地区尚属首次。 相似文献
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The ability of an atmospheric general circulation model to reproduce fundamental features of the wintertime extratropical Southern Hemisphere (SH) circulation is evaluated with emphasis on the daily variability of the SH mean flow and the mean flow-transient perturbations interaction. Two 10-year simulations using a new version of the LMDZ GCM with a stretched grid scheme centered at 45 °S and forced by climatological SST are performed: a high (144Ꮡ) and low (64Ꭹ) horizontal resolution runs. The performance of both simulations was determined by comparing several simulated fields (zonal wind, temperature, kinetic energy, transient eddy momentum and heat fluxes, Eliassen-Palm fluxes, Eady growth rate and baroclinic conversion term) against the European Centre for Medium Range Weather Forecast reanalyses (ERA). High and low-resolution simulations are similar in many respects; in particular, both experiments reproduce the main patterns of the southern extratropical large-scale circulation satisfactorily. Increasing resolution does not improve universally some spurious aspects of the low resolution simulation (e.g. the cold bias in the high polar troposphere, the debilitated subtropical jet, the low baroclinic conversion rate). Those aspects present little sensitivity to the model resolution. The interaction between transient eddies and zonal mean flow are examined. The low-resolution experiment is able to qualitatively represent the acceleration/deceleration of the mean flow by transient perturbations, south/north of 30 °S with an accuracy similar to that of the high-resolution experiment. Although both experiments represent the baroclinic structure of the mean flow satisfactorily, the model underestimates some transient properties due to the underestimation of the baroclinic conversion term in middle latitudes. Such misrepresentation does not improve with increasing resolution and is related to the relatively weak meridional temperature gradient and the inadequate geographical distribution of the eddy heat fluxes. In particular, the eddy kinetic energy is always underestimated. Eddy kinetic energy does not improve convincingly with increasing resolution, suggesting that the adequate representation of the storm tracks is highly influenced by the physical parametrizations. 相似文献
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The chronological data obtained by a variety of dating methods have confirmed that the sodium enriched metavolcanite series
in the area of the Longbohe copper deposit at Jinping, Yunnan Province, was formed during the Proterozoic (its Pb−Pb isochron
age=1595±75 Ma), corresponding to the Dahongshan Group sodium enriched metavolcanites. The Sm−Nd isochron age of 1336±46Ma
should represent the time at which this series of volcanic rocks experienced spilitization in response to sodium metasomatism,
equivalent to the time of sedimentation of the Ailaoshan Group and Yashan Group rocks. The Rb−Sr ages of the volcanic rocks
and the Pb−Pb ages of copper ores have recorded the events of strong dynamic metamorphism and of strong reworking-metallogenesis
of copper during the Jinningian period. Similarities in forming age, rock assemblage and isotopic characteristics between
the sodium enriched metavolcanite series and the Dahongshan Group sodium enriched metavolcanite series have provided new clues
to the exploration of the Dahongshan-type copper deposits in this area.
Granted jointly by the National Natural Science Foundation of China (Nos. 49702022, 40073001) and the State 973 Program (No.
G1999043215). 相似文献