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81.
Cheng San Zhang Zhi-Yong Zhou Feng Li Man Chen Hui Shi Fu-Sheng Huang Lin-Pin Li Yong 《应用地球物理》2021,(3):375-385
A three-dimensional (3D) step-by-step inversion strategy for audio magnetotellurics(AMT) is investigated in this study.The objective function is minimized by it... 相似文献
82.
83.
Silicon limitation on primary production and its destiny in Jiaozhou Bay, China——Ⅳ:Study on cross-bay transect from estuary to ocean 总被引:1,自引:0,他引:1
The authors analyzed the data collected in the Ecological Station Jiaozhou Bay from May 1991 to November 1994, including 12
seasonal investigations, to determine the characteristics, dynamic cycles and variation trends of the silicate in the bay.
The results indicated that the rivers around Jiaozhou Bay provided abundant supply of silicate to the bay. The silicate concentration
there depended on river flow variation. The horizontal variation of silicate concentration on the transect showed that the
silicate concentration decreased with distance from shorelines. The vertical variation of it showed that silicate sank and
deposited on the sea bottom by phytoplankton uptake and death, and zooplankton excretion. In this way, silicon would endlessly
be transferred from terrestrial sources to the sea bottom. The silicon took up by phytoplankton and by other biogeochemical
processes led to insufficient silicon supply for phytoplankton growth. In this paper, a 2D dynamic model of river flow versus
silicate concentration was established by which silicate concentrations of 0.028–0.062 μmol/L in seawater was yielded by inputting
certain seasonal unit river flows (m3/s), or in other words, the silicate supply rate; and when the unit river flow was set to zero, meaning no river input, the
silicate concentrations were between 0.05–0.69 μmol/L in the bay. In terms of the silicate supply rate, Jiaozhou Bay was divided
into three parts. The division shows a given river flow could generate several different silicon levels in corresponding regions,
so as to the silicon-limitation levels to the phytoplankton in these regions. Another dynamic model of river flow versus primary
production was set up by which the phytoplankton primary production of 5.21–15.55 (mgC/m2·d)/(m3/s) were obtained in our case at unit river flow values via silicate concentration or primary production conversion rate.
Similarly, the values of primary production of 121.98–195.33 (mgC/m2·d) were achieved at zero unit river flow condition. A primary production conversion rate reflects the sensitivity to silicon
depletion so as to different phytoplankton primary production and silicon requirements by different phytoplankton assemblages
in different marine areas. In addition, the authors differentiated two equations (Eqs. 1 and 2) in the models to obtain the
river flow variation that determines the silicate concentration variation, and in turn, the variation of primary production.
These results proved further that nutrient silicon is a limiting factor for phytoplankton growth.
This study was funded by NSFC (No. 40036010), and the Director's Fund of the Beihai Sea Monitoring Center, the State Oceanic
Administration. 相似文献
84.
王双绪 《大地测量与地球动力学》1992,(2)
本文利用四川西部地区近二十年来的水准资料,分析了该区近期大地垂直形变场演化状况。指出了川西地区自八十年代后期以来继承性构造运动增强,断裂控制区域升、降差异运动加剧的地壳运动特征;同时,鲜水河断裂带之乾宁-康定一带已形成闭锁区。 相似文献
85.
A preliminary application GIS in glaciological research along the traverse route from Zhongshan Station to Dome A, Antarctica 总被引:1,自引:0,他引:1
1 IntroductionGeographicalinformationsystem (GIS)isanefficientwayandimportanttechniquetomanage,displayandanalyzeAntarcticspatialdata.GIScanbeusedtomakeandre newmapproductsquickly ,evaluateenvironment,supportlogisticmanagementandfieldoperation,providechancetoextractnewknowledge,andtopromoteinformationex changeamongnationsunderthedemandoftheMadridProtocol(AADC 2 0 0 1 ;MAGIC1 998;1 999) .WorkingGroupofGeodesyandGeographicInformation (WG GGI)ofScientificCommitteeonAntarcticResearch (… 相似文献
86.
河南省嵩箕地区登封群变质杂岩,原岩为一套造山带和岛弧的中基性、少部分为酸性的火山岩组合。其中郭家窑组为基性,常窑组、石牌河组逐渐向酸性火山岩过渡,石梯沟组属正常沉积岩系列。该群微量元素丰度值与地壳克拉克值相比,普遍偏低,其中Rb、Sr、Ba、F、Li等元素明显偏低。 相似文献
87.
Helium, Argon, and Xenon Isotopic Compositions of Ore-formingFluids in Jinding-Baiyangping Polymetallic Deposits,Yunnan, Southwest China 总被引:13,自引:0,他引:13
The Jinding superlarge lead and zinc deposit has attracted the attention of geologists of the world and its metallogenesis has long been in dispute. This paper takes the Jinding deposit and the Baiyangping Cu-Ag-Co deposit which was recently found at about 30 km north of Jinding as one ore belt, and, based on researches on the helium, argon, and xenon isotopic compositions of primary inclusions in ore-forming solutions of the main stage, the authors have found that the 3He/4He ratio of the ore-forming fluid is 2.7′ 10- 6 (varying from 0.19 to 1.97 Ra), the 4He/40Ar ratio (0.24- 3.12) is close to the mantle characteristic ratio, and the xenon isotopic composition and evolution show characters of the mantle xenon. The above results reveal the characteristics of mantle source and crust-mantle fluid mixing (mantle helium reaching 32%) and the metallogenic contributions of the deep processes in the Jinding-Baiyangping ore belt. 相似文献
88.
MO Jia-qi LIN Yi-hua WANG Hui 《中国地理科学(英文版)》2005,15(3):227-230
1IN T R O D U C T IO NInteractionsbetween the ocean and atmosphere con-tributeto climatefluctuationosver a broad spectrum oftime scales.Studiesof those interactionhsave farfo-cused on El Ni o-SouthernOscillation(ENSO)phe-nomenon thathas a period of3to4yea… 相似文献
89.
构造块体的相对运动和应变 总被引:4,自引:0,他引:4
在确定构造块体在球面上相对运动参数的基础上,进一步给出了描述构造块体内的应变变化及参数和确定这些参数的方法。讨论了将相对运动和应变变化综合起来以更充分地描述地壳运动和变形的模型。结合相对运动参数,提出了一种逐渐趋近的变形分析方法。 相似文献
90.