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1.
在调查东亚冷槽西壁冰川遗迹及其海拔梯度的过程中,发现了甘山冰斗系统与磨光面、擦痕、漂砾等冰川遗迹。进而对该冰斗系统进行成因分析的过程中,发现了冰斗系统的"冰斗环退"的形成方式。以此为基础,就甘山冰斗系统与MIS之间的耦合关系进行了对比分析。研究表明,甘山冰斗系统是以"冰斗环退"方式形成的,该冰斗环退系统完整展现了我国东部第四纪冰川作用的过程,对研究冰期的雪线高程、环境演化规律、冰川作用的进退等,都有着极其重要的意义。在"冰斗环退"的研究基础上,发现了对应的"冰斗环进"机制。冰斗环进代表了冰川作用由高向低推进过程,冰斗环退代表了冰川作用由低向高撤退过程。通过影像分析,初步将甘山冰斗系统划分四段,共解析出了50余套冰斗环,冰川作用的时代可追溯到2.56 Ma。根据冰斗的环进、环退特征,进而发现C28冰斗环所对应MIS56,也即1.60Ma,可能为我国第四纪冰川作用过程中的冰进向冰退演化的重要拐点。 相似文献
2.
Development and characterization of a cell line from the embryos of half smooth tongue sole (Cynoglossus semilaevis) 总被引：3，自引：1，他引：2
A new cell line,CSEC,has been successfully established from embryos at gastrula stage of a cultured marine fish,half smooth tongue sole(Cynoglossus semilaevis).CSEC cells grow actively and stably more than 50 passages for over 200 d in DMEM medium supplemented with 15% FBS(fetal bovine serum),2.5 ng/cm 3 bFGF(basic fibroblast growth factor),1 ng/cm 3 LIF(leukemia inhibitory factor) and 50 mmol/dm 3 2-ME(2-mecaptoethanol).The cells grew well in the temperature range of 24-30 ℃ and the optimal growth temperature was 24℃.FBS and bFGF concentrations are the two key components for CSEC cells proliferation.Chromosome analysis reveals that CSEC cells have a normal diploid karyotype with 2n=42t.The significant fluorescent signals were observed in CSEC after transfection with the GFP reporter gene,suggesting that the CSEC cell line can be used as a useful tool for transgenic and genetic manipulation studies.CSEC cells showed the cytopathic effect(CPE) after infection with lymphosystis disease virus(LCDV) in 2 d.Moreover,the LCDV particles can be observed in the cytoplasm of virus-infected cells by electron microscopy.It suggests that CSEC could be potentially used for the study of aquatic virus. 相似文献
3.
衡山南岳岩体北侧,地质构造复杂,岩浆活动频繁,金矿成矿地质条件有利,已发现一个具有远景的金矿带,其中石子坳矿区为构造蚀变岩型金矿。本文简要地介绍了区域和矿区地质特征,总结出花岗闪长斑岩,硅化带和As元素化探异常等3条找矿标志,建议在该区开展大比例尺化探测量和地质填图,普查北西向硅化断裂破碎带,并对石子坳含金破碎带进行深部验证,寻找隐伏金矿床。 相似文献
4.
在辽东半岛元古宙陆间裂谷某些矿床岩石矿物研究中,发现北瓦沟铅锌矿床含有一定量的块硫锑铅矿,常与方铅矿、黄铁矿、脆硫锑铅矿、硫锑铁矿、金银矿等共生,呈连晶或包裹产出,且与金银矿关系密切。当铅锌矿出现块硫锑铅矿物时,在镜下且见有韧性变形特征时,必见金银产出,其金银含量与块硫锑铅矿含量呈消长关系。因此,认为块硫锑铅矿的产出是寻找金银矿床的标志 相似文献
5.
Parametamorphic rocks from Arong County in southeastern Inner Mongolia-Daxinganling district are regarded as Proterozoic in age,belonging to the Wolegen Group and composed of volcanoclastic and sandstone in origin,and have been disputed in tectonic setting.Because of the stability in metamorphism,the rare earth dements indicate the features of their protoliths.The authors integrated the petrologic methods with the geochemical parameters which include ∑REE,∑LREE/∑HREE,δCe,δEu,La/Yb,Sm/Nd,Th/Sc and the standard values of chondrite.The results show that the protoliths of Wolengen Group may be a group of voleanoclastic and continental margin elastic rocks,and their tectonic setting is the continent island arc. 相似文献
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Over the last century, afforestation in Ireland has increased from 1% of the land area to 10%, with most plantations on upland drained blanket peatlands. This land use change is considered to have altered the hydrological response and water balance of upland catchments with implications for water resources. Because of the difficulty of observing these long‐term changes in the field, the aim of this study was to utilize a hydrological model to simulate the rainfall runoff processes of an existing pristine blanket peatland and then to simulate the hydrology of the peatland if it were drained and afforested. The hydrological rainfall runoff model (GEOtop) was calibrated and validated for an existing small (76 ha) pristine blanket peatland in the southwest of Ireland for the 2‐year period, 2007–2008. The current hydrological response of the pristine blanket peatland catchment with regard to streamflow and water table (WT) levels was captured well in the simulations. Two land use change scenarios of afforestation were also examined, (A) a young 10‐year‐old and (B) a semi‐mature 15‐year‐old Sitka Spruce forest. Scenario A produced similar streamflow dynamics to the pristine peatland, whereas total annual streamflow from Scenario B was 20% lower. For Scenarios A and B, on an annual average basis, the WT was drawn down by 16 and 20 cm below that observed in the pristine peatland, respectively. The maximum WT draw down in Scenario B was 61 cm and occurred in the summer months, resulting in a significant decrease in summer streamflow. Occasionally in the winter (following rainfall), the WT for Scenario B was just 2 cm lower than the pristine peatland, which when coupled with the drainage networks associated with afforestation led to higher peak streamflows. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
9.
黔北务—正—道铝土矿集区为黔中—渝南铝土矿成矿带的重要组成部分,是贵州省主要的铝土矿成矿区带之一。含矿岩系为中二叠统梁山组,矿床成因属古风化壳沉积型。矿石化学成分分析显示,土状、碎屑状铝土矿中Al2O3含量较高,Al2O3/ SiO2值大,质量好,而豆鲕状、致密块状铝土矿中Al2O3含量较低,Al2O3/ SiO2值小,质量较差。显微观察、粉晶衍射和电子探针分析表明,铝土矿石中主要矿物为一水硬铝石、勃姆石和粘土矿物,其中一水硬铝石多为短柱、半自形-自形晶体,呈集合体分布,粘土矿物以高岭石为主,呈孤岛、残留环状产出,其次见伊利石、蒙托石、绿泥石等,副矿物有黄铁矿、磁铁矿、长石、石英、金红石、锆石、锐钛矿、方解石和白云石等。铝土岩中主要矿物为粘土矿物,以高岭石为主,其它矿物和铝土矿相似。铝土矿石的主要元素Al2O3、SiO2、TFe2O3 和TiO2含量之和大于83%,烧失量小于14%,而铝土岩的Al2O3、SiO2、TFe2O3 和TiO2含量之和小于80%,烧失量大于15%。可见铝土矿和铝土岩在主要矿物组成和主要组分总量上具有明显差异。结合以往研究资料,本文解析铝土矿形成过程为韩家店组砂页岩(成矿母岩)在适宜的气候条件下,经风化、淋滤等作用,形成富集Al、Ti等惰性元素的风化残积物和以高岭石为主的粘土矿物,随后被迁移、搬运至河湖盆地环境中,在沉积分过程中粘土矿物不断脱硅、去铁、富铝,形成铝土岩层,经埋深压实、成岩成矿作用后进一步脱硅、去铁、富铝,最终在中二叠世形成以一水硬铝石为主的铝土矿工业矿体。 相似文献
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