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731.
732.
研究区位于大兴安岭兴安地块的东北部。本文主要讨论了碱长花岗岩和花岗斑岩两种岩石类型,并对其成岩年代、地球化学特征、成因及构造环境进行了深入讨论。研究结果显示:具有高SiO2、A12O3、TFeO/MgO,贫MgO、TiO2、P2O5等特征;A/NK-A/CNK和w(K2O)-w(SiO2)图解显示,样品主要为过铝质、高钾钙碱性岩石。并且(Na2O+K2O)/CaO-w(Zr+Nb+Ce+Y)、TFeO/MgO-w(Zr+Nb+Ce+Y)图解和锆石饱和温度都显示,研究区花岗岩类岩石具有高分异Ⅰ型花岗岩的特征。锆石LA-ICP-MS U-Pb定年研究获得128~124 Ma的岩体侵位年龄,其形成的大地构造背景为蒙古-鄂霍茨克洋消亡之后,陆陆碰撞造山演化晚期地壳伸展背景,岩浆起源于壳内火成岩源岩的部分熔融。 相似文献
733.
A passive sampling system for use with rhodamine WT (RWT) in groundwater tracing experiments was developed to assist in the
characterisation of groundwater flow paths. Amberlite XAD-7 resin was found to be suitable for adsorption of RWT, which can
then be extracted using an ethanol/water mix and analysed fluorometrically. Batch and column experiments showed that XAD-7
resin has a high RWT capacity. The adsorption was slightly dependent on pH, but was always above 75% under batch conditions.
The resin had a high percentage mass recovery at flow velocities around 1.5 m/day, but this decreased with increasing flow
velocities. Desorption of RWT off the resin in water is dependent on the flow velocity of water and the time after the peak
RWT has passed. The mass of RWT extracted from the resin bags correlated very well with both the RWT mass flux in the water
and the peak concentrations observed in the monitoring wells in a field experiment. The results of resin bags were reproducible
in the field with a mean coefficient of variation equal to 16%. This method has been successfully applied to two field situations
with different flow velocities to indicate groundwater flow paths.
Electronic Publication 相似文献
734.
Hong-Jiao Pang Shuang-Shuang Lyu Xue-Gang Chen Ai-Min Jin Pei-Sun Loh Fei Li Yan Jiang Xian-Hui Yang Kang-Kang Yan Zhang-Hua Lou 《Environmental Earth Sciences》2017,76(17):627
In order to study the heavy metal accumulation and distribution in the roots, stems, and leaves of Spartina alterniflora, we collected S. alterniflora samples and the associated sediments along three transects at the Andong tidal flat, Hangzhou Bay. Co, Ni, Cd, Pb, Cu, and Zn were mainly accumulated in the aerial parts (stems and leaves) of the plants, and their distributions depended on their mobility and their roles during the metabolism processes of S. alterniflora. The concentrations of Cu, Zn, Cd, Hg, and Pb were significantly enhanced with the increasing of heavy metal concentrations in the sediments, while those of Co and Ni remained relatively constant. Bioaccumulation factors results showed that the serious heavy metal contamination in the sediments from the transect A may overwhelm the accumulation capability of the plants. In addition, the physicochemical properties of the sediments and the pore water therein also play a role in the heavy metal concentrations and accumulations in the plants, because they can influence the behaviors and bioavailabilities of heavy metals during nutrition and bioaccumulation processes of the plants. The sediments with vegetation did not show significantly decreased heavy metal concentration with respect to the unvegetated sediments, although the plants did absorb heavy metals from the sediments. Principal component analysis and correlation analyses indicated that Co–Ni, Cu–Cd–Hg behaved coherently during accumulation, which may be ascribed to their similar accumulation mechanisms. This work provided essential information on the heavy metal accumulation by plants in a tidal flat, which will be useful for the environmental control through phytoremediation at estuaries. 相似文献
735.
应用定量颗粒荧光技术研究岩性油气藏的隐蔽输导通道 总被引:2,自引:0,他引:2
应用定量颗粒荧光技术对东营凹陷牛庄洼陷5口井101块沙三段致密储层、薄层粉砂岩进行了定量荧光QGF-E和QGF分析。分析表明,牛24、牛83、牛876、王550、牛872等5口井致密薄储层颗粒具有相对较高的荧光,显示这些较致密的粉砂岩为过去或现在的油气运移路径/运载层,表明致密砂岩、粉砂岩、薄层砂岩可作为烃类运移的通道。这类薄层隐蔽输导通道为深凹带牛庄洼陷深部沙四段上亚段烃源岩生成的油气进入无断层切割的沙三段中、下亚段的砂岩透镜体而成藏提供了重要的依据。该研究结果对于东营凹陷正在进行的隐蔽油气藏成藏机理的研究可能具有重要意义。 相似文献
736.
基于江苏省66个站点逐日降水观测资料,利用降水集中度指数PCD和Q,分析了1961—2014年江苏省降水集中度的非均匀性特征。结果表明:1) 江苏省降水集中度指数PCD和Q的历年平均值分别为0416和0353,PCD年际变化较大,多年呈减小的趋势,而Q的年际变化较小,呈增大趋势,但PCD和Q的多年变化趋势均较小。2) 全省从北部到南部降水集中程度逐渐减小,即江苏省北部地区降水比南部地区集中,但前者的降水集中时段较后者略晚。3) 多水年的降水集中度指数PCD比少水年大,即多水年降水比少水年更集中,而Q值在多水年和少水年差别不大,甚至少水年降水更集中。4) 降水集中度指数PCD和Q在多水年和少水年的空间分布均呈现“北高南低”特征,无论多水年还是少水年,江苏省北部地区降水均比南部更为集中。 相似文献
737.
GPS Solutions - Under high dynamic conditions, a robust tracking loop is essential for accuracy positioning with the global position system. In previous studies, the extended Kalman filter... 相似文献
738.
空间关联规则可以从空间数据库中发现空间对象之间的隐含的、不明确的空间关系。空间数据库中空间关联规则挖掘研究是空间数据挖掘和知识发现(SDMKD)的主要内容,其主要问题是多层,多关系的规则发现问题。本文把元模式与空间关联规则挖掘相结合介绍了挖掘地理信息系统(GIS)中空间数据库关联规则的常用步骤方法。 相似文献
739.
Petrogenetic implications of mineral chemical data for the Permian Baima igneous complex, SW China 总被引:1,自引:0,他引:1
The Late Permian Fe-Ti oxide ore-bearing Baima igneous complex (BIC) is one of three gabbro-granitoid complexes with the Emeishan large igneous province. Mineral compositions are determined for the BIC layered gabbro in order to constrain subsolidus and magma chamber processes. The averaged compositions of cumulus olivine, clinopyroxene and plagioclase within individual samples range from Fo65-76, Mg# = 75 to 82 and An49-64 but they are not correlative. The observed mineral compositions are consistent with those modeled using the pHMELTS program. Highly variable magnetite compositions are consistent with extensive subsolidus re-equilibration and exsolution. The occurrence of reversely-zoned granular olivine in Fe-Ti oxide ores is a manifestation of Mg transfer between Fe-Ti oxides and olivine at relatively high (<1150?°C) subsolidus temperatures. The primary oxide is inferred to be an aluminous titanomagnetite. Similar to other layered intrusions in the region, the gabbroic unit of the BIC displays Zr depletion which is consistent with loss of a residual liquid during magma differentiation. If the most Zr-rich syenites of the complex are taken into account, the Zr budgets between the combined gabbro-syenite and the basalts are similar. This indicates that the BIC most likely represents a closed system in terms of magma extraction. 相似文献
740.
Liang Zhou Chun Chang Huang Yali Zhou Jiangli Pang Xiaochun Zha Jie Xu Yuzhu Zhang Yongqiang Guo 《Boreas: An International Journal of Quaternary Research》2016,45(4):673-687
This paper reports an investigation into palaeoflooding along the upper reaches of the Hanjiang River valley, China. Based on the sedimentary evidence of the palaeohydrological regime, two bedsets of palaeoflood slackwater deposits (SWDs) were identified interbedded within the Holocene loess–soil sequence along the riverbanks of the Ankang east reach. Optical Stimulated Luminescence (OSL) dating and stratigraphical correlation with previously dated sites were used to reconstruct the chronology of the palaeoflood events. The results show that the palaeoflood events represented by SWD1 occurred between 13 000 and 12 400 a, coincident with the climatic transition from the Bølling–Allerød (BL+AL) stage to the Younger Dryas (YD) event. The palaeoflood events recorded by SWD2 were dated to 1000–800 a, corresponding to the later stages of the North Song Dynasty (AD 960–1127) and the subsequent South Song Dynasty (AD 1127–1279), which was a time of climatic decline according to historical documents. Palaeoflood discharges were estimated using the step‐backwater method, and the peak discharges were estimated to be in the range 35 200–47 400 m3 s?1. These results are of significance to our understanding of the regional hydrological response to global climatic change, the utilization of water resources, hydraulic engineering, flood control and disaster reduction. 相似文献