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401.
Geochemical behavior of chemical elements is studied in a dolomitite weathering profile in upland of karst terrain in northern
Guizhou. Two stages can be recognized during the process ofin situ weathering of dolomitite: the stage of sedentary accumulation of leaching residue of dolomitite and the stage of chemical
weathering evolution of sedentary soil. Ni, Cr, Mo, W and Ti are the least mobile elements with reference to Al. The geochemical
behavior of REE is similar to that observed in weathering of other types of rocks. Fractionation of REE is noticed during
weathering, and the two layers of REE enrichments are thought to result from downward movement of the weathering front in
response to changes in the environment. It is considered that the chemistry of the upper part of the profile, which was more
intensively weathered, is representative of the mobile components of the upper curst at the time the dolomitite was formed,
while the less weathered lower profile is chemically representative of the immobile constitution. Like glacial till and loess,
the “insoluble” materials in carbonate rocks originating from chemical sedimentation may also provide valuable information
about the average chemical composition of the upper continental crust. 相似文献
402.
Selecting three half orbits near the epicenter of Pu’er earthquake, we analyzed the Ne data recorded in their revis-ited orbits during a year before this earthquake, and extracted Ne precursors. The results show that: ① There are significant seasonal variations of ionospheric Ne in night time, which exhibit different shapes respectively in four seasons; ② There are three main shapes of Ne: single-peak, saddle-shaped and even-shaped, all of which may oc-cur in four seasons, but each season with its typical shape relatively; ③ Spatial images of Ne showed high values near the epicenter in 30 days before the earthquake, and there is a good correlation between anomaly and distribu-tion of earthquake in space and time, which reflects that these spatial anomalies were indeed concerned with the earthquake; ④There shows a certain similarity of the Ne curves among revisited orbits, which can provide back-ground information for distinguishing and identification of seismic anomaly. 相似文献
403.
404.
变质矿物生长的局部平衡体系——以贺兰山北段孔兹岩系为例 总被引:1,自引:0,他引:1
贺兰山北段孔兹岩系详细的岩石学和矿物学的研究表明 ,岩石中的特征变质矿物如石榴子石、堇青石等的成分与其周围相邻的同世代变质矿物具有很好的相关性 ,而与其寄生主岩成分的相关性较小 ,而贯通矿物如斜长石却与其寄生主岩成分的相关性较为密切 ,同时天然块状样品的脱水熔融实验的结果也显示 ,变质反应是在一个局部平衡体系中进行的。说明在变质作用过程中 ,变质反应的进行以及新矿物的形成是在一个局部平衡的体系下完成的 ,因此在矿物对温压计的使用上 ,应利用处于平衡状态的相邻变质矿物来计算。 相似文献
405.
欧阳祖熙 《大地测量与地球动力学》2013,33(1):153-156
?????RZB??????????????????????????????????????????????в?????????????????????????????????????λ?????????????????λ??????????????RZB??????????????????????????????е????????????????????????????????淶??????????????????λ????????????REMA??????????????????λ???????????????????????????????????????±?????????????????? 相似文献
406.
Priyantha Jayakody Prem B. Parajuli Gretchen F. Sassenrath Ying Ouyang 《Ground water》2014,52(2):303-310
This research was conducted to develop relationships among evapotranspiration (ET), percolation (PERC), groundwater discharge to the stream (GWQ), and water table fluctuations through a modeling approach. The Soil and Water Assessment Tool (SWAT) hydrologic and crop models were applied in the Big Sunflower River watershed (BSRW; 7660 km2) within the Yazoo River Basin of the Lower Mississippi River alluvial plain. Results of this study showed good to very good model performances with the coefficient of determination (R2) and Nash‐Sutcliffe efficiency (NSE) index from 0.4 to 0.9, respectively, during both hydrologic and crop model calibration and validation. An empirical relationship between ET, PERC, GWQ, and water table fluctuations was able to predict 64% of the water table variation of the alluvial plain in this study. Thematic maps were developed to identify areas with overuse of groundwater, which can help watershed managers to develop water resource programs. 相似文献
407.
408.
正Erratum to:Earthq Sci(2013)26(2):137–145DOI 10.1007/s11589-013-0009-0In the published article,first author’s name was misspelt.The correct name appears in this erratum. 相似文献
409.
Fen Ouyang Haishen Lü Yonghua Zhu Jianyun Zhang Zhongbo Yu Xi Chen Min Li 《Stochastic Environmental Research and Risk Assessment (SERRA)》2014,28(4):991-1010
Five downscaling techniques, namely the statistical downscaling model, the automated statistical downscaling method, the change factor (CF) method, the advanced CF method, the Weather generator (LarsWG5) method, are applied to the upstream basin of the Huaihe River. Changes in regional climate scenarios and hydrology variables are compared in future periods to investigate the uncertainty associated with the downscaling techniques. Paired-sample T test is applied to evaluation the significant of the difference of the means between the observed data and the downscaled data in the future. The Xinanjiang rainfall–runoff model is employed to simulate the rainfall–runoff relation. The results demonstrate that the downscaling techniques utilized herein predict an increased tendency in the future. The increases range of maximum temperature (Tmax) is between 3.7 and 4.7 °C until the time period of 2070–2099 (2080s). While, the increases range of minimum temperature (Tmin) is between 2.8 and 4.9 °C until 2080s. The research presented herein determined that there is an increase predicted for the peaks over threshold (discussed in the paper) and a decrease predicted for the peaks below the threshold (discussed in the paper) in the future, which illustrates that the temperature would rise gradually in the future. Precipitation changes are not as obvious as temperatures changes and tend to be influence by the season. Most downscaling techniques predict increases, and others indict decreases. The annual mean precipitation range changes between 3.2 and 53.3 %, and moreover, these changes vary from season to season. 相似文献
410.
三峡库区崩滑地质灾害变形监测技术研究及应用 总被引:1,自引:1,他引:0
以三峡库区巫山-万州段为例,介绍了GPS在滑坡变形监测中的应用,并开展了InSAR和声发射技术在滑坡、危岩体变形监测应用的试验性研究。同时,根据实际需要,还研制了基于GPRS的地质灾害无线遥测系统,实践证明,该系统具有工程应用价值。 相似文献