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排序方式: 共有2211条查询结果,搜索用时 31 毫秒
991.
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Chengli Liu Bin Shan Yong Zheng Ying Jiang Xiong Xiong Key Laboratory of Dynamic Geodesy 《地震学报(英文版)》2011,(2):177-183
Based on the elastic dislocation theory, multilayered crustal model, and rupture model obtained by seismic waveform inversion, we calculated the coand post-seismic surface deformation and gravity changes caused by the Yushu M W 6.9 earthquake occurred on April 14, 2010. The observed GPS velocity field and gravity field in Yushu areas are disturbed by the coand post-seismic effects induced by Yushu earthquake, thus the theoretical coand post-seismic deformation and gravity changes will provide important modi... 相似文献
994.
995.
G. V. Vergasova E. S. Kazimirovskii N. M. Polekh J. Xiong L. Liu 《Geomagnetism and Aeronomy》2011,51(6):762-773
Results of studies of the wave structure of the critical frequencies of the ionospheric F2 layer with periods of planetary waves for two Asian stations—Irkutsk and Wuhan (China)—are presented. Estimates of the appearance
frequency, amplitudes, and the lifetime of oscillations with periods typical of planetary waves (2–25 days) are obtained.
It is shown that these characteristics depend on the season and place of observation. The appearance of joint periodicities
in the critical frequencies at both stations, as well as in the planetary index of geomagnetic activity Ap, is noted. 相似文献
996.
997.
Partitioning of Nb and Ta between rutile and felsic melt and the fractionation of Nb/Ta during partial melting of hydrous metabasalt 总被引:5,自引:0,他引:5
In order to fully assess the role of rutile in fractionation of Nb/Ta during partial melting of hydrous metabasalt, we have measured rutile - felsic melt partition coefficients (D values) for Nb and Ta with tonalitic to trondhjemitic compositions at 1.5-3.5 GPa, 900-1350 °C and ∼5.0-20 wt% H2O. DNb, DTa and DNb/DTa range from 17 ± 1 to 246 ± 13, 34 ± 2 to 232 ± 25 and 0.51 ± 0.04 to 1.06 ± 0.13, respectively. For the compositions investigated, melt composition appears to have no observable effect on the partitioning; the effect of pressure is also slight; whereas temperature and H2O have marked effects. DNb, DTa and DNb/DTa increase with decreasing temperature and H2O content, showing a reversal of DNb/DTa from <1.0 to >1.0. Using the data that approached equilibrium and obeyed Henry’s law, expressions describing the dependences of DNb, DTa and DNb/DTa on temperature, pressure and melt H2O content were obtained:
(1) 相似文献
998.
Yun LiYongqiang Xiong Chenchen FangQianyong Liang Jingru ZhangPing’an Peng 《Organic Geochemistry》2011,42(5):559-565
In this study, headspace single-drop microextraction (HS-SDME) coupled with gas chromatography-isotope ratio mass spectrometry (GC-IRMS), was employed to determine compound specific carbon isotopic values (δ13C) of gasoline range hydrocarbons. The reproducibility of the method was found to be satisfactory. By comparison with the δ13C values of the twelve target compounds determined using direct injection of their n-C16 solution, no obvious isotopic fractionation was observed during the HS-SDME procedures. Some parameters that could affect the carbon isotopic fractionation, such as ionic strength of working solutions and inlet split ratio, were examined. The results also suggest that these factors had no significant effect on the carbon isotopic determination of gasoline range hydrocarbons. The application of HS-SDME to a crude oil sample proved that this method could be a promising tool for the determination of carbon isotopic values of gasoline range hydrocarbons in oils or aqueous samples. 相似文献
999.
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1000.
靖州盆地是位于雪峰构造带南段的一个NE向晚三叠世-中侏罗世小型陆相盆地。作者对盆地周缘上古生界及盆地侏罗系中不同产状与运动性质的小型断裂和节理进行了大量观察研究,据此识别出近SN向挤压、NNE向挤压、NEE向挤压、近EW向挤压、NW向挤压、NW向伸展等应力事件。根据断裂构造赋存层位和部分断裂显示的次序,结合靖州盆地构造特征及区域构造演化背景,初步厘定了研究区中生代以来构造体制演化过程:中三叠世晚期印支运动中区域NW向挤压;晚三叠世-早侏罗世区域近SN向挤压;中侏罗世早、中期区域NW向挤压;中侏罗世晚期因区域NE-NNE向溆浦-靖州断裂左行走滑而具SN向挤压;白垩纪因区域NE向挤压而形成NW向伸展;晚白垩世晚期-古新世溆浦-靖州断裂右行走滑派生NEE向挤压;始新世-渐新世区域近EW向挤压;新近纪区域NNE向挤压。 相似文献