Based on the polarization analysis of teleseismic data,SKS (SKKS) fast-wave directions and delay times between fast and slow shear waves were determined for each of the 111 seismic stations from both permanent and tem...Based on the polarization analysis of teleseismic data,SKS (SKKS) fast-wave directions and delay times between fast and slow shear waves were determined for each of the 111 seismic stations from both permanent and temporary broadband seismograph networks deployed in the Ordos Block and its margins.Both the Silver and Chan and stacking analysis methods were used.In this way,an image of upper mantle anisotropy in the Ordos Block and its margins was acquired.In the western and northern margins of the Ordos Block,the fast-wave directions are consistently NW-SE.The fast-wave directions are mainly NWW-SEE and EW in the southern margin of the Ordos Block.In the eastern margin of the Ordos Block,the fast-wave directions are generally EW,although some run NEE-SWW or NWW-SEE.In the Ordos Block,the fast-wave directions trend near N-S in the north,but switch to near EW in the south.The delay time between fast and slow waves falls into the interval 0.48-1.50 s,and the average delay time at the stations in the Ordos Block is less than that in its margins.We suggest that the anisotropy of the stable Ordos Block is mainly caused by "fossil" anisotropy frozen in the ancient North China Craton.The NE-trending push of the northeastern margin of the Tibetan Plateau has caused NW-SE-trending lithospheric extension in the western and northern margins of the Ordos Block,and made the upper mantle flow southeastwards.This in turn has resulted in the alignment of the upper mantle peridotite lattice with the direction of material deformation.In the southern margin of the Ordos Block,the collision between the North China and Yangtze blocks resulted in the fast-wave direction running parallel to the collision boundary and the Qinling Orogen.Combining this with the APM and velocity structure of the Qinling Orogen,we propose that eastward-directed asthenospheric-mantle channel flow may have occurred beneath the Qinling Orogen.In the eastern margin of the Ordos Block,the complex anisotropic characteristics of the Fenhe Graben and Taihang Orogen展开更多
本文按 ASTMG 48—76标准推荐的10%FeCl_3溶液完全浸入法研究了 Ti 稳定的/8—8不锈钢在55℃—300℃范围内热处理的点蚀性能,提出了点蚀的敏感温度区间;研究了冷一变形及其蚀后的时效处理对点蚀性能的影响,观察了点蚀的形貌并指出了点...本文按 ASTMG 48—76标准推荐的10%FeCl_3溶液完全浸入法研究了 Ti 稳定的/8—8不锈钢在55℃—300℃范围内热处理的点蚀性能,提出了点蚀的敏感温度区间;研究了冷一变形及其蚀后的时效处理对点蚀性能的影响,观察了点蚀的形貌并指出了点蚀起源.从而提出了改善这材料抗点蚀性能的加工热处理途径.展开更多
基金supported by National Natural Science Foundation of China (Grant Nos. 40904023 and 90914005)the Special Project for the Fundamental R & D of Institute of Geophysics,China Earthquake Administration (Grant Nos. DQJB06B06, DQJB10B16)the Special Program of the Ministry of Science and Technology of China (Grant No. 2006FY110100)
文摘Based on the polarization analysis of teleseismic data,SKS (SKKS) fast-wave directions and delay times between fast and slow shear waves were determined for each of the 111 seismic stations from both permanent and temporary broadband seismograph networks deployed in the Ordos Block and its margins.Both the Silver and Chan and stacking analysis methods were used.In this way,an image of upper mantle anisotropy in the Ordos Block and its margins was acquired.In the western and northern margins of the Ordos Block,the fast-wave directions are consistently NW-SE.The fast-wave directions are mainly NWW-SEE and EW in the southern margin of the Ordos Block.In the eastern margin of the Ordos Block,the fast-wave directions are generally EW,although some run NEE-SWW or NWW-SEE.In the Ordos Block,the fast-wave directions trend near N-S in the north,but switch to near EW in the south.The delay time between fast and slow waves falls into the interval 0.48-1.50 s,and the average delay time at the stations in the Ordos Block is less than that in its margins.We suggest that the anisotropy of the stable Ordos Block is mainly caused by "fossil" anisotropy frozen in the ancient North China Craton.The NE-trending push of the northeastern margin of the Tibetan Plateau has caused NW-SE-trending lithospheric extension in the western and northern margins of the Ordos Block,and made the upper mantle flow southeastwards.This in turn has resulted in the alignment of the upper mantle peridotite lattice with the direction of material deformation.In the southern margin of the Ordos Block,the collision between the North China and Yangtze blocks resulted in the fast-wave direction running parallel to the collision boundary and the Qinling Orogen.Combining this with the APM and velocity structure of the Qinling Orogen,we propose that eastward-directed asthenospheric-mantle channel flow may have occurred beneath the Qinling Orogen.In the eastern margin of the Ordos Block,the complex anisotropic characteristics of the Fenhe Graben and Taihang Orogen
文摘本文按 ASTMG 48—76标准推荐的10%FeCl_3溶液完全浸入法研究了 Ti 稳定的/8—8不锈钢在55℃—300℃范围内热处理的点蚀性能,提出了点蚀的敏感温度区间;研究了冷一变形及其蚀后的时效处理对点蚀性能的影响,观察了点蚀的形貌并指出了点蚀起源.从而提出了改善这材料抗点蚀性能的加工热处理途径.
