The tensile properties and fatigue behavior of an Al-Zn-Mg-Cu alloy were investigated by performing tensile tests and fatigue crack propagation （FCP） tests. The tensile results show that lower aging temperature modi...The tensile properties and fatigue behavior of an Al-Zn-Mg-Cu alloy were investigated by performing tensile tests and fatigue crack propagation （FCP） tests. The tensile results show that lower aging temperature modified retrogression and re-aging （RRA） process enhances the elongation, but reduces the strength of the alloy, as compared to conventional RRA process which employs peak aging temperature. Both ductility and strength, however, are increased by employing a natural aging prior to re-aging based on the former modified RRA process. Fatigue test results show that both routes reduce FCP rate. Especially, the lower re-aging temperature modified RRA process obtains the lowest FCP rate. Natural aging treatment could enhance the nucleation rate of GP zones. A large amount of GP zones could be cut by dislocations, which is responsible for the highest tensile strength and elongation, as well as lower FCP rate.展开更多
Based on the data from 4 times of repeated measurements (1996-1999) of GPS monitoring network arranged along Shanxi fault zone, the current horizontal movement of Shanxi fault zone and its relationship with Yangyuan-H...Based on the data from 4 times of repeated measurements (1996-1999) of GPS monitoring network arranged along Shanxi fault zone, the current horizontal movement of Shanxi fault zone and its relationship with Yangyuan-Hunyuan earthquake (M=5.6; 39.8°N, 113.9°E; November 1, 1999) which occurred at the north part of the monitoring network is analyzed. The results from the analysis indicate: (1) The horizontal movement along Shanxi fault zone was not obvious from 1996 to 1997; (2) The intensity of horizontal movement along Shanxi fault zone increased at the period of 1997 to 1998, and there are three areas with relatively higher strain (1×10-6) appeared, i.e., the source region, Xinzhou region and northeastern part of Jiexiu; (3) Although the dominant movement direction of Shanxi fault zone in the period of 1998 to 1999 was consistent with the fault striking direction, but as compared with the movement in the passed year, the direction was almost reversed, while the absolute value of the movement was close each other; (4) The accumulated horizontal movement along Shanxi fault zone from 1996 to 1999 became obvious gradually. It can be divided into three parts by considering its tendency: (a) the dominant direction of movement in north of Xinzhou is NNE (0.8 cm); (b) in south of Quwo it is SSW (1 cm); (c) in the central area it is rather complicated, the deformation in the southern part is little more large, but in the view of whole area there is no dominant movement exist. Generally speaking, Shanxi fault zone is mainly controlled by the NNE-SSW-trending extension stress field, but there is no strike-slip movement. In the period of 1997 to 1998, there might be a clear stress disturb and it was essentially recovered in 1999. Then the Yangyuan-Hunyuan earthquake occurred. Very possible, this disturb is the triggering to the earthquake.展开更多
The Guinier-Preston zone, which has been found in both lunar and terrestrial orthopyroxenes, is a metastable phase of orthopyroxenes with a wollastonite content～25％ and a new pyroxene space-group symmetry Pbc 21. It...The Guinier-Preston zone, which has been found in both lunar and terrestrial orthopyroxenes, is a metastable phase of orthopyroxenes with a wollastonite content～25％ and a new pyroxene space-group symmetry Pbc 21. Its size, distribution, composition and structure may be important indicators of the low-temperature thermal history of orthopyroxene. The ultrastructures of two terrestrial bronzites have been observed under HREM (TEM-100CXII). The size, shape and展开更多
In this paper, various dominating factors affecting crustal movement of the coastal zone in eastern China are analyzed, and major characteristics of crustal movement are summarized. Subduction of the pacific plate and...In this paper, various dominating factors affecting crustal movement of the coastal zone in eastern China are analyzed, and major characteristics of crustal movement are summarized. Subduction of the pacific plate and Philippine plate and southeastward "escape" of Qinghai-Tibet plateau are believed to be dominating factors affecting crustal movement of that zone. Undoubtedly, it is a best way to monitor this kind of large-scale crustal movement with GPS technique. The feasibility of monitoring crustal m...展开更多
Based on the rotation in the entire block and homogeneous strain model ( REHSM) ,we firstly analyze the motion and deformation features across the southern part of Tancheng- Lujiang fault zone from GPS velocity fields...Based on the rotation in the entire block and homogeneous strain model ( REHSM) ,we firstly analyze the motion and deformation features across the southern part of Tancheng- Lujiang fault zone from GPS velocity fields in period of 1999 ～ 2001,2001 ～ 2004,2004 ～ 2007 and 2007 ～ 2009. The results show a dextral strike-slip feature in the Weifang- Tancheng segment and sinistral strike-slip in the Tancheng-Lujiang segment. And the deformation perpendicular to the Tancheng-Lujiang fault zone alternates between tension and compression in different time-intervals. Then we resolve the relative rigid motion of blocks around Bohai Bay to the Circum-Bohai Sea area by deducting the entire rigid motion of the Circum-Bohai Sea area. We find that the Yanshan-Bohai seismic belt split this area into two parts,the northern part moving NW,and the other SE.展开更多
Al Zn Mg Cu系合金在较低温度时效时,形成2种类型的GP区:GP(Ⅰ)区和GP(Ⅱ)区。选用7075,7075+0.58%Li,7075+0.89%Li和7075+1.0%Li4种合金进行343K,240h和393K,24h时效,以获得GP区,并通过DSC实验结果,用Avrami Johnson Mehl(AJM)表达式...Al Zn Mg Cu系合金在较低温度时效时,形成2种类型的GP区:GP(Ⅰ)区和GP(Ⅱ)区。选用7075,7075+0.58%Li,7075+0.89%Li和7075+1.0%Li4种合金进行343K,240h和393K,24h时效,以获得GP区,并通过DSC实验结果,用Avrami Johnson Mehl(AJM)表达式计算了GP区溶解动力学参数,从而定量地研究Li对7075合金GP区转变的影响。结果表明:经过343K,240h时效后,含Li的7075合金的GP(Ⅰ)区溶解激活能较7075合金的略低,Li促进GP(Ⅰ)区的形成;经过393K,24h时效后,2种合金GP区溶解激活能相差不大。展开更多
基金Project(51171209)supported by the National Natural Science Foundation of ChinaProject(2012CB619506)supported by the National Basic Research Program of Chinasupported by the 2011 Program of Nonferrous Metals and Materials,China
文摘The tensile properties and fatigue behavior of an Al-Zn-Mg-Cu alloy were investigated by performing tensile tests and fatigue crack propagation （FCP） tests. The tensile results show that lower aging temperature modified retrogression and re-aging （RRA） process enhances the elongation, but reduces the strength of the alloy, as compared to conventional RRA process which employs peak aging temperature. Both ductility and strength, however, are increased by employing a natural aging prior to re-aging based on the former modified RRA process. Fatigue test results show that both routes reduce FCP rate. Especially, the lower re-aging temperature modified RRA process obtains the lowest FCP rate. Natural aging treatment could enhance the nucleation rate of GP zones. A large amount of GP zones could be cut by dislocations, which is responsible for the highest tensile strength and elongation, as well as lower FCP rate.
基金The Project (Continental Geodynamics and Continental Earthquakes! (95-13-03-06).
文摘Based on the data from 4 times of repeated measurements (1996-1999) of GPS monitoring network arranged along Shanxi fault zone, the current horizontal movement of Shanxi fault zone and its relationship with Yangyuan-Hunyuan earthquake (M=5.6; 39.8°N, 113.9°E; November 1, 1999) which occurred at the north part of the monitoring network is analyzed. The results from the analysis indicate: (1) The horizontal movement along Shanxi fault zone was not obvious from 1996 to 1997; (2) The intensity of horizontal movement along Shanxi fault zone increased at the period of 1997 to 1998, and there are three areas with relatively higher strain (1×10-6) appeared, i.e., the source region, Xinzhou region and northeastern part of Jiexiu; (3) Although the dominant movement direction of Shanxi fault zone in the period of 1998 to 1999 was consistent with the fault striking direction, but as compared with the movement in the passed year, the direction was almost reversed, while the absolute value of the movement was close each other; (4) The accumulated horizontal movement along Shanxi fault zone from 1996 to 1999 became obvious gradually. It can be divided into three parts by considering its tendency: (a) the dominant direction of movement in north of Xinzhou is NNE (0.8 cm); (b) in south of Quwo it is SSW (1 cm); (c) in the central area it is rather complicated, the deformation in the southern part is little more large, but in the view of whole area there is no dominant movement exist. Generally speaking, Shanxi fault zone is mainly controlled by the NNE-SSW-trending extension stress field, but there is no strike-slip movement. In the period of 1997 to 1998, there might be a clear stress disturb and it was essentially recovered in 1999. Then the Yangyuan-Hunyuan earthquake occurred. Very possible, this disturb is the triggering to the earthquake.
文摘The Guinier-Preston zone, which has been found in both lunar and terrestrial orthopyroxenes, is a metastable phase of orthopyroxenes with a wollastonite content～25％ and a new pyroxene space-group symmetry Pbc 21. Its size, distribution, composition and structure may be important indicators of the low-temperature thermal history of orthopyroxene. The ultrastructures of two terrestrial bronzites have been observed under HREM (TEM-100CXII). The size, shape and
基金Special founds for major state basic roaearch project (NO. 2002CB412701)This research is subsidized by Special Funds for Major State Basic research Projects(NO. 2002CB412701)
文摘In this paper, various dominating factors affecting crustal movement of the coastal zone in eastern China are analyzed, and major characteristics of crustal movement are summarized. Subduction of the pacific plate and Philippine plate and southeastward "escape" of Qinghai-Tibet plateau are believed to be dominating factors affecting crustal movement of that zone. Undoubtedly, it is a best way to monitor this kind of large-scale crustal movement with GPS technique. The feasibility of monitoring crustal m...
基金sponsored by the Basic Research Project of Institute of Earthquake Science,China Earthquake Administration ( 2011IES010102)
文摘Based on the rotation in the entire block and homogeneous strain model ( REHSM) ,we firstly analyze the motion and deformation features across the southern part of Tancheng- Lujiang fault zone from GPS velocity fields in period of 1999 ～ 2001,2001 ～ 2004,2004 ～ 2007 and 2007 ～ 2009. The results show a dextral strike-slip feature in the Weifang- Tancheng segment and sinistral strike-slip in the Tancheng-Lujiang segment. And the deformation perpendicular to the Tancheng-Lujiang fault zone alternates between tension and compression in different time-intervals. Then we resolve the relative rigid motion of blocks around Bohai Bay to the Circum-Bohai Sea area by deducting the entire rigid motion of the Circum-Bohai Sea area. We find that the Yanshan-Bohai seismic belt split this area into two parts,the northern part moving NW,and the other SE.
