Based on the hypothesis of the active tectonic blocks on the Chinese continent and its adjacent regions (both the method of the DDA on a spherical surface and the GPS survey results observed from 1991 to 2001 are used...Based on the hypothesis of the active tectonic blocks on the Chinese continent and its adjacent regions (both the method of the DDA on a spherical surface and the GPS survey results observed from 1991 to 2001 are used), the movements and deformations of each active tectonic block are calculated. The calculation results show that although the movements and deformations of active tectonic blocks in the eastern region and in the western region of China are different, active tectonic blocks in the same active tectonic block region are coherent. Then, the relative velocities of the active tectonic blocks’ boundary zones are calculated, and the relationship between current crustal motion and strong seismic activities is discussed. Earthquakes ( M S≥7 0) on the Chinese continent since 1988 all occurred on boundary zones of active tectonic blocks with high slipping speed.展开更多
Based on data from an across-fault survey along the Sichuan-Yunnan rhombic block boundaries, the recent deformation characteristics on each fault have been analyzed. It was found that the rate of crustal deformation i...Based on data from an across-fault survey along the Sichuan-Yunnan rhombic block boundaries, the recent deformation characteristics on each fault have been analyzed. It was found that the rate of crustal deformation is slowing down along the northern segment and increasing along the southern segment. Each fault has different features of deformation. The horizontal deformation is mainly characterized by left-lateral strike-slip. The rate of vertical deformation is less than that of the horizontal deformation. The faults have the feature of upper wall uplifting alternated with descending. The anomaly changes of crustal deformation at some sites are closely related to the seismicities near the sites.展开更多
Block-matching motion estimation plays an important role in video coding. The simple and efficient fast block-matching algorithm using Variable Shape Search (VSS) proposed in this paper is based on diamond search and ...Block-matching motion estimation plays an important role in video coding. The simple and efficient fast block-matching algorithm using Variable Shape Search (VSS) proposed in this paper is based on diamond search and hexagon search. The initial big diamond search is designed to fit the directional centre-biased characteristics of the real-world video se- quence, and the directional hexagon search is designed to identify a small region where the best motion vector is expected to locate. Finally, the small diamond search is used to select the best motion vector in the located small region. Experimental results showed that the proposed VSS algorithm can significantly reduce the computational complexity, and provide competitive computational speedup with similar distortion performance as compared with the popular Diamond-based Search (DS) algorithm in the MPEG-4 Simple Profile.展开更多
Multistage superimposed deformation has been discussed systematically based on the progress of the stratigraphic sequences of the northeastern margin of Yangtze Block.The new-discovered first stage deformation of thos...Multistage superimposed deformation has been discussed systematically based on the progress of the stratigraphic sequences of the northeastern margin of Yangtze Block.The new-discovered first stage deformation of those sequences occurred from the middle Triassic to the end of early Jurassic together with development of regional folding, which was resulted from the deep detachment shearing tending toward NW-WNW. The folds dip to east and fall down toward west, and were superimposed by the main stage folding.Thereafter, a series of folds were developed with axes trending toward northeast.Consequently normal folds occurred on the normal limbs while overturned fold on the overturned limbs during the first stage folding. The detachment or thrust was formed from late Jurassic to early Cretaceous. Due to the uplifting of Dabie and the Wannan Mountains in the north and south sides, the bi-directional thrusting belt was formed by gravity flowing from the Mountains toward the center of the basin along the north side of Xuancheng and south side of Guichi. The deformation geodynamics was discussed simply based on the newly recognized information about the tectonic evolution.展开更多
In this paper, a new idea that combines Quasi-Accurate Detection of gross errors (QUAD) with discontinuous deformation positive analysis, is brought forward to divide the regional active blocks. The method can improve...In this paper, a new idea that combines Quasi-Accurate Detection of gross errors (QUAD) with discontinuous deformation positive analysis, is brought forward to divide the regional active blocks. The method can improve the demarcation of active blocks for areas lacking with observation data and offer a new train of through for the complete study of the regional deformation of active blocks. In addition, using the Sichuan-Yunnan area as example, the practice process of the method is introduced briefly.展开更多
The latest sharp uplift of the Tibetan Plateau and adjacent mountains occurred at the end of the early Pleistocene. The uplift of the Plateau resulted from Late Mesozoic--Cenozoic compressional structure due to the su...The latest sharp uplift of the Tibetan Plateau and adjacent mountains occurred at the end of the early Pleistocene. The uplift of the Plateau resulted from Late Mesozoic--Cenozoic compressional structure due to the subduction of the Indian Plate beneath the Asian continent. This event definitively effected the formation of basin-mountain relief, Cenozoic basin deformation, large scale aridity and desertification of western China. The Australasian meteorites impact event happened ca. 0.8 Ma ago, located in the triangle area of the Indian Ocean ridge (20°S/67°E). The impact may have resulted in an acceleration of speeding of the Indian Ocean ridge pushing the Indian Plate to subduct rapidly northward. Thus, the impact event can give reasonable explanation for the dynamic background of the latest rapid uplift of the Tibetan Plateau and the continental deformation of western China and even of the Middle Asia.展开更多
On the basis of Discontinuous Deformation Analysis (DDA), and considering the moderate intrusion of specific block boundaries to different extents, the first-order block motion model is established for the northeaster...On the basis of Discontinuous Deformation Analysis (DDA), and considering the moderate intrusion of specific block boundaries to different extents, the first-order block motion model is established for the northeastern margin of Qinghai-Xizang(Tibet) block and the kinematical model for depicting deformation of small regions as well by using GPS observations of three periods (1991, 1999 and 2001). By simulating, we obtained the motion features of the first-order blocks between the large WWN faults on the sides of the studied region, the distribution features of the principal strain rate field and the inhomogeneous motion features with space-time of the faults in the northern boundary of the Qinghai-Xizang (Tibet) block.展开更多
We study the concept of module twistor for a module over an algebra. This concept provides a unifying framework for various deformed constructions of modules over algebras, such as module R-matrices,(n-factor iterated...We study the concept of module twistor for a module over an algebra. This concept provides a unifying framework for various deformed constructions of modules over algebras, such as module R-matrices,(n-factor iterated) twisted tensor products and L-R-twisted tensor products of algebras. Among the main results,we find the relations among these constructions. Furthermore, we study some properties of module twistors.展开更多
Softening behavior of lath martensitic steels is related to the coarsening of laths and dislocation evolution during cyclic deformation.Involving the physical mechanism,we developed a dislocation-based model to study ...Softening behavior of lath martensitic steels is related to the coarsening of laths and dislocation evolution during cyclic deformation.Involving the physical mechanism,we developed a dislocation-based model to study the cyclic plastic response for lath martensitic steels.For a block,we proposed an interfacial dislocation evolution model to physically present the interaction between mobile dislocations in the block and interfacial dislocations by considering the coarsening mechanism of the laths.Moreover,the evolution behavior of backstress caused by dislocation pile up at the block boundary has been considered.Then,a hierarchical model based on the elastic-viscoplastic self-consistent(EVPSC)theory is developed,which can realize the scale transition among representative volume element(RVE),prior austenite grains(PAGs)and blocks.According to the proposed model,the effective mechanical responses including the cyclic hysteretic loop and peak stress at different cycles for lath martensitic steel have been theoretically predicted and investigated.展开更多
文摘Based on the hypothesis of the active tectonic blocks on the Chinese continent and its adjacent regions (both the method of the DDA on a spherical surface and the GPS survey results observed from 1991 to 2001 are used), the movements and deformations of each active tectonic block are calculated. The calculation results show that although the movements and deformations of active tectonic blocks in the eastern region and in the western region of China are different, active tectonic blocks in the same active tectonic block region are coherent. Then, the relative velocities of the active tectonic blocks’ boundary zones are calculated, and the relationship between current crustal motion and strong seismic activities is discussed. Earthquakes ( M S≥7 0) on the Chinese continent since 1988 all occurred on boundary zones of active tectonic blocks with high slipping speed.
文摘Based on data from an across-fault survey along the Sichuan-Yunnan rhombic block boundaries, the recent deformation characteristics on each fault have been analyzed. It was found that the rate of crustal deformation is slowing down along the northern segment and increasing along the southern segment. Each fault has different features of deformation. The horizontal deformation is mainly characterized by left-lateral strike-slip. The rate of vertical deformation is less than that of the horizontal deformation. The faults have the feature of upper wall uplifting alternated with descending. The anomaly changes of crustal deformation at some sites are closely related to the seismicities near the sites.
文摘Block-matching motion estimation plays an important role in video coding. The simple and efficient fast block-matching algorithm using Variable Shape Search (VSS) proposed in this paper is based on diamond search and hexagon search. The initial big diamond search is designed to fit the directional centre-biased characteristics of the real-world video se- quence, and the directional hexagon search is designed to identify a small region where the best motion vector is expected to locate. Finally, the small diamond search is used to select the best motion vector in the located small region. Experimental results showed that the proposed VSS algorithm can significantly reduce the computational complexity, and provide competitive computational speedup with similar distortion performance as compared with the popular Diamond-based Search (DS) algorithm in the MPEG-4 Simple Profile.
文摘Multistage superimposed deformation has been discussed systematically based on the progress of the stratigraphic sequences of the northeastern margin of Yangtze Block.The new-discovered first stage deformation of those sequences occurred from the middle Triassic to the end of early Jurassic together with development of regional folding, which was resulted from the deep detachment shearing tending toward NW-WNW. The folds dip to east and fall down toward west, and were superimposed by the main stage folding.Thereafter, a series of folds were developed with axes trending toward northeast.Consequently normal folds occurred on the normal limbs while overturned fold on the overturned limbs during the first stage folding. The detachment or thrust was formed from late Jurassic to early Cretaceous. Due to the uplifting of Dabie and the Wannan Mountains in the north and south sides, the bi-directional thrusting belt was formed by gravity flowing from the Mountains toward the center of the basin along the north side of Xuancheng and south side of Guichi. The deformation geodynamics was discussed simply based on the newly recognized information about the tectonic evolution.
基金This research was sponsored by the Joint EarthquakeScience Foundation (603002) and 104011)the sub-project of the 10th"Five-Year"Key Research Program ofCEA,entitled"Variation patterns of tectonic deformation and strain accumulation state in the key areas on the Chinesecontinent".
文摘In this paper, a new idea that combines Quasi-Accurate Detection of gross errors (QUAD) with discontinuous deformation positive analysis, is brought forward to divide the regional active blocks. The method can improve the demarcation of active blocks for areas lacking with observation data and offer a new train of through for the complete study of the regional deformation of active blocks. In addition, using the Sichuan-Yunnan area as example, the practice process of the method is introduced briefly.
基金Supported by Projects of NSFC (Nos. 40872127, 40572135)
文摘The latest sharp uplift of the Tibetan Plateau and adjacent mountains occurred at the end of the early Pleistocene. The uplift of the Plateau resulted from Late Mesozoic--Cenozoic compressional structure due to the subduction of the Indian Plate beneath the Asian continent. This event definitively effected the formation of basin-mountain relief, Cenozoic basin deformation, large scale aridity and desertification of western China. The Australasian meteorites impact event happened ca. 0.8 Ma ago, located in the triangle area of the Indian Ocean ridge (20°S/67°E). The impact may have resulted in an acceleration of speeding of the Indian Ocean ridge pushing the Indian Plate to subduct rapidly northward. Thus, the impact event can give reasonable explanation for the dynamic background of the latest rapid uplift of the Tibetan Plateau and the continental deformation of western China and even of the Middle Asia.
文摘On the basis of Discontinuous Deformation Analysis (DDA), and considering the moderate intrusion of specific block boundaries to different extents, the first-order block motion model is established for the northeastern margin of Qinghai-Xizang(Tibet) block and the kinematical model for depicting deformation of small regions as well by using GPS observations of three periods (1991, 1999 and 2001). By simulating, we obtained the motion features of the first-order blocks between the large WWN faults on the sides of the studied region, the distribution features of the principal strain rate field and the inhomogeneous motion features with space-time of the faults in the northern boundary of the Qinghai-Xizang (Tibet) block.
基金supported by National Natural Science Foundation of China (Grant Nos. 11201285 and 11371238)the First-class Discipline of Universities in Shanghai
文摘We study the concept of module twistor for a module over an algebra. This concept provides a unifying framework for various deformed constructions of modules over algebras, such as module R-matrices,(n-factor iterated) twisted tensor products and L-R-twisted tensor products of algebras. Among the main results,we find the relations among these constructions. Furthermore, we study some properties of module twistors.
基金supported by the National Natural Science Foundation of China(Grant Nos.11988102,12002005,11632001,11521202)the Science Challenge Project(Grant No.TZ2018001).
文摘Softening behavior of lath martensitic steels is related to the coarsening of laths and dislocation evolution during cyclic deformation.Involving the physical mechanism,we developed a dislocation-based model to study the cyclic plastic response for lath martensitic steels.For a block,we proposed an interfacial dislocation evolution model to physically present the interaction between mobile dislocations in the block and interfacial dislocations by considering the coarsening mechanism of the laths.Moreover,the evolution behavior of backstress caused by dislocation pile up at the block boundary has been considered.Then,a hierarchical model based on the elastic-viscoplastic self-consistent(EVPSC)theory is developed,which can realize the scale transition among representative volume element(RVE),prior austenite grains(PAGs)and blocks.According to the proposed model,the effective mechanical responses including the cyclic hysteretic loop and peak stress at different cycles for lath martensitic steel have been theoretically predicted and investigated.
