The safety of submarine pipelines is largely influenced by free spans and corrosions. Previous studies on free spans caused by seabed scours are mainly based on the stable environment, where the background seabed scou...The safety of submarine pipelines is largely influenced by free spans and corrosions. Previous studies on free spans caused by seabed scours are mainly based on the stable environment, where the background seabed scour is in equilibrium and the soil is homogeneous. To study the effects of background erosion on the free span development of subsea pipelines, a submarine pipe- line located at the abandoned Yellow River subaqueous delta lobe was investigated with an integrated surveying system which in- eluded a Multibeam bathymetric system, a dual-frequency side-scan sonar, a high resolution sub-bottom profiler, and a Magnetic Flux Leakage (MFL) sensor. We found that seabed homogeneity has a great influence on the free span development of the pipeline. More specifically, for homogeneous background scours, the morphology of scour hole below the pipeline is quite similar to that without the background scour, whereas for inhomogeneous background scour, the nature of spanning is mainly dependent on the evolution of seabed morphology near the pipeline. Magnetic Flux Leakage (MFL) detection results also reveal the possible connec- tion between long free spans and accelerated corrosion of the pipeline.展开更多
Based on the construction of the 8-inch fabricat ion line, advanced process technology of 8-inch wafer, as well as the fourth-generation high-voltage double-diffused metal-oxide semiconductor(DMOS+) insulated-gate bip...Based on the construction of the 8-inch fabricat ion line, advanced process technology of 8-inch wafer, as well as the fourth-generation high-voltage double-diffused metal-oxide semiconductor(DMOS+) insulated-gate bipolar transistor(IGBT) technology and the fifth-generation trench gate IGBT technology, have been developed, realizing a great-leap forward technological development for the manufacturing of high-voltage IGBT from 6-inch to 8-inch. The 1600 A/1.7 kV and 1500 A/3.3 kV IGBT modules have been successfully fabricated, qualified, and applied in rail transportation traction system.展开更多
As an emerging industry in China, cross-border e-commerce has enjoyed the leap-forward development, along with increasingly prominent problems. This paper aims at finding out the problems and related roots that hinder...As an emerging industry in China, cross-border e-commerce has enjoyed the leap-forward development, along with increasingly prominent problems. This paper aims at finding out the problems and related roots that hinder its development, through conducting an analysis on the export development of cross-border e-commerce, in order to look for solutions and countermeasures in favor of its sound development and to promote the liberalization development of foreign trade in China.展开更多
The condition of Marxist college ethnic areas will directly affect how the beliefs of national unity and stability of the region, the survival and development by leaps and bounds and the Chinese nation. In order to in...The condition of Marxist college ethnic areas will directly affect how the beliefs of national unity and stability of the region, the survival and development by leaps and bounds and the Chinese nation. In order to internalize the Marxist belief in the heart and outside of the line, it needs to start from the cognitive, emotional, and behavioral levels.展开更多
We report a unique shell margin that differed from the usual shell structure of Pinctada fucata.We observed empty organic envelopes in the prismatic layer and the formation of the nacreous layer in the shell margin.Al...We report a unique shell margin that differed from the usual shell structure of Pinctada fucata.We observed empty organic envelopes in the prismatic layer and the formation of the nacreous layer in the shell margin.All the characteristics of the growing margin indicated that the shell was growing rapidly.To explain this anomaly,we propose the concept of "jumping development".During jumping development,the center of growth in the bivalve shell jumps forward over a short time interval when the position of the mantle changes.Jumping development explains the unusual structure of the anomalous shell and the development of annual growth lines in typical shells.Annual growth lines are the result of a discontinuity in the shell microstructure induced by jumping development.展开更多
基金financially supported by the National Natural Science Foundation of China(Grant No.41006024)Marine Specific Research for Public‘Forecast and appraisal for geologic hazard of inshore seafloor and study of key technology for protection’(Grant No.201005005)
文摘The safety of submarine pipelines is largely influenced by free spans and corrosions. Previous studies on free spans caused by seabed scours are mainly based on the stable environment, where the background seabed scour is in equilibrium and the soil is homogeneous. To study the effects of background erosion on the free span development of subsea pipelines, a submarine pipe- line located at the abandoned Yellow River subaqueous delta lobe was investigated with an integrated surveying system which in- eluded a Multibeam bathymetric system, a dual-frequency side-scan sonar, a high resolution sub-bottom profiler, and a Magnetic Flux Leakage (MFL) sensor. We found that seabed homogeneity has a great influence on the free span development of the pipeline. More specifically, for homogeneous background scours, the morphology of scour hole below the pipeline is quite similar to that without the background scour, whereas for inhomogeneous background scour, the nature of spanning is mainly dependent on the evolution of seabed morphology near the pipeline. Magnetic Flux Leakage (MFL) detection results also reveal the possible connec- tion between long free spans and accelerated corrosion of the pipeline.
文摘Based on the construction of the 8-inch fabricat ion line, advanced process technology of 8-inch wafer, as well as the fourth-generation high-voltage double-diffused metal-oxide semiconductor(DMOS+) insulated-gate bipolar transistor(IGBT) technology and the fifth-generation trench gate IGBT technology, have been developed, realizing a great-leap forward technological development for the manufacturing of high-voltage IGBT from 6-inch to 8-inch. The 1600 A/1.7 kV and 1500 A/3.3 kV IGBT modules have been successfully fabricated, qualified, and applied in rail transportation traction system.
文摘As an emerging industry in China, cross-border e-commerce has enjoyed the leap-forward development, along with increasingly prominent problems. This paper aims at finding out the problems and related roots that hinder its development, through conducting an analysis on the export development of cross-border e-commerce, in order to look for solutions and countermeasures in favor of its sound development and to promote the liberalization development of foreign trade in China.
文摘The condition of Marxist college ethnic areas will directly affect how the beliefs of national unity and stability of the region, the survival and development by leaps and bounds and the Chinese nation. In order to internalize the Marxist belief in the heart and outside of the line, it needs to start from the cognitive, emotional, and behavioral levels.
基金supported by the National Natural Science Foundation of China (Grant Nos. U0831001 and 40876068)the National High Technology Research and Development Program of China (Grant Nos. 2010CB126405 and 2010AA09Z405)
文摘We report a unique shell margin that differed from the usual shell structure of Pinctada fucata.We observed empty organic envelopes in the prismatic layer and the formation of the nacreous layer in the shell margin.All the characteristics of the growing margin indicated that the shell was growing rapidly.To explain this anomaly,we propose the concept of "jumping development".During jumping development,the center of growth in the bivalve shell jumps forward over a short time interval when the position of the mantle changes.Jumping development explains the unusual structure of the anomalous shell and the development of annual growth lines in typical shells.Annual growth lines are the result of a discontinuity in the shell microstructure induced by jumping development.