In the A?r massif, and more particularly in the Iférouane area, the basement is flush. Thus, the essential of water resources is contained in the discontinuous aquifers of basement. Indeed, the weathered and crac...In the A?r massif, and more particularly in the Iférouane area, the basement is flush. Thus, the essential of water resources is contained in the discontinuous aquifers of basement. Indeed, the weathered and cracked basement is an excellent reservoir of groundwater. The objective of this study is to determine the areas favorable to establishment of productive drilling in the village of Ebourkoum. A methodological approach based on the combination of remote sensing and geophysics methods was implemented. The fracturing map developed highlighted three main accidents of directions N0° - N10°, N30° - N50° and N130° - N140° in the said locality. The geophysical investigation mainly electrical prospecting has allowed to locate structures with high hydraulic potential below alluvium and alterites. Subsequently, drilling will be carried out in the areas retained.展开更多
A new mechanism of light-to-electricity conversion that uses InGaN/GaN QWs with a p-n junction is reported.According to the well established light-to-electricity conversion theory,quantum wells（QWs） cannot be used i...A new mechanism of light-to-electricity conversion that uses InGaN/GaN QWs with a p-n junction is reported.According to the well established light-to-electricity conversion theory,quantum wells（QWs） cannot be used in solar cells and photodetectors because the photogenerated carriers in QWs usually relax to ground energy levels,owing to quantum confinement,and cannot form a photocurrent.We observe directly that more than 95% of the photoexcited carriers escape from InGaN/GaN QWs to generate a photocurrent,indicating that the thermionic emission and tunneling processes proposed previously cannot explain carriers escaping from QWs.We show that photoexcited carriers can escape directly from the QWs when the device is under working conditions.Our finding challenges the current theory and demonstrates a new prospect for developing highly efficient solar cells and photodetectors.展开更多
China is a large developing country with rapid growth rate. To the year 2050, its electric power will be increased by six to eight times, reaching 1.5—1.8 TW total installed capacity. The development can not only rel...China is a large developing country with rapid growth rate. To the year 2050, its electric power will be increased by six to eight times, reaching 1.5—1.8 TW total installed capacity. The development can not only rely on the existing technology, it is crucial to accelerate the new technology development. This article discusses the perspective of various new technologies from the available energy resources and the required increase of electric power.展开更多
文摘In the A?r massif, and more particularly in the Iférouane area, the basement is flush. Thus, the essential of water resources is contained in the discontinuous aquifers of basement. Indeed, the weathered and cracked basement is an excellent reservoir of groundwater. The objective of this study is to determine the areas favorable to establishment of productive drilling in the village of Ebourkoum. A methodological approach based on the combination of remote sensing and geophysics methods was implemented. The fracturing map developed highlighted three main accidents of directions N0° - N10°, N30° - N50° and N130° - N140° in the said locality. The geophysical investigation mainly electrical prospecting has allowed to locate structures with high hydraulic potential below alluvium and alterites. Subsequently, drilling will be carried out in the areas retained.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11574362,61210014,and 11374340)the Innovative Clean-energy Research and Application Program of Beijing Municipal Science and Technology Commission,China(Grant No.Z151100003515001)
文摘A new mechanism of light-to-electricity conversion that uses InGaN/GaN QWs with a p-n junction is reported.According to the well established light-to-electricity conversion theory,quantum wells（QWs） cannot be used in solar cells and photodetectors because the photogenerated carriers in QWs usually relax to ground energy levels,owing to quantum confinement,and cannot form a photocurrent.We observe directly that more than 95% of the photoexcited carriers escape from InGaN/GaN QWs to generate a photocurrent,indicating that the thermionic emission and tunneling processes proposed previously cannot explain carriers escaping from QWs.We show that photoexcited carriers can escape directly from the QWs when the device is under working conditions.Our finding challenges the current theory and demonstrates a new prospect for developing highly efficient solar cells and photodetectors.
文摘China is a large developing country with rapid growth rate. To the year 2050, its electric power will be increased by six to eight times, reaching 1.5—1.8 TW total installed capacity. The development can not only rely on the existing technology, it is crucial to accelerate the new technology development. This article discusses the perspective of various new technologies from the available energy resources and the required increase of electric power.
