To meet the requirements of developing SFRFQ and upgrading the 1 MeV ISR RFQ accelerator,an ECR O^+ ion source and LEBT system have been developed.Using two Einzel Lenses to focus the beam,more than 3mA O^+ beam with ...To meet the requirements of developing SFRFQ and upgrading the 1 MeV ISR RFQ accelerator,an ECR O^+ ion source and LEBT system have been developed.Using two Einzel Lenses to focus the beam,more than 3mA O^+ beam with the energy of 22keV can be obtained at the end of LEBT.Its normalized root-mean-square emittance is about 0.12πmm·mrad.展开更多
In multi-spool engines, the downstream compressor experiences a rotating inlet distortion if rotating stall occurs in upstream compressor, which may induce the instability of the whole compressor. In this paper, the c...In multi-spool engines, the downstream compressor experiences a rotating inlet distortion if rotating stall occurs in upstream compressor, which may induce the instability of the whole compressor. In this paper, the compressor dynamic behavior is the major focus. The experiment was carried out on a single-stage low-speed axial-flow compressor. A rotating distortion generator equipped with different distortion sector（s） was designed to produce different rotating inlet distortion clockwise or counterclockwise with up to 100% of the compressor design speed. The distortion sector can be installed single or in some combination such as four sectors together. Three types of distortion sector/combination are used in the research work, which are single 30 degree sector, four 30 degree sec- tors and single 120 degree sector. It is found that the total pressure loss caused by rotating sector（s） increases when the distortion speed rises. For co-rotating distortions, all the three types of inlet distortion exhibited a peak in stall margin degradation when the distortion speed corresponded to roughly 50% of rotor speed. The two-dimensional numerical simulations of the compressor flow field clearly show the propagation of the distur- bances trigged by the distortion sector（s）.展开更多
We investigate an electron transport bilayer fabricated at 〈110℃ to form all low-temperature processed, thermally stable, efficient perovskite solar cells with negligible hysteresis. The components of the bilayer cr...We investigate an electron transport bilayer fabricated at 〈110℃ to form all low-temperature processed, thermally stable, efficient perovskite solar cells with negligible hysteresis. The components of the bilayer create a symbiosis that results in improved devices compared with either of the components being used in isolation. A sol-gel derived ZnO layer facilitates improved energy level alignment and enhanced charge carrier extraction and a [6,6]-phenyl-C61-butyric acid methyl ester （PCBM） layer to reduce hysteresis and enhance perovskite thermal stability. The creation of a bilayer structure allows materials that are inherently unsuitable to be in contact with the perovskite active layer to be used in efficient devices through simple surface modification strategies.展开更多
文摘To meet the requirements of developing SFRFQ and upgrading the 1 MeV ISR RFQ accelerator,an ECR O^+ ion source and LEBT system have been developed.Using two Einzel Lenses to focus the beam,more than 3mA O^+ beam with the energy of 22keV can be obtained at the end of LEBT.Its normalized root-mean-square emittance is about 0.12πmm·mrad.
基金The support of National Natural Science Foundation of China through Grant 50336050 is gratefully acknowledged.
文摘In multi-spool engines, the downstream compressor experiences a rotating inlet distortion if rotating stall occurs in upstream compressor, which may induce the instability of the whole compressor. In this paper, the compressor dynamic behavior is the major focus. The experiment was carried out on a single-stage low-speed axial-flow compressor. A rotating distortion generator equipped with different distortion sector（s） was designed to produce different rotating inlet distortion clockwise or counterclockwise with up to 100% of the compressor design speed. The distortion sector can be installed single or in some combination such as four sectors together. Three types of distortion sector/combination are used in the research work, which are single 30 degree sector, four 30 degree sec- tors and single 120 degree sector. It is found that the total pressure loss caused by rotating sector（s） increases when the distortion speed rises. For co-rotating distortions, all the three types of inlet distortion exhibited a peak in stall margin degradation when the distortion speed corresponded to roughly 50% of rotor speed. The two-dimensional numerical simulations of the compressor flow field clearly show the propagation of the distur- bances trigged by the distortion sector（s）.
基金the China Scholarship Council for financial support for PhD studiessupport through the EPSRC Centre for Doctoral Training in Plastic Electronics(EP/L016702/1)
文摘We investigate an electron transport bilayer fabricated at 〈110℃ to form all low-temperature processed, thermally stable, efficient perovskite solar cells with negligible hysteresis. The components of the bilayer create a symbiosis that results in improved devices compared with either of the components being used in isolation. A sol-gel derived ZnO layer facilitates improved energy level alignment and enhanced charge carrier extraction and a [6,6]-phenyl-C61-butyric acid methyl ester （PCBM） layer to reduce hysteresis and enhance perovskite thermal stability. The creation of a bilayer structure allows materials that are inherently unsuitable to be in contact with the perovskite active layer to be used in efficient devices through simple surface modification strategies.
