A novel approach for the synthesis of 4-aminoquinazolines has been developed via rhodium(Ⅲ)-catalyzed [4+2] annulation of N-arylbenzamidines with 1,4,2-dioxazol-5-ones.This reaction features excellent regioselectivit...A novel approach for the synthesis of 4-aminoquinazolines has been developed via rhodium(Ⅲ)-catalyzed [4+2] annulation of N-arylbenzamidines with 1,4,2-dioxazol-5-ones.This reaction features excellent regioselectivity,broad substrate scope and high step economy,which would provide the refe rence for the construction of the fused 4-aminoquinazolines with biologically and pharmacologically active compounds.展开更多
Following a welcome that included a 21-gun salute, Chinese President Hu Jintao delivered a clear message on the South Lawn of the White House on January 19. In the moderate
An output amplitude configurable wideband automatic gain control（AGC） with high gain step accuracy for the GNSS receiver is presented.The amplitude of an AGC is configurable in order to cooperate with baseband chips...An output amplitude configurable wideband automatic gain control（AGC） with high gain step accuracy for the GNSS receiver is presented.The amplitude of an AGC is configurable in order to cooperate with baseband chips to achieve interference suppression and be compatible with different full range ADCs.And what’s more,the gain-boosting technology is introduced and the circuit is improved to increase the step accuracy.A zero,which is composed by the source feedback resistance and the source capacity,is introduced to compensate for the pole.The AGC is fabricated in a 0.18μm CMOS process.The AGC shows a 62 dB gain control range by 1 dB each step with a gain error of less than 0.2 dB.The AGC provides 3 dB bandwidth larger than 80 MHz and the overall power consumption is less than 1.8 mA,and the die area is 800 x 300μm^2.展开更多
基金financial support from the Ministry of Science and Technology of China (No.2016YFE0132600)Henan Center for Outstanding Overseas Scientists (No.GZS2020001)Zhengzhou University。
文摘A novel approach for the synthesis of 4-aminoquinazolines has been developed via rhodium(Ⅲ)-catalyzed [4+2] annulation of N-arylbenzamidines with 1,4,2-dioxazol-5-ones.This reaction features excellent regioselectivity,broad substrate scope and high step economy,which would provide the refe rence for the construction of the fused 4-aminoquinazolines with biologically and pharmacologically active compounds.
文摘Following a welcome that included a 21-gun salute, Chinese President Hu Jintao delivered a clear message on the South Lawn of the White House on January 19. In the moderate
基金supported by the Core Electronic Devices,High-End General Chips and Basic Software Products Major Projects,China(No. 2009ZX01031-002-008)the National High Technology Research and Development Program of China(No.2009AA011601)
文摘An output amplitude configurable wideband automatic gain control（AGC） with high gain step accuracy for the GNSS receiver is presented.The amplitude of an AGC is configurable in order to cooperate with baseband chips to achieve interference suppression and be compatible with different full range ADCs.And what’s more,the gain-boosting technology is introduced and the circuit is improved to increase the step accuracy.A zero,which is composed by the source feedback resistance and the source capacity,is introduced to compensate for the pole.The AGC is fabricated in a 0.18μm CMOS process.The AGC shows a 62 dB gain control range by 1 dB each step with a gain error of less than 0.2 dB.The AGC provides 3 dB bandwidth larger than 80 MHz and the overall power consumption is less than 1.8 mA,and the die area is 800 x 300μm^2.
