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A visible-light-induced tandem radical brominative addition/spiro-cyclization/1,2-ester migration of activated alkynes with CBr4is developed. This protocol features good functional group tolerance, operational simplicity, and mild reaction conditions without the use of catalysts and external additives, providing easy access to valuable 3-bromocoumarins in generally high yields.

This paper makes a prediction about the daily power generation of the photovoltaic power station in Wuhan International Exhibition Center by the application of multivariable grey theory model and compares the forecasted results with the real results. This research proves that the application of the theory of multivariable grey model on short-term prediction of photovoltaic power generation can achieve a good prediction effect, which also has certain engineering application value.

Supersonic swirling separator had a good ability in separating gas-liquid. In this paper, the Laval-nozzle and straight-tube of the non-central cone supersonic swirling separator were optimized designing. The separation performance of the optimized supersonic swirling separator was researched by CFX. The results show that,with the relative pressure ratio decreasing, the shock waves which occurred in the diffuser moved towards the extraction device, the maximum Mach number decreasing. When the relative pressure ratio down to 1.4, the outlet total pressure recovered to 73% of the inlet total pressure, the flow in the divergent section of Laval-nozzle and the straight-tube was supersonic, the lowest temperature can be down to-84.5°C and the maximum centrifugal acceleration was 261,800g, which provided a swirling and cold environment for the separation of gas-liquid; With the straight-tubes length-diameter ratio increased, a normal shock wave occurred in the straight-tube. Further increased the length-diameter ratio, the normal shock wave moved towards the throat and the strength of the shock wave was increasing, which was a disadvantage to the separation of the gas-liquid.