Analysis of a Typical Case of Meteorological Service in Tangpu Reservoir

The continuous rainy precipitation process from February to March in 2019 was selected to analyze the effect of meteorological service in Tangpu Reservoir basin,so as to sum up service experience and then lay a better foundation for subsequent services.In response to the rainy weather from December 2018 to early 2019,three rounds of flood discharge were carried out in Tangpu Reservoir.During February-March in 2019,the hit rate of short-term area rainfall forecast for Tangpu Reservoir was 80.0%.Compared with the median of forecast interval,the average absolute error was 7.6 mm,and the relative error was 32.7%.The large deviation in the forecast from March 27 to 28 was deeply analyzed,and it is found that the main reasons were excessive reliance on and trust in a single model,insufficient correction of the actual situation,and insufficient judgment of the nature of precipitation.For the future reservoir meteorological service,three aspects of thinking were put forward,such as further strengthening the sharing of hydrological and meteorological information,improving the forecasting ability,and deepening the research of runoff forecast models.

Development of a more efficient catalyst for the redox-neutral organocatalytic mitsunobu reaction by DFT-guided catalyst design

The study of a Mitsunobu reaction is an important topic.Denton and co-workers first reported a novel(2-hydroxybenzyl)diphenylphosphine oxide for realizing the catalytic Mitsunobu reaction via a five-membered phosphonium species.However,it is still worth investigating how to improve catalysts with higher efficiency.Guided by computational and experimental studies,we designed a new type of biphenyl-based phosphine oxide that would form a six-membered phosphonium species as a key intermediate to trigger the catalytic Mitsunobu reaction with a lower barrier of the rate-determining step(30.3 kcal/mol).DFT calculations revealed that only trans dehydration was participated in our catalytic progress and a strongπ-πinteraction and small spatial constraint of TS-V were crucial for high behavior.This readily accessible,highly stable,easily recyclable and efficient catalyst would boost the catalytic Mitsunobu reaction.