Improved simulation of winter wheat yield in North China Plain by using PRYM-Wheat integrated dry matter distribution coefficient

The accurate simulation of regional-scale winter wheat yield is important for national food security and the balance of grain supply and demand in China.Presently,most remote sensing process models use the“biomass×harvest index(HI)”method to simulate regional-scale winter wheat yield.However,spatiotemporal differences in HI contribute to inaccuracies in yield simulation at the regional scale.Time-series dry matter partition coefficients(Fr)can dynamically reflect the dry matter partition of winter wheat.In this study,Fr equations were fitted for each organ of winter wheat using site-scale data.These equations were then coupled into a process-based and remote sensingdriven crop yield model for wheat(PRYM-Wheat)to improve the regional simulation of winter wheat yield over the North China Plain(NCP).The improved PRYM-Wheat model integrated with the fitted Fr equations(PRYM-Wheat-Fr)was validated using data obtained from provincial yearbooks.A 3-year(2000-2002)averaged validation showed that PRYM-Wheat-Fr had a higher coefficient of determination(R^(2)=0.55)and lower root mean square error(RMSE=0.94 t ha^(-1))than PRYM-Wheat with a stable HI(abbreviated as PRYM-Wheat-HI),which had R^(2) and RMSE values of 0.30 and 1.62 t ha^(-1),respectively.The PRYM-Wheat-Fr model also performed better than PRYM-Wheat-HI for simulating yield in verification years(2013-2015).In conclusion,the PRYM-Wheat-Fr model exhibited a better accuracy than the original PRYM-Wheat model,making it a useful tool for the simulation of regional winter wheat yield.

Acceptor-Donor-Acceptor π-Stacking Boosts Intramolecular Through-Space Charge Transfer towards Efficient Red TADF and High-PerformanceOLEDS

Organic push-pull systems featuring through-space charge transfer(TSCT)excited states have been disclosed to be capable of exhibiting thermally activated delayed fluorescence(TADF),but to realize high-efficiency long-wavelength emission still remains a challenge.Herein,we report a series of strongly emissive orange-red and red TSCT-TADF emitters having(quasi)planar and rigid donor and acceptor segments which are placed in close proximity and orientated in a cofacial manner.Emission maxima(λ_(em))of 594−599 nm with photoluminescence quantum yields(PLQYs)of up to 91%and delayed fluorescence lifetimes of down to 4.9μs have been achieved for new acceptor-donor-acceptor(A-D-A)molecules in doped thin films.The presence of multiple acceptors and the strong intramolecularπ-stacking interactions have been unveiled to be crucial for the efficient low-energy TSCT-TADF emissions.Organic light-emitting diodes(OLEDs)based on the new A-D-A emitters demonstrated electroluminescence with maximum external quantum efficiencies(EQEs)of up to 23.2%for the red TSCT-TADF emitters.An EQE of 18.9%at the brightness of 1000 cd m^(-2) represents one of the highest values for red TADF OLEDs.This work demonstrates a modular approach for developing high-performance red TADF emitters through engineering through-space interactions,and it may also provide implications to the design of TADF emitter with other colours.