Energy partitioning and evapotranspiration in a black locust plantation on the Yellow River Delta,China

Plantations of woody tree species play a crucial role in ecological security along coastal zones.Understanding energy partitioning and evapotranspiration can reveal land–atmosphere interaction processes.We investigated energy fluxes,evapotranspiration,and their related biophysical factors using eddy covariance techniques in a black locust(Robinia pseudoacacia L.)plantation in 2016,2018,and 2019 on the Yellow River Delta.Downward longwave radiation offsets 84–85%of upward longwave radiation;upward shortwave radiation accounted for 12–13%of downward shortwave radiation.The ratio of net radiation to downward radiation was 18–19%over the three years.During the growing season,latent heat flux was the largest component of net radiation;during the dormant season,the sensible heat flux was the dominant component of net radiation.The seasonal variation in daily evapotranspiration was mainly controlled by net radiation,air temperature,vapor pressure deficit,and leaf area index.Black locust phenology influenced daily evapotranspiration variations,and evapotranspiration was greater under sea winds than under land winds because soil water content at 10-cm depth was greater under sea winds during the day.Seasonal patterns of daily evaporative fraction,Bowen ratio,crop coefficient,Priestley–Taylor coefficient,surface conductance,and decoupling coefficient were mainly controlled by leaf area index.The threshold value of daily surface conductance was approximately 8 mm sover the plantation.

Boron nitride-enabled printing of a highly sensitive and flexible iontronic pressure sensing system for spatial mapping

Recently,flexible iontronic pressure sensors(FIPSs)with higher sensitivities and wider sensing ranges than conventional capacitive sensors have been widely investigated.Due to the difficulty of fabricating the nanostructures that are commonly used on electrodes and ionic layers by screen printing techniques,strategies for fabricating such devices using these techniques to drive their mass production have rarely been reported.Herein,for the first time,we employed a 2-dimensional(2D)hexagonal boron nitride(h-BN)as both an additive and an ionic liquid reservoir in an ionic film,making the sensor printable and significantly improving its sensitivity and sensing range through screen printing.The engineered sensor exhibited high sensitivity(S_(min)>261.4 kPa^(−1))and a broad sensing range(0.05-450 kPa),and it was capable of stable operation at a high pressure(400 kPa)for more than 5000 cycles.In addition,the integrated sensor array system allowed accurate monitoring of wrist pressure and showed great potential for health care systems.We believe that using h-BN as an additive in an ionic material for screen-printed FIPS could greatly inspire research on 2D materials for similar systems and other types of sensors.