Photocatalytic reduction of carbon dioxide to methanol by Cu_2O/SiC nanocrystallite under visible light irradiation

The Cu2O/SiC photocatalyst was obtained from SiC nanoparticles （NPs） modified by Cu2O. Their photocatalytic activities for reducing CO2 to CH3OH under visible light irradiation have been investigated. The results indicated that besides a small quantity of 6H-SiC, SiC NPs mainly consisted of 3C-SiC. The band gaps of SiC and Cu2O were estimated to be about 1.95 and 2.23 eV from UV-Vis spectra, respectively. The Cu2O modification can enhance the photocatalytic performance of SiC NPs, and the largest yields of methanol on SiC, Cu2O and Cu2O/SiC photocatalysts under visible light irradiation were 153, 104 and 191μmol/g, respectively.

Enhanced Water Resistance Performance of Castor Oil—Based Waterborne Polyurethane Modified by Methoxysilane Coupling Agents via Thiol-Ene Photo Click Reaction

Nowadays,waterborne polyurethanes(WPUs)prepared from renewable resources has attracted more and more attention.However,due to its structure,the prepared films easily swells in water and greatly affects the application range of WPUs.Therefore,solving the problem of water resistance is a way to improve the application range of WPUs.In this study,a series of WPU dispersions were prepared using castor oil as the bio-based polyol.Besides,the thiol-ene photo click reaction was carried out on the WPU films for silane modification.The effect of the silane modification on the chemical structures of the WPU dispersions and the properties of the WPU films was investigated and discussed.The results revealed that the WPU dispersions had a smaller particle size and potential,showing excellent stability.In addition,the modified WPU films showed highly water resistance which 72 h water absorption could be reduced to 1.94%and the contact angle was up to 99.34?.Moreover,the modified WPU films also exhibited excellent solvent resistance(in acid and salt solution)and thermal stability.This study can provide a new way to improve the water-resistance,hydrophobicity,and thermal stability of bio-based waterborne polyurethane for potential application in painting,adhesives and inks.

Effects of Different Irrigation Methods on Growth,Fruit Quality and Yield of Apple Trees

Water-saving irrigation is an important way to realize the sustainable development of the apple industry.In order to screen the best irrigation pattern for apple,taking 9-year-old‘Yanfu 10'Fuji/Malus robusta apple as the material,the effects of different irrigation methods(drip irrigation,sprinkling irrigation,and flood irrigation) on the growth,fruit quality,and yield of apple trees were studied.The results showed that compared with the flood irrigation,drip irrigation and sprinkling irrigation significantly increased the spring shoot length by 14.8%and 9.1%,respectively,and decreased the autumn shoot length by 11.7% and 8.8%,respectively.Drip irrigation and sprinkling irrigation significantly increased the leaf area,chlorophyll content,and leaf weight,the leaf area increased by 3.0% and 1.9%,respectively,the chlorophyll content increased by 13.9% and 11.5%,respectively,and the leaf weight increased by 5.8% and 5.1%,respectively.Drip irrigation and sprinkling irrigation could slightly increase the single fruit weight and fruit shape index,significantly increase the coloring index and smoothness index.The single fruit weight increased by 3.2% and 1.9%,the coloring index increased by 6.1% and 4.1%,the smoothness index increased by 4.7% and 2.8%,and the proportion of red fruit increased by 4.2% and 2.2%,respectively.The content of soluble solids in drip irrigation and sprinkling irrigation was significantly higher than that in flood irrigation,which was 13.0% and 2.6% higher than CK,respectively.The fruit hardness in drip irrigation and sprinkling irrigation was 7.9% and 2.2% higher than CK,respectively,and that in drip irrigation increased significantly.The yield in drip irrigation and sprinkling irrigation was 12.1% and 8.2% higher than CK,respectively.In conclusion,drip irrigation and sprinkling irrigation could promote the growth of apple trees,improve the fruit quality,and increase the yield of apple trees,and the effect of drip irrigation is better than sprinkling irrigation.

Frequency-Resolved Connectome Hubs and Their Test-Retest Reliability in the Resting Human Brain

Functional hubs with disproportionately extensive connectivities play a crucial role in global information integration in human brain networks.However,most resting-state functional magnetic resonance imaging(R-fMRI)studies have identified functional hubs by examining spontaneous fluctuations of the blood oxygen level-dependent signal within a typical low-frequency band(e.g.,0.01–0.08 Hz or 0.01–0.1 Hz).Little is known about how the spatial distributions of functional hubs depend on frequency bands of interest.Here,we used repeatedly measured R-fMRI data from 53 healthy young adults and a degree centrality analysis to identify voxelwise frequency-resolved functional hubs and further examined their test-retest reliability across two sessions.We showed that a wide-range frequency band(0.01–0.24 Hz)accessible with a typical sampling rate(fsample=0.5 Hz)could be classified into three frequency bands with distinct patterns,namely,low-frequency(LF,0.01–0.06 Hz),middle-frequency(MF,0.06–0.16 Hz),and high-frequency(HF,0.16–0.24 Hz)bands.The functional hubs were mainly located in the medial and lateral frontal and parietal cortices in the LF band,and in the medial prefrontal cortex,superior temporal gyrus,parahippocampal gyrus,amygdala,and several cerebellar regions in the MF and HF bands.These hub regions exhibited fair to good test-retest reliability,regardless of the frequency band.The presence of the three frequency bands was well replicated using an independent R-fMRI dataset from 45 healthy young adults.Our findings demonstrate reliable frequency-resolved functional connectivity hubs in three categories,thus providing insights into the frequency-specific connectome organization in healthy and disordered brains.