Water electrolysis has attracted a lot of attention in recent years for hydrogen production.CoP has been widely investigated as a traditional electrocatalyst for hydrogen evolution reaction(HER).However,the strong bon...Water electrolysis has attracted a lot of attention in recent years for hydrogen production.CoP has been widely investigated as a traditional electrocatalyst for hydrogen evolution reaction(HER).However,the strong bond strength of P-H bond and weak chemical stability are still the key problems in affecting catalytic performance of CoP.In this work,we synthesized rambutan-like CoP@Mo-Co-O hollow microspheres as HER electrocatalyst,solving the two problems of CoP as electrocatalyst.Benefiting from the unique three-dimensional space structure and interface effect between CoP and Mo-Co-O,the synthesized CoP@Mo-Co-O shows a small overpotential of 62 mV at the current density of 10 mA cm^-2 for HER,which is much lower than the corresponding overpotential of pure CoP microspheres(117 mV).Rambutan-like CoP@Mo-Co-O hollow microspheres also show robust long-term stability and excellent cycling stability.This work provides a new method for the design and improvement of non-precious HER electrocatalysts.展开更多
In this study,an ultra‐fast and simple solvent‐free microwave method was successfully demonstrated using a series of ultra‐small(~2.5 nm)surfactant‐free Ru_(2)P@Ru/CNT heterostructures for the first time.The struc...In this study,an ultra‐fast and simple solvent‐free microwave method was successfully demonstrated using a series of ultra‐small(~2.5 nm)surfactant‐free Ru_(2)P@Ru/CNT heterostructures for the first time.The structure has a high‐density Ru component and Ru_(2)P component interface,which accelerates the hydrogen evolution reaction(HER).The prepared Ru_(2)P@Ru/CNT demonstrated excellent catalytic effects for the HER in alkaline media and real seawater.The experimental results indicate that ratio‐optimized Ru_(2)P@Ru/CNT(Ru_(2)P:Ru=66:34)requires only 23 and 29 mV to reach 10 mA cm^(-2)in 1.0 mol/L KOH and real seawater,respectively.These values are 10 and 24 mV lower than those of commercial Pt/C in 1.0 mol/L KOH(33 mV)and real seawater(53 mV),respectively,making it among the best non‐Pt HER reported in the literature.Additionally,the TOF of Ru_(2)P@Ru/CNT in alkaline freshwater and seawater were 13.1 and 8.5 s^(-1),respectively.These exceed the corresponding values for Pt/C,indicating that the catalyst has excellent intrinsic activity.The high current activity of Ru_(2)P@Ru/CNT in 1.0 mol/L KOH was explored,and only 77 and 104 mV were required to reach 500 and 1000 mA cm^(-2),respectively.After 100 h of durability testing,the catalyst retained excellent catalytic and structural stability in low current density,high current density,and seawater.展开更多
Evapotranspiration （ETc） is an important quantity for hydrological cycle. This study shows evapotranspiration, the ratio of evaporation to evapotranspiration （E/ETc） of winter wheat and maize in north China. Sever...Evapotranspiration （ETc） is an important quantity for hydrological cycle. This study shows evapotranspiration, the ratio of evaporation to evapotranspiration （E/ETc） of winter wheat and maize in north China. Several relationships, namely, E/ET0 and soil surface moisture, E/ET0 and leaf area index （LAI）, are also analyzed. The average seasonal ETc values for winter wheat, maize （2008） and maize （2009） are 431.21,456.3 and 341.4mm. The value of E/ET0 varied from 1 at initial growth stage to 0.295 at the later growth for winter wheat, and from 1 to 0.492, from 1 to 0.566 for maize （2008） and maize （2009）. The relationship between E/ET0 and surface soil water content, and E/ET0 and LAI are fitted to a quadratic parabola equation with significant correlation coefficients, respectively, for wheat and maize. These results should help the precise planning and efficient management of irrigation for these crops in this region.展开更多
This research was carried out to study the effect of fermentation on the chemical composition, anti-nutrient content, PH, titratable acidity, and microbiological changes of millet and soyabean blend. Millet and soyabe...This research was carried out to study the effect of fermentation on the chemical composition, anti-nutrient content, PH, titratable acidity, and microbiological changes of millet and soyabean blend. Millet and soyabean composite flours were mixed in gram of six combinations as follows millet and soyabean （A） = 100：0, millet and soyabean （B） = 90：10, millet and soyabean （C） = 80：20, millet and soyabean （D） = 70：30, millet and soyabean （E） = 60：40, millet and soyabean （F） = 50：50 and subjected to natural fermentation for 72 h. The following bacteria isolates were obtained from the fermentation; Lacobacillus fermentum, L. acidophilus, L. bulgaricus, L. plantarum, L. dextranicum, L. rhamnosus, L. delbrueckii, L. leichemanii, L. divergens, L. reuteri, L. jenseni, L. casei, L. salivarius, L. cellubiosus, Leuconostoc mesenteroide and Pediococcus acidilactis, of which L. plantarum was the most dominant the throughout the period of fermentation. There was decrease in pH with increase in TTA in all the samples. The result of the proximate analysis revealed a marginal increase in crude protein content of each sample （from 44.41 to 63.14, from 11.02 to 24.02, from 16.64 to 23.10, from 20.83 to 26.93, from 25.43 to 30.12, 39.12 to 35.86 and from 40.66 to 54.24%） There was increase in ash content and decrease in carbohydrate, fibre and fat contents of the fermented samples. Results from this research also show significant reduction in anti-nutritional content which are hydrogen cyanide, oxalate and phytate. Fermentation has modified the microbial and nutritional quality of the millet and soyabean blend and this has greatly improved the nutrient content of the blend.展开更多
文摘Water electrolysis has attracted a lot of attention in recent years for hydrogen production.CoP has been widely investigated as a traditional electrocatalyst for hydrogen evolution reaction(HER).However,the strong bond strength of P-H bond and weak chemical stability are still the key problems in affecting catalytic performance of CoP.In this work,we synthesized rambutan-like CoP@Mo-Co-O hollow microspheres as HER electrocatalyst,solving the two problems of CoP as electrocatalyst.Benefiting from the unique three-dimensional space structure and interface effect between CoP and Mo-Co-O,the synthesized CoP@Mo-Co-O shows a small overpotential of 62 mV at the current density of 10 mA cm^-2 for HER,which is much lower than the corresponding overpotential of pure CoP microspheres(117 mV).Rambutan-like CoP@Mo-Co-O hollow microspheres also show robust long-term stability and excellent cycling stability.This work provides a new method for the design and improvement of non-precious HER electrocatalysts.
文摘In this study,an ultra‐fast and simple solvent‐free microwave method was successfully demonstrated using a series of ultra‐small(~2.5 nm)surfactant‐free Ru_(2)P@Ru/CNT heterostructures for the first time.The structure has a high‐density Ru component and Ru_(2)P component interface,which accelerates the hydrogen evolution reaction(HER).The prepared Ru_(2)P@Ru/CNT demonstrated excellent catalytic effects for the HER in alkaline media and real seawater.The experimental results indicate that ratio‐optimized Ru_(2)P@Ru/CNT(Ru_(2)P:Ru=66:34)requires only 23 and 29 mV to reach 10 mA cm^(-2)in 1.0 mol/L KOH and real seawater,respectively.These values are 10 and 24 mV lower than those of commercial Pt/C in 1.0 mol/L KOH(33 mV)and real seawater(53 mV),respectively,making it among the best non‐Pt HER reported in the literature.Additionally,the TOF of Ru_(2)P@Ru/CNT in alkaline freshwater and seawater were 13.1 and 8.5 s^(-1),respectively.These exceed the corresponding values for Pt/C,indicating that the catalyst has excellent intrinsic activity.The high current activity of Ru_(2)P@Ru/CNT in 1.0 mol/L KOH was explored,and only 77 and 104 mV were required to reach 500 and 1000 mA cm^(-2),respectively.After 100 h of durability testing,the catalyst retained excellent catalytic and structural stability in low current density,high current density,and seawater.
文摘Evapotranspiration （ETc） is an important quantity for hydrological cycle. This study shows evapotranspiration, the ratio of evaporation to evapotranspiration （E/ETc） of winter wheat and maize in north China. Several relationships, namely, E/ET0 and soil surface moisture, E/ET0 and leaf area index （LAI）, are also analyzed. The average seasonal ETc values for winter wheat, maize （2008） and maize （2009） are 431.21,456.3 and 341.4mm. The value of E/ET0 varied from 1 at initial growth stage to 0.295 at the later growth for winter wheat, and from 1 to 0.492, from 1 to 0.566 for maize （2008） and maize （2009）. The relationship between E/ET0 and surface soil water content, and E/ET0 and LAI are fitted to a quadratic parabola equation with significant correlation coefficients, respectively, for wheat and maize. These results should help the precise planning and efficient management of irrigation for these crops in this region.
文摘This research was carried out to study the effect of fermentation on the chemical composition, anti-nutrient content, PH, titratable acidity, and microbiological changes of millet and soyabean blend. Millet and soyabean composite flours were mixed in gram of six combinations as follows millet and soyabean （A） = 100：0, millet and soyabean （B） = 90：10, millet and soyabean （C） = 80：20, millet and soyabean （D） = 70：30, millet and soyabean （E） = 60：40, millet and soyabean （F） = 50：50 and subjected to natural fermentation for 72 h. The following bacteria isolates were obtained from the fermentation; Lacobacillus fermentum, L. acidophilus, L. bulgaricus, L. plantarum, L. dextranicum, L. rhamnosus, L. delbrueckii, L. leichemanii, L. divergens, L. reuteri, L. jenseni, L. casei, L. salivarius, L. cellubiosus, Leuconostoc mesenteroide and Pediococcus acidilactis, of which L. plantarum was the most dominant the throughout the period of fermentation. There was decrease in pH with increase in TTA in all the samples. The result of the proximate analysis revealed a marginal increase in crude protein content of each sample （from 44.41 to 63.14, from 11.02 to 24.02, from 16.64 to 23.10, from 20.83 to 26.93, from 25.43 to 30.12, 39.12 to 35.86 and from 40.66 to 54.24%） There was increase in ash content and decrease in carbohydrate, fibre and fat contents of the fermented samples. Results from this research also show significant reduction in anti-nutritional content which are hydrogen cyanide, oxalate and phytate. Fermentation has modified the microbial and nutritional quality of the millet and soyabean blend and this has greatly improved the nutrient content of the blend.
