Understanding the characteristics and influences of various factors on phosphorus(P)fractions is of significance for promoting the efficiency of soil P.Based on long-term experiments on black soil,fluvo-aquic soil,and...Understanding the characteristics and influences of various factors on phosphorus(P)fractions is of significance for promoting the efficiency of soil P.Based on long-term experiments on black soil,fluvo-aquic soil,and loess soil,which belong to Phaeozems,Cambisols,and Anthrosols in the World Reference Base for Soil Resources(WRB),respectively,five fertilization practices were selected and divided into three groups:no P fertilizer(CK/NK),balanced fertilizer(NPK/NPKS),and manure plus mineral fertilizer(NPKM).Soil inorganic P(Pi)fractions and soil properties were analyzed to investigate the characteristics of the Pi fractions and the relationships between Pi fractions and various soil properties.The results showed that the proportion of Ca_(10)-P in the sum of total Pi fractions was the highest in the three soils,accounting for 33.5%in black soil,48.8%in fluvo-aquic soil,and 44.8%in loess soil.Long-term fertilization practices resulted in periodic changes in soil Pi accumulation or depletion.For black soil and fluvo-aquic soil,the Pi accumulation was higher in the late period(10–20 years)of fertilization than in the early period(0–10 years)under NPK/NPKS and NPKM,whereas the opposite result was found in loess soil.The Pi accumulation occurred in all Pi fractions in black soil;mainly in Ca_(8)-P,Fe-P,and Ca_(10)-P in fluvo-aquic soil;and in Ca_(2)-P,Ca_(8)-P,and O-P in loess soil.Under CK/NK,the soil Pi was depleted mainly in the early period in each of the three soils.In addition to the labile Pi(Ca_(2)-P)and moderately labile Pi(Ca_(8)-P,Fe-P,Al-P),the Ca_(10)-P in black soil and fluvo-aquic soil and O-P in loess soil could also be used by crops.Redundancy analysis showed that soil properties explained more than 90%of the variation in the Pi fractions in each soil,and the explanatory percentages of soil organic matter(SOM)were 43.6%in black soil,74.6%in fluvo-aquic,and 38.2%in loess soil.Consequently,decisions regarding the application of P fertilizer should consider the accumulation rate and the variations in Pi fractions driven by soil properties in non-acidic soils.展开更多
AIM:To determine whether an increased number and duration of non-acid reflux events as measured using the multichannel intraluminal impedance pH(MII-pH)is linked to gastroparesis(GP).METHODS:A case control study was c...AIM:To determine whether an increased number and duration of non-acid reflux events as measured using the multichannel intraluminal impedance pH(MII-pH)is linked to gastroparesis(GP).METHODS:A case control study was conducted in which 42 patients undergoing clinical evaluation for continued symptoms of gastroesophageal reflux disease(both typical and atypical symptoms)despite acid suppression therapy.MII-pH technology was used over 24 h to detect reflux episodes and record patients’symptoms.Parameters evaluated in patients with documented GP and controls without GP by scintigraphy included total,upright,and supine number of acid and non-acid reflux episodes(pH<4 and pH>4,respectively),the duration of acid and non-acid reflux in a 24-h period,and the number of reflux episodes lasting longer than 5 min.RESULTS:No statistical difference was seen between the patients with GP and controls with respect to the total number or duration of acid reflux events,total number and duration of non-acid reflux events or the duration of longest reflux episodes.The number of nonacid reflux episodes with a pH>7 was higher in subjects with GP than in controls.In addition,acid reflux episodes were more prolonged(lasting longer than 5min)in the GP patients than in controls;however,these values did not reach statistical significance.Thirty-five patients had recorded symptoms during the 24 h study and of the 35 subjects,only 9%(n=3)had a positive symptom association probability(SAP)for acid/non-acid reflux and 91%had a negative SAP.CONCLUSION:The evaluation of patients with a documented history of GP did not show an association between GP and more frequent episodes of non-acid reflux based on MII-pH testing.展开更多
Water splitting is regarded as among the most prospective methods of generating green hydrogen.Switching electrolytes of water electrolysis from acidic to non-acidic ones will enable the use of noble-metal-free electr...Water splitting is regarded as among the most prospective methods of generating green hydrogen.Switching electrolytes of water electrolysis from acidic to non-acidic ones will enable the use of noble-metal-free electrocatalysts and mitigate material corrosion,thus lowering the capital cost of water electrolyzers and improving their operational stability.However,increasing electrolyte pH will degrade the hydrogen evolution reaction(HER)activity because of the reduced concentration of H_(3)O^(+)as reactants,making non-acidic HER sluggish.To accelerate HER,MoS_(2)-based materials with the advantages of unique atomistic structure,low cost,and high abundance have been considered prospective electrocatalysts to substitute for Pt in acid.Great efforts are being spent on extending MoS_(2)-based materials into the catalysis of non-acidic HER,and their further development requires clarification of the existing challenges and current progress.However,it has not yet been discussed for non-acidic HER on MoS_(2)-based electrocatalysts.To mitigate the disparity,we systematically overview MoS_(2)-based electrocatalysts for non-acidic HER,covering catalytic mechanisms,modulation strategies,materials development,current challenges,research progress,and perspectives.This review will contribute to the rational design of MoS_(2)-based materials for high-performance HER in non-acidic conditions.展开更多
基金the National Key Research and Development Program of China(2021YFD1500205)the National Natural Science Foundation of China(41977103).
文摘Understanding the characteristics and influences of various factors on phosphorus(P)fractions is of significance for promoting the efficiency of soil P.Based on long-term experiments on black soil,fluvo-aquic soil,and loess soil,which belong to Phaeozems,Cambisols,and Anthrosols in the World Reference Base for Soil Resources(WRB),respectively,five fertilization practices were selected and divided into three groups:no P fertilizer(CK/NK),balanced fertilizer(NPK/NPKS),and manure plus mineral fertilizer(NPKM).Soil inorganic P(Pi)fractions and soil properties were analyzed to investigate the characteristics of the Pi fractions and the relationships between Pi fractions and various soil properties.The results showed that the proportion of Ca_(10)-P in the sum of total Pi fractions was the highest in the three soils,accounting for 33.5%in black soil,48.8%in fluvo-aquic soil,and 44.8%in loess soil.Long-term fertilization practices resulted in periodic changes in soil Pi accumulation or depletion.For black soil and fluvo-aquic soil,the Pi accumulation was higher in the late period(10–20 years)of fertilization than in the early period(0–10 years)under NPK/NPKS and NPKM,whereas the opposite result was found in loess soil.The Pi accumulation occurred in all Pi fractions in black soil;mainly in Ca_(8)-P,Fe-P,and Ca_(10)-P in fluvo-aquic soil;and in Ca_(2)-P,Ca_(8)-P,and O-P in loess soil.Under CK/NK,the soil Pi was depleted mainly in the early period in each of the three soils.In addition to the labile Pi(Ca_(2)-P)and moderately labile Pi(Ca_(8)-P,Fe-P,Al-P),the Ca_(10)-P in black soil and fluvo-aquic soil and O-P in loess soil could also be used by crops.Redundancy analysis showed that soil properties explained more than 90%of the variation in the Pi fractions in each soil,and the explanatory percentages of soil organic matter(SOM)were 43.6%in black soil,74.6%in fluvo-aquic,and 38.2%in loess soil.Consequently,decisions regarding the application of P fertilizer should consider the accumulation rate and the variations in Pi fractions driven by soil properties in non-acidic soils.
文摘AIM:To determine whether an increased number and duration of non-acid reflux events as measured using the multichannel intraluminal impedance pH(MII-pH)is linked to gastroparesis(GP).METHODS:A case control study was conducted in which 42 patients undergoing clinical evaluation for continued symptoms of gastroesophageal reflux disease(both typical and atypical symptoms)despite acid suppression therapy.MII-pH technology was used over 24 h to detect reflux episodes and record patients’symptoms.Parameters evaluated in patients with documented GP and controls without GP by scintigraphy included total,upright,and supine number of acid and non-acid reflux episodes(pH<4 and pH>4,respectively),the duration of acid and non-acid reflux in a 24-h period,and the number of reflux episodes lasting longer than 5 min.RESULTS:No statistical difference was seen between the patients with GP and controls with respect to the total number or duration of acid reflux events,total number and duration of non-acid reflux events or the duration of longest reflux episodes.The number of nonacid reflux episodes with a pH>7 was higher in subjects with GP than in controls.In addition,acid reflux episodes were more prolonged(lasting longer than 5min)in the GP patients than in controls;however,these values did not reach statistical significance.Thirty-five patients had recorded symptoms during the 24 h study and of the 35 subjects,only 9%(n=3)had a positive symptom association probability(SAP)for acid/non-acid reflux and 91%had a negative SAP.CONCLUSION:The evaluation of patients with a documented history of GP did not show an association between GP and more frequent episodes of non-acid reflux based on MII-pH testing.
基金the City University of Hong Kong through Projects 9610537 and 7005921the Department of Science and Technology of Guangdong Province through Project 2022A1515010212Guangdong Provincial Key Laboratory of Materials and Technology for Energy Conversion,and Guangdong Technion-Israel Institute of Technology through Project MATEC2022KF008.
文摘Water splitting is regarded as among the most prospective methods of generating green hydrogen.Switching electrolytes of water electrolysis from acidic to non-acidic ones will enable the use of noble-metal-free electrocatalysts and mitigate material corrosion,thus lowering the capital cost of water electrolyzers and improving their operational stability.However,increasing electrolyte pH will degrade the hydrogen evolution reaction(HER)activity because of the reduced concentration of H_(3)O^(+)as reactants,making non-acidic HER sluggish.To accelerate HER,MoS_(2)-based materials with the advantages of unique atomistic structure,low cost,and high abundance have been considered prospective electrocatalysts to substitute for Pt in acid.Great efforts are being spent on extending MoS_(2)-based materials into the catalysis of non-acidic HER,and their further development requires clarification of the existing challenges and current progress.However,it has not yet been discussed for non-acidic HER on MoS_(2)-based electrocatalysts.To mitigate the disparity,we systematically overview MoS_(2)-based electrocatalysts for non-acidic HER,covering catalytic mechanisms,modulation strategies,materials development,current challenges,research progress,and perspectives.This review will contribute to the rational design of MoS_(2)-based materials for high-performance HER in non-acidic conditions.
