This paper presents results of nitrites and nitrates determination in two types of baby foods： commercial products in jars and their homemade conventional counterparts. Nitrites levels in all analyzed samples were be...This paper presents results of nitrites and nitrates determination in two types of baby foods： commercial products in jars and their homemade conventional counterparts. Nitrites levels in all analyzed samples were below of the detection limit （〈 0.9 mg/kg） of applied spectrophotometric method with Griess reagent. Nitrates contents in commercial products ranged： 9.1-38.1 mg/kg while in homemade baby foods levels between 26.6 mg/kg and 118.8 mg/kg were obtained. All the contents of nitrates were lower than the EU legislation maximum limit （200 mg/kg）. Comparison of each type of commercial product with its homemade counterpart baby food evidenced significant differences （p 〈 0.05） in average nitrates levels in favor of the first type. Apart from determining and comparing the levels of nitrates in the baby food samples also risk assessment for an average 6-months old infant to nitrates exposure was conducted. The estimated nitrates intake with a typical portion of 200g of baby food ranged between 6% and 25.7% of acceptable daily intake for commercial and from 18.0% to 80.3% for homemade ones.展开更多
Perovskite solar cells(PSCs)attract widespread research interest due to their exceptional properties.However,the instability of the perovskite layer,especially the moisture instability,and existing defects seriously r...Perovskite solar cells(PSCs)attract widespread research interest due to their exceptional properties.However,the instability of the perovskite layer,especially the moisture instability,and existing defects seriously restrict the performance and limit the development of PSCs towards commercialization.Herein,we fabricate moisture-stable and efficient PSCs by incorporating a thiamine(THM)additive into a lead iodide(PbI_(2))precursor using a two-step spin-coating method.This strategy enables a better interaction between the THM additive and PbI_(2).Then,a higher energy barrier is produced when the material reacts with A-site cations to form perovskite crystals,resulting in larger grains and better-quality perovskite films.Through optimization of the concentration of the THM additive,the optimal perovskite achieves improved moisture stability and decreased trap states;thus,the corresponding unencapsulated devices achieve a remarkable power conversion efficiency(PCE)of 21.40%and maintain>92%of their initial PCE after 180 h in ambient air(~50%humidity).The excellent performance is mainly attributed to the fact that THM promotes crystal growth and passivates defects in perovskite films.展开更多
文摘This paper presents results of nitrites and nitrates determination in two types of baby foods： commercial products in jars and their homemade conventional counterparts. Nitrites levels in all analyzed samples were below of the detection limit （〈 0.9 mg/kg） of applied spectrophotometric method with Griess reagent. Nitrates contents in commercial products ranged： 9.1-38.1 mg/kg while in homemade baby foods levels between 26.6 mg/kg and 118.8 mg/kg were obtained. All the contents of nitrates were lower than the EU legislation maximum limit （200 mg/kg）. Comparison of each type of commercial product with its homemade counterpart baby food evidenced significant differences （p 〈 0.05） in average nitrates levels in favor of the first type. Apart from determining and comparing the levels of nitrates in the baby food samples also risk assessment for an average 6-months old infant to nitrates exposure was conducted. The estimated nitrates intake with a typical portion of 200g of baby food ranged between 6% and 25.7% of acceptable daily intake for commercial and from 18.0% to 80.3% for homemade ones.
基金financially supported by the National Natural Science Foundation of China(52025028,52072254,and 52002258)the Natural Science Foundation of Jiangsu Province(BK20200877)+1 种基金the"Shuangchuang"Program of Jiangsu Provincethe Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutions。
文摘Perovskite solar cells(PSCs)attract widespread research interest due to their exceptional properties.However,the instability of the perovskite layer,especially the moisture instability,and existing defects seriously restrict the performance and limit the development of PSCs towards commercialization.Herein,we fabricate moisture-stable and efficient PSCs by incorporating a thiamine(THM)additive into a lead iodide(PbI_(2))precursor using a two-step spin-coating method.This strategy enables a better interaction between the THM additive and PbI_(2).Then,a higher energy barrier is produced when the material reacts with A-site cations to form perovskite crystals,resulting in larger grains and better-quality perovskite films.Through optimization of the concentration of the THM additive,the optimal perovskite achieves improved moisture stability and decreased trap states;thus,the corresponding unencapsulated devices achieve a remarkable power conversion efficiency(PCE)of 21.40%and maintain>92%of their initial PCE after 180 h in ambient air(~50%humidity).The excellent performance is mainly attributed to the fact that THM promotes crystal growth and passivates defects in perovskite films.
