The college students are the main force of contemporary youth, their involvement in the ideological and political course of study is very favorable on their personal development. But affected by the traditional educat...The college students are the main force of contemporary youth, their involvement in the ideological and political course of study is very favorable on their personal development. But affected by the traditional education ideas, in colleges there are many deficiencies appeared in the process of ideological and political education, which have restricted the promotion of college students＇ Ideological and political awareness. This paper firstly analyzes the deficiencies of the traditional ideological and political education, discusses the key points of creating the intemet interactive mode, and puts forward the creative decision on ideological and political education based on the internet interactive mode, in hopes of providing helps to the follow-up study.展开更多
Red-emissive carbon dots(R-CDs)have been widely studied because of their potential application in tissue imaging and optoelectronic devices.At present,most R-CDs are synthesized by using aromatic precursors,but the sy...Red-emissive carbon dots(R-CDs)have been widely studied because of their potential application in tissue imaging and optoelectronic devices.At present,most R-CDs are synthesized by using aromatic precursors,but the synthesis of R-CDs from non-aromatic precursors is challenging,and the emission mechanism remains unclear.Herein,different R-CDs were rationally synthesized using citric acid(CA),a prototype non-aromatic precursor,with the assistance of ammonia.Their structural evolution and optical mechanism were investigated.The addition of NH_(3)·H_(2)O played a key role in the synthesis of CA-based R-CDs,which shifted the emission wavelength of CA-based CDs from 423 to 667 nm.Mass spectrometry(MS)analysis indicated that the amino groups served as N dopants and promoted the formation of localized conjugated domains through an intermolecular amide ring,thereby inducing a significant emission redshift.The red-emissive mechanism of CDs was further confirmed by control experiments using other CA-like molecules(e.g.,aconitic acid,tartaric acid,aspartic acid,malic acid,and maleic acid)as precursors.MS,nuclear magnetic resonance characterization,and computational modeling revealed that the main carbon chain length of CA-like precursors tailored the cyclization mode,leading to hexatomic,pentatomic,unstable three/four-membered ring systems or cyclization failure.Among these systems,the hexatomic ring led to the largest emission redshift(244 nm,known for CA-based CDs).This work determined the origin of red emission in CA-based CDs,which would guide research on the controlled synthesis of R-CDs from other non-aromatic precursors.展开更多
文摘The college students are the main force of contemporary youth, their involvement in the ideological and political course of study is very favorable on their personal development. But affected by the traditional education ideas, in colleges there are many deficiencies appeared in the process of ideological and political education, which have restricted the promotion of college students＇ Ideological and political awareness. This paper firstly analyzes the deficiencies of the traditional ideological and political education, discusses the key points of creating the intemet interactive mode, and puts forward the creative decision on ideological and political education based on the internet interactive mode, in hopes of providing helps to the follow-up study.
基金supported by the National Natural Science Foundation of China(52122308,21905253,51973200,and 52103239)Natural Science Foundation of Henan Province(202300410372)Henan Postdoctoral Foundation。
文摘Red-emissive carbon dots(R-CDs)have been widely studied because of their potential application in tissue imaging and optoelectronic devices.At present,most R-CDs are synthesized by using aromatic precursors,but the synthesis of R-CDs from non-aromatic precursors is challenging,and the emission mechanism remains unclear.Herein,different R-CDs were rationally synthesized using citric acid(CA),a prototype non-aromatic precursor,with the assistance of ammonia.Their structural evolution and optical mechanism were investigated.The addition of NH_(3)·H_(2)O played a key role in the synthesis of CA-based R-CDs,which shifted the emission wavelength of CA-based CDs from 423 to 667 nm.Mass spectrometry(MS)analysis indicated that the amino groups served as N dopants and promoted the formation of localized conjugated domains through an intermolecular amide ring,thereby inducing a significant emission redshift.The red-emissive mechanism of CDs was further confirmed by control experiments using other CA-like molecules(e.g.,aconitic acid,tartaric acid,aspartic acid,malic acid,and maleic acid)as precursors.MS,nuclear magnetic resonance characterization,and computational modeling revealed that the main carbon chain length of CA-like precursors tailored the cyclization mode,leading to hexatomic,pentatomic,unstable three/four-membered ring systems or cyclization failure.Among these systems,the hexatomic ring led to the largest emission redshift(244 nm,known for CA-based CDs).This work determined the origin of red emission in CA-based CDs,which would guide research on the controlled synthesis of R-CDs from other non-aromatic precursors.
