Stretchable color-changing fibers are urgently demanded for smart textiles/clothing due to their perfect implantability,permeability of vapor and heat,and flexibility/stretchability.Herein,stretchable electrothermochr...Stretchable color-changing fibers are urgently demanded for smart textiles/clothing due to their perfect implantability,permeability of vapor and heat,and flexibility/stretchability.Herein,stretchable electrothermochromic fibers were fabricated with unconventional stretchable conductive fibers as core layers and thermochromic coatings as shell layers.In the stretchable conductive fibers,hierarchical porous structures with percolative one-dimensional(1 D)conductive networks were constructed through phase inversion of carbon nanotube/polyurethane(CNT/PU)solutions.With the deposition of silver nanoparticles(AgN Ps)on the surface of micro-pores,electrically conductive dual-pathways consisting of0 D AgN Ps and 1 D CNTs were formed to significantly enhance the electric conductivity and thus improve the electrothermal performance of the fibers.More importantly,because of the connective CNTs and AgN Ps,such dual-pathways ensured the electron transport under the stretching state,preventing the sharp decay of conductivity and electrothermal performance.Through the continuous wet-spinning method,the stretchable conductive fibers can be easily obtained with the length up to several meters.At last,stretchable electrothermochromic fibers were prepared with two color-changing modes and implanted into textile perfectly,advancing their applications in wearable display and military adaptive camouflage of smart clothing.展开更多
Nitrate(NO_(3)^(−))has been the dominant ion of secondary inorganic aerosols(SIAs)in PM_(2.5) in North China.Tracking the formation mechanisms and sources of particulate nitrate are vital to mitigate air pollution.In ...Nitrate(NO_(3)^(−))has been the dominant ion of secondary inorganic aerosols(SIAs)in PM_(2.5) in North China.Tracking the formation mechanisms and sources of particulate nitrate are vital to mitigate air pollution.In this study,PM_(2.5) samples in winter(January 2020)and in summer(June 2020)were collected in Jiaozuo,China,andwater-soluble ions and(δ_(15)N,δ_(18)O)-NO_(3)^(−)were analyzed.The results showed that the increase of NO_(3)^(−)concentrations was the most remarkable with increasing PM_(2.5) pollution level.δ_(18)O-NO_(3)^(−)values for winter samples(82.7‰ to 103.9‰)were close to calculated δ_(18)O-HNO_(3)(103‰±0.8‰)values by N_(2)O_(5) pathway,while δ_(18)O-NO_(3)^(−)values(67.8‰ to 85.7‰)for summer samples were close to calculated δ_(18)O-HNO_(3) values(61‰±0.8‰)by OH oxidation pathway,suggesting that PM_(2.5) nitrate is largely from N_(2)O_(5) pathway inwinter,while is largely from OH pathway in summer.Averaged fractional contributions of P_(N2O5+H2O) were 70% and 39% in winter and summer sampling periods,respectively,those of POH were 30% and 61%,respectively.Higher δ_(15)N-NO_(3)−values for winter samples(3.0‰to 14.4‰)than those for summer samples(-3.7‰to 8.6‰)might be due to more contributions from coal combustion in winter.Coal combustion(31%±9%,25%±9%in winter and summer,respectively)and biomass burning(30%±12%,36%±12%in winter and summer,respectively)were the main sources using Bayesian mixing model.These results provided clear evidence of particulate nitrate formation and sources under different PM_(2.5) levels,and aided in reducing atmospheric nitrate in urban environments.展开更多
This study delves into the current state and challenges of vocational education through a comparative study of cross-national vocational education and an analysis of the Zhaixing Academy case.The research reveals that...This study delves into the current state and challenges of vocational education through a comparative study of cross-national vocational education and an analysis of the Zhaixing Academy case.The research reveals that vocational education reform can draw on the experiences of the German dual system,American community colleges,and Chinese vocational education reforms,with a focus on informal education pathways,practice-oriented teaching,and flexible training methods.The Zhaixing Academy case demonstrates the application of practice-oriented teaching approaches in the field of vocational education,emphasizing individual student development needs and the advantages of education outside formal institutions,offering new insights and references for the current Chinese education system.The study proposes that governments and education departments should increase investment in vocational education,encourage collaboration between enterprises and vocational education institutions,and support innovative practice-oriented education.In the future,Zhaixing Academy can continue to focus on education reform,expand the realm of practice-oriented education,promote its educational philosophy and methods,and contribute to the diversification and sustainable development of education.展开更多
Hydrogen peroxide(H_(2)O_(2))is a chemical that is widely of interest in both environmental and energy fields.On the one hand,as a clean oxidant,H_(2)O_(2)has been commonly used in the field of bleaching,disinfection,...Hydrogen peroxide(H_(2)O_(2))is a chemical that is widely of interest in both environmental and energy fields.On the one hand,as a clean oxidant,H_(2)O_(2)has been commonly used in the field of bleaching,disinfection,and advanced oxidation processes.On the other hand,H_(2)O_(2)has also been explored as a liquid fuel alternative to H_(2)or fossil fuels in fuel cells due to its high energy density.However,the current industrial production of H_(2)O_(2)relies on the anthraquinone(AO)method that involves palladium-catalyzed hydrogenation-oxidation steps.展开更多
基金supported by the National Natural Science Foundation of China(51672043)Donghua University Distinguished Young Professor Program(LZB2019002)+1 种基金Young Elite Scientists Sponsorship Program by China Association for Science and Technology(2017QNRC001)the Fundamental Research Funds for the Central Universities(CUSF-DH-D-2018006)。
文摘Stretchable color-changing fibers are urgently demanded for smart textiles/clothing due to their perfect implantability,permeability of vapor and heat,and flexibility/stretchability.Herein,stretchable electrothermochromic fibers were fabricated with unconventional stretchable conductive fibers as core layers and thermochromic coatings as shell layers.In the stretchable conductive fibers,hierarchical porous structures with percolative one-dimensional(1 D)conductive networks were constructed through phase inversion of carbon nanotube/polyurethane(CNT/PU)solutions.With the deposition of silver nanoparticles(AgN Ps)on the surface of micro-pores,electrically conductive dual-pathways consisting of0 D AgN Ps and 1 D CNTs were formed to significantly enhance the electric conductivity and thus improve the electrothermal performance of the fibers.More importantly,because of the connective CNTs and AgN Ps,such dual-pathways ensured the electron transport under the stretching state,preventing the sharp decay of conductivity and electrothermal performance.Through the continuous wet-spinning method,the stretchable conductive fibers can be easily obtained with the length up to several meters.At last,stretchable electrothermochromic fibers were prepared with two color-changing modes and implanted into textile perfectly,advancing their applications in wearable display and military adaptive camouflage of smart clothing.
基金supported by the National Natural Science Foundation of China (Nos. 41401029, U1704241)the Key Project of Research of Henan province in China (No. 19A170006)the Program for technical innovation on air pollution (H21-169)。
文摘Nitrate(NO_(3)^(−))has been the dominant ion of secondary inorganic aerosols(SIAs)in PM_(2.5) in North China.Tracking the formation mechanisms and sources of particulate nitrate are vital to mitigate air pollution.In this study,PM_(2.5) samples in winter(January 2020)and in summer(June 2020)were collected in Jiaozuo,China,andwater-soluble ions and(δ_(15)N,δ_(18)O)-NO_(3)^(−)were analyzed.The results showed that the increase of NO_(3)^(−)concentrations was the most remarkable with increasing PM_(2.5) pollution level.δ_(18)O-NO_(3)^(−)values for winter samples(82.7‰ to 103.9‰)were close to calculated δ_(18)O-HNO_(3)(103‰±0.8‰)values by N_(2)O_(5) pathway,while δ_(18)O-NO_(3)^(−)values(67.8‰ to 85.7‰)for summer samples were close to calculated δ_(18)O-HNO_(3) values(61‰±0.8‰)by OH oxidation pathway,suggesting that PM_(2.5) nitrate is largely from N_(2)O_(5) pathway inwinter,while is largely from OH pathway in summer.Averaged fractional contributions of P_(N2O5+H2O) were 70% and 39% in winter and summer sampling periods,respectively,those of POH were 30% and 61%,respectively.Higher δ_(15)N-NO_(3)−values for winter samples(3.0‰to 14.4‰)than those for summer samples(-3.7‰to 8.6‰)might be due to more contributions from coal combustion in winter.Coal combustion(31%±9%,25%±9%in winter and summer,respectively)and biomass burning(30%±12%,36%±12%in winter and summer,respectively)were the main sources using Bayesian mixing model.These results provided clear evidence of particulate nitrate formation and sources under different PM_(2.5) levels,and aided in reducing atmospheric nitrate in urban environments.
文摘This study delves into the current state and challenges of vocational education through a comparative study of cross-national vocational education and an analysis of the Zhaixing Academy case.The research reveals that vocational education reform can draw on the experiences of the German dual system,American community colleges,and Chinese vocational education reforms,with a focus on informal education pathways,practice-oriented teaching,and flexible training methods.The Zhaixing Academy case demonstrates the application of practice-oriented teaching approaches in the field of vocational education,emphasizing individual student development needs and the advantages of education outside formal institutions,offering new insights and references for the current Chinese education system.The study proposes that governments and education departments should increase investment in vocational education,encourage collaboration between enterprises and vocational education institutions,and support innovative practice-oriented education.In the future,Zhaixing Academy can continue to focus on education reform,expand the realm of practice-oriented education,promote its educational philosophy and methods,and contribute to the diversification and sustainable development of education.
文摘Hydrogen peroxide(H_(2)O_(2))is a chemical that is widely of interest in both environmental and energy fields.On the one hand,as a clean oxidant,H_(2)O_(2)has been commonly used in the field of bleaching,disinfection,and advanced oxidation processes.On the other hand,H_(2)O_(2)has also been explored as a liquid fuel alternative to H_(2)or fossil fuels in fuel cells due to its high energy density.However,the current industrial production of H_(2)O_(2)relies on the anthraquinone(AO)method that involves palladium-catalyzed hydrogenation-oxidation steps.
