Aerosol observational data for 2012 obtained from Dunhuang Station of CARE-China（Campaign on Atmospheric Aerosol Research Network of China） were analyzed to achieve in-depth knowledge of aerosol optical properties o...Aerosol observational data for 2012 obtained from Dunhuang Station of CARE-China（Campaign on Atmospheric Aerosol Research Network of China） were analyzed to achieve in-depth knowledge of aerosol optical properties over Dunhuang region. The results showed that the annual average aerosol optical depth（AOD） at 500 nm was 0.32 ± 0.06, and the ？ngstr？m exponent（α） was 0.73 ± 0.27. Aerosol optical properties revealed significant seasonal characteristics. Frequent sandstorms in MAM（March–April–May） resulted in the seasonal maximum AOD, 0.41 ± 0.04, and a relatively smaller αvalue, 0.44 ± 0.04. The tourism seasons, JJA（June–July–August） and SON（September–October–November） coincide with serious emissions of small anthropogenic aerosols. While in DJF（December–January–February）, the composition of the atmosphere was a mixture of dust particles and polluted aerosols released by domestic heating; the average AOD and αwere 0.29 ± 0.02 and 0.66 ± 0.17, respectively. Different air masses exhibited different degrees of influence on the aerosol concentration over Dunhuang in different seasons. During MAM, ranges of AOD（0.11–1.18） and α（0.06–0.82） were the largest under the dust influence of northwest-short-distance air mass in the four trajectories. Urban aerosols transported by northwest-short-distance air mass accounted for a very large proportion in JJA and the mixed aerosols observed in SON were mainly conveyed by air masses from the west. In DJF, the similar ranges of AOD and α under the three air mass demonstrated the analogous diffusion effects on regional pollutants over Dunhuang.展开更多
Industrial pollution has a significant effect on aerosol properties in Changsha City,a typical city of central China.Therefore,year-round measurements of aerosol optical,radiative and chemical properties from 2012 to ...Industrial pollution has a significant effect on aerosol properties in Changsha City,a typical city of central China.Therefore,year-round measurements of aerosol optical,radiative and chemical properties from 2012 to 2014 at an urban site in Changsha were analyzed.During the observation period,the energy structure was continuously optimized,which was characterized by the reduction of coal combustion.The aerosol properties have obvious seasonal variations.The seasonal average aerosol optical depth(AOD)at 500 nm ranged from 0.49 to 1.00,single scattering albedo(SSA)ranged from 0.93 to 0.97,and aerosol radiative forcing at the top of the atmosphere(TOA)ranged from−24.0 to 3.8 W m^−2.The chemical components also showed seasonal variations.Meanwhile,the scattering aerosol,such as organic carbon,SO42−,NO3−,and NH4+showed a decrease,and elemental carbon increased.Compared with observation in winter 2012,AOD and TOA decreased by 0.14 and−1.49 W m^−2 in winter 2014.The scattering components,SO42−,NO3−and NH4+,decreased by 12.8μg m^−3(56.8%),9.2μg m^−3(48.8%)and 6.4μg m^−3(45.2%),respectively.The atmospheric visibility and pollution diffusion conditions improved.The extinction and radiative forcing of aerosol were significantly controlled by the scattering aerosol.The results indicate that Changsha is an industrial city with strong scattering aerosol.The energy structure optimization had a marked effect on controlling pollution,especially in winter(strong scattering aerosol).展开更多
Flavonoids are secondary metabolites in plants and possess extensive pharmacological activities.Flavonoids have remarkable effect in prevent anti-tumor and cancer,but flavonoids can't be synthesized directly in th...Flavonoids are secondary metabolites in plants and possess extensive pharmacological activities.Flavonoids have remarkable effect in prevent anti-tumor and cancer,but flavonoids can't be synthesized directly in the body.According to the different properties and structures of flavonoids in Traditional Chinese medicines,different extraction methods should be selected.Besides,flavonoids have good anti-aging effects.Based on three theories of modern aging,the anti-aging effect of flavonoids was discussed.It is expected to provide a beneficial reference for further development and utilization of natural flavonoid resources.展开更多
The three-dimensional porous network polytetrafluoroethylene （PTFE） thin films were achieved by a vacuum technique through evaporating the pure PTFE powders. The surfaces of PTFE thin films showed various morphologi...The three-dimensional porous network polytetrafluoroethylene （PTFE） thin films were achieved by a vacuum technique through evaporating the pure PTFE powders. The surfaces of PTFE thin films showed various morphologies by adjusting the evaporation temperature and the corresponding contact angle ranging from 133° to 155°. Further analyses of surface chemical composition and morphology by FTIR and FE-SEM revealed that the origin of hydrophobicity for the PTFE thin films could be ascribed to the fluorine-containing groups and the surface morphologies, indicating that abundant -CF2 groups and network structures with appropriate pore sizes played a vital role in superhydrophobicity. By characterization of UV-Vis, the films also showed high transmittance and antireflection effect. The films prepared by this simple method have potential applications such as waterproof membrane and self-cleaning coating.展开更多
Palladium(Pd)plays a significant role in substantial catalytic reactions.On account of the strong affinity for hydrogen,various Pd-based nanostructures with different shapes and sizes have been extensively utilized in...Palladium(Pd)plays a significant role in substantial catalytic reactions.On account of the strong affinity for hydrogen,various Pd-based nanostructures with different shapes and sizes have been extensively utilized in hydrogenation reactions.In particular,Pd reveals extraordinary properties while interacting with hydrogen,including strong adsorption,barrier-less dissociation,and large storage of hydrogen under ambient temperatures and pressures.展开更多
The rapid development of medical micromotors draws a beautiful blueprint for the noninvasive or minimally invasive diagnosis and therapy.By combining stimuli-sensitive hydrogel materials,micromotors are bestowed with ...The rapid development of medical micromotors draws a beautiful blueprint for the noninvasive or minimally invasive diagnosis and therapy.By combining stimuli-sensitive hydrogel materials,micromotors are bestowed with new characteristics such as stimuli-responsive shape transformation/morphing.excellent biocompatibility and biodegradability,and drug loading ability.Actuated by chemical fuels or external fields(eg,magnetic field,ultrasound,light,and electric field),hydrogel-based stimuli-responsive(HBSR)micromotors can be utilized to load therapeutic agents into the hydrogel networks or directly grip the target cargos(eg.,drug-loaded partides,cells,and thrombus),transport them to sites of interest(e.g.,tumor area and diseased tissues),and unload the cargos or execute a specific task(e.g.,cell capture,targeted sampling,and removal of blood dots)in response to a stimulus(eg.,change of temperature,pH,ion strength,and chemicals)in the physiological environment.The high flexibility,adaptive capacity,and shape morphing property enable the H BSR micromotors to complete specific medical tasks in complex physiological scenarios,especially in confined,hard to-reach tissues,and vessels of the body.Herein,this review summarizes the current progress in hydrogel-based medical micromotors with stimuli responsiveness.The thermo-responsive,photothermal-responsive,magnetocaloric-responsive,pH-responsive,ionic strength-responsive,and chemoresponsive micromotors are discussed in detail.Finally,curent challenges and future perspectives for the development of HBSR micromotors in the biomedical field are discussed.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.41375036 and 41222033)the National Basic Research Program of China(Grant No.2016YFC0202001,973 Program 2014CB441200)the CAS Strategic Priority Research Program(Grant No.XDB05020103).
文摘Aerosol observational data for 2012 obtained from Dunhuang Station of CARE-China（Campaign on Atmospheric Aerosol Research Network of China） were analyzed to achieve in-depth knowledge of aerosol optical properties over Dunhuang region. The results showed that the annual average aerosol optical depth（AOD） at 500 nm was 0.32 ± 0.06, and the ？ngstr？m exponent（α） was 0.73 ± 0.27. Aerosol optical properties revealed significant seasonal characteristics. Frequent sandstorms in MAM（March–April–May） resulted in the seasonal maximum AOD, 0.41 ± 0.04, and a relatively smaller αvalue, 0.44 ± 0.04. The tourism seasons, JJA（June–July–August） and SON（September–October–November） coincide with serious emissions of small anthropogenic aerosols. While in DJF（December–January–February）, the composition of the atmosphere was a mixture of dust particles and polluted aerosols released by domestic heating; the average AOD and αwere 0.29 ± 0.02 and 0.66 ± 0.17, respectively. Different air masses exhibited different degrees of influence on the aerosol concentration over Dunhuang in different seasons. During MAM, ranges of AOD（0.11–1.18） and α（0.06–0.82） were the largest under the dust influence of northwest-short-distance air mass in the four trajectories. Urban aerosols transported by northwest-short-distance air mass accounted for a very large proportion in JJA and the mixed aerosols observed in SON were mainly conveyed by air masses from the west. In DJF, the similar ranges of AOD and α under the three air mass demonstrated the analogous diffusion effects on regional pollutants over Dunhuang.
基金This study was supported by the National Key Research and Development Program of China(Grant No.2016YFC0202001)the Chinese Academy of Sciences Strategic Priority Research Program(Grant No.XDA23020301)the National Natural Science Foundation of China(Grant Nos.42061130215 and 41605119).
文摘Industrial pollution has a significant effect on aerosol properties in Changsha City,a typical city of central China.Therefore,year-round measurements of aerosol optical,radiative and chemical properties from 2012 to 2014 at an urban site in Changsha were analyzed.During the observation period,the energy structure was continuously optimized,which was characterized by the reduction of coal combustion.The aerosol properties have obvious seasonal variations.The seasonal average aerosol optical depth(AOD)at 500 nm ranged from 0.49 to 1.00,single scattering albedo(SSA)ranged from 0.93 to 0.97,and aerosol radiative forcing at the top of the atmosphere(TOA)ranged from−24.0 to 3.8 W m^−2.The chemical components also showed seasonal variations.Meanwhile,the scattering aerosol,such as organic carbon,SO42−,NO3−,and NH4+showed a decrease,and elemental carbon increased.Compared with observation in winter 2012,AOD and TOA decreased by 0.14 and−1.49 W m^−2 in winter 2014.The scattering components,SO42−,NO3−and NH4+,decreased by 12.8μg m^−3(56.8%),9.2μg m^−3(48.8%)and 6.4μg m^−3(45.2%),respectively.The atmospheric visibility and pollution diffusion conditions improved.The extinction and radiative forcing of aerosol were significantly controlled by the scattering aerosol.The results indicate that Changsha is an industrial city with strong scattering aerosol.The energy structure optimization had a marked effect on controlling pollution,especially in winter(strong scattering aerosol).
基金the Innovation and Entrepreneurship Training Program for College Students of Xiamen Medical College(202112631045).
文摘Flavonoids are secondary metabolites in plants and possess extensive pharmacological activities.Flavonoids have remarkable effect in prevent anti-tumor and cancer,but flavonoids can't be synthesized directly in the body.According to the different properties and structures of flavonoids in Traditional Chinese medicines,different extraction methods should be selected.Besides,flavonoids have good anti-aging effects.Based on three theories of modern aging,the anti-aging effect of flavonoids was discussed.It is expected to provide a beneficial reference for further development and utilization of natural flavonoid resources.
基金This study was financially supported by the high-tech project of MOST （Grant No. 2014AA032802） and the national sci-tech support plan of the National Natural Science Foundation of China （NSFC Grant Nos. 51272273 and 51272271）.
文摘The three-dimensional porous network polytetrafluoroethylene （PTFE） thin films were achieved by a vacuum technique through evaporating the pure PTFE powders. The surfaces of PTFE thin films showed various morphologies by adjusting the evaporation temperature and the corresponding contact angle ranging from 133° to 155°. Further analyses of surface chemical composition and morphology by FTIR and FE-SEM revealed that the origin of hydrophobicity for the PTFE thin films could be ascribed to the fluorine-containing groups and the surface morphologies, indicating that abundant -CF2 groups and network structures with appropriate pore sizes played a vital role in superhydrophobicity. By characterization of UV-Vis, the films also showed high transmittance and antireflection effect. The films prepared by this simple method have potential applications such as waterproof membrane and self-cleaning coating.
基金supported by the National Key Projects for Fundamental Research and Development of China(2018YFB1502002)the National Natural Science Foundation of China(51825205,52120105002,22088102,and 21902168)the Youth Innovation Promotion Association of the CAS.
文摘Palladium(Pd)plays a significant role in substantial catalytic reactions.On account of the strong affinity for hydrogen,various Pd-based nanostructures with different shapes and sizes have been extensively utilized in hydrogenation reactions.In particular,Pd reveals extraordinary properties while interacting with hydrogen,including strong adsorption,barrier-less dissociation,and large storage of hydrogen under ambient temperatures and pressures.
基金support from the National Key R&D Program of China(2020YFC2007300)the National Natural Science Foundation of China(U20A20388)+2 种基金support from the Beijing Institute of Technology Research Fund Program for Young Scholars(XSQD-202123003)support from the Natu-ral Science Foundation of Jiangsu Province of China(BK20190809)support from the Beijing Institute of Technology Teli Young Fellow Program(33012222218).
文摘The rapid development of medical micromotors draws a beautiful blueprint for the noninvasive or minimally invasive diagnosis and therapy.By combining stimuli-sensitive hydrogel materials,micromotors are bestowed with new characteristics such as stimuli-responsive shape transformation/morphing.excellent biocompatibility and biodegradability,and drug loading ability.Actuated by chemical fuels or external fields(eg,magnetic field,ultrasound,light,and electric field),hydrogel-based stimuli-responsive(HBSR)micromotors can be utilized to load therapeutic agents into the hydrogel networks or directly grip the target cargos(eg.,drug-loaded partides,cells,and thrombus),transport them to sites of interest(e.g.,tumor area and diseased tissues),and unload the cargos or execute a specific task(e.g.,cell capture,targeted sampling,and removal of blood dots)in response to a stimulus(eg.,change of temperature,pH,ion strength,and chemicals)in the physiological environment.The high flexibility,adaptive capacity,and shape morphing property enable the H BSR micromotors to complete specific medical tasks in complex physiological scenarios,especially in confined,hard to-reach tissues,and vessels of the body.Herein,this review summarizes the current progress in hydrogel-based medical micromotors with stimuli responsiveness.The thermo-responsive,photothermal-responsive,magnetocaloric-responsive,pH-responsive,ionic strength-responsive,and chemoresponsive micromotors are discussed in detail.Finally,curent challenges and future perspectives for the development of HBSR micromotors in the biomedical field are discussed.
