Based on the characters of plant potentials, it introduced the construction and technology in developing the measuring system of plant electrical potentials, the input impedance of the amplifier must be enough high(= ...Based on the characters of plant potentials, it introduced the construction and technology in developing the measuring system of plant electrical potentials, the input impedance of the amplifier must be enough high(= 1010~ 1012Ω) in order to measuring the plant weak signals and ensuring high common mode rejection ratio (CMRR). And wavelet transform was applied in denoising based on cross-validation (CV)threshold value. the experiment showed that this system could effectively detect the change of plant potentials,four-week old cucumber was stimulated by heat wounding, the variation potential (VP) and action potential(AP) would be evoked, the AP's varying amplitude can reach 40mV; the AP changed very fast, its duration time is about 0.01~0.02s and its amplitude often change from 15μV~5mV.展开更多
The purpose of this study is to explore the associations among dry eye disease(DED),air pollution,and meteorological conditions in the cold region of a northeastern Chinese metropolis(i.e.,Changchun).Data on ambient a...The purpose of this study is to explore the associations among dry eye disease(DED),air pollution,and meteorological conditions in the cold region of a northeastern Chinese metropolis(i.e.,Changchun).Data on ambient air pollutants and meteorological parameters as well as diagnosed DED outpatients during 2015–2021 were collected.The associations between DED and environmental factors were analysed at multiple time scales using various statistical methods(i.e.,correlation,regression and machine learning).Among the 10,809 DED patients(21,617 eyes)studied,64.60%were female and 35.40%were male.A higher frequency of DED was observed in March and April,followed by January,August and October.Individual and multiple factor models showed the positive importance of particles with aerodynamic diameters<10μm(PM10),carbon monoxide(CO),and ozone(O_(3))among normal air pollutants and air pressure(AP),air temperature(AT)and wind speed(WS)among normal meteorological parameters.Air pollutants(PM10,nitrogen dioxide:NO_(2))and meteorological parameters(AT,AP)have combined impacts on DED occurrence.For the first time,we further explored the associations of detailed components of atmospheric particles and DED,suggesting potential emission sources,including spring dust from bare soil and roads and precursor pollutants of summer O_(3)formation from vehicles and industry in Northeast China.Our results revealed the quantitative associations among air pollutants,meteorological conditions and DED outpatients in cold regions,highlighting the importance of coordinated policies in air pollution control and climate change mitigation.展开更多
Superhydrophobic surfaces are often found in nature, such as plant leaves and insect wings. Inspired by superhydrophobic phenomenon of the rose petals and the lotus leaves, biomimetic hydrophnbic surfaces with high or...Superhydrophobic surfaces are often found in nature, such as plant leaves and insect wings. Inspired by superhydrophobic phenomenon of the rose petals and the lotus leaves, biomimetic hydrophnbic surfaces with high or low adhesion were prepared with a facile drop-coating approach in this paper. Poly(vinyl alcohol) (PVA) was used as adhesive and SiO2 nanoparticles were used to fabricate surface micro-structure. Stearic acid or dodecafluoroheptyl-propyl-trimethoxysilane (DFTMS) were used as low surface energy materials to modify the prepared PVA/SiO2 coating surfaces. The effects of size of SiO2 nanoparticles, concentration of SiO2 nanoparticle suspensions and the modifications on the wettability of the surface were investigated. The morphology of the PVA/SiO2 coating surfaces was observed by using scanning electron microscope. Water contact angle of the obtained superhydrophilic surface could reach to 3°. Stearic acid modified PVA/SiO2 coating surfaces showed hydrophobicity with high adhesion. By mixing the SiO2 nanoparticles with sizes of 40 nm and 200 nm and modifying with DFTMS, water contact angle of the obtained coating surface could be up to 155° and slide angle was only 5°. This work provides a facile and useful method to control surface wettability through changing the roughness and chemical composition of a surface.展开更多
文摘Based on the characters of plant potentials, it introduced the construction and technology in developing the measuring system of plant electrical potentials, the input impedance of the amplifier must be enough high(= 1010~ 1012Ω) in order to measuring the plant weak signals and ensuring high common mode rejection ratio (CMRR). And wavelet transform was applied in denoising based on cross-validation (CV)threshold value. the experiment showed that this system could effectively detect the change of plant potentials,four-week old cucumber was stimulated by heat wounding, the variation potential (VP) and action potential(AP) would be evoked, the AP's varying amplitude can reach 40mV; the AP changed very fast, its duration time is about 0.01~0.02s and its amplitude often change from 15μV~5mV.
基金supported by the Funds from the Key Research Program of Frontier Sciences,Chinese Academy of Sciences(QYZDB-SSW-DQC045)the Ecology and Environment Department of Jilin Province(2022-07,2023-11)+3 种基金the Northeast Institute of Geography and Agroecology,Chinese Academy of Sciences(ZWJSS-07)Technology Development Plan of Jilin Province(20210101279JC)National Natural Science Foundation of China(82171023)Bethune Center for Medical Engineering and Instrumentation(BQEGCZX20210XX).
文摘The purpose of this study is to explore the associations among dry eye disease(DED),air pollution,and meteorological conditions in the cold region of a northeastern Chinese metropolis(i.e.,Changchun).Data on ambient air pollutants and meteorological parameters as well as diagnosed DED outpatients during 2015–2021 were collected.The associations between DED and environmental factors were analysed at multiple time scales using various statistical methods(i.e.,correlation,regression and machine learning).Among the 10,809 DED patients(21,617 eyes)studied,64.60%were female and 35.40%were male.A higher frequency of DED was observed in March and April,followed by January,August and October.Individual and multiple factor models showed the positive importance of particles with aerodynamic diameters<10μm(PM10),carbon monoxide(CO),and ozone(O_(3))among normal air pollutants and air pressure(AP),air temperature(AT)and wind speed(WS)among normal meteorological parameters.Air pollutants(PM10,nitrogen dioxide:NO_(2))and meteorological parameters(AT,AP)have combined impacts on DED occurrence.For the first time,we further explored the associations of detailed components of atmospheric particles and DED,suggesting potential emission sources,including spring dust from bare soil and roads and precursor pollutants of summer O_(3)formation from vehicles and industry in Northeast China.Our results revealed the quantitative associations among air pollutants,meteorological conditions and DED outpatients in cold regions,highlighting the importance of coordinated policies in air pollution control and climate change mitigation.
基金This work is supported by the National Natural Science Foundation of China (51273083 and 51405188) and China Postdoctoral Science Foundation (2015T80307).
文摘Superhydrophobic surfaces are often found in nature, such as plant leaves and insect wings. Inspired by superhydrophobic phenomenon of the rose petals and the lotus leaves, biomimetic hydrophnbic surfaces with high or low adhesion were prepared with a facile drop-coating approach in this paper. Poly(vinyl alcohol) (PVA) was used as adhesive and SiO2 nanoparticles were used to fabricate surface micro-structure. Stearic acid or dodecafluoroheptyl-propyl-trimethoxysilane (DFTMS) were used as low surface energy materials to modify the prepared PVA/SiO2 coating surfaces. The effects of size of SiO2 nanoparticles, concentration of SiO2 nanoparticle suspensions and the modifications on the wettability of the surface were investigated. The morphology of the PVA/SiO2 coating surfaces was observed by using scanning electron microscope. Water contact angle of the obtained superhydrophilic surface could reach to 3°. Stearic acid modified PVA/SiO2 coating surfaces showed hydrophobicity with high adhesion. By mixing the SiO2 nanoparticles with sizes of 40 nm and 200 nm and modifying with DFTMS, water contact angle of the obtained coating surface could be up to 155° and slide angle was only 5°. This work provides a facile and useful method to control surface wettability through changing the roughness and chemical composition of a surface.