1.Introduction,The interconnection among food-energy-water(FEW)systems in meeting societal demands is broadly acknowledged[1].Similarly,competitive or synergistic allocations of water and energy resources for agricult...1.Introduction,The interconnection among food-energy-water(FEW)systems in meeting societal demands is broadly acknowledged[1].Similarly,competitive or synergistic allocations of water and energy resources for agricultural production,manufacturing,and human consumption are understood,and their economic impacts can be predicted[2].Far less appreciated and understood are the outcomes of the FEW nexus in response to operation changes in agricultural practices and the associated technological innovations for future generations[3,4].Also,the inter-scale and feedback effects of emerging technology-driven resource reallocation and decision-making on FEW systems are largely unknown.For example,how do the agroeconomic feedbacks of intelligent technologies influence the FEW nexus of agricultural production under environmental and demographic changes?How does the necessary water allocation for powering non-powered dams and pumped-storage hydropower generation influence agricultural production and municipal water supply maintenance?How do solar and wind energy farms influence land use for agriculture and the rural economy?展开更多
Background:Meeting 24-h movement guidelines by children and adolescents has been associated with improved indicators of health,although it has been under-studied in China.Hence,this study aimed to investigate the prev...Background:Meeting 24-h movement guidelines by children and adolescents has been associated with improved indicators of health,although it has been under-studied in China.Hence,this study aimed to investigate the prevalence of meeting the 24-h movement guidelines,its correlates,and its relationships with body mass index in children and adolescents in China.Methods:Cross-sectional data from the 2017 Youth Study in China of 114,072 children and adolescents(mean age=13.75 years,49.18%boys)were used.Meeting 24-h movement guidelines(60 min of daily moderate-to-vigorous physical activity,2 h of daily leisure screen time,911 h and 810 h nightly sleep duration for 613-year-olds and 1417-year-olds,respectively)and height and weight of all participants were assessed.The prevalence of meeting the 24-h movement guidelines and World Health Organization weight status categories were determined.Generalized linear models were used to determine the correlates of meeting the 24-h movement guidelines and the relationships of meeting the 24-h movement guidelines with overweight(OW)and obesity(OB).Results:Only 5.12%of Chinese children and adolescents met the 24-h movement guidelines,and 22.44%were classified as OW/OB.Older children and adolescents were less likely to meet the 24-h movement guidelines.Parental education level and family income were positively related to meeting the 24-h movement guidelines.Children and adolescents meeting the 24-h movement guidelines showed lower odds ratios for OW/OB.Compared with participants meeting the 24-h movement guidelines,boys in 4th6th grades met none of the recommendations(OR=1.22,95%CI:1.061.40),met the screen time recommendation only(OR=1.13,95%CI:1.011.28),met the nightly sleep duration recommendation only(OR=1.14,95%CI:1.031.28),and had significantly higher odds ratios for OW/OB.Similar trends were observed for girls in 4th6th grades:meeting none of the guidelines(OR=1.35,95%CI:1.141.59),meeting sleep duration guidelines only(OR=1.23,95%CI:1.081.39),and meeting moderate-to-vigorous physical activity+nightly sleep duration guidelines(OR=1.24,95%CI:1.011.54).For girls in 7th9th grades,the following trend was observed:meeting none of the guidelines(OR=1.30,95%CI:1.011.67).Conclusion:Very few Chinese children and adolescents met the 24-h movement guidelines.Age(negatively correlated),parental education level,and family income(both positively correlated)were correlates of meeting the 24-h movement guidelines.Children and adolescents meeting the 24-h movement guidelines were more likely to have lower risks for OW/OB,especially in the youngest age group(Grades 46);and girls in the middle age group(Grades 79)were also more likely to have lower risks for OW/OB.Further research studies should explore additional correlates and determinants for meeting the 24-h movement guidelines.Also,future studies should use longitudinal or interventional designs to determine the relationships between meeting the 24-h movement guidelines and OW/OB and other health indicators,while taking sex and age differences into account.展开更多
Purpose: This study was to present the 2016 prevalence estimates of Chinese school-aged children meeting physical fitness standards and to examine differences by sex and residence locales in children who did not meet ...Purpose: This study was to present the 2016 prevalence estimates of Chinese school-aged children meeting physical fitness standards and to examine differences by sex and residence locales in children who did not meet fitness standards.Methods: We conducted cross-sectional analyses of 171,991 children and adolescents(boy: 50.0%, Grades 1–12) who participated in the 2016 Physical Activity and Fitness in China—The Youth Study. The main outcomes were fitness measures, assessed by the 2014 revised Chinese National Student Physical Fitness Standard(CNSPFS), covering areas of aerobic capacity, upper body strength, flexibility, body mass index,abdominal strength, and trunk strength. Children's overall physical fitness performance was categorized, per CNSPFS standards, as excellent,good, pass, or no pass. Data on the prevalence of physical fitness categories and not meeting fitness standards(i.e., among children who received a "no pass" mark) were analyzed, through logistic regression, by sex(boy, girl) and residence locales(urban, rural) across 3 school grades(primary,junior middle, and junior high).Results: In 2016, 5.95% of Chinese children and adolescents achieved an "excellent" mark, 25.80% received a "good" rating, 59.90% received a "pass", and 8.35% received a "no pass". Overall, boys were more likely to not pass the fitness standards compared with girls(adjusted odds ratio(a OR) = 1.710; 95% confidence interval(CI): 1.708–1.712) and children living in urban areas were more likely to not pass the standards than those living in rural areas(a OR = 1.298; 95%CI: 1.296–1.299). Consistent patterns of not meeting fitness standards were also found by sex and residence locales across all 3 school grades.Conclusion: In the Chinese school-aged population, about 3 in 10 children achieved an "excellent" or "good" fitness standard in 2016, and about8% of this population did not meet CNSPFS standards. Children living in urban areas were more likely to not meet minimum fitness performance levels, and boys in school were more likely to not meet minimum fitness performance levels than girls.展开更多
The stimulatory effects of atmospheric pressure cold plasma(APCP)on plant growth have attracted much attention due to its great potential as a new approach to increase crop growth and production.However,the transcript...The stimulatory effects of atmospheric pressure cold plasma(APCP)on plant growth have attracted much attention due to its great potential as a new approach to increase crop growth and production.However,the transcriptome changes of plants induced by APCP treatment are unknown.Herein,the comparative transcriptome analysis was performed to identify the transcriptional response of Arabidopsis thaliana seedlings to APCP.Results showed that APCP exhibited a dual effect(stimulation or inhibition)on Arabidopsis seedling growth dependent on the treatment time and the maximum stimulatory effects were achieved by 1 min APCP treatment.The metabolic analysis of amino acid,glutathione(GSH)and phytohormone demonstrated that 1 min APCP treatment decreased most amino acids concentrations in Arabidopsis seedling,while the accumulations of GSH,gibberellins and cytokinin were significantly increased.The RNA-Seq analysis showed that a total of218 differentially expressed genes(DEGs)were identified in 1 min APCP-treated seedlings versus the control,including 20 up-regulated and 198 down-regulated genes.The DEGs were enriched in pathways related to GSH metabolism,mitogen-activated protein kinase(MAPK)signaling transduction and plant resistance against pathogens.Moreover,most of the DEGs were defense,stimuli or stressresponsive genes and encoded proteins with oxidoreductase activity.Expression determination of six randomly selected DEGs by quantitative real-time PCR demonstrated similar pattern with the RNASeq data.These results indicated that the moderate APCP treatment may regulate the expression of stimuli/stress-responsive genes involved in GSH,phytohormone/amino metabolism and plant defense against pathogens via MAPK signal transduction pathway,accordingly enhance Arabidopsis seedling growth.This study provides a theoretical basis for the application of APCP in agriculture.展开更多
Urbanization,population growth,and the accelerating consumption of food,energy,and water(FEW)resources bring unprecedented challenges for economic,environmental,and social(EES)sustainability.It is imperative to unders...Urbanization,population growth,and the accelerating consumption of food,energy,and water(FEW)resources bring unprecedented challenges for economic,environmental,and social(EES)sustainability.It is imperative to understand the potential impacts of FEW systems on the realization of the United Nation’s Sustainable Development Goals(SDGs)as the world transitions from natural ecosystems to managed ecosystems at an accelerating rate.A major obstacle is the complexity and emergent behavior of FEW systems and associated networks,for which no single discipline can generate a holistic understanding or meaningful projections.We propose a research enterprise framework for promoting transdisciplinarity and top-down quantification of the interrelationships between FEW and EES systems.Relevant enterprise efforts would emphasize increasing FEW resource accessibility by improving coordinated interplays across sectors and scales,expanding and diversifying supply-chain networks,and innovating technologies for efficient resource utilization.This framework can guide the development of strategic solutions for diminishing the competition among FEW-consuming sectors in a region or country,and for minimizing existing inequalities in FEW availability when a sustainable development agenda is implemented.展开更多
Mung bean(Vigna radiata)sprouts are widely consumed worldwide due to their high nutritional value.However,the low yield and microbial contamination of mung bean sprouts seriously reduces their economic value.This stud...Mung bean(Vigna radiata)sprouts are widely consumed worldwide due to their high nutritional value.However,the low yield and microbial contamination of mung bean sprouts seriously reduces their economic value.This study investigates the effects of non-thermal plasma on the quality and microbial reduction of mung bean sprouts by pretreatment of seeds in water for different times(0,1,3 and 6 min).The quality results showed that short-time plasma treatment(1 and 3 min)promoted seed germination and seedling growth,whereas long-time plasma treatment(6 min)had inhibitory effects.Plasma also had a similar dose effects on the total flavonoid and phenolic contents of mung bean sprouts.The microbiological results showed that plasma treatment achieved a reduction of native microorganisms ranging from 0.54 to 7.09 log for fungi and 0.29 to 6.80 log for bacteria at 96 h incubation.Meanwhile,plasma treatment could also efficiently inactivate artificially inoculated Salmonella typhimurium(1.83–6.22 log)and yeast(0.53–3.19 log)on mung bean seeds.The results of seed coat permeability tests and scanning electron microscopy showed that plasma could damage the seed coat structure,consequently increasing the electrical conductivity of mung bean seeds.The physicochemical analysis of plasma-treated water showed that plasma generated various long-and short-lived active species[nitric oxide radicals(NO·),hydroxyl radicals(·OH),singlet oxygen(1O2),hydrogen peroxide(H_(2)O_(2)),nitrate(NO_(3)^(-)),and nitrite(NO_(2)^(-))]in water,thus the oxidizability,acidity and conductivity of plasma-treated water were all increased in a treatment timedependent manner.The result for mimicked chemical mixtures confirmed the synergistic effect of activity of H_(2)O_(2),NO_(3)^(-)and NO_(2)^(-)on bacterial inactivation and plant growth promotion.Taken together,these results imply that plasma pretreatment of mung bean seeds in water with moderate oxidizability and acidity is an effective method to improve the yield of mung bean sprouts and reduce microbial contamination.展开更多
Most reactors for non‐thermal plasma excitation are capacitive to pulse generators.The density and temperature of electrons in plasma are dominated by the discharging currents which are proportional to the pulse edge...Most reactors for non‐thermal plasma excitation are capacitive to pulse generators.The density and temperature of electrons in plasma are dominated by the discharging currents which are proportional to the pulse edges.However,adjusting the pulse edges is quite challenging since the switching speed and the inductance and capacitance in the discharging loops dominate them.This study proposes a drive circuit for solid‐state Marx generators with adjustable edges.The drive circuit controls the Miller plateau by adjusting the gate voltage amplitude to adjust both the rise time and fall time of pulses continuously and independently.The influence of the gate voltage on the Miller plateau and the rise time is studied.The feasibility is verified by both simulating and experimental results.An 8‐stage solid‐state Marx generator prototype was built,and 4.8‐kV pulses with a rise time in the range of 79 ns‐22.21μs were obtained over capacitive loads.Adjusting pulse edges can control the current amplitudes in dielectric barrier discharge loads.展开更多
Streamer discharges in liquids have received lots of attention with respect to their considerable applications invarious disciplines. Much effort has been spent to understand the basis of streamer ignition and propaga...Streamer discharges in liquids have received lots of attention with respect to their considerable applications invarious disciplines. Much effort has been spent to understand the basis of streamer ignition and propagation in dielectricliquids, but a comprehensive mechanism is far from conclusive. In this review, based on an introduction to the streamerphysics and experimentally observed characteristics in various liquids, the authors emphasise on the current status ofstreamer discharge ignition mechanisms and present their understanding for each theory.展开更多
Nanoparticles are easily to be taken up by cells but hard to be transported across epithelia, which plays an important role in absorption and toxicity. This paper aims to elucidate the effect of nanoparticle shape on ...Nanoparticles are easily to be taken up by cells but hard to be transported across epithelia, which plays an important role in absorption and toxicity. This paper aims to elucidate the effect of nanoparticle shape on bilateral exocytosis of Caco-2 cells. The fluorescent resonance energy transfer(FRET) probes(DiO and Dil)were utilized to label nanospheres and nanorods for determining and tracking nanoparticles. The results showed that more nanorods were internalized into Caco-2 cells than nanospheres. But the apical exocytosis rate of nanospheres from Caco-2 cells was faster than that of nanorods significantly. In addition, only less than 2% of intact nanoparticles were transported across monolayers for both nanoparticles, but the exocytosis behaviors between them was absolutely different. Compared to nanospheres, nanorods preferred basolateral exocytosis to apical exocytosis. Therefore, the shape is a critical parameter in cellular uptake and transport, even intracellular fate, which should be primarily considered in design of oral nanoparticles.展开更多
基金supported by the US National Science Foundation(CBET-2021956).
文摘1.Introduction,The interconnection among food-energy-water(FEW)systems in meeting societal demands is broadly acknowledged[1].Similarly,competitive or synergistic allocations of water and energy resources for agricultural production,manufacturing,and human consumption are understood,and their economic impacts can be predicted[2].Far less appreciated and understood are the outcomes of the FEW nexus in response to operation changes in agricultural practices and the associated technological innovations for future generations[3,4].Also,the inter-scale and feedback effects of emerging technology-driven resource reallocation and decision-making on FEW systems are largely unknown.For example,how do the agroeconomic feedbacks of intelligent technologies influence the FEW nexus of agricultural production under environmental and demographic changes?How does the necessary water allocation for powering non-powered dams and pumped-storage hydropower generation influence agricultural production and municipal water supply maintenance?How do solar and wind energy farms influence land use for agriculture and the rural economy?
基金the Key Project of the National Social Science Foundation of China(No.16ZDA227)The first and corresponding authors(STC and YL)are supported by grants from the National Social Science Foundation of China(No.19BTY077)+1 种基金the Philosophy and Social Science Foundation of Shanghai(No.A1904)the Shanghai Key Laboratory of Human Performance(Shanghai University of Sport,No.11DZ2261100)。
文摘Background:Meeting 24-h movement guidelines by children and adolescents has been associated with improved indicators of health,although it has been under-studied in China.Hence,this study aimed to investigate the prevalence of meeting the 24-h movement guidelines,its correlates,and its relationships with body mass index in children and adolescents in China.Methods:Cross-sectional data from the 2017 Youth Study in China of 114,072 children and adolescents(mean age=13.75 years,49.18%boys)were used.Meeting 24-h movement guidelines(60 min of daily moderate-to-vigorous physical activity,2 h of daily leisure screen time,911 h and 810 h nightly sleep duration for 613-year-olds and 1417-year-olds,respectively)and height and weight of all participants were assessed.The prevalence of meeting the 24-h movement guidelines and World Health Organization weight status categories were determined.Generalized linear models were used to determine the correlates of meeting the 24-h movement guidelines and the relationships of meeting the 24-h movement guidelines with overweight(OW)and obesity(OB).Results:Only 5.12%of Chinese children and adolescents met the 24-h movement guidelines,and 22.44%were classified as OW/OB.Older children and adolescents were less likely to meet the 24-h movement guidelines.Parental education level and family income were positively related to meeting the 24-h movement guidelines.Children and adolescents meeting the 24-h movement guidelines showed lower odds ratios for OW/OB.Compared with participants meeting the 24-h movement guidelines,boys in 4th6th grades met none of the recommendations(OR=1.22,95%CI:1.061.40),met the screen time recommendation only(OR=1.13,95%CI:1.011.28),met the nightly sleep duration recommendation only(OR=1.14,95%CI:1.031.28),and had significantly higher odds ratios for OW/OB.Similar trends were observed for girls in 4th6th grades:meeting none of the guidelines(OR=1.35,95%CI:1.141.59),meeting sleep duration guidelines only(OR=1.23,95%CI:1.081.39),and meeting moderate-to-vigorous physical activity+nightly sleep duration guidelines(OR=1.24,95%CI:1.011.54).For girls in 7th9th grades,the following trend was observed:meeting none of the guidelines(OR=1.30,95%CI:1.011.67).Conclusion:Very few Chinese children and adolescents met the 24-h movement guidelines.Age(negatively correlated),parental education level,and family income(both positively correlated)were correlates of meeting the 24-h movement guidelines.Children and adolescents meeting the 24-h movement guidelines were more likely to have lower risks for OW/OB,especially in the youngest age group(Grades 46);and girls in the middle age group(Grades 79)were also more likely to have lower risks for OW/OB.Further research studies should explore additional correlates and determinants for meeting the 24-h movement guidelines.Also,future studies should use longitudinal or interventional designs to determine the relationships between meeting the 24-h movement guidelines and OW/OB and other health indicators,while taking sex and age differences into account.
基金supported by the Key Project of the National Social Science Foundation of China (No. 16ZDA227)
文摘Purpose: This study was to present the 2016 prevalence estimates of Chinese school-aged children meeting physical fitness standards and to examine differences by sex and residence locales in children who did not meet fitness standards.Methods: We conducted cross-sectional analyses of 171,991 children and adolescents(boy: 50.0%, Grades 1–12) who participated in the 2016 Physical Activity and Fitness in China—The Youth Study. The main outcomes were fitness measures, assessed by the 2014 revised Chinese National Student Physical Fitness Standard(CNSPFS), covering areas of aerobic capacity, upper body strength, flexibility, body mass index,abdominal strength, and trunk strength. Children's overall physical fitness performance was categorized, per CNSPFS standards, as excellent,good, pass, or no pass. Data on the prevalence of physical fitness categories and not meeting fitness standards(i.e., among children who received a "no pass" mark) were analyzed, through logistic regression, by sex(boy, girl) and residence locales(urban, rural) across 3 school grades(primary,junior middle, and junior high).Results: In 2016, 5.95% of Chinese children and adolescents achieved an "excellent" mark, 25.80% received a "good" rating, 59.90% received a "pass", and 8.35% received a "no pass". Overall, boys were more likely to not pass the fitness standards compared with girls(adjusted odds ratio(a OR) = 1.710; 95% confidence interval(CI): 1.708–1.712) and children living in urban areas were more likely to not pass the standards than those living in rural areas(a OR = 1.298; 95%CI: 1.296–1.299). Consistent patterns of not meeting fitness standards were also found by sex and residence locales across all 3 school grades.Conclusion: In the Chinese school-aged population, about 3 in 10 children achieved an "excellent" or "good" fitness standard in 2016, and about8% of this population did not meet CNSPFS standards. Children living in urban areas were more likely to not meet minimum fitness performance levels, and boys in school were more likely to not meet minimum fitness performance levels than girls.
基金supported by National Natural Science Foundation of China(Nos.11605159,11405147)Chinese Postdoctoral Science Foundation(No.2017M612412)+2 种基金the Foundation of Key Technology Research Project of Henan Province(No.182102311115)Key Discipline Construction Project of Zhengzhou University(No.32410257)Youth Innovation Project of Key Discipline of Zhengzhou University(No.XKZDQN202002)。
文摘The stimulatory effects of atmospheric pressure cold plasma(APCP)on plant growth have attracted much attention due to its great potential as a new approach to increase crop growth and production.However,the transcriptome changes of plants induced by APCP treatment are unknown.Herein,the comparative transcriptome analysis was performed to identify the transcriptional response of Arabidopsis thaliana seedlings to APCP.Results showed that APCP exhibited a dual effect(stimulation or inhibition)on Arabidopsis seedling growth dependent on the treatment time and the maximum stimulatory effects were achieved by 1 min APCP treatment.The metabolic analysis of amino acid,glutathione(GSH)and phytohormone demonstrated that 1 min APCP treatment decreased most amino acids concentrations in Arabidopsis seedling,while the accumulations of GSH,gibberellins and cytokinin were significantly increased.The RNA-Seq analysis showed that a total of218 differentially expressed genes(DEGs)were identified in 1 min APCP-treated seedlings versus the control,including 20 up-regulated and 198 down-regulated genes.The DEGs were enriched in pathways related to GSH metabolism,mitogen-activated protein kinase(MAPK)signaling transduction and plant resistance against pathogens.Moreover,most of the DEGs were defense,stimuli or stressresponsive genes and encoded proteins with oxidoreductase activity.Expression determination of six randomly selected DEGs by quantitative real-time PCR demonstrated similar pattern with the RNASeq data.These results indicated that the moderate APCP treatment may regulate the expression of stimuli/stress-responsive genes involved in GSH,phytohormone/amino metabolism and plant defense against pathogens via MAPK signal transduction pathway,accordingly enhance Arabidopsis seedling growth.This study provides a theoretical basis for the application of APCP in agriculture.
基金supported by the US National Science Foundation (CBET-1739474 and CBET-2021956)
文摘Urbanization,population growth,and the accelerating consumption of food,energy,and water(FEW)resources bring unprecedented challenges for economic,environmental,and social(EES)sustainability.It is imperative to understand the potential impacts of FEW systems on the realization of the United Nation’s Sustainable Development Goals(SDGs)as the world transitions from natural ecosystems to managed ecosystems at an accelerating rate.A major obstacle is the complexity and emergent behavior of FEW systems and associated networks,for which no single discipline can generate a holistic understanding or meaningful projections.We propose a research enterprise framework for promoting transdisciplinarity and top-down quantification of the interrelationships between FEW and EES systems.Relevant enterprise efforts would emphasize increasing FEW resource accessibility by improving coordinated interplays across sectors and scales,expanding and diversifying supply-chain networks,and innovating technologies for efficient resource utilization.This framework can guide the development of strategic solutions for diminishing the competition among FEW-consuming sectors in a region or country,and for minimizing existing inequalities in FEW availability when a sustainable development agenda is implemented.
基金supported by National Natural Science Foundation of China(Nos.11605159 and 11405147)Chinese Postdoctoral Science Foundation(No.2017M612412)+3 种基金the Foundation of Key Technology Research Project of Henan Province(No.182102311115)Key Discipline Construction Project of Zhengzhou University(No.32410257)Youth Innovation Project of Key Discipline of Zhengzhou University(No.XKZDQN202002)Natural Science Foundation of Henan Province(No.202300410013)。
文摘Mung bean(Vigna radiata)sprouts are widely consumed worldwide due to their high nutritional value.However,the low yield and microbial contamination of mung bean sprouts seriously reduces their economic value.This study investigates the effects of non-thermal plasma on the quality and microbial reduction of mung bean sprouts by pretreatment of seeds in water for different times(0,1,3 and 6 min).The quality results showed that short-time plasma treatment(1 and 3 min)promoted seed germination and seedling growth,whereas long-time plasma treatment(6 min)had inhibitory effects.Plasma also had a similar dose effects on the total flavonoid and phenolic contents of mung bean sprouts.The microbiological results showed that plasma treatment achieved a reduction of native microorganisms ranging from 0.54 to 7.09 log for fungi and 0.29 to 6.80 log for bacteria at 96 h incubation.Meanwhile,plasma treatment could also efficiently inactivate artificially inoculated Salmonella typhimurium(1.83–6.22 log)and yeast(0.53–3.19 log)on mung bean seeds.The results of seed coat permeability tests and scanning electron microscopy showed that plasma could damage the seed coat structure,consequently increasing the electrical conductivity of mung bean seeds.The physicochemical analysis of plasma-treated water showed that plasma generated various long-and short-lived active species[nitric oxide radicals(NO·),hydroxyl radicals(·OH),singlet oxygen(1O2),hydrogen peroxide(H_(2)O_(2)),nitrate(NO_(3)^(-)),and nitrite(NO_(2)^(-))]in water,thus the oxidizability,acidity and conductivity of plasma-treated water were all increased in a treatment timedependent manner.The result for mimicked chemical mixtures confirmed the synergistic effect of activity of H_(2)O_(2),NO_(3)^(-)and NO_(2)^(-)on bacterial inactivation and plant growth promotion.Taken together,these results imply that plasma pretreatment of mung bean seeds in water with moderate oxidizability and acidity is an effective method to improve the yield of mung bean sprouts and reduce microbial contamination.
基金National Key R&D plan of China,Grant/Award Number:2019YFC0119102。
文摘Most reactors for non‐thermal plasma excitation are capacitive to pulse generators.The density and temperature of electrons in plasma are dominated by the discharging currents which are proportional to the pulse edges.However,adjusting the pulse edges is quite challenging since the switching speed and the inductance and capacitance in the discharging loops dominate them.This study proposes a drive circuit for solid‐state Marx generators with adjustable edges.The drive circuit controls the Miller plateau by adjusting the gate voltage amplitude to adjust both the rise time and fall time of pulses continuously and independently.The influence of the gate voltage on the Miller plateau and the rise time is studied.The feasibility is verified by both simulating and experimental results.An 8‐stage solid‐state Marx generator prototype was built,and 4.8‐kV pulses with a rise time in the range of 79 ns‐22.21μs were obtained over capacitive loads.Adjusting pulse edges can control the current amplitudes in dielectric barrier discharge loads.
基金the PlasmaShape project from the European Union under grant agreement no 316216.
文摘Streamer discharges in liquids have received lots of attention with respect to their considerable applications invarious disciplines. Much effort has been spent to understand the basis of streamer ignition and propagation in dielectricliquids, but a comprehensive mechanism is far from conclusive. In this review, based on an introduction to the streamerphysics and experimentally observed characteristics in various liquids, the authors emphasise on the current status ofstreamer discharge ignition mechanisms and present their understanding for each theory.
基金financially supported by Science and Technology Commission of Shanghai Municipality(No.18ZR1404100)Shanghai Pujiang Program(No.18PJD001)+2 种基金the National Natural Science Foundation of China(Nos.81573363 and 81690263)the Youth Teacher Training Program of Shanghai Municipal Education Commission(No.ZZJKYX16011)Shanghai Municipal Commission of Health and Family Planning(No.20164Y0213)
文摘Nanoparticles are easily to be taken up by cells but hard to be transported across epithelia, which plays an important role in absorption and toxicity. This paper aims to elucidate the effect of nanoparticle shape on bilateral exocytosis of Caco-2 cells. The fluorescent resonance energy transfer(FRET) probes(DiO and Dil)were utilized to label nanospheres and nanorods for determining and tracking nanoparticles. The results showed that more nanorods were internalized into Caco-2 cells than nanospheres. But the apical exocytosis rate of nanospheres from Caco-2 cells was faster than that of nanorods significantly. In addition, only less than 2% of intact nanoparticles were transported across monolayers for both nanoparticles, but the exocytosis behaviors between them was absolutely different. Compared to nanospheres, nanorods preferred basolateral exocytosis to apical exocytosis. Therefore, the shape is a critical parameter in cellular uptake and transport, even intracellular fate, which should be primarily considered in design of oral nanoparticles.
