Lead and Zn uptake and chemical changes in rhizosphere soils of four emergent-rooted wetland plants;Aneilema bracteatum,Cyperus alternifolius,Ludwigia hyssopifolia and Veronica serpyllifolia were investigated by two e...Lead and Zn uptake and chemical changes in rhizosphere soils of four emergent-rooted wetland plants;Aneilema bracteatum,Cyperus alternifolius,Ludwigia hyssopifolia and Veronica serpyllifolia were investigated by two experiments：（1） rhizobag filled with ＂clean＂ or metal-contaminated soil for analysis of Pb and Zn in plants and rhizosphere soils;and （2） applied deoxygenated solution for analyzing their rates of radial oxygen loss （ROL）.The results showed that the wetland plants with different ROL rates had significant effects on the mobility and chemical forms of Pb and Zn in rhizosphere under flooded conditions.These effects were varied with different metal elements and metal concentrations in the soils.Lead mobility in rhizosphere of the four plants both in the ＂clean＂ and contaminated soils was decreased,while Zn mobility was increased in the rhizosphere of the ＂clean＂ soil,but decreased in the contaminated soil.Among the four plants,V.serpyllifolia,with the highest ROL,formed the highest degree of Fe plaque on the root surface,immobilized more Zn in Fe plaque,and has the highest effects on the changes of Zn form （EXC-Zn） in rhizosphere under both ＂clean＂ and contaminated soil conditions.These results suggested that ROL of wetland plants could play an important role in Fe plaque formation and mobility and chemical changes of metals in rhizosphere soil under flood conditions.展开更多
Though oxygen defects are associated with deteriorated structures and aggravated cycling performance in traditional layered cathodes,the role of oxygen defects is still ambiguous in Li-rich layered oxides due to the i...Though oxygen defects are associated with deteriorated structures and aggravated cycling performance in traditional layered cathodes,the role of oxygen defects is still ambiguous in Li-rich layered oxides due to the involvement of oxygen redox.Herein,a Co-free Li-rich layered oxide Li_(1.286)Ni_(0.071)Mn_(0.643)O_(2)has been prepared by a co-precipitation method to systematically investigate the undefined effects of the oxygen defects.A significant O_(2)release and the propagation of oxygen vacancies were detected by operando differential electrochemical mass spectroscopy(DEMS)and electron energy loss spectroscopy(EELS),respectively.Scanning transmission electron microscopy-high angle annular dark field(STEMHAADF)reveals the oxygen vacancies fusing to nanovoids and monitors a stepwise electrochemical activation process of the large Li_(2)MnO_(3)domain upon cycling.Combined with the quantitative analysis conducted by the energy dispersive spectrometer(EDS),existed nano-scale oxygen defects actually expose more surface to the electrolyte for facilitating the electrochemical activation and subsequently increasing available capacity.Overall,this work persuasively elucidates the function of oxygen defects on oxygen redox in Co-free Li-rich layered oxides.展开更多
Anthropogenic methane emissions are a leading cause of the increase in global averagetemperatures,often referred to as global warming.Flooded soils play a significant role in methaneproduction,where the anaerobic cond...Anthropogenic methane emissions are a leading cause of the increase in global averagetemperatures,often referred to as global warming.Flooded soils play a significant role in methaneproduction,where the anaerobic conditions promote the production of methane by methanogenicmicroorganisms.Rice fields contribute a considerable portion of agricultural methane emissions,as riceplants provide both factors that enhance and limit methane production.Rice plants harbor both methaneproducingand methane-oxidizing microorganisms.Exudates from rice roots provide source for methaneproduction,while oxygen delivered from the root aerenchyma enhances methane oxidation.Studies haveshown that the diversity of these microorganisms depends on rice cultivars with some genes characterizedas harboring specific groups of microorganisms related to methane emissions.However,there is still aneed for research to determine the balance between methane production and oxidation,as rice plantspossess the ability to regulate net methane production.Various agronomical practices,such as fertilizerand water management,have been employed to mitigate methane emissions.Nevertheless,studiescorrelating agronomic and chemical management of methane with productivity are limited.Moreover,evidences for breeding low-methane-emitting rice varieties are scattered largely due to the absence ofcoordinated breeding programs.Research has indicated that phenotypic characteristics,such as rootbiomass,shoot architecture,and aerenchyma,are highly correlated with methane emissions.This reviewdiscusses available studies that involve the correlation between plant characteristics and methaneemissions.It emphasizes the necessity and importance of breeding low-methane-emitting rice varieties inaddition to existing agronomic,biological,and chemical practices.The review also delves into the idealphenotypic and physiological characteristics of low-methane-emitting rice and potential breeding techniques,drawing from studies conducted with diverse varieties,mutants,and transgenic plants.展开更多
该研究将24名拳击运动员按照是否穿着暴汗服分为实验组(n=12)和对照组(n=12),进行4周赛前训练,通过最大摄氧量和心率变异性指标来反映穿着暴汗服进行赛前减重对拳击运动员机能状态影响的差异。组内最大摄氧量指标前后比较,实验组提升3.0...该研究将24名拳击运动员按照是否穿着暴汗服分为实验组(n=12)和对照组(n=12),进行4周赛前训练,通过最大摄氧量和心率变异性指标来反映穿着暴汗服进行赛前减重对拳击运动员机能状态影响的差异。组内最大摄氧量指标前后比较,实验组提升3.04mL/(kg·min)(P<0.01),对照组提升1.16mL/(kg·min)(P<0.01);前、后比较均存在显著性差异。组间最大摄氧量指标提升百分比横向比较结果为:实验组与对照组之间存在显著性差异(P<0.05)。组内心率变异性指标前后纵向比较结果为:实验组的频域指标——相邻R-R间期差值均方根(Root Mean Square of SDs Between Adjacent NN Intervals,RMSSD)、相邻间期的差值标准差(Adjacent Normal RR Interval of the Difference Between the Standard Deviation,SDSD),以及总功率(Total Power,TP)、高频功率(High Frequency,HF)指标存在显著性差异(P<0.05);对照组的时域指标——R-R间期标准差(Standard Deviation of the NN Interval,SDNN)、RMSSD、SDSD,以及TP、低频功率(Low Frequency,LF)指标前后存在显著性差异(P<0.05)。组间心率变异性指标提升百分比横向比较结果为不存在显著性差异。得出结论:穿着暴汗服在赛前减重的同时有利于最大摄氧量的提高,且提升效果高于不穿暴汗服;穿着暴汗服进行赛前训练有利于提高拳击运动员的心率变异性。但是,穿和不穿暴汗服对心率变异性的提升效果并无显著差别。展开更多
基金supported by the National Natural Science Foundation of China (No. 30570345,30770417)the Guangdong Natural Science Group Foundation (No.06202438)the Specialized Research Fund for the Doctoral Program of Higher Education,China (No. 20558097)
文摘Lead and Zn uptake and chemical changes in rhizosphere soils of four emergent-rooted wetland plants;Aneilema bracteatum,Cyperus alternifolius,Ludwigia hyssopifolia and Veronica serpyllifolia were investigated by two experiments：（1） rhizobag filled with ＂clean＂ or metal-contaminated soil for analysis of Pb and Zn in plants and rhizosphere soils;and （2） applied deoxygenated solution for analyzing their rates of radial oxygen loss （ROL）.The results showed that the wetland plants with different ROL rates had significant effects on the mobility and chemical forms of Pb and Zn in rhizosphere under flooded conditions.These effects were varied with different metal elements and metal concentrations in the soils.Lead mobility in rhizosphere of the four plants both in the ＂clean＂ and contaminated soils was decreased,while Zn mobility was increased in the rhizosphere of the ＂clean＂ soil,but decreased in the contaminated soil.Among the four plants,V.serpyllifolia,with the highest ROL,formed the highest degree of Fe plaque on the root surface,immobilized more Zn in Fe plaque,and has the highest effects on the changes of Zn form （EXC-Zn） in rhizosphere under both ＂clean＂ and contaminated soil conditions.These results suggested that ROL of wetland plants could play an important role in Fe plaque formation and mobility and chemical changes of metals in rhizosphere soil under flood conditions.
基金supported by the National Natural Science Foundation of China(52272253)the"Lingyan"Research and Development Plan of Zhejiang Province(2022C01071)+2 种基金the S&T Innovation 2025 Major Special Programme of Ningbo(2018B10081)the Natural Science Foundation of Ningbo(202003N4030)the Youth Innovation Promotion Association of Chinese Academy of Sciences(2022299)。
文摘Though oxygen defects are associated with deteriorated structures and aggravated cycling performance in traditional layered cathodes,the role of oxygen defects is still ambiguous in Li-rich layered oxides due to the involvement of oxygen redox.Herein,a Co-free Li-rich layered oxide Li_(1.286)Ni_(0.071)Mn_(0.643)O_(2)has been prepared by a co-precipitation method to systematically investigate the undefined effects of the oxygen defects.A significant O_(2)release and the propagation of oxygen vacancies were detected by operando differential electrochemical mass spectroscopy(DEMS)and electron energy loss spectroscopy(EELS),respectively.Scanning transmission electron microscopy-high angle annular dark field(STEMHAADF)reveals the oxygen vacancies fusing to nanovoids and monitors a stepwise electrochemical activation process of the large Li_(2)MnO_(3)domain upon cycling.Combined with the quantitative analysis conducted by the energy dispersive spectrometer(EDS),existed nano-scale oxygen defects actually expose more surface to the electrolyte for facilitating the electrochemical activation and subsequently increasing available capacity.Overall,this work persuasively elucidates the function of oxygen defects on oxygen redox in Co-free Li-rich layered oxides.
基金supported by the Improvement of Green Rice Plant Type Using Genetic Information Program, Rural Development Administration, Korea (Grant No. PJ01699202)
文摘Anthropogenic methane emissions are a leading cause of the increase in global averagetemperatures,often referred to as global warming.Flooded soils play a significant role in methaneproduction,where the anaerobic conditions promote the production of methane by methanogenicmicroorganisms.Rice fields contribute a considerable portion of agricultural methane emissions,as riceplants provide both factors that enhance and limit methane production.Rice plants harbor both methaneproducingand methane-oxidizing microorganisms.Exudates from rice roots provide source for methaneproduction,while oxygen delivered from the root aerenchyma enhances methane oxidation.Studies haveshown that the diversity of these microorganisms depends on rice cultivars with some genes characterizedas harboring specific groups of microorganisms related to methane emissions.However,there is still aneed for research to determine the balance between methane production and oxidation,as rice plantspossess the ability to regulate net methane production.Various agronomical practices,such as fertilizerand water management,have been employed to mitigate methane emissions.Nevertheless,studiescorrelating agronomic and chemical management of methane with productivity are limited.Moreover,evidences for breeding low-methane-emitting rice varieties are scattered largely due to the absence ofcoordinated breeding programs.Research has indicated that phenotypic characteristics,such as rootbiomass,shoot architecture,and aerenchyma,are highly correlated with methane emissions.This reviewdiscusses available studies that involve the correlation between plant characteristics and methaneemissions.It emphasizes the necessity and importance of breeding low-methane-emitting rice varieties inaddition to existing agronomic,biological,and chemical practices.The review also delves into the idealphenotypic and physiological characteristics of low-methane-emitting rice and potential breeding techniques,drawing from studies conducted with diverse varieties,mutants,and transgenic plants.
文摘该研究将24名拳击运动员按照是否穿着暴汗服分为实验组(n=12)和对照组(n=12),进行4周赛前训练,通过最大摄氧量和心率变异性指标来反映穿着暴汗服进行赛前减重对拳击运动员机能状态影响的差异。组内最大摄氧量指标前后比较,实验组提升3.04mL/(kg·min)(P<0.01),对照组提升1.16mL/(kg·min)(P<0.01);前、后比较均存在显著性差异。组间最大摄氧量指标提升百分比横向比较结果为:实验组与对照组之间存在显著性差异(P<0.05)。组内心率变异性指标前后纵向比较结果为:实验组的频域指标——相邻R-R间期差值均方根(Root Mean Square of SDs Between Adjacent NN Intervals,RMSSD)、相邻间期的差值标准差(Adjacent Normal RR Interval of the Difference Between the Standard Deviation,SDSD),以及总功率(Total Power,TP)、高频功率(High Frequency,HF)指标存在显著性差异(P<0.05);对照组的时域指标——R-R间期标准差(Standard Deviation of the NN Interval,SDNN)、RMSSD、SDSD,以及TP、低频功率(Low Frequency,LF)指标前后存在显著性差异(P<0.05)。组间心率变异性指标提升百分比横向比较结果为不存在显著性差异。得出结论:穿着暴汗服在赛前减重的同时有利于最大摄氧量的提高,且提升效果高于不穿暴汗服;穿着暴汗服进行赛前训练有利于提高拳击运动员的心率变异性。但是,穿和不穿暴汗服对心率变异性的提升效果并无显著差别。
