The aim of this research was to study the influence of chlorsulfuron residue and cadmium on the enzymatic activity and photosynthetic apparatus of maize(Zea mays L.) plants. Chlorsulfuron and cadmium at 0.001 and 5.0 ...The aim of this research was to study the influence of chlorsulfuron residue and cadmium on the enzymatic activity and photosynthetic apparatus of maize(Zea mays L.) plants. Chlorsulfuron and cadmium at 0.001 and 5.0 mg kg–1, respectively, were mixed and applied to soil prior to planting. The levels of chlorsulfuron-and cadmium-induced stress to plants were estimated by growth, chlorophyll content, lipid peroxide content, enzyme activities, and major fluorescence parameters of chlorophyll(revealed by the fluorescence imaging system Fluor Cam). Chlorsulfuron negatively affected the chlorophyll content, photochemical efficiency of photosystem II in the dark-adapted state, the maximum efficiency of photosystem II, photochemical quenching coefficient, and steady-state fluorescence decline ratio in the leaves of maize seedlings. However, cadmium did not produce noticeable changes. Plants that were exposed to both chlorsulfuron and cadmium showed an obvious increase in the steady-state fluorescence decline ratio. These results implied that the seedlings possessed more resistance to cadmium than to chlorsulfuron and their resistance to chlorsulfuron toxicity was enhanced by the presence of cadmium. The results also suggested that chlorophyll fluorescence imaging reveals overall alterations within the leaves but may not reflect small-scale effects on tissues, as numeric values of specific parameters are averages of the data collected from the whole leaf.展开更多
Stone coal is a special resource, because it is associated with a variety of rare metal elements. The elemental geochemical characteristics of stone coal can provide useful information for the study of its formation a...Stone coal is a special resource, because it is associated with a variety of rare metal elements. The elemental geochemical characteristics of stone coal can provide useful information for the study of its formation and evolution history. The content of rare earth elements in stone coal has been the focus of attention. Stone coal is widely distributed in southern Shaanxi province of China. In order to study the content and distribution of rare earth elements in stone coal, and provide a plan for the comprehensive development and utilization of stone coal, this study tested the rare earth elements content of stone coal, parting and coal ash samples, respectively, compared the content of rare earth elements in stone coal, parting, coal ash with the mean value of China coal, the mean value of world coal and the abundance value of upper crust, and discussed the features of rare earth elements content in different types of samples in southern Shaanxi province of China. The average contents of rare earth elements in the samples of stone coal, parting and coal ash were calculated, and the enrichment coefficients of the samples with the mean value of China coal, the mean value of world coal and the abundance value of upper crust were listed. The distribution rules and characteristics of the contents of rare earth elements in different types of samples in southern Shaanxi province of China were summarized.展开更多
Although TiO_(2)nanotubes is a promising electrode as supercapacitors due to its high energy density,easy synthesis and chemical stability,there are draw backs such as low conductivity and capacitance.Many studies con...Although TiO_(2)nanotubes is a promising electrode as supercapacitors due to its high energy density,easy synthesis and chemical stability,there are draw backs such as low conductivity and capacitance.Many studies concentrated on improving its electrochemical performance itself but little attention was payed to the reason of capacitance differences caused by its different crystal structures.Herein,we prepare amorphous and anatase TiO_(2)nanotubes and hydrogenated them by a simple electrochemical hydrogenation method to improve their conductivity and capacitance.And then study and compare their morphology and structure differences by SEM,TEM,XRD and BET.The results show that the pore size distribution,internal structure order and internal carrier concentration are the main reasons for their electrochemical performance differences.The microporous structure less than 2 nm in amorphous nanotubes act as a trap of electrolyte ions at current density larger than 0.1μA cm^(-2),leading to small charge and discharge capacitance.The long-range ordered crystal structure of anatase is more favorable for the orderly diffusion of carriers,reducing the inelastic scattering of carrier diffusion process and the electron hole-complexing probability,making anatase nanotubes exhibit higher coulomb efficiency and cycle stability than that of amorphous ones.展开更多
基金supported by grants from the National Natural Science Foundation of China(30740037)the Special Fund for Agro-scientific Research in the Public Interest,China(201103024)the Foundation for Graduate Innovation,Shanxi University,China(011452901009)
文摘The aim of this research was to study the influence of chlorsulfuron residue and cadmium on the enzymatic activity and photosynthetic apparatus of maize(Zea mays L.) plants. Chlorsulfuron and cadmium at 0.001 and 5.0 mg kg–1, respectively, were mixed and applied to soil prior to planting. The levels of chlorsulfuron-and cadmium-induced stress to plants were estimated by growth, chlorophyll content, lipid peroxide content, enzyme activities, and major fluorescence parameters of chlorophyll(revealed by the fluorescence imaging system Fluor Cam). Chlorsulfuron negatively affected the chlorophyll content, photochemical efficiency of photosystem II in the dark-adapted state, the maximum efficiency of photosystem II, photochemical quenching coefficient, and steady-state fluorescence decline ratio in the leaves of maize seedlings. However, cadmium did not produce noticeable changes. Plants that were exposed to both chlorsulfuron and cadmium showed an obvious increase in the steady-state fluorescence decline ratio. These results implied that the seedlings possessed more resistance to cadmium than to chlorsulfuron and their resistance to chlorsulfuron toxicity was enhanced by the presence of cadmium. The results also suggested that chlorophyll fluorescence imaging reveals overall alterations within the leaves but may not reflect small-scale effects on tissues, as numeric values of specific parameters are averages of the data collected from the whole leaf.
文摘Stone coal is a special resource, because it is associated with a variety of rare metal elements. The elemental geochemical characteristics of stone coal can provide useful information for the study of its formation and evolution history. The content of rare earth elements in stone coal has been the focus of attention. Stone coal is widely distributed in southern Shaanxi province of China. In order to study the content and distribution of rare earth elements in stone coal, and provide a plan for the comprehensive development and utilization of stone coal, this study tested the rare earth elements content of stone coal, parting and coal ash samples, respectively, compared the content of rare earth elements in stone coal, parting, coal ash with the mean value of China coal, the mean value of world coal and the abundance value of upper crust, and discussed the features of rare earth elements content in different types of samples in southern Shaanxi province of China. The average contents of rare earth elements in the samples of stone coal, parting and coal ash were calculated, and the enrichment coefficients of the samples with the mean value of China coal, the mean value of world coal and the abundance value of upper crust were listed. The distribution rules and characteristics of the contents of rare earth elements in different types of samples in southern Shaanxi province of China were summarized.
基金support of the National Natural Science Foundation of China(grant no.22075197)support of the Shanxi Provincial Natural Science Foundation of China(201903D421081)+1 种基金Research and Development Project of Key Core and Common Technology of Shanxi Province(20201102018)support of the Shanxi Provincial Natural Science Foundation of China(201801D221140)
文摘Although TiO_(2)nanotubes is a promising electrode as supercapacitors due to its high energy density,easy synthesis and chemical stability,there are draw backs such as low conductivity and capacitance.Many studies concentrated on improving its electrochemical performance itself but little attention was payed to the reason of capacitance differences caused by its different crystal structures.Herein,we prepare amorphous and anatase TiO_(2)nanotubes and hydrogenated them by a simple electrochemical hydrogenation method to improve their conductivity and capacitance.And then study and compare their morphology and structure differences by SEM,TEM,XRD and BET.The results show that the pore size distribution,internal structure order and internal carrier concentration are the main reasons for their electrochemical performance differences.The microporous structure less than 2 nm in amorphous nanotubes act as a trap of electrolyte ions at current density larger than 0.1μA cm^(-2),leading to small charge and discharge capacitance.The long-range ordered crystal structure of anatase is more favorable for the orderly diffusion of carriers,reducing the inelastic scattering of carrier diffusion process and the electron hole-complexing probability,making anatase nanotubes exhibit higher coulomb efficiency and cycle stability than that of amorphous ones.