Sodium-ion batteries(SIBs)employ P2-type layered transition metal oxides as promising cathode materials,primarily due to their abundant natural reserves and environmentally friendly characteristics.However,structural ...Sodium-ion batteries(SIBs)employ P2-type layered transition metal oxides as promising cathode materials,primarily due to their abundant natural reserves and environmentally friendly characteristics.However,structural instability and complex phase transitions during electrochemical cycling pose significant challenges to their practical applications.Employing cation substitution serves as a straightforward yet effective strategy for stabilizing the structure and improving the kinetics of the active material.In this study,we introduce a Ni-rich honeycomb-layered Na_(2+x)Ni_(2)TeO_(6)(NNTO)cathode material with variable sodium content(x=0,0.03,0.05,0.10).Physicochemical characterizations reveal that excess sodium content at the atomic scale modifies the surface and suppresses phase transitions,while preserving the crystal structure.This results in enhanced cyclic performance and improved electrochemical kinetics at room temperature.Furthermore,we investigate the performance of the NNTO cathode material containing 10%excess sodium at a relatively high temperature of 60℃,where it exhibits 71.6%capacity retention compared to 60%for the pristine.Overall,our results confirm that a preconstructed surface layer(induced by excess sodium)effectively safeguards the Ni-based cathode material from surface degradation and phase transitions during the electrochemical processes,thus exhibiting superior capacity retention relative to the pristine NNTO cathode.This study of the correlation between structure and performance can potentially be applied to the commercialization of SIBs.展开更多
The effect of partial substitution of Mg for Ni on a high-sodium and lithium-free layered P2-type Na_(45/54)Mg_(6)/_(54)Ni_(12/54)Mn_(34/54)O_(2) cathode with high initial Coulombic efficiency and excellent cyclic sta...The effect of partial substitution of Mg for Ni on a high-sodium and lithium-free layered P2-type Na_(45/54)Mg_(6)/_(54)Ni_(12/54)Mn_(34/54)O_(2) cathode with high initial Coulombic efficiency and excellent cyclic stability has been investigated in this study.Based on the crystal structural analysis,the Mg doping can retain the P2 structure up to 4.3 V,thus restraining the detrimental phase transformation of P2-02during the Na-ion intercalation/deintercalation process.Therefore,the obtained Mg-doped P2-type cathode exhibits a reversible specific capacity of 109 mAh·g^(-1) at 0.1C between 2.0 and 4.3 V and a retention rate of 81.5% after 200cycles at 1C.In addition,the full cell consisting of Mg-doped P2-type cathode and hard carbon anode shows a capacity retention rate of 85.6% after 100 cycles.This study provides new insight into the development of durable cathode materials for sodium-ion batteries.展开更多
Objective: The aim of the present study was to evaluate salt levels in popular hot takeaway meals in three large China cities, and to compare the difference in sodium content in different types of takeaway meals. Meth...Objective: The aim of the present study was to evaluate salt levels in popular hot takeaway meals in three large China cities, and to compare the difference in sodium content in different types of takeaway meals. Methods: We randomly collected a total of 4450 samples of 7 different types of takeaway meals, which were the most consumed by local residents from takeaway platforms. The main ingredients, auxiliary ingredients, as well as the weight used in takeaway meals were collected. The sodium content in takeaway meals was obtained by calculation. Results: Obtained results show that the sodium content in three large China cities is alarmingly high. Comparing medians (interquartile range) of takeaway meals from different cities, Beijing contained the highest sodium content per portion (1371.3 mg (890.3 - 2137.4)), followed by Hangzhou (1348.45 mg (694.25 - 1541.62)) and Shanghai (340.1 (259.75 - 942.25)). In addition, the sodium content between pasta and porridge, Chinese meals, and western meals show significant differences (p 0.05). Compared with Chinese Dietary Reference Intakes, the average sodium content exceeded dietary recommendations for one takeaway meal. The sodium content differed among takeaway meals prepared with various cooking methods and meats. Conclusion: Notable differences are detected in takeaway meals’ sodium content between several large cities in China. To meet China’s target salt intake, consumers in these cities are highly recommended to reduce sodium content in their everyday meals.展开更多
In this paper, Ni/Zr–Yb–O catalysts with different sodium contents are prepared by a co-precipitation method, using aqueous Na2CO3 solution as a precipitant, and the effect of sodium on the catalyst structure and ca...In this paper, Ni/Zr–Yb–O catalysts with different sodium contents are prepared by a co-precipitation method, using aqueous Na2CO3 solution as a precipitant, and the effect of sodium on the catalyst structure and catalytic performance for syngas methanation is extensively investigated using five Ni/Zr–Yb–O catalysts, containing 0, 0.5, 1.5,4.5 and 13.5 wt% Na^+, those are denoted as Cat-1, Cat-2, Cat-3, Cat-4 and Cat-5 respectively. It is found that the interaction between Ni and support determines the catalytic performance of Ni/Zr–Yb–O and the residual sodium content negatively affects the interaction between Ni and support. Cat-1 exhibits an excellent catalytic performance.During a long run time of 380 h, no deactivation is observed and both CO conversion and CH4 selectivity maintain a level above 90%. However, Cat-3 and Cat-5 suffer rapid deactivation under the same reaction condition. The characterization results indicate the strong interaction between Ni and support enables Cat-1 to possess well dispersed Ni species, resistance to sintering and carbon deposition and thus the excellent catalytic performance. However, the presence of sodium ions over Ni/Zr–Yb–O degrades the interaction between Ni and support and the catalytic performance, especially for the stability. The relative weak interaction between Ni and support results in severe sintering of both ZrO2 and Ni under the reaction condition, carbon deposition and the poor catalytic performance.展开更多
Two wheat varieties with similar yield and significantly different protein content were chosen to study the effect of foliage spraying sodium bisulfite (NaHSO3) at low concentration to wheat plants receiving different...Two wheat varieties with similar yield and significantly different protein content were chosen to study the effect of foliage spraying sodium bisulfite (NaHSO3) at low concentration to wheat plants receiving different levels of nitrogen on nitrate reduction along with yield and protein content of grain, so as to discuss the relationship between carbon metabolism and nitrogen metabolism, and find out the intrinsic mechanism of grain yield and protein content formation. The results showed that spraying NaHSO3 at grain-filing stage increased the yield of grain, but declined the capacity of nitrate reduction, which might result in decrease of protein content in the end. Whether receiving NaHSO, or not, the variety with high protein content had higher final protein level and nitrate reduction capacity than that with low protein content.展开更多
Ecological restoration by Taman＇x plants on semi-arid saline lands affects the accumulation, distribution patterns and related mechanisms of soil water content and salinity. In this study, spatio-temporal variations ...Ecological restoration by Taman＇x plants on semi-arid saline lands affects the accumulation, distribution patterns and related mechanisms of soil water content and salinity. In this study, spatio-temporal variations of soil water content and salinity around natural individual Tamarix ramosissiraa Ledeb. were invetigated in a semi-arid saline region of the upper Yellow River, Northwest China. Specifically, soil water content, electrical conductivity （EC）, sodium adsorption ratio （SARa）, and salt ions （including Na＋, K＋, Ca2＋, Mg2＋ and 8042-） were measured at different soil depths and at different distances from the trunk of T. ramasissima in May, July, and September 2016. The soil water content at the 20-80 cm depth was significantly lower in July and September than in May, indicating that T. ramosissima plants absorb a large amount of water through the roots during the growing period, leading to the decreasing of soil water content in the deep soil layer. At the 0-20 cm depth, there was a salt island effect around individual T. ramosissima, and the ECe differed significantly inside and outside the canopy of T. ramosissima in May and July. Salt bioaccumulation and stemflow were two major contributing factors to this difference. The SAR at the 0-20 cm depth was significantly different inside and outside the canopy of T. ramosissima in the three sampling months. The values of SAR~ at the 60-80 cm depth in May and July were significantly higher than those at the 0-60 cm depth and higher than that at the corresponding depth in September. The distribution of Na＋ in the soil was similar to that of the SAI, while the concentrations of K＋, Ca2＋, and Mg2＋ showed significant differences among the sampling months and soil depths. Both season and soil depth had highly significant effects on soil water content, ECe and SARa, whereas distance from the trunk of T. ramosissima only significantly affected ECe. Based on these results, we recommend co-planting of shallow-rooted salt-tolerant species near the Tamarx plants and avoiding planting herbaceous plants inside the canopy of T. ramodssima for afforestation in this semi-arid saline region. The results of this study may provide a reference for appropriate restoration in the semi-arid saline regions of the upper Yellow River.展开更多
Sodium alginate is a polysaccharide that is largely obtained from the brown algae （Sargassum sp.）.It has been used as a wonderful growth promoting substance in its depolymerized form for various plants.The aim of th...Sodium alginate is a polysaccharide that is largely obtained from the brown algae （Sargassum sp.）.It has been used as a wonderful growth promoting substance in its depolymerized form for various plants.The aim of this study was to find out the effects of various concentrations of γ-irradiated sodium alginate （ISA）,viz.,deionized water （control,T0）,20 （T1）,40 （T2）,60 （T3）,80 （T4）,and 100 ppm （T5） on the agricultural performance of Catharanthus roseus L.（Rosea） in terms of growth attributes,photosynthesis,physiological activities,and alkaloid production.The present work revealed that ISA applied as leaf-sprays at concentrations from 20 to 100 ppm might improve growth,photosynthesis,physiological activities,and alkaloid production in C.roseus L.significantly.Of the various ISA concentrations,80 ppm proved to be the best one compared to other concentrations applied.展开更多
基金Korea Institute of Science and Technology,Grant/Award Number:2E33270National Research Foundation of Korea,Grant/Award Number:2020M3H4A3081889。
文摘Sodium-ion batteries(SIBs)employ P2-type layered transition metal oxides as promising cathode materials,primarily due to their abundant natural reserves and environmentally friendly characteristics.However,structural instability and complex phase transitions during electrochemical cycling pose significant challenges to their practical applications.Employing cation substitution serves as a straightforward yet effective strategy for stabilizing the structure and improving the kinetics of the active material.In this study,we introduce a Ni-rich honeycomb-layered Na_(2+x)Ni_(2)TeO_(6)(NNTO)cathode material with variable sodium content(x=0,0.03,0.05,0.10).Physicochemical characterizations reveal that excess sodium content at the atomic scale modifies the surface and suppresses phase transitions,while preserving the crystal structure.This results in enhanced cyclic performance and improved electrochemical kinetics at room temperature.Furthermore,we investigate the performance of the NNTO cathode material containing 10%excess sodium at a relatively high temperature of 60℃,where it exhibits 71.6%capacity retention compared to 60%for the pristine.Overall,our results confirm that a preconstructed surface layer(induced by excess sodium)effectively safeguards the Ni-based cathode material from surface degradation and phase transitions during the electrochemical processes,thus exhibiting superior capacity retention relative to the pristine NNTO cathode.This study of the correlation between structure and performance can potentially be applied to the commercialization of SIBs.
基金financially supported by the National Natural Science Foundation of China (No.21978193)the Natural Science Foundation of Shanxi Province (Nos.20210302123107, 20181102005, and 20181102019)。
文摘The effect of partial substitution of Mg for Ni on a high-sodium and lithium-free layered P2-type Na_(45/54)Mg_(6)/_(54)Ni_(12/54)Mn_(34/54)O_(2) cathode with high initial Coulombic efficiency and excellent cyclic stability has been investigated in this study.Based on the crystal structural analysis,the Mg doping can retain the P2 structure up to 4.3 V,thus restraining the detrimental phase transformation of P2-02during the Na-ion intercalation/deintercalation process.Therefore,the obtained Mg-doped P2-type cathode exhibits a reversible specific capacity of 109 mAh·g^(-1) at 0.1C between 2.0 and 4.3 V and a retention rate of 81.5% after 200cycles at 1C.In addition,the full cell consisting of Mg-doped P2-type cathode and hard carbon anode shows a capacity retention rate of 85.6% after 100 cycles.This study provides new insight into the development of durable cathode materials for sodium-ion batteries.
文摘Objective: The aim of the present study was to evaluate salt levels in popular hot takeaway meals in three large China cities, and to compare the difference in sodium content in different types of takeaway meals. Methods: We randomly collected a total of 4450 samples of 7 different types of takeaway meals, which were the most consumed by local residents from takeaway platforms. The main ingredients, auxiliary ingredients, as well as the weight used in takeaway meals were collected. The sodium content in takeaway meals was obtained by calculation. Results: Obtained results show that the sodium content in three large China cities is alarmingly high. Comparing medians (interquartile range) of takeaway meals from different cities, Beijing contained the highest sodium content per portion (1371.3 mg (890.3 - 2137.4)), followed by Hangzhou (1348.45 mg (694.25 - 1541.62)) and Shanghai (340.1 (259.75 - 942.25)). In addition, the sodium content between pasta and porridge, Chinese meals, and western meals show significant differences (p 0.05). Compared with Chinese Dietary Reference Intakes, the average sodium content exceeded dietary recommendations for one takeaway meal. The sodium content differed among takeaway meals prepared with various cooking methods and meats. Conclusion: Notable differences are detected in takeaway meals’ sodium content between several large cities in China. To meet China’s target salt intake, consumers in these cities are highly recommended to reduce sodium content in their everyday meals.
基金Supported by the National Natural Science Foundation of China(21673187,21336009,21576228)National Key Technology Support Program of China(2014BAC10B01).
文摘In this paper, Ni/Zr–Yb–O catalysts with different sodium contents are prepared by a co-precipitation method, using aqueous Na2CO3 solution as a precipitant, and the effect of sodium on the catalyst structure and catalytic performance for syngas methanation is extensively investigated using five Ni/Zr–Yb–O catalysts, containing 0, 0.5, 1.5,4.5 and 13.5 wt% Na^+, those are denoted as Cat-1, Cat-2, Cat-3, Cat-4 and Cat-5 respectively. It is found that the interaction between Ni and support determines the catalytic performance of Ni/Zr–Yb–O and the residual sodium content negatively affects the interaction between Ni and support. Cat-1 exhibits an excellent catalytic performance.During a long run time of 380 h, no deactivation is observed and both CO conversion and CH4 selectivity maintain a level above 90%. However, Cat-3 and Cat-5 suffer rapid deactivation under the same reaction condition. The characterization results indicate the strong interaction between Ni and support enables Cat-1 to possess well dispersed Ni species, resistance to sintering and carbon deposition and thus the excellent catalytic performance. However, the presence of sodium ions over Ni/Zr–Yb–O degrades the interaction between Ni and support and the catalytic performance, especially for the stability. The relative weak interaction between Ni and support results in severe sintering of both ZrO2 and Ni under the reaction condition, carbon deposition and the poor catalytic performance.
文摘Two wheat varieties with similar yield and significantly different protein content were chosen to study the effect of foliage spraying sodium bisulfite (NaHSO3) at low concentration to wheat plants receiving different levels of nitrogen on nitrate reduction along with yield and protein content of grain, so as to discuss the relationship between carbon metabolism and nitrogen metabolism, and find out the intrinsic mechanism of grain yield and protein content formation. The results showed that spraying NaHSO3 at grain-filing stage increased the yield of grain, but declined the capacity of nitrate reduction, which might result in decrease of protein content in the end. Whether receiving NaHSO, or not, the variety with high protein content had higher final protein level and nitrate reduction capacity than that with low protein content.
基金funded by the Fundamental Research Funds for the Central Universities (2016ZCQ06)the Forestry Industry Research Special Funds for Public Welfare Projects (201504402)the Application Technology of Seaweed Fertilizer Based on Desertification Control and Saline-alkili Soil Improvement (2016HXFWSBXY002)
文摘Ecological restoration by Taman＇x plants on semi-arid saline lands affects the accumulation, distribution patterns and related mechanisms of soil water content and salinity. In this study, spatio-temporal variations of soil water content and salinity around natural individual Tamarix ramosissiraa Ledeb. were invetigated in a semi-arid saline region of the upper Yellow River, Northwest China. Specifically, soil water content, electrical conductivity （EC）, sodium adsorption ratio （SARa）, and salt ions （including Na＋, K＋, Ca2＋, Mg2＋ and 8042-） were measured at different soil depths and at different distances from the trunk of T. ramasissima in May, July, and September 2016. The soil water content at the 20-80 cm depth was significantly lower in July and September than in May, indicating that T. ramosissima plants absorb a large amount of water through the roots during the growing period, leading to the decreasing of soil water content in the deep soil layer. At the 0-20 cm depth, there was a salt island effect around individual T. ramosissima, and the ECe differed significantly inside and outside the canopy of T. ramosissima in May and July. Salt bioaccumulation and stemflow were two major contributing factors to this difference. The SAR at the 0-20 cm depth was significantly different inside and outside the canopy of T. ramosissima in the three sampling months. The values of SAR~ at the 60-80 cm depth in May and July were significantly higher than those at the 0-60 cm depth and higher than that at the corresponding depth in September. The distribution of Na＋ in the soil was similar to that of the SAI, while the concentrations of K＋, Ca2＋, and Mg2＋ showed significant differences among the sampling months and soil depths. Both season and soil depth had highly significant effects on soil water content, ECe and SARa, whereas distance from the trunk of T. ramosissima only significantly affected ECe. Based on these results, we recommend co-planting of shallow-rooted salt-tolerant species near the Tamarx plants and avoiding planting herbaceous plants inside the canopy of T. ramodssima for afforestation in this semi-arid saline region. The results of this study may provide a reference for appropriate restoration in the semi-arid saline regions of the upper Yellow River.
文摘Sodium alginate is a polysaccharide that is largely obtained from the brown algae （Sargassum sp.）.It has been used as a wonderful growth promoting substance in its depolymerized form for various plants.The aim of this study was to find out the effects of various concentrations of γ-irradiated sodium alginate （ISA）,viz.,deionized water （control,T0）,20 （T1）,40 （T2）,60 （T3）,80 （T4）,and 100 ppm （T5） on the agricultural performance of Catharanthus roseus L.（Rosea） in terms of growth attributes,photosynthesis,physiological activities,and alkaloid production.The present work revealed that ISA applied as leaf-sprays at concentrations from 20 to 100 ppm might improve growth,photosynthesis,physiological activities,and alkaloid production in C.roseus L.significantly.Of the various ISA concentrations,80 ppm proved to be the best one compared to other concentrations applied.
