Sulfur utilization improvement and control of dissolved lithium polysulfide(LiPS;Li_(2)S x,2<x≤8)are cru-cial aspects of the development of lithium-sulfur(Li-S)batteries,especially in high-loading sulfur elec-trode...Sulfur utilization improvement and control of dissolved lithium polysulfide(LiPS;Li_(2)S x,2<x≤8)are cru-cial aspects of the development of lithium-sulfur(Li-S)batteries,especially in high-loading sulfur elec-trodes and low electrolyte/sulfur(E/S)ratios.The sluggish reaction in the low E/S ratio induces poor LiPS solubility and unstable Li_(2)S electrodeposition,resulting in limited sulfur utilization,especially under high-loading sulfur electrode.In this study,we report on salt concentration effects that improve sulfur utilization with a high-loading cathode(6 mgs ulfurcm^(-2)),a high sulfur content(80 wt%)and a low E/S ratio(5 m L gs ulfur^(-1)).On the basis of the rapid LiPS dissolving in a low concentration electrolyte,we estab-lished that the quantity of Li_(2)S electrodeposition from a high Li+diffusion coefficient,referring to the reduction of LiPS precipitation,was significantly enhanced by a faster kinetic.These results demonstrate the importance of kinetic factors for the rate capability and cycle life stability of Li-S battery electrolytes through high Li_(2)S deposition under high-loading sulfur electrode.展开更多
The literature shows that investor attention to customer–supplier disclosure increases when suppliers’information arrival is anticipated.Due to the widespread of city lockdowns in China and the implementation of soc...The literature shows that investor attention to customer–supplier disclosure increases when suppliers’information arrival is anticipated.Due to the widespread of city lockdowns in China and the implementation of social distancing to control the COVID-19 pandemic,investor attention to potential disruption of the supply chain spikes,leading to a price devaluation for firms with high supplier concentration risk.We find that a higher degree of supplier concentration is related to more serious stock price declines over the short-term and medium-term windows right after the Wuhan lockdown.This result lends support to the argument that the concentration risk of suppliers is a significant consideration for China stock market investors,especially under the potential financial distress at the firm level induced by the COVID-19 crisis.展开更多
In this article, we consider the continuous gas in a bounded domain ∧ of R^＋ or R^d described by a Gibbsian probability measure μη∧ associated with a pair interaction φ, the inverse temperature β, the activity...In this article, we consider the continuous gas in a bounded domain ∧ of R^＋ or R^d described by a Gibbsian probability measure μη∧ associated with a pair interaction φ, the inverse temperature β, the activity z 〉 0, and the boundary condition η. Define F ∫ωf（s）wA（ds）. Applying the generalized Ito＇s formula for forward-backward martingales （see Klein et M. [5]）, we obtain convex concentration inequalities for F with respect to the Gibbs measure μη∧. On the other hand, by FKG inequality on the Poisson space, we also give a new simple argument for the stochastic domination for the Gibbs measure.展开更多
Copper complexing ligand concentrations in the Daya Bay, Qingdao coast, Jiaozhou Bay, South China Sea and Huanghe Estuary waters were determined by the anodic stripping voltammetry technique. The distribution regulari...Copper complexing ligand concentrations in the Daya Bay, Qingdao coast, Jiaozhou Bay, South China Sea and Huanghe Estuary waters were determined by the anodic stripping voltammetry technique. The distribution regularity and the relationship with other parameters were discussed. The results were as follows： Copper complexing ligand concentrations of the South China Sea were a little higher than those of other sea areas, and they were apparently higher than those of the ocean. Compared with the subsurface layer （SSL） in the sea surface microlayer copper complexing ligand concentrations showed an enrichment phenomenon, of which the mechanism is similar to dissolved organic matter. The metal complexing ligand concentration profiles of the South China Sea showed that the value in the sea surface was the highest, then it decreased with depth accruing, and a higher value appeared at the bottom. Copper complex- ing ligand concentrations were higher than those of cadmium and lead. Ligands in each sea area exhibited a complicated property. In short, the distribution regularity of copper complexing ligand concentrations in China＇s coastal waters was consistent with that of other regions in the world. Meanwhile, the positive relationship between the copper complexing ligand concentrations and biological oxygen demand, chemical oxygen demand, dissolved organic carbon, and viscosity were found clearly.展开更多
This paper reveals the variations of S concentration among the leaf surface and other organs of variousplant species, and presents the distribution natures of S storage in the evergreen broad-leaved forest vege-tation...This paper reveals the variations of S concentration among the leaf surface and other organs of variousplant species, and presents the distribution natures of S storage in the evergreen broad-leaved forest vege-tation in Hangzhou on the basis of the tested data concerning plant S contents. The result was that theS concentrations on the tree leaf surfaces varied with the testing time and plant species. The range of Scontents in various organs of a plant was 2.086- 4.245 S g kg￣(-1), varying with plant species in this forest.The S content in the leaves was the highest, followed by that in the branches, trunks and roots, which showedthat there was an apical dominance of S distribution. The total amount of S storage in the vegetation wasas large as 349.97 S kg ha￣(-1). The S distribution in this vegetation had two characteristics as follows: 1)for the vegetation layers, arbor layer > renewal layer > herb layer > shrub layer; and 2) for the verticaldistribution per unit height (m), root stratum (0 - 0.20 m of soil depth)> stratum nearby the ground surface(0 - 0.5m) > canopy (4.0- 9.5m) > trunk stratum (2.0- 4.0m).展开更多
In engineering practice, tubular X-joints have been widely used in offshore structures. The fatigue failure of tubular X-joints in offshore engineering is mainly caused by axial tensile stress. In this study, the stre...In engineering practice, tubular X-joints have been widely used in offshore structures. The fatigue failure of tubular X-joints in offshore engineering is mainly caused by axial tensile stress. In this study, the stress concentration factor distribution along the weld toe in the hot spot stress region for tubular X-joints subject to axial loads have been analyzed by use of finite element method. Through numerical analysis, it has been found that the peak stress concentration factor is located at the saddle position. Thereafter, 80 models have been analyzed, and the effect of the geometric parameters of a tubular X-joint on the stress concentration factor has been investigated. Based on the experimental values of the numerical stress concentration factor, a parametric equation to calculate the stress concentration factor of tubular X-joints has been proposed. The accuracy of this equation has been verified against the requirement of the Fatigue Guidance Review Panel, and the proposed equation is found capable of producing reasonably accurate stress concentration factor values for tubular X-joints subject to axial loads.展开更多
A group of binary Sn-xAg alloys (x = 0.5, 1.5, 2.5, 3.5, 4.5, 5.5 and 6.5 wt%) has been produced by a single copper roller melt-spinning technique. In this study the interaction between Fermi sphere and Brillouin zone...A group of binary Sn-xAg alloys (x = 0.5, 1.5, 2.5, 3.5, 4.5, 5.5 and 6.5 wt%) has been produced by a single copper roller melt-spinning technique. In this study the interaction between Fermi sphere and Brillouin zone and Hume-Rothery condition of phase stability have been verified. It is found that by increasing valence electron concentration VEC the diameter of Fermi sphere 2kF increases which leads to the increase in the diameter of Brillouin zone which arises from the decrease in volume of the unit cell. It is found that the electrical resistivity increases by increasing VEC due to the decrease in relaxation time τ with increasing VEC. Also it has been confirmed that the correlation between Young’s modulus and the axial ratio c/a of β-Sn unit cell.展开更多
The present work gives a methodology for assessing radiological concentration of 131I, 132I, 133I, 134I, and 135I due to a hypothetical accident of TRIGA Mark-II research Reactor at AERE, Savar, Bangladesh. The concen...The present work gives a methodology for assessing radiological concentration of 131I, 132I, 133I, 134I, and 135I due to a hypothetical accident of TRIGA Mark-II research Reactor at AERE, Savar, Bangladesh. The concentrations were estimated through different pathways like ingestion of vegetation, milk, and meat from air and ground deposition. The maximum air concentrations for all 16 directions were found at 110 m distance from the core of the reactor and it was found to be highest in the southern (S) direction. The maximum ground concentration occurred immediately just after the accident in different directions. In all pathways, the most concentration was found to be in S-direction. The concentrations in vegetation of 131I, 133I, 135I were significant, while no concentrations of 132I and 134I were observed. The concentration in vegetation for 131I was found to be highest than all other isotopes of iodine. The concentrations of 133I were found to be higher and concentrations of 134I were observed to be lower in both milk and meat compared to other radio isotopes of iodine. In the case of a radiological accident, the results of the present study will be a valuable guide for adopting radiological safety measures for radiation protection against the ingestion of vegetables, milk and meat from around the research reactor at AERE, Savar, Bangladesh.展开更多
The impacts of low and high-frequency variability from teleconnections between large scale atmospheric processes and local weather as well as emissions changes on concentrations of particulate matter of 2.5 μm or les...The impacts of low and high-frequency variability from teleconnections between large scale atmospheric processes and local weather as well as emissions changes on concentrations of particulate matter of 2.5 μm or less in diameter ([PM2.5]) were examined for the Fairbanks Metropolitan Area (FMA). October to March and May to August mean [PM2.5] were 1.8 and 3.1 μg·m-3 higher for positive than negative annual mean Pacific Decadal Oscillation. Annual mean [PM2.5] were 3.8 μg·m-3 lower for positive than negative Southern Oscillation Index. On 1999-2018 average, [PM2.5] decreased 2.9 μg·m-3·decade-1. On average over October to March, decadal and inter-annual variability caused higher or similar differences in mean observed [PM2.5] and its species than emission-control measures. The 2006 implementation of Tier 2 for new vehicles decreased observed sulfate concentrations the strongest (~4.95 μg·m-3·decade-1) of all occurred emissions changes. On average, observed [PM2.5] showed elevated values at all sites when wind blew from directions of hot springs. The same was found for the sulfate, ammonium and non-metal components of PM2.5. Observations showed that these geothermal waters contain sulfate, ammonia, boric acid and non-metals. Hot springs of such composition are known to emit hydrogen sulfide and ammonia that can serve as precursors for ammonium and sulfate aerosols.展开更多
To identify interactions among evaluation criteria and describe their importance,a new identification method making use of a fuzzy measure is presented.The relative weight and interaction degree of every evaluation cr...To identify interactions among evaluation criteria and describe their importance,a new identification method making use of a fuzzy measure is presented.The relative weight and interaction degree of every evaluation criteria pair are obtained by using the diamond pairwise comparison method.Based on comparison results,the maximum eigenvector method of analytic hierarchy process （AHP）,the hierarchical clustering method,and the phi（s） transformation are utilized to generate values of the fuzzy measure for each subset of the evaluation criterion set.Overall evaluation on each supplier is aggregated by Choquet integral with respect to the fuzzy measure.Finally,an illustrative example demonstrates the practical feasibility and validity of the proposed method.展开更多
基金supported by a grant from the Korea Evaluation Institute of Industrial Technology(KEIT)funded by the Ministry of Trade,Industry and Energy(MOTIE)(No.20012341)。
文摘Sulfur utilization improvement and control of dissolved lithium polysulfide(LiPS;Li_(2)S x,2<x≤8)are cru-cial aspects of the development of lithium-sulfur(Li-S)batteries,especially in high-loading sulfur elec-trodes and low electrolyte/sulfur(E/S)ratios.The sluggish reaction in the low E/S ratio induces poor LiPS solubility and unstable Li_(2)S electrodeposition,resulting in limited sulfur utilization,especially under high-loading sulfur electrode.In this study,we report on salt concentration effects that improve sulfur utilization with a high-loading cathode(6 mgs ulfurcm^(-2)),a high sulfur content(80 wt%)and a low E/S ratio(5 m L gs ulfur^(-1)).On the basis of the rapid LiPS dissolving in a low concentration electrolyte,we estab-lished that the quantity of Li_(2)S electrodeposition from a high Li+diffusion coefficient,referring to the reduction of LiPS precipitation,was significantly enhanced by a faster kinetic.These results demonstrate the importance of kinetic factors for the rate capability and cycle life stability of Li-S battery electrolytes through high Li_(2)S deposition under high-loading sulfur electrode.
基金supported by UIC college research grant and Guangdong Office of Philosophy and Social Sci-ence Foundation(GD19CGL01).
文摘The literature shows that investor attention to customer–supplier disclosure increases when suppliers’information arrival is anticipated.Due to the widespread of city lockdowns in China and the implementation of social distancing to control the COVID-19 pandemic,investor attention to potential disruption of the supply chain spikes,leading to a price devaluation for firms with high supplier concentration risk.We find that a higher degree of supplier concentration is related to more serious stock price declines over the short-term and medium-term windows right after the Wuhan lockdown.This result lends support to the argument that the concentration risk of suppliers is a significant consideration for China stock market investors,especially under the potential financial distress at the firm level induced by the COVID-19 crisis.
文摘In this article, we consider the continuous gas in a bounded domain ∧ of R^＋ or R^d described by a Gibbsian probability measure μη∧ associated with a pair interaction φ, the inverse temperature β, the activity z 〉 0, and the boundary condition η. Define F ∫ωf（s）wA（ds）. Applying the generalized Ito＇s formula for forward-backward martingales （see Klein et M. [5]）, we obtain convex concentration inequalities for F with respect to the Gibbs measure μη∧. On the other hand, by FKG inequality on the Poisson space, we also give a new simple argument for the stochastic domination for the Gibbs measure.
基金supported by the National"Ninth Five-Year Plan"Scientific Research Project of China under contract No.979260403the National"Tenth Five-Year Plan"Scientific Research Project of China under contract No.2001CB409700+1 种基金the National Natural Science Foundation of China under contract Nos 40076020 and 40376022National Natural Science Special Key Foundation of China under contract No.40490263.
文摘Copper complexing ligand concentrations in the Daya Bay, Qingdao coast, Jiaozhou Bay, South China Sea and Huanghe Estuary waters were determined by the anodic stripping voltammetry technique. The distribution regularity and the relationship with other parameters were discussed. The results were as follows： Copper complexing ligand concentrations of the South China Sea were a little higher than those of other sea areas, and they were apparently higher than those of the ocean. Compared with the subsurface layer （SSL） in the sea surface microlayer copper complexing ligand concentrations showed an enrichment phenomenon, of which the mechanism is similar to dissolved organic matter. The metal complexing ligand concentration profiles of the South China Sea showed that the value in the sea surface was the highest, then it decreased with depth accruing, and a higher value appeared at the bottom. Copper complex- ing ligand concentrations were higher than those of cadmium and lead. Ligands in each sea area exhibited a complicated property. In short, the distribution regularity of copper complexing ligand concentrations in China＇s coastal waters was consistent with that of other regions in the world. Meanwhile, the positive relationship between the copper complexing ligand concentrations and biological oxygen demand, chemical oxygen demand, dissolved organic carbon, and viscosity were found clearly.
文摘This paper reveals the variations of S concentration among the leaf surface and other organs of variousplant species, and presents the distribution natures of S storage in the evergreen broad-leaved forest vege-tation in Hangzhou on the basis of the tested data concerning plant S contents. The result was that theS concentrations on the tree leaf surfaces varied with the testing time and plant species. The range of Scontents in various organs of a plant was 2.086- 4.245 S g kg￣(-1), varying with plant species in this forest.The S content in the leaves was the highest, followed by that in the branches, trunks and roots, which showedthat there was an apical dominance of S distribution. The total amount of S storage in the vegetation wasas large as 349.97 S kg ha￣(-1). The S distribution in this vegetation had two characteristics as follows: 1)for the vegetation layers, arbor layer > renewal layer > herb layer > shrub layer; and 2) for the verticaldistribution per unit height (m), root stratum (0 - 0.20 m of soil depth)> stratum nearby the ground surface(0 - 0.5m) > canopy (4.0- 9.5m) > trunk stratum (2.0- 4.0m).
基金The research work was financially supported by the National Natural Scientice Foundation of China(Grant No.10142001)by the Shandong Provincial Natural Scientice Foundation(Grant No.Y2006F46)
文摘In engineering practice, tubular X-joints have been widely used in offshore structures. The fatigue failure of tubular X-joints in offshore engineering is mainly caused by axial tensile stress. In this study, the stress concentration factor distribution along the weld toe in the hot spot stress region for tubular X-joints subject to axial loads have been analyzed by use of finite element method. Through numerical analysis, it has been found that the peak stress concentration factor is located at the saddle position. Thereafter, 80 models have been analyzed, and the effect of the geometric parameters of a tubular X-joint on the stress concentration factor has been investigated. Based on the experimental values of the numerical stress concentration factor, a parametric equation to calculate the stress concentration factor of tubular X-joints has been proposed. The accuracy of this equation has been verified against the requirement of the Fatigue Guidance Review Panel, and the proposed equation is found capable of producing reasonably accurate stress concentration factor values for tubular X-joints subject to axial loads.
文摘A group of binary Sn-xAg alloys (x = 0.5, 1.5, 2.5, 3.5, 4.5, 5.5 and 6.5 wt%) has been produced by a single copper roller melt-spinning technique. In this study the interaction between Fermi sphere and Brillouin zone and Hume-Rothery condition of phase stability have been verified. It is found that by increasing valence electron concentration VEC the diameter of Fermi sphere 2kF increases which leads to the increase in the diameter of Brillouin zone which arises from the decrease in volume of the unit cell. It is found that the electrical resistivity increases by increasing VEC due to the decrease in relaxation time τ with increasing VEC. Also it has been confirmed that the correlation between Young’s modulus and the axial ratio c/a of β-Sn unit cell.
文摘The present work gives a methodology for assessing radiological concentration of 131I, 132I, 133I, 134I, and 135I due to a hypothetical accident of TRIGA Mark-II research Reactor at AERE, Savar, Bangladesh. The concentrations were estimated through different pathways like ingestion of vegetation, milk, and meat from air and ground deposition. The maximum air concentrations for all 16 directions were found at 110 m distance from the core of the reactor and it was found to be highest in the southern (S) direction. The maximum ground concentration occurred immediately just after the accident in different directions. In all pathways, the most concentration was found to be in S-direction. The concentrations in vegetation of 131I, 133I, 135I were significant, while no concentrations of 132I and 134I were observed. The concentration in vegetation for 131I was found to be highest than all other isotopes of iodine. The concentrations of 133I were found to be higher and concentrations of 134I were observed to be lower in both milk and meat compared to other radio isotopes of iodine. In the case of a radiological accident, the results of the present study will be a valuable guide for adopting radiological safety measures for radiation protection against the ingestion of vegetables, milk and meat from around the research reactor at AERE, Savar, Bangladesh.
文摘The impacts of low and high-frequency variability from teleconnections between large scale atmospheric processes and local weather as well as emissions changes on concentrations of particulate matter of 2.5 μm or less in diameter ([PM2.5]) were examined for the Fairbanks Metropolitan Area (FMA). October to March and May to August mean [PM2.5] were 1.8 and 3.1 μg·m-3 higher for positive than negative annual mean Pacific Decadal Oscillation. Annual mean [PM2.5] were 3.8 μg·m-3 lower for positive than negative Southern Oscillation Index. On 1999-2018 average, [PM2.5] decreased 2.9 μg·m-3·decade-1. On average over October to March, decadal and inter-annual variability caused higher or similar differences in mean observed [PM2.5] and its species than emission-control measures. The 2006 implementation of Tier 2 for new vehicles decreased observed sulfate concentrations the strongest (~4.95 μg·m-3·decade-1) of all occurred emissions changes. On average, observed [PM2.5] showed elevated values at all sites when wind blew from directions of hot springs. The same was found for the sulfate, ammonium and non-metal components of PM2.5. Observations showed that these geothermal waters contain sulfate, ammonia, boric acid and non-metals. Hot springs of such composition are known to emit hydrogen sulfide and ammonia that can serve as precursors for ammonium and sulfate aerosols.
基金Sponsored by the National Natural Science Foundation of China(7047106370771010)
文摘To identify interactions among evaluation criteria and describe their importance,a new identification method making use of a fuzzy measure is presented.The relative weight and interaction degree of every evaluation criteria pair are obtained by using the diamond pairwise comparison method.Based on comparison results,the maximum eigenvector method of analytic hierarchy process （AHP）,the hierarchical clustering method,and the phi（s） transformation are utilized to generate values of the fuzzy measure for each subset of the evaluation criterion set.Overall evaluation on each supplier is aggregated by Choquet integral with respect to the fuzzy measure.Finally,an illustrative example demonstrates the practical feasibility and validity of the proposed method.
