目的揭示亚热带湿润气候区大气气溶胶中^(210)Pb与^(210)Po的长期动态规律及环境行为机制,评估其公众吸入辐射剂量风险。方法基于广西南宁站点2019—2023年连续监测数据,采用鲁棒性STL时间序列分解解析大气气溶胶中^(210)Pb与^(210)Po...目的揭示亚热带湿润气候区大气气溶胶中^(210)Pb与^(210)Po的长期动态规律及环境行为机制,评估其公众吸入辐射剂量风险。方法基于广西南宁站点2019—2023年连续监测数据,采用鲁棒性STL时间序列分解解析大气气溶胶中^(210)Pb与^(210)Po活度浓度的长期趋势和季节周期特征,结合Q检验验证模型可靠性;通过^(210)Pb/^(210)Po比值时间-空间差异探讨气溶胶迁移转化机制;依据ICRP 71、89号报告计算不同年龄组吸入待积有效剂量。结果^(210)Pb活度浓度年均值(1.22~2.67 m Bq/m^(3))呈显著上升趋势(复合增长率14.7%),与区域性燃煤活动及气象条件相关;^(210)Po活度浓度(0.280~0.459 m Bq/m^(3))未呈现持续趋势但存在秋冬季峰值。时间序列分解显示二者均具秋冬高、春夏低的季节周期(经Q检验,P>0.05),^(210)Pb在2022年1月、9月出现异常高值(7.20 m Bq/m^(3))。^(210)Pb/^(210)Po比值呈现季节分异:冬季最高(7.57±3.31),夏季最低(4.70±1.99),春夏季异常高比值(>9.23)反映^(210)Po强降水清除效应,秋冬季极端高值(15.4)与秸秆焚烧等突发污染事件相关。吸入剂量评估表明,成人年均待积有效剂量为9.49~33.4μSv,低于公众限值但呈现^(210)Pb贡献占比逐年升高特征。结论亚热带湿润区^(210)Pb活度增长反映人为排放与气候波动协同效应,^(210)Po季节性清除主导比值分异。虽当前辐射风险可控,但需关注秋冬排放高峰敏感人群暴露及^(210)Pb长期累积效应。本研究首次揭示了华南五年度连续放射性气溶胶特征,为湿润气候区辐射安全管控提供时序动态依据。其局限性在于未耦合气象-社会因子多维度建模。展开更多
The proof-of-stake(PoS)mechanism is a consensus protocol within blockchain technology that determines the validation of transactions and the minting of new blocks based on the participant’s stake in the cryptocurrenc...The proof-of-stake(PoS)mechanism is a consensus protocol within blockchain technology that determines the validation of transactions and the minting of new blocks based on the participant’s stake in the cryptocurrency network.In contrast to proof-of-work(PoW),which relies on computational power to validate transactions,PoS employs a deterministic and resourceefficient approach to elect validators.Whereas,an inherent risk of PoS is the potential for centralization among a small cohort of network participants possessing substantial stakes,jeopardizing system decentralization and posing security threats.To mitigate centralization issues within PoS,this study introduces an incentive-aligned mechanism named decentralized proof-of-stake(DePoS),wherein the second-largest stakeholder is chosen as the final validator with a higher probability.Integrated with the verifiable random function(VRF),DePoS rewards the largest stakeholder with uncertainty,thus disincentivizing stakeholders from accumulating the largest stake.Additionally,a dynamic evolutionary game model is innovatively developed to simulate the evolution of staking pools,thus facilitating the investigation of staking pool selection dynamics and equilibrium stability across PoS and DePoS systems.The findings demonstrate that DePoS generally fosters wealth decentralization by discouraging the accumulation of significant cryptocurrency holdings.Through theoretical analysis of stakeholder predilection in staking pool selection and the simulation of the evolutionary tendency in pool scale,this research demonstrates the comparative advantage in decentralization offered by DePoS over the conventional PoS.展开更多
The main objectives of this study were to investigate the distribution features of the ^(210)Po in abiotic(water and bottom sediments)and biotic(zooplankton,mollusks,fish)components of the North Crimean Canal(NCC)aqua...The main objectives of this study were to investigate the distribution features of the ^(210)Po in abiotic(water and bottom sediments)and biotic(zooplankton,mollusks,fish)components of the North Crimean Canal(NCC)aquatic ecosystem and adjacent irrigated soils as well as assessment of the doses received by water organisms from α-radiation of absorbed ^(210)Po.The samples were processed using standard radiochemical methods accepted in international practice.The activity of ^(210)Po in the samples was measured using the alpha-spectrometric OCTETE Plus complex(ORTEC-AMETEK,USA).The measurement error did not exceed 20%.Activity concentration of ^(210)Po in the studied objects decreased in the following rank:suspended matter(73.6 Bq/kg d.w.)>soils(32.5 Bq/kg d.w.)≈bottom sediments(32.1 Bq/kg d.w.)>mollusks(23.4 Bq/kg w.w.)>fish(6.4 Bq/kg w.w.).The ^(210)Po distribution coefficient(K_(d))values in water between suspended matter and its dissolved parts varied within the 1.4×10^(4)-1.4×10^(5) L/kg range.The concentration factors(CF)of ^(210)Po for hydrobionts of the NCC were in the range 10^(3)-10^(4) L/kg.The calculated absorbed radiation doses from ^(210)Po alpha radiation for the hydrobionts of the North Crimean Canal were significantly below the recommended dose limits.展开更多
The experiment addressed the effects of preharvest KH_(2)PO_(4)foliar spraying(20 mmol·L^(-1))on fruit quality and composition(including volatile organic compounds,VOCs)of cherry tomatoes(‘Caravaggio’,‘Sugarl...The experiment addressed the effects of preharvest KH_(2)PO_(4)foliar spraying(20 mmol·L^(-1))on fruit quality and composition(including volatile organic compounds,VOCs)of cherry tomatoes(‘Caravaggio’,‘Sugarland’and‘Top Stellina’)after 0(S0),7(S7)and 14 days(S14)of storage at 8.0°C.On the average of the 3 genotypes,the KH_(2)PO_(4)treatment improved fruit pressure firmness,total soluble solids(TSS),titratable acidity(TA),total phenols and carotenoids concentrations,along with the fruits'antioxidant capacity(by up to 17%for FRAP assay).Within the S7–S14 period,control fruits showed the highest reductions in TSS,TSS/TA ratio and total carotenoids(-17,-12 and-45,respectively),whereas treated fruits proved the strongest increase in DPPH(+12%).Sixteen out of 32 VOCs were promoted following KH_(2)PO_(4)application,including the aldehydes hexanal,(E)-2-hexenal and(Z)-3-hexenal and the apocarotenoids(E)-citral,(E)-β-ionone,geranylacetone and 6-methyl-5-hepten-2-one.Proceeding from S0 to S14,several VOCs decreased more strongly in control fruits,as for hexanal(-48%)and total aldehydes(-42%,whereas at S14 treated fruits had higher concentrations of linalool,geranylacetone and 6-methyl-5-hepten-2-one(1.06,52.50 and 79.27μg·kg^(-1),respectively).‘Caravaggio’demonstrated the strongest apocarotenoid reduction at S14,whereas‘Top Stellina’was more responsive to KH_(2)PO_(4)(mainly forβ-cyclocitral,geranylacetone and total terpenes/terpenoids),thus highlighting the central role of the genotype in responding to other experimental factors.Nonetheless,these results suggest that proper preharvest KH_(2)PO_(4)applications can preserve specific commercial,nutritional and quality traits of cold-stored cherry tomatoes.展开更多
Propylene oxide(PO),with its reactive three-membered epoxide functional group,exhibits remarkable functional versatility and serves as a crucial bridge connecting the gaps between fossil energy utilization and chemica...Propylene oxide(PO),with its reactive three-membered epoxide functional group,exhibits remarkable functional versatility and serves as a crucial bridge connecting the gaps between fossil energy utilization and chemical intermediate generation for new material innovation [1].For instance,PO's downstream derivatives,such as polyether polyols,carbonic esters,and polyurethanes,are widely utilized in wind power generation,battery electrolytes,solar cells,and CO_(2)-based degradable polymers,contributing to sustainable decarbonization in industry [2].展开更多
利用实际航摄资料评价了WGS 84和国家80坐标系下机载POS(position and orientation system)系统直接对地目标定位的精度,分析了不同大地水准面拟合方法对高程精度的影响,检校了POS系统的视准轴误差,讨论了检校场的检校结果。试验表明,基...利用实际航摄资料评价了WGS 84和国家80坐标系下机载POS(position and orientation system)系统直接对地目标定位的精度,分析了不同大地水准面拟合方法对高程精度的影响,检校了POS系统的视准轴误差,讨论了检校场的检校结果。试验表明,基于POS系统的航空遥感直接对地目标定位至少需要利用带有1个平高地面控制点的检校场对POS系统进行检校才能消除系统误差;在WGS84坐标系中,可以获得较高的定位精度,而转换到国家80坐标系下,必须对高程进行大地水准面拟合改正。展开更多
文摘目的揭示亚热带湿润气候区大气气溶胶中^(210)Pb与^(210)Po的长期动态规律及环境行为机制,评估其公众吸入辐射剂量风险。方法基于广西南宁站点2019—2023年连续监测数据,采用鲁棒性STL时间序列分解解析大气气溶胶中^(210)Pb与^(210)Po活度浓度的长期趋势和季节周期特征,结合Q检验验证模型可靠性;通过^(210)Pb/^(210)Po比值时间-空间差异探讨气溶胶迁移转化机制;依据ICRP 71、89号报告计算不同年龄组吸入待积有效剂量。结果^(210)Pb活度浓度年均值(1.22~2.67 m Bq/m^(3))呈显著上升趋势(复合增长率14.7%),与区域性燃煤活动及气象条件相关;^(210)Po活度浓度(0.280~0.459 m Bq/m^(3))未呈现持续趋势但存在秋冬季峰值。时间序列分解显示二者均具秋冬高、春夏低的季节周期(经Q检验,P>0.05),^(210)Pb在2022年1月、9月出现异常高值(7.20 m Bq/m^(3))。^(210)Pb/^(210)Po比值呈现季节分异:冬季最高(7.57±3.31),夏季最低(4.70±1.99),春夏季异常高比值(>9.23)反映^(210)Po强降水清除效应,秋冬季极端高值(15.4)与秸秆焚烧等突发污染事件相关。吸入剂量评估表明,成人年均待积有效剂量为9.49~33.4μSv,低于公众限值但呈现^(210)Pb贡献占比逐年升高特征。结论亚热带湿润区^(210)Pb活度增长反映人为排放与气候波动协同效应,^(210)Po季节性清除主导比值分异。虽当前辐射风险可控,但需关注秋冬排放高峰敏感人群暴露及^(210)Pb长期累积效应。本研究首次揭示了华南五年度连续放射性气溶胶特征,为湿润气候区辐射安全管控提供时序动态依据。其局限性在于未耦合气象-社会因子多维度建模。
文摘The proof-of-stake(PoS)mechanism is a consensus protocol within blockchain technology that determines the validation of transactions and the minting of new blocks based on the participant’s stake in the cryptocurrency network.In contrast to proof-of-work(PoW),which relies on computational power to validate transactions,PoS employs a deterministic and resourceefficient approach to elect validators.Whereas,an inherent risk of PoS is the potential for centralization among a small cohort of network participants possessing substantial stakes,jeopardizing system decentralization and posing security threats.To mitigate centralization issues within PoS,this study introduces an incentive-aligned mechanism named decentralized proof-of-stake(DePoS),wherein the second-largest stakeholder is chosen as the final validator with a higher probability.Integrated with the verifiable random function(VRF),DePoS rewards the largest stakeholder with uncertainty,thus disincentivizing stakeholders from accumulating the largest stake.Additionally,a dynamic evolutionary game model is innovatively developed to simulate the evolution of staking pools,thus facilitating the investigation of staking pool selection dynamics and equilibrium stability across PoS and DePoS systems.The findings demonstrate that DePoS generally fosters wealth decentralization by discouraging the accumulation of significant cryptocurrency holdings.Through theoretical analysis of stakeholder predilection in staking pool selection and the simulation of the evolutionary tendency in pool scale,this research demonstrates the comparative advantage in decentralization offered by DePoS over the conventional PoS.
基金supported by the Russian Science Foundation,grant number 23-26-00128,“The role of the irrigation system of the North Crimean Canal in the transfer of long-lived radionuclides of Chernobyl origin,heavy metals,as well as hydrocarbons from the Dnieper water to irrigated farmlands of the Crimea.”。
文摘The main objectives of this study were to investigate the distribution features of the ^(210)Po in abiotic(water and bottom sediments)and biotic(zooplankton,mollusks,fish)components of the North Crimean Canal(NCC)aquatic ecosystem and adjacent irrigated soils as well as assessment of the doses received by water organisms from α-radiation of absorbed ^(210)Po.The samples were processed using standard radiochemical methods accepted in international practice.The activity of ^(210)Po in the samples was measured using the alpha-spectrometric OCTETE Plus complex(ORTEC-AMETEK,USA).The measurement error did not exceed 20%.Activity concentration of ^(210)Po in the studied objects decreased in the following rank:suspended matter(73.6 Bq/kg d.w.)>soils(32.5 Bq/kg d.w.)≈bottom sediments(32.1 Bq/kg d.w.)>mollusks(23.4 Bq/kg w.w.)>fish(6.4 Bq/kg w.w.).The ^(210)Po distribution coefficient(K_(d))values in water between suspended matter and its dissolved parts varied within the 1.4×10^(4)-1.4×10^(5) L/kg range.The concentration factors(CF)of ^(210)Po for hydrobionts of the NCC were in the range 10^(3)-10^(4) L/kg.The calculated absorbed radiation doses from ^(210)Po alpha radiation for the hydrobionts of the North Crimean Canal were significantly below the recommended dose limits.
基金funded by the National Recovery and Resilience Plan(NRRP),Mission 4 Component 2 Investment 1.3—Call for proposals No.341 of 15 March 2022 of Italian Ministry of University and Research funded by the European Union—NextGenerationEU,Award Number:Project code PE00000003Concession Decree No.1550 of 11 October 2022 adopted by the Italian Ministry of University and Research,CUP E63C22002060006+1 种基金Project title“ON Foods—Research and innovation network on food and nutrition Sustainability,Safety and Security—Working ON Foodsfunded by the Italian Ministry of University and Research(MUR)under the project“Conservabilità,qualitàe sicurezza dei prodotti ortofrutticoli ad alto contenuto di servizio-ARS01_00640–POFACS”(Grant Nos.D.D.1211/2020 and 1104/2021).
文摘The experiment addressed the effects of preharvest KH_(2)PO_(4)foliar spraying(20 mmol·L^(-1))on fruit quality and composition(including volatile organic compounds,VOCs)of cherry tomatoes(‘Caravaggio’,‘Sugarland’and‘Top Stellina’)after 0(S0),7(S7)and 14 days(S14)of storage at 8.0°C.On the average of the 3 genotypes,the KH_(2)PO_(4)treatment improved fruit pressure firmness,total soluble solids(TSS),titratable acidity(TA),total phenols and carotenoids concentrations,along with the fruits'antioxidant capacity(by up to 17%for FRAP assay).Within the S7–S14 period,control fruits showed the highest reductions in TSS,TSS/TA ratio and total carotenoids(-17,-12 and-45,respectively),whereas treated fruits proved the strongest increase in DPPH(+12%).Sixteen out of 32 VOCs were promoted following KH_(2)PO_(4)application,including the aldehydes hexanal,(E)-2-hexenal and(Z)-3-hexenal and the apocarotenoids(E)-citral,(E)-β-ionone,geranylacetone and 6-methyl-5-hepten-2-one.Proceeding from S0 to S14,several VOCs decreased more strongly in control fruits,as for hexanal(-48%)and total aldehydes(-42%,whereas at S14 treated fruits had higher concentrations of linalool,geranylacetone and 6-methyl-5-hepten-2-one(1.06,52.50 and 79.27μg·kg^(-1),respectively).‘Caravaggio’demonstrated the strongest apocarotenoid reduction at S14,whereas‘Top Stellina’was more responsive to KH_(2)PO_(4)(mainly forβ-cyclocitral,geranylacetone and total terpenes/terpenoids),thus highlighting the central role of the genotype in responding to other experimental factors.Nonetheless,these results suggest that proper preharvest KH_(2)PO_(4)applications can preserve specific commercial,nutritional and quality traits of cold-stored cherry tomatoes.
基金supported by the National Natural Science Foundation of China (29792072, 22278441, 22478452)National Key Research and Development Program of China (937) (2006CB202508)the SINOPEC Project (419019-2, 413108)。
文摘Propylene oxide(PO),with its reactive three-membered epoxide functional group,exhibits remarkable functional versatility and serves as a crucial bridge connecting the gaps between fossil energy utilization and chemical intermediate generation for new material innovation [1].For instance,PO's downstream derivatives,such as polyether polyols,carbonic esters,and polyurethanes,are widely utilized in wind power generation,battery electrolytes,solar cells,and CO_(2)-based degradable polymers,contributing to sustainable decarbonization in industry [2].
文摘利用实际航摄资料评价了WGS 84和国家80坐标系下机载POS(position and orientation system)系统直接对地目标定位的精度,分析了不同大地水准面拟合方法对高程精度的影响,检校了POS系统的视准轴误差,讨论了检校场的检校结果。试验表明,基于POS系统的航空遥感直接对地目标定位至少需要利用带有1个平高地面控制点的检校场对POS系统进行检校才能消除系统误差;在WGS84坐标系中,可以获得较高的定位精度,而转换到国家80坐标系下,必须对高程进行大地水准面拟合改正。
