Human-emitted greenhouse gases(GHGs)have resulted in a long-term and unequivocal warming of the planet(IPCC,2019).More than 90%of the excess heat is stored within the world's oceans,where it accumulates and causes...Human-emitted greenhouse gases(GHGs)have resulted in a long-term and unequivocal warming of the planet(IPCC,2019).More than 90%of the excess heat is stored within the world's oceans,where it accumulates and causes increases in ocean temperature(Rhein et al.,2013;Abram et al.,2019).展开更多
目的探讨Astograph法乙酰甲胆碱气道反应性测定对胸闷变异性哮喘的诊断价值。方法将2011年1月至2017年2月华北理工大学附属开滦总医院呼吸内科门诊或住院的胸闷变异性哮喘患者156例作为病例组(胸闷变异性哮喘组),将同期确诊间质性肺疾病...目的探讨Astograph法乙酰甲胆碱气道反应性测定对胸闷变异性哮喘的诊断价值。方法将2011年1月至2017年2月华北理工大学附属开滦总医院呼吸内科门诊或住院的胸闷变异性哮喘患者156例作为病例组(胸闷变异性哮喘组),将同期确诊间质性肺疾病(23例)、冠心病(157例)、高血压性心脏病(22例)、心肌病(16例)、先天性心脏病(3例)、风湿性心脏瓣膜病(6例)、中心气道病变(3例)、甲状腺肿大(10例)、纵隔肿瘤(5例)、胸廓或脊柱畸形(8例)、膈肌麻痹症(2例)及自主神经功能紊乱(106例)的非哮喘患者361例做为对照组。所有受试者均行肺通气功能检查、呼吸流量峰值(peak expiratory flow,PEF)平均每日昼夜变异率或PEF周变异率、Astograph法乙酰甲胆碱气道反应性测定[基础第一秒用力呼气容积(Forced expiratory volume in one second,FEV1)≥70%预计值时]检查及引起胸闷的各种疾病的相关检查。通过分析Astograph法乙酰甲胆碱气道反应性测定诊断胸闷变异型哮喘的敏感度、特异度、阳性预测值、阴性预测值、诊断准确性及Yunden指数,探讨Astograph法乙酰甲胆碱气道反应性测定对胸闷变异型哮喘的诊断价值。结果胸闷变异性哮喘组与对照组比较用力呼气75%肺活量时气道流速差异有统计学意义[1.18±0.44)%与(1.29±0.50)%;t=2.96,P=0.006]。Astograph法乙酰甲胆碱气道反应性测定诊断胸闷变异型哮喘的敏感度、特异度、阳性预测值、阴性预测值、Yunden指数及诊断准确性分别为0.81、0.69、0.53、0.30、0.50及0.73。结论Astograph法乙酰甲胆碱气道反应性测定诊断胸闷变异性哮喘的敏感度、阴性预测值、Youden指数和诊断准确性均较高,特异度和阳性预测值偏低,提示Astograph法乙酰甲胆碱气道反应性测定对胸闷变异性哮喘有较高的诊断价值,假阴性偏低,假阳性略高。展开更多
Layered Ni-rich materials for lithium-ion batteries exhibit high discharge capacities but degraded cyclability at the same time.The limited cycling stability originates from many aspects.One of the critical factors is...Layered Ni-rich materials for lithium-ion batteries exhibit high discharge capacities but degraded cyclability at the same time.The limited cycling stability originates from many aspects.One of the critical factors is the intrinsic insulating residual lithium compounds and the rock-salt(NiO)phase on the surface of particles.In this work,LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) material is etched with a trace amount of boric acid and used as a model to demonstrate the influences of weak acid treatment on the surface phase regulations.After the etching process,the pH of the material is reduced from 12.08 to 11.82,along with a lower cation mixing degree and promoting electrochemical performances.Corresponding measurements demonstrate that weak acids such as H_(3)BO_(3) can also etch the NiO phase on the surface to adjust the surface of the particles to a pure layered structure.This process improves the lithium-ion diffusion and electron transport in the interface between material and electrolyte,consequently leading to better cycling performance and rate capability.This study provides a novel strategy and comprehensive understanding of acid modification and surface phase regulation process of Ni-rich cathode materials for lithium-ion batteries.展开更多
The increased concentration of greenhouse gases in the atmosphere from human activities traps heat within the climate system and increases ocean heat content(OHC). Here, we provide the first analysis of recent OHC cha...The increased concentration of greenhouse gases in the atmosphere from human activities traps heat within the climate system and increases ocean heat content(OHC). Here, we provide the first analysis of recent OHC changes through 2021 from two international groups. The world ocean, in 2021, was the hottest ever recorded by humans, and the 2021 annual OHC value is even higher than last year’s record value by 14 ± 11 ZJ(1 zetta J = 1021 J) using the IAP/CAS dataset and by16 ± 10 ZJ using NCEI/NOAA dataset. The long-term ocean warming is larger in the Atlantic and Southern Oceans than in other regions and is mainly attributed, via climate model simulations, to an increase in anthropogenic greenhouse gas concentrations. The year-to-year variation of OHC is primarily tied to the El Nino-Southern Oscillation(ENSO). In the seven maritime domains of the Indian, Tropical Atlantic, North Atlantic, Northwest Pacific, North Pacific, Southern oceans,and the Mediterranean Sea, robust warming is observed but with distinct inter-annual to decadal variability. Four out of seven domains showed record-high heat content in 2021. The anomalous global and regional ocean warming established in this study should be incorporated into climate risk assessments, adaptation, and mitigation.展开更多
The distribution characteristics of phosphorus （P） forms in the sediment profile of Lake Erhai, in southwestern China has been investigated by sequential extraction and 31p nuclear magnetic resonance spectroscopy （...The distribution characteristics of phosphorus （P） forms in the sediment profile of Lake Erhai, in southwestern China has been investigated by sequential extraction and 31p nuclear magnetic resonance spectroscopy （NMR） of NaOH extracts to understand P dynamics and its potential contribution to lake eutrophication. Contents of P fractions varied in the order of NH4C1 extracted P （NH4C1- P） 〈 bicarbonate-dithionite extracted P （BD-P） 〈 HC1-P, Residual-P 〈 NaOH extracted P （NaOH-P）. The highly available NH4C1-P represented less than 1% of total P （TP）. BD-P and NaOH extracted reactive P （NaOH-rP） averaged 39%, while the ratio of Fe/P was higher than 15, indicating low P release from the sediments under permanent oxic condition. The less bio-available HC1-P, NaOH extracted nonreactive P （NaOH-nrP） and residual-P contributed 61% of TP. Regression analysis revealed that BD-P, NaOH-rP and HC1-P were positively correlated with the contents of Fe and Mn, A1 and Fe, and Ca, respectively. The investigation of P compound groups in NaOH extracts by 31p NMR showed that ortho-P and monoester-P were the largest two constituents of the P pool, followed by diester-P, phosphonate and pyro-P. A comparison of vertical variations of P groups in the sediment profile suggested that these compounds were involved in the P recycling to different extents in Lake Erhai. In particular, the lake exhibits high potential for labile P release from the surface sediments, which should be taken into consideration even after the outsourced P runoff ceased.展开更多
The global physical and biogeochemical environment has been substantially altered in response to increased atmospheric greenhouse gases from human activities.In 2023,the sea surface temperature(SST)and upper 2000 m oc...The global physical and biogeochemical environment has been substantially altered in response to increased atmospheric greenhouse gases from human activities.In 2023,the sea surface temperature(SST)and upper 2000 m ocean heat content(OHC)reached record highs.The 0–2000 m OHC in 2023 exceeded that of 2022 by 15±10 ZJ(1 Zetta Joules=1021 Joules)(updated IAP/CAS data);9±5 ZJ(NCEI/NOAA data).The Tropical Atlantic Ocean,the Mediterranean Sea,and southern oceans recorded their highest OHC observed since the 1950s.Associated with the onset of a strong El Niño,the global SST reached its record high in 2023 with an annual mean of~0.23℃ higher than 2022 and an astounding>0.3℃ above 2022 values for the second half of 2023.The density stratification and spatial temperature inhomogeneity indexes reached their highest values in 2023.展开更多
Changes in ocean heat content(OHC), salinity, and stratification provide critical indicators for changes in Earth’s energy and water cycles. These cycles have been profoundly altered due to the emission of greenhouse...Changes in ocean heat content(OHC), salinity, and stratification provide critical indicators for changes in Earth’s energy and water cycles. These cycles have been profoundly altered due to the emission of greenhouse gasses and other anthropogenic substances by human activities, driving pervasive changes in Earth’s climate system. In 2022, the world’s oceans, as given by OHC, were again the hottest in the historical record and exceeded the previous 2021 record maximum.According to IAP/CAS data, the 0–2000 m OHC in 2022 exceeded that of 2021 by 10.9 ± 8.3 ZJ(1 Zetta Joules = 1021Joules);and according to NCEI/NOAA data, by 9.1 ± 8.7 ZJ. Among seven regions, four basins(the North Pacific, North Atlantic, the Mediterranean Sea, and southern oceans) recorded their highest OHC since the 1950s. The salinity-contrast index, a quantification of the “salty gets saltier–fresh gets fresher” pattern, also reached its highest level on record in 2022,implying continued amplification of the global hydrological cycle. Regional OHC and salinity changes in 2022 were dominated by a strong La Ni?a event. Global upper-ocean stratification continued its increasing trend and was among the top seven in 2022.展开更多
Microstructure, electrical conductivity, and electromagnetic interference(EMI) shielding effectiveness(SE) of cast Mg-x Zn-y Y(x = 2–5, y = 1–10) alloys were systematically investigated to understand the effects of ...Microstructure, electrical conductivity, and electromagnetic interference(EMI) shielding effectiveness(SE) of cast Mg-x Zn-y Y(x = 2–5, y = 1–10) alloys were systematically investigated to understand the effects of Zn and Y additions on electrical conductivity and electromagnetic shielding effectiveness of the alloys.Experimental results indicate that the electrical conductivity and SE of the Mg-x Zn-y Y alloys decrease with Y/Zn ratio. Electrical conductivity is the main factor that affects the electromagnetic shielding properties and the variation tendency of electromagnetic shielding properties of the Mg-x Zn-y Y alloys is consistent with conductivity. Valence of Y and Zn atoms, configuration of extranuclear electron and volumetric difference are main reasons for the variations in the electrical conductivity. A high density of second phase and the formation of semi-continuous network structure can also improve the SE value at high frequencies.展开更多
基金supported by the National Key Research and Development Program of China (Grant Nos. 2016YFC1401806 and 2017YFA0603202)sponsored by the US National Science Foundation+2 种基金funded in partnership with the NOAA OAR Ocean Observing and Monitoring Divisionpartially supported by the Regional and Global Model Analysis (RGMA) component of the Earth and Environmental System Modeling Program of the U.S. Department of Energy’s Office of Biological & Environmental Research (BER) via National Science Foundation IA 1844590supported in part by NSF Award #AGS-1419571
文摘Human-emitted greenhouse gases(GHGs)have resulted in a long-term and unequivocal warming of the planet(IPCC,2019).More than 90%of the excess heat is stored within the world's oceans,where it accumulates and causes increases in ocean temperature(Rhein et al.,2013;Abram et al.,2019).
文摘目的探讨Astograph法乙酰甲胆碱气道反应性测定对胸闷变异性哮喘的诊断价值。方法将2011年1月至2017年2月华北理工大学附属开滦总医院呼吸内科门诊或住院的胸闷变异性哮喘患者156例作为病例组(胸闷变异性哮喘组),将同期确诊间质性肺疾病(23例)、冠心病(157例)、高血压性心脏病(22例)、心肌病(16例)、先天性心脏病(3例)、风湿性心脏瓣膜病(6例)、中心气道病变(3例)、甲状腺肿大(10例)、纵隔肿瘤(5例)、胸廓或脊柱畸形(8例)、膈肌麻痹症(2例)及自主神经功能紊乱(106例)的非哮喘患者361例做为对照组。所有受试者均行肺通气功能检查、呼吸流量峰值(peak expiratory flow,PEF)平均每日昼夜变异率或PEF周变异率、Astograph法乙酰甲胆碱气道反应性测定[基础第一秒用力呼气容积(Forced expiratory volume in one second,FEV1)≥70%预计值时]检查及引起胸闷的各种疾病的相关检查。通过分析Astograph法乙酰甲胆碱气道反应性测定诊断胸闷变异型哮喘的敏感度、特异度、阳性预测值、阴性预测值、诊断准确性及Yunden指数,探讨Astograph法乙酰甲胆碱气道反应性测定对胸闷变异型哮喘的诊断价值。结果胸闷变异性哮喘组与对照组比较用力呼气75%肺活量时气道流速差异有统计学意义[1.18±0.44)%与(1.29±0.50)%;t=2.96,P=0.006]。Astograph法乙酰甲胆碱气道反应性测定诊断胸闷变异型哮喘的敏感度、特异度、阳性预测值、阴性预测值、Yunden指数及诊断准确性分别为0.81、0.69、0.53、0.30、0.50及0.73。结论Astograph法乙酰甲胆碱气道反应性测定诊断胸闷变异性哮喘的敏感度、阴性预测值、Youden指数和诊断准确性均较高,特异度和阳性预测值偏低,提示Astograph法乙酰甲胆碱气道反应性测定对胸闷变异性哮喘有较高的诊断价值,假阴性偏低,假阳性略高。
基金National Key Research and Development Program of China(2021YFB2401800)National Natural Science Foundation of China(2217090605 and 21875022)Natural Science Foundation of Chongqing,China(cstc2020jcyj-msxmX0654 and cstc2020jcyj-msxmX0589).
文摘Layered Ni-rich materials for lithium-ion batteries exhibit high discharge capacities but degraded cyclability at the same time.The limited cycling stability originates from many aspects.One of the critical factors is the intrinsic insulating residual lithium compounds and the rock-salt(NiO)phase on the surface of particles.In this work,LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) material is etched with a trace amount of boric acid and used as a model to demonstrate the influences of weak acid treatment on the surface phase regulations.After the etching process,the pH of the material is reduced from 12.08 to 11.82,along with a lower cation mixing degree and promoting electrochemical performances.Corresponding measurements demonstrate that weak acids such as H_(3)BO_(3) can also etch the NiO phase on the surface to adjust the surface of the particles to a pure layered structure.This process improves the lithium-ion diffusion and electron transport in the interface between material and electrolyte,consequently leading to better cycling performance and rate capability.This study provides a novel strategy and comprehensive understanding of acid modification and surface phase regulation process of Ni-rich cathode materials for lithium-ion batteries.
基金supported by the National Natural Science Foundation of China(Grant No.42122046,42076202)Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB42040402)+5 种基金National Natural Science Foundation of China(Grant No.42076202)National Key R&D Program of China(Grant No.2017YFA0603202)Key Deployment Project of Centre for Ocean Mega-Research of Science,CAS(Grant Nos.COMS2019Q01 and COMS2019Q07)NCAR is sponsored by the US National Science Foundationsupported by NASA Award 80NSSC17K0565the Regional and Global Model Analysis(RGMA)component of the Earth and Environmental System Modeling Program of the U.S.Department of Energy’s Office of Biological&Environmental Research(BER)via National Science Foundation IA 1844590。
文摘The increased concentration of greenhouse gases in the atmosphere from human activities traps heat within the climate system and increases ocean heat content(OHC). Here, we provide the first analysis of recent OHC changes through 2021 from two international groups. The world ocean, in 2021, was the hottest ever recorded by humans, and the 2021 annual OHC value is even higher than last year’s record value by 14 ± 11 ZJ(1 zetta J = 1021 J) using the IAP/CAS dataset and by16 ± 10 ZJ using NCEI/NOAA dataset. The long-term ocean warming is larger in the Atlantic and Southern Oceans than in other regions and is mainly attributed, via climate model simulations, to an increase in anthropogenic greenhouse gas concentrations. The year-to-year variation of OHC is primarily tied to the El Nino-Southern Oscillation(ENSO). In the seven maritime domains of the Indian, Tropical Atlantic, North Atlantic, Northwest Pacific, North Pacific, Southern oceans,and the Mediterranean Sea, robust warming is observed but with distinct inter-annual to decadal variability. Four out of seven domains showed record-high heat content in 2021. The anomalous global and regional ocean warming established in this study should be incorporated into climate risk assessments, adaptation, and mitigation.
基金supported by the National Natural Science Foundation of China (No. 40903052,41273151)the National Basic Research Program (973) of China (No.2008CB418006)the opening foundation of Guizhou University (No. 2009GDGP0105)
文摘The distribution characteristics of phosphorus （P） forms in the sediment profile of Lake Erhai, in southwestern China has been investigated by sequential extraction and 31p nuclear magnetic resonance spectroscopy （NMR） of NaOH extracts to understand P dynamics and its potential contribution to lake eutrophication. Contents of P fractions varied in the order of NH4C1 extracted P （NH4C1- P） 〈 bicarbonate-dithionite extracted P （BD-P） 〈 HC1-P, Residual-P 〈 NaOH extracted P （NaOH-P）. The highly available NH4C1-P represented less than 1% of total P （TP）. BD-P and NaOH extracted reactive P （NaOH-rP） averaged 39%, while the ratio of Fe/P was higher than 15, indicating low P release from the sediments under permanent oxic condition. The less bio-available HC1-P, NaOH extracted nonreactive P （NaOH-nrP） and residual-P contributed 61% of TP. Regression analysis revealed that BD-P, NaOH-rP and HC1-P were positively correlated with the contents of Fe and Mn, A1 and Fe, and Ca, respectively. The investigation of P compound groups in NaOH extracts by 31p NMR showed that ortho-P and monoester-P were the largest two constituents of the P pool, followed by diester-P, phosphonate and pyro-P. A comparison of vertical variations of P groups in the sediment profile suggested that these compounds were involved in the P recycling to different extents in Lake Erhai. In particular, the lake exhibits high potential for labile P release from the surface sediments, which should be taken into consideration even after the outsourced P runoff ceased.
基金supported by the National Natural Science Foundation of China (Grant Nos. 42076202, 42122046, 42206208 and 42261134536)the Open Research Cruise NORC2022-10+NORC2022-303 supported by NSFC shiptime Sharing Projects 42149910+7 种基金the new Cornerstone Science Foundation through the XPLORER PRIZE, DAMO Academy Young Fellow, Youth Innovation Promotion Association, Chinese Academy of SciencesNational Key Scientific and Technological Infrastructure project “Earth System Science Numerical Simulator Facility” (EarthLab)sponsored by the US National Science Foundationsupported by NASA Awards 80NSSC17K0565, 80NSSC21K1191, and 80NSSC22K0046by the Regional and Global Model Analysis (RGMA) component of the Earth and Environmental System Modeling Program of the U.S. Department of Energy’s Office of Biological & Environmental Research (BER) via National Science Foundation IA 1947282supported by NOAA (Grant No. NA19NES4320002 to CISESS-MD at the University of Maryland)supported by the Young Talent Support Project of Guangzhou Association for Science and Technologyfunded by the Istituto Nazionale di Geofisica e Vulcanologia (INGV) in agreement between INGV, ENEA, and GNV SpA shipping company that provides hospitality on its commercial vessels
文摘The global physical and biogeochemical environment has been substantially altered in response to increased atmospheric greenhouse gases from human activities.In 2023,the sea surface temperature(SST)and upper 2000 m ocean heat content(OHC)reached record highs.The 0–2000 m OHC in 2023 exceeded that of 2022 by 15±10 ZJ(1 Zetta Joules=1021 Joules)(updated IAP/CAS data);9±5 ZJ(NCEI/NOAA data).The Tropical Atlantic Ocean,the Mediterranean Sea,and southern oceans recorded their highest OHC observed since the 1950s.Associated with the onset of a strong El Niño,the global SST reached its record high in 2023 with an annual mean of~0.23℃ higher than 2022 and an astounding>0.3℃ above 2022 values for the second half of 2023.The density stratification and spatial temperature inhomogeneity indexes reached their highest values in 2023.
基金supported by the National Natural Science Foundation of China (Grant Nos. 42122046 and 42076202)the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDB42040402)+4 种基金sponsored by the US National Science Foundationsupported by NASA Awards 80NSSC17K0565 and 80NSSC22K0046by the Regional and Global Model Analysis (RGMA) component of the Earth and Environmental System Modeling Program of the U.S. Department of Energy’s Office of Biological & Environmental Research (BER) via National Science Foundation IA 1947282supported by NOAA (Grant No. NA19NES4320002 to CISESS-MD at the University of Maryland)supported by the Young Talent Support Project of Guangzhou Association for Science and Technology。
文摘Changes in ocean heat content(OHC), salinity, and stratification provide critical indicators for changes in Earth’s energy and water cycles. These cycles have been profoundly altered due to the emission of greenhouse gasses and other anthropogenic substances by human activities, driving pervasive changes in Earth’s climate system. In 2022, the world’s oceans, as given by OHC, were again the hottest in the historical record and exceeded the previous 2021 record maximum.According to IAP/CAS data, the 0–2000 m OHC in 2022 exceeded that of 2021 by 10.9 ± 8.3 ZJ(1 Zetta Joules = 1021Joules);and according to NCEI/NOAA data, by 9.1 ± 8.7 ZJ. Among seven regions, four basins(the North Pacific, North Atlantic, the Mediterranean Sea, and southern oceans) recorded their highest OHC since the 1950s. The salinity-contrast index, a quantification of the “salty gets saltier–fresh gets fresher” pattern, also reached its highest level on record in 2022,implying continued amplification of the global hydrological cycle. Regional OHC and salinity changes in 2022 were dominated by a strong La Ni?a event. Global upper-ocean stratification continued its increasing trend and was among the top seven in 2022.
基金the National Key R&D Program of China(2016YFB0301100)the National Natural Science Foundation of China(51571043 and 51531002)+1 种基金the Fundamental Research Funds for the Central Universities(2018CDJDCL0019and cqu2018CDHB1A08)Chongqing Technology Innovation and Application Demonstration(Social and Livelihood)Project(cstc2018jscx-msybX0090)
文摘Microstructure, electrical conductivity, and electromagnetic interference(EMI) shielding effectiveness(SE) of cast Mg-x Zn-y Y(x = 2–5, y = 1–10) alloys were systematically investigated to understand the effects of Zn and Y additions on electrical conductivity and electromagnetic shielding effectiveness of the alloys.Experimental results indicate that the electrical conductivity and SE of the Mg-x Zn-y Y alloys decrease with Y/Zn ratio. Electrical conductivity is the main factor that affects the electromagnetic shielding properties and the variation tendency of electromagnetic shielding properties of the Mg-x Zn-y Y alloys is consistent with conductivity. Valence of Y and Zn atoms, configuration of extranuclear electron and volumetric difference are main reasons for the variations in the electrical conductivity. A high density of second phase and the formation of semi-continuous network structure can also improve the SE value at high frequencies.
