BACKGROUND Blood glucose and serum albumin have been associated with cardiovascular disease prognosis,but the impact of admission-blood-glucose-to-albumin ratio(AAR)on adverse outcomes in critical ill coronary artery ...BACKGROUND Blood glucose and serum albumin have been associated with cardiovascular disease prognosis,but the impact of admission-blood-glucose-to-albumin ratio(AAR)on adverse outcomes in critical ill coronary artery disease(CAD)patients was not investigated.METHODS Patients diagnosed with CAD were non-consecutively selected from the MIMIC-IV database and categorized into quartiles based on their AAR.The primary outcome was 1-year mortality,and secondary endpoints were in-hospital mortality,acute kidney injury(AKI),and renal replacement therapy(RRT).A restricted cubic splines model and Cox proportional hazard models assessed the association between AAR and adverse outcomes in CAD patients.Kaplan-Meier survival analysis determined differences in endpoints across subgroups.RESULTS A total of 8360 patients were included.There were 726 patients(8.7%)died in the hospital and 1944 patients(23%)died at 1 year.The incidence of AKI and RRT was 63%and 4.3%,respectively.High AAR was markedly associated with in-hospital mortality(HR=1.587,P=0.003),1-year mortality(HR=1.502,P<0.001),AKI incidence(HR=1.579,P<0.001),and RRT(HR=1.640,P<0.016)in CAD patients in the completely adjusted Cox proportional hazard model.Kaplan-Meier survival analysis noted substantial differences in all endpoints based on AAR quartiles.Stratified analysis and interaction test demonstrated stable correlations between AAR and outcomes.CONCLUSIONS The results highlight that AAR may be a potential indicator for assessing in-hospital mortality,1-year mortality,and adverse renal prognosis in critical CAD patients.展开更多
Damage to electrical equipment in an earthquake can lead to power outage of power systems.Seismic fragility analysis is a common method to assess the seismic reliability of electrical equipment.To further guarantee th...Damage to electrical equipment in an earthquake can lead to power outage of power systems.Seismic fragility analysis is a common method to assess the seismic reliability of electrical equipment.To further guarantee the efficiency of analysis,multi-source uncertainties including the structure itself and seismic excitation need to be considered.A method for seismic fragility analysis that reflects structural and seismic parameter uncertainty was developed in this study.The proposed method used a random sampling method based on Latin hypercube sampling(LHS)to account for the structure parameter uncertainty and the group structure characteristics of electrical equipment.Then,logistic Lasso regression(LLR)was used to find the seismic fragility surface based on double ground motion intensity measures(IM).The seismic fragility based on the finite element model of an±1000 kV main transformer(UHVMT)was analyzed using the proposed method.The results show that the seismic fragility function obtained by this method can be used to construct the relationship between the uncertainty parameters and the failure probability.The seismic fragility surface did not only provide the probabilities of seismic damage states under different IMs,but also had better stability than the fragility curve.Furthermore,the sensitivity analysis of the structural parameters revealed that the elastic module of the bushing and the height of the high-voltage bushing may have a greater influence.展开更多
As a key material for lithium metal batteries(LMBs),lithium metal is one of the most promising anode materials to break the bottleneck of battery energy density and a commonly used active material for reference electr...As a key material for lithium metal batteries(LMBs),lithium metal is one of the most promising anode materials to break the bottleneck of battery energy density and a commonly used active material for reference electrodes.Although lithium anodes are regarded as the holy grail of lithium batteries,decades of exploration have not led to the successful commercialization of LMBs,due mainly to the challenges related to the inherent properties of lithium metal.To pave the way for further investigation,herein,a comprehensive review focusing on the fundamental science of lithium are provided.Firstly,the natures of lithium atoms and their isotopes,lithium clusters and lithium crystals are revisited,especially their structural and energetic properties.Subsequently,the electrochemical properties of lithium metal are reviewed.Numerous important concepts and scientific questions,including the electronic structure of lithium,influence of high pressure and low temperature on the properties of lithium,factors influencing lithium deposition,generation of lithium dendrites,and electrode potential of lithium in different electrolytes,are explained and analyzed in detail.Approaches to improve the performance of lithium anodes and thoughtfulness about the electrode potential in lithium battery research are proposed.展开更多
基于钻井、测井、实验分析及生产等资料,以磨溪气田嘉二气藏主力产层嘉二^(2)亚段B层(T_(1)j_(2)^(2B))白云岩储层为研究对象,利用流动单元来表征气藏白云岩储层非均质性,通过对比流动层带指数、孔喉半径(R_(35))及聚类分析的流动单元...基于钻井、测井、实验分析及生产等资料,以磨溪气田嘉二气藏主力产层嘉二^(2)亚段B层(T_(1)j_(2)^(2B))白云岩储层为研究对象,利用流动单元来表征气藏白云岩储层非均质性,通过对比流动层带指数、孔喉半径(R_(35))及聚类分析的流动单元划分方法,在取心井流动单元的研究基础上,利用多元回归的方式定量评价FZI(Flow Zone Index)值,未取心井通过fisher判别分析函数精细划分.从压汞参数与生产动态资料验证其流动单元划分合理性.研究结果表明:对于薄层的白云岩储层,采用流动层带指数法划分的流动单元为一组具有较好孔渗关系的岩石类型,R_(35)所划分的流动单元为一组具有相似孔喉半径(不同孔隙度有着相近的渗透率)的岩石类型,通过聚类方法,能将具有相似的孔隙结构的储层归位一类流动单元;流动层带指数的测井识别是流动单元划分的难点,机器学习、神经网络等算法对于精度具有较大提升,但需要大量数据,对于研究区,常规的线性回归方式成为了最佳的选择;流动单元预测结果与压汞参数、初期产能存在较强相关性,流动单元划分结果可靠,可为后续气藏的开发提供参考.展开更多
To ensure the long-term safety and stability of bridge pile foundations in permafrost regions,it is necessary to investigate the rheological effects on the pile tip and pile side bearing capacities.The creep character...To ensure the long-term safety and stability of bridge pile foundations in permafrost regions,it is necessary to investigate the rheological effects on the pile tip and pile side bearing capacities.The creep characteristics of the pile-frozen soil interface are critical for determining the long-term stability of permafrost pile foundations.This study utilized a self-developed large stress-controlled shear apparatus to investigate the shear creep characteristics of the frozen silt-concrete interface,and examined the influence of freezing temperatures(−1,−2,and−5°C),contact surface roughness(0,0.60,0.75,and 1.15 mm),normal stress(50,100,and 150 kPa),and shear stress on the creep characteristics of the contact surface.By incorporating the contact surface’s creep behavior and development trends,we established a creep constitutive model for the frozen silt-concrete interface based on the Nishihara model,introducing nonlinear elements and a damage factor.The results revealed significant creep effects on the frozen silt-concrete interface under constant load,with creep displacement at approximately 2-15 times the instantaneous displacement and a failure creep displacement ranging from 6 to 8 mm.Under different experimental conditions,the creep characteristics of the frozen silt-concrete interface varied.A larger roughness,lower freezing temperatures,and higher normal stresses resulted in a longer sample attenuation creep time,a lower steady-state creep rate,higher long-term creep strength,and stronger creep stability.Building upon the Nishihara model,we considered the influence of shear stress and time on the viscoelastic viscosity coefficient and introduced a damage factor to the viscoplasticity.The improved model effectively described the entire creep process of the frozen silt-concrete interface.The results provide theoretical support for the interaction between pile and soil in permafrost regions.展开更多
基金supported by the National Nature Science Foundation of China(No.82370336&No.82330014)the Key Research and Development Plan of Heilongjiang Province(2022ZX06C23&JD2023SJ44)the Research Project of the First Affiliated Hospital of Harbin Medical University(No.2021M19).
文摘BACKGROUND Blood glucose and serum albumin have been associated with cardiovascular disease prognosis,but the impact of admission-blood-glucose-to-albumin ratio(AAR)on adverse outcomes in critical ill coronary artery disease(CAD)patients was not investigated.METHODS Patients diagnosed with CAD were non-consecutively selected from the MIMIC-IV database and categorized into quartiles based on their AAR.The primary outcome was 1-year mortality,and secondary endpoints were in-hospital mortality,acute kidney injury(AKI),and renal replacement therapy(RRT).A restricted cubic splines model and Cox proportional hazard models assessed the association between AAR and adverse outcomes in CAD patients.Kaplan-Meier survival analysis determined differences in endpoints across subgroups.RESULTS A total of 8360 patients were included.There were 726 patients(8.7%)died in the hospital and 1944 patients(23%)died at 1 year.The incidence of AKI and RRT was 63%and 4.3%,respectively.High AAR was markedly associated with in-hospital mortality(HR=1.587,P=0.003),1-year mortality(HR=1.502,P<0.001),AKI incidence(HR=1.579,P<0.001),and RRT(HR=1.640,P<0.016)in CAD patients in the completely adjusted Cox proportional hazard model.Kaplan-Meier survival analysis noted substantial differences in all endpoints based on AAR quartiles.Stratified analysis and interaction test demonstrated stable correlations between AAR and outcomes.CONCLUSIONS The results highlight that AAR may be a potential indicator for assessing in-hospital mortality,1-year mortality,and adverse renal prognosis in critical CAD patients.
基金National Key R&D Program of China under Grant Nos.2018YFC1504504 and 2018YFC0809404。
文摘Damage to electrical equipment in an earthquake can lead to power outage of power systems.Seismic fragility analysis is a common method to assess the seismic reliability of electrical equipment.To further guarantee the efficiency of analysis,multi-source uncertainties including the structure itself and seismic excitation need to be considered.A method for seismic fragility analysis that reflects structural and seismic parameter uncertainty was developed in this study.The proposed method used a random sampling method based on Latin hypercube sampling(LHS)to account for the structure parameter uncertainty and the group structure characteristics of electrical equipment.Then,logistic Lasso regression(LLR)was used to find the seismic fragility surface based on double ground motion intensity measures(IM).The seismic fragility based on the finite element model of an±1000 kV main transformer(UHVMT)was analyzed using the proposed method.The results show that the seismic fragility function obtained by this method can be used to construct the relationship between the uncertainty parameters and the failure probability.The seismic fragility surface did not only provide the probabilities of seismic damage states under different IMs,but also had better stability than the fragility curve.Furthermore,the sensitivity analysis of the structural parameters revealed that the elastic module of the bushing and the height of the high-voltage bushing may have a greater influence.
基金gratitude to the National Natural Science Foundation of China(No.22279070,U21A20170,22279071 and 52206263)the Ministry of Science and Technology of China(No.2019YFA0705703 and 2019YFE0100200)The authors thank Joint Work Plan for Research Projects under the Clean Vehicles Consortium at U.S.and China-Clean Energy Research Center(CERCCVC2.0,2016-2020)。
文摘As a key material for lithium metal batteries(LMBs),lithium metal is one of the most promising anode materials to break the bottleneck of battery energy density and a commonly used active material for reference electrodes.Although lithium anodes are regarded as the holy grail of lithium batteries,decades of exploration have not led to the successful commercialization of LMBs,due mainly to the challenges related to the inherent properties of lithium metal.To pave the way for further investigation,herein,a comprehensive review focusing on the fundamental science of lithium are provided.Firstly,the natures of lithium atoms and their isotopes,lithium clusters and lithium crystals are revisited,especially their structural and energetic properties.Subsequently,the electrochemical properties of lithium metal are reviewed.Numerous important concepts and scientific questions,including the electronic structure of lithium,influence of high pressure and low temperature on the properties of lithium,factors influencing lithium deposition,generation of lithium dendrites,and electrode potential of lithium in different electrolytes,are explained and analyzed in detail.Approaches to improve the performance of lithium anodes and thoughtfulness about the electrode potential in lithium battery research are proposed.
文摘基于钻井、测井、实验分析及生产等资料,以磨溪气田嘉二气藏主力产层嘉二^(2)亚段B层(T_(1)j_(2)^(2B))白云岩储层为研究对象,利用流动单元来表征气藏白云岩储层非均质性,通过对比流动层带指数、孔喉半径(R_(35))及聚类分析的流动单元划分方法,在取心井流动单元的研究基础上,利用多元回归的方式定量评价FZI(Flow Zone Index)值,未取心井通过fisher判别分析函数精细划分.从压汞参数与生产动态资料验证其流动单元划分合理性.研究结果表明:对于薄层的白云岩储层,采用流动层带指数法划分的流动单元为一组具有较好孔渗关系的岩石类型,R_(35)所划分的流动单元为一组具有相似孔喉半径(不同孔隙度有着相近的渗透率)的岩石类型,通过聚类方法,能将具有相似的孔隙结构的储层归位一类流动单元;流动层带指数的测井识别是流动单元划分的难点,机器学习、神经网络等算法对于精度具有较大提升,但需要大量数据,对于研究区,常规的线性回归方式成为了最佳的选择;流动单元预测结果与压汞参数、初期产能存在较强相关性,流动单元划分结果可靠,可为后续气藏的开发提供参考.
基金financial support from the National Natural Science Foundation of China(41902272)Gansu Province Basic Research Innovation Group Project(21JR7RA347).
文摘To ensure the long-term safety and stability of bridge pile foundations in permafrost regions,it is necessary to investigate the rheological effects on the pile tip and pile side bearing capacities.The creep characteristics of the pile-frozen soil interface are critical for determining the long-term stability of permafrost pile foundations.This study utilized a self-developed large stress-controlled shear apparatus to investigate the shear creep characteristics of the frozen silt-concrete interface,and examined the influence of freezing temperatures(−1,−2,and−5°C),contact surface roughness(0,0.60,0.75,and 1.15 mm),normal stress(50,100,and 150 kPa),and shear stress on the creep characteristics of the contact surface.By incorporating the contact surface’s creep behavior and development trends,we established a creep constitutive model for the frozen silt-concrete interface based on the Nishihara model,introducing nonlinear elements and a damage factor.The results revealed significant creep effects on the frozen silt-concrete interface under constant load,with creep displacement at approximately 2-15 times the instantaneous displacement and a failure creep displacement ranging from 6 to 8 mm.Under different experimental conditions,the creep characteristics of the frozen silt-concrete interface varied.A larger roughness,lower freezing temperatures,and higher normal stresses resulted in a longer sample attenuation creep time,a lower steady-state creep rate,higher long-term creep strength,and stronger creep stability.Building upon the Nishihara model,we considered the influence of shear stress and time on the viscoelastic viscosity coefficient and introduced a damage factor to the viscoplasticity.The improved model effectively described the entire creep process of the frozen silt-concrete interface.The results provide theoretical support for the interaction between pile and soil in permafrost regions.
