The mechanisms of enhancing spin-orbit torque(SOT) have attracted significant attention, particularly regarding the influence of extrinsic scattering mechanisms on SOT efficiency, as they complement intrinsic contribu...The mechanisms of enhancing spin-orbit torque(SOT) have attracted significant attention, particularly regarding the influence of extrinsic scattering mechanisms on SOT efficiency, as they complement intrinsic contributions. In multilayer systems, extrinsic interfacial scattering, along with scattering from defects or impurities inside the materials, plays a crucial role in affecting the SOT efficiency. In this study, we successfully fabricated high-quality epitaxially grown [Ir/Pt]N superlattices with an increasing number of interfaces using a magnetron sputtering system to investigate the contribution of extrinsic interfacial scattering to SOT efficiency. We measured SOT efficiency through spin-torque ferromagnetic resonance methods and determined the spin Hall angle using the spin pumping technique. Additionally, we calculated spin transparency based on the SOT efficiency and spin Hall angle. Our findings indicate that the values of SOT efficiency, spin Hall angle, and spin transparency are enhanced in the superlattice structure compared to Pt, which we attribute to the increase in interfacial scattering.This research offers an effective strategy for designing and fabricating advanced spintronic devices.展开更多
Medicinal and dietary plants provide numerous nutritional and functional compounds and also have various potential health benefits to humanity.The specific and efficient techniques for accurate identification of nutri...Medicinal and dietary plants provide numerous nutritional and functional compounds and also have various potential health benefits to humanity.The specific and efficient techniques for accurate identification of nutritional compounds and functional metabolites is crucial for the development of functional foods from medicinal and dietary plants.Nuclear magnetic resonance(NMR)and mass spectrometry(MS)are indispensable and essential technologies that provide an unsurpassed wealth of untargeted identification,quantitative and qualitative analysis,and structural information in the study of food and plant products.In the past decade,the rapid development of modern analytical technology has led to the emergence of new approaches and strategies for natural products discovery.Especially the application of novel NMRand MS-based identification and dereplication strategies aided by artificial intelligence and machine learning algorithms have brought about a significant shift in the natural products discovery process.These developments and changes in the natural products filed have given us insights into how to accurately target and mining nutritional,functional,and bioactive compounds.Thus,we have summarized recent research on novel NMR and MS based strategies and methods focusing on functional compounds,accurate identification and efficient discovery mainly in medicinal and dietary plants.This review could provide a comprehensive perspective for a better understanding of novel strategies and methods based on NMR and MS technologies,which could provide valuable insights and ideas for functional compounds mining.展开更多
Rechargeable aqueous zinc-metal batteries (AZMBs) are promising candidates for large-scale energy storage systems due to their low cost and high safety.However,their performance and sustainability are significantly hi...Rechargeable aqueous zinc-metal batteries (AZMBs) are promising candidates for large-scale energy storage systems due to their low cost and high safety.However,their performance and sustainability are significantly hindered by the sluggish desolvation kinetics at the electrode/electrolyte interface and the corresponding hydrogen evolution reaction where active water molecules tightly participate in the Zn(H_(2)O)_(6)^(2+)solvation shell.Herein,learnt from self-generated solid electrolyte interphase (SEI) in anodes,the dielectric but ion-conductive zinc niobate nanoparticles artificial layer is constructed on metallic Zn surface (ZNB@Zn),acting as a rapid desolvation promotor.The zincophilic and dielectric-conductive properties of ZNB layer accelerate interfacial desolvation/diffusion and suppress surface corrosion or dendrite formation,achieving uniform Zn plating/stripping behavior,as confirmed by electronic/optical microscopies and interface spectroscopical measurements together with theoretical calculations.Consequently,the as-prepared ZNB@Zn electrode exhibits excellent cycling stability of over 2000 h and robust reversibility (99.54%) even under high current density and depth of discharge conditions.Meanwhile,the assembled ZNB@Zn-based full cell displays high capacity-retention rate of 80.21%after 3000 cycles at 5 A g^(-1)and outstanding rate performance up to 10 A g^(-1).The large-areal pouch cell is stabilized for hundreds of cycles,highlighting the bright prospects of the dielectric but ion-conductive layer in further application of AZMBs.展开更多
Perovskites have garnered significant attention in recent years. However, the presence of La atoms at the B-site in ABX_(3) structures has not yet been observed. Under high pressure, perovskites exhibit unexpected pha...Perovskites have garnered significant attention in recent years. However, the presence of La atoms at the B-site in ABX_(3) structures has not yet been observed. Under high pressure, perovskites exhibit unexpected phase transitions. In this study, we report the discovery of SbLaO_(3) under ambient pressure, with a space group of R3m. Mechanical property calculations indicate that it is a brittle material, and it possesses a band gap of 4.0266 e V, classifying it as an insulator.We also investigate the phase at 300 GPa, where the space group shifts to P2_(1/m). Additionally, the P2_(1/m) phase of LaInO_(3) under 300 GPa is explored. Ab initio molecular dynamics calculations reveal that the melting point of SbLaO_(3) is exceptionally high. The inclusion of Sb alters the electronic structure compared with LaInO_(3), and the Vickers hardness(H_(v)) is estimated to reach 20.97 GPa. This research provides insights into the phase transitions of perovskites under high pressure.展开更多
Recently,a breakthrough in the high-pressure synthesis of sp^(3)-bonded clathrate-like R-3m-L_(a)B_(8)featuring Latrapped B_(26)cages was achieved.Although the superconducting critical temperature(T_(c))and Vickers ha...Recently,a breakthrough in the high-pressure synthesis of sp^(3)-bonded clathrate-like R-3m-L_(a)B_(8)featuring Latrapped B_(26)cages was achieved.Although the superconducting critical temperature(T_(c))and Vickers hardness(H_(v))of L_(a)B_(8)were estimated,the anisotropic superconductivity and superconducting gap nature remain unclear.The stability of pure B_(26)cages under ambient conditions is of interest for exploring the B_(26)hardness and the role of La atoms in the L_(a)B_(8)hardness.By resolving the Allen–Dynes modified Mc Millan equation and the anisotropic Eliashberg equations,it was found that L_(a)B_(8)exhibits anisotropic single-gap superconductivity with T_(c)=19.0~26.5 K,and the superconducting gap anisotropic ratio reaches 48.50%at 5 K.Most significantly,our work fundamentally validated the coupling of B-2p orbitals with the optical double-degenerate E_(g)phonon modes and A_(g)phonon mode from a novel perspective.The H_(v)of B_(26)cages was determined to be 18.6 GPa,which is lower than that of La-trapped B_(26)cages(i.e.,L_(a)B_(8)),indicating that La acts as a hardness enhancer for L_(a)B_(8).展开更多
为解决短波辐射源到达时间差(time difference of arrival,TDOA)定位(简称时差定位)方法受电离层影响导致的定位精度下降的问题,提出了一种利用参考源修正的短波辐射源目标时差定位方法。针对地球表面短波辐射源,基于电离层球面反射模...为解决短波辐射源到达时间差(time difference of arrival,TDOA)定位(简称时差定位)方法受电离层影响导致的定位精度下降的问题,提出了一种利用参考源修正的短波辐射源目标时差定位方法。针对地球表面短波辐射源,基于电离层球面反射模型的电离层反射虚高近似方法,建立了利用参考修正的短波目标时差定位模型。考虑参考源与目标共用电离层反射区域对电离层虚高的影响,将各电离层反射点的距离相关性引入电离层虚高的协方差矩阵中,实现了目标定位精度的修正。通过推导和仿真所提模型的克拉美·罗下界,分析了参考源修正目标定位精度的可行性。进一步给出基于Armijo直线搜索Newton法的最大似然估计方法,通过仿真数据验证了所提算法的有效性,实现了良好的定位效果。展开更多
With the 5th Generation(5G)Mobile network being rolled out gradually in 2019,the research for the next generation mobile network has been started and targeted for 2030.To pave the way for the development of the 6th Ge...With the 5th Generation(5G)Mobile network being rolled out gradually in 2019,the research for the next generation mobile network has been started and targeted for 2030.To pave the way for the development of the 6th Generation(6G)mobile network,the vision and requirements should be identified first for the potential key technology identification and comprehensive system design.This article first identifies the vision of the society development towards 2030 and the new application scenarios for mobile communication,and then the key performance requirements are derived from the service and application perspective.Taken into account the convergence of information technology,communication technology and big data technology,a logical mobile network architecture is proposed to resolve the lessons from 5G network design.To compromise among the cost,capability and flexibility of the network,the features of the 6G mobile network are proposed based on the latest progress and applications of the relevant fields,namely,on-demand fulfillment,lite network,soft network,native AI and native security.Ultimately,the intent of this article is to serve as a basis for stimulating more promising research on 6G.展开更多
The sixth generation(6G)mobile network is envisaged to be commercially deployed around 2030,which will profoundly change people's lifestyles and accelerate the digitalization of society.To ensure that the requirem...The sixth generation(6G)mobile network is envisaged to be commercially deployed around 2030,which will profoundly change people's lifestyles and accelerate the digitalization of society.To ensure that the requirements of 6G can be achieved,it is essential to establish a set of key performance indicators(KPIs).This paper comprehensively assesses the KPIs not only from the service requirements but also from the technical feasibility points of view.Specifically,theoretical derivations of KPIs have been clarified,and numerical evaluations have been conducted with reasonable technical assumptions.Evaluation results show that some KPIs defined from the service requirements can be improved through advanced technologies while some are still challenging for practical implementations,such as Tbps-level peak data rate and 0.1 ms user plane latency.In addition,it is also necessary to comply with multiple KPIs for some cases.Furthermore,based on the technical analysis,the potential enabling technologies are outlined and foreseeable implementation challenges as well as possible solutions are presented,which promotes a more reasonable design for 6G mobile network.展开更多
OBJECTIVE To establish a prediction model of coronary heart disease(CHD)in elderly patients with diabetes mellitus(DM)based on machine learning(ML)algorithms.METHODS Based on the Medical Big Data Research Centre of Ch...OBJECTIVE To establish a prediction model of coronary heart disease(CHD)in elderly patients with diabetes mellitus(DM)based on machine learning(ML)algorithms.METHODS Based on the Medical Big Data Research Centre of Chinese PLA General Hospital in Beijing,China,we identified a cohort of elderly inpatients(≥60 years),including 10,533 patients with DM complicated with CHD and 12,634 patients with DM without CHD,from January 2008 to December 2017.We collected demographic characteristics and clinical data.After selecting the important features,we established five ML models,including extreme gradient boosting(XGBoost),random forest(RF),decision tree(DT),adaptive boosting(Adaboost)and logistic regression(LR).We compared the receiver operating characteristic curves,area under the curve(AUC)and other relevant parameters of different models and determined the optimal classification model.The model was then applied to 7447 elderly patients with DM admitted from January 2018 to December 2019 to further validate the performance of the model.RESULTS Fifteen features were selected and included in the ML model.The classification precision in the test set of the XGBoost,RF,DT,Adaboost and LR models was 0.778,0.789,0.753,0.750 and 0.689,respectively;and the AUCs of the subjects were 0.851,0.845,0.823,0.833 and 0.731,respectively.Applying the XGBoost model with optimal performance to a newly recruited dataset for validation,the diagnostic sensitivity,specificity,precision,and AUC were 0.792,0.808,0.748 and 0.880,respectively.CONCLUSIONS The XGBoost model established in the present study had certain predictive value for elderly patients with DM complicated with CHD.展开更多
Biobutanol is attracting increasingly interest as a source of renewable energy and biofuels because of its many advantages over bioethanol that include higher energy density, fuel efficiency, and reduced engine damage...Biobutanol is attracting increasingly interest as a source of renewable energy and biofuels because of its many advantages over bioethanol that include higher energy density, fuel efficiency, and reduced engine damages. Currently, there is a growing interest in producing biobutanol from bioethanol, in view of the tremendous potential benefits of this transformation for the bulk production of biobutanol in a target specific manner. This perspective paper describes recent progress for the ethanol to butanol process. The different catalysts, including homogeneous and heterogeneous catalytic systems, for ethanol to butanol are outlined and compared, and the key issues and requirements for future developments are highlighted. A major challenge for further development and application of ethanol to butanol process is to find an optimal balance between different catalytic functions and to suppress the formation of side products that has plagued most catalytic bioethanol upgrading systems. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B. V. and Science Press. All rights reserved.展开更多
Severe performance drop and fire risk due to the uneven lithium(Li) dendrite formation and growth during charge/discharge process has been considered as the major obstacle to the practical application of Li metal batt...Severe performance drop and fire risk due to the uneven lithium(Li) dendrite formation and growth during charge/discharge process has been considered as the major obstacle to the practical application of Li metal batteries.So inhibiting dendrite growth and producing a stable and robust solid electrolyte interface(SEI) layer are essential to enable the use of Li metal anodes.In this work,a functional lithiophilic polymer composed of chitosan(CTS),polyethylene oxide(PEO),and poly(triethylene glycol dimethacrylate)(PTEGDMA),was homogeneously deposited on a commercial Celgard separator by combining electrospraying and polymer photopolymerization techniques.The lithiophilic environment offered by the CTS-PEO-PTEGDMA layer enables uniform Li deposition and facilitates the formation of a robust homogeneous SEI layer,thus prevent the formation and growth of Li dendrites.As a result,both Li/Li symmetric cells and LiFePO4/Li full cells deliver significantly enhanced electrochemical performance and cycle life.Even after 1000 cycles,the specific capacity of the modified full cell could be maintained at65.8 mAh g^(-1), twice which of the unmodified cell(32.8 mAh g^(-1)).The long-term cycling stability in Li/Li symmetric cells,dendrite-free anodes in SEM images and XPS analysis suggest that the pulverization of the Li anode was effectively suppressed by the lithiophilic polymer layer.展开更多
With thermal fluctuation strongly suppressed,low temperature environment is essential for studies of condensed matter physics and developments of quantum technologies.Ultra-low temperature below 20 m K has demonstrate...With thermal fluctuation strongly suppressed,low temperature environment is essential for studies of condensed matter physics and developments of quantum technologies.Ultra-low temperature below 20 m K has demonstrated its importance and significance in physical sciences and information techniques.Dilution refrigeration is by far the best feasible and reliable method to generate and keep lattice temperature in this range.With a potential shortage of helium supply,cryogen-free dilution refrigerator(CFDR),eliminating the necessity of regular helium refill,becomes the main facility for the purpose of creating ultralow temperature environments.Here we describe our successful construction of a CFDR which reached a base temperature of around 10.9 m K for continuous circulation and 8.6 m K for single-shot operation.We describe its operating mechanism and the designs of key components,especially some unique designs including heat switch and alumina thermal link.Possible improvements in the future are also discussed.展开更多
基金financially supported by the Science Center of the National Science Foundation of China (Grant No. 52088101)the National Natural Science Foundation of China (Grant Nos. 52161160334, 12274437, 12174426, and 52271237)+1 种基金the Chinese Academy of Sciences (CAS) Project for Young Scientists in Basic Research No. YSBR-084the CAS Youth Interdisciplinary Team。
文摘The mechanisms of enhancing spin-orbit torque(SOT) have attracted significant attention, particularly regarding the influence of extrinsic scattering mechanisms on SOT efficiency, as they complement intrinsic contributions. In multilayer systems, extrinsic interfacial scattering, along with scattering from defects or impurities inside the materials, plays a crucial role in affecting the SOT efficiency. In this study, we successfully fabricated high-quality epitaxially grown [Ir/Pt]N superlattices with an increasing number of interfaces using a magnetron sputtering system to investigate the contribution of extrinsic interfacial scattering to SOT efficiency. We measured SOT efficiency through spin-torque ferromagnetic resonance methods and determined the spin Hall angle using the spin pumping technique. Additionally, we calculated spin transparency based on the SOT efficiency and spin Hall angle. Our findings indicate that the values of SOT efficiency, spin Hall angle, and spin transparency are enhanced in the superlattice structure compared to Pt, which we attribute to the increase in interfacial scattering.This research offers an effective strategy for designing and fabricating advanced spintronic devices.
基金financially supported by the National Key R&D Program of China(2022YFF1100301)Major Science and Technology Project of Henan Province(231100310200)+1 种基金National Natural Science Foundation of China(32370426)Yunnan Province Science and Technology Department(202305AH340005),and Dr Plant。
文摘Medicinal and dietary plants provide numerous nutritional and functional compounds and also have various potential health benefits to humanity.The specific and efficient techniques for accurate identification of nutritional compounds and functional metabolites is crucial for the development of functional foods from medicinal and dietary plants.Nuclear magnetic resonance(NMR)and mass spectrometry(MS)are indispensable and essential technologies that provide an unsurpassed wealth of untargeted identification,quantitative and qualitative analysis,and structural information in the study of food and plant products.In the past decade,the rapid development of modern analytical technology has led to the emergence of new approaches and strategies for natural products discovery.Especially the application of novel NMRand MS-based identification and dereplication strategies aided by artificial intelligence and machine learning algorithms have brought about a significant shift in the natural products discovery process.These developments and changes in the natural products filed have given us insights into how to accurately target and mining nutritional,functional,and bioactive compounds.Thus,we have summarized recent research on novel NMR and MS based strategies and methods focusing on functional compounds,accurate identification and efficient discovery mainly in medicinal and dietary plants.This review could provide a comprehensive perspective for a better understanding of novel strategies and methods based on NMR and MS technologies,which could provide valuable insights and ideas for functional compounds mining.
基金National Key R&D Program of China (2021YFA1201503)National Natural Science Foundation of China (21972164, 22279161, 12264038, 22309144)+4 种基金Natural Science Foundation of Jiangsu Province (BK. 20210130)China Postdoctoral Science Foundation (2023M733189)Jiangsu Double-Innovation PhD Program in 2022 (JSSCBS20221241)Senior Talents Fund of Jiangsu University (5501220014)fellowship funding provided by the Alexander von Humboldt Foundation。
文摘Rechargeable aqueous zinc-metal batteries (AZMBs) are promising candidates for large-scale energy storage systems due to their low cost and high safety.However,their performance and sustainability are significantly hindered by the sluggish desolvation kinetics at the electrode/electrolyte interface and the corresponding hydrogen evolution reaction where active water molecules tightly participate in the Zn(H_(2)O)_(6)^(2+)solvation shell.Herein,learnt from self-generated solid electrolyte interphase (SEI) in anodes,the dielectric but ion-conductive zinc niobate nanoparticles artificial layer is constructed on metallic Zn surface (ZNB@Zn),acting as a rapid desolvation promotor.The zincophilic and dielectric-conductive properties of ZNB layer accelerate interfacial desolvation/diffusion and suppress surface corrosion or dendrite formation,achieving uniform Zn plating/stripping behavior,as confirmed by electronic/optical microscopies and interface spectroscopical measurements together with theoretical calculations.Consequently,the as-prepared ZNB@Zn electrode exhibits excellent cycling stability of over 2000 h and robust reversibility (99.54%) even under high current density and depth of discharge conditions.Meanwhile,the assembled ZNB@Zn-based full cell displays high capacity-retention rate of 80.21%after 3000 cycles at 5 A g^(-1)and outstanding rate performance up to 10 A g^(-1).The large-areal pouch cell is stabilized for hundreds of cycles,highlighting the bright prospects of the dielectric but ion-conductive layer in further application of AZMBs.
基金Project supported by the National Natural Science Foundation of China (Grant No. 11904067)。
文摘Perovskites have garnered significant attention in recent years. However, the presence of La atoms at the B-site in ABX_(3) structures has not yet been observed. Under high pressure, perovskites exhibit unexpected phase transitions. In this study, we report the discovery of SbLaO_(3) under ambient pressure, with a space group of R3m. Mechanical property calculations indicate that it is a brittle material, and it possesses a band gap of 4.0266 e V, classifying it as an insulator.We also investigate the phase at 300 GPa, where the space group shifts to P2_(1/m). Additionally, the P2_(1/m) phase of LaInO_(3) under 300 GPa is explored. Ab initio molecular dynamics calculations reveal that the melting point of SbLaO_(3) is exceptionally high. The inclusion of Sb alters the electronic structure compared with LaInO_(3), and the Vickers hardness(H_(v)) is estimated to reach 20.97 GPa. This research provides insights into the phase transitions of perovskites under high pressure.
基金supported by the National Natural Science Foundation of China(Grant Nos.11904067,12122405,52072188,1227416951632002)。
文摘Recently,a breakthrough in the high-pressure synthesis of sp^(3)-bonded clathrate-like R-3m-L_(a)B_(8)featuring Latrapped B_(26)cages was achieved.Although the superconducting critical temperature(T_(c))and Vickers hardness(H_(v))of L_(a)B_(8)were estimated,the anisotropic superconductivity and superconducting gap nature remain unclear.The stability of pure B_(26)cages under ambient conditions is of interest for exploring the B_(26)hardness and the role of La atoms in the L_(a)B_(8)hardness.By resolving the Allen–Dynes modified Mc Millan equation and the anisotropic Eliashberg equations,it was found that L_(a)B_(8)exhibits anisotropic single-gap superconductivity with T_(c)=19.0~26.5 K,and the superconducting gap anisotropic ratio reaches 48.50%at 5 K.Most significantly,our work fundamentally validated the coupling of B-2p orbitals with the optical double-degenerate E_(g)phonon modes and A_(g)phonon mode from a novel perspective.The H_(v)of B_(26)cages was determined to be 18.6 GPa,which is lower than that of La-trapped B_(26)cages(i.e.,L_(a)B_(8)),indicating that La acts as a hardness enhancer for L_(a)B_(8).
文摘为解决短波辐射源到达时间差(time difference of arrival,TDOA)定位(简称时差定位)方法受电离层影响导致的定位精度下降的问题,提出了一种利用参考源修正的短波辐射源目标时差定位方法。针对地球表面短波辐射源,基于电离层球面反射模型的电离层反射虚高近似方法,建立了利用参考修正的短波目标时差定位模型。考虑参考源与目标共用电离层反射区域对电离层虚高的影响,将各电离层反射点的距离相关性引入电离层虚高的协方差矩阵中,实现了目标定位精度的修正。通过推导和仿真所提模型的克拉美·罗下界,分析了参考源修正目标定位精度的可行性。进一步给出基于Armijo直线搜索Newton法的最大似然估计方法,通过仿真数据验证了所提算法的有效性,实现了良好的定位效果。
文摘With the 5th Generation(5G)Mobile network being rolled out gradually in 2019,the research for the next generation mobile network has been started and targeted for 2030.To pave the way for the development of the 6th Generation(6G)mobile network,the vision and requirements should be identified first for the potential key technology identification and comprehensive system design.This article first identifies the vision of the society development towards 2030 and the new application scenarios for mobile communication,and then the key performance requirements are derived from the service and application perspective.Taken into account the convergence of information technology,communication technology and big data technology,a logical mobile network architecture is proposed to resolve the lessons from 5G network design.To compromise among the cost,capability and flexibility of the network,the features of the 6G mobile network are proposed based on the latest progress and applications of the relevant fields,namely,on-demand fulfillment,lite network,soft network,native AI and native security.Ultimately,the intent of this article is to serve as a basis for stimulating more promising research on 6G.
文摘The sixth generation(6G)mobile network is envisaged to be commercially deployed around 2030,which will profoundly change people's lifestyles and accelerate the digitalization of society.To ensure that the requirements of 6G can be achieved,it is essential to establish a set of key performance indicators(KPIs).This paper comprehensively assesses the KPIs not only from the service requirements but also from the technical feasibility points of view.Specifically,theoretical derivations of KPIs have been clarified,and numerical evaluations have been conducted with reasonable technical assumptions.Evaluation results show that some KPIs defined from the service requirements can be improved through advanced technologies while some are still challenging for practical implementations,such as Tbps-level peak data rate and 0.1 ms user plane latency.In addition,it is also necessary to comply with multiple KPIs for some cases.Furthermore,based on the technical analysis,the potential enabling technologies are outlined and foreseeable implementation challenges as well as possible solutions are presented,which promotes a more reasonable design for 6G mobile network.
基金supported by the Key Project of Chinese Military Health Care Projects(No.18BJZ32)the Projects of International Cooperation and Exchanges NSFC(No.81820108019)+2 种基金the Technical Fund for the Foundation Strengthening Program of China(2021-JCJG-JJ-1079)the Chinese Military Innovation Project(CX19028)the Project of National Clinical Research Center for Geriatric Disease(NCRCG-PLAGH-2019024).
文摘OBJECTIVE To establish a prediction model of coronary heart disease(CHD)in elderly patients with diabetes mellitus(DM)based on machine learning(ML)algorithms.METHODS Based on the Medical Big Data Research Centre of Chinese PLA General Hospital in Beijing,China,we identified a cohort of elderly inpatients(≥60 years),including 10,533 patients with DM complicated with CHD and 12,634 patients with DM without CHD,from January 2008 to December 2017.We collected demographic characteristics and clinical data.After selecting the important features,we established five ML models,including extreme gradient boosting(XGBoost),random forest(RF),decision tree(DT),adaptive boosting(Adaboost)and logistic regression(LR).We compared the receiver operating characteristic curves,area under the curve(AUC)and other relevant parameters of different models and determined the optimal classification model.The model was then applied to 7447 elderly patients with DM admitted from January 2018 to December 2019 to further validate the performance of the model.RESULTS Fifteen features were selected and included in the ML model.The classification precision in the test set of the XGBoost,RF,DT,Adaboost and LR models was 0.778,0.789,0.753,0.750 and 0.689,respectively;and the AUCs of the subjects were 0.851,0.845,0.823,0.833 and 0.731,respectively.Applying the XGBoost model with optimal performance to a newly recruited dataset for validation,the diagnostic sensitivity,specificity,precision,and AUC were 0.792,0.808,0.748 and 0.880,respectively.CONCLUSIONS The XGBoost model established in the present study had certain predictive value for elderly patients with DM complicated with CHD.
基金supported by the National Natural Science Foundation of China(21273044,21473035,and 91545108)SINOPEC(X514005)the Open project of State Key Laboratory of Chemical Engineering(SKL-Ch E-15C02)
文摘Biobutanol is attracting increasingly interest as a source of renewable energy and biofuels because of its many advantages over bioethanol that include higher energy density, fuel efficiency, and reduced engine damages. Currently, there is a growing interest in producing biobutanol from bioethanol, in view of the tremendous potential benefits of this transformation for the bulk production of biobutanol in a target specific manner. This perspective paper describes recent progress for the ethanol to butanol process. The different catalysts, including homogeneous and heterogeneous catalytic systems, for ethanol to butanol are outlined and compared, and the key issues and requirements for future developments are highlighted. A major challenge for further development and application of ethanol to butanol process is to find an optimal balance between different catalytic functions and to suppress the formation of side products that has plagued most catalytic bioethanol upgrading systems. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B. V. and Science Press. All rights reserved.
基金supported by the Natural Science Foundation of Jiangsu Province (BK20170237)National Natural Science Foundation of China (21808094 and 51871113)+1 种基金Key Research and Development Program of Xuzhou (KC17004)Startup Funding for Introduced Talents of Jiangsu Normal University (16XLR015)。
文摘Severe performance drop and fire risk due to the uneven lithium(Li) dendrite formation and growth during charge/discharge process has been considered as the major obstacle to the practical application of Li metal batteries.So inhibiting dendrite growth and producing a stable and robust solid electrolyte interface(SEI) layer are essential to enable the use of Li metal anodes.In this work,a functional lithiophilic polymer composed of chitosan(CTS),polyethylene oxide(PEO),and poly(triethylene glycol dimethacrylate)(PTEGDMA),was homogeneously deposited on a commercial Celgard separator by combining electrospraying and polymer photopolymerization techniques.The lithiophilic environment offered by the CTS-PEO-PTEGDMA layer enables uniform Li deposition and facilitates the formation of a robust homogeneous SEI layer,thus prevent the formation and growth of Li dendrites.As a result,both Li/Li symmetric cells and LiFePO4/Li full cells deliver significantly enhanced electrochemical performance and cycle life.Even after 1000 cycles,the specific capacity of the modified full cell could be maintained at65.8 mAh g^(-1), twice which of the unmodified cell(32.8 mAh g^(-1)).The long-term cycling stability in Li/Li symmetric cells,dendrite-free anodes in SEM images and XPS analysis suggest that the pulverization of the Li anode was effectively suppressed by the lithiophilic polymer layer.
基金supported by Key Research Program of Frontier Sciences,CAS(Grant No.ZDBS-LY-SLH0010)Beijing Natural Science Foundation(Grant No.JQ21002)Beijing Council of Science and Technology(Grant Nos.Z201100008420006 and Z211100004021012)
文摘With thermal fluctuation strongly suppressed,low temperature environment is essential for studies of condensed matter physics and developments of quantum technologies.Ultra-low temperature below 20 m K has demonstrated its importance and significance in physical sciences and information techniques.Dilution refrigeration is by far the best feasible and reliable method to generate and keep lattice temperature in this range.With a potential shortage of helium supply,cryogen-free dilution refrigerator(CFDR),eliminating the necessity of regular helium refill,becomes the main facility for the purpose of creating ultralow temperature environments.Here we describe our successful construction of a CFDR which reached a base temperature of around 10.9 m K for continuous circulation and 8.6 m K for single-shot operation.We describe its operating mechanism and the designs of key components,especially some unique designs including heat switch and alumina thermal link.Possible improvements in the future are also discussed.
