This opinion review paper explores the application of artificial intelligence(AI)as a decisive tool in managing complex coronavirus disease 2019(COVID-19)cases within critical care medicine.Available data have shown t...This opinion review paper explores the application of artificial intelligence(AI)as a decisive tool in managing complex coronavirus disease 2019(COVID-19)cases within critical care medicine.Available data have shown that very severe cases required intensive care,most of which required endotracheal intubation and mechanical ventilation to avoid a lethal outcome if possible.The unprecedented challenges posed by the COVID-19 pandemic necessitate innovative approaches to patient care.AI offers significant potential in enhancing diagnostic accuracy,predicting patient outcomes,and optimizing treatment strategies.By analyzing vast amounts of clinical data,AI can support healthcare professionals in making informed decisions,thus improving patient outcomes.We also focus on current technologies,their implementation in critical care settings,and their impact on patient management during the COVID-19 crisis.Future directions for AI integration in critical care are also discussed.展开更多
Higher-order topological insulators,which host topologically protected states at boundaries that are at least two dimensions lower than the bulk,are an emerging class of topological materials.They provide great opport...Higher-order topological insulators,which host topologically protected states at boundaries that are at least two dimensions lower than the bulk,are an emerging class of topological materials.They provide great opportunities for exploring novel topological phenomena and fascinating applications.Utilizing a low-temperature scanning tunneling microscope,we construct breathing-kagome lattices with Fe adatoms on Ag(111)and investigate their electronic properties.We observe the higher-order topological boundary states in the topological phase but not in the trivial one,which is consistent with the theory.These states are found to be robust against the removal of bulk or edge adatoms.Further,we show the arbitrary positioning of these states either at corner,edge,or bulk sites by slightly modifying their neighbors.Our study not only demonstrates the formation and robustness of the electronic higher-order topological boundary states in real atomic systems but also provides a route for controlling their positions.展开更多
Piezoelectric devices exhibit unique properties that vary with different vibration modes,closely influenced by their polarization direction.This paper presents an analysis on the free vibration of laminated piezoelect...Piezoelectric devices exhibit unique properties that vary with different vibration modes,closely influenced by their polarization direction.This paper presents an analysis on the free vibration of laminated piezoelectric beams with varying polarization directions,using a state-space-based differential quadrature method.First,based on the electro-elasticity theory,the state-space method is extended to anisotropic piezoelectric materials,establishing state-space equations for arbitrary polarized piezoelectric beams.A semi-analytical solution for the natural frequency is then obtained via the differential quadrature method.The study commences by examining the impact of a uniform polarization direction,and then proceeds to analyze six polarization schemes relevant to the current research and applications.Additionally,the effects of geometric dimensions and gradient index on the natural frequencies are explored.The numerical results demonstrate that varying the polarization direction can significantly influence the natural frequencies,offering distinct advantages for piezoelectric elements with different polarizations.This research provides both theoretical insights and numerical methods for the structural design of piezoelectric devices.展开更多
Laminated composites are widely used in many engineering industries such as aircraft, spacecraft, boat hulls, racing car bodies, and storage tanks. We analyze the 3D deformations of a multilayered, linear elastic, ani...Laminated composites are widely used in many engineering industries such as aircraft, spacecraft, boat hulls, racing car bodies, and storage tanks. We analyze the 3D deformations of a multilayered, linear elastic, anisotropic rectangular plate subjected to arbitrary boundary conditions on one edge and simply supported on other edge. The rectangular laminate consists of anisotropic and homogeneous laminae of arbitrary thicknesses. This study presents the elastic analysis of laminated composite plates subjected to sinusoidal mechanical loading under arbitrary boundary conditions. Least square finite element solutions for displacements and stresses are investigated using a mathematical model, called a state-space model, which allows us to simultaneously solve for these field variables in the composite structure’s domain and ensure that continuity conditions are satisfied at layer interfaces. The governing equations are derived from this model using a numerical technique called the least-squares finite element method (LSFEM). These LSFEMs seek to minimize the squares of the governing equations and the associated side conditions residuals over the computational domain. The model is comprised of layerwise variables such as displacements, out-of-plane stresses, and in- plane strains, treated as independent variables. Numerical results are presented to demonstrate the response of the laminated composite plates under various arbitrary boundary conditions using LSFEM and compared with the 3D elasticity solution available in the literature.展开更多
路基工后沉降直接关乎公路的安全性能,蠕变行为的预测对保障路基工程的长期安全具有重要意义。对蠕变行为进行有限元数值模拟时,复杂结构模型的网格划分需要耗费大量的计算资源,且计算量大计算时间长。提出了一种考虑蠕变的任意多边形...路基工后沉降直接关乎公路的安全性能,蠕变行为的预测对保障路基工程的长期安全具有重要意义。对蠕变行为进行有限元数值模拟时,复杂结构模型的网格划分需要耗费大量的计算资源,且计算量大计算时间长。提出了一种考虑蠕变的任意多边形杂交应力新单元(polygonal hybrid stress element method,PHSEM),用于工程中的路基沉降问题研究。基于杂交应力元法及路基土的蠕变行为,推导PHSEM的单元基本格式,分析表明该单元引入了高阶应力场,能更好地提高计算精度,进一步建立路基蠕变的数值计算模型,结合有限元软件MARC开展对比分析。研究表明:PHSEM的数值仿真曲线拟合良好,验证了考虑蠕变的任意多边形杂交应力单元的有效性;PHSEM在划分网格时形状可以是任意边数的多边形,能够很好地模拟多种介质的路基模型,真实地计算出不同部位的应力分布情况;PHSEM的构造为实际工程中的蠕变研究提供了一种可参考的新思路。展开更多
基金Supported by European Union-NextGenerationEU,Through The National Recovery and Resilience Plan of the Republic of Bulgaria,No.BG-RRP-2.004-0008.
文摘This opinion review paper explores the application of artificial intelligence(AI)as a decisive tool in managing complex coronavirus disease 2019(COVID-19)cases within critical care medicine.Available data have shown that very severe cases required intensive care,most of which required endotracheal intubation and mechanical ventilation to avoid a lethal outcome if possible.The unprecedented challenges posed by the COVID-19 pandemic necessitate innovative approaches to patient care.AI offers significant potential in enhancing diagnostic accuracy,predicting patient outcomes,and optimizing treatment strategies.By analyzing vast amounts of clinical data,AI can support healthcare professionals in making informed decisions,thus improving patient outcomes.We also focus on current technologies,their implementation in critical care settings,and their impact on patient management during the COVID-19 crisis.Future directions for AI integration in critical care are also discussed.
基金supported by the National Key R&D Program of China(Grant Nos.2024YFA140850,2022YFA1403601,and 2023YFC2410501)the National Natural Science Foundation of China(Grants Nos.12241402,12474059,12274203,12374113,and 12274204)。
文摘Higher-order topological insulators,which host topologically protected states at boundaries that are at least two dimensions lower than the bulk,are an emerging class of topological materials.They provide great opportunities for exploring novel topological phenomena and fascinating applications.Utilizing a low-temperature scanning tunneling microscope,we construct breathing-kagome lattices with Fe adatoms on Ag(111)and investigate their electronic properties.We observe the higher-order topological boundary states in the topological phase but not in the trivial one,which is consistent with the theory.These states are found to be robust against the removal of bulk or edge adatoms.Further,we show the arbitrary positioning of these states either at corner,edge,or bulk sites by slightly modifying their neighbors.Our study not only demonstrates the formation and robustness of the electronic higher-order topological boundary states in real atomic systems but also provides a route for controlling their positions.
基金Project supported by the National Natural Science Foundation of China(Nos.12272353 and 12002316)the Key Scientific and Technological Research Projects in Henan Province of China(No.232102211075)。
文摘Piezoelectric devices exhibit unique properties that vary with different vibration modes,closely influenced by their polarization direction.This paper presents an analysis on the free vibration of laminated piezoelectric beams with varying polarization directions,using a state-space-based differential quadrature method.First,based on the electro-elasticity theory,the state-space method is extended to anisotropic piezoelectric materials,establishing state-space equations for arbitrary polarized piezoelectric beams.A semi-analytical solution for the natural frequency is then obtained via the differential quadrature method.The study commences by examining the impact of a uniform polarization direction,and then proceeds to analyze six polarization schemes relevant to the current research and applications.Additionally,the effects of geometric dimensions and gradient index on the natural frequencies are explored.The numerical results demonstrate that varying the polarization direction can significantly influence the natural frequencies,offering distinct advantages for piezoelectric elements with different polarizations.This research provides both theoretical insights and numerical methods for the structural design of piezoelectric devices.
文摘Laminated composites are widely used in many engineering industries such as aircraft, spacecraft, boat hulls, racing car bodies, and storage tanks. We analyze the 3D deformations of a multilayered, linear elastic, anisotropic rectangular plate subjected to arbitrary boundary conditions on one edge and simply supported on other edge. The rectangular laminate consists of anisotropic and homogeneous laminae of arbitrary thicknesses. This study presents the elastic analysis of laminated composite plates subjected to sinusoidal mechanical loading under arbitrary boundary conditions. Least square finite element solutions for displacements and stresses are investigated using a mathematical model, called a state-space model, which allows us to simultaneously solve for these field variables in the composite structure’s domain and ensure that continuity conditions are satisfied at layer interfaces. The governing equations are derived from this model using a numerical technique called the least-squares finite element method (LSFEM). These LSFEMs seek to minimize the squares of the governing equations and the associated side conditions residuals over the computational domain. The model is comprised of layerwise variables such as displacements, out-of-plane stresses, and in- plane strains, treated as independent variables. Numerical results are presented to demonstrate the response of the laminated composite plates under various arbitrary boundary conditions using LSFEM and compared with the 3D elasticity solution available in the literature.
文摘路基工后沉降直接关乎公路的安全性能,蠕变行为的预测对保障路基工程的长期安全具有重要意义。对蠕变行为进行有限元数值模拟时,复杂结构模型的网格划分需要耗费大量的计算资源,且计算量大计算时间长。提出了一种考虑蠕变的任意多边形杂交应力新单元(polygonal hybrid stress element method,PHSEM),用于工程中的路基沉降问题研究。基于杂交应力元法及路基土的蠕变行为,推导PHSEM的单元基本格式,分析表明该单元引入了高阶应力场,能更好地提高计算精度,进一步建立路基蠕变的数值计算模型,结合有限元软件MARC开展对比分析。研究表明:PHSEM的数值仿真曲线拟合良好,验证了考虑蠕变的任意多边形杂交应力单元的有效性;PHSEM在划分网格时形状可以是任意边数的多边形,能够很好地模拟多种介质的路基模型,真实地计算出不同部位的应力分布情况;PHSEM的构造为实际工程中的蠕变研究提供了一种可参考的新思路。
