The authors used Landau-Pekar variational method to investigate a strong-coupling singlet optical bipolaron in different configuration of quantum confinement. Numerical and analytical results showed that when configur...The authors used Landau-Pekar variational method to investigate a strong-coupling singlet optical bipolaron in different configuration of quantum confinement. Numerical and analytical results showed that when configuration changes from quantum dot and wire to well, confinement shows different effect on the formation of a bipolaron. In contrast to a bipolaron in a quantum dot or wire, the binding energy of a bipolaron in a quantum well increases with increasing con-finement, indicating that confinement favors bipolaron formation in a quantum well.展开更多
High-speed vehicle dynamic envelope curve is defined as the maximum limit outline affected by a variety of adverse factors while the train is running. Considering the difficulties in the current measurement system suc...High-speed vehicle dynamic envelope curve is defined as the maximum limit outline affected by a variety of adverse factors while the train is running. Considering the difficulties in the current measurement system such as complicated calibration process,cumbersome aided-instruments,strict limitation of working distance, this paper carries out an optical method in which two high-speed cameras with variable-zoom lenses are adopted as binocular stereo sensors of measurement system and a high-ac-curacy 3D target with fast reconstruction is designed. The intrinsic parameters of the sensors and the relative positions between coordinate systems are solved by the method of colinearity constrained optimization algorithm. The calibration process is easy to operate and the device is also of portability. Most importantly, the severe working distance limitation between sensors and measured body is solved, enhancing the adaptability of measurement system to environment. Experimental results show that when the sensors are in the range of 8 -16 m away from the measured body, system accuracy can reach up to ±0. 5 mm, which meets the requirements to measure the dynamic envelope curve of high-speed vehicle.展开更多
Sparse optimization has witnessed advancements in recent decades,and the step function finds extensive applications across various machine learning and signal processing domains.This paper integrates zero norm and the...Sparse optimization has witnessed advancements in recent decades,and the step function finds extensive applications across various machine learning and signal processing domains.This paper integrates zero norm and the step function to formulate a doublesparsity constrained optimization problem,wherein a linear equality constraint is also taken into consideration.By defining aτ-Lagrangian stationary point and a KKT point,we establish the first-order and second-order necessary and sufficient optimality conditions for the problem.Furthermore,we thoroughly elucidate their relationships to local and global optimal solutions.Finally,special cases and examples are presented to illustrate the obtained theorems.展开更多
This work studies new petrological and geochemical data and zircon U-Pb ages for bimodal intrusive rocks from Xinglong re- gion, Hainan Island. Zircon U-Pb dating yields mean 238U/26pb ages of 238 ± 2 Ma and 234&...This work studies new petrological and geochemical data and zircon U-Pb ages for bimodal intrusive rocks from Xinglong re- gion, Hainan Island. Zircon U-Pb dating yields mean 238U/26pb ages of 238 ± 2 Ma and 234±2 Ma for diabasic and granitic phases, respectively, representing the Middle Triassic emplacement. The diabase and granite bodies were formed from discrete mafic and acidic magma sources that experienced local mechanical mixing at their mutual contacts. Although SiO2 content of intrusions is bimodal, trace element ratios indicate that both were formed in a post-orogenic extensional setting. Sr-Nd isotopic composition reflects a shared EMII type enriched mantle source component, possibly influenced by subduction-fluid metaso- matism.展开更多
文摘The authors used Landau-Pekar variational method to investigate a strong-coupling singlet optical bipolaron in different configuration of quantum confinement. Numerical and analytical results showed that when configuration changes from quantum dot and wire to well, confinement shows different effect on the formation of a bipolaron. In contrast to a bipolaron in a quantum dot or wire, the binding energy of a bipolaron in a quantum well increases with increasing con-finement, indicating that confinement favors bipolaron formation in a quantum well.
基金National Science and Technology Major Project(No.2016ZX04003001)
文摘High-speed vehicle dynamic envelope curve is defined as the maximum limit outline affected by a variety of adverse factors while the train is running. Considering the difficulties in the current measurement system such as complicated calibration process,cumbersome aided-instruments,strict limitation of working distance, this paper carries out an optical method in which two high-speed cameras with variable-zoom lenses are adopted as binocular stereo sensors of measurement system and a high-ac-curacy 3D target with fast reconstruction is designed. The intrinsic parameters of the sensors and the relative positions between coordinate systems are solved by the method of colinearity constrained optimization algorithm. The calibration process is easy to operate and the device is also of portability. Most importantly, the severe working distance limitation between sensors and measured body is solved, enhancing the adaptability of measurement system to environment. Experimental results show that when the sensors are in the range of 8 -16 m away from the measured body, system accuracy can reach up to ±0. 5 mm, which meets the requirements to measure the dynamic envelope curve of high-speed vehicle.
基金Supported by the National Key R&D Program of China(No.2023YFA1011100)NSFC(No.12131004)。
文摘Sparse optimization has witnessed advancements in recent decades,and the step function finds extensive applications across various machine learning and signal processing domains.This paper integrates zero norm and the step function to formulate a doublesparsity constrained optimization problem,wherein a linear equality constraint is also taken into consideration.By defining aτ-Lagrangian stationary point and a KKT point,we establish the first-order and second-order necessary and sufficient optimality conditions for the problem.Furthermore,we thoroughly elucidate their relationships to local and global optimal solutions.Finally,special cases and examples are presented to illustrate the obtained theorems.
基金supported China Postdoctoral Science Foundation (Grant No. 2011M500991)Basic Scientific Research Specific Foundation of Second Insitute of Oceanography, SIO (Grant No. JT1104)
文摘This work studies new petrological and geochemical data and zircon U-Pb ages for bimodal intrusive rocks from Xinglong re- gion, Hainan Island. Zircon U-Pb dating yields mean 238U/26pb ages of 238 ± 2 Ma and 234±2 Ma for diabasic and granitic phases, respectively, representing the Middle Triassic emplacement. The diabase and granite bodies were formed from discrete mafic and acidic magma sources that experienced local mechanical mixing at their mutual contacts. Although SiO2 content of intrusions is bimodal, trace element ratios indicate that both were formed in a post-orogenic extensional setting. Sr-Nd isotopic composition reflects a shared EMII type enriched mantle source component, possibly influenced by subduction-fluid metaso- matism.
