To develop advanced electromagnetic interference(EMI)shielding materials,Mn-Mo ferrites doped with Ce were investigated for their electric,dielectric,and magnetic properties.Using Density Functional Theory(DFT)calcula...To develop advanced electromagnetic interference(EMI)shielding materials,Mn-Mo ferrites doped with Ce were investigated for their electric,dielectric,and magnetic properties.Using Density Functional Theory(DFT)calculation,the effect of doping different elements was evaluated in ferrite structures to optimize the performance of these ferrites.The calculated results revealed that the Mn-Mo ferrites which combined with Ce significantly lowered the bandgap and increased the total density of states(TDOS),leading to improved electrical conductivity.Additionally,the dielectric constant(ε')dielectric loss(ε'')and AC conductivity were found to be highest in the Mn-Mo-Ce-doped ferrites,contributing to superior EMI shielding effectiveness(SE),particularly in the low-frequency range.Mn-Mo-Ce doped ferrite was synthesized using auto-combustion method and evaluated for the EMI SE.The experimental and DFT calculated EMI SE both are close to 55 dB.This computational and experimental analysis,supported by structural and electronic localization function(ELF)mapping,underscores the potential of Mn-Mo-Ce-doped ferrites as highly efficient materials for EMI shielding in advanced electronic applications.展开更多
Semiconducting single-walled carbon nanotubes(s-SWCNTs)with narrow diameters are promising for future applications in many fields,especially in nanoelectronics and optoelectronics.In this study,the oxygen vacancy conc...Semiconducting single-walled carbon nanotubes(s-SWCNTs)with narrow diameters are promising for future applications in many fields,especially in nanoelectronics and optoelectronics.In this study,the oxygen vacancy concentration modulating strategy was utilized for growing narrow diameters s-SWCNTs by the chemical vapor deposition(CVD)method.The Fe_(0.01)Mg_(0.99)O solid solution based catalyst was syn-thesized to anchor the Fe particles and inhibit aggregation for growing SWCNTs with uniform diameters.CeO_(2)was introduced into the catalyst to provide oxygen vacancies through H_(2)prereduction.These oxygen vacancies could form an oxidative environment during the growth of SWCNTs,and the chemically active metallic carbon nanotube caps are selectively etched away under this environment.The Fe/Ce molar ratio and H2 prereduction time were optimized to modulate the oxygen vacancy concentration.Ultimately,us-ing the Fe_(0.01)Mg_(0.99)O/CeO_(2)(3)catalyst with 10 min of H_(2)prereduction time,high purity s-SWCNTs with diameters ranging from 1.41 to 1.71 nm and a content of 95.1%were obtained with high selectivity and carbon yield(1.33 wt%).The mechanism behind this phenomenon was elucidated through experimental characterizations and first-principle simulations,further expanding the understanding of the growth of s-SWCNTs through the modulation of oxygen vacancy concentration.展开更多
Visual object tracking （VOT） is an important sub- field of computer vision. It has widespread application do- mains, and has been considered as an important part of surveillance and security system. VOA facilitates ...Visual object tracking （VOT） is an important sub- field of computer vision. It has widespread application do- mains, and has been considered as an important part of surveillance and security system. VOA facilitates finding the position of target in image coordinates of video frames. While doing this, VOA also faces many challenges such as noise, clutter, occlusion, rapid change in object appearances, highly maneuvered （complex） object motion, illumination changes. In recent years, VOT has made significant progress due to availability of low-cost high-quality video cameras as well as fast computational resources, and many modern techniques have been proposed to handle the challenges faced by VOT. This article introduces the readers to 1） VOT and its applica- tions in other domains, 2） different issues which arise in it, 3） various classical as well as contemporary approaches for object tracking, 4） evaluation methodologies for VOT, and 5） online resources, i.e., annotated datasets and source code available for various tracking techniques.展开更多
The strong economic growth in China is difficult to reconcile with its inefficient financial system. The puzzle of China＇s financial development and growth can be explained through a dynamic criterion of adaptive eff...The strong economic growth in China is difficult to reconcile with its inefficient financial system. The puzzle of China＇s financial development and growth can be explained through a dynamic criterion of adaptive efficiency, rather than through allocative efficiency. Using the framework of an autoregressive distributed lag model, the present paper tests the hypothesis that the GDP growth rate is dependent on financial development along with other variables in China and Pakistan. The hypothesis cannot be rejected in both cases. However, the results show that economic growth has a negative relationship with credit to the private sector in China. We conclude that financial development is a source of China＇s high growth rate and that the banking system is still under an evolutionary process, involving the pursuit of social objectives instead of the sole objective of profit maximization. Our results provide some implications for other developing countries like Pakistan.展开更多
基金supported by the National Natural Science Foundation of China,China(51872231,51672221)the Key Industrial Chain Project of Shaanxi Province,China(2018ZDCXL-GY-08–07).
文摘To develop advanced electromagnetic interference(EMI)shielding materials,Mn-Mo ferrites doped with Ce were investigated for their electric,dielectric,and magnetic properties.Using Density Functional Theory(DFT)calculation,the effect of doping different elements was evaluated in ferrite structures to optimize the performance of these ferrites.The calculated results revealed that the Mn-Mo ferrites which combined with Ce significantly lowered the bandgap and increased the total density of states(TDOS),leading to improved electrical conductivity.Additionally,the dielectric constant(ε')dielectric loss(ε'')and AC conductivity were found to be highest in the Mn-Mo-Ce-doped ferrites,contributing to superior EMI shielding effectiveness(SE),particularly in the low-frequency range.Mn-Mo-Ce doped ferrite was synthesized using auto-combustion method and evaluated for the EMI SE.The experimental and DFT calculated EMI SE both are close to 55 dB.This computational and experimental analysis,supported by structural and electronic localization function(ELF)mapping,underscores the potential of Mn-Mo-Ce-doped ferrites as highly efficient materials for EMI shielding in advanced electronic applications.
基金supported by the National Natural Science Foun-dation of China(Nos.51872231 and 51672221)the Key Indus-trial Chain Project of Shaanxi Province,China(No.2018ZDCXL-GY-08-07).
文摘Semiconducting single-walled carbon nanotubes(s-SWCNTs)with narrow diameters are promising for future applications in many fields,especially in nanoelectronics and optoelectronics.In this study,the oxygen vacancy concentration modulating strategy was utilized for growing narrow diameters s-SWCNTs by the chemical vapor deposition(CVD)method.The Fe_(0.01)Mg_(0.99)O solid solution based catalyst was syn-thesized to anchor the Fe particles and inhibit aggregation for growing SWCNTs with uniform diameters.CeO_(2)was introduced into the catalyst to provide oxygen vacancies through H_(2)prereduction.These oxygen vacancies could form an oxidative environment during the growth of SWCNTs,and the chemically active metallic carbon nanotube caps are selectively etched away under this environment.The Fe/Ce molar ratio and H2 prereduction time were optimized to modulate the oxygen vacancy concentration.Ultimately,us-ing the Fe_(0.01)Mg_(0.99)O/CeO_(2)(3)catalyst with 10 min of H_(2)prereduction time,high purity s-SWCNTs with diameters ranging from 1.41 to 1.71 nm and a content of 95.1%were obtained with high selectivity and carbon yield(1.33 wt%).The mechanism behind this phenomenon was elucidated through experimental characterizations and first-principle simulations,further expanding the understanding of the growth of s-SWCNTs through the modulation of oxygen vacancy concentration.
文摘Visual object tracking （VOT） is an important sub- field of computer vision. It has widespread application do- mains, and has been considered as an important part of surveillance and security system. VOA facilitates finding the position of target in image coordinates of video frames. While doing this, VOA also faces many challenges such as noise, clutter, occlusion, rapid change in object appearances, highly maneuvered （complex） object motion, illumination changes. In recent years, VOT has made significant progress due to availability of low-cost high-quality video cameras as well as fast computational resources, and many modern techniques have been proposed to handle the challenges faced by VOT. This article introduces the readers to 1） VOT and its applica- tions in other domains, 2） different issues which arise in it, 3） various classical as well as contemporary approaches for object tracking, 4） evaluation methodologies for VOT, and 5） online resources, i.e., annotated datasets and source code available for various tracking techniques.
文摘The strong economic growth in China is difficult to reconcile with its inefficient financial system. The puzzle of China＇s financial development and growth can be explained through a dynamic criterion of adaptive efficiency, rather than through allocative efficiency. Using the framework of an autoregressive distributed lag model, the present paper tests the hypothesis that the GDP growth rate is dependent on financial development along with other variables in China and Pakistan. The hypothesis cannot be rejected in both cases. However, the results show that economic growth has a negative relationship with credit to the private sector in China. We conclude that financial development is a source of China＇s high growth rate and that the banking system is still under an evolutionary process, involving the pursuit of social objectives instead of the sole objective of profit maximization. Our results provide some implications for other developing countries like Pakistan.
