In this study, free and forced vibration analysis of nano-composite rotating pressurized microbeam reinforced by carbon nanotubes (CNTs) under magnetic field based on modify couple stress theory (MCST) with temper...In this study, free and forced vibration analysis of nano-composite rotating pressurized microbeam reinforced by carbon nanotubes (CNTs) under magnetic field based on modify couple stress theory (MCST) with temperature-variable material propertiesis presented. Also, the boundary conditions at two ends of nano-composite rotating pressurized microbeam reinforced by CNTs are considered as simply supported. The governing equations are obtained based on the Hamilton's principle and then computed these equations by using Navier's solution. The magnetic field is inserted in the thickness direction of the nano-composite microbeam. The effects of various parameters such as angular velocity, temperature changes, and pressure between of the inside and outside, the magnetic field, material length scale parameter, and volume fraction of nanocomposite microbeam on the natural frequency and response systemare studied. The results show that with increasing volume fraction of nano-composite microbeam, thickness, material length scale parameter, and magnetic fields, the natural frequency increases. The results of this research can be used for optimization of micro-structures and manufacturing sensors, displacement fluid, and drug delivery.展开更多
High-spin yrast structures of even-even superheavy nuclei 254-25SRf are investigated by means of total- Routhian-surface approach in three-dimensional (f12, 7, f14) space. The behavior in the moments of inertia of 2...High-spin yrast structures of even-even superheavy nuclei 254-25SRf are investigated by means of total- Routhian-surface approach in three-dimensional (f12, 7, f14) space. The behavior in the moments of inertia of 256Rf is well reproduced by our calculations, which is attributed to the J15/2 neutron rotation-alignment. The competition between the rotationally aligned ila/2 proton and j15/2 neutron may occur to a large extent in 256Rf. High-spin predictions are also made for its neighboring isotopes 254'2ssRf, showing that the alignment of the j15/2 neutron pair is more favored than that of the i13/2 proton pair.展开更多
The existing directions-of-arrival (DOAs) estimation methods for two-dimensional (2D) coherently distributed sources need one- or two-dimensional search, and the computational complexities of them are high. In add...The existing directions-of-arrival (DOAs) estimation methods for two-dimensional (2D) coherently distributed sources need one- or two-dimensional search, and the computational complexities of them are high. In addition, most of them are designed for special angular signal distribution functions. As a result, their performances will degenerate when deal with different sources with different angular signal distribution functions or unknown angular signal distribution functions. In this paper, a low-complexity decoupled DOAs estimation method without searching using two parallel uniform linear arrays (ULAs) is proposed for coherently distributed sources, as well as a novel parameter matching method. It can resolve the problems mentioned above efficiently. Simulation results validate the effectiveness of our approach.展开更多
基金the Iranian Nanotechnology Development Committee for their financial supportthe University of Kashan (463855/7)
文摘In this study, free and forced vibration analysis of nano-composite rotating pressurized microbeam reinforced by carbon nanotubes (CNTs) under magnetic field based on modify couple stress theory (MCST) with temperature-variable material propertiesis presented. Also, the boundary conditions at two ends of nano-composite rotating pressurized microbeam reinforced by CNTs are considered as simply supported. The governing equations are obtained based on the Hamilton's principle and then computed these equations by using Navier's solution. The magnetic field is inserted in the thickness direction of the nano-composite microbeam. The effects of various parameters such as angular velocity, temperature changes, and pressure between of the inside and outside, the magnetic field, material length scale parameter, and volume fraction of nanocomposite microbeam on the natural frequency and response systemare studied. The results show that with increasing volume fraction of nano-composite microbeam, thickness, material length scale parameter, and magnetic fields, the natural frequency increases. The results of this research can be used for optimization of micro-structures and manufacturing sensors, displacement fluid, and drug delivery.
基金Supported by National Natural Science Foundation of China(10805040,11175217)Foundation and Advanced Technology Research Program of Henan Province(132300410125)S&T Research Key Program of Henan Province Education Department(13A140667)
文摘High-spin yrast structures of even-even superheavy nuclei 254-25SRf are investigated by means of total- Routhian-surface approach in three-dimensional (f12, 7, f14) space. The behavior in the moments of inertia of 256Rf is well reproduced by our calculations, which is attributed to the J15/2 neutron rotation-alignment. The competition between the rotationally aligned ila/2 proton and j15/2 neutron may occur to a large extent in 256Rf. High-spin predictions are also made for its neighboring isotopes 254'2ssRf, showing that the alignment of the j15/2 neutron pair is more favored than that of the i13/2 proton pair.
基金Supported by the National Natural Science Foundation of China (Grant No. 60772146)the Program for New Century Excellent Talents in University (Grant No. NCET-05-0806)
文摘The existing directions-of-arrival (DOAs) estimation methods for two-dimensional (2D) coherently distributed sources need one- or two-dimensional search, and the computational complexities of them are high. In addition, most of them are designed for special angular signal distribution functions. As a result, their performances will degenerate when deal with different sources with different angular signal distribution functions or unknown angular signal distribution functions. In this paper, a low-complexity decoupled DOAs estimation method without searching using two parallel uniform linear arrays (ULAs) is proposed for coherently distributed sources, as well as a novel parameter matching method. It can resolve the problems mentioned above efficiently. Simulation results validate the effectiveness of our approach.