Age and gender differences in the self-esteem of Chinese children

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Optimizing the flight route of UAV using biology migration algorithm

Funding Information: This work is supported by the National Natural Science Foundation of China under Grants 62006103 and 61872168, in part by the Jiangsu national science research of high education under Grand 20KJB110021.Peer reviewedPublisher PD

Flexible constant force grinding of rare earth metal ingot

The rare earth metal ingots obtained by molten salt electrolysis method have oxide layers, salt layers, and other impurities on the surface, which require polishing processing. However, currently, manual polishing processing has problems such as low processing efficiency and resource waste. By designing a flexible end effector and adopting a parallel fuzzy Proportion Integration Differentiation (PID) control strategy for constant force control of the end effector, automation and high efficiency of rare earth metal ingot grinding are achieved

Suppressing longitudinal double-layer oscillations by using elliptically polarized laser pulses in the hole-boring radiation pressure acceleration regime

It is shown that well collimated mono-energetic ion beams with a large particle number can be generated in the hole-boring radiation pressure acceleration regime by using an elliptically polarized laser pulse with appropriate theoretically determined laser polarization ratio. Due to the $\bm{J}\times\bm{B}$ effect, the double-layer charge separation region is imbued with hot electrons that prevent ion pileup, thus suppressing the double-layer oscillations. The proposed mechanism is well confirmed by Particle-in-Cell simulations, and after suppressing the longitudinal double-layer oscillations, the ion beams driven by the elliptically polarized lasers own much better energy spectrum than those by circularly polarized lasers.Comment: 6 pages, 5 figures, Phys. Plasmas (2013) accepte

Effect of inclined mainline on smoke backlayering length in a naturally branched tunnel fire

In this study, the effect of the slope of the mainline tunnel on the characteristics of smoke movement and the distance of smoke backflow in a branched tunnel with an inclined downstream mainline was investigated. The downstream mainline tunnel slope varied from 0% to 7% at intervals of 1%. A virtual wind velocity was proposed as a means to correlate with the airflow velocity induced by the stack effect. The results showed that a significant airflow velocity was formed in the branched tunnel with an inclination of the mainline before shunting. When the tunnel slope and fire size were larger, the induced airflow velocity was enhanced due to the greater thermal pressure difference induced by the stack effect. The effect of the bifurcation angle on induced airflow velocity was limited, but could not be neglected under relatively large heat release rates. The smoke was well controlled into the horizontal mainline region due to the induced wind by the stack effect. The backlayering length was slightly reduced under stronger heat release rates but was more sensitive to the slope of the mainline tunnel. A prediction model for smoke backlayering length in a branched tunnel with a tilted downstream mainline was developed based on dimensionless velocity. The predicted value of the smoke backlayering length agreed well with the simulated results. This study contributes to the understanding of smoke movement in naturally branched tunnels with inclined downstream sections and guides extraction design

2-D DOA Estimation for L-Shaped Array With Array Aperture and Snapshots Extension Techniques

A two-dimensional (2-D) direction of arrival estimation method for L-shaped array with automatic pairing is proposed. It exploits the conjugate symmetry property of the array manifold matrix to increase the effective array aperture and the number of virtual snapshots simultaneously, and then applies the principle of MUSIC to construct an angle cost function and transforms the conventional 2-D search into 1-D via a Rayleigh quotient, which can greatly reduce the computation complexity. Finally, the azimuth and elevation angles are estimated without pair matching. Simulation results show that the proposed method has a better performance and can resolve more sources than some existing computationally efficient methods

Surface phase separation in nanosized charge-ordered manganites

Recent experiments showed that the robust charge-ordering in manganites can be weakened by reducing the grain size down to nanoscale. Weak ferromagnetism was evidenced in both nanoparticles and nanowires of charge-ordered manganites. To explain these observations, a phenomenological model based on surface phase separation is proposed. The relaxation of superexchange interaction on the surface layer allows formation of a ferromagnetic shell, whose thickness increases with decreasing grain size. Possible exchange bias and softening of the ferromagnetic transition in nanosized charge-ordered manganites are predicted.Comment: 4 pages, 3 figure