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According to the "little boy" data from the United States, this paper simulates the primary γ-ray of the nuclear explosion and the secondary γ-ray produced by neutron, γ-ray and material interaction. At the same time, the linear attenuation coefficient spectra of 0.001mev to 100mev was calculated. The information was obtained from the point of the source projection of 500 meters to 1km. The results showed in the observation distance: The attenuation of the primary γ-ray energy was in line with the spectral γ-ray passing through the law of shielding the decay of the material. and it showed the phenomenon of the "hardening" of the energy spectrum. The fluence decreases an order of magnitude. The energy of the secondary γ-ray does not showed obvious attenuation laws, and the fluence decreases by about two orders of magnitude. It was worth noting that the average energy of the two kinds of γ-ray was around 2.100 MeV, and the fluence was in the same order of magnitude at 1km from the distance simulation.

The intrinsic variability of memristor switching behavior can be used as a natural source of randomness, this variability is valuable for safe applications in hardware, such as the true random number generator (TRNG). However, the speed of TRNG is still be further improved. Here, we propose a reliable Ag/SiNx/n-Si volatile memristor, which exhibits a typical threshold switching device with stable repeat ability and fast switching speed. This volatile-memristor-based TRNG is combined with nonlinear feedback shift register (NFSR) to form a new type of high-speed dual output TRNG. Interestingly, the bit generation rate reaches a high speed of 112 kb/s. In addition, this new TRNG passed all 15 National Institute of Standards and Technology (NIST) randomness tests without post-processing steps, proving its performance as a hardware security application. This work shows that the SiNx-based volatile memristor can realize TRNG and has great potential in hardware network security. [ABSTRACT FROM AUTHOR]

Neuromorphic computing aims to achieve artificial intelligence by mimicking the mechanisms of biological neurons and synapses that make up the human brain. However, the possibility of using one reconfigurable memristor as both artificial neuron and synapse still requires intensive research in detail. In this work, Ag/SrTiO3(STO)/Pt memristor with low operating voltage is manufactured and reconfigurable as both neuron and synapse for neuromorphic computing chip. By modulating the compliance current, two types of resistance switching, volatile and nonvolatile, can be obtained in amorphous STO thin film. This is attributed to the manipulation of the Ag conductive filament. Furthermore, through regulating electrical pulses and designing bionic circuits, the neuronal functions of leaky integrate and fire, as well as synaptic biomimicry with spike-timing-dependent plasticity and paired-pulse facilitation neural regulation, are successfully realized. This study shows that the reconfigurable devices based on STO thin film are promising for the application of neuromorphic computing systems. [ABSTRACT FROM AUTHOR]

This paper studies the automatic carrier landing controller design problem with output constraint and fixed-time convergence requirements. The proposed flight controller is separated into guidance, attitude control, and approach power compensation system. In each submodule, universal barrier Lyapunov function and fixed-time control scheme are applied in the controller design. In addition, adaptive estimation method is incorporated to improve the robustness to the external disturbances. The proposed controller ensures the position tracking error, attitude tracking error, and angle of attack tracking error not violate the predesigned boundaries, while the tracking errors will converge to a small set around zero in fixed-time. The output constraint and fixed-time convergence properties of the proposed controller improve the landing security to a narrow flight deck in a limited operation time. The simulation results verify the proposed controller in automatic carrier landing mission. [ABSTRACT FROM AUTHOR]