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Homogenisation has been used to eliminate solute segregation of CrMnFeCoNi high-entropy alloys (HEAs) before thermomechanical processing. To overcome the deficiencies caused by high-temperature homogenisation, we cancelled the homogenisation and studied the solute segregation feature and its effect on the grain growth and the mechanical property. The HEA forms equiaxed grains with the solute segregation in the range of tens of micrometres after cold rolling and recrystallisation. The grain growth in recrystallisation still abides by the classical grain growth kinetics, but with a higher power index of 3.33 and activation energy of 392.4 kJ mol−1 than those of the homogenised HEA, indicating a solute-drag effect. The relationship between the yield stress and grain size follows the Hall–Petch dependence with a higher intrinsic strength.

This paper addresses the end-to-end average BER (ABER) performance of decode-and-forward (DF) relay free-space optical (FSO) communications over weak and strong turbulence channels with pointing errors. For the weak and strong turbulence channels, the probability distribution function (PDF) of the irradiance can be modeled by a lognormal and Gamma–Gamma distribution, respectively. Considering the effects from atmospheric attenuation, turbulence and pointing errors, we present a statistical model for the optical intensity fluctuation at the receiver. Then the end-to-end ABER performances are analyzed and derived closed-form expressions are obtained. The simulation results indicate that the derived closed-form expressions provide sufficiently accurate approximations.

Low levels of acceptor-type dopants can introduce appreciable levels of oxide-ion conductivity into NB0.51T due to a synergistic effect from defect chemistry and ceramic microstructure.

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