TE material research has attracted intense interest over the past few decades. [1] The TE performance of a material is measured by zT = σS 2 T/κ, where T, σ, S, and κ are the absolute temperature, electrical conductivity, Seebeck coefficient, and total thermal conductivity, respectively. Typically, κ = κ el + κ ph , where the κ el and κ ph are the carrier and lattice thermal conductivity, respectively. Since σ, S, and κ el are adversely interrelated whereas the κ ph is relatively independent of σ, S, and κ el , the stride toward high zT is in line with a two-pronged strategy, coined by Slack as "electron-crystal phonon-glass" (ECPG): [2] i) decoupling σ, S, and κ el through band structure engineering toward a high power factor (PF) = σS 2 ; [3,4] and ii) suppressing the κ ph via all-scale hierarchical microstructures. [5][6][7] Rooted in the core effects of high entropy alloys (HEAs), entropy engineering enables a synergy of band structure engineering and multiscale hierarchical microstructures through high entropy alloying. HEAs typically refer to the solid solutions in which more than five principal elements each in 5-35% molar ratio compete for the same crystallographic site, yielding high entropy of mixing and a wider variety of exciting properties. [8] HEA is a subset of multielement-doped materials. Neither the doping process nor the resulting composition would differentiate aThe core effects of high entropy alloys distinguish high entropy alloying from ordinary multielement doping, allowing for a synergy of band structure and microstructure engineering. Here, a systematic synthesis, structural, theoretical, and thermoelectric study of multi-principal-element-alloyed SnTe is reported. Toward high thermoelectric performance, the entropy of mixing needs to be high enough to make good use of the core effects, yet low enough to minimize the degradation of carrier mobility. It is demonstrated that high entropy of mixing extends the solubility limit of Mn while retaining the lattice symmetry, the enhanced Mn content elicits multiscale microstructures. The resulting ultralow lattice thermal conductivity of ≈0.32 W m −1 K −1 at 900 K in (Sn 0.7 Ge 0.2 Pb 0.1 ) 0.75 Mn 0.275 Te is not only lower than the amorphous limit of SnTe but also comparable to those thermoelectric materials with complex crystal structures and strong anharmonicity. Co-alloying of (Sn,Ge,Pb,Mn) also enhances band convergence and band effective mass, yielding good power factors. Further tuning of the Sn excess yields a state-of-the-art zT ≈1.42 at 900 K in (Sn 0.74 Ge 0.2 Pb 0.1 ) 0.75 Mn 0.275 Te. In view of the simple face-centeredcubic structure of SnTe-based alloys, these results attest to the efficacy of entropy engineering toward a new paradigm of high entropy thermoelecrics.

Gliding arc discharge has been proved to be effective in treatment of gas and liquid contaminants. In this study, physical characteristics of dc gliding arc discharge and its application to naphthalene destruction are investigated with different external resistances and carrier gases. The decomposition rate increases with increasing of oxygen concentration and decreases with external resistance. This value can be achieved up to 92.3% at the external resistance of 50 kOmega in the oxygen discharge, while the highest destruction energy efficiency reaches 3.6 g (kW h)(-1) with the external resistance of 93 kOmega. Possible reaction pathways and degradation mechanisms in the plasma with different gases are proposed by qualitative analysis of postdestructed products. In the air and oxygen gliding arc discharges, the naphthalene degradation is mainly governed by reactions with oxygen-derived radicals.

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A computational and experimental method on biomechanics of stent is presented to analyze the stress distribution of different phases and evaluate the fatigue life according to Goodman criteria. As a result, the maximum stress and alternating stress were always located at the curvature area of rings, the fatigue bands in the experiment also verified the computation rationality. Matching between the numerical simulation and experimental results was satisfactory, which proved that the finite element analysis could provide theoretical evidence and help design and optimize the stent structure.