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Helium-hydrogen separation bed is an important part of tritium extraction system. In order to deeply study penetration performance of the radial flow bed and guide the structure design, the mathematical model of radial bed breakthrough capacity was established by coupling material hydrogen absorption kinetics equation, mass transfer equation and fluid flow momentum equation in COMSOL Multiphysics, which was used to carry out parametric scanning of the characteristic parameters, and the effect of the model on the breakthrough capacity was analyzed. The results show that the breakthrough experiment results are in good agreement with the simulated data, and the model is reliable. The effect of temperature, height-diameter ratio and porosity on the breakthrough capacity was analyzed. The adsorption temperature of the bed is from room temperature to 343 K. In this temperature range, increasing the temperature has less effect on the length of the mass transfer zone and the concentration-time curve at the outlet. With the increase of the height-diameter ratio, the efficiency of the bed decreases significantly, in which the high efficiency is maintained for a longer period of time when the hieght-diameter ratio is 2.00-8.33. With the increase of porosity, the adsorption efficiency of the bed decreases significantly. Considering the adsorption efficiency, the flow resistance and the difficulty of powder loading, the powder porosity is recommended from 0.56 to 0.64. Therefore, the model established in this study can better predict the adsorption performance, and can be used to optimize the structure design basis and process parameters.

The resistance temperature characteristics and thermal stability of graphite based flexible grounding materials were studied. With the method of current heating and constant temperature protection, the resistance of grounding body at each temperature was measured by voltammetry, and the average resistance temperature coefficient was derived. With the resistance temperature characteristic parameters of the grounding body obtained from the experiment, the maximum temperature rise of the graphite based flexible grounding body under the power frequency grounding fault current and lightning impulse current was calculated iteratively, which is verified by the calculation of the thermal stability coefficient. The experimental results show that the graphite based flexible grounding body has a negative temperature coefficient. When the maximum allowable service temperature of the graphite based flexible grounding body is 450 ℃, the maximum allowable current under 0.5 s power frequency current is about 1.4 kA, which is 8/20 μs the maximum allowable passing current amplitude of graphite based flexible grounding body under the impact of high frequency lightning current is 287.9 kA.

helium-3 influence was analyzed by combining with the Ortman model. The results showed that helium blanketing effect affected the adsorption performance of Zr0.85Ti0.15Co alloy significantly, but the blanketing effect could not completely inhibit the tritium absorption reaction, and it could continue to absorb tritium at a low rate until the adsorption was completed. The completion time of tritium absorption was mainly affected by helium-3 concentration when helium-3 concentrations was low, while when the helium concentration was high, it was mainly affected by the initial tritium partial pressure. Helium-3 blanketing process included two steps, that was “bulk flow” and “diffusion flow”, and Ortman model could predict the helium shielding pressure in “bulk flow”.

Mitochondrial dysfunction and oxidative stress play a crucial role in the pathogenesis of Alzheimer's disease (AD). The neuroprotective effects of the diosgenin derivative ML5 were investigated in vitro and in vivo, and the underlying mechanisms were explored. The results showed that ML5 ameliorated the study and cognitive deficits in beta-amyloid (Aβ1-42)-induced mouse model and protected neurons in the hippocampal region. In addition, ML5 attenuated H2O2-induced damage to SH-SY5Y cells and increased mitochondrial membrane potential and ATP levels. Western blot and immunofluorescence results showed that ML5 activated nuclear factor-erythroid-2-related factor 2 (NRF2) signaling pathway and increased the expression of NRF2, heme oxygenase-1 (HO-1), and NAD(P)H:quinone oxidoreductase-1 (NQO-1). Our findings suggest that ML5 may be used as a therapeutic drug for AD treatment via targeting the NRF2 pathway, thereby exerting antioxidant and neuroprotective effects. [ABSTRACT FROM AUTHOR]