Novel octopus shaped organic-inorganic composite membranes for PEMFCs

© 2016 Hydrogen Energy Publications LLC.Phosphoric acid doped polybenzimidazoles are among the most interesting proton exchange membrane materials for high temperature proton exchange membrane fuel cell applications. As a major challenge the proton conducting decline due to free phosphoric acid leaching during the long term fuel cell operation is addressed by fixing overmuch phosphoric acid in the polymer matrix. Novel organic-inorganic composite membranes are prepared via in situ synthesis of poly(2,5-benzimidazole) (ABPBI) and OctaAmmonium POSS (AM-POSS) hybrid composites (ABPBI/AM-POSS) following phosphoric acid doping and membrane casting procedures. Compared with the pristine ABPBI membrane, the introduction of AM-POSS into ABPBI polymer membrane caused water and phosphoric acid absorbilities increasing dramatically, resulting in the significant increase of proton conductivities at whether hydrous or anhydrous condition. ABPBI/3AM composite membranes with phosphoric acid uptake above 250% showed best proton conductivities from room temperature to 160 °C, indicating these composite membranes could be excellent candidates as a polymer electrolyte membrane for low and intermediate temperature applications

Zemax design file of the objective

This is a Zemax design file of the objective with a NA of 0.44. It contains the design parameters in detail. And the objective consists of five commercial singlets

Apply Non-Hermitian Physics to Realize Ultra-High-Quality Factors of Optically Trapped Particles

Optical trapping and binding systems are non-Hermitian. On one hand, the optical force is non-Hermitian and may pump energy into the trapped particle when the non-Hermiticity is sufficiently large. On the other hand, the ambient damping constitutes a loss to the particle. Here, we show that in a low-friction environment, the interplay between the energy pumped-in by light and the ambient dissipation can give rise to either instability or a periodic vibration characterized by a finite quality factor (Q-factor). Through a comprehensive exploration, we analyze the influence of various parameters on the non-Hermitian force field. Our investigation reveals several strategies for enhancing the non-Hermitian force field, such as augmenting particle radius and refractive index, utilizing triangular lattice optical clusters, and reducing lattice constants

The Short-Selling Hypothesis of Weekend Effect and T + 1 Trading Mechanism

Utilizing a difference-in-difference regression model, we conduct cross-sectional and time-series analysis to explore effect of short sales on the weekend effect in the Chinese stock market, which uses a T + 1 trading mechanism. Our empirical results show that (1) significant negative returns associated with the weekend effect in the Chinese stock market before short selling was allowed, but the effect becomes almost insignificant when the short selling ban was lifted; (2) a significant increase in the returns associated with the weekend effect of shortable stocks from the period before to the period after they became eligible for short-selling; and (3) the change in the weekend effect is greater for more volatile stocks than for less volatile stocks. Our findings support the short-selling hypothesis of the weekend effect

Pairwise correlations.

Pairwise correlations.</p

Regression results based on PSM sample.

Regression results based on PSM sample.</p

Test results for heckman two-step model.

Test results for heckman two-step model.</p

Results for STATE = 1 and STATE = 0.

Results for STATE = 1 and STATE = 0.</p

Variable name and description.

Variable name and description.</p

Regression results for re-measuring IC effectiveness.

Regression results for re-measuring IC effectiveness.</p