Tuning ferroelectric photovoltaic performance in R3c-CuNbO3 through compressive strain engineering: a first-principles study.

Most ferroelectric oxides exhibit relatively wide bandgaps, which pose limitations on their suitability for photovoltaics application. CuNbO3 possesses potential ferroelectric properties with an R3c polar structure that facilitate the separation of charge carriers under illumination, promoting the generation of photovoltaic effects. The optical and ferroelectric properties of R3c-CuNbO3, as well as the effect of strain on the properties are investigated by first-principles calculation in this paper. The calculated results indicate that R3c-CuNbO3 possesses a moderate band gap to absorb visible light. The interaction of Cu-O and Nb-O bonds is considered to have a crucial role in the photovoltaic properties of CuNbO3, contributing to the efficient absorption of visible light. The bandgap of CuNbO3 becomes smaller and the density of states near the conduction and valence bands becomes relatively uniform in distribution under compressive conditions, which improves the photoelectric conversion efficiency to 29.9% under conditions of bulk absorption saturation. The ferroelectric properties of CuNbO3 are driven by the Nb-O bond interactions, which are not significantly weakened by the compressive strain. CuNbO3 is expected to be an excellent ferroelectric photovoltaic material by modulation of compressive strain due to the stronger visible light absorption and excellent ferroelectric behavior.

Venous-arterial extracorporeal membrane oxygenation support for patients poisoned by Macleaya cordata.

Macleaya cordata is a Chinese herbal medicine containing a variety of highly cardiotoxic alkaloids, and might result in cardiac failure. Venous-arterial Extracorporeal membrane oxygenation (VA-ECMO) could be used as a therapeutic option in patients poisoned by Macleaya cordata complicating refractory cardiogenic shock or cardiac arrest. A 60-year-old man suffered from severe arrhythmia, cardiogenic shock and cardiac arrest after consuming Macleaya cordata. The patient received VA-ECMO support in the emergency department at 5 hours after hospitalization, and was weaned from VA-ECMO on day 4, and was discharged with complete clinical improvement on Day 12. VA-ECMO is an effective method in treating cardiogenic shock or cardiac arrest induced by severe poisoning from Chinese herbal medicine. Timely and appropriate interventions with venoarterial extracorporeal membrane oxygenation devices could improve clinical outcomes in these patients.

Theoretical study on the stability, ferroelectricity and photocatalytic properties of CaBiO3.

Materials with high ferroelectric polarization strength and sufficient absorption of visible light have unique advantages in photocatalysis. Based on the results of structure search, phonon frequency, and elasticity coefficient calculations, CaBiO3 has a stable R3 polar structure. First-principles calculations indicate that R3-CaBiO3 is a potentially efficient ferroelectric visible-light photocatalytic material for hydrogen production. CaBiO3 under slight strain can maintain high ferroelectric polarization strength, strong visible light absorption capacity and small effective mass. CaBiO3 under tensile strain has potentially ferroelectric photogeneration of hydrogen with a band edge position that crosses the redox potential of water. These results can expand the application of Bi-based materials in photocatalytic hydrogen production.

Stability conditions for moving dissipative solitons in one- and multidimensional systems with a linear potential.

We analyze stability of moving dissipative solitons in the one-, two, and three-dimensional cubic-quintic complex Ginzburg-Landau equations in the presence of a linear potential (linear refractive index modulation). The expressions of stability conditions and propagation trajectory of solitons are derived by means of a generalized variational approximation. Predictions of the variational analysis are fully confirmed by direct numerical simulations. The results have potential applications to using spatial dissipative solitons in optics as individually addressable and shift registers of the all-optical data processing systems.

[Luminescence dynamics analysis on ruthenium polypyridyl complexes bonding to DNA].

Time-resolved spectra of six kinds of ruthenium polypyridyl complexes [Ru(L)2 (R)]2+ (L = bpy, phen, bpy = 2,2'-bipyridine, phen = 1,10-phenanthroline, R = 7-CH3-dppz, 7-F-dppz, dpbpd(NH2)2) bonding to calf thymus DNA in aqueous solution were compared and analyzed by using the three energy level kinetic model. And the effects of the substituent groups on the interaction ways for the ruthenium complexes bonding to DNA were discussed. The result shows that first, the six complexes all show two binding modes on bonding to DNA, i.e. the side-on binding mode and the perpendicular binding mode, and the later one is considered as a main binding way. Second, the properties of substituent groups have an important impact on the relative weight of the two binding modes. The conclusion offers a dynamics argument to study the interaction mechanism for the complex bonding to DNA further.