Band gap tuning and p to n-type transition in Mn-doped CuO nanostructured thin films

Here we discuss the synthesis of copper (II) oxide (CuO) and manganese (Mn)-doped CuO thin films varying with 0 to 8 at% Mn using the spray pyrolysis technique. As-deposited film surfaces comprised of agglomerated spherical nanoparticles and a semi-spongy porous structure for 4 at% Mn doping. Energy dispersive analysis of X-rays confirmed the chemical composition of the films. X-ray diffraction spectra showed a polycrystalline monoclinic structure with the predominance of the ( 11) peak. Optical band gap energy for direct and indirect transitions was estimated in the ranges from 2.67–2.90 eV and 0.11–1.73 eV, respectively. Refractive index and static dielectric constants were computed from the optical spectra. Electrical resistivity of CuO and Mn-doped CuO (Mn:CuO) thin films was found in the range from 10.5 to 28.6 Ω·cm. The tiniest electron effective mass was calculated for 4 at% Mn:CuO thin films. P to n-type transition was observed for 4 at% Mn doping in CuO films. Carrier concentration and mobility were found in the orders of 1017 cm–3 and 10–1 cm2/(V·s), respectively. The Hall coefficient was found to be between 9.9 and 29.8 cm3/C. The above results suggest the suitability of Mn:CuO thin films in optoelectronic applications.

Detection of the Mass-dependent Dual Type Transition of Galaxy Spins in IllustrisTNG Simulations

A numerical detection of the mass-dependent spin transition of the galaxies is presented. Analyzing a sample of the galaxies with stellar masses in the range of 109 < (M ⋆/M ⊙) ≤ 1011 from the IllustrisTNG300-1 simulations, we explore the alignment tendency between the galaxy baryon spins and the three eigenvectors of the linearly reconstructed tidal field as a function of M ⋆ and its evolution in the redshift range of 0 ≤ z ≤ 1.5. Detecting a significant signal of the occurrence of the mass-dependent transition of the galaxy spins, we show that the centrals differ from the satellites in their spin transition type. As M ⋆ increases beyond a certain threshold mass, the preferred directions of the central galaxy spins transit from the minor to the intermediate tidal eigenvectors (type two) at z = 0.5 and 1, while those of the satellites transit from the minor to the major tidal eigenvectors (type one) at z = 1 and 1.5. It is also shown that the mass range and type of the spin transition depend on the galaxy morphology, the degree of the alignments between the baryon and total spin vectors, and the environmental density. Meanwhile, the stellar spins of the galaxies are found to yield a weak signal of the T1 transitions at z = 0, whose strength and trend depend on the degree of the alignments between the stellar and baryon spins. The possible mechanisms responsible for the T1 and T2 spin transitions are discussed.

Copper Mediated C(sp2)–H Sulfonylation of Aldehydes using a Catalytic Transient Imine Directing Group

The copper mediated β–C(sp2)–H sulfonylation of benzaldehydes with sulfinate salts is accomplished using β-alanine as a catalytic transient directing group. A broad range of sulfonylated benzaldehydes are prepared us-ing copper fluoride as both copper source and oxidant. Both b-(ortho) and g-(peri)-sulfonylation are demon-strated. Mechanistic studies indicate the turnover limiting step to be a concerted asynchronous C–H cleavage via a Wheland-type transition state.

Nuclear factor E2-related factor 2 (NRF2) deficiency accelerates fast fibre type transition in soleus muscle during space flight

Microgravity induces skeletal muscle atrophy, particularly in the soleus muscle, which is predominantly composed of slow-twitch myofibre (type I) and is sensitive to disuse. Muscle atrophy is commonly known to be associated with increased production of reactive oxygen species. However, the role of NRF2, a master regulator of antioxidative response, in skeletal muscle plasticity during microgravity-induced atrophy, is not known. To investigate the role of NRF2 in skeletal muscle within a microgravity environment, wild-type and Nrf2-knockout (KO) mice were housed in the International Space Station for 31 days. Gene expression and histological analyses demonstrated that, under microgravity conditions, the transition of type I (oxidative) muscle fibres to type IIa (glycolytic) was accelerated in Nrf2-KO mice without affecting skeletal muscle mass. Therefore, our results suggest that NRF2 affects myofibre type transition during space flight.