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1. Triple Emission of 5′-( para -R-Phenylene)vinylene-2-(2′-hydroxyphenyl)benzoxazole ( PVHBO ). Part II: Emission from Anions

   https://doi.org/10.1021/acs.jpca.1c10167  

   Hurley, Joseph J. ; Meisner, Quinton J. ; Guo, Peijun ; Schaller, Richard D. ; Gosztola, David J. ; Wiederrecht, Gary P. ; Zhu, Lei ( February 2022 , The Journal of Physical Chemistry A)
2. Dramatically Enhanced Valley‐Polarized Emission by Alloying and Electrical Tuning of Monolayer WTe 2 x S 2(1‐ x ) Alloys at Room Temperature with 1T′‐WTe 2 ‐Contact

   https://doi.org/10.1002/advs.202304890  

   Lin, Wei‐Hsiang ; Li, Chia‐Shuo ; Wu, Chih‐I ; Rossman, George R. ; Atwater, Harry A. ; Yeh, Nai‐Chang ( November 2023 , Advanced Science)

   Monolayer ternary tellurides based on alloying different transition metal dichalcogenides (TMDs) can result in new two‐dimensional (2D) materials ranging from semiconductors to metals and superconductors with tunable optical and electrical properties. Semiconducting WTe_2xS_2(1‐x)monolayer possesses two inequivalent valleys in the Brillouin zone, each valley coupling selectively with circularly polarized light (CPL). The degree of valley polarization (DVP) under the excitation of CPL represents the purity of valley polarized photoluminescence (PL), a critical parameter for opto‐valleytronic applications. Here, new strategies to efficiently tailor the valley‐polarized PL from semiconducting monolayer WTe_2xS_2(1‐x)at room temperature (RT) through alloying and back‐gating are presented. The DVP at RT is found to increase drastically from < 5% in WS₂to 40% in WTe_0.12S_1.88by Te‐alloying to enhance the spin‐orbit coupling. Further enhancement and control of the DVP from 40% up to 75% is demonstrated by electrostatically doping the monolayer WTe_0.12S_1.88via metallic 1T′‐WTe₂electrodes, where the use of 1T′‐WTe₂substantially lowers the Schottky barrier height (SBH) and weakens the Fermi‐level pinning of the electrical contacts. The demonstration of drastically enhanced DVP and electrical tunability in the valley‐polarized emission from 1T′‐WTe₂/WTe_0.12S_1.88heterostructures paves new pathways towards harnessing valley excitons in ultrathin valleytronic devices for RT applications.

    

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3. White light emission from co-doped La 2 Hf 2 O 7 nanoparticles with suppressed host → Eu 3+ energy transfer via a U 6+ co-dopant

   https://doi.org/10.1039/D1QI00134E  

   Gupta, Santosh K. ; Modak, Brindaban ; Modak, Pampa ; Mao, Yuanbing ( August 2021 , Inorganic Chemistry Frontiers)

   null (Ed.)

   Controlled energy transfer has been found to be one of the most effective ways of designing tunable and white photoluminescent phosphors. Utilizing host emission to achieve the same would lead to a new dimension in the design strategy for novel luminescent materials in solid state lighting and display devices. In this work, we have achieved controlled energy transfer by suppressing the host to dopant energy transfer in La 2 Hf 2 O 7 :Eu 3+ nanoparticles (NPs) by co-doping with uranium ions. Uranium acts as a barrier between the oxygen vacancies of the La 2 Hf 2 O 7 host and Eu 3+ doping ions to increase their separation and reduce the non-radiative energy transfer between them. Density functional theory (DFT) calculations of defect formation energy showed that the Eu 3+ dopant occupies the La 3+ site and the uranium ion occupies the Hf 4+ site. Co-doping the La 2 Hf 2 O 7 :Eu 3+ NPs with uranium ions creates negatively charged lanthanum and hafnium vacancies making the system highly electron rich. Formation of cation vacancies is expected to compensate the excess charge in the U and Eu co-doped La 2 Hf 2 O 7 NPs suppressing the formation of oxygen vacancies. This work shows how one can utilize the full color gamut in the La 2 Hf 2 O 7 :Eu 3+ ,U 6+ NPs with blue, green and red emissions from the host, uranium and europium, respectively, to produce near perfect white light emission. 

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4. Positron emission tomography evaluation of oxime countermeasures in live rats using the tracer O ‐(2‐[ 18 F]fluoroethyl)‐ O ‐( p‐ nitrophenyl)methylphosphonate [ 18 F]‐VXS

   https://doi.org/10.1111/nyas.14363  

   Hayes, Thomas R. ; Blecha, Joseph E. ; Chao, Chih‐Kai ; Huynh, Tony L. ; VanBrocklin, Henry F. ; Zinn, Kurt R. ; Taylor, Palmer W. ; Gerdes, John M. ; Thompson, Charles M. ( May 2020 , Annals of the New York Academy of Sciences)

   Oxime antidotes regenerate organophosphate‐inhibited acetylcholinesterase (AChE). Although they share a common mechanism of AChE reactivation, the rate and amount of oxime that enters the brain are critical to the efficacy, a process linked to the oxime structure and charge. Using a platform based on the organophosphate [¹⁸F]‐VXS as a positron emission tomography tracer for active AChE, thein vivodistribution of [¹⁸F]‐VXS was evaluated after an LD₅₀dose (250 μg/kg) of the organophosphate paraoxon (POX) and following oximes as antidotes. Rats given [¹⁸F]‐VXS tracer alone had significantly higher radioactivity (two‐ to threefold) in the heart and lung than rats given LD₅₀POX at 20 or 60 min prior to [¹⁸F]‐VXS. When rats were given LD₅₀POX followed by 2‐PAM (cationic), RS194b (ionizable), or monoisonitrosoacetone (MINA) (neutral), central nervous system (CNS) radioactivity returned to levels at or above untreated naive rats (no POX), whereas CNS radioactivity did not increase in rats given the dication oximes HI‐6 or MMB‐4. MINA showed a significant, pairwise increase in CNS brain radioactivity compared with POX‐treated rats. This newin vivodynamic platform using [¹⁸F]‐VXS tracer measures and quantifies peripheral and CNS relative changes in AChE availability after POX exposure and is suitable for comparing oxime delivery and AChE reactivation in rats.

    

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5. Photometric and Spectroscopic Properties of Type Ia Supernova 2018oh with Early Excess Emission from the Kepler 2 Observations

   https://doi.org/10.3847/1538-4357/aaec74  

   Li, W. ; Wang, X. ; Vinkó, J. ; Mo, J. ; Hosseinzadeh, G. ; Sand, D. J. ; Zhang, J. ; Lin, H. ; Zhang, T. ; Wang, L. ; et al ( January 2019 , The Astrophysical Journal)