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1. Conjugated Polymer Mesocrystals with Structural and Optoelectronic Coherence and Anisotropy in Three Dimensions

   https://doi.org/10.1002/adma.202103002  

   Yu, Liyang; Pavlica, Egon; Li, Ruipeng; Zhong, Yufei; Silva, Carlos; Bratina, Gvido; Müller, Christian; Amassian, Aram; Stingelin, Natalie (November 2021, Advanced Materials)

   Abstract Semiconducting mesocrystalline bulk polymer specimens that exhibit near‐intrinsic properties using channel‐die pressing are demonstrated. A predominant edge‐on orientation is obtained for poly(3‐hexylthiophene‐2,5‐diyl) (P3HT) throughout 2 mm‐thick/wide samples. This persistent mesocrystalline arrangement at macroscopic scales allows reliable evaluation of the electronic charge‐transport anisotropy along all three crystallographic axes, with high mobilities found along the π‐stacking. Indeed, charge‐carrier mobilities of up to 2.3 cm²V⁻¹s⁻¹are measured along the π‐stack, which are some of the highest mobilities reported for polymers at low charge‐carrier densities (drop‐cast films display mobilities of maximum ≈10⁻³cm²V⁻¹s⁻¹). The structural coherence also leads to an unusually well‐defined photoluminescence line‐shape characteristic of an H‐aggregate (measured from the surface perpendicular to the materials flow), rather than the typical HJ‐aggregate feature usually found for P3HT. The approach is widely applicable: to electrical conductors and materials used in n‐type devices, such as poly{[N,N′‐bis(2‐octyldodecyl)‐naphthalene‐1,4,5,8‐bis(dicarboximide)‐2,6‐diyl]‐alt‐5,5′‐(2,2′‐bithiophene)} (N2200) where the mesocrystalline structure leads to high electron transport along the polymer backbones (≈1.3 cm²V⁻¹s⁻¹). This versatility and the broad applicability of channel‐die pressing signifies its promise as a straightforward, readily scalable method to fabricate bulk semiconducting polymer structures at macroscopic scales with properties typically accessible only by the tedious growth of single crystals. 

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2. Dinitrogen reduction chemistry with scandium provides a complex with two side-on (NN) ²⁻ ligands bound to one metal: (C ₅ Me ₅ )Sc[(µ-η ² :η ² -N ₂ )Sc(C ₅ Me ₅ ) ₂ ] ₂

   https://doi.org/10.1039/d4sc03977g  

   Queen, Joshua D; Rajabi, Ahmadreza; Goudzwaard, Quinn E; Yuan, Qiong; Nguyen, Dang Khoa; Ziller, Joseph W; Furche, Filipp; Xi, Zhenfeng; Evans, William J (January 2024, Chemical Science)

   Although there are few reduced dinitrogen complexes of scandium, this metal has revealed a new structural type in reductive dinitrogen chemistry by reduction of bis(pentamethylcyclopentadienyl) scandium halides under N2. 

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3. Oxygen Incorporation in the Molecular Beam Epitaxy Growth of Sc _x Ga _1−x N and Sc _x Al _1−x N

   https://doi.org/10.1002/pssb.201900612  

   Casamento, Joseph; Xing, Huili Grace; Jena, Debdeep (January 2020, physica status solidi (b))

   Secondary‐ion mass spectrometry (SIMS) is used to determine impurity concentrations of carbon and oxygen in two scandium‐containing nitride semiconductor multilayer heterostructures: Sc_xGa_1−xN/GaN and Sc_xAl_1−xN/AlN grown by molecular beam epitaxy (MBE). In the Sc_xGa_1−xN/GaN heterostructure grown in metal‐rich conditions on GaN–SiC template substrates with Sc contents up to 28 at%, the oxygen concentration is found to be below 1 × 10¹⁹ cm⁻³, with an increase directly correlated with the scandium content. In the Sc_xAl_1−xN–AlN heterostructure grown in nitrogen‐rich conditions on AlN–Al₂O₃template substrates with Sc contents up to 26 at%, the oxygen concentration is found to be between 10¹⁹and 10²¹ cm⁻³, again directly correlated with the Sc content. The increase in oxygen and carbon takes place during the deposition of scandium‐alloyed layers. 

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4. Misinformation Campaigns. Applying Motivated Reasoning and Information Manipulation Theory to Understand the Role and Impact of Social Media in the Digital Transformation

   Al-khateeb, S. (July 2022, Die digitale Transformation der Medien)

   Die digitale Transformation der Medien 

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5. Contrasting the Marine Biogeochemical Cycles of Iron and Scandium in the California Current System

   https://doi.org/10.1029/2024JC022087  

   Till, Claire_P; Hurst, Matthew_P; Freiberger, Robert_B; Ohnemus, Daniel_C; Twining, Benjamin_S; Marchetti, Adrian; Coale, Tyler_H; Pierce, Emily (March 2025, Journal of Geophysical Research: Oceans)

   Abstract The oceanic biogeochemical cycling of iron is globally important yet difficult to fully understand due to the many chemical processes involved. There is potential to use scandium, which has a similar ionic size and charge density to trivalent iron but lacks redox cycling, as a simpler analog for specific parts of the iron cycle, if we can sufficiently develop our understanding of scandium's reactivity. Here we move closer to this understanding. We look at particle reactivity and solubility through a 24‐hr incubation experiment: 5 nmol/kg of dissolved scandium and/or iron were added to filtered and unfiltered California Current System water. Particulate scandium formed only in the unfiltered treatments, at a quantity unlikely to have been taken up biologically. This is the first direct observation of scavenging of scandium, an attribute shared with iron. Our results also serve as the first test of scandium solubility in seawater: 1.9 nmol/kg of dissolved scandium was stable in the filtered treatment, 50 times more than the highest natural concentrations so far observed. This indicates that, in contrast to iron, scandium's oceanic cycling is unlikely to be influenced by solubility limits. We also compare particulate depth profiles: labile particulate iron was disproportionally higher than that of scandium in shelf‐influenced samples, likely due to iron reductively dissolving in the sediments, which scandium cannot do, and then precipitating in oxic seawater. Due to this combination of behaviors, our results suggest that paired observations of scandium and iron may help distinguish between iron sourced from sediment resuspension and reductive dissolution. 

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