Experiments on visually grounded, definite reference production often manipulate simple visual scenes in the form of grids filled with objects, for example, to test how speakers are affected by the number of objects that are visible. Regarding the latter, it was found that speech onset times increase along with domain size, at least when speakers refer to nonsalient target objects that do not pop out of the visual domain. This finding suggests that even in the case of many distractors, speakers perform object-by-object scans of the visual scene. The current study investigates whether this systematic processing strategy can be explained by the simplified nature of the scenes that were used, and if different strategies can be identified for photo-realistic visual scenes. In doing so, we conducted a preregistered experiment that manipulated domain size and saturation; replicated the measures of speech onset times; and recorded eye movements to measure speakers\' viewing strategies more directly. Using controlled photo-realistic scenes, we find (1) that speech onset times increase linearly as more distractors are present; (2) that larger domains elicit relatively fewer fixation switches back and forth between the target and its distractors, mainly before speech onset; and (3) that speakers fixate the target relatively less often in larger domains, mainly after speech onset. We conclude that careful object-by-object scans remain the dominant strategy in our photo-realistic scenes, to a limited extent combined with low-level saliency mechanisms. A relevant direction for future research would be to employ less controlled photo-realistic stimuli that do allow for interpretation based on context.

The relatively low thermal depolarization temperature (Td) has hindered the development and practical application of lead-free Bi0.5Na0.5TiO3-based systems; therefore, a feasible strategy is urgently needed to defer the depolarization behavior. In this work, a perovskite/metal 0.78 Bi0.5Na0.5TiO3-0.22 Bi0.5K0.5TiO3/xAg (BNT-22BKT/xAg) composite ceramic is designed and successfully prepared. The introduction of metal Ag with a larger thermal expansion coefficient leads to an increased fraction and enhanced lattice distortion of the rhombohedral phase, as well as an enlarged domain size. The thermal stability thus is effectively improved, and the optimal Td value of 166 °C is obtained at x = 0.03, which is about 60 °C higher than that of prototype ceramics. This research provides a perovskite/metal composite scheme to increase the depolarization temperature of BNT-based ceramics and promotes their potential for practical applications.

Flexoelectricity is the universal electric polarization of dielectrics upon exertion of a non-uniform strain gradient. With the advancement of nano-technology and miniaturization of electronic devices, flexoelectricity holds the promise to address the power requirements for such device operation. The direct flexoelectric effect in liquid crystal (LC) embedded poly(vinylidene fluoride) (PVDF) polymer films is examined for the first time by the application of external strain on the films. Physical characterizations such as Differential Scanning Calorimetry (DSC), dielectric spectroscopy, X-ray diffraction, and field emission scanning electron microscopy (FESEM) are carried out to study the composite films\' intrinsic and extrinsic properties like dielectric, crystallinity, and morphologies. The value of the flexoelectric coefficient (μ12) increases with the concentration of LC incorporation. At 3 wt%, μ12 attains a maximum value of 68 nC m-1, which is more than a threefold increase compared to that of the pure PVDF film. The role of Maxwell-Wagner-Sillars (MWS) polarization in determining flexoelectric polarization in polymer composites is also discussed. Moreover, the influence of the microstructure and domain size formation in determining the flexoelectric response are discussed in detail to infer the behavior of the flexoelectric coefficients of the films. Potential device applications based on this phenomenon have been proposed for future research in sensing and actuation.

In this study, we comprehensively investigate the constant voltage stress (CVS) time-dependent breakdown and cycle-to-breakdown while considering metal-ferroelectric-metal (MFM) memory, which has distinct domain sizes induced by different doping species, i.e., Yttrium (Y) (Sample A) and Silicon (Si) (Sample B). Firstly, Y-doped and Si-doped HfO2 MFM devices exhibit domain sizes of 5.64 nm and 12.47 nm, respectively. Secondly, Si-doped HfO2 MFM devices (Sample B) have better CVS time-dependent breakdown and cycle-to-breakdown stability than Y-doped HfO2 MFM devices (Sample A). Therefore, a larger domain size showing higher extrapolated voltage under CVS time-dependent breakdown and cycle-to-breakdown evaluations was observed, indicating that the domain size crucially impacts the stability of MFM memory.

The highest-efficiency organic photovoltaic (OPV)-based solar cells, made from blends of electron-donating and electron-accepting organic semiconductors, are often characterized by strongly reduced (non-Langevin) bimolecular recombination. Although the origins of the reduced recombination are debated, mechanisms related to the charge-transfer (CT) state and free-carrier encounter dynamics controlled by the size of donor and acceptor domains are proposed as underlying factors. Here, a novel photoluminescence-based probe is reported to accurately quantify the donor-acceptor domain size in OPV blends. Specifically, the domain size is measured in high-efficiency non-fullerene acceptor (NFA) systems and a comparative conventional fullerene system. It is found that the NFA-based blends form larger domains but that the expected reductions in bimolecular recombination attributed to the enhanced domain sizes are too small to account for the observed reduction factors. Further, it is shown that the reduction of bimolecular recombination is correlated to enhanced exciton dynamics within the NFA domains. This indicates that the processes responsible for efficient exciton transport also enable strongly non-Langevin recombination in high-efficiency NFA-based solar cells with low-energy offsets.

Amorphous-Amorphous phase separation (AAPS) is an important phenomenon that can impede the performance of amorphous solid dispersions (ASDs). The purpose of this study was to develop a sensitive approach relying on dielectric spectroscopy (DS) to characterize AAPS in ASDs. This includes detecting AAPS, determining the size of the active ingredient (AI) discrete domains in the phase-separated systems, and accessing the molecular mobility in each phase. Using a model system consisting of the insecticide imidacloprid (IMI) and the polymer polystyrene (PS), the dielectric results were further confirmed by confocal fluorescence microscopy (CFM). The detection of AAPS by DS was accomplished by identifying the decoupled structural (α-)dynamics of the AI and the polymer phase. The α-relaxation times corresponding to each phase correlated reasonably well with those of the pure components, implying nearly complete macroscopic phase separation. Congruent with the DS results, the occurrence of the AAPS was detected by means of CFM, making use of the autofluorescent property of IMI. Oscillatory shear rheology and differential scanning calorimetry (DSC) detected the glass transition of the polymer phase but not that of the AI phase. Furthermore, the otherwise undesired effects of interfacial and electrode polarization, which can appear in DS, were exploited to determine the effective domain size of the discrete AI phase in this work. Here, stereological analysis of CFM images probing the mean diameter of the phase-separated IMI domains directly stayed in reasonably good agreement with the DS-based estimates. The size of phase-separated microclusters showed little variation with AI loading, implying that the ASDs have presumably undergone AAPS upon manufacturing. DSC provided further support to the immiscibility of IMI and PS, as no discernible melting point depression of the corresponding physical mixtures was detected. Moreover, no signatures of strong attractive AI-polymer interactions could be detected by mid-infrared spectroscopy within this ASD system. Finally, dielectric cold crystallization experiments of the pure AI and the 60 wt % dispersion revealed comparable crystallization onset times, hinting at a poor inhibition of the AI crystallization within the ASD. These observations are in harmony with the occurrence of AAPS. In conclusion, our multifaceted experimental approach opens new venues for rationalizing the mechanisms and kinetics of phase separation in amorphous solid dispersions.

A set of aromatic-oxyaliphatic polyurethanes (PUs) with different mass fractions of components also containing fluorinated fragments was synthesized and studied using various solid-state NMR techniques and dielectric spectroscopy. In contrast to the common model suggested by Cooper and Tobolsky in 1966, the rigid domains of microphase separated PUs are formed, not only by units containing urethane bonds, but also by oxyethylene fragments that form a common rigid phase. The urethane bonds and oxyethylene fragments are incorporated into both rigid and soft phases. Good agreement with the Cooper and Tobolsky model is observed only when solubility parameters are significantly different for the hard and soft segments, such as hydrocarbon aromatics and perfluoroaliphatic blocks.

Piezoelectric semiconductor-based piezocatalysis has emerged as a promising approach for converting mechanical energy into chemical energy for renewable hydrogen generation and wastewater treatment under the action of mechanical vibration. Similar to photocatalysis, piezocatalysis is triggered by the separation, transfer, and consumption of piezo-generated electrons and holes. Inspired by this, herein, we report that the cocatalyst, which is widely used in photocatalysis, can also improve the semiconductor-based piezocatalytic properties. In the proof-of-concept design, well-defined Pd as a model cocatalyst has been deposited on the surface of piezoelectric BiFeO3 nanosheets, which not only facilitates the separation of charge carriers by accepting the piezoelectrons from BiFeO3 but also lowers the activation energy/overpotential through supplying highly active sites for the proton reduction reaction. Consequently, the as-obtained hybrid piezocatalyst delivers a high H2 evolution rate of 11.4 μmol h-1 (10 mg of catalyst), 19.0 times as high as that of bare BiFeO3. The band tilting induced by the piezoelectric potential is proposed to lower or eliminate the Schottky barrier and smooth the electron transfer from BiFeO3 to Pd, while the exposed facet, domain size, and loading amount of Pd cocatalyst are proved to be the key parameters determining the ultimate piezocatalytic activity. Our work provides some enlightenment on advancing the design and fabrication of more efficient piezocatalysts for H2 evolution based on rational engineering on the cocatalyst.

Metal-organic chemical vapor deposition (MOCVD) is one of the main methodologies used for thin-film fabrication in the semiconductor industry today and is considered one of the most promising routes to achieve large-scale and high-quality 2D transition metal dichalcogenides (TMDCs). However, if special measures are not taken, MOCVD suffers from some serious drawbacks, such as small domain size and carbon contamination, resulting in poor optical and crystal quality, which may inhibit its implementation for the large-scale fabrication of atomic-thin semiconductors. Here we present a growth-etch MOCVD (GE-MOCVD) methodology, in which a small amount of water vapor is introduced during the growth, while the precursors are delivered in pulses. The evolution of the growth as a function of the amount of water vapor, the number and type of cycles, and the gas composition is described. We show a significant domain size increase is achieved relative to our conventional process. The improved crystal quality of WS2 (and WSe2) domains wasis demonstrated by means of Raman spectroscopy, photoluminescence (PL) spectroscopy, and HRTEM studies. Moreover, time-resolved PL studies show very long exciton lifetimes, comparable to those observed in mechanically exfoliated flakes. Thus, the GE-MOCVD approach presented here may facilitate their integration into a wide range of applications.

Unsaturated and saturated phospholipids tend to laterally segregate, especially in the presence of cholesterol. Small molecules such as neurotransmitters, toxins, drugs etc. possibly modulate this lateral segregation. The small aromatic neurotransmitter serotonin (5-HT) has been found to bind to membranes. We studied the lipid structure and packing of a ternary membrane mixture consisting of palmitoyl-oleoyl-phosphatidylcholine, palmitoyl-sphingomyelin, and cholesterol at a molar ratio of 4/4/2 in the absence and in the presence of 5-HT, using a combination of solid-state 2H NMR, atomic force microscopy, and atomistic molecular dynamics (MD) simulations. Both NMR and MD report formation of a liquid ordered (L o ) and a liquid disordered (L d ) phase coexistence with small domains. Lipid exchange between the domains was fast such that single component 2H NMR spectra are detected over a wide temperature range. A drastic restructuring of the domains was induced when 5-HT is added to the membranes at a 9 mol% concentration relative to the lipids. 2H NMR spectra of all components of the mixture showed two prominent contributions indicative of molecules of the same kind residing both in the disordered and the ordered phase. Compared to the data in the absence of 5-HT, the lipid chain order in the disordered phase was further decreased in the presence of 5-HT. Likewise, addition of serotonin increased lipid chain order within the ordered phase. These characteristic lipid chain order changes were confirmed by MD simulations. The 5-HT-induced larger difference in lipid chain order results in more pronounced differences in the hydrophobic thickness of the individual membrane domains. The correspondingly enlarged hydrophobic mismatch between ordered and disordered phases is assumed to increase the line tension at the domain boundary, which drives the system into formation of larger size domains. These results not only demonstrate that small membrane binding molecules such as neurotransmitters have a profound impact on essential membrane properties. It also suggests a mechanism by which the interaction of small molecules with membranes can influence the function of membrane proteins and non-cognate receptors. Altered membrane properties may modify lateral sorting of membrane protein, membrane protein conformation, and thus influence their function as suspected for neurotransmitters, local anesthetics, and other small drug molecules.