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• The adsorption capacity of FOSA by PS was the highest, similarly, PS displayed the highest adsorption capacity to PFOA. • The pH and salinity of solution can influence adsorption of FOSA and PFOA on microplastics. • The calculated adsorption energy values of FOSA and PFOA on PS are similar to the experimental adsorption constant values. • FOSA can be photodegraded and its main product is PFOA, while the presence of microplastics has little effect on the photodegradation of FOSA. PFAS (per- and polyfluoroalkyl substances) are omnipresent in the environment and their transportation and transformation have attracted increased attention. Microplastics are another potential risk substances that can serve as a carrier for ubiquitous pollutants, thus affecting the presence of PFAS in the environment. In this study, the adsorption of perfluorooctane sulfonamide (FOSA) and perfluorooctanoic acid (PFOA) on four microplastics (PE, PVC, PS, and PTFE) and their effect on the photodegradation of FOSA were studied. The adsorption capacity of FOSA by PS was the highest, in similar, PS displayed the highest adsorption capacity in the presence of PFOA. Different effects of pH and salinity on the adsorption of FOSA and PFOA were observed among different microplastics indicating inconsistent interaction mechanisms. Furthermore, FOSA could be photodegraded, with PFOA as the main product, while the presence of microplastics had a negligible effect on the degradation of this contaminant. The results indicated that microplastics could act as PFAS concentrators. Moreover, their photochemical inertias make the pollutants enriched on microplastics more resistant to degradation. [Display omitted] [ABSTRACT FROM AUTHOR]

Recently, a family of [Fe2Co2] molecular capsules that display tunable electron transfer-coupled spin transition (ETCST) behavior were reported via a smart approach through Schiff-base condensation of aldehyde-functionalized 2,2-bipyridines (bpyCHO) and 1,7-heptanediamine (H2N(CH2)7NH2). Here, three more capsule complexes {[(TpR)Fe(CN)3]2[Co(bpyC＝N(CH2)nN＝Cbpy)]2[ClO4]2}·n(solvent) (1, TpR = Tp*, n = 5, sol = 8DMF; 2, TpR = TpMe, n = 9, sol = 5MeCN; and 3, TpR = Tp*, n = 11, sol = 5MeCN), where Tp* = hydridotris(3,5-dimethylpyrazol-1-yl)borate and TpMe = hydridotris(3-methylpyrazol-1-yl)borate are reported, demonstrating a successful extension of such an approach with other alkyldiamines of different lengths. Combined X-ray crystallographic, infrared spectroscopic and magnetic studies reveal incomplete electron transfer with either changing temperature or upon light exposure. [ABSTRACT FROM AUTHOR]

It has been recognized that both the ligand fields and intermolecular interactions may greatly impact the electron-transfer-coupled spin transition (ETCST) events in switchable magnetic materials; however, the engineering of these factors within a given system is still challenging. In this article, we chose the 4,4′-substituent 2,2′-bipyridine derivatives as chelating ligands according to their increasing electron-donating strength and incremental potential for forming hydrogen bonds (bpyCHO,CH3(L1) < bpyCH2OH,CH3 (L2) < bpyCH2OH,CH2OH (L3)), and prepared three new [Fe2Co2] complexes, {[(Tp*)Fe(CN)3Co(L)2]2[ClO4]2}·Sol (1, L = L1, Sol = 4MeCN·2H2O; 2, L = L2, Sol = 3MeCN; 3, L = L3, Sol = 4MeOH; Tp* = hydrotris(3,5-dimethylpyrazol-1-yl)borate). X-ray crystallography studies revealed that all the complexes share similar cyanide-bridged [Fe2Co2] square compositions except for the different substituted groups of L ligands, which led to the clearly evidenced intercluster hydrogen bonds between the neighbouring hydroxyl groups in 2 and 3. As a result, 1 remained in the paramagnetic [Fe III,LS2 Co II,HS2 ] state over the whole temperature range, while 2 and 3 showed complete ETCST behaviour with the transition temperatures (T1/2) being 221 and 294 K, respectively. [ABSTRACT FROM AUTHOR]

• High level of PFOA was found in fluoropolymer raw materials and products made in China. • The concentration of PFOA in fluoropolymer raw materials was higher than products. • Hexafluoropropylene oxide oligomers have been heavily used to substitute PFOA in fluoropolymer manufacture in China. • HFPO-TrA, a PFOA substitute, was found in high level in some emulsion samples. Perfluorooctanoic acid (PFOA), its salts, and related compounds were listed as new persistent organic pollutants by the Stockholm Convention in 2019. In this study, the occurrence of residues of PFOA and other per- and polyfluoroalkyl substances (PFASs) in raw materials and fluoropolymer products from the Chinese fluoropolymer industries are reported for the first time. The PFOA concentrations in raw materials and fluoropolymer products were in the range of 6.7 to 1.1 × 106 ng/g, and

A supramolecular polymer has been prepared by sequential assembly of a distyrylanthracene derivative monomer with CB[7] and CB[8], which exhibits enhanced near infrared emission in the solid state on account of aggregation induced emission and noncovalent isolation effects. The supramolecular polymer forms spherulite layers followed by surface nucleation and 2D growth, and eventually constructs pyramidal crystalline aggregates with a size of about 500 nm. The preliminary study presents the supramolecular polymers crystallization behavior which relates to the aggregation states and functionalities of polymeric supramolecular materials and is worth further investigation both in theory and experiments. [ABSTRACT FROM AUTHOR]

Driven by external compressions or shears, the granular material composed of non-convex shapes often undergoes self-assembly and becomes entangled, resulting in denser packings. In this work, the biaxial compression of monophasic and binary mixture composed of 2D intersecting crosses have been simulated via the discrete element method. As the aspect ratio increases, both the yield strength and elastic modulus initially increase before reaching a peak at w = 0.5. In binary mixtures, an antagonistic effect has been observed in mechanical properties of granular material. The decrease in strength and stiffness in binary mixtures can be attributed to the constraints imposed by multi-point contacts, along with the local order degree, which is particularly unique for non-convex particle packings. Building upon this understanding, we have extended the empirical formula into predicting the mechanical behavior of non-convex binary mixtures. This extension incorporates an additional non-linear term determined by both the shape factor and component fraction. [Display omitted] • Non-convex granular material shows an elastic-plastic behavior after the biaxial compression. • The maximum yield strength and elastic modulus are obtained when w equals to 0.5. • An antagonistic effect is observed for binary mixtures due to the multi-point contacts. • An explicit formula is proposed to predict the mechanical property. [ABSTRACT FROM AUTHOR]

A frequency-domain quantum mechanics and electromagnetics (QM/EM) method is developed. Compared with the time-domain QM/EM method [Meng et al., J. Chem. Theory Comput. 8, 1190-1199 (2012)], the newly developed frequency-domain QM/EM method could effectively capture the dynamic properties of electronic devices over a broader range of operating frequencies. The system is divided into QM and EM regions and solved in a self-consistent manner via updating the boundary conditions at the QM and EM interface. The calculated potential distributions and current densities at the interface are taken as the boundary conditions for the QM and EM calculations, respectively, which facilitate the information exchange between the QM and EM calculations and ensure that the potential, charge, and current distributions are continuous across the QM/EM interface. Via Fourier transformation, the dynamic admittance calculated from the time-domain and frequency-domain QM/EM methods is compared for a carbon nanotube based molecular device. [ABSTRACT FROM AUTHOR]

We describe a new dynamic Monte Carlo model to simulate the operation of a polymer-blend solar cell; this model provides major improvements with respect to the one we developed earlier [J. Phys. Chem. B 114, 36 (2010)] by incorporating the Poisson equation and a charge thermoactivation mechanism. The advantage of the present approach is its capacity to deal with a nonuniform electrostatic potential that dynamically depends on the charge distribution. In this way, the unbalance in electron and hole mobilities and the space-charge induced potential distribution can be treated explicitly. Simulations reproduce well the experimental I-V curve in the dark and the open-circuit voltage under illumination of a polymer-blend solar cell. The dependence of the photovoltaic performance on the difference in electron and hole mobilities is discussed. [ABSTRACT FROM AUTHOR]

Geometric shape is an important factor that affects the packing and mechanical properties of granular material. In this paper, we use four families of assembled rods to model an entangled material in simulations. The particles are all non-convex and have the ability to interpenetrate. Together with elongation, central symmetry, which is attributed to the intersection location of the elementary rods, is also a main factor that produces varieties of particle shapes. With a certain total elongation, the dense disordered packing density is verified to be independent of the elongation distribution of the elementary rods. The specific shape hardly affects the packing densities. Therefore, the empirical formula to predict the packing density is extended to apply to all assembled rods with any elongation distribution. Different from the packing density, the shape disparity caused by central symmetry is found to significantly influence the contacts between neighboring particles. Due to more multipoint contacts contributing more constraints around the central particle, the centrally symmetric 3DX-shaped particles can more easily interpenetrate in the granular system. Moreover, the higher number of constraints contributed by neighboring contacts reflects the hyperstaticity of packings, which suggests mechanical stability for disordered packings of non-convex assembled rods. • Effects of central symmetry and elongation have been studied via simulations. • An empirical formula to predict the packing density has been proposed. • Central symmetry is verified to make effect on contacts in the granular system. [ABSTRACT FROM AUTHOR]

In previous studies, the influence of flaws on macro-scale and nano-scale metallic glasses (MGs) has always been a topic of great interest, with important applications in engineering. Moreover, through experiments and simulations, many researchers draw contradictory conclusions of the notch sensitivity, including the notch strengthening, weakening, and insensitivity in different MGs. In order to better understand its atomic mechanism, classical molecular dynamics simulations have been performed on the nano-scale notched MGs in the present work to investigate the deformation modes under the uniaxial tension. According to the results, after setting notches, the MG samples exhibit a significant change from the shear to necking failure, which indicates a notch strengthening phenomenon. At the same time, the evolution of atomic structures suggests that the introduction of notches will increase the degree of shear localization and further disturb the structural order of MGs. The atomic displacement, which is different from shear strain, can also be used as an index to visually describe the deformation behavior of MGs and shows the high notch sensitivity. [ABSTRACT FROM AUTHOR]

By modifying more non-polar aromatic rings in the stable ethane-selective MOF (UiO-67), more C-H∙∙∙π interactions between ethane and the main framework (UiO-67-BN) are generated, thus improving C 2 H 6 /C 2 H 4 separation while ensuring stability. [Display omitted] • With more C 2 H 6 binding sites, C 2 H 4 can be separated in one step. • UiO-67-BN has suitable pore size and a large number of non-polar surfaces, making it an excellent C 2 H 6 -selective adsorbent. • Compared with the basic material (UiO-67), the adsorption capacity, selectivity and actual separation time of the optimized material (UiO-67-BN) are greatly improved. • The material has good stability, soaking in water and various solvents for more than a week, the adsorption capacity remains unchanged. • This material can still maintain good separation effect under different humidity, temperature and flow rate, which meets the requirements of industrial production. Ethylene is an important raw material in chemical production. Reducing energy consumption by one-step separation of ethylene from C 2 H 6 /C 2 H 4 mixtures is a significant and challenging task. Designing a material with high C 2 H 6 selectivity and adsorption capacity is very demanding. Here, we report a method to improve the performance of C 2 H 6 /C 2 H 4 separation. By changing the carboxylic ligand in UiO-67, we synthesized a new material called UiO-67-BN. At room temperature, compared with the base material UiO-67, the optimized material UiO-67-BN has a significant increase in the adsorption capacity of C 2 H 6 and the selectivity of C 2 H 6 /C 2 H 4 due to its suitable pore size and numerous non-polar aromatic rings on the pore surface. Theoretical calculation results reveal that the optimized material can provide more C-H∙∙∙π interactions with C 2 H 6. The breakthrough experiments demonstrate that UiO-67-BN can efficiently capture C 2 H 6 from 50/50 and 1/99 C 2 H 6 /C 2 H 4 mixtures at various conditions and realize one-step acquisition of C 2 H 4. [ABSTRACT FROM AUTHOR]

Abstract: Room‐temperature phosphorescence (RTP) was realized for the first time in a polyoxometalate‐based charge‐transfer (CT) hybrid material bearing polyoxometalates (POMs) as electron‐donors (D) and rigid naphthalene diimides (NDIs) as electron‐acceptors (A), meanwhile, this hybrid material displayed photochromism as well. The significant D‐A anion–π interaction induced an additional through‐space charge‐transfer pathway. The resulting suitable D‐A CT states can efficiently bridge the relatively large energy gap between the NDI‐localized 1π–π* and 3π–π* states and thus trigger the ligand‐localized phosphorescence (3π–π*). [ABSTRACT FROM AUTHOR]

The packing of rod-like particles, which is common in physical and mathematical studies, has arisen in a variety of industrial applications. Elongation effect on the packing properties of rod-like particle has been well investigated. Besides that, rod-like particles can be easily deformed into a large amount of non-convex shapes by simply bending or assembling several particles, in which effects of non-convex deformations should also be concerned. In this work, the packing behaviors of particulate systems composed of various non-convex deformations of rod-like particles are numerically simulated via the analytical model and the relaxation algorithm. The packing configurations are further optimized using the Monte Carlo method to eliminate the local ordered structures. 8 shapes of non-convex particles including 2-dimensional and 3-dimensional particles are employed in the packing systems. Independent of aspect ratio, the dense random packing densities of identical assembled rods are up to 20% higher than those of spherocylinders and are less dependent from the specific particle shape. However, the coordination numbers of various non-convex particle packings are quite different. With a parameter of convex ratio defined, a packing composed of more non-convex particles will have a higher coordination number. This indicates that for more non-convex particle packings, there are more constraints and entanglements among neighboring particles, resulting in a more stable configuration. The nearest-neighbor contact to a centered particle in 3DX-shaped particle packings is quite different from those of other shapes, which can be identified from the location of the first peak in the radial distribution function. It is also the cause to the distinct disparities of estimated excluded volumes of non-convex particles simulated in this work. [ABSTRACT FROM AUTHOR]

The packing of rod-like particles has arisen in a variety of scientific and industrial applications. For the factors that attribute to the packing properties of such particles, elongation effect is one of the most important. However, rod-like particles can be easily assembled into non-convex shapes, in which the effects of non-convex deformations should be concerned. In this paper, the dense random packings of identical intersecting spherocylinders with central symmetry are numerically simulated through an analytical model and the relaxation algorithm. The maximally dense random packing (MDRP) states of 2D and 3D intersecting spherocylinders with various aspect ratios are determined from the order maps. In the MDRP states, the specific volume V , defined as the reciprocal of the packing density ϕ , shows a highly linear correlation with the aspect ratio ( w ≥ 1.0), which is similar to the monophasic packing of spherocylinders. This indicates that the elongation effect is the main shape factor that attributes to the packing density. Consequently, the explicit formulas to predict the packing densities of 2D and 3D intersecting spherocylinders are built as single-variable functions of the aspect ratio. The dense random packing density of 2D intersecting spherocylinders equals to that of identical spherocylinders when w = 1.25. This suggests that a balance exists between the relative excluded volume effect and the multi-point contact effect to the packing density of non-convex particles. [ABSTRACT FROM AUTHOR]

In this paper, numerical simulations are proposed to investigate mechanical properties of bi-continuous and particulate reinforced composite materials using a non-local voxel-based discrete computational model. Special focus of this article is the effect of 3D microstructure and its heterogeneity on elastic deformation and fracture behaviors. First, a review on model formulation is presented. Model parameters are derived in terms of material constants using the concept of energy equivalency. Interface representation and numerical homogenization scheme are discussed. Following this, numerical investigations on the effects of interface properties and inclusion characteristics, i.e. the volume fraction and material constants, on homogenized elastic constants and fracture behaviors of statistically isotropic bi-phase composites are performed. The effective elastic constants predicted by the proposed model agree well with analytical results. Fracture simulation demonstrates good capability of the proposed model for the microstructure-sensitive failure analysis. Conclusions and future work are drawn based on the proposed study. [ABSTRACT FROM AUTHOR]

A spherocylinder, a convex 3D object consisting of a cylinder with two hemispherical ends, can possess a wide range of aspect ratios and is one of the most studied non-spherical particle shapes. Previous investigations on disordered spherocylinder packings yielded inconsistent packing characteristics, especially the packing density φ, indicating that density alone is not sufficient to uniquely characterize a packing. In this paper, we delineate in the density–order–metric diagram (i.e. order map) the border curve that separates geometrically feasible and infeasible packings of congruent spherocylinders via the geometric-structure approach, i.e., by generating and analyzing a large number of packing configurations with a diversity of densities and degrees of order generated via a relaxation algorithm. We find that the border curve possesses a sharp transition as the packing density increases, i.e., the initial increase of φ is not associated with any notable increase of the degree of order, while beyond a threshold φ value, the increase of density is strongly positively correlated with the increase of order. This allows us to propose the concept of maximally dense random packing (MDRP) state for spherocylinders, which corresponds to the transition point in the boarder curve and characterizes the on-set of nontrivial spatial correlations among the particles. It can also be considered as the maximally dense packing arrangement of spherocylinders without nontrivial spatial correlations. The degree of order of a spherocylinder packing is quantified via the nematic order parameter ( S ) and the local order metric ( S Local ), which respectively characterize the level of global orientational order and local order in particle clusters. The latter metric S Local , which measures the average order in the neighborhoods of particles with the second Legendre polynomial, is a new order metric for spherocylinder systems. We find that the packing density of the MDRPs initially increases with the increase of the aspect ratio w from 0, and reaches the maximal value of 0.725 when w = 0.5, then drops with further increase of w . The MDRP at w = 0.5 is verified to be jammed via a Monte Carlo jamming-testing algorithm and thus, should also represent the maximally random jammed (MRJ) packing state as well. [ABSTRACT FROM AUTHOR]

Shear banding behavior plays a significant role in the deformation and failure mechanisms of metallic glasses (MGs). However, due to the limits of dynamic loading and associated characterization methodologies, relevant studies of shear band in dynamic loading remain hazy. Using digital image correlation technologies, the spatial–temporal evolutions of shear bands such as formation, propagation, effective thickness, and instability are in-situ revealed and discussed during the SHPB test. Specific determinism exists for the nucleated locations and orientations of the primary shear band, which is responsible for final failure. The progressive propagation front of the shear band is found to be strongly correlated to the primary shear stress profile, suggesting that the importance of the principal shear stress in driving shear-band propagation. Additionally, a long-range stress zone of the shear band on the order of hundreds of microns is found, which exhibits uniform shear viscosity. The findings of this article shed light on the viability of artificially created shear bands in metallic glasses. • The spatial–temporal evolutions of shear bands in metallic glass under SHPB test are in-situ revealed. • Specific determinism of shear-band formation is observed. • The principal shear stress is a vital factor controlling propagation front of shear band in metallic glass. • A hundreds microns viscoplastic flow layer around shear band is found, of which the shear viscosity is almost homogeneous. [ABSTRACT FROM AUTHOR]

Multiscale modeling has become a popular tool for research applying to different areas including materials science, microelectronics, biology, chemistry, etc. In this tutorial review, we describe a newly developed multiscale computational method, incorporating quantum mechanics into electronic device modeling with the electromagnetic environment included through classical electrodynamics. In the quantum mechanics/electromagnetics (QM/EM) method, the regions of the system where active electron scattering processes take place are treated quantum mechanically, while the surroundings are described by Maxwell's equations and a semiclassical drift-diffusion model. The QM model and the EM model are solved, respectively, in different regions of the system in a self-consistent manner. Potential distributions and current densities at the interface between QM and EM regions are employed as the boundary conditions for the quantum mechanical and electromagnetic simulations, respectively. The method is illustrated in the simulation of several realistic systems. In the case of junctionless field-effect transistors, transfer characteristics are obtained and a good agreement between experiments and simulations is achieved. Optical properties of a tandem photovoltaic cell are studied and the simulations demonstrate that multiple QM regions are coupled through the classical EM model. Finally, the study of a carbon nanotube-based molecular device shows the accuracy and efficiency of the QM/EM method. [ABSTRACT FROM AUTHOR]

• Eight-carbon PFAS were dominant in the Bohai Sea. • The highest ∑PFAS were observed in the Laizhou Bay for seawater and in the Liaodong Bay for sea sediments, respectively. • Six primary sources were revealed by using PMF 5.0 software. • The environmental risk of PFAS was not high in the Bohai Sea. In this study, the occurrence, distribution, sources, and risk of 29 legacy and emerging per- and polyfluoroalkyl substances (PFAS) in four kinds of environmental matrices in the Bohai Sea were investigated. The ∑PFAS concentrations were in the range of 0.40 ~ 61.4 ng/g dry weight (dw) in inflow river sediments, 0.48 ~ 61.4 ng/g dw in soil near river inflow, 0.37 ~ 4.18 ng/g dw in sea sediments, and 13.3 ~ 718 ng/L in seawater. PFAS with eight carbons accounted for > 62.2% by mass, in all samples. Perfluorooctanoic acid (PFOA) was the dominant PFAS both by mass and occurrence. Seawater from Laizhou Bay (south of the Bohai Sea) and sediments of Liaodong Bay (northeast of the Bohai Sea) had the highest levels of ∑PFAS. The sediment–water partition coefficient and organic carbon content normalized partition coefficient (log K d and log K oc ) were calculated using measured PFAS concentrations to determine their distribution in seawater and sea sediments. The values of log K d and log K oc values increased with the increasing CF 2 units for perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkane sulfonic acids (PFSAs). Six primary sources were identified in this region, including aqueous film-forming foams (AFFF), metal plating, food packages, fluorine chemical industry, fluoropolymer manufacture, and domestic pollution. The risk quotient (RQ) values of PFAS were all < 1, indicating that organisms of the Bohai Sea were at low risk of PFAS exposure. [ABSTRACT FROM AUTHOR]

ABSTRACT The effect of end point cooking temperature on quality of goat semimembranosus muscle was evaluated. The semimembranosus muscles were removed from 15 goat legs, cut into strips (4.0 cm × 4.0 cm × 5.0 cm) and vacuum packaged. Vacuum-packed strips were heated to one of nine end point temperatures: raw, 50, 55, 60, 65, 70, 75, 80, 85 and 90C. Cooking losses (CLs), shear force (SF), color, protein solubility and microstructure of strips were determined. Increasing end point temperature to more than 60C led to a significant increase in CL. SF showed a four-phase change as a result of increasing end point temperature from raw to 90C. The redness a* decreased significantly ( P < 0.05) during the range of 50-80C. The collagen solubility significantly increased with increasing temperature up to 55C. The sarcoplasmic protein solubility decreased significantly ( P < 0.01), while the myofibrillar protein solubility only increased a little with increasing temperature between 55 and 90C. PRACTICAL APPLICATIONS Cooking temperature has great influence on meat textural and eating qualities. This investigation measures the effects of end point cooking temperature on CLs, SF, color, protein solubility and microstructure of goat meat. The results are beneficial in terms of providing evidence of the trend and thus allow the industries and consumers to choose the best cooking temperature during processing of goat meat. [ABSTRACT FROM AUTHOR]

Realizing multiple stimuli responsiveness in organic molecular systems is very important and highly desirable to broaden their potential applications in smart materials. Such stimuli responsive materials are usually required in nontrivial multistep synthesis. In the present research, a series of asymmetrical naphthalene diimide derivatives (NDIs), which display interesting multiple external stimuli responsiveness including ultrafast photochromism and chemical stimulation chromism, with the generations of organic radical anions and charge transfer, were obtained by simple synthetic process. Importantly, the multicolored functionality was ingeniously achieved by mixing commercially available materials (guest molecules) and the readily-made asymmetrical NDIs through mechanical grinding under solvent-free conditions. Noteworthy the charge transfer processes, strongly depending on the distinctive structures of NDIs molecules as well as the weak intermolecular interactions, can be induced by external stimuli (i. e. light, chemical, or grinding). Subsequently, significant stimuli responsiveness as well as multicolored properties were realized and the underlying weak interactions-assisted charge transfer mechanism was thoroughly unearthed. A series of asymmetrical naphthalene diimide derivatives (NDIs) display interesting multiple external stimuli responsiveness including ultrafast photochromism and chemical stimulation chromism, which result from the generations of organic radical anions and charge transfer. Moreover, this system shows mechanical grinding toning with certain organic molecules, which have potential applications in smart materials. [Display omitted] • Radical-doped asymmetrical NDIs possess significant photochromism, chemical stimuli chromism and mechanical grinding toning. • Weak interactions-assisted charge transfer enable the generation of organic radicals, leading to multiple stimuli chromism. • Involved solvent-free synthesis and charge transfer process play key role in green synthesis and electron transfer chemistry. [ABSTRACT FROM AUTHOR]

Thermally activated delayed fluorescence (TADF) materials that exhibit simultaneously high photoluminescence quantum yield (PLQY), rapid reverse intersystem crossing (RISC), and a high horizontal transition dipole ratio are highly desirable for realizing high‐performance organic light‐emitting diodes (OLEDs). However, achieving this goal remains a formidable challenge due to the stringent molecular design principles involved. Herein, three highly efficient TADF materials based on lactam‐type electron‐acceptors are reported. The inherent rigidity and planar structure of lactam units, along with the ordered molecular arrangement in solid states, contribute to the reduction of nonradiative decay and the high horizontal transition dipole ratio in the optimized TADF emitters. Moreover, through precise control of the alignment of the lowest excited states by adjusting the charge transfer strength, the rate constants for reverse intersystem crossing (kRISC) are dramatically boosted. Consequently, the two optimized emitters exhibit outstanding merits of ultra‐high PLQYs (98% and 99%), high horizontal transition dipole ratios (91% and 87%), and fast RISC (kRISC ≈ 1.7 × 106 s−1). Thanks to these merits, the doped OLEDs achieve excellent performance. The top‐performing device achieve a maximum external quantum efficiency of 34.3%, a peak luminance of 57376 cd m−2, and small efficiency roll‐off. [ABSTRACT FROM AUTHOR]

Hybrid gold-based perovskite derivatives typically exhibit low optical bandgaps and high optical absorption coefficients, rendering them promising for photovoltaic applications. In this study, we successfully synthesized six new hybrid gold-based perovskite derivatives, namely [(C6H8N2)(AuI4)(AuI2)](3AMPY), [(C6H14N2)(AuI4)(AuI2)](3AMP), [(C8H12N)(AuI4)](2PEAI), [(C4H14N2O)(AuI4)2](OBA), [(C6H18N2O2)3(AuI4)4(I3)2](DDA), and [(C10H26N2O3)(AuI4)(I3)](TOTA), through a straightforward and efficient hydrothermal method, achieving millimeter-sized single crystals. The structural analysis of the single crystals revealed variations in crystal structures arising from differences in constituent units and their spatial positioning relationships. First-principles calculations ascertained their high optical absorption coefficients in the visible light spectrum and indirect bandgap properties. Theoretical models indicated that the spectroscopic limited maximum efficiency (SLME) values of 3AMPY, 2PEAI, DDA, and TOTA approached approximately 30% in films of 0.5 μm thickness, signifying their potential candidacy as solar cell absorbers. [ABSTRACT FROM AUTHOR]

The luminescence property of various compounds is developed in the photoelectric applications field, while the near‐infrared (NIR) dual‐band emission of compounds is extremely challenging. Herein, 0D Cu(I)‐based organic–inorganic module (ETA)3Cu6I9 is synthesized to achieve NIR and cyan dual‐band emission in metal halide systems. Density functional theory (DFT) calculations combined with comprehensive spectroscopic data reveal its emission mechanism. Under the excitation at 371 nm, (ETA)3Cu6I9 shows the broadband NIR emission peaking at 775 nm with a large wavelength, attributed to the triple‐cluster‐center (3CC) transition. Meanwhile, under 286 nm excitation, (ETA)3Cu6I9 shows a bright cyan emission peaking at 490 nm, attributed to the metal‐to‐ligand charge transfer (MLCT) or halide‐to‐ligand charge transfer (XLCT) transitions. Moreover, (ETA)3Cu6I9 presents relatively superior thermal and air stability. Benefiting from the good stability of (ETA)3Cu6I9, the as‐fabricated NIR‐LED device demonstrates great potential in biological imaging and night vision. This study opens up a new way for designing new non‐toxic NIR and cyan dual‐band emission materials, which guides to synthesize new materials in metal halide field. [ABSTRACT FROM AUTHOR]

Lithium-ion batteries (LIBs) industry is expanding rapidly in the context of addressing the challenge of climate change and energy crisis. As a technology-intensive product, large number of new synthetic chemicals are applied in LIBs production. Organic fluorine additives are added in multiple components of LIBs, many of these additives are novel per-and polyfluoroalkyl substances (with fully fluorinated methyl or methylene carbon atom), here, in this work we referred to this kind of compounds as LIB-PFAS. LIB-PFAS may cause high exposure to personnel in contact with LIBs materials during production and disposal processes, thus posing potential health risks to these occupational workers. The general population can be exposed to LIB-PFAS when they are released into the surrounding air, soil, and water. In order to assess potential health risks associated with LIB-PFAS, this review systematically summarizes the chemical structures, analytical methods, possible emission routes and human exposure pathways, their bioaccumulation, distribution, and elimination behaviors in humans, and existing toxicity data of LIB-PFAS. In particular, the screening and identification methods for 57 LIB-PFAS are discussed, as well as the investigation of emission processes and exposure risks during the manufacturing and disposal of LIB. Although the available scientific data is still limited, this review provide an insightful view and novel perspective for further research on the occupational and environmental health impacts of LIB-PFAS. [ABSTRACT FROM AUTHOR]

Secondary aluminum ash (SAD) disposal is challenging, particularly in developing countries, and presents severe eco-environmental risks. This paper presents the treatment techniques, mechanisms, and effects of SAD at the current technical-economic level based on aluminum ash's resource utilization and environmental properties. Five recovery techniques were summarized based on aluminum's recoverability in SAD. Four traditional utilization methods were outlined as per the utilization of alumina in SAD. Three new utilization methods of SAD were summarized based on the removability (or convertibility) of aluminum nitride in SAD. The R-U-R (recoverability, utilizability, and removability) theory of SAD was formed based on several studies that helped identify the fingerprint of SAD. Furthermore, the utilization strategies of SAD, which supported the recycling of aluminum ash, were proposed. To form a perfect fingerprint database and develop various relevant techniques, future research must focus on an extensive examination of the characteristics of aluminum ash. This research will be advantageous for addressing the resource and environmental challenges of aluminum ash. [Display omitted] • Generation and properties of SAD were fully identified. • Ceramsite or ceramics were SAD's high-value products. • New recycling methods of SAD were discussed. • R-U-R theory and SAD treatment strategy were proposed. [ABSTRACT FROM AUTHOR]

Radiative divertor is an effective method for the divertor heat flux control, but excessive core impurity radiation can deteriorate the confinement in tokamaks. In recent EAST experiments, the compatibility of divertor detachment and impurity control with good core confinement (H98,y2 ∼1) has been achieved simultaneously by combining an upstream deuterium (D2) puff and divertor argon (Ar) seeding. Both experimental and SOLPS-ITER modeling reveal that additional D2 puff can further mitigate the target heat load and facilitate the detachment. The SOLPS-ITER results also show that the D2 puff makes a limited contribution to the Ar line radiation but a significant contribution to the neutral radiation in the SOL and divertor regions. The physical mechanism behind the effect of the D2 puff on the Ar retention is also revealed by the modeling. The increase in the Ar velocity is the major reason for the improved Ar retention in the partial detachment state. The increase in vAr is mainly caused by the strengthening of frictional drag of D+, which is because the additional D2 puff increases the pressure gradient force (FPG) and the electric field force (FE) on D+. Further analysis reveals that in the deep detachment state, some other negative effects play a dominant role in determining the Ar retention, such as the shift of the region of the Ar+ ionization source, the decrease in the strength of the Ar+ ionization source, and the net force on the Ar ions near the target. [ABSTRACT FROM AUTHOR]

The migration mechanisms, sources, and environmental risks of 29 legacy and emerging perfluorinated and polyfluoroalkyl species present in an oxidation pond (Ya'Er Lake) were investigated for treating sewage based on the analysis of their occurrence and distribution. The concentration of per- and polyfluoroalkyl substances (PFAS) in pond area was between 0.30 and 63.2 ng/g dw (dry weight), with the overall average concentration of 8.00 ng/g dw. Notably, the PFAS concentrations in the surface sediments near the sewage outlet in Pond-1 (50.2 ng/g dw) and Pond-5 (average 15.1 ng/g dw) were 1–2 orders of magnitude higher than those in other areas. In general, the legacy PFAS, i.e., perfluorooctane sulfonic acid was considered to be the major pollutant in the polluted area, on average, accounting for 73.0% of the total concentration of PFAS pollutants. By evaluating the regional distribution of different PFAS homologs, the short-chain PFAS pollutants with lower K ow were found to migrate farther in both horizontal and vertical directions. The sewage outlets in Pond-1 and Pond-5 are the main pollution sources in polluted area and the emerging PFAS pollutants in Pond-5 have replaced the legacy PFAS pollutants as the main pollutants. Based on positive matrix factorization analysis, three main industrial sources of PFAS pollutants in the study area were identified: protective coating, fire-fighting, and food packaging sources. Moreover, the environmental risk assessment results showed that most study areas exhibited medium environmental risk (0.01 ≤ Risk quotient (RQ) < 1), indicating that the ecological environment risks in this area need further attention. [Display omitted] [ABSTRACT FROM AUTHOR]

Experiments and peridynamic simulations of the split-Hopkinson pressure bar (SHPB) have been conducted to investigate the dynamic mechanical behaviors of magnesium aluminate (Mg-Al) spinel. The high-speed camera and scanning electron microscopy were used to observe the failure process and the fracture surface. In our modified model, the crystal orientation and grain boundary strength were explicitly quantified, accompanied by the dual-horizon peridynamic technique, resulting in high calculation accuracy and efficiency. Then effects of the stress state and strain rate on the failure mechanism of spinel have been investigated with the damage evolution process. Micro-pores tend to be generated at the intersection of grain boundaries, while cracks will propagate along these micro-pores, leading to trans-granular and inter-granular failures. Finally, the microstructure effects on the mechanical properties of spinel have been systemically investigated. The strength and distribution of grain boundaries were found to significantly affect the strength and crack propagation of Mg-Al spinel. [ABSTRACT FROM AUTHOR]

ZnIn 2 S 4 /ZnO heterostructures have been synthesized by a simple one-step hydrothermal synthesis method, which lead to ZnO grow on the surface of ZnIn 2 S 4 nanosheets, forming a strong electronic interaction between the two semiconductors. Under the full spectrum irradiation, the optimal photocatalyst 2ZnIn 2 S 4 /ZnO shows the H 2 evolution rate of 13,638 (water/ethanol = 1:1) and 3036 (water) μmol•g−1h−1, which is correspondingly 4 and 5 times higher than that of pure ZnIn 2 S 4. ISI-XPS analysis and DFT calculations show that electrons are transferred from ZnIn 2 S 4 to ZnO through hybridization and an internal electric field (IEF) is formed between ZnIn 2 S 4 and ZnO. The improvement of photocatalytic performance can be attributed to the effect of internal electric field, the increase of photo-generated electron and hole transport rate, the suppression of charge carrier recombination, and the enhancement of light collection. The photoelectrochemical and EPR results show that a stepped (S-scheme) heterojunction is formed in the ZnIn 2 S 4 /ZnO redox center, which greatly promotes separation of electron-hole pairs to promote efficient hydrogen evolution. This work provides a new strategy for the design of S-scheme photocatalytic systems for hydrogen evolution. [Display omitted] ZnIn 2 S 4 /ZnO heterostructures have been achieved by a simple in-situ growth solvothermal method. Under full spectrum irradiation, the optimal photocatalyst 2ZnIn 2 S 4 /ZnO exhibits H 2 evolution rate of 13,638 (water/ethanol = 1:1) and 3036 (water) μmol·g−1h−1, which is respectively 4 and 5 times higher than that of pure ZnIn 2 S 4. In situ illumination X-ray photoelectron spectroscopy (ISI-XPS) analysis and density functional theory (DFT) calculations show that the electrons of ZnIn 2 S 4 are removed to ZnO through hybridization and form an internal electric field between ZnIn 2 S 4 and ZnO. The optical properties of the catalyst and the effect of internal electric field (IEF) can increase photo-generated electrons (e−)–holes (h+) transport rate and enhance light collection, resulting in profitable photocatalytic properties. The photoelectrochemical and EPR results show that a stepped (S-scheme) heterojunction is formed in the ZnIn 2 S 4 /ZnO redox center, which greatly promotes separation of e−–h+ pairs and efficient H 2 evolution. This research offers an effective method for constructing an efficient S-Scheme photocatalytic system for H 2 evolution. [ABSTRACT FROM AUTHOR]

In the present work, we have introduced a series of stable radical-doped coordination compounds composed of donor–acceptor structures and shown to produce organic radicals in situ as a result of unconventional lone pair–π interactions in ambient conditions. Inconspicuous lone pair–π and C–H⋯π interactions were shown to play a key role in self-assembly as well as the charge transfer process, resulting in a long-lived charge-separated state able to generate organic radicals. The resultant species displayed broad-spectrum antimicrobial activity, including against multi-drug-resistant bacteria. This study unveiled the promise of reactive organic radical-doped materials as a new platform for developing antimicrobial agents that can overcome antibiotic resistance. [ABSTRACT FROM AUTHOR]

Tandem solar cells (TSCs) comprising stacked narrow‐bandgap and wide‐bandgap subcells are regarded as the most promising approach to break the Shockley–Queisser limit of single‐junction solar cells. As the game‐changer in the photovoltaic community, organic–inorganic hybrid perovskites became the front‐runner candidate for mating with other efficient photovoltaic technologies in the tandem configuration for higher power conversion efficiency, by virtue of their tunable and complementary bandgaps, excellent photoelectric properties, and solution processability. In this review, a perspective that critically dilates the progress of perovskite material selection and device design for perovskite‐based TSCs, including perovskite/silicon, perovskite/copper indium gallium selenide, perovskite/perovskite, perovskite/CdTe, and perovskite/GaAs are presented. Besides, all‐inorganic perovskite CsPbI3 with high thermal stability is proposed as the top subcell in TSCs due to its suitable bandgap of ≈1.73 eV and rapidly increasing efficiency. To minimize the optical and electrical losses for high‐efficiency TSCs, the optimization of transparent electrodes, recombination layers, and the current‐matching principles are highlighted. Through big data analysis, wide‐bandgap perovskite solar cells with high open‐circuit voltage (Voc) are in dire need in further study. In the end, opportunities and challenges to realize the commercialization of TSCs, including long‐term stability, area upscaling, and mitigation of toxicity, are also envisioned. [ABSTRACT FROM AUTHOR]

The development of orange‐red/red thermally activated delayed fluorescence (TADF) materials with both high emission efficiencies and short lifetimes is highly desirable for electroluminescence (EL) applications, but remains a formidable challenge owing to the strict molecular design principles. Herein, two new orange‐red/red TADF emitters, namely AC‐PCNCF3 and TAC‐PCNCF3, composed of pyridine‐3,5‐dicarbonitrile‐derived electron‐acceptor (PCNCF3) and acridine electron‐donors (AC/TAC) are developed. These emitters in doped films exhibit excellent photophysical properties, including high photoluminescence quantum yields of up to 0.91, tiny singlet‐triplet energy gaps of 0.01 eV, and ultrashort TADF lifetimes of less than 1 µs. The TADF‐organic light‐emitting diodes employing the AC‐PCNCF3 as emitter achieve orange‐red and red EL with high external quantum efficiencies of up to 25.0% and nearly 20% at doping concentrations of 5 and 40 wt%, respectively, both accompanied by well‐suppressed efficiency roll‐offs. This work provides an efficient molecular design strategy for developing high‐performance red TADF materials. [ABSTRACT FROM AUTHOR]

A sextuple ordered interpenetrated copper-naphthalenediimide network has been constructed by combining the features of porous metal–organic frameworks and π-conjugated supramolecular aggregation. The material exhibits intrinsic semiconductive features with narrow bandgap energy (1.2 eV) and outstanding electron transport. Theoretical calculations combined with experiments indicate that the high electron conduction may originate from π–d coupling and J-aggregation. [ABSTRACT FROM AUTHOR]

Lone pair-π interaction-induced charge-transfer was successfully used for switching the conductance of a coordination network, through variation of the degree of charge transfer caused by external photostimulation. The underlying mechanism is attributed to the changes in efficient charge-carriers by photoinduced strong charge transfer, which was investigated by in situ UV-Vis absorption, ESR, and computational studies. [ABSTRACT FROM AUTHOR]

Thermally activated delayed fluorescence (TADF) materials based on multiple resonance (MR) molecular structures can achieve advantages, such as high fluorescence efficiency, reduced structural relaxation and narrow emission. It still remains a challenge to design highly efficient MR structure-based TADF materials with fast reverse intersystem crossing processes and easy emission-color tuning. Herein, we theoretically investigated the recently reported TADF molecule, which has the MR structure of quinolino[3,2,1-de] acridine-5,9-dione (QAD) as the acceptor and the moiety of carbazole (Cz) as the donor, namely QAD-Cz. The calculated fluorescence quantum efficiency of QAD-Cz is as high as 96.5%, which agrees with the experimental results (99.6%) very well. Moreover, we designed two new TADF materials based on the MR-QAD structure with different electron-donating moieties, namely QAD-TPA and QAD-DPTZ. The two newly designed molecules can theoretically achieve high fluorescence quantum efficiencies (over 90%) and fast reverse intersystem crossing rates (e.g. as high as 107 s−1 for QAD-DPTZ). The calculated emission wavelength of the QAD-DPTZ molecule is 638 nm, which obviously widens the emission color range of the reported MR-QAD-based TADF materials. Furthermore, we have analyzed the aggregation effects of the QAD-DPTZ molecule and demonstrated that this novel compound can likewise exhibit excellent luminescence performance in amorphous states. [ABSTRACT FROM AUTHOR]

In the EAST radiative divertor experiments, stable detachment and divertor protection have been achieved with mixed impurity gas seeding. Experiments indicate that neon (Ne) is an appropriate external impurity for plasma detachment in EAST. In this work, the physical mechanism of plasma detachment with Ne seeding in EAST is studied by using the SOLPS-ITER code package. The electron temperature Tet on the upper outer divertor target decreases to below 10 eV with Ne seeding, which is mainly due to the power loss and upstream power drop caused by the impurity radiation. For Tet < 10 eV, the significant drop of the poloidal saturation ion current js,p occurs around the upper outer strike point. The simulation results show that the js,p drop is mainly driven by the rise of the momentum loss and the upstream pressure loss. The increase in the momentum loss is mainly caused by the plasma–neutral interactions in the region from the X-point to the upper outer divertor target. The upstream pressure loss around the X-point is related to the decrease in the upstream electron temperature Teu, which originates from the increased radiation loss with Ne seeding. [ABSTRACT FROM AUTHOR]

The investigations on the relationship between geometrical structures, excited state properties, and photophysical performance can accelerate the design of thermally activated delayed fluorescence (TADF) molecules. Herein, the photophysical properties of newly proposed organic TADF molecule: [4‐(9,9‐dimethyl‐9,10‐dihydroacridine) phenyl] (pyridin‐4‐yl)‐methanone (PyB‐DMAC), are theoretically investigated by using the quantum mechanics and molecular mechanics method. The photophysical performance dependency of PyB‐DMAC molecule on its geometrical and electronic structures, and aggregation effects are systematically analyzed. The calculated fluorescence quantum efficiencies are in good agreement with the experimental results, for instance, the calculated fluorescence efficiency of 61.2% (exp. 49%) for PyB‐DMAC molecule in the crystal phase. Based on these investigations, novel organic TADF molecules can be designed by balancing the singlet–triplet energy gap (ΔEST) and transition dipole moment. Sixteen unexplored candidates are screened with similar structures to PyB‐DMAC molecule, while two new TADF organic molecules (PyBF‐DMAC and OSOF‐DMAC) are selected with enhanced luminescence performance. The newly designed TADF molecules reveal lower reorganization energies and reduced nonradiative decay rates. The simulation results exhibit that their luminescence quantum efficiencies in toluene solvent and amorphous state are as high as 63.7%, 53.2% and 90%, 97.4%, respectively. [ABSTRACT FROM AUTHOR]

We apply the ideal octahedron model and the relaxation algorithm in generating octahedron packings. The cubatic order parameter [ P 4 ] 1 , bond-orientational order metric Q 6 , and local cubatic order parameter P 4 l o c a l of the packings are calculated and their correlations with the packing density are investigated in the order maps. The border curve of packing density separates the geometrically feasible and infeasible regions in the order maps. Observing the transition phenomenon on the border curve, we propose the concept of the maximally dense random packing (MDRP) as the densest packing in the random state in which the particle positions and orientations are randomly distributed and there is no nontrivial spatial correlations among particles. The MDRP characterizes the onset of nontrivial spatial correlations among particles. A special packing with a density about 0.7 is found in the order maps and considered to be the MDRP of octahedra. The P 4 l o c a l is proposed as a new order parameter for octahedron packings, which measures the average order degree in the neighborhoods of particles. The [ P 4 ] 1 , Q 6 and P 4 l o c a l evaluate the order degree of orientation, bond orientation and local structures, respectively and are applied simultaneously to measure the order degree of the octahedron packings. Their thresholds in the random state are determined by Monte Carlo simulations. [ABSTRACT FROM AUTHOR]

Previous studies commonly used dual laterolog or induction logging in vertical wells to study fractured reservoirs. However, there are few studies about the response characteristics of dual induction logging of horizontal wells in fractured reservoirs, which interferes with the evaluation of horizontal wells in fractured reservoirs. In this study, firstly, the finite element method is used to establish the fractured reservoir model and the dual induction instrument of horizontal well. Then, the response characteristics of dual induction logging in fractured reservoirs with different fracture conductivity, fracture dip angle, fracture width and fracture length are simulated and analyzed. The results show the response characteristics as follows: (1) The apparent conductivity of dual induction logging increases first and then decreases along with the increase of fracture conductivity, when the fracture conductivity is lower than formation conductivity, the apparent conductivity is similar to formation conductivity; (2) The fracture dip angle has little effect on the apparent conductivity of induction logging, when the fracture conductivity is high, the apparent conductivity decreases with the increase of the fracture dip angle; (3) The effect of fracture width and fracture length on apparent conductivity is similar. The larger the fracture width or length, the greater their influence on the apparent conductivity, which is different from the response characteristics of laterologs. In applications, these characteristics can be demonstrated by two wells in the southwest Ordos Basin, China. Finally, advantages and disadvantages of the simulation method, applications, logging responses discussed in detail, as well as the response characteristics and the shielding effect of fractures on electromagnetic waves of dual induction instrument are discussed in detail. The applications and discussions show that this study can provide response characteristics and novel understandings for the evaluations of horizontal wells in fractured reservoirs, especially in areas where dual induction logging is widely used. • The dual induction logging responses of horizontal well in fractured reservoirs were simulated. • The influences of fracture occurrence on dual induction logging were analyzed. • The shielding effect of fractures on the electromagnetic signal of dual induction tools is discussed. [ABSTRACT FROM AUTHOR]

Low-dimensional organo-inorganic hybrid halide perovskites with broadband emission characteristics are crucial for achieving excellent color rendering indices in solid-state lighting devices. Tin-based perovskites are promising lead-free candidates for their narrow band gaps, high charge mobility, and low toxicity. However, the susceptibility of Sn2+ to oxidation results in poor stability and strict synthetic conditions, posing a challenge for commercial applications. Herein, two tin-based perovskites, [Br(CH 2) 2 NH 3 ] 4 SnBr 6 ((BEA) 4 SnBr 6) and [Br(CH 2) 3 NH 3 ] 4 SnBr 6 ((BPA) 4 SnBr 6), were synthesized using an economical and environmental-friendly micromechanical chemical method under air conditions. Both perovskites exhibit a stable broadband orange-red light emission. Despite similar emission wavelengths (∼610 nm) and full width at half maximum (FWHM) (∼110 nm), they show a huge difference in lifetimes and photoluminescence quantum yields (PLQYs). (BPA) 4 SnBr 6 has a much longer lifetime (3.12 μs) and higher PLQY (79 %) than that of (BEA) 4 SnBr 6 due to its triplet self-trapped excitons (STEs) luminescence mechanism. Both compounds demonstrated good air stability; their photoluminescence intensity can be recovered to more than one times the initial value after 18 days in the air. Moreover, a stable warm white LED device with a color rendering index of 95.1 % was fabricated by coating blue phosphor BaMgAl 10 O 17 : Eu2+, green (Sr,Ba) 2 SiO 4 : Eu2+, and orange-red (BPA) 4 SnBr 6 on a commercial 365 nm LED chip. This study provides a novel approach for rapidly synthesizing high-performance tin-based perovskites and fabricating white LED devices with superior color rendering indices. • Two tin-based perovskites of (BEA) 4 SnBr 6 and (BPA) 4 SnBr 6 were prepared by a simple micromechanical chemical method. • The two tin-based perovskites showed excellent stability after 18 days in the air environment. • A broadband emission with a FWHM of ∼112–115 nm and a large Stokes shift of ∼264–270 nm was obtained. • The PLQY of (BPA) 4 SnBr 6 is up to 79 %. • The white LED prepared by (BPA) 4 SnBr 6 achieves a color rendering index of 95.1 %. [ABSTRACT FROM AUTHOR]

• The microstructural evolution of shear band is found to follow the four-stage law. • The increase of strain rate delays the initiation and retards the propagation of DSB. • The clusters in the regions of strain localization are not dominated by the DSB. The shear bands (SBs) evolution of Cu 50 Zr 50 metallic glasses (MGs) by the uniaxial loading under different strain rates are investigated on the temporal and spatial scales using the molecular dynamics (MD) simulation. The stress-strain curve shows a corresponding relation to the microstructure parameter curve in the form of four-stage, together with a synchronized evolution of multiple shear bands. During the propagation of the dominate shear band (DSB), the rearrangement of global microstructure is induced by the different transformation of three categories of clusters located in different zones. The synchronized evolutions of the microstructure, the deformation and the mechanical property are found to be less affected by loading condition or strain rate. However, with the increase of strain rate, the initiation and propagation of the DSB are observably retarded. As a consequence, the fracture mode of the MGs presents a change from a sliding along the DSB to a uniform deformation. [ABSTRACT FROM AUTHOR]

Organic light-emitting diodes (OLEDs) with tunable emission colors, especially white OLEDs, have rarely been observed with a single emitter in a single emissive layer. In this paper, we report a new compound featuring a D–A–D structure, 9,9′-(pyrimidine-2,5-diylbis(2,1-phenylene))bis(3,6-di-tert-butyl-9H-carbazole) (PDPC). A nondoped OLED using this compound as a single emitter exhibits unique voltage-dependent dual emission. The emission colors range from blue to orange–red with an increase in voltage, during which white electroluminescence with a Commission Internationale De L'Eclairage (CIE) coordinate of (0.35, 0.29) and a color render index (CRI) value of 93 was observed. A comparative study revealed that the dual emission simultaneously originates from the monomers and excimers of the emitter. This study provides insight into understanding the multimer-excited mechanism and developing novel color-tunable OLEDs. [ABSTRACT FROM AUTHOR]

A novel double‐peaked emission profile has been observed by the visible light imaging system in EAST. In the upper divertor region, two emission peaks in the high‐field side (HFS) scrape‐off layer (SOL) and near the X‐point are identified by tomographic reconstruction. In our previous SOLPS‐ITER simulation work, the emission peaks in the HFS SOL and near the X‐point are attributed to the carbon deposition on the HFS baffle and the dome of the upper tungsten divertor, respectively. The appearance of the emission peak near the X‐point when the outer target is attached was understood by analysing the carbon transport in the private flux region (PFR). However, the simulated intensity of the emission peak in the HFS SOL is lower by one order of magnitude than that in the PFR, while they are at the similar level in the experiment. In this work, the influence of the drifts is further studied by SOLPS‐ITER simulations. Under the favourable toroidal field condition, the HFS SOL plasma transits to the detachment regime. The chemical sputtering of the carbon deposited on the inner baffle increases significantly, as well as the emission intensity of the peak in the HFS SOL. Meanwhile, the C2+ density peak in the PFR decreases due to the E × B drift towards inner target. The emission intensity in the PFR near the X‐point, therefore, decreases moderately. As a result, the intensities of the two emission peaks become comparable, which matches better with the experiment. [ABSTRACT FROM AUTHOR]

Organic donor–acceptor (D–A) type thermally activated delayed fluorescence (TADF) materials exhibit high luminous quantum efficiencies and therefore attract considerable research interest as organic light-emitting diodes (OLEDs). Accurately calculating the photoluminescence efficiency is crucial for the design of new TADF materials. In this work, we comprehensively quantify the luminous quantum efficiencies and related photophysical process rates of dimethylacridan-based blue-color TADF emitters (AC-OSO and ACRXTN), and demonstrate that the higher reverse intersystem crossing rates (e.g. KRISC = 4.98 × 108 s−1) from T1 to S1 and the suppressed non-radiative decay rates (e.g. K Snr = 1.68 × 106 s−1) together lead to a theoretical luminous quantum efficiency of around 100%. Our calculations predict well fluorescence efficiencies observed in experiments (Φcal = 95%). In both molecules, the nonradiative rates of S1–S0 and reverse intersystem crossing rates are affected by the reorganization energies due to the twisting vibration of the donor DMAC and acceptor moiety. Our theoretical study on the TADF mechanism will be beneficial for designing highly efficient TADF based OLED materials. [ABSTRACT FROM AUTHOR]

Abstract: We investigate the excluded volumes of clusters in tetrahedral particle packing using an ideal tetrahedron model and Monte Carlo simulation. Both the influences of the size and topology of clusters on the excluded volume are studied. We find that the excluded volumes of the dimer composed of two tetrahedra and the wagon wheel composed of five tetrahedra are relatively lower than other cluster forms. For large clusters, the excluded volume decreases when the topology of a cluster approaches the wagon-wheel geometry. The results give an explanation to the cluster distribution which demonstrates that the dimer and wagon wheel are the dominative cluster forms in the packing structure of tetrahedra. [Copyright &y& Elsevier]

[Display omitted] • New ionic TADF emitters based on O/S-fused arylphosphonium electron acceptors. • Simultaneously attaining high PLQYs, short exciton lifetimes, and high RISC rates. • Realizing solution-processed OLEDs with high EQEs and small efficiency roll-offs. Ionic thermally activated delayed fluorescence (iTADF) materials are newly emerging as promising candidates for constructing solution-processed electroluminescence devices. Developing iTADF materials with high emission efficiency, short exciton lifetime, and fast reverse intersystem crossing (RISC) is crucial for achieving stable and efficient organic light-emitting diodes (OLEDs), but it remains challenging. Here we report two high-performance iTADF emitters, namely DMAC-TPPO[BF 4 ] and DMAC-TPPS[BF 4 ], which consist of a conventional acridine as the electron-donor and newly developed oxygen/sulfur-fused arylphosphonium derivatives as the electron-acceptor. DMAC-TPPO[BF 4 ] and DMAC-TPPS[BF 4 ] exhibit high photoluminescence quantum yields of 77 % and 83 %, coupled with short exciton lifetimes of 1.2 and 1.1 μs, and RISC rate constants reaching up to 2.60 × 106 and 2.73 × 106 s−1, respectively. Theoretical and experimental investigations demonstrate that the imbedding of bridging heteroatoms into the phosphonium cation is pivotal for enhancing emission efficiency through molecular skeleton rigidification, as well as for accelerating the RISC process by capitalizing on the non-metal heavy-atom effect. Eventually, solution-processed OLEDs utilizing DMAC-TPPS[BF 4 ] realize a peak external quantum efficiency (EQE) of 17.8 % and show a minor efficiency roll-off of 7.3 % (EQE = 16.5 %) even at a practical high luminance of 1000 cd/m2. [ABSTRACT FROM AUTHOR]

We present recent progresses on applying the theoretical models and computational tools in assessing the performance of organic solar cells, especially the bulk heterojunction solar cells. Both the continuum device model and the dynamic Monte Carlo model are developed to investigate the photocurrent-voltage characteristics based on the exciton and charge carrier dynamics. Insights into key factors influencing the organic photovoltaic performances have been gained from these studies. [ABSTRACT FROM AUTHOR]

To investigate the optimal scenario of impurity seeding to obtain divertor plasma detachment for target protection, experiments with Ar&D2 seeding from two different poloidal locations, the upper outer (UO) divertor target and lower outer (LO) target, were carried out on EAST. Partial energy detachment (the electron temperature near the strike point Te,spt ⩽ 10 eV) were obtained with Ar&D2 mixture puffing from the UO target and, for the first time, from the LO target into H-mode plasmas in the upper single null (USN) configuration. The peak heat flux qt on the UO target was significantly reduced (by ∼80%). The rollover of ion flux density js did not appear probably due to insufficient momentum loss, which is independent of the puff locations. The poloidal asymmetries of particle and heat fluxes on the targets have also been investigated. The UO-dominant asymmetry of particle flux was reversed, while the UO-dominant asymmetry of heat flux was mitigated but not reversed. The plasma confinement dropped by only 14% and 8.2% in the LO-puff case and UO-puff case, respectively, during detachment. The high level of C may contributed greatly to the higher radiation in the bulk plasma region and the greater decline in WMHD in the LO-puff case. [ABSTRACT FROM AUTHOR]

Edge localized mode (ELM) mitigation accompanied by density pump-out has been achieved during the application of resonant magnetic perturbation (RMP) with a toroidal mode number of n = 4 on EAST recently. The mean ELM frequency increases by a factor of 2.7 from 86 to 235 Hz with a decreased reduction in ELM loss. The evolution of pedestal electron density measured by a profile reflectometer before and after turning on the RMP current is presented. Both the pedestal density and density gradient show a decrease with application of RMP. The density fluctuation in the pedestal region has been measured by an O-mode fluctuation reflectometer. The broadband density fluctuation with a frequency range of 20–115 kHz is enhanced at the later period of the inter-ELM phase during ELM mitigation. This phenomenon is also observed for magnetic fluctuation measured by magnetic probes mounted in the vacuum vessel. A further study shows that the enhanced broadband fluctuations lead to a decrease in the growth rate of the pedestal density and an increase in divert or particle flux. This result implies that these enhanced broadband fluctuations could lead to an enhancement of outward particle transport. The possible roles of the enhanced fluctuations observed in ELM mitigation are also discussed. [ABSTRACT FROM AUTHOR]