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As the first endeavor in the context of Mindlin's strain gradient theory, this study contributes a systematic and rigorous derivation for governing equations and boundary conditions of planar arbitrarily curved microbeams. The Timoshenko–Ehrenfest beam model is incorporated into a simplified version of Mindlin's strain gradient theory. Kinematic unknowns include displacement components of the beam axis in the local coordinate system and the rotation of cross-section. Since the derived governing equations and boundary conditions are extremely complex, analytical solutions are not achievable for microbeams having non-uniform curvature. To facilitate the numerical analysis, two isogeometric collocation formulations are proposed, that is, displacement-based and mixed formulations. Several tests are designed to evaluate the accuracy and reliability of the proposed isogeometric collocation formulations, especially with respect to the well-known locking pathology. It is found that the mixed formulation is more accurate and robust than the displacement-based one. Therefore, the mixed formulation is then used to numerically investigate the size-dependent behavior and stiffening effect. Furthermore, some informative tests are performed to delineate the significance of the curviness in the prediction of structural responses of planar arbitrarily curved microbeams, which appears to be still an unanswered issue. [ABSTRACT FROM AUTHOR]

Pollution by microplastics and nanoplastics (MNPs) raises concerns, not only regarding their environmental effects, but also their potential impact on human health by internalization via the small intestine. However, the detailed pathways of MNP internalization and their toxicities to the human intestine have not sufficiently been understood, thus, further investigations are required. This work aimed to understand the behavior of MNPs, using in vitro human intestine models, tri-culture models composed of enterocyte Caco-2 cells, goblet-like HT29-MTX-E12 cells, and microfold cells (M cells) induced by the lymphoblast cell line Raji B. Three sizes (50, 100, and 500 nm) of polystyrene (PS) particles were exposed as MNPs on the culture model, and size-dependent translocation of the MNPs and the contributions of each cell were clarified, emphasizing the significance of the tri-culture model. In addition, potential concerns of MNPs were suggested when they invaded the circulatory system of the human body. [ABSTRACT FROM AUTHOR]

Opposed to piloted ignition, where a substance is ignited by an external flame or spark, the term auto-ignition describes the onset of combustion by spontaneous ignition without an external source. In this study, the influence of the size of spherical wood samples and the temperature surrounding the samples was investigated by performing ignition experiments in a muffle furnace with beech and spruce wood. On a specially constructed rig, spheres with four different diameters (8 mm, 12 mm, 18 mm, and 25 mm) were put into a preheated furnace at five isothermal temperatures (240 °C, 270 °C, 300 °C, 330 °C, and 360 °C). For every temperature, diameter, and wood species, the experiments were repeated eight times, and positions of the spheres on the rig were changed for every measurement. Temperatures inside the samples were recorded with thermocouples (TC) positioned in holes drilled to the middle of the spheres. With rising size and temperature, samples were more prone to auto-ignition in a glowing mode, due to a larger, highly reactive pyrolyzed surface and internal overheating. During heating and oxidative pyrolysis, isothermal phases were present at approximately 360 °C in the recorded temperature curves. The comparison to simultaneous thermal analysis (STA) measurements shows decomposition of hemicelluloses, and cellulose is highest around 360 °C. It is concluded that pyrolysis and disintegration of the main wood constituents use up all arising energy. Due to differences in the composition of the wood polymers, beech wood samples already ignite at lower temperatures compared to spruce wood samples with the same diameter. It can be concluded that the size is a critical factor for auto-ignition at the used temperatures. Larger samples will produce more volatile compounds during pyrolysis and have a larger pyrolyzed, porous surface area where heterogenous oxidation reactions can happen. The influence of the size is already critical at differences on the millimetre scale. [ABSTRACT FROM AUTHOR]

The size tunable color of colloidal semiconductor quantum dots (QDs) is probably the most elegant illustration of the quantum confinement effect. As explained by the simple "particle‐in‐a‐box" model, the transition energies between the levels increase when the "box" becomes smaller. To investigate quantum confinement effects, typically a well‐defined narrow size distribution of the nanoparticles is needed. In this contribution, how coherent electronic two‐dimensional spectroscopy (2DES) can directly visualize the quantum size effect in a sample with broad size distribution of QDs is demonstrated. The method is based on two features of the 2DES – the ability to resolve inhomogeneous broadening and the capability to reveal correlations between the states. In QD samples, inhomogeneous spectral broadening is mainly caused by the size distribution and leads to elongated diagonal peaks of the spectra. Since the cross peaks correlate the energies of two states, they allow drawing conclusions about the size dependence of the corresponding states. It is also found that the biexciton binding energy changes between 3 and 8 meV with the QD size. Remarkably, the size dependence is non‐monotonic with a clear minimum. [ABSTRACT FROM AUTHOR]

Summary: The effect of pathogens on host diversity has attracted much attention in recent years, yet how the influence of pathogens on individual plants scales up to affect community‐level host diversity remains unclear.Here, we assessed the effects of foliar fungal pathogens on plant growth and species richness using allometric growth theory in population‐level and community‐level foliar fungal pathogen exclusion experiments. We calculated growth scaling exponents of 24 species to reveal the intraspecific size‐dependent effects of foliar fungal pathogens on plant growth. We also calculated the intercepts to infer the growth rates of relatively larger conspecific individuals.We found that foliar fungal pathogens inhibited the growth of small conspecific individuals more than large individuals, resulting in a positive allometric growth. After foliar fungal pathogen exclusion, species‐specific growth scaling exponents and intercepts decreased, but became positively related to species' relative abundance, providing a growth advantage for individuals of abundant species with a higher growth scaling exponent and intercept compared with rare species, and thus reduced species diversity.By adopting allometric growth theory, we elucidate the size‐dependent mechanisms through which pathogens regulate species diversity and provide a powerful framework to incorporate antagonistic size‐dependent processes in understanding species coexistence. [ABSTRACT FROM AUTHOR]

Lead halide perovskite nanocrystals (NCs) have emerged as next‐generation semiconductors capable of unifying superior photoemission properties, facile and inexpensive preparation, compositional and structural versatility. Among them, CsPbBr3 is a model system in theoretical and experimental studies owing to its intrinsic chemical stability. Nonetheless, knowledge of the precise magnitude and the size‐ and temperature‐dependent lattice and structural distortions is lacking, and the static/dynamic nature of disorder in NCs remains an open question. Herein, robust reciprocal space X‐ray total scattering analysis is applied and accurate lattice distortions, PbBr bond distances, and PbBrPb angles versus NCs size are extracted. The lattice anisotropy increases upon expansion on downsizing while, upon contraction on cooling, the lattice distortion behaves differently at intermediate (9 nm) and ultrasmall (5 nm) sizes and from the bulk. Bond distances (stretched by ≈1%) do not show any size dependence, whereas equatorial and axial angles denote more symmetric octahedral arrangements in the smallest sizes, where they differ by ≈2° compared to ≈8° in the bulk. Anomalously high atomic displacement parameters of axial bromine ions persisting down to cryogenic temperatures suggest statically disordered octahedral tilts. These results provide insights having important implications on size‐dependent emission properties and the exciton fine structure. [ABSTRACT FROM AUTHOR]

The development of microelectronic devices to the nanoscale intensifies self-heating challenges, affecting efficiency and durability. Understanding the mechanisms of heat generation at this scale is crucial, yet research extending beyond Joule heat remains limited. This paper simulates the self-heating effect of Silicon-On-Insulator Metal-Oxide-Semiconductor Field Effect Transistors (SOI-MOS) at the nanoscale and researches the characteristic and influence of different heat generation mechanisms, including the Joule heat, recombination heat and Peltier-Thomson heat. Our results provide a detailed two-dimensional distribution and intensity of various heat generation mechanisms within the silicon channel layer. It is found that Peltier-Thomson heat has the same magnitude as Joule heat at the nanoscale, and exhibits an alternating distribution pattern of hot and cold sources under the gate. But recombination heat is relatively negligible. The analysis of the influence of different heat mechanisms emphasizes the important role of Joule heat. While the offset effect limits the impact of Peltier-Thomson heat, its significance to device thermal performance should not be ignored. More importantly, this study investigates the impact of characteristic size on different heat generation mechanisms, revealing the size dependence of Peltier-Thomson heat.

Variation in the recruitment of salmon is often found to be correlated with marine climate indices, but mechanisms behind environment–recruitment relationships remain unclear and correlations often break down over time. We used an ecosystem modeling approach to explore bottom‐up and top‐down mechanisms linking a variable environment to salmon recruitment variations. Our ecosystem model incorporates a regional ocean circulation submodel for hydrodynamics, a nutrient‐phytoplankton‐zooplankton submodel for producing planktonic prey fields, and an individual‐based model (IBM) representing juvenile Chinook salmon (Oncorhynchus tshawytscha), combined with observations of foraging distributions and diet of a seabird predator. The salmon IBM consists of modules, including a juvenile salmon growth module based on temperature and salmon–prey availability, a behavior‐based movement module, and a juvenile salmon predation mortality module based on juvenile salmon size distribution and predator–prey interaction probability. Seabird–salmon interactions depend on spatial overlap and juvenile salmon size, whereby salmon that grow past the size range of the prey distribution of the predator will escape predation. We used a 21‐year historical simulation to explore interannual variability in juvenile Chinook salmon growth and predation‐mediated survival under a range of ocean conditions for sized‐based mortality scenarios. We based a series of increasingly complex predation scenarios on seabird observational data to explore variability in predation mortality on juvenile Chinook salmon. We initially included information about the predator spatial distribution, then added population size, and finally the predator's diet percentage made up of juvenile salmon. Model agreement improves with added predator complexity, especially during periods when predator abundance is high. Overall, our model found that when the fraction of juvenile salmon in seabird diet increased relative to alternate prey (e.g., Northern anchovy Engraulis mordax, and juvenile rockfish Sebastes spp.), there was a concomitant decrease in salmon cohort survival during their first year at sea. [ABSTRACT FROM AUTHOR]

New mathematical models of a sessile drop and a captive bubble are constructed taking into account the size dependence of surface tension. If the Tolman length tends to zero, the well-known Bashforth–Adams model can be considered a special case of the constructed models. The contact angles at various values of the equilibrium volume are numerically calculated. The size dependence of surface tension is shown to lead to a violation of the conditions of consistency between the contact angles of a drop and a bubble in an external force field. [ABSTRACT FROM AUTHOR]

C2N-ring-based molecular chains were designed at the molecular level and theoretically demonstrated to show distinctive and valuable electron transport properties that were superior to the parent carbonaceous system and other similar nanoribbon-based molecular chains. This new -type molecular chain presented an exponential attenuation of the conductance and electron transmission with the length. Essentially, the molecular chain retained the electron-resonant tunneling within 7 nm and the dominant transport orbital was the LUMO. Shorter molecular chains with stronger conductance anomalously possessed a larger tunnel barrier energy, attributing to the compensation of a much smaller HOMO–LUMO gap, and these two internal factors codetermined the transport capacity. Some influencing factors were also studied. In contrast to the common O impurity with a tiny effect on electron transmission of the C2N rings chain, the common H impurity clearly improved it. When the temperature was less than 400 K, the electron transmission varied with temperature within a narrow range, and the structural disorder deriving from proper heating did not greatly modify the transmission possibility and the exponentially decreasing tendency with the length. In a non-equilibrium condition, the current increased overall with the bias but the growth rate varied with size. A valuable negative differential resistance (NDR) effect appeared in longer molecular chains with an even number of big carbon–nitrogen rings and strengthened with size. The emergence of such an effect originated from the reduction in transmission peaks. The conductance of longer molecular chains was enhanced with the voltage but the two shortest ones presented completely different trends. Applying the bias was demonstrated to be an effective way for C2N-ring-based molecular chains to slow down the conductance decay constant and affect the transport regime. C2N-ring-based molecular chains show a perfect application in tunneling diodes and controllable molecular devices. [ABSTRACT FROM AUTHOR]

Lead halide perovskite nanocrystals (NCs) have emerged as next‐generation semiconductors capable of unifying superior photoemission properties, facile and inexpensive preparation, compositional and structural versatility. Among them, CsPbBr3 is a model system in theoretical and experimental studies owing to its intrinsic chemical stability. Nonetheless, knowledge of the precise magnitude and the size‐ and temperature‐dependent lattice and structural distortions is lacking, and the static/dynamic nature of disorder in NCs remains an open question. Herein, robust reciprocal space X‐ray total scattering analysis is applied and accurate lattice distortions, PbBr bond distances, and PbBrPb angles versus NCs size are extracted. The lattice anisotropy increases upon expansion on downsizing while, upon contraction on cooling, the lattice distortion behaves differently at intermediate (9 nm) and ultrasmall (5 nm) sizes and from the bulk. Bond distances (stretched by ≈1%) do not show any size dependence, whereas equatorial and axial angles denote more symmetric octahedral arrangements in the smallest sizes, where they differ by ≈2° compared to ≈8° in the bulk. Anomalously high atomic displacement parameters of axial bromine ions persisting down to cryogenic temperatures suggest statically disordered octahedral tilts. These results provide insights having important implications on size‐dependent emission properties and the exciton fine structure.

The present study is devoted to constructing a method for calculating the solubility curves for molybdenum and ruthenium in the solid state in the binary Mo–Ru system with consideration for nanoscale effects. The approach is based on the thermodynamics of phase equilibria, taking into account the surface phenomena within the framework of the Gibbs thermodynamic method of separating surfaces. The tension surface is chosen as such a separating surface. Calculations of the solubility were performed considering the size dependences of the individual characteristics of metals and the parameters of interparticle interaction in the phases. A good agreement of the obtained results with the available experimental data is observed for the macroscopic case. [ABSTRACT FROM AUTHOR]

In this study, we explored the electrical characteristics of micro‐LEDs with various pixel sizes on GaN substrates, demonstrating that small sizes have high current density due to superior current spreading. Due to the p‐electrode ohmic contact's temperature dependence, which is supported by TLM measurements, the ideal factor declines as temperature rises. We also show the temperature sensitivity in proportion to device size at a certain current density, which is susceptible to carrier non‐radiative recombination brought on by surface defects. We comprehensively present the thermal properties of GaN‐on‐GaN homoepitaxy micro‐LEDs, laying the groundwork for improved device stability and reliability. [ABSTRACT FROM AUTHOR]

ABSTRACTThe yield stress of magnetorheological (MR) fluids has been shown to depend on particle morphology, but the exact nature of this contribution is still not fully understood. In this study, MR fluids containing 4 vol. % cobalt particles (spherical particles vs. nanowires) suspended in silicone oil were investigated. The influence of the aspect ratio on the rheological properties of suspensions that contained cobalt nanowires with aspect ratios ranging from 10 to 101 in increments of ~6 is described. The cobalt nanowires were fabricated using alumina template-based electrodeposition, producing wires with 305 ± 66 nm diameters. The shear stress was measured as a function of shear rate for increasing applied magnetic fields. The apparent yield stress and viscosity as a function of changing aspect ratio of the nanowire suspensions were determined. At a saturated magnetic flux density, the yield stress was found to increase linearly up to an aspect ratio of 23 (7.1 μm long wires) at which time the yield stress reached a plateau of 3.7 kPa even as the aspect ratio was further increased. As a comparison, suspensions containing 4 vol. % 1.6 μm spherical cobalt particles only reached a maximum yield stress of 1.6 kPa.

In this study, we explored the electrical characteristics of micro-LEDs with various pixel sizes on GaN substrates, demonstrating that small sizes have high current density due to superior current spreading. Due to the p-electrode ohmic contact's temperature dependence, which is supported by TLM measurements, the ideal factor declines as temperature rises. We also show the temperature sensitivity in proportion to device size at a certain current density, which is susceptible to carrier non-radiative recombination brought on by surface defects. We comprehensively present the thermal properties of GaN-on-GaN homoepitaxy micro-LEDs, laying the groundwork for improved device stability and reliability. [ABSTRACT FROM AUTHOR]

A precise understanding of nano‐bio interactions in the sub‐nanometer regime is necessary for advancements in nanomedicine. However, this is currently hindered by the control of the nanoparticle size in the sub‐nanometer regime. Herein, we report a facile in situ Mn2+‐guided centrifugation strategy for the synthesis of large‐scale ultrasmall gold nanoparticles (AuNPs) with a precisely controlled size gradient at the sub‐nanometer regime. With the discovery that [Mn(OH)]+, especially metallic manganese (Mn0@[Mn(OH)]+) nanoparticles, could selectively interact with larger AuNPs through synergistic coordination and hydrogen bonding to form aggregates, we also realized the fast (<1 h) synthesis of water‐soluble atomically precise Au25 with high yields (>56 %). We further demonstrated that sub‐nanometer size differences (approximately 0.5 nm) significantly alter non‐specific phagocytosis of AuNPs in the reticuloendothelial system macrophages, elimination rate, and nanotoxicology. [ABSTRACT FROM AUTHOR]

C2N-ring-based molecular chains were designed at the molecular level and theoretically demonstrated to show distinctive and valuable electron transport properties that were superior to the parent carbonaceous system and other similar nanoribbon-based molecular chains. This new -type molecular chain presented an exponential attenuation of the conductance and electron transmission with the length. Essentially, the molecular chain retained the electron-resonant tunneling within 7 nm and the dominant transport orbital was the LUMO. Shorter molecular chains with stronger conductance anomalously possessed a larger tunnel barrier energy, attributing to the compensation of a much smaller HOMO–LUMO gap, and these two internal factors codetermined the transport capacity. Some influencing factors were also studied. In contrast to the common O impurity with a tiny effect on electron transmission of the C2N rings chain, the common H impurity clearly improved it. When the temperature was less than 400 K, the electron transmission varied with temperature within a narrow range, and the structural disorder deriving from proper heating did not greatly modify the transmission possibility and the exponentially decreasing tendency with the length. In a non-equilibrium condition, the current increased overall with the bias but the growth rate varied with size. A valuable negative differential resistance (NDR) effect appeared in longer molecular chains with an even number of big carbon–nitrogen rings and strengthened with size. The emergence of such an effect originated from the reduction in transmission peaks. The conductance of longer molecular chains was enhanced with the voltage but the two shortest ones presented completely different trends. Applying the bias was demonstrated to be an effective way for C2N-ring-based molecular chains to slow down the conductance decay constant and affect the transport regime. C2N-ring-based molecular chains show a perfect application in tunneling diodes and controllable molecular devices.

The paper considers the issue of the equilibrium shape of the rolled out capillary meniscus in a homogeneous gravitational field. The approach used in this work differs from the earlier ones, as it takes into account the size dependence of the surface tension. With the help of such models, it will be possible to understand better the behaviour of small capillary bodies and to reveal the effects caused by the size dependence of physical parameters. For the purpose of the study, we propose to use an analogue of the well-known Tolman formula expressing the size dependence of the surface tension for the case of an interface with an arbitrary geometry. Taking into account the size dependence of the surface tension gives us equations which are predictably more complicated than the classical ones. Because of their complex nonlinearity, they cannot be solved by elementary functions, hence numerical methods are applied. The mathematical model of the meniscus is presented in a form that is better suited for numerical modelling of the profiles. We carried out computational experiments to determine the degree and nature of the effect of the parameter responsible for the size dependence of the surface tension on the equilibrium shape of the meniscus. We analysed the special cases when the exact solution of the Laplace equation and the exact relations between the meniscus profile coordinates can be obtained.

• Analysis of planar arbitrarily curved microbeams with modified couple stress theory and Euler-Bernoulli beam model. • Derivation of governing equations and boundary conditions. • Numerical formulations with isogeometric analysis approach. • In-depth theoretical and numerical studies on size-dependent behavior. • Size effects on validity of the Euler-Bernoulli beam model for microbeams. This study addresses the deficiency of means for analysis of planar arbitrarily curved microbeams. More precisely, a formulation is developed for static analysis employing the modified couple stress theory and the Euler-Bernoulli beam model. Geometric and kinematic descriptions of a slender three-dimensional continuum body are consistently reduced to those of its beam axis. A systematic framework is presented to enable elegant determination of essential strain and stress measures. Then, the virtual work principle is employed to derive governing equations and boundary conditions. Some remarks are given on the numerical implementation with the isogeometric approach. In addition, to facilitate the verification of the derivation, the isogeometric approach is also applied to two-dimensional problems of the modified couple stress theory, and the implementation is detailed. Two comprehensive examples are used to investigate the size-dependent behavior of planar arbitrarily curved microbeams. Several rigorous tests are designed to examine the accuracy of the derived beam formulation and the validity of kinematic assumptions of the Euler-Bernoulli beam model. Finally, the robustness and efficiency of the isogeometric implementation for the proposed beam formulation are verified. [ABSTRACT FROM AUTHOR]

The lattice strain ε(D) function of nanocrystals within different interface environments was modeled. For nanoparticles and nanocrystals embedded in incoherent interfaces, the lattice shrinks with the decrease of size, resulting in the reduction of ε(D). For nanostructure materials and the nanocrystals embedded in the coherent interfaces, ε(D) increases due to lattice expansion. These changes in interfacial lattice parameters depend on the sign of interfacial stress fss, i.e., the lattice contracts when fss > 0 and expands when fss < 0. In addition, we also give a criterion to judge the sign of fss, fss is negative when the surface stress f of the matrix is larger than that of the embedded nanocrystals, and vice versa. The variation in the sign of fss is also applicable to explain the thermal stability of the interface. [ABSTRACT FROM AUTHOR]

The yield stress of magnetorheological (MR) fluids has been shown to depend on particle morphology, but the exact nature of this contribution is still not fully understood. In this study, MR fluids containing 4 vol. % cobalt particles (spherical particles vs. nanowires) suspended in silicone oil were investigated. The influence of the aspect ratio on the rheological properties of suspensions that contained cobalt nanowires with aspect ratios ranging from 10 to 101 in increments of ~6 is described. The cobalt nanowires were fabricated using alumina template-based electrodeposition, producing wires with 305 ± 66 nm diameters. The shear stress was measured as a function of shear rate for increasing applied magnetic fields. The apparent yield stress and viscosity as a function of changing aspect ratio of the nanowire suspensions were determined. At a saturated magnetic flux density, the yield stress was found to increase linearly up to an aspect ratio of 23 (7.1 μm long wires) at which time the yield stress reached a plateau of 3.7 kPa even as the aspect ratio was further increased. As a comparison, suspensions containing 4 vol. % 1.6 μm spherical cobalt particles only reached a maximum yield stress of 1.6 kPa. [ABSTRACT FROM AUTHOR]

In this work, we fabricated and characterized 4 × 4 parallel flip-chip AlGaN-based micro-LED arrays with varied mesa diameters of 120 µm, 100 µm, 80 µm, and 60 µm. The reported micro-LED arrays have a maximum bandwidth of 380 MHz and a peak wavelength of ∼275 nm. It is found that the electrical and optical characteristics of AlGaN-based micro-LED arrays show strong size dependence for ultraviolet communication (UVC). The differential resistance increases from 28.8 Ω to 112 Ω, the external quantum efficiency (EQE) is increased by ∼30%, and the bandwidth doubles as the diameter of individual micro-LED decreases from 120 µm to 60 µm. Our research proves that tailoring the mesa size of parallel flip-chip AlGaN-based micro-LED arrays can further enhance its bandwidth and promote its application in UVC.

В работе рассмотрены математические модели осесимметричных капиллярных менисков — лежащая и висящая капли, развернутый мениск, учитывающие размерную зависимость поверхностного натяжения. Доказаны теоремы существования и единственности решений задач, описывающих равновесные поверхности менисков. Разработаны и протестированы эффективные численные методы, предназначенные для приближенного расчета профилей менисков. На языке «Wolfram Language» написана компьютерная программа, с помощью которой проведены масштабные вычислительные эксперименты по выявлению степени и характера влияния параметров моделей на равновесную форму каждого из рассматриваемых менисков

The stability of the stored information in magnetic recording media depends on the anisotropy energy Ea (=KeffV) of nanoparticles (NPs) of volume V or diameter D. Therefore, it is important to know how the effective anisotropy constant Keff varies with size D of the NPs. In a recent paper [Appl. Phys. Lett. 110, 222409 (2017)], the observed Keff versus D variation in NPs of maghemite (γ-Fe2O3) was explained on the basis of the core-shell-surface layer (CSSL) model given by Eq.: Keff = Kb + (6KS/D) +Ksh{[1-(2d/D)]−3–1}, where Kb,KS, and Ksh are the anisotropy constants of spins in the core, surface layer, and a shell of thickness d, respectively. This CSSL model is an extension of an earlier core-surface layer (CSL) model described by Keff = Kb + (6KS/D) [Phys. Rev. Lett. 72, 282 (1994)] proposed to explain the Keff versus D variation in Fe NPs. For the NPs of γ-Fe2O3, the additional term of the CSSL model involving Ksh was found to be necessary to fit the data for sizes D < 5 nm. In this paper, we report the validity of the CSSL model for NPs of several other systems viz. Co, Ni, NiO, and Fe3O4 using the available data from literature. In selecting the data, care was taken to consider data only for non-interacting NPs since the interparticle interactions generally overshadow the actual value of Keff in NPs. It is shown that the new CSSL model describes very well the Keff vs. D variation for all particle sizes whereas the CSL model fails for smaller particles with the notable exception of Fe NPs. This validation of the CSSL model for the NPs of Co, Ni, NiO, Fe3O4, and γ-Fe2O3 suggests its general validity for magnetic NPs. Discussion is also presented on the comparative magnitudes of the parameters Kb, KS, and Ksh obtained from the fits to the CSSL model.

The sample size effect on the deformation behavior of metallic glasses (MGs) has recently become research of intense interest. An inverse sample size effect is observed in previous experimental studies; where the yield strength decreases with decreasing sample size, rather than increasing. We propose a theoretical analysis based on the shear banding process to rationalize the inherent size dependence of yield strength, showing an excellent agreement with experimental results. Our model reveals that the anomalous inverse size effect is, in fact, caused by a transition in failure mode; from a rapid shear banding process with a shear band (SB) traversing the entire sample in bulk MGs, to an immature shear banding process with propagated SBs only at the surface in micron-sized MGs. Our results fill the gap in the current understanding of size effects in the strength and failure mechanism of MGs at different length scales. [ABSTRACT FROM AUTHOR]

Pulsed supplies of prey generally increase predator food intake. However, it is unclear whether this holds true when predators and pulsed prey are in the same guild (i.e. intraguild (IG) predators and prey). IG prey may increase IG-predator food intake through predation, but they may decrease food intake through competition. To test these hypotheses, we compared the food intake of white-spotted charr (Salvelinus leucomaenis) (IG predator) in streams that were stocked or unstocked with masu salmon (Oncorhynchus masou) fry (IG prey) in streams in Hokkaido, Japan. One day after stocking, mean stomach content weight of charr was six times higher than in unstocked streams due to fry consumption. In particular, large charr showed intense piscivory. However, predation on fry was rare after about three weeks. Some factors that could explain this time-limited IG predation include the growth and decreasing abundance of fry over time and the acquisition of predator-avoidance behaviour. In days other than the first-day post-stocking, food intake by charr did not differ between stocked and unstocked streams. No effects of interspecific competition on charr food intake were observed.

Pt/Ce0.5Zr0.5O2 (Pt/CZ11) was synthesized with different Pt size from 1.80 to 2.89 nm. Meanwhile, Pt/γ‐Al2O3 (Pt/Al2O3) with same Pt loading was prepared, and its dimension varied from 1.45 to 1.76 nm. Ethane complete oxidation was investigated over as‐synthesized catalysts. Different size‐dependence was illustrated over Pt/CZ11 and Pt/Al2O3. There was a volcanic relationship between Pt size and catalytic activity for Pt/CZ11, while the catalytic activity increased linearly as the dimension of Pt decreased for Pt/Al2O3. In combination with H2‐TPR, O2‐TPD, XPS, and Raman results, it was revealed that various size‐dependence was associated strongly with the amount of oxygen species and Pt dispersion. For inert support Al2O3, Pt dispersion was dominant. Whereas the activity on Pt/CZ11 was dependent on the synergistic effect between oxygen vacancy and active sites. Pt/CZ11‐2.70 exhibited the most superior ethane combustion activity due to moderate Pt dispersion and abundant oxygen vacancy. [ABSTRACT FROM AUTHOR]

The plasmonic properties of tetrahedral aluminum nanoparticles have been investigated using time‐dependent functional theory (TDDFT) calculations. The excitation energies are calculated for tetrahedral aluminum nanoparticles (Aln, n = 10–120) with different charge states. The BP86/DZ model is used to perform geometric optimization calculations for these clusters. The SAOP/DZ and LB94/DZ levels of theory have been used for the excitation energy calculations of these tetrahedral aluminum clusters. The absorption peaks are red‐shifted upon increasing the size of the aluminum nanoparticles. [ABSTRACT FROM AUTHOR]

This paper introduces an effective and simple approach to analyze functionally graded triply periodic minimal surface (FG-TPMS) nanoplates, taking advantage of a novel nonlocal strain gradient nonlinear analysis. TPMS has recently gained attention as an extraordinary solution for constructing structures, drawing inspiration from natural architectures. It offers remarkable features, including high interconnectivity porous architectures, smooth surfaces, and the ability to achieve mathematically controllable geometry features. However, the extensive potential and benefits of TPMS structures have not been fully explored in current research. Hence, this study aims to address this limitation and unlock new possibilities for FG-TPMS nanoplates. Three patterns of FG-TPMS nanoplates, namely Primitive (P), Gyroid (G), and I-gragh and Wrapped Package-graph (IWP), are utilized in this investigation. The proposed model effectively incorporates the nonlocal,strain gradient and nonlinear effects into nanoplate structures. It enables a comprehensive understanding of the mechanisms responsible for both reducing and enhancing stiffness in the nanoplate by fine-tuning the nonlocal and strain gradient parameters. This research offers promising prospects for future design and optimization, providing a robust approach to address the intricate nonlinear behavior observed in FG-TPMS nanoplates. [ABSTRACT FROM AUTHOR]

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A series of molecular dynamics experiments on cooling disordered Au, Cu, Al, Ti metal nanoparticles and Au — Cu, Ti — Al bimetallic nanoalloys using the tight-binding potential have been performed. The size dependences of the temperature coefficient of linear expansion and the elasticity modulus for mono- and bimetallic particles are obtained. In the first approximation, the size dependence of the linear expansion coefficient is inversely proportional to the corresponding dependence for the melting temperature of a nanoparticle, which correlates with an analytical model. Molecular dynamics results predict a more moderate relative increase in the linear expansion coefficient compared to the analytical model. It was found that the modulus of elasticity increases with decreasing the nanoparticle size.

Utilization of biomass waste and solid industrial waste, one of the basic solutions of green economy, has become an important topic in both chemical and materials science. Individual bio-carbon, magnetic oxides, and their composites have been used in making microwave absorbers. Here, by utilizing coffee waste bio-carbon and industrial waste MnFe2O4 particles, an efficient microwave absorber has been realized based on their composites. The microwave absorption performance as well as the magnetization of as-synthesized composites can be tuned by adjusting the particle size of MnFe2O4. The minimum reflection loss (RLmini) can be enhanced around 5 times from -7.7 dB to -38.80 dB at 9.8 GHz when mean particle size of MnFe2O4 in the composites is reduced from 9.7 down to 0.9 μm. Meanwhile, a wide effective absorption bandwidth (7.8–11.4 GHz) is achieved in this bio-industrial-waste composite. Such enhancement is explained from viewpoint of appropriate impedance matching as well as the synergetic effect between the bio-carbon and the MnFe2O4. Our work provides a route for the utilization of bio-carbon waste and industrial magnetic waste in the field of microwave absorption.

Two-dimensional materials are among the most efficient optical materials for Q-switched pulse applications, rising to unprecedented heights. Although the exploration of 2D nanomaterials has attracted strong interest, the results from current studies remain questionable, requiring further achievements in tailored control of their properties. In this work, antimony sulfide (Sb2S3) nanosheets are prepared by liquid-phase exfoliation, and nanosheets of different sizes are obtained by regulating ultrasonication parameters and centrifugation speed. The nonlinear optical properties of Sb2S3 nanosheets are investigated using the Z-scan technique for the first time, which exhibit excellent saturable absorption and thereby promising potential for saturable absorber applications. Among the different sizes of Sb2S3 nanosheets, the smaller-sized nanosheets exhibit better nonlinear optical properties, which is ascribed to the higher proportion of surfaces and edges. Finally, stable laser pulses with peak power as high as 2.68 W are readily generated at the wavelength of 1064 nm. This work opens an innovative avenue toward nonlinear optical devices based on Sb2S3 and provides reasonable regulation of 2D saturable absorbers. [ABSTRACT FROM AUTHOR]

In this paper, the GaN/InGaN multiple quantum wells (MQWs) micro‐light‐emitting diode (micro‐LED) devices of different size with green light emission were fabricated. The ideality factor of micro‐LED was discussed. For temperature‐dependent electrical characterization, the current–voltage relationship within a temperature category of 303–573 K was measured. The contact resistance between electrodes and GaN was exhibited, and a favorable ohmic contact was achieved for p‐electrode and p‐GaN. Next, the temperature and size effect of ideality factor was demonstrated. All size devices showed an extremely low factor smaller than 1.9. In order to better evaluate the temperature dependence, the thermal characterization was performed with a constant current and voltage mode. The 80‐μm device revealed a satisfactory temperature coefficient, namely, 1.92 mV/K at the forward voltage and 2.66 kA·K at the reverse bias. For temperature‐dependent optical characterization, the irradiance and brightness from 303 to 453 K of 100 μm were demonstrated. Even at 453 K, the brightness is still favorable as 34,520 nits. Following this, the luminous efficiency droop with increasing injection current density was described and discussed. [ABSTRACT FROM AUTHOR]

Abstract Periodically ordered arrays of vertically aligned Si nanowires (Si NWs) are successfully fabricated by nanosphere lithography combined with metal-assisted chemical etching. By adjusting the etching time, both the nanowires’ diameter and length can be well controlled. The conductive properties of such Si NWs and particularly their size dependence are investigated by conductive atomic force microscopy (CAFM) on individual nanowires. The results indicate that the conductance of Si NWs is greatly relevant to their diameter and length. Si NWs with smaller diameters and shorter lengths exhibit better conductive properties. Together with the I–V curve characterization, a possible mechanism is supposed with the viewpoint of size-dependent Schottky barrier height, which is further verified by the electrostatic force microscopy (EFM) measurements. This study also suggests that CAFM can act as an effective means to explore the size (or other parameters) dependence of conductive properties on individual nanostructures, which should be essential for both fabrication optimization and potential applications of nanostructures.

Most studies on European hake focus on the recruitment process and nursery areas, whereas the information is comparatively limited on the ecology of the juvenile stage (ca. second year of life)—the one most exploited by the Mediterranean trawl fisheries. Using information of the MEDITS programme, we provide a spatial and temporal assessment of the influence of body size and growth on hake survival from recruits (age 0) to juveniles (age 1), along with the impact of surface temperature and chlorophyll variability. At a biogeographic scale, size-dependent survival is supported, with areas with higher mean length of recruits and juveniles yielding higher survival. A similar pattern was observed at interannual level in some western Mediterranean areas, also mediated by a density-dependent effect on growth. However, the most recurrent inter-annual pattern was a negative effect of size on survival, which could be attributed to potential ontogenetic changes in catchability and underrepresentation of intra-annual recruitment pulses that are seasonally inaccessible to the MEDITS survey. Results also evidence that survival in the Alboran and Adriatic seas is dependent on the primary production variability, and that Corsica and Sardinia could be potential feeding grounds receiving juveniles from neighbouring areas. The present study reveals the importance of size- and growth-dependent survival in the juvenile stage of European hake in the Mediterranean Sea.

In this paper a molecular-dynamic study of melting of binary metal nanowires with different initial composition and mesoscopic structure is carried out. For the Ni – Cu system it is shown that the melting temperature is significantly affected not only by the percentage of components, but also by their location in the particle, i.e. by the mesoscopic structure. Thus, the Ni nanowire coated with Cu atoms retains its stability at much higher temperatures than the Cu nanowire coated with Ni atoms, ceteris paribus.

Nanostructures of drug carriers play a crucial role in nanomedicine due to their ability to influence drug delivery. There is yet no clear consensus regarding the optimal size and shape (e.g., aspect ratio) of nanoparticles for minimizing macrophage uptake, given the difficulties in controlling the shape and size of nanoparticles while maintaining identical surface properties. Here, we employed graft copolymer self-assembly to prepare polymer micelles with aspect ratios ranging from 1.0 (spherical) to 10.8 (cylindrical) and closely matched interfacial properties. Notably, our findings emphasize that cylindrical micelles with an aspect ratio of 2.4 are the least susceptible to macrophage uptake compared with both their longer counterparts and spherical micelles. This reduced uptake of the short cylindrical micelles results in a 3.3-fold increase in blood circulation time compared with their spherical counterparts. Controlling the aspect ratio of nanoparticles is crucial for improving drug delivery efficacy through better nanoparticle design.

Theoretical and experimental studies have revealed that at small length scales, surface effects contribute significantly to overall elastic deformation. In this paper, we analyze a torsional problem for a nanosized penny-shaped crack in an infinite homogeneous isotropic elastic medium with surface elasticity on the boundary of the crack. The resulting model of deformation leads to a nonclassical mixed boundary value problem which is analyzed using the Hankel transform technique leading to a pair of dual integral equations. The latter are solved numerically with the solution demonstrating excellent convergence. We examine the contribution of surface elasticity by comparing the calculated torsional displacement and bulk stresses to their counterparts in the absence of surface elasticity. The influence of surface and bulk shear modulus on the torsional stress intensity factors is analyzed and displayed graphically. Our results show that stress intensity factors are dependent on both the crack size and the bulk/surface material properties, revealing that the presence of surface elasticity may hinder or promote crack growth, depending on whether the surface shear modulus takes positive or negative values. As a check, we also note that our results indeed reduce to the corresponding classical results in the absence of surface elasticity. [ABSTRACT FROM AUTHOR]

Stocking and electrofishing occurrence and abundance data for northern pike Esoxlucius L. in >3800 km of French rivers across 7 years were compared to assess the effect of recreational fisheries stocking programmes on wild pike populations. A positive relationship was found between the additive effect of stocking and the size of the stocked pike. However, the stocking programmes implemented in France by recreational fishery managers from 2008 to 2013 increased the probability of pike occurring in the river network, without increasing abundance in well‐established pike populations, because pike stocked in their early‐life stages were used in most of the stocking programmes. [ABSTRACT FROM AUTHOR]