BINA

Synthesis of complex magnesium cations in ethereal solutions, is receiving a lot of attention due to their potential utilization in rechargeable magnesium batteries (RMB). The simplest complex cation, namely, solvated MgCl+, was hypothesized and reported as the most important cation in nonaqueous magnesium electrolyte solutions chemistry. However, such ions have never been isolated as the only cationic species in ethereal solutions developed for RMB. In this study, we report on successful isolation of the pure electrolyte MgCl(THF)5+ - PhAlCl3−, and on the electrochemical behavior of it in ethereal solutions. The structure of this compound was proved by single-crystal X-ray diffraction, Raman, and NMR spectroscopies. The novel MgCl(THF)5PhAlCl3/THF electrolyte solutions exhibit reversible Mg deposition/dissolution processes with anodic stability up to 2.7 V. The application of electrochemical cleaning pre …

We present an experimental study of bilayers of a disordered Ag metal layer close to the metal-insulator transition and an indium-oxide film which is on the insulating side of the superconductor insulator transition. Our results show that superconducting fluctuations within the indium-oxide film, that proximitize the underlying metal layer, induce insulating rather than superconducting behavior. This is ascribed to suppression of density of states (due to the superconducting energy gap) for quasiparticles in the proximitized regions. Our results present a manifestation of the proximity effect phenomenon and provide important insight into the nature of the insulating phase of the disorder driven superconductor insulator transition.

Intracellular monitoring of pH and polarity is crucial for understanding cellular processes and functions. This study employed pH- and polarity-sensitive nanomaterials such as carbon dots (CDs) for the intracellular sensing of pH, polarity, and viscosity using integrated time-resolved fluorescence anisotropy (FA) imaging (TR-FAIM) and fluorescence lifetime (FLT) imaging microscopy (FLIM), thereby enabling comprehensive characterization. The functional groups on the surface of CDs exhibit sensitivity to changes in the microenvironment, leading to variations in fluorescence intensity (FI) and FLT according to pH and polarity. The FLT of CDs in aqueous solution changed gradually from 6.38 ± 0.05 ns to 8.03 ± 0.21 ns within a pH range of 2–8. Interestingly, a complex relationship of FI and FLT was observed during measurements of CDs with decreasing polarity. However, the FA and rotational correlation time (θ) increased from 0.062 ± 0.019 to 0.112 ± 0.023 and from 0.49 ± 0.03 ns to 2.01 ± 0.27 ns, respectively. This increase in FA and θ was attributed to the higher viscosity accompanying the decrease in polarity. Furthermore, CDs were found to bind to three locations in Escherichia coli: the cell wall, inner membrane, and cytoplasm, enabling intracellular characterization using FI and FA decay imaging. FLT provided insights into cytoplasmic pH (7.67 ± 0.48), which agreed with previous works, as well as the decrease in polarity in the cell wall and inner membrane. The CD aggregation was suspected in certain areas based on FA, and the θ provided information on cytoplasmic heterogeneity due to the aggregation and/or interactions with …

Localized surface plasmon resonance (LSPR) holds great promise for the next generation of fast nanoscale optoelectronic devices, as silicon-based electronic devices approach fundamental speed and scaling limitations. However, in order to fully exploit the potential of plasmonics, devices and material systems capable of actively controlling and manipulating plasmonic response are essential. Here, we demonstrate active control of the electric field distribution of a microantenna by coupling LSPRs to a photosynthetic protein with outstanding optoelectronic properties and a long-range and efficient exciton transfer ability. The hybrid biosolid state active platform is able to tune and modulate the optical activity of a microplasmonic antenna via the interaction of the bioactive material with plasmon oscillations occurring in the antennae. In addition, we demonstrate that the effect of the coupling can be further enhanced …

We present a highly diagonal “split-well resonant-phonon” (SWRP) active region design for GaAs/Al_0.3Ga_0.7As terahertz quantum cascade lasers (THz-QCLs). Negative differential resistance is observed at room temperature, which indicates the suppression of thermally activated leakage channels. The overlap between the doped region and the active level states is reduced relative to that of the split-well direct-phonon (SWDP) design. The energy gap between the lower laser level (LLL) and the injector is kept at 36 meV, enabling a fast depopulation of the LLL. Within this work, we investigated the temperature performance and potential of this structure.

Quantum reference frames have attracted renewed interest recently, as their exploration is relevant and instructive in many areas of quantum theory. Among the different types, position and time reference frames have captivated special attention. Here, we introduce and analyze a non-relativistic framework in which each system contains an internal clock, in addition to its external (spatial) degree of freedom and, hence, can be used as a spatiotemporal quantum reference frame. Among other applications of this framework, we show that even in simple scenarios with no interactions, the relative uncertainty between clocks affects the relative spatial spread of the systems.

Hydrogen produced from neutral seawater electrolysis faces many challenges including high energy consumption, the corrosion/side reactions caused by Cl-, and the blockage of active sites by Ca2+/Mg2+ precipitates. Herein, we design a pH-asymmetric electrolyzer with a Na+ exchange membrane for direct seawater electrolysis, which can simultaneously prevent Cl- corrosion and Ca2+/Mg2+ precipitation and harvest the chemical potentials between the different electrolytes to reduce the required voltage. In-situ Raman spectroscopy and density functional theory calculations reveal that water dissociation can be promoted with a catalyst based on atomically dispersed Pt anchored to Ni-Fe-P nanowires with a reduced energy barrier (by 0.26 eV), thus accelerating the hydrogen evolution kinetics in seawater. Consequently, the asymmetric electrolyzer exhibits current densities of 10 mA cm−2 and 100 mA cm …

Intracellular monitoring of pH and polarity is crucial for understanding cellular processes and functions. This study employed pH- and polarity-sensitive nanomaterials such as carbon dots (CDs) for the intracellular sensing of pH, polarity, and viscosity using integrated time-resolved fluorescence anisotropy (FA) imaging (TR-FAIM) and fluorescence lifetime (FLT) imaging microscopy (FLIM), thereby enabling comprehensive characterization. The functional groups on the surface of CDs exhibit sensitivity to changes in the microenvironment, leading to variations in fluorescence intensity (FI) and FLT according to pH and polarity. The FLT of CDs in aqueous solution changed gradually from 6.38 ± 0.05 ns to 8.03 ± 0.21 ns within a pH range of 2–8. Interestingly, a complex relationship of FI and FLT was observed during measurements of CDs with decreasing polarity. However, the FA and rotational correlation time (θ) increased from 0.062 ± 0.019 to 0.112 ± 0.023 and from 0.49 ± 0.03 ns to 2.01 ± 0.27 ns, respectively. This increase in FA and θ was attributed to the higher viscosity accompanying the decrease in polarity. Furthermore, CDs were found to bind to three locations in Escherichia coli: the cell wall, inner membrane, and cytoplasm, enabling intracellular characterization using FI and FA decay imaging. FLT provided insights into cytoplasmic pH (7.67 ± 0.48), which agreed with previous works, as well as the decrease in polarity in the cell wall and inner membrane. The CD aggregation was suspected in certain areas based on FA, and the θ provided information on cytoplasmic heterogeneity due to the aggregation and/or interactions with …

Rechargeable Zn-air batteries (RZABs) with non-alkaline electrolytes are a promising type of energy storage devices that potentially combine low cost, high energy density and safety. However, cathode materials for these devices remain poorly developed. We present a systematic study of how structure of carbons affects their performance as cathode scaffolds in non-alkaline RZABs. Ten commercially available types of carbon are characterized and tested in Zn-air battery cathodes with 1 M Zn(OAc)2 or ZnSO4 solutions in H2O as electrolytes. At a low current density (0.1 mA cm−2), there is a roughly linear dependence between the roundtrip energy efficiency and the logarithm of BET surface area, and this dependence is relevant across materials with different morphology and graphitization degree. Lower overpotentials at the initial cycles are observed for cathodes that are more hydrophilic. At higher currents (1 mA …

Since 2011, 2D transition metal carbides, carbonitrides and nitrides known as MXenes have gained huge attention due to their attractive chemical and electronic properties. The diverse functionalities of MXenes make them a promising candidate for multitude of applications. Recently, doping MXene with metallic and non-metallic elements has emerged as an exciting new approach to endow new properties to this 2D systems, opening a new paradigm of theoretical and experimental studies. In this review, we present a comprehensive overview on the recent progress in this emerging field of doped MXenes. We compare the different doping strategies; techniques used for their characterization and discuss the enhanced properties. The distinct advantages of doping in applications such as electrocatalysis, energy storage, photovoltaics, electronics, photonics, environmental remediation, sensors, and biomedical …

Scattering-type scanning near-field optical microscopy is a powerful imaging technique for studying materials beyond the diffraction limit. However, interpreting near-field measurements poses challenges in mapping the response of polaritonic structures to meaningful physical properties. To address this, we propose a theory based on the transfer matrix method to simulate the near-field response of 1D polaritonic structures. Our approach provides a computationally efficient and accurate analytical theory, relating the near-field response to well-defined physical properties. This work enhances the understanding of near-field images and complex polaritonic phenomena. Finally, this scattering theory can extend to other systems like atoms or nanoparticles near a waveguide.

We present a highly diagonal “split-well resonant-phonon” (SWRP) active region design for GaAs/Al_0.3Ga_0.7As terahertz quantum cascade lasers (THz-QCLs). Negative differential resistance is observed at room temperature, which indicates the suppression of thermally activated leakage channels. The overlap between the doped region and the active level states is reduced relative to that of the split-well direct-phonon (SWDP) design. The energy gap between the lower laser level (LLL) and the injector is kept at 36 meV, enabling a fast depopulation of the LLL. Within this work, we investigated the temperature performance and potential of this structure.

Courtship behaviors in Drosophila melanogaster are innate and contain highly stereotyped but also experience-and state-dependent elements. They have been the subject of intense study for more than 100 years. The power of Drosophila as a genetic experimental system has allowed the dissection of reproductive behaviors at a molecular, cellular, and physiological level. As a result, we know a great deal about how flies perceive sensory cues from potential mates, how this information is integrated in higher brain centers to execute reproductive decisions, and how state and social contexts modulate these responses. The simplicity of the assay has allowed for its broad application. Here, we introduce methods for studying male and female innate reproductive behaviors as well as their plastic responses.

Optical fibers are an excellent sensor platform. However, the detection and analysis of media outside the cladding and coating of standard fibers represent a long-standing challenge: light that is guided in the single optical core mode does not reach these media. Cladding modes help work around this difficulty, as their transverse profiles span the entire cross-section of the fiber cladding and reach its outer boundary. In this tutorial, we introduce and discuss in detail two recent advances in optical fiber sensors that make use of cladding modes. Both concepts share optomechanics as a common underlying theme. First, we describe a spatially continuous distributed analysis using the optical cladding modes of the fiber. Light is coupled to these modes using Brillouin dynamic gratings, which are index perturbations associated with acoustic waves in the core that are stimulated by light. Unlike permanent gratings, which …

We propose and demonstrate a holographic imaging scheme exploiting random illuminations for recording hologram and then applying numerical reconstruction and twin image removal. We use an in-line holographic geometry to record the hologram in terms of the second-order correlation and apply the numerical approach to reconstruct the recorded hologram. This strategy helps to reconstruct high-quality quantitative images in comparison to the conventional holography where the hologram is recorded in the intensity rather than the second-order intensity correlation. The twin image issue of the in-line holographic scheme is resolved by an unsupervised deep learning based method using an auto-encoder scheme. Proposed learning technique leverages the main characteristic of autoencoders to perform blind single-shot hologram reconstruction, and this does not require a dataset of samples with available …

Three-dimensional porous nanostructured materials are considered superior materials for energy storage applications due to their high storage capability. A nickel copper-cobalt oxide (NCC) composite with a uniform 3-D porous nanostructure (positive electrode materials) and luffa sponge-derived activated carbon (LPAC) with honeycomb-like structure (negative electrode materials) were synthesized by a simple hydrothermal and chemical method. A sample of the nickel-copper cobalt oxide-5 (NCC-5) nanocomposite reached a high specific capacitance of 1048 F/g at the current density of 0.5 A/g. The NCC-5 nanocomposite sample shows a retention capacity of 93 % after 10,000 charge and discharge cycles with 95 % of Coulombic efficiency (CE). The LPAC illustrates a remarkable specific capacitance of 909 F/g at 1 A/g of current density, compared to the best literature value of 400 F/g. The full-cell NCC-5//LPAC …

Hydrogen produced from neutral seawater electrolysis faces many challenges including high energy consumption, the corrosion/side reactions caused by Cl-, and the blockage of active sites by Ca2+/Mg2+ precipitates. Herein, we design a pH-asymmetric electrolyzer with a Na+ exchange membrane for direct seawater electrolysis, which can simultaneously prevent Cl- corrosion and Ca2+/Mg2+ precipitation and harvest the chemical potentials between the different electrolytes to reduce the required voltage. In-situ Raman spectroscopy and density functional theory calculations reveal that water dissociation can be promoted with a catalyst based on atomically dispersed Pt anchored to Ni-Fe-P nanowires with a reduced energy barrier (by 0.26 eV), thus accelerating the hydrogen evolution kinetics in seawater. Consequently, the asymmetric electrolyzer exhibits current densities of 10 mA cm−2 and 100 mA cm …

The need for new, reliable, and sustainable energy sources led to the development of new types of fuel cells. Fuel cells that rely on liquid hydrogen carriers may be the ultimate solution to the expensive hydrogen logistics issues. In this category, direct quinone fuel cells (DQFCs) are a promising new technology that solves many of the issues of traditional fuel cells. As a new technology, DQFCs need to be studied thoroughly to reach their full potential. Here, we use a distribution of relaxation times (DRT) analysis to analyze the impedance data of DQFCs, to gain a better understanding of the system. We systematically changed the operating parameters and attributed the changes in the DRT spectra to the physical processes they correspond to. The four main peaks observed in the DRT measurements were assigned to oxygen reduction reaction (ORR), quinone diffusion resistance, proton diffusion in the membrane …

The development of platinum group metal-free catalysts is considered the most prominent path for reducing the cost of low-temperature fuel cells (LTFC). Despite the great advancement in the field, its further progress is currently limited by the ability to understand and mitigate the catalysts’ degradation mechanisms, which up to recent years was limited by the lack of activity descriptors. Recent work showed that this could be solved using Fourier-transformed alternating current voltammetry that enables to deconvolute Faradaic currents arising from the redox reaction of the active sites from the capacitive currents, and by that accurately measure the electrochemically active site density of these catalysts in situ fuel cells. However, the analysis of the results can be complex, requiring simulation software for accurate parameter extraction. Herein, a simplified analysis of Fourier-transformed alternating current voltammetry is …

Entanglement is a uniquely quantum resource giving rise to many quantum technologies. It is therefore important to detect and characterize entangled states, but this is known to be a challenging task, especially for multipartite mixed states. The correlation minor norm (CMN) was recently suggested as a bi-partite entanglement detector employing bounds on the quantum correlation matrix. In this paper, we explore generalizations of the CMN to multipartite systems based on matricizations of the correlation tensor. It is shown that the CMN is able to detect and differentiate classes of multipartite entangled states. We further analyze the correlations within the reduced density matrices and show their significance for entanglement detection. Finally, we employ matricizations of the correlation tensor for introducing a measure of global quantum discord.

Hydrogels have a significant impact on the fields of biological study and medical diagnosis. They are becoming more useful in bioanalytical and biosensing applications. The intriguing new nanomaterials quantum dots-hydrogel composites have gained a lot of interest because of their unmatched biocompatibility and tolerable biodegradability, which opens up a wide range of possible applications. Focusing on synthesis techniques, this review describes current developments in quantum dots-hydrogel composites, such as hydrogel gelation in quantum dots (QDs) solution, inserting prepared QDs into hydrogels after gelation, generating QDs in situ inside the preformed gel, and cross-linking through QDs. Biomedical applications such as bioimaging and biosensing are specifically examined, and then the inherent problems of design optimisation, biocompatibility, and bimodal applications, as well as the potential of …