Persistence Properties Research Articles

A note on ideal Magneto-Hydrodynamics with perfectly conducting boundary conditions in the quarter space

We consider the initial–boundary value problem in the quarter space for the system of equations of ideal Magneto-Hydrodynamics for compressible fluids with perfectly conducting wall boundary conditions. On the two parts of the boundary the solution satisfies different boundary conditions, which make the problem an initial–boundary value problem with non-uniformly characteristic boundary.We identify a subspace H3(Ω) of the Sobolev space H3(Ω), obtained by addition of suitable boundary conditions on one portion of the boundary, such that for initial data in H3(Ω) there exists a solution in the same space H3(Ω), for all times in a small time interval. This yields the well-posedness of the problem combined with a persistence property of full H3-regularity, although in general we expect a loss of normal regularity near the boundary. Thanks to the special geometry of the quarter space the proof easily follows by the “reflection technique”.

Evaluating the Impact of Dermal Absorption on Internal Doses of Dechlorane Plus in Chinese E-waste Recycling Employees

E-waste recycling employees represent a specific population with a high potential for exposure to dechlorane plus (DP). However, the impact of skin-adherent DP on human exposure within this group has not been well characterized. This study aimed to address this gap by collecting handwipe and matched serum samples (n=86 pairs) of Chinese e-waste recycling employees. In vivo human dermal bioavailability of DP was also examined to achieve effective exposure estimation. As a result, DP was detected in all handwipe and serum samples, indicating the occurrence of widespread exposure in the study population. For all the participants, the median level of ∑DP (the sum of syn-DP and anti-DP) in the serum was 45.1 ng g-1 lipid weight (lw), while handwipe samples showed the loading of 10.8 ng per wipe. Notably, significant associations were found between DP handwipe loadings and matched serum levels (p<0.05). Next, the in vivo human dermal bioavailability was estimated to be 9.54% for ∑DP. Based on this value, the estimated average daily dose was 0.231 ng kg-1 d-1 (median values), contributing 10.9% to serum levels of ∑DP. The significant associations and 10.9% percentage contribution together underscore the non-negligible influence of dermal absorption on DP internal doses in the e-waste recycling employees. Moreover, the extremely high levels of DP (up to 3.64E+04 ng g-1 lw) detected in serum highlight the extent of DP accumulation in humans. Continuous monitoring and assessment are warranted among e-waste workers due to the persistent organic pollutant properties of DP.

Exploring an indirect quantification strategy for PFOA in rat tissues via efficient degradation and fluorescence spectroscopy

Perfluorooctanoic acid (PFOA) has aroused global attention due to its persistence, biotoxicity and bioaccumulative properties. Monitoring PFOA levels in biological samples could give significant insights into its toxicity mechanism and health risk evaluation. Herein, to explore the distribution of PFOA in biological tissues, an indirect quantitation strategy for PFOA in biological samples was proposed based on fluorescence spectroscopy. F- ion was produced through highly efficient degradation of PFOA in polar aprotic solvent, and then F- ion was detected with highly selective F- ion fluorescent probe, which enabled the indirect quantitative detection of PFOA in biological samples. The sensitivity for PFOA was exhibited with limit of detection of 3.55 μM. The method’s accuracy and precision were validated by spiked biological sample experiment, with recovery rate ranging from 93.2 % to 105.5 % and relative standard deviation below 9.2 %. The content of PFOA was successfully detected in rats livers, kidneys and lungs tissues. Density function theory was employed to explore defluorination pathway, indicating that heating, alkaline and water conditions played a crucial role in the degradation of PFOA to produce F- ion. Thus, this novel strategy is suitable for quantitative analysis of PFOA in biological samples with high selectivity, sensitivity, recovery ratio, and simple sample preparation, which also provides a strategy for evaluating the levels of per- and polyfluoroalkyl substances in biological samples.

Energy trapping to substitutional and charge compensation defects in persistent luminescent BaAl2O4:Tb3+

The holistic approach of the photoluminescence (PL), thermoluminescence (TL), and persistent luminescence properties at room temperature of BaAl2O4:Tb3+ were investigated in detail using a wide range of techniques. Materials were obtained using a solution combustion synthesis. The x-ray powder diffraction patterns of nondoped and Tb3+ doped BaAl2O4 indicated the hexagonal phase, and a Tb4O7 solid solution was observed at 4 and 5 mol% Tb doped aluminate. X-ray photoelectron spectroscopy revealed that Ba occupied one site and that Tb ions occupied this site as Tb3+ as well as TbIV. PL emission in blue, green, and red was observed under an excitation at 228 nm, that originated from the interconfigurational 4f8–4f75d1 transitions of Tb3+. Time-of-flight secondary ion mass spectroscopy, UV–vis diffuse reflectance, and PL revealed the presence of a Cr3+ impurity. The 0.5 mol% Tb3+ doped BaAl2O4 exhibited a strong TL band at 354, 437 and 598 K, which were attributed to the traps formed by Tb3+ doping and subsequent O2− charge compensation. A persistent luminescence mechanism was constructed for the Tb3+ doped BaAl2O4. After the energy was stored in thermally liberated Tb3+ in the Ba2+ substitution sites and charge compensation defects, the Tb3+ was the source of the continuous luminescence.

Combined toxicity of perfluoroalkyl substances and microplastics on the sentinel species Daphnia magna: Implications for freshwater ecosystems

Persistent chemicals from industrial processes, particularly perfluoroalkyl substances (PFAS), have become pervasive in the environment due to their persistence, long half-lives, and bioaccumulative properties. Used globally for their thermal resistance and repellence to water and oil, PFAS have led to widespread environmental contamination. These compounds pose significant health risks with exposure through food, water, and dermal contact. Aquatic wildlife is particularly vulnerable as water bodies act as major transport and transformation mediums for PFAS. Their co-occurrence with microplastics may intensify the impact on aquatic species by influencing PFAS sorption and transport. Despite progress in understanding the occurrence and fate of PFAS and microplastics in aquatic ecosystems, the toxicity of PFAS mixtures and their co-occurrence with other high-concern compounds remains poorly understood, especially over organisms’ life cycles.Our study investigates the chronic toxicity of PFAS and microplastics on the sentinel species Daphnia, a species central to aquatic foodwebs and an ecotoxicology model. We examined the effects of perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), and polyethylene terephthalate microplastics (PET) both individually and in mixtures on Daphnia ecological endpoints. Unlike conventional studies, we used two Daphnia genotypes with distinct histories of chemical exposure. This approach revealed that PFAS and microplastics cause developmental failures, delayed sexual maturity and reduced somatic growth, with historical exposure to environmental pollution reducing tolerance to these persistent chemicals due to cumulative fitness costs. We also observed that the combined effect of the persistent chemicals analysed was 59% additive and 41% synergistic, whereas no antagonistic interactions were observed. The genotype-specific responses observed highlight the complex interplay between genetic background and pollutant exposure, emphasizing the importance of incorporating multiple genotypes in environmental risk assessments to more accurately predict the ecological impact of chemical pollutants.

The influence of a composition based on exometabolites of Saccharomyces boulardii in relation to the pathogenic and persistent properties of fungi of the genus Candida

Clinical manifestations of mycoses vary widely from mild mucosal damage to severe invasive forms. Currently, the pharmaceutical market offers a wide range of antimycotic drugs, including oral and injectable drugs for systemic and external and local use. Varying degrees of effectiveness are due to the chemical structure and pharmacokinetics. A significant problem is the recurrence of mucosal candidiasis. One of the possible solutions to this problem can be considered the use of exometabolites of bacterial or fungal origin, affecting the morphofunctional structures of fungi of the genus Candida spp. The purpose of the study was to obtain cell-free supernatant of Saccharomyces boulardii (S. boulardii) and herbal extracts, which are the basis of a composition with a preventive effect against fungi of the genus Candida. The authors proposed a composition based on the exometabolite of S. boulardii and herbal extracts for the prevention of candidiasis. Propylene glycol served as a control. The effectiveness of the composition was assessed on clinical isolates of C. albicans, C. glabrata and C. krusei isolated from the vaginal biotope at a dilution of 103-106 CFU/mL. At the first stage, we studied the effect of S. boulardii metabolites on the biological properties of fungi. Next, the fungicidal activity of metabolites and extracts was determined by serial dilution against micromycete isolates. At the final stage, the effect of the composition with the most effective extracts was studied. Under the influence of the supernatant of S. boulardii, micromycetes lost the ability to form growth tubes, and a decrease in the catalase activity of Candida spp. was observed both during carriage and disease. Exometabolites significantly reduced the ability to form film in cultures isolated from patients with vaginal candidiasis. The most effective among the extracts were the extracts of St. John’s wort and coriander. The fungicidal properties of the composition were maintained for 12 hours after co-incubation with all isolates of Candida spp. Thus, the composition is effective against both C. albicans and C. non-albicans carriage and disease.

LaCo0.95Mo0.05O3/CeO2 composite can promote the effective activation of peroxymonosulfate via Co3+/Co2+ cycle and realize the efficient degradation of hydroxychloroquine sulfate

Hydroxychloroquine sulfate (HCQ) is extensively utilized due to its numerous therapeutic effects. Because of its properties of high solubility, persistence, bioaccumulation, and biotoxicity, HCQ can potentially affect water bodies and human health. In this study, the LaCo0.95Mo0.05O3-CeO2 material was successfully prepared by the sol–gel process, and it was applied to the experiment of degrading HCQ by activating peroxymonosulfate (PMS). The results of characterization analysis showed that LaCo0.95Mo0.05O3-CeO2 material had good stability, and the problem of particle agglomeration had been solved to some extent. Compared with LaCo0.95Mo0.05O3 material, it had a larger specific surface area and more oxygen vacancies, which was helpful to improve the catalytic activity for PMS. Under optimal conditions, the LaCo0.95Mo0.05O3-CeO2/PMS system degraded 95.5 % of HCQ in 10 min. The singlet oxygen, superoxide radicals, and sulfate radicals were the main radicals for HCQ degradation. The addition of Mo6+/Mo4+ and Ce4+/Ce3+ promoted the redox cycle of Co3+/Co2+ and enhanced the degradation rate of HCQ. Based on density functional theory and experimental analysis, three HCQ degradation pathways were proposed. The analysis of T.E.S.T software showed that the toxicity of HCQ was obviously reduced after degradation. The LaCo0.95Mo0.05O3-CeO2/PMS system displayed excellent reusability and the ability to remove pollutants in a wide range of real-world aqueous environments, with the ability to treat a wide range of pharmaceutical wastewater. In summary, this study provides some ideas for developing heterogeneous catalysts for advanced oxidation systems and provide an efficient, simple, and low-cost method for treating pharmaceutical wastewater that has good practical application potential.

Simultaneously enhanced photoluminescence and persistent luminescence in SrLaAlO4: Tb type layered perovskite via Gd3+ codoping

Gd3+ co-doping is effective to enhance the photoluminescence of rare earth activators in various host due to energy transfer, however, it is rarely reported via such strategy to regulate persistent luminescence properties. In this work, Gd3+ was co-doped into the SrLaAlO4: Tb persistent luminescence phosphors, and it is found that the photoluminescence and persistent luminescence of the products can be simultaneously improved. The results indicate that as the doping concentration of Gd3+ increases, the particle diameters increase which contributes the increased luminescence. Additionally, an energy transfer process from Gd3+ to Tb3+ ions was observed, which enhances the emission of Tb3+ ions. Furthermore, the persistent luminescence properties of the synthesized phosphors were improved. When the UV light source is turned off, the persistent luminescence of SrLaAlO4: 0.03Tb3+, xGd3+ (x = 0.00–0.97) can last for more than 2 h, which is 100 % enhanced compared to SrLaAlO4: 0.03Tb3+. The trap distribution of SrLaAlO4: 0.03Tb3+, xGd3+ (x = 0.00–0.97) phosphors was analyzed by thermoluminescence. It is found that after the substitution of La3+ with Gd3+, the trap position shifted towards higher temperatures and the trap concentration increased. The initial intensity of the persistent luminescence was also enhanced after Gd3+ co-doping. Based on the experimental findings, the luminescence and persistent luminescence mechanism of SrLaAlO4: 0.03Tb3+, xGd3+ (x = 0.00–0.97) phosphors were described and discussed.

Demonstrating the principal mechanism of action of medical devices intended for vaginal use on reconstructed human vaginal epithelium: the case of two hyaluronic acid-containing devices

Regulation (EU) 2017/745 on medical devices (MDR) has significantly modified the rules to be adopted for MD qualifications and classification. New requirements require robust evidence on mechanisms of action (MoAs) that cannot be produced by existing common EU or ISO standards. Therefore, on a “case-by-case basis,” a new evidence-based non-clinical approach to MD qualification must be defined. In this study, an in vitro experimental approach is described to assess the physicochemical and mechanical MoA of two hyaluronic acid (HA)-based medical devices: Mucogyne® Gel and Mucogyne® Ovule for vaginal use. They both act as moisturizers and lubricants as well as a healing adjuvant by promoting the continued moisture of the vulvovaginal area. The MoA of these two products has been demonstrated by using a 3D reconstructed human vaginal epithelium (HVE) model in a homeostatic physiological state and in stressed conditions. Film forming and persistency properties were assessed on intact HVE tissues by caffeine permeation assay and Lucifer Yellow (LY) localization on HVE vertical sections. Healing properties were assessed on injured HVE tissues by trans-electrical epithelial resistance (TEER) measurements associated with histo-morphological analysis (H&amp;amp;E), and moisturizing efficacy was evaluated on HVE tissues cultured in dry conditions by histomorphological analysis (H&amp;amp;E) and aquaporin 3 (AQP3) expression and localization by immunohistochemistry (IHC). Using the same “dry” HVE model, the non-pharmacological action of the two products was addressed by CD44 (hyaluronic acid receptor) expression and localization. The results suggest that in vitro evaluations can provide robust results on a human-relevant experimental model for the intended use of the products and supports clinical data with mechanistic information which may not be achieved with in vivo studies but are particularly important for product qualification. The results also underline the specific relative efficacy of the mechanisms investigated for Mucogyne® Gel and Mucogyne® Ovule in line with their different formulation types (respectively, hydrophilic and lipophilic) that influence the action of the active ingredient HA. The present in vitro non-clinical evaluation of HVE combined with clinical investigation data obtained in women explain why Mucogyne MDs provide significant benefits in various physiological or pathological situations, including vaginal dryness and healing.

Time-Synchronized Convergence Control for n-DOF Robotic Manipulators with System Uncertainties.

A time-synchronized (TS) convergence control method for robotic manipulators is proposed. Adversely to finite-time control, a notion of time-synchronization convergence is introduced based on the ratio persistence property, which can ensure that all system components converge simultaneously in a finite time. Firstly, a robust disturbance observer is constructed to be compatible with the time-synchronized control framework and precisely estimate system uncertainties. Furthermore, we design a (finite) time-synchronized controller to ensure that all states of the robotic manipulator simultaneously converge to an equilibrium point, irrespective of initial conditions. Stability analysis shows the feasibility of the proposed TS control method. At last, simulations are performed with a two-link rehabilitation robotic system, and the comparison results indicate its superiority.

Dynamics of a nonlinear infection viral propagation model with one fixed boundary and one free boundary

In this paper we study a nonlinear infection viral propagation model with diffusion, in which, the left boundary is fixed and with homogeneous Dirichlet boundary conditions, while the right boundary is free. We find that the habitat always expands to the half line [0,∞), and that the virus and infected cells always die out when the Basic Reproduction NumberR0≤1, while the virus and infected cells have persistence properties when R0>1. To obtain the persistence properties of virus and infected cells when R0>1, the most work of this paper focuses on the existence and uniqueness of bounded positive equilibrium solutions for subsystems and the existence of positive equilibrium solutions for the entire system.

Persistent ultraviolet luminescence and photocatalytic properties of SiO2-Zn2SiO4:Ga,Pb nanoparticles

Persistent phosphors possess unique afterglow optical properties. In this paper, a class of ultra-violet (UV) persistent luminescence nanoparticles were developed for catalytic photodegradation applications. UV persistent luminescence nanoparticles of SiO2-Zn2SiO4:Ga and SiO2-Zn2SiO4:Ga,Pb were successfully synthesized by using a mesoporous template method. The UV persistent luminescence intensity of SiO2-Zn2SiO4:Ga at 405 nm was enhanced up to ca. 3.5 times by co-doping with Pb2+ (396 nm), along with longer persistent luminescence duration. The photodegradation results indicate that it is useful to introduce UV persistent luminescence property into SiO2-Zn2SiO4:Ga,Pb to obtain enhanced catalytic activity of SiO2-Zn2SiO4 with a bigger catalytic oxidation reaction kinetic constant (up to ∼4 times). This kind of UV persistent catalysis strategy may become a potential feasible method for better catalytic photodegradation activity. The UV persistent photocatalyst has potential applications in the photooxidation of organic molecules in high chroma and/or turbidity aqueous systems.

Persistence properties for a two-component b-family system with higher-order nonlinearity in weighted Lp spaces

In this paper, we focus on a two-component b-family system with higher-order nonlinearity, which contains some integrable Camassa–Holm type models. By virtue of moderate weight functions, we demonstrate the persistence properties for solutions to this system in weighted Lp spaces. Our persistence results cover and improve the related results of some Camassa–Holm type models.

Persistent Luminescent Nanoparticle-Loaded Filaments for Identification of Fabrics in the Visible and Infrared.

Persistent luminescent materials are those which can store an amount of energy locally and release it slowly in the form of light. In this work, persistent luminescent nanoparticles (PLNPs) were synthesized and incorporated into polypropylene (PP) filaments at various loading percentages. We investigated the optical properties of both the as-prepared PLNPs and the PLNP-loaded filaments, focusing on any changes resulting from the integration into the filaments. Specifically, visible and near-infrared spectroscopy were used to analyze the emission, excitation, and persistent luminescence of the PLNPs and PLNP-loaded filaments. The tensile properties of the extruded filaments were also investigated through breaking tenacity, elongation at break, Young's modulus, and secant modulus. All PLNP-loaded filaments were shown to exhibit persistent luminescence when exposed to ultraviolet light. While there were no significant changes in the elongation at break or Young's modulus for the loading percentages tested, there was a slight increase in breaking tenacity and a decrease in the secant modulus. Finally, the filaments were shown to maintain their optical properties and persistent luminescence even after abrasion testing used to simulate the normal wear and tear that fabric experiences during use. These results show that PLNPs can be successfully incorporated into filaments which can be used in fabrics and will maintain the persistent luminescent properties.

The impact of discontinuities on spalling failure in excavations under high-stress conditions

The Continuum Voronoi Block Model (CVBM), a pseudo-discontinuum modeling technique based on the Finite Element Method, was employed to investigate the impact of discontinuities on spalling phenomena around excavations in rocks under high-stress conditions. The CVBM’s ability to produce numerical results consistent with spalling was demonstrated through a case study of the Mine-by tunnel. The results show that the model can explicitly capture the formation of macro-fractures parallel to excavation walls, intact rock slabs, and V-shaped notches. The results of this case study support the application of CVBM for parametric analyses to investigate the role of discontinuities in spalling failure, integrating discrete fracture network (DFN) into the model. The influence of DFN parameters such as dip angle, spacing, persistence, position, and mechanical properties is also evaluated. It was found that discontinuities promote stress relief due to shear, thereby altering spalling damage around the excavation in highly stressed rock. This finding highlights the crucial role of discontinuities in influencing the behavior of excavations under such conditions.

Persistent polarization effects and memory properties in ionic-liquid gated InAs nanowire transistors

Iontronics exploits mobile ions within electrolytes to control the electronic properties of materials and devices' electrical and optical response. In this frame, ionic liquids are widely exploited for the gating of semiconducting nanostructure devices, offering superior performance compared to conventional dielectric gating. In this work, we engineer ionic liquid gated InAs nanowire-based field effect transistors and adopt the set-and-freeze dual gate device operation to probe the nanowires in several ionic gate regimes. We exploit standard back-gating at 150 K, when the ionic liquid is frozen and any crosstalk between the ionic gate and the back gate is ruled out. We demonstrate that the liquid gate polarization has a persistent effect on the nanowire properties. This effect can be conveniently exploited to fine-tune the properties of the nanowires and enable new device functionalities. Specifically, we correlate the modification of the ionic environment around the nanowire to the transistor threshold voltage and hysteresis, on/off ratio and current level retention times. Based on this, we demonstrate memory operations of the nanowire field effect transistors. Our work shines a new light on the interaction between electrolytes and semiconducting nanostructures, providing useful insights for future applications of nanodevice iontronics.

Polybrominated diphenyl ethers in indoor dust from Brazil: assessing demographic differences and human health exposure.

Indoor house dust is considered an important human exposure route to polybrominated diphenyl ethers (PBDEs), which has raised concern about their environmental persistence and toxicity properties. In this study, eight PBDEs (BDE-28, -47, -99, -100, -153, -154, -183, and -209) were determined in house dust from two cities with different socio-demographic characteristics from Brazil, examining possible relationships with factors that potentially influence contamination (population density, economic activities, presence of electronic equipment, and so on) and also estimating the risk of human exposure through oral ingestion and dermal contact. The Σ8PBDE concentration in Sorocaba city ranged between 380 and 4269ng/g dw, while in Itapetininga city ranged from 106 to 1000ng/g dw. In both regions, BDE-209 was the most abundantly found congener, followed by BDE-99. House dust from Sorocaba presented significantly greater concentrations of BDE-183 and BDE-209 than Itapetininga. Regarding risk exposure assessment, the estimated daily intake (EDI) of PBDEs was much lower than their respective reference doses (RfDs) in all pathways estimated (non-dietary ingestion and dermal contact). This study provided valuable data to improve the knowledge about the presence and exposure to PBDEs in Brazilian house dust in comparison to other developing countries and the need to control environmental pollution and protect human health.

Advancing PFAS risk assessment: Integrative approaches using agent-based modelling and physiologically-based kinetic for environmental and health safety

Per- and polyfluoroalkyl substances (PFAS), ubiquitous in a myriad of consumer and industrial products, and depending on the doses of exposure represent a hazard to both environmental and public health, owing to their persistent, mobile, and bio accumulative properties. These substances exhibit long half-lives in humans and can induce potential immunotoxic effects at low exposure levels, sparking growing concerns. While the European Food Safety Authority (EFSA) has assessed the risk to human health related to the presence of PFAS in food, in which a reduced antibody response to vaccination in infants was considered as the most critical human health effect, a comprehensive grasp of the molecular mechanisms spearheading PFAS-induced immunotoxicity is yet to be attained. Leveraging modern computational tools, including the Agent-Based Model (ABM) Universal Immune System Simulator (UISS) and Physiologically Based Kinetic (PBK) models, a deeper insight into the complex mechanisms of PFAS was sought. The adapted UISS serves as a vital tool in chemical risk assessments, simulating the host immune system's reactions to diverse stimuli and monitoring biological entities within specific adverse health contexts. In tandem, PBK models unravelling PFAS' biokinetics within the body i.e. absorption, distribution, metabolism, and elimination, facilitating the development of time-concentration profiles from birth to 75 years at varied dosage levels, thereby enhancing UISS-TOX's predictive abilities. The integrated use of these computational frameworks shows promises in leveraging new scientific evidence to support risk assessments of PFAS. This innovative approach not only allowed to bridge existing data gaps but also unveiled complex mechanisms and the identification of unanticipated dynamics, potentially guiding more informed risk assessments, regulatory decisions, and associated risk mitigations measures for the future.

Semi-time-dependent stabilization results for asynchronously switched systems: An extended persistent dwell time switching strategy involving admissible transition information

This study investigates the stabilization problem for a kind of continuous-time asynchronously switched systems via a set of edge- or mode-dependent state-feedback controllers. To this end, an innovative switching strategy of admissible chain-dependent (or admissible edge-dependent) persistent dwell time property is presented by injecting the admissible transition chain (or admissible transition edge) notion into the existing persistent dwell time concept. Based on the admissible transition edges in a directed graph reported in the literature, the corresponding admissible transition chains can be determined. The individual allocation of transition weights for each admissible transition chain makes the presented admissible chain-dependent persistent dwell time switching less conservative than the other presented admissible edge-dependent persistent dwell time and the already existing mode-dependent persistent dwell time switching. Further, different from the Lyapunov functions commonly used in previous asynchronous stabilization works, a new semi-time-dependent Lyapunov function in a unique form that fits the nature of the discussed systems is suggested to provide a broader family of allowable switching signals. By the introduced switching and Lyapunov function approaches, new stability and stabilization criteria are formulated, through which the expected edge- or mode-dependent state-feedback controllers are devised. At last, the validity and applicability of the obtained stabilization solutions are demonstrated by a numerical example and a practical thermal system.

Polarization‐Sensitive Artificial Optoelectronic Synapse Based on Anisotropic β‐Ga2O3 Single Crystal for Neuromorphic Vision Systems and Information Encryption

AbstractA novel polarization‐sensitive artificial optoelectronic synapse based on β‐Ga2O3 single‐crystal is proposed in this work, featuring reconfigurable anisotropic vision. A series of polarization‐sensitive synaptic activities and polarization‐sensitive image recognition functions are successfully simulated using this device. The intriguing performance of this device, stems from the crystal anisotropy in β‐Ga2O3, which is confirmed through polarization Raman measurements and first‐principles theoretical calculations. Furthermore, a comprehensive analysis of the persistent photoelectric properties of the device unveils that the adaptability of the optoelectronic synapse device stems from the ionization and dissociation of oxygen vacancies. Ultimately, the device is utilized in the fields of image recognition and information encryption. A four‐layer artificial neural network with two hidden layers is constructed for recognizing handwritten digits. After training, the recognition accuracy reaches over 91.5% for both unpolarized and polarized light. Information encryption is achieved by controlling polarization states. The device enables data generation and encryption to be conducted on the same platform, mitigating exposure risks during transmission and significantly enhancing data security and confidentiality. This work presents new opportunities for future applications of polarization‐based perception systems.