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Interfacial reactions of hydride- and halide-containing argyrodite solid electrolytes with Li metal anode in all-solid-state batteries
No full textAll-solid-state batteries (ASSBs) using solid electrolytes and lithium metal anodes have garnered significant attention as next-generation batteries due to their potential for achieving high energy density and improved safety. Among various solid electrolytes, argyrodite-type sulfide-based electrolytes have emerged as promising candidates. Recent studies have focused on enhancing ionic conductivity at room temperature by substituting free S2− anions with alternative anions. However, argyrodite electrolytes still face challenges related to interfacial incompatibility with lithium metal anodes. In this study, we investigate the interfacial phenomena of hydride- and halide-containing argyrodite solid electrolytes with Li metal anode under low potentials. The results reveal contrasting interfacial stability for the two electrolytes. Li6PS5Cl exhibited significant interfacial instability with lithium metal, as evidenced by dendrite growth during cycling and continuous P-S bond decomposition upon contact. In contrast, Li5PS4(BH4)2 demonstrated stable interfacial behavior, with reversible and uniform lithium ion deposition and dissolution. Despite initial P-S bond decomposition, a stable interfacial phase was formed, ensuring consistent cycling performance. Based on these insights, consistent results were observed in lithium metal all-solid-state batteries fabricated with TiS2. These findings provide valuable insights into the interfacial behavior of argyrodite-type solid electrolytes and the design of anion-substituted solid electrolytes to improve lithium metal compatibility. This study underscores the importance of understanding interfacial phenomena to achieve enhanced electrochemical performance and reliability in next-generation lithium metal batteries.MasterI. Introduction
II. Experimental
2.1. Synthesis of solid electrolytes
2.2. Characterization
2.3. Ionic conductivity measurement
2.4. Cell assembly and electrochemical test
Ⅲ. Results and discussion
3.1. Structural characterization and ionic conductivity of solid electrolytes
3.1.1. Structure analysis of solid electrolytes
3.1.2. Lithium ion conductivity
3.2. Electrochemical stability test
3.2.1. Cyclic voltammetry
3.2.2. Lithium plating/stripping test
3.3. Chemical stability test
3.3.1. Electrochemical impedance spectroscopy
3.3.2. X-ray photoelectron spectroscopy
3.4. All-solid-state TiS2-Li batteries
Ⅳ. Conclusion
Ⅴ. Reference
Thermal protection of wearable devices under outdoor conditions using radiative cooling films
No full textWearable electronic devices operating outdoors are vulnerable to overheating under prolonged exposure to intense solar radiation and elevated ambient temperatures. Such thermal stress compromises device performance, inducing functional failure, and poses safety risks such as skin burns. Therefore, we developed a passive radiative cooling film (RCF) providing energy-free thermal management for wearable electronics. The RCF, fabricated via electrospinning of a polyvinyl alcohol matrix embedded with silicon dioxide (SiO2) and aluminum oxide (Al2O3) nanoparticles, exhibits optimized optical properties, including a high average solar reflectance of 0.88 (0.3-2.5 mu m) and thermal emissivity of 0.95 in the atmospheric window (8-13 mu m). These properties enable effective radiative heat dissipation and reduce the solar heat gain. Under high-temperature outdoor conditions, RCF-integrated wearable sensors maintained an average surface temperature of 42.5 degrees C, which was up to 8.6 degrees C lower than that of sensors without the film, ensuring stable operation without thermal failure. Additionally, the RCF effectively mitigated thermal accumulation in smartphone batteries, reducing peak surface temperature from 60.0 degrees C to 37.1 degrees C under direct sunlight. These results demonstrate the potential of the RCF as a scalable and energy-efficient solution for enhancing thermal reliability and user safety of next-generation wearable outdoor electronic devices.sciescopu
Performance Improvement and Overcurrent Limiting of a Grid-Forming Inverter with Two Electromotive Forces
No full textModern power systems are undergoing a significant transition with the increasing integration of inverter-based resources (IBRs). However, many challenges related to power system control and stability arise in the IBR-dominated power grid. Unlike traditional synchronous generators, conventional IBRs cannot provide inertial responses, resulting in more severe fluctuations in grid frequency. Additionally, low grid strength causes control instability issues, as IBRs are often connected to weak parts of the grid. In weak grid conditions, the sensitivity of the voltage at the point of connection (PoC) to the output current of IBRs is high, leading to reduced stability of conventional grid-following (GFL) control. To address these issues, grid-forming (GFM) control has emerged as a promising alternative to conventional GFL control. However, since GFM inverters are primarily designed for the responses to grid disturbances, their regulation performance according to the input references is compromised. In addition, GFM inverters can exhibit low damping characteristics depending on grid conditions and are vulnerable to overcurrent issues during large disturbances caused by grid faults. To overcome the limitations of GFM inverters, this dissertation proposes a method to enhance the performance of GFM inverters and limit overcurrent by utilizing a virtually emulated circuit structure with two electromotive forces (EMFs) connected in parallel. Fundamental control laws with active disturbance rejection control are developed to implement the control structure, which includes two EMFs produced by independent control algorithms in a single inverter. Each EMF operates as a voltage source and a current source, respectively. As a result, the proposed control structure represents a hybrid approach that integrates GFM and GFL functionalities into a single inverter. The dissertation is organized into three main parts. First, the control structure of the previously proposed method utilizing two EMFs, so-called current-referencing electrified synchronous machine (CURESYM), is reinterpreted based on the proposed parallel control structure. Through this reinterpretation, the conventional CURESYM is revised to a more straightforward structure, and its hybrid responses are clearly described. Second, a virtual impedance implementation method utilizing a disturbance observer (DOB), which has been adopted for improved control accuracy, is introduced. The DOB-based virtual impedance provides a more simple and robust approach to virtual impedance realization. Through a detailed analysis of the effects of virtual impedance applications, the usefulness of high output impedance in enhancing system damping is validated. Finally, a novel overcurrent limiting strategy for the GFM inverter based on the parallel EMF structure is proposed. The mechanism of the proposed method is highly intuitive and straightforward. Furthermore, the proposed method can preserve the original GFM responses as much as possible. The overall performances of the proposed methods are evaluated through simulations utilizing a practical 250 kVA inverter model and experimental results with a scaled-down inverter prototype.DoctorAbstract ............ i
Contents ............ ii
List of Tables ............ iv
List of Figures ............ v
Chapter 1. Introduction ............ 1
1. 1. Background ............ 1
1. 2. Research Objectives ............ 6
1. 3. Dissertation Outline ............ 8
Chapter 2. Parallel control structure with two EMFs ............ 9
2. 1. Introduction ............ 9
2. 1. 1. System description ............ 9
2. 1. 2. Conventional CURESYM ............ 11
2. 2. Revised CURESYM based on the parallel connection of two EMFs ............ 12
2. 2. 1. Fundamental control laws ............ 13
2. 2. 2. Virtual current regulator ............ 16
2. 2. 3. Virtual synchronous condenser ............ 18
2. 2. 4. Disturbance observer ............ 25
2. 3. Simulation results ............ 29
2. 3. 1. Active power control responses ............ 30
2. 3. 2. Frequency droop control ............ 34
2. 3. 3. Voltage droop control ............ 34
2. 4. Summary ............ 38
Chapter 3. DOB-Based Virtual Impedance ............ 39
3. 1. Necessity of virtual impedance ............ 39
3. 2. Conventional virtual impedance ............ 44
3. 3. DOB-based virtual impedance ............ 48
3. 4. Effects of high virtual impedance ............ 52
3. 5. Summary ............ 55
Chapter 4. Overcurrent Limiting in CURESYM ............ 56
4. 1. Introduction ............ 56
4. 2. Overcurrent situations in CURESYM ............ 57
4. 3. Virtual current regulator-aided overcurrent limiting ............ 59
4. 4. Simulation results ............ 62
4. 5. Summary ............ 68
Chapter 5. Experimental Results ............ 69
5. 1. Experimental setup ............ 69
5. 2. Experimental results ............ 71
5. 2. 1. Active power control responses ............ 71
5. 2. 2. Frequency droop control ............ 74
5. 2. 3. Voltage droop control ............ 74
5. 2. 4. Impedance reshaping ............ 77
5. 2. 5. Overcurrent limiting ............ 78
5. 3. Summary ............ 78
6. Conclusion ............ 81
6. 1. Summary ............ 81
6. 2. Future Works ............ 82
Bibliography ............ 83
Acknowledgement
Curriculum Vita
Identification of Functional Brain Dynamics Based on Structural Connectivity Constrained Functional Time Series
No full textSpontaneous brain activity involves temporally fluctuating dynamic patterns across anatomically connected regions, yet conventional resting-state functional connectivity (FC) analyses based on blood oxygen level-dependent (BOLD) signals typically neglect underlying anatomical structure, when investigating temporal dynamics. To address this limitation, we propose a novel structural connectivity constrained BOLD (SCC-BOLD) framework that integrates anatomical pathways into functional time series estimation. Specifically, we use a graph-constrained regression model to estimate SCC-BOLD signals that explicitly reflect structural connectivity (SC). We then compute the SCC-BOLD-based time lag (STL) matrix and compare it with the intrinsic neural timescale (INT) to evaluate its biological plausibility. Using data from 982 participants in the Human Connectome Project database, we observe that the SCC-BOLD and original BOLD signals show similar but distinct patterns (r=0.625±0.108). The mean inter-regional time delay across the brain, based on the SCC-BOLD, is 2.25s, significantly shorter than the 38.38s observed with the BOLD. Moreover, the correlation between STL and INT (r=0.429) outperforms that of the BOLD-based TL (r=0.333), indicating the improved biological plausibility of the proposed framework. Our results suggest that explicitly incorporating structural constraints into resting-state functional magnetic resonance imaging provides a principled approach for understanding the temporal architecture of brain function. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2026
Analysis of Pixel Noise in Dynamic Vision Sensors
No full textTo date, pixel noise in a dynamic vision sensor (DVS) has not been accurately analyzed in the literature, and its optimization has been performed empirically. This paper presents a theoretical analysis of the DVS pixel noise. The mean-squared noise voltage at the pixel output from each noise source in a pixel is mathematically derived and verified based on simulations and measurements. A design method to determine the pixel bias currents for a given photocurrent is also presented based on the noise analysis to improve noise performance while maintaining pixel latency. A prototype DVS chip was fabricated in a 110 nm complementary metal-oxide-semiconductor image sensor process and tested under various light and pixel bias conditions. It is shown that the proposed noise analysis and design method successfully predicted the noise performance of the DVS chip. © 2025 IEEE. All rights reserved,FALSEsciescopu
Corrigendum to “Facile one-pot solvothermal synthesis of enlarged mesoporous nickel phyllosilicate spherical catalyst for CO2 methanation” [J. Alloy. Compd. 1029 (2025) 180743] (Journal of Alloys and Compounds (2025) 1029, (S0925838825023047), (10.1016/j.jallcom.2025.180743))
No full textThe authors regret “Inset of Fig. 7 (d) “Phyllosilicate 2θ = 37°, 43°, 62°” should be replaced by “Phyllosilicate 2θ = 20°, 34°, 61°””. The authors would like to apologise for any inconvenience caused. The revised Fig. 7 is attached as below: [Figure presented] © 2025 Elsevier B.V.FALSEsciescopu
High glucose induces FABP3-mediated membrane rigidity via downregulation of SIRT1
No full textHigh glucose induces an atypical lipid composition in skeletal muscle, leading to loss of muscle mass and strength. However, the mechanisms underlying this glucose toxicity are not fully understood. Analysis of genes associated with a phenotype using the BXD phenome resource revealed that increased Fabp3 expression in skeletal muscle correlated with hyperglycemia. FABP3 expression was also increased in hyperglycemic mouse models such as leptin-deficient ob/ob, Ins2Akita, and high-fat fed mice, as well as in aged mice. In cultured myotubes, high glucose elevated the mRNA and protein levels of FABP3, which contributes to decreased membrane fluidity, along with other mechanisms. FABP3 expression was dependent on the NAD+/NADH ratio and SIRT1 activity, suggesting a mechanism by which FABP3 is upregulated in hyperglycemic conditions. Our findings propose that FABP3 links hyperglycemia to atypical membrane physicochemical properties, which may weaken contractile and metabolic function, particularly in skeletal muscle. © 2024FALSEsciescopu
Ultraviolet photodetectors based on non-stoichiometric amorphous Ga2O3−δ thin films deposited by radio-frequency powder sputtering
No full textWe report the performance of ultraviolet (UV) photodetectors based on non-stoichiometric amorphous Ga2O3−δ thin films deposited using the radio-frequency powder sputtering method. At a substrate temperature of 25 °C, the Ga2O3−δ film grew with an amorphous phase on a sapphire (0001) substrate. Hard X-ray photoelectron spectroscopy analysis revealed that the chemical composition of the as-deposited thin film was highly non-stoichiometric owing to the oxygen deficiency associated with sub-oxide Ga2O and metallic Ga species. Metal–semiconductor–metal photodetectors were fabricated, and their photoresponse properties under UV exposure were investigated. The photo-to-dark current ratio was estimated to be 2.91 × 105. The photoresponsivity and specific detectivity were calculated to be ∼29.54 A/W and 8.95 × 1014 Jones, respectively, at an applied bias of 10 V and a wavelength of 250 nm. Our results indicate that non-stoichiometric amorphous Ga2O3−δ thin films with thicknesses less than 100 nm are suitable for the fabrication of solar-blind photodetectors with self-powered characteristics. © 2025 Elsevier B.V., All rights reserved.FALSEsciescopu
Untargeted Analysis of Plastic Additives in Organic and Aqueous Extracts of Road Marking Paint Microplastics for Screening of Leachable Toxicants
No full textThe structure of liquid carbon elucidated by in situ X-ray diffraction
No full textAbstract
Carbon has a central role in biology and organic chemistry, and its solid allotropes provide the basis of much of our modern technology1. However, the liquid form of carbon remains nearly uncharted2, and the structure of liquid carbon and most of its physical properties are essentially unknown3. But liquid carbon is relevant for modelling planetary interiors4,5 and the atmospheres of white dwarfs6, as an intermediate state for the synthesis of advanced carbon materials7,8, inertial confinement fusion implosions9, hypervelocity impact events on carbon materials10 and our general understanding of structured fluids at extreme conditions11. Here we present a precise structure measurement of liquid carbon at pressures of around 1 million atmospheres obtained by in situ X-ray diffraction at an X-ray free-electron laser. Our results show a complex fluid with transient bonding and approximately four nearest neighbours on average, in agreement with quantum molecular dynamics simulations. The obtained data substantiate the understanding of the liquid state of one of the most abundant elements in the universe and can test models of the melting line. The demonstrated experimental abilities open the path to performing similar studies of the structure of liquids composed of light elements at extreme conditions.TRUEsciescopu