Search Results (319)

Traffic in large cities is increasing due to continuous urbanization, the construction of new housing complexes and the accompanying new street network. The growth of cities creates prerequisites for increasing the intensity of transport, pedestrian, and bicycle flows, especially during peak periods. To improve the conditions in which traffic flows, it is necessary to introduce an effective method for reducing delays that arise at intersections, especially those regulated by traffic light systems. One of the possible approaches to this is to coordinate the operation of traffic light systems. The main thing in this is to determine relatively accurate times for the movement of individual flows, for which adequate traffic models are needed. This article presents a model of the movement of transport flows when starting from the first intersection in a coordinated mode of operation of traffic light systems. This is of particular importance when determining the times of individual signals and, above all, has an impact on the moment for switching on the permitting signal at the next intersection. The presented model aims to provide an opportunity to determine accurate times of passage of vehicles through consecutive intersections that operate in a coordinated mode of traffic light systems. Full article

According to previous studies, dynamic light regimes might enhance seedling development, survival rates, or economic efficiency in factory-based seedling production systems compared to continuous red and blue light irradiation. However, there have been few studies revealing the effects of discontinuous red and blue light on the carbohydrate accumulation and metabolism of tomato seedlings. Therefore, we planted tomato seedlings in an artificial light plant factory under a red background light with intermittent blue light intervention, namely R (as the control), R/RB₃₂, R/RB₄₀, R/RB₆₄, and R/RB₈₀ at an equal daily light integral. The growth, carbohydrate accumulation, and sugar metabolism were analyzed to investigate the effects of dynamic lighting modes on tomato seedlings. The results demonstrated the following: (1) Pure red light induced spindling of tomato seedlings, while intermittent blue light treatments enhanced stem thickness, leaf number, and leaf area, resulting in greater biomass accumulation. Among these treatments, the highest antioxidant enzyme activity and the lowest reactive oxygen species (ROS) content, accompanied by the highest biomass, were all observed in tomato seedlings subjected to R/RB₈₀ (intermittent supplementation of 80 μmol·m⁻²·s⁻¹ blue light under red light background). (2) The carbohydrate accumulation in tomato seedlings was increased under all treatments relative to the control. The sucrose content, enzyme activity, and gene expression level of sucrose phosphate synthase (SPS) were all up-regulated in tomato leaves treated with blue light irradiation compared with pure R. In addition, the highest soluble sugar content, along with the peak SPS activity and gene expression, was observed under the R/RB₈₀ treatment. Meanwhile, the lowest fructose content accompanied by the lowest activity and gene expression of sucrose synthase (SS) were observed in tomato leaves treated with R/RB₃₂. This implies that blue light supplementation may regulate sugar accumulation by modulating the activity or expression of enzymes involved in sucrose metabolism. (3) Moreover, shoot biomass, enzyme activity, and expression level of SPS were all found to increase with the increase in supplementary blue light intensity, indicating that short-duration high-intensity blue light was more effective in promoting carbohydrate accumulation in tomato seedlings than long-term low-intensity blue light based on the equal DLI. Full article

Ru/TiO₂ catalysts are well known for their high activity in the hydrogenation of CO₂ to CH₄ (the Sabatier reaction). This activity is commonly attributed to strong metal–support interactions (SMSIs), associated with reducible oxide layers partly covering the Ru-metal particles. Moreover, isothermal rates of formation of CH₄ can be significantly enhanced by the exposure of Ru/TiO₂ to light of UV/visible wavelengths, even at relatively low intensities. In this study, we confirm the significant enhancement in the rate of formation of methane in the conversion of CO₂, e.g., at 200 °C from ~1.2 mol g_Ru⁻¹·h⁻¹ to ~1.8 mol g_Ru⁻¹·h⁻¹ by UV/Vis illumination of a hydrogen-treated Ru/TiO_x catalyst. The activation energy does not change upon illumination—the rate enhancement coincides with a temperature increase of approximately 10 °C in steady state (flow) conditions. In-situ DRIFT experiments, performed in batch mode, demonstrate that the Ru–CO absorption frequency is shifted and the intensity reduced by combined UV/Vis illumination in the temperature range of 200–350 °C, which is more significant than can be explained by temperature enhancement alone. Moreover, exposing the catalyst to either UV (predominantly exciting TiO₂) or visible illumination (exclusively exciting Ru) at small intensities leads to very similar effects on Ru–CO IR intensities, formed in situ by exposure to CO₂. This further confirms that the temperature increase is likely not the only explanation for the enhancement in the reaction rates. Rather, as corroborated by photophysical studies reported in the literature, we propose that illumination induces changes in the electron density of Ru partly covered by a thin layer of TiO_x, lowering the CO coverage, and thus enhancing the methane formation rate upon illumination. Full article

Reducing fertilizer and pesticide use is a crucial path for the green transformation of agricultural production, which has garnered sustained attention in research on sustainable agricultural development. Based on the theoretical analysis, this article analyzes the spatiotemporal evolution characteristics of fertilizer and pesticide usage intensity (FUI and PUI) in the Yangtze River Delta (YRD) over the past 20 years and uses a Two-Way Fixed Effects Model to test their impacts and mechanisms. Findings show that agricultural development in the YRD shows a pattern of specialization and intensification with a significant north–south divide, with zero growth and reduction in fertilizer and pesticide use across the region from 2010 to 2015, but the current FUI and PUI are still nearly three and five times higher than the global average. Over the past 20 years, the FUI is high in the north and low in the south, high in the plains and low in mountainous-hilly areas, and high in suburban areas and low in remote counties. Adversely, the PUI is high in the south and low in the north, high in mountainous-hilly areas and low in plains, and high in suburban areas and low in remote counties. The FUI and PUI of characteristic agricultural areas of fruit, tea, and forestry in southern Anhui and southwestern Zhejiang, as well as the agroecological and facility agriculture clusters in southern Jiangsu and the suburbs of Shanghai, have approached the peak and successfully moved into the new green development stage earlier compared to other areas. In contrast, the grain and oil production plains areas along the Yangtze River, the coast, in northern Anhui, and in northern Jiangsu are relatively lagging behind. The combination of soil, water, light, and heat resource conditions and modes of agriculture production shape the absolute figures of FUI and PUI, and factors such as the level of local economic development and public fiscal expenditure significantly influence the trajectories of spatiotemporal differentiation in the progress of reducing fertilizer and pesticide in the YRD. Full article

Optical properties and chemical composition of atmospheric fine particles (PM_2.5) are critical to their environmental and health effects. In this study, we analyzed the organic aerosols (OA) in PM_2.5 samples in Nanjing, China, collected during the summer and winter of 2019 and 2023. Results show a decline in both concentrations and light-absorbing abilities of methanol—soluble organic carbon (MSOC) and water-soluble OC (WSOC) in OA from 2019 to 2023. Due to increased combustion activities, MSOC and WSOC concentrations, and their corresponding mass absorption efficiencies were all higher in winter than in summer. Furthermore, fluorescence indices suggest that OA in Nanjing was influenced by a mix of microbial/biogenic sources. Fluorescent properties of both WSOC and MSOC were dominated by humic-like components but the remaining contribution from protein-like components was more significant in MSOC. The molecular composition of OA did not show a remarkable difference between 2019 and 2023. Overall, CHON compounds were the most abundant species, followed by CHO and CHN compounds, and aliphatic compounds dominated all molecular types except for CHN (in positive mode) and CHON, CHOS (in negative mode). Regarding the OA sources, the numbers of molecules from fossil fuel combustion and biomass burning (BB) were a bit more in 2023 than in 2019, and signal intensities of BB-related molecules were also higher in winter than in summer; the presence of organosulfates indicate the contribution of aqueous-phase oxidation to OA, especially during high relative humidity conditions. At last, correlations between OA molecules and light absorption efficiencies indicate that the key light-absorbing species in winter and summer were likely quite different despite similar chemical compositions, and in summer, CH and CHN compounds were important to light absorption, whereas CHNS compounds became more important in winter. Full article

Nanoplasmonic structures have emerged as a promising approach to address light trapping limitations in thin-film optoelectronic devices. This study investigates the integration of metallic nanoparticle arrays onto nanocrystalline silicon (nc-Si:H) thin films to enhance optical absorption through plasmonic effects. Using finite-difference time-domain (FDTD) simulations, we systematically optimize key design parameters, including nanoparticle geometry, spacing, metal type (Ag and Al), dielectric spacer material, and absorber layer thickness. The results show that localized surface plasmon resonances (LSPRs) significantly amplify near-field intensities, improve forward scattering, and facilitate coupling into waveguide modes within the active layer. These effects lead to a measurable increase in integrated quantum efficiency, with absorption improvements reaching up to 30% compared to bare nc-Si:H films. The findings establish a reliable design framework for engineering nanoplasmonic architectures that can be applied to enhance performance in photovoltaic devices, photodetectors, and other optoelectronic systems. Full article

Pectin methylesterases (PMEs) and their inhibitors (PMEIs) serve as pivotal enzymes in pectin methylation modifications, playing crucial roles in plant morphogenesis, cell adhesion, and maintenance of the cell wall integrity. However, there have been limited studies exploring the functions of the PME/PMEI gene families in the healing process of grafted-cucumber seedlings and their responses to stress conditions. In this study, we identified 52 CsaPME family members and 33 CsaPMEI family members as well as 86 CmoPME family members and 36 CmoPMEI family members. Comprehensive analyses of the PME/PMEI gene families in cucumber and pumpkin were conducted using bioinformatics techniques. Additionally, the PME/PMEI gene families in cucumber and pumpkin exhibited distinct expression modes in different vegetative organs of homologous/heterologous-grafted seedlings and under chilling stress. Notably, the cucumber/pumpkin-grafted seedlings exhibited responses in the roots and leaves involving PMEI and type I proPME genes, facilitating their adaptation to chilling stress. Additionally, an investigation into the responsiveness of cucumber/pumpkin-grafted seedlings during the healing phase to varying light intensity modes revealed that the implementation of a higher light intensity mode resulted in an upregulation of the expression levels of the majority of PME/PMEI family genes, particularly those belonging to the PME family, during the critical stages of isolation layer and callus formation. Based on these findings, six key PME/PMEI family members responsive to different light intensity modes during graft healing were selected. Through the prediction of transcription factor binding sites and an analysis of the response to different light intensity modes during graft healing, four Dof transcription factors with potential regulatory relationships with these six key PME/PMEI genes were identified. This suggests that cucumber/pumpkin-grafted seedlings can regulate key PME/PMEI genes via Dof factors in response to different light intensity modes during the healing process, thereby influencing the progression of graft healing. Full article

In this paper, the far-field topological structures (FFTSs) of the second harmonic (SH) from higher-order Poincaré sphere (HOPS) beams, including circularly polarized vortex beams (VBs), cylindrically vector beams (CVBs) and elliptically polarized CVBs (EPCVBs), were demonstrated and reported. To begin with, the hidden FFTSs of the SH after propagating the twice Rayleigh range were simulated based on the vectorial coupled wave equations and the Collins formula. Then, the experimental setup was established to achieve the SH from the HOPS by applying two orthogonal 5% MgO: PPLN crystals, the FFTSs of which were demonstrated. The theoretical and experimental results indicate that for the circularly polarized VBs, the FFTSs of the SH still exhibit the 135°-linearly polarized VBs, which is similar to that of the SH in-source plane, because the SH is the eigen-mode of free space, while for the CVBs, the FFTSs of the SH generally show the disappearance of the central dark core, replaced by the maximum light intensity at the center due to the topological phase transition during propagation. Especially of note, for the EPCVBs, the FFTSs of the SH display the maximum light intensity at the center, but the FFTSs in the horizontal and vertical directions reveal rotational symmetry related to the chirality of the EPCVBs. The results reveal the evolution mechanisms of the SH from the HOPS in the far field, which may facilitate the applications of the SH from HOPS beam. Full article

The spatial equality of urban public services and their accessibility are a crucial aspect of urban sustainability. However, there is currently a lack of a composite proxy that can effectively assess public service equality with fine granularity. To address this gap, we have developed a new indicator based on the concept of location dominance. This indicator accumulates access opportunities to public services with a time-weighted decay function at granular level. Our findings reveal that location dominance in Shijiazhuang follows a pronounced core–periphery pattern. Efficient travel modes can significantly enhance location dominance and increase spatial equality, aligning with people’s travel preferences. Additionally, we discovered an extremely strong linear correlation between three key urban development elements (i.e., nighttime lighting data, land use intensity, and population retention rate) and location dominance. The discussion of these findings confirms the validity of our method and the reliability of our results. Consequently, this method and its outputs can aid policymakers and urban planners in swiftly identifying subtle disparities in spatial accessibility for public services, thereby promoting urban equality and sustainability. Full article

Constructing van der Waals heterojunctions with excellent properties has attracted considerable attention in the field of photocatalytic water splitting. In this study, four patterns, coined A, B, C, and D of Janus Ga₂SSe/Bi₂O₃ van der Waals (vdW) heterojunctions with different stacking modes, were investigated using first-principles calculations. Their stability, electronic structure, and optical properties were analyzed in detail. Among these, patterns A and C heterojunctions demonstrate stable behavior and operate as direct Z-scheme photocatalysts, exhibiting band gaps of 1.83 eV and 1.62 eV. In addition, the suitable band edge positions make them effective for photocatalytic water decomposition. The built-in electric field across the heterojunction interface effectively inhibits electron-hole recombination, thereby improving the photocatalytic efficiency. The optical absorption coefficients show that patterns A and C heterojunctions exhibit higher light absorption intensity than Ga₂SSe and Bi₂O₃ monolayers, spanning from the ultraviolet to visible range. Their corrected solar-to-hydrogen (STH) efficiencies are 13.60% and 12.08%, respectively. The application of hydrostatic pressure and biaxial tensile strain demonstrate distinct effects on photocatalytic performance: hydrostatic pressure preferentially enhances the hydrogen evolution reaction (HER), while biaxial tensile strain primarily improves the oxygen evolution reaction (OER). Furthermore, the heterojunctions exhibited enhanced optical absorption across the UV-visible spectrum with increasing hydrostatic pressure. Notably, a 1% tensile strain results in an improvement in visible light absorption efficiency. These results demonstrate that Ga₂SSe/Bi₂O₃ heterojunctions hold great promise as direct Z-scheme photocatalysts for overall water splitting. Full article

Recent advancements in metal/perovskite photodetectors have leveraged plasmonic effects to enhance the efficiency of photogenerated carrier separation. In this work, we present an innovative approach to designing heterostructure photodetectors that involved integrating a perovskite film with a plasmonic metasurface. Using finite-difference time-domain (FDTD) simulations, we investigated the formation of hybrid photonic–plasmonic modes and examined their quality factors in relation to loss mechanisms. Our results demonstrate that these hybrid modes facilitated strong light confinement within the perovskite layer, with significant intensity enhancement at the metal–perovskite interface—an ideal condition for efficient charge carrier generation. We also propose the use of low-bandgap perovskites for direct infrared passive detection and explore the potential of highly Stokes-shifted perovskites for active detection applications, including ultraviolet and X-ray radiation. Full article

The interaction of a Gaussian vortex beam (GVB) with metamaterials during its propagation is of significant interest to the optical community. These GVBs are classified as structured light beams that possess orbital angular momentum (OAM). Understanding the behavior of structured light beams is essential for clarifying fundamental interaction mechanisms with metamaterial structures. So, this work delves into the investigation of the propagation characteristics of a GVB within a chiral material. The analytical expressions for GVB propagating through a chiral medium are obtained by using the extended Huygens–Fresnel diffraction integral formula and the optical ABCD matrix system. In a chiral medium, GVB exhibits a tendency to fragment into a left circularly polarized (LCP) beam and a right circularly polarized (RCP) beam, each following its unique propagation paths. The beam intensity and gradient force are computed and discussed for OAM mode number, beam waist radius, and chirality parameter. This research will be quite helpful for light manipulation, optical sorting, optical radiation force, the radiative transfer process, and optical guiding. Full article

This paper pursues a phenomenological investigation of the nature of absorbed listening in Western, classical music concert audiences. This investigation is based on a data-set of 16 in-depth phenomenological interviews with audience members from three classical concerts with the Stavanger Symphony Orchestra and the Norwegian Radio Orchestra conducted in spring 2024. We identify seven major themes, namely “sharedness”, “attention”, “spontaneous thought/mental imagery”, “modes of listening” “absorption”, “distraction”, and “strong emotional experiences”, and interpret these in light of relevant ideas in phenomenology, cognitive psychology, and ecological aesthetics, more precisely “passive synthesis” from Husserl, the “sense of agency” from Gallagher, and “mind surfing” from Høffding, Nielsen, and Laeng. We show that, like absorbed musical performance, absorbed musical listening comes in many shapes and can be grasped as instantiating variations of passive synthesis, the sense of agency, and mind surfing. We conclude that absorbed listening circles around a kind of paradox of passivity, characterised by a sense of loss of egoic control arising from particular forms of invested, intensive perceptual, cognitive, and affective engagement. Full article

In this study, silver nanoparticles (Ag NPs) were synthesized on the surface of rutile-phase titanium dioxide (R-TiO₂) using a plasma-assisted technique. Comprehensive analyses were conducted to investigate the structural, morphological, optical, and electrical properties of the synthesized nanocomposites. Transmission electron microscopy (TEM) images revealed the uniform decoration of Ag NPs (average size: 29.8 nm) on the R-TiO₂ surface. X-ray diffraction (XRD) confirmed the polycrystalline nature of the samples, with decreased diffraction peak intensity indicating reduced crystallinity due to Ag decoration. The Williamson–Hall analysis showed increased crystallite size and reduced tensile strain, suggesting grain growth and stress relief. Raman spectroscopy revealed quenching and broadening of R-TiO₂ vibrational modes, likely due to increased oxygen vacancies. X-ray photoelectron spectroscopy (XPS) confirmed successful plasma-assisted deposition and the coexistence of Ag⁰ and Ag⁺ states, enhancing surface reactivity. UV-Vis spectroscopy demonstrated enhanced light absorption across the spectral range, attributed to localized surface plasmon resonance (LSPR), and a reduced optical bandgap. Dielectric properties, including dielectric constants, loss factor, and AC conductivity, were evaluated across frequencies (4–8 MHz) and temperatures (20–240 °C). The AC conductivity results indicated correlated barrier hopping (CBH) and overlapping large polaron tunneling (OLPT) as the primary conduction mechanisms. Composition-dependent dielectric behavior was interpreted through the Coulomb blockade effect. These findings suggest the potential of plasma assisted Ag NP-decorated R-TiO₂ nanostructures for photocatalysis, sensor and specific electro electrochemical systems applications. Full article

Vehicle acceleration typically occurs at traffic lights, intersections, or congested sections within urban streets, where high densities of pedestrians and vehicles pose a direct threat to respiratory health due to PM_2.5 dispersion. Computational Fluid Dynamics (CFD) simulations, combined with the Dynamic Mode Decomposition (DMD) method, are used to analyze the dynamic characteristics of PM_2.5 dispersion during vehicle acceleration. The DMD method can effectively analyze the dynamic change in pollutant concentration in an unsteady flow field and clarify the influence mechanism of vehicle acceleration on pollutant dispersion. The results indicate that PM_2.5 dispersion during the initial stage of acceleration is primarily influenced by low-frequency and large-scale flows, such as exhaust emissions, natural wind, and trailing vortices. In the middle stage, PM_2.5 dispersion tends to stabilize, while in the final stage, high-frequency modes dominate, and intense flow field fluctuations significantly enhance PM_2.5 dispersion. Furthermore, the analysis reveals the critical role of upward and downward airflow phenomena around the vehicle in driving PM_2.5 dispersion. This study offers a new perspective on the dispersion characteristics of PM_2.5 under unsteady flow conditions in urban streets and provides a scientific basis for developing speed management strategies to mitigate the impact of pollutant dispersion. Full article