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ZnO/g-C3N4 heterojunction modified with Ag nanoparticles (ZnO/CN/Ag) was synthesized by depositing ZnO nanorods/Ag nanoparticles onto g-C3N4 nanosheets. Under xenon lamp irradiation, 99% of Rhodamine B (RhB) was degraded by ZnO/CN/Ag-5% composite within 30 min, which was much higher than the degradation efficiency of ZnO and ZnO/CN. The synergistic effect of g-C3N4 and ZnO, along with the localized surface plasmon resonance effect of Ag NPs, contributes to the improvement of photocatalytic performance. Ag nanoparticle provides another charge transfer path from g-C3N4 to ZnO, which speeds up the separation of electron–hole pairs. Meanwhile, the catalyst had good stability and recyclability. Finite-difference time-domain method and the density functional theory were used to obtain the charge transfer process. The photodegradation process has been studied in depth. [ABSTRACT FROM AUTHOR]

In response to the increasing traffic noise problem, we designed a combined acoustic metamaterial (CAM) based on the multi-channel Fano resonance principle. By utilizing the Fano resonance coupling between the acoustic spiral structure and the hollow structure, efficient sound insulation under effective ventilation conditions is achieved. Simulation results of acoustic transmission loss show that the acoustic transmission loss of CAM is more than 13 dB in the frequency band of 520–989 Hz. The broadband sound insulation characteristic can block the oblique angle incident sound waves from different angles. Simulation results of the elastic strain energy and acoustic pressure field validate the sound insulation mechanism of the Fano resonance of the combined acoustic metamaterial. The experimental results in the impedance tube generally agree with the simulation results. To explore the possibility of wider engineering applications of CAM, we propose a combined CAM and CAM0.7 structure. The results show that a series structure of acoustic metamaterials can be selected to further realize broadband sound insulation within 500–1574 Hz. [ABSTRACT FROM AUTHOR]

The angular dependence of the indirect short‐range spin‐spin coupling constants (SSCC), the geminal J(C3,C1′)$$ J\left({C}_3,{C}_{1^{\prime }}\right) $$, J(O1,O)$$ J\left({O}_1,O\right) $$, and J(O,C1′)$$ J\left(O,{C}_{1^{\prime }}\right) $$ in A‐type dimeric proanthocyanidin, was investigated using density functional theory. We studied the rotation of ring B around the C2–C1′$$ {C}_2\hbox{--} {C}_{1^{\prime }} $$ bond. Therefore, we calculated hyperconjugative charge transfers and bond polarizations within the natural bond orbital (NBO) approach, performing a topological study based on Bader's theory, AIM (atoms in molecules), and analyzing the angular dependence of AIM/NBO parameters. The results describe a relationship between the geminal coupling that changes with angular variation and NBO charge transfers to the bonds involved in the coupling pathways that can explain the behavior of the former property. Based on AIM/NBO data, inductive and mesomeric effects were described and quantified, showing a clear correlation with the stabilization of the structure, demonstrating a resonance‐assisted inductive effect. We also set out strong hyperconjugative interactions (anomeric effect) involving nonbonding electron pairs of oxygen atoms. This analysis of coupling constants supports previous models by other authors and shows the application in this particular case. Moreover, the SSCCs studied herein are used for identifying stable structures and conformational search analysis of flavonoids. Finally, our results show the relationship between SSCCs and the structure stabilization and charge delocalization effects. [ABSTRACT FROM AUTHOR]

Microfluidics made of dimethylpolysiloxane were developed for chemical synthesis using microwave heating at 24.125 GHz, and microwave efficiency was enhanced by the microwave resonance effect. In addition, the device was fabricated using a mold created using a 3D printer to reduce production costs. The microchip structure comprised a post‐wall waveguide and a microchannel that passed through the waveguide. This post‐wall waveguide also comprises metal columns (post‐wall) instead of a conductor side wall, and easily introduces microchannels through the gaps between the metal columns. The waveguide length was adjusted to achieve a resonance frequency of 24 GHz using an electromagnetic wave simulation, assuming that the microchannel was filled with pure water. Microwaves with an input power of 4 W caused a maximum temperature increase of 93 °C; this result is ~10 °C higher than that of a microchip with non‐resonant structure. In this study, Ag nanoparticles were synthesized using a chemical reaction induced by microwave irradiation of a chip flow system. Owing to irradiating the mixing reagent with microwaves of an input power of 4 W while controlling the flow rate at 0.7 μl/min, the formation of Ag nanoparticles with an average particle size of ~19.2 ± 2.4 nm was demonstrated by absorbance measurements and dynamic light scattering. It is expected that microwave microfluidics enhanced by the resonance effect will substantialize nanoparticle synthesis and high‐efficiency automated chemical synthesis combined with multichemical unit operations. © 2024 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

There are great demands of developing ultra‐narrow bandgap electron acceptors for multifunctional electronic devices, particularly semi‐transparent organic photovoltaics (OPVs) for building‐integrated applications. However, current ultra‐narrow bandgap materials applied in OPVs, primarily based on electron‐rich cores, exhibit defects of high‐lying energy levels and inferior performance. We herein proposed a novel strategy by designing the benzothiazole‐fused cyanoindone (BTC) unit with ultra‐strong electron‐withdrawing ability as the terminal to synthesize the acceptor BTC‐2. The BTC unit imparts red‐shifted absorption up to 1000 nm to BTC‐2, attributed to enhanced intramolecular charge transfer and the quinoid resonance effect. Additionally, BTC‐2 features deep‐lying energy levels with the highest occupied molecular orbital level of −5.81 eV, due to the ultra‐strong electron‐withdrawing ability of BTC. Furthermore, BTC‐2 exhibits long‐range ordering in both molecular packing and macroscopic blend morphology, resulting from shoulder‐to‐shoulder packing of two BTC units, leading to an ultra‐long exciton lifetime over 1.1 ns. These superiorities facilitated a 17.17 % efficiency in the binary OPV device with an extremely high photocurrent of 30.34 mA cm−2, representing the best performance for ultra‐narrow bandgap electron acceptors, and a record light utilization efficiency of 4.88 % in binary semi‐transparent systems. Overall, BTC is a superior building block for designing ultra‐narrow bandgap electron acceptors. [ABSTRACT FROM AUTHOR]

Constructing highly efficient catalysts for the degradation of organic pollutants driven by solar light in aquatic environments is a promising and green strategy. In this study, a novel hexagonal sheet-like Pt/SnS2 heterojunction photocatalyst is successfully designed and fabricated using a hydrothermal method and photodeposition process for photocatalytic tetracycline (TC) degradation. The optimal Pt/SnS2 hybrid behaves with excellent photocatalytic performance, with a degradation efficiency of 91.27% after 120 min, a reaction rate constant of 0.0187 min−1, and durability, which can be attributed to (i) the formation of a metal/semiconductor interface field caused by loading Pt nanoparticles (NPs) on the surface of SnS2, facilitating the separation of photo-induced charge carriers; (ii) the local surface plasmon resonance (LSPR) effect of Pt NPs, extending the light absorption range; and (iii) the sheet-like structure of SnS2, which can shorten the transmission distance of charge carriers, thereby allowing more electrons (e−) and holes (h+) to transfer to the surface of the catalyst. This work provides new insights with the utilization of sheet-like structured materials for highly active photocatalytic TC degradation in wastewater treatment and environmental remediation. [ABSTRACT FROM AUTHOR]

[Display omitted] The present paper reports the fabrication of novel types of hybrid fibrous photocatalysts by combining block copolymer (BCP) templating, sol–gel processing, and coaxial electrospinning techniques. Coaxial electrospinning produces core–shell nanofibers (NFs), which are converted into hollow porous TiO 2 NFs using an oxidative calcination step. Hybrid BCP micelles comprising a single plasmonic nanoparticle (NP) in their core and thereof derived silica-coated core–shell particles are utilized as precursors to generate yolk-shell type particulate inclusions in photocatalytically active NFs. The catalytic and photocatalytic activity of calcined NFs comprising different types of yolk-shell particles is systematically investigated and compared. Interestingly, calcined NFs comprising silica-coated yolk-shells demonstrate enhanced catalytic and photocatalytic performance despite the presence of silica shell separating plasmonic NP from the TiO 2 matrix. Electromagnetic simulations indicate that this enhancement is caused by a localized surface plasmon resonance and a confinement effect in silica-coated yolk-shells embedded in porous TiO 2 NFs. Utilization of the coaxially electrospun TiO 2 NFs in combination with yolk-shells comprising plasmonic NPs reveals to be a potent method for the photocatalytic decomposition of numerous pollutants. It is worth noting that this study stands as the first occurrence of combining yolk-shells (Au@void@SiO 2) with porous electrospun NFs (TiO 2) for photocatalytic purposes and gaining an understanding of plasmon and confinement effects for photocatalytic performance. This approach represents a promising route for fabricating highly active and up-scalable fibrous photocatalytic systems. [ABSTRACT FROM AUTHOR]

The limited yield of H2 production has posed a significant challenge in contemporary research. To address this issue, researchers have turned to the application of surface plasmon resonance (SPR) materials in photocatalytic H2 generation. SPR, arising from collective electron oscillations, enhances light absorption and facilitates efficient separation and transfer of electron‐hole pairs in semiconductor systems, thereby boosting photocatalytic H2 production efficiency. However, existing reviews predominantly focus on SPR noble metals, neglecting non‐noble metals and SPR semiconductors. In this review, we begin by elucidating five different SPR mechanisms, covering hot electron injection, electric field enhancement, light scattering, plasmon‐induced resonant energy transfer, and photo‐thermionic effect, by which SPR enhances photocatalytic activity. Subsequently, a comprehensive overview follows, detailing the application of SPR materials‐metals, non‐noble metals, and SPR semiconductors‐in photocatalytic H2 production. Additionally, a personal perspective is offered on developing highly efficient SPR‐based photocatalysis systems for solar‐to‐H2 conversion in the future. This review aims to guide the development of next‐gen SPR‐based materials for advancing solar‐to‐fuel conversion. [ABSTRACT FROM AUTHOR]

We consider an abstract linear wave equation with a time-dependent dissipation that decays at infinity with the so-called scale invariant rate, which represents the critical case. We do not assume that the coefficient of the dissipation term is smooth, and we investigate the effect of its oscillations on the decay rate of solutions. We prove a decay estimate that holds true regardless of the oscillations. Then we show that oscillations that are too fast have no effect on the decay rate, while oscillations that are in resonance with one of the frequencies of the elastic part can alter the decay rate. In the proof we first reduce ourselves to estimating the decay of solutions to a family of ordinary differential equations, then by using polar coordinates we obtain explicit formulae for the energy decay of these solutions, so that in the end the problem is reduced to the analysis of the asymptotic behavior of suitable oscillating integrals. [ABSTRACT FROM AUTHOR]

This work presents a novel study on the water-splitting behavior of organic curcumin (C), based on its photoelectrochemical activity. The photodynamics and the kinetics, transfer mechanism, and generation of charges are evaluated for organic curcumin in 0.1 M NaOH electrolyte under visible irradiation. A charge-transfer resistance of 30.03 Ω and induced photocurrent density of 0.9 mA cm−2 are achieved from curcumin nanosheets. The metal-sandwich effect on the kinetics, transfer mechanism, current generation, and potentiodynamics of organic curcumin is explored with Au/C, C/Au, and Au/C/Au photoelectrodes. The Au/C/Au photoelectrodes exhibit extraordinary enhancements in the kinetics, transfer mechanism, current generation, and potentiodynamics, owing to the surface plasmon resonance effect of Au. The Au/C/Au photoelectrode exhibits the lowest charge-transfer resistance of 8.18 Ω and the highest photocurrent density of 3.5 mAcm−2, among the electrodes considered in this work. The obtained photocurrent density of Au/C/Au is 3.9 times higher than that of the pristine organic curcumin photoelectrode. Hence, organic curcumin can be utilized for photoelectrochemical water splitting, instead of the toxic chemicals used in the synthesis of photoelectrodes. [ABSTRACT FROM AUTHOR]

Multi‐electron involved photoreduction of CO2 to hydrocarbon fuels is a long‐standing challenge, particularly in manipulating the selectivity of the target products. Here, a novel Ag–Pt bimetallic alloy on Zn‐based supports by photo‐deposition is designed for photocatalytic CO2 reduction to CH4 without any additives. This photocatalyst exhibits ≈ 98.9% selectivity for CH4. Experimental and theoretical calculations demonstrated that the excellent performance of the photocatalyst can be attributed to the localized surface plasmon resonance effect of metals, as well as the synergistic effects of the bimetallic sites. These factors are found to be beneficial not only for capturing solar radiation and facilitating electron migration but also for promoting the adsorption and activation of CO2 and the protonation of *CO. As a result, the photocatalyst achieved high selectivity and activity of photoreduction of CO2 to CH4. This work provides insights into the design of photocatalysts with highly selective target products for CO2 reduction. [ABSTRACT FROM AUTHOR]

Lateral flow assay (LFA) systems use metal nanoparticles for rapid and convenient target detection and are extensively studied for the diagnostics of various diseases. Gold nanoparticles (AuNPs) are often used as probes in LFAs, displaying a single red color. However, there is a high demand for colorimetric LFAs to detect multiple biomarkers, requiring the use of multicolored NPs. Here, we present a highly sensitive multiplexed colorimetric lateral flow immunoassay by multicolored Plasmon-controlled metal–silica Isoform Nanocomposites (PINs). We utilized the localized surface plasmon resonance effect to create multi-colored PINs by precisely adjusting the distance between the NPs on the surface of PINs through the controlled addition of reduced gold and silver precursors. Through simulations, we also confirmed that the distance between nanoparticles on the surface of PINs significantly affects the color and colorimetric signal intensity of the PINs. We achieved multicolored PINs that exhibit stronger colorimetric signals, offering a new solution for LFA detection with high sensitivity and a 33 times reduced limit of detection (LOD) while maintaining consistent size deviations within 5%. We expect that our PINs-based colorimetric LFA will facilitate the sensitive and simultaneous detection of multiple biomarkers in point-of-care testing. [ABSTRACT FROM AUTHOR]

Plasmon-induced photocatalysis showed great potential to improve the photocatalytic nitrogen fixation efficiency, due to the localized surface plasmon resonance effect. The performances of the photocatalytic nitrogen fixation were evaluated by ammonia production rate, apparent quantum efficiency, solar-to-ammonia efficiency, and turnover frequency. The ammonia production rate was compared with three kinds of catalyst, i.e. nano-metals, nano-metal modified semiconductors and highly doped semiconductors. The outstanding contributions of hot electron injection effect, near-field enhancement effect, photothermal effect to nitrogen fixation efficiency were described. The creation of active sites, construct vacancies, and doping regulation were effective methods to prepare high performance catalysts for photocatalytic nitrogen fixation. • Nano-metal-modified semiconductor catalysts achieve ammonia production rate of 785 μmol g−1 h−1. • Highiy doped semiconductors re-define the landscape of photocatalytic NH 3 generation. • The ammonia production rate, apparent quantum efficiency and Solar-to-Ammonia can be used to evaluate the performance ofphotocatalyst. • Hot electron injection effect as a guide for the synthesis of plasma-induced photocatalysts. [ABSTRACT FROM AUTHOR]

The vibration caused by blasting load may result in damage to high-rise buildings. In view of this consideration, an investigation of the vibration law was conducted in the context of an actual engineering project. The objective of this study was to analyze the peak particle velocity (PPV), vibration frequency, and peak particle stress (PPS) of the buildings within a range of 50 m to 250 m from the epicenter, under the condition of a single-shot charge of 30 kg. To achieve this, a combination of theoretical analysis, field tests, and numerical experiments was employed. Sadovsky's formula was used in combination with the least squares method to fit the propagation law of ground PPV. ANSYS 17.0/LS-DYNA and Origin 8.0 software were applied to study the amplification effect of building PPV and the relationship between PPV and PPS. Taking into account the difference between the height of the ground measuring point and the height of the explosive center, we investigated the PPV of high-rise buildings under three conditions of 36 m, 6 m, and −24 m drop from the explosive center, to strengthen the in-depth understanding of resonance effect. The following conclusions were reached: the ground PPV decreases with increasing horizontal distance from the explosive center, with the radial PPV being the largest. The vertical PPV of buildings exhibits a height amplification effect, with a magnification factor of 2.66. The radial and tangential PPVs of buildings demonstrate that the middle layer exhibits a relatively modest speed, whereas the low and high layers demonstrate considerably higher speeds. The greater the vertical distance from the explosion center is, the greater is the PPV. The vibration frequency is irregular, with an average of 10 Hz. The PPV of buildings is not proportional to the PPS, which is the highest at the bottom. It is recommended that the PPS of buildings be included in the criteria for safety allowances in blasting vibration. [ABSTRACT FROM AUTHOR]

AgIn5S8, a narrow, direct bandgap semiconductor, has gained much attention in photocatalysis due to its excellent visible-light absorption coefficient, good photoconductivity, light stability and biocompatibility. Thus, it is a promising active material for photocatalytic degradation of organic pollutants. In this review, synthesis methods of different AgIn5S8-based photocatalysts are introduced in detail first, such as solid-state reaction methods, hydrothermal/solvothermal methods, and microwave synthesis methods. Subsequently, photocatalytic degradation improvement strategies of AgIn5S8-based photocatalysts are systematically summarized, mainly including morphology control, defect engineering, doping, surface plasmon resonance effects and constructing heterojunctions. The perspective and the future challenge are provided at the end. This review can accelerate the development of AgIn5S8-based photocatalysts in related applications. [ABSTRACT FROM AUTHOR]

Purpose: To use cardiac magnetic resonance (CMR) imaging to investigate the effect of anthracyclinebased chemotherapy on cardiac structure and function in breast cancer patients. Methods: A total of 20 breast cancer patients who received treatment at Shandong Cancer Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, China between October 2021 and October 2022 were included in this study. The patients underwent surgical treatment and also received anthracycline-based chemotherapy after surgery. Before chemotherapy, and at 3 months and 6 months after chemotherapy, CMR examinations were performed on all the participants. Cardiac function parameters, viz, left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), and left ventricular ejection fraction (LVEF), were measured and compared at different time points. Results: There were no significant differences in LVEF, LVEDV, and LVESV among different time points (p > 0.05). Similarly, there were no significant differences in RS, CS, LS, SRSR, SCSR, SLSR, DCSR, and DLSR among the different time points (p > 0.05). However, diastolic radial strain rate (DRSR) level at 6 months after treatment was significantly lower than the corresponding values before treatment and at 3 months post-treatment (p > 0.05), indicating a progressive decrease in DRSR over time. Conclusion: Cardiac magnetic resonance imaging provides a valuable assessment of myocardial damage in breast cancer patients following anthracycline-based chemotherapy, while DRSR may serve as a sensitive parameter for early detection of myocardial injury using CMR. However, an improved study protocol should enhance the applicability of the approach. [ABSTRACT FROM AUTHOR]

In this paper, we design a Fano resonance sensor based on Al 2 O 3 and Ag hybrid metamaterial, the proposed hybrid structure is composed of two concentric cylinders with the same radius. Finite difference time domain (FDTD) simulation and coupled mode theory (CMT) are used to study the transmission characteristics of the structure. The results indicate that the Fano resonance in this structure is caused by the destructive interaction between the surface plasmon polaritons (SPPs) generated at the interface of Al 2 O 3 /Ag and the local surface plasmon resonances (LSPRs) excited at the Ag boundary. The resonance wavelength and line shape of the Fano resonance can be adjusted by the structural geometrical parameters. Additionally, we incorporate four silver bars into the proposed structure to induce a dual Fano resonance, and the dual Fano resonances can be tuned by the size and position of the silver bars. After optimizing the geometric parameters, the maximum sensitivity of the single Fano resonance structure is S = 119 nm/RIU , and its figure of merit is F O M = 63. 4 RIU - 1 . The maximum sensitivity of the dual Fano resonance configuration is S = 407. 8 nm/RIU , which is more than three times as sensitive in the Ag/Al 2 O 3 hybrid metamaterial without the four silver bars, while its figure of merit is F O M = 203. 7 RIU - 1 . The Fano resonance effect has potential applications in various nanophotonic devices, such as switches, sensors, and modulators. [ABSTRACT FROM AUTHOR]

This paper considers the interaction of a rising bubble and a sedimenting fine particle in a liquid with a soluble surfactant subjected to the gravity field, forced flow, and vibrations. The frequency of vibrations is close to the resonance value. The particle motion trajectories are calculated, taking into account its inertia, fluid viscosity, Basset force, buoyancy force, and the mean force acting on the particle due to the inhomogeneity of the pulsating field. The collision efficiency is evaluated, and the cross sections of the sedimenting particles captured by the rising bubble are found. It is demonstrated that even at low vibration intensity but in the presence of a weak surfactant effect, a significant increase in the probability of particle–bubble collision and in the capture cross section can be achieved. The obtained results can be used to intensify the flotation processes by ultrasonic treatment. [ABSTRACT FROM AUTHOR]

The oscillating quartz tuning fork method has been used to study resonance phenomena in experimental cells of different sizes filled with superfluid 4He and concentrated liquid mixtures of 3He–4He. An analysis of the temperature dependence of the resonance frequencies of the tuning forks showed that in a number of cases, the incompressible fluid model is not sufficient to interpret the experimental results and that acoustic processes in the cell should be taken into account. The frequencies of the resonances of the first sound in cylindrical geometry are estimated and their influence on the resonant frequencies of the tuning fork is shown, which can lead to a distortion of the shape of the resonant line. A comparison is made between experimental results for superfluid 4He and mixtures of 3He-4He with light isotope concentrations of 5% and 15%. It is shown that, in contrast to pure helium, the model of a viscous incompressible fluid cannot be applied to mixtures, even in the absence of first acoustic resonances. This can be explained by the fact that, when studying concentrated solutions, the excitation of the second sound along with the first can have a noticeable effect on the resonance characteristics of the tuning fork. [ABSTRACT FROM AUTHOR]

This study presents the polarization photodetection enhancement in Sb2Se3 nanotube (NT)‐based near‐infrared (NIR) photodetectors through simulation‐based and experimental investigations. High‐quality single‐crystal Sb2Se3 NTs are grown via chemical vapor deposition and characterized by using multiple techniques. The optical simulation reveals a remarkable difference in the light absorption ratio (specifically, absorption along the NT/nanowire (NW) against absorption perpendicular to the NT/NW) between Sb2Se3 NT and NW of the same size in the NIR region. The complementary photodetection experiments present that the fabricated Sb2Se3 NT photodetector demonstrates enhanced polarization photodetection in the NIR range, as indicated by a significantly increased dichroic ratio (3.03 at 850 nm) compared to that of similar‐sized NW counterpart (1.81 at 850 nm). Additionally, the Sb2Se3 NT photodetector exhibits exceptional performance, with a high responsivity of 4.18 A W−1 and specific detectivity of 8.94 × 1010 Jones under 830 nm light illumination. This study provides a comprehensive understanding of the microcavity resonance effect and its role in polarization photodetection enhancement, highlighting the potential of self‐assembled Sb2Se3 NTs in high‐performance near‐infrared polarized photodetection and other relevant applications. [ABSTRACT FROM AUTHOR]

Analysis of the ordinary mode (O‐mode) instability is performed to comprehend the nonthermal continuum (NTC) radiation near the plasmapause, taking into account the relativistic wave‐electron resonance effect. The energy source is the anisotropy in the velocity of the minority suprathermal electron population. Numerical solutions demonstrate that the O‐mode can be unstable with multiple narrow frequency bands located close to harmonics of the electron cyclotron frequency above the local electron plasma frequency. These waves have narrow beaming angle bands of nearly 90° $90{}^{\circ}$ relative to the ambient magnetic field. Our findings indicate that NTC radiation generated by this wave‐electron resonance instability near the plasmapause can propagate nearer to the magnetic equator with multiple harmonics, which is in agreement with a recent statistical study using Van Allen Probes. Key Points: The ordinary mode electron anisotropy instability is examined to comprehend the non‐thermal continuum radiation near the plasmapauseResonant ordinary modes are unstable over multiple narrow frequency and wavevector rangesNTC radiation generated by the instability near the plasmapause can propagate nearer to the magnetic equator [ABSTRACT FROM AUTHOR]

In Doubly Fed Induction Generator (DFIG)-based wind farms with Static Var Generators (SVGs), high-frequency resonance will be more like to occur when an unloaded cable is put into operation, which will threaten the stable operation of the wind farm. To address this issue, the influence of power outer loops on the impedance of grid-connected inverters is considered. Based on harmonic linearization, theoretical models for the sequence impedances of DFIGs, Grid-following (GFL) SVGs, and Grid-forming (GFM) SVGs are established. The correctness of the three models is verified by impedance scanning using the frequency sweep method. Through a comparative analysis of these sequence impedances, it is found that unlike the GFM SVG (which exhibits inductive impedance), the GFL SVG exhibits capacitive impedance in the high-frequency band, which leads to negative damping characteristics in the high-frequency band for the wind farm system with the grid-following SVG; thereby, the risk of high-frequency resonance also increases accordingly. On the contrary, GFM control adopted by SVGs can effectively eliminate the negative damping region in the high-frequency band for wind farms to suppress high-frequency resonance. Meanwhile, for grid-forming SVGs, the parameter variations in power synchronous loops have no significant impact on the suppressing effect of high-frequency resonance for wind farms. Finally, an electromagnetic simulation model for a DFIG-based wind farm system with an SVG is established using the StarSim-HIL (hardware-in-the-loop) experiment platform, and the simulation results validate the correctness of the theoretical analysis. [ABSTRACT FROM AUTHOR]

The Krauklis wave is a special seismic phenomenon in fluid saturated fracture medium. The wave can prompt a unique resonance effect and enhance the amplitude at special frequencies. These frequencies have a quantitative relationship with the fracture geometry parameters and can be used for quantitative interpretation of geometry parameters. Such frequency information can be transmitted to body waves by the transformation between the Krauklis wave and the body wave. Both P- and S-waves become frequency dependent. In this study, an original numerical method is brought out to solve the equation of the Krauklis wave dispersion relation. The method has fine computational performance, and the frequency band for numerical solution is extended to the megahertz level. The dispersion, resonance, and attenuation of the Krauklis wave can be analyzed within the entire frequency range for Krauklis wave existence. What is more, the formation mechanism, existence, and observability are illuminated. The analysis shows that there are upper limits of frequency and fracture aperture for Krauklis wave existence, but within the frequency band for artificial seismic and micro-seismic exploration, the Krauklis wave exists widely. For experimental research, the frequency and fracture aperture should be well designed to ensure the generation of the Krauklis wave. The attenuation of the Krauklis wave can suppress the resonance effect. The influence of the attenuation should be taken into account, when the wave is used for seismic characterization of fracture reservoirs or micro-seismic monitoring of hydraulic fracturing. [ABSTRACT FROM AUTHOR]

In this study, the influence of the torsional rigidity of the connected shafts, couplings and the working body of the machine, as well as the damping capacity of the coupling, on the torsional impact moment generated in the machine transmission is investigated. Unlike existing classical calculation models, the torsional stiffness of the connected shafts, the torsional damping ability of the coupling and the effects of the moment ratio are taken into consideration together. Under these conditions an analytical expression for the shock moment or resonance coefficient is obtained. The main novelties in obtaining of this expression are the ratio of the torsional stiffness of the connected shafts with the torsional stiffness of the coupling and the acceptance of the moment of resistance of the working body of the machine depending on the torsional stiffness. It has been found that the considered factors have a significant effect on the resonance zone. Finally, different and overlapping conditions are determined when determining the value of the resonance coefficient characterizing the torque impact moment, calculated according to the classical and proposed models. [ABSTRACT FROM AUTHOR]

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The operating bandwidth of miniaturized magnetoelectric (ME) antenna is generally narrow due to the acoustic wave driven magneto-electromechanical resonance effect, parallel connection of multiple ME antennas with different resonant frequencies is an effective way to broaden the operating bandwidth of the antenna. This paper presents an ME antenna array consisting of three units, which are constructed of a sandwich stack of Metglas/Pb(Mg1/3Nb2/3)O3–PbTiO3/Metglas. The −3 dB operating bandwidth of 152.4–172.8 kHz is achieved, and the relative bandwidth is 12.5%. Experimental results indicated that the bias magnetic field and coupling effect between the ME antenna units significantly influence the performance of ME antenna array. A modified Butterworth–Van Dyke (MBVD) equivalent circuit model is used and improved to analyze the influence of sound waves, electric fields, magnetic fields, parasitic capacitance, and bias magnetic field on the ME antenna array. The simulation results of the MBVD equivalent circuit model are agreed well with the experimental results. The improved MBVD model is beneficial for the design of acoustic wave driven antenna array. [ABSTRACT FROM AUTHOR]

The IR spectra of CDF3 in the solid Ar and N2 matrices were measured and analyzed in the region of the Fermi polyads 2ν4/ν1/2ν2/ν4 + ν5, complicated by a close Fermi resonance ν4/ν3 + ν6. The symmetry lifting effect, observed in the N2 matrix, was found helpful for an accurate assignment of the individual components. The anharmonic calculation of the potential energy surface and the dipole moment function was performed on the MP2/aug-cc-pVTZ level. The unperturbed values of vibrational eigenstates were determined in the region of ν1 (CD stretching vibration) in both matrices. The experimental findings and theoretical analysis are in good agreement. [ABSTRACT FROM AUTHOR]

This paper presents the investigation of a metastructure, built with periodic arrays of inertial amplification (IA) cantilever-type resonators on a host beam, to improve its low-frequency flexural wave attenuation performance. The IA mechanism is composed of an additional mass and three rigid bars, which are connected by hinges and embedded on the host beam and cantilever-type resonators, respectively. The dynamical model of an IA cantilever-type resonant beam (IACRB) is established by the spectral element method, and its bandgap characteristics and vibration transmissibility are verified numerically and experimentally. The bandgaps of the lumped mass cantilever-type resonant beam are compared to those of the IACRB, showing that the latter has better low-frequency wave attenuation ability. To reveal the underlying physics, the effects of the amplification ratio, IA span, and length ratio of cantilever-type resonators on the band diagram of the IACRB are investigated. It is found that the variation of the amplification ratio results in the bandgap near-coupling phenomenon and the bandgap transposition phenomenon. The increase of IA span by changing position 1 weakens the coupling effect of local resonance and IA. However, the increase of IA span by changing position 2 creates the super-wide pseudo-bandgap as well, which is potential in engineering practices. The variation of the length ratio of cantilever-type resonators decreases its first bending modal frequency and shifts the IA bandgap to a lower frequency range slightly. The modal analysis results of the IACRB show that the proposed mechanism affects the modal distributions of the host structure. The modal frequencies existing in bandgaps are caused by the local vibration mode of the ends of the IACRB. [ABSTRACT FROM AUTHOR]

This paper proposes a novel segmented underdamped asymmetric tristable stochastic resonance (SUATSR) system. The research involves deriving the equivalent potential function for the underdamped background and analyzing the system’s output saturation. Results demonstrate that the SUATSR system effectively mitigates output saturation issues, enhancing the output amplitude. The study also employs adiabatic approximation theory to derive theoretical expressions for mean first passage time (MFPT) and spectral amplification (SA). The paper discusses the impact of varying system parameters on these performance indicators. Numerical simulations of the classical tristable stochastic resonance (CTSR), segmented underdamped tristable stochastic resonance (SUTSR) and SUATSR systems validate the theoretical derivations. Furthermore, the three systems are applied to different bearing fault tests and optimized using the adaptive genetic algorithm (AGA). The results demonstrate that the SUATSR system outperforms the other two systems, exhibiting higher SA and signal-to-noise ratio (SNR) values at the fault frequency. This highlights the SUATSR system’s superior noise resistance and its effectiveness in detecting and enhancing fault signals. [ABSTRACT FROM AUTHOR]

In this study, a novel N, S-co-doped carbon-based Ag3PO4 composite photocatalyst (N,S-Ag3PO4@ACB) was synthesized using activated biochar (ACB) as a carrier and used for the efficient removal of norfloxacin (NOR), a typical bio-refractory antibiotic. We systematically investigated the degradation effects, actual wastewater treatment, the impacts of environmental factors, and the degradation pathways. The results show that N,S-Ag3PO4@ACB is essentially a p-n heterojunction with Z-scheme of Ag2S/Ag3PO4/ACB composite containing Ag nanoparticles. After 120 min of irradiation, N,S-Ag3PO4@ACB removed 90.42% of an initial NOR concentration of 50 mg L–1. The activation of graphitic N and the lone electron pairs of N and S, promoted rapid photogenerated charge transfer. Furthermore, the surface properties of ACB promoted free radicals generation, and the surface plasmon resonance effect of the Ag nanoparticles synergistically enhanced the photocatalytic activity. A new degradation intermediate of NOR was identified, and the degradation dynamics were elucidated with three main pathways. [ABSTRACT FROM AUTHOR]

A novel surface plasmon resonance (SPR) refractive index (RI) sensor based on the D-type dual-mode photonic crystal fiber (PCF) is proposed. The sensor employs a side-polished few-mode PCF that facilitates the transmission of the fundamental and second-order modes, with an integrated microfluidic channel positioned directly above the fiber core. This design minimizes the distance to the analyte and maximizes the interaction between the optical field and the analyte, thereby enhancing the SPR effect and resonance loss for improved sensing performance. Au-TiO2 dual-layer material was coated on the surface of a microfluidic channel to enhance the penetration depth of the core evanescent field and tune the resonance wavelength to the near-infrared band, meeting the special needs of chemical and biomedical detection fields. The finite element method was utilized to systematically investigate the coupling characteristics between various modes and surface plasmon polariton (SPP) modes, as well as the impact of structural parameters on the sensor performance. The results indicate that the LP11b_y mode exhibits greater wavelength sensitivity than the HE11_y mode, with a maximum sensitivity of 33,000 nm/RIU and an average sensitivity of 8272.7 nm/RIU in the RI sensing range of 1.25–1.36, which is higher than the maximum sensitivity of 16,000 nm/RIU and average sensitivity of 5666.7 nm/RIU for the HE11b_y mode. It is believed that the proposed PCF-SPR sensor features both high sensitivity and high resolution, which will become a critical device for wide RI detection in mid-infrared fields. [ABSTRACT FROM AUTHOR]

We have studied the evolution of near-Earth asteroid (NEA) families and pairs to inform future searches. To do so, we integrated clusters of simulated NEAs with different initial conditions, namely the orbital inclination, ejection speed, and the effects of mean-motion resonances on the parent body prior to breakup while also varying the orbit, mass, and number of perturbing planetary bodies. We studied the orbital element dispersion rates of NEA family members and found a power-law increase in those families whose orbits brought them close to a planet. This allowed us to conclude that family dispersion is significantly affected by the Kozai–Lidov effect due to oscillations in the eccentricity, and that the rate of dispersion is slowest at high inclination relatively far from the nearest planet. In most cases, the ejection speed of the initial breakup does not affect the dispersion, except within weaker mean-motion resonances where more violent breakups will result in the ejection of a fraction of the asteroids, causing a large increase in dispersion. Within mean-motion resonances, where Kozai–Lidov oscillations are slowed, increases in the dispersion of a family are delayed, leading them to be identifiable for longer. [ABSTRACT FROM AUTHOR]

A customized metamaterial tailored for a specific functionality holds significant appeal in practical applications, yet its alteration after the structure is established can be challenging. A novel design for Fibonacci‐array inspired acoustic metamaterials is introduced, which are constructed using metamaterial bricks with unique physical mechanisms. This design aims to achieve multifunctional low‐frequency sound absorption. The Fibonacci sequence arrangement flexibly modulates the coupling between metamaterial bricks, thereby improving energy‐dissipating efficiency. Additionally, the strategic alignment enhances the wave‐absorbing properties of the metamaterial, allowing it to demonstrate remarkable absorption effects across targeted frequency bands. By controlling the resonance effect of metamaterial bricks in intensive and sparse modes, the proposed design exhibited frequency‐selective performance, resulting in three absorption peaks at 323, 687, and 1113 Hz, respectively, across low‐ to high‐frequency ranges. Furthermore, the broadband absorption performance, characterized by strong coupling strength, enables continuous sound absorption over a low‐frequency band from 290 to 440 Hz. This is supported by theoretical analysis, numerical simulations, and experimental results, showcasing the flexible modulation of the propagation characteristics of sound waves. Overall, this functionally actuated design dramatically enhances the tunability of the metamaterials and offers a promising avenue for multifunctional application in noise‐control engineering. [ABSTRACT FROM AUTHOR]

BiOBr with different preferred growth orientation facets would show a different photocatalytic performance. When decorated in situ with metallic Bi nanoparticles, Bi/BiOBr would commonly display an enhanced photocatalytic performance. In this paper, the BiOBr nanoplates with preferred growth orientation (102) facet and (110) facet were first synthesized using a hydrothermal method. Then, some metallic Bi nanoparticles were modified in situ onto the (110)BiOBr nanoplates, which was expected to show a much more enhanced photocatalytic performance. All samples were characterized using XRD, FE-SEM, TEM, N2 adsorption–desorption, UV–vis and XPS. FE-SEM and TEM images showed that the grain size of the metallic Bi particles was about 5 nm to 10 nm. UV–vis spectra showed that, after some metallic Bi nanoparticles were modified on (110)BiOBr nanoplates, the light absorbance in the visible light region at 400–700 nm became stronger and their optical band gap became larger. N2 adsorption–desorption tests showed that the Bi(x)/(110)BiOBr nanosheets possessed larger specific surface areas than that of the (102)BiOBr and (110)BiOBr nanoplates. The XPS results showed that Bi(x)/(110)BiOBr contained more oxygen vacancies and a more negative value of the conduction band minimum. The photocatalytic performance of (102)BiOBr, (110)BiOBr and Bi(x)/(110)BiOBr were tested in the photocatalytic degradation of rhodamine B under visible light irradiation for 2 h; their photocatalytic efficiency was 45%, 75% and 80%, respectively. In comparison to (102)BiOBr, (110)BiOBr exhibited much higher photocatalytic activity, while for Bi(x)/(110)BiOBr, despite the surface Plasmon resonance effect, a larger specific surface area and more oxygen vacancies, the enhancement of the efficiency was limited, which might have resulted from the larger optical band gap. [ABSTRACT FROM AUTHOR]

Background: Magnetic resonance imaging (MRI) noninvasively quantifies disc structure but requires segmentation that is both time intensive and susceptible to human error. Recent advances in neural networks can improve on manual segmentation. The aim of this study was to establish a method for automatic slice‐wise segmentation of 3D disc volumes from subjects with a wide range of age and degrees of disc degeneration. A U‐Net convolutional neural network was trained to segment 3D T1‐weighted spine MRI. Methods: Lumbar spine MRIs were acquired from 43 subjects (23–83 years old) and manually segmented. A U‐Net architecture was trained using the TensorFlow framework. Two rounds of model tuning were performed. The performance of the model was measured using a validation set that did not cross over from the training set. The model version with the best Dice similarity coefficient (DSC) was selected in each tuning round. After model development was complete and a final U‐Net model was selected, performance of this model was compared between disc levels and degeneration grades. Results: Performance of the final model was equivalent to manual segmentation, with a mean DSC = 0.935 ± 0.014 for degeneration grades I–IV. Neither the manual segmentation nor the U‐Net model performed as well for grade V disc segmentation. Compared with the baseline model at the beginning of round 1, the best model had fewer filters/parameters (75%), was trained using only slices with at least one disc‐labeled pixel, applied contrast stretching to its input images, and used a greater dropout rate. Conclusion: This study successfully trained a U‐Net model for automatic slice‐wise segmentation of 3D disc volumes from populations with a wide range of ages and disc degeneration. The final trained model is available to support scientific use. [ABSTRACT FROM AUTHOR]

Copyright of Coal Geology & Exploration is the property of Xian Research Institute of China Coal Research Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the field of ultrasonic grinding of SiCp/Al composites, the resonant tool system plays a crucial role in grinding. However, large-size cup wheels have been rarely investigated within this domain. To this end, an effective method is proposed for designing a rotary ultrasonic grinding tool with a large-sized cup wheel. The cup wheel transformer can be represented as a combination of four components: a plate, a tube, a conical horn, and a cylindrical horn. A theoretical model for the vibration analysis of the cup wheel transformer is developed based on the Mindlin plate theory and the one-dimensional longitudinal vibration theory. Finite element simulations are utilized to validate the accuracy of the design theory. The performance testing results confirm that the rotary ultrasonic grinding tool exhibits a good resonance effect. Furthermore, the comparison grinding machining between conventional grinding and rotary ultrasonic grinding of SiCp/Al test pieces was completed. The results reveal that the rotary ultrasonic grinding has a small tangential grinding force but a larger axial grinding force. The machining traces left by abrasive grains on the grinding surface resemble sinusoids and cosines. In addition, the wear debris are smaller with a granular shape. Interestingly, the surface roughness has no discernible relationship with the spindle speed in rotary ultrasonic grinding. Overall, the findings of this investigation can boost the development and practical application of rotary ultrasonic grinding technology with large size cup wheels. [ABSTRACT FROM AUTHOR]

1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU) was used as a mild and efficient catalyst for synthesis of various dihydropyrano[3,2-c]chromene-3-carboxylate derivatives via one-pot, three-component condensation of aromatic aldehydes, active methylene and 4-hydroxycoumarin in ethanol under reflux. The distinctive features of this process are mild reaction conditions, reusability of the reaction media, short reaction time, easy isolation of products and good yield. In addition, the effect of electron donating and withdrawing groups on the reactivity of chromene derivatives was investigated and evaluated by quantum chemical tools. For this purpose, the FMO analyses were performed and considered in terms of the new perspectives of the C-DFT. Also, the NBO analyses of the chromene derivatives were conducted to look for and compare the resonance and inductive effect on the possible reactivity behaviors. [ABSTRACT FROM AUTHOR]

We pioneered an angle-adjustable photonic crystal fluorescence platform (APC-Fluor) that integrates PCs, an angular resolution spectrometer and a strategically aligned laser source. This configuration, featuring a coaxial rotating swing arm, allows for precise control over the angles of incidence and emission. The presence of photonic crystal microcavities facilitates the dispersion of fluorescent materials and promotes the transition of electrons from the excited state to the lowest vibrational energy level. The optical resonance effect triggered by modulating the alignment of the reflection peaks of the photonic crystals with the emission peaks of the fluorescent materials can significantly enhance the fluorescence intensity. Compared with the single BSA-AuNCs, the optimized fluorescence intensity can be significantly increased by 11.9-fold. The APC-Fluor system showcases rapid and highly sensitive detection capabilities for oxytetracycline (OTC), exhibiting a response across a concentration range from 2 to 1 × 104 nM and achieving a notably low detection limit of 1.03 nM. [ABSTRACT FROM AUTHOR]

Multi‐resonant thermally activated delayed fluorescent (MR‐TADF) materials, which combine large oscillator strengths, small singlet‐triplet energy gaps, high photoluminescence quantum yields, and color purity, have attracted great interest in both experimental and theoretical research in recent years. However, the differences between two classes of MR‐TADF, utilizing carbonyl groups and boron atoms as acceptors respectively, have not been clearly delineated, and the implementation of strategies combining both is extremely limited. This limitation hampers the diversity in composition and structure of MR‐TADF. In this study, we employed boron as the central acceptor and carbonyl groups as peripheral acceptors, designing and investigating 7 merged systems of MR‐TADF molecules. Calculations revealed that, in contrast to the strong acceptor characteristics of boron atoms, carbonyl groups do not exhibit absolute acceptor features, and their resonance effects depend on the surrounding environment. This unique resonance effect induces LRCT features to varying degrees, enabling the emission coverage of these molecules across almost the entire visible spectrum (theoretical emission wavelengths covering 452–751 nm). We gained an understanding of the differences between boron acceptors and carbonyl groups, achieving full‐color emission by adjusting only the MR cores. This provides insights into the rational design of complex‐component full‐color MR‐TADF emitters. [ABSTRACT FROM AUTHOR]

In the present work, we synthesized ZnO–Ag heterophase nanoparticles and ZnO–Ag modified polypropylene (PP) granules toward the degradation of dye under visible light irradiation. The nanoparticles (NPs) were produced by electrical explosion of zinc and silver twisted wires in oxygen-containing atmosphere. The heterophase structure of ZnO–Ag nanoparticles plays an important role in the enhancing the photocatalytic dye removal through the localized surface plasmon resonance effect of silver. In our investigation, the 0.5 wt.% NPs on the PP granule surface are the best composite samples to achieve the best methylene blue dye degradation (99.7%). The ZnO–Ag heterojunction retains an excellent performance of 46.4% even after being used repetitively for 4 cycling tests. This is the first report on the ZnO–Ag–ZnO/polypropylene granules to advance polymer technology for food storage and self-cleaning coating in the near future. [ABSTRACT FROM AUTHOR]

Within the widely used EvtGen framework, we have added a new event generator model for B → K*ℓ+ℓ− with improved standard model (SM) decay amplitudes and possible BSM physics contributions, which are implemented in the operator product expansion in terms of Wilson coefficients. This event generator can then be used to estimate the statistical sensitivity of a simulated experiment to the most general BSM signal resulting from dimension-six operators. We describe the advantages and potential of the newly developed 'Sibidanov Physics Generator' in improving the experimental sensitivity of searches for lepton non-universal BSM physics and clarifying signatures. The new generator can properly simulate BSM scenarios, interference between SM and BSM amplitudes, and correlations between different BSM observables as well as acceptance bias. We show that exploiting such correlations substantially improves experimental sensitivity. As a demonstration of the utility of the MC generator, we examine the prospects for improved measurements of lepton non-universality in angular distributions for B → K*ℓ+ℓ− decays from the expected 50 ab−1 data set of the Belle II experiment, using a four-dimensional unbinned maximum likelihood fit. We describe promising experimental signatures and correlations between observables. The use of lepton-universality violating ∆-observables significantly reduces uncertainties in the SM expectations due to QCD and resonance effects and is ideally suited for Belle II with the large data sets expected in the next decade. Thanks to the clean experimental environment of an e+e− machine, Belle II should be able to probe BSM physics in the Wilson coefficients C7 and C 7 ′ , which appear at low q2 in the di-electron channel. [ABSTRACT FROM AUTHOR]

The current inverter control strategies have limitations in suppressing grid resonance, especially in complex grid environments with high penetration of renewable energy sources. These strate-gies often focus on suppressing resonance at a single frequency point, but their effectiveness is constrained when dealing with multi-band resonance or dynamically changing grid conditions. The study investigates the application of parallel-operated inverters in the grid, particularly their impact on grid stability. A novel active damping strategy is developed to enhance the grid's dynamic response and suppress grid resonance. The effectiveness of the control strategy is verified through simulation by establishing Norton equivalent circuit models for multiple in-verters. Fast Through simulation, this study comprehensively evaluates the performance and adaptability of the strategy under various conditions. Results demonstrate that implementing the active damping strategy increases the inverter output power from 9.5 kW to 10 kW, an im-provement of 5.26%. System response time is reduced from 50 ms to 30 ms, and post-stabilization fluctuations decrease to 1.5%. These data conclusively prove the effectiveness of the control strategy in enhancing grid stability and reducing resonance effects. The findings underscore the potential of active damping strategies in improving grid performance and in-verter efficiency. However, further research and optimization are necessary to assess the adapt-ability of these strategies under different grid conditions. [ABSTRACT FROM AUTHOR]

Metal nanomaterials have emerged as compelling candidates for ultrafast photonics applications, owing to their outstanding saturable absorption properties induced by surface plasmon resonance effects. In recent years, the exploration of saturable absorbers has encompassed noble to non-noble metals as well as diverse structures such as clusters, nanowires and nanoplates. Herein, we comprehensively elucidate the operational principles of metal nanomaterials in ultrafast lasers, including the surface plasmon resonance effect and their complex optical properties. Furthermore, recent advancements in metal nanomaterials utilized in ultrafast lasers have been systematically summarized and classified according to the dimensional structure that profoundly affects their properties. Moreover, the operating parameters of saturable absorbers based on metal nanomaterials are listed in detail. Finally, we look ahead to further directions of metal nanomaterials in ultrafast photonics, presenting explorations in metasurfaces, potential alternatives, and novel integration methods. [ABSTRACT FROM AUTHOR]

Porphyrins were identified some years ago as a promising, easily accessible, and tunable class of organic photoredox catalysts, but a systematic study on the effect of the electronic nature and of the position of the substituents on both the ground-state and the excited-state redox potentials of these compounds is still lacking. We prepared a set of known functionalized porphyrin derivatives containing different substituents either in one of the meso positions or at a β-pyrrole carbon, and we determined their ground- and (singlet) excited-state redox potentials. We found that while the estimated singlet excited-state energies are essentially unaffected by the introduction of substituents, the redox potentials (both in the ground- and in the singlet excited-state) depend on the electron-withdrawing or electron-donating nature of the substituents. Thus, the presence of groups with electron-withdrawing resonance effects results in an enhancement of the reduction facility of the photocatalyst, both in the ground and in the excited state. We next prepared a second set of four previously unknown meso-substituted porphyrins, having a benzoyl group at different positions. The reduction facility of the porphyrin increases with the proximity of the substituent to the porphine core, reaching a maximum when the benzoyl substituent is introduced at a meso position. [ABSTRACT FROM AUTHOR]

We present an experimental study of the spin rectification effects produced by ferromagnetic resonance in a NiFe wire. A system of four independent nonmagnetic contact probes was used to supply both rf and dc currents to the wire and to measure dc voltages at different locations in the wire. The rf current drives the ferromagnet's magnetization into resonance and produces a dc photovoltage which results from the rectification of rf current in the ferromagnet with oscillating magnetization. Our 4-probe system provided a means to detect the photovoltage and separate contributions from the ferromagnet/nonmagnet contacts and the bulk of the ferromagnet. The contact photovoltage was found to increase approximately linearly with the dc bias applied to the wire. In contrast, the bulk contribution was found to be almost independent of the dc bias. By tuning properties of individual contact probes we were able to change the magnitude of the contact photovoltage and even reverse its sign. Our results highlight the different contributions to photovoltage and the importance of contact properties/nonlinearities for rectification effects in spintronic devices. [ABSTRACT FROM AUTHOR]

The hypothesis of chaotic population dynamics was proposed in ecology by Robert May in the mid-1970s. At that time the idea was controversial, and it remains a fascinating and unsettled issue today. We report the results of a 20-year laboratory research programme that continued in the tradition of the pioneering ecologist Thomas Park using the Tribolium flour beetle model. We present biological evidence of complex population dynamics – including bifurcations, chaos, saddle nodes, phase switching, resonance effects, and multiple attractors – by using a low-dimensional difference equation model for Tribolium together with carefully designed, conducted, and statistically analysed experiments. The model, parameterized with data, also explains the results of historical Tribolium experiments, such as the classical competition studies of Thomas Park and his colleagues. Our research programme has inspired other studies using the Tribolium mathematical and laboratory model. This work was conducted by a multidisciplinary team, which included Jim Cushing. [ABSTRACT FROM AUTHOR]

Investigating the influence of varying shaft steelwork stiffness on the stability of horizontal mass displacements, which are crucial elements of a conveyance-shaft steelwork system, is a significant step in evaluating the risk of parametric vibrations in steel constructions. While the Rayleigh method is limited to the first approximation in the solution to this analysis, it still provides valuable insights. Our examination indicates that the impact of a varying shaft steelwork system may not be noticeable in practical applications. This is a significant finding, as it suggests that the impact of varying stiffness in real working objects may be ignored, because the increase in the parametric resonance effects is negligible. This underscores the importance of our research in understanding the stability of steel constructions. This research, which involves theoretical analysis, simplifies the dynamic analysis of the conveyance-shaft steelwork system's behavior. The result of the performed analysis is a valuable equation for predicting stable work in real hoist installations. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Hebei University of Science & Technology is the property of Hebei University of Science & Technology, Journal of Hebei University of Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)