The modern definition of the wave concept,which is based on the functional connection between the parameters of the spatial structure of an instantaneous flow pattern and the characteristics of the temporal variabilit...The modern definition of the wave concept,which is based on the functional connection between the parameters of the spatial structure of an instantaneous flow pattern and the characteristics of the temporal variability at a given point,is discussed.The dispersion relation for 2D plane periodic perturbations on the surface of viscous stratified fluid is selected as the characteristic function defining the wave motion.Using the theory of singular perturbations,a method for calculating complete solutions to the dispersion relations of periodic flows,including regular wave and singular ligament solutions is presented.Properties of the complete exact solution of the dispersion relation containing regular and singular functions are compared with asymptotic solutions.In limiting cases,obtained dispersion relations are matched with well⁃known expressions for waves in homogeneous viscous and ideal liquids.展开更多
Disordered ferromagnets with a domain structure that exhibit a hysteresis loop when driven by the external magnetic field are essential materials for modern technological applications.Therefore,the understanding and p...Disordered ferromagnets with a domain structure that exhibit a hysteresis loop when driven by the external magnetic field are essential materials for modern technological applications.Therefore,the understanding and potential for controlling the hysteresis phenomenon in thesematerials,especially concerning the disorder-induced critical behavior on the hysteresis loop,have attracted significant experimental,theoretical,and numerical research efforts.We review the challenges of the numerical modeling of physical phenomena behind the hysteresis loop critical behavior in disordered ferromagnetic systems related to the non-equilibriumstochastic dynamics of domain walls driven by external fields.Specifically,using the extended Random Field Ising Model,we present different simulation approaches and advanced numerical techniques that adequately describe the hysteresis loop shapes and the collective nature of the magnetization fluctuations associated with the criticality of the hysteresis loop for different sample shapes and varied parameters of disorder and rate of change of the external field,as well as the influence of thermal fluctuations and demagnetizing fields.The studied examples demonstrate how these numerical approaches reveal newphysical insights,providing quantitativemeasures of pertinent variables extracted from the systems’simulated or experimentally measured Barkhausen noise signals.The described computational techniques using inherent scale-invariance can be applied to the analysis of various complex systems,both quantum and classical,exhibiting non-equilibrium dynamical critical point or self-organized criticality.展开更多
In this study,we investigate an innovative hybrid structure of silicon nanowires(SiNWs)coated with polyaniline(PANI):metal oxide(MO_(x))nanoparticles,i.e.,WO_(3)and TiO_(2),for respiratory sensing.To date,few attempts...In this study,we investigate an innovative hybrid structure of silicon nanowires(SiNWs)coated with polyaniline(PANI):metal oxide(MO_(x))nanoparticles,i.e.,WO_(3)and TiO_(2),for respiratory sensing.To date,few attempts have been made to utilize such hybrid structures for that application.The Si NWs were fabricated using metal-assisted chemical etching(MACE),whereas PANI:MO_(x)was deposited using chemical oxidative polymerization.The structures were characterized using Raman spectroscopy,X-ray diffraction,and scanning electron microscopy.The sensing characteristics revealed that the hybrid sensor exhibited a considerably better response than pure Si NWs:MO_(x)and Si NWs:PANI.Such an enhancement in sensitivity is attributed to the formation of a p-n heterojunction between PANI and MO_(x),the wider conduction channel provided by PANI,increased porosity in SiNWs/PANI:WO_(3)hybrid structures,which creates active sites,increased oxygen vacancies,and the large surface area compared to that available in pure MO_(x)nanoparticles.Furthermore,less baseline drift and increased sensor stability were established for the SiNWs structure coated with PANI:WO_(3),as compared to PANI:TiO_(2).展开更多
Anomaly detection in wind turbines involves emphasizing its ability to improve operational efficiency,reduce maintenance costs,extend their lifespan,and enhance reliability in the wind energy sector.This is particular...Anomaly detection in wind turbines involves emphasizing its ability to improve operational efficiency,reduce maintenance costs,extend their lifespan,and enhance reliability in the wind energy sector.This is particularly necessary in offshore wind,currently one of the most critical assets for achieving sustainable energy generation goals,due to the harsh marine environment and the difficulty of maintenance tasks.To address this problem,this work proposes a data-driven methodology for detecting power generation anomalies in offshore wind turbines,using normalized and linearized operational data.The proposed framework transforms heterogeneous wind speed and power measurements into a unified scale,enabling the development of a new wind power index(WPi)that quantifies deviations from expected performance.Additionally,spatial and temporal coherence analyses of turbines within a wind farm ensure the validity of these normalized measurements across different wind turbine models and operating conditions.Furthermore,a Support Vector Machine(SVM)refines the classification process,effectively distinguishing measurement errors from actual power generation failures.Validation of this strategy using real-world data from the Alpha Ventus wind farm demonstrates that the proposed approach not only improves predictive maintenance but also optimizes energy production,highlighting its potential for broad application in offshore wind installations.展开更多
In this work,we studied the persistent photoconductivity(PPC)spectra in single HgTe/CdHgTe quantum wells with different growth parameters and different types of dark conductivity.The studies were performed in a wide r...In this work,we studied the persistent photoconductivity(PPC)spectra in single HgTe/CdHgTe quantum wells with different growth parameters and different types of dark conductivity.The studies were performed in a wide radiation quantum energy range of 0.62–3.1 eV both at T=4.2 K and at T=77 K.Common features of the PPC spectra for all structures were revealed,and their relation to the presence of a CdTe cap layer in all structures and the appropriate cadmium fraction in the CdHgTe barrier layers was shown.One of the features was associated with the presence of a deep level in the CdTe layer.In addition,the oscillatory behavior of the PPC spectra in the region from 0.8–1.1 eV to 1.2–1.5 eV was observed.It is associated with the cascade emission of longitudinal optical phonons in CdHgTe barrier.展开更多
This work continues the studies on searching for plasma media with the inverse electron energy distribution function(EEDF)and providing recommendations for setting up subsequent experiments.The inverse EEDF is a distr...This work continues the studies on searching for plasma media with the inverse electron energy distribution function(EEDF)and providing recommendations for setting up subsequent experiments.The inverse EEDF is a distribution function that increases with an increase in energy at zero electron energy.The inverse EEDF plays a central role in the problem of negative conductivity.Based on the previously obtained criterion for the formation of an inverse EEDF in a spatially inhomogeneous plasma,a heuristic method is proposed that allows one to avoid resource-intensive calculations for spatially two-dimensional(2D)kinetic modeling on a large array of different glow discharges.It is shown that the conditions for EEDF inversion can be realized in two-chamber discharge structures due to violating the known Boltzmann distribution for electron density.The theoretical conclusions are validated by numerical modeling of lowpressure two-chamber inductively-coupled plasma(ICP)discharges in the COMSOL Multiphysics environment.As a result,areas of conditions with inverse EEDF were found for subsequent detailed kinetic analysis and experimental studies.展开更多
The aim of this study is to develop magnetopolymer composites suitable for fabricating soft magnetoactive robots via extrusion-based3D printing.Polysiloxane copolymers with urea fragments were synthesized and characte...The aim of this study is to develop magnetopolymer composites suitable for fabricating soft magnetoactive robots via extrusion-based3D printing.Polysiloxane copolymers with urea fragments were synthesized and characterized,and their thermophysical and rheological properties were investigated.This study provides an assessment of the potential for their further use in additive manufacturing.The obtained materials were utilized as matrices for creating magnetically active polymer composites by incorporating microparticles of carbonyl iron.Samples of complex geometries were printed using both neat and filled filaments,demonstrating the feasibility of employing these materials in extrusion-based 3D printing.展开更多
High-power laser systems have opened new frontiers in scientifi research and have revolutionized various scientifi fields offering unprecedented capabilities for understanding fundamental physics and allowing unique a...High-power laser systems have opened new frontiers in scientifi research and have revolutionized various scientifi fields offering unprecedented capabilities for understanding fundamental physics and allowing unique applications.This paper details the successful commissioning of the 1 PW experimental area at the Extreme Light Infrastructure–Nuclear Physics(ELI-NP)facility in Romania,using both of the available laser arms.The experimental setup featured a short focal parabolic mirror to accelerate protons through the target normal sheath acceleration mechanism.Detailed experiments were conducted using various metallic and diamond-like carbon targets to investigate the dependence of the proton acceleration on different laser parameters.Furthermore,the paper discusses the critical role of the laser temporal profil in optimizing proton acceleration,supported by hydrodynamic simulations that are correlated with experimental outcomes.The finding underscore the potential of the ELI-NP facility to advance research in laser–plasma physics and contribute significantl to high-energy physics applications.The results of this commissioning establish a strong foundation for experiments by future users.展开更多
Starch retrogradation is a primary contributor to the staling of bread.The impact of the surfactant glyceryl monostearate(GMS)on the structure and retrogradation characteristics of wheat starch gels was explored durin...Starch retrogradation is a primary contributor to the staling of bread.The impact of the surfactant glyceryl monostearate(GMS)on the structure and retrogradation characteristics of wheat starch gels was explored during storage at 4℃ for 2 h and 5 d.In this research,the incorporation of GMS(0.14%,W/W,based on flour weight)significantly reduced the crumb firmness(P<0.05).Molecular dynamics simulation vividly demonstrated the formation process of the single-helical amylose-GMS complex within 150 ns during the short-term retrogradation process of cooling the gelatinized starch for 2 h.X-ray diffraction analysis revealed that GMS slightly decreased the relative crystallinity of starch from 8.9%to 7.8%during long-term retrogradation.The reduction in R1047/1022 detected by Fourier-transform infrared spectroscopy indicated that GMS could reduce the degree of retrogradation.Solid-state ^(13)C NMR analysis showed a characteristic resonance peak at 31.7 ppm for the GMSstarch complex.This study indicates that GMS holds great application potential in retarding starch retrogradation.展开更多
Objective: We describe patients with MCS, the evolution of the Quick Environmental Exposure and Sensitivity Inventory (QEESI) score with a special focus on people whose fillings were removed. Methods: We have conducte...Objective: We describe patients with MCS, the evolution of the Quick Environmental Exposure and Sensitivity Inventory (QEESI) score with a special focus on people whose fillings were removed. Methods: We have conducted a retrospective longitudinal cohort study in patients diagnosed with MCS and attended in the outpatient Internal Medicine department of the University Hospital of San Juan de Alicante, from January 1, 2008 to January 1, 2021. Sociodemographic, clinical, QEESI and treatment-related variables were collected. We performed descriptive and inferential analyses. Mixed linear models were used to analyze the QEESI. Calculations were carried out with an α error of 5%. Results: Thirty-three patients were included (72.7% women, mean age 56.2). MCS was mainly triggered by mercury (N = 20) and food intolerance (N = 22). The mean interval from symptoms onset was 120 months (SD 81.6). 114 QEESIs were analyzed: 82 (N = 17 without amalgams) and 32 (N = 16 with amalgams). In patients without amalgams, severity scores increased across all subscales except the masking index (vs. with amalgams). Mean scores for the group without amalgams (vs. with amalgams) were: chemical intolerance, 62.8 points (vs. 63.4 and 46.7);other intolerances, 52.7 points (vs. 62.8 and 50.3);symptom severity, 63.2 (vs. 76.7 and 63.3);masking index, 3.9 (vs. 3.2 and 2.8);and life impacts, 63.1 (vs. 58.4 and 49.8). Conclusion: The profile of patient with MCS is a middle-aged woman who is a frequent user of healthcare services, presents a long diagnostic delay and has borne a great personal, work and socioeconomic impact. The QEESI is useful for the clinical follow-up of patients, including the optimal treatment response in the case of amalgams. Clinical Significance: People affected by Multiple Chemical Sensitivity deserve the attention, understanding and help of health professionals and family members, to face an invisible illness for those who do not suffer from it. Support is needed and doctors must raise awareness, and make an effort to understand and address this pathology. We suggest that protocolized amalgam extraction in accredited and prepared centers can reduce symptoms and improve quality of life, generating clinical, personal, family, occupational, social and occupational benefits.展开更多
Developing ultrabroad radar-infrared compatible stealth materials has turned into a research hotspot,which is still a problem to be solved.Herein,the copper sulfide wrapped by reduced graphene oxide to obtain three-di...Developing ultrabroad radar-infrared compatible stealth materials has turned into a research hotspot,which is still a problem to be solved.Herein,the copper sulfide wrapped by reduced graphene oxide to obtain three-dimensional(3D)porous network composite aerogels(CuS@rGO)were synthesized via thermal reduction ways(hydrothermal,ascorbic acid reduction)and freeze-drying strategy.It was discovered that the phase components(rGO and CuS phases)and micro/nano structure(microporous and nanosheet)were well-modified by modulating the additive amounts of CuS and changing the reduction ways,which resulted in the variation of the pore structure,defects,complex permittivity,microwave absorption,radar cross section(RCS)reduction value and infrared(IR)emissivity.Notably,the obtained CuS@rGO aerogels with a single dielectric loss type can achieve an ultrabroad bandwidth of 8.44 GHz at 2.8 mm with the low filler content of 6 wt%by a hydrothermal method.Besides,the composite aerogel via the ascorbic acid reduction realizes the minimum reflection loss(RL_(min))of−60.3 dB with the lower filler content of 2 wt%.The RCS reduction value can reach 53.3 dB m^(2),which effectively reduces the probability of the target being detected by the radar detector.Furthermore,the laminated porous architecture and multicomponent endowed composite aerogels with thermal insulation and IR stealth versatility.Thus,this work offers a facile method to design and develop porous rGO-based composite aerogel absorbers with radar-IR compatible stealth.展开更多
This article is about the absorbed-dose-dependent threshold voltage shift of the MOSFET transistors.Performance of the MOSFETs has been tested in different gate voltages.Sensitivity of the transistors for 662 ke V gam...This article is about the absorbed-dose-dependent threshold voltage shift of the MOSFET transistors.Performance of the MOSFETs has been tested in different gate voltages.Sensitivity of the transistors for 662 ke V gamma ray is studied in 1–5 Gy dose range.It was found that for transistors irradiated in biased mode,significant changes in the threshold voltage occurred,and the sensitivity to gamma rays increased with the bias voltage.展开更多
The deformation behavior of the Mg-Y-Nd-Zr （WE54） alloy at temperatures between 25 and 400 ℃ was investigated by uniaxial and plans strain compression tests at strain rate values of 10-2 and 10^-4 s^-1. The results...The deformation behavior of the Mg-Y-Nd-Zr （WE54） alloy at temperatures between 25 and 400 ℃ was investigated by uniaxial and plans strain compression tests at strain rate values of 10-2 and 10^-4 s^-1. The results showed that the flow stress had a strong dependency on the loading condition. Yield stress and peak stress decreased with increasing deformation temperature and with decrease in the strain rate for both deformation types. The serration flow behavior was observed markedly at high temperatures and under a strain rate of 10^-4S^-1. The serration amplitude for samples deformed by plans strain compression was larger than that by uni- axial compression. Serrated flow was attributed to the interaction of dislocations with precipitates at 300 ℃ and to dynamic discon- tinuous recrystallization effects at 400 ℃.展开更多
The interaction between a two-level atom and a single-mode field in the k-photon Jaynes-Cummings model （JCM） in the presence of the Stark shift and a Kerr medium is studied. All terms in the Hamiltonian, such as the...The interaction between a two-level atom and a single-mode field in the k-photon Jaynes-Cummings model （JCM） in the presence of the Stark shift and a Kerr medium is studied. All terms in the Hamiltonian, such as the single-mode field, its interaction with the atom, the contribution of the Stark shift and the Kerr medium effects are considered to be f-deformed. In particular, the effect of the initial state of the radiation field on the dynamical evolution of some physical properties such as atomic inversion and entropy squeezing are investigated by considering different initial field states （coherent, squeezed and thermal states）.展开更多
A Pb-0.08Ca-2Sn alloy was subjected to rolling at room temperature to different final thicknesses.Annealing treatments at temperature ranging from 80 to 120 °C led to recrystallization of the samples as shown by ...A Pb-0.08Ca-2Sn alloy was subjected to rolling at room temperature to different final thicknesses.Annealing treatments at temperature ranging from 80 to 120 °C led to recrystallization of the samples as shown by resistivity and micro-hardness measurements.The deformation texture determined through X-ray diffraction is qualitatively the Brass type.The measured Lankford anisotropy parameter R and its evolution are close to the determined one using a self consistent approach.The R value evolution with angle to rolling direction shows the presence of planar anisotropy and poor drawability.The recrystallization in annealing at 80-120 °C is achieved within time period up to 3×104 s.The recrystallization texture is a retained deformation texture with an emerging Cube component.展开更多
A series of Pr-Co thin films were deposited on the Si (100) substrates with Cr underlayer by magnetron sputtering. The effects of both the post-annealing temperature and the annealing time on the microstructure and ma...A series of Pr-Co thin films were deposited on the Si (100) substrates with Cr underlayer by magnetron sputtering. The effects of both the post-annealing temperature and the annealing time on the microstructure and magnetic properties for the Pr-Co films were studied systemati- cally. The as-deposited Pr-Co thin films are mostly amorphous and tend to crystallize after annealing at temperatures above 600 C. When the annealing time is increased, the films show a complicated structure with various phases coexisting. Accordingly, the as-deposited film and low temperature annealed films are soft magnets and films annealed at temperatures beyond 600 C tend to be hard magnets. When the annealing time is increased from 5 min to 2 h, the films transfer from hard magnets to soft again. The sample annealed at 600 C for 10 min shows the largest coercivity of 0.59 T.展开更多
We propose a self-organized optimization mechanism to improve the transport capacity of complex gradient networks. We find that, regardless of network topology, the congestion pressure can be strongly reduced by the s...We propose a self-organized optimization mechanism to improve the transport capacity of complex gradient networks. We find that, regardless of network topology, the congestion pressure can be strongly reduced by the self-organized optimization mechanism. Furthermore, the random scale-free topology is more efficient to reduce congestion compared with the random Poisson topology under the optimization mechanism. The reason is that the optimization mechanism introduces the correlations between the gradient field and the local topology of the substrate network. Due to the correlations, the cutoff degree of the gradient network is strongly reduced and the number of the nodes exerting their maximal transport capacity consumedly increases. Our work presents evidence supporting the idea that scale-free networks can efficiently improve their transport capacity by self- organized mechanism under gradient-driven transport mode.展开更多
Electrochemical CO2 reduction is a promising strategy for the utilization of CO2 and intermittent excess electricity.Cu is the only single metal catalyst that can electrochemically convert CO2 into multicarbon product...Electrochemical CO2 reduction is a promising strategy for the utilization of CO2 and intermittent excess electricity.Cu is the only single metal catalyst that can electrochemically convert CO2 into multicarbon products.However,Cu exhibits an unfavorable activity and selectivity for the generation of C2 products because of the insufficient amount of CO*provided for the C‐C coupling.Based on the strong CO2 adsorption and ultrafast reaction kinetics of CO*formation on Pd,an intimate CuPd(100)interface was designed to lower the intermediate reaction barriers and improve the efficiency of C2 product formation.Density functional theory(DFT)calculations showed that the CuPd(100)interface enhanced the CO2 adsorption and decreased the CO2*hydrogenation energy barrier,which was beneficial for the C‐C coupling.The potential‐determining step(PDS)barrier of CO2 to C2 products on the CuPd(100)interface was 0.61 eV,which was lower than that on Cu(100)(0.72 eV).Encouraged by the DFT calculation results,the CuPd(100)interface catalyst was prepared by a facile chemical solution method and characterized by transmission electron microscopy.CO2 temperature‐programmed desorption and gas sensor experiments further confirmed the enhancement of the CO2 adsorption and CO2*hydrogenation ability of the CuPd(100)interface catalyst.Specifically,the obtained CuPd(100)interface catalyst exhibited a C2 Faradaic efficiency of 50.3%±1.2%at‒1.4 VRHE in 0.1 M KHCO3,which was 2.1 times higher than that of the Cu catalyst(23.6%±1.5%).This study provides the basis for the rational design of Cu‐based electrocatalysts for the generation of multicarbon products by fine‐tuning the intermediate reaction barriers.展开更多
A mobile fiber-optic laser-induced breakdown spectrometer(FO-LIBS) prototype was developed to rapidly detect a large quantity of steel material online and quantitatively analyze the trace elements in a large-diameter ...A mobile fiber-optic laser-induced breakdown spectrometer(FO-LIBS) prototype was developed to rapidly detect a large quantity of steel material online and quantitatively analyze the trace elements in a large-diameter steel tube.Twenty-four standard samples and a polynomial fitting method were used to establish calibration curve models.The R^2 factors of the calibration curves were all above 0.99,except for Cu,indicating the elements’ strong self-absorption effect.Five special steel materials were rapidly detected in the steel mill.The average absolute errors of Mn,Cr,Ni,V,Cu,and Mo in the special steel materials were 0.039,0.440,0.033,0.057,0.003,and0.07 wt%,respectively,and their average relative errors fluctuated from 2.9% to 15.7%.The results demonstrated that the performance of this mobile FO-LIBS prototype can be compared with that of most conventional LIBS systems,but the more robust and flexible characteristics of the FO-LIBS prototype provide a feasible approach for promoting LIBS from the laboratory to the industry.展开更多
基金Sponsored by Ministry of Science and Higher Education within the Framework of Russian State Assignment(Grant No.124012500442⁃3).
文摘The modern definition of the wave concept,which is based on the functional connection between the parameters of the spatial structure of an instantaneous flow pattern and the characteristics of the temporal variability at a given point,is discussed.The dispersion relation for 2D plane periodic perturbations on the surface of viscous stratified fluid is selected as the characteristic function defining the wave motion.Using the theory of singular perturbations,a method for calculating complete solutions to the dispersion relations of periodic flows,including regular wave and singular ligament solutions is presented.Properties of the complete exact solution of the dispersion relation containing regular and singular functions are compared with asymptotic solutions.In limiting cases,obtained dispersion relations are matched with well⁃known expressions for waves in homogeneous viscous and ideal liquids.
基金Djordje Spasojevic and Svetislav Mijatovic acknowledge the support from the Ministry of Science,TechnologicalDevelopment and Innovation of the Republic of Serbia(Agreement No.451-03-65/2024-03/200162)S.J.ibid.(Agreement No.451-03-65/2024-03/200122)Bosiljka Tadic from the Slovenian Research Agency(program P1-0044).
文摘Disordered ferromagnets with a domain structure that exhibit a hysteresis loop when driven by the external magnetic field are essential materials for modern technological applications.Therefore,the understanding and potential for controlling the hysteresis phenomenon in thesematerials,especially concerning the disorder-induced critical behavior on the hysteresis loop,have attracted significant experimental,theoretical,and numerical research efforts.We review the challenges of the numerical modeling of physical phenomena behind the hysteresis loop critical behavior in disordered ferromagnetic systems related to the non-equilibriumstochastic dynamics of domain walls driven by external fields.Specifically,using the extended Random Field Ising Model,we present different simulation approaches and advanced numerical techniques that adequately describe the hysteresis loop shapes and the collective nature of the magnetization fluctuations associated with the criticality of the hysteresis loop for different sample shapes and varied parameters of disorder and rate of change of the external field,as well as the influence of thermal fluctuations and demagnetizing fields.The studied examples demonstrate how these numerical approaches reveal newphysical insights,providing quantitativemeasures of pertinent variables extracted from the systems’simulated or experimentally measured Barkhausen noise signals.The described computational techniques using inherent scale-invariance can be applied to the analysis of various complex systems,both quantum and classical,exhibiting non-equilibrium dynamical critical point or self-organized criticality.
基金supported by the Icelandic research fund,Grant No.239987-051by Landsvirkjun-Energy Research Fund,Grant No.NYR-29-2024。
文摘In this study,we investigate an innovative hybrid structure of silicon nanowires(SiNWs)coated with polyaniline(PANI):metal oxide(MO_(x))nanoparticles,i.e.,WO_(3)and TiO_(2),for respiratory sensing.To date,few attempts have been made to utilize such hybrid structures for that application.The Si NWs were fabricated using metal-assisted chemical etching(MACE),whereas PANI:MO_(x)was deposited using chemical oxidative polymerization.The structures were characterized using Raman spectroscopy,X-ray diffraction,and scanning electron microscopy.The sensing characteristics revealed that the hybrid sensor exhibited a considerably better response than pure Si NWs:MO_(x)and Si NWs:PANI.Such an enhancement in sensitivity is attributed to the formation of a p-n heterojunction between PANI and MO_(x),the wider conduction channel provided by PANI,increased porosity in SiNWs/PANI:WO_(3)hybrid structures,which creates active sites,increased oxygen vacancies,and the large surface area compared to that available in pure MO_(x)nanoparticles.Furthermore,less baseline drift and increased sensor stability were established for the SiNWs structure coated with PANI:WO_(3),as compared to PANI:TiO_(2).
基金supported by the Spanish Ministry of Science and Innovation under the MCI/AEI/FEDER project number PID2021-123543OBC21.
文摘Anomaly detection in wind turbines involves emphasizing its ability to improve operational efficiency,reduce maintenance costs,extend their lifespan,and enhance reliability in the wind energy sector.This is particularly necessary in offshore wind,currently one of the most critical assets for achieving sustainable energy generation goals,due to the harsh marine environment and the difficulty of maintenance tasks.To address this problem,this work proposes a data-driven methodology for detecting power generation anomalies in offshore wind turbines,using normalized and linearized operational data.The proposed framework transforms heterogeneous wind speed and power measurements into a unified scale,enabling the development of a new wind power index(WPi)that quantifies deviations from expected performance.Additionally,spatial and temporal coherence analyses of turbines within a wind farm ensure the validity of these normalized measurements across different wind turbine models and operating conditions.Furthermore,a Support Vector Machine(SVM)refines the classification process,effectively distinguishing measurement errors from actual power generation failures.Validation of this strategy using real-world data from the Alpha Ventus wind farm demonstrates that the proposed approach not only improves predictive maintenance but also optimizes energy production,highlighting its potential for broad application in offshore wind installations.
基金supported by the Russian Science Foundation (Grant No. 22-12-00298)supported by the Center of Excellence "Center of Photonics" funded by the Ministry of Science and Higher Education of the Russian Federation, Contract #075-15-2022-316the Theoretical Physics and Mathematics Advancement Foundation "BASIS" scholarship for the support.
文摘In this work,we studied the persistent photoconductivity(PPC)spectra in single HgTe/CdHgTe quantum wells with different growth parameters and different types of dark conductivity.The studies were performed in a wide radiation quantum energy range of 0.62–3.1 eV both at T=4.2 K and at T=77 K.Common features of the PPC spectra for all structures were revealed,and their relation to the presence of a CdTe cap layer in all structures and the appropriate cadmium fraction in the CdHgTe barrier layers was shown.One of the features was associated with the presence of a deep level in the CdTe layer.In addition,the oscillatory behavior of the PPC spectra in the region from 0.8–1.1 eV to 1.2–1.5 eV was observed.It is associated with the cascade emission of longitudinal optical phonons in CdHgTe barrier.
基金supported by the National Key R&D Program of China(No.2022YFE0204100)National Natural Science Foundation of China(Nos.12205067 and 12375199)the Fundamental Research Funds for the Central University(No.HIT.D?J.2023178)。
文摘This work continues the studies on searching for plasma media with the inverse electron energy distribution function(EEDF)and providing recommendations for setting up subsequent experiments.The inverse EEDF is a distribution function that increases with an increase in energy at zero electron energy.The inverse EEDF plays a central role in the problem of negative conductivity.Based on the previously obtained criterion for the formation of an inverse EEDF in a spatially inhomogeneous plasma,a heuristic method is proposed that allows one to avoid resource-intensive calculations for spatially two-dimensional(2D)kinetic modeling on a large array of different glow discharges.It is shown that the conditions for EEDF inversion can be realized in two-chamber discharge structures due to violating the known Boltzmann distribution for electron density.The theoretical conclusions are validated by numerical modeling of lowpressure two-chamber inductively-coupled plasma(ICP)discharges in the COMSOL Multiphysics environment.As a result,areas of conditions with inverse EEDF were found for subsequent detailed kinetic analysis and experimental studies.
基金financially supported by the Russian Science Foundation(No.23-43-00057)the International Cooperation Program of the Natural Science Foundation of China(No.52261135542)。
文摘The aim of this study is to develop magnetopolymer composites suitable for fabricating soft magnetoactive robots via extrusion-based3D printing.Polysiloxane copolymers with urea fragments were synthesized and characterized,and their thermophysical and rheological properties were investigated.This study provides an assessment of the potential for their further use in additive manufacturing.The obtained materials were utilized as matrices for creating magnetically active polymer composites by incorporating microparticles of carbonyl iron.Samples of complex geometries were printed using both neat and filled filaments,demonstrating the feasibility of employing these materials in extrusion-based 3D printing.
基金supported by the Extreme Light Infrastructure–Nuclear Physics(ELI-NP)PhaseⅡa project co-finance by the Romanian Government and the European Union through the European Regional Development Fund,by the Romanian Ministry of Education and Research CNCS-UEFISCDI(Project No.PN-ⅡIP4-IDPCCF-2016-0164)+1 种基金Nucleu Projects(Grant No.PN 23210105 and 19060105)supports ELI-NP through IOSIN funds as a Facility of National Interest。
文摘High-power laser systems have opened new frontiers in scientifi research and have revolutionized various scientifi fields offering unprecedented capabilities for understanding fundamental physics and allowing unique applications.This paper details the successful commissioning of the 1 PW experimental area at the Extreme Light Infrastructure–Nuclear Physics(ELI-NP)facility in Romania,using both of the available laser arms.The experimental setup featured a short focal parabolic mirror to accelerate protons through the target normal sheath acceleration mechanism.Detailed experiments were conducted using various metallic and diamond-like carbon targets to investigate the dependence of the proton acceleration on different laser parameters.Furthermore,the paper discusses the critical role of the laser temporal profil in optimizing proton acceleration,supported by hydrodynamic simulations that are correlated with experimental outcomes.The finding underscore the potential of the ELI-NP facility to advance research in laser–plasma physics and contribute significantl to high-energy physics applications.The results of this commissioning establish a strong foundation for experiments by future users.
基金supported by the Zhejiang Provincial Natural Science Foundation of China(LQ23C200003)National Natural Science Foundation of China(32202076)Natural Science Foundation of Shandong Province(Project No.ZR2023QC083).
文摘Starch retrogradation is a primary contributor to the staling of bread.The impact of the surfactant glyceryl monostearate(GMS)on the structure and retrogradation characteristics of wheat starch gels was explored during storage at 4℃ for 2 h and 5 d.In this research,the incorporation of GMS(0.14%,W/W,based on flour weight)significantly reduced the crumb firmness(P<0.05).Molecular dynamics simulation vividly demonstrated the formation process of the single-helical amylose-GMS complex within 150 ns during the short-term retrogradation process of cooling the gelatinized starch for 2 h.X-ray diffraction analysis revealed that GMS slightly decreased the relative crystallinity of starch from 8.9%to 7.8%during long-term retrogradation.The reduction in R1047/1022 detected by Fourier-transform infrared spectroscopy indicated that GMS could reduce the degree of retrogradation.Solid-state ^(13)C NMR analysis showed a characteristic resonance peak at 31.7 ppm for the GMSstarch complex.This study indicates that GMS holds great application potential in retarding starch retrogradation.
文摘Objective: We describe patients with MCS, the evolution of the Quick Environmental Exposure and Sensitivity Inventory (QEESI) score with a special focus on people whose fillings were removed. Methods: We have conducted a retrospective longitudinal cohort study in patients diagnosed with MCS and attended in the outpatient Internal Medicine department of the University Hospital of San Juan de Alicante, from January 1, 2008 to January 1, 2021. Sociodemographic, clinical, QEESI and treatment-related variables were collected. We performed descriptive and inferential analyses. Mixed linear models were used to analyze the QEESI. Calculations were carried out with an α error of 5%. Results: Thirty-three patients were included (72.7% women, mean age 56.2). MCS was mainly triggered by mercury (N = 20) and food intolerance (N = 22). The mean interval from symptoms onset was 120 months (SD 81.6). 114 QEESIs were analyzed: 82 (N = 17 without amalgams) and 32 (N = 16 with amalgams). In patients without amalgams, severity scores increased across all subscales except the masking index (vs. with amalgams). Mean scores for the group without amalgams (vs. with amalgams) were: chemical intolerance, 62.8 points (vs. 63.4 and 46.7);other intolerances, 52.7 points (vs. 62.8 and 50.3);symptom severity, 63.2 (vs. 76.7 and 63.3);masking index, 3.9 (vs. 3.2 and 2.8);and life impacts, 63.1 (vs. 58.4 and 49.8). Conclusion: The profile of patient with MCS is a middle-aged woman who is a frequent user of healthcare services, presents a long diagnostic delay and has borne a great personal, work and socioeconomic impact. The QEESI is useful for the clinical follow-up of patients, including the optimal treatment response in the case of amalgams. Clinical Significance: People affected by Multiple Chemical Sensitivity deserve the attention, understanding and help of health professionals and family members, to face an invisible illness for those who do not suffer from it. Support is needed and doctors must raise awareness, and make an effort to understand and address this pathology. We suggest that protocolized amalgam extraction in accredited and prepared centers can reduce symptoms and improve quality of life, generating clinical, personal, family, occupational, social and occupational benefits.
基金financial support from the National Nature Science Foundation of China(No.51971111).
文摘Developing ultrabroad radar-infrared compatible stealth materials has turned into a research hotspot,which is still a problem to be solved.Herein,the copper sulfide wrapped by reduced graphene oxide to obtain three-dimensional(3D)porous network composite aerogels(CuS@rGO)were synthesized via thermal reduction ways(hydrothermal,ascorbic acid reduction)and freeze-drying strategy.It was discovered that the phase components(rGO and CuS phases)and micro/nano structure(microporous and nanosheet)were well-modified by modulating the additive amounts of CuS and changing the reduction ways,which resulted in the variation of the pore structure,defects,complex permittivity,microwave absorption,radar cross section(RCS)reduction value and infrared(IR)emissivity.Notably,the obtained CuS@rGO aerogels with a single dielectric loss type can achieve an ultrabroad bandwidth of 8.44 GHz at 2.8 mm with the low filler content of 6 wt%by a hydrothermal method.Besides,the composite aerogel via the ascorbic acid reduction realizes the minimum reflection loss(RL_(min))of−60.3 dB with the lower filler content of 2 wt%.The RCS reduction value can reach 53.3 dB m^(2),which effectively reduces the probability of the target being detected by the radar detector.Furthermore,the laminated porous architecture and multicomponent endowed composite aerogels with thermal insulation and IR stealth versatility.Thus,this work offers a facile method to design and develop porous rGO-based composite aerogel absorbers with radar-IR compatible stealth.
文摘This article is about the absorbed-dose-dependent threshold voltage shift of the MOSFET transistors.Performance of the MOSFETs has been tested in different gate voltages.Sensitivity of the transistors for 662 ke V gamma ray is studied in 1–5 Gy dose range.It was found that for transistors irradiated in biased mode,significant changes in the threshold voltage occurred,and the sensitivity to gamma rays increased with the bias voltage.
文摘The deformation behavior of the Mg-Y-Nd-Zr （WE54） alloy at temperatures between 25 and 400 ℃ was investigated by uniaxial and plans strain compression tests at strain rate values of 10-2 and 10^-4 s^-1. The results showed that the flow stress had a strong dependency on the loading condition. Yield stress and peak stress decreased with increasing deformation temperature and with decrease in the strain rate for both deformation types. The serration flow behavior was observed markedly at high temperatures and under a strain rate of 10^-4S^-1. The serration amplitude for samples deformed by plans strain compression was larger than that by uni- axial compression. Serrated flow was attributed to the interaction of dislocations with precipitates at 300 ℃ and to dynamic discon- tinuous recrystallization effects at 400 ℃.
文摘The interaction between a two-level atom and a single-mode field in the k-photon Jaynes-Cummings model （JCM） in the presence of the Stark shift and a Kerr medium is studied. All terms in the Hamiltonian, such as the single-mode field, its interaction with the atom, the contribution of the Stark shift and the Kerr medium effects are considered to be f-deformed. In particular, the effect of the initial state of the radiation field on the dynamical evolution of some physical properties such as atomic inversion and entropy squeezing are investigated by considering different initial field states （coherent, squeezed and thermal states）.
文摘A Pb-0.08Ca-2Sn alloy was subjected to rolling at room temperature to different final thicknesses.Annealing treatments at temperature ranging from 80 to 120 °C led to recrystallization of the samples as shown by resistivity and micro-hardness measurements.The deformation texture determined through X-ray diffraction is qualitatively the Brass type.The measured Lankford anisotropy parameter R and its evolution are close to the determined one using a self consistent approach.The R value evolution with angle to rolling direction shows the presence of planar anisotropy and poor drawability.The recrystallization in annealing at 80-120 °C is achieved within time period up to 3×104 s.The recrystallization texture is a retained deformation texture with an emerging Cube component.
基金supported by the National Natural Science Foundation of China (No. 50801023)Educational Commission of Hubei Province (No. D20091008)the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry (SRF for ROCS, SEM)
文摘A series of Pr-Co thin films were deposited on the Si (100) substrates with Cr underlayer by magnetron sputtering. The effects of both the post-annealing temperature and the annealing time on the microstructure and magnetic properties for the Pr-Co films were studied systemati- cally. The as-deposited Pr-Co thin films are mostly amorphous and tend to crystallize after annealing at temperatures above 600 C. When the annealing time is increased, the films show a complicated structure with various phases coexisting. Accordingly, the as-deposited film and low temperature annealed films are soft magnets and films annealed at temperatures beyond 600 C tend to be hard magnets. When the annealing time is increased from 5 min to 2 h, the films transfer from hard magnets to soft again. The sample annealed at 600 C for 10 min shows the largest coercivity of 0.59 T.
基金Supported by the Education Foundation of Hubei Province under Grant No D20120104
文摘We propose a self-organized optimization mechanism to improve the transport capacity of complex gradient networks. We find that, regardless of network topology, the congestion pressure can be strongly reduced by the self-organized optimization mechanism. Furthermore, the random scale-free topology is more efficient to reduce congestion compared with the random Poisson topology under the optimization mechanism. The reason is that the optimization mechanism introduces the correlations between the gradient field and the local topology of the substrate network. Due to the correlations, the cutoff degree of the gradient network is strongly reduced and the number of the nodes exerting their maximal transport capacity consumedly increases. Our work presents evidence supporting the idea that scale-free networks can efficiently improve their transport capacity by self- organized mechanism under gradient-driven transport mode.
文摘Electrochemical CO2 reduction is a promising strategy for the utilization of CO2 and intermittent excess electricity.Cu is the only single metal catalyst that can electrochemically convert CO2 into multicarbon products.However,Cu exhibits an unfavorable activity and selectivity for the generation of C2 products because of the insufficient amount of CO*provided for the C‐C coupling.Based on the strong CO2 adsorption and ultrafast reaction kinetics of CO*formation on Pd,an intimate CuPd(100)interface was designed to lower the intermediate reaction barriers and improve the efficiency of C2 product formation.Density functional theory(DFT)calculations showed that the CuPd(100)interface enhanced the CO2 adsorption and decreased the CO2*hydrogenation energy barrier,which was beneficial for the C‐C coupling.The potential‐determining step(PDS)barrier of CO2 to C2 products on the CuPd(100)interface was 0.61 eV,which was lower than that on Cu(100)(0.72 eV).Encouraged by the DFT calculation results,the CuPd(100)interface catalyst was prepared by a facile chemical solution method and characterized by transmission electron microscopy.CO2 temperature‐programmed desorption and gas sensor experiments further confirmed the enhancement of the CO2 adsorption and CO2*hydrogenation ability of the CuPd(100)interface catalyst.Specifically,the obtained CuPd(100)interface catalyst exhibited a C2 Faradaic efficiency of 50.3%±1.2%at‒1.4 VRHE in 0.1 M KHCO3,which was 2.1 times higher than that of the Cu catalyst(23.6%±1.5%).This study provides the basis for the rational design of Cu‐based electrocatalysts for the generation of multicarbon products by fine‐tuning the intermediate reaction barriers.
基金supported by National Natural Science Foundation of China(Nos.61705064,11647122)the Natural Science Foundation of Hubei Province(Nos.2018CFB773,2018CFB672)the Project of the Hubei Provincial Department of Education(No.T201617)。
文摘A mobile fiber-optic laser-induced breakdown spectrometer(FO-LIBS) prototype was developed to rapidly detect a large quantity of steel material online and quantitatively analyze the trace elements in a large-diameter steel tube.Twenty-four standard samples and a polynomial fitting method were used to establish calibration curve models.The R^2 factors of the calibration curves were all above 0.99,except for Cu,indicating the elements’ strong self-absorption effect.Five special steel materials were rapidly detected in the steel mill.The average absolute errors of Mn,Cr,Ni,V,Cu,and Mo in the special steel materials were 0.039,0.440,0.033,0.057,0.003,and0.07 wt%,respectively,and their average relative errors fluctuated from 2.9% to 15.7%.The results demonstrated that the performance of this mobile FO-LIBS prototype can be compared with that of most conventional LIBS systems,but the more robust and flexible characteristics of the FO-LIBS prototype provide a feasible approach for promoting LIBS from the laboratory to the industry.
