- 标题
- 摘要
- 关键词
- 实验方案
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Handling Electromagnetic Radiation beyond Terahertz using Chromophores to Transition from Visible Light to Petahertz Technology
摘要： An increase of the operating frequencies of electromagnetic waves leads from the well-established terahertz technology to the visual and reaches petahertz radiation. It is shown that electromagnetic radiation close to petahertz is attractive for technology where knowledge about radio waves can be applied. The dimensions of such radiation are still classically macroscopic; however, molecular components such as resonators were used where quantum mechanics rules have to be considered. Constructions of coupled resonators for energy transfer are as well demonstrated as molecular components for optical metamaterials.
关键词： Dyes,FRET,Energy transfer,Reflectance,Petahertz,Visible light,Resonators,Metamaterials,Terahertz,Electromagnetic radiation
更新于2025-09-23 15:23:52
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[IEEE 2018 Applications of Electromagnetics in Modern Techniques and Medicine (PTZE) - Rac?awice (2018.9.9-2018.9.12)] 2018 Applications of Electromagnetics in Modern Techniques and Medicine (PTZE) - Attenuation of High Frequency Electromagnetic Waves by Polymer Composites with Waste Materials
摘要： Composite materials with polymers and waste materials like zinc ore, mill scale, and iron dust are studied with respect to attenuation of electromagnetic radiation of high frequency. Samples of such composites were prepared and tested for several frequencies in 8-12 GHz band. The composites relatively strongly attenuate electromagnetic radiation in the considered band. Using various waste materials has also ecological aspect.
关键词： electromagnetic radiation,high frequency,attenuation,polymer composites,waste materials
更新于2025-09-23 15:22:29
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[IEEE 2018 20th International Symposium on High-Current Electronics (ISHCE) - Tomsk, Russia (2018.9.16-2018.9.22)] 2018 20th International Symposium on High-Current Electronics (ISHCE) - Cherenkov Ka-Band Oscillator with 45% Efficiency of Beam-to-Microwave Power Conversion
摘要： The paper describes a study of a new relativistic microwave Cherenkov generator of millimeter wavelength range with the transverse dimension of the electrodynamic system D>2.5λ, where D is the average diameter of the slow wave structure, and λ is the radiation wavelength. The investigations were carried out with a high-current SINUS-200 electron accelerator at a voltage of 473 kV and an electron beam current of 3.8 kA. The use of several, complementing each other, mechanisms of suppression of parasitic waves provides stable microwave generation at a specified frequency of 36.4 GHz. The microwave power in the experiment 804 MW with 45% beam-to microwave power conversion.
关键词： amplitude modulation of high-current electron beam,slow wave structures,Cherenkov radiation,electromagnetic radiation
更新于2025-09-23 15:21:21
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Adaptive Synchronization of Fractional-Order Coupled Neurons Under Electromagnetic Radiation
摘要： In this paper, we investigate the dynamical characteristics of four-variable fractional-order Hindmarsh–Rose neuronal model under electromagnetic radiation. The numerical results show that the improved model exhibits more complex dynamical behavior with more bifurcation parameters. Meanwhile, based on the fractional-order Lyapunov stability theory, we propose two adaptive control methods with a single controller to realize chaotic synchronization between two coupled neurons. Finally, numerical simulations show the feasibility and effectiveness of the presented method.
关键词： fractional-order,neuron,adaptive control,synchronization,Electromagnetic radiation
更新于2025-09-23 15:21:01
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Structural Modification of Graphene on Copper Substrates Irradiated by Nanosecond High-Intensity Ion Beams
摘要： Interaction of a nanosecond high-intensity pulsed ion beam with thin graphene films on copper substrates is analyzed. Methods of Raman spectroscopy are used to investigate the degree of graphene degradation depending on the integral implanted dose. The role of the substrate in the structural degradation of graphene irradiated by charged particle beams is demonstrated using the software package SRIM, intended for modeling radiative defect cascades under irradiation by charged particle beams, and the data on radiation resistance of graphene available in the literature.
关键词： graphene,electromagnetic radiation,high-intensity ion beams
更新于2025-09-23 15:19:57
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PC 12 Pheochromocytoma Cell Response to Super High Frequency Terahertz Radiation from Synchrotron Source
摘要： High frequency (HF) electromagnetic ?elds (EMFs) have been widely used in many wireless communication devices, yet within the terahertz (THz) range, their effects on biological systems are poorly understood. In this study, electromagnetic radiation in the range of 0.3–19.5 × 1012 Hz, generated using a synchrotron light source, was used to investigate the response of PC 12 neuron-like pheochromocytoma cells to THz irradiation. The PC 12 cells remained viable and physiologically healthy, as con?rmed by a panel of biological assays; however, exposure to THz radiation for 10 min at 25.2 ± 0.4 ?C was suf?cient to induce a temporary increase in their cell membrane permeability. High-resolution transmission electron microscopy (TEM) con?rmed cell membrane permeabilization via visualisation of the translocation of silica nanospheres (d = 23.5 ± 0.2 nm) and their clusters (d = 63 nm) into the PC 12 cells. Analysis of scanning electron microscopy (SEM) micrographs revealed the formation of atypically large (up to 1 μm) blebs on the surface of PC 12 cells when exposed to THz radiation. Long-term analysis showed no substantial differences in metabolic activity between the PC 12 cells exposed to THz radiation and untreated cells; however, a higher population of the THz-treated PC 12 cells responded to the nerve growth factor (NGF) by extending longer neurites (up to 0–20 μm) compared to the untreated PC12 cells (up to 20 μm). These ?ndings present implications for the development of nanoparticle-mediated drug delivery and gene therapy strategies since THz irradiation can promote nanoparticle uptake by cells without causing apoptosis, necrosis or physiological damage, as well as provide a deeper fundamental insight into the biological effects of environmental exposure of cells to electromagnetic radiation of super high frequencies.
关键词： super high frequency,electromagnetic radiation,cell viability,PC 12 neuronal cells,terahertz exposure
更新于2025-09-19 17:15:36
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The Encyclopedia of Archaeological Sciences || Multispectral and Hyperspectral Imaging
摘要： In the field of archaeology (and heritage in general), many documentation and examination methods are based on imaging techniques that characterize and depict artifacts in a nondestructive and mechanically noninvasive way. Multi- and hyperspectral imaging (together denoted spectral imaging) are two possible forms of such noninvasive imaging. Both are based on the detection of reflected or emitted optical electromagnetic radiation, the latter being defined as electromagnetic waves with wavelengths between 10 nm (0.01 μm) and 1 mm (1,000 μm). This detection can be better understood when considering that optical digital imaging usually generates a signal that is the outcome of a three-variable process: electromagnetic radiation of a radiation source falls onto the object; this radiation is partly absorbed, transmitted, and reflected by the object, with the interaction being wavelength dependent; and the imager detects and digitizes the incoming radiance in specific spectral regions. Spectral imaging extends traditional trichromatic digital camera approaches by capturing data in at least four different spectral bands, with hyperspectral imaging featuring higher spectral resolution and more contiguous spectra. Applications include archaeological prospection, color-accurate documentation, material identification, and enhancing the reading of old documents. Drawbacks involve data quantity, noise proneness, and reliance on specialized hardware and software, with future research focusing on active systems like multi-wavelength laser scanners.
关键词： multispectral imaging,archaeology,hyperspectral imaging,data cube,spectral signature,future research,drawbacks,electromagnetic radiation,noninvasive imaging,applications,spectral imaging,heritage
更新于2025-09-19 17:15:36
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[IEEE 2019 IEEE Innovative Smart Grid Technologies - Asia (ISGT Asia) - Chengdu, China (2019.5.21-2019.5.24)] 2019 IEEE Innovative Smart Grid Technologies - Asia (ISGT Asia) - Designs and Applications for the Controller Parameters of the Photovoltaic System
摘要： Many economically important minerals have absorption features in the short-wave infrared (SWIR; 2000–2500 nm). Sensors which measure this part of the spectrum cannot detect the wavelength minimum of a feature at ～900 nm (F900), indicative of ferric iron mineralogy. A method based on Gaussian processes (GPs) was developed and compared with multiple linear regression (MLR) to estimate the wavelength position of F900 from SWIR data (1002–1355 nm). SWIR data with different signal-to-noise ratios were acquired from crushed rock samples by a nonimaging spectrometer and an imaging spectrometer. GP estimates of wavelength position were converted to the proportion of goethite using coefficients from a regression of the proportion of goethite determined from X-ray diffraction (XRD) on wavelength position measured directly from spectra. GP-estimated wavelength positions were within the 2-nm and ～4-nm root-mean-square error of measurements made directly from spectra for nonimaging and imaging spectrometer data, respectively. Proportions of goethite derived from these estimates were respectively within 4% and 6% of the values measured by XRD. MLR performed poorly compared to GPs when applied to data with no added noise and failed when applied to data with added noise or to imaging spectrometer data. These findings indicate that the wavelength position of F900—an indicator of ferric iron mineralogy—can be estimated from data acquired at SWIR wavelengths (1002–1355 nm). This opens up possibilities for using a single (SWIR) sensor to acquire information on ferric iron mineralogy (using F900) and other minerals with diagnostic absorptions between 1000 and 2500 nm.
关键词： geology,infrared spectroscopy,iron,image sensors,remote sensing,Gaussian processes (GPs),mining industry,Electromagnetic radiation,spectral analysis,signal processing
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers (CAOL) - Sozopol, Bulgaria (2019.9.6-2019.9.8)] 2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers (CAOL) - Spontaneous bremsstrahlung of ultrarelativistic electrons within the resonant conditions in the field of a nucleus and external electromagnetic field
摘要： We have developed small-sized terahertz free-electron lasers by using low-cost and compact microtrons combining with magnetrons as high-power RF sources. We could stabilize the bunch repetition rate by optimizing a modulator for the magnetron and by coupling the magnetron with an accelerating cavity in the microtron. By developing high-performance undulators and low-loss waveguide-mode resonators having small cross-sectional areas, we could strengthen the interaction between the electron beam and the THz wave inside the FEL resonators to achieve lasing even with low-current electron beams from the microtron. We used a parallel-plate waveguide in a planar electromagnet undulator for our ?rst THz FEL. We try to reduce the size of the FEL resonator by combining a dielectric-coated circular waveguide and a variable-period helical undulator to realize a table-top THz FEL for applying it to the security inspection on airports.
关键词： submillimeter wave technology,free electron lasers,submillimeter wave propagation,electron beams,undulators,Electromagnetic radiation
更新于2025-09-16 10:30:52
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Bursting and Synchronization of Coupled Neurons under Electromagnetic Radiation
摘要： Bursting is an important firing activity of neurons, which is caused by a slow process that modulates fast spiking activity. Based on the original second-order Morris-Lecar neuron model, an improved third-order Morris-Lecar neuron model can produce bursting activity is proposed, in which the effect of electromagnetic radiation is considered as a slow process and the original equation of Morris-Lecar neuron model as a fast process. Extensive numerical simulation results show that the improved neuron model can produce different types of bursting, and bursting activity shows a deep dependence on system parameters and electromagnetic radiation parameters. In addition, synchronization transitions of identical as well as no-identical coupled third-order Morris-Lecar neurons are studied, the results show that identical coupled neurons experience a complex synchronization process and reach complete synchronization finally with the increase of coupling intensity. For no-identical coupled neurons, only anti-phase synchronization and in-phase synchronization can be reached. The studies of bursting activity of single neuron and synchronization transition of coupled neurons have important guiding significance for further understanding the information processing of neurons and collective behaviors in neuronal network under electromagnetic radiation environment.
关键词： Synchronization,Morris-Lecar neuron model,Bursting,Electromagnetic radiation,Neuronal network
更新于2025-09-12 10:27:22