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Molecular electronic spin qubits from a spin-frustrated trinuclear copper complex
摘要： The trinuclear copper(II) complex [Cu3(saltag)(py)6]ClO4 (H5saltag = tris(2-hydroxybenzylidene)triaminoguanidine) was synthesized and characterized by experimental as well as theoretical methods. This complex exhibits a strong antiferromagnetic coupling (J = (cid:2)298 cm(cid:2)1) between the copper(II) ions, mediated by the N–N diazine bridges of the tritopic ligand, leading to a spin-frustrated system. This compound shows a T2 coherence time of 340 ns in frozen pyridine solution, which extends to 591 ns by changing the solvent to pyridine-d5. Hence, the presented compound is a promising candidate as a building block for molecular spintronics.
关键词： antiferromagnetic coupling,trinuclear copper(II) complex,molecular spintronics,spin-frustrated system
更新于2025-09-04 15:30:14
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Hypercolorimetric multispectral imaging system for cultural heritage diagnostics: an innovative study for copper painting examination
摘要： The aim of this work is to test the application of a new multispectral imaging system, named Hypercolorimetric Multispectral Imaging, on two little 17th century oil paintings on copper in order to support the restoration activities. Hypercolorimetric Multispectral Imaging is a non-invasive, rapid and diagnostic technique that allows in situ accurate and reproducible spectral reflectance measurements between 300 nm and 1000 nm to obtain seven monochromatic very high spatial resolution images (36 megapixels starting from RAW format). The acquired images are transformed into radiometric and colorimetric measurements, consisting of 7 monochromatic images of spectral reflectance and one colorimetric image. All these calibrated images constitute the base for further processing performed through a dedicated software that implements a number of functions. In the present paper, a subset of those functions has been used. Specifically: Principal Component Analysis, spectral clustering, spectral mapping, multiband contrast enhancement and edge detection. Combining calibrated images of different spectral regions acquisitions, it was possible to extract relevant information about the state of conservation of the two copper paintings and further significant details were readable compared with the data coming from each single acquisition. The Hypercolorimetric Multispectral Imaging acquisition process revealed to be fast allowing to be performed during the cleaning stage of the paintings. The imaging nature of the analysis allowed to compare and map different areas of the surfaces producing degradation maps of the painting layers, which represents a precious decision-making tool for conservators.
关键词： copper painting examination,non-invasive technique,cultural heritage diagnostics,restoration support,Hypercolorimetric Multispectral Imaging
更新于2025-09-04 15:30:14
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Filmes de disseleneto de cobre e índio depositados por spray-pirólise
摘要： Cu1-xInxSe2 (0.45≤x≤0.80) films were deposited on glass substrate by spray pyrolysis technique, for use as absorbing layer of photovoltaic cells. The structural, morphological, optical and electrical properties of the films were analyzed according to the variation of the stoichiometry used. The analysis by X-ray diffraction showed that the most intense peaks were of orientation (204/220) and the films have the phases CuSe, CuSe2 and CuInSe2. The films showed uniform surface without cracks independently of the stoichiometry used. In the electrical characterization, the deposited films showed activation energy of the electrical conduction process with average value of 0.74 eV and typical behavior for semiconductors. The optical characterization was performed at the wavelength gap of 350 to 1100 nm, and the films showed absorption coefficient on the order of 103 cm-1 in the wavelength of 550 nm and optical band gap of 1.4 eV. The results indicated that the most suitable condition for deposition of films for their application as absorbing layer had as substrate temperature 400 °C, a solution flow rate of 1 mL/min, deposition time of 10 min and stoichiometry of Cu0.2In0.8Se2, thus obtaining films without cracks, with large absorption coefficient of 6.8x103 cm-1 for the wavelength of 550 nm, thickness of approximately 2.5 μm and electrical resistivity of 0.13 k .m at room temperature.
关键词： absorbing layer,copper indium diselenide,spray-pyrolysis
更新于2025-09-04 15:30:14
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CHARACTERISATION OF COPPER NANOPARTICLE INK PRINTED FSS FOR CELLULAR SIGNALS SUPPRESSION
摘要： This paper proposes a copper nanoparticle ink printed frequency selective surface (FSS) for cellular signals suppression. The FSS pattern is deposited on a polyimide film by using an inkjet printing technique. The printed FSS elements undergo the post-processing called sintering, where the optimum exposure duration and temperature are determined in order to form a conductive path across the metal pattern. Later, the conductivity of the printed FSS structure deposited on polyimide film is observed. The signal suppression ability of the printed FSS is conducted using the Computer Simulation Technology (CST) Microwave Studio software.
关键词： cellular signals suppression,inkjet printing,copper nanoparticle ink,frequency selective surface,sintering
更新于2025-09-04 15:30:14
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Analysis of Secondary Photons Emergent from Combined Material Slab as a Function of Slab Thickness
摘要： Material science is very important for developing the linear accelerator. Determination and understanding of material behavior face to X-rays is a basic study for photon beam modifiers improvements. In this study, the 6 MV photon beams produced by Varian Clinac 2100 was modelled by Monte Carlo simulation using BEAMnrc code and thereafter the flattening filter was replaced by a slab of aluminum and copper separately and by slab of both materials combined together with different thickness of 2.5, 5, 7.5, and 10 mm. The purpose of this study is to investigate the scattered photons with thickness of combined material slab as a function of off-axis distance. The scattered photons increased with thickness of copper alone slab, combined aluminum-copper slab and copper-aluminum slab, but for aluminum alone slab they decreased with slab thickness. The stacking order of these two materials affects the characterization of scattered photons emergent from material slab with thickness. The combination of materials and the manner that the stacking was done affects the scattered photons production. The material combination could improve the radiotherapy efficiency in beam modifier development using more than two materials.
关键词： Monte Carlo simulation,BEAMnrc code,scattered photons,copper slab,aluminum slab,BEAMDP code
更新于2025-09-04 15:30:14
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Raman spectroscopy analysis of new copper‐cysteamine photosensitizer
摘要： Raman spectroscopy and several microstructure analysis techniques have been used to better characterize recently synthesized copper‐cysteamine Cu3Cl(SR)2, where R = CH2CH2NH2. Nanoparticles of this new copper‐cysteamine have been identified as having potential applications in radiation detection and cancer treatment because of the fact that they can be activated by light, X‐rays, ultrasound, and microwave radiation to produce reactive oxygen species. Three samples were grown under different conditions, and their microstructure was examined by using Raman spectroscopy, Fourier transform infrared, scanning electron microscopy, energy dispersive X‐ray scattering, and X‐ray diffraction. The Raman spectroscopy and Fourier transform infrared measurements identify numerous Raman active and infrared absorption bonds with wavenumbers ranging from 200 to 3,500 cm?1. Scanning electron microscopy scans show well‐faceted crystals varying in size from approximately 10 nm to 4 μm, energy dispersive X‐ray scattering measurements identify relative elemental composition (C = 48%, N = 37.5%, S = 5%, Cl = 2.6%, Cu = 7%), X‐ray diffraction data show the crystal plane spacing varies from 0.8454 to 0.8616 nm. The microstructure observed for the three samples is consistent with variations in the growth conditions.
关键词： microstructure,optical spectroscopy of interatomic bonds,cancer treatment,radiation detection,copper‐cysteamine
更新于2025-09-04 15:30:14
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The Role of Humidity in Tuning the Texture and Electrical Properties of Cu <sub/>2</sub> O Thin Films Deposited via Aerosol‐Assisted CVD
摘要： A study on the effect of carrier gas (CG) humidity on the texture and the resulting electronic properties of Cu2O thin films deposited using aerosol-assisted chemical vapor deposition (AA-CVD) at low temperatures (<365 °C) is reported. By increasing the CG humidity, the preferred orientation of the films can be tuned from [110] to [111]. By studying the initial stages of film deposition, a different growth mode is found for dry and humid conditions, which in turn directs the final texture of the films. The analysis of the electric properties of the films by Hall effect shows that carrier concentration remains in the order of 1015 cm?3 when using both dry and humid conditions. Conversely, Cu2O samples deposited with humid CG generally present a higher mobility, up to 17 cm2 V?1 s?1. [111]-textured Cu2O films with high mobility were used to fabricate a diode by depositing a ZnO layer on top using atmospheric pressure spatial atomic layer deposition (AP-SALD). The diode shows an excellent rectifying behavior with a high asymmetry close to 104 between ?1 and +1 V.
关键词： textured thin films,copper oxides,aerosol-assisted CVD,carrier mobility,atmospheric pressure processing
更新于2025-09-04 15:30:14
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Dinuclear Cu(I) and Ag(I) pyrazolates supported with tertiary phosphines: Synthesis, structures and photophysical properties
摘要： New copper(I) and silver(I) dinuclear 3,5-bis(trifluoromethyl)pyrazolate compounds were prepared by the reaction of corresponding trinuclear metal complexes with the tertiary phosphines (PPh3, PCy3). In the case of copper(I) trinuclear pyrazolate it was shown that the product structure depends on the reagents ratio: mono- and dinuclear complexes were obtained. All the dinuclear complexes obtained exhibit light emission in the solid state under UV irradiation. Observed photoluminescent behavior was confirmed by the TD-DFT study.
关键词： silver(I) pyrazolates,copper(I) pyrazolates,X-Ray,luminescence,tertiary phosphines
更新于2025-09-04 15:30:14
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On the Fluorescent, Steric and Electronic Factors Affecting the Detection of Metallic Ions Using an Imidazolyl-Phenolic Derived Fluorescent Probe
摘要： The imidazolyl-phenolic probe used at the present study has its photophysic properties regulated by a tautomeric equilibrium. After the absorption of a photon, an excited state intramolecular proton transfer process generates a ketonic species, responsible for the 440 nm emission (in CH3CN/H2O, 95:5, v/v). Addition of Cu2+, Al3+, Cr3+ and Fe3+ suppresses emission through a combination of dynamic and static-like quenching, as indicated by Stern-Volmer plots, with a higher sensitivity for Cu2+ (KSV = 1.90 × 105 and 2.40 × 104 L mol–1, respectively, for Cu2+ and Fe3+). The trivalent ions led to the formation of a locked-enol tautomer that emits at shorter wavelengths; this coordinated compound is also quenched at metallic ions concentrations above 20 μmol L–1, due to a collisional process. When compared to another imidazolyl-phenolic probe, experimental and simulated data revealed that fluorescent, steric and electronic effects regulate their sensitivity towards the ions.
关键词： iron(III),copper(II),fluorescent sensor,ESIPT,tautomerization
更新于2025-09-04 15:30:14