2,664 research outputs found
Giant nonreciprocal emission of spin waves in Ta/Py bilayers
No full textSpin waves are propagating disturbances in themagnetization of magnetic materials. One of their interesting properties is nonreciprocity, exhibiting that their amplitude depends on themagnetization direction. Nonreciprocity in spin waves is of great interest in both fundamental science and applications because it offers an extra knob to control the flow of waves for the technological fields of logics and switch applications. We show a high nonreciprocity in spin waves from Ta/Py bilayer systems with out-of-plane magnetic fields. The nonreciprocity depends on the thickness of Ta underlayer, which is found to induce an interfacial anisotropy. The origin of observed high nonreciprocity is twofold: different polarities of the in-planemagnetization due to different angles of canted out-of-plane anisotropy and the spin pumping effect at the Ta/Py interface. Our findings provide an opportunity to engineer highly efficient, nonreciprocal spin wave-based applications, such as nonreciprocal microwave devices, magnonic logic gates, and information transports.
Oral Administered Recombinant Dp2 Induced Oral Tolerance and Affected Peyer’s Patch Gene Expression in Murine Model of Allergic Asthma
No full textOrigin of threshold current density for asymmetric magnetoresistance in Pt/Py bilayers
No full textThe asymmetric magnetoresistance (MR) in Py/Pt bilayers is investigated. It increases linearly with respect to the current density up to a threshold and increases more rapidly above this threshold. To reveal the origin of the threshold behavior, we investigate the magnetic field dependence of the asymmetric MR. It is found that the magnetic field strongly suppresses the asymmetric MR only above the threshold current density. Micromagnetic simulation reveals that the reduction of magnetization due to the spin-torque oscillation can be the origin of the threshold behavior of the asymmetric MR. (C) 2017 The Japan Society of Applied Physics
Dibenzo[: B, d] furan and dibenzo [b, d] thiophene molecular dimers as hole blocking materials for high-efficiency and long-lived blue phosphorescent organic light-emitting diodes
No full textNovel hole blocking materials (HBMs) based on dibenzo[b,d]furan and dibenzo[b,d]thiophene molecular dimers have been rationally designed and synthesized for high-efficiency and long-lived blue phosphorescent organic light-emitting diodes (PhOLEDs). Thermal, optical, and electrochemical analyses show that [2,2′-bidibenzo[b,d]furan]-6,6′-diylbis(diphenylphosphine oxide) (DBF-d-PO), [2,2′-bidibenzo[b,d]thiophene]-6,6′-diylbis(diphenylphosphine oxide) (DBT-d-PO), 6,6′-di(pyridine-3-yl)-2,2′-bidibenzo[b,d]furan (DBF-d-Py), and 6,6′-di(pyridine-3-yl)-2,2′-bidibenzo[b,d]thiophene (DBT-d-Py) possess high thermal stability, deep highest occupied molecular orbital energy levels (-6.61 to -6.95 eV), and high triplet energy (ET) (2.68-2.95 eV). Blue PhOLEDs with DBF-d-PO, DBT-d-PO, DBF-d-Py, and DBT-d-Py exhibit low turn-on and operating voltages, excellent external quantum efficiency, and high current and power efficiencies. A blue PhOLED with DBF-d-Py shows the best efficiency with a maximum external quantum efficiency of 24.3%, a maximum current efficiency of 44.3 cd A-1, and a maximum power efficiency of 46.4 lm W-1. In addition, it exhibits an outstanding external quantum efficiency of 22.4% at a practical luminance of 1000 cd m-2 and a very high maximum luminance of 88953 cd m-2 at 12 V. Furthermore, blue PhOLEDs with DBF-d-Py and DBT-d-Py exhibit highly improved lifetimes compared with the conventional HBM, BmPyPB, because of the efficient hole blocking by the deep HOMO energy level and the high thermal stability stabilizing hole blocking layer morphology. © 2019 The Royal Society of Chemistry.1
Microstrain in pyrope-grossular garnet solid solution at high pressure: a case study of Py(90)Gr(10) and Py(10)Gr(90) up to 15 GPa
No full textSingle-phase, well-sintered, translucent polycrystalline garnets with compositions of Py(90)Gr(10) and Py(10)Gr(90) were synthesized at 6 GPa and 1400 degrees C using a multi-anvil apparatus. X-ray diffraction (XRD) data for these garnet solid solutions were collected with both high-resolution synchrotron X-ray and standard laboratory X-ray sources. Analysis of the FWHM of the XRD peaks using Williamson-Hall plot yields microstrains around 0.12% for Py(90)Gr(10) and 0.09% for Py(10)Gr(90). The FWHM of Py(10)Gr(90) garnet as well as the derived microstrain remains constant up to 11 GPa, followed by a continuous increase to the experimental peak pressure 15 GPa caused by elastic strain in response to deviatoric/anisotropic stresses. The FWHM and microstrain for Py(90)Gr(10) remain constant to the measurement limit at 7 GPa. The microstrain of pyrope-grossular garnets exhibits a nonlinear dependence on composition, showing two peaks near Py(20)Gr(80) and Py(80)Gr(20), which may be associated with local structural heterogeneities arising from Mg and Ca substitution. Using a third-order Birch-Murnaghan equation of state, the bulk modulus is constrained to be Ie (0) = 171.8 +/- 2.1 GPa (with K-0(') fixed to 5.92) for Py(10)Gr(90) and Ie (0) = 174.3 +/- 2.5 GPa (with K-0(') fixed to 4.4) for Py(90)Gr(10), both of which are much larger than that for intermediate composition close to Py(50)Gr(50) but comparable to that for their corresponding end members. The relatively larger microstrain and higher bulk moduli for Py(10)Gr(90) and Py(90)Gr(10) garnets could be related to short-range ordering of Mg and Ca cations in garnet structure due to substitution, which results in different local environments for Mg and Ca cations along the pyrope-grossular solid solution.DOE/NNSA [DE-NA0002907]; NSF [EAR1524078]SCI(E)ARTICLE6377-3884
High-performance transparent conductive pyrolyzed carbon (Py-C) ultrathin film
No full text© The Royal Society of Chemistry.Pyrolyzed carbon (Py-C) film, a member of graphene family, has not been paid significant attention despite its potential advantages in synthesis procedure and opto-electro-mechanical properties. This academic indifference is due to the lack of a low-cost synthesis method for Py-C ultrathin films whose properties are comparable to those of graphene. In this study, we proposed the direct synthesis of Py-C ultrathin films on various target substrates. We produced a hydrogenated amorphous carbon (a-C:H) ultrathin film in a microwave oven and used it as a transferable precursor film for conversion into the Py-C ultrathin film. The thickness of the Py-C ultrathin film was controlled in the range of 0.7-12 nm. The Py-C ultrathin film has opto-electro-mechanical properties comparable to those of graphene, work function (4.57 eV) similar to that of graphene, high transparency with a relatively low sheet resistance (83% at 1.1 kΩ sq-1), excellent flexibility, stable electrical resistance upon folding, anti-oxidation, and chemical protection. This Py-C ultrathin film is expected to find various practical applications as an alternative to graphene. As an example, we demonstrated a highly flexible pixelated display fabricated using the Py-C ultrathin film as an electrode for alternating current electroluminescent (ACEL) devices. This journal i11sci
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Chelation of [ 111 In]In 3+ with the dual-size-selective macrocycles py-macrodipa and py 2 -macrodipa
Full text linkIndium-111 (111In) is a diagnostic radiometal that is important in nuclear medicine for single-photon emission computed tomography (SPECT). In order to apply this radiometal, it needs to be stably chelated and conjugated to a targeting vector that delivers it to diseased tissue. Identifying effective chelators that are capable of binding and retaining [111In]In3+in vivo is an important research area. In this study, two 18-membered macrocyclic chelators, py-macrodipa and py2-macrodipa, were investigated for their ability to form stable coordination complexes with In3+ and to be effectively radiolabeled with [111In]In3+. The In3+ complexes of these two chelators were characterized by NMR spectroscopy, X-ray crystallography, and density functional theory calculations. These studies show that both py-macrodipa and py2-macrodipa form 8-coordinate In3+ complexes and attain an asymmetric conformation, consistent with prior studies on this ligand class with small rare earth metal ions. Spectrophotometric titrations were carried out to determine the thermodynamic stability constants (log KML) of [In(py-macrodipa)]+ and [In(py2-macrodipa)]+, which were found to be 18.96(6) and 19.53(5), respectively, where the values in parentheses are the errors of the last significant figures obtained from the standard deviation from three independent replicates. Radiolabeling studies showed that py-macrodipa and py2-macrodipa can quantitatively be radiolabeled with [111In]In3+ at 25 °C within 5 min, even at ligand concentrations as low as 1 μM. The in vitro stability of the radiolabeled complexes was investigated in human serum at 37 °C, revealing that ∼90% of [111In][In(py-macrodipa)]+ and [111In][In(py2-macrodipa)]+ remained intact after 7 days. The biodistribution of these radiolabeled complexes in mice was investigated, showing lower uptake in the kidneys, liver, and blood at the 24 h mark compared to [111In]InCl3. These results demonstrate the potential of py-macrodipa and py2-macrodipa as chelators for [111In]In3+, suggesting their value for SPECT radiopharmaceuticals
Observation of Py-12-O-2-DMA fluorescence in sodium dodecyl sulfate aqueous solution
No full textVarious fluorescent molecules have been developed for cell observation using a fluorescence microscope. There is also a need to develop magnetic sensitive fluorescent molecules to be used in research to determine whether cells are affected by magnetic field effect. Pyrene-(CH2)12-O-(CH2)2-N, N-dimethylaniline (Py-12-O2-DMA) is one of the molecules synthesized for the research of the magnetic field effect. Py-12-O-2-DMA is a structure in which pyrene, a fluorescent molecule that acts as an electron acceptor molecule, and N, Ndimethylaniline, which acts as an electron donor molecule, are connected by an alkyl chain consisting of 12 carbons. Py-12-O-2-DMA with this structure forms exciplex and RIP through photo-induced electron transfer. In non-polar solvents, the intensity of fluorescence emitted by the exciplex is changed by the magnetic field effect. Due to charge recombination of the non-radiative product RIP, magnetic field effect can be observed
through the change in the exciplex fluorescence intensity. However, water is an extremely strong polar solvent and the same characteristic of the molecules that make up Py-12-O-2-DMA is that they all have very low solubility in water. The way to dissolve molecules with low solubility in water is to use a surfactant. Surfactants with hydrophilic groups and hydrophobic groups create a structure called micelles above the critical micelle concentration (CMC). As insoluble substances exist inside micelles made of hydrophobic groups, they dissolve in water, which is called solubilization. Solubilization of insoluble substances using surfactants is a well-known method in everyday life, such as washing clothes with surfactants to remove oil or oil-soluble pigments from fabric. Several studies have already been reported on the physical properties of surfactants observed through the emission spectrum of several organic fluorescent molecules. Also, many studies have been conducted using
micelles for the application of organic fluorescent molecules. In this study, Py-12-O-2-DMA is dissolved in micelles using sodium dodecyl sulfate, a surfactant, and the fluorescence spectrum is measured to determine whether the magnetic field effect appears in water.Maste
atomneb/AtomNeb-py: AtomNeb-py.0.3.0
No full textAtomNeb - Python Package for Atomic Data of Ionized Nebulae
AtomNeb is a database containing atomic data stored in FITS file format generated for for spectral analysis. The AtomNeb Python Package is equipped with several API functions developed in the Python language, which can be used to read atomic data from the AtomNeb FITS files. The API functions of the AtomNeb Python Package, together with the pyEQUIB Python Package, can be used to carry out plasma diagnostics and abundance analysis of spectra emitted from ionized nebulae.
Update Summary
Change data structures from pandas.DataFrame to NumPy
Add Chianti 9.0 atomic data
Citation
@article{Danehkar2020,
author = {{Danehkar}, Ashkbiz},
title = {AtomNeb Python Package, an addendum to AtomNeb: IDL Library for Atomic Data of Ionized Nebulae},
journal = {Journal of Open Source Software},
volume = {5},
number = {55},
pages = {2797},
year = {2020},
doi = {10.21105/joss.02797}
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