scholarly journals Фрагментация молекулы глютамина электронным ударом

2019 ◽  
Vol 45 (20) ◽  
pp. 43
Author(s):  
А.В. Папп ◽  
В.С. Вукстич ◽  
Л.Г. Романова ◽  
Т.А. Снегурская ◽  
И.Г. Мегела ◽  
...  
Keyword(s):  
Mass Spectra ◽  
High Energy ◽  
Electron Gun ◽  
Spectrometric Analysis ◽  
Analysis Technique ◽  
Yield Functions ◽  
Initial Molecule ◽  
Ionic Fragment ◽  
Energy Irradiation ◽  
Fragment Yield

Using the mass-spectrometric analysis technique, formation of the ionic products of the single and dissociative ionization of the glutamine molecule (C5H10N2O3) at its interaction with the low (70 eV) and high (11.5 MeV) energy electrons has been studied. The experimental mass-spectra of the above molecule measured at different irradiation doses (5, 10 and 20 kGy) and the near-threshold areas of the ionic fragment yield functions have been analyzed, the absolute ion fragment appearance energies have been found. The three-electrode electron gun and the electron accelerator (microtron) were used as the electron beam sources. The analysis of the behaviour of the measured glutamine molecule mass-spectra irradiated at the above doses demonstrates, as compared to the irradiated molecule mass-spectrum, that the high-energy irradiation of the initial molecule results in the irreversible changes of its structure.

The Determination of T-2 Toxin, Diacetoxyscirpenol, and Deoxynivalenol in Foods and Feeds

1979 ◽  
Vol 33 (3) ◽  
pp. 294-297 ◽  
Author(s):  
H. M. Stahr ◽  
A. A. Kraft ◽  
Max Schuh
Keyword(s):  
Thin Layer ◽  
Chicken Embryo ◽  
Mass Spectra ◽  
Spectrometric Analysis ◽  
Animal Tissues ◽  
Analysis Technique ◽  
Layer Analysis ◽  
Biological Effectiveness ◽  
Layer Chromatography

A method is presented for the analysis of mycotoxins using acetonitrile (90) water (10) extraction, petroleum ether defatting and ferric gel decolorization, chloroform partitioning, and a 1000-fold concentration. Gas chromatography and thin layer chromatography are used to separate and analyze the three most common thichothecene mycotoxins. The analysis has been applied to animal feeds, human foods, and animal tissues. Confirmation of the presence of the mycotoxins is made by IR, NMR, and/or mass spectrometric analysis and/or the chicken embryo test. The sensitivity of the method is 1 ppm for the three trichothecenes, the level of biological effectiveness. The gas chromatographic analysis technique is sensitive to 10 ng of each mycotoxin; the thin layer analysis is sensitive to 100 ng of each compound. Mass spectra may be obtained from 100 ng of each toxin taken from a thin layer chromatogram and the LD50 for chicken embryos is 100 ng/egg for T-2 toxin and diacetoxyscirpenol. Vomitoxin (deoxynivalenol) has not been subjected to the chicken embryo test due to the lack of authentic pure vomitoxin.

Analysis of Voltage Contrast in Secondary Electron Images Using a High-Energy Electron Spectrometer

2019 ◽  
Author(s):  
Natsuko Asano ◽  
Shunsuke Asahina ◽  
Natasha Erdman
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Sample Surface ◽  
High Energy ◽  
Secondary Electrons ◽  
Analysis Technique ◽  
Quantitative Understanding ◽  
Voltage Contrast ◽  
Acceleration Voltage ◽  
Failure Localization

Abstract Voltage contrast (VC) observation using a scanning electron microscope (SEM) or a focused ion beam (FIB) is a common failure analysis technique for semiconductor devices.[1] The VC information allows understanding of failure localization issues. In general, VC images are acquired using secondary electrons (SEs) from a sample surface at an acceleration voltage of 0.8–2.0 kV in SEM. In this study, we aimed to find an optimized electron energy range for VC acquisition using Auger electron spectroscopy (AES) for quantitative understanding.

Combining low- and high-energy tandem mass spectra for optimized peptide quantification with isobaric tags

2010 ◽  
Vol 73 (4) ◽  
pp. 769-777 ◽  
Author(s):  
Loïc Dayon ◽  
Carla Pasquarello ◽  
Christine Hoogland ◽  
Jean-Charles Sanchez ◽  
Alexander Scherl
Keyword(s):  
Mass Spectra ◽  
High Energy ◽  
Tandem Mass ◽  
Peptide Quantification ◽  
Tandem Mass Spectra ◽  
Isobaric Tags

scholarly journals Temporal Evolution of the High-energy Irradiation and Water Content of TRAPPIST-1 Exoplanets

2017 ◽  
Vol 154 (3) ◽  
pp. 121 ◽  
Author(s):  
V. Bourrier ◽  
J. de Wit ◽  
E. Bolmont ◽  
V. Stamenković ◽  
P. J. Wheatley ◽  
...  
Keyword(s):  
Water Content ◽  
Temporal Evolution ◽  
High Energy ◽  
Energy Irradiation ◽  
High Energy Irradiation

scholarly journals The CARMENES search for exoplanets around M dwarfs

2020 ◽  
Vol 640 ◽  
pp. A52
Author(s):  
B. Fuhrmeister ◽  
S. Czesla ◽  
L. Hildebrandt ◽  
E. Nagel ◽  
J. H. M. M. Schmitt ◽  
...  
Keyword(s):  
Near Infrared ◽  
Extreme Ultraviolet ◽  
High Energy ◽  
M Dwarfs ◽  
Dwarf Stars ◽  
Transmission Spectroscopy ◽  
Solar Type ◽  
Energy Irradiation ◽  
Planetary Transmission ◽  
M Dwarf Stars

The He I infrared (IR) triplet at 10 830 Å is known as an activity indicator in solar-type stars and has become a primary diagnostic in exoplanetary transmission spectroscopy. He I IR lines are a tracer of the stellar extreme-ultraviolet irradiation from the transition region and corona. We study the variability of the He I triplet lines in a spectral time series of 319 M dwarf stars that was obtained with the CARMENES high-resolution optical and near-infrared spectrograph at Calar Alto. We detect He I IR line variability in 18% of our sample stars, all of which show Hα in emission. Therefore, we find detectable He I variability in 78% of the sub-sample of stars with Hα emission. Detectable variability is strongly concentrated in the latest spectral sub-types, where the He I lines during quiescence are typically weak. The fraction of stars with detectable He I variation remains lower than 10% for stars earlier than M3.0 V, while it exceeds 30% for the later spectral sub-types. Flares are accompanied by particularly pronounced line variations, including strongly broadened lines with red and blue asymmetries. However, we also find evidence for enhanced He I absorption, which is potentially associated with increased high-energy irradiation levels at flare onset. Generally, He I and Hα line variations tend to be correlated, with Hα being the most sensitive indicator in terms of pseudo-equivalent width variation. This makes the He I triplet a favourable target for planetary transmission spectroscopy.

scholarly journals Apparent and Actual Shifts in Mass and Width of ϕ Mesons Produced in Heavy-Ion Collisions

1997 ◽  
Vol 12 (02) ◽  
pp. 127-134 ◽  
Author(s):  
R. S. Bhalerao ◽  
S. K. Gupta
Keyword(s):  
Invariant Mass ◽  
Preliminary Data ◽  
Heavy Ion Collisions ◽  
Mass Spectra ◽  
Dense Matter ◽  
Heavy Ion ◽  
High Energy ◽  
Mass Shift ◽  
Ion Collisions ◽  
Invariant Mass Spectra

We present a method of analyzing invariant-mass spectra of kaon pairs resulting from decay of ϕ mesons produced in high-energy heavy-ion collisions. It can be used to extract the shifts in the mass and the width (ΔM and ΔΓ) of the ϕ mesons when they are inside the dense matter formed in these collisions. We illustrate our method with the help of available preliminary data. Extracted values of ΔM and ΔΓ are significantly larger than those obtained with an earlier method. Our results are consistent with the experimentally observed pT dependence of the mass shift. Finally, we present a phenomenological relation between ΔM and ΔΓ. It provides a useful constraint on theories which predict the values of these two quantities.

scholarly journals Mass loss from the exoplanet WASP-12b inferred from Spitzer phase curves

2019 ◽  
Vol 489 (2) ◽  
pp. 1995-2013 ◽  
Author(s):  
Taylor J Bell ◽  
Michael Zhang ◽  
Patricio E Cubillos ◽  
Lisa Dang ◽  
Luca Fossati ◽  
...  
Keyword(s):  
Mass Loss ◽  
Infrared Radiation ◽  
High Energy ◽  
The Other ◽  
Phase Curve ◽  
Near Ultraviolet ◽  
Energy Irradiation ◽  
Ultraviolet Observations ◽  
Host Stars ◽  
Co Emission

ABSTRACT The exoplanet WASP-12b is the prototype for the emerging class of ultrahot, Jupiter-mass exoplanets. Past models have predicted – and near-ultraviolet observations have shown – that this planet is losing mass. We present an analysis of two sets of 3.6 and 4.5 $\mu \rm{m}$Spitzer phase curve observations of the system which show clear evidence of infrared radiation from gas stripped from the planet, and the gas appears to be flowing directly toward or away from the host star. This accretion signature is only seen at 4.5 $\mu \rm{m}$, not at 3.6 $\mu \rm{m}$, which is indicative either of CO emission at the longer wavelength or blackbody emission from cool, ≲600 K gas. It is unclear why WASP-12b is the only ultrahot Jupiter to exhibit this mass-loss signature, but perhaps WASP-12b’s orbit is decaying as some have claimed, while the orbits of other exoplanets may be more stable; alternatively, the high-energy irradiation from WASP-12A may be stronger than the other host stars. We also find evidence for phase offset variability at the level of 6.4σ (46.2°) at 3.6 $\mu \rm{m}$.

Über Metalltrifluorphosphin-Komplexe. XL. / On Metaltrifluorophosphine-Complexes, XL.

1973 ◽  
Vol 28 (1-2) ◽  
pp. 38-44 ◽  
Author(s):  
Thomas Kruck ◽  
Gerd Sylvester ◽  
Inge-Petra Kunau
Keyword(s):  
Mass Spectrum ◽  
Uv Irradiation ◽  
Mass Spectra ◽  
High Energy ◽  
Metal Bond ◽  
High Energy Electrons ◽  
Metal Metal ◽  
Successive Removal

Orange-red crystals of μ3-phosphido-nonakis(trifluorophosphine)-triiridium, PIr3(PF3)9, are obtained by reductive fluorophosphination of IrCl3 at 80-200 atm PF3-pressure. The structure of the new complex is proven by its mass spectrum, displaying a successive removal of nine PF3-groups. Rupture of the PIr3-cluster occurs only to an extremely small amount even with high energy electrons. UV-irradiation of HCo(PF3)4 and a mixture of HCo(PF3)4 with HIr(PF3)4 yields the bridged complexes (PF3)3Co(H)(PF2)Co(PF3)3 and (PF3)3Co(H)(PF2) Ir(PF3)3. The three complexes (PF3)4M-M(PF3)4 (M = Co or Ir) with a direct metal-metal bond are not obtainable under these conditions. The mass spectra of all compounds and of Ir2(PF3)8 are discussed.

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