Unexpected Negative-Ion Conversion in Grazing Scattering of Negative Ions on HOPG

2021 ◽  
Author(s):  
Xinyue Guo ◽  
Pinyang Liu ◽  
Bin Ding ◽  
Luyao Zhang ◽  
Jiawei Wang ◽  
...  
Keyword(s):  
Negative Ions ◽  
Negative Ion ◽  
Grazing Scattering

Carbon Nitride Film Formation by Low Energy Positive and Negative Ion Beam Deposition

1996 ◽  
Vol 438 ◽  
Author(s):  
N. Tsubouchi ◽  
Y. Horino ◽  
B. Enders ◽  
A. Chayahara ◽  
A. Kinomura ◽  
...  
Keyword(s):  
Carbon Nitride ◽  
Rutherford Backscattering Spectrometry ◽  
Ion Beam ◽  
High Vacuum ◽  
Negative Ions ◽  
Low Energy ◽  
Ultra High Vacuum ◽  
Negative Ion ◽  
Nitride Film ◽  
Ion Energy

AbstractUsing a newly developed ion beam apparatus, PANDA (Positive And Negative ions Deposition Apparatus), carbon nitride films were prepared by simultaneous deposition of mass-analyzed low energy positive and negative ions such as C2-, N+, under ultra high vacuum conditions, in the order of 10−6 Pa on silicon wafer. The ion energy was varied from 50 to 400 eV. The film properties as a function of their beam energy were evaluated by Rutherford Backscattering Spectrometry (RBS), Fourier Transform Infrared spectroscopy (FTIR) and Raman scattering. From the results, it is suggested that the C-N triple bond contents in films depends on nitrogen ion energy.

Note on radiationless transitions involving three-body collisions

1936 ◽  
Vol 32 (3) ◽  
pp. 482-485 ◽  
Author(s):  
R. A. Smith
Keyword(s):  
Continuous Spectrum ◽  
Negative Ions ◽  
Bound State ◽  
Excess Energy ◽  
Negative Ion ◽  
Positive Ions ◽  
Continuous State ◽  
Direct Formation ◽  
Three Body ◽  
Positive Ion

When an electron makes a transition from a continuous state to a bound state, for example in the case of neutralization of a positive ion or formation of a negative ion, its excess energy must be disposed of in some way. It is usually given off as radiation. In the case of neutralization of positive ions the radiation forms the well-known continuous spectrum. No such spectrum due to the direct formation of negative ions has, however, been observed. This process has been fully discussed in a recent paper by Massey and Smith. It is shown that in this case the spectrum would be difficult to observe.

Chaos in positive ion–negative ion magnetized plasmas

2020 ◽  
Vol 86 (6) ◽  
Author(s):  
Samiran Ghosh ◽  
Biplab Maity ◽  
Swarup Poria
Keyword(s):  
Nonlinear Wave ◽  
Low Frequency ◽  
Negative Ions ◽  
Dynamical Behaviour ◽  
Negative Ion ◽  
Sound Waves ◽  
Weakly Nonlinear ◽  
Positive Ions ◽  
Experimental Parameters ◽  
Map Analysis

The dynamical behaviour of weakly nonlinear, low-frequency sound waves are investigated in a plasma composed of only positive and negative ions incorporating the effects of a weak external uniform magnetic field. In the plasma model the mass (temperature) of the positive ions is smaller (larger) than that of the negative ions. The dynamics of the nonlinear wave is shown to be governed by a novel nonlinear equation. The stationary plane wave (analytical and numerical) nonlinear analysis on the basis of experimental parameters reveals that the nonlinear wave does have quasi-periodic and chaotic solutions. The Poincarè return map analysis confirms these observed complex structures.

Negative-Ion Implantation

1994 ◽  
Vol 354 ◽  
Author(s):  
Junzo Ishikawa
Keyword(s):  
Ion Implantation ◽  
Negative Ions ◽  
Ion Source ◽  
Negative Ion ◽  
Rf Plasma ◽  
Ion Currents ◽  
Promising Technique ◽  
Surface Charging ◽  
Silicon Carbon ◽  
A Charge

AbstractNegative-ion implantation is a promising technique for forthcoming ULSI (more than 256 M bits) fabrication and TFT (for color LCD) fabrication, since the surface charging voltage of insulated electrodes or insulators implanted by negative ions is found to saturate within so few as several volts, no breakdown of insulators would be expected without a charge neutralizer in these fabrication processes. Scatter-less negative-ion implantation into powders is also possible. For this purpose an rf-plasma-sputter type heavy negative-ion source was developed, which can deliver several milliamperes of various kinds of negative ion currents such as boron, phosphor, silicon, carbon, copper, oxygen, etc. A medium current negative-ion implanter with a small version of this type of ion source has been developed.

Negative Ion Preference in “Old” Rats

1963 ◽  
Vol 12 (2) ◽  
pp. 439-440
Author(s):  
Gerald J. Driessen ◽  
Richard A. Maier ◽  
Frank J. Macchitelli
Keyword(s):  
Negative Ions ◽  
Negative Ion ◽  
Old Rats

Old rats (20 months) were given a choice between a chamber containing negative ions and a neutral chamber. Significantly more rats indicated a preference for the ionized chamber than controls. It was concluded that old rats are able in some way to perceive the presence of negative ions.

scholarly journals Time and Temperature Kinetics for the Development of Volatile and Non-Volatile Flavor Compounds in Steaks

2019 ◽  
Vol 3 (2) ◽  
Author(s):  
K. Wall ◽  
C. Kerth
Keyword(s):  
Surface Temperature ◽  
Least Squares ◽  
Solid Phase ◽  
Negative Ions ◽  
Temperature Treatment ◽  
Negative Ion ◽  
Flavor Compounds ◽  
Wine Aroma ◽  
Least Squares Regression ◽  
Quadratic Effects

ObjectivesThe objective of this study was to utilize mass spectrometry (MS) instrumentation to define flavor differences in beef strip loin steaks cooked on five different surface temperatures.Materials and MethodsUSDA Select strip loins (n = 30) were selected from carcasses at a commercial major packing plant in Texas. After aging 14d, the loins were cut into 2.54 cm thick steaks, randomly assigned a grill surface temperature of 149, 177, 204, 232, or 260°C, individually vacuum-packaged and frozen at –10°C until analysis. Steaks were cooked on an electric flat top grill pre-heated to the corresponding temperature treatment. Steaks were turned at an internal temperature of 35°C and removed at 71°C (medium degree of doneness). Cubes (1.3cm × 1.3cm × steak thickness) representative of those served to a trained sensory panel were frozen and held at –80°C until further analysis. For GC/MS analysis, the samples were weighed and placed in a 473 mL glass jar with a Teflon lid held in a water bath at 60°C for 2h. The collection of volatiles from the headspace was done with a solid phase micro-extraction (SPME) sampler and a multi-dimensional GC/MS. For HPLC/MS-QTOF analysis, frozen samples were homogenized in a blender and 2 g were mixed with 8 mL acidified acetonitrile (0.1% formic acid). The supernatant was exposed to dSPE Enhanced Matrix Removal and dried with 3.5 g MgSO4. Samples were analyzed at a 1:5 dilution using reverse-phase chromatography on an Agilent 6545 LC/MS-QTOF with a gradient mobile phase in both positive and negative ion modes. Data were analyzed as linear and/or quadratic effects (P < 0.05) with grill surface temperature as the independent variable. Least squares means, discriminant analyses, and partial least squares regression analyses for compounds were calculated.ResultsBoth octane (gasoline aroma) and undecane (allspice aroma) increased (P < 0.02) linearly with grill temperature. With the exception of pentanal (fermented wine aroma), which decreased (P = 0.027) as grill temperature increased, all other aldehyde compounds increased (P < 0.05) linearly as the grill temperature increased. Pyrazines (roasted, coffee, and nutty aromas) and ketones (fruity, fatty aromas) generally increased (P < 0.03) as grill temperature increased. 2,3,5-trimethyl-6-ethyl pyrazine, 2,3-diethyl-5-methyl pyrazine, 2,5-dimethyl pyrazine and 3,5,-diethyl-2-methyl-pyrazine were only present when the grill temperature reached 260°C. Nonvolatile compounds (n = 247 positive ion and 140 negative ions) were identified. Significant (P < 0.05) patterns of increasing intensity with increased grill temperature were observed in sugar-amino derivatives such as betaine, 2-dimethylamino-5,6-dimethylpyrimidin-4-ol, and (S)-N-(4,5-dihydro-1-methyl-4-oxo-1H-imidazol-2-yl) alanine. A point of inflection was observed at a grill temperature of 232°C across a majority of increasing compounds, suggesting a critical temperature for the regulation of flavorful products from the Maillard reaction.ConclusionVolatile and nonvolatile compounds known to contribute to positive flavor attributes associated with the Maillard reaction are considerably influenced by grill surface temperature. It appears that a grill temperature from 204 to 232°C is optimal for generation of volatile and nonvolatile flavor compounds.

scholarly journals Fullerene Negative Ions: Formation and Catalysis

2020 ◽  
Author(s):  
Zineb Felfli ◽  
Kelvin Suggs ◽  
Nantambu Nicholas ◽  
Alfred Z. Msezane
Keyword(s):  
Transition State ◽  
Cross Sections ◽  
Water Oxidation ◽  
Regge Pole ◽  
Negative Ions ◽  
Negative Ion ◽  
Total Cross Sections ◽  
Hydrogen Bond Strength ◽  
Low Energy Electron ◽  
Fundamental Mechanism

We first explore negative-ion formation in fullerenes C44, C60, C70, C98, C112, C120, C132 and C136 through low-energy electron elastic scattering total cross sections calculations using our Regge-pole methodology. Water oxidation to peroxide and water synthesis from H2 and O2 are then investigated using the anionic catalysts C44ˉ to C136ˉ. The fundamental mechanism underlying negative-ion catalysis involves hydrogen bond strength-weakening in the transition state. DFT transition state calculations found C60ˉ numerically stable for both water and peroxide synthesis, C100ˉ increases the energy barrier the most and C136ˉ the most effective catalyst in both water synthesis and oxidation to H2O2.

Solitary Wave with Quantisation of Electron’s Orbit in a Magnetised Plasma in the Presence of Heavy Negative Ions

2020 ◽  
Vol 75 (3) ◽  
pp. 211-223 ◽  
Author(s):  
Manoj Kr. Deka ◽  
Apul N. Dev
Keyword(s):  
Magnetic Field ◽  
Solitary Wave ◽  
Electron Density ◽  
Maximum Amplitude ◽  
Negative Ions ◽  
Ion Concentration ◽  
Negative Ion ◽  
Maximum Height ◽  
Degenerate Plasma ◽  
Analytical Scheme

AbstractThe propagation characteristics of solitary wave in a degenerate plasma in the presence of Landau-quantised magnetic field and heavy negative ion are studied. The nature of solitary wave in such plasma under the influence of magnetic quantisation and the concentration of both electrons and negative ions, as well as in the presence of degenerate temperature, are studied with the help of a time-independent analytical scheme of the solution of Zakharov–Kuznetsov equation. The electron density, as well as the magnetic quantisation parameter, has an outstanding effect on the features of solitary wave proliferation in such plasma. Interestingly, for any fixed electron density, the magnetic quantisation parameter has an equal control on the maximum height and dispersive properties of the solitary wave. Toward higher temperatures and higher magnetic fields, the width of the solitary wave decreases. For a lower magnetic field, the maximum amplitude of the solitary wave decreases rapidly at higher values of degenerate temperature and negative ion concentration; however, at a lower value of degenerate temperature, the maximum amplitude increases with increasing negative ion concentration.

THE ELECTRON SPIN RESONANCE SPECTRA OF THE POSITIVE AND NEGATIVE IONS OF DIPHENYLENE

1960 ◽  
Vol 38 (4) ◽  
pp. 503-507 ◽  
Author(s):  
C. A. McDowell ◽  
J. R. Rowlands
Keyword(s):  
Electron Spin Resonance ◽  
Hyperfine Interaction ◽  
Electron Spin ◽  
Negative Ions ◽  
Negative Ion ◽  
Spin Resonance ◽  
Hyperfine Splittings ◽  
Positive Ion

The electron spin resonance spectra of the positive and negative ions of diphenylene have been measured. It has been found that these spectra consist of five lines showing that the observed hyperfine interaction is caused by four equivalent protons. The over-all extent of the positive ion spectrum is 18 gauss compared with that of 12.9 gauss for the negative ion. The hyperfine splittings observed are 4.0 gauss and 2.75 gauss respectively.

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