Number of populated electronic configurations in a hot dense plasma

Protons in the Sun’s core are a dense plasma allowing fusion events where two protons initially join to produce a deuteron. Eventually this leads to alpha particles, the mass-four nucleus of helium, releasing kinetic energy. Schrodinger’s equation allows particles to penetrate classically forbidden Coulomb barriers with small but important probabilities. The approximation known as Wentzel–Kramers–Brillouin (WKB) is used by Gamow to predict the rate of proton–proton fusion in the Sun, shown to be in agreement with measurements. A simplified formula is given for the power density due to fusion in the plasma constituting the Sun’s core. The properties of atomic nuclei are briefly summarized.

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Structural tuning of heterogeneous molecular catalysts for electrochemical energy conversion

Science Advances ◽

10.1126/sciadv.abf3989 ◽

2021 ◽

Vol 7 (13) ◽

pp. eabf3989

Author(s):

Jiong Wang ◽

Shuo Dou ◽

Xin Wang

Keyword(s):

Energy Conversion ◽

Model Systems ◽

Structural Variations ◽

Metal Centers ◽

Electrochemical Energy Conversion ◽

Electronic Configurations ◽

Coordination Spheres ◽

The Stability ◽

Molecular Catalysts ◽

Electrochemical Energy

Heterogeneous molecular catalysts based on transition metal complexes have received increasing attention for their potential application in electrochemical energy conversion. The structural tuning of first and second coordination spheres of complexes provides versatile strategies for optimizing the activities of heterogeneous molecular catalysts and appropriate model systems for investigating the mechanism of structural variations on the activity. In this review, we first discuss the variation of first spheres by tuning ligated atoms; afterward, the structural tuning of second spheres by appending adjacent metal centers, pendant groups, electron withdrawing/donating, and conjugating moieties on the ligands is elaborated. Overall, these structural tuning resulted in different impacts on the geometric and electronic configurations of complexes, and the improved activity is achieved through tuning the stability of chemisorbed reactants and the redox behaviors of immobilized complexes.

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Characterization of Charge States in Conducting Organic Nanoparticles by X-ray Photoemission Spectroscopy

Materials ◽

10.3390/ma14082058 ◽

2021 ◽

Vol 14 (8) ◽

pp. 2058

Author(s):

Jordi Fraxedas ◽

Antje Vollmer ◽

Norbert Koch ◽

Dominique de Caro ◽

Kane Jacob ◽

...

Keyword(s):

Partial Oxidation ◽

Chemical Shifts ◽

Large Family ◽

Photoemission Spectroscopy ◽

Intrinsic Structure ◽

X Ray ◽

Level Lines ◽

Donor And Acceptor ◽

Electronic Configurations

The metallic and semiconducting character of a large family of organic materials based on the electron donor molecule tetrathiafulvalene (TTF) is rooted in the partial oxidation (charge transfer or mixed valency) of TTF derivatives leading to partially filled molecular orbital-based electronic bands. The intrinsic structure of such complexes, with segregated donor and acceptor molecular chains or planes, leads to anisotropic electronic properties (quasi one-dimensional or two-dimensional) and morphology (needle-like or platelet-like crystals). Recently, such materials have been synthesized as nanoparticles by intentionally frustrating the intrinsic anisotropic growth. X-ray photoemission spectroscopy (XPS) has emerged as a valuable technique to characterize the transfer of charge due to its ability to discriminate the different chemical environments or electronic configurations manifested by chemical shifts of core level lines in high-resolution spectra. Since the photoemission process is inherently fast (well below the femtosecond time scale), dynamic processes can be efficiently explored. We determine here the fingerprint of partial oxidation on the photoemission lines of nanoparticles of selected TTF-based conductors.

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Ion Acoustic Cnoidal Waves in Ion-Beam Dense Plasma in the Presence of Quantizing Magnetic Field

IEEE Transactions on Plasma Science ◽

10.1109/tps.2021.3069892 ◽

2021 ◽

pp. 1-8

Author(s):

Rupinder Kaur ◽

Kuldeep Singh ◽

N. S. Saini

Keyword(s):

Magnetic Field ◽

Dense Plasma ◽

Ion Beam ◽

Cnoidal Waves ◽

Ion Acoustic ◽

Quantizing Magnetic Field

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Propagation of nonlinear electron acoustic solitons in magnetized dense plasma with quantum effects of degenerate electrons

10.1063/5.0052436 ◽

2021 ◽

Author(s):

Neelam Rani ◽

Manikant Yadav

Keyword(s):

Dense Plasma ◽

Quantum Effects ◽

Electron Acoustic

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Spectroscopic Studies of Laser-Based Far-Ultraviolet Plasma Light Source

Applied Sciences ◽

10.3390/app11156919 ◽

2021 ◽

Vol 11 (15) ◽

pp. 6919

Author(s):

Majid Masnavi ◽

Martin Richardson

Keyword(s):

Dense Plasma ◽

Wavelength Region ◽

Spectroscopic Studies ◽

Radiation Hydrodynamics ◽

Full Width ◽

Half Maximum ◽

Laser Plasmas ◽

Series Of Experiments ◽

Far Ultraviolet ◽

Radiation Conversion

A series of experiments is described which were conducted to measure the absolute spectral irradiances of laser plasmas created from metal targets over the wavelength region of 123–164 nm by two separate 1.0 μm lasers, i.e., using 100 Hz, 10 ns, 2–20 kHz, 60–100 ns full-width-at-half-maximum pulses. A maximum radiation conversion efficiency of ≈ 3%/2πsr is measured over a wavelength region from ≈ 125 to 160 nm. A developed collisional-radiative solver and radiation-hydrodynamics simulations in comparison to the spectra detected by the Seya–Namioka-type monochromator reveal the strong broadband experimental radiations which mainly originate from bound–bound transitions of low-ionized charges superimposed on a strong continuum from a dense plasma with an electron temperature of less than 10 eV.

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