scholarly journals Correlation-Induced Electron-Electron Attraction

2018 ◽  
Vol 09 (09) ◽  
pp. 1761-1772
Author(s):  
Hubert Klar
Keyword(s):  
Electron Attraction

CRUCIAL ROLE OF THE COULOMB INTERACTION IN HTSC MECHANISM

2005 ◽  
Vol 19 (01n03) ◽  
pp. 107-109 ◽  
Author(s):  
E. A. PASHITSKII ◽  
V. I. PENTEGOV
Keyword(s):  
Coulomb Interaction ◽  
Vertex Function ◽  
Cooper Pairing ◽  
Superconducting Transition ◽  
Coulomb Correlation ◽  
Critical Temperatures ◽  
Effective Electron ◽  
Electron Attraction ◽  
D Wave

We present results of numerical calculations emphasizing the central role of the Coulomb interaction in the mechanism of d-wave Cooper pairing in layered cuprate metal-oxides. We demonstrate that many-particle Coulomb correlation described by the Coulomb vertex function Γ substantially enhances the effective electron-electron attraction in the d-wave Cooper-pairing channel in these compounds. Such a "Coulomb" mechanism of anisotropic Cooper pairing may provide high superconducting transition critical temperatures (Tc⩾100 K ) for optimum-doped cuprates.

Interactions of polynucleotides and their components

1968 ◽  
Vol 23 (1) ◽  
pp. 25-30 ◽  
Author(s):  
J. Clauwaert ◽  
J. Stockx
Keyword(s):  
Ionic Strength ◽  
Inductive Effect ◽  
Large Range ◽  
Electrostatic Attraction ◽  
Screening Off ◽  
Electron Withdrawal ◽  
New Treatment ◽  
Ribose Moiety ◽  
Phosphate Groups ◽  
Electron Attraction

The pK' values of the current bases, nucleosides, nucleotides, nucleotide derivatives and poly U have been determined over a large range of ionic strength. The pK' shifts of the monomers due to variations in ionic strength can be accounted for qualitatively and quantitatively by means of the relationThe collision diameters of uracil, uridine, uridine cyclic -2':3'-phosphate and 3' (2') -uridylic acid were determined. The introduction of phosphate affects the charge, resulting into differences in activity coefficient between nucleotides and their corresponding nucleosides and bases. A substitution of -H by ribose at N(3) of uracil or cytosine or at N(9) of adenine or guanine results into an electron withdrawal from the bases with lowering of the pK' value. 2'-Deoxyribose exhibits a weaker electron attraction. Introducing -CH3 at C(5) of uracil yields electrons to the base and the pK values of various thymine derivatives are about 0.5 pH units higher than those of the corresponding uracil derivatives. A phosphate group on C2 or C3 results in an electrostatic attraction of the dissociable proton, so that the pK' is increased at low ionic strengths; at higher ionic strengths screening off occurs and the pK' values of the nucleotides become almost the same as those of the corresponding nucleosides. The site of substitution on the ribose moiety is important: C2'-O-phosphate seems to exert a stronger electrostatic attraction on - NH3⊕ groups than C3'-O-phosphate, whereas C5'-O-phosphate exerts in addition an inductive effect that is dependent on the presence of - OH on C2. The electrostatic influence of the phosphate groups on the uracil moiety in UpU, UpC and CpUpC runs roughly parallel to that found in cyclic-2':3'-nucleotides. The pK' shifts experienced in poly U are related to the polyelectrolyte character of this polymer. A new treatment for the evaluation of the electrostatic potential of polynucleotides (poly U) is proposed that is based on the usual rodlike (polyelectrolyte) model.

Theoretical Study on Ru2+, Cu+, and Fe2+ Complexes Toward the Application in Dye Sensitized Solar Cell

2014 ◽  
Vol 137 (2) ◽  
Author(s):  
Nguyen Ngoc Ha ◽  
Mai Anh Tuan ◽  
Dang Xuan Thu ◽  
Luong T. Thu Thuy
Keyword(s):  
Solar Cell ◽  
Theoretical Study ◽  
Organic Ligand ◽  
Absorption Capacity ◽  
Photon Absorption ◽  
Dye Sensitized Solar Cell ◽  
Dye Sensitized ◽  
Calculation Results ◽  
The One ◽  
Electron Attraction

This paper reports the application of the Ru2+, Cu+, and Fe2+ complexes in form of RuL2(SCN)2, CuL2(SCN)2− for dye-sensitized solar cell (DSSC) development. The calculation results, given by quantum chemistry, demonstrated that the complex containing copper is more suitable than the one containing iron. The modification of Cu(I) complex by using various numbers of ligands enhanced photon absorption capacity as well as the absorption range. The addition of an organic ligand such as an electron attraction group to the benzene ring gave a better result as compared to the inorganic ones. Based on the analysis conducted, CuM2(SCN)2− is considered as potential material for N3 replacement.

scholarly journals Oxygen-doped carbon host with enhanced bonding and electron attraction abilities for efficient and stable SnO2/carbon composite battery anode

2018 ◽  
Vol 61 (8) ◽  
pp. 1067-1077 ◽  
Author(s):  
Zhen Geng ◽  
Bing Li ◽  
Hezhi Liu ◽  
Hong Lv ◽  
Qiangfeng Xiao ◽  
...  
Keyword(s):  
Carbon Composite ◽  
Electron Attraction ◽  
Battery Anode

scholarly journals Periodic Table of the Elements, History, Education and Evaluation

2021 ◽  
pp. 147-164
Author(s):  
Francisco Torrens Zaragozá
Keyword(s):  
Transition Metal ◽  
Periodic Table ◽  
Nuclear Charge ◽  
Chemical Elements ◽  
Principal Quantum Number ◽  
Transition Metal Dichalcogenides ◽  
Toxic Trace Elements ◽  
Metal Dichalcogenides ◽  
Effective Principal ◽  
Electron Attraction

The periodic tables of transition metal thiophosphates MPS3, transition metal dichalcogenides MX2 and other materials, the origin of chemical elements and toxic trace elements in dried mushrooms are provided. The effective nucleus-electron  attraction is proportional to the effective nuclear charge (Zeff) and inversely proportional to the effective principal quantum number (n*). The periodic arch is one of many modern visual displays that have been developed to augment the traditional periodic table of the chemical elements. The table is related with the multiparameter optimisation of N atom, nuclear magnetic resonance and everyday life. Educational activities are developed with evaluation.

scholarly journals On Electron Attraction in the Diatomic Bond

1992 ◽  
Vol 5 (4) ◽  
pp. 554-560 ◽  
Author(s):  
Donald Greenspan
Keyword(s):  
Electron Attraction

Calculation of Arrhenius Parameters by the Rrkm Method for the Carbon–Hydrogen Bond Fission Reaction of Fluorobenzene

2017 ◽  
Vol 42 (2) ◽  
pp. 182-190
Author(s):  
Afshin Taghva Manesh ◽  
Zabialah Heidarnezhad ◽  
Morteza Vahedpour ◽  
Nasrin Masnabadi
Keyword(s):  
Rate Constants ◽  
Potential Energy Surfaces ◽  
Elevated Temperatures ◽  
Basis Set ◽  
Fission Reaction ◽  
Different Temperatures ◽  
Exponential Factors ◽  
Quantitative Results ◽  
Energy Surfaces ◽  
Electron Attraction

The present study provides quantitative results for the rate of the unimolecular hydrogen–carbon bond fission reaction of fluorobenzene at elevated temperatures up to 2000 K. The potential energy surfaces for each C–H bond fission reaction (in the ortho, meta, and para sites) of fluorobenzene were investigated using ab initio calculations. The geometry and vibrational frequencies of the species involved in these reactions were optimised at the unrestricted MP2 level of theory, using the cc-pVDZ basis set. Since the C–H bond fission channel is a barrier-less reaction, we have used variational Rice–Ramsperger–Kassel–Marcus (RRKM) theory to predict rate constants. The difficulty in the application of the RRKM method to molecules bigger than benzene is discussed and a method is offered to solve the problem. Using calculated rate constants at different temperatures, the activation energies and exponential factors were determined. The Arrhenius expressions for the C–H bond fission reactions of fluorobenzene at the ortho, meta and para sites were obtained as k( T) = 6.1 × 1016 e−57328/ T, k( T) = 1.8 × 1017 e−59080/ T and k( T) = 1.3 × 1017 e−59600/ T respectively. Moreover, the effect of the fluorine atom including electron attraction and resonance with the benzene ring, on molecular rotation and the tunnelling effect on the rate expression have been discussed.

Electron inelastic lifetime and electron-electron attraction strength in Al films

1983 ◽  
Vol 28 (7) ◽  
pp. 4046-4049 ◽  
Author(s):  
James M. Gordon ◽  
C. J. Lobb ◽  
M. Tinkham
Keyword(s):  
Electron Attraction
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