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The aim of this brief report is to study the behaviour of sheath structure in a multi-component plasma with dust-neutral collisions.
The plasma consists of electrons, ions, micron size negatively charged dust particles and neutrals. The sheath-edge potential
and sheath width are calculated for collisionally dominated sheath. Comparison of collisionless and collisionally dominated
sheath are made. 相似文献
3.
We discuss the notion of spin squeezing considering two mutually exclusive classes of spin-s states, namely, oriented and non-oriented states. Our analysis shows that the oriented states are not squeezed while non-oriented
states exhibit squeezing. We also present a new scheme for construction of spin-s states using 2s spinors oriented along different axes. Taking the case of s=1, we show that the ‘non-oriented’ nature and hence squeezing arise from the intrinsic quantum correlations that exist among
the spinors in the coupled state. 相似文献
4.
We report time-dependent density functional theory calculations of the vertical excitation energies for the singlet states of three-coordinate 5H-dibenzoborole (DBB) derivatives and four-coordinate 5-fluoro-5H-dibenzoborole ion (FDBB) derivatives. These molecules show remarkable hypsochromic (blue) shifts in their fluorescence spectra and bathochromic (red) shifts in their absorption spectra when the bridging boron atoms change their coordination number from three to four. We constructed a series of derivatives of DBB and FDBB and studied how the energies of the electronic excitations change. The states with prominent oscillator strength in all of the DBB and FDBB derivatives show similar shifts of their excitation energies upon coordination. The three-coordinate DBB derivative 5-(2,4,6-triisopropylphenyl)-2,8-dimethoxy-3,7-bis[p-(N,N-diphenylamino)phenyl]-5H-dibenzo[d,b]borole has an intense absorption at 3.25 eV, which shifts in the four-coordinate FDBB derivative 5-fluro-5-(2,4,6-triisopropylphenyl)-2,8-dimethoxy-3,7-bis[p-(N,N-dip henylamino)phenyl]-5H-dibenzo[d,b]borole ion to 3.17 eV. The experimental absorption peaks are 3.43 and 3.31 eV, respectively. In addition, we investigated and analyzed the nature of these electronic excitations using attachment/detachment density plots, with which we characterized the changes in electron density that arose from the excitations. 相似文献
5.
Thomas Vent‐Schmidt Lester Andrews K. Sahan Thanthiriwatte David A. Dixon Sebastian Riedel 《ChemInform》2015,46(51):no-no
H2ThSe (I) and H2USe (II) are obtained by the reaction of laser‐ablated U and Th with a ≈1:1:1 molar mixture of H2Se, HDSe, and D2Se under cryogenic conditions (CsI window as substrate, 10 K). 相似文献
6.
Analysis of a TE011 mode composite sapphire-rutile dielectric resonator has been carried out to study the temperature variation of resonance
frequency, close to the Cs atomic clock hyperfine frequency of 9.192 GHz. The complementary behavior of dielectric permittivity
with temperature of the composite has been exploited to obtain the desired turning point in the resonant frequency. The frequency
of the composite structure is found to be independent of the shield diameter beyond four times the puck diameter. 相似文献
7.
Laser‐ablated Th atoms are reacted with different F2 concentrations to produce ThFx (x = 1, 2, 3, 4), ThF3(F2) and ThF5‐. 相似文献
8.
Y Gong L Andrews CW Bauschlicher KS Thanthiriwatte DA Dixon 《Dalton transactions (Cambridge, England : 2003)》2012,41(38):11706-11715
The isolated group 4 metal oxydifluoride molecules OMF(2) (M = Ti, Zr, Hf) with terminal oxo groups are produced specifically on the spontaneous reactions of metal atoms with OF(2) through annealing in solid argon. The product structures and vibrational spectra are characterized using matrix isolation infrared spectroscopy as well as B3LYP density functional and CCSD(T) frequency calculations. OTiF(2) is predicted to have a planar structure while both OZrF(2) and OHfF(2) possess pyramidal structures, all with singlet ground states. Three infrared absorptions are observed for each product molecule, one M-O and two M-F stretching modes, and assignments of these molecules are further supported by the corresponding (18)O shifts. The molecular orbitals of the group 4 OMF(2) molecules show triple bond character for the terminal oxo groups, which are also supported by an NBO analysis. These molecular orbitals include a σ bond (O(2p) + Ti(sd hybrid)), a normal electron pair π bond (O(2p) + Ti(d)), and a dative π bond arising from O lone pair donation to the overlapping Ti d orbital. The M-O bond dissociation energies for OMF(2) are comparable to those in the diatomic oxide molecules. The OTiF intermediate is also observed through two slightly lower frequency bond stretching modes, and its yield is increased in complementary TiO + F(2) experiments. Finally, the formation of group 4 OMF(2) molecules is highly exothermic due to the weak O-F bonds in OF(2) as well as the strong new MO and M-F bonds formed. 相似文献
9.
Explicit expressions have been derived for the volume dependence of electron-phonon coupling strength (λ) and the Coulomb pseudopotential (μ*) considering the variation of Fermi momentum (κ
F) and Debye temperature (θ
D) with volume. Ashcroft’s model pseudopotential and RPA form of dielectric screening have been used for obtaining pressure
dependence of transition temperature (T
C) and the logarithmic volume derivative (Φ) of the effective interaction strength (N
0
V) for metallic glass superconductor Mg70Zn30. It has been observed that T
C of the metallic glass Mg70Zn30 decreases rapidly with increase of pressure and the superconducting phase disappears at about 30% decrease of volume, for
which the μ* curve shows a minimum and an elbow is formed in the Φ graph. 相似文献
10.
Atomization energies at 0 K and heats of formation at 0 and 298 K are calculated for the title halogen fluorides and oxofluorides using a composite electronic structure approach based on CCSD(T) computations extrapolated to the complete basis set limit. 相似文献