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41.
S. Kar Y. K. Ho 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,48(2):157-165
We have investigated the bound states and resonance states of
plasma-embedded tdμ and ddμ molecular ions using accurate
correlated basis functions. The plasma effect has been taken care of by
considering the Debye shielding approach of plasma modeling which admits a
variety of plasma conditions. The density of resonance states are calculated
using the stabilization method. The ground and excited states energies, and
the S-wave resonance energies of tdμ and ddμ molecular ions
immersed in plasmas are reported for various shielding parameters, along
with the 1S and 2S threshold energies of the tμ and dμ atoms. 相似文献
42.
43.
44.
Mathematical definitions are an important mathematical construct which has been noted as a challenging topic for both teachers and students. This study provides an analysis of the form and content of a set of 308 definitions of quadrilateral types provided by 44 novice pre-service elementary teachers (NPSTs) who had not yet studied geometry or definitions on the college level. Analysis of definition structure including necessary, sufficient, and minimal conditions, as well as hierarchical and partitional structure, provides insight into what NPSTs may think about the form of mathematical definitions in general. Analysis of the properties used in definitions of each shape type and the frequency of those properties reveals the shape types with which NPSTs are most and least familiar. These results are presented alongside possible applications and implications for instruction. 相似文献
45.
Yuriy Zinchenko 《Optimization Letters》2008,2(3):389-402
Elementary symmetric polynomials can be thought of as derivative polynomials of . Their associated hyperbolicity cones give a natural sequence of relaxations for . We establish a recursive structure for these cones, namely, that the coordinate projections of these cones are themselves
hyperbolicity cones associated with elementary symmetric polynomials. As a consequence of this recursion, we give an alternative
characterization of these cones, and give an algebraic characterization for one particular dual cone associated with together with its self-concordant barrier functional. 相似文献
46.
Young-Dae Jung 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2000,11(2):291-294
The classical electron-ion Coulomb Bremsstrahlung process is investigated in nonideal plasmas. An effective pseudopotential
model taking into account the plasma screening and collective effects is applied to describe the electron-ion interaction
potential in a classical nonideal plasma. The classical straight-line trajectory method is applied to the motion of the projectile
electron in order to visualize the variation of the differential Bremsstrahlung radiation cross-section (DBRCS) as a function
of the scaled impact parameter, nonideal plasma parameter, projectile energy, photon energy, and Debye length. The results
show that the DBRCS in ideal plasmas described by the Debye-Hückel potential is always greater than that in nonideal plasmas,
i.e., the collective effects reduce the DBRCS for both the soft and hard photon cases. For large impact parameters, the DBRCS
for the soft photon case is found to be always greater than that for the hard photon case.
Received 1st December 1999 相似文献
47.
R. Plasil I. Korolov T. Kotrik P. Dohnal G. Bano Z. Donko J. Glosik 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,54(2):391-398
Experimental studies of the electron energy distribution function “EEDF” under well defined conditions in flowing afterglow
plasma, using a Langmuir probe are reported. The EEDF is measured in He2
+ and Ar+ dominated plasmas and in XeH+ and XeD+ dominated recombining plasmas. He is used as a buffer gas at medium pressures in all experiments (1600 Pa, 250 K). The deviation
of the measured EEDF from Maxwellian distribution is shown to depend on plasma composition and on the processes governing
the plasma decay. The influence of energetic electrons produced during the plasma decay on the body and tail of the EEDF is
observed. The mechanism of energy balance in afterglow plasma is discussed. 相似文献
48.
A. Laricchiuta D. Bruno M. Capitelli C. Catalfamo R. Celiberto G. Colonna P. Diomede D. Giordano C. Gorse S. Longo D. Pagano F. Pirani 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,54(3):607-612
In the perspective of higher approximations of the Chapman-Enskog theory for transport property calculations, existing transport
cross sections databases for interactions involving Earth atmosphere species have been updated and extended to Mars atmosphere
components, proposing a phenomenological approach for the derivation of the relevant elastic collision integrals in neutral-neutral
and neutral-ion interactions. Inelastic collision integrals terms, due to resonant charge exchange channels, have been considered
and the asymptotic approach extended to the estimation of charge transfer cross section of multiple resonant processes.
Electronic supplementary material Supplementary Online Material 相似文献
49.
I. Bombaci D. Logoteta P.K. Panda C. Providência I. Vidaa 《Physics letters. [Part B]》2009,680(5):448-452
We study the quark deconfinement phase transition in hot β-stable hadronic matter. Assuming a first order phase transition, we calculate the enthalpy per baryon of the hadron–quark phase transition. We calculate and compare the nucleation rate and the nucleation time due to thermal and quantum nucleation mechanisms. We compute the crossover temperature above which thermal nucleation dominates the finite temperature quantum nucleation mechanism. We next discuss the consequences for the physics of proto-neutron stars. We introduce the concept of limiting conversion temperature and critical mass Mcr for proto-hadronic stars, and we show that proto-hadronic stars with a mass M<Mcr could survive the early stages of their evolution without decaying to a quark star. 相似文献
50.
By using elementary symmetric functions, this paper presents an explicit representation for the Lagrangian numerical differentiation formula as well as the error estimate for local approximation. And we also point out that the numerical differentiation formula constructed by Li [J.P. Li, General explicit difference formulas for numerical differentiation, J. Comput. Appl. Math. 183 (2005) 29-52] is actually a special case of the Lagrangian numerical differentiation formula to approximate the values of the derivatives at the nodes. 相似文献