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相关论文: Collisional broadening of alkali doublets by heliu…

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Collision broadening by molecular hydrogen of sodium and potassium is one of the major broadening mechanisms in the atmospheres of brown dwarf stars and exoplanets at an effective temperature of about 1000K. The accurate computation of line…

地球与行星天体物理 · 物理学 2025-10-08 N. F. Allard , J. F. Kielkopf

Ultracool stellar atmospheres show absorption by alkali resonance lines severely broadened by collisions with neutral perturbers. In the coolest and densest atmospheres, such as those of T dwarfs, Na I and K I broadened by molecular…

太阳与恒星天体物理 · 物理学 2023-06-21 N. F. Allard , K. Myneni , J. N. Blakely , G. Guillon

We calculate the density shift and broadening of selected dipole transition lines of pionic helium in gaseous helium at low temperatures up to T=12 K and pressure up to a few bar. In the approximation of binary collisions the shift and…

原子物理 · 物理学 2016-06-15 Boyan Obreshkov , Dimitar Bakalov

We report on our new calculations of unified line profiles of K perturbed by He using ab initio potential data for the conditions prevailing in cool substellar brown dwarfs and hot dense planetary atmospheres with temperatures from…

太阳与恒星天体物理 · 物理学 2024-03-06 N. F. Allard , J. F. Kielkopf , K. Myneni , J. N. Blakely

We present PHOENIX atmosphere models for metal-rich cool white dwarfs using improved line shapes for the Na I and K I resonance doublets. Profiles for collisional broadening due to H2 and He based on the adiabatic representation show strong…

Rate coefficients for inelastic collisions between Li and H atoms covering all transitions between the asymptotic states Li(2s,2p,3s,3p,3d,4s,4p,4d,4f)+H(1s) and Li^+ +H^- are presented for the temperature range 2000-8000 K based on recent…

天体物理学 · 物理学 2009-11-10 P. S. Barklem , A. K. Belyaev , M. Asplund

Quantum mechanical calculations are performed of the emission and absorption profiles of the lithium 2s-2p resonance line under the influence of a helium perturbing gas. We use carefully constructed potential energy surfaces and transition…

原子物理 · 物理学 2007-05-23 Cheng Zhu , James F. Babb , Alex Dalgarno

Ultracool stellar atmospheres show absorption by alkali resonance lines severely broadened by collisions with neutral perturbers. In the coolest and densest atmospheres, such as those of T dwarfs, Na I and K I broadened by molecular…

天体物理学 · 物理学 2009-06-23 Derek Homeier , Nicole F. Allard , France Allard

We study Coulomb drag in a pair of parallel one-dimensional electron systems within the framework of the Tomanaga-Luttinger model. We find that Coulomb coupling has a much stronger effect on one dimensional wires than on two-dimensional…

介观与纳米尺度物理 · 物理学 2009-10-31 Rochus Klesse , Ady Stern

We study electronic transport through a one-dimensional, finite-length quantum wire of correlated electrons (Luttinger liquid) coupled at arbitrary position via tunnel barriers to two semi-infinite, one-dimensional as well as stripe-like…

强关联电子 · 物理学 2015-05-13 P. Wächter , V. Meden , K. Schönhammer

Theoretical cross sections for the pressure broadening by hydrogen of rotational transitions of water are compared to the latest available measurements in the temperature range 65-220 K. A high accuracy interaction potential is employed in…

化学物理 · 物理学 2015-05-19 Laurent Wiesenfeld , Alexandre Faure

We report the low temperature current-voltage (I-V) characteristics studies in quasi-one dimensional conducting polymer nanofibers. We find a threshold voltage Vt below which little current flows at temperatures below 30-40 K. For V > Vt…

软凝聚态物质 · 物理学 2009-11-11 A. N. Aleshin , H. J. Lee , S. H. Jhang , H. S. Kim , K. Akagi , Y. W. Park

Using the semiclassical perturbation method, electron-, proton-, and ionized helium-impact line widths and shifts for the nine Cr I spectral lines from the $4p^7P^0-4d^7D$ multiplet, have been calculated for a perturbers density of…

天体物理学 · 物理学 2009-11-10 M. S. Dimitrijevic , T. Ryabchikova , L. C. Popovic , D. Shulyak , S. Khan

We report pressure broadening coefficients for the 21 electric-dipole transitions between the eight lowest rotational levels of ortho-H$_2$O and para-H$_2$O molecules by collisions with He at temperatures from 20 to 120 K. These…

化学物理 · 物理学 2016-06-07 M. I. Hernández , J. M. Fernández , G. Tejeda , E. Moreno , S. Montero

The dependence on applied electric field ($0 - 40$ kV/cm) of the scintillation light produced by fast electrons and $\alpha$ particles stopped in liquid helium in the temperature range of 0.44 K to 3.12 K is reported. For both types of…

The paper presents a simplified formula to determine an electron temperature, Te(He I), for planetary nebulae (PNe) using the He I 7281/6678 line flux ratio. In our previous studies of Te(He I) (Zhang et al. 2005), we used the He I line…

天体物理学 · 物理学 2007-05-23 Y. Zhang , R. H. Rubin , X. -W. Liu

Thermophysical properties of hydrogen, helium, and hydrogen-helium mixtures have been investigated in the warm dense matter regime at electron number densities ranging from $6.02\times10^{29}\sim2.41\times10^{30}$/m$^{3}$ and temperatures…

材料科学 · 物理学 2015-06-16 Cong Wang , Xian-Tu He , Ping Zhang

We report our transport studies in quasi one-dimensional (1D) conductors - helical polyacetylene fibers doped with iodine and the data analysis for other polymer single fibers and tubes. We found that at 30 K < T < 300 K the conductance and…

软凝聚态物质 · 物理学 2009-11-10 A. N. Aleshin , H. J. Lee , Y. W. Park , K. Akagi

The specific heat of liquid helium was calculated theoretically in the Landau theory. The results deviate from experimental data in the temperature region of 1.3 - 2.1 K. Many theorists subsequently improved the results of the Landau theory…

其他凝聚态物理 · 物理学 2009-11-13 Shosuke Sasaki

Recent experiments have revealed that the temperature dependence of the conductance of quasi-ballistic quantum wires bears clear features of the Luttinger-liquid state. In this paper, the conductance of an N-channel quantum wire is…

介观与纳米尺度物理 · 物理学 2009-10-30 Nancy Sandler , Dmitrii L. Maslov
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