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1.
A miniature tunable TEA CO2 laser using isotope 13C16O2 as the active medium is developed to extend the spectral range of CO2 lasers for further application. The optimization of the energy parameters of the tunable TEA 13C16O2 laser and the same laser using 12C16O2 are studied. When a gas mixture (13C16O2: N2: He = 1: 1: 3) at a total pressure of 6.4 × 104 Pa is used, the TEA 13C16O2 laser of a 45-cm3 active volume obtains 51 emission lines in the [0001–1000] and [0001–0200] bands. The maximum pulse energy of the TEA 13C16O2 laser is about 357 mJ. The same laser using the conventional gas mixture (12C16O2: N2: He = 1: 1: 3) at a pressure of 6.66 × 104 Pa is measured to obtain 69 laser emission lines and the maximum pulse energy of laser radiation is about 409 mJ. 相似文献
2.
I. Sherstov S. Liu Ch. Lisdat H. Schnatz S. Jung H. Knöckel E. Tiemann 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,41(3):485-492
Absolute transition frequencies of the b 3Π(0u
+) - X 1Σg
+ system of K2 were measured in a molecular beam with Lamb dip absorption spectroscopy applying a frequency comb from a femtosecond pulsed
laser. Both, K atoms and K2 molecules are present in the beam and are expected to interact by collisions. The atoms can be deflected optically out of
the beam, and thus the collision rate between K atoms and K2 molecules is changed by about an order of magnitude. The molecular transition frequencies for low collisional rate are compared
with those for high one. Limits for the collisional frequency shift within the beam are determined. 相似文献
3.
H. Cherkani-Hassani D. S. Belic J. J. Jureta J. Lecointre P. Defrance 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2010,58(1):85-94
Absolute cross-sections for electron-impact dissociative ionization of C2
H2+ and C2 D2+ to CH+, C+, C2+ , H+, CH2+
and C2D+ fragments are determined for electron energies ranging
from the corresponding threshold to 2.5 keV. Results obtained in a crossed
beams experiment are analyzed to estimate the contribution of dissociative
ionization to each fragment formation. The dissociative ionization cross
sections are seen to decrease for more than an order of magnitude, from
CH+ (5.37±0.10) × 10-17 cm2 over C+ (4.19±
0.16) × 10-17 cm2, C2D+ (3.94±0.38) ×
10-17 cm2, C2+ (3.82±0.15) × 10-17 cm2
and H+ (3.37±0.21) × 10-17 cm2 to CH2+
(2.66±0.14) × 10-18 cm2. Kinetic energy release
distributions of fragment ions are also determined from the analysis of the
product velocity distribution. Cross section values, threshold energies and
kinetic energies are compared with the data available from the literature.
Conforming to the scheme used in the study of the dissociative excitation of
C2H2+
( C2 D2+ )\left( {\rm C}_2 {\rm D}_2^+ \right), the cross-sections are presented in
a format suitable for their implementation in plasma simulation codes. 相似文献
4.
D. Hennequin P. Verkerk 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2010,57(1):95-104
The dynamics of cold atoms in conservative optical lattices obviously depends on the geometry of the lattice. But very similar
lattices may lead to deeply different dynamics. In a 2D optical lattice with a square mesh, it is expected that the coupling
between the degrees of freedom leads to chaotic motions. However, in some conditions, chaos remains marginal. The aim of this
paper is to understand the dynamical mechanisms inhibiting the appearance of chaos in such a case. As the quantum dynamics
of a system is defined as a function of its classical dynamics – e.g. quantum chaos is defined as the quantum regime of a
system whose classical dynamics is chaotic – we focus here on the dynamical regimes of classical atoms inside a well. We show
that when chaos is inhibited, the motions in the two directions of space are frequency locked in most of the phase space,
for most of the parameters of the lattice and atoms. This synchronization, not as strict as that of a dissipative system,
is nevertheless a mechanism powerful enough to explain that chaos cannot appear in such conditions. 相似文献
5.
A. P. Severyukhin N. N. Arsenyev N. Pietralla V. Werner 《Physics of Atomic Nuclei》2016,79(4):469-473
Starting fromthe Skyrme interaction f_ together with the volume pairing interaction, we study the g factors for the 21,2+ excitations of 132,134,136Te. The coupling between one- and two-phonon terms in the wave functions of excited states is taken into account within the finite-rank separable approximation. Using the same set of parameters we describe the available experimental data and give the prediction for 136Te, g(21+) = ?0.18 in comparison to +0.32 in the case of 132Te. 相似文献
6.
The Dy3+ and Eu3+ activated K3Al2 (PO4)3 phosphors were prepared by a combustion synthesis. From a powder X-ray diffraction (XRD) analysis the formation of K3Al2 (PO4)3 was confirmed. In the photoluminescence emission spectra, the K3Al2(PO4)3:Dy3+ phosphor emits two distinctive colors: blue and yellow whereas K3Al2(PO4)3:Eu3+ emits red color. Thus the combination of colors gives BYR (blue–yellow–red) emissions can produce white light. These phosphors
exhibit a strong absorption between 340 and 400 nm which suggest that present phosphor is a promising candidate for producing
white light-emitting diodes (LED). 相似文献
7.
P. Masłowski J. Domysławska K. Bielska R. Ciuryło D. Lisak R. S. Trawiński J. Szudy 《The European physical journal. Special topics》2007,144(1):239-242
Experimental results of a systematic study of profiles of the
hyperfine-structure components of the intercombination 51S0 – 5 3P1 line of
the even-odd 113Cd isotope perturbed by argon performed by means of a
laser-induced fluorescence method are reported. We have found that the values
of total line asymmetries of both hfs line components are different. 相似文献
8.
Deuterofullerites C60Dx have been studied by 2H and 13C NMR. These fullerites have two types of carbon–deuterium bonds: C–D terminal bonds, characterized by the quadrupole coupling constant (QCC) of 171 kHz, and –C ··· D ··· C– bridging bonds with a QCC of 56 kHz. The latter is responsible for the rigid lattice found in these fullerites, which is untypical of fullerenes. PACS 81.05.Tp; 82.56.Fk; 61.48.+c; 61.18.Fs; 61.10.Nz 相似文献
9.
This paper reports on the photoluminescence (PL) and time-resolved properties of Ce3+, Eu3+, and Tb3+ in novel LiSr4(BO3)3 powder phosphors. Ce3+ shows an emission band peaking at 420 nm under 350-nm UV excitation. Energy transfer from Ce3+ to Mn2+ takes place in the co-doped samples. Eu3+ shows red emission under near UV excitation. LiSr4(BO3)3:Eu3+ phosphor could be a suitable candidate for phosphor-converted solid state lighting. The luminescence lifetime is 2.13 ms
for Eu3+ in LiSr4(BO3)3:0.001Eu3+. As Eu3+ concentration increasing, the decay curves deviate from exponential behavior. Tb3+ shows the strongest 5D4→7 F5 emission line at 540 nm. Decay curves of 5D4→7 F5 and 5D3→7 F5 emission with different Tb3+ concentrations were also measured. Cross-relaxation process is discussed based on the decay curves. 相似文献
10.
T. Grahn J. Pakarinen L. Jokiniemi M. Albers K. Auranen C. Bauer C. Bernards A. Blazhev P. A. Butler S. Bönig A. Damyanova T. De Coster H. De Witte J. Elseviers L. P. Gaffney M. Huyse A. Herzáň U. Jakobsson R. Julin N. Kesteloot J. Konki Th. Kröll L. Lewandowski K. Moschner P. Peura M. Pfeiffer D. Radeck P. Rahkila E. Rapisarda P. Reiter K. Reynders M. Rudiger M. -D. Salsac S. Sambi M. Scheck M. Seidlitz B. Siebeck T. Steinbach S. Stolze J. Suhonen P. Thoele M. Thürauf N. Warr P. Van Duppen M. Venhart M. J. Vermeulen V. Werner M. Veselsky A. Vogt K. Wrzosek-Lipska M. Zielińska 《The European Physical Journal A - Hadrons and Nuclei》2016,52(11):340
11.
M. Niemietz M. Engelke Y.D. Kim G. Ganteför 《Applied Physics A: Materials Science & Processing》2007,87(4):615-619
We present time-resolved photoelectron spectra of mass-selected Ag2O2 anions. The anions are photoexcited by photons with an energy of 3.1 eV, and photoelectron spectra of the excited species
Ag2O2
-
* and the subsequently appearing fragments are recorded using a probe laser pulse with a photon energy of 1.5 eV. The excited
state of Ag2O2
- has a short lifetime of 130 fs±70 fs only and decays by direct photodesorption of O2. The data demonstrate the ability of time-resolved photoelectron spectroscopy (TR-PES) to observe the breaking of chemical
bonds if the decay process of the excited state is direct (non-thermal desorption). The data are compared to recent results
of a NeNePo experiment [1] on the same system.
PACS 68.43.Tj; 78.47.+p; 33.80.Eh; 36.40.-c 相似文献
12.
1H and 19F spin-lattice relaxation times in polycrystalline diammonium hexafluorozirconate have been measured in the temperature range
of 10–400 K to elucidate the molecular motion of both cation and anion. Interesting features such as translational diffusion
at higher temperatures, molecular reorientational motion of both cation and anion groups at intermediate temperatures and
quantum rotational tunneling of the ammonium group at lower temperatures have been observed. Nuclear magnetic resonance (NMR)
relaxation time results correlate well with the NMR second moment and conductivity studies reported earlier. 相似文献
13.
The general analysis of the rare Bc→Ds
*ℓ+ℓ- decay is presented by using the most general, model independent effective Hamiltonian. The dependencies of the branching
ratios and of the longitudinal, normal and transversal polarization asymmetries for ℓ- and the combined asymmetries for ℓ- and ℓ+ on the new Wilson coefficients are investigated. Our analysis shows that the lepton polarization asymmetries are very sensitive
to the scalar and tensor type interactions, which will be very useful in looking for new physics beyond the standard model. 相似文献
14.
H. Cherkani-Hassani S. Cherkani-Hassani D. S. Belic J. J. Jureta J. Lecointre P. Defrance 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2010,58(1):75-83
Absolute cross-sections for electron-impact ionization and dissociation of
C2H2+ and C2D2+ have been measured for electron energies
ranging from the corresponding thresholds up to 2.5 keV. The animated
crossed beams experiment has been used. Light as well as heavy fragment ions
that are produced from the ionization and the dissociation of the target
have been detected for the first time. The maximum of the cross-section for
single ionization is found to be (5.56 ± 0.03)× 10-17 cm2 around 140 eV. Cross-sections for dissociation of C2
H2+ (C2D2+) to ionic products are seen to decrease for two orders
of magnitude, from C2D+ (12.6 ± 0.3) × 10-17 cm2 over CH+(9.55 ± 0.06) × 10-17 cm2,
C+ (6.66 ± 0.05) × 10-17 cm2, C2+ (5.36 ± 0.27) × 10-17 cm2, H+ (4.73 ±
0.29) × 10-17 cm2 and CH2+ (4.56 ± 0.27) × 10-18 cm2 to H2+ (5.68 ± 0.49) ×
10-19 cm2. Absolute
cross-sections and threshold energies have been compared with the scarce
data available in the literature. 相似文献
15.
A. V. Burenin 《Optics and Spectroscopy》2009,107(2):228-234
An algebraic model that describes the internal dynamics of the ionic complexes ArH3+ and ArD3+ in the ground electronic-vibrational state taking into account the torsional motion of the structure of identical hydrogen
nuclei is constructed by symmetry-group chain methods. It is important that the correctness of this model is only limited
by the correctness of the choice of geometric symmetry of the internal dynamics of the ionic complex. 相似文献
16.
E. S. Mironchuk 《Bulletin of the Lebedev Physics Institute》2010,37(6):180-181
A method for determining the relative concentration of 13C/12C isotopes by the vibrational-rotational spectrum of CO2 molecule absorption in the range near 2 μm was proposed. The use of the entire region of the diode laser tuning (∼7 cm−1) and multivariate linear regression for spectrum approximation allow measurements at atmospheric pressure. The laser frequency
is additionally stabilized by injection current variation. The ultimate sensitivity of the setup, determined by the plot of
the squared Alan variance, is 0.03% for 2-min signal acquisition. The system does not contain elements cooled by liquid nitrogen
and can be used in medical diagnostics. 相似文献
17.
M. D. Volnyanskiĭ M. P. Trubitsyn Yakh’ya A. Kh. Obaĭdat 《Physics of the Solid State》2007,49(8):1453-1456
The temperature-frequency dependences of the permittivity of crystals of lithium heptagermanate Li2Ge7O15 doped with Cr3+ ions are investigated. A dielectric response to reorientation of the dipole moments of the chromium impurity centers is revealed. Anomalies of the permittivity are described within the model of a Debye relaxator. 相似文献
18.
M. C. Birse 《The European Physical Journal A - Hadrons and Nuclei》2010,46(2):231-240
A distorted-wave method is used to analyse nucleon-nucleon scattering in the 1
S
0 channel. Effects of one-pion exchange are removed from the empirical phase shift to all orders by using a modified effective-range
expansion. Two-pion exchange is then subtracted in the distorted-wave Born approximation, with matrix elements taken between
scattering waves for the one-pion exchange potential. The residual short-range interaction shows a very rapid energy dependence
for kinetic energies above about 100MeV, suggesting that the breakdown scale of the corresponding effective theory is only
270MeV. This may signal the need to include the D \Delta -resonance as an explicit degree of freedom in order to describe scattering at these energies. An alternative strategy of
keeping the cutoff finite to reduce large, but finite, contributions from the long-range forces is also discussed. 相似文献
19.
P. Masłowski K. Bielska R. S. Trawiński 《The European physical journal. Special topics》2007,144(1):243-245
Experimental results of a spectroscopic study of argon broadened
profiles of the hyperfine-structure components of the intercombination
326.1 nm line 113Cd isotope are reported. We have found that the values of
Lorentzian (collisional) widths of both hfs line components are different. 相似文献
20.
The electron paramagnetic resonance (EPR) spectra of Ce3+ and Nd3+ impurity ions in unoriented powders of the YBa2Cu3O6.13 compound are observed and interpreted for the first time. It is demonstrated that, upon long-term storage of the samples
at room temperature, the EPR signals of these ions are masked by the spectral line (with the g factor of approximately 2) associated with the intrinsic magnetic centers due to the significant increase in its intensity. 相似文献