bluuebunny/crossref_metadata_2025 huggingface dataset:
Tunable resonance in a superstrate-loaded lossy circular disk microstrip structure
Authors: Gürel Ç S , Yazgan E
Published: April 2011

The tunable resonance characteristics of a superstrate-loaded circular disk microstrip structure having a lossy ground plane are analysed for various structural parameters. It is shown that the decrease in the resonant frequency as a result of the occurence of the superstrate layer or increase in the medium temperature can be compensated for by using the opposite effect of an air gap inserted between the substrate and the ground plane. By means of this tuning scheme it is possible to stabilize the resonant-frequency variations and to control radiational loss characteristic of the structure without disturbing the original configuration. PACS No.: 40.00
Real time interferometric manipulation of a neutral atomic beam by electric field
Authors: Shimizu F , Fujita J , Mitake S
Published: April 2011

Electric-field-controlled holography for atoms is demonstrated. Platinum electrodes are deposited among the array of parallel slits that are made on a silicon nitride film. A cold neon atomic beam in the 1s3[2p5(2Po1/2)3s : J = 0] metastable state is sent through the film and form a Fraunhofer diffraction pattern on a microchannel plate detector that is placed in the downstream of the film. By controlling the potential of each electrode an arbitrary one-dimensional diffraction pattern of atoms has been generated.PACS No. 78.90
On the concept of kinetic energy
Authors: Antippa A F
Published: April 2011

We analyze, in their historic perspective, the three alternative traditional definitions of kinetic energy and then propose a new definition according to which the change in kinetic energy is equal to the scalar product of the velocity and the change in momentum. We justify this definition on conceptual grounds, and show that it follows from Hamilton's equations. From this definition, the explicit classical and relativistic expressions for kinetic energy follow simply upon using the appropriate mass function. The definition given here has the added advantage of being naturally generalizable to a canonical kinetic energy per degree of freedom. This latter takes into account both particle and field kinetic energies. PACS Nos.: 01.55+b, 03.30+p, 03.20+i, 46.10+z
Analytical expressions for the energies of anharmonic oscillators
Authors: Fernández F M , Tipping R H
Published: April 2011

We propose a systematic construction of algebraic approximants for the bound-state energies of anharmonic oscillators. The approximants are based on the Rayleigh-Schrödinger perturbation series and take into account the analytical behavior of the energies at large values of the perturbation parameter. A simple expression obtained from a low-order perturbation series compares favorably with alternative approximants. Present approximants converge in the large-coupling limit and are suitable for the calculation of the energy of highly excited states. Moreover, we obtain some branch points of the eigenvalues of the anharmonic oscillator as functions of the coupling constant.

PACS No.: 03.65Ge
The motion of a curling rock: Analytical approach
Authors: Shegelski M R
Published: April 2011

A simplified version of a previously proposed model is presented and used to illustrate the salient features of the motion of a slowly rotating curling rock. A one-parameter model is presented. Analytical approximations for the chief aspects of the motion are derived. The simplified analytical model accounts quite well for the principal features of the motion of a slowly rotating curling rock, in particular that most of the curl occurs in the final few metres of the rock's motion. A discussion is also given concerning a popular misconception as to why curling rocks curl.

PACS No.: 46.00
Electron impact ionization of the ground state of singly ionized helium
Authors: Bhattacharya M , Deb N C , Msezane A Z , Mazumdar P S
Published: April 2011

We calculate the total and single differential cross sections for the electron impact ionization of the ground state of singly ionized helium at various energies in a distorted wave approximation. Present results are compared with existing theoretical and experimental results. PACS Nos.: 34.80.Dp, 34.50.Fa
Far-infrared LMR spectroscopic investigation of the quasi-linear molecule DCCN: The v5(1 0) transition
Authors: Jones W E , Sun F , Curl R F , Allen M D , Evenson K M , Brown J M
Published: April 2011

The far-infrared laser magnetic resonance spectrum (FIR LMR) of the v5 bending vibrational transition of DCCN in its X3 Σ state is reported. The DCCN radical was produced inside the spectrometer cavity by the reaction of deuterated acetonitrile with F atoms. DCCN resonances were measured on seven laser lines. Nitrogen hyperfine structure was observed on a number of the resonances. The analysis provides improved accuracy for the separation v5= 1 [Formula: see text] 0 and some of the 14N hyperfine coupling constants for this isotopomer.PACS No.: 33.20Ea
Broadening and shifting of four rovibrational Raman lines of D2 at 100.7 K
Authors: Forsman J W , Sheldon G D , Fakhr-Eslam S H , Drummond J R , May A D
Published: April 2011

Line widths and shifts of the S1(0), S1(1), S1(2), and the O1(2) Raman lines in pure D2 at 100.7 K are reported. These measurements, made with a high-resolution cw Raman gain spectrometer, can be used to test future theoretical calculations.PACS Nos.: 33.70-w 33.20Fb
A canonical approach for computing the eigenvalues of the Schrödinger equation for double-well potentials
Authors: Korek M , Fakhreddine K
Published: April 2011

The problem of obtaining the eigenvalues of the Schrödinger equation for a double-well potential function is considered. By replacing the differential Schrödinger equation by a Volterra integral equation the wave function will be given by [Formula: see text] where the coefficients ai are obtained from the boundary conditions and the fi are two well-defined canonical functions. Using these canonical functions, we define an eigenvalue function F(E) = 0; its roots E1, E2, ... are the eigenvalues of the corresponding double-well potential. The numerical application to analytical potentials (either symmetric or asymmetric) and to a numerical potential of the (2)1 [Formula: see text] state of the molecule Na2 shows the validity and the high accuracy of the present formulation. PACS No.: 03.65Ge
The gravitational field about a spinning particle
Authors: McKeon D.G.C.
Published: April 2011

We consider the action for N = 1 and N = 2 spinning particles in the presence of a background gravitational field. The action for the gravitational field induced by one-loop effects is examined to lowest order in the metric. This is the one-dimensional analogue of calculations performed in two-dimensional nonlinear sigma models. The inherent infrared divergences are quite severe, and it is found that the effective action depends crucially on how they are treated, as is the case in two-dimensional nonlinear sigma models. Using one approach, an intractable infrared divergence arises, while with another technique, the effective action vanishes. A calculational technique introduced by Onofri is employed. A novel N = 4 spinning particle is considered briefly.PACS No.: 12.60Jv
Theoretical study of the electronic structure of LiCs, NaCs, and KCs molecules
Authors: Korek M , Allouche A R , Fakhreddine K , Chaalan A
Published: April 2011

The potential energy has been calculated over a wide range of internuclear distance for 28 lowest molecular states of LiCs, 32 lowest states of NaCs, and 30 lowest states of KCs molecules. This calculation is done by using an ab initio method based on nonempirical pseudopotentials, parameterized l-dependent polarization potentials, and full valence configuration interaction calculations. Extensive tables of energy values versus internuclear distance are displayed at the following address http://hplasim2.univ-lyon1.fr/allouche. Molecular spectroscopic constants have been derived for the bound states with regular shape. PACS Nos.: 31.15Ar, 31.25-u
The torsion-rotation spectrum of D2O2
Authors: Flaud J -M , Johns J WC , Lu Z , Winnewisser G , Klein H
Published: April 2011

High-resolution Fourier transform and sub-millimetre torsion-rotation spectra of D2O2 have been recorded between 20 and 1200 cm1. Spectra involving the torsional levels (n,τ) = (0,1), (0,3), (1,1), (1,3), (2,1), (2,3), and (3,1) have been observed and assigned.The Hamiltonian that has been used with success in the analysis of H2O2 surprisingly proved to be inadequate for D2O2 because the smaller torsional spacings give rise to some near resonances with |Δ Ka| = 3 that do not occur in H2O2. Once this extra interaction was included the spectra have been fitted fairly well. The observed levels are too far below the cis-torsional barrier for the staggering of the even and odd K values to be observed. PACS Nos.: 3310, 3320B, 3320E, 3520J, 3520P
High-resolution study of the υ9 fundamental band of trans-glyoxal
Authors: Braund D B , Cole A RH
Published: April 2011

The spectrum of trans-glyoxal has been recorded at a resolution of about 0.004 cm1 in the region from 2770 to 2900 cm1. 1549 lines have been assigned to the type B band due to the υ9 (bu) fundamental (antisymmetric CH stretching vibration). The ground-state rotational constants confirm earlier values and new constants are determined for the excited state of υ9. PACS No.: 33.20E
Absorption spectroscopy of singlet CH2 near 11 200 cm1
Authors: Kobayashi K , Sears T J
Published: April 2011

New spectra of methylene, CH2, in the near infrared region of the singlet band system have been obtained. They were detected by laser transient absorption spectroscopy following excimer laser flash photolysis of ketene, CH2CO, at 308 nm. The new data provide information on the nature and energies of rotational levels in three vibronic states that lie between approximately 11 500 and 13 000 cm1 above the zero point level of the lower, ã1A1, state. Taken together with previous measurements, a fairly complete picture of the vibronic energy levels of CH2 in this region can be built up. There is generally good agreement with the recent computational studies on the singlet states of CH2, but some evidence for discrepancies for levels with K = 3 and higher near the minimum of the [Formula: see text]1B1 potential surface. PACS No.: 33.20Ea
Infrared spectrum of the CH3OH  CO complex in the CO stretching region
Authors: Xia C , McKellar A RW
Published: April 2011

The infrared spectrum of the weakly-bound molecular complex methanol - carbon monoxide has been observed, for the first time in the gas phase, by means of a parallel (Δ K = 0) band in the region of the carbon monoxide CO stretching vibration. The band origin, 2154.5 cm1, represents a blue shift of 11.2 cm1 relative to the free CO molecule; its proximity to that of the H2O  CO complex points to a similarity of the hydrogen bonding in the two systems. The observed structure of the band could be well reproduced by a simulation based on the methyl internal rotation component of A-symmetry. A component of E-symmetry must also be present, with roughly equal intensity, but the two components were not individually resolved. The observed transitions showed evidence of predissociation broadening, leading to an estimate of t [Formula: see text] 0.5 ns for the lifetime of the upper (CO stretching) state.PACS Nos.: 3320E, 3425, 3520P, 3640
Diode laser spectroscopy of the weakly bound complex NeCH4
Authors: Wangler M , Roth D A , Winnewisser G , Pak I , McKellar A R
Published: April 2011

The infrared absorption spectrum of the weakly bound rare-gasspherical-top complex NeCH4 was discovered and analyzed for the first time. Measurements were made with tunable diode laser spectrometers using a pulsed supersonic jet and a long-path low-temperature absorption cell. Close to the R(0) transition of the methane ν4 fundamental band at 1311.430 cm1, the NeCH4 spectrum was recorded as a very compact absorption pattern. Within a total wave-number range of about 0.1 cm1, P-, Q-, and R-branches are located. As the first step, the NeCH4 spectrum was recorded and analyzed in a supersonic jet at low rotational temperature of about 5 K. Three branches were identified, of which the P- and R-branches were partially resolved and the Q-branch remained unresolved. Compared with the previously measured spectra of ArCH4 and KrCH4 [Z. Naturforsch. A, 53, 725 (1998).], the absorption pattern in the spectrum of NeCH4 is much denser and considerably more compact. However, by analogy with the spectra of ArCH4 and KrCH4, assignment and analysis were carried out using a Hamiltonian model that incorporates a Coriolis interaction between the total angular momentum of the complex and the angular momentum of the methane monomer. This analysis then allowed us to assign the same spectrum as recorded in a long-path (160 m) cell at a higher temperature of 62 K. The observed rotational constant for NeCH4, B"= 0.129(9) cm1, corresponds to an effective intermolecular separation of 3.8 Å. PACS Nos.: 33.20E, 34.25, 35.20P, 36.40
Trends in the alkaline-earth amide series: The millimetre-wave spectrum of MgNH2 and MgND2 (2A1)
Authors: Sheridan P M , Ziurys L M
Published: April 2011

The pure rotational spectra of MgNH2 ([Formula: see text]2A1) and its deuterium isotopomer have been recorded using millimetre/sub-millimetre wave direct absorption techniques. Both species were synthesized by the reaction of magnesium vapor and either NH3 or ND3 in a dc discharge. Twelve rotational transitions were measured for MgNH2, and eight transitions were observed for MgND2, both in the range 120530 GHz. Asymmetry components with Ka= 05,7, and sometimes 6, were measured for nearly every transition. Rotational, centrifugal distortion, and spinrotation parameters have been accurately determined for both molecules, as well as an r0 structure for magnesium amide. The data indicate that MgNH2is a planar molecule with C2v symmetry, similar to CaNH2 and SrNH2, and does not undergo inversion. However, there appears to be subtle differences between MgNH2 and its calcium and strontium analogs. Magnesium amide, for example, has a significantly larger HNH bond angle than CaNH2and SrNH2. In addition, the spinrotation constants indicate slightly more in-plane p character for the unpaired electron in this molecule relative to that in calcium or strontium amide. Such differences may result from more covalent character in the bonding of MgNH2 in comparison to the heavier alkaline-earth amide species. PACS No.: 32.20Bx
Measurement of the pressure-broadening coefficient of NO by saturation spectroscopy of LMR
Authors: Liu Y , Lin J , Guo Y
Published: April 2011

This paper presents a method for the determination of the pressure-broadening coefficient of 15N16O by 14N16O. The hyperfine-structure-resolved spectral lines of NO were obtained with an intracavity laser magnetic resonance spectrometer via Lamb dips. From the spectra, the self-broadening coefficient of the P2(5/2) transition of the 15N16O fundamental band due to its collision with 14N16O at 293 K is determined to be 0.092(7) cm1/atm. PACS No.: 32.40
Effect of iron chloride on the polaronic conduction in potassium phosphateglasses containing iron oxide
Authors: Moustafa Y M
Published: April 2011

DC electrical conductivity measurements of Fe2O3K2OP2O5 glasses containing iron chloride have been carried out in the temperature range from room temperature to 360°C. The DC conductivity was analyzed in terms of small polaron hopping theory. The hopping regime between Fe ions was confirmed to be nonadiabatic. The increase in the conductivity was of the same order of magnitude as the change in the pre-exponential factor upon increasing the FeCl3 content. The decrease in the activation energy with increasing FeCl3 content was interpreted in terms of a decrease in the distance between the iron sites. The increase in electrical conductivity was ascribed to the difference in the activation energy. The variation in the conductivity parameters was interpreted in terms of the structural changes that take place upon increasing the FeCl3 content of the glasses. PACS No.72.20Ee
Plasma waves in two-dimensional conductors with impurity electron states
Authors: Haghighi B , Ermolaev A M
Published: April 2011

The dispersion relation and the damping of plasma waves in two-dimensional conductors are calculated under the condition of localization of electrons by impurity atoms. It has been shown that localization of electrons decreases plasma-wave frequency as well as causing their damping when the frequency exceeds some threshold value. The data obtained resulted in an explanation of experiments on electromagnetic wave absorption in inversion layers of silicon and silicon dioxide interfaces.

PACS Nos.: 73.20Mf, 73.40Qv, 72.10Bg
The ClO bond in chlorine oxides: Electronic structure and empirical force constants
Authors: Escribano R , Mosteo R G , Gómez P C
Published: April 2011

The nature of the ClO chemical bond is investigated in a series of chlorine oxides. Several parameters, both experimental and theoretical, are used for this purpose. The geometrical structure is taken from the literature. Force constants are derived from experimental frequencies for 11 molecules, where data from isotopic species, up to a number of 52, are used. Also a topological study of the B3LYP/6-311+G(2d) electron density is carried out. All the parameters mentioned are related and discussed to analyse the different kinds of ClO bonds, and a classification is put forward, in which three different types of ClO bonds are found.PACS No.: 31.10tz
High-resolution Fourier transform infrared spectra of the CH3 ν3and CH2D ν4 bands
Authors: Kawaguchi K
Published: April 2011

The spectrum of the ν3 band CH3 was observed in the 28003100 cm1 region with a Fourier transform infrared spectrometer. The 76 observed lines were analyzed together with the previous difference frequency data to determine the molecular constants including sextic centrifugal distortion constants and the A1  A2 splitting constant in the ground state. The ν4 band (out-of-plane vibrational mode) of CH2D was observed in the 550700 cm1 region by a discharge in a mixture of CH2DI and Ar. The molecular constants in both the ground and the ν4 states of this radical have been determined for the first time. PACS No.: 33.20Ea
Line mixing in the Raman Q branch in D2 and mixtures of D2 in He and Ar
Authors: Sheldon G D , Fakhr-Eslam S H , Sinclair P M , Drummond J R , May A D
Published: April 2011

Weak mixing coefficients for D2 and D2He mixtures at 305.2 and 100.7 K are reported and compared with ab initio quantal calculations. The measurements support but do not provide a critical test of the calculations. Measurements of 50% D2 in Ar at 305.2 K are at variance with the measurements in the pure gas and in mixtures with He and below 20 amagat exhibit an increasing line asymmetry with decreasing density. The results are also at variance with the asymmetries measured in 5% H2 in Ar. PACS No.: 33.70.Jg, 33.20.Fb
HartreeFock calculation for the electronic structure of H+3 using numerically optimized orbitals
Authors: Talman J D
Published: April 2011

The HartreeFock wave functions for the ground state of the H2 molecule and the H+3 molecular ion are computed using radial orbitals that are numerically optimized. It is shown that these orbitals yield results comparable in accuracy to those obtained using much larger bases of Gaussian orbitals. As in previous calculations, the equilibrium geometry for H+3 is found to be that of an equilateral triangle, with an interatomic spacing of 1.64a0. PACS No.: 13.15+q
On transition radiation
Authors: Hirose A , Wishart J
Published: April 2011

The problem of transition radiation has been revisited in terms of reflection and transmission of the radiation magnetic field based on Fresnel's formula. In contrast to the prediction made a half century ago, transition radiation does not vanish in the direction perpendicular to the charged particle trajectory (θ = π /2). PACS No.: 42.20
Méthode BKW formelle et spectre des molécules polyatomiques dans l'approximation de BornOppenheimer
Authors: Messirdi B , Senoussaoui A
Published: April 2011

We studied the spectrum of P = -h2Δx  Δy + V (x,y) on L2(IRx3n × IRy3p), when h tends to zero, n [Formula: see text] 2, p [Formula: see text] IN*, in the case where the potential V(x,y) is singular and of Coulomb type and the first eigenvalue of Q (x) = -Δy + V(x,y) on L (IRy3p) admits an unbounded well. Using a formal version of the h-pseudodifferential calculus on the regularized operator of P with adapted changes, we obtained WKB-type expansions of eigenvalues and associated eigenfunctions of P.
Anomalous transitions in two-level systems driven by the ac Stark effect
Authors: Meerts W L , Ozier I , Hougen J T
Published: April 2011

An unusual type of nonresonant absorption signal produced by the ac Stark effect has been observed in a two-level avoided-crossing system. The theory for these anomalous transitions has been developed. The nonresonant signals have been shown to be caused by the perturbation by the oscillating field of the dephasing of the two-level system at the avoided crossing. A series of measurements of these anomalous transitions has been carried out using the avoided-crossing molecular-beam electric-resonance technique. In addition, different types of resonant multiphoton transitions have been investigated. Results are reported for the AE-barrier anticrossing with J = 1 in CH3SiH3. The experimental findings are in good agreement with the theory developed. PACS Nos.: 33.20Bx, 33.80Be, 42.50Hz
Modeling water emission induced by the Shoemaker-Levy 9/Jupiter catastrophic impact
Authors: Cecchi-Pestellini C , Scappini F
Published: April 2011

We reconsider the water emission observed at 22.2 GHz by Cosmovici et al. (1996) during the ShoemakerLevy 9/Jupiter impact. In contrast to the maser effect proposed by the authors, we discuss the detection in terms of thermal emission. A statistical equilibrium and radiative transfer model is constructed and the results that can be obtained depending on different input parameters are evaluated in the light of literature data. PACS No.: 96.30K
Low-lying electronic states of CuBr
Authors: Hirao T , Bernath P F
Published: April 2011

The A1Π  X1Σ+ and B1Σ+  X1Σ+ transitions of copper monobromide, CuBr, were recorded with a Fourier transform spectrometer. The emission was generated by using a hollow cathode discharge of Ar buffer gas and a mixture of Cu and CuBr powders. The mass-dependent Dunham expansion formula was used to obtain improved molecular constants for the ground, A and B states. These molecular constants provided RKR potential curves and FranckCondon factors for the AX and BX transitions.PACS No. 35.80 transitions.

PACS No. 35.80
Molecular astronomy from a Canadian perspective: The early years
Authors: Feldman P A
Published: April 2011

The early history of the discovery and study of molecules in space was heavily influenced by three Canadians: Gerhard Herzberg, Alex Douglas, and Andrew McKellar. In writing this paper I have tried to cover the most important aspects of the objective scientific history and to give readers a glimpse of my personal knowledge of these men who played such important roles. PACS Nos.: 98.38Bn, 33.20-+
Exceptional algebraic properties of the three quadratic irrationalities observed in quasicrystals
Authors: Masáková Z , Patera J , Pelantová E
Published: April 2011

There are only three irrationalities directly related to experimentally observed quasicrystals, namely, those which appear in extensions of rational numbers by Ö5, Ö2, Ö3. In this article, we demonstrate that the algebraically defined aperiodic point sets with precisely these three irrational numbers play an exceptional role. The exceptional role stems from the possibility of equivalent characterization of these point sets using one binary operation. PACS Nos.: 61.90+d, 61.50-f
On the dissociation energy of molecular hydrogen
Authors: Stoicheff B P
Published: April 2011

The status of our knowledge of the dissociation energy of molecular hydrogen (H2, HD, D2) from the earliest determinations in 19261927 is briefly reviewed. Present values obtained by high-resolution laser spectroscopy and by ab initio computations that include nonadiabatic, relativistic, and radiative corrections are in good agreement to 2 x 106.PACS No.: 33.15Fn
Three- and two-photon absorption spectroscopy: REMPI of HCl and HBr
Authors: Kvaran Á. , Wang H , Waage B G
Published: April 2011

Approximation expressions for absorption line strengths due to Ω' = 0,1,2,3 ¬ Ω" = 0 (Σ, Π, Δ, and Φ ¬ Σ) transitions for three-, two-, and one-photon absorptions are summarized. Those for three- and two-photon absorptions are used to analyse room temperature (3+1) and (2+1) REMPI (resonance enhanced multiphoton ionization) spectra due to transitions to Rydberg states in HCl and HBr to give spectroscopic parameters. A mechanism of the three-photon excitation process for the (E1 Σ+) ¬ X(1Σ+), (0,0) transition in HCl is proposed. A Rydberg state, not observed in single- or two-photon absorption, with a band origin at 80 167 cm-1 was identified in (3+1) REMPI of HBr and analysed for the first time. It was assigned to the l(3(Φ(Ω' = 3)) ((σ2π3)5dδ) state, (0,0) band. Use of the three-photon absorption line strength expressions for deriving rotational population distributions in ground-state HBr is demonstrated. PACS Nos.: 03.40Kf, 42.65Tg, 42.81Dp
Spectroscopy of van der Waals molecules: Isomers and vibrational predissociation
Authors: Klemperer W , Chuang C -C , Higgins K J , Miller A Stevens , Fu H C
Published: April 2011

The inert-gas-halogen complexes have been studied for several decades by jet spectroscopy. Much of the seemingly bizarre behavior has become understandable in terms of two virtually isoenergetic isomer forms. The recently recognized linear isomer of ArI2 has a virtually continuous B ¬ X excitation spectrum. It also undergoes a very rapid vibrational predissociation, and suffers no electronic quenching from the B state. The well-known T-shaped isomer shows slow vibrational predissociation, which is competitive with electronic quenching. The quenching distorts the vibrational distribution of the I2 B state photofragments, consequently leading to a false estimation of the T-shaped ArI2 (B) state dissociation energy. The binding energies for the T-shaped ArI2 (X) and ArI2 (B) are unambiguously determined from the recent dispersed fluorescence study, which are also in good accord with the ab initio calculation. We discuss aspects of pure vibrational laser-induced fluorescence of hydrogen fluoride complexes. We contrast the behavior of ArHF with NeHF and present new results for the vHF = 3 level of NeHF. PACS Nos.: 33.80Gj, 34.30th
Photodissociation of superexcited states of hydrogen iodide: A photofragment imaging study using resonant multiphoton excitation at 13.39 and 15.59 eV
Authors: Loock H -P , Bakker B LG , Parker D H
Published: April 2011

Jet-cooled HI has been excited using a resonant three-photon excitation scheme to energies corresponding to 13.39 and 15.59 eV. Analysis of velocity mapping images of the iodine atom fragments allowed the identification of the HI excited states at these energies as the (4Σ1/2) 6p superexcited state and the repulsive 4Σ1/2 state of HI+, respectively. Following excitation at 13.39 eV, we observe formation of iodine atomic fragments through the H(2S) + I[(3PJ) 6p] (J = 0, 1, 2) fragment channels, as well as through the H(2S) + I[(1D2) 6p] channel. This observation is explained by extensive nonadiabatic interactions between the (4Σ1/2) 6p state with the repulsive (4Π1/2) 6p state and the weakly bound (A 2Σ+) 6p state. In support for this proposed dissociation mechanism excitation of the corresponding ionic 4Σ1/2 state at 15.59 eV also results in formation of comparable quantities of I+ in its 1D2, 3P0,1, and 3P2 levels indicating again extensive nonadiabatic interactions with other repulsive curves. A similar mechanism based on the local interaction of the 4Σ1/2 state with the A 2Σ+ and the 4Π1/2 state is proposed. PACS Nos.: 82.50F, 32.80R
Ionization energies of multicharged fullerenes: Application and validity of an electrostatic model
Authors: Leach S
Published: April 2011

A simple relation between the successive ionization energies of polycyclic aromatic hydrocarbons obtained in 1961 by Smith from a calculation of the work required to remove electrons in small particles, is extended here to the fullerene species Cnz+, n = 5070, z = 15, and in some cases up to z = 8. Tests of the validity of the effective values of the parameters of the model, the work function and molecular capacitance, are given. The predicted ionization appearance energies are in excellent agreement with experimental values. A comparison is made between our model and other theoretical approaches to the calculation of the ionization energies of fullerenes. PACS Nos.: 31.20W, 33.80E, 35.20V
Calculations of "blue-body" spectra for cosmic dust emission
Authors: Pollanen M D , Feldman P A
Published: April 2011

We derive useful relations for "blue-body" thermal dust spectra that are analogous to the Wien displacement laws for blackbody radiation. PACS No.: 94.10Nh
The near infrared 2Π3/2(aβJ) ¬ X 2Σ+(bβS) band systems of TiCo and ZrCo
Authors: Sickafoose S M , Morse M D , Hales D A
Published: April 2011

Resonant two-photon ionization spectroscopy has been used to provide the first rotationally resolved work involving multiply-bonded mixed earlylate transition metal dimers. The mixed metal dimers TiCo and ZrCo are shown to possess 2Σ+ ground states, in agreement with a previous matrix isolation ESR (electron spin resonance) study on TiCo. Two previously observed vibronic bands in ZrCo are rotationally resolved, as is one of several newly discovered vibronic transitions in TiCo. Ground-state rotational constants for 48Ti59Co and 90Zr59Co are measured to be B''0 = 0.186 15(8) cm1 and B''0 = 0.119 78(5) cm1, giving r''0 = 1.8508(4) and r''0 = 1.9883(4) Å, respectively. In both molecules the ground state conforms to the Hund's case (bβ S) coupling scheme, with Fermi contact interactions between the unpaired σ electron and the 59Co (I = 7/2) nucleus of b''F = 0.0468(7) cm1 for 48Ti59Co and b''F = 0.0549(6) cm1 for 90Zr59Co. These values indicate that the unpaired electron occupies a σ orbital having 32% and 37% Co 4s character in TiCo and ZrCo, respectively. All three of the rotationally resolved bands are 2Π3/2 ¬ X2Σ+ transitions. For 90Zr59Co the 0 ¬ 0 and 1 ¬ 0 bands were resolved at ν0 = 10 496.1452(28) and 10 884.3794(25) cm1, giving B'0 = 0.119 82(6) and B'1 = 0.121 44(5) cm1. For 48Ti59Co the rotationally resolved band has ν0 = 9873.8342(19) cm1 and B' = 0.191 07(6) cm1. These results are discussed in the context of prior work on these and related molecules. PACS No.: 33.20Eq
AutlerTownes splitting and the AC Stark effect in nonpolar molecules: Prospects for all-optical alignment
Authors: Lyyra A M , Qi J , Spano F C
Published: April 2011

This paper describes an extension of the familiar coherence effects from atomic systems to the molecular regime. Such effects are inherent in the interaction of multiple laser fields with molecular systems. We have observed AutlerTownes splitting and the AC Stark shift in diatomic Lithium using the continuous wave all-optical triple resonance (AOTR) techniques. By using the AutlerTownes effect, we have partially resolved the magnetic sublevels of a molecular rovibrational level in a Doppler broadened sample, allowing all-optical alignment of the angular momentum in excited states of nonpolar molecules. The AutlerTownes effect in a molecular system extends the rovibrational state selectivity of the AOTR excitation technique to magnetic sublevels. PACS Nos.: 33.40tf, 42.50Hz
The r-centroid concept revisited
Authors: Nicholls R W , Amani M , Mandelman M
Published: April 2011

The r-centroid concept, was proposed the in 1950s to permit factoring of the band strength integral Sυ',υ'' into the product of the FranckCondon factor qυ',υ'', and of the square of the electronic transition moment Re (r), when taken at the r-centroid value of the internuclear separation, r = [Formula: see text]υ',υ'', which is the most likely value r at which the υ' « υ'' transition will occur. It has been much used since then in the interpretation of intensity measurements on many band systems of importance in astrophysics, atmospheric physics, space physics, and chemical physics to determine the variation of the electronic transition moment with internuclear separation, and thereby to derive band strengths, and other molecular transition probability parameters. It has been somewhat less used in recent years in the study of individual band systems, since the development of powerful computing facilities now allow for exact ab initio numerical studies to be made of individual molecules and their radiative transitions. Nevertheless the r-centroid concept, and some of its recent developments, provide much insight into the general systematics of diatomic molecular band systems and their spectra. This partly tutorial paper reviews the origins, properties, applications, and recent developments of the r-centroid concept. PACS No.: 33.70
Dielectric relaxation of nonionic microemulsion: influence of the salinity
Authors: Delbos G , Keita M , Bose T K
Published: April 2011

Study of dielectric properties of a quaternary microemulsion system composed of water, oil, a nonionic surfactant, and an alcohol, in the frequency range 100 kHz  15 GHz is reported as a function of salt (NaCl) concentration. Depending on the salinity, the decomposition of the dielectric spectra shows the presence of two or three main relaxation domains. The lower relaxation frequency and the corresponding spectral amplitude increase as a function of salinity. The other observed relaxation mechanisms are shown to be dipolar in origin.PACS No.: 97.22Gn
Eigenvectors of the Faraday tensor of a point charge in arbitrary motion
Authors: López-Bonilla J L , Gaftoi V , Ovando G
Published: April 2011

We study the eigenvalue problem of the Faraday tensor associated with the LiénardWiechert electromagnetic field. We find all the eigenvectors (null and nonnull ones) that do not appear explicitly in the literature. PACS Nos.: 03.50De, 02.10Sp, 41.20-q
Satellite dielectronic spectra created from autoionizing 2lnl' and 1s2lnl' states with n = 45
Authors: Safronova U I , Vasilyev A A , Smith R K
Published: April 2011

The relative intensities of dielectronic satellite lines determined by radiative transition probabilities and autoionization rates are calculated for the transitions 2lnl'  1snl'', 2lnl'  1s2l (n = 45, l' = 03, l'' = 03, l = 01) in He-like ions and for the transitions 1s2lnl'  1s2nl'', 1s2lnl'  1s22l (n = 45, l' =03, l'' = 03, l = 01) in Li-like ions, for all Z = 554, using the perturbation theory method (Z-expansion). Relativistic effects are taken into account using the BreitPauli operators. The asymptotic dependence on n of the energy matrix is discussed for 2lnl' and 1s2lnl' autoionizing states. The intermediate coupling coefficients obtained after diagonalization of the energy matrices are also studied. It was observed that these coefficients change very sharply with n and Z due to a redistribution of the contributions of relativistic and correlation effects. As a result, all other atomic characteristics (radiative and nonradiative transition rates, branching ratios, and relative intensity factor) display nonmonotonic Z- and n-dependencies with maxima and minima. PACS Nos.: 32.80D, 31.20G, 31.30J, 31.50
Tomographic reconstruction of composite small-screen in-line holograms
Authors: Rothwell T A , Shegelski M R.A.
Published: April 2011

We generate and combine simulated holograms for low energy electron point source (LEEPS) microscopy. Using a relatively small screen size, we build a ``composite hologram'' from four different holograms, each obtained using the small screen. We show that reconstructions of high quality can be extracted from the composite hologram by implementing methods we developed in previous investigations. These high-quality reconstructions are obtained using a screen size that is one quarter the size of screens we have used previously. The implications of our results for experimental investigations is discussed. PACS No.: 61.14Nm
Détection d'états de fonctionnement à partir d'une analyse du signal d'alimentation
Authors: Attaf M T
Published: April 2011

We want to solve a problem one faces in the automobile industry. We aim to develop a method capable of precision measurements on systems made up of four coupled electric machines hermetically enclosed, each having three possible states of operation. The main problem comes from the impossibility of making direct measurements inside the enclosure, the only measurable quantity being the global input signal. The method introduces a technique to separate the states of operation from that of failure, using an analysis in Fourier space of the small variations of the input signal.[Journal translation]
The contribution of the ozonolysis of terpenes to tropospheric OH concentrations
Authors: Pfeiffer T , Forberich O , Comes F J
Published: April 2011

The recent finding that OH is formed as a direct product of the ozonolysis of terpenes is used to investigate the influence of this new OH source on the tropospheric OH budget applying model calculations. The results show that the OH production following UV photolysis of ozone leads to the main competition for ozonolysis at daytime. OH may increase considerably in its concentration as a result of the ozonolysis of terpenes at low photolysis frequencies, however, at high photolysis frequencies and moderate NOx concentrations this effect is reversed due to the fast reaction of OH with terpenes. At night ozone competes with NO3 in its reactions with the terpenes. Integrated over a full day of 24 h the terpene reactions lead to a source of OH in the troposphere. PACS No.: 82.40We
Tomographic reconstruction of multiple in-line holograms for multiple scattering in low energy electron holography
Authors: Shegelski M R.A. , Whitwick M B , Holenstein R , Rothwell T A
Published: April 2011

We generate simulated holograms for low energy electron point source (LEEPS) microscopy. For a given object (atomic cluster) we construct a number of different holograms by varying the position or the orientation of the object relative to the screen. We then compare the three-dimensional structures of the reconstructions obtained from these holograms using methods developed and reported in previous works. In this investigation, we focus on clusters for which multiple scattering must be taken into account. We report results for bcc-type clusters, a spiral configuration, and some random arrangements. We find that the methods employed give vastly improved reconstructions even when multiple scattering is important. PACS No.: 61.14Nm
Asymptotic expansions of the oblate spheroidal eigenvalues and wave functions for large parameter c
Authors: Do-Nhat Tam
Published: April 2011

The asymptotic expansion of the oblate spheroidal eigenfunctions can be expanded in terms of the Laguerre functions of the first and second kinds, from which their asymptotic eigenvalue can be expressed in an inverse power series of c, where the parameter c is proportional to the operating frequency. Analytical expressions of the eigenvalue coefficients, as well as those of the expansion coefficients of the eigenfunctions, are derived and verified with numerical results.

PACS Nos.: 02.30Gp, 03.65ge
Photon-added one-photon and two-photon nonlinear coherent states
Authors: Wang Xiaoguang
Published: April 2011

From the photon-added one-photon nonlinear coherent states a†m|α, 〉, we introduce a new type of nonlinear coherent states with negative values of m. The nonlinear coherent states corresponding to the positive and negative values of m are shown to be the result of nonunitarily deforming the number states |m〉 and |0〉, respectively. As an example, we study the sub-Poissonian statistics and squeezing effects of the photon-added geometric states with negative values of m in detail. Finally, we investigate the photon-added two-photon nonlinear coherent states and find that they are still the two-photon nonlinear coherent states with certain nonlinear functions.

PACS Nos.: 42.50Dv, 03.65Fd
Transverse-energy distribution in protonnucleus collisions at high energy
Authors: Liu F -H
Published: April 2011

Based on the model of nuclear-collision geometry, the independent NN collision picture and participant contribution picture are used to describe the transverse-energy distribution in pA collisions at high energy. In the independent NN collision picture, the energy loss of leading proton in each pN collision is considered. The calculated results are in agreement with the experimental data of pAl, pCu, and pU collisions at 200 GeV/c. PACS Nos.: 13.85-t, 13.85Hd, 25.75-q
Some analytic results on the Uehling correction to the g-factor of a bound electron (muon)
Authors: Karshenboim S G , Ivanov V G , Shabaev V M
Published: April 2011

We calculate vacuum-polarization corrections to the g-factor of a bound electron in the ground state of a hydrogenlike atom. The result is found in a closed analytic form for an arbitrary value of the nuclear charge Z. It is valid for both electronic and muonic atoms. Some useful asymptotics are also presented. The result for the electronic atoms is consistent with published numerical data. PACS Nos.: 31.30Jv
Cavity ring-down spectroscopy of transient O2-O2 dimers
Authors: Tiedje H F , DeMille S , MacArthur L , Brooks R L
Published: April 2011

Cavity ring-down spectroscopy has been used to obtain the spectra of transient (O2)2 at 577 and 629 nm, at room temperature and pressures ranging from about 0.25 to 10.0 atm. A selection of these spectra are displayed showing the overlapping monomer and dimer features. Pressure-dependent cross sections have been obtained and Rayleigh extinction has been observed. The derived band parameters are compared to recent results from others.

PACS Nos.: 33.20kf, 33.70Fd
Thermal radiation and buoyancy effects on MHD free convective heat generating flow over an accelerating permeable surface with temperature-dependent viscosity
Authors: Seddeek M A
Published: April 2011

The paper presents a study of the flow of a viscous incompressible fluid over an accelerating permeable surface with temperature-dependent viscosity, taking into account the effect of thermal radiation and thermal buoyancy in the presence of a magnetic field. The fluid viscosity is assumed to vary as an inverse linear function of temperature. The governing equations for laminar free convection of fluid are changed to dimensionless ordinary differential equations by similarity transformation. They are solved by a shooting method. The effects of various parameters on the velocity and temperature profiles as well as the skin friction coefficient and wall heat transfer are presented graphically and in tabulated form.

PACS Nos.: 47.65ta, 52.30q
Morphology changes of Hg1-xCdxTe target in the PLD process
Authors: Virt I S , Kuzma M , Rudyi I O , Frugynskyi M S , Kurilo I V , Lopatynskyj I Ye
Published: April 2011

The surfaces of Hg1-xCdxTe samples used as targets in laser epitaxy were investigated by electron microscope methods. The samples were modified by two lasers: the YAG:Nd3+ and the excimer XeCl with pulse lengths of 40 and 25 ns, respectively, at different laser powers. The electrophysical properties of the samples were studied before and after irradiation. The morphological and structural properties of the surface investigated depend strongly on the type of laser pulse and on its energy. This provides two mechanisms for laser ablation of this material.

PACS Nos.: 70, 72.27JV
Convective heat transfer, by the presence of radiation, in an electrically conducting fluid at a stretching surface
Authors: AboEldahab E M
Published: April 2011

The problem of free-convection heat transfer due to the simultaneous action of buoyancy, radiation, and transverse magnetic field is investigated near an isothermal sheet. The sheet is linearly stretched in the presence of heat generation or absorption. The resulting coupled nonlinear differential equations are solved numerically. A parametric study is performed to illustrate the influence of the radiation parameter, magnetic parameter, heat generation or absorption parameter, and Prandtl number on the profiles of the velocity and temperature functions. Numerical data for the skin friction and the heat flux functions have been tabulated for various parametric conditions.

PACS No.: 44.25+f
Seasonal and diurnal variations of geomagnetic activity and their role in Space Weather forecast
Authors: Lyatsky W , Hamza A M
Published: April 2011

A possible test for different models explaining the seasonal variation in geomagnetic activity is the diurnal variation. We computed diurnal variations both in the occurrence of large AE (auroral electrojet) indices and in the AO index. (AO is the auroral electrojet index that provides a measure of the equivalent zonal current.) Both methods show a similar diurnal variation in geomagnetic activity with a deep minimum around (37) UT (universal time) in winter and a shallower minimum near 59 UT in equinoctial months. The observed UT variation is consistent with the results of other scientists, but it is different from that expected from the RussellMcPherron mechanism proposed to explain the seasonal variation. It is suggested that the possible cause for the diurnal and seasonal variations may be variations in nightside ionospheric conductivity. Recent experimental results show an important role for ionospheric conductivity in particle acceleration and geomagnetic disturbance generation. They also show that low ionospheric conductivity is favorable to the generation of auroral and geomagnetic activity. The conductivity in conjugate nightside auroral zones (where substorm generation takes place) is minimum at equinoxes, when both auroral zones are in darkness. The low ionospheric conductivity at equinoxes may be a possible cause for the seasonal variation in the geomagnetic activity with maxima in equinoctial months. The diurnal variation in geomagnetic activity can be produced by the UT variation in the nightside ionospheric conductivity, which in winter and at equinoxes has a maximum around 45 UT that may lead to a minimum in geomagnetic activity at this time. We calculated the correlation patterns for the AE index versus solar-wind parameters inside and outside the (27) UT sector related to the minimum in geomagnetic activity. The correlation patterns appear different in these two sectors indeed, which is well consistent with the UT variation in geomagnetic activity. It also shows that it is possible to improve significantly the reliability of the Space Weather forecast by taking into account the dependence of geomagnetic activity not only on solar-wind parameters but also on UT and season. Our test shows that a simple account for the dependence of geomagnetic activity on UT can improve the reliability of the Space Weather forecast by at least 50% in the 27 UT sector in winter and equinoctial months.

PACS No.: 91.25Le
The growth of vapour bubbles in superheated water between two finite boundaries
Authors: Mohammadein S A , El-Rab RA Gab
Published: April 2011

The paper analyses the behaviour of vapour-bubble growth between finite boundaries. The Plesset and Zwick theory is modified by assumptions that are different than those studied before. The growth problem is solved analytically in terms of initial bubble velocity and initial void fraction. The results are compared with those obtained from previous theories and experiment. Good agreement is obtained for certain values of the initial void fraction and the initial bubble velocity.

PACS No.: 47.50Dz
The front-form Hamiltonian and BRST formulations of the Harada-gauged FloreaniniJackiw action
Authors: Kulshreshtha Usha
Published: April 2011

The Hamiltonian and BRST formulations of the Harada-gauged FloreaniniJackiw action, which describes a chiral Schwinger model in terms of chiral bosonization, are investigated in the light-front frame.

PACS No.: 11.15-q