Constant volume specific heat at constant volume and at zero pressure volume

Using an Improved Self-Consistent Phonon calculation including three phonon processes, the difference between the constant volume specific heat at constant volume (C_υ(T, V_O)) and at zero pressure volume (C_υ(T, V(T))) is shown for the inert gas solids.     

Oscillator strengths from line absorption in a high-temperature furnace—II. The (0,0) band of the B2σ+—X2σ+ transition in CN*

Quantitative high-resolution absorption spectroscopy was applied to the (0,0) violet band of CN. The CN radical was prepared in a furnace at 1421°K containing pure cyanogen gas. Since the calculated CN concentration is dependent on the controversial CN heat of formation, only the relationship, f_υ = 6·84 X 10^-3exp (0·354δ), where f_υ is the excess over the initially assumed ΔH⁰_f(CN) = 100·8 kcal/mole, could be directly determined in this study with an estimated error in f_υ of ±20%. For δ = 0, our f_υ is a factor of 4·8 smaller than an average value of 0·033±0· derived from other measurements. If this latter value of f_υ is assumed, our relationship yields ΔH⁰_f(CN) = 105·3±1· kcal/mole or D₀(CN) = 7·66±0·05 eV. The rotational temperature and line widths for this band were also measured.     

The D state of I2: a case study of statistical error propagation in the computation of RKR potential curves, spectroscopic constants, and Franck-Condon factors

Existing spectroscopic data for the ion-pair state of I₂ are reanalyzed with the primary goal of improving and extending to higher υ the rotational constants B_υ. To this end, data for several precisely known (υ,J) levels in the υ=203-207 region are analyzed together with vibrational and rotational data from a number of sources. The lack of rotational data for the υ=130-200 region makes the structure of this data set unusual, and has prompted a thorough study of the propagated statistical error in the directly fitted spectroscopic constants, T_υ and B_υ, and in the RKR potential curve calculated therefrom. For the first time, such error propagation computations have been extended to properties computed by numerical solution of the Schrödinger equation for the state in question: the quantum vibrational energy G_υ and rotational constant B_υ, centrifugal distortion constants D_υ and H_υ, and Franck-Condon factors for the D-X transition.     

Fourier transform spectroscopy of CH3OH: rotation-torsion-vibration structure for the CH3-rocking and OH-bending modes

High-resolution Fourier transform spectra of CH₃OH have been investigated in the infrared region from 930 to 1450 cm⁻¹ in order to map the torsion-rotation energy manifolds associated with the ν₇ in-plane CH₃ rock, the ν₁₁ out-of-plane CH₃ rock, and the ν₆ OH bend. Upper-state term values have been determined from the assigned spectral subbands, and have been fitted to power-series expansions to obtain substate origins and effective B-values for the three modes. The substate origins have been grouped into related families according to systematic trends observed in the torsion-vibration energy map, but there are substantial differences from the traditional torsional patterns. There appears to be significant torsion-mediated spectral mixing, and a variety of “forbidden” torsional combination subbands with |Δυ_t|>1 have been observed, where υ_t denotes the torsional quantum number (equivalent to υ₁₂). For example, coupling of the (υ₆,υ_t)=(1,0) OH bend to nearby torsionally excited (υ₇,υ_t)=(1,1) CH₃-rock and (υ₈,υ_t)=(1,1) CO-stretch states introduces (υ₆,υ_t)=(1,0)←(0,1) subbands into the spectrum and makes the ν₇+ν₁₂−ν₁₂ torsional hot band stronger than the ν₇ fundamental. The results suggest a picture of strong coupling among the OH-bending, CH₃-rocking, and CO-stretching modes that significantly modifies the traditional energy structure and raises interesting and provocative questions about the torsion-vibration identity of a number of the observed states.     

Variation of electronic transition moment with the internuclear separation for the (AO+−X1Σ+) band system of PbO

Relative integrated intensities of the (AO⁺?X¹Σ⁺) band system of PbO have been measured by photographic photometry. These have been interpreted with the aid of Franck-Condon factors (q_υ′υ″) and r-centroids ($\text{r}{}_{\mathrm{\upsilon \prime \upsilon ″}}$) to show that the variation of electronic transition moment with internuclear separation is R_e(r)=const.(0.521r?1). Arrays are shown for the band strengths S_υ′υ″.     

Exact analytical expressions for diatomic rotational and centrifugal distortion constants for a Kratzer-Fues oscillator

The exact closed-form expression for the vibrational-rotational eigenvalues of the Kratzer-Fues oscillator served as the starting point for a derivation of exact analytical expressions for the rotational constant B_υ, and the set D_υ to S_υ of centrifugal distortion constants up to 11th-order. The derivations employed the MAPLE symbolic algebra coprocessor. The expressions for B_υ to S_υ were then employed in the calculation of a set of constants for a Kratzer-Fues potential with specified dissociation energy and equilibrium internuclear separation for a hypothetical diatomic molecule with a reduced mass of unity. The tabulated constants serve as a benchmark against which the reliability of various existing or future numerical methods for the determination of rotational and centrifugal distortion constants may be assessed. The near-dissociation behaviour of the calculated constants was also examined and is useful in predicting the behaviour of such constants for real electronic states having pure ionic long-range form.     

A method of implementation of frequency encoded all optical logic gates based on non-linear total reflectional switch at the interface

A novel method of implementation of frequency encoded logic gates NOT, OR, AND, NOR, NAND, X-OR, X-NOR is discussed. The frequency sources and physical requirements for the implementation are also discussed. The non-linear material (liquid) suitable for these operations to be performed should be of large non-linear coefficient, high reverse saturation absorption, large thermo-optic coefficient and low viscosity. The input controlling beams used to induce non-linearity in the switch are either of frequency υ₁ or υ₂ and the probe beam is a mixed signal of frequencies υ₁ and υ₂. Depending on the nature of the controlling inputs the output conditions of the probe can be adjusted to get different logic gates.     

L ∞ estimates for the space-homogeneous Boltzmann equation

This paper studies the boundedness of solutionsf of the initial-value problem for the space-homogeneous Boltzmann equation for inverse kth power forces, whenk>5, and under angular cutoff. The main result is that if the initial value isf ₀ ? 0 with (1 + ¦υ¦²)φ₀ εL ¹ and (1 + ¦υ¦)^s f ₀ε L^∞ for somes > 2, then (1 + ¦υ¦^s'f _tεL ^∞ fort>0 and ess_υ,t sup(1 + ¦υ¦)^s'f(υ, t,) < ∞ for anys′ ? s whens ? 5, and anys′ ? s ifs > 5.     

Instability of polarons and bipolarons in conducting polymers at various 3-d ordering types

Interchain electron hopping t_⊥ in conducting polymers with the small confinement parameter γ leads to the antiferromagnetic (AB) 3-d ordering of the dimerization pattern only at 2t²_γ >γΔ² (2Δ being the Peierls gap), otherwise the ferromagnetic (AA) one occurs. Polarons (Ps, υ = 1) and bipolarons (BPs, υ = 2) stability areas: t_⊥/Δ<t_c (υ,γ) are found in the phase plane “t_⊥ vs γ” with critical t_c being larger in the AB phase and for BPs. At the AA-AB transition interface, “deconfinement” of kink-solitons is possible. Photogeneration of Ps and BPs may proceed via metastable free states separated by the self-trapping barriers (STBs) which are also different in AA and AB (in the latter STBs exist even in 2-d systems) and are lower for BPs.     

Photoionization and photoelectron angular distribution for H2

Photoionization of H₂(¹Σ_g⁺) in a vibrational υ″ and rotational N″ state into H₂⁺(²Σ_g⁺) in a vibrational υ′ and rotational N′ state is studied theoretically. The differential cross section, after summing over the final states, is expressed in the well-known simple form of $\text{(}\text{σ}{}_{\mathrm{T}}\text{4π}\text{)[1 + βP}{}_2\text{(}\text{cos}\text{θ)]}$. Parallel expressions are obtained for H₂⁺ in a specific υ′ state (in terms of σ(υ′) and β(υ′)) and for H₂⁺ in a rotational fine level υ′N′ (in terms of σ(υ′N′) and β(υ′N′)). Asymmetry parameters β, β(υ′) and β υ′N′), which are expressed in terms of Racah and Clebsch-Gordan coefficients and electronic transition moments, can be reduced approximately to 2 lineary polarized light and to -1 for unpolarized light. Using single-center electronic wave functions and including partial eaves l = 1, 3, and 5, σ(υ′) and β(υ′) are computed as a function of υ′ at 584 Å. The computed σ(υ′) divided by the Frank-Condon overlap, in agreement with experimental results, increases monotonically with υ′; σ_T and β are computed in the incident photon energy range of 600–4000 Å and the results compare favorably with previous calculations.     

The use of electron impact dissociation and the photon-photon cascade technique to measure the lifetime of the B2Σ+ state of CN

The lifetime of the (B³Σ⁺_{υ= 0, 1} state of the CN radical has been measured by the photon-photon delayed coincidence technique, the CN radical being produced by electron impact dissociation of acetonitrile. This is the first lifetime measurement in a free radical by this method. The optical cascade in the band spectrum of CN used for the present measurement is H²Π_r - B²Σ⁺ - X²Σ⁺. The lifetime of the (B²Σ⁺)_{υ=0, 1} state in CN has been found to be 61.1 ± 7.6 ns.     

Gravitational radiation and the ultimate speed in Rosen's bimetric theory of gravity

In Rosen's “bimetric” theory of gravity the (local) speed of gravitational radiation υ_g is determined by the combined effects of cosmological boundary values and nearby concentrations of matter. It is possible for υ_g to be less than the speed of light. I show here that emission of gravitational radiation prevents particles of nonzero rest mass from exceeding the speed of gravitational radiation. Observations of relativistic particles place limits on υ_g and the cosmological boundary values today, and observations of synchrotron radiation from compact radio sources place limits on the cosmological boundary values in the past.     

Determination ofβ-particle longitudinal polarization in the decay of210Bi

The longitudinal polarization ofβ-particles from²¹⁰Bi has been measured at three values of the energy, using a double-focusing crossed field electron spin polarimeter. The results are:E=150keV,P/(?υ/c)=0.70±0.07,E=220keVP/(?υ/c)=0.70±0.05,E=300keV,P/(?υ/c)=0.71±0.05.     

1+ state and effective g-factor

The effects of nuclear field r²(Y₂σ₁)_1υ on magnetic properties of single-particle states in odd-A nuclei (^208±1Pb) are considered. The coupling constant associated with this type of field is estimated by an argument that realtes it to the coupling constant for the field (γ₀σ₁)_1υ. The effects of including the r²(Y₂σ₁)_1υ field on the M1 moments and transitions are estimated.     

Investigation of the e<Subscript>0</Subscript>-electron yield from the surface of thin films under bombardment by α and β particles from radioactive sources

The yields of near-zero (e₀) electrons from the surface of targets with different Z under their bombardment by α particles from ²²⁶Ra decay were measured by the method of e_α coincidences. The ratios of the e₀-electron yields for α particles with different energies E _α are described well by the dependence Y _e (E _α) ～ υ _α ^?1 , where υ _α is the α-particle velocity. The e₀-electron yield from the surface of thin films under their bombardment by β particles from radioactive sources with ¹⁵²Eu, ¹⁵⁴Eu, and ²²⁶Ra has been investigated by the method of eγ coincidences. It is established that ionization rate of target atoms in this case is inversely proportional to the velocity of incident β particles (υ _β ^?1 ), i.e., is proportional to the time of atomic electron perturbation induced by a β particle passing near an atom.     

Elliptic flow of particles in heavy-ion collisions and possibility of its observation at the LHC energies

The azimuthal anisotropy of particle distributions is one of the important observables that characterize collective effects at the initial stage of the formation and expansion of quark-gluon matter in collisions of relativistic nuclei. It is expected that an increase in energy from RHIC to LHC values will be accompanied by the growth of the azimuthal-anisotropy coefficient υ ₂ and the growth of nonflow effects (contribution of minijets and other correlations between particles). In the present study, methods for determining the azimuthal-anisotropy coefficient υ ₂ are analyzed on the basis of events simulated with the aid of the HYDJET generator for Pb + Pb collisions at the LHC energies, the contribution of nonflow effects being estimated. The accuracy of measuring the coefficient υ ₂ as a function the transverse momentum and pseudorapidity under experimental conditions at LHC is assessed.     

Elementary excitations,electronic correlation functions and sum rule in noble-metal chalcogenides

Noble-metal chalcogenides are known as both electronic and ionic conductors. Physics in superionic conductors is investigated on the basis of the idea of elementary excitations. First, the semiconducting properties of noble-metal chalcogenides are investigated by preparing the full Hamiltonian for conduction electrons and phonons. The influence of electron interactions on the longitudinal acoustic wave frequencies and the matrix element for the electron–phonon interaction are investigated. Three cases of ω >> kυ_F, ω < kυ_F and ω = 0 are investigated for polar semiconductors like noble-metal chalcogenides. Next, the structure factors, and the f-sum rule of conductivity are investigated in silver chalcogenides by making use of a continuum model. The structure factors S_ee, S_Ae and S_Be with which electrons are connected are expressed symmetrically in terms of the structure factors S_AA, S_BB and S_AB of ions in the long-wavelength limit using the fluctuation–dissipation theorem and the Kramers–Kronig relation. The obtained conductivity satisfies the f-sum rule.     

Dispersion studies of the 22 GHz water vapor line shape II. Instrumental correction

Anomalies in the resonance dispersion of the pressure-broadened water vapor line at υ₀ = 22.235 GHz, which were reported in Part I,⁽¹⁾ are resolved. The pressure-scanning differential-refraction spectrometer (microwave dispersometer) gives rise to a signal enhancement as the line center moves within the width of the dispersion discriminator which is a dual-mode transmission cavity. Resonance absorption prevents the frequency of peak transmitted power from coinciding with the resonance condition of zero phase, thus systematically distorting the molecular resonance dispersion. An expression, valid for |υ − υ₀| greater than the cavity half width, is derived which predicts apparent departure from Lorentzian behavior. The results reported in I as well as results for the 23.6 GHz rotational 3_1,2 → 3_2,1 line of C₂H₄O (ethylene oxide) show a Lorentzian molecular line shape. At pressures above 1 torr nonresonant polarization effects become detectable. Instrumental distortion, and Doppler-, wall-, and saturation-broadening effects at low pressures (<50 mtorr) are accounted for only qualitatively to determine the resolving power and to define v₀.     

Multi-band infrared CO2 absorption sensor for sensitive temperature and species measurements in high-temperature gases

A continuous-wave laser absorption diagnostic, based on the infrared CO₂ bands near 4.2 and 2.7 μm, was developed for sensitive temperature and concentration measurements in high-temperature gas systems using fixed-wavelength methods. Transitions in the respective R-branches of both the fundamental υ ₃ band (~2,350 cm^?1) and combination υ ₁ + υ ₃ band (~3,610 cm^?1) were chosen based on absorption line-strength, spectral isolation, and temperature sensitivity. The R(76) line near 2,390.52 cm^?1 was selected for sensitive CO₂ concentration measurements, and a detection limit of <5 ppm was achieved in shock tube kinetics experiments (~1,300 K). A cross-band, two-line thermometry technique was also established utilizing the R(96) line near 2,395.14 cm^?1, paired with the R(28) line near 3,633.08 cm^?1. This combination yields high temperature sensitivity (ΔE” = 3,305 cm^-1) and expanded range compared with previous intra-band CO₂ sensors. Thermometry performance was validated in a shock tube over a range of temperatures (600–1,800 K) important for combustion. Measured temperature accuracy was demonstrated to be better than 1 % over the entire range of conditions, with a standard error of ~0.5 % and µs temporal resolution.