bluuebunny/crossref_metadata_2025_split huggingface dataset:
On Forces and Interactions between Fields
Authors: Pandres Dave 
Published: January 2005

After a discussion of certain properties of multivalued functions is given, these functions are used to give a scalar representation of electromagnetic theory. In this representation, the four-vector potential A appears as the four-gradient of a multivalued function φ. The problem of solving the time-dependent Schrödinger equation for a particle of charge e in an electromagnetic field is equivalent to the problem of solving the corresponding field-free equation in a space of multivalued functions ψ̄, which is connected to the space of single-valued functions ψ by the relation ψ̄=Uψ where U = exp (—ieφ). Further, if L0(ψ̄, A) is the Lagrangian for a noninteracting particle field ψ̄ and photon field A, then L0(Uψ, A), regarded as a functional of ψ rather than ψ̄, is the Lagrangian for interacting fields ψ and A. This suggests that other interactions (e.g., strong and weak interactions) should be introduced by using a transformation T which is more general than U.
More fundamental reasons for believing that this is the case arise when one considers multivalued coordinate transformations. It is shown that any curved Riemannian space may be connected with a flat space by a multivalued coordinate transformation. This is possible because the metric transforms like a tensor under these transformations, but the Riemann curvature symbol does not. If one writes the equations of motion of a free, classical, relativistic particle in flat-space coordinates and assumes that the equations transform covariantly under multivalued coordinate transformations (this is a natural generalization of the equivalence principle), one obtains equations of motion in the curved-space coordinates which describe a particle in a gravitational and electromagnetic field. Unfortunately, however, the electromagnetic field at any point of space-time depends on the four-velocity of the test particle at that point. This defect, together with the known existence of essentially quantum-mechanical forces and the fact that the uncertainty principle prevents one from measuring velocity when position is measured exactly, suggests that one should write the Klein-Gordon (or Dirac) equation for a free particle in flat-space coordinates, and then make a change of independent variables into curved-space coordinates. When this is done, it is seen that a corresponding change of dependent variable ψ̄=Tψ is required in order that the curved-space wave function shall be a single-valued function of the curved-space coordinates. The fully transformed equation describes a particle in a gravitational and electromagnetic field as well as certain other fields whose properties are not fully understood.
Analytic Properties of the Quantum Corrections to the Second Virial Coefficient
Authors: DeWitt Hugh E. 
Published: January 2005

The usefulness of the perturbation expansion and the Wigner-Kirkwood expansion of the quantum-mechanical partition function is discussed for various interaction potentials. It is shown that, contrary to what is expected from the Wigner-Kirkwood expansion, quantum-mechanical diffraction corrections at high temperature to the classical partition function may involve nonanalytic forms of ℏ2. This occurs when the second-order perturbation term is finite in the classical limit, and the interaction potential has a cusp or singularity in any derivative. The second-order perturbation term is evaluated exactly for the exponential, screened Coulomb, and square barrier potentials, and the nonanalytic form (ℏ2)½ is found. For potentials more singular than 1/r at the origin, the diffraction corrections are analytic in ℏ2.
A new method of deriving the Wigner-Kirkwood expansion from the perturbation expansion is given. The method allows one to subtract off any order of the perturbation expansion which may be evaluated separately, and is particularly useful for the screened Coulomb potential.
The classical second virial coefficient and the O(ℏ2) and O(ℏ4) diffraction corrections are evaluated for the singular potential, u(r) = (gp/rp)e−r/ro, by using the Mellin transform of e−βu.
Photosensitivity of Germanium Electrodes as a Function of Quantum Energy
Authors: Hemilä Simo 
Published: January 2005

In this work the relative photosensitivities H = | Δφ/F |i=const of a germanium anode and a germanium cathode were determined as a function of quantum energy (Δφ=electrode potential change caused by light, F = quantum flux, measured in quanta/cm2 sec, and i = current density of electrode). The first increase in the photosensitivity H (Eν) of a n-Ge anode occurs at a quantum energy Eν≈0.93 eV, the second increase at Eν≈1.10 eV, and one relative sensitivity minimum at Eν≈1.27 eV. The sensitivity was approximately constant at larger quantum energies.
According to earlier experimental results, the slow phase in a dissolution reaction of Ge at a Ge anode is the breaking of the bond. The form of the sensitivity spectrum can therefore be explained on this basis. The holes, which have an excess energy for activation, break the bond of a Ge atom to the lattice immediately and lead to a fast excess reaction and to a strong photosensitivity.
The photosensitivity spectrum of a p-Ge cathode is of the same shape as that of a n-Ge anode. One may therefore make a conclusion, that the photoeffect of a Ge cathode is due to the fast dissolution reaction caused by holes with excess energy. The author proposes that this reaction is the dissolution of germanium as germane.
Heat Capacities of Solid Deuterium (33.1%—87.2% Para) from 1.5°K to the Triple Points. Heats of Fusion and Heat Capacity of Liquid
Authors: Grenier George , White David 
Published: January 2005

The heat capacities of a number of deuterium samples enriched in para content have been measured in the temperature range 1.5° to 22°K. The variation of the triple points and heats of fusion as a function of ortho—para composition have also been measured.
All the heat capacities of the solid show anomalies due to the quenching of the molecular rotation of the J = 1 species present in the mixtures. For para compositions above 60% para-D2 a sharp λ transition is observed. A linear dependance of the transition temperature with para content is observed. The high-temperature heat capacities of the solid show a dependence on ortho—para composition, suggesting a structural dependence on composition.
A calculation of the entropy from the data shows that the threefold degeneracy of the J = 1 species is completely removed at the absolute zero. An analysis of the anomalies resulting from the removal of the degeneracy confirm Nakamura's conclusions that the quenching of the molecular rotations is principally a result of quadrupolar interactions. The anomalous heat capacities of the solid, at sufficiently high temperatures, are expressed by the relation CT2/R=αx+βx2just as in the case of hydrogen. The ratio of the experimental β's for the two isotopes is in excellent agreement with the theoretical ratio. This ratio is a measure of quadrupolar interactions in the two isotopic solids.
Molecular Theory of Dissipative Processes in Gases
Authors: McLaughlin I. L. 
Published: January 2005

The velocity distribution function associated with a molecule entering a dilute gas, either in equilibrium or with a temperature gradient, is evaluated by solving a forward Boltzmann equation.
In the equilibrium case, the velocity distribution function associated with the molecules, other than the incoming molecule, is also evaluated and the contributions to the Kubo-type coefficient of thermal conduction from both distribution functions are evaluated for Maxwellian molecules. These contributions give the coefficient of thermal conduction obtained by the Chapman—Enskog method.
The various mean accelerations experienced by a molecule moving in a gas are calculated using the above solutions of the forward equation and also the solutions of a backward Boltzmann equation. These expressions are then used to evaluate the friction coefficients, first introduced by Kirkwood, for both equilibrium and nonequilibrium gases.
An experimental procedure using radioactive particles injected into a gas is also suggested as a method of confirming the obtained results.
Mass Spectrometric Study of the Vaporization of Uranium Monophosphide
Authors: Gingerich Karl A. , Lee Peng Kei 
Published: January 2005

The vaporization of uranium monophosphide, UP, and its mixtures with uranium oxide, UO2, have been investigated by Knudsen effusion techniques in combination with a mass spectrometer.
The vaporization of UP occurs by decomposition according to UP(s)=U(g)+(1/x)Px(g)      (x is either 1 or 2).If UO2 is present approximately in equimolar ratio with UP the principal reaction is according to UP(s)+UO2(s)=2UO(g)+(1/x)Px(g)    (x is either 1 or 2).The partial pressures of P, P2, and U over UP have been obtained from the silver calibration for the temperature range of 1750°—2250°K. The temperature dependence of logKp for Reaction (1), where x=1 was determined to be the following: logKp=−(54888/T)+14.6056±0.1392.From the second-law treatment, the heat of vaporization in kcal/mole of UP is obtained for Reaction (1) as 251.17±4.88 when x=1.
Vapor pressures derived from other methods, such as (a) from known dissociation energy of P2 and thermodynamic functions of P and P2, and (b) from the amounts of sample evaporated are discussed.
Infrared and Raman Spectra of Digermane
Authors: Griffiths James E. , Walrafen George E. 
Published: January 2005

Infrared spectra of gaseous digermane and of digermane-d6 were recorded under medium resolution from 4000–250 cm—1 and the Raman displacements were obtained photoelectrically from 100–2600 cm—1 for the liquid state. The 12 fundamental frequencies for each molecule were assigned to the normal modes and digermane was shown to have the D3d ethanelike structure.
The rotational structures of the eu fundamentals of Ge2H6 and the ν8 fundamental of Ge2D6 were resolved and analyzed. Results from the zeta sum rule confirmed the hindered rotator structure and four combination bands were used to estimate the barrier hindering internal rotation as 1490±200 cal/mole.
Infrared Spectra of Gaseous Diazomethane
Authors: Moore C. Bradley , Pimentel George C. 
Published: January 2005

The gaseous infrared spectra of CH2N2, CHDN2, CD2N2, and CH2N15N have been examined between 230 and 4000 cm—1 under medium resolution. Band positions have been measured for all the distinguishable parallel features. Nearly all of the perpendicular fundamentals have been resolved and analyzed. The [A″—½(B″+C″)] rotational constants derived are: CH2N15N, 8.747±0.015 cm—1; CD2N2, 4.253±0.01 cm—1; CHDN2, 5.72±0.1 cm—1. These data combined with that given earlier for the CH2N2 isotope, show that the averaged distance of the hydrogen atoms from the molecular axis (in CH2N2 and in CH2N15N) is 0.9580±0.0006 Å and of the deuterium atoms (in CD2N2) is 0.9560±0.001 Å.
In contrast to earlier studies, we were able to find no evidence for the presence of a tautomeric form of diazomethane in the samples studied.
Analysis of Calculations on Some Oxygen Hydrides
Authors: Rosenfeld J. L. J. 
Published: January 2005

Wavefunctions for OH— and H4O++ are presented in the self-consistent field molecular orbital approximation, using a minimum basis set of Slater-type atomic orbitals. A wavefunction for H4O++ based on a one-center model is also included. A comparison is made, for the isoelectronic series OH—, H2O, H3O+, H4O++ of three methods of calculating molecular energies, namely the two methods already mentioned and a valence bond method.
The changing properties of the OH bond in the series are discussed within the self-consistent field approximation by an analysis of the electron distribution. A good correlation is found between the bond strength and the maximum in the bond of the δ function first introduced by Roux.
Off—Diagonal Hypervirial Theorem and Its Applications
Authors: Chen Joseph C. Y. 
Published: January 2005

A hypervirial operator, by definition, is a time-independent linear operator with an arbitrary functional structure expressed in terms of the dynamical variables of the system under consideration. In the energy representation, the diagonal matrix elements of the hypervirial operator are constant in time; this is known as the hypervirial theorem. The off-diagonal matrix elements of the hypervirial operator in the energy representation oscillate in time with frequencies related to the energy differences between their corresponding stationary states of the system. This is known as the off-diagonal hypervirial theorem.
The latter theorem is as powerful as the former for dealing with many quantum-mechanical problems. Several aspects of the possible applications of the theorem to the problem of construction and improvement of wavefunctions are considered. As a special example, the restricted fourth alternative expression for dipole transition matrix elements is derived for pair functions not belonging to states with zero orbital angular momentum. A scheme is also outlined for improving wavefunctions of the excited states. The statistical implications of the sum rule, which is expressed in terms of an appropriate hypervirial operator, are discussed in connection with uncertainty principles.
Surface-Limited Vapor Solvent Growth of Crystals
Authors: Mandel Gerald 
Published: January 2005

A general analysis is presented of surface reaction limitations in a vapor solvent system. A previous treatment of a multicomponent multireaction vapor diffusion limited system is extended to include finite supersaturations in the neighborhoods of the growing deposit and the etching source. The appropriate natural definitions of supersaturations are found to be in agreement with the usual conventions of irreversible thermodynamics.
A more detailed connection between the supersaturations above a growing crystal and the growth rate of the crystal is developed by means of an extension of the crystal growth theory of Burton, Cabrera, and Frank to apply to a multiple species multireaction vapor solvent system. It is found, at least in the limit of low supersaturations, that the flux of any particular species to the surface may be treated in terms of the formalism developed by Burton, Cabrera, and Frank for a monatomic crystal—monatomic vapor system, except that some of the parameters which characterize the process, e.g., diffusion length on the surface, lifetime on the surface, etc., have more phenomenological character. Relationships between the fluxes of different species are developed in the same manner as in the previously treated vapor diffusion limited system.
Quantitative calculation of the important parameters is apparently impossible in our present state of knowledge of surface processes. Qualitatively, we expect surface diffusion effects to be far more important than in simple crystal—vapor systems. Other effects, however, are also expected to be important in vapor solvent systems, e.g., ``kink-reaction'' limitations, impurity effects, etc. Disentanglement of these several processes is an unsolved problem and it is concluded that detailed quantitative understanding of surface-limited crystal growth in a vapor solvent system is presently out of reach.
Specific Ionic Effects on Reaction Rates. The Reaction between Persulfate and Iodide Ions in the Presence of High Concentrations of Added Salts
Authors: Perlmutter-Hayman B. , Stein Gabriel 
Published: January 2005

The effect of added electrolytes (up to 2M) on the reaction between persulfate and iodide ions was reinvestigated, utilizing the absorption of I3— in the near ultraviolet to follow the reaction. The effect could be represented very well by the empirical relation logk=logk0+[Ac/(B+c)]+Dcover the entire range, where A, B, and D are constants specific for the cation (uni-, di-, or trivalent) employed, and k0 and k are the rate constants in the absence and in the presence of added electrolyte at concentration c.
The inapplicability of the concept of ionic strength to the reaction between two anions is discussed and contrasted with the behavior of reactions between ions of unlike sign.
Hydride and Proton Transfer Reactions Involving Sec-Propyl Ions
Authors: Borkowski R. P. , Ausloos P. 
Published: January 2005

The reactions of sec-propyl ions produced in the radiolysis of n-C4D10 and i-C4D10 with hydrocarbons has been investigated. When the additive (RH) is a saturated hydrocarbon, the hydride transfer reaction: C3D7++RH→C3D7H+R+is the major mode of reaction. For straight chain hydrocarbons, the cross section of this reaction, relative to that of the reference reaction C3D7++C4D10→C3D8+C4D9+is shown to increase with the molecular weight of RH. For different hydrocarbon isomers, the relative cross section of the hydride transfer reaction decreases with an increase in branching while the analogous reactions involving ethyl ions show no such discrimination.
From the isotopic analysis of the propanes and propylenes produced in the radiolysis of C4D10 carried out in the presence of olefins, it was concluded that the proton transfer reactionC3D7++RH→C3D6+RHD+occurs.
Comparison of the data obtained, using C3D8, n-C4D10, and i-C4D10 as sources of ethyl or propyl ions, indicated that the relative cross sections of the hydride transfer reactions are independent of the origin of the carbonium ion.
Calculation of Electron Scattering Factors. I. Nonrelativistic Theory
Authors: Karle J. , Bonham R. A. 
Published: January 2005

Scattering factors for the elastic scattering from uranium and argon of 40-kV electrons have been obtained by partial wave analysis. In the case of argon both Thomas—Fermi—Dirac and Hartree—Fock fields were used in the calculation. For uranium, only the Thomas—Fermi—Dirac field was utilized.
Various approximate techniques for obtaining the partial waves as well as direct numerical integration of the Schrödinger equation were employed. For the first time accurate numerical solutions of the electron scattering problem in the kilovolt energy range, within the framework of the usual nonrelativistic scattering theory, have been obtained. Uncertainties in the scattering factors and in the use of the various approximate techniques for obtaining partial waves are discussed.
Order—Disorder Transitions in Biocolloids
Authors: Peticolas Warner L. 
Published: January 2005

The author's theory of order—disorder transitions in associative colloids is tested by comparison with measurements of the viscosity of different colloidal systems as a function of temperature or concentration. The theory predicts that an order—disorder transition from a random array of monomers to a segmented one-dimensional helical rod will occur as the temperature is reduced to the one-dimensional freezing point or the concentration increased to the critical micelle concentration. Under these conditions as enormous increase in the solution viscosity is predicted to occur.
Semiquantitative agreement is obtained between theory and experiment for a variety of associative colloids. Fully quantitative agreement cannot be obtained because the solutions become birefringent upon aggregation of the monomers, due to the large rod lengths which are obtained. This birefringence is well known to be due to the fact that the rods bump into each other and do not have their full freedom of rotation. Although this situation more closely resembles the statistical mechanical theory which neglects rotation of the rods, there is unfortunately no adequate theory of the viscosity of such solutions and the Simha—Kuhn theory which we have used can only be approximate under these conditions.
ESR Study of NO2 and NO3 in Irradiated Lead Nitrate
Authors: Golding R. M. , Henchman Michael 
Published: January 2005

Lead nitrate crystals have been irradiated with electrons at room temperature and their electron spin resonance spectra examined at 77°K to reveal three paramagnetic species. One species shows no hyperfine structure and has an isotropic g tensor with a g value at the free spin value: little can be said of its nature. The others are located, by their spectral anisotropy, at nitrate sites in the crystal with the axes of their axially symmetric g tensors parallel to the nitrate triad axes. One of these species is interpreted as NO3: it shows no nitrogen hyperfine structure but a slight interaction with 207Pb. The other is identified as NO2 rotating in the plane of the nitrate site. Theoretical predictions are in accord with these assignments.
Various conclusions are drawn for the radiation chemistry. Other species than the NO2— and O2, revealed by chemical analysis, are significant products. The particular lattice determines the nature of these products, their stability and, in the case of NO2, its mechanism of formation. The annealing kinetics of NO2 and NO3 differ from that of the NO2—: Mechanisms previously postulated for the latter are almost certainly too simple.
Systematic Approach to Explanation of the Rigid Disk Phase Transition
Authors: Stillinger F. H. , DiMarzio E. A. , Kornegay R. L. 
Published: January 2005

By classifying particle center positions with a hexagonal grid, evaluation of the two-dimensional rigid sphere partition function is reduced to a special lattice statistics problem, with precisely defined nearest-neighbor effective pair interactions. The hexagonal cell size is chosen to be the maximum consistent with no more than double occupancy. Since the resulting lattice partition function (with three states per site) contains a collectively determined many-cell effective interaction Δ*, as well as nearest-neighbor contributions, it becomes necessary to examine in detail the statistical geometry of available phase space for the original spheres, under varying restraints of nearest-neighbor cell distribution. Accordingly, we obtain for the first time an unambiguous definition of ``random close-packed'' or ``glassy'' arrangements of spheres (which however are not themselves equilibrium states), and to relations between properties of these arrangements, and of Δ*. The key features which subsequently allow description of rigid sphere order—disorder behavior are: (1) the observation that certain nearest-neighbor cell pairs which occur in the glassy state (both unoccupied and both doubly occupied) are geometrically excluded completely in the ordered, close-packed arrangement; (2) Δ* sensitively depends upon these pair distributions. In spite of the fact that Δ* is thereby assigned a specially generalized free-volume form, the theory leads to a proper virial series development at low density.
In addition, we report some preliminary results for the effective cell interactions, for glassy state parameters, and some calculations designed to reveal the structure of Δ*.
Although this analysis does not yet represent a full quantitative theory of the two-dimensional rigid disk system, it does lead to a novel qualitative explanation of how a fluid—solid transition can occur, and suggestions are given for completing the quantification.