摘要:

Simulations of rare-gas gaseous mixtures taking ternary interactions into account are performed. Simulations include Ne-Ar-Kr at 300 K and He-Ar, with Ar in excess, at 165 K. The He-Ar mixtures, which were studied in more detail, give rise to a collision-induced absorption spectrum with a well-formed dip at zero frequency. The dip becomes discernible at a Ar density of 132 amagat when the ternary contribution to the zeroth moment amounts to only 2%. Interactions are assumed to be pairwise-additive.

ISSN:0026-8976    

DOI:10.1080/00268979000102011

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

The properties of two-dimensional continuum-model suspensions of deformable particles are studied by Monte Carlo simulation. Two types of deformable particle are introduced, the tethered cluster and the tethered ring. Both types of particle are composed of four interaction sites, but differ in the specification of the intraparticle interactions. All of the intra- and interparticle interactions are characterised by a single parameter, the system temperature. Tethered rings show a continuous degree of deformability as a function of temperature, whereas tethered clusters show a sharp order-disorder transition in the intraparticle structure with increasing temperature. The dependence of intra- and interparticle order on particle density is studied for both model suspensions at low and high temperatures. For suspensions of tethered clusters, at temperatures corresponding to intraparticle disorder in dilute systems, increasing particle density gives rise to an intraparticle ordering transition prior to long-range interparticle ordering.

ISSN:0026-8976    

DOI:10.1080/00268979000102021

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

We formulate and solve a Nosé-like constraint form that keeps the average bond length of a diatomic molecule fixed. Changing the Nosé parameter from zero to its critical value changes the distribution of bond lengths from the usual classical harmonic-oscillator form to a form that has its maximum at the average bond length and resembles the zero-point-energy wavefunction for the quantum oscillator. We propose this model as a more accurate classical representation of a diatomic molecules in its ground state.

ISSN:0026-8976    

DOI:10.1080/00268979000102031

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

The relationships between the adiabatic approximation and a transformation of the coordinates or the Hamiltonian are investigated for a two-dimensional coupled oscillator. The Smith transformation is used systematically to obtain a transformation returning the adiabatic form of the Hamiltonian to its original ‘diabatic’ form and thus provides a method of obtaining the unitary transformation that is equivalent to the coordinate transformation.

ISSN:0026-8976    

DOI:10.1080/00268979000102041

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

The relation between the Verdet constantVand the ‘normal’ Verdet constantVNis explored for diatomic molecules. It is found to depend upon both the mean Πuand Σ+uexcitation energies as well as upon the frequency dependence of the isotropic and anisotropic dipole polarizabilities. An approximate formula is presented that allows the ratio of the two constants to be calculated from the frequency-dependent polarizability components alone and hence forVto be found from the much more accessibleVN. H2and N2are taken as prototypical examples.

ISSN:0026-8976    

DOI:10.1080/00268979000102051

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor