Thermotropic liquid-crystalline behaviour from mixtures of non-mesogenic molecules

A class of non-mesogenic molecules, which as mixtures exhibit monotropic nematic phases, is described.     

A new class of long-tailed pausing time densities for the CTRW

We present some asymptotic results for the family of pausing time densities having the asymptotic (t) property(t) [t ln¹⁺(t/T)]^–1. In particular, we show that for this class of pausing time densities the mean-squared displacement r ²(t) is asymptotically proportional to ln(t/T), and the asymptotic distribution of the displacement has a negative exponential form.     

Linear AAD potentials and the consistency of two conservation law approaches

For the linear action-at-a-distance (AAD) potentials, generated from the function Lagrangian, the equivalence of the direct-interaction and field-mediated energies is proved. It is next shown that in dynamics built on these potentials the virial theorem acquires the same form as in dynamics of the Liénard-Wiechert potentials.The author is grateful to Prof. H. C. von Baeyer for his proposal to explore the virial theorem by the designated manner and for other valuable remarks.     

Properties of noninteger moments in a first passage time problem

We calculate the moments t ^q , whereq is not necessarily an integer, of the first passage time to trapping for a simple diffusion problem in one dimension. If a characteristic length of the system isL and t _q ~L (q) asL, then we show that there is a phase transition atq=q _c such that whenq<q _c ,(g)=0, and forq>q _c , (q) is a linear function ofq. These analytical results can be used to explain results for large moments for diffusion on a hierarchic structure. We also show how to calculate noninteger moments in terms of characteristic functions.     

Polarization Fourier transform infrared spectroscopy on ionic single crystal surfaces: Davydov splittings, adsorbated structures and 2D-phase transitions on NaCl(100) and MgO(100)

Polarized infrared spectra of adsorbates on NaCl(100) and MgO(100) single crystal cleavage planes reveal Davydov splittings, structures with adsorbate orientations and/or 2D-phase transitions, in concert with diffraction studies. CO₂ on NaCl shows the sharpest adsorbate spectra known ( ).