A theory has been developed for estimation of the electronic structure of molecules embedded in an anisotropic (inhomogeneous) medium. It is assumed that the medium surrounding a solute molecule is composed of more than two polarizable dielectrics with different dielectric constants and that the dielectrics contact each other through arbitrary shaped boundaries. Then, the charge distribution in the solute molecule interacts with the dielectrics through a reaction field. The boundary element method is introduced to obtain a numerical solution to the Poisson equation with necessary boundary conditions. The expressions for the total energy of the molecule and the Helmholtz free energy of the system are given under the Hartree–Fock–Roothaan approximation. The Fock matrix is derived by taking into account nonlinearity of the Schrödinger equation in wave function. The present theory is generally applicable to the problem of medium effects when the medium surrounding a molecule is inhomogeneous and could be approximated by a multidielectric system.
Lasing via a phase retardation defect mode is reported for the first time. The Figure shows the far‐field pattern of laser emission realized by inserting an anisotropic nematic liquid crystal (LC) defect layer between polymer cholesteric LC layers. The system mimics the cuticle of Plusiotis resplendens, a beetle, using the birefringence of the anisotropic layer to achieve reflectance greater than the 50 % provided by simple cholesteric LC photonic bandgaps.
Patients with malignant biliary stenosis due to pancreatic head cancer often have the associated problem of duodenal obstruction. We report here the case of a 78-year-old woman with this clinical situation, who was treated with self-expanding Gianturco metal stents placed in the distal common bile duct and, nine months later, placed in the descending duodenum. The patient's frequent vomiting resolved, and she was able to tolerate peroral solid food; jaundice also decreased (bilirubin pre-stenting: 7.8; post-stenting: 1.2). Self-expanding metal stents therefore appear to be effective for the palliative treatment of malignant duodenal stenosis as well as biliary stenosis.
Optical second- and third-harmonic generations in C60 film have been studied using a Nd:YAG laser as the fundamental light source. Observed dependences of the generated second- and third-harmonic intensities on the polarization of light and on the angle of incidence are discussed based on the symmetry of the film structure. The relatively large third-order nonlinear response of ||
χ(3)(-3ω; ω, ω, ω)||
≃2×10-10 esu has been observed.
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