Fabrication of a Near-Field Optical Fiber Probe with a Nanometric Metallized Protrusion

We have developed a novel probe with a nanometric metallized protrusion extending through a subwavelength aperture to increase optical near-field excitation and collection efficiencies. The apex diameter of the fabricated metallized protrusion was 35 nm. The Intensity distribution of the optical near-field at the apex of the probe was measured by scanning another probe across the apex, and it was observed that strong optical near-field was generated at the apex of the metallized protrusion. The width of the intensity distribution was 150 nm including instrumental resolution. Probes with spherical and ellipsoidal metallized protrusion were also fabricated, by which enhancement of the optical near-field is expected due to localized plasmon excitation.     

A concise representation of adsorbate-surface interactions. I. Formulation and model calculation for adsorption of Co on Cu(100) surface

A method is presented to clarify the concepts of the chemisorptive bonds among many chemisorptive interactions. The eigenfunctions of the system are transformed into new orbitals, and the chemisorptive interactions are represented in terms of a few transformed orbitals. To show the usefulness of the present method, the adsorption of CO on the Cu(100) surface is examined within the CNDO/2 approximation. The donation and the type interaction is clearly visualized, and the information of the spatial extent of the chemisorptive interactions is also obtained.     

Algebraically Decaying Modes in Many Dimensions: Application of Fubini’s Identity to Guided-Wave Optics

We show analytically that application of an identity in conformal invariant field theories to multidimensional guided-wave optics predicts a generic family of modes with algebraic (power-law) tails in the evanescent field.     

On the fragmentation modes in PMO analyses

The molecular species 1,1- and 1,2-disubstituted alkenes have been used as model systems for a comparative discussion of the results obtained with quantitative orbital analyses using different fragmentation modes. It is shown that when indices of the overall energy effects are used, the results of a quantitative orbital analysis are independent of the chosen fragmentation mode. On the other hand, the results of such analysis can depend on the fragmentation mode when indices of partial energy effects are used.     

多孔介质中两相不可压缩可混溶驱动问题的动态混合元方法及其特征修正格式

许多依赖时间的问题涉及到局部化现象,如突出的前沿位置、激波、边界层等, 其位置随时间而变动.多孔介质中两相不可压缩可混溶驱动问题是一典型的、有代表性 的"局部化现象"问题,其数学模型为耦合非线性偏微分方程组的初边值问题.为减轻数 值解在局部前沿位置的数值振荡,提高解的精确性,本文给出了该问题的动态混合元格 式和沿特征线修正的动态混合元格式,证明了其收敛性,并给出了误差估计.     

Uniform blow-up profiles and boundary layer for a parabolic system with localized nonlinear reaction terms

This paper deals with the blow-up properties of the solution to a semilin-ear parabolic system with localized nonlinear reaction terms, subject to the null Dirichlet boundary condition. We first give sufficient conditions for that the classical solution blows up in the finite time, secondly give necessary conditions and a sufficient condition for that two components blow up simultaneously, and then obtain the uniform blow-up profiles in the interior. Finally we describe the asymptotic behavior of the blow-up solution in the boundary layer.     

NDDO MO calculations

Three valence-only schemes based on the Roby version of NDDO MO theory, which differ only in the core-valence treatment and the choice of the basis set, have been applied to the study of molecules containing first-row atoms. Orbital energies, charge distribution, dipole moments, field gradients, and a few other one-electron molecular properties are calculated to satisfactory accuracy. The schemes appear unreliable in the prediction of barriers to internal rotation in molecules, presumably due to errors in the core contribution to the total energy. An alternative treatment is suggested.     

Use of pseudopotential towards time-evolution of a nonstationary state: Spatially localized excitation in a crystal

Pseudopotential is used as a formal operator to write the exact time-dependence of a pseudoexciton and hence that of an initial excitation spatially localized in a crystal. The exponential operator where pseudopotential occurs at the argument is readily evaluated using the property of projection operators. Migration of an initially localized excitation is of considerable experimental importance and can be of conceptual use since it should eventually generate the characteristics of a migrating exciton. From the formal time-dependence of a localized excitation, its spread with time can be calculated with relative ease. In a concurrent discussion, the previous work of Merrifield (1958) on the propagation of excitation is criticized and an error is pointed out. The spread, however, remains wavelike and is not dissipative in the absence of a collisional mechanism.     

A porous medium equation with nonlocal boundary condition and a localized source

This article studies the blow-up properties of solutions to a porous medium equation with nonlocal boundary condition and a general localized source. Conditions for the existence of global or blow-up solutions are obtained. Moreover, it is proved that the unique solution has global blow-up property whenever blow-up occurs. Blow-up rate estimates are also obtained for some special cases.     

Localized orbitals for optimal decomposition of molecular properties

We present the procedure for transforming delocalized molecular orbitals into the localized property-optimized orbitals (LPOs) designed for building the most accurate, in the Frobenius norm sense, approximation to the first-order reduced density matrix in form of the sum of localized monoatomic and diatomic terms. In this way, a decomposition of molecular properties into contributions associated with individual atoms and the pairs of atoms is obtained with the a priori known upper bound for the decomposition accuracy. Additional algorithm is proposed for obtaining the set of “the Chemist's LPOs” (CLPOs) containing a single localized orbital, with nearly double occupancy, per a pair of electrons. CLPOs form an idealized Lewis structure optimized for the closest possible reproduction of one-electron properties derived from the original many-electron wavefunction. The computational algorithms for constructing LPOs and CLPOs from a general wavefunction are presented and their implementation within the open-source freeware program JANPA ( http://janpa.sourceforge.net /) is discussed. The performance of the proposed procedures is assessed using the test set of density matrices of 33 432 small molecules obtained at both Hartree-Fock and second-order Moller-Plesset theory levels and excellent agreement with the chemist's Lewis-structure picture is found.