Self-adaptive spatial filtering by use of azo chromophores doped in low glass-transition-temperature polymers

We report on self-adaptive spatial filtering by combination of the self-adaptive polarization-rotation property of Disperse Red1-doped polymers with low glass-transition-temperature and Fourier-transform operation. Our system can be operated with only an action beam with object information and without a probe beam for image readout. Edge enhancement by the action beam-probe beam is demonstrated as an example of the system's application to spatial filtering.     

Investigation into the evolution of the structure of K1−x LixTa1−y NbyO3 single crystals under variations in temperature

The evolution of the structure of K_1?x Li_xTa_1?y Nb_yO₃ single crystals with x = 0.001, y = 0.026, and 1900 ppm Cu (KLTN277) and with x = 0.0014 and y = 0.024 (KLTN123), which exhibit an extremely high permittivity (up to 4 × 10⁵ in the quasi-static regime for the KLTN277 crystal), is investigated in the range from room temperature to 20 K. It is demonstrated that, upon cooling to the lowest temperatures, both crystals retain their cubic structure, but the lattice parameters pass through a minimum at the temperature of the observed anomalies of the dielectric response (～50 K). In the neutron diffraction pattern of the KLTN123 sample, satellites appear in the vicinity of the (hhh) reflections at temperatures below ～50 K. These satellites can be associated with the nucleation of the rhombohedral phase.     

A unified treatment of dividend payment problems under fixed cost and implementation delays

In this paper we study the dividend optimization problem for a corporation or a financial institution when the management faces (regulatory) implementation delays. We consider several cash reservoir models for the firm including two mean-reverting processes, Ornstein–Uhlenbeck and square-root processes. Since the cash flow structure of different companies have different qualitative behaviors, it makes sense to use different diffusions to model them. The delay causes significant difficulties to the optimization problem since the cash reservoir fluctuates during the delay period. We provide a uniform mathematical framework to analyze all the models and provide optimal threshold strategies at which the management initiates actions, i.e., declaration and payment of dividends. Our solution depends on a new characterization of the value function for one-dimensional diffusions and provide easily implementable algorithms to find the optimal control and the value function.     

What factors influence the catalytic activity of iron-salan complexes for aerobic oxidative coupling of 2-naphthols?

A few Fe-salan dimer complexes serve as catalysts for aerobic oxidative coupling (AOC) of 2-naphthols, but some others do not. X-Ray and cyclic voltammetry studies of various Fe-salan complexes revealed that the absence or the presence of double hydrogen bonding in Fe-salan dimers, the oxidation potential of monomeric Fe-salan species and the location of the resulting radical cation are critical factors for the catalytic activity of iron-salan complexes for the AOC.     

Confocal nonlinear optical microscopy for high-resolution measurement of absorptive objects

We demonstrate a new scheme to enhance the spatial resolution of a confocal optical microscope. Our scheme improves the spatial resolution in the direction of the optical axis. The confocal optical microscope, by use of a four-wave mixing geometry, can obtain optical information about weakly absorptive objects with organic dyes. Owing to the third-order nonlinear dependence of absorptive objects, the optical signal is confined to the focal region of the focusing incident beam.     

High contrast measurement of nanoparticle with polarization interferometric nonlinear confocal microscope

Polarization interferometric nonlinear confocal microscope has been developed to observe a submicron size object in high contrast. The microscope succeeded in resolving the inside of a 200-nm-diameter polymeric nanoparticle. According to CTF (contrast transfer function) measurement and three-dimensional imaging with the microscope, the best spatial resolution for the microscope is 10 nm.     

Sequential Chiral Induction and Regulator-Assisted Chiral Memory of Pillar[5]arenes

Chirality transfer is widely observed in life processes, and many artificial chiral transfer systems have been developed. In these systems, chiral information is transferred from chiral inducers to chiral acceptors by a direct chiral induction process and a direct chiral memorization process. We have developed ternary nondirect chiral transfer systems based on pillar[5]arenes, in which a third factor was introduced as a regulator. The planar chirality of an acceptor was induced and memorized by a chiral inducer with precise control by a regulator. In the chiral induction period, the feed sequence of the chiral inducer and regulator affected the chiral induction behavior of the chiral acceptor. The chiral memory ability of the acceptor was substantially improved by the combined action of the chiral inducer and regulator.     

Giant dielectric susceptibility and magnetocapacitance effect in manganites at room temperature

Extremely high values of the relative permittivity up to 10⁷ and the magnetocapacitance up to 10⁵% have been found in La_{1 − x} Sr _x MnO₃ single crystals (x = 0.1, 0.11). These phenomena are observed even at room temperature. The observed behavior can be a consequence of the strong interaction among charge, spin, and lattice degrees of freedom, which leads to charge and phase separation in the regime before the percolation threshold. Original Russian Text ? R.F. Mamin, T. Egami, Z. Marton, C.A. Migachev, M.F. Sadykov, 2007, published in Pis’ma v Zhurnal éksperimental’noĭ i Teoreticheskoĭ Fiziki, 2007, Vol. 86, No. 10, pp. 731–735.