Photochromism of single crystals composed of dioxazolylethene and dithiazolylethene

Although dioxazolylethene 1a did not show any photocoloration in the single crystalline phase, 1a displayed photochromism in the mixed crystal containing both 1a and dithiazolylethene 2a ; the mixed crystal changed color from colorless to red, orange, and yellow upon irradiation with light of appropriate wavelengths.     

Laser ceramics with rare-earth-doped anisotropic materials

The fabrication of laser-grade anisotropic ceramics by a conventional sintering process is not possible owing to optical scattering at randomly oriented grain boundaries. In this Letter, we report the first (to our knowledge) realization of transparent anisotropic ceramics by using a new crystal orientation process based on large magnetic anisotropy induced by 4f electrons. By slip casting in a 1.4 T magnetic field and subsequent heat treatments, we could successfully fabricate laser-grade calcium fluorapatite ceramics with a loss coefficient of 1.5 cm(-1).     

Multiple Solutions of Semilinear Elliptic Problems with Degenerate Boundary Conditions

The purpose of this paper is to study a class of semilinear elliptic boundary value problems with degenerate boundary conditions which include as particular cases the Dirichlet and Robin problems. The approach here is distinguished by the extensive use of the ideas and techniques characteristic of the recent developments in the theory of partial differential equations. By making use of the Leray–Schauder degree, we prove very exact results on the number of solutions of our problem. The results here extend earlier theorems due to Berger–Podolak, Castro–Lazer and Ambrosetti–Mancini to the degenerate case.     

Direct synthesis of 1,3-diketones by Rh-catalyzed reductive alpha-acylation of enones

1,3-Diketones were synthesized from alpha,beta-unsaturated ketones by treatment with acid chlorides and Et(2)Zn in the presence of RhCl(PPh(3))3. This is a very simple and extremely chemoselective reaction to give the adduct at the alpha-position of alpha,beta-unsaturated ketones.     

Degenerate Elliptic Eigenvalue Problems with Indefinite Weights

The purpose of this paper is to provide a careful and accessible exposition of the Kreĭn and Rutman Theory of degenerate elliptic eigenvalue problems with indefinite weights that model population dynamics in environments with spatial heterogeneity. We prove that the first eigenvalue of our problem is algebraically simple and its corresponding eigenfunction may be chosen to be positive everywhere. Here the approach is distinguished by the extensive use of the ideas and techniques characteristic of the recent developments in the theory of partial differential equations. The results extend an earlier theorem due to Manes and Micheletti to the degenerate case. Dedicated to the memory of Professor Sigeru Mizohata (1924–2002)     

Measurement of sugars using the laser spray technique with a gold capillary

A gold (Au) capillary has higher thermal conductivity than a stainless steel capillary and can withstand capillary over-heating induced by high CO(2) laser irradiation (over 2.5 W) better than a stainless steel capillary. For this study, a laser spray using an Au capillary was applied for the detection of sugars. The signal of cationized compounds [M+Na](+) can be detected with higher sensitivity than with conventional laser sprays using high laser power (over 2.7 W). Using 3.5 W of laser power, the signal intensity is 15 times higher than the maximum value with stainless steel (2.3 W) in a 10(-5) M maltose aqueous solution. It is considered that almost all the water molecules evaporate by laser irradiation, which is impossible to achieve using a stainless steel capillary.     

Patterning reactive microdomains inside polydimethylsiloxane microchannels by trapping and melting functional polymer particles

This paper describes a facile technique to pattern reactive microdomains inside polydimethylsiloxane microchannels by utilizing polymer particles as the carrier of functional groups. The air/liquid interface formed in microchannels equipped with microwells exerts lateral force on the particles, trapping particles only inside the wells. We then fix the polymer matrix on the wells by melting the trapped particles to form reactive domains with flexible shapes and high resolution. We employed monodisperse poly(styrene-co-glycidyl methacrylate) microparticles having an epoxy group and patterned various types of microdomains with a resolution of several micrometers. Several tests confirmed the presence of the epoxy group and the flatness of the patterned domain. The presented scheme provides a new way of preparing highly functional microsystems by using simple operations and would be useful for various applications, including local patterning of graft polymers and the site-specific cultivation of cells in a confined space.