Growth of KLN fiber crystals and its application for blue-violet light geration

Potassium lithium niobate (KLN) fiber crystals have been grown by μ-pulling down method. The KLN fibers doubled around 806 nm radiation for type I noncritical phase matching at room temperature. We observed ～0.6 mW output power from single-pass second harmonic generation at an input power of 700 mW.     

Compatibility and mesophase separation in blends of α-helical polyglutamates

Blends composed of the α-helical polymers, poly-L-glutamates [(? NHC^αHRC′O? )_n, R = ? CH₂CH₂COO? (CH₂)_m(C₆H₅] (Lm) and the corresponding D enantiomers (Dm), have been studied by x-ray diffraction and viscoelastic measurements. Binary blends of L2, D2, L3, and D3 are compatible and form isomorphous mixed crystals at all compositions, whereas other pairs, with the exception of L1/D1, are incompatible. The demixing process is described for a ternary system consisting of L1, D3, and a diluent chloroform at 40°C. The phase diagram comprises four regions, I, IA, A, and AA, with increasing polymer concentration; I: isotropic, A: anisotropic, IA: I–A biphasic, and AA: A–A biphasic. The IA biphasic gap is greater in the ternary system than in the binary ones. The high-molecular-weight component (D3) is partitioned into the A phase in the IA region. The AA separation originates from incompatibility of the polymers. The phase behavior is discussed on the basis of the Abe-Flory theory by incorporating the polymer-polymer interaction parameter.     

Electron-boson interaction in nonsuperconducting magnetic metals

Gadolinium-and chromium-based normal metal-insulator-metal tunnel junctions were studied. Spectral functions of the Gd and Cr electron-boson interaction were reconstructed, from which it follows that the magnetic subsystem plays a noticeable role in the electron transport in magnetic metals.     

Equivalence of certain convex and nonconvex models of spatially modulated structures

The ground states of a certain class of one-dimensional models with a nonconvex interatomic interaction which exhibit spatially modulated structures are proved to be equivalent to those of the Frenkel-Kontorova-type models with a convex interatomic interaction. One of the nonconvex models numerically studied by Marchandet al. belongs to this class, and it turns out to be equivalent to the exactly solvable model with a complete devil's staircase studied by Aubry.     

Micro-optical components based on silicon mold technology

Two micro-optical components fabricated by silicon molds are described. One component is micro-cavity in micro-scales and the other is sub-micron grating with a pitch of 200 nm. The feasibility of two methods for the micro-fabrication of the silicon molds is investigated: one method is for making hundreds of micrometer size silicon molds by using conventional photolithography and deep reactive ion etching (Deep-RIE) technique combined with wet etching; and the other is for fabricating sub-micron grating molds by using electron beam lithography and fast atom beam etching (FAB). Sub-wavelength structure is successfully transferred from silicon mold to poly-methyl methacrylate (PMMA) material. The yield and repeatability of the original master are quite good. This technique can also be used to fabricate other micro-scale structures.     

Development of muon polarization preserved scintillators

We measured the residual μ⁺ polarizations in various liquid scintillators to search for an ideal material for an active muon stopper in which the muon spin polarization can be preserved and at the same time their energy loss and tracks can be measured by scintillation lights from the stopper material. We found the residual polarizations of mineral‐oil base liquid scintillators were \sim 4 times larger than that of a plastic scintillator. Further increase of the residual polarization was observed with a mixture of CCl₄. This revised version was published online in August 2006 with corrections to the Cover Date.     

定量构效关系研究中图论方法:烷烃13C NMR化学位移

系统研究了图论方法在定量构效(性)关系(QSAR/QSPR)中的应用.本文研究提出了一种新的指数L,并发现它与烷烃¹³C NMR有良好线性相关性.