Oxidative degradations of the side chain of unsaturated ent-labdanes. Part I

A selective route for the degradation of the unsaturated side chain of ent-labdanes has been devised, giving two useful synthons: 2beta-acetoxy-14,15,17-trinor-ent-labdane-8,13- dione (5) and 2beta-acetoxy-14,15-dinor-ent-labd-8(17)-en-13-one (7), the use of which for the preparation of terpenylquinone derivatives shall be reported elsewhere.     

Raman and surface enhanced Raman scattering of a black dyed silk

The Raman and surface enhanced Raman scattering (SERS) spectra of a black dyed silk sample (BDS) were registered. The spectral analysis was performed on the basis of Raman and SERS spectral data of isolated samples of Bombyx mori silk fibroin, its motif peptide component (GAGAGS) and the synthetic reactive black 5 dye (RB5). The macro FT‐Raman spectrum of the silk sample is consistent with a silk II‐Cp crystalline fraction of Bombyx mori silk fibroin; the SERS spectrum is highly consistent with conformational modifications of the fibroin due to the interactions with the Ag nanoparticles. The GAGAGS peptide sequence dominates the Raman spectrum of the silk. The SERS spectrum of the peptide suggests a random coil conformation imposed by the surface interaction; the serine residue in the new conformation is exposed to the surface. Quantum chemical calculations for a model of the GAGAGS–Ag surface predict a nearly extended conformation at the Ag surface. The Raman spectrum of the dye was analysed, and a complete band assignment was proposed; it was not possible to propose a preferential orientation or organization of the molecule on the metal surface. Quantum chemical calculations for a model of the dye interacting with a silver surface predict a rather coplanar orientation of the RB5 on the Ag metal surface. The Raman spectrum of the BDS sample is dominated by signals from the dye; the general spectral behaviour indicates that the dye mainly interacts with the silk through the sulphone (–SO₂–) and sulphonate (–SO₂–O–) groups. Besides the presence of dye signals, mainly ascribed to the sulphone and sulphonate bands, the SERS spectrum of the BDS sample also displays bands belonging to the amino acids alanine, glycine, serine and particularly tyrosine. Copyright © 2013 John Wiley & Sons, Ltd.     

Exceptional Sequences over Path Algebras of Type A n and Non-Crossing Spanning Trees

Exceptional sequences are fundamental to investigate the derived categories of finite dimensional algebras. The aim of this note is to classify all the complete exceptional sequences over the path algebra of a Dynkin quiver of type A _n in terms of non-crossing spanning trees.     

Direct meso-alkynylation of porphyrins doubly assisted by pyridyl coordination

Direct meso-alkynylation of β,β'-dipyridylporphyrin with various alkynyllithium reagents has been achieved, in which the β,β'-dipyridyl groups play an important role in facilitating the nucleophilic addition of the reagents through double coordination. This method enabled the synthesis of a meso-ethynylene-bridged diporphyrin.     

Four types of nonlinear scalarizations and some applications in set optimization

There are two types of criteria of solutions for the set-valued optimization problem, the vectorial criterion and set optimization criterion. The first criterion consists of looking for efficient points of set valued map and is called set-valued vector optimization problem. On the other hand, Kuroiwa–Tanaka–Ha started developing a new approach to set-valued optimization which is based on comparison among values of the set-valued map. In this paper, we treat the second type criterion and call set optimization problem. The aim of this paper is to investigate four types of nonlinear scalarizing functions for set valued maps and their relationships. These scalarizing functions are generalization of Tammer–Weidner’s scalarizing functions for vectors. As applications of the scalarizing functions for sets, we present nonconvex separation type theorems, Gordan’s type alternative theorems for set-valued map, optimality conditions for set optimization problem and Takahashi’s minimization theorems for set-valued map.     

N,N-Dilauryl Chitosan：Synthesis and Surface Pressure-area Isotherm

With sodium dodecyl sulfonate(SDS) as the phase transferring catalyst, N,N-Dilauryl chitosans with a high degree of alkyl group substitution were prepared and characterized by means of FTIR, ^1H NMR and elemental analyses. The results indicate that the average degree of alkyl group substitution on the chitosan increases with decreasing the molecular weight of the chitosan. The fully N,N-dilaurylated chitosan was found to be dissolvable in chloroform. The collapsed pressures of the samples derived from chitosan with 3000,5000 and 10000 dalton are 47.6, 48. 2 and 51.0 mN/m, respectively. The surface area occupied by the monomer unit(glucosamine) of all. those samples is 0:6 nm^2.     

Optimal Dispersion of NZ-DSF in 40 Gbit/s DWDM Transmission

Numerical and experimental verification of optimal dispersion of NZ-DSF in 40Gb/s-based DWDM transmission are performed using 240km simple transmission line. The results show that dispersion of +8ps/nm/km is effective in 40Gb/s as well as 10Gb/s.     

Highly active supported catalysts for olefin polymerization. Supports from a grignard reagent for preparation of highly active catalysts

Supports were obtained by the interaction of C₄H₉MgCl with the reaction mixture of AlCl₃ and CH₃Si(OC₂H₅)₃ or Si(OC₂H₅)₄ (Mg/Al/Si = 2/1/1). With the combination of Al(C₂H₅)₃ and methyl-p-toluate, immobilized titanium catalysts prepared by the treatment of the supports with TiCl₄ and ethylbenzoate showed extraordinary high activity and stereoregularity in the polymerization of propylene.¹ By the study of the reaction of AlCl₃ with CH₃Si(OC₂H₅)₃, the elemental analysis and powder x-ray diffractometric measurements of the supports, it was found that the supports comprised of Cl, Mg, Al, and Si atoms, OC₂H₅ groups, C₄H₉ groups, and ethers, and that they were amorphous solids to the extent that the x-ray diffraction peak assigned to the 003 plane in MgCl₂ crystals completely disappeared.     

A New Method of Photopatterning with LB Films Based on a Chemically Amplified Mechanism

IntroductionDeep-UV lithography is generally recognized asthe most promising lithographic technology, for the pro-duction of high-resolution devices. However, lithogra-phy requires high sensitivity, high resolution, and highresistance. To make this techno…