Total synthesis of (+--oudemansin

($\text{+}\text{-}$)-Oudemansin has been synthesized starting from $\text{trans}$-cinnamaldehyde by a route involving the stereoselective Zn(BH₄)₂ reduction of β-keto ester.     

Determination of acetaldehyde by a chemiluminescence method

The determination of acetaldehyde was achieved by monitoring the chemiluminescence emission from the luminol-potassium hexacyanoferrate (III) reaction in the presence of xanthine oxidase. The linear range was three orders of magnitude, the detection limit (2σ) was 4 × 10^?7 M and the relative standard deviation (n = 5) was 10.6% for 4.3 × 10^?7 M. No interference was observed from seven organic and inorganic species at a 1000-fold excess relative to a concentration of 1 × 10^?5 M acetaldehyde.     

Convergent synthesis of the E'FGH' ring fragment of ciguatoxin 1B via an acetylene cobalt complex strategy

[reaction: see text] A convergent synthesis of the E'FGH' ring fragment of ciguatoxin has been accomplished through (i) coupling between the E' ring-acetylide and the H' ring-aldehyde, (ii) stereoselective F ring cyclization via an acetylene cobalt complex, (iii) conversion to a carbonyl function, and (iv) reductive hydroxy-ketone cyclization to construct the G ring.     

Hydrothermal precipitation of ZrO2 powder

Since 1980 much attention has been payed to hydrothermal processing. There are several papers related to hydrothermal fine Zirconia powders by authors 1), 2), 3) and 3).

The authors 3) prepared ZrO₂ and Y₂O₃-ZrO₂ powders under hydrothermal conditions. Several methods were used to prepare fine ZrO₂ powders under hydrothermal conditions: hydrothermal precipatation, hydrothermal crystallization, hydrothermal oxidation, hydrothermal decomposition, hydrothermal synthesis, hydrothermal anodic oxidation, RESA (reactive electrode submerged arc) process, etc.

This paper describes hydrothermal precipatation processing of ZrO₂ and Y-ZrO₂ powder.     

Theory of optical rotation,Faraday effect,and inverse Faraday effect

The Hamiltonian for these problems is arranged appropriately in the nonrelativistic limit of the Dirac Hamiltonian. The unified view is tried to elucidate the mechanisms responsible for these phenomena by connecting the polarization vector of light and molecular properties inherent in the species or the external magnetic field. ©1999 John Wiley & Sons, Inc. Int J Quant Chem 75: 33–45, 1999     

Augmenting forests to meet odd diameter requirements

Given a graph G=(V,E) and an integer D≥1, we consider the problem of augmenting G by the smallest number of new edges so that the diameter becomes at most D. It is known that no constant approximation algorithms to this problem with an arbitrary graph G can be obtained unless P=NP. For a forest G and an odd D≥3, it was open whether the problem is approximable within a constant factor. In this paper, we give the first constant factor approximation algorithm to the problem with a forest G and an odd D; our algorithm delivers an 8-approximate solution in O(|V|³) time. We also show that a 4-approximate solution to the problem with a forest G and an odd D can be obtained in linear time if the augmented graph is additionally required to be biconnected.     

On Aluthge Transforms of p-hyponormal Operators

In this note we give an example of an ∞-hyponormal operator T whose Aluthge transform is not (1+ɛ)-hyponormal for any ɛ > 0 and show that the sequence of interated Aluthge transforms of T need not converge in the weak operator topology, which solve two problems in [6].     

Pyrolysis and gas chromatographic examination of phytol and isoprenoid hydrocarbons: Pre-calculation of retention indices by computer

For the identification of isoprenoid-type compounds and other degradation products derived from the pyrolysis of phytol and plant pigments, a calculation method was developed to the evaluate the chromatograms, determining the retention indices or net retention volumes of different compounds. Calculations were made by means of computer for different stationary phases and temperatures. Gas chromatographic and derivatographic measurements were made with natural plant pigments and phytol, including the thermal degradation of the compounds mentioned above. Close agreement was found between the measured and calculated data and with literature data.     

Deformation of a submanifold in a Euclidean space with fixed gauss image: II

Deformation of an m-dimensional submanifold immersed in a Euclidean n-space is studied when the Gauss image does not move pointwise. The present paper is the third one and contains deformations where the tensor of deformation satisfies some differential equations, normal deformations and deformations of totally-real submanifolds in a complex space.