Notes on subtlety and ineffability in P κ λ

A type of subtlety for P_κλ called “strongly subtle” is introduced to show almost ineffability is consistencywise stronger than Shelah property. The following are also shown: is strongly subtle” has rather strong consequences. (ii) The ideal is not strongly subtle} is not λ-saturated , and completely ineffable ideal is not precipitous. (iii) In case that λ^<κ=2^λ, almost λ-ineffability coincides with λ-ineffability. (iv) It is not provable that κ is λ^<κ-ineffable whenever κ is λ-ineffable.Research partially supported by “Grant-in-Aid for Scientific research (C), The Ministry of Education, Science, Sports and Culture of Japan 09640299”, and “Japan Society for the Promotion of Science 14540142”.The author is very grateful to the referee for his correcting many errors and helpful suggestions.     

Substoichiometric extraction of chromium

Substoichiometric extraction of chromium with tetraphenylarsonium chloride (TPACl), tri-n-octylamine (TNOA), diethylammonium diethyldithiocarbamate (DDDC) and ammonium pyrrolidinedithiocarbamate (APDC) was examined in detail. Chromium can be extracted substoichiometrically in a pH range, which is 1.1–2.6 for the TPACl compound, 0.6–2.3 for the TNOA compound, 5.1–6.4 for the DDCC chelate and 3.9–4.9 for the APDC chelate. Chromium in high-purity calcium carbonate, Orchard Leaves (NBS SRM-1571) and Brewers Yeast (NBS SRM-1569) was determined by neutron activation analysis combined with substoichiometric extraction by DDDC and APDC. The values of 2.0±0.02 ppm and 2.6±0.2 ppm were obtained for Brewers Yeast and Orchard Leaves, respectively. These values were in good agreement with the values reported by NBS. The reaction mechanism and the reaction ratio between hexavalent chromium and dithiocarbamate were also discussed.     

Emission from evaporated anthracene films

Emission spectra, excitation spectra and decay times of fluorescence of anthracene films prepared by evaporation on to substrate cooled with liquid nitrogen were measured. The fluorescence spectra of such films show a broad structureless band. The fluorescence excitation spectra and decay times of the emission in the shorter wavelength side of the band are different from those in the longer wavelength side. The decay times of the emissions on the shorter and longer wavelength sides are about 6.0 and 190 ns, respectively, at liquid nitrogen temperature. It may be that the former emission is due to a crystalline structure and the latter emission to an amorphous structure. Next, in anthracene evaporated films containing tetracene as a dopant, the energy transfer from the host to the guest could be observed and this was attributed to the exciton diffusion through the crystalline structure.     

Measurements of complex degree of spatial coherence at the end face of an optical fiber

The phase and modulus of the complex degree of spatial coherence at the exit end face of an optical fiber are measured with the help of a real-time data processing computer. Interference fringes produced by superimposing wavefronts of the image of the end cross-section are scanned by a linear photodiode array to calculate the one dimensional value of spatial coherence. Evolution of phase measured at the different positions in the fringe pattern reveals that the phase is intimately related to modal structures of the propagating field in an optical fiber supporting a small number of guided modes.     

A new method of radioactivation analysis based on the quantitative isotope dilution principle

The simple quantitative isotope dilution method proposed, allows the errors due to flux fluctuation and self-shielding, normal to ordinary radioactivation analysis, to be avoided. Three different methods are discussed. The most satisfactory method from a theoretical viewpoint involves division of the irradiated sample into two parts; in one part, an amount m is extracted and the radioactivity a is measured. An amount of carrier M is added to the other part, an amount m is again extracted and its radioactivity a' is measured. The unknown amount M_x is then calculated from (a/a') I = M/Mx. A method for the determination of traces of copper and silver in metallic tin and zinc based on this principle is described.     

Determination of indium,copper and nickel in glassmaking materials and NBS standard reference materials by substoichiometric radioactivation analysis

The paper describes a method of radioactivation analysis for the determination of indium, copper and nickel. In the determination of indium, ordinary and displacement substoichiometries were applied for glassmaking materials while ordinary substoichiometry was applied for NBS standard reference materials. Copper and nickel in glassmaking materials and NBS standard reference materials were also determined by the displacement and ordinary substoichiometries. Indium contents in glassmaking materials by the two methods agreed with each other. The analytical results of indium, copper and nickel in NBS' SRM were also in good agreement with published values and certified values by NBS.     

Mixed-valent tetranuclear manganese complexes with pentadentate Schiff-base ligand having a Y-shaped core

Reaction of pentadentate Schiff-base ligands, 1,3-bis(3-methoxysalicylideneamino)-2-propanol (H₃msap) with manganese(II) salts afforded tetranuclear mixed-valent manganese complexes, [Mn₄(msap)₂(CH₃CO₂)₃(CH₃O)(H₂O)]·H₂O (1) and [Mn₄(msap)₂(C₆H₅CO₂)₃(CH₃O)] (2), which were characterized by elemental analysis, infrared and diffused reflectance spectra and temperature dependence of magnetic susceptibilities (4.5–300 K). Single-crystal X-ray crystallography of these complexes showed that four manganese atoms are chelated by two Schiff-base ligands and further coordinated by syn–syn bridging, syn–anti bridging, and monodentate or bidentate-carboxylato groups, forming a Y-shaped cluster made up of two Mn^II and two Mn^III atoms. Diffused reflectance spectra are featureless, showing broad bands around at near-UV and visible regions. Magnetic moments decrease with lowering of temperature, showing an antiferromagnetic behavior of these complexes.     

Synthesis of fluspidine via asymmetric NaBH4 reduction of silicon enolates of β-keto esters

Asymmetric NaBH₄ reduction catalyzed by the Co(II) complex of a chiral diamidine-type sp²N ligand, Naph-diPIM-dioxo-iPr, was successfully applied to 3-silyloxycinnamate substrates without over-reduction, giving quantitatively 3-silyloxy-3-arylpropionates with an enantiomer ratio of up to 99:1. The high utility was confirmed on a 30-g scale using 0.1?mol% catalyst. Both Z and E substrates could be converted to a single enantiomeric product by changing the ligand chirality. The relationship between the Z/E stereochemistry and the absolute configuration of the 1,4-reduction product provided important information about the mechanism underlying enantioface selection. Combination of the asymmetric catalysis with two other key steps, Suzuki coupling with an N-protected tetrahydropyridine boronic acid derivative and intramolecular bromo etherification, realized an efficient synthetic route to both enantiomers of fluspidine. The new strategy permits the introduction of substituents on the two aryl groups and piperidine ring, allowing for structural variations toward the development of higher performance σ1 receptor antagonists.