Nested PLS

In this note we will introduce a class of search problems, called nested Polynomial Local Search (nPLS) problems, and show that definable NP search problems, i.e., ${\Sigma^{b}_{1}}$ -definable functions in ${T^{2}_{2}}$ are characterized in terms of the nested PLS.     

Inelastic scattering on 12Be and disappearance of the N = 8 magic number

Experimental studies on in-beam γ-ray spectroscopy using a ¹²Be radioactive beam are presented. Inelastic scattering of the neutron-rich ¹²Be nucleus on ²⁰⁸Pb, ¹²C, and (CH₂)_n targets has been studied by measuring de-excitation γ-rays in coincidence with scattered particles. The level schemes and transition probabilities are determined for low-lying excited states in ¹²Be. The present paper presents a brief review of the spectroscopic results, which may be associated with the N = 8 shell quenching near the drip line. Received: 1 May 2001 / Accepted: 4 December 2001     

Correction method for X-ray fluorescent determination of chromium in high-alloy steels and nickel-base alloys

Summary A new interelement correction method has been developed for the X-ray fluorescent determination of chromium in high-alloy steels and nickel-base alloys. The calibration equation which was derived from the JIS (Japanese Industrial Standards) model is applicable over wide ranges of compositions by preparation of only Fe-Cr binary standards.The new approach gave better accuracy than that based on Rasberry-Heinrich correction model. The accuracies (_d) were 0.08% for high-alloy steels and 0.14% for nickel-base alloys.

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Korrekturmethode für die röntgenfluorescenzspektrometrische Bestimmung von Chrom in hochlegierten Stählen und Nickellegierungen

Zusammenfassung Die Eich-Gleichung für das neue Korrekturverfahren wurde vom JIS-Modell (Japanese Industrial Standards) abgeleitet und ist über einen weiten Bereich von Zusammensetzungen durch Herstellung von lediglich binären Fe-Cr-Standards einsetzbar. Das beschriebene Verfahren bietet eine bessere Genauigkeit als die Methode nach dem Korrekturmodell von Rasberry-Heinrich. Sie betrug 0,08% für hochlegierte Stähle und 0,14% für Nickellegierungen.

     

Novel indoline dye tetrabutylammonium carboxylates attached with a methyl group on the cyclopentane ring for dye-sensitized solar cells

(2R,3aR,8bR)- and (2S,3aS,8bS)-2-Methyl indoline dye tetrabutylammonium carboxylates exhibited the highest conversion efficiency among four regio and stereo isomers. These indoline dyes also showed higher conversion efficiency than DN350.     

The elastic constant and molar volume of sodium and potassium germanate glasses and the germanate anomaly

The composition dependences of molar volume and elastic constants were investigated for sodium and potassium germanate glasses of composition xR₂O·GeO₂ (O < x < 0.65 in the sodium-glasses and O < x < 0.75 in the potassium-ones). The variation of the molar volume could be approximated by straight lines crossing at 0.18 and 0.16 in x in the sodium- and potassium-glasses, respectively. At these compositions the elastic constants showed maxima. With reference to the structures of several alkali germanate crystals, it was concluded that the fraction of GeO₆ units, N₆, reaches a maximum at 0.18 in x in the sodium-glasses (15.6) mol.% Na₂O) and at 0.16 in x in the potassium-glasses (13.8 mol.% K₂O). It was also considered that N₆ is not null at 0.5 but is null probably at 1.0 in x in the glasses. A network model of the germanate glasses was discussed.     

Iron-catalysed green synthesis of carboxylic esters by the intermolecular addition of carboxylic acids to alkenes

Iron triflate, in situ-formed from FeCl3 and triflic acid, or FeCl3 and silver triflate efficiently catalyse the intermolecular addition of carboxylic acids to various alkenes to yield carboxylic esters; the reaction is applicable to the synthesis of unstable esters, such as acrylates.     

Diffusion of non-volatile phenolic compounds in zeolite beta and silicalite in liquid phase

The present study aims to systematically investigate the adsorption kinetics of “non-volatile” phenolic compounds with different critical diameters (p-coumaric acid, ferulic acid, sinapinic acid, p-hydroxybenzoic acid, vanillic acid, syringic acid, and vanillin) onto zeolite beta and silicalite in several solvents. In the aqueous phase, the corrected diffusivity of non-volatile phenolic compounds is 2–5 orders of magnitude smaller than that of volatile aromatic compounds with the same critical diameter. On the other hand, the corrected diffusivity in zeolite beta is on the same order of magnitude among non-volatile phenolic compounds, despite the significant difference in critical diameter of the adsorbate. This suggests that the intracrystalline diffusivity of the non-volatile adsorbate is strongly affected by its original molecular immobility, rather than by the size (narrowness) of the adsorbate and micropore aperture. Non-volatility is considered to remarkably lower the molecular mobility of adsorbate on the surface of zeolite, even in the liquid phase. In addition, the intracrystalline diffusivity of non-volatile adsorbate is strongly affected by the type of solvent, and a close correlation was found between intracrystalline diffusivity and adsorption affinity. Revelations as to the kinetic behavior of non-volatile adsorbate in zeolite are expected to supply more information on the kinetic separation of compounds in the liquid phase. The significant difference in diffusivity among non-volatile and volatile adsorbates in zeolite leads to the possibility of kinetic separation among these adsorbates.     

Dalitz plot analysis of Coulomb exploding O3 in ultrashort intense laser fields

The three-body Coulomb explosion of O3, O3(3+)-->O++O++O+, in ultrashort intense laser fields (2x10(15) W/cm2) is studied with two different pulse durations (9 and 40 fs) by the coincidence momentum imaging method. In addition to a decrease in the total kinetic energy release, a broadening in the Dalitz plot distribution [Philos. Mag. 44, 1068 (1953)] is observed when the pulse duration is increased from 9 to 40 fs. The analysis based on a simple Coulomb explosion model shows that the geometrical structure of O3 remains almost unchanged during the interaction with the few-cycle intense laser fields, while a significant structural deformation along all the three vibrational coordinates, including the antisymmetric stretching coordinate, is identified in the 40 fs intense laser fields. The observed nuclear dynamics are discussed in terms of the population transfer to the excited states of O3.     

Botryoidal assembly of cholesteryl-pullulan/poly(N-isopropylacrylamide) nanogels

Hybrid nanogels consisting of cholesteryl-modified pullulan (CHP) and poly(N-isopropylacrylamide) (PNIPAM) were synthesized by graft free-radical copolymerization of N-isopropylacrylamide (NIPAM) onto methacryloyl-substituted CHP nanogels (CHPMA) in water at 50 degrees C in the presence of a water-soluble free radical initiator. Depending on the initial NIPAM/CHPMA ratio, CHP-PNIPAM (CN) nanogels containing 30.8-84.8 wt % PNIPAM were obtained in the form of self-assembled nanoparticles with a hydrodynamic radius (Rh) of 69.0-116.0 nm in water kept at 20 degrees C. Hybrid nanogels of sufficiently high NIPAM content, such as the sample CN90, which contains 79.6 wt % NIPAM, exhibited a two-step response to changes in solution (3 mg/mL) temperature: a decrease in Rh from 93 to 57 nm as the temperature increased from 20 to 35 degrees C, followed by a sharp increase in Rh from 57 nm to 90 nm at 55 degrees C. Both steps in this temperature response were reversible. The multistep response to temperature of the CN nanogels was attributed to the morphology of the nanogels, which are seen as consisting of grape-like (botryoidal) clusters of associated native nanogels held together via cholesteryl cross-linking points and held together by the grafted PNIPAM chains.