PIV measurement of particle motion in spiral gas–solid two-phase flow

With a concise review on some basic and novel algorithms and methods for the techniques of particle-imaging velocimetry (PIV), the paper reports an application of the PIV techniques to the investigation of particle motion in a gas–solid two-phase spiral flow in a horizontal tube. Axial velocities of the transported particles are obtained. Some important features of particle motion governing high transportation efficiency of the spiral flow are revealed by investigating probability density distribution of particle locations in a pipe cross-section.     

Spectroscopy of light Λ hypernuclei

We recently measured high-statistics and high-resolution spectra of p-shell Λ hypernuclei produced by the (π⁺, K⁺) reaction. In this article, cross sections and their angular distributions of _Λ¹²C and _Λ¹⁶O are reported. The obtained cross sections are well reproduced by DWIA calculations.     

Merging Pd0/PdII Redox and PdII/PdII Non-redox Catalytic Cycles for the Allylarylation of Electron-Deficient Alkenes

An allylarylation of electron-deficient alkenes with aryl boronates and allylic carbonates has been developed. This method allows access to a wide variety of carbon skeletons from readily available starting materials. Mechanistic studies indicate that this reaction is enabled by a cooperative catalysis based on merging Pd⁰/Pd^II redox and Pd^II/Pd^II non-redox catalytic cycles.     

Large scale production of 64Cu and 67Cu via the 64Zn(n,p)64Cu and 68Zn(n,np/d)67Cu reactions using accelerator neutrons

Journal of Radioanalytical and Nuclear Chemistry - Both 64Cu and 67Cu are promising radionuclides in nuclear medicine. Production yields of these radionuclides were quantified by irradiating...     

Organische S?uren in biologischen Stoffen

Ohne Zusammenfassung     

Characterization and Reactivity of a Tetrahedral Copper(II) Alkylperoxido Complex

A tetrahedral Cu^II alkylperoxido complex [Cu^II(TMG₃tach)(OOCm)]⁺ ( 1^OOCm ) (TMG₃tach={2,2′,2′′-[(1s,3s,5s)-cyclohexane-1,3,5-triyl]tris-(1,1,3,3-tetramethyl guanidine)}, OOCm=cumyl peroxide) is prepared and characterized by UV/Vis, cold-spray ionization mass spectroscopy (CSI-MS), resonance Raman, and EPR spectroscopic methods. Product analysis of the self-decomposition reaction of 1^OOCm in acetonitrile (MeCN) indicates that the reaction involves O−O bond homolytic cleavage of the peroxide moiety with concomitant C−H bond activation of the solvent molecule. When an external substrate such as 1,4-cyclohexadiene (CHD) is added, the O−O bond homolysis leads to C−H activation of the substrate. Furthermore, the reaction of 1^OOCm with 2,6-di-tert-butylphenol derivatives produces the corresponding phenoxyl radical species (ArO^.) together with a Cu^I complex through a concerted proton-electron transfer (CPET) mechanism. Details of the reaction mechanisms are explored by DFT calculations.     

Intramolecular Catalyst Transfer on a Variety of Functional Groups between Benzene Rings in a Suzuki–Miyaura Coupling Reaction

Suzuki–Miyaura coupling reaction of BrC₆H₄-X-C₆H₄Br 1 (X=CH₂, CO, N-Bu, O, S, SO, and SO₂) with arylboronic acid 2 was investigated in the presence of tBu₃PPd precatalyst and CsF/[18]crown-6 as a base to establish whether or not the Pd catalyst can undergo catalyst transfer on these functional groups. In the reaction of 1 (X=CH₂, CO, N-Bu, O, and SO₂) with 2 , aryl-disubstituted product 3 (Ar-C₆H₄-X-C₆H₄-Ar) was exclusively obtained, indicating that the Pd catalyst undergoes catalyst transfer on these functional groups. On the other hand, the reaction of 1 e (X=S) and 1 f (X=SO) with 2 afforded only aryl-monosubstituted product 4 (Ar-C₆H₄-X-C₆H₄-Br) and a mixture of 3 and 4 , respectively, indicating that S and SO interfere with intramolecular catalyst transfer. Furthermore, we found that Suzuki–Miyaura polycondensation of 1 (X=CH₂, CO, N-Bu, O, and SO₂) and phenylenediboronic acid 5 in the presence of tBu₃PPd precatalyst afforded high-molecular-weight polymer even when excess 1 was used. The polymers obtained from 1 (X=CH₂, N-Bu, and O) and 5 turned out to be cyclic.     

Morphology and the Thermoelectric Properties of γ-GdxDy1 – xS1.5 – y Solid Solution Ceramics

Physics of the Solid State - The temperature dependences of the Seebeck coefficient, the electrical conductivity (T = 300–873 K) and also the heat conductivity coefficient, and the...     

Determination of trace amount of nickel in cosmic spherules by photon activation analysis

Trace amount of nickel in high-purity iron and iron oxide samples was determined by photon activation analysis (PAA) using the Electron Linear Accelerator at the Research Center for Electron Photon Science, Tohoku University. It was confirmed that about 0.015 μg of nickel in the high-purity iron oxide sample could be determined with an experimental uncertainty of 20% by PAA, that is, it was possible to determine 1% of nickel at least in a few μg of cosmic spherules. PAA was applied to the nickel-determination in cosmic spherules. Nickel in cosmic spherules was determined by PAA more accurately than by instrumental neutron activation analysis done in a reactor neutron spectrum with the fluence rate ratio of thermal neutrons to fast of 4–5 which has so far been applied to the analysis of spherule samples. Additionally, trace amount of nickel in the reference material Giant Clam JCt-1 supplied by the Geological Survey of Japan was determined by PAA with radiochemical treatment.     

(Hyper)polarizability density analysis for open-shell molecular systems based on natural orbitals and occupation numbers

We have developed a method for analyzing the (hyper)polarizabilities of open-shell molecular systems. This method employs the (hyper)polarizability densities based on the natural orbitals and occupation numbers, which enables us to analyze the contributions of odd electrons having various open-shell (diradical) characters. Within broken-symmetry, i.e., spin-unrestricted, single-determinant molecular orbital and density functional theory approaches, we can also remove the spin contamination effects on these quantities through spin projection. To do that, an approximate spin projected method has been elaborated and applied to the analysis of the (hyper)polarizability of multi-radical systems. As examples, typical open-shell singlet systems, 1,3-dipoles and rectangular graphene nanoflakes, are examined.