Magnetic moment measurement of baryons with heavy-flavored quarks by planar channeling through a bent crystal

The precession angle of a polarization vector is calculated for a positively charged short-lived baryon channeling between single-crystal planes. When very energetic polarized baryons are produced such that the production plane of the baryon is almost parallel to the crystal plane, it is shown that the interaction of the polarization with inhomogeneous electric fields inside the crystal can be neglected from the equation of motion of the particle. In this case, the equation of motion of the polarization vector becomes the same as when the electric field is homogeneous. It is also shown that when the crystal is bent perpendicular to the planar direction, the precession angle of the polarization vector of short-lived baryons can be expressed ass $\text{Δθ}{}_{\mathrm{<mtext>R</mtext>}}{}^{\mathrm{\tau }}\text{=}\text{1}\text{2}\text{γ}{}^2\text{[(2 ? g + g/γ}{}^2\text{)]ντ/R}$ under the same condition as above, where γ is the Lorentz factor, g the g factor of the magnetic moment, R the bending radius of the crystal and τ the lifetime of the particle. It is also shown that in some cases this precession should be large enough to determine the magnetic moment of short-lived particles, such as the charmed baryon Λ_c⁺.     

Stereospecific polymerization of methacrylonitrile. IV. Polymerization by ate complex-type catalysts

Methacrylonitrile was polymerized by a number of ate-complex catalysts. The catalysts used were NaAlR₄, LiAlR₄, LiZnR₃, Li₂ZnR₄, RMg[AlR₄], and Mg[AlR₄]₂. It was found that the ate-complex catalysts in which one of the alkyls is replaced by a diphenylamino group are capable of producing polymers with higher degrees of crystallinity than those of polymers obtained by unmodified catalysts. It was shown that the diphenylamide linkage in these catalytic systems must play an important role in the steric control in the propagation steps of this type of polymerization, although the mechanism is not clear at present. The crystallinity index used in this research gave a linear relation against I measured by NMR, and can be used as a measure of the stereo-regularity of the polymer.     

Dimension and entropy analysis of MEG time series from human α-rhythm

Magnetoencephalograms (MEG) from human brain were measured by means of a 37 channel SQUID magnetometer (KRENIKON). Correlation integrals were calculated from time series exhibiting strong -rhythm in order to give estimates of correlation dimension andK ₂ entropy. The results are discussed regarding the length and the stationarity of the data. It is shown that low spurious correlation dimensions andK ₂-entropies may easily be obtained as artefacts due to time correlations in phase space and data length. When time correlations are avoided and the length of time series is taken into account, estimates of correlation dimension andK ₂ entropy indicate no evidence of the existence of low dimensionality.     

Stereospecific polymerization of methacrylonitrile. V. Formation of the carbonyl in the polymer

The isotactic polymethacrylonitrile prepared by the organometallic catalysts has carbonyl groups in the polymer. Thus, the carbonyl formation during the polymerization by diethylmagnesium was carefully studied by infrared spectrometry. It was found that the imino anion formed by monomolecular termination of the propagating chain end in the cyclization reaction successively attacks the vicinal pendent nitriles in the polymer so as to form the conjugated cyclic imines, which are hydrolyzed to acid amines during the catalyst decomposition with acidic methanol.     

A Convergent Strategy for the Modification of Peptide Nucleic Acids: Novel Mismatch-Specific PNA-Hybridization Probes

Coupling of nonnatural nucleobases to the orthogonally protected backbone 1 on the solid phase provided access to novel peptide nucleic acid (PNA) conjugates 2 , which are difficult to synthesize by standard routes. Hybridization probes containing the thiazolorange dye might allow DNA sequence analysis in real time. B−CH₂CO=modified nucleobase, fluorescent dye, etc; Boc, Fmoc=protecting groups.     

The as-Grown SiC (0001) Surface as Observed by Reflection Electron Microscopy

Reflection electron microscopy (REM), capable of imaging surfaces in high resolution, reveals that the risers and treads in the terrace growth surfaces of vapor grown SiC(0001) bulk crystals are characterized on a microscopic scale by growth steps. At the risers microscopic growth occurs by the ‘step flow mode’. At the treads, growth occurs by island formation and by operation of growth spirals.     

Tuning and predicting biological affinity: aryl nitriles as cysteine protease inhibitors

A series of aryl nitrile-based ligands were prepared to investigate the effect of their electrophilicity on the affinity against the cysteine proteases rhodesain and human cathepsin L. Density functional theory calculations provided relative reactivities of the nitriles, enabling prediction of their biological affinity and cytotoxicity and a clear structure-activity relationship.