Electron cyclotron heating in high density toroidal plasmas

Wave trajectories of the ordinary mode as well as the extraordinary one injected obliquely into a magnetic field in high density toroidal plasmas, are studied theoretically. Both waves are finally converted into the electron Bernstein mode and cyclotron damped.     

Dynamic light scattering of polystyrene single chains in a semidilute solution of poly(methyl methacrylate) and benzene

Translational diffusion and internal motion have been observed by dynamic light scattering of optically labeled single chains of polystyrene (PS) in a semidilute solution of poly(methyl methacrylate) and benzene for the case in which the dimension R_g of the PS chain is comparable to the correlation length of the matrix solution. The molecular weight M_w dependence of the hydrodynamic radius R_h is expressed as R_h ～ M, while R_h ～ M in pure benzene. The average linewidth Γ for internal motions (KR_g > 1) appears to depend on the magnitude K of the scattering vector approximately as Γ ∝ K⁴ at higher KR_g ( > 1), in contrast with the fact that Γ ∝ K³ approximately for KR_g > 1 in pure benzene. The scaling law for the K dependence of Γ does not hold in low-molecular-weight PS owing to the K dependence of Γ /K² for KR_g < 1.     

Anion-exchange separation of rhodium and iridium by ECTEOLA-cellulose column

Summary The separation of Rh(III) and Ir(IV) in amounts of 20–5300 and 20–7700 g, respectively, and in ratios of RhIr=1100 to 1001 was achieved without cross-contamination by use of a 3 g ECTEOLA-cellulose column. Rh was first eluted with 40 ml of a 3 mol/l HCl-1% (w/v) NaClO₃ solution. Ir(IV) was desorbed with 60 ml of a 6 mol/l HCl-0.1% (w/v) NaClO₃ solution. Quantitative recoveries were obtained for each metal. The present method provides much better resolution than the other existing anion-exchange methods and can effectively be applied to the separations and recoveries of Rh and Ir(III or IV) present in a more extensive range of amounts and ratios.

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Anionenaustausch-Trennung von Rhodium und Iridium mit Hilfe einer ECTEOLA-Cellulose-Säule

     

Configurational studies on amylose. I. Scattering functions

Scattering functions for amylose chains have been calculated as a statistical mechanical average over eligible configurations based on the rotational isomeric state approximation. Main emphasis has been placed on an intermediate-angle range (0.1 < h = (4π/γ)sinθ < 1.0 Å^?1) where the scattering function is sensitive to local chain configurations. In order to avoid overestimation of the regularity of chain configurations, the rotational isomeric states for each glycosidic bond have been defined by a set of discrete torsion angles at intervals of 5°. Pair correlation functions for atoms separated by sequences shorter than 31 glucose units are evaluated by the Monte Carlo method, while the interference for longer sequences is calculated by a series expansion in the even moments of the chain. All carbons and all skeletal oxygens are treated as point scatterers in order to incorporate all the interferences between atoms in unit pairs in the calculations. The calculated scattering function shows appreciable oscillation at intermediate angles, reflecting the characteristic helical tendency of the configurations. The Debye function is found to be inadequate in the intermediate-angle region owing to the non-Gaussian character of the distribution function and to breakdown of the assumption that the mean-square distance between a pair of atoms is proportional to the number of bonds between them, because of the bulkiness of the glucose unit.     

New methods and reagents in organic synthesis. 55. Total syntheses of patellamides B and C,cytotoxic cyclic peptides from a tunicate 1. Their proposed structures should be corrected.

Patellamides B and C, cytotoxic lipophilic cyclic peptides from a marine tunicate, with proposed structures have been synthesized by the use of diphenyl phosphorazidate(DPPA) and diethyl phosphorocyanidate(DEPC). Their physicochemical properties lead to reassign the structures of patellamides B and C on the bonding order.     

Depinning line of granular YBa2Cu3O7?δ measured with vibrating-reed method

The depinning temperatures in YBa₂Cu₃O_7−δ ceramics and grains have been studied at magnetic field up to 4 T and various amplitudes of vibration. For ceramics sample, large amplitude dependence of depinning temperature T_D was observed, which indicate the decoupling of grains. In the case of a suspension sample (grain), T_D was much lower than that of ceramics.     

Force fields of allylamine conformers as studied by an ab initio calculation and infrared spectroscopy

The quadratic force constants of the five possible conformers of allylamine were calculated by an ab initio MC method. The infrared spectra of this molecule in the gas phase were remeasured and analyzed on the basis of the calculated vibrational frequencies. A potential energy surface with respect to the skeletal torsions was also calculated. The relative abundances of the S⁺G⁺, ST, CT, CG, and S⁺G^? conformers, predicted to be 44:32:16:7:1 at room temperature, are consistent with the experimental data.