A mild method for the conversion of proipiolic esters to β-keto esters. application to the formal total synthesis of (±)-thienamycin

An extremely mild method for the transformation of propiolic esters to β-keto esters via thiol addition is reported, including its successful application to the synthesis of (±)-thienamycin.     

Spin of leading clusters and slope of the overlap function

It is pointed out that the spin structure of leading clusters appearing in the final state of inelastic collisions at high energies influences strongly the estimate of the slope of the overlap function. It is also argued that this effect may drastically improve the agreement with experimental data.     

Structure of ophiorines A and B; novel type gluco indole alkaloids isolated from ophiorrhiza spp.

Two novel type gluco indole alkaloids, ophiorines A and B, were found in Rubiaceous plants, Ophiorrhiza japonica B1. and O. kuroiwai Mak., and their structures were elucidated by chemical and spectroscopical methods.     

57Fe Mössbauer study YBa2Cu3−xFexO7−y

Mössbauer measurement is made on the system YBa₂Cu_3?xFe_xO_7?y (0.03≤x≤1.0) at various temperatures. It is found that the sites occupied by Fe ions can be classified into major two and minor one groups. The isomer shifts for the major two groups are nearly zero relative to metallic iron, and their quadrupole splittings are large (about 1.9 and 1.1 mm/s). By comparison of the spectra measured before and after a heat-treatment in vacuum, it is concluded that the Fe ions with the largest quadrupole splitting occupy the pyramidal sites, and the other the planer sites. Two different hyperfine magnetic fields (240 and 442 k0e) are observed at 1.7 K for the specimen with x=0.2. It is proposed that the valence states of Fe ions of the major two groups are pentavalent.     

Continuous versions of an inequality due to Hoffman and Wielandt

Two continuous versions of a celebrated inequality due to Hoffman and Wielandt are obtained as a consequence of an inequality due to Horn and Weyl's majorant theorem.     

Numerical analysis of trajectories of a quantum particle in two-slit experiment

It is well known that the concept of a trajectory of a quantum particle is itself nonsense in the so-called Copenhagen interpretation. However, if the interpretation proposed by Ishikawa [International Journal of Theoretical Physics,30(4), 401 (1991)] can be accepted in quantum mechanics, the trajectory of a quantum particle is significant (though it includes errors). In this paper we numerically analyze discrete trajectories of a quantum particle in a two-slit experiment under this new interpretation.