Three derivatives of 4‐fluoro‐5‐sulfonylisoquinoline

In 4‐fluoroisoquinoline‐5‐sulfonyl chloride, C₉H₅ClFNO₂S, (I), one of the two sulfonyl O atoms lies approximately on the isoquinoline plane as a result of minimizing the steric repulsion between the chlorosulfonyl group and the neighbouring F atom. In (S)‐(−)‐4‐fluoro‐N‐(1‐hydroxypropan‐2‐yl)isoquinoline‐5‐sulfonamide, C₁₂H₁₃FN₂O₃S, (II), there are two crystallographically independent molecules (Z′ = 2). The molecular conformations of these two molecules differ in that the amine group of one forms an intramolecular bifurcated hydrogen bond with the F and OH groups, whilst the other forms only a single intramolecular N—H...F hydrogen bond. The N—H...F hydrogen bonds correspond to weak coupling between the N(H) and ¹⁹F nuclei, observed in the ¹H NMR solution‐state spectra. In (S)‐(−)‐4‐[(4‐fluoroisoquinolin‐5‐yl)sulfonyl]‐3‐methyl‐1,4‐diazepan‐1‐ium chloride, C₁₅H₁₉FN₃O₂S⁺·Cl⁻, (III), the isoquinoline plane is slightly deformed, suggestive of a steric effect induced by the bulky substituent on the sulfonyl group.     

Chaotic oscillation in diffusion flame induced by radiative heat loss

We numerically investigate the dynamic behavior of flame front instability in a diffusion flame caused by radiative heat loss from the viewpoint of nonlinear dynamics. As the Damköhler number increases at a high activation temperature, the dynamic behavior of the flame front undergoes a significant transition from a steady-state to high-dimensional deterministic chaos through the period-doubling cascade process known as the Feigenbaum transition. The existence of high-dimensional chaos in flame dynamics is clearly demonstrated using a sophisticated nonlinear time series analysis technique based on chaos theory.     

Structure and total synthesis of chryscandin,a new antifungal antibiotic

The structure elucidation and total synthesis of chryscandin (1), a new antifungal antibiotic produced by $\text{Chrysosporium pannorum}$ No.4629, is reported.     

Indications of neutrino oscillation in a 250 km long-baseline experiment

The K2K experiment observes indications of neutrino oscillation: a reduction of nu(mu) flux together with a distortion of the energy spectrum. Fifty-six beam neutrino events are observed in Super-Kamiokande (SK), 250 km from the neutrino production point, with an expectation of 80.1(+6.2)(-5.4). Twenty-nine one ring mu-like events are used to reconstruct the neutrino energy spectrum, which is better matched to the expected spectrum with neutrino oscillation than without. The probability that the observed flux at SK is explained by statistical fluctuation without neutrino oscillation is less than 1%.     

Molecular doping in amorphous selenium

The transport properties of vacuum evaporated selenium doped with small quantities of atoms (Li, Ga, In, Cl, etc.), and compounds (LiCl, GaF₃, In₂O₃, etc.) are examined using time-of-flight technique. When doped with certain compounds (for example, GeO₂), electrons and holes show comlex transport behavior different from the compensation effect due to co-doping of the component atoms (Ge, O). This suggests that these compounds are taken into selenium in the “molecular form”.     

Equation of state based on the weeks-chandler-andersen perturbation theory

An equation of state based on the Weeks-Chandler-Andersen (WCA) perturbation theory utilizing the simplified random-phase approximation (RPA) term is p of state is applied successfully to calculate the P-V-T relationship for a spherical molecule, argon.For nonspherical molecules, the effects of anisotropic interactions are treated empirically. The calculated P-V-T relationships and saturated properties for nonspherical and nonpolar molecules agree well with experimental data. The potential parameters for nonpolar substances are well correlated with the acentric factors.     

Residual-stress measurement in SS304 seamless tube

This paper involves the experimental measurement of residual stresses in a nonwelded nuclear-grade 304 stainless-steel seamless tube subjected to one-sided quenching of its outside surface. Because this grade of tube is used extensively in nuclear power plants, the residual stresses measured are of interest to the nuclear industry. The Sach's boring method was used to obtain residual stresses. The longitudinal and tangential residual stresses at the inner wall were found to be 69 MPa to 138 MPa compressive. The results indicate that the residual-stress distribution would allow the tube to be highly resistant to the formation and propagation of stress-corrosion cracks.