Overlapping chemical and genetic diversity in Ligularia lamarum and Ligularia subspicata. Isolation of ten new eremophilanes and a new seco-bakkane compound

Root chemicals and DNA sequences were analyzed for Ligularialamarum samples collected in Yunnan and Sichuan Provinces of China and the relationship between the plant and Ligulariasubspicata, its taxonomically closest species, was examined. Both species produce furanoeremophilanes and eremophilan-8-one derivatives as the major components. Eleven new compounds, including a new seco-bakkane compound, were isolated. The two species were found to harbor overlapping intra-specific diversities with respect to the chemicals and the DNA sequences.     

Molecular Structure and Dimerization of d-Cycloserine in the Solid State

d-cycloserine (CS) is transformed into cis-3, 6-bis(aminooxymethyl)-2, 5-piperazinedione (CS-dimer) in the solid state under a humid atmosphere. This dimerization process was followed by measuring the IR bands characteristic of CS and CS-dimer. The reaction was accelerated by the presence of increased water vapor. The X-ray analysis of CS monohydrate (CS · H₂O) revealed that the CS molecules exist as a zwitter ion where the α-amino N atom is protonated and the amide N atom is deprotonated in the crystal. Participation of water molecules was suggested in the dimerization of CS.     

Translocation of cesium in the branches of Japanese cedar (Cryptomeria japonica) and Konara oak (Quercus serrata)

Journal of Radioanalytical and Nuclear Chemistry - 133CsCl solution was applied to the foliage of Japanese cedar (Cryptomeria japonica) and Konara oak (Quercus serrata) under field conditions to...     

Development of dry polymer electrolyte based on polyethylene oxide with co-bridging agent crosslinked by electron beam

Polyethylene oxide (PEO)-based electrolytes were crosslinked using electron beam (EB) irradiation. The gel contents of a polymer film were increased after irradiation doses of 0, 140, 280, and 420 kGy, with ionic conductivities of 0.831, 1.55, 6.08, and 7.95 (× 10^? 5) S cm^? 1 at 40 °C, respectively. The slight decrease in conductivity at higher temperatures after irradiation is due to the retardation of polymer motion by crosslinking. The electrolyte with higher EB dose amount exhibits higher conductivity due to stabilization of the amorphous state. The EB crosslinking with a co-bridging agent shows enhanced conductivities of 4.71, 6.59, and 7.18 (× 10^? 5) S cm^? 1 at 40 °C, after irradiation with 140, 280, and 420 kGy. Addition of the co-bridging agent is effective for developing a crosslinked structure with a smaller EB dose. Tensile strength becomes two to three times higher with irradiation compared to the non-treated polymer. Combination of the EB technique with a co-bridging agent is a simple and effective method to prepare strong dry polymer electrolyte films with improved room temperature conductivity.     

Conversion electron Mössbauer spectroscopic study of YIG substituted with Bi,Ti, Ga and La

YIG films, substituted with Bi, Ti, Ga and La, were grown on a (111) plane of Gd₃Ga₅O₁₂ or (Gd, Ca)₃(Ga, Mg, Zr)₅O₁₂ by a liquid phase epitaxial method. With the increase of the concentration of Bi atoms, which are substituted at 24c sites of YIG, the magnetic hyperfine fields at 16a and 24d Fe sites increased and the direction of magnetic moments changed from parallel to 45° to the (111) plane. With the increase of Ga concentration, the hyperfine fields at 16a and 24d Fe sites decreased. The hyperfine interaction and the substitution effect of YIG films are discussed.     

Droplet combustion experiments in varying forced convection using microgravity environment

A new microscopic model of the interaction between droplet flames and fine vortex tubes which compose a coherent structure of turbulence was developed. Three non-dimensional numbers were introduced to extend the length scale and time scale so as to be suitable for microgravity experiments using droplets of combustion of about 1 mm in diameter. An experimental apparatus for combustion of a single droplet and that of an array of two droplets in varying airflow was developed, and experiments were performed in microgravity and normal gravity at pressures up to 2.0 MPa for n-nonane and ethanol as fuels. Variations of the instantaneous burning rate constant, K_i, in response to the varying flow velocity was successfully observed. At high pressure, the effects of droplet Reynolds number Re on K_i was clearly seen, while the effects of natural convection, which increases K_i with Re, was seen in normal gravity even in the forced airflows. As for the experiments on combustion of an array of two droplets, K_i reduction of the downstream droplet became weak when the flow direction was varied. However, the K_i reduction of the downstream droplet for flow direction variations was clearly seen for n-nonane droplets but almost not for ethanol droplets. The interaction mechanism between upstream and downstream droplets is considered to result from the elimination of oxidizer supply to the downstream droplet, indicating strong interaction effects of n-nonane droplets for a stoichiometric oxygen-fuel ratio of n-nonane (i.e., 14.0) greater than that of ethanol (i.e., 3.0).