A synthetic approach to macromolecules of acetylenic arrays and luminescent properties is proposed and the execution of initial steps is described. Palladium-catalyzed coupling of 1,3,5-triiodobenzene with trimethylsilylbuta-1,3-diyne, trimethylsilylocta-1,3,5,7-tetrayne, and trimethylsilylhexadeca-1,3,5,7,9,11,13,15-octayne to yield the new 1,3,5-tris(trimethylsilylbuta-1,3-diynyl)benzene and the proposed 1,3,5-tris(8-(trimethylsilyl)octa-1,3,5,7-tetraynyl)benzene and 1,3,5-tris(trimethylsilyl)hexadeca-1,3,5,7,9,11,13,15-octaynyl)benzene respectively. The proposed three-coordinate Au (I) complexed macromolecules will be derived from the metallation of the aforementioned alkynylated arenes.

This diploma thesis is focused on comparison of plasma and oxygen - acetylene cutting. A literature review of this issue is included in the work. For technological - economic evaluation, there were proposed a sample part to assess how optimal the cutting process is. Observed resulst and there comparison are stated in conclusion.

In situ assays of N2 fixation activity, using the acetylene reduction technique, were performed in four successional stages of a Northern Wasatch Mountain subalpine forest ecosystem, elevation 2,800 m. Emphasis was made on rhizosphere fixation in association with Antennaria microphylla and Achillea millefolium. The vegetation period was approximately 100 days. Assays were performed in Saran bags. A defined amount of propane was injected at initiation of the assay and acetylene was generated from CaC2. Samples were analyzed for ethylene and propane. Data were evaluated assuming that the ethylene production was directly proportional to the increase in the ratio of ethylene to propane in the samples. Input of N by soil free-living N2 fixers in the meadow, the aspen, the fir and the spruce was 0.5, 0.3, 0.2 and 0.3 kg N ha-1 y-1, respectively. A higher activity in the presence of plant, as compared to the soil activity, was measured in 10 of the 16 assays, however, the increase was significant at three testings only. This might indicate a contribution by rhizosphere N2 fixation, but to an extent lower than was expected and therefore not detectable with the method used Leakage of gases from the test device was not corrected for in the method used for evaluation of data. This introduces and overestimation of the obtained activities that increases exponentially with a more rapid effusion rate. Correction for effusion from a closed device can be made provided quantitative analyses of the tracer gas. To determine a small difference between enclosures with and without plants the accuracies in the effusion rates must be high. Quantitative analyses were not required for evaluation according to the method used and therefore, the obtained effusion rates have too wide standard deviations for correction of the effusion rate. It was shown that the determined effusion rates with corresponding standard deviations might obscure a low rhizosphere N2 fixation activity. Acetylene reduction assays performed in open devices can not easily be corrected for diffusion of gases. The initial very rapid diffusion from an open device leads to a vastly overestimated acetylene reduction activity, when the diffusion is not corrected for.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第18290号 / 工博第3882号 / 新制||工||1596(附属図書館) / 31148 / 京都大学大学院工学研究科高分子化学専攻 / (主査)教授 秋吉 一成, 教授 澤本 光男, 教授 松原 誠二郎 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

The work describes the preparation of some acetylene complexes of nickel, palladium and platinum. The structure of and the bonding in these complexes is discussed in the light of their infrared and nuclear magnetic resonance spectra. Some reactions of the complexes are described. / Thesis / Master of Science (MSc)

No description available.

No description available.

No description available.

No description available.

A nearly stoichiometric, (1×1) Cr₂O₃ (101̲2) surface was prepared from a single crystal of α-Cr₂O₃. The five-coordinate cations exposed at the stoichiometric surface dissociatively adsorb molecular oxygen to form a (1×1), terminating chromyl (Cr=O) layer that is stable to >1100 K. TDS and AES were used to investigate the reactivity of the halo-alkanes CFCl₂CH₂Cl, CF₂ClCH₂Cl, CF₃CH₂Cl, and CF₂CH₂F, in addition to the halo-alkenes CFCl=CH₂ and CF₂=CH₂. The halo-alkanes CFCl₂CH₂Cl, CF₂ClCH₂Cl, and CF₃CH₂Cl undergo 1,2-dihalo elimination similar to the Zn-catalyzed dehalogenation of vicinal dihalides to form alkenes. Some acetylene is also formed. The halo-alkenes CFCl=CH₂ and CF₂=CH₂ decompose to yield acetylene. Halogen removed from the molecules remains bound to the surface following TDS experiments and eventually terminates the surface chemistry due to site blocking of the cations. Reactivity is directly related to the chlorine content of the molecules investigated. Only CFCl₂CH₂Cl was reactive on a chromyl-terminated surface. / Ph. D.