The dislocation structure evolution of polycrystalline copper at constant strain amplitude during low cycle fatigue develops loop patches, vein structure, persistent slip bands, dislocation walls, dislocation cells, and cells with misorientation dislocation step-by-step by increasing fatigue cycles. However, the dislocation structure evolution will change in low cycle fatigue under reduced loading amplitude. The polycrystalline copper of 99.99 at% purity and 60µm in grain size was used in the low cycle fatigue test. First, the test is controlled at £G£`/2= ¡Ó0.4%, ¡Ó0.2%, and ¡Ó0.1% strain amplitude until the specimens crack. And control the fatigue test after 2500 cycles at ¡Ó0.4% strain amplitude. Then we can observe the dislocation structure of above specimens by electron microscope. After 2500 cycles at ¡Ó0.4% strain amplitude, change the strain amplitude from ¡Ó0.4% to ¡Ó0.2%. We chose the steps of low cycle fatigue test under reduced loading amplitude at 1000, 10000, and 30000 cycles. By the same token, change the strain amplitude from ¡Ó0.4% to ¡Ó0.2%. We chose the steps of low cycle fatigue test under reduced loading amplitude at 1000, and 50000 cycles. Then observe the dislocation structure of above specimens by electron microscope, and we can know the dislocation morphology of evolution process under reduced loading amplitude. After 2500 cycles at ¡Ó0.4% strain amplitude, change the strain amplitude from ¡Ó0.4% to ¡Ó0.2% and from ¡Ó0.4% to ¡Ó0.1%. After 1000 cycles, the dislocation wall can be observed at grain boundary. After 10000 cycles under changed loading amplitude from ¡Ó0.4% to ¡Ó0.2%, we can observe that the dislocation cells are broken and evolve loop patches. And after 50000 cycles under changed loading amplitude from ¡Ó0.4% to ¡Ó0.1%, large area of dislocation walls and some loop patches can be observed.

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Abstract The objective of this study is to compare the performance over copper oxide catalyst under nonselective catalytic reduction of nitric oxide with methane and selective catalytic reduction of nitric oxide with propane. The copper catalysts was prepared by impregnating the support Al2O3 with copper nitrate. In order to find the favorable kind and concentration of acid solution¡Awe conducted the modification of three acid solutions on the support Al2O3 in the same normal concentration in the first¡Aand followed by the test of various concentration of the most-favoured acid. The experiment operated condition was as follow¡G reaction temperature 623K-1023K¡AF/W¡×108000ml/hr.g¡Aoxygen concentration 2¢M¡ANOx inlet concentration 1000ppm. In view of the result of NSCR reactions with methane over Cu/£^-Al2O3 catalyst¡Athe conversion of De-NOx increased with the increasing loading of copper on Cu/£^-Al2O3¡Aand achieved a max. value when copper loading was 8¢Mwt.. The performance of De-NOx over the modified copper catalysts three different acid with the same normal concentraion¡Ashowed that the best reduction efficiency was with nitric acid modified¡Athen with¡Aand followed with acetic acid¡Aphosphoric acids. Through compared the conversion of De-NOx between non-modified Cu/£^-Al2O3 with modified Cu/£^-Al2O3¡Athere had the best efficiency in treating for NO conversion. It showed that the best efficiency in raising the conversion of NO over copper catalyst is modified with nitric acid¡Athere is not helpful on reduction efficiency of NO by modification with acetic and phosphatic acids. Nevertheless¡Athe higher concentration¡]N¡^ of nitric acid is¡Athe higher efficiency of De-NO is¡F For the SCR reactions with propane, when the inlet concentraion NO/C3H8 was 1¡Athere has better reductive activity. The trends for the NO conversion versus reaction temperature were similar for the same catalysts used. In general, the NO conversion was an increasing function of copper loading for these copper catalysts. The 8¢Mwt. Cu/£^-Al2O3 was found to enhance the NO conversion. The activity of acid-treated catalysts in nitric acid with 2¢MO2 present had the best NO conversion, while the same order was in NSCR reaction. Treating the supports with a higher concentration of acid would result in a higher activity for the copper catalyst, implying that acid treatment not only duces surface area to decrease on catalyst and enhance the reactivity, but also the presence of Cu+ and Cu2+ might be responsible for the reaction efficiency. no matter what the reactant is propane or methan , propane is better reactant to catalyst NO to N2.

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Abstract The dislocation structure evolution of polycrystalline copper at constant strain amplitude during low cycle fatigue has been studied sufficiently. The dislocation structure develops loop patches, vein structure, persistent slip bands (PSBs), dislocation walls, dislocation cells, and misorientation dislocation cells step-by-step by increasing fatigue cycles. However, the dislocation structure evolution will change as the strain amplitude decreasing from high to low. In order to realize that the dislocation structure of polycrystalline copper how to evolve with reducing strain amplitude during low cycle fatigue, I use the copper of 99.99% purity in this experiment. The test is controlled 4¡Ñ103 cycles at 0.2% strain amplitude, and the strain amplitude is decreased from 0.2% to 0.1%. It keeps the 0.1% strain amplitude after 4¡Ñ103 cycles. I chose the four steps of the low cycle fatigue at 5¡Ñ103 , 9¡Ñ103, 15¡Ñ103 cycles, and the specimen cracking then observe the dislocation structure. Then we can know the dislocation morphology under evolution process after decreasing the strain amplitude. From the fatigue tests data by dropping the strain amplitude we can see the dislocation cells fast creaking to loop patches at 5¡Ñ103 cycles; The dislocation cells scatter and become vein structure with loop patches like a band at 9¡Ñ103 cycles. To observe clearly that the scattering loop patches normal develop dislocation walls near the grain boundary at 15¡Ñ103 cycles; At last, all of the dislocations form dislocation cells again and progress misorientation when becoming equiaxis cell. The morphology is between 0.2% strain amplitude and 0.1% strain amplitude. So we can understand the process of dislocation reverse evolution is the dislocation cells diffusing to bands. Then the bands creak to loop patches.

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The active center of copper proteins can divide into Type I, Type II and Type III categories according to their copper coordinated environment. The synthesis and characterization of thiol ligands, NSC2SN(1c): N1,N2-bis(2-mercaptoethyl)-N1,N2-bis-(2-pyridinylmethyl)- 1,2-ethanediamine and NSC4SN(1d): N1,N4-bis(2-mercaptoethyl)-N1,N4- bis(2-pyridinylmethyl)-1,4-butane-diamine to mimic that active center of copper proteins are described. Those new types of ligands (1c and 1d) react with [Cu(CH3CN)4]ClO4 afford the mononuclear copper complexes. On the other hand, the synthesis of the known tripodal ligand TNPA(4b): 2,2¡¦2,¡¨-nitrilotris(N-(pyridine-2-yl)acetamide) and new tripodal ligand TNPMA(4c): 2,2¡¦2¡¨-nitrilotris(N-(pyridin-2-ylmethyl)acetamide) are also characterized. The reactivity of [Cu(CH3CN)4]BF4 of two tripodal ligands are described.

The mechanical properties and the deformation mechanism of Cu single crystal metal and bi-crystal Cu metals are explored by the molecular statics simulations for the nanoindentation and nanoscratching process. In the simulation of nanoindentation, the relationship of load, influenced depth and displacement are obtained to investigate the deformation mechanism of Cu metals. The variations of averaged bond length are used to understand condition of atoms deformation. For the nanoindentation on two single crystal surfaces, our results indicate that the influenced depths can be affected by the tip indentation and the motion of dislocations. In the case of the bi-crystal system, because the interfaces between two crystal orientations can provide the resistance to the motions of dislocation, the influenced depths can be affected by the existence of the interface. Eventually, the variations of averaged bond length are also used to explore the structural deformation under the different nanoindentation depths and nanoscratching distances during the nanoscratching process. Moreover, the deformation mechanism during nanoindentation and nanoscratching process are also discussed in this article.

Thesis (Ph. D.)--University of Queensland, 2002. / Includes bibliographical references.