Die vorliegende Arbeit untersucht Struktur und Mn-Wertigkeit von La0,7Sr0,3MnO3 (LSMO)/SrTiO3 (STO)-Dünnschichten, die mit außeraxialer gepulster Laserdeposition auf STO(0 0 1)-Substrat abgeschieden wurden. Aufgrund der hohen Spinpolarisation der Ladungsträger und der hohen Curie-Temperatur von LSMO sowie der geringen Gitterfehlpassung zwischen LSMO und STO erscheinen solche Dünnschichtsysteme interessant für magnetoresistive elektronische Bauelemente wie LSMO/STO/LSMO-Tunnelkontakte. Da das mit steigender Temperatur rasch abnehmende Magnetwiderstandsverhältnis derartiger Tunnelkontakte vor allem auf die atomistische Struktur der LSMO/STO-Grenz?fläche und den damit gekoppelten Ladungszustand der Mn-Ionen zurückgeht, stellt diese Arbeit eine hoch ortsaufgelöste Charakterisierung von Kristallstruktur und Mn-Wertigkeit mit im TEM aufgezeichneten Abbildungen und Elektronen-Energieverlust-Ionisationskanten vor. Der hinsichtlich des Einfl?usses auf die Qualität der Messdaten durchgeführte Vergleich verschiedener TEM-Präparationsverfahren zeigt, dass die konventionell ionengedünnten Querschnitte geringere Verbiegungen aufweisen als die mit fokussiertem Ionenstrahl präparierten und daher besser für die hochau?flösende TEM geeignet sind. Zur Quantifizierung der Mn-Wertigkeit werden die O-K- und Mn-L2,3-Nahkantenfeinstrukturen herangezogen, die sich in charakteristischer Weise mit dem Sr-Gehalt x und damit der Mn-Valenz in La1-xSrxMnO3 ändern. Hierbei reagieren die Kantenenergieabstandsmaße am empfindlichsten auf die Mn-Wertigkeit und ermöglichen eine Valenzbestimmung mit einer Genauigkeit von bis zu ?0,08. Die für das Innere der untersuchten LSMO-Schichten ermittelte Mn-Wertigkeit stimmt mit dem nominalen Wert von 3,3 überein, wohingegen an manchen LSMO/STO-Grenz?flächen zwischen Substrat und Schicht sowie zwischen den Schichten von Multilagen eine Reduktion um 0,1...0,2 zu beobachten ist. Dies kann auf eine La0,7Sr0,3O/TiO2-terminierte Grenz?fläche zurückgeführt werden und deutet darauf hin, dass sich die abschließenden Atomlagen messbar auf die grenzfl?ächennahe Mn-Wertigkeit auswirken. Weiterhin äußert sich der Ein?fluss der Grenz?fläche in dem Auftreten einer Schulter an der Flanke geringeren Energieverlusts der Mn-L3-Kante. Hierfür werden mögliche Ursachen wie Gitterdeformationen und Sauerstoffleerstellen diskutiert. Die geometrische Phasenanalyse von HRTEM-Aufnahmen und TEM-Hellfeldaufnahmen belegen eine tetragonale Verzerrung des LSMO-Schichtkristalls, der aus nadelförmigen Zwillingsdomänen besteht. Aus hochaufgelösten Raster-TEM-Abbildungen mit den unter großem Winkel gestreuten Elektronen geht hervor, dass die LSMO/STO-Grenz?flächen eine kohärente, gelegentlich mit Elementarzellenstufen versehene Gitterstruktur aufweisen. Insbesondere vermitteln die Stufen (Einfach- und Mehrfachstufen) die wellige Struktur der LSMO/STO-Multilagen. Schließlich wird gezeigt, dass die mit konvergenter Beugung bestimmte Fehlorientierung zwischen LSMO-Schicht und STO-Substrat bei geringer durchstrahlter Dicke der TEM-Lamelle die erwartete Netzebenenneigung der Zwillinge übersteigt. Dafür wird eine nachträgliche Relaxation der LSMO-Schicht während der Ionendünnung verantwortlich gemacht.

The rapid adaptation of insect species on environment changes can represent a significant advantage for their development and consequently a great negative effect for the stability of forest ecosystems. Larval individuals of Cabera pusaria and Lymantria dispar and adults of Melolontha hippocastani and Phillobius arborator is in general widely expanded species of herbivorous insects in European regions and with them are connected huge economic and ecological losses. The composition of food (biogenic elements, trace elements, heavy metals, proteins, carbohydrates etc.) is the main parameter of food quality. Laboratory experiment with natural diet (assimilation apparatus of Quercus petraea and Betula pendula) in control conditions (temperature, humidity, and light) were used for determination of insects’ reactions to increased concentration of manganese in the diet. Food was contaminated by soaking in solutions of MnCl2.4H2O with graded manganese concentrations. On the base of experiment design and character of reared experimental species we determined the food consumption, the activity period of adults, the mortality of larvae, the quantity of eggs laying, the dry mass and live weight of experimental individuals, concentrations of manganese in unconsumed food, excrement and lyophilized bodies, larval and pupal exuviae. Mentioned parameters were observed for determination of reactions of experimental insect species on changed food quality via the presence of high manganese contents. The results showed, that the reactions of individual experimental animals were very different. We observed the negative reaction to high manganese content in the diet of L. dispar larvae with the tendency of its compensation (the increasing food consumption rate and prolongation of development). Caterpillars of C. pusaria were very sensitive to changed food quality and therefore we observed high mortality. On the other side, the high manganese content in the diet of P. arborator in the laboratory conditions influenced neither their food intake nor their mortality. For individuals of M. hippocastani very high content of manganese in the diet significantly influenced the food consumption and thereby their development(distortion of copulation and consequent eggs laying). We observed the repellent effect of high levels of manganese in the diet. In all cases, the elimination mechanisms of surplus manganese in the diet were observed. Individuals in experiments exuded manganese through the digestive system into excrements and by incorporation of it into unspecified parts of their adult body without direct physiology activity or in exuviae of caterpillars.

Manganese (Mn) is an important element in soil, it occur natural in minerals and precipitated as Mn-oxides. Several factors could decide the solubility and mobility of Mn in soil water. In this study, the impact of road de-icing salts (NaCl) on manganese mobilization and transport to groundwater in roadside soils has been investigated by leaching tests. Generally, in the salt solution leachates, the water-soluble concentrations of Mn tended to increase with elevated salt concentrations, suggesting that ion exchange mainly affected the mobilization. The process was also attributed to the complexion with Cl. Associated with exchangeable concentration of Mn and soil properties such as pH and acidity, the mobilizations of Mn varied. Mn-oxides can dissolve when reduced condition exists, therefore the oxalate extractable Mn was extracted to estimate the change of redox potential condition in roadside soils. The redox potential of soil samples is higher in general. Redox condition has little effect on the Mn solubility and mobility in this research. Although groundwater samples indicated that only a few periods and sites were under threaten of elevated concentrations of manganese, there is still great risk of transport of high water-soluble concentrations of Mn in roadside soils to groundwater, especially the areas exposed to de-icing salts. In addition, lower value of Mn concentrations in groundwater for considering good drinking water quality for the well-being of children should be paid more attention to.

There are many kinds of elements, especially heavy metallic elements, presentin the industrial slags. These elements bring big environmental problems ifthey are directly used in land filling. And the recovery of these elements canalso have benefits for the resource conservation. This paper reports the use ofelectrochemical method to extract the metal elements from both industrial slagand pure oxide. The mixture of NaCl-KCl was used as the electrolyte for thisprocess. Some proposals are alsomentioned for the further work.

Domain wall dynamics is the one of the most interesting topics in the field of Spintronics because of its potential applications in the development of memory devices. These studies of dynamics are particularly focused on dilute magnetic semiconductors (DMS) or ferromagnetic semiconductors, which are believed to be one of the future materials for Spintronics devices. Despite the fact that the Curie temperature of these DMS is still lower than room temperature the knowledge gained in this study can be applicable to other DMS systems and will unravel new phenomena for the dynamic behavior of domain walls. In this work the dynamic behavior of magnetic domain walls in (Ga, Mn) (As, P) nanometric layers was studied. This was achieved with the use of longitudinal Kerr microscopy working at cryogenic temperature. The domain wall displacements were measured with the application of high enough magnetic fields for very short durations at two different temperatures. These magnetic fields were applied with the help of homemade microcoils used for the first time in this kind of study on DMS. A comparison is shown with the previous results obtained on the same material with a different magnetic anisotropy. The results show very high domain wall velocities for this type of material, not reported previously. The velocity curves clearly show two distinct regions with different mobilities. Finally quantitative analyses are presented to explain these velocities.

Als Prüfung auf das genotoxische Potenzial einer Substanz ist die Entstehung von Micronuclei in proliferierendem Gewebe als genetischer Endpunkt wissenschaftlich und behördlich anerkannt. Zugrunde liegendes Experimentalmodell für diesen Test sind zumeist Mäuse und Ratten, deren Knochenmark das Zielgewebe dieses Tests darstellt. Dieses Testmodell geht mit dem Tod der verwendeten Tiere einher. Die vorliegende Arbeit greift den von Wolf & Lüpke (1997) sowie Wolf (1999) vorgestellten HET-MN (Hen’s Egg Test for MicroNucleus induction) auf, der angebrütete Hühnereier als Experimentalmodell verwendet (Bebrütungsdauer 11 Tage, d11). Zielorgan ist das periphere Blut der extraembryonalen Membranen. Das entnommene Blut wurde nach modifizierten hämatologischen Standard-verfahren angefärbt und die Zellen im Hellfeld-Durchlicht-Mikroskop bei 1000-facher Vergrößerung ausgezählt. Anhand der nucleosidanalogen Reverse Transkriptase Hemmer Zidovudin, Stavudin, Zalcitabin, Lamivudin und Didanosin fand ein Abgleich mit den durch Tierversuche gewonnenen Daten statt. In den versuchsreihen zu Zidovudin, Stavudin Zalcitabin, Didanosin und in den Kombinationsversuchen mit Zidovudin und Didanosin konnten die Daten aus der Literatur reproduzierbar bestätigt werden; wobei der HET-MN sensitiver reagierte als das Testmodell am Tier. Für Lamivudin konnte reproduzierbar eine biologisch und statistisch relevante, dosisabhängige Erhöhung der Micronucleusfrequenz erzielt werden. Damit steht der HET-MN in Kontrast zu den in der Literatur verfügbaren Informationen. Die im HET-MN gewonnenen Daten ließen in allen Versuchsreihen auf vergleichbare oder höhere Sensitivität als im Micronucleustest an Nagern schließen. Damit stellt der HET-MN eine kostengünstige und methodisch leicht durchführbare Alternative zum Tierversuch dar und wird trotz seiner hohen Komplexität und den damit verbundenen in-vivo-ähnlichen Bedingungen allen Belangen des Tierschutzes gerecht.

京都大学 / 0048 / 新制・課程博士 / 博士(エネルギー科学) / 甲第17912号 / エネ博第284号 / 新制||エネ||59(附属図書館) / 30732 / 京都大学大学院エネルギー科学研究科エネルギー基礎科学専攻 / (主査)教授 八尾 健, 教授 森井 孝, 教授 佐川 尚 / 学位規則第4条第1項該当 / Doctor of Energy Science / Kyoto University / DGAM

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We are living in a world of steel. Although there are a lot of other material in use, our most used material is steel. From building industry to transportation and even mother industries like mining, we use steel in different grades and amounts. There is always need for different grades of steel, and there is always interest in better properties and lower costs. Fe-Mn-Al-C steel group is one of the grades of steel is from the TWIP family. Beside its interesting mechanical properties, its corrosion resistance and cryogenic properties makes it very desirable to substitute more expensive current classes of the steel used in the industry. The automobile industry is also looking forward to implement this family of the steel in their products. This group of steel based on their chemical content can created a carbide ordered phase called κ which is one of the reasons of its interesting mechanical properties beside the TWIP properties. While κ may give more hardness due to precipitation hardening, it will make the steel brittle. Thus we need an understanding of the phase diagram of this group of the steels in order to choose our material and process accordingly. Phase diagrams are material engineers’ road maps for the processes and material choice as the initial steps, since we can predict the processes results and stable phases based on the equilibrium state from the diagrams. As the number of components gets more than three the phase diagram calculations and determination gets harder. For the ternary alloying systems we can only show sections of the phase diagrams as isothermal sections, or consider an element constant and depict the diagram as a “binary” system for the other two alloying elements at the other element concentration. In this work, we tried to experiment on the experimental data for equilibrium phases of Fe-Mn-Al-C alloying system based on the Equilibrated Alloys for alloys containing 20, 30 and 40 weight percent Manganese. The results were compared to the current database of the Thermo-Calc software for this family and we found some inconsistencies between the experimental data and the calculations which shows that the calculated results for this alloying system with its high Mn-content, is not reliable and that the thermodynamic descriptions must be adjusted. / PrecHiMn (RFSR-CT-2010-00018)

The Proterozoic syn-orogenic supra-crustal package exposed in the Tusas Mountain Range in northern New Mexico includes the anomalously thick, clean, ultramature Ortega Formation quartzite (Bauer and Williams, 1989). A unique Mn-bearing horizon spans the basal contact of the quartzite and contains Mn-andalusite, quartz, hematite, rutile, zircon, monazite, phyllosilicates, and locally kyanite and gahnite in intermittent aluminous, hematite-bearing layers, on the surface of cross-beds, concentrated in high strain zones, and on cleavage planes. Large-scale Mn zoning in Mn-andalusite results from a decrease in Mn content away from localized Mn highs (XMn of up to 0.76) that commonly correspond with the location of high-Mn core regions. High Mn core regions are included in Mn-andalusite, preserve some of the earliest fabrics, and are associated with sedimentary structures (i.e. cross beds and graded beds). Both hematite and rutile from the Mn horizon are rich in trace elements, and hematite contains zones of rutile mineralization that create patchy/mottled, wormy, cross-hatched, and/or banded textures within the hematite that could be linked with oxidation-exsolution textures in ilmenite and spinel. The Mn horizon may be a result of (1) the formation of an Fe-Mn oxyhydroxide crust through extensive lateritic weathering of the metavolcanic units and/or (2) the chemical deposition of Fe and Mn phases in an oxygen stratified enriched basin environment. Mn-andalusite preserves subtle textures in the Mn distribution and interference colors of the birefringence that can be used to understand mineral replacement and microstructural relationships in otherwise an well-annealed quartzite. A feathery texture that resembles the vi crystal habit of a phyllosilicate, such as pyrophyllite, locally preserves crenulation cleavages. High-Mn halos around kyanite and localized areas of low Mn content in Mn-andalusite that mimic crystal shapes together represent areas of kyanite replacement. The general tectonic histories preserved in the Mn-andalusite layer of the Hopewell Lake-Jawbone Mountain area, Quartzite Peak, and Kiowa Mountain of the Tusas Mountains include the growth of an M1 mineral assemblage in association with D1 (kyanite and/or pyrophyllite), the growth of an M2 assemblage post-D2 (kyanite and/or Mn-andalusite), and the growth of an M3 assemblage syn-D3 (a second generation of kyanite and/or Mn-andalusite). In the Hopewell Lake-Jawbone Mountain region, Mn-andalusite of the Hopewell anticline preserves phyllosilicate defined crenulation cleavages while the Jawbone syncline is dominated by a history of only kyanite growth suggesting a metamorphic divide between the anticline and syncline that could be a result of the movement along a late-stage D3 fault at or near Route 64. At Kiowa Mountain, high-Mn halos and low Mn regions suggest that Mn-andalusite replaced kyanite when changing P-T conditions during M2 lead to an Mn-andalusite-only M2 assemblage. Textures preserved in the Mn-distribution and interference colors of Mnandalusite are an essential tool for understanding the structural and metamorphic histories of the Mn horizon and the Ortega Formation quartzite.