Im Rahmen dieser Arbeit wurde die Kontrastbildung in der Rasterkraftmikroskopie im Kontaktmodus und im dynamischen Modus analysiert. Kontaktmodus Die Abbildungsprozesse im Kontaktmodus wurden anhand der Au (111) 22 (± 1) x Ö 3 - Oberfläche untersucht. Messungen an Terrassen zeigen, dass die rasternde Spitze Material transportiert. Die Transportrichtung wird durch die Lage der 22 (± 1) x Ö 3 - Überstruktur bezüglich der Rasterrichung vorgegeben. Die Struktur der Goldoberfläche beeinflusst die Reibung, die aus der Lateralkraft bestimmt wird. Auf glatten Terrassen wurde eine deutlich größere Lateralkraft gemessen als auf rauhen. Bisher konnte nur der Spitzenradius in Rasterrichtung abgeschätzt werden, indem über Stufenkanten gerastert wurde und die Stufenbreite im Linienprofil ausgemessen wurde. Die eigentliche Kontaktfläche zwischen Spitze und Probe ist dadurch nicht zugänglich. Hier hat sich die Verwendung der langreichweitigen Überstruktur als vorteilhaft erwiesen. Aus den unterschiedlichen Abbildungen der Überstruktur wurden Informationen über den Einfluss und die Größe der Kontaktfläche gewonnen. Erstmals konnte im UHV die atomare Struktur einer Metalloberfläche reproduziert werden. Weder eine Schichtung der abzubildenden Proben, noch ein Wasserfilm zwischen Spitze und Probenoberfläche ist Voraussetzung zur Abbildung der atomaren Struktur. Die bei den Abbildungen gefundenen Überhöhungen der atomaren Korrugation ist zum einen auf einen stick slip und buckling Prozess zwischen Spitze und Probe zurückzuführen, wie dies bereits für HOPG und Mica gefunden wurde. Zum anderen wird die "giant corrugation" durch die Kopplung von Normal- und Torsionsverbiegung der Blattfeder verstärkt. Der Spitze - Probe - Kontakt stabilisiert sich, indem die Spitze beim Rastern Gold aufnimmt. Dies zeigen Z (V) - Kurven, in denen sich die Kontaktspannung zwischen Spitze und Probe vor und nach den Messungen um bis zu 1 V von ca. 1,2 V auf 0,3 V verringerte. Durch Messungen an der Au (110) - Oberfläche konnte gezeigt werden, dass auch eine anisotrope Oberflächenstruktur durch die Rasterkraftmikroskopie im Kontaktmodus im atomaren Maßstab abgebildet werden kann. Eine hohe Symmetrie der Oberfläche ist, entgegen den bisherigen Annahmen keine zwingende Vorraussetzung für die Reproduktion der atomaren Struktur einer Oberfläche. Strukturen mit großem Unterschied in den Gitterabständen, wie z.B. C60 - Inseln auf einem Cu (111) - Substrat, konnten nacheinander in ihrer atomaren Struktur abgebildet werden. Eine gleichzeitige Abbildung gelang nicht. Vermutlich muss die Spitze immer mit dem Material bedeckt sein, dessen Struktur gerade reproduziert werden soll. Dynamischer Modus Die Wechselwirkungsmechanismen zwischen Spitze und Probe im dynamischen Modus wurden an der Au (111) 22 (± 1) x Ö 3 - Oberfläche und an der Si (111) 7 x 7-Struktur untersucht. Die Topographie der Probenoberfläche wird aus der Verschiebung der Eigenfrequenz des in Resonanz schwingenden Cantilevers gewonnen. Zusätzlich enthält das Anregungssignal der Schwingung (Damping) Informationen über die Energiedissipation zwischen Spitze und Probe. In den Damping - Bildern gibt es besonders an Stufenkanten einen deutlichen Kontrast, der u.a. durch die Aufladung der Stufenkanten (Smoluchowski) verursacht wird. Die durch die schwingende Spitze bewegten Ladungen dämpfen die Cantilever -Schwingung durch Joulsche Reibung. Eine Anregung der Stufenkanten - Atome zu Schwingungen sowie eine veränderte chemische WW der Spitzenatome mit den Stufenatomen trägt ebenfalls zu einer von den Terrassen unterschiedlichen Energiedissipation und damit zu einem Kontrast im Damping an Stufen bei. Während der Kontrast bei Stufen der Si (111) - Oberfläche immer einheitlich ist, gibt es einen wechselnden D - Kontrast bei Au (111) - Stufen. Es handelt sich um die beiden unterschiedliche Stufentypen ((111) bzw. (100)), die sich auf einer fcc -Oberfläche ausbilden können. Die Stufentypen unterscheiden sich in ihrer Austrittsarbeit. Dies äußert sich in einer unterschiedlichen Kontaktspannung UCPD zwischen Spitze und Probe. Die langreichweitige Dissipation GE ist proportional zu U2Spitze-Probe. Daher ist der D - Kontrast abhängig von UCPD . Die Kontaktspannung erzeugt außerdem eine elektrostatische Wechselwirkung, die die Resonanzfrequenz des Cantilevers verschiebt. Dadurch wird die Kontrastbildung im Bild der Topographie abhängig von der lokalen Struktur der Oberfläche. Einen großen Einfluss auf die Kontrastbildung im dynamischen Modus haben die Spitzengeometrie, die Schwingungsamplitude und der mittlere Spitze - Probe - Abstand. Alle drei Faktoren bestimmen den Anteil der langreichweitigen gegenüber der kurzreichweitigen Wechselwirkung. Die Kontrastbildung bei atomarer Auflösung wurde anhand der Si (111) 7 x 7 - Oberfläche untersucht. Der Bildkontrast wird empfindlich von der angelegten Spannung zwischen Spitze und Probe beeinflusst. Je nach Wahl der extern angelegten Spannung sind Aufladungen von den Dotierungs - Atomen und den sie umgebenden Bildladungen sichtbar. Atomare Auflösung ist nur in einem sehr kleinen Abstandsbereich möglich. Der Abstand entspricht in etwa den Abständen in der RTM, wie gleichzeitige Aufnahmen des Tunnelstroms zwischen Spitze und Probe belegen. Mit abnehmendem Spitz-Probe-Abstand wechselt der Kraftgradient das Vorzeichen. Wurden die Atome vorher als Erhebungen abgebildet, werden sie im Abstandsbereich kurzreichweitiger starker repulsiver WW als Löcher dargestellt (Kontrastinversion). Die Summe der Wechselwirkung bleibt aufgrund des großen langreichweitigen Anteils stets attraktiv. Die unterschiedlichen Kontrastbereiche konnten sowohl anhand der Si (111) 7 x 7 - Oberfläche als auch anhand der Au (111) 22 (± 1) x Ö 3 - Oberfläche nachgewiesen werden.

In dieser Arbeit konnte erstmals die Stapelfolge der reinen Pd(111)-Oberfläche aus atomar aufgelösten RTM-Messungen einer Stufe bestimmt werden. Die Ergebnisse dieser Messungen wurden durch LEED-Messungen bestätigt. Damit ist es möglich, in einer RTM-Messung zwischen den unterschiedlichen dreifach koordinierten Adsrptionsplätzen zu unterscheiden. Basierend auf diesen Ergebnissen wurden die unterschiedlichen Strukturen von einer schwefelbedeckten Pd(111)-Oberfläche untersucht. Dabei bestimmen die Präparationsbedingungen die sich bildende Struktur. Die Oberfläche wurde sowohl durch Adsorption von H²S-Gas als auch durch Segregation von Schwefelverunreinigungen aus dem Volumen präpariert. Unterschiede zwischen den beiden Präparationsmechanismen wurden herausgearbeitet, Präparationsbedingungen zur selektiven Präparation einzelner Strukturen wurden bestimmt. Basierend auf atomar aufgelösten Spektroskopiemessungen und Simulationsrechnungen konnte ein neues Modell der (√7 × √7)R19°-Struktur entwickelt werden. Die Messungen an der (2 × 2)- bzw. der √3 × √3)-Struktur bestätigen die bekannten Strukturmodelle.

The studies presented in this work are aimed towards a better understanding of the fundamental physics of the electrode/organic molecule interface in both the ground and excited state manifolds. Systematic investigations of single systems using two-photon photoemission (TPPE) and ultraviolet photoelectron spectroscopy (UPS) were undertaken in order to assess the evolution of the electronic structure and molecular organization at the interface. The adsorbate molecule vanadyl naphthalocyanine (VONc) was used whose properties are well-suited to this purpose. Interfacial electronic states of thin films of VONc were studied with two different substrates: highly ordered pyrolytic graphite (HOPG) and Au(111).The substrate of HOPG is a surface which does not possess reactive dangling bonds and the electron density close to the Fermi edge is very low, permitting high resolution spectroscopic band analysis of VONc and revealing subtle changes to the electronic structure. From interfacial studies of this weakly interacting substrate/ adsorbate system, it is shown in this work that molecular electronic levels in both the ground and excited state manifolds can shift independently of the vacuum level. Further, electron transfer between close lying electron donor and acceptor energy levels may be influenced by energy level shifts caused by depolarization effects as a function of dipole density.The VONc/Au(111) interface is investigated in order to examine energy level alignment in a system with the additional complexity of molecule/substrate interactions. The electron rich Au(111) surface leads to a strong interface dipole upon addition of VONc. Joint experimental and computational data is presented showing that the underlying cause of this interface dipole is Pauli repulsion. Additionally, investigations of energy level alignment in the excited state manifold are presented and the possibility of quantum interference is discussed.The interfacial electronic structure is quite different among these two model systems. The interfacial alignment observed in the HOPG/VONc system was largely due to depolarization of the intrinsic molecular dipole as a function of density, whereas the Au(111)/VONc interface is dominated by interfacial Pauli repulsion interactions.

Metal and metal oxides are widely used in industry, and to optimize their performance their surfaces are commonly functionalized by the formation of thin films. Self-assembled monolayers (SAMs) are deposited on metals or metal oxides either from solution or by gas deposition. Thiols with polar terminal groups are utilized for creating the responsive surfaces which can interact electrostatically with other adsorbates. Surface charge effects wetting and adhesion, and many other surface properties. Polar terminal groups in thiols could be used to modify these factors. Mixed SAMs can provide more flexible surfaces, and could change the resulting surface properties under the influence of factors such as pH, temperature, and photo-illumination. Therefore, in order to control these phenomena by mixed polar-terminated thiols, it is necessary to understand the composition and conformation of the mixed SAMs and their response to these factors. In this work, mixtures of thiols with carboxylic and amino terminal groups were studied. Carboxylic and amino terminal groups of thiol interact with each other via hydrogen bonding in solution and form a complex. Complexes adsorb to the surface in non-conventional orientations. Unmixed SAMs from each type, either carboxylic terminated thiols or amino terminated thiols are in standing up orientation while SAMs from complexes are in an axially in-plane orientation. Selenol is an alternative to replace thiols for particular applications such as contact with biological matter which has a better compatibility with selenol than sulfur. However, the    Se-C bond is weaker than the S-C bond which limits the application of selenol. Understanding the selenol adsorption mechanism on gold surfaces could shed some light on Se-C cleavage and so is investigated in this work. Se-C cleavage happens in the low coverage areas on the step since atoms at steps have lower coordination making them more reactive than atoms on the terraces.  Another area where the self-assembly of molecules is of importance is for dye sensitized solar cells, which are based on the adsorption of the dye onto metal oxides surfaces such as TiO2.The interface between the SAM of dye and the substrate is an important factor to consider when designing dyes and surfaces in dye sensitized solar cells (DSSCs). The quality of the self-assembled monolayers of the dye on the TiO2 surface has a critical influence on the efficiency of the DSSCs.  Creation of just a monolayer of dye on the surface could lead to an efficient current of photo-excited electrons to the TiO2 and degeneration of the dye by redox. This work, T-PAC dye showed island growth with some ad-layer that is not in contact with the surface, whereas the MP13 dye adsorption is laminar growth.  Cuprite (Cu2O) is the initial and most common corrosion product for copper under atmospheric conditions. Copper could be a good replacement for noble metal as catalysts for methanol dehydrogenation. Knowledge about the structure of Cu2O(100) and Cu2O(111) surfaces could be used to obtain a deeper understanding of methanol dehydrogenation mechanisms with respect to adsorption sites on the surfaces. In this work, a detailed study was done of Cu2O(100) surface which revealed the possible surface structures as the result of different preparation conditions. Studies of the structure of Cu2O(100) and Cu2O(111) surfaces show that Cu2O(100) has a comparatively stable surface and reduces surface reactivity. As a consequence, dehydrogenation of methanol is more efficient on the Cu2O(111) surface. The hydrogen produced from methanol dehydrogenation is stored in oxygen adatom sites on both surfaces. / <p>QC 20161107</p>

En 1971, Linda Nochlin s'interrogeait sur la visibilité des femmes dans le monde de l'art. A travers ce travail de recherches, il sera question de reprendre ce questionnement fondateur afin d'analyser les diverses étapes que la femme a dû traverser du XIXe siècle jusqu'à nos jours. De par un discours centré essentiellement sur Camille Claudel et Louise Bourgeois, d'autres artistes femmes vont être sollicitées afin de comparer leurs parcours. Ceci pour comprendre la démarche artistique de ces femmes dont l'intimité surgit au travers de leurs œuvres. L'intime, sous diverses formes et médiums proposés, est le moteur de leurs créations. A cela, vient s'ajouter la possible interrogation sur l'existence d'un « art féminin » ou d'un art des femmes dont le noyau central serait l'éclosion de cet intime qu'elles font partager au public. L'analyse des œuvres et leur réception par le public seront des éléments clés de ce discours. La redécouverte et la reconnaissance dite tardive de Camille Claudel et Louise Bourgeois dans les années quatre-vingt est l 'un des éléments importants qui sont étudiés dans ce travail. Ces deux artistes, sculptrices, sont liées par le temps -1982- et par la vie dont le passé est la source majeure de leurs œuvres. / In 1971, Linda Nochlin was questioning herself about the visibility of the women artists in artʼs world. This thesis analyses this question and has an overview of womenʼs path in Art from the XIXth Century up to this day. Camille Claudel and Louise Bourgeois are the central artists of this work and others women are introduced too in a comparative way. You will see that their intimacy shine trough their work. The intimacy, in all its shapes, layers and mediums, is the motion of theirs creations.Up to this merges the questioning about “feminine art” or “women art” in which the intimacy is discovered by the public. The analysis of their work and the reception of it by the public are the central elements of this argumentation. The rediscovering and the recognition of Camille Claudel and Louise Bourgeois in the eighties is one of the importants elements studying in thisthesis. These two women artists, sculptors, are linked by the time - 1982 - and life in which the past is the key source of their work.STAR

Abstract The Copper Catalyzed Azide-Alkyne Cycloaddition (CuAAC) is a paradigm of ¡§click¡¨ chemistry which has been applied in different fields. To understand the interaction between organic azides and a copper surface, we use benzyl azide (Bn¡ÐN£\¡ÐN£]¡ÝN£^) as an adsorbate on Cu(111) under ultrahigh vacuum conditions. The thermal reaction process was explored by a combination of temperature-programmed desorption (TPD), reflection absorption infrared spectroscopy (RAIRS), and X-ray photoemission spectroscopy (XPS) techniques. The TPD profiles show a multilayer desorption peak at 190K, two peaks for N2 , and H2 from 270K to 390K. At 345K, peak of desorption product (m/z=103) represents phenyl cyanide (PhCN) or phenyl isocyanide (PhNC). RAIR and XP spectra demonstrate that at 190K benzyl azide on Cu(111) readily adopt the imine intermediate formalism involving N£\¡ÐN£] scission and phenyl group shift from carbon to nitrogen. The mechanism is analogous to the organic reaction of Schmidt rearrangement. To heat the surface to 250K, the CH2 group of the imine intermediate undergoes C¡ÐH bond scission to produce a surface isocyanide intermediate, (M=C=N¡ÐPh). Therefore the final desorption product is phenyl isocyanide at ~350K. Intriguingly, the thermal chemistry of benzyl azide involves both imine and isocyanide intermediacy, despite the fact that azido species usually generate nitrene or imido complexes under thermal conditions.

Samples are from I-Shou university Department of Materials Science and Engineering, Dr. Huy-Zu Cheng¡¦s laboratory, First, using sol-gel method to produce silicon dioxide (SiO2) with iron catalysts, and with chemical vapor deposition (CVD) to produce carbon nanotubes. To operate these instruments, for example X-Ray diffractometry (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) to analyze. The research point is judging the crystallographic orientation relationships between carbon nanotube and catalysts. Using transmission electron microscopy (TEM) to do diffraction patterns with carbon nanotubes and catalysts. From diffraction patterns results, we can decide what catalysts is? And it¡¦s crystallographic relationship. After affirming from diffraction patterns, there are three chemical compositions in the carbon nanotubes, including Fe3C¡B

Conventional electrocardiography (ECG) is an essential tool for investigating cardiac disorders such as arrhythmias or myocardial infarction. It consists of interpretation of potentials recorded at the body surface that occur due to the electrical activity of the heart. However, electrical signals originated at the heart suffer from attenuation and smoothing within the thorax, therefore ECG signal measured on the body surface lacks some important details. The goal of forward and inverse ECG problems is to recover these lost details by estimating the heart&amp / #8217 / s electrical activity non-invasively from body surface potential measurements. In the forward problem, one calculates the body surface potential distribution (i.e. torso potentials) using an appropriate source model for the equivalent cardiac sources. In the inverse problem of ECG, one estimates cardiac electrical activity based on measured torso potentials and a geometric model of the torso. Due to attenuation and spatial smoothing that occur within the thorax, inverse ECG problem is ill-posed and the forward model matrix is badly conditioned. Thus, small disturbances in the measurements lead to amplified errors in inverse solutions. It is difficult to solve this problem for effective cardiac imaging due to the ill-posed nature and high dimensionality of the problem. Tikhonov regularization, Truncated Singular Value Decomposition (TSVD) and Bayesian MAP estimation are some of the methods proposed in literature to cope with the ill-posedness of the problem. The most common approach in these methods is to ignore temporal relations of epicardial potentials and to solve the inverse problem at every time instant independently (column sequential approach). This is the fastest and the easiest approach / however, it does not include temporal correlations. The goal of this thesis is to include temporal constraints as well as spatial constraints in solving the inverse ECG problem. For this purpose, two methods are used. In the first method, we solved the augmented problem directly. Alternatively, we solve the problem with column sequential approach after applying temporal whitening. The performance of each method is evaluated.

In this work pentacene adsorption on both flat and stepped Ag(111) surfaces were investigated by using Density Functional Theory within Projected Augmented Wave method. On the flat Ag(111) surface favorable adsorption site for a single pentacene molecule was determined to be the bridge site with an angle of 60&amp / #9702 / between pentacene molecular long axis and [011] lattice direction. Potential energy surface was found to be flat, especially along lattice directions. Diffusion and rotation barriers for pentacene on this surface were found to be smaller than 40 meV indicating the possibility of a two dimensional gas phase. Calculated adsorption energies for the flat surface indicate a weak interaction between molecule and the surface indicating physisorption. On the flat surface monolayer case is found to have lower adsorption energy than the isolated case due to pentacene&amp / #8722 / pentacene interactions. On the stepped Ag(233) surface, close to the step edge, adsorption energy increased significantly due to the stronger interaction between pentacene molecule and low coordinated silver step atoms. On the terraces of this surface, far from step edges, however a flat potential energy surface was observed similar to the case of flat Ag(111) surface. On the stepped surface pentacene found its favorable configuration as parallel to the step with a tilt angle similar to the observed thin film phase of pentacene on Ag(111) surface. Pentacene molecule showed small distortions on stepped surface and are closer to the silver step atoms 1 &Aring / more than the case of flat surface, hinting a chemical interaction as well as van der Waals interactions. However on Ag(799) surface, the perpendicular orientation of the pentacene molecule to the step direction showed no strong interaction due to less matching of carbon atoms with silver step atoms.

The heart is a muscular organ which acts as a biomechanical pump. Electrical impulses are generated in specialized cells and flow through the heart myocardium by the ion changes on the cell membrane which is the beginning of both the electrical and the mechanical activity. Both the electrical and the mechanical states of the organ will directly affect the pumping activity. The main motivation of this thesis is to better understand physiological and pathological properties of the heart muscle via studying the electro-mechanics of the heart. This model could be used to gain better solutions of the ill-posed inverse problem of ECG and Body Surface Potential Maps (BSPM) or to estimate the electrical propagation and mechanical response on patient specific heart geometry models which can be obtained by using MRI technique. Cellular automaton technique will be used to simulate the physiological function of the left ventricle to estimate the cardiac functions. To model the heart tissue firstly the anatomical knowledge of the heart will be used such as properties of the myocardium, fiber orientations, etc. to simulate the three dimensional electrical propagation. Then the mechanical activity consisting of contraction and relaxation will be simulated according to the material properties of the heart. Using this simulation, the effects of the cardiac arrhythmias such as reentry will be generated. In this study, electrical and mechanical properties of the heart tissue are modeled for normal heart beat and heart beat in case of ischemic heart tissue. Contraction of the tissue via electrical activation has also been considered in terms of time synchronization. &ldquo / Cellular automaton&rdquo / method is used for modeling the electromechanical interactions in the heart tissue. A simplified left ventricle model is used to observe the electrical and the mechanical behavior. Using this method, both the normal heart beat&rsquo / s electrical activation and the arrhythmia excitation could be taken on, without using complex differential equations. To consider the anisotropy of the heart tissue, fiber orientations have also been added to the model. In this thesis work, electro-mechanic models at cellular, macroscopic and heart left ventricle level are presented. The electro-mechanical adaptation is performed by cellular electrophysiology and cellular force development due to intercellular excitation propagation. Varying densities of transmembrane proteins, changes on concentration of calcium, metabolic and hormonal effects are neglected. Also in simplified ventricular model the fluid mechanics and mechanoelectrical feed-back is not taken into-account.