Os W-operadores são operadores invariantes por translação e localmente definidos dentro de uma janela W. Devido a sua grande utilidade em análise de imagens, estes operadores foram extensamente pesquisados, sendo que uma abordagem para o seu estudo é a partir da Morfologia Matemática. Uma propriedade interessante de W-operadores é que eles possuem uma sup-decomposição, ou seja, um W-operador pode ser decomposto em termos de uma família de operadores sup-geradores que, por sua vez, são parametrizados por elementos da base desse $W$-operador. No entanto, a sup-decomposição tem uma estrutura intrinsecamente paralela que não permite uma implementação eficiente em máquinas de processamento sequencial. Em um trabalho publicado em 2001, Hashimoto e Barrera formalizaram o problema de transformar a sup-decomposição em decomposições puramente sequenciais como um problema de encontrar soluções discretas de uma equação. Neste texto, estendemos o trabalho desenvolvido por eles. Estudamos e exploramos as propriedades matemáticas do problema, e desenvolvemos estratégias heurísticas para encontrar uma decomposição sequencial de um $W$-operador a partir de sua base que seja eficiente ao ser executado. / W-operators are defined as operators which are translation invariant and locally defined within a finite window W. Due to their great contribution to image processing, these operators have been widely researched and used, specially in Mathematical Morphology. An interesting property of W-operators is that they have a sup-decomposition in terms of a family of sup-generating operators, that are parameterized by their basis. However, the sup-decomposition has a parallel structure that is not efficient in sequential machines. In a paper published in 2001, Hashimoto and Barrera formalized the problem of transforming sup-decompositions into purely sequential decompositions as a problem of finding discrete solutions of an equation. In this work, we extend Hashimoto and Barrera\'s approach. We study and explore mathematical properties of this problem and we elaborate heuristic strategies to find a sequential decomposition of a $W$-operator from its basis that can be executed efficiently.

Orientador: Andréa Cristina Prokopczyk Arita / Abstract: This work presents some results of the theory of the (a,k)-regularized resolvent families, that are the main tool used in this thesis. Related with this families, one result proved in this work is the zero-one law, providing new insights on the structural properties of the theory of (a,k)-regularized resolvent families including strongly continuous semigroups, strongly continuous cosine families, integrated semigroups, among others. Moreover, an abstract nonlinear degenerate hyperbolic equation is considered, that includes the semilinear Blackstock-Crighton-Westervelt equation. By proposing a new approach based on strongly continuous semigroups and resolvent families of operators, it is proved an explicit representation of the strong and mild solutions for the linearized model by means of a kind of variation of parameters formula. In addition, under nonlocal initial conditions, a mild solution of the nonlinear equation is established. / Resumo: Este trabalho apresenta alguns resultados da teoria de famílias resolventes (a,k)- regularizadas, que é a principal ferramenta utilizada nesta tese. Relacionado com estas famílias, um resultado provado neste trabalho é a lei zero-um, que fornece novas percepções de propriedades estruturais da teoria de famílias resolventes (a,k)- regularizadas, incluindo os semigrupos fortemente contínuos, as famílias cosseno fortemente contínuas, os semigrupos integrados, entre outras. Além disso, uma equação hiperbólica degenerada não-linear abstrata é considerada, a qual inclui a equação semilinear de Blackstock-Crighton-Westervelt. Propondo uma nova abordagem baseada em semigrupos fortemente contínuos e famílias resolvente, é demonstrada uma representação explícita das soluções forte e branda para a linearização do modelo por uma espécie de método de variação dos parâmetros. Por fim, sob condições iniciais não-locais, uma solução branda da equação não-linear é estabelecida. / Doutor

MIMO systems are mainly used in application for wireless communication. Their principle is to use a large number of antennas for transmition and the reception of a signal. The core of these systems is to use space-time coding and either block or trellis space-time code. In the future, it is assumed enormous enlargement MIMO systems in many applications

[pt] A China estabeleceu as bases para sua ascensão meteórica na década de 1970, porém foi durante os anos 1990 e particularmente 2000 que ela chamou a atenção do mundo. Atualmente, o país tem uma posição extremamente relevante nas relações internacionais, e o crescente interesse nele é inevitável, especialmente em seu desenvolvimento e em suas iniciativas de cooperação internacional. Esta dissertação objetiva verificar a ascensão recente da China à categoria de potência global e comparar a abordagem ocidental e tradicional de cooperação internacional e a política externa chinesa relacionada a essa agenda, de forma a discutir sobre a estratégia da China de Xi Jinping no campo da cooperação internacional e sobre como o país asiático poderá modificar sua operação. Nesse sentido, primeiramente, ela analisará brevemente as reformas econômicas da China e sua trajetória desenvolvimentista, bem como recentes transformações políticas, econômicas e diplomáticas. Posteriormente, examinará similaridades e diferenças entre a cooperação internacional ocidental e chinesa. Finalmente, inspecionará as mudanças de conjuntura da cooperação internacional para o desenvolvimento, baseando-se na retórica e na prática chinesas e na natureza experimental de suas iniciativas, como Um Cinturão, Uma Rota, que, se bem-sucedida, pode favorecer a China na arena global. / [en] China provided the bases for its meteoric rise in the 1970s, but it was during the 1990s and particularly the 2000s that it really called the world s attention. Now, the country holds an extremely relevant place in international relations, and the growing interest in it is inevitable, especially in its development and in its international cooperation initiatives. This dissertation aims to check China s recent rise as a global power and to compare Western traditional approach to international cooperation and Chinese foreign policy related to this agenda in order to discuss China s strategy during Xi Jinping s presidency in the field of development cooperation and how the Asian country may change its operation. In this regard, firstly, it will briefly analyse China s economic reforms and developmental trajectory, as well as more recent political, economic and diplomatic transformations. Afterwards, it will examine Western and Chinese similarities and differences regarding international cooperation. Finally, it will inspect the changing landscape of international development cooperation, based on China s rhetoric and practice and on the experimental nature of its initiatives, such as the Belt and Road Initiative, which, if successful, might favour China in the global stage.

[pt] Muitos dos movimentos de massa gravitacionais estão fortemente associados a uma perda de sucção na resistência ao cisalhamento do solo, decorrente de variações de umidade de origem natural (variações atmosféricas) ou de origem artificial (atividade humana). Dentro deste contexto, no presente trabalho analisou-se a influência da sucção na resistência ao cisalhamento, determinaram-se as envoltórias de resistência ao cisalhamento na condição não saturada e avaliou-se a influência de ciclos de umedecimento e secagem na resistência dos solos. Dois tipos de solos da região de Tinguá/RJ foram selecionados para estudo: um solo Residual Jovem e um Colúvio. Estes solos foram submetidos a um programa experimental que consistiu da caracterização granulométrica e mineralógica do material, seguido da obtenção da curva de retenção de água pelo método do papel filtro. Os ensaios de resistência ao cisalhamento envolveram ensaios de cisalhamento direto na condição saturada ou inundada e, para a condição não saturada, utilizou-se o equipamento de cisalhamento direto com sucção controlada (CDSC) da PUC-Rio, projetado por de Campos (1988) e implementado por Fonseca (1991) e Delgado (1993). O equipamento está baseado na técnica de translação de eixos. Para a determinação da velocidade de cisalhamento na condição não saturada utilizou-se a metodologia proposta por Ho e Fredlund (1982). A partir dos resultados obtidos foi possível obter os parâmetros da envoltória do solo não saturado, parâmetros efetivos de resistência do solo saturado, parâmetro que quantifica o aumento na resistência devido a um aumento na sucção matricial; , e c; e plotar a superfície 3D da envoltória que relaciona a resistência do solo não saturado com a tensão normal líquida e a sucção. / [en] Many of gravitational mass movements are strongly associated with a loss of suction on shear strength of the soil due to moisture variations of natural origin (atmospheric variations) or artificial sources (human activity). Within this context, the present study examined the influence of suction on shear strength, determined whether the envelopes of shear strength in unsaturated condition and evaluated the influence of wetting and drying cycles in soil strength. Two types of soils in the region of Tinguá / RJ were selected for study: A Young Residual soil and colluvium. These soils were subjected to an experimental program that consisted of particle size and mineralogical characterization of the material, followed by obtaining the curve of water retention by the filter paper method. The shear strength tests involved direct shear tests on saturated or flooded condition and to unsaturated condition, we used the direct shear device with controlled suction (CDSC) of PUC-Rio, designed by Field (1988) and implemented by Fonseca (1991) and Delgado (1993). The device is based on the technique of translation of the axes. For the determination of the shear rate in the unsaturated condition used the methodology proposed by Ho and Fredlund (1982). From the results it was possible to obtain the parameters of the envelope of unsaturated soil, effective resistance parameters of saturated soil, b, and c; and plot the 3D surface of the envelope which relates the strength of unsaturated soil with net normal stress and suction.

Diese Arbeit befasst sich mit der vibronischen Kopplung zweier angeregter Elektronenniveaus in Diphenylhexatrien (DPH) und mit der Rolle von Schwingungsmoden beim ultraschnellen photoinduzierten intramolekularen Elektronentransfer in Betain-30. Mit Hilfe von Pikosekunden-zeitaufgelöster Kohärenter Antistokes Ramanspektroskopie im angeregten Zustand des DPH haben wir zum ersten Mal das Auftreten zweier extrem frequenzverbreiterter Ramanlinien beobachtet, die gegenüber dem C=C Streckschwingungsbereich zu höheren Wellenzahlen verschoben sind. Beide Ramanlinien lassen sich mit Erhöhung der Lösungsmittelpolarisierbarkeit um mehr als 50 cm-1 in Richtung niedrigerer Frequenzen verschieben. Zur Erklärung des Sachverhalts werden zwei Modelle diskutiert: (i) die Existenz zweier Isomere im ersten angeregten Elektronenniveau des DPH und (ii) vibronische Kopplung der beiden Elektronenniveaus durch eine niederfrequente asymmetrische bu Schwingungsbewegung (pseudo-Jahn-Teller Effekt). Mit Hilfe von stationärer Ramanspektroskopie und insbesondere Messungen der Stokes- und anti-Stokes-Ramanspektren mit Pikosekunden-Zeitauflösung, die Beteiligung von Molekülschwingungen beim Elektronentransfer in Betain-30 wurde untersucht. Zum ersten Mal wurde eine modenspezifische Kinetik der Ramanaktiven Schwingungen nach Elektronen Rücktransfer in Betain-30 beobachtet. Die hochfrequenten Ramanaktiven Moden werden beim Elektronen Rücktransfer bevorzugt, was zu einer nicht-thermischen Besetzung der Schwingungen führt. Das ist zumindest qualitativ in Übereinstimmung mit Rechnungen die auf Fermi's Goldener Regel basieren. Eine Thermalisierung zwischen den beobachteten Ramanaktiven Moden stellt sich frühestens 10 ps nach Anregung ein. Die Thermalisierung in dem gesamten Molekül ist aber noch nicht beendet. / This thesis deals with vibronic coupling effects between two excited electronic singlet states in Diphenylhexatriene (DPH), and with the role of vibrational modes in photoinduced ultrafast electron transfer in Betaine-30. By using the picosecond time-resolved Coherent Antistokes Raman Spectroscopy method, it was possible to observe for the first time two very broad and unusual up-shifted vibrational frequencies in the excited singlet state of DPH, which have frequencies higher than frequency region of the C=C stretching mode. These two frequencies shift towards lower frequencies with increasing solvent polarizability. Two explanations have been discussed: (i) the simultaneous existence of two rotamers, where the two frequencies originate from "different molecules" and (ii) a model of vibronic coupling by an asymmetric low frequency bu-mode (pseudo-Jahn-Teller effect). By using the picosecond time-resolved anti-Stokes Raman spectroscopy method, we observed for the first time mode-specific excitation of vibrational modes after back-electron transfer in Betaine-30. In the primary event, high frequency Raman active modes are most effective in accepting energy, which leads to a non-thermal distribution of the relative populations of Raman active modes. This is qualitatively in accordance with predictions derived from Fermi's Golden Rule. Although energy transfer between the Raman active modes has been finished after about 10 to 15 ps, thermalization is not yet complete in the whole molecule.

Methoden der transienten Vierwellenmischung mit Femtosekunden-Zeitauflösung werden angewendet, um die Phasen- und Energierelaxation optisch selektiv erzeugter Anregungszustände im Lichtsammelkomplex II höherer Pflanzen (LHC II) sowie im Halbleiter Cadmiumsulfid (CdS) bei verschiedenen Temperaturen zu untersuchen. Für den LHC II werden die Ergebnisse der Messungen des zeitaufgelösten und integrierten Zweipuls-Photonenechos mit Resultaten aus Pump-Test-Experimenten verglichen, um unter Einbeziehung von Literaturdaten Rückschlüsse über den Charakter der phasenzerstörenden Prozesse zu ziehen und Zusammenhänge zu Strukturdaten des Komplexes aufzudecken. Die vorliegende Arbeit liefert erstmals einen systematischen Überblick über die totalen Phasenrelaxationszeiten T2 im Bereich der Qy-Bande des LHC II von 640 bis 685 nm bei 5 K. Das bei 5 K beobachtete Photonenechosignal am LHC II zeigt in Abhängigkeit von der Verzögerung der beiden Anregungsimpulse ein multiexponentielles Abklingen, das auf die Überlagerung der Einflüsse mehrerer Relaxationsprozesse zurückgeführt wird. Dabei lassen sich drei charakteristische Bereiche der Phasenrelaxationszeit unterscheiden, die verschiedenen phasenzerstörenden Prozessen zugeordnet werden. Ein Vergleich mit Resultaten aus Pump-Test-Experimenten führt zu der Schlußfolgerung, daß die Phasenrelaxation im LHC II bei 5 K für Wellenlängen £ 675 nm im wesentlichen durch den Energietransfer auf einer sub-ps Zeitskala bestimmt wird. Für Wellenlängen > 675 nm steigt die Phasenrelaxationszeit stark an und wird insbesondere im Bereich der tiefsten Anregungszustände um 680 nm durch reine Phasenzerstörung dominiert. Ab 20 K setzt bei dieser Wellenlänge ein zusätzlicher phasenzerstörender Prozeß ein, der mit steigender Temperatur zu einem mäßigen linearen Anstieg der Phasenrelaxationsrate (T2)-1 führt. Die Ursache ist vermutlich ein Aufwärts-Energietransfer. Im Bereich der Chlorophyll a-Absorption vernichten außerdem (physiologisch irrelevante) Multiexzitoneneffekte die Kohärenz der angeregten Zustände, verursacht durch die hohe Anregungsintensität. Zusammenfassend kann festgestellt werden, daß die Erhaltung der Kohärenz für die Funktionalität des LHC II eine untergeordnete Rolle spielt. Die wesentlichen Prozesse sind der schnelle räumliche Energietransfer und die Energierelaxation auf das Niveau des primären Elektrondonators P680 im Reaktionszentrum. Am Halbleiter CdS wird erstmals ein mittels Zwei-Photonen-Absorption angeregtes Photonenecho beschrieben, das in Abhängigkeit von der Wellenlänge charakteristische Quantenbeats mit einer Periode von 700 bis 800 fs zeigt. Das stark gedämpfte periodische Echosignal tritt sowohl für positive als auch für negative Verzögerungszeiten t der Anregungsimpulse auf, wobei die Abklingzeit für t>0 mit 170±10 fs doppelt so groß ist wie für t / Transient four-wave-mixing experiments with femtosecond resolution are performed in order to investigate phase and energy relaxation processes of optically excited states in the light harvesting complex II of higher plants (LHC II) and in the semiconductor cadmium sulfide (CdS) at different wavelengths and temperatures. Extensive studies of the time resolved and integrated two-pulse photon echo on LHC II are combined with pump-probe experiments. Results of both methods together with literature data are used to characterize the nature of dephasing processes and to reveal connections with structural data of the complex. This study gives the first systematic survey of total dephasing times T2 in the spectral region of the Qy-absorption band of LHC II from 640 to 685 nm at 5 K. In the case of LHC II, the photon echo signal at 5 K monitored as a function of delay between both excitation pulses shows a multi-exponential decay which is attributed to the superposition of several relaxation processes. Three characteristic dephasing time domains can be distinguished, ascribed to different dephasing processes. Comparing photon echo and pump-probe results it can be concluded that dephasing in LHC II at 5 K and for wavelengths £ 675 nm is dominated by the fast excitation energy transfer on a sub-ps time scale. At wavelengths > 675 nm the total dephasing time increases drastically. The loss of coherence of the lowest excited states around 680 nm at 5 K is mainly determined by pure dephasing. An additional dephasing process, probably uphill energy transfer, occurs at temperatures higher than 20 K leading to a moderate linear rise of the dephasing rate (T2)-1 with increasing temperature. Furthermore, the dephasing in the spectral region of chlorophyll a absorption is affected by (physiologically irrelevant) multi-excitonic effects caused by the high excitation energy. In summary, it can be concluded that the preservation of coherence plays a minor role in the functionality of LHC II. The main processes are the fast spatial excitation energy transfer and the energy relaxation down to the energetic level of the primary electron donor P680 of the reaction center. Investigations of four-wave mixing signals of the semiconductor CdS resulted in the first description of a two-photon excited photon echo in CdS showing characteristic quantum beats with a period of 700 to 800 fs in dependence on wavelength. The strongly damped periodical echo signal is found for both positive and negative delay times t between the excitation pulses. The decay time for t>0 amounts to 170±10 fs and is twice as large as for t

Die vorliegende Arbeit verallgemeinert die Methode der Wellenpaketpropagation fuer isolierte molekulare Systeme auf molekulare Systeme mit Umgebungswechselwirkung. Im Rahmen der Dichtematrixtheorie werden am Beispiel des linearen Absorptionskoeffizienten und des Raman-Streuquerschnitts Ausdruecke fuer stationaere optische Funktionen abgeleitet. Diese Ausdruecke lassen sich als Fouriertransformation einer durch Dichtematrixpropagation erhaltenen Groesse verstehen, deren Dynamik auch durch die Umgebung des molekularen Systems beeinflusst wird. Am Beispiel von drei Modellsystemen (OH-Streckschwingung von Wasser, NO in Ar-Matrizen, HCl in Ar-Matrizen) wird der lineare Absorptionskoeffizient im infraroten und ultravioletten Spektralbereich berechnet. Die Ergebnisse werden mit experimentellen Daten verglichen. Aus der numerisch ansruchsvollen drei-dimensionalen Behandlung des HCl in Ar werden zusaetzlich Schluesse ueber die Dynamik des H-Atoms bei der Photodissoziation gezogen. Der Ausdruck fuer den Raman-Streuquerschnitt wird an einem theoretischen Modellsystem untersucht. Insbesondere wird die Temperatur- und Feldstaerkeabhaengigkeit des Spektrums diskutiert. / The well-known wave paket propagation method is extended from isolated molecular systems to molekular systems interacting with a dissipative environment. In the framework of density matrix theory formulations of stationary optical properties (linear absorption and Raman scattering cross section) are found. Essentially these formulations contain the Fourier-transform of a term given by density matrix propagation which is influenced by the environment. For three examples (OH stretching vibration in liquid water, NO in Ar-matrices, HCl in Ar-matrices) the linear absorption coefficient is calculated in the infrared and ultraviolett spectral range. Comparisons with experimental data are given. For the case of HCl in Ar-matrices additional information concerning the dynamics of the H-atom during the photodissociation is given. The Raman scattering cross section is calculated for a theoretical model system. Especially temperature dependence and the influence of the electric field strength on the spectra is discussed.

Die Umsetzung von Kohlenwasserstoffen mit Wasserstoff auf Pd-Modellkatalysatoren wurde anhand von Molekularstrahlmethoden (MB) und IR-Spektroskopie mit Schwerpunkt auf dem Verständnis von mikroskopischen Faktoren, die die Aktivität und Selektivität bestimmen, studiert. Exemplarisch wurden die Reaktionen von cis-2-Buten mit H2(D2), cis-trans-Isomerisierung und Hydrierung, über einem geträgterten Pd/Fe3O4/Pt(1111)-Modellkatalysator und einem Pd(111)-Einkristall erforscht. Es wurde gezeigt, dass die Aktivität und Selektivität des Pd-Modellkatalysators stark von dessen Fähigkeit abhängt, ausreichend hohe Konzentrationen von H auf und in den Pd-Partikeln aufzubauen und aufrechtzuerhalten. Während Isomerisierung effektiv abläuft, wenn nur Oberflächen-H verfügbar ist, wird für die Hydrierung eine zweite Art von H-Spezies benötigt, welche mit Volumen-H assoziert ist. Kohlenstoffablagerungen auf niedrig-koordinierten Plätzen der Pd-Partikel induzieren anhaltende Hydrierung, was einer Begünstigung der H-Diffusion ins Pd-Volumen zugeschrieben wurde. Kohlenwasserstoffspezies hingegen inhibieren die Bildung von Oberflächen-H sowie noch stärker die von Volumen-H. Gepulste MB-Experimente zum H/D-Austausch zur Untersuchung der H-Verteilung zeigten, dass neben regulärem Oberflächen-H, eine zweite Art von H-Spezies, vermutlich Volumen-H, in die HD-Bildung involviert ist. C auf niedrig-koordinierten Plätzen beeinflusst die HD-Bildung vermutlich durch eine Erleichterung der H-Diffusion ins Pd-Volumen. Kohlenwasserstoffe hingegen inhibieren den H/D-Austausch. Die ersten Ergebnisse zur Adsorption und Reaktion von Isophoron, einem alpha,beta-ungesättigtem Keton, mit H2 auf einer Pd(111)-Oberfläche werden präsentiert. Veränderungen der Adsorptionsgeometrie wurden mit steigender Bedeckung und in Anwesenheit von H anhand von IRAS detektiert. In Übereinstimmung mit realistischen Katalysestudien wurde in TPR-Messungen eine deutliche Selektivität zur Hydrierung der C=C-Bindung festgestellt. / The conversion of hydrocarbons with hydrogen over well-defined Pd model catalysts has been studied using pulsed molecular beam (MB) techniques and IR spectroscopy with a special focus on the understanding of microscopic factors governing the activity and selectivity. Exemplarily, the conversion of cis-2-butene with H2(D2) toward cis-trans isomerization and hydrogenation was studied over a supported Pd/Fe3O4/Pt(111) model catalyst and a Pd(111) single crystal surface. It was found that the activity and selectivity of the Pd model catalyst depend strongly on its ability to build up and maintain a sufficiently high concentration of H on and in the Pd particles. While isomerization proceeds effectively when merely surface H is available, for hydrogenation a second hydrogen species is required that is associated with subsurface hydrogen. Carbonaceous deposits located on low-coordinated sites of the Pd particles were found to induce persisting hydrogenation activity which could be attributed to facilitation of H diffusion to subsurface sites. Hydrocarbon species, in contrast, were found to inhibit the formation of surface H and even more pronounced subsurface H. Pulsed MB experiments on the H/D exchange to probe the H distribution showed that - next to regular surface H - a second type of hydrogen species is involved in the formation of HD, most likely subsurface hydrogen. C deposited on low-coordinated sites was shown to affect the HD formation presumably by facilitating subsurface H diffusion. Hydrocarbons strongly inhibit the H/D exchange. The first results on the adsorption and reaction of isophorone, an alpha,beta-unsaturated ketone, with hydrogen over a Pd(111) single crystal surface are presented. Changes in the adsorption geometry with increasing coverage and due to co-adsorbed H were detected using IRAS. In line with realistic catalytic studies, a strong chemoselectivity toward the hydrogenation of the C=C double bond was found in TPR measurements.

Um hochsensitive räumliche Auflösung zu erreichen, wurden oberflächenverstärkte Raman-Spektroskopie (SERS) und spitzenverstärkte Raman-Spektroskopie (TERS) weiterentwickelt. Das grundlegende Funktionsprinzip ist jedoch noch nicht vollständig verstanden und auch Experimente dazu fehlen teilweise. In dieser Arbeit habe ich zuerst Gap-mode TERS eingesetzt, bei welcher ein starkes elektromagnetisches Feld es ermöglicht, dünne Schichten von sehr schwach streuenden Molekülen zu untersuchen. Mit der Nanometerauflösung von TERS konnte ein auf der Goldoberfläche spontan phasen-getrennten, gemischtes Thiolsystem räumlich aufgelöst werden, während STM die Nanodomänen nicht über ihre Höhenunterschiede erkennen konnte. Neue Studien deuten auf eine Raman-Verstärkung durch Graphen und Flachgold aufgrund eines chemischen Mechanismus hin. Kupfer Phthalocyanin (CuPc)-Moleküle zwischen Graphen und einer flachen Goldoberfläche erlauben Elektronenübertragungen in beide Richtungen und damit stellt sich die Frage, ob chemische Verstärkungen von SERS zueinander addiert werden können. Die Ergebnisse deuten auf eine Kopplung von den zwei einzelnen Oberflächen hin. Es wurde eine 68-fache Verstärkung von geschichtetem CuPc zwischen Graphen und Gold beobachtet, jeweils bezogen auf CuPc auf Glimmer. Zuletzt wurde mittels TERS diese Schichtstruktur untersucht. Moleküle, die sich auf der Goldoberfläche selbstanordnen und mit Graphen bedeckt worden sind, fungieren als optische Sensoren, bei welchen die Graphenverkapselung die Moleküle beschützt. Außerdem kann eine sehr hohe Raman-Verstärkung mit großer lokaler Auflösung aufgrund der kombinierten Effekte von SERS und TERS herbeigeführt werden. Die Ergebnisse zeigen, dass eine Spitze, die Graphen-verstärkte Raman-Streuung (GERS) zusätzlich um vier Größenordnungen verbessern kann, aber Gap-mode TERS abschirmt. / The quest to achieve ultrahigh sensitivity, surface specificity and high spatial resolution has led to the development of plasmon- and chemically- enhanced Raman spectroscopy, including techniques such as surface-enhanced Raman spectroscopy (SERS) and tip-enhanced Raman spectroscopy (TERS). However, a lack of fundamentally experimental demonstrations still remains. In this thesis, I firstly used gap-mode TERS, which allows studying even molecularly thin layers of very weakly scattering molecules. With the nanoscale spatial resolution provided by TERS, the spontaneous segregation in a mixed thiol system on a gold surface could be resolved, while scanning tunneling microscopy (STM) could not discern the nanodomains via their apparent height difference. Furthermore, since graphene and a flat gold surface both were known to provide some Raman enhancement through mainly a chemical mechanism, sandwiching copper phthalocyanine (CuPc) molecules between graphene and a flat gold surface allowed electrons to be transferred in both directions, and thereby to address the question whether chemical enhancements with different origins in SERS can add to each other. The results suggest that the chemical enhancements were influenced by the two individual surfaces, and a 68-fold enhancement of sandwiched CuPc between graphene and gold was observed, as compared to CuPc on mica. Last, TERS was applied to study this sandwiched structure. Molecules self-assembled on a gold surface and covered by transferred graphene acted as optical probes. Such an arrangement has interesting properties in the sense that molecules are protected and encapsulated by graphene. Also, a possible ultrahigh Raman enhancement together with localized spatial resolution may be achieved due to the combined effects from SERS and TERS. The results showed that a tip can improve graphene-enhanced Raman scattering (GERS) further by 4 orders of magnitude, but graphene exerts some shielding effect to gap-mode TERS.