Дисертації з теми "Pump and probe techniques"
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Griessel, Annelle. "The investigation of resveratrol with conventional and ultrafast pump-probe spectroscopy techniques." Thesis, Stellenbosch : University of Stellenbosch, 2009. http://hdl.handle.net/10019.1/3098.
Повний текст джерелаAn ultrafast pump-probe spectroscopy experiment was developed in order to investigate the fast photoinduced isomerization reaction of the molecule resveratrol. Characteristics of the resveratrol molecule are discussed, including the photoisomerization reaction from trans- to cis-resveratrol. The experimental setup for the conventional spectroscopy measurement was developed and characterized in order to investigate and understand the conventional absorption and uorescence spectroscopy of resveratrol thoroughly. The absorption spectra for both trans- and cis-resveratrol, as well as the uorescence spectra were measured, discussed and explained. This therefore forms a foundation and serves as an initial step to develop a pump-probe spectroscopy experiment for resveratrol. A general overview of ultrafast pump-probe spectroscopy is presented, as well as an explanation of the nal developed experimental setup. The principles and characteristics of the chirped pulse ampli cation (CPA) femtosecond laser source and the tunable noncollinear optical parametric ampli er (NOPA) employed as the pump pulse are discussed. The process of white light continuum (WLC) generation was investigated to utilize as the ultrashort probe pulse. Two white light continuum generation experimental setups were developed and characterized for WLC generation in a transparent medium with the fundamental CPA laser light at 775 nm (in sapphire) and with the second harmonic (SH) of the CPA light at 387 nm (in quartz). A spectrometer was designed, built and characterized in conjuction with a line focus, for simultaneous measurement of the absorption in the pumped, unpumped and reference regions in the sample. In this way the photoisomerization of resveratrol could be measured with temporal resolution as a transient absorption signal. A 420 μg/ml resveratrol solution in ethanol was investigated in this pump-probe spectroscopy experiment and the results obtained are discussed accordingly.
Nargelas, Saulius. "Investigation of carrier dynamics in InN, InGaN, and GaAsBi by optical pump-probe techniques." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2013. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2012~D_20130227_085934-75237.
Повний текст джерелаDisertacija skirta nepusiausvirųjų krūvininkų dinamikos tyrimams InN, InGaN ir GaAsBi heterosandarose naudojant šviesa indukuotų dinaminių gardelių ir skirtuminio pralaidumo metodikas. Atlikti tyrimai plačiame nepusiausvirųjų krūvininkų tankių ir bandinio temperatūrų intervale parodė, kad krūvininkų rekombinacijos sparta MBE būdu užaugintuose InN sluoksniuose dominuojantis rekombinacijos mechanizmas kambario temperatūroje yra gaudyklių įtakota Ožė rekombinacija. Nustatyta koreliacija tarp krūvininkų gyvavimo trukmės ir difuzijos koeficiento MOCVD būdu užaugintame InGaN sluoksnyje su 13% In parodė, kad krūvininkų gyvavimo trukmę lemia difuzinė jų perneša link rekobinacijos centrų. Parodoma, kad MBE metodu užaugintuose InGaN sluoksniuose su dideliu In kiekiu (x>0,7) didėjant Ga kiekiui didėja nespindulinės rekombinacijos centrų tankis, o krūvininkų rekombinacijos sparta yra termiškai aktyvuojama. MOCVD metodu užaugintose InGaN kvantinėse sandarose dinaminių gardelių tyrimais parodoma, kad spartėjančią krūvininkų rekombinaciją didėjant sužadinimo intensyvumui lemia ne tik spindulinė rekombinacija, tačiau reikia atsižvelgti ir į nespindulinės rekombinacijos spartėjimą. Nustatyta, kad į GaAs įterpiant Bi atomus daugiau nei dešimt kartų sumažėja skylių judris dėl Bi atomų kuriamų valentinės juostos fliuktuacijų.
Lakehal, Massil. "Out of Equilibrium Lattice Dynamics in Pump Probe Setups." Thesis, Université de Paris (2019-....), 2020. http://www.theses.fr/2020UNIP7039.
Повний текст джерелаThe study of the out of equilibrium dynamics of strongly correlated systems, using ultrafast pulses, uncovered a plethora of phenomena with no analog in equilibrium physics. In this thesis, we theoretically investigate the out of equilibrium dynamics of the lattice degrees of freedom and their signature in pump-probe spectroscopy. We develop a Hamiltonian-based microscopic description of laser pump induced displacive coherent phonons. The theory captures the feedback of the phonon excitation upon the electronic fluid, which is missing in the state-of-the-art phenomenological formulation. We show that this feedback leads to chirping at short timescales, even if the phonon motion is harmonic. At long times, this feedback appears as a finite phase in the oscillatory signal. We apply the theory to BaFe2As2, explain the origin of the phase in the oscillatory signal reported in recent experiments, and we predict that the system will exhibit redshifted chirping at larger fluence. Our theory also opens the possibility to extract equilibrium information from coherent phonon dynamics. Another interesting phenomenon that have been reported in pump-probe spectroscopy is the oscillation of the lattice fluctuations at double phonon frequency. These oscillations are invariably interpreted as a signature of macroscopic squeezed phonon states. In this work, we identify other mechanisms of double phonon frequency oscillations that do not involve squeezing. We show that a pump induced temperature quench of the bath, to which the phonon is coupled to, or exciting a coherent phonon for which cubic anharmonicity is allowed by symmetry can also produce such oscillations in noise spectroscopy without squeezing the phonon state. We conclude that, in contrast with what is commonly believed, double phonon frequency oscillations in noise spectroscopy are not necessarily a signature of macroscopic phonon squeezing. We point out what can be a reliable criterion to identify a squeezed phonon using pump-probe spectroscopy
隼人, 市橋, and Hayato Ichihashi. "Studies on optical spectroscopy techniques with surface plasmon resonance." Thesis, https://doors.doshisha.ac.jp/opac/opac_link/bibid/BB13127436/?lang=0, 2020. https://doors.doshisha.ac.jp/opac/opac_link/bibid/BB13127436/?lang=0.
Повний текст джерелаSurface plasmon resonance (SPR) sensor has been expected as a ultrasonic sensor used in high resolution photoacoustic microscopy (PAM). In this thesis, thermoelastic transient responses in SPR sensor were evaluated by a pump probe system with a developed sub-nanosecond pulsed laser. Especially, the mechanism of the transient response to be observed as a reflectivity change of the probe light was studied by two approaches of the experiment and the theoretical estimation. As consequence of these approaches, it was revealed that the transient response was caused by the change of the plasma frequency in a thin metal film of SPR sensor.
博士(工学)
Doctor of Philosophy in Engineering
同志社大学
Doshisha University
Wald, Hagen. "Ultrafast carrier dynamics investigated by a novel pump and probe terahertz technique." [S.l.] : [s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=971803943.
Повний текст джерелаLozan, Olga. "Surface plasmons and hot electrons imaging with femtosecond pump-probe thermoreflectance." Thesis, Bordeaux, 2015. http://www.theses.fr/2015BORD0021/document.
Повний текст джерелаIn this work we explored the ultrafast dynamics of photo-excited hot electrons in plasmonic structures. The particular interest of this field resides on the fact surface plasmons (SP), because of their unrivaled temporal and spatial characteristics, provide a technological route for ultrafast information processes at the nanoscale. In this context, this manuscript provides a comprehension and the harnessing of one of the major limitation of the SP-based technologies : absorption losses by Joule heating. We exploit the fact that the mechanism of plasmon absorption in metals is followed by generation of hot electrons at femtosecond time scale, thus losses can be seen as a plasmon-to-hot-electron energy conversion. This energy conversion is measured with femtosecond pump-probe technique. Femtosecond SP pulses are launched and probed over hundred femtoseconds through the permittivity variations induced by the hot-electron gas and which accompany the SP propagation. The measured electron temperature profile is therefore an image of plasmon power density distribution (absorption) not broadened spatially and temporally by energy carrier diffusion. As an important result we demonstrated the capability to link the electronic temperature measurement to the plasmonic absorption, revealing an anomalous light absorption for a sub- slit surroundings, in quantitative agreement with predictions of the power density distribution. In a second part we studied plasmon losses and their characteristics when they propagate on semi-infinite metal film. We determined the electronic thermal wave velocity and damping. In the last part we used a focusing taper-structure to adiabatically guide and focus the plasmon at the apex. Was demonstrated the generation of a nanoscale hot spot and put in evidence a delayed electron heating at the taper apex. Perspectives and the remaining open questions are also discussed
Titimbo, Chaparro Kelvin Ruben. "CREATION AND DETECTION OF SQUEEZED PHONONS IN PUMP AND PROBE EXPERIMENTS: A FULLY QUANTUM TREATMENT." Doctoral thesis, Università degli studi di Trieste, 2015. http://hdl.handle.net/10077/10941.
Повний текст джерелаFemtosecond pump and probe techniques are standard experimental methodologies used for studying ultrafast dynamics in solids, in particular phonon oscillations in target materials. So far, only semiclassical methods have been employed in order to theoretically interpret the experimental data. In contrast, a fully quantum treatment will be presented here taking into account the quantum features of the generation mechanism of excited phonons by pump laser pulses, and of the process of accessing their behaviour by probe laser pulses. A single effective Hamiltonian will be used to model the interaction between photons and phonons both for the pumping and probing processes. In addition, as they interact with their environment, mainly electrons in the target, the excited phonons cannot be considered an isolated system. Their dynamics is then that typical of open quantum systems and generated by a master equation of Lindblad form, that takes into account the dissipative and noisy effects due to the environment.In this formalism, phonon oscillations can be analysed through suitable probe photon observables. Specifically, unlike in the existing literature, we will not focus only upon the scattered probe pulse intensity, namely on the probe photon number, but also on the number variance. Through the latter some quantum features of the phonon state can be accessed; in particular, specific signals of the presence of squeezed phonons can thus be identified.
Le tecniche di "pump and probe" impulsato sono metodologie sperimentali standard usate nello studio delle dinamiche ultraveloci nei solidi, in particolare delle oscillazioni di fononi. Usualmente l'interpretazione teorica dei dati sperimentali si basa su approssimazioni semiclassiche. Una descrizione completamente quantistica e` invece sviluppata nella presente trattazione: e` basata sull'introduzione di un'unica hamiltoniana di interazione tra fotoni e fononi, capace di descrivere in modo effettivo sia il processo di eccitazione che di rivelazione dei fononi. In generale, tali fononi non possono essere considerati come isolati, ma costituiscono un sistema quantistico aperto, cioe` in interazione debole con l'ambiente esterno, formato principalmente da elettroni e dagli altri costituenti del materiale in studio. La loro dinamica deve percio` venir descritta tramite una equazione master, che tenga conto di effetti di rumore e dissipazione. In questo formalismo, le proprieta` dei fononi eccitati dagli impulsi laser di "pump" possono essere analizzate attraverso lo studio di opportune osservabili caratterizzanti i fotoni di "probe". Piu` specificatamente, si e` analizzato il comportamento non solo dell'intensita` media della luce di "probe" riflessa, cioe` del numero medio di fotoni, ma anche della relativa varianza. In questo modo, si possono evidenziare alcune caratteristiche quantistiche dei fononi: in particolare, sono stati individuati segnali specifici della presenza di fononi "squeezed"
XXVII Ciclo
1986
Liu, Yingliang. "Structural Dynamics of DNA Hydration Shell Studied by 2D IR and Pump-Probe Technique." Doctoral thesis, Humboldt-Universität zu Berlin, 2017. http://dx.doi.org/10.18452/18559.
Повний текст джерелаBiochemical processes occur in an aqueous environment and interactions of the water shell with biomolecules play a key role for their structure and function. In this thesis, the structural dynamics of water molecules and counterions in the hydration shell of DNA is investigated by two-dimensional infrared (2D IR) spectroscopy and pump-probe transient spectroscopy. 2D IR spectroscopy is a powerful technique that can track molecular couplings between different vibrational modes and structural fluctuations of the chemical environment on a femto- to picosecond time scale. In the present study, vibrational modes of the DNA backbone serve as probes located at the DNA-water interface. The results of this thesis demonstrate the strong potential of interfacial vibrational modes for mapping and understanding interactions between biomolecules and their water shell. In future, this concept will be applied to other biomolecular systems.
ARESTI, MAURO. "Ultrafast Optical Spectroscopy Techniques applied to colloidal nanocrystals." Doctoral thesis, Università degli Studi di Cagliari, 2014. http://hdl.handle.net/11584/266450.
Повний текст джерелаGiese, Christian [Verfasser], and Frank [Akademischer Betreuer] Stienkemeier. "Vibrational structure and dynamics of triatomic alkali molecules and RbHe exciplexes on helium nanodroplets investigated with femtosecond and picosecond pump-probe techniques = Vibrationsstruktur und Dynamik von dreiatomigen Alkalimolekülen und RbHe Exziplexen auf Helium Nanotröpfchen, untersucht mit Femtosekunden und Picosekunden Pump-Probe Techniken." Freiburg : Universität, 2012. http://d-nb.info/1123469385/34.
Повний текст джерелаPlogmaker, Stefan. "Techniques and Application of Electron Spectroscopy Based on Novel X-ray Sources." Doctoral thesis, Uppsala universitet, Yt- och gränsskiktsvetenskap, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-168799.
Повний текст джерелаLiu, Yingliang [Verfasser], Thomas [Gutachter] Elsässer, Klaus [Gutachter] Rademann, and Kannan [Gutachter] Balasubramanian. "Structural Dynamics of DNA Hydration Shell Studied by 2D IR and Pump-Probe Technique / Yingliang Liu ; Gutachter: Thomas Elsässer, Klaus Rademann, Kannan Balasubramanian." Berlin : Humboldt-Universität zu Berlin, 2017. http://d-nb.info/1189327031/34.
Повний текст джерелаZhang, Bo. "Experimental Studies of Quantum Dynamics and Coherent Control in Homonuclear Alkali Diatomic Molecules." Doctoral thesis, KTH, Physics, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3420.
Повний текст джерелаThe main theme covered in this thesis is experimentalstudies of quantum dynamics and coherent control in homonuclearalkali diatomic molecules by ultrafast laser spectroscopy iththe implementation of pump-probe techniques.
A series of experiments have been performed on the Rb2molecules in a molecular beam as well as in a thermal oven. Thereal-time molecular quantum dynamics of the predissociatingelectronically excited D(3)1Πu state of Rb2, which couples to/intersects several otherneighbouring states, is investigated using wavepackets. Thepredissociation of the D state, explored by this wavepacketmethod, arises from two independent states, the (4)3Σu+and (1)3∆u, for which the second corresponds to a much fasterdecay channel above a sharp energy threshold around 430 nm. Thelifetime of the D state above the energy threshold is obtained,τ ≈ 5 ps, by measuring the decay time of thewavepacket in a thermal oven. Further experimentalinvestigation performed in a molecular beam together withquantum calculations of wavepacket dynamics on the D state haveexplored new probe channels of wavepacket evolution: theD′(3)1Σu+ channel, which exhibits vibrational motionin a shelf state and the (4)3Σu+ channel, where direct build-up of thewavefunction is observed due to its spin-orbit oupling to the Dstate.
The real-time quantum dynamics of wavepackets confined totwo bound states, A1Σu+(0u+) and b3Πu(0u+), have been studied by experiment andcalculations. It is shown that these two states are fullycoupled by spin-orbit interaction, characterised by itsintermediate strength. The intermediate character of thedynamics is established by complicated wavepacket oscillationatterns and a value of 75 cm-1is estimated for the coupling strength at thestate crossing.
The experiments on the Li2molecule are performed by coherent control ofrovibrational molecular wavepackets. First, the Deutsch-Jozsaalgorithm is experimentally demonstrated for three-qubitfunctions using a pure coherent superposition of Li2rovibrational eigenstates. The functionscharacter, either constant or balanced, is evaluated by firstimprinting the function, using a phase-tailored femtosecond(fs) pulse, on a coherent superposition of the molecularstates, and then projecting the superposition onto an ionicfinal state using a second fs pulse at a specific delay time.Furthermore, an amplitude-tailored fs pulse is used to exciteselected rovibrational eigenstates and collision induceddephasing of the wavepacket signal, due to Li2-Ar collisions, is studied experimentally. Theintensities of quantum beats decaying with the delay time aremeasured under various pressures and the collisional crosssections are calculated for each well-defined rovibrationalquantum beat, which set the upper limitsfor ure dephasingcross sections.
Keywords:Ultrafast laser spectroscopy, pump-probetechnique, predissociation, wavepacket, pin-orbit interaction,coherent control, (pure) dephasing
Panov, Maxim S. "Early Events in Photochemistry of Aryl Azides Used as Photoaffinity Labeling Agents." Bowling Green State University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1321571677.
Повний текст джерелаPopov, Oleg Igorevich. "Quantum beat spectroscopy of hyperfine structure in the 8p2P3/2 level of atomic cesium." Miami University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=miami1344713056.
Повний текст джерелаBalducci, Lodovico. "Dynamics of hemeproteins by femtosecond X-ray techniques." Thesis, Rennes 1, 2019. http://www.theses.fr/2019REN1S115.
Повний текст джерелаRecently, the development of time resolved X-ray techniques has added the time dimension to structural biology studies, and have proven to be great tools to track proteins during the course of a reaction, or a specific conformational change. In particular the 4th generation X-ray sources (so called X-ray Free-Electron Lasers), with femtosecond pulses and extremely high fluences, are capable of probing ensembles of molecules essentially frozen in time under physiological conditions. After an overview of the past studies in the field, a basic introduction of the used techniques, the description of the experimental set-up and the flow of data reduction are presented. The last two chapters are devoted to present the results obtained during two separate sets of experiments, conducted at the XPP beamline of the Linac Coherent Light Source (SLAC, Menlo Park, CA, USA), to study the protein's structural changes, upon prototypical photo-dissociation reaction of carbon monoxide from heme proteins. During the first experiment, the global structural modification of three heme proteins has been probed by means of time resolved scattering technique, in order to observe eventual differences in the so called “protein-quake” depending on the protein's structure. In the second experiment, the active site of myoglobin was probed, during the same reaction, by X-ray absorption. The time resolved XANES spectra have been compared with theoretical calculations, in the framework of the multiple scattering theory, in order to retrieve a detailed picture of the ultra-fast dynamics. A further small side-project dealt with the precise measurement of static scattering patterns of carboxy hemoglobin with the goal of defining its multiple equilibrium structures by comparison with linear combinations of known crystallographic structures. In conclusion, in this Ph.D. thesis we tried to add some small pieces in the understanding of ultra-fast proteins dynamics by applying both standard (Guinier) and almost unexplored (multiple scattering calculations on time resolved data) analysis methods: depending on the system and the level of details required, these methodologies, here applied on model systems, can be considered excellent tools for further research on more complicated proteins
Volte, Alix. "Photo-induced cooperativity in bistable volume-changing materials." Thesis, Rennes 1, 2020. http://www.theses.fr/2020REN1S037.
Повний текст джерелаThe field of ultrafast structural dynamics is based on remarkable developments of available pulse sources, from THz to x-rays. Currently, pump-probe techniques operate on the femtosecond time scales, i.e. faster than atomic motions. Typically, a laser pump pulse drives a system onto an electronically excited state, while the structural dynamics temporal evolution is tracked with a delayed probe pulse. Moreover, laser light sources can generate intense pulses with a number of photons approaching the number of potentially photo-excited species. Such pulses can induce highly excited states, involving a macroscopic number of atoms or molecules and driving the system far from equilibrium. These precursor effects may be followed by the establishment of a new electronic and structural order and thus may bring about a phase transition of the excited system. This represents a new approach to direct materials functionalities: timely acting on an atomic or molecular excited state, rather than switching from an equilibrium state to another by tuning a static control parameter. Moreover, such induced atomic displacements may occur in a collective coherent motion, in a fundamentally different way from incoherent thermal excitation.The goal of this PhD was to explore through ultrafast x-ray diffraction some aspects of the coupled strain-transformation dynamics, in the frame of phase transitions induced by a laser pulse in volume-changing materials. This project stands between the field of photo-induced phase transitions, the physics of photo-acoustics and non-linear wave phenomena, as well as the study of the elastic field effects in correlated electrons materials. We expect this photo-induced elastic cooperative process to be particularly efficient in bistable materials showing significant volume change at the transition, as those investigated here. It is the case of spin crossover materials, where cooperativity is governed by long-range elastic field arising from the swelling of molecules between the two spin states. Other promising candidate materials to explore the universality of photo-induced elastic cooperativity are Mott insulators exhibiting resistive switching, and metal oxide nano-crystals with a bistable regime at room temperature
Mondal, Rajib. "Synthesis and Study of Higher Poly(Acene)s: Hexacene, Heptacene, and Derivatives." Bowling Green, Ohio : Bowling Green State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=bgsu1187812264.
Повний текст джерелаCyril, Jean. "Confinement élastique au sein de nanostructures : le nanofil isolé, un système modèle." Thesis, Paris 6, 2017. http://www.theses.fr/2017PA066728/document.
Повний текст джерелаVibrational dynamics of individual nano-objects is studied experimentally using pump and probe time-resolved spectroscopy. First, suspended and individual nano-objects avoid the inhomogeneous broadening of the acoustic properties and increase the acoustics confinement inside the nano-object. Elastic properties of metallic, semiconducting, porous, alloys or core-shell nanowires are thus studied in this advantageous geometry. The increased acoustic confinement in the suspended geometry also lead us to the observation of gigahertz coherent guided acoustic phonons in single copper nanowires and gold nanobeams. We show that the observation of propagating acoustic waves in nanoscale waveguides provide additional elastic informations. Furthermore, it gives the opportunity to unambiguously discriminate which mode is excited and detected using pump and probe time-resolved spectroscopy. On the contrary, nanowires can be used as monochromatic acoustic sources of longitudinal waves when deposited on a substrate. As the acoustic source radiates longitudinal waves inside the substrate, the spatiotemporal imaging of the generated acoustic field is undergone and the nanowire’s orientation is detected in transmission thanks to the acoustic field’s anisotropy. Finally, as another step toward acoustic microscopy with nanoscale spatial resolutions, an atomic force microscopy tip is used as a waveguide and an acoustic transducer with nanometric spatial extension
Costa, Felicissimo Viviane. "Infrared - X-ray pump probe spectroscopy." Licentiate thesis, Stockholm : Theoretical Chemistry, Royal Institute of Technology, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-324.
Повний текст джерелаSpencer, Ben. "Pump-probe spectroscopy of photovoltaic materials." Thesis, University of Manchester, 2011. https://www.research.manchester.ac.uk/portal/en/theses/pumpprobe-spectroscopy-of-photovoltaic-materials(f4b7f755-338a-4fad-814c-4dcc95d5b72d).html.
Повний текст джерелаFaleiros, Marcelo Meira. "Espectroscopia ultrarrápida do polímero semicondutor luminescente MEH-PPV com excitação no ultravioleta." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/76/76132/tde-06122012-084909/.
Повний текст джерелаThe optoelectronics industry is currently undergoing a transition period in which inorganic materials are being replaced by organic materials, oligomers and polymers, in the fabrication of some types of devices. However, factors such as low efficiency and low lifetime prevent polymer based devices on entering the market definitely. The solution of these issues requires a thorough knowledge of the electronic structure of these materials, but despite of scientific advances, there are still points to be clarified. For example, there is no consensus on the nature of the primary optical excitations and non-radiative processes in conjugated polymers, specially with ultraviolet excitation. Such processes limit the efficiency and can influence the photochemical processes, determining the device lifetime. These phenomena occur on a femtosecond timescale and therefore, ultrafast spectroscopy is the most appropriate technique for their study. In this work, we implemented the apparatus for pump-probe ultrafast spectroscopy on thin films of conjugated polymers, which can be used with two methods of data acquisition, phase-sensitive and shot-by-shot. The first is the standard method reported in the literature in which the excitation beam is modulated by a chopper and the signals measured by lock-in amplifiers. In the second, the detector signal conditioning is done by conventional amplifier circuits, followed shot-to-shot signal processing. This method provides the best statistics, in principle, because the laser fluctuations are normalized for each pulse, instead of using the average. In addition, the apparatus has a lower cost and the experiment is simpler, having as critical procedures the alignment of the beams on the sample and the determination of zero delay, with all other procedures done via software. The electronic circuitry for signal conditioning was designed and built and data acquisition software that enables measurements with both methods was developed in the LabVIEW programming language. However, the shot-by-shot method provided an inadequate sensitivity for the study of polymeric films (ΔT⁄T ~0.7%, limited by electronic noise in the amplification of detector signals), compared with ΔT⁄T ~ 0.1%, which was achieved by the phase sensitive method, and was the goal at the beginning of the project. Thus, the latter method was used to study the evolution of the spectrum and dynamics of stimulated emission of a film of MEH-PPV, with excitation in the visible and UV, allowing the study of the dynamics of higher lying electronic states. The results in the visible are consistent with those reported in the literature, which demonstrates the performance of the apparatus with respect to sensitivity and time/spectral resolution. The results with UV excitation indicate that the energy transfer among the more energetic bands to the π - π* band (internal conversion) occurs in about 300 fs, confirming the assumptions of the literature on the ultrafast energy relaxation processes (Kashas rule), besides suggesting the existence of even more energetic bands than those currently known. As future work, we plan to measure the efficiency of this energy transfer process, since it may be the limiting step in determining the overall photoluminescence efficiency of conjugated polymers with ultraviolet excitation.
Costa, Felicissimo Viviane. "Principles of Infrared - X-ray Pump-probe Spectroscopy." Doctoral thesis, KTH, School of Biotechnology (BIO), 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4245.
Повний текст джерелаThe present thesis concerns theoretical studies of molecular interactions investigated by infrared and X-ray spectroscopic techniques, with emphasis on using these two techniques combined in pump-probe experiments. Four main types of studies are addressed: the use of near-edge X-ray absorption fine structure spectra (NEXAFS) to manifest through-bond and through-space interactions; the role of hydrogen bonding in the formation of X-ray photoelectron spectra as evidenced by simulations of the water dimer; the development of theory, with sample applications, for infrared X-ray pump-probe spectroscopy; and molecular dynamics simulations of light-induced fragmentation of water clusters.
Ab initio calculations indicate that NEXAFS spectra give direct information about the through-bond and through-space interactions between vacant non-conjugated π* orbitals. It is found out that the X-ray photoelectron spectrum of the water dimer differs dramatically from the monomer spectrum in that two bands are observed, separated by the chemically shifted ionization potentials of the donor and the acceptor. The hydrogen bond is responsible for the anomalously strong broadening of these two bands. The studies show that X-ray core electron ionization of the water dimer driven by an infrared field is a proper technique to prove the proton transfered state contrary to conventional X-ray photoelectron spectroscopy.
The physical aspects of the proposed new X-ray spectroscopic method - phase sensitive Infrared - X-Ray Pump-Probe Spectroscopy - are examined in detail using the wave packet technique in three applications; the NO molecule and the dynamics of proton transfer in core ionized water dimer and glyoxalmonoxime. It is found out that the phase of the infrared pump field strongly influences the trajectory of the nuclear wave packet on the ground state potential, which results in a phase dependence of the X-ray pump-probe spectra. A proper choice of the delay time of the X-ray pulse allows the direct observation of the X-ray transition in the proton transfered well of the core excited potential. It is found out that the glyoxalmonoxime molecule possesses an important feature; proton transfer accompanied by core hole hopping. Special attention is paid to the quantum control of the populations of vibrational level which is of crucial importance to shape the wave packet of desirable size.
The wave packet technique becomes computationally very expensive when the number of nuclear degrees of freedom is large. Molecular dynamics is used instead in studies of light-induced nuclear kinetics in the water hexamer cluster. We predict a novel mechanism of the mechanical action of light on atoms and molecules. This mechanism is based on the rectification of the Lorentz force, which gives a unique opportunity of direct site selective mechanical action of light on atoms and molecules inside large systems like clusters or biomolecules.
Costa, Felicíssimo Viviane. "Principles of infrared - x-ray pump-probe spectroscopy /." Stockholm : Royal Insitute of Technology, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4245.
Повний текст джерелаReinertsen, Johannes F. "Simulation of Ultrafast Pump-Probe Measurements for Semiconductors." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for elektronikk og telekommunikasjon, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-19336.
Повний текст джерелаSpecht, Marion. "Comportement mécanique de films minces de chalcogénures sous irradiation de photons." Thesis, Rennes 1, 2017. http://www.theses.fr/2017REN1S087/document.
Повний текст джерелаThis work aims to understand photoinduced phenomena in chalcogenide glasses. These phenomena are known for years but yet not fully understood. Studying thin films, deposited by co-sputtering here, adds an other difficulty : the light-matter interaction takes place in a small amount of matter and it is inevitable to deal with the substrate. To study these photoinduced effects, it was necessary to adapt some already existing methods such as pump-probe spectroscopy which measures ultrafast electronic dynamics (less than a nanosecond), piezoelectric quartz sensors which gives density and mechanical modulus of the materials deposited on. Preliminary tests were run to investigate optical transmission resonance and are promising. A DMA machine (Dynamical Mechanical Analysis) was especially designed in the laboratory to study the behaviour of fibers and films. All these experimental setups allow to study photoinduced phenomena at various timescale and to better understand them
FLE, Guillaume. "Extending the pump energy range for a pump-probe system using High Harmonics Generation." Thesis, Uppsala universitet, Molekyl- och kondenserade materiens fysik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-266350.
Повний текст джерелаDominguez, Pablo Nahuel. "Pump-probe measurements of reaction centers from Rhodobacter sphaeroides." Diss., Ludwig-Maximilians-Universität München, 2014. http://nbn-resolving.de/urn:nbn:de:bvb:19-185735.
Повний текст джерелаWalke, Daniel John. "New instrumentation and methods for ultrafast pump-probe spectroscopy." Thesis, Imperial College London, 2016. http://hdl.handle.net/10044/1/48040.
Повний текст джерелаHenriksen, Lisa Grav. "Pump-probe experiments of multicrystalline silicon for solar cell applications." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for fysikk, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-19207.
Повний текст джерелаEhrler, Oli T. "Ultraschnelle zeitaufgelöste Pump-Probe-Photoelektronenspektroskopie an isolierten und massenselektierten Anionen." Karlsruhe : Univ.-Verl. Karlsruhe, 2006. http://www.uvka.de/univerlag/volltexte/2006/181/.
Повний текст джерелаWu, Jing. "Optical pump-probe studies of spin dynamics in ferromagnetic materials." Thesis, University of Exeter, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.364427.
Повний текст джерелаMatía, Hernando Paloma. "Attosecond pump-probe methods for measurement of molecular hole dynamics." Thesis, Imperial College London, 2017. http://hdl.handle.net/10044/1/50155.
Повний текст джерелаFabris, Davide. "Ultrafast light sources and methods for attosecond pump-probe experiments." Thesis, Imperial College London, 2015. http://hdl.handle.net/10044/1/25283.
Повний текст джерелаOmbinda-Lemboumba, Saturnin. "Femtosecond pump probe spectroscopy of light harvesting complexes and Phthalocyanines." Thesis, Stellenbosch : Stellenbosch University, 2011. http://hdl.handle.net/10019.1/17894.
Повний текст джерелаENGLISH ABSTRACT: The generation of ultrafast light pulses and the development of time resolved spectroscopic techniques, such as the femtosecond pump probe spectroscopy technique, have facilitated the study of ultrafast energy transfer in the photosynthetic systems of green plants and photodynamic therapy drugs. It has allowed the investigation of biological and chemical processes that take place on the ultrafast timescale and has allowed us to obtain spectral and kinetic information on energy transfer. In addition, it has allowed time resolved experiments in which the transient absorption of species under investigation was observed and has elucidated molecular dynamics. In the present work this was done with a temporal resolution of approximately 200 fs and covering a pump-to-probe delay range of 300 fs to 2 ns. The main aims of this study were to characterise the femtosecond pump probe spectroscopy system, to investigate the energy transfer in the natural light harvesting complex II (LHC II) in view of future expansion to the study of synthesized arti cial functional light harvesting complexes and nally to study ultrafast processes in zinc phthalocyanine (ZnPc) systems. In photosynthetic organisms, LHC II is the most abundant light harvesting complex and it plays an important role in light harvesting and photoprotection. The light energy is absorbed by light harvesting complexes and transferred to a reaction centre (RC) in an ultrafast timescale. Phthalocyanines are a new class of photosensitiser used for photodynamic therapy. These drugs are used to treat small and super cial tumours. The energy transfer from the singlet excited state to the triplet excited state occurs on an ultrafast timescale. However, recent work done on zinc phthalocyanine has proved that the determination of the ultrafast component remains a challenge. Several ultrafast studies carried out on ZnPc in solvents have been not only unsuccessful to give a clear picture of the ultrafast dynamics but have also produced divergent results. In this study, a characterisation of the femtosecond pump probe spectroscopy setup was done. The samples under investigation were probed by a white light continuum. The generation of the white light continuum introduced chirp, which in uenced the temporal evolution of the transient absorption results. The technique used to correct the chirp introduced by white light generation is discussed in detail. Our femtosecond pump probe spectroscopy setup was benchmarked by using a well known dye, namely malachite green. In addition, the investigation of the transient absorption change of LHC II, an active component in photosynthesis, as extracted from spinach leaves and the ultrafast dynamics of a promising photosensitiser ZnPc in dimethyl sulfoxide (DMSO) as well as in dimethyl formamide (DMF) was done. The spectral and dynamic results obtained using these three samples are described and exponential ts to the absorbance decay curves used to estimate the timescales of the energy transfer processes are presented. In this experiment, the dynamics and measured time constants related to the energy transfer between the different types of chlorophyll in LHC II was monitored, whereas with ZnPc, the dynamics and the measured time constants associated with solvation dynamics and vibrational relaxation was examined.
AFRIKAANSE OPSOMMING: Die vorming van ultravinnige lig pulse en die ontwikkeling van tyd opgelosde spektroskopiese tegnieke, soos die femtosekonde pomp proef spektroskopie tegniek, het die studie van ultravinnige energie oordrag in fotosintetiese stelsels van groen plante en chemiese prosesse gefasiliteer, wat kan plaasvind op die ultravinnige tyd skaal en laat dit toe om spektrale en kinetiese informasie oor die energie oordrag te kan bepaal. Dit het ook dit moontlik gemaak om tyd opgelosde eksperimente te kan doen waarin ons veranderlike absorbsie van die monster kon ondersoek en die molekulere dinamika kon ontrafel. In hierdie werk is dit gedoen met n tyd resolusie van omtrent 200 fs termyl 'n pomp-tot-proef tydvertraging van 300 fs tot 2 ns gebruik is. Die hoof doelwitte van hierdie werk was om 'n femtosekonde pomp proef spektroskopie stelsel te karakteriseer, die energie oordrag in die natuurlike ligoes kompleks II te ondersoek met die toekomstige uitbreiding van die studie na sintetiese lig-oes komplekse as oogmerk en laastens om ultravinnige prosesse in Sink Ftalosianiene stelsels te ondersoek. In fotosintetiese organismes, is lig oes kompleks II die mees volop lig oes kompleks en speel 'n belangrike rol in lig oes en foto skerming. Die lig energie word geabsorbeer deur lig oes komplekse en dan oorgedra na reaksie middelpunte in 'n ultravinnige tydskaal. Ftalosianiene is 'n nuwe klas fotosensiteerder wat gebruik word in fotodinamiese terapie. Hierdie dwelms word gebruik om klein en oppervlakkige gewasse te behandel. Die energie oordrag van die opgewekte singlet tot die triplet toestand vind plaas op die ultravinnige tydskaal. Onlangse navorsingswerke het getoon dat die bepaling van die ultravinnige komponent 'n uitdaging bly. Verskeie vorige ondersoeke is gedoen op Sink Ftalosianiene in verskeie oplosmiddels, en nie net het hierdie studies nie 'n helder prentjie verskaf van die ultravinnige dinamika nie, maar het ook divergerende resultate opgelewer. In hierdie werk word 'n karakterisering van die femtosekonde pomp proef spektroskopie stelsel gedoen. Die monsters is ondersoek met 'n wit lig kontinuum proef. Die vorming van die wit lig kontinuum het tjirp veroorsaak, wat die tyd evolusie van die veranderlike absorbsie resultate beinvloed het. Die tegniek wat gebruik was om die tjirp te korregeer word bespreek. Ons femtosekonde pomp proef spektroskopie stelsel is gestandardiseer deur die welbekende kleurstof malachiet groen. Ons het ook die veranderlike absorbsie van lig oes kompleks II ondersoek, 'n aktiewe komponent in fotosintese, soos dit onttrek is uit spinasie blare, asook die ultravinnige dinamika van die belowende photosensitizer Sink Ftalosianiene in DMSO asook DMF. Die spektrale en dinamiese resultate verkry vanaf hierdie drie monsters word beskryf en eksponensiele passings aan die absorbsie verval kurwes is gebruik om die tydskale van die energie oordrag prosesse te skat. In hierdie eksperiment is dinamika en gemete tydkonstantes waargeneem wat toegeskryf kan word aan die energie oordrag tussen verskillende soorte chloro l in lig oes kompleks II. In die Sink Ftalosianien eksperimente is dinamika en gemete tydkonstantes waargeneem wat toegeskryf kan word aan solverings dinamika asook vibrasionele ontspanning.
Cheng, Yu-Hsiang. "Photoinduced dynamics studied by ultrafast single-shot pump-probe spectroscopy." Thesis, Massachusetts Institute of Technology, 2019. https://hdl.handle.net/1721.1/122684.
Повний текст джерелаThesis: Ph. D., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2019
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 155-168).
This thesis focuses on the development of dual-echelon single-shot spectroscopy and its applications to study irreversible photoinduced dynamics. First, the ultrafast laser sources and the related control and characterization techniques are discussed. In particular, we have invented a two-stage dual-beam noncollinear optical parametric amplifier to provide tunable sources for pump-probe spectroscopy. Next, the experimental setup of dual-echelon single-shot spectroscopy is illustrated with great detail and possible noise sources and correction methods are explored. Using the single- shot technique, we studied photoinduced dynamics in three different materials. In bismuth, we found a transition into a transient symmetric phase at high fluences. We showed the coherent control of phonon parameters with pump-pump-probe experiments. We also simulated the carrier and phonon dynamics using a modified two-temperature model. In tellurium, we demonstrated that the amorphization of crystalline tellurium induced by femtosecond pulses is a thermal process. We also estimated the lattice temperature by the change in phonon frequency. In a strained manganite film, we observed a photoinduced persistent insulator-to-metal transition and showed the partial recovery of the generated metallic phase to the insulating phase.
by Yu-Hsiang Cheng.
Ph. D.
Ph.D. Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science
Harper, Matthew R. "Control and measurement of ultrafast pulses for pump/probe-based metrology." Thesis, St Andrews, 2007. http://hdl.handle.net/10023/430.
Повний текст джерелаIssenmann, Daniel [Verfasser]. "Studium der Phononendynamik mit Pump-Probe-Experimenten im Röntgenbereich / Daniel Issenmann." Konstanz : Bibliothek der Universität Konstanz, 2014. http://d-nb.info/1050348818/34.
Повний текст джерелаChung, Dutch D. 1969. "Femtosecond pump-probe spectroscopy of chemical reactions in liquids and crystals." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/10022.
Повний текст джерелаBacon, David Robert. "Time-resolved pump-probe investigation of the terahertz quantum cascade laser." Thesis, University of Leeds, 2017. http://etheses.whiterose.ac.uk/17968/.
Повний текст джерелаKim, Yang-Hyo. "Wide-field structured illumination microscopy for fluorescence and pump-probe imaging." Thesis, Massachusetts Institute of Technology, 2018. https://hdl.handle.net/1721.1/121846.
Повний текст джерелаCataloged from PDF version of thesis.
Includes bibliographical references.
The optical resolution of microscopy is limited by the wave-like characteristic of the light. There are many recent advances in overcoming this diffraction limited resolution, but mostly focused on fluorescent imaging. Furthermore, there are few non-fluorescence wide-field super-resolution techniques that can fully utilize the applicable laser power to optimize imaging speed. Structured illumination microscopy is a super-resolution method that relies on patterned excitation. This thesis has presented novel applications of structured illumination microscopy to surface plasmon resonance fluorescence and pump-probe scattering imaging. First, structured illumination microscopy was introduced to surface plasmon resonance fluorescence imaging for high signal-to-noise and high resolution. Secondly, a theoretical framework for three-dimensional wide-field pump-probe structured illumination microscopy has been developed to increase the lateral resolution and enable depth sectioning. Further, structured illumination wide-field photothermal digital phase microscopy is proposed as a high throughput, high sensitivity super-resolution imaging tool to diagnose ovarian cancer. Finally, I have derived the exact analytical solution to the heat conduction problem in which a sphere absorbs temporally modulated laser beam for photothermal microscopy. The proposed method also has a great potential to be applied to other pump-probe modalities such as transient absorption and stimulated Raman scattering.
Funding sources and sponsors: National Institutes of Health (9P41EB015871-26A1, 5R01NS051320, 4R44EB012415, and 1R01HL121386-OlAl), National Science Foundation (CBET-09395 11), Hamamatsu Corporation, Singapore-Massachusetts Institute of Technology Alliance for Research and Technology (SMART) Center, BioSystems and Micromechanics (BioSyM), and Samsung Scholarship
by Yang-Hyo Kim.
Ph. D.
Ph.D. Massachusetts Institute of Technology, Department of Mechanical Engineering
Pincelli, T. "PROBING ELECTRON CORRELATION DYNAMICS: A MULTI-TECHNIQUE STUDY APPLIED TO THE HALF-METALLIC OXIDE LA1-XSRXMNO3." Doctoral thesis, Università degli Studi di Milano, 2017. http://hdl.handle.net/2434/543731.
Повний текст джерелаFlögel, Martin [Verfasser]. "Raising the XUV Intensity towards Attosecond-Attosecond Pump-Probe Experiments / Martin Flögel." Berlin : Freie Universität Berlin, 2017. http://d-nb.info/1133492347/34.
Повний текст джерелаSouther, Nathan Jon. "Light Shift Measurements of Cold Rubidium Atoms using Raman Pump-Probe Spectroscopy." Miami University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=miami1250622906.
Повний текст джерелаStangoni, Maria Virginia. "Scanning probe techniques for dopant profile characterization /." [S.l.] : [s.n.], 2005. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=16024.
Повний текст джерелаTaylor, Christopher George. "Novel fluorescence techniques to probe protein aggregation." Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/276197.
Повний текст джерелаAttwood, Simon. "Nanoscale chemical specification using scanning probe techniques." Thesis, University of Cambridge, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.608912.
Повний текст джерелаBene, J. G. (József Gergely). "Pump schedule optimisation techniques for water distribution systems." Doctoral thesis, Oulun yliopisto, 2013. http://urn.fi/urn:isbn:9789526202662.
Повний текст джерелаTiivistelmä Työ käsittelee alueellisten vedenjakelujärjestelmien pumppauksen aikataulutuksen optimointia. Esitettyjen menetelmien tavoitteet ja mahdolliset sovellukset poikkeavat toisistaan. Kaikki on kuitenkin tarkoitettu tiettyjen todellisten ongelmien ratkaisemiseen. Kehitetyt tekniikat käyttävät vesivarastojen kapasiteettia optimaalisen pumppausohjelman löytämiseksi. Jokainen optimointitehtävä on aikadiskreetti ja deterministinen, vedenkulutuksen stokastista käyttäytymistä on approksimoitu odotusarvoilla. Ensimmäiseksi työssä esitetään ns. neutraaleja geneettisiä algoritmeja varustettuna rajoitusten käsittelyllä. Menetelmällä voidaan ratkaista skedulointiohjelmia reaalimittakaavaisille ja monimutkaisille verkostoille (esim. Budapestin verkosto varustettuna hydraulisilla simuloinneilla, sekä muuttuvanopeuksisilla että vakionopeuksisilla verkoston pumpuilla). Tuloksia verrataan toisiin yleisesti käytössä olevilla geneettisillä algoritmeilla saatuihin, sekä johtavilla yleiskäyttöisillä optimointitekniikoilla saatuihin tuloksiin. Työssä käytettiin myös dynaamiseen ohjelmointiin pohjaavaa menetelmää, jolla saadaan globaali optimi ns. "kombinatoorisille" pumppauksen aikataulutusongelmille. Tällainen mallinnustapa on hyvin yleistä teollisuudessa. Sitä voidaan käyttää, jos pumppujen toimintapisteet saavat diskreettejä arvoja. Menetelmän perusajatuksena on "permutationaalisen invarianssin" hyväksikäyttäminen, josta seuraa tila-avaruuden virheetön diskretointi ilman informaation häviämistä. Työssä esitellään myös approksimoidun dynaamisen ohjelmoinnin tekniikka, jonka avulla voidaan ratkaista samantyyppisiä ongelmia kuin yllämainituilla geneettisillä algoritmeilla. Tämä tekniikka jakaa vesijohtoverkoston mallin pienempiin yksiköihin: lähdekenttiin ja pääjakeluverkostoon. Pääjakeluverkoston tila-avaruutta voitiin edelleen pienentää ilman, että tulosten laatu heikkeni. Osa käsitellyistä esimerkkitapauksista on samoja kuin edellämainittujen geneettisten algoritmien osalla, joten tuloksia voidaan verrata. Lopuksi tutkittiin pienen muuttuvanopeuksisella pumpulla syötetyn vesijohtoverkoston toimintaa. Esitetyt menetelmät perustuvat ominaisenergiankulutuksen minimointiin. Saatuja tuloksia verrataan korkearesoluutioisella diskreetillä dynaamisella ohjelmoinnilla saatuihin tuloksiin. Työssä kehitettiin uusia optimointitekniikoita vedenjakelujärjestelmien pumppauksen aikataulutuksen optimintiin. Erityisesti työssä keskityttiin pumppauksen, vesitornien ja kuluttajien käyttäytymisen väliseen dynamiikkaan. Työssä osoitettiin tekniikoiden toimivuus realististen esimerkkisimulointien avulla
Kivonat Jelen doktori disszertáció regionális ivóvízellátó-hálózatok üzemvitel-optimalizációjával foglalkozik. A bemutatott módszerek alkalmazhatósági köre rendszerint eltér egymástól, mindegyik egy-egy speciális, de a való életben is előforduló problémára kíván megoldást nyújtani. A kidolgozott módszerek a medencék tárolókapacitását kihasználva, az optimális szivattyú-menetrendet keresve kívánják megtalálni az adott vízműhálózat üzemviteloptimumát. Az optimalizáció egy időben diszkrét, ugyanakkor determinisztikus feladat megoldását igényli, a vízfogyasztások sztochasztikus viselkedését a várható értékekkel közelítettem. Elsőként egy új mellékfeltétel-kezeléssel ellátott, ún. neutrális genetikus algoritmus bemutatása a cél. A kidolgozott módszer alkalmas nagy, valós méretű (pl. Budapest) és bonyolultságú (kapcsolt hidraulikai szimulációk, frekvenciaváltós és direkt szivattyúk a hálózatban) ivóvízhálózatok napi üzemvitel optimalizálására. Az eredményeket más genetikus algoritmusokkal és a világ élvonalába tartozó, de általános célú optimalizációs módszerekkel hasonlítottam össze. Kidolgozásra került egy dinamikus programozás alapú, a valós, globális optimumot adó módszer is. Az algoritmus a gyakorlatban elterjedt, ún. "kombinációs" hálózatként modellezhető vízműhálózat típusokra alkalmazható, ahol a szivattyúk munkapontjai diszkrét értékek. A megoldás alapját az ún. "permutációs invariancia" jelensége adja, mely lehetővé teszi az állapottér információveszteség nélküli, tökéletes diszkretizációját. Egy, a korábban bemutatott genetikus algoritmuséhoz hasonló problémakört megoldó, de közelítő dinamikus programozás alapú módszer is bemutatásra kerül. Az algoritmus a hálózat kisebb részegységekre (víztermelő területekre és fő elosztó hálózatra) való felbontásával és a fő elosztó hálózat állapotterének önkényes, de a megoldás jóságán jelentősen nem rontó csökkentésével éri el a program futtatásához szükséges számítási igény csökkentését. A tesztfeladatok egy része megegyezik a genetikus algoritmus tesztfeladataival, így azok közvetlenül összehasonlíthatóak. Végül bemutatásra kerül egy kisméretű, mindössze egy darab változtatható fordulat- számú szivattyúval táplált rendszer energetikai vizsgálata. Az itt bemutatott módszerek mind a fajlagos energiafelhasználás minimalizálásán alapulnak. Az eredményeket egy nagyfelbontású dinamikus programozás alapú módszerhez hasonlítottam
Cavanagh, Molly Christine. "Using the ultrafast pump-probe spectroscopy of atomic anions and the solvated electron to probe solvent structure and solvation dynamics." Diss., Restricted to subscribing institutions, 2008. http://proquest.umi.com/pqdweb?did=1581642021&sid=1&Fmt=2&clientId=1564&RQT=309&VName=PQD.
Повний текст джерелаKruglyak, Volodymyr. "Femtosecond optical pump-probe investigations of ultrafast electron and spin dynamics in metals." Thesis, University of Exeter, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.410811.
Повний текст джерела