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Laser absorption spectroscopy
Vyhlídka, Štěpán ; Plašil, Radek (advisor) ; Hrubý, Vojtěch (referee)
Study of recombination of molecular ionts in cold plasma plays a key role in our understanding of chemical kinetics in interstellar space or in upper layers of planetar atmospheres. Various metods are used for its study of which important part is laser absorption spectroscopy. Concentration or temperature of measured ionts can be found from their absorption spectra. In the presented work two spectroscopic techniques are briefly introduced - Cavity ringdown spectroscopy and Laser induced reaction technique. Main me- chanisms for spectral linewidth broadening are described and from absorption spectra of H+ 3 and N+ 2 ionts measured by above-mentioned techniques their kine- tic temperature is discovered. Because it is affected by spectral width of applied laser diodes, a part of this work also deals with description of its measurement by self-heterodyne method or Fabry-Pérot interferometer. The spectral width is found for infrared diode DFB laser. 1
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Dispersion management of a 10 PW laser system
Vyhlídka, Štěpán ; Rus, Bedřich (advisor) ; Jelínková, Helena (referee) ; Kozák, Martin (referee)
This thesis deals with the design of a stretcher and compressor systems used for the chirped pulse amplification method for the L4 beamline. The L4 beamline is being developed for the ELI Beamlines project and aims to deliver pulses with peak power of 10 petawatt, central wavelength of 1060 nanometers, pulse duration of 150 femtoseconds and energy of 1500 Joules. Since the laser induced damage threshold and aperture of commercial diffraction gratings is currently a limiting factor in reaching higher peak powers, it was necessary to increase the effective aperture of the compressor using either tiled grating or object-image-grating self tiling methods. These two methods are compared for two compressor configurations using either 1740 ln/mm or 1136 ln/mm diffraction gratings, methods for their alignment are discussed and the selected alignment method is experimentally tested. Moreover, an analytical theory connecting the Seidel aberrations of the stretcher imaging system with the spectral phase deviation of the stretched pulse is presented. This theory is applied to commonly used Banks and Offner stretcher designs and it is demonstrated how it can be employed for the suppression of residual spectral phase of compressed pulses. Next, the design of the stretcher for the L4 beamline based on this theory is...
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Business dealings and negotiation strategies in China
Žežulík, Michal ; Křečková Kroupová, Zuzana (advisor) ; Vyhlídka, Štěpán (referee)
This Bachelor thesis analyzes conduct of business dealings in China in order to provide deeper insight for Czech negotiators into motivation and way of thinking of their Chinese business partners. The work summarizes knowledge of foreign authors devoted to research of Chinese business dealings specifics, including dirty negotiation tactics, and experiences of Czech businessmen from this region. The thesis uncovers main causes of misunderstandings and disagreements among Chinese and Czech business partners arising from different cultural background and expectations of parties involved. The work concludes with description of usual negotiation strategies of Chines business negotiators, major negotiation rigors and suggestions to overcome them.
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Modulation of time dispersion of femtosecond laser pulses
Vyhlídka, Štěpán ; Straka, Petr (advisor) ; Ostatnický, Tomáš (referee)
In the presented thesis the topic of femtosecond pulse dispersion and methods of characterizing pulse profile are briefly introduced. Then, a functionality of a spatial light modulator is described. The spatial light modulator was used in an experimental scheme called the pulse shaper, which allowed independent amplitude and phase modulation of pulses. Duration and dispersion of pulses was measured by two methods called MIIPS and PICASO. MIIPS was also used for a reconstruction of a spectral phase of pulses. The autocorrelator was constructed on a design of the Mach-Zehnder interferometer. The duration of the shortest measured pulse (13.3 ± 0.5) fs was retrieved from measured interferometric autocorrelations by PICASO. Furthermore, theoretical dependence of pulse duration on the group delay dispersion was confirmed for pulses shorter than 120 fs. The group velocity dispersion was measured for fused silica windows and for a pair of diffraction gratings in the pulse shaper. Both values confirmed theoretical expectations.
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Laser absorption spectroscopy
Vyhlídka, Štěpán ; Plašil, Radek (advisor) ; Hrubý, Vojtěch (referee)
Study of recombination of molecular ionts in cold plasma plays a key role in our understanding of chemical kinetics in interstellar space or in upper layers of planetar atmospheres. Various metods are used for its study of which important part is laser absorption spectroscopy. Concentration or temperature of measured ionts can be found from their absorption spectra. In the presented work two spectroscopic techniques are briefly introduced - Cavity ringdown spectroscopy and Laser induced reaction technique. Main me- chanisms for spectral linewidth broadening are described and from absorption spectra of H+ 3 and N+ 2 ionts measured by above-mentioned techniques their kine- tic temperature is discovered. Because it is affected by spectral width of applied laser diodes, a part of this work also deals with description of its measurement by self-heterodyne method or Fabry-Pérot interferometer. The spectral width is found for infrared diode DFB laser. 1
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Cao Cao - historical prsonality and literary figure through centuries
Vyhlídka, Štěpán ; Lomová, Olga (referee) ; Maršálek, Jakub (advisor)
V čínské historii je mnoho velkých a důležitých postav, které se dostaly do lidového vyprávění, jsou ztvárněny v literatuře, různě velebeny a oslavovány, či naopak haněny a kritizovány. Důležitým hrdinou a nepřehlédnutelnou postavou čínských dějin je bezesporu vojevůdce Cao Cao lf~. Příběhy o jeho životě jsou vypravovány po staletí. Lidé se k nim stále vracejí a také v současné době cítí potřebu se k nim vyjadřovat. Cao Cao má v historii Číny své nezastupitelné místo. Kdyby se události vyvíjely jinak, možná by dnes zaujímal přední místo mezi nejslavnějšími kladnými čínskými hrdiny a ztělesňoval by ctnostného panovníka sjednotitele. V čínském povědomí je však většinou obecně spojován s prototypem záporného hrdiny. Tak tomu ale nebylo vždy. Zobrazení jeho osobnosti mělo svůj vývoj. Vznikl určitý rozpor mezi reálnou historickou osobností a jejím výrazně záporným obrazem. O hodnocení Cao Caoovy osobnosti se vedly diskuse a nejednotné bylo i umělecké ztvárnění jeho postavy. Ve své diplomové práci se budu věnovat tomuto kontrastu. Chtěl bych zjistit, jak velké jsou rozpory mezi historickou osobností Cao Caoa a jeho postavou zpodobněnou v literatuře a čínském tradičním divadle a zda se jedná o kontrast, který je dán vývojem hodnocení Cao Caoovy postavy. Chci popsat, jaký byl tento vývoj a co ovlivňovalo formování...
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