@article{PingelFayUrbach2019, author = {Pingel, Ruta and Fay, Doris and Urbach, Tina}, title = {A resources perspective on when and how proactive work behaviour leads to employee withdrawal}, series = {Journal of occupational and organizational psychology}, volume = {92}, journal = {Journal of occupational and organizational psychology}, number = {2}, publisher = {Wiley}, address = {Hoboken}, issn = {0963-1798}, doi = {10.1111/joop.12254}, pages = {410 -- 435}, year = {2019}, abstract = {Previous organizational behaviour research has mainly focused on the benefits of proactivity while disregarding its possible drawbacks. The present study examines the ways in which proactive behaviour may foster counterproductive behaviour through increased emotional and cognitive strain. Drawing on conservation of resources theory, we propose that proactive behaviour is a resource-consuming activity that causes irritability and work-related rumination, which, in turn, leads to instrumentally driven employee withdrawal. Further, we hypothesize that external motivation towards proactivity amplifies its strain-eliciting effects. We conducted a longitudinal three-wave questionnaire study (N = 231) and tested hypotheses using an autoregressive, time-lagged model with latent variables. Results showed that when external motivation for proactivity was high, proactivity led to increased irritability and rumination; irritability was, in turn, related to higher levels of withdrawal. The moderated mediation analysis revealed that when external motivation towards proactive behaviour was high, proactive behaviour had an indirect effect on withdrawal behaviour via irritability. The direct effect of proactivity on work-related rumination was in the expected direction, but failed to reach conventional levels of significance (beta = .09, p = .08). Our results indicate that proactivity is not without costs, most clearly if motivated by external reasons.}, language = {en} } @phdthesis{Sander2018, author = {Sander, Mathias}, title = {Ultrafast tailored strain fields in nanostructures}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-417863}, school = {Universit{\"a}t Potsdam}, pages = {xvii, 119}, year = {2018}, abstract = {This publication based thesis, which consists of seven published articles, summarizes my contributions to the research field of laser excited ultrafast structural dynamics. The coherent and incoherent lattice dynamics on microscopic length scales are detected by ultrashort optical and X-ray pulses. The understanding of the complex physical processes is essential for future improvements of technological applications. For this purpose, tabletop soruces and large scale facilities, e.g. synchrotrons, are employed to study structural dynamics of longitudinal acoustic strain waves and heat transport. The investigated effects cover timescales from hundreds of femtoseconds up to several microseconds. The main part of this thesis is dedicated to the investigation of tailored phonon wave packets propagating in perovskite nanostructures. Tailoring is achieved either by laser excitation of nanostructured bilayer samples or by a temporal series of laser pulses. Due to the propagation of longitudinal acoustic phonons, the out-of-plane lattice spacing of a thin film insulator-metal bilayer sample is modulated on an ultrafast timescale. This leads to an ultrafast modulation of the X-ray diffraction efficiency which is employed as a phonon Bragg switch to shorten hard X-ray pulses emitted from a 3rd generation synchrotron. In addition, we have observed nonlinear mixing of high amplitude phonon wave packets which originates from an anharmonic interatomic potential. A chirped optical pulse sequence excites a narrow band phonon wave packet with specific momentum and energy. The second harmonic generation of these phonon wave packets is followed by ultrafast X-ray diffraction. Phonon upconversion takes place because the high amplitude phonon wave packet modulates the acoustic properties of the crystal which leads to self steepening and to the successive generation of higher harmonics of the phonon wave packet. Furthermore, we have demonstrated ultrafast strain in direction parallel to the sample surface. Two consecutive so-called transient grating excitations displaced in space and time are used to coherently control thermal gradients and surface acoustic modes. The amplitude of the coherent and incoherent surface excursion is disentangled by time resolved X-ray reflectivity measurements. We calibrate the absolute amplitude of thermal and acoustic surface excursion with measurements of longitudinal phonon propagation. In addition, we develop a diffraction model which allows for measuring the surface excursion on an absolute length scale with sub-{\"A}angstr{\"o}m precision. Finally, I demonstrate full coherent control of an excited surface deformation by amplifying and suppressing thermal and coherent excitations at the surface of a laser-excited Yttrium-manganite sample.}, language = {en} }