Christian-Albrechts-Universität zu Kiel
Institut für Physikalische Chemie
We apply and explore techniques aiming at enhancing the tunneling by laser fields, originally developed for a one-dimensional model, to a complete six-dimensional vibrational model of the inversion motion in NHD 2 . The computational... more
We apply and explore techniques aiming at enhancing the tunneling by laser fields, originally developed for a one-dimensional model, to a complete six-dimensional vibrational model of the inversion motion in NHD 2 . The computational study is performed with the multi-configuration time-dependent Hartree method. Assuming an ideal three-dimensional alignment we obtain a driven tunneling time twenty times smaller than the natural one, in rather good agreement with an oversimplified three-state model. In the case of one-dimensional alignment, a linearly polarized field leads to a poor enhancement of the tunneling probability, after averaging over the rotation about the alignment axis, whereas a circularly polarized field improves the rotationally averaged tunneling probability at the end of the pulse.
Rovibrational eigenenergies of HONO are computed and compared to experimental energies available in the literature. For their computation, we use a previously developed potential energy surface (PES) and a newly derived exact kinetic... more
Rovibrational eigenenergies of HONO are computed and compared to experimental energies available in the literature. For their computation, we use a previously developed potential energy surface (PES) and a newly derived exact kinetic energy operator (KEO) including the overall rotation for a tetra-atomic molecule in non-orthogonal coordinates. In addition, we use the Heidelberg Multi-Configuration Time-Dependent Hartree (MCTDH) package. We compare the experimental rovibrational eigenvalues of HONO available in the literature with those obtained with MCTDH and a previously developed potential energy surface (PES) [F. Richter et al., J. Chem. Phys., 2004, 120, 1306 for the cis geometry. The effect of the overall rotation on the process studied in our previous work on HONO [F. Richter et al., J. Chem. Phys., 2007, 127, 164315.] leading to the cistrans isomerization of HONO is investigated. This effect on this process is found to be weak.
- by Hans-dieter Meyer and +2
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- Physical sciences, CHEMICAL SCIENCES
We present a full quantum-mechanical study of the laser control of the radiationless decay between the B3u(nπ(*)) and B2u(ππ(*)) states of pyrazine using the dynamic Stark effect. In contrast to our previous study [Sala et al., J. Chem.... more
We present a full quantum-mechanical study of the laser control of the radiationless decay between the B3u(nπ(*)) and B2u(ππ(*)) states of pyrazine using the dynamic Stark effect. In contrast to our previous study [Sala et al., J. Chem. Phys. 140, 194309 (2014)], where a four-dimensional model was used, all the 24 degrees of freedom are now included in order to test the robustness of the strategy of control. Using a vibronic coupling Hamiltonian model in a diabatic representation, the multi-layer version of the multi-configuration time-dependent Hartree method is exploited to propagate the corresponding wave packets. We still observe a trapping of the wavepacket on the B2u(ππ(*)) potential energy surface due to the Stark effect for a longer time than the "non-resonant field-free" B2u(ππ(*)) lifetime.
- by Stephane Guerin and +3
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- Engineering, Physical sciences, CHEMICAL SCIENCES
Chapter No.1 : Introduction 1 Diabetes Mellitus • Classification of diabetes mellitus 2 • Diagnosis of diabetes mellitus: 3 • Pathogenesis of type 2 diabetes mellitus 3 ACKNOWLEDGMENTS Praise be to ALLAH the Cherisher and Sustainer of the... more
Chapter No.1 : Introduction 1 Diabetes Mellitus • Classification of diabetes mellitus 2 • Diagnosis of diabetes mellitus: 3 • Pathogenesis of type 2 diabetes mellitus 3 ACKNOWLEDGMENTS Praise be to ALLAH the Cherisher and Sustainer of the worlds: Who granted man with knowledge from His unseen treasures. All regards and respects are for the Holy Prophet Hazrat MUHAMMAD (SalAllahu 'alaihi wa sallam), whose blessings and teachings flourished my thoughts and thrived my ambitions. No works can suffice to express my indebtedness to my supervisor, Dr. Abdul Khaliq Naveed for his brilliant versatility, devoted guidance and for being so supportive and dependable, for his unflinching support and immense patience at all stages of this work. I am also grateful to him for being extremely supportive of all research activities going on in this department.
Within the last few decades, interlanguage pragmatics research has risen to its due prominence under the influence of Hymes and the subsequent models of Communicative Competence (CC). Among different components of CC, a large number of L2... more
Within the last few decades, interlanguage pragmatics research has risen to its due prominence under the influence of Hymes and the subsequent models of Communicative Competence (CC). Among different components of CC, a large number of L2 studies have attended to the construct pragmatic competence, which deals with both pragmalinguistic knowledge and sociopragmatic knowledge. As such, interlanguage pragmatics research is interested in the pragmatic competence and pragmatic performance of L2 learners; however, teaching pragmatics to Non-native Speakers (NNSs), especially EFL learners, is a thorny issue. As a result, pragmatic competence has been noticeably absent from ELT curricula, despite the fact that it has an assured place in different models of CC. The reasons for this neglect lie behind the obstacles to teaching and learning pragmatics in the ESL/EFL classroom settings. Thus, drawing on the published literature, this very paper primarily aims at discussing challenges and lacunas in teaching and learning pragmatics within the confines of EFL classrooms. Subsequent to this, the paper enlists suggestions to overcome these obstacles. To this end, the paper focuses on four broad areas: the EFL context, ELT materials and resources available to L2 learners in the EFL context, teacher education, and assessment of pragmatic knowledge.