Search results for "Simple harmonic motion"
showing 4 items of 4 documents
DFT and experimental studies on structure and spectroscopic parameters of 3,6-diiodo-9-ethyl-9H-carbazole
2015
The first report on crystal and molecular structure of 3,6-diiodo-9-ethyl-9H-carbazole is presented. Experimental room-temperature X-ray and 13C chemical shift studies were supported by advanced theoretical calculations using density functional theory (DFT). The 13C nuclear magnetic shieldings were predicted at the non-relativistic and relativistic level of theory using the zeroth-order regular approximation (ZORA). Theoretical relativistic calculations of chemical shifts of carbons C3 and C6, directly bonded to iodine atoms, produced a reasonable agreement with experiment (initial deviation from experiment of 44.3 dropped to 4.25 ppm). The changes in ring aromatic character via simple harm…
Few-neutron removal from238U at relativistic energies
1995
As part of a comprehensive study of uranium fragmentation at relativistic energies at the GSI projectile fragment separator, FRS, inclusive neutron-removal cross sections have been measured for severalxn channels at projectile energies of 600 and 950A MeV using targets of Al, Cu and Pb. The variation of the experimental cross sections with target nuclear charge is used to disentangle nuclear and electromagnetic contributions. The electromagnetic cross sections agree surprisingly well with a simple harmonic oscillator calculation of giant dipole resonances based on measured photonuclear cross sections and do not require an extra enhancement of the two-phonon giant dipole excitation as conclu…
Scanning force microscopy based rapid force curve acquisition on supported lipid bilayers: experiments and simulations using pulsed force mode.
2004
In situ pulsed force mode scanning force microscopy (PFM-SFM) images of phase separated solid-supported lipid bilayers are discussed with the help of computer simulations. Simultaneous imaging of material properties and topography in a liquid environment by means of PFM-SFM is severely hampered by hydrodynamic damping of the cantilever. Stiffness and adhesion images of solid-supported membranes consisting of cholesterol, sphingomyelin, and 1,2-dioleyl-phosphatidylcholine obtained in aqueous solution exhibit contrast inversion of adhesion and stiff. ness images depending on parameters such as driving frequency, amplitude, and trigger setting. Simulations using a simple harmonic oscillator mo…
Lagrangian dynamics and possible isochronous behavior in several classes of non-linear second order oscillators via the use of Jacobi last multiplier
2015
Abstract In this paper, we employ the technique of Jacobi Last Multiplier (JLM) to derive Lagrangians for several important and topical classes of non-linear second-order oscillators, including systems with variable and parametric dissipation, a generalized anharmonic oscillator, and a generalized Lane–Emden equation. For several of these systems, it is very difficult to obtain the Lagrangians directly, i.e., by solving the inverse problem of matching the Euler–Lagrange equations to the actual oscillator equation. In order to facilitate the derivation of exact solutions, and also investigate possible isochronous behavior in the analyzed systems, we next invoke some recent theoretical result…