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191.
zur Capellen Walther Meyer 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》1960,11(3):207-218
Summary The rotational energy of a link in a mechanism is proportional to the square of its angular velocity. This square, in contrast to the angular velocity itself, can be expanded into a Fourier series, having finite values for its coefficients. The problem is solved by splitting it into partial fractions, leading to the harmonic analysis of the slotted lever mechanism. Further related series are given at the end. 相似文献
192.
Triplet-state X traps in naphthalene single crystals were investigated using ENDOR spectroscopy. In addition to the intramolecular hyperfine interaction with the X-trap protons the intermolecular hyperfine interaction with 12 protons of molecules in the vicinity of the X trap as well as that with the fluorine nucleus of the trap-inducing guest molecule could be analyzed. 相似文献
193.
194.
Size-dependent magnetic single-domain versus vortex state stability of Co/Ru(0001) nanodots is explored with spin-polarized low-energy electron microscopy, analytical modeling, and micromagnetic simulations. We show that both single-domain and vortex states can be stabilized in a broad region near the phase boundary. The calculated width of the bistability region and temperature dependent heights of the energy barriers between both states agree well with our experimental findings. 相似文献
195.
Linear optics quantum logic gates are the best tool to generate multiphoton entanglement. Simplifying a recent approach, we were able to implement the conditional phase gate with only one second-order interference at a polarization dependent beam splitter, thereby significantly increasing its stability. The improved quality of the gate is evaluated by analyzing its entangling capability and by performing full process tomography. The achieved results ensure that this device is well suited for implementation in various multiphoton quantum information protocols. 相似文献
196.
Neutron scattering studies of single crystal LiNiPO4 reveal a spontaneous first-order commensurate-incommensurate magnetic phase transition. Short- and long-range incommensurate phases are intermediate between the high temperature paramagnetic and the low temperature antiferromagnetic phases. The modulated structure has a predominant antiferromagnetic component, giving rise to satellite peaks in the vicinity of the fundamental antiferromagnetic Bragg reflection, and a ferromagnetic component, giving rise to peaks at small momentum transfers around the origin at (0,+/-Q,0). The wavelength of the modulated magnetic structure varies continuously with temperature. It is argued that the incommensurate short- and long-range phases are due to spin-dimensionality crossover from a continuous to the discrete Ising state. 相似文献
197.
de La Figuera J Pohl K de La Fuente OR Schmid AK Bartelt NC Carter CB Hwang RQ 《Physical review letters》2001,86(17):3819-3822
Using scanning tunneling microscopy we have observed thermally induced dislocation glide in monolayer Cu films on Ru(0001) at room temperature. The motion is governed by a Peierls barrier that depends on the detailed structure of the dislocations, in particular upon whether the threading dislocations that terminate them are dissociated or not. Calculations based on the Frenkel-Kontorova model reproduce the threading dislocation structure and provide estimates of the Peierls barrier and dislocation stiffness which are consistent with experiment. 相似文献
198.
Hebenstreit W Schmid M Redinger J Podloucky R Varga P 《Physical review letters》2000,85(25):5376-5379
Atomically resolved scanning tunneling microscopy reveals the existence of triangular (111) bulk terminated NaCl islands. The islands can be grown by subsequent adsorption of Na and Cl2 on Al(111) and Al(100) or by conversion of stoichiometric NaCl(100) islands to NaCl(111) via additional Na adsorption. The NaCl(111) islands have Na-Cl-Na sandwich structure. Ab initio calculations of the electronic structure of these islands show that each of the Na atoms carries half a positive elementary charge, leaving the islands neutral and explaining the existence of an otherwise unstable surface. 相似文献
199.
Second harmonic generation (SHG) spectroscopy is a recently developed technique for the investigation of surface properties
of particles. To apply the method to technical colloidal systems, the dependences of several experimental parameters on the
signal have to be studied. In this work the influence of particle concentration on the SHG signal from the surfaces of colloids
(polystyrene beads in a size range of 0.1 μm to 2.9 μm) is investigated. A simple model, based on Lambert–Beer’s law, to describe
the measured dependences is derived. The model agrees with the experimental observations for particles smaller 1.1 μm and
with a small modification also for larger particles. Based on the new model an analytical equation for determining the optimum
concentration, where highest signals in colloidal SHG spectroscopy measurements are obtained, is derived.
PACS 42.25.Fx; 42.65.-k; 82.70.Dd 相似文献