Low frequency limits of third-order harmonic coefficients for atomic hydrogen in any level of discrete energy spectrum

1981 ◽  
Vol 31 (3) ◽  
pp. 269-274
Author(s):  
Nguyen Ai Viet
Keyword(s):  
Energy Spectrum ◽  
Atomic Hydrogen ◽  
Low Frequency ◽  
Third Order ◽  
Discrete Energy

DISCRETE ENERGY SPECTRUM IN DISCRETE TIME DYNAMICS

2007 ◽  
Author(s):  
A. KHRENNIKOV ◽  
Ya. VOLOVICH
Keyword(s):  
Energy Spectrum ◽  
Discrete Time ◽  
Discrete Energy ◽  
Time Dynamics

scholarly journals Contribution of low-frequency climatic–oceanic oscillations to streamflow variability in small, coastal rivers of the Sierra Nevada de Santa Marta (Colombia)

2019 ◽  
Vol 23 (5) ◽  
pp. 2379-2400 ◽  
Author(s):  
Juan Camilo Restrepo ◽  
Aldemar Higgins ◽  
Jaime Escobar ◽  
Silvio Ospino ◽  
Natalia Hoyos
Keyword(s):  
Energy Spectrum ◽  
Sierra Nevada ◽  
Large Scale ◽  
Low Frequency ◽  
Maximum Power ◽  
Simultaneous Occurrence ◽  
Atmospheric Processes ◽  
Low Frequency Oscillations ◽  
Streamflow Variability

Abstract. This study evaluated the influence of low-frequency oscillations, that are linked to large-scale oceanographic–atmospheric processes, on streamflow variability in small tropical coastal mountain rivers of the Sierra Nevada de Santa Marta, Colombia. We used data from six rivers that had > 32 years of complete, continuous monthly streamflow records. This investigation employed spectral analyses to (1) explore temporal characteristics of streamflow variability, (2) estimate the net contribution to the energy spectrum of low-frequency oscillations to streamflow anomalies, and (3) analyze the linkages between streamflow anomalies and large-scale, low-frequency oceanographic–atmospheric processes. Wavelet analyses indicate that the 8–12-year component exhibited a quasi-stationary state, with a peak of maximum power between 1985 and 2005. These oscillations were nearly in phase in all rivers. Maximum power peaks occurred for the Palomino and Rancheria rivers in 1985 and 1995, respectively. The wavelet spectrum highlights a change in river variability patterns between 1995 and 2015, characterized by a shift towards the low-frequency oscillations' domain (8–12 years). The net contribution of these oscillations to the energy spectrum was as high as 51 %, a value much larger than previously thought for rivers in northwestern South America. The simultaneous occurrence of hydrologic oscillations, as well as the increase in the amplitude of the 8–12-year band, defined periods of extremely anomalous wet seasons during 1989–1990, 1998–2002 and 2010–2011, reflecting the role of low-frequency oscillations in modulating streamflow variability in these rivers. Cross-wavelet transform and wavelet coherence revealed high common powers and significant coherences in low-frequency bands (>96 months) between streamflow anomalies and Atlantic Meridional Oscillation (AMO), Pacific Decadal Oscillation (PDO) and the Tropical North Atlantic Index (TNA). These results show the role of large-scale, low-frequency oceanographic–climate processes in modulating the long-term hydrological variability of these rivers.

E×B guiding-centre motion in three electrostatic waves: statistics of separatrix crossings

1998 ◽  
Vol 59 (4) ◽  
pp. 761-772
Author(s):  
B. WEYSSOW
Keyword(s):  
Phase Space ◽  
Low Frequency ◽  
Integration Scheme ◽  
Symplectic Integrator ◽  
Third Order ◽  
Special Configuration ◽  
Electrostatic Waves ◽  
Hamiltonian Theory ◽  
Numerical Integration Methods ◽  
Adiabatic Motion

E×B guiding-centre (GC) motion in a special configuration of three low-frequency electrostatic waves can be considered as a paradigmatic Hamiltonian system for studying adiabatic motion and separatrix crossings. A peculiarity of this system is that a single initial condition gives rise to two stroboscopic phase-space trajectories. According to the classical Hamiltonian theory, the proportion of points on the stroboscopic trajectories is a function of the time evolution of the surfaces enclosed by the separatrices in the phase space. This behaviour is qualitatively observed in test-particle numerical experiments. The ability of numerical integration methods like the ‘classical’ fourth-order Runge–Kutta integration scheme or a third-order symplectic integrator to reproduce the statistics is analysed.

Quadratic Electro-Optical Characterization of Molecular Nonlinear optical Materials

1987 ◽  
Vol 109 ◽  
Author(s):  
John C. Luong ◽  
N. F. Borrelli ◽  
A. R. Olszeuski
Keyword(s):  
Optical Materials ◽  
Nonlinear Optical ◽  
Second Harmonic ◽  
Low Frequency ◽  
Second Order ◽  
Third Order ◽  
Kerr Coefficient ◽  
Molecular Compounds ◽  
Order Susceptibility

ABSTRACTA convenient method of measuring the nonlinear optical properties of molecular compounds is described. The method involves measuring the quadratic electro-optical coefficient of a polymer composite containing a variable concentration of the candidate NLO material. The X(3) (ω) value obtained by this low-frequency Kerr measurement, after local-field corrections, can be compared to the nonresonant third-order susceptibility measured by degenerate-four-wave-mixing technique on selective samples. We find that the choice of the polymer matrix dictates the contribution of second-order susceptibility to the Kerr coefficient. Therefore, our method can also be extended to the measurement of second-order susceptibility, analogous to the technique of field-induced second-harmonic-generation.

Induction of floquet topological phases in honeycomb nanoribbon irradiated by circularly polarized laser field

2021 ◽  
pp. 2150180
Author(s):  
Chol Jun Kang ◽  
Mun Gwon Jo
Keyword(s):  
Energy Spectrum ◽  
Laser Field ◽  
Low Frequency ◽  
Edge States ◽  
Circularly Polarized ◽  
Properties Of Materials ◽  
The Stability ◽  
External Time ◽  
Time Periodic ◽  
Topological Phase Transitions

The stability of the existence of the topological properties even in non-equilibrium condition such as irradiation of external time-periodic perturbation paves the way for designing and controlling the properties of materials. We study the change in the structure of the quasi-energy spectrum under the influence of the circularly polarized laser field with various intensities. The system is two-dimensional honeycomb nanoribbon of having zig-zag edges. Two cases where the onsite energies are present and absent are considered. We find that the topological phase transitions occur at some critical intensities of the laser field in both cases, which are recognized by the gap closing, the appearance of two crossing edge states, and sudden raise of the first Chern number from 0 to 1. The critical laser intensity is raised when either the frequency increases or the width of the ribbon decreases. Furthermore, band folding is observed in low-frequency domain in the quasi-energy spectrum and becomes more pronounced for the lower frequencies.

Third Order Low Frequency Sinusoidal Oscillators Employing CFOAs and Grounded Capacitors

2021 ◽  
Author(s):  
Ajishek Raj ◽  
Pragati Kumar ◽  
D. R. Bhaskar
Keyword(s):  
Low Frequency ◽  
Third Order ◽  
Sinusoidal Oscillators

The energy spectrum of photoelectrons produced by multiphoton ionization of atomic hydrogen

1992 ◽  
Vol 25 (12) ◽  
pp. L275-L280 ◽  
Author(s):  
M Dörr ◽  
D Feldmann ◽  
R M Potvliege ◽  
H Rottke ◽  
R Shakeshaft ◽  
...  
Keyword(s):  
Energy Spectrum ◽  
Atomic Hydrogen ◽  
Multiphoton Ionization
Sign in / Sign up

Export Citation Format

Share Document