Quantization with operators appropriate to shapes of trajectories and classical perturbation theory

Quantization is discussed for molecular systems having a zeroth order pair of doubly degenerate normal modes. Algebraic quantization is employed using quantum operators appropriate to the shape of the classical trajectories or wave functions, together with Birkhoff-Gustavson perturbation theory and the W eyl correspondence for operators. The results are compared with a previous algebraic quantization made with operators not appropriate to the trajectory shape. Analogous results are given for a uniform semiclassical quantization based on Mathieu functions of fractional order. The relative sensitivities of these two methods (AQ and US) to the use of operators and coordinates related to and not related to the trajectory shape is discussed. The arguments are illustrated using principally a Hamiltonian for which many previous results are available

TEACHING READING NARRATIVE TEXTS THROUGH UNCOVER CONCENTRATE MONITOR EVALUATE (U-C-ME) STRATEGY

Abstract: The objective of the study was to find out whether or not it is effective to teach readingnarrative texts through Uncover Concentrate Monitor Evaluate (U-C-Me) strategy to the tenthgrade students of State Senior High School 8Palembang. In data analysis, it found that the result ofpaired sample, the result of t-obtained was 26.64, where the value of t-table was 1.671 atsignificance level of 0.05 and with one tailed testing. Since the value of t-table obtained was lowerthan the value of t-table (26.64 < 1.671) consequently the null hypothesis (Ho) was rejected andalternative hypothesis was accepted and the result of t-obtained was 5.09 at significance level of0.05 and with one tailed testing. Since the value of t-obtained was higher than the value of t-table(5.09 > 1.671) consequently the null hypothesis (Ho) was rejected and the alternatif hypothesis(Ha) was accepted. It means that it was effective to teach reading narrative texts through UncoverMonitor Evaluate (U-C-ME) strategy to the tenth grade students of state Senior High School 8Palembang

Time-frequency analysis of chaotic systems

We describe a method for analyzing the phase space structures of Hamiltonian systems. This method is based on a time-frequency decomposition of a trajectory using wavelets. The ridges of the time-frequency landscape of a trajectory, also called instantaneous frequencies, enable us to analyze the phase space structures. In particular, this method detects resonance trappings and transitions and allows a characterization of the notion of weak and strong chaos. We illustrate the method with the trajectories of the standard map and the hydrogen atom in crossed magnetic and elliptically polarized microwave fields.Comment: 36 pages, 18 figure

From recollisions to the knee: A road map for double ionization in intense laser fields

We examine the nature and statistical properties of electron-electron collisions in the recollision process in a strong laser field. The separation of the double ionization yield into sequential and nonsequential components leads to a bell-shaped curve for the nonsequential probability and a monotonically rising one for the sequential process. We identify key features of the nonsequential process and connect our findings in a simplified model which reproduces the knee shape for the probability of double ionization with laser intensity and associated trends

Nonlinear dynamics of recollisions in the double ionization processes of atoms in strong fields

Double ionization processes triggered by intense linearly polarized laser fields have revealed the paramount role of electron-electron collisions. It has been shown that the correlated dynamics of such electronic collisions can be modeled by a two dimensional symplectic map which captures the bare essentials of the energy exchange processes occurring during a recollision between the two electrons. We investigate linear and nonlinear properties of this map and connect them to the dynamical organization of phase space and related statistical dat

Recollisions and correlated double ionization with circularly polarized light

It is generally believed that the recollision mechanism of atomic nonsequential double ionization is suppressed in circularly polarized laser fields because the returning electron is unlikely to encounter the core. On the contrary, we find that recollision can and does significantly enhance double ionization, even to the extent of forming a "knee", the signature of the nonsequential process. Using a classical model, we explain two apparently contradictory experiments, the absence of a knee for helium and its presence for magnesium

Improving the Students' Speaking Competence through Jigsaw-Type Cooperative Learning Method by Using Multimedia Devices in Sjakhyakirti Senior High School Palembang

The title of the study is improving the students' speaking competence through jigsaw-type cooperative learning methods by using multimedia devices in Sjakhyakirti Senior High School Palembang. The problem of the study, “Is it effective improve the students' speaking competence through Jigsaw-type cooperative learning method by using multimedia devices in Sjakhyakirti Senior High School Palembang?”. The result shows that: The students speaking competence improved. The students weren’t doubts, afraid, shy and lack of confidence in their presentation. They could interact to the presented topic which was discussed in the expert group or jigsaw group with the teacher’s instruction or guidance. The have become more active and have been excited to join it. Besides, when the researcher as the teacher evaluate them to do test orally, the result was good enough. The mean of the score from pre-test and from the cycle one to the following, cycle two always has better progress. The students‟ motivation in the learning improved. The students‟ attitude inside the class during the English teaching and learning process was more cooperative. They become more intensive in following and paying attention to the lesson. Besides, they are more active, excited, and creative in joining the learning. Its means that it is effective in improving the students' speaking competence through jigsaw-type cooperative learning methods by using multimedia devices in Sjakhyakirti Senior High School Palembang. Keywords: Speaking, jigsaw, multimedia devices

Circularly Polarized Molecular High Harmonic Generation Using a Bicircular Laser

We investigate the process of circularly polarized high harmonic generation in molecules using a bicircular laser field. In this context, we show that molecules offer a very robust framework for the production of circularly polarized harmonics, provided their symmetry is compatible with that of the laser field. Using a discrete time-dependent symmetry analysis, we show how all the features (harmonic order and polarization) of spectra can be explained and predicted. The symmetry analysis is generic and can easily be applied to other target and/or field configurations