1,881 research outputs found
Imaging-based Parametric Resonance in an Optical Dipole Atom Trap
We report sensitive detection of parametric resonances in a high-density
sample of ultracold atoms confined to a far-off-resonance optical
dipole trap. Fluorescence imaging of the expanded ultracold atom cloud after a
period of parametric excitation shows significant modification of the atomic
spatial distribution and has high sensitivity compared with traditional
measurements of parametrically-driven trap loss. Using this approach, a
significant shift of the parametric resonance frequency is observed, and
attributed to the anharmonic shape of the dipole trap potential
Psychological Problems and Challenge in EFL Speaking Classroom
Psychological aspect regarding to learning attitudes plays in determining learning achievement. Psychological problems also involve not only to the students but also teacher. Less-confidence, speech anxiety, and low self-esteem are almost common problem in classroom, and occur on both teachers and students. Students who have low of self-confidence are often hardly able to control themselves for public speaking in the classroom, like, Governing his/ her behavior on that his/her peers think, lose belief on self, thinking that his/her friends dis-appraising, afraid of getting mistakes, etc. However, teachers which are low self-esteem and confidence also lose their performance and ability to manage their classroom optimally. Low self-esteem may caused by teacher's poor understanding on subject matter. Both of psychological problems impact on dis-effectiveness of classroom activities. This paper takes accounts of some psychological problems of students and teachers in English speaking classroom, and some guidelines to overcome. At the last discus, this paper also provides some keys of how to make good classroom atmosphere
Possible approach to improve sensitivity of a Michelson interferometer
We propose a possible approach to achieve an 1/N sensitivity of Michelson
interferometer by using a properly designed random phase modulation. Different
from other approaches, the sensitivity improvement does not depend on
increasing optical powers or utilizing the quantum properties of light.
Moreover the requirements for optical losses and the quantum efficiencies of
photodetection systems might be lower than the quantum approaches and the
sensitivity improvement is frequency independent in all detection band.Comment: 8 pages, 3 figures, new versio
The thermal evolution of nuclear matter at zero temperature and definite baryon number density in chiral perturbation theory
The thermal properties of cold dense nuclear matter are investigated with
chiral perturbation theory.
The evolution curves for the baryon number density, baryon number
susceptibility, pressure and the equation of state are obtained.
The chiral condensate is calculated and our result shows that when the baryon
chemical potential goes beyond , the absolute value of the
quark condensate decreases rapidly, which indicates a tendency of chiral
restoration.Comment: 17 pages, 9 figures, revtex
Australia's national health programs: An ontological mapping
Australia has a large number of health program initiatives whose comprehensive assessment will help refine and redefine priorities by highlighting areas of emphasis, under-emphasis, and non-emphasis. The objectives of our research are to: (a) systematically map all the programs onto an ontological framework, and (b) systemically analyse their relative emphases at different levels of granularity. We mapped all the health program initiatives onto an ontology with five dimensions, namely: (a) Policy-scope, (b) Policy-focus, (c) Outcomes, (d) Type of care, and (e) Population served. Each dimension is expanded into a taxonomy of its constituent elements. Each combination of elements from the five dimensions is a possible policy initiative component. There are 30,030 possible components encapsulated in the ontology. It includes, for example: (a) National financial policies on accessibility of preventive care for family, and (b) Local-urban regulatory policies on cost of palliative care for individual-aged. Four of the authors mapped all of Australia's health programs and initiatives on to the ontology. Visualizations of the data are used to highlight the relative emphases in the program initiatives. The dominant emphasis of the program initiatives is: [National] [educational, personnel-physician, information] policies on [accessibility, quality] of [preventive, wellness] care for the [community]. However, although (a) information is emphasized technology is not and (b) accessibility and quality are emphasized cost, satisfaction, and quality are not. The ontology and the results of the mapping can help systematically reassess and redirect the relative emphases of the programs and initiatives from a systemic perspective
College Students’ Purchase Behaviors of Single-Serve Premium Juices
There has been a surge in demand for premium single-serve juices, and college students may be in the forefront of this growing trend because of the perceived social status accompanied by their consumption. External influence (i.e., peer influence and social status) emerged as a component of motivation for the use of premium juices. Findings contribute to Veblen’s theory of conspicuous consumption, demonstrating that consumer motivation for status-laden products occurs even for consumable products that are relatively low cost
Catalysis of Stark-Tuned Interactions Between Ultracold Rydberg Atoms
We have experimentally investigated a catalysis effect in the resonant energy transfer between ultracold 85Rb Rydberg atoms. We studied the time dependence of the process, 34p+34p→34s+35s, and observed an enhancement of 34s state population when 34d state atoms are added. We have also performed numerical model simulations, which are in qualitative agreement with experiment and indicate that the enhancement arises from a redistribution of p-state atoms due to the presence of the d-state atoms
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