754 research outputs found
Self-Excitation and Feedback Cooling of an Isolated Proton
The first one-proton self-excited oscillator (SEO) and one-proton feedback
cooling are demonstrated. In a Penning trap with a large magnetic gradient, the
SEO frequency is resolved to the high precision needed to detect a one-proton
spin flip. This is after undamped magnetron motion is sideband-cooled to a 14
mK theoretical limit, and despite random frequency shifts (larger than those
from a spin flip) that take place every time sideband cooling is applied in the
gradient. The observations open a possible path towards a million-fold improved
comparison of the antiproton and proton magnetic moments
Recommended from our members
A Survey of Public School Library Resources in Arkansas
The purpose of this study was an examination of elementary- and secondary-school libraries in Arkansas to determine the adequacy of their resources as compared with the 1960 and the 1969 national school library standards. The findings served as a base for establishing goals and recommendations for improved school library programs in Arkansas
Lost and found: the radial quantum number of Laguerre-Gauss modes
We introduce an operator linked with the radial index in the Laguerre-Gauss
modes of a two-dimensional harmonic oscillator in cylindrical coordinates. We
discuss ladder operators for this variable, and confirm that they obey the
commutation relations of the su(1,1) algebra. Using this fact, we examine how
basic quantum optical concepts can be recast in terms of radial modes.Comment: Some minor typos fixed
Chondrosarcoma: A Report of 65 Cases
A statistical analysis is presented of 65 cases of chondrosarcoma treated at Henry Ford Hospital from 1916 to 1976, with adequate follow-up data
Osteogenic sarcoma: Report of one hundred and fifty-seven cases
This study presents the clinical features, roentgenographic manifestations, pathological features, abnormal laboratory studies, treatment and prognosis of 157 cases of osteogenic sarcoma. The series is the fifth largest ever reported. The authors favor prompt surgical ablation followed by controlled intensive chemotherapy as a prophylactic or combined chemotherapy and radiation therapy for metastatic osteogenic sarcoma. All case reports but one present rare or unusual situations
‘What’s it like to have ME?’ The discursive construction of ME in computer-mediated communication and face-to-face interaction
ME/CFS (chronic fatigue syndrome) is a debilitating illness for which no cause or medical tests have been identified. Debates over its nature have generated interest from qualitative researchers. However, participants are difficult to recruit because of the nature of their condition. Therefore, this study explores the utility of the internet as a means of eliciting accounts. We analyse data from focus groups and the internet in order to ascertain the extent to which previous research findings apply to the internet domain. Interviews were conducted among 49 members of internet (38 chatline, 11 personal) and 7 members of two face-to-face support groups. Discourse analysis of descriptions and accounts of ME/CFS revealed similar devices and interactional concerns in both internet and face-to-face communication. Participants constructed their condition as serious, enigmatic and not psychological. These functioned to deflect problematic assumptions about ME/CFS and to manage their accountability for the illness and its effects
SU(N)-symmetric quasi-probability distribution functions
We present a set of N-dimensional functions, based on generalized
SU(N)-symmetric coherent states, that represent finite-dimensional Wigner
functions, Q-functions, and P-functions. We then show the fundamental
properties of these functions and discuss their usefulness for analyzing
N-dimensional pure and mixed quantum states.Comment: 16 pages, 2 figures. Updated text to reflect referee comment
- …