Zobrazeno 1 - 10
of 96
pro vyhledávání: '"Fred L. Walls"'
Publikováno v:
Scientific Reports, Vol 7, Iss 1, Pp 1-12 (2017)
Scientific Reports
Scientific Reports
The speed of conventional antimicrobial susceptibility testing (AST) is intrinsically limited by observation of cell colony growth, which can extend over days and allow bacterial infections to advance before effective antibiotics are identified. This
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::cfd45cac80072b009efdaf38aff85e31
http://link.springer.com/article/10.1038/s41598-017-12063-6
http://link.springer.com/article/10.1038/s41598-017-12063-6
Autor:
James C. Bergquist, Fred L. Walls, David J. Wineland, Thomas E. Parker, John J. Bollinger, Wayne M. Itano, D. M. Meekhof, Robert E. Drullinger, Jefferts, W D. Lee, D. B. Sullivan
Publikováno v:
Journal of Research of the National Institute of Standards and Technology
The development of atomic frequency standards at NIST is discussed and three of the key frequency-standard technologies of the current era are described. For each of these technologies, the most recent NIST implementation of the particular type of st
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::6913c111c5a47bc56cb42460027c6e9b
https://pubmed.ncbi.nlm.nih.gov/27500017
https://pubmed.ncbi.nlm.nih.gov/27500017
Autor:
Amitava Sen Gupta, Fred L. Walls
Publikováno v:
Measurement Science and Technology. 15:1982-1985
We show that the noise and spurious signals over the entire input frequency response of a binary digital divider contribute with equal weight to the output signal. Similar results are also obtained using non-binary digital dividers. We present a simp
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::9064f33372500f38f1cab7d518cf6fcd
https://doi.org/10.1088/0957-0233/15/10/006
https://doi.org/10.1088/0957-0233/15/10/006
Publikováno v:
IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control. 51:271-276
We discuss a novel design of a self-starting regenerative divider that permits division by 3, 4, 5, 6 ... instead of the usual 2. This is accomplished by having the loop oscillate simultaneously at two harmonically related conjugate frequencies, e.g.
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::315db1bf4a38f39db65460a0fc1cb29a
https://doi.org/10.1109/tuffc.2004.1295406
https://doi.org/10.1109/tuffc.2004.1295406
Autor:
A. De Marchi, Jon H. Shirley, Filippo Levi, W D. Lee, Robert E. Drullinger, Fred L. Walls, Thomas E. Parker, Craig W. Nelson, Thomas P. Heavner, Giovanni Antonio Costanzo, Leo W. Hollberg, D. M. Meekhof, Steven R. Jefferts
Publikováno v:
Metrologia. 39:321-336
The evaluation procedure of a new laser-cooled caesium fountain primary frequency standard developed at the National Institute of Standards and Technology (NIST) is described. The new standard, NIST-F1, is described in some detail and typical operati
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::af75ac9974311a28d8e35610d3898fc7
https://doi.org/10.1088/0026-1394/39/4/1
https://doi.org/10.1088/0026-1394/39/4/1
Publikováno v:
Physical Review A. 59:2094-2104
The parametric oscillation of a single trapped electron is studied and used to measure enhanced spontaneous emission. Hysteresis in this motion provides a 1-bit memory to store information about excitations made with the electron ``in the dark.'' The
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::aae47daa36d05b8853c63eb0cc3853b1
https://doi.org/10.1103/physreva.59.2094
https://doi.org/10.1103/physreva.59.2094
Publikováno v:
Physical Review A. 59:773-777
Many areas of science require locking a probe signal to the center of a Lorentzian line. In this paper we experimentally explore the limits to the resolution for locking a sine-wave modulated probe signal to a Lorentzian line. Surprisingly we find th
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::d3667f9b04ee9f7a604aed87b4357d1b
https://doi.org/10.1103/physreva.59.773
https://doi.org/10.1103/physreva.59.773
Publikováno v:
IEEE Journal of Quantum Electronics. 34:233-237
We have achieved a stability of 3/spl middot/10/sup -13/ /spl tau//sup -1/2/ for 3
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::3e3f38780e2f0a23d3bd6aa95764a50c
https://doi.org/10.1109/3.658700
https://doi.org/10.1109/3.658700
Publikováno v:
IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control. 44:326-334
In this paper we report the results of extensive research on phase modulation (PM) and amplitude modulation (AM) noise in linear bipolar junction transistor (BJT) amplifiers. BJT amplifiers exhibit 1/f PM and AM noise about a carrier signal that is m
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::34ecab2eecd4dcd16ae165108918e7e9
https://doi.org/10.1109/58.585117
https://doi.org/10.1109/58.585117
Publikováno v:
IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control. 41:518-521
We report on the experimental test of a new concept for reducing the limitation on short-term frequency stability of passive frequency standards due to local oscillator phase noise. This concept is general and can be applied to many passive frequency
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::8c4c5c6c3e458e418f3cc48eedfa3f7e
https://doi.org/10.1109/58.294113
https://doi.org/10.1109/58.294113