نتایج جستجو برای: cesium

تعداد نتایج: 4416  

2010
Lei Liang Guodong Rao Hao-Ling Sun Jun-Long Zhang

We have developed a new protocol involving the “copper(II) chloride-cesium carbonate” system for the aerobic oxidation of primary alcohols. Cesium carbonates and the solvents such as toluene and 1,2-dichloroethane play important roles to form a catalytically active intermediate containing a m-hydroxyl-bridged trinuclear copper moiety (complex 1). From the X-ray crystal structure of complex 1, a...

2002
M. RICHARDSON

In recognition of the 0ct)ober 1964 declaration of the International Committee of Weights and Measures that the physical measurement of time be based on a particular transition between two hyperfine levels in the ground state of cesium 133, a review of the characteristics of cesium beam atomic frequency standards is presented. This article discusses the general requirements for frequency and ti...

2017
M. Arditi

Analysis of experimental microwave Xamsey patterns, obtained with a laser pumped cesium beam frequency standard, shows the cesium atoms velocities to follow a broad 14axwellian distribution. As a consequence, the estimate of the second-order D6ppler-shift and cavity 2hase-shift could be more accurately obtained with this device than with the classical cesium beam frequency standard .

2004
Li-Anne Liew Svenja Knappe John Moreland Hugh Robinson Leo Hollberg John Kitching

We describe the fabrication of chip-sized alkali atom vapor cells using silicon micromachining and anodic bonding technology. Such cells may find use in highly miniaturized atomic frequency references or magnetometers. The cells consist of cavities etched in silicon, with internal volumes as small as 1 mm. Two techniques for introducing cesium and a buffer gas into the cells are described: one ...

Journal: :Journal of neurophysiology 1997
D M Campbell P K Rose

The specific membrane resistivity of motoneurons at or near the soma (Rms) is much lower than the specific membrane resistivity of the dendritic tree (Rmd). The goal of the present experiments was to investigate the contribution of tonically active voltage-dependent potassium channels at or near the soma to the low Rms. These channels were blocked with the use of intracellular injections of ces...

2008
E. J. Montgomery D. W. Feldman P. G. O’Shea Z. Pan N. Sennett K. L. Jensen N. A. Moody

Photocathodes are critical to the design of electron sources in high-power free-electron lasers but must maintain operational readiness and reliability with a long lifetime despite requisite high current density (hence high quantum efficiency), possible drive laser heating, and vacuum contamination. We at the University of Maryland have already demonstrated extended lifetime of cesiated metal p...

Journal: :Applied and environmental microbiology 1992
N Tomioka H Uchiyama O Yagi

Cesium-accumulating bacteria, strains CS98 and CS402, were isolated from soil by a radioactive autoradiographic method using 137Cs. These strains displayed the rod-coccus growth cycle and contained mesodiaminopimelic acid, mycolic acids, and tuberculostearic acids. The major menaquinone of CS98 was MK-8(H2). On the basis of these characteristics, strain CS98 was identified as Rhodococcus erythr...

2004
A. C. Andrello C. R. Appoloni

With the nuclear fission discovery and development of nuclear weapons in 1940s, artificial radioisotopes were introduced in the environment. This contamination is due to worldwide fallout by superficial nuclear tests realized from early 1950s to late 1970s by USA, former URSS, UK, France and China. One of theses radioisotopes that have been very studied is cesium-137. Cesium-137 has a half-life...

Journal: :Shokuhin eiseigaku zasshi. Journal of the Food Hygienic Society of Japan 2013
Hiromi Nabeshi Tomoaki Tsutsumi Akiko Hachisuka Rieko Matsuda

It is important to obtain information about ways of removing radioactive cesium from foods in order to reduce internal radiation exposure from food and to ensure the safety and security of food. In this study, we investigated the change of radioactive cesium content in beef due to soaking in seasoning. Our results revealed that soaking beef in liquid seasoning (salt concentration: 8-10%) for 24...

2014
Yoshihisa Namiki Toshihiko Ueyama Takayuki Yoshida Ryoei Watanabe Shigeo Koido Tamami Namiki

Decontamination of the radioactive cesium that is widely dispersed owing to a nuclear power station accident and concentrated in fly ash requires an effective elimination system. Radioactive fly ash contains large amounts of water-soluble cesium that can cause severe secondary contamination and represents a serious health risk, yet its complete removal is complicated and difficult. Here it is s...

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