منابع مشابه
Measuring Time and other Spatio-Temporal Quantities
Ordinary clocks do not measure time in the common and Newtonian sense, and there is a similar problem for spatial measurements due to effects of motion and gravitation. Einstein’s theories of relativity are based on the denial of the possibility of the ‘absolute’ measurements that would be required. Nevertheless, here it is shown how such measurements can be performed. For this purpose, a “ligh...
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The quantities of outer and inner"halves" produced by freeze-fracturing human erythrocyte membranes have been measured by visible and fluorescence spectroscopy. Assays have been developed that are based on the use of two membrane surface markers: hemoglobin (Hb), a native marker for the cytoplasmic side of the membrane, and fluoresceinated concanavalin A (FITC-Con-A), a marker for the extracell...
متن کاملMeasuring photon quantities in the International System of Units
Advances in nanotechnology, biotechnology and quantum communication need access to even more accurate photon measurements traceable to the SI, from one hand, and open up the possibility of counting and controlling photons one by one, on the other, affecting photometry and present realizations at the National Metrology Institutes. This paper deals with this technological revolution.
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A fully automatic horizontal mobile measuring system (HMMS) for atmospheric quantities has been developed. The HMMS is based on the drive mechanism of a garden railway system and can be installed at any location and along any measuring track. In addition to meteorological quantities (temperature, humidity and short-/longwave down/upwelling radiation), HMMS also measures trace gas concentrations...
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Structural analysis of MRI data on the cortical surface usually focuses on cortical thickness. Cortical surface area, when considered, has been measured only over gross regions or approached indirectly via comparisons with a standard brain. Here we demonstrate that direct measurement and comparison of the surface area of the cerebral cortex at a fine scale is possible using mass conservative in...
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ژورنال
عنوان ژورنال: Scientific American
سال: 1888
ISSN: 0036-8733
DOI: 10.1038/scientificamerican01141888-10035asupp