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REMINDER OF SOME
DEFINITIONS
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LENGTH
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micron (µ) | = 10-6 meter |
| millimicron (mµ) or nanometer (nm) | = 10-9 meter | |
| angström (Å) | = 10-10 meter | |
| wavelength (lambda) | = Distance between 2 consecutive identical amplitudes of periodic motion | |
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FREQUENCY
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hertz (Hz) | = Unit of frequency (number of vibrations per second) of a periodic motion |
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ENERGY
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calorie per square centimeter per minute (cal / cm 2 / min) or (cal.cm -2. min -1) |
= Unit irradiance (or hourly, daily, monthly or yearly) |
| calorie per square centimeter (cal / cm 2) | = Also called langley (ly) | |
| calories per minute (cal / min) | = Equivalent to 0.07 watts | |
| d° | = Equivalent to 4.186 joules / minute or 4,186.10 7 ergs / minute | |
| electron-volts (eV) | = Kinetic energy gained by an electron submitted to a potential difference of 1 volt | |
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PHOTOMETRY
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lux | = Illuminance received at 1 meter from a point source of luminous intensity of 1 candle (candela), on a surface normal to the direction of the source |
| Candle (candela) per square meter | = Brightness (luminance) of a light source of a candle (candela) an area of 1 square meter (extension: brightness energy) | |
| transmittance optics (T) |
= Ratio of the luminous flux transmitted by a body to the luminous flux incident (extension: energy transmission) | |
| optical density (D) | = Logarithm of the inverse of optical transmittance (extension: energy density) | |
| albedo (A) | = Reflectance of a diffuse surface (rock, snow, crop, forest, etc ...) or aquatic | |
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TEST
STATISTICS
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In research in plant biology, are used more and more "statistical tests" that assess the degree of significance to be attached to the results of various experiments. The main tests are used in the experiments reported below: | |
| X 2 test of Pearson | = Adjustment results obtained experimentally with values calculated theoretically | |
| correlation coefficient r |
= Definition of the degree of connection between two sets
of quantitative traits: |
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| test "t" Student Fisher | = Determination of the value of a comparative experiment on a small number of subjects | |
| When the probability of intervention by chance is less than 5%, we say that the experience is significant (indicating s ° text) - when this probability is less than 1%, we say that the experience is very significant (indicated s ° ° text) - when this probability is less than 0, l%, we say that the experience is highly significant (indicating S ° ° ° text). | ||