A method to determine the optical parameters of thin films deposited on the thick transparent substrate is proposed. The method is based on the calculation of probability amplitude by the Feynman sum over trajectories. We can reproduce quickly known relation used in optics of thin films by this method and it could be generalized to other cases. We have discussed theoretically an accuracy of the method developed by Manifacier et al. [2]. and Je navržena metoda určení optických parametrů tenkých vrstev nanesených na tlustém transparentním substrátu. Metoda je založena na výpočtu amplitudy pravděpodobnosti pomocí Feynmanovy sumace přes trajektorie. Stručně reprodukujeme známé relace z optiky tenkých vrstev touto metodou, které lze zobecnit na jiné případy. Teoreticky diskutujeme o přesnosti metody navržené Manifacierem et al. [2].
We conducted an experiment to assess the predictive capability of a leaf optical meter for determining leaf pigment status of Acer mono Maxim., A. ginnala Maxim., Quercus mongolica Fisch., and Cornus alba displaying a range of visually different leaf colors during senescence. Concentrations of chlorophyll (Chl) a, Chl b, and total Chl [i.e., Chl (a+b)] decreased while the concentration of carotenoids (Car) remained relatively static for all species as leaf development continued from maturity to senescence. C. alba exhibited the lowest average concentration of Chl (a+b), Chl a, and Car, but the highest relative anthocyanin concentration, while Q. mongolica exhibited the highest Chl (a+b), Chl b, and the lowest relative anthocyanin concentration. A. mono exhibited the highest Chl a and Car concentrations. The relationships between leaf pigments and the values measured by the optical meter generally followed an exponential function. The strongest relationships between leaf pigments and optical measurements were for A. mono, A. ginnala, and Q. mongolica (R2 ranged from 0.64 to 0.95), and the weakest relationships were for C. alba (R2 ranged from 0.13 to 0.67). Moreover, optical measurements were more strongly related to Chl a than to Chl b or Chl (a+b). Optical measurements were not related to Car or relative anthocyanin concentrations. We predicted that weak relationships between leaf pigments and optical measurements would occur under very low Chl concentrations or under very high anthocyanin concentrations; however, these factors could not explain the weak relationship between Chl and optical measurements observed in C. alba. Overall, our results indicated that an optical meter can accurately estimate leaf pigment concentrations during leaf senescence - a time when pigment concentrations are dynamically changing - but that the accuracy of the estimate varies across species., Future research should investigate how species-specific leaf traits may influence the accuracy of pigment estimates derived from optical meters., G. Y. Li, D. P. Aubrey, H. Z. Sun., and Obsahuje bibliografii
UV screening by plant surfaces can be determined by exposing plant organs to UV radiation and measuring the chlorophyll (Chl) fluorescence elicited. From this fluorescence, the UV transmittance can be derived: the more intense the screening the lower the reporter Chl fluorescence and the lower the UV transmittance. The relationships between UV screening at 375 nm, as determined in the field by a portable UV-A-PAM fluorimeter, and UV screening at 314 and 360 nm, measured in the laboratory with the non-portable XE-PAM fluorimeter, were investigated in leaves of grapevine (Vitis vinifera L. cv. Bacchus) and barley (Hordeum vulgare cv. Ricarda), as well as in white grape berries. With leaves, linear trends were observed between XE-PAM measurements at 314 nm and UV-A-PAM measurements at 375 nm but the relationship between transmittance at 360 and 375 nm in barley was curved: a simple model calculation suggests that this curvi-linearity arises from particularly weak absorbance of barley flavonoids at 375 nm relative to absorbance at 360 nm. Transmittance values at 314 nm plotted against 375 nm yielded a much smaller slope in grapevine leaves than in barley leaves, which was attributed to screening in the short-wavelength UV by hydroxycinnamic acids in the former but not in the latter species. With grape berries, a poor correlation was detected between transmittances at 314 and 375 nm which might arise from high scattering of UV radiation at the berry surface. Such artefacts appear to be confined to the UV-B region, as berry transmittance at 360 nm correlated very well with that at 375 nm. Thus, assessment of UV screening in the field at short UV wavelengths using 375 nm readings from a UV-A-PAM fluorimeter is possible provided that information is available on the relationship between the transmittance at the UV wavelength of interest and at 375 nm for the sample tissue being investigated. and C. A. Kolb ... [et al.].
In radiometric measurement of the object temperature, in measurement and evaluation of heat escape from buildings we meet with materials, which can be characterised as transparent or semitransparent. One of them is glass. The objective of the present article is to analyse glass features, including emissivity in dependence to wavelength and temperature and also the thermal transmissivity of glass. and Pri bezkontaktných meraniach teploty objektov, pri meraní a vyhodnotení úniku tepla z budov sa stretávame s materiálmi, ktoré možno označiť ako priezračné alebo polopriepustné. Jedným z bežne používaných materiálov je sklo. V príspevku sa pokúšame analyzovať vlastnosti skla, jeho emisivitu v závislosti na vlnovej dĺžke a teplote.
Diamond like carbon (DLC) layers exhibit excellent biocompatible properties and because of high hardness and transmittance in VIS-IR range it is possible to utilize this material in ophthalmic optics field. In this paper, we present our study on transmittance and wear resistance of different commercial spectacle lenses with surface coatings and lenses with newly fabricated DLC layer. The lens transmittance is dependent on lens material and its surface coating. All commercially manufactured lenses exhibit transmittance 90 ± 5 %, while the transmittance of DLC coated lenses was 15 % lower. Wear resistance is extremely dependant on the coating. We were able to reach same or better results than the best commercially manufactured lenses. and Diamantu podobné uhlíkové (DLC) vrstvy mají vynikající biokompatibilní vlastnosti a díky své vysoké tvrdosti a vysoké propustnosti ve viditelné i IR oblasti spektra je lze použít i v aplikacích oční optiky. V tomto článku byla studována propustnost a odolnost proti opotřebení různých komerčních brýlových čoček s povrchovou úpravou a čoček potažených DLC vrstvou. Propustnost čoček je závislá na základním materiálu čočky a na její povrchové úpravě. Všechny komerčně vyráběné čočky měly propustnost 90 ± 5 %, zatímco propustnost čoček potažených DLC byla asi o 15 % nižší. Odolnost proti poškození je hodně závislá na povrchové úpravě. Zde bylo dosaženo pro DLC vrstvy podobných nebo lepších výsledků jako pro nejlepší komerčně vyráběné čočky.