We investigated the variation in body colour and its thermoregulatory function in Meteorus pulchricornis (Wesmael) (Hymenoptera: Braconidae), a parasitoid wasp of Spodoptera and other free-living lepidopteran larvae. We show that the body colour of adult wasps darkens when cocoons are kept at low temperatures. The range in the variation in colour, however, differs for different parts of the body and among uniparental (thelytokous) strains. This melanism enables these wasps to attain a body temperature in sunshine up to 2°C. Moreover, this small gain in body temperature can markedly increase the flight activity of wasps at low ambient temperatures. We conclude that the variation in body colour that resulted from rearing the cocoons at different temperatures enable the wasps to adapt to changing thermal environments. The ecological significance of the difference in the degree of melanism of the different strains is discussed., Yosuke Abe, Takuma Nishimura, Kaoru Maeto., and Seznam literatury
Energy prices are increasing all the time. Further worldwide supplies of fossil fuels are decreased. These supplies will be exhausted in the future. Therefore, it is necessary to find new energy sources. The direct transformation of solar energy into electrical energy through the use of photovoltaic cells is one of the possibilities. The aim of this paper is to illustrate the working principle of the photovoltaic system FVS 2001E that is located on an external wall of a building of Tomas Bata University in Zlín.
The individual plant of Chinese ivy can produce three types of branches (creepy, climbing, and reproductive) during its development, which adapt to different environmental factors. An eco-physiological model was constructed to simulate leaf net photosynthetic rate (PN) of Chinese ivy (Hedera nepalensis var. sinensis) in subtropical evergreen broad-leaved forest based on leaf physiological and mathematical analysis. The model integrated the rate-limiting biochemical process of photosynthesis and the processes of stomatal regulation. Influence of environmental factors (solar radiation, temperature, CO2 concentration, vapour pressure deficit, etc.) on PN was also considered in our model; its parameters were estimated for leaves on three types of branch in the whole growing season. The model was validated with field data. The model could simulate PN of leaf on three types of branches accurately. Influence of solar radiation on leaf PN of three types of branches in different seasons was analyzed through the model with numerical analysis. and J. Yang ... [et al.].
In this brief communication we provide an estimate of the part of the incident solar energy used for oxygen evolution as well as the time, in years, needed for the generation of the present amount of molecular oxygen in the biosphere by photosynthesis on land and in the ocean. We find this to be ~3,000 yr. We also find that the ocean produces 22% more oxygen than the land surface., A. Yu. Borisov, L. O. Björn., and Obsahuje bibliografické odkazy
V tomto příspěvku se budeme zabývat úlohami fyzikální olympiády zaměřenými na sluneční záření dopadající na povrch Země, které lze považovat za součást kosmického záření. Úloh s touto tematikou nalezneme ve fyzikální olympiádě na různých úrovních celou řadu, my zde představíme dvě teoretické úlohy. První z nich byla zadána na 46. mezinárodní fyzikální olympiádě (MFO) v Indii v roce 2015. I druhá úloha je ze 46. ročníku, ale tentokrát slovenské fyzikální olympiády. Tento ročník proběhl již ve školním roce 2004/05. and Filip Studnička, Ľubomír Konrád, Jan Kříž, Bohumil Vybíral.
This paper focuses on the impact of changes in temperature on one bay of St Vitus’ Cathedral in Prague Castle. The objective of the study is to simulate as correctly as possible the distribution of temperatures in the structure, and then to compute the thermal dilatation movements. Theoretical simulation of dilatation movements involves simulating the temperatures in the structure and then computing the displacements. Insolation and changes in air temperature around the structure are included in the temperature simulation. The computed temperature fields are used as a loading for computing the forces and deformations of one bay of St Vitus’ Cathedral. The theoretical deformation values obtained by means of the 3-D finite element model were compared with the measurements. The computed surface temperatures were also confronted with the surface temperatures measured in the interior and on the exterior of the cathedral. The results obtained from the simulations correspond well with the measured surface temperatures and deformations., Pavel Beran, Jiří Máca and Petr Fajman., and Obsahuje bibliografii
Direct transformation of solar radiation energy into electrical energy is realized through solar panels. The efficiency of the energetic transformation is very low. It is influenced by many factors, mainly by used semiconductor material of solar panels and incidence angle of solar radiation on solar panels. The aim of the paper is to examine an influence of atmospheric pollution on solar panels efficiency. and Přímá transformace energie slunečního záření v elektrickou energii se uskutečňuje prostřednictvím solárních panelů. Účinnost této energetické přeměny je velmi nízká. Je ovlivněna mnoha faktory, především použitým polovodičovým materiálem solárních panelů a úhlem dopadu slunečního záření na solární panely. Předmětem tohoto příspěvku je posouzení vlivu znečištění atmosféry na výkonnost solárních panelů.