865 research outputs found

    Evaluating ecohydrological modelling framework to link atmospheric CO2 and stomatal conductance

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    The establishment of an accurate stomatal conductance (gs) model in responding to CO2 enrichment under diverse environmental conditions remains an important issue as gs is the key to understand the plant–water–atmosphere interactions. A better representation of gs is important to reduce uncertainties in predicting the climate change impacts on various ecosystem functions. In this study, we evaluated three most commonly used gs formulations for the estimation of the stomatal response to environmental factors using in situ measurements under different environmental conditions. The three gs models were Leuning's modified Ball–Berry model and two specific cases of the optimization models (i.e., Rubisco limitation model and RuBP regeneration limitation model). On the basis of an analysis of 234 data points obtained from experiments under instantaneous, semicontrolled, and the free‐air CO2 experiment conditions, we found that Leuning's modified Ball–Berry model and RuBP‐limited optimization model showed similar performance, and both performed better than Rubisco limitation model. Functional groups (e.g., C3 vs. C4 species) and life form (e.g., annual vs. perennial species) play an important role in determining the gs model performance and thus pose a challenge for gs predictions in mixed vegetation communities

    Evaluation Boundary and Design Method for Insulating Packages

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    To evaluate the failure potential of insulated packaging to heat outside, a so-called evaluation boundary for insulating packages was proposed for designing and estimating insulating packages based on the heat transfer law between the environment and a packaged product through packaging. Three evaluation parameters were suggested for describing the failure mechanism of insulating packages. The validity of the presented evaluation boundary was verified by the experimental data. Finally, a new design method of insulating packages based on the boundary was proposed and an application example was performed as a demonstration. The results indicated that the three evaluation parameters (which are thermal load, adsorption ability of phase change material (PCM) and system thermal resistance of insulating packages) are the key parameters for designing insulating package and that the performance of insulating packages is only determined by the thermal load. Moreover, the proposed evaluation boundary shows a good agreement with experimental results, and the availability of the new method to design insulating packages was affirmative through the application example
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