Study on Anti-collapse Behavior of Solar Greenhouses Covering Rigid Plate under Snowstorm

International audienceTo analyze the effect of stressed skin action of rigid plate covering on anti-collapse behavior of solar greenhouses under snow load, the numerical simulation on the overall collapse process of single skeleton structure and 6-skeleton overall spatial structure with rigid plate covering were conducted on ANSYS. The collapse modes of solar greenhouses and snow load-displacement curves were obtained. The effects of different parameters on the anti-collapse behavior of solar greenhouses under snow load were also analyzed. The results showed that the stressed skin action of the covering could provide lateral support for the skeleton and increase integral rigidity of the structure and the bearing capacity to resist snowstorm. The lateral support of 8mm thick PC sun board equals that of 4 purlins, 10mm thick PC sun board equals 6 purlins, and 12mm thick PC sun board equals 8 purlins. It is suggested that skeleton interval is about 1m

Circumventing the Theoretical Scaling Relation Limit for the Oxygen Evolution Reaction

Transition metal hydr(oxy)oxides (TMHs) are considered efficient electrocatalysts for the oxygen evolution reaction (OER) under alkaline conditions. Toward identification of potential descriptors to circumvent the scaling relation limit for the OER, first-principles calculations were used to quantify the effects on the overpotential of different s (Mg), p (Al), and d (Ti, V, Cr, Fe, Co, Sc, and Zn) electron dopants in Ni-based TMHs. Both the adsorbate evolution mechanism (AEM) and the lattice oxygen-mediated mechanism (LOM) were examined. The results demonstrate that the formation energy of oxygen vacancies (EVO) is strongly affected by the chemical nature of the dopants. A linear relationship is identified between EVO and the free energy difference for the oxygen–oxygen coupling. A descriptor could be employed to discriminate whether the LOM is energetically favored over the AEM. These findings fill existing gaps in appropriate yet computationally light descriptors for direct identification between the AEM and LOM

Genome-Wide Analysis Elucidates the Role of CONSTANS-like Genes in Stress Responses of Cotton

The CONSTANS (CO)-like gene family has been well studied for its role in the regulation of plant flowering time. However, their role remains poorly understood in cotton. To better understand the possible roles of CO-like in cotton, we performed a comprehensive genome-wide analysis of CO-like genes in cotton. Phylogenetic tree analysis showed that CO-like genes naturally clustered into three groups. Segmental duplication and whole genome duplication (WGD), which occurred before polyploidy, were important contributors to its expansion within the At (“t” indicates tetraploid) and Dt subgenomes, particularly in Group III. Long-terminal repeat retroelements were identified as the main transposable elements accompanying 18 genes. The genotype of GhCOL12_Dt displayed low diversity; it was a candidate involved in domestication. Selection pressure analyses indicated that relaxed purifying selection might have provided the main impetus during the evolution of CO-like genes in upland cotton. In addition, the high expression in the torus and calycle indicated that CO-like genes might affect flowering. The genes from Group II, and those from Group III involved in segmental duplication or WGD, might play important roles in response to drought and salt stress. Overall, this comprehensive genome-wide study of the CO-like gene family would facilitate further detailed studies in cotton