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The T700/HT280 composites were subjected to vacuum thermal cycling (-140-180℃,10-3 Pa). The mass loss rate, dynamic mechanical properties and low-speed impact of composites were tested before and after vacuum thermal cycling respectively. The visual observation, ultrasonic C-scan and finite element (FE) analysis were used to analyze, characterize and simulate the low-speed impact damage. The results show that the mass loss rates of T700/HT280 composites and matrix resin are increased rapidly and then level off with the increase of the number of vacuum thermal cycles, which is due to the gassing effect. After the vacuum thermal cycle treatment, T700/HT280 composites show some degree of post-cure, thermal aging and partial interface debonding. The main damage mode at low impact energy is that the matrix resin is compressed. However, matrix cracking and delamination are deemed as the damage mode at high impact energy. The FE simulation results are consistent with the experimental results. As the impact energy increases, the absorption energy of the composites is increased. Under the condition of 30-40 J impact energy, the absorption energy can effectively characterize the environmental damage effects of vacuum thermal cycle on composites.

Maleic anhydride was used to functionalize the graphene oxide (GO). The prepared functionalized GO was used to modify the bismaleimide (BMI) resin and the carbon fiber/BMI composites. The structure and properties of the composites were characterized. The results indicate that the maleic anhydride molecules are successfully grafted onto the GO surfaces. Due to the introduction of functionalized GO, the tensile strength, elastic modulus, blending strength, impact strength and glass transition temperature of the BMI resin were substantially improved. The impact fracture morphologies show that brittle fracture is transformed into ductile fracture after modification; moreover, the interfacial adhesions of carbon fiber/BMI composites were also enhanced obviously. The ILSS of composites increased from 84.0MPa to 104.6MPa after modification.

SUMMARY: As sessile organisms, plants need to respond to rapid changes in numerous environmental factors, mainly diurnal changes of light, temperature, and humidity. Maize is the world's most grown crop, and as a C4 plant it exhibits high photosynthesis capacity, reaching the highest rate of net photosynthesis at midday; that is, there is no "midday depression." Revealing the physiological responses to diurnal changes and underlying mechanisms will be of great significance for guiding maize improvement efforts. In this study, we collected maize leaf samples and analyzed the proteome and phosphoproteome at nine time points during a single day/night cycle, quantifying 7424 proteins and 5361 phosphosites. The new phosphosites identified in our study increased the total maize phosphoproteome coverage by 8.5%. Kinase‐substrate network analysis indicated that 997 potential substrates were phosphorylated by 20 activated kinases. Through analysis of proteins with significant changes in abundance and phosphorylation, we found that the response to a heat stimulus involves a change in the abundance of numerous proteins. By contrast, the high light at noon and rapidly changing light conditions induced changes in the phosphorylation level of proteins involved in processes such as chloroplast movement, photosynthesis, and C4 pathways. Phosphorylation is involved in regulating the activity of large number of enzymes; for example, phosphorylation of S55 significantly enhanced the activity of maize phosphoenolpyruvate carboxykinase1 (ZmPEPCK1). Overall, the database of dynamic protein abundance and phosphorylation we have generated provides a resource for the improvement of C4 crop plants. Significance Statement: As a classic C4 plant, maize has high photosynthetic efficiency, but little is known about the mechanisms involved in the response to natural diurnal changes. Our results suggested that the response to a heat stimulus in maize primarily involves a change protein abundance but that the response to changes in light intensity, particularly high light and fast changing light, tends to involve regulation of protein phosphorylation. [ABSTRACT FROM AUTHOR]

Summary: The Populus shoot undergoes primary growth (longitudinal growth) followed by secondary growth (radial growth), which produces biomass that is an important source of energy worldwide. We adopted joint PacBio Iso‐Seq and RNA‐seq analysis to identify differentially expressed transcripts along a developmental gradient from the shoot apex to the fifth internode of Populus Nanlin895. We obtained 87 150 full‐length transcripts, including 2081 new isoforms and 62 058 new alternatively spliced isoforms, most of which were produced by intron retention, that were used to update the Populus annotation. Among these novel isoforms, there are 1187 long non‐coding RNAs and 356 fusion genes. Using this annotation, we found 15 838 differentially expressed transcripts along the shoot developmental gradient, of which 1216 were transcription factors (TFs). Only a few of these genes were reported previously. The differential expression of these TFs suggests that they may play important roles in primary and secondary growth. AP2, ARF, YABBY and GRF TFs are highly expressed in the apex, whereas NAC, bZIP, PLATZ and HSF TFs are likely to be important for secondary growth. Overall, our findings provide evidence that long‐read sequencing can complement short‐read sequencing for cataloguing and quantifying eukaryotic transcripts and increase our understanding of the vital and dynamic process of shoot development. [ABSTRACT FROM AUTHOR]