Wenlei Zhang,Yang Gao,Yifan Zhou,Hou Wu,Zhigang Suo,Tongqing Lu
Adhesives are commonly assessed by two properties: strength and toughness. Here we study how strength and toughness are affected by adhesive thickness. We sandwich gelatin adhesives of various thicknesses between glass substrates. The transparency of the adhesives and substrates enables us to observe crack nucleation and growth. We measure strength by lap shear of samples without precrack, and measure toughness by lap shear of samples with precrack. Our data show a characteristic adhesive thickness, about 0.5 mm. For adhesives below the characteristic thickness, strength is independent of thickness, but toughness increases with thickness. For adhesives above the characteristic thickness, strength decreases as thickness increases, but toughness is a constant. Strength scatters narrowly for samples of a thin adhesive, but broadly for samples of a thick adhesive. By contrast, toughness scatters narrowly for samples of all thicknesses. This work shows the importance of assessing adhesives of various thicknesses.
Both pericarp shrinkage and the sugar-acid ratio are vital factors influencing consumer preference in the apple industry. Our study examines the relationship between extrinsic appearance and intrinsic properties by investigating the effects of sugar-acid content on shrinkage, apple fruit development and shrinkage presence were investigated while the fruit was stored at 5 °C with 60 % relative humidity for up to 70 days, which categorized by packaging in microporous plastic bags. Pericarp shrinkage was assessed by exploring fruit sensory preferences, variations in structural differences, and physiological compositional status, and correlations were analyzed. Shrinkage significantly reduced water loss rate (4.44 %), accelerated water core dissipation and microcrack growth, and correlated with total sugar (r = 0.59) and total acid (r = 0.75). Summarily, pericarp shrinkage correlated positively with fructose (r = 0.37), glucose (r = 0.56), and succinic acid (r = 0.55) accumulation, but negatively with citric acid (r = -30) accumulation. The present study serves as a novel exploration of how pericarp shrinkage and sugar-acid biosynthesis and distribution in apples, losses due to cosmetic defects can be reduced for further research.
危险品化学品经营许可证（带存储）