Investigation of Frost-Heaving Characteristics of Horizontal- Cup-Shape Frozen Ground Surface for Reinforced End Soil Mass in Shield Tunnel Construction

Artificial freezing method is commonly adopted for reinforcingend soil mass of shield tunnel in the weak and rich aqueousformation, which is expected to prevent the construction riskin the originating and arriving of shield machine, whereas thearrangement of freezing pipes is sometimes varied due to variouscomplex limitations, and the corresponding frost-heavingcharacteristics of ground surface also differs from others. Inthis paper, a case of artificial freezing end soil mass with cupshape arrangement of horizontal freezing pipes is studied byfield investigation and numerical analysis, in which a numericalmodel coupled with water-heat-force interactions is proposedfor appropriately evaluating the frost-heaving characteristicsof ground surface in artificial freezing method. Theresults demonstrate that all the considered factors on brinetemperature, buried depth and cup bottom thickness have significantlyinfluences of frost-heaving characteristics of groundsurface in the artificial ground freezing (AGF) with cup shapearrangement of horizontal freezing pipes, in which the frostheave displacement of horizontal-cup-shape frozen groundsurface is increased with the increasing brine temperature andburied depth, whereas that is decreased with the increasing cupbottom thickness.

“Red-to-blue” colorimetric detection of cysteine via anti-etching of silver nanoprisms

A mechanistic scheme of the AgNPR system for Cys detection is presented. In the absence of Cys, I−could attach to the corners and edges of AgNPRsviathe Ag–I bond resulting in the morphology transition from nanoprism to nanodisk. Cys can prevent I−from attaching to the AgNPRs' surface and keep the shape frozen.

Investigation of Thermomechanical Behaviors of Epoxy Shape Memory Polymers by Molecular Dynamics Simulation

Shape memory polymers (SMPs) possess the capability of shape frozen and recovery via thermomechanical processing. Over the last decades, great work has focused on their macro-properties. In order to have a better understanding of the micro-deformation mechanisms of this class of functional materials, the thermomechanical behaviors of three types of epoxy SMPs with varied curing agent contents were simulated by the molecular dynamics (MD) method. Special attention was paid on the different responses of the materials in the rubbery and glassy states. Moreover, structure-property analyses were presented.