Power Relations in Older Adults’ Cognitive Interaction in Clinical Setting: A Multimodal Pragmatic Perspective

This study explored the construction of power relations in the cognitive assessment of older adults within the Chinese clinical context.Data is derived from audio and video recordings that nine older adults produced in the cognitive assessment of the Chinese version of the Montreal Cognitive Assessment-Basic(MoCA-B),which were then annotated and analyzed from a multimodal pragmatic perspective.The study reveals that examiners and older adults employed various speech acts to achieve distinct communicative goals,with power relations between them being reflected through these speech acts.Examiners tend to claim high power,utilizing discourse strategies such as request,interruption,evaluation,rhetorical questions,and directive speech acts.In contrast,older adults assert high power through directive speech acts,rhetorical questions,and interruptions.Both parties also exhibit low power by using confirming questions and explanations.Additionally,gestures,smiles,prosody features,and other non-verbal communicative resources are synergistically employed to exercise power.The interactive mechanism of constructing power relations reveals that age affects older adults’power relations construction even in a professional setting of the Chinese context.The negotiation between the advanced age of older adults and the expertise of examiners jointly shapes power relations in their interactions.

Fabrication and Optical Properties of Silicon Nanowires Arrays by Electroless Ag-catalyzed Etching

In order to realize ultralow surface reflectance and broadband antireflection effects which common pyramidal textures and antireflection coatings can't achieve in photovoltaic industry,we used low-cost and easy-made Ag-catalyzed etching techniques to synthesize silicon nanowires(Si NWs) arrays on the substrate of single-crystalline silicon.The dense vertically-aligned Si NWs arrays are fabricated by local oxidation and selective dissolution of Si in etching solution containing Ag catalyst.The Si NWs arrays with 3 μm in depth make reflectance reduce to less than 3% in the range of 400 to 1000 nm while reflectance gradually reached the optimum value with the increasing of etching time.The antireflection of Si NWs arrays are based on indexgraded mechanism:Si NWs arrays on a subwavelength scale strongly scatter incident light and have graded refractive index that enhance the incidence of light in usable wavelength range.However,surface recombination of Si NWs arrays are deteriorated due to numerous dangling bonds and residual Ag particles.