Semantic relations and prosodic features of ranhou in spontaneous Mandarin conversation

Ranhou ‘then’ is traditionally defined as a conjunction, indicating succession of two events. Adopting the methodology of Interactional Linguistics, this study explores semantic relations of ranhou in Mandarin face-to-face and telephone conversations. An examination of the data shows that besides succession, ranhou can express other nine semantic relations, including causality, progression relation, coordinating relation, adversative relation, additive relation, enumeration, hypothesis, alternative relation, concession and be no practical meaning as well. Meanwhile, prosodic features of ranhou are explored with the help of software Praat and Audacity. It is suggested that eleven semantic relations vary in mean pitch range and mean length. Although each token of ranhou differs from each other in prosody, with respect to loudness, ranhou can be stressed on ran, or hou and also be articulated without loudness. But in a whole, loudness of ranhou is mostly put on hou

Elastic metamaterials with simultaneously negative effective shear modulus and mass density

We propose a type of elastic metamaterial comprising fluid-solid composite inclusions which can possess negative shear modulus and negative mass density over a large frequency region. Such a solid metamaterial has a unique elastic property that only transverse waves can propagate with a negative dispersion while longitudinal waves are forbidden. This leads to many interesting phenomena such as negative refraction, which is demonstrated by using a wedge sample, and a significant amount of mode conversion from transverse waves to longitudinal waves that cannot occur on the interface of two natural solids

Illusion optics: The optical transformation of an object into another object

We propose to use transformation optics to generate a general illusion such that an arbitrary object appears to be like some other object of our choice. This is achieved by using a remote device that transforms the scattered light outside a virtual boundary into that of the object chosen for the illusion, regardless of the profile of the incident wave. This type of illusion device also enables people to see through walls. Our work extends the concept of cloaking as a special form of illusion to the wider realm of illusion optics.Comment: Including a paper and its auxiliary materia