Polynomial Functions and the Riesz Interpolation Property

Building on a proof by D. Handelman of a generalisation of an example due to L. Fuchs, we show that the space of real-valued polynomials on a non-empty set X of reals has the Riesz Interpolation Property if and only if X is bounded.

Force-induced activation of covalent bonds in mechanoresponsive polymeric materials

Mechanochemical transduction enables an extraordinary range of physiological processes such as the sense of touch, hearing, balance, muscle contraction, and the growth and remodelling of tissue and
bone1–6. Although biology is replete with materials systems that actively and functionally respond to mechanical stimuli, the default mechanochemical reaction of bulk polymers to large external stress is the unselective scission of covalent bonds, resulting in damage or failure7. An alternative to this degradation process is the rational molecular design of synthetic materials such that mechanical stress
favourably altersmaterial properties. A few mechanosensitive polymers with this property have been developed8–14; but their active response is mediated through non-covalent processes, which may
limit the extent to which properties can be modified and the longterm stability in structural materials. Previously, we have shown with dissolved polymer strands incorporating mechanically sensitive chemical groups—so-called mechanophores—that the directional nature of mechanical forces can selectively break and re-form covalent bonds15,16. We now demonstrate that such forceinduced covalent-bond activation can also be realized with mechanophore-linked elastomeric and glassy polymers, by using a mechanophore that changes colour as it undergoes a reversible electrocyclic ring-opening reaction under tensile stress and thus allows us to directly and locally visualize the mechanochemical reaction. We find that pronounced changes in colour and fluorescence emerge with the accumulation of plastic deformation, indicating that in these polymeric materials the transduction of mechanical force into the ring-opening reaction is an activated process. We anticipate that force activation of covalent bonds can serve as a general strategy for the development of new mechanophore building blocks that impart polymeric materials with desirable functionalities ranging from damage sensing to fully regenerative self-healing.

ARTICLE: Property and the Definition of Slavery

Currently there is no clear understanding of the meaning of ‘slavery’ in modern international law. While generally it is accepted that the
authoritative definition of slavery is provided by Article 1 of the Slavery Convention 1926, in recent times slavery has been understood in such a wide variety of ways that effectively it is a meaningless term. This paper reflects on this interpretation problem and aims to redress this balance by reclaiming the core meaning of the legal definition. It applies property law perspectives to explain the conception of ownership invoked by Article 1, to argue that it remains relevant and to explore how it might be applied in identifying modern cases of slavery.

The City as Laboratory and the Urban-Rural Divide: the Revival of Private Property and its Limits in Post-Mao China

This paper focuses on the revival of private property and its limits in urban China. It explores the emergence of urban property markets; urban property-holding in relation to the complexity of urban governance; “minor property rights apartments” that form a de facto real estate market and cross over the urban-rural divide; the “grey areas” of blurring legal and administrative boundaries in modern China; and recent changes to the rural land system and the rural-urban divide. The conclusion flags the theme of the city as laboratory with regard to the blurring legal and governmental urban-rural distinction.

Possession Taken by Theft and the Original Acquisition of Personal Property Rights

This paper queries the soundness of the view that wrongful possession (eg a thief’s possession of goods he has stolen) should be protected by the standard actions for interference with goods. It uses close historical analysis of the development of the relevant concepts through the cases to argue that this is not a proposition that is compelled on the authorities, nor one demanded as a matter of principle. It then abstracts to consider the implications of this argument at a theoretical level, exposing great need for development in the common law’s basic principles of possessory protection. It argues innovatively that the objects of the law might be better served by the creation of a more limited form of possessory protection, achieved through the possessor’s acquisition of a personal right, and correlatively that the values that underpin and justify our basic rules of possessory protection entail a more nuanced response to matters of property acquisition.

Effect of post-weld-annealing on the tensile deformation characteristics of laser-welded NiTi thin foil

Laser welding is an important process for fabricating complex components involving NiTi shape memory
alloy. As welding is a thermal process, the amount of heat input and the rate of cooling have significant
impact on the microstructure and hence the resultant characteristics of NiTi. In this study, the effect of
laser welding and post-weld-annealing from 573 K to 1173 K on the thermal phase transformation behaviors,
tensile deformation and micro-hardness characteristics of the laser-welded NiTi thin foils were investigated.
It was found that the as-welded sample exhibited inferior super-elasticity compared to the base
material, and the super-elasticity could be partially restored by annealing at 573 K. On the other hand,
annealing of the weldment above the recrystallization temperature would lower the super-elasticity.