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RAFT step-growth polymerizationviathe Z-group approach was developed, offering a facile method to prepare deconstructable (multiblock) polymers by combining RAFT chain-growth polymerization and RAFT interchange. 

Abstract Non-volatile phase-change memory devices utilize local heating to toggle between crystalline and amorphous states with distinct electrical properties. Expanding on this kind of switching to two topologically distinct phases requires controlled non-volatile switching between two crystalline phases with distinct symmetries. Here, we report the observation of reversible and non-volatile switching between two stable and closely related crystal structures, with remarkably distinct electronic structures, in the near-room-temperature van der Waals ferromagnet Fe_5−δGeTe₂. We show that the switching is enabled by the ordering and disordering of Fe site vacancies that results in distinct crystalline symmetries of the two phases, which can be controlled by a thermal annealing and quenching method. The two phases are distinguished by the presence of topological nodal lines due to the preserved global inversion symmetry in the site-disordered phase, flat bands resulting from quantum destructive interference on a bipartite lattice, and broken inversion symmetry in the site-ordered phase. 

New words are regularly introduced to communities, yet not all of these words persist in a community's lexicon. Among the many factors contributing to lexical change, we focus on the understudied effect of social networks. We conduct a large-scale analysis of over 80k neologisms in 4420 online communities across a decade. Using Poisson regression and survival analysis, our study demonstrates that the community's network structure plays a significant role in lexical change. Apart from overall size, properties including dense connections, the lack of local clusters and more external contacts promote lexical innovation and retention. Unlike offline communities, these topic-based communities do not experience strong lexical levelling despite increased contact but accommodate more niche words. Our work provides support for the sociolinguistic hypothesis that lexical change is partially shaped by the structure of the underlying network but also uncovers findings specific to online communities. 

Abstract After a CO 2 increase, whether the early transient and final equilibrium climate change patterns are similar has major implications. Here, we analyze long-term simulations from multiple climate models under increased CO 2 , together with the extended simulations from CMIP5, to compare the transient and equilibrium climate change patterns under different forcing scenarios. Results show that the normalized warming patterns (per 1 K of global warming) are broadly similar among different forcing scenarios (including abrupt 2 × CO 2 , 4 × CO 2 , and 1% CO 2 increase per year) and during different time periods, except for the first 50 years or so when warming is weaker over the North Atlantic and Southern Ocean but stronger over most continents. During the first 200 years, this consistency is stronger over land than over ocean, but is lower in midlatitudes than other regions. Normalized precipitation change patterns are also similar, albeit to a lesser degree, among different forcing scenarios and across different time periods, although noticeable differences exist during the first few hundred years with smaller increases over the tropical Pacific. Precipitation over many subtropical oceans and land areas decreases consistently under different forcing scenarios and over all time periods. In particular, the transient and near-equilibrium change patterns for both surface air temperature and precipitation are similar over most of the globe, except for the North Atlantic warming hole, which is mainly a transient feature. The Arctic amplification and land–ocean warming contrast are largest during the first 100–200 years after CO 2 quadrupling but they still exist in the equilibrium response.