Spin and Lattice Structure of Single Crystal SrFe2As2

We use neutron scattering to study the spin and lattice structure on single crystals of SrFe2As2, the parent compound of the FeAs based superconductor (Sr,K)Fe2As2. We find that SrFe2As2 exhibits an abrupt structural phase transitions at 220K, where the structure changes from tetragonal with lattice parameters c > a = b to orthorhombic with c > a > b. At almost the same temperature, Fe spins in SrFe2As2 develop a collinear antiferromagnetic structure along the orthorhombic a-axis with spin direction parallel to this a-axis. These results are consistent with earlier work on the RFeAsO (R = rare earth elements) families of materials and on BaFe2As2, and therefore suggest that static antiferromagnetic order is ubiquitous for the parent compound of these FeAs-based high-transition temperature superconductors.Comment: 14 pages with 4 figure

Predictions on the Development Dimensions of Provincial Tourism Discipline Based on the Artificial Neural Network BP Model

As the tourism industry has gradually become the strategic mainstay industry of the national economy, the scope of the tourism discipline has developed rigorously. This paper makes a predictive study on the development of the scope of Guangdong provincial tourism discipline based on the artificial neural network BP model in order to find out how the branch of tourism studies can better adapt to the development of the tourism industry. The research findings indicate that the BP model can be applied to the predictions of the scope of the tourism discipline and provide a quantitative basis for decision making with regard to the spatial layout and optimal allocation of the tourism discipline

Designing research prototype for the elderly: a case study

This paper describes a research study regarding intergenerational story sharing of the elderly living in the nursing home, including four iterations, applyinga Research-through-Design approach. It started from an exploration prototype named Interactive Gallery(1st iteration), and its findings helped to narrow down our research area and define our research question.To answer it, the prototype named Slots-story (2nd iteration) and Slots-memento (3rd iteration) were designed and implemented, which focused on life story and memento story of the elderly respectively. While the 4th iteration aimed at facilitating intergenerational story sharing and sustainably. The above research iterations offer an example of how research prototypes supports to focus research area, and answer the research question in stages. We finally conclude witha discussion of insights on designing prototype for the non-tech-savvy elderly

Birational cobordism invariance of uniruled symplectic manifolds

A symplectic manifold $(M,\omega)$ is called {\em (symplectically) uniruled} if there is a nonzero genus zero GW invariant involving a point constraint. We prove that symplectic uniruledness is invariant under symplectic blow-up and blow-down. This theorem follows from a general Relative/Absolute correspondence for a symplectic manifold together with a symplectic submanifold. A direct consequence is that symplectic uniruledness is a symplectic birational invariant. Here we use Guillemin and Sternberg's notion of cobordism as the symplectic analogue of the birational equivalence.Comment: To appear in Invent. Mat

Co-refining interactive systems with older adults from function, form and interaction

Designing interactive systems that are pragmatic, attractive and easy to use for older adults is challenging. Participatory design, as an approach to enhance the mutual understanding between designers and end users, has been proved to be useful to improve the quality of design for older people. However, PD research has long been criticized for extensively dealing with the early-phase design while putting less emphasis on the later stages. In this paper, we argue for the importance of collaborative refinement when designing interactive systems for older adults. Through a case study, we describe our experience of co-refining the preliminary design of an interactive system with older participants from three perspectives: function, form and interaction. We also explored to adopt some potential PD methods and conclude by discussing the effectiveness of the chosen approach and methods