Construction of Geo-Ontology Knowledge Base about Spatial Relations

The Chinese Academy of Science (CAS); National Natural Science Foundation of China (NSFC); Inst. Geogr. Sci. Nat. Resour. Res. Chin. Acad. Sci. (CAS); Fuzhou University; University of Calabria<span class="MedBlackText">The spatial relation analysis, query and reasoning in current geographic information systems usually generalize geographic objects into geometric points, lines and polygons. However, in the real world and human's cognition, geographic objects are not simply geometric objects but spatially distributed objects with geographic semantics. If the geographic entities belong to different types, we may use different words to describe their spatial relationship although their shapes and geometric relationships are exactly the same. Aiming at above phenomenon, this paper analyzes what kinds of semantic information are involved in spatial relationship descriptions and queries. Based on the semantic analysis of geographic relations, an ontological knowledge base is established to store the knowledge of spatial relations between geographic objects. The knowledge base is implemented with Prote&acute;ge&acute; and OWL, and finally is connected to the spatial relation query system.</span

Notes on monotone Lindelöf property

summary:We provide a necessary and sufficient condition under which a generalized ordered topological product (GOTP) of two GO-spaces is monotonically Lindelöf

Exploring the total Galactic extinction with SDSS BHB stars

Aims: We used 12,530 photometrically-selected blue horizontal branch (BHB) stars from the Sloan Digital Sky Survey (SDSS) to estimate the total extinction of the Milky Way at the high Galactic latitudes, $R_V$ and $A_V$ in each line of sight. Methods: A Bayesian method was developed to estimate the reddening values in the given lines of sight. Based on the most likely values of reddening in multiple colors, we were able to derive the values of $R_V$ and $A_V$. Results: We selected 94 zero-reddened BHB stars from seven globular clusters as the template. The reddening in the four SDSS colors for the northern Galactic cap were estimated by comparing the field BHB stars with the template stars. The accuracy of this estimation is around 0.01\,mag for most lines of sight. We also obtained $$ to be around 2.40$\pm1.05$ and $A_V$ map within an uncertainty of 0.1\,mag. The results, including reddening values in the four SDSS colors, $A_V$, and $R_V$ in each line of sight, are released on line. In this work, we employ an up-to-date parallel technique on GPU card to overcome time-consuming computations. We plan to release online the C++ CUDA code used for this analysis. Conclusions: The extinction map derived from BHB stars is highly consistent with that from Schlegel, Finkbeiner & Davis(1998). The derived $R_V$ is around 2.40$\pm1.05$. The contamination probably makes the $R_V$ be larger.Comment: 16 pages, 13 figures, 4 tables, accepted for publication in A&

Multistaged discharge constructing heterostructure with enhanced solid-solution behavior for long-life lithium-oxygen batteries.

Inferior charge transport in insulating and bulk discharge products is one of the main factors resulting in poor cycling stability of lithium-oxygen batteries with high overpotential and large capacity decay. Here we report a two-step oxygen reduction approach by pre-depositing a potassium carbonate layer on the cathode surface in a potassium-oxygen battery to direct the growth of defective film-like discharge products in the successive cycling of lithium-oxygen batteries. The formation of defective film with improved charge transport and large contact area with a catalyst plays a critical role in the facile decomposition of discharge products and the sustained stability of the battery. Multistaged discharge constructing lithium peroxide-based heterostructure with band discontinuities and a relatively low lithium diffusion barrier may be responsible for the growth of defective film-like discharge products. This strategy offers a promising route for future development of cathode catalysts that can be used to extend the cycling life of lithium-oxygen batteries