A new kind of VTi2.6O7.2 ultrafine nanocrystals is designed via constructing substitutional solid solution, and it exhibits improved Mg2+ and Li+ storage performances.

This paper proposes a novel short-term air temperature prediction with three-layer Back Propagation Neural Network (BPNN) for the regional application of next 1-12 hours. With the continuous collection of eight real-time micro-climate parameters in the experimentation and demonstration stations in our university, the Multiple Stepwise Regression (MSR) is employed to screen the original historical data to find the parameter factors with greater contribution rate. On the basis of the Root Mean Square Error (RMSE) value evaluating the optimal fitting degree of the stepwise regression, the Levenberg-Marquardt (LM) and the Resilient Propagation (R-Prop) training algorithm are employed to construct a Combined BPNN (CBPNN) with two MSR inputs. Compared with the known micro-climate data sets, the Mean Absolute Error (MAE) is to evaluate the applicability of CBPNN prediction model. The experimentation shows that the MAE is within 4°C in the next 12 hours. This proposal will be deployed in stations in our university for extreme weather warnings, and could be applied to some regional short-term parameter prediction for the future agricultural production service.

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Hydroxyapatite (HA) has been commonly used as an alternative bone substitute. But it has drawbacks, such as poor degradation and limited osteogenesis. Low-crystalline carbonated hydroxyapatite (L-CHA), which has greater biodegradability than HA, is suggested as one of the main components of bone minerals, but the exact mechanism behind the roles of carbonate substituted in biological behaviors of low-crystalline HA is still a mystery. In this study, L-CHAs with different carbonate contents were prepared, and the effects of the content on the physicochemical properties, in vitro cytological responses, and in vivo bone defects repair effects of L-CHAs were investigated. The results demonstrated that CO 3 2− had successfully entered the lattice structure of L-CHAs with a maximum content of 9.2 wt %. Both low-crystalline undoped HA (L-HA) and L-CHAs were nanocrystalline (20−30 nm) with significantly higher specific surface areas, protein adsorption capacities, and biodegradability compared to high-crystalline HA (H-HA) with submicron crystalline size (200− 400 nm). Besides, the amounts of the adsorbed protein and released Ca 2+ ions increased in a carbonate-content-dependent manner. Compared to L-HA and H-HA, L-CHAs promoted the adhesion and proliferation of bone marrow mesenchymal stem cells and significantly upregulated the levels of alkaline phosphatase (ALP) activity and the expression of osteogenesis-related genes. In addition, L-CHA-9 not only showed a faster biodegradation rate but also effectively promoted bone regeneration when implanted in the critical-sized bone defects of rabbit femora. This study provided evidence for the development of L-CHA as a promising biodegradable and bioactive material with great osteoconductivity and osteogenic capability with respect to conventional HA.

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