No abstract

No abstract

Photoluminescence (PL) efficiency plots versus laser excitation power are presented for bare and Na2S treated n-GaAs. The plots demonstrate an increase in PL quantum yield with increasing excitation power density for both samples. The PL enhancement observed in the Na2S treated sample is presented and is shown to depend strongly on excitation power density. Application of the deadlayer model to the analysis of low power PL efficiency from bare GaAs indicates that surface electron-hole recombination is significantly slower than surface minority carrier trapping.

Vanadium (III) oxide nanomaterials have been investigated and considered as potential anode materials for Li-ion batteries (LIBs). Fabrication of two-dimensional (2D) mesoporous nanomeshes from carbon-encapsulated V2O3, though is technically challenging, can further enhance its electrochemical performances due to the shortening of the Li+-ion diffusion distance, the highly conductive pathway for electrons, and the tremendous increase of surface areas. In this paper, an ice-templated assembly approach is utilized to fabricate a 2D mesoporous nanomesh from N-doped carbon-encapsulated V2O3 (V2O3@N-C Nm). The V2O3@N-C Nm anode exhibits a highly reversible capacity of ∼651 mA h g–1 at a current density of 200 mA g–1 over 100 cycles, which is 2.5 times and 1.3 times higher than those of V2O3 Nm and V2O3@N-C nanocomposite (V2O3@N-C Nc), respectively. The superior electrochemical performances of V2O3@N-C Nm are mainly due to its unique nanomesh nanostructure, which facilitates the lithiation/delithiation process, alleviates structural collapse, enhances electrical conductivity, and provides efficient diffusion channels.

Porous calcium phosphate cement (CPC) scaffolds were successfully fabricated utilizing particle-leaching method. Mesenchymal stem cells (MSCs) were cultured, expanded and seeded on the scaffolds and the proliferation and differentiation of MSCs into osteoblastic phenotype were determined using MTT assay, ALP activity and ESEM. The results revealed that the CPC scaffolds were biocompatible and had no negative effects on the MSCs in vitro. The in vivo biocompatibility and osteogenicity of the scaffolds were investigated. Both pure scaffolds and MSCs/scaffold constructs were implanted in rabbit mandibles and studied histologically. The results showed that CPC scaffolds exhibited good biocompatibility and osteoconductivity. Moreover, the introduction of MSCs into the scaffolds dramatically enhanced the efficiency of new bone formation initially.