Lithium–sulfur (Li–S) batteries are highly attractive due to their high energy density, potentially low cost, and environmental compatibility. However, their commercialization has been greatly hindered by their poor cycle life and severe self‐discharge, which can be attributed to the polysulfides dissolution. To overcome these issues, much effort has been devoted to engineering the electrode structure and composition to improve the performance which is often expensive and laborious. In this study, an ultralight multiwall carbon nanotube/N‐doped carbon quantum dot (MWCNT/NCQD)‐coated separator is first designed, which is cost effective and facile. The MWCNTs/NCQDs‐coated separator is then applied in Li–S batteries. The MWCNTs/NCQDs coating provides a physical shield against polysulfide shuttling and chemical adsorption of polysulfides by MWCNTs and NCQDs. The synergetic effect of MWCNTs and NCQDs enables the production of Li–S cell with a relative high initial discharge capacity of 1330.8 mA h g−1 and excellent cyclic performance with a corresponding capacity fade rate of as low as 0.05% per cycle at 0.5 C over 1000 cycles. Excellent rate capability and anti‐self‐discharge behavior are also displayed. The design of MWCNTs/NCQDs‐coated separator is a viable approach for successfully developing practical Li–S batteries.

Background Virtual Reality (VR) is increasingly used in health-related fields and interventions using VR have the potential to be powerful tools in patient management. The aim of this study was to synthesize the effects of VR interventions for people with mild cognitive impairment (MCI) or dementia. Methods Electronic databases were searched to identify studies that used an experimental design to investigate VR intervention outcomes for patients with MCI or dementia. Studies were excluded if the intervention did not focus on VR, if relevant quantitative outcomes were not reported, or if the intended study purpose was assessment or diagnosis. Data were extracted and analyzed from studies that met criteria. To synthesize the intervention effect sizes (ES), we used random effects models to accommodate heterogeneity in the main effect and sub-group analyses. To identify the potential reason for heterogeneity and compare ES according to the moderator variables, subgroup analyses were conducted based on study characteristics and intervention outcomes. Results Data from eleven studies that met eligibility criteria were analyzed. VR intervention delivered to participants with MCI or dementia produced small to medium effects (ES = 0.29, CI = 0.16, 0.42). The ES for studies using semi-immersive technology (ES = 0.37, CI = 0.25, 0.49) was greater than the studies using full-immersive VR (ES = 0.03, CI = -0.14, 0.21). The results showed small-to-medium effects for VR interventions affecting key outcome variables such as cognition (ES = 0.42, CI = 0.24, 0.60) and physical fitness (ES = 0.41, CI = 0.16, 0.65). Conclusion VR interventions, particularly of the semi-immersive type, are useful for people with MCI or dementia. These results should contribute to the establishment of practical guidelines for VR interventions for patients with cognitive decline.

This paper illustrates a simpler method for the preparation of gel polymer electrolytes.

We show here that the boundaries of individual grains in dense polycrystals prefer certain crystallographic habit planes, almost as if they were independent of the neighboring crystals. In MgO, SrTiO3, MgAl2O4, TiO2, and aluminum, the specific habit planes within the polycrystal correspond to the same planes that dominate the external growth forms and equilibrium shapes of isolated crystals of the same phase. The observations decrease the apparent complexity of interfacial networks and suggest that the mechanisms of solid‐state grain growth may be analogous to conventional crystal growth. The results also indicate that a model for grain‐boundary energy and structure based on grain surface relationships is more appropriate than the widely accepted models based on lattice orientation relationships.