No abstract

Longer lives and fertility far below the replacement level of 2.1 births per woman are leading to rapid population aging in many countries. Many observers are concerned that aging will adversely affect public finances and standards of living. Analysis of newly available National Transfer Accounts data for 40 countries shows that fertility well above replacement would typically be most beneficial for government budgets. However, fertility near replacement would be most beneficial for standards of living when the analysis includes the effects of age structure on families as well as governments. And fertility below replacement would maximize per capita consumption when the cost of providing capital for a growing labor force is taken into account. While low fertility will indeed challenge government programs and very low fertility undermines living standards, we find that moderately low fertility and population decline favor the broader material standard of living

Product 1 (82.25% valencene), product 2 (73.36% decanal), product 3 (78.12% octanal), and product 4 (90.61% linalool) were isolated from sweet orange oil by combined usage of molecular distillation and column chromatography. The antioxidant activity of sweet orange oil and these products was investigated using 2,2-diphenyl-1-picrylhydrazyl and reducing power assays. In this test, product 1 (82.25% valencene), product 2 (73.36% decanal), and product 4 (90.61% linalool) had antioxidant activity, but lower than sweet orange oil. The antimicrobial activity was investigated in order to evaluate their efficacy against 5 microorganisms. The results showed that sweet orange oil, product 2 (73.36% decanal), product 3 (78.12% octanal), and product 4 (90.61% linalool) had inhibitory and bactericidal effect on the test microorganisms (except Penicillium citrinum). Valencene did not show any inhibitory effect. Saccharomyces cerivisiae was more susceptible, especially to the crude sweet orange oil (minimal inhibitory concentration 6.25 μL/mL). The cytotoxicity was evaluated on Hela cells using the 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay. All test samples showed significant cytotoxicity on the cell lines with IC(50) values much less than 20 μg/mL.

The shuttle effect and sluggish conversion kinetics of lithium polysulfides (LiPS) hamper the practical application of lithium–sulfur batteries (LSBs). Toward overcoming these limitations, herein an in situ grown C2N@NbSe2 heterostructure is presented with remarkable specific surface area, as a Li–S catalyst and LiPS absorber. Density functional theory (DFT) calculations and experimental results comprehensively demonstrate that C2N@NbSe2 is characterized by a suitable electronic structure and charge rearrangement that strongly accelerates the LiPS electrocatalytic conversion. In addition, heterostructured C2N@NbSe2 strongly interacts with LiPS species, confining them at the cathode. As a result, LSBs cathodes based on C2N@NbSe2/S exhibit a high initial capacity of 1545 mAh g−1 at 0.1 C. Even more excitingly, C2N@NbSe2/S cathodes are characterized by impressive cycling stability with only 0.012% capacity decay per cycle after 2000 cycles at 3 C. Even at a sulfur loading of 5.6 mg cm−2, a high areal capacity of 5.65 mAh cm−2 is delivered. These results demonstrate that C2N@NbSe2 heterostructures can act as multifunctional polysulfide mediators to chemically adsorb LiPS, accelerate Li‐ion diffusion, chemically catalyze LiPS conversion, and lower the energy barrier for Li2S precipitation/decomposition, realizing the “adsorption‐diffusion‐conversion” of polysulfides.

With its high theoretical capacity, lithium (Li) metal is recognized as the most potential anode for realizing a high-performance energy storage system. A series of questions (severe safety hazard, low Coulombic efficiency, short lifetime, etc.) induced by uncontrollable dendrites growth, unstable solid electrolyte interface layer, and large volume change, make practical application of Li-metal anodes still a threshold. Due to their highly appealing properties, carbon-based materials as hosts to composite with Li metal have been passionately investigated for improving the performance of Li-metal batteries. This review displays an overview of the critical role of carbon-based hosts for improving the comprehensive performance of Li-metal anodes. Based on correlated mainstream models, the main failure mechanism of Li-metal anodes is introduced. The advantages and strategies of carbon-based hosts to address the corresponding challenges are generalized. The unique function, existing limitation, and recent research progress of key carbon-based host materials for Li-metal anodes are reviewed. Finally, a conclusion and an outlook for future research of carbon-based hosts are presented. This review is dedicated to summarizing the advances of carbon-based materials hosts in recent years and providing a reference for the further development of carbonbased hosts for advanced Li-metal anodes.

Nickel terephthalate is grown on Ni foam with high mass-loading and its electrochemical performance can be greatly enhanced by polyaniline electrodeposition.

A 3D porous lithiophilic–lithiophobic–lithiophilic dual-gradient CAZPZ current collector is designed to regulate homogeneous Li deposition, and the CAZPZ–Li hybrid anode has superb practical applications in different full cells.

There is a significant need to identify cyan-emitting phosphors capable of filling the “cyan-gap” (480-520 nm) in full-visible-spectrum phosphor-converted white light-emitting diodes (pc-wLEDs). Here, a new broadband cyan-emitting phosphor enabling...