Reduction of the anthropogenic emission of CO 2 is currently a top priority because CO 2 emission is closely associated with climate change. Carbon capture and storage (CCS) [1] and the development of renewable and clean energy sources are two approaches for the reduction of CO 2 emission. One of the most promising alternative fuels is CH 4 , which is the major component of natural gas. The efficient storage of CH 4 is still one of the main challenges for its widespread application. Accordingly, the development of more efficient approaches for CO 2 capture and CH 4 storage is critically important.Recently, metal-organic frameworks (MOFs, e.g., MOF-210 and NU-100) [2] have shown great potential for gas storage because of their high specific surface area (SSA) and functionalized pore walls. However, most MOF materials still show relatively low CO 2 and CH 4 uptakes. To enhance CO 2 and CH 4 adsorption, it is imperative to develop new materials, such as covalent organic frameworks (COFs), [3] or to modify MOFs by using postsynthetic approaches. [2b, 4] Herein, we focus on the latter strategy. One of the modification approaches is incorporation of carbon nanotubes (CNTs) into MOFs in order to achieve enhanced composite performance, because of the unusual mechanical and hydrophobicity properties of CNTs.[5] Another approach is doping MOFs or COFs with electropositive metals.Recent studies indicate that the surface carboxylate functional groups of a substrate could act as nucleation sites to form MOFs by heterogeneous nucleation and crystal growth.[6] Both experimental and theoretical investigations indicate that the H 2 adsorption capacities of MOFs can be enhanced significantly by doping alkali-metal ions, in particular Li + ions, to the frameworks, owing to the strong affinity of Li + ions towards H 2 molecules. [3d, 7] Similarly, Lan et al. also showed theoretically that doping of COFs with Li + ions can significantly enhance the CH 4 uptake of COFs.[8] Most recently, the multiscale simulations performed by Lan et al. indicate that Li is the best surface modifier of COFs for CO 2 capture among a series of metals (Li, Na, K, Be, Mg Ca, Sc and Ti).[9] Furthermore, their simulations show that the excess CO 2 uptakes of the lithium-doped COFs can be enhanced by four to eight times compared to the undoped COFs at 298 K and 1 bar. [9] Motivated by these experimental and theoretical results, we synthesized hybrid MOF materials by using the two modification techniques outlined above, that is, 1) incorporation of CNTs into [Cu 3 (C 9 sites that become available for interaction with other molecules after removal of H 2 O in from Cu 2+ carbonyl complexes, and can also be easily rehydrated without change of the crystalline nature of the material after exposure to air [11] (see Figure S1 in the Supporting Information). Although the btc ligand can not act as an electron receptor for the electron transfer from the naphthalenide radical anion, [7c] the rehydration of the Cu 2+ sites in the framework makes the electron trans...
Reduction of the anthropogenic emission of CO 2 is currently a top priority because CO 2 emission is closely associated with climate change. Carbon capture and storage (CCS) [1] and the development of renewable and clean energy sources are two approaches for the reduction of CO 2 emission. One of the most promising alternative fuels is CH 4 , which is the major component of natural gas. The efficient storage of CH 4 is still one of the main challenges for its widespread application. Accordingly, the development of more efficient approaches for CO 2 capture and CH 4 storage is critically important.Recently, metal-organic frameworks (MOFs, e.g., MOF-210 and NU-100) [2] have shown great potential for gas storage because of their high specific surface area (SSA) and functionalized pore walls. However, most MOF materials still show relatively low CO 2 and CH 4 uptakes. To enhance CO 2 and CH 4 adsorption, it is imperative to develop new materials, such as covalent organic frameworks (COFs), [3] or to modify MOFs by using postsynthetic approaches. [2b, 4] Herein, we focus on the latter strategy. One of the modification approaches is incorporation of carbon nanotubes (CNTs) into MOFs in order to achieve enhanced composite performance, because of the unusual mechanical and hydrophobicity properties of CNTs. [5] Another approach is doping MOFs or COFs with electropositive metals.Recent studies indicate that the surface carboxylate functional groups of a substrate could act as nucleation sites to form MOFs by heterogeneous nucleation and crystal
Background In this article, we use cross-sectional data obtained from the 2018 China Health and Aging Tracking Survey (CHARLS) to examine the impact of neighborhood mental health at the community level on the mental health of older adults aged 60 years and older. Methods NMH is the average mental health of older adults in the same community, excluding the older adults themselves. The explained variable mental health in this paper was measured using the simple CES-D depression scale. The mediating variables were social connectedness, social participation and social inclusion, and the instrumental variables were physical exercise and amusement. regression analysis was conducted using OLS regression models, two-stage least squares (IV-2SLS) instrumental variables to address the two-way causality of NMH and MH, and KHB decomposition was used to investigate the effect mechanism. Results Baseline regressions showed that the neighborhood mental health effect positively influenced the mental health of older adults (Coef. = 0.356, 95% CI 0.315,0.397). The neighborhood mental health effect estimated by IV-2SLS (Coef. = 0.251, 95% CI 0.096,0.405) was higher than the OLS regression, indicating endogeneity. The mediated effects of KHB showed total (Coef. = 0.356, 95% CI 0.314,0.398), direct (Coef. = 0.281, 95% CI 0.232,0.330), and indirect effects (Coef. = 0.075, 95% CI 0.049,0.101). While the total effect was 1.266 times higher than the direct effect, 21.03% of the total effect came from mediating variables. Conclusions First, the neighborhood mental health effect has a positive impact on the mental health of older adults, but there are heterogeneous differences based on gender, age, and place of residence. Second, the results of the IV-2SLS estimation showed that the effect of the neighborhood mental health effect was underestimated if endogenous problems were not controlled for. Third, the effect of neighborhood mental health on older adults' mental health was tested to be stable. Moreover, social connectedness, social participation, and social interaction are important mediating mechanisms for the effect of neighborhood mental health on older adults' mental health. This study provides new perspectives and ideas for an in-depth understanding of the mental health of older adults in the context of social transformation in China.
Background:The health problems of aging have attracted immense attention in recent years. Researchers are concentrating on the health of older adults from different perspectives.This report attempts to explore the impact of neighborhood mental health effects on the mental health of older adults from the neighborhood relationship. Methods:Based on the data received from the China Health and Retirement Tracking Survey (CHARLS) in 2018, people aged 60 and above were selected as the research objects (N=7713). The ordinary least square (OLS) regression model was used to analyze the influence of neighborhood mental health effect on the mental health of older adults. Furthermore, instrumental variables estimation using two-stage least-squares (IV-2SLS), heterogeneity analysis, and robustness test were used to strictly verify the effect of neighborhood mental health on the mental health of older adults. The KHB decomposition was used to examine the mechanism of effect. Results:Baseline regression showed that the neighborhood mental health effect positively affected the mental health of older adults (B=0.356, CI= [0.315,0.397]). The neighborhood mental health effect estimated by IV-2SLS (B=0.251, CI=[0.096,0.405]) was higher than that of OLS regression, indicating endogeneity. The mediating effect of KHB showed that the total effect (B=0.356, CI=[0.314,0.398]), direct effect (B=0.281, CI=[0.232,0.330]), indirect effect (B=0.075, CI=[0.049,0.101]). and the total effect was 1.266 times of the direct effect, and 21.03% of the total effect came from the intermediary variable. Conclusions:First, the neighborhood mental health effect had a positive impact on the mental health of older adults, but there are heterogeneity differences based on gender, age, residence, and other aspects. Second, the results of IV-2SLS estimation revealed that without controlling for endogenous problems, the effect of neighborhood mental health effects was underestimated. Third, county-level neighborhood mental health, life satisfaction, three-year self-assessment health change, and physical health were used to replace variables, and physical disability (small sample) and non-disability (large sample) were grouped. The effect of neighborhood mental health on older adults' mental health is stable. Finally, social connection, participation, and interaction are important mediating mechanisms for the effect of neighborhood mental health on the mental health of older adults.
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