We investigate the different mechanisms concerning how employees' perceptions of external and internal corporate social responsibility (CSR) serve to influence employees' work engagement. By ...combining social exchange theory and social identity theory, we implement and examine an integrated moderated mediation framework in which employees' value orientations (e.g., collectivism or individualism) impact the mediating mechanism between their perceived external and internal CSR, organizational pride and perceived organizational support (POS), and work engagement. This work fills a research gap to examine the indirect relationship between employees' perceptions of external and internal CSR and work engagement. Using two periods of survey data from 250 working employees in China, we find that employees' perceptions of external CSR positively influence work engagement via organizational pride. The value of collectivism strengthens the direct effect of employees' perceptions of external CSR on work engagement, and the indirect effect of employees' perceptions of external CSR on work engagement via organizational pride. Moreover, employees' perceptions of internal CSR positively influence work engagement via POS. The value of individualism strengthens the direct effect of employees' perceptions of internal CSR on work engagement, and the indirect effect of employees' perceptions of internal CSR on work engagement via POS. The results contribute to both theory and practice.
In response to mechanical and pathological stress, adult mammalian hearts often undergo mal-remodeling, a process commonly characterized as pathological hypertrophy, which is associated with ...upregulation of fetal genes, increased fibrosis, and reduction of cardiac dysfunction. The molecular pathways that regulate this process are not fully understood.
To explore the function of microRNA-155 (miR-155) in cardiac hypertrophy and remodeling.
Our previous work identified miR-155 as a critical microRNA that repressed the expression and function of the myocyte enhancer factor 2A. In this study, we found that miR-155 is expressed in cardiomyocytes and that its expression is reduced in pressure overload-induced hypertrophic hearts. In mouse models of cardiac hypertrophy, miR-155 null hearts suppressed cardiac hypertrophy and cardiac remodeling in response to 2 independent pathological stressors, transverse aortic restriction and an activated calcineurin transgene. Most importantly, loss of miR-155 prevents the progress of heart failure and substantially extends the survival of calcineurin transgenic mice. The function of miR-155 in hypertrophy is confirmed in isolated cardiomyocytes. We identified jumonji, AT rich interactive domain 2 (Jarid2) as an miR-155 target in the heart. miR-155 directly represses Jarid2, whose expression is increased in miR-155 null hearts. Inhibition of endogenous Jarid2 partially rescues the effect of miR-155 loss in isolated cardiomyocytes.
Our studies uncover miR-155 as an inducer of pathological cardiomyocyte hypertrophy and suggest that inhibition of endogenous miR-155 might have clinical potential to suppress cardiac hypertrophy and heart failure.
This study examined the association between self-reported nature exposure and depression among Chinese prisoners, as well as the mediating and moderating effects of meaning in life and ...callous-unemotional (CU) traits, respectively.
Prisoners are more likely to experience depression than any other mental illness. Exposure to nature has been proposed as a highly cost-effective method of treating their depressive symptoms. However, the mechanism underlying the link between nature exposure and depression among prisoners needs further investigation, as the findings may provide new insights into how to address depression in incarcerated populations.
Data were collected through a survey conducted in four prisons in southern China from April to May 2022. The participants were 574 prisoners who anonymously completed four questionnaires about nature exposure, meaning in life, depression, and CU traits.
The results show that: (1) meaning in life significantly mediates the association between nature exposure and depression, and (2) CU traits moderate the connection between nature exposure and meaning in life.
The current study uncovered that prisoners who contact more with the natural environment have a higher meaning in life and lower depression, and individuals with higher CU traits can benefit more from nature exposure.
Aurora Battery is a corresponding test of successful intelligence. This study aims to examine the factorial structure of the Chinese version of Aurora Battery and to investigate its internal ...consistency and validity, as well as to discover the developmental features of Chinese students. A total number of 2007 students were recruited from 13 schools across eastern, central, and western China, ranging from 4th to 8th grade (mean age = 12.29 years) and among them, 43.9% are girls. Confirmatory factor analysis (CFA) was used to examine the factorial structure. Among the tested models, a second-order factor model, in which the three ability factors serve as indicators of a general factor, provided an acceptable model fit to the data. Moreover, measurement invariance across gender and grades were supported, which suggests the mean scores of analytical, creative, and practical abilities are comparable in this research. The criterion-related validity analysis suggests that the battery and its three subscales have good criterion validity. The scale reliability analysis shows that the Cronbach's alpha and the McDonald's omega value of the whole test were .84 and .87, respectively, indicating the scale's internal reliability is good. For ability differences among grades, students' analytical and practical abilities increase across all grades, while creativity presents an upward trend from grade 4 to 6, followed by a downward trend from grade 6 to 7, and an increase from grade 7 to 8. Female students outperform male students on both analytical and creative ability, while with no obvious difference on practical abilities.
To comprehensively study the theoretical system of the pneumatic conveying of a material, the first step should be to study its conveying characteristics. Here, we develop a CFD-DEM coupling model ...for simulating the pneumatic conveying of polyacrylamide and build a set of pneumatic conveying test beds to experimentally verify the accuracy of the model. The horizontal pipes in this study are divided into three sections, including the acceleration section after feeding, the section with bends at both ends, and the section with a bend at only one end. The pressure drop characteristics of these three horizontal pipe sections are investigated through simulation. Then, the relationship between the pressure drop and the solid-gas ratio for only the pipe section with bends at both ends is discussed. The results show that there is a turning point with an optimal solid-gas ratio of 20.44 that corresponds to the minimum pressure drop.
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•A CFD-DEM hybrid model for pneumatic conveying of polyacrylamide is developed.•The correlations between the pressure drop and particle mass flow rate is discussed.•The solid-gas ratio is introduced to greatly improve the universality of results.•The minimum pressure drop gas velocity is determined.
The optimization of a turboexpander can significantly improve the performance of the organic Rankine cycle (ORC) system, which can use in low‐temperature geothermal energy for high‐efficiency power ...generation. Therefore, this paper studies and optimizes the expander in the ORC of low‐temperature geothermal energy around 90°C. Firstly, the influence of impeller parameters on the performance of the expander is analyzed. Then, the grid is divided by the turbine mesh, and numerical simulation is performed by CFX. The gas state equation selects the Peng–Robinson equation, and the turbulence equation selects the SST model. Finally, the effect of tip clearance on the performance of the expander was studied. Research on impeller blade parameters shows that with the increase in the outer diameter of the impeller blade outlet, the isentropic efficiency of the expander decreases, and the output power increases. As the increase in the angle between the direction of the impeller blade and the meridian plane, the outlet velocity of the blade increases, the temperature decreases, and the efficiency and control of the turboexpander will decrease. The meridional section width has few effects on the performance of the expander. The study of the tip clearance by numerical simulation shows that the existence of tip clearance will cause clearance flow between pressure surface and suction surface that interferes with the mainstream direction. When the tip clearance increases from 0 mm to 1.2 mm, the efficiency of the expander is reduced by 8.9%.
This paper illustrated the performance of the organic Rankine cycle system (ORC), which can be used in low‐temperature geothermal energy for high‐efficiency power generation and can be significantly improved by the optimization of a turboexpander.
The hydrogen adsorption behaviour of cup-stacked carbon nanotubes (CSCNTs) decorated with the platinum atom at four positions of the conical graphene layer (CGL) is investigated using density ...functional theory. The optimization shows that the inside lower edge position (IL) results have the best hydrogen adsorption parameters among the four positions. The Pt–H2 distance is 1.54 Å, the H–H bond length (lH-H) is 1.942 Å, and the hydrogen adsorption energy (Eads) is 1.51 eV. The hydrogen adsorption of CSCNTs decorated by Pt at the IL position also has larger Eads and lH-H than the Pt-doped planar graphene, Pt-doped single-wall carbon nanotubes and Pt-doped carbon nanocones. The Pt atom at the IL position has a more significant polarization effect on the adsorbed H2, it has trends to convert H2 into two separate H atoms. While the hydrogen adsorption behaviour at other positions belongs to the Kubas coordination, the lH-H and the Eads increased not significantly.
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•The H2 adsorption behaviour on CSCNTs decorated by Pt atoms is studied.•CGL-Pt at the IL position have the best hydrogen adsorption results.•The H2 adsorbed at the IL position has trends to convert to two separate H atoms.•The adsorption behaviour at the IL position is mainly affected by polarization.•The adsorption behaviour at other positions belongs to Kubas coordination.
Many phenomena remain to be investigated regarding the micro adsorption kinetics of hydrogen storage in different carbon nanomaterials. The hydrogen adsorption behaviour on the wall surface of the ...conical graphene layers (CGL) of three kinds of different cup-stacked carbon nanotubes (CSCNTs) is investigated using density functional theory (DFT). Furthermore, Pt decoration of the CGL wall was also investigated. The hydrogen adsorption result of the Pt-CGL is examined through the charge transfer and electron density difference approach. The optimisation results show that as the cone angle increases, the hydrogen adsorption capacity on the outside of the CGL wall increases gradually. In contrast, the hydrogen adsorption capacity on the inside of the wall decreases as the cone angle increases. The adsorption energy (Eads) of intrinsic CGL can only reach 5 kJ/mol, and the Eads of defective CGL can reach 10 kJ/mol. In contrast, the Eads of Pt-CGL can reach more than 30 kJ/mol, indicating that the hydrogen adsorption capacity of the CGL can be effectively increased by the Pt atom decoration, which can meet the adsorption energy target of hydrogen storage material formulated by the United States Department of Energy (DOE).
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•The hydrogen adsorption behaviour on the cup-stacked carbon nanotube wall surface was investigated.•The conical graphene layer wall has weak physical adsorption on hydrogen.•With the cone angle increase, the inside of the conical graphene layer wall adsorption capacity decreases.•The adsorption energy of the C–Pt–H2 unit can meet the United States Department of Energy targets.•The adsorption behaviour of the C–Pt–H2 unit belongs to Kubas coordination.
Abstract
In this study, the effect of agglomerate sizes for a fractal dimension (
D
f
) of 2.5 on the hydrodynamics at intermediate Reynolds numbers (Re) of 1–120 was assessed. The results show that ...a core behaves like a solid sphere that exists in the central region inside the agglomerate. In addition, increasing the agglomerate diameter represents adding an extra permeable layer outside the agglomerate. For a larger Re or a smaller agglomerate diameter, the fluid can enter and penetrate through the agglomerate more easily, and the hydrodynamic characteristics of agglomerates deviate more from those of solid spheres. The effect of diameters on the velocity and pressure profiles becomes less significant with the increase in the diameter. Based on the simulated results, the drag ratio has an approximately linear relationship with Re, and its intercept has an exponential relationship with the dimensionless agglomerate diameter. Compared with homogeneous porous spheres, the drag ratio of the agglomerate is different. The effect of diameters on the drag ratio decreases as the diameter increases. It should be noted that the effect of radially varying permeability on inhomogeneous agglomerates should not be ignored and that the effect weakens as Re increases.
In this study, the effect of agglomerate sizes for a fractal dimension (Df) of 2.5 on the hydrodynamics at intermediate Reynolds numbers (Re) of 1–120 was assessed. The results show that a core ...behaves like a solid sphere that exists in the central region inside the agglomerate. In addition, increasing the agglomerate diameter represents adding an extra permeable layer outside the agglomerate. For a larger Re or a smaller agglomerate diameter, the fluid can enter and penetrate through the agglomerate more easily, and the hydrodynamic characteristics of agglomerates deviate more from those of solid spheres. The effect of diameters on the velocity and pressure profiles becomes less significant with the increase in the diameter. Based on the simulated results, the drag ratio has an approximately linear relationship with Re, and its intercept has an exponential relationship with the dimensionless agglomerate diameter. Compared with homogeneous porous spheres, the drag ratio of the agglomerate is different. The effect of diameters on the drag ratio decreases as the diameter increases. It should be noted that the effect of radially varying permeability on inhomogeneous agglomerates should not be ignored and that the effect weakens as Re increases.
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