COVID-19, which is characterized by uncertainty, makes the employment anxiety of college graduates in the period of career change more and more intense. How to deal with this challenge is ...particularly important. The present study took career planning as a moderating variable to explore the relationship between intolerance of uncertainty (IU) and employment anxiety, as well as the role of career planning. In this quantitative study, the data of 563 college graduates from different schools were collected by using the Intolerance of Uncertainty Scale-12, Vocational Selection Anxiety Questionnaire of University Graduate, and Career Planning Scale. The final effective sample size was 550 (the overall recovery rate was 97.7%). The results of correlation analysis showed that there was a significant positive correlation between IU and employment anxiety, while there was a significant negative correlation between career planning and IU, as well as the relationship between career planning and employment anxiety. The results of hierarchical regression analysis showed that IU significantly positively predicted the employment anxiety of graduates, and career planning moderated the relationship between IU and employment anxiety. These findings suggested that maintaining a sense of career planning can help college graduates get through smoothly in the face of uncertainty of COVID-19.
Energy scarcity and environmental pollution are getting worse as science and technology advance, which has a significant influence on people's living conditions. Therefore, in light of the present ...sustainable development plan, the discovery and implementation of new energy sources are crucial for sustainable development. Lithium-ion batteries have been playing an increasingly significant role in the field of smart grids, electric vehicles, and personal electronic devices due to the fact that solar, wind, hydropower, and nuclear energy are new renewable energy sources in this context, but these energy sources are seasonal, regional, and discontinuous. There are currently more demanding specifications for lithium-ion batteries, including high energy density and high power density, due to the growth of electric vehicles and other energy storage technologies. In order to enhance the electrochemical performance of lithium-ion batteries, this thesis focuses on the incorporation of nanomaterials into the cathode materials. It is discovered that there is still much opportunity for nanomaterial development in the cathode materials of batteries.
A molecular model of the interaction between alkaline NaCl solution (Sol) and carbon-supported silver/graphene oxide (Ag/GO/C) composite electrode during oxygen reduction reaction was designed and ...constructed, and the Molecular dynamics (MD) simulation of the model was carried out. Based on the calculation and analysis of interaction energy (Δ
E
), diffusion coefficient (
D
) and radial distribution function (RDF), depending on the type and number of oxygen-containing functional groups of GO, the interaction law between alkaline solution and Ag/GO/C composite electrode was found out, and the interaction mechanism was revealed. The results showed that the interaction force between Sol and Ag/GO/C composite electrodes with 4 different GO structures (GO1, GO2, GO3 and GO4) is mutual attraction at 353 K. The interaction energy between the Sol and the Ag/GO2/C electrode is the highest in numerical terms, and the diffusion capacity of Na
+
and Cl
–
in the Sol is the weakest in the electrode system, indicating that the interaction between the Sol and the Ag/GO2/C electrode prevents the diffusion of solution molecules or ions on the surface of the electrode. The results of RDF showed that O
2
, Na
+
and Cl
–
in solution within 3.5 Å have no obvious bonding effect with the electrode, while Sol has obvious bonding effect. When the interaction distance is 5–8 Å, O
2
, Na
+
, Cl
–
, Sol in the system and Ag atoms in different composite electrodes all have obvious non-bond interaction, indicating that Sol and the electrode are prone to bond interaction in the short-range region and non-bond interaction in the remote region, while O
2
, Na
+
, Cl
–
, and the electrode are only prone to non-bond interaction in the remote region. In other words, Ag/GO/C composite electrode has bonding and non-bonding effects in the formation of ORR system in alkaline NaCl solution, and it is mainly provided by non-bonding effects. When the number of –O–, –OH, –COOH in GO is 5 : 5 : 2 (GO2), that is, Ag/GO2/C composite electrode is most prone to ORR. This further proved that adding GO to the composite electrode can improve the catalytic performance of the electrode. These results are helpful to provide theoretical support for the research and development of electrodes in electrolytic chlor-alkali industry.
If individuals do not have good peer social relationships, they will not only fail to benefit from social groups, but will have more solitary behaviors due to being excluded and rejected. And the ...withdrawal of choosing to be alone will induce further social exclusion. However, previous studies on social exclusion and social withdrawal have focused on children, college students, and adults, and few studies have explored adolescents as subjects. There is evidence that problematic peer relationship experiences (e.g., rejection, exclusion) are indeed a cause and consequence of social withdrawal in adolescents, and fortunately, interventions that connect people to nature may lead to many positive changes in multiple domains of functioning, such as indirect exposure to the natural environment can moderate the negative effects of an individual's exclusion. Therefore, to test the causal relationship between social exclusion and adolescent social withdrawal behavior and the effect of natural associations on adolescent social withdrawal behavior, we found through three studies that social exclusion significantly affected adolescent social withdrawal behavior, connectedness of nature, i.e., simply viewing nature pictures, significantly diminishes the effect of social exclusion on adolescents' social withdrawal behavior. Taken together, these findings underscore the importance of natural associations in influencing social withdrawal after exclusion.
•Social exclusion and adolescent withdrawal behavior were positively correlated.•Adolescents in the social exclusion group showed more withdrawal behaviors.•Viewing nature pictures moderates the above relationship.
The present study explored the influence of emotion and learner control on learners in multimedia learning environment. Study 1 investigated the effects of emotion on the learning outcomes ...(recognition test scores, transfer test scores) and learning performance (internal motivation level, cognitive load, learning satisfaction, perceived achievement) of multimedia learners. The results showed that compared with the learners in positive emotional state, the learners in negative emotional state had poor learning scores, but had lower cognitive load and higher perceived achievement level. Study 2 investigated the effect of learner control on multimedia learning in negative emotional state. The results showed that for the learners with negative emotions, the recognition test scores and transfer tests scores of the learner control group were significantly higher than those of the program control group. The present study showed that control strategies could help multimedia learners benefit from negative emotions.
At present, the hydrogen evolution reaction (HER) of Ni-based electrode has an important influence on water electrolysis hydrogen production technology, involving complex electrochemical process of ...electrode. In this project, Materials Studio (MS) software was used to design and construct Ni-based electrode surface (NES) models with monatomic Mo, Co, Fe, Cr doping, and the NES models attached 1 H atom and 2H atoms were denoted as the NES-H models and NES-2H model, respectively. Then the first-principles calculation was carried out.
The results showed that the doping of different atoms can effectively change the work function of the pure Ni. In the charge transfer process of the four NES-2H models, the distance between the two H atoms is most affected by Mo doping, and they leave the Ni electrode surface as a single H ion, respectively, while the effect on Co, Fe and Cr doping is relatively consistent, and they leave the Ni electrode surface with H2 molecules, respectively. The doping of four single atoms changes the distance of valence band (VB) top and conduction band (CB) bottom from Fermi level in NES, NES-H and NES-2H models, and affects the HER, in which Mo doping has the greatest effect. The TDOS of the above models is mainly derived from the PDOS of the d orbitals of the doped atoms and Ni atoms. The results will provide a theoretical basis for the research and development of Ni-based electrode materials in HER.
The optimizated NES-2H molels with different monatomic doping. (a), (b), (c) and (d) represent Mo@Ni–2H, Co@Ni–2H, Fe@Ni–2H and Cr@Ni–2H(d) models, respectively. The dotted black line represents the distance between H–H atoms. Two hydrogen atoms leave the Ni electrode surface as a single H ion in the Mo@Ni–2H model, however, They leave the surface as a H2 molecule in the Co@Ni–2H, Fe@Ni–2H, and Cr@Ni–2H models., respectively. Display omitted
•The 4 doping elements can reduce the work function of NES, which is beneficial to HER.•The EDD change of Mo doping between NES-H and NES-2H models is stronger than that of Co, Fe, Cr doping, respectively.•The top of VBs of 4 doping NES-2H models all pass through the Fermi level upward.•In the NES-2H model, The two H atoms bond with neighboring atoms in Mo doping, but not in Co, Fe, Cr doping.
In the process of degradation of aqueous fluoro-nitrobenzene (FNB) solution by titanium (Ti) electrode, the interaction between aqueous FNB solution and Ti electrode has an important impact on the ...performance and catalytic performance of electrode materials. The interaction involves complex physical, chemical and physical chemical processes, however, the mechanism of action is still unclear. In this study, Materials Studio software was used to design and construct molecular models of the interactions between aqueous FNB (p-, m-, o-FNB) solutions and Ti electrode, and molecular dynamics (MD) simulation was carried out in the absence of applied electric field and external electric field of 0.02 V/Å, respectively. Density functional theory (DFT) method was used to calculate the frontier molecular orbitals of three FNB molecules. Based on the calculation and analysis of the interaction energy (ΔE), diffusion coefficient (D) and radial distribution function (RDF), the interaction mechanism was discussed. It provides a theoretical basis for further research and development of Ti electrode degradation of fluorine compounds.
The results showed that the order of ΔE between the three different aqueous FNB solutions and Ti surface is m-FNB > p-FNB > o-FNB when there is no external electric field. Under electric field of 0.02 V/Å, the order is p-FNB > m-FNB > o-FNB. The substitution position of F has an important effect on the HOMO of the nitro group and the LUMO of C–H in the three FNB molecules, and also affects the chemical reaction activity. In the model system, the diffusivity of different FNB solutions with electric field is less than that without electric field. The presence of an external electric field makes the diffusion of water and FNB molecules more orderly. The analysis results of RDF show that the bonding interactions between different FNB molecules and Ti surface is not much different before 3.5 Å, and all of them are weak. At about 8 Å, FNB molecule forms a non-bond with Ti electrode. ΔE, D and RDF of the model system can be changed by applying a certain external electric field, and the results are in better agreement with the experimental results.
The distribution of p-FNB and H2O molecules on the Ti surface after MD simulation of 2000ps in NVT ensemble under no electric field (a) and electric field of 0.02 V/Å (b). Ball and stick, line and CPK models represent p-FNB, H2O and Ti structures. Display omitted
•The simulation results under electric fieldare more consistent with the experimental results.•The electron delocalization around -NO2 of p-FNB is weaker, the stronger reaction activity.•The external electric field has the greatest influence on the diffusion of p-FNB solution.•The electric field is more conducive to the interaction between FNB and Ti electrode.
Persimmon fruit quickly softens after harvest, which limits its industrial value. The hormone melatonin has been reported to delay fruit ripening and softening. However, the effect of melatonin on ...postharvest persimmon fruit remains inconclusive. In this study, we found 10 μM melatonin treatment delayed the softening of persimmon fruit, accompanying with lower levels of endogenous ethylene and abscisic acid (ABA). Further, transcriptomic and metabolomic analysis were applied to investigate the regulatory mechanism. In total, 6831 differentially expressed genes (DEGs) and 1224 differentially accumulated metabolites (DAMs) were identified. We also investigated the metabolism pathways and regulatory networks incorporating crucial structural genes and TF during persimmon fruit softening. They were involving functions of saccharides, organic acids, ethylene biosynthesis, and ABA biosynthesis. In conclusion, our results indicate that melatonin can delay the biosynthesis of ethylene and ABA during persimmon softening and provide new insights into the regulatory pathways of melatonin-maintained persimmon fruit quality.
•Melatonin delayed persimmon fruit softening and suppressed the biosynthesis of endogenous ethylene and abscisic acid.•A total of 6831 DEGs and 1224 DAMs were obtained.•Complex regulatory networks involved in pathways of saccharides and organic acids, ethylene biosynthesis and ABA biosynthesis were constructed.
The development of nanoporous metal–organic frameworks (MOFs) capable of effectively separating and purifying CH4 is of significant importance. High surface polarity and suitable pore diameter are ...two key factors that can synergistically enhance separation performance. Herein, we report two hydroxyl-functionalized Al-MOFs (CAU-1-OH and CAU-1-(OH)2) for the separation and purification of natural gas. They both possess two different types of nanocages as well as a densely hydroxyl-functionalized surface. Significantly, CAU-1-(OH)2 demonstrated exceptional selectivity in separating C3H8/CH4 (50:50, v/v) and C2H6/CH4 (50:50, v/v), with selectivity values of 990 and 36, respectively, surpassing those of most reported porous materials. The dynamic breakthrough experiment of the ternary mixture can generate pure CH4 exceeding 3.46 mmol g–1, which adequately demonstrates the actual CH4 purification performance of CAU-1-(OH)2. Finally, molecular simulations and in situ infrared experiments verified that the high surface polarity and suitable pore diameter synergistically enhance the affinity of the frameworks toward C3H8 and C2H6, giving rise to the high loading capacity and selectivity for C3H8 and C2H6. These results support the significant potential of the double hydroxyl-modified nanomaterial CAU-1-(OH)2 for purifying methane from natural gas.
PDF
