First-principles calculation on electronic properties of hydrogen evolution reaction of Ni-based electrode surfaces with different monatomic doping.

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.

Molecular dynamics simulation of the interaction between monofluoronitrobenzene and Ti electrode.

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 Relationship Between Intolerance of Uncertainty and Employment Anxiety of Graduates During COVID-19: The Moderating Role of Career Planning.

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.

Clinical and prognostic features of 512 cases of cholangiocarcinoma. / 512例胆管细胞癌的临床及预后特点.

OBJECTIVES: Cholangiocarcinoma (CCA) is an aggressive malignant tumor with a poor overall prognosis. Given that CCA is often diagnosed at the late stage, the current treatments are less effective for most local advanced patients leading to high CCA mortality. This study aims to explore the clinical characteristics and prognostic factors affecting the occurrence and development of CCA and to provide potential methods for early diagnosis and clinical treatment of CCA. METHODS: We retrospectively analyzed the medical records of 512 patients with CCA who had been diagnosed by pathology and had completely clinical data in the Second Xiangya Hospital of Central South University in the past 16 years. The clinical features and prognosis related factors that affect the occurrence and development of CCA were investigated. Survival curves were plotted by the Kaplan-Meier method. P-values were calculated by log-rank for univariate analysis, and multivariate Cox regression was used to analyze multivariate analysis of meaningful variables. RESULTS: The incidence of CCA among ≤60 years old people was higher than of that >60 years old one (61.13% vs 38.87%), and was greater in men than women (52.5% vs 47.5%). Carbohydrate antigen 19-9 (CA19-9) level ≥35 µg/L accounted for 66.21%. The single tumor accounted for 86.91%, and patients in pathological stage III and IV accounted for 49.22% and 17.58%, respectively. Univariate analysis showed that ALB, ALP, CA19-9, and other factors were relevant to the prognosis. The results of multivariate analysis showed that ALP, CA19-9, tmaximum tumor diameter, and other factors were significant prognostic predictors. CONCLUSIONS: The incidence of CCA is higher in ≤60 years old people, and the stage is later at the initial diagnosis. CA19-9 level is a sensitive laboratory indicator. ALP, CA19-9, maximum tumor diameter, merged tumor, cirrhosis, and TNM stage are independent prognostic factors for CCA.