Search

Objective To explore the characteristics of positive and negative affect in young male military personnel and the effect of trait anxiety (TA), rumination and educational level on positive and negative affect. Methods We surveyed the military personnel serving in an army unit of PLA using cluster sampling in October 19 to 20, 2018. We arranged 4 survey sessions, in which a total of 4 004 participants aged 18~38 years were asked to complete Trait Anxiety Subscale, Ruminative Responses Scale (RSS), Positive and Negative Affect Schedule (PANAS) and a demographic information questionnaire with on-site guidance by professional psychologists. Results ① The scores of positive affect (PA) and negative affect (NA) were 2.51~3.97 and 1.86~2.70 among the surveyed participants, respectively. ②NA was positively correlated with TA and RSS (r=0.322-0.365, P < 0.01), while PA was negatively correlated with TA (r=-0.463, P < 0.01). ③The participants with a bachelor degree or above had significantly higher scores for PA and NA than those with a junior college or a senior high school education (P < 0.001 or 0.05). ④The mediating effect of rumination on the relationship between TA and PA was presented as a suppressive effect, and the absolute ratio of its mediating effect to direct effect was |0.024/-0.383|. Rumination could partially mediate the relationship between TA and NA, and its mediating effect accounted for 13.86% of the total effect. ⑤With PA as the criterion variable, the value of Δχ2(Δdf) was differed significantly between the structured weight model and the structural residual model (P < 0.001). Pairwise parameter comparisons showed significant differences in rumination-PA path coefficients between the participants with different education levels (-3.666 vs -2.323, P < 0.05). Conclusion Young male military personnel presents with a high positive affect and a low negative affect with a good affect balance. Rumination has a suppressive effect on the relationship between trait anxiety and PA, and rumination-PA path is moderated by the education level; rumination is also a partial mediator of the relationship between TA and NA.

With high activity h-BN powders as raw materials and without the using of any sintering additives, AlN–BN composite ceramics with 0–30 vol% were prepared by hot-pressing sintering in N2 at 1850 °C. Effect of h-BN content on the microstructure and properties of the composite ceramics was investigated. The results show that fully dense composite ceramics with h-BN content up to 20 vol% can be obtained and all composites show a fine-grain-microstructure with clean and clear boundaries. No “card room structure” of h-BN was formed in the samples. With the increasing h-BN content, the composites show a decreased bending strength, fracture toughness, Vickers hardness, thermal conductivity and dielectric constant. The application of high activity raw materials produces a significant grain-refinement strengthening effect and makes the composites exhibit a much higher strength and toughness compared with the results reported by other researchers. Due to the absence of sintering additive, the composite ceramics also show a quite low dielectric loss at both low and high frequency. An optimal comprehensive properties are obtained for the AlN-20 vol% BN composite: bending strength of 410 ± 21 MPa, fracture toughness of 4.21 ± 0.19 MPa·m1/2, Vickers hardness of 7.7 ± 0.2 GPa, thermal conductivity of 46.6 W·m−1·K−1, dielectric constant of 7.4 (1 MHz) and 7.48 (18 GHz), dielectric loss of 6.7 × 10−4 (1 MHz) and 6.18 × 10−3 (18 GHz).