圆柱壳体非线性分析关键技术研究

ANSYS是通用的、大型的有限元分析CAE软件,使用ANSYS软件可以求解静态和瞬态非线性问题.本文在分析了圆柱薄壳结构的特点、分类和应用的基础上,对圆柱壳体的稳定性进行了研究,建立了圆柱壳体非线性力学方程.在ANSYS平台下,对典型的圆柱壳体进行了仿真,为进一步深入研究圆柱壳体非线性问题提供了借鉴.     

具分布时滞的HIV感染模型稳定性分析

通过讨论一类含CTL免疫应答的具分布时滞的HIV感染模型,分析了在分布时滞情况下未感染平衡点及感染无免疫平衡点的全局渐近稳定性,并给出了感染免疫平衡点局部渐近稳定的充分条件。     

Q2黄土中隧道断面扩大开挖优化分析

黄土强度低、抗扰动性差,在其中进行隧道施工时,采用不同的开挖步骤直接影响着其施工的安全、效率及稳定性控制效果。通过对Q2黄土中原有隧道断面扩大开挖过程的数值模拟,以应力、位移等为指标,分析不同的开挖顺序对隧道结构稳定性影响的优劣性,进而确定合理的开挖顺序,以降低施工风险,优化断面扩大开挖效果,并得出隧道扩挖对围岩影响的规律。     

The relationship between exposure to family violence in childhood and post-traumatic stress symptoms in young adulthood: The mediating role of social support

BackgroundExtensive research has examined the relationship between exposure to family violence and its long-term mental health effects. Social support has been found to moderate this relationship, but there is a dearth of research on its mediating role.ObjectivesThe article presents the results of a study on the relationship between witnessing interparental violence and experiencing parental violence during childhood and adolescence on the one hand, and post-traumatic stress symptoms (PTSS) during young adulthood on the other. In addition, the article presents results on the role of social support as a mediator in this relationship.Method, participants, and settingA cross-sectional survey was conducted among 516 Israeli university and college students (90.7% female, and 9.3% male; M age = 24.9, SD = 2.7) using a retrospective, self-administered questionnaire.ResultsThe results revealed that exposure to each pattern of family violence (i.e., witnessing interparental violence and experiencing parental violence) predicted higher levels of PTSS. Furthermore, social support was found to partially mediate the relationship between exposure to family violence during childhood and adolescence and current PTSS as well as its four symptoms, i.e., depression, sleep disturbance, dissociation, and anxiety.ConclusionsThe results of the current study highlight the important role of social support in the association between adversities experienced early in life and young adulthood outcomes. The findings are interpreted on the basis of Conservation of Resources Theory (Hobfoll et al., 1990), which served as the conceptual framework for the study. The limitations of the study and implications for future research are discussed.     

集料级配对混合料疲劳特性的影响研究

集料是混合料结构形成的决定性成分,其岩性性质、物理力学指标以及外观形状的差异,对于混合料的工作性能产生很大的影响,集料级配的不同混合料的工作性能差异很大.文中就集料级配对沥青混合料的疲劳性能的影响进行了系统试验研究,得出了相应结论.     

中西部高职教育对区域稳就业的支持作用及对策研究——以襄阳职业技术学院就业统计为例

本文针对我国中西部地区(以湖北襄阳为例)高职教育对区域稳就业的支持作用,通过调研与实证分析,从地方政府与高职院校两个视角提出稳就业的对策建议,地方政府应出台相应政策吸引人才,留住本地人才。高职院校需进一步深化人才培养模式改革、建立与区域产业发展相适应的动态调整专业结构的机制,通过深度产教融合,提升人才培养质量,培养"适...     

Postural balance and rifle stability in a standing shooting position after specific physical effort in biathletes

The aim of the study was to evaluate the effect of maximal specific physical effort on postural balance and rifle stability in biathletes in a standing shooting position. The study included 10 junior elite biathletes. The measurements were taken with the Vicon system and AMTI force platform. Postural balance and rifle stability characteristics were determined at rest as well as 1 and 5 min post maximal specific physical effort which was performed on a ski ergometer and continued until exhaustion. Maximal physical effort exerted a significant effect on all examined postural sway and rifle sway characteristics. The duration of the post-exercise changes was longer than 5 minutes. Higher post-effort rifle sway was observed in the vertical direction than in the across the shooting line direction. Post-effort postural balance impairment in the shooting line was much greater than in the across the shooting line direction. Moreover, a strong correlation was found between postural balance and rifle stability. Maximal physical effort influenced postural balance and rifle stability during aiming. Rifle sway during aiming in a standing shooting position seems to be coordinated with the postural sway of the biathlete’s body. Thus, an increase in postural sway contributes to greater sway and lesser stability of the rifle.     

乒乓球运动员以预防损伤为主的功能训练

功能训练的理念来源于康复领域,现已逐步应用到运动训练中。由于乒乓球运动的项目特征,乒乓球运动员肩关节、腰椎关节、膝关节、踝关节、腕关节等部位容易出现运动损伤。通过对乒乓球运动员常出现的功能问题进行分析,寻找存在的常见问题,进而提出相应的功能训练建议。乒乓球运动员可根据情况,增加改善肩关节、胸椎关节、髋关节、踝关节的活动范围的训练,提高肩胛骨、核心和下肢稳定性的训练,以及改善肩袖、躯干肌力不平衡的训练,通过针对性的功能训练有效减少乒乓球运动员损伤的发生。     

石膏/蚯蚓粪肥对赤泥团聚体结构稳定性的影响

赤泥是氧化铝工业生产过程中排放的高碱性固体废弃物,迄今尚无经济有效的处置方法。以华中地区某堆场赤泥为研究对象,通过土培实验研究改良剂（石膏、蚯蚓粪肥、石膏+蚯蚓粪肥）对赤泥团聚体稳定性的影响。结果表明：石膏的添加能显著降低赤泥pH,而蚯蚓粪肥能显著增加赤泥有机碳含量。土培60 d时,石膏添加后赤泥pH由10.54降到8.75,蚯蚓粪肥添加后赤泥有机碳含量由3.54 g·kg^-1增加至14.31 g·kg^-1。土培180 d时,石膏、蚯蚓粪肥、石膏+蚯蚓粪肥添加后赤泥水稳性团聚体含量由12.04%分别增加到23.49%、29.24%、33.94%;团聚体平均重量直径由0.15 mm分别增加到0.26、0.30、0.34 mm;可蚀性因子由0.36分别降低到0.31、0.30、0.29。石膏和蚯蚓粪肥的添加促进水稳性团聚体形成,提高赤泥团聚体稳定性。基质改良对赤泥团聚体稳定性的影响效果依次为：石膏+蚯蚓粪肥 > 蚯蚓粪肥 > 石膏。研究结果对赤泥土壤化处置和规模化消纳研究有科学参考意义。     

中职专任教师职业稳定的影响因素研究

加强中职学校师资队伍的建设中,专任教师的稳定性是一个值得关注的问题.基于大连中等职业学校专任教师的实证调查数据,构建了影响职业稳定的logistic模型.研究发现,职业兴趣、工作成就感、学校对教师进修培训的支持力度、预期收入差距、职业教育事业的认同程度对专任教师的职业稳定具有显著影响.