指数型功能梯度材料平面问题应力场通解修正形式

以指数型功能梯度材料为模型,修正了文献[2]中某个公式的推导,并利用此结果改进了文献[2]中关于平面问题应力场通解的结果.     

一种腐蚀疲劳损伤的非线性累加演化模型

研究目的：提出一种新的腐蚀疲劳损伤演化模型,建立基于损伤演化的腐蚀疲劳寿命预测模型。创新要点：将应力腐蚀损伤与疲劳损伤非线性耦合,建立腐蚀疲劳损伤演化律,依托实验确定腐蚀疲劳损伤演化参数,形成基于损伤演化律的腐蚀疲劳寿命预测模型。研究方法：采用理论研究与实验验证相结合的研究方法。选取特定材料设计应力腐蚀实验,回归应力腐蚀门槛值应力和损伤参数（图2）;查阅疲劳实验数据建：立变幅疲劳损伤模型,将应力腐蚀损伤与变幅疲劳损伤非线性累加形成腐蚀疲劳损伤非线性演化模型。根据腐蚀疲劳实验结果,验证腐蚀疲劳损伤演化模型并确定非线性损伤累加参数（图5和6）,形成基于损伤演化律的腐蚀疲劳寿命预测模型。重要结论：从损伤力学角度,将材料的腐蚀疲劳损伤处理成应力腐蚀损伤与疲劳损伤的非线性累加,形成腐蚀疲劳损伤演化模型。结合LY12CZ铝合金的试验结果,验证了损伤演化模型的可行性。该方法可以为材料腐蚀疲劳的寿命评价研究提供新的思路。     

刑法中的“暴力”与“胁迫”手段

"暴力"和"胁迫"作为刑法中的重要犯罪手段,一直在刑法中有着重要的地位,在刑法分则中二者也经常同时出现,足见二者之间有着密切的联系。相比"暴力"来说,"胁迫"的内容更加广泛,即包括以暴力相威胁,还包括以揭发隐私、破坏名誉、对与被害人有特定关系的人进行伤害或者其他能够使被害人产生恐惧心理的内容相威胁。而随着社会的发展,犯罪手段也有多样化和复杂化的发展趋势,在这种情况下,如果放任自流的话,会对今后的司法实践造成巨大的困难。论文从"暴力"与"胁迫"的含义及特点入手,进一步分析我国刑法中对其的规定,并进行总结和分析,将二者进行区别。指出我国刑法中关于"暴力"和"胁迫"方面的一些不足之处,并提出自己对于以后司法实践的期待以及法律修改的意见。     

城市自来水管道腐蚀对水质和管道的影响

本文通过对发生泄漏的自来水管道取样分析,找出了管道腐蚀和水质劣化的影响因素,指出了管道腐蚀机理,对腐蚀管道的安全性进行了评估。     

边远地区中小学女教师职业压力现状分析

采用问卷调查的形式,对边远地区300名在职中小学女教师的职业压力基本表现进行研究,并分析了影响边远地区中小学女教师职业压力的主要因素。结果表明:(1)边远地区中小学女教师职业压力普遍较大,24.1%的女教师体验着重度的职业压力。(2)边远地区初中女教师在职业压力总分及各因子得分均显著高于小学和高中女教师;主科教师在考试压力和工作负荷方面压力显著高于副科教师;班主任教师在考试压力和工作负荷方面压力显著高于非班主任教师。(3)部分女教师面临家庭与事业发展的双重冲突,尤以研究生学历女性为最。(4)建立良好的社会支持系统是缓解教师职业压力的重要前提,增强自我职业压力管理能力是缓释教师职业压力的关键策略。     

Simulation of top-down crack propagation in asphalt pavements

Top-down crack in asphalt pavements has been reported as a widespread mode of failure.A solid understanding of the mechanisms of crack growth is essential to predict pavement performance in the context of thickness design,as well as in the design and optimization of mixtures.Using the coupled element free Galerkin (EFG) and finite element (FE) method,top-down crack propagation in asphalt pavements is numerically simulated on the basis of fracture mechanics.A parametric study is conducted to isolate the effects of overlay thickness and stiffness,base thickness and stiffness on top-down crack propagation in asphalt pavements.The results show that longitudinal wheel loads are disadvantageous to top-down crack because it increases the compound stress intensity factor (SIF) at the tip of top-down crack and shortens the crack path,and thus the fatigue life descends.The SIF experiences a process "sharply ascending—slowly descending—slowly ascending—sharply ascending again" with the crack propagating.The thicker the overlay or the base,the lower the SIF; the greater the overlay stiffness,the higher the SIF.The crack path is hardly affected by stiffness of the overlay and base.     

NaCl胁迫紫色辣椒新品系YN99007的发芽试验生理研究

紫色辣椒新品系(YN99007)在5种不同NaCl浓度(0.0%、0.5%、1.0%、1.5%、2.0%)处理下进行发芽试验(以日本天鹰椒作为对照),研究各浓度下的发芽率、发芽势、发芽指数、过氧化氢酶(catalase,CAT)活性及根系活力等指标.结果表明:NaCl浓度范围为1.0%～1.5%时,紫色辣椒YN99007的发芽率、发芽势和发芽指数高于对照品种;而其芽中的过氧化氢酶活性及根系活力均低于对照品种,但高盐浓度下YN99007的两个指标值下降缓慢.     

Classroom Learning Environment, Brain Research and The No Child Left Behind Initiative: 6?years Later

Six years have gone by since the passing of No Child Left Behind (2002) and due to the ‘high-stake’ riders attached to this legislation, educators at all levels have found themselves in a state of both emotional and cognitive dissonance. Recent research in the field of neuroscience combined with principles gained from constructivism support the importance of developing and implementing both a child-centered curriculum and a positive learning environment that is appropriate for young children. This paper addresses some of the difficulties that arise from the No Child Left Behind act and teaching from a constructivist model. Additionally, positive suggestions are provided for the early childhood educator in order to support current teaching philosophies despite the pressures of high-stakes testing.     

试论巴克《再生》三部曲对“创伤后压力症”的描写

帕特 巴克(Pat Barker)是20世纪80年代英国文坛上崛起的著名作家,被誉为“英国现当代重要作家”。在《再生》三部曲里,她描写了许多参加过第一次世界大战的士兵因为在战场上遭受的痛苦经历而患上创伤后压力症,并随之产生一系列心理躯体化反应,真实地再现了战争给人类带来的灾难和痛苦,并且控诉了战争的残酷。     

Persistence of pediatric post traumatic stress disorder after 2 years

One-hundred and fifty-six children were randomly evaluated at an inner-city juvenile/family court. These children were removed from their parent's custody subsequent to a finding of severe child maltreatment. From our original sample of 156 children, 62 met strict criteria for Post Traumatic Stress Disorder (PTSD). Fifty-two of these 62 were successfully recruited and participated in the 2 year re-examination. Each PTSD diagnosis was conferred by the Diagnostic Interview for Children and Adolescents (DICA). From our sample of 52 PTSD children re-examined after 2 years, 17 (32.7%) retained the full PTSD diagnosis, while 67.3% did not meet criteria.