提高焊接接头疲劳强度途径的探讨     

尚盈宇 《商丘职业技术学院学报》2006,5(5):71-73

焊接接头的疲劳强度是焊接结构能否承受动载荷的关键指标,它关系到焊接技术在工程中的应用.采用改善焊缝几何形状、减少消除应力、低相变点焊条、覆盖涂层等是提高焊接接头疲劳强度的有效方法.  相似文献   

中学教师职业压力调查分析   总被引：5，自引：0，他引：5  

周晓晔  秦巍 《辽宁师范大学学报(社会科学版)》2004,27(3):69-71

教育学、心理学、工效学、医学等多学科的研究均发现职业压力已成为一种严重影响人的身心健康和工作、生活质量的社会流行病。教师，尤其是中学教师，由于其职业的特殊性，压力过大或过于持久，不仅会严重损害他们的身心健康，还会影响到他们的学生——青少年的健康成长。这里运用自编的中学教师职业压力问卷，对428名城市普通中学教师的职业压力现状进行了调查研究和分析。  相似文献   

乙烯对盐胁迫过程中玉米种子活力和超氧化物岐化酶活性的影响   总被引：3，自引：0，他引：3  

郭丽红杨晓虹  陈子牛 《昆明师范高等专科学校学报》2004,26(4):50-52,62

通过研究乙烯对盐胁迫中玉米种子活力、幼苗生长及SOD活性的影响，发现外源乙烯可提高盐胁迫下两品种玉米种子活力和SOD活性，但幼苗鲜重和高度低于对照，表明盐胁迫中乙烯通过提高玉米种子活力和SOD活性，且使生长受到抑制来增加玉米的抗盐性．  相似文献   

Word stress production in three‐year‐old children at risk of dyslexia     

Elise De Bree  Frank Wijnen  Wim Zonneveld 《Journal of Research in Reading》2006,29(3):304-317

We investigated Dutch word stress acquisition in 3‐year‐old children at risk of dyslexia (children with at least one parent or older sibling with reading difficulties) and normally developing children, in order to shed light on language acquisition delays in children at risk of dyslexia, as well as to investigate further phonological deficits in dyslexia. The children had to repeat non‐words with stress patterns varying in regularity. Both the at‐risk and control children performed better on imitation of regular stress targets and worse on irregular and prohibited stress patterns. However, the at‐risk children showed more difficulty imitating irregular and prohibited patterns, and had lower percentages phonemes correct than the control group. The results can be interpreted as a delay in word stress acquisition in the at‐risk group. The findings thus point towards a phonological deficit early in language development.  相似文献   

分组教学在警察职业压力调适能力训练中的运用浅析     

彭文会  杨淑霞  郑雪茹 《教育教学论坛》2020,(8):183-184

在压力调适能力训练课的分组教学过程中,作为指导者的教师可以采取以下三个方面的指导策略:一是选择分组方法时,应有利于促进每个学生的体验交流;二是为了更好地打造团队合作精神,可适时开展团队建设活动;三是在教学环节设计中,应根据教学目标采用适当的小组活动。  相似文献   

A Nonlinear Dynamical Theory of Non-Classical Plates     

Zhiming Ye Ph. D. 《上海大学学报(英文版)》1997,1(1):28-35

In this paper, a new nonlinear formulation of plates, including shear and rotatory inertia and transverse normal stress effects, is developed by means of general assumptions, of which the von Karman-type formulation and some thick plate theories are special cases. To keep the formulation fairly general, the problem addressed in this paper simultaneously includes: the effects of shear deformation according to the geometric deformation similarity of the cross-section, the rotatory inertia, and the transverse normal stress. The three-dimensional compatible equations are applied to derive the basic equations. Numerical results are given for linear and non-linear analysis of plates. This Work was supported by the Natural Science Fundation of Shanghai for Returning Scholars  相似文献   

论英语节奏     

王守芳 《临沂师范学院学报》2001,23(2):118-120

阐述了英语节奏的特点，论述了英语节奏与词重音、句重音、重音规整性，音长、元音的音质、语调和语言的可理解性三者之间的相互关系和影响。提出了掌握英语节奏的正确方法。  相似文献   

用有限元法合理设计压力容器凸形封头     

詹世平 《大连大学学报》1996,(2)

运用有限元法,考虑封头的结构、封头与简体的连接形式、开孔位置、接管与封头的连接结构等因素,对受内压的凸形封头(球形封头、椭圆形封头、碟形封头及锥形封头)进行了应力分析计算。  相似文献   

Fuzzy Comprehensive Assessment Method to Determine Tectonic Stress Patterns     

张海  戚蓝  郝彩哲  郭磊 《天津大学学报(英文版)》2007,13(6):462-468

The tectonic stress patterns were determined by a fuzzy comprehensive assessment method. Data of in-situ survey and fault information were utilized in the method. First, by making pressure and tension in the directions of along-river, cross-river, shear clockwise, and shear counterclockwise , 26 types of tectonic stress patterns were presented. And the stress vector of each pattern was obtained with FE software by taking unit displacement as boundary load. Then, by taking the 26 types of tectonic stress patterns as index set and 3 main stresses as factor set and choosing various operators, comparison of directions of computational stress vector and survey stress vector was made and the most possible tectonic stress pattern was obtained. Taking the 26 types of tectonic stress patterns as index set and strike angle as factor set, comparison of relationships between formation of fault and tectonic stress was made,and the tectonic stress patterns were assessed with known fault information. By summarizing the above assessment results, the most impossible tectonic stress pattern was obtained . Finally an engineering case was quoted to validate that the method is more feasible and reliable than traditional empirical method.  相似文献   

仿生种植牙应力分布的有限元分析     

王宗篪  庄国铭  赖森财  谢培庆  黄庆杰  黄跃 《三明学院学报》2002,19(4):1-3

以上颌中切牙为解剖学基础 ,提出了仿生种植牙模型。相同载荷分别作用于天然牙、仿生牙及骨性结合种植牙模型 ,用二维有限元法计算得到牙周膜和仿生牙周膜的应力分布 ,对三种模型骨界面上的应力分布进行了比较研究  相似文献