初中生心理应激及其与一般生活满意度的关系     

田丽丽  刘旺  石孟磊 《中国特殊教育》2007,(2):86-90

运用《中学生应激源量表》和《多维学生生活满意度量表》对431名初中生的心理应激和一般生活满意度进行测量,考察初中生心理应激状况及其与一般生活满意度的关系。结果发现:(1)男生承受来自教师、家庭环境、同学朋友、社会文化四个方面的压力高于女生。初中生的学习压力呈现出随年级的升高而增加的趋势。(2)生活在关系很融洽家庭中的学生的学习压力和自我身心压力在三种家庭关系状况的学生中最低,家庭关系不融洽的学生承受来自家庭环境的压力高于家庭关系很融洽的学生。生活在单亲家庭中的学生承受来自父母管教方式和自我身心两方面的压力高于生活在几代同堂和核心家庭中的学生。(3)初中生在父母管教方式、同学朋友、社会文化、自我身心四个方面的心理应激对一般生活满意度具有显著的负向预测作用。  相似文献   

Hierarchical models for failure analysis of plates bent by distributed and localized transverse loadings     

Erasmo Carrera  Gaetano Giunta 《浙江大学学报(A卷英文版)》2008,9(5):600-613

The failure analysis of simply supported, isotropic, square plates is addressed. Attention focuses on minimum failure load amplitudes and failure locations, von Mises＇ equivalent stress along the plate thickness is also addressed. Several distributed and localized loading conditions are considered. Loads act on the top of the plate. Bi-sinusoidal and uniform loads are taken into account for distributed loadings, while stepwise constant centric and off-centric loadings are addressed in the case of localized loadings. Analysis is performed considering plates whose length-to-thickness ratio a/h can be as high as 100 （thin plates） and as low as 2 （very thick plates）. Results are obtained via several 2D plate models. Classical theories （CTs） and higher order models are applied. Those theories are based on polynomial approximation of the displacement field. Among the higher order theories （HOTs） HOTsa models account for the transverse shear deformations, while HOTs models account for both transverse shear and transverse normal deformations. LHOTs represent a local application of the higher order theories. A layerwise approach is thus assumed： by means of mathematical interfaces, the plate is considered to be made of several fictitious layers. The exact 3D solution is presented in order to determine the accuracy of the results obtained via the 2D models. In this way a hierarchy among the 2D theories is established. CTs provide highly accurate results for a/h greater than 10 in the case of distributed loadings and greater than 20 for localized loadings. Results obtained via HOTs are highly accurate in the case of very thick plates for bi-sinusoidal and centric loadings. In the case of uniform and off-centric loadings a high gradient is present in the neighborhood of the plate top. In those cases, LHOTs yield results that match the exact solution.  相似文献   

高水平运动员学业投入及影响因素研究     

谭术魁  王若昕  郑君怡 《教育与教学研究》2021,(3)

高水平运动员文化素质教育是培养优秀体育人才的关键环节,也是实现我国体育强国战略目标的重要举措。文章基于学业投入度理论,在自编问卷的基础上,对湖北省9所高校的高水平运动员学业情况进行调查,从高水平运动员学业投入的三个维度,即行为投入、认知投入和情感投入的现状及其影响因素进行分析。研究结果显示:高水平运动员学业投入处于一般水平,其中学习行为投入较为不足;不同个体特征高水平运动员的学业投入情况存在显著差异;其中,内部学习动机、专业志向和院校学业环境支持度对学业投入有正面影响;训练压力对学业投入有负面影响。基于上述结论,各高校可从高水平运动员个体特征差异、学训安排、院校培养模式等方面着手推进高水平运动员的学业发展。  相似文献   

金属燃油箱吊耳结构设计     

卓义盛  徐靖  唐龙  吕兆平 《大众科技》2016,(5)

文章通过对某微车燃油箱吊耳结构优化改进,总结出影响吊耳受力的若干因素。基于对这几个因素的分析,提出了相应的解决方法。通过有限元模拟分析的方法对相应结论进行验证找到了对应力的降低起到显著作用关键因素。  相似文献   

施工期不同加载过程对拱坝应力场影响研究     

严静  彭辉 《科技创业月刊》2007,20(12):202-204

拱坝整体结构随大坝浇筑、封拱不断推进而逐渐形成,坝体结构形式在施工过程中是变化的,因此,在浇筑、封拱过程中坝体承受的荷载形成的力学效应也是不断变化的。研究了不同封拱过程和不同蓄水过程以及施工期温度荷载对拱坝坝体应力场的影响,导出了不同加载过程条件下坝体应力的表达式。  相似文献   

横贯亚洲巨型构造带的基本特征和成矿作用     

陈炳蔚  陈廷愚 《中国科技期刊研究》2007,23(5):865-876

本文将位于西伯利亚地台与中朝、塔里木地台之间的广大地区称为横贯亚洲巨型构造带（The Trans-Asian Tectonic Mega-Belt：TATMB）.按其发育历史和构造位置,横贯亚洲巨型构造带可大体分为：（1）阿尔泰-萨彦-蒙古-鄂霍茨克构造带、（2）巴尔喀什-兴安构造带和（3）乌拉尔-南天山构造带等三个大的构造带.阿尔泰-萨彦-蒙古-鄂霍茨克构造带以中央蒙古构造线为南界,以叶尼塞-穆亚断裂、贝加尔断裂及斯塔诺夫南缘断裂为北界,与西伯利亚地台毗邻.巴尔喀什-兴安构造带位于中央蒙古构造线以南;其南界的西段为尼古拉耶夫线及南天山北缘断裂,东段以中-朝地台北缘逆冲断层与中-朝地台直接相连.这一构造带又可分为南、北两大亚带,即巴尔喀什-准噶尔-北、中天山-内蒙-锡林浩特亚带和斋桑-额尔齐斯-南蒙古-大兴安岭亚带.乌拉尔-南天山构造带从中国新疆境内西延经中亚地区直达乌拉尔.夹持该巨型构造带的南、北两大陆决,都发育有太古宙和古元古代的结晶基底和中元古代开始的沉积盖层,并在中元古代早期陆块的边缘都出现过裂解事件.然而位于这两大陆块之间的横贯亚洲巨型构造带地区却未见有中-新元古代的沉积盖层直接不整合覆盖在古老的结晶地块之上,也未见有地壳裂解的直接证据.在一些地区寒武纪地层与新元古代晚期地层是连续的.古生代时,该区以发育各类成分的海底喷发火山岩系为特征,其中包括被动陆缘火山岩、岛弧火山岩和洋壳上的喷发物等.整个构造带大致表现为西伯利亚地台和中朝、塔里木地台南、北两大陆块的相向运动和相向增生过程.其发育时间大致始于新元古代,主要为古生代,止于中生代.从晚三叠世开始,该带进入西太平洋边缘活动阶段.从区域成矿作用的角度来看,该区可分出相应的构造-成矿单元：（1）阿尔泰-萨彦-蒙古-鄂霍茨克构造-成矿带,包括1）阿尔泰-萨彦带和2）蒙古-鄂霍茨克带;（2）巴尔喀什-兴安构造-成矿带,包括1）斋桑-额尔齐斯-南蒙古-大兴安岭带和2）巴尔喀什-准噶尔-北、中天山-内蒙-锡林浩特带;（3）南天山构造-成矿带.主要矿种有金、铀、银、铜、钼、铅锌、钨、锡、稀有金属、铁、镍、云母、宝石、萤石、石墨、菱镁矿和沸石等.区内的成矿作用主要与古生代的岩浆作用和热液活动有关;但在蒙古-鄂霍茨克带主要发生在中生代.  相似文献   

JDCS模型的修正及其在高校科研人员中的应用     

杜健梅  廖建桥 《科学学研究》2003,21(4):414-418

JDCS模型是工作压力研究中的一个经典模型。本文运用我国高校科研人员工作压力的问卷调查数据 ,对该模型进行了本土化修正 ,并对我国高校科研人员的工作压力现状进行了研究。研究结果显示 :我国高校科研人员的工作压力总体水平偏低 ;近 3 4的科研人员处于高社会支持水平 ;近八成科研人员处于低工作要求和高健康水平状态。  相似文献   

品牌资产构成的关键因素及其类型探讨   总被引：9，自引：0，他引：9  

卫海英  王贵明 《预测》2003,22(3):39-42,30

本文在对100家大中型企业的实证调查基础上，运用数理统计方法，分析了品牌资产各组成要素，提取了品牌资产五个最重要的构成因子，首次从量化角度提出品牌资产最重要的因子是品牌地位和顾客价值取向，其次为品牌定位、品牌创新能力和市场执行能力。根据品牌资产的构成因子，对品牌资产进行了类型划分，按照品牌构成品性将企业分为领导型、成熟型、务实型、顾客导向型和创新型品牌企业。  相似文献   

Effect of immobilisation stress on lipid peroxidation and lipid profile in rabbits     

Hem Lata  G. K. Ahuja  A. P. S. Narang  Lily Walia 《Indian journal of clinical biochemistry : IJCB》2004,19(2):1-4

Stress is one of the basic factors in the aetiology of a number of diseases such as atherosclerosis, coronary heart disease, aging, liver disease etc. Hence this work was designed to study the effect of stress in the form of forced immobilisation stress on lipid peroxidation and lipid profile in rabbits. The study was conducted in 25 healthy rabbits of either sex. Rabbits were subjected to forced immobilisation for two hours everyday for consecutive seven days. Blood samples were collected on day 1, 3 and 7 after immobilisation period. Malondialdehyde (MDA), a marker of lipid peroxidation was estimated by TBA assay method. Lipid profile was analysed by multichannel autoanalyser. There was statistically significant increase in MDA, total cholesterol, LDL, VLDL and triglycerides with immobilisation. These findings indicate that stress in the form of forced immobilisation increases lipid peroxidation and alter lipid profile, which may be responsible for pathophysiology of various diseases.  相似文献   

The evolution of local production systems: the emergence of the “invisible mind” and the evolutionary pressures towards more visible “minds”     

Mauro Lombardi 《Research Policy》2003,32(8):1443-1462

The aim of this paper is to propose an explanation of the changes of dynamic matching between systemic properties of local production systems (LPS) and characteristics of the competitive environment. An evolutionary sequence travelled during the last three decades by Italian LPS is identified and an explanation of long-term dynamics is based on how information flows and knowledge are structured within a local environment. The “traditional” pattern of interlocking behaviours of different agents is defined as cognitive architecture, which evolutionarily emerges as invisible mind. Evolutionary pressures lead new patterns of relationships and interlocking behaviours, which we define as a tendency for more visible “minds” to assert themselves.  相似文献