工程图学课程的教学改革

工程图学是高职院校普遍开设的一门重要的技术基础课,目前工程实际中手工绘图耗时长,效率低、劳动强度大,绘图精度不容易保证,而计算机绘图则速度快、效率高、准确性好.因此已得到了普遍的运用,正因如此,在工程图学教学中"甩图板"的呼声此起彼伏.如何在教学中摆正二者的关系,已成为各个院校急待解决的问题.     

安钢高线品种开发的优势与实践

介绍了安钢高线的技术装备、工艺转化及创新，以及自投产以来的产品结构调整和重点产品的开发情况。     

压力AGC系统与其它厚控系统共用的相关性分析

分析证明了动态设定型厚度控制系统与监控、前馈厚度控制系统是相容的,而且保持各自的独立性,无相互影响。BISRA变刚度厚度控制系统和测厚计型厚控系统与监控、前馈厚度控制系统也是相容的,但它们之间有相互影响。BISRA恒压力厚度控制系统与监控、前馈厚度控制系统是不相容的,而动态设定型的恒压力方案是相容的。     

Mothers' Affect in the Homework Context: The Importance of Staying Positive.

This research investigated mothers' affect in the context of children's homework. Mothers (N=109) of children 8 to 12 years old were interviewed daily about their affect while interacting with children, their assistance with children's homework, and children's behavior while completing homework. At this time and 6 months later, children's motivational and emotional functioning was assessed. Although mothers' negative affect was lower than their positive affect, it was elevated on days their assistance with homework was high. This was accounted for by mothers' perceptions of children as helpless on days they provided heightened assistance. Mothers' positive affect in the homework context buffered children's motivational and emotional functioning against mothers' negative affect as well as children's helplessness. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

风机动力型末端在变风量空调系统中的应用

通过对从低温送风技术中发展起来的变风量系统末端--风机动力箱的分析,在实际应用中对比两种型式的该种末端,分析其优缺点,认为这是一种值得在高级办公大楼中优先考虑和推广的系统形式.     

A refined beam theory based on the refined plate theory

Summary Based on the refined plate theory, a refined theory of rectangular beams is derived by using the Papkovich-Neuber solution and Lur’e method without ad hoc assumptions. It is shown that the displacements and stresses of the beam can be represented by the angle of rotation and the deflection of the neutral surface. The solutions based on the new theory are the same as the exact solutions of elasticity theory. In three examples it is shown that the new theory provides as good or better results than Levinson’s beam theory when compared to those obtained from the linear theory of elasticity.     

Investigation of failure mechanism and modification for film-lubricated precise angular-contact ball bearing

This paper describes an experimental investigation into the performance and lubrication failure mechanism of precise angular-contact ball bearings treated with MoS₂-sputtered film, etc. As an important executive component of various spacecrafts, there are some strict requirements on the lubrication performance of angular-contact ball bearing, but the related experimental data are rare to see in literatures. In this experiment, the lubrication performances of MoS₂-sputtered ball bearing pairs were evaluated by using lifetime test as a main method, and the topographies and compositions of working surfaces were investigated through SEM, AES and EDS. The systematical experiment results reveal that the degradation and failure process of solid lubrication for such ball bearing is divided into three stages with different characters. A supposed failure mechanism has been proposed. An improved lubrication treatment based on above mechanism was conducted for the precise ball bearings, and a later test showed that long endurance life with more than 10⁸ revolutions has been reached.