球磨法制备锆英砂粉体研究

利用扫描电子显微镜、震筛机、激光粒度分析仪等仪器,对实验球磨机上制备的锆英粉进行了形貌观察和粒度分析,结果表明:锆英粉呈不规则形状,粒径分布为近似的正态分布,曲线左端细粉分布广,球磨50 h后开始出现"翘尾"现象;锆英粉粒径尺寸随着球磨时间增加下降平缓,达到150 h后,D50为26μm。同雷蒙磨生产的锆英粉相比,球磨机生产的锆英粉堆积密度较大。     

‘If this was real … ’: researching student meaning making in a digital rolling role drama

ABSTRACT

This article explores the interplay of the ‘live’ experience of drama learning in the classroom and curated digital content on learner meaning making, collaborative creation and subjectivities. It examines a case study conducted in an inner-city secondary school in Sydney, Australia, as part of a larger innovative international collaborative drama exercise entitled ‘The Water Reckoning Project’ (http://www.water-reckoning.net) which focussed on sustainability education. Data collected and analysed included ethnographic observations, video documentation and digital curation of students’ creative work, focus groups, and pre- and post-surveys. Findings of this study reveal the importance of the aesthetically charged, embodied experience of drama as the key driver of learning when integrating drama with digital technologies. This unique project enabled students to critically and creatively engage with significant real and fictional contexts, as well as issues of local and global relevance.     

机耕船驱动轮入土深度调节技术研究

机耕船驱动轮入土深度不仅影响驱动轮的最大水平推力、驱动轮和船体的支承反力、滚动阻力以及船体的行驶阻力等,而且影响机耕船的滑转率、牵引效率、燃油经济性等。增加入土深度,虽然增大了剪切面积,可使最大水平推力增加,牵引附着性能增强,滑转损失功率减小,但会使滚动阻力增加,功率损耗增大。因此,在保证牵引性能的前提下,入土深度必须可调,而且应尽量减小。入土深度有驱动轴、船体和驱动轮半径可调等三种方式。通过对关于机耕船驱动轮入土深度的文献进行研究,为研制更加方便地调节入土深度的装置提供借鉴意义。     

小组滚动同课异构 提升教师实践智慧——“领雁工程”教学培训的实践与思考

“领雁工程”是浙江省为提升农村教师素质开展的培训活动,参加培训的教师有一定的实践经验,在参加了理论的学习后需要将理论内化并用于指导教学实践,而他们自己所在的学校缺少同伴研讨的氛围和环境,在教学实践培训中需要提高教师的实践智慧。采取小组滚动同课异构的方法,强调以微格分析为手段、以同伴互助为桥梁、以解决问题为目标,帮助学员：准确理解课程标准,个性解读教材的能力;深度理解学生需求,合理设置目标的能力;理性认识自身特征,使教学设计进入“有我之境”,实现教学设计的个性化的能力,为今后的教学实践和教研活动的开展提供基础。     

武钢热轧厂精轧工作辊断裂原因分析

本文通过对武钢热轧厂3支精轧工作辊断裂事故所做的调查和取样检验分析，找出了断绝原因，并提出了预防措施。     

实验教学电路板的设计制作及其应用

介绍了利用计算机、激光打印机和制板机设计制作实验教学电路板的方法．即在单面覆铜板的铜面设计制作印制电路板。在鲍缘玻纤环氧树脂基面设计制作电路原理图．这是适于单件、小批量、新产品试制的双面制板工艺，它具有廉价快捷、操作简单、精度较高的特点．此外，还介绍了谊电路板在实验教学中的应用情况．     

试析民办教育若干理论与政策问题

中国民办教育将进入振兴发展的新阶段,创新是民办教育振兴的不竭动力;“不以营利为目的”与利益回报之间既存在对立、矛盾的方面,也存在统一、协调的方面;要改变现行成本收费方式,运用市场调节为主的收费方式,促进民办教育滚动发展;中介组织参与管理是民办教育管理创新的重要内容。     

基于振动和声发射信号参数的滚动轴承故障试验研究

建立了滚动轴承故障模拟试验台,对无故障轴承、外圈故障、滚动体故障和内圈故障滚动轴承在不同转速工况下同时进行声发射测试和振动测试。分析各种工况下声发射信号和振动信号的有效值、峰值、峰值因数和峭度的变化规律。研究结果显示所选取的信号参数对故障轴承的转速及轴承元件的故障较敏感,故障点数量变化对所选参数无明显规律。     

轧钢中的浪费模型

研究轧钢中的浪费问题，运用概率理论知识，建立浪费模型，并求最优值。     

纯滚动状态下的氮化硅球的滚动接触疲劳

A newly developed pure rolling fatigue test rig with three contact points for bearing balls was used to perform rolling contact fatigue (RCF) tests. The fatigue properties of GCr15 steel balls and two kinds of Si3N4 ceramic balls (GSN-200 and NBD-200) produced with different technologies were compared. Ball surfaces were examined after failure with optical microscope and scanning electron microscope (SEM). It was identified by tests that the failure mode of ceramic balls was surface spall. The main factor of ceramic ball failure was principal tensile stress. Life tests data, summarized in accordance with the Weibull theory, showed that the life of GSN-200 balls was close to that of GCr15 balls, whereas the life of NBD-200balls was much longer than those of GSN-200 and GCr15. Under the same working condition, the temperature rise of all ceramic balls was lower than that of steel balls, and their crack propagation rates were slower than that of steel balls.