高精度轧制在本钢浦项合营公司的应用

介绍了本钢浦项合营公司采用的先进轧制技术的概况.     

船舶参-强横摇动力学系统的调和解分岔与次调和解分岔

应用平面周期系统的Poincaré映射、Poincaré定理以及m阶次调和解和Melnikov函数,系统地论证了船舶参-强激励非线性横摇动力学系统存在调和解和次调和解。     

SAPH400汽车结构用热轧钢的研制

SAPH400汽车结构用热轧钢的生产采用喂Re丝对夹杂物进行变性处理,使SAPH400钢具有良好的冷成型性能。钢的金相组织为铁素体＋少量的珠光体,无明显的带状组织。SAPH400钢质纯净、组织均匀、晶粒适中,适于复杂冷冲压成型加工,具有优良的综合性能,能满足用户的需要,是一种比较理想的代替普碳钢用于制造车架的新型材料。     

Comparison of vibration rolling,nonvibration rolling,and static stretching as a warm-up exercise on flexibility,joint proprioception,muscle strength,and balance in young adults

Warm-up is an essential component for optimizing performance before an exercise session. This study investigated that the immediate effects of vibration rolling (VR), nonvibration rolling (NVR), and static stretching as a part of a warm-up regimen on the flexibility, knee joint proprioception, muscle strength, and dynamic balance of the lower extremity in young adults. Compared with the preintervention, VR induced the range of motion of knee flexion and extension significantly increased by 2.5% and 6%, respectively, and isokinetic peak torque and dynamic balance for muscle strength and dynamic balance increased by 33%–35% and 1.5%, respectively. In the three conditions, most outcomes between VR and NVR were comparable; however, the participants had a significantly higher knee joint reposition error after NVR than after VR, indicating that NVR would have a hampering knee joint proprioception effect. In particular, compared with static stretching, VR significantly increased the quadriceps muscle strength by 2-fold and dynamic balance by 1.8-fold. These findings suggest that athletic professionals may take VR into account for designing more efficient and effective preperformance routine to improve exercise performances. VR has high potential to translate into an on-field practical application.     

‘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.     

锻钢轧辊质量控制

本文从制造和使用两个方面对锻钢轧辊的质量控制进行了分析。指出为了保证锻钢轧辊的使用特性,在轧辊制造上应建立严格的质量控制体系,使用上应制定切实可行的轧辊修磨制度。提出了质量控制的要点。     

梯度铝合金压制板材的热轧变形研究

研究了Alsi/al梯度铝合金压制板材在热轧大塑性变形后的组织、成分和性能变化,特别是梯度过渡区的塑性变形特征。结果说明:在变形温度为757K下,压制态合金板材经过热轧的大塑性变形后仍然保持着良好的梯度分布特征。随着变形量的增加,热轧板材梯度过渡层的非均匀性有所减少,芯部显微硬度值有所增加。     

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．     

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.     

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。