浅谈增安型无刷励磁同步电机定、转子装配的两种工艺方法

根据不同的装配条件采用不同的装配工艺措施，满足同步电机装配要求，并对两种较简易的同步电机装配工艺进行了探讨。     

发生桩基沉降在役压力管道的断裂失效风险分析

含缺陷管道和压力容器的安全评定是石油化工行业中的一个重要课题，断裂力学的出现和发展为它们的安全评定提供了有力的手段。充分考虑工况载荷、缺陷尺寸、断裂韧度、机械强度等参数的不确定性，根据R6双判据准则，通过Monte Carlo模拟方法对发生桩基沉降的管道进行了失效风险分析，得到它的失效概率，对于掌握发生桩基沉降管道的安全可靠性具有一定的实用价值。     

翻滚目标安全走廊内的碰撞可能性判断方法

在接近空间带大附件翻滚目标过程中,由于目标章动运动,空间会被划分为目标扫过的危险区与不被扫过的安全区.追踪星在目标安全区内飞行过程中,为规避航天器间的碰撞,应判断追踪星与目标安全区之间是否存在碰撞可能性.为解决这一问题,参考区域判定法思想,将判断碰撞可能性的问题转化为目标安全区与追踪星轨迹的位置判定问题.通过分析目标安全区特征与追踪星轨迹特点,分别建立锥面状的目标星安全走廊和椭球状的追踪星位置误差曲面,从而进一步将问题转化为目标星安全走廊锥面与追踪星位置误差椭球的位置判定问题.经过射影变换和平面投影过程,原锥面与椭球在不改变位置关系的前提下分别被转化为平面上圆与椭圆.利用平面曲线位置判据,判定圆与椭圆的位置关系,反推出锥面与椭球的位置关系,从而判断追踪星在目标安全走廊内飞行有无碰撞可能性.数值仿真表明,该方法可以准确判断锥面与椭球的空间位置关系,并可用于目标安全走廊内的碰撞可能性判断.     

Optimisation of immobilisation conditions for chick pea β-galactosidase (CpGAL) to alkylamine glass using response surface methodology and its applications in lactose hydrolysis

Response surface methodology was advantageously used to optimally immobilise a β-galactosidase from chick pea onto alkylamine glass using Box–Behnken experimental design, resulting in an overall 91% immobilisation efficiency. Analysis of variance was performed to determine the adequacy and significance of the quadratic model. Immobilised enzyme showed a shift in the optimum pH; however, optimum temperature remained unaffected. Thermal denaturation kinetics demonstrated significant improvement in thermal stability of the enzyme after immobilisation. Galactose competitively inhibits the enzyme in both soluble and immobilised conditions. Lactose in milk whey was hydrolysed at comparatively higher rate than that of milk. Immobilised enzyme showed excellent reusability with retention of more than 82% enzymatic activity after 15 uses. The immobilised enzyme was found to be fairly stable in both dry and wet conditions for three months with retention of more than 80% residual activity.     

磁力作用式汽车防追尾系统设计

为了弥补被动安全系统的不足,引进了磁力作用式主动安全概念,采用速度、距离传感器测定两车间的距离和速度差,然后分析制动距离特性;引入了危险估计系统,当结果为危险时,发送信息至前车,使两车电磁铁形成相同极性的磁场,从而产生"排斥力"阻止两车相撞。结合理论计算和模拟测试,结果表明这种方法在实际工程中具有实用价值。     

宏远煤矿液压柔掩支架的技术应用

为了解决4.2 m柔掩工钢支架强度有限,在顶板压力大或地质变化时经常造成支架挤架、摞架、架斜等现象给安全生产带来的重大安全隐患。宏远煤矿大胆尝试采用ZRY36/45L型柔性液压支架采煤工艺,结果表明采用该液压支架后保证了工作面的安全生产,生产效率得到了较大的提高,促进了安全高效矿井的建设。     

提高本安火花试验装置灵敏度的方法研究

为提高本安火花试验装置的灵敏度,提高检验效率,基于火花试验装置的结构及标定电路要求,通过合理制备和清理钨丝、调试镉盘、改善装置回路参数,以及应用流量法配气、扫气法进气的配气方式,保证所配制的混合气体的浓度,提高混合气体均匀度等方法来提高本安火花试验装置的灵敏度,并对每种方法作了详细介绍。实践证明,综合运用以上方法能够很好地提高装置的灵敏度,大幅提升本质安全型设备的检验效率及检验质量。     

边坡主要因素对强度折减法计算精度的影响

采用强度折减法和极限平衡法对粘土边坡进行稳定性分析,并将计算所得的安全系数加以对比,进行误差分析,通过研究粘聚力、内摩擦角、坡高和坡角等指标对计算精度的影响,揭示影响计算精度的主要因素和次要因素,为以后的数值模拟研究提供有利的参考。     

浅谈安全用电的屏护和间距

主要讨论了安全用电的屏护和间距问题,用一系列数据使计量检定员懂得现场操作高低压设备的安全技术、最小安全距离等,工作中知己知彼,不出差错,从而达到事半功倍的效果.     

Fire hazard assessment for a green railway station

A green railway station adopting natural ventilation was built in Hong Kong to promote sustainable architectural design. Similar to many other green or sustainable projects, such design failed to comply with the local fire safety codes. There are potential fire hazards due to the adopted green features. Better ventilation provision would supply more air to burn the combustibles in case of fire. Performance‐based design was applied using the timeline analysis to determine the fire safety provisions. In this paper, fire simulations were carried out to predict the available safe egress time (ASET) under low design fires with smoke toxicity including only the carbon monoxide concentration. Evacuation simulations were conducted to predict the required safe egress time (RSET) under low passenger loadings. Studies on human behaviour under big fires and heavy passenger loadings were not included. Problems to be encountered in this green railway station using the timeline analysis will be pointed out in this paper. ASET was estimated by computational fluid dynamics with bigger fires resulted from the green features. RSET was estimated by evacuation software under local passenger loadings. The results indicated that ASET are less than RSET under big fires with heavy passenger loadings. Copyright © 2013 John Wiley & Sons, Ltd.