慢磨出好课——教学《用字母表示数》磨课感悟

好课多磨，在磨课的过程中，教师不仅要养成质疑思考的习惯，而且要关注在合作互助中深入的思考，更要提升自身理论研究、外力引领的反思内化能力，并以此为导航系统，把准方向，驶入专业化成长的快车道!应该：磨透教材；磨就学生；磨锐方法；磨精语言。

岫岩发现蛇纹石河磨玉

近日,岫岩玉都展出一块罕见的宝石--蛇纹石河磨玉.它的发现和展出,雄辩地证明岫岩不仅产透闪石河磨玉,也产蛇纹石河磨玉.它的发现为岫岩玉家族增添了一颗耀眼的新星.

散粮流程系统半气垫皮带机上盘槽维修更换工艺与技术的推广与应用

本文主要针对散粮流程系统半气垫皮带机作业过程输送带被大豆物料压停,输送带在运转过程中盘槽内时常伴有刺耳异音现象,因皮带机气室盘槽磨透导致除尘器气流进入气室无法形成气膜,输送带长时间摩擦将会加速上盘槽磨损,产生高温造成皮带机起火的重大安全隐患,可能造成企业更大安全事故或经济损失,本文介绍了一种气室上盘槽维修更换的工艺技术方案,并阐述了应用效果。

Microstructure,mechanical properties and wear resistance of SiC_(p)/AZ91 composite prepared by vacuum pressure infiltration

SiC_(p)/AZ91 composites were prepared by vacuum pressure infiltration.The microstructure,mechanical properties and wear resistance of composite were studied.Results indicated that SiC particles were uniformly distributed in the metal matrix and had a good interface bonding with the metal matrix.Mg_(17)Al_(12) preferably precipitated near the SiC particles,and high-density dislocations were induced by the mismatch of the coefficient of thermal expansion(CTE)between the SiC particle and the AZ91 matrix,thereby accelerating the aging precipitation of the matrix.Compared with AZ91 alloy,the addition of SiC particles improves the hardness and compressive strength of the composite,which is mainly due to the load transfer strengthening and grain refinement strengthening mechanisms.Furthermore,a stable support surface-protecting matrix formed during the wear process because of the excellent wear resistance of SiC.

浅论ZK101—1孔钻具糊钻的事故处理技术措施

对ZK101—1孔糊钻的事故发生情况和孔内事故的现状进行了介绍，制定出处理事故有针对性的技术措施，提出了处理事故中应注意的问题。