一、平键连接 工作原理:平键的两侧是工作面,上表面与轮毂键槽底面间有间隙(如图),工作时靠轴槽、键及毂槽的侧面受挤压来传递转矩

Teaching Points l. Background knowledge l l. Introduction to the passage l l l. ext Analysis V. Rhetorica| devices V. Questions

酶是一种具有催化活性的蛋白质,因此酶具有催化剂的特点,即:能够加快特定反应 的速率但不能改变反应的平衡,在反应中不消耗,反应结束时回复到原来的形态;同时酶又 具有蛋白质的属性,即:酶由氨基酸通过肽键连接而成,只有在适当的温度,pH和离子强 度下才具有生物活性,有些酶还需要辅酶或者辅因子由于酶催化反应能够在常温常压下进 行,而且具有很高的效率和专一性,酶的应用日益受到了人们的重视

Teaching Points I. Background knowledge II. Introduction to the passage III. Text Analysis IV. Rhetorical devices V. Questions

Teaching points I. Background information II. Introduction to the passage III. Text analysis IV rhetorical devices V. Questions for discussion

Teaching points I. Background information II. Introduction to the passage III. Text analysis IV rhetorical devices V. Questions for discussion

Teaching points I. Background information II. Introduction to the passage III. Text analysis IV rhetorical devices V. Questions for discussion

Teaching points I. Background information II. Introduction to the passage III. Text analysis IV rhetorical devices V. Questions for discussion

Teaching points I. Background information II. Introduction to the passage III. Text analysis IV rhetorical devices V. Questions for discussion

Teaching points I. Background information II. Introduction to the passage III. Text analysis IV rhetorical devices V. Questions for discussion