加强中国革命史教学中的国情教育

本文就加强革命史教学中国情教育的战略意义,以及对怎样认识和把握国情,提出了一些想法。在此基础上,探讨了国情教育的基本内容和贯彻方法,来达到解决学生当前深层次认识问题的目的。     

用比较方法进行中国革命史教学初探

用纵向和横向比较研究的方法,进行中国革命史的教学,是整体的综合研究的一个方面。所谓纵向比较研究,是指对不同时期,同一民族或同一国家相似或相近似的历史发展、历史事件进行比较研究。如中国共产党与在近代史发生的太平天国农民运动,洋务运动,戊戌变法、辛亥革命进行比较,证明中国共产党的产生发展及其取得胜利。是历史的选择,时代的要求。所谓横向比较研究,是指对同一时期并存的事物进行比较研究。这里主要指的是在现代史的时限内,中国共产党和国民党以及中间党派的比较,以此说明中国革命和建设必须坚持四项基本原则。     

Investigation of Coolant Fluid through Grinding Zone in High-Speed Precision Grinding

In the grinding process,grinding fluid is delivered for the purposes of chip flushing,cooling,lubrication,and chemical protection of the work surface.Due to the high-speed rotation of the grinding wheel,a boundary layer of air forms around the grinding wheel and moves most of the grinding fluid away from the grinding zone.Hence,the conventional method of delivering coolant fluid that floods delivery with high fluid pressure and nozzle fluid rare supply coolant fluid to achieve high performance grinding.The flood grinding typically delivering large volumes of grinding fluid is ineffective,especially under high speed grinding conditions.In the paper,a theoretical model is presented for flow of grinding fluid through the grinding zone in high-speed precision grinding.The model shows that the flow rate through the grinding zone between the wheel and the workpiece surface not only depends on wheel porosity and wheel speed,but also depends on nozzle volumetric flow rate and fluid jet velocity.Furthermore,the model is tested by a surface grinding machine in order to correlate between experiment and theory.Consequently,the useful flow-rate model is found to give a good agreement with the experimental results and the model can well forecast the useful flow-rate in high-speed precision grinding.