Plunge milling is a high-speed machining way and the cutter is fed in the direction of the Z axis, which is used to remove excess material rapidly in roughing operations. In this paper, the orthogonal cutting theory w...Plunge milling is a high-speed machining way and the cutter is fed in the direction of the Z axis, which is used to remove excess material rapidly in roughing operations. In this paper, the orthogonal cutting theory was used to study the plunge milling of LY12 alloy. A mathematic model for cutting force in plunge milling was established, and the milling process was simulated by using Matlab. It is found that the single tooth cutting experimental result is unstable because of unsymmetrical single tooth in the milling process, which leads to the difference between the simulation and experimental results. The trend of multiple teeth cutting experimental result is similar to that of the simulation result; however, the peak values in the experimental result are different, which is caused by the error of cutter’s position, and the error of peak value is less than 10%.展开更多
Previous studies have shown that children learn from educational television; however, these studies have not explored how closely the educational content of the program is integrated to the narrative. The following st...Previous studies have shown that children learn from educational television; however, these studies have not explored how closely the educational content of the program is integrated to the narrative. The following study uses a systematic content analysis of 100 top-rated U.S. children＇s television programs to explore the tangential relationship （i.e., distance） of narrative and educational content through the lens of the capacity model--which is built upon three basic components： narrative content, educational content, and the distance between them. Programs were analyzed for distance by examining lesson clarity and integration, show type, target audience age, and station type. One-way ANOVAs indicates significant differences between the means of these variables. Programs targeting younger children presented educational content that was closely integrated into the plotline of the program and helped further the story. However, as the target audience aged, the educational content became more tangential to the narrative content and was less tied to the plotline of the program.展开更多
基金Supported by Advanced Manufacturing Technology-Key Laboratory of Beijing Municipality Project(No.10200531)Tianjin University-Kenna-metal Joint Project+1 种基金Young Teacher Foundation of Tianjin UniversityApparatus Foundation of Tianjin University.
文摘Plunge milling is a high-speed machining way and the cutter is fed in the direction of the Z axis, which is used to remove excess material rapidly in roughing operations. In this paper, the orthogonal cutting theory was used to study the plunge milling of LY12 alloy. A mathematic model for cutting force in plunge milling was established, and the milling process was simulated by using Matlab. It is found that the single tooth cutting experimental result is unstable because of unsymmetrical single tooth in the milling process, which leads to the difference between the simulation and experimental results. The trend of multiple teeth cutting experimental result is similar to that of the simulation result; however, the peak values in the experimental result are different, which is caused by the error of cutter’s position, and the error of peak value is less than 10%.
文摘Previous studies have shown that children learn from educational television; however, these studies have not explored how closely the educational content of the program is integrated to the narrative. The following study uses a systematic content analysis of 100 top-rated U.S. children＇s television programs to explore the tangential relationship （i.e., distance） of narrative and educational content through the lens of the capacity model--which is built upon three basic components： narrative content, educational content, and the distance between them. Programs were analyzed for distance by examining lesson clarity and integration, show type, target audience age, and station type. One-way ANOVAs indicates significant differences between the means of these variables. Programs targeting younger children presented educational content that was closely integrated into the plotline of the program and helped further the story. However, as the target audience aged, the educational content became more tangential to the narrative content and was less tied to the plotline of the program.
