Based on a simulation model of a semiconductor manufacturer, operator-machine ratio （OMR） analysis is made using work study and time study. Through sensitivity analysis, it is found that labor utilization decreases ...Based on a simulation model of a semiconductor manufacturer, operator-machine ratio （OMR） analysis is made using work study and time study. Through sensitivity analysis, it is found that labor utilization decreases with the increase of lot size. Meanwhile, it is able to identify that the OMR for this company should be improved from 1 ： 3 to 1 ： 5. An application result shows that the proposed model can effectively improve the OMR by 33%.展开更多
In order to clarify the reason why the creep rupture time of pre-strained Ni-23Cr-7W Alloy (HR6W) is longer than that of the non-pre-strained HR6W, microstructures of HR6W after a series of creep tests were investigat...In order to clarify the reason why the creep rupture time of pre-strained Ni-23Cr-7W Alloy (HR6W) is longer than that of the non-pre-strained HR6W, microstructures of HR6W after a series of creep tests were investigated. The creep tests were conducted at 750°C, 90 and 100 MPa. In the pre-strained samples, the grain boundary shielding ratio by precipitates was larger than that of the non-pre-strained sample. In addition, in the pre-strained samples the size of the M23C6 carbide in the grains was finer than in the non-pre-strained sample. The W content in the M23C6 carbide in the pre-strained samples tended to be larger than in the non-pre-strained sample. Therefore, the Ostwald ripening of the carbide was delayed and the size of M23C6 carbide was thought to be fine for a long time. These observations show that creep strength in the pre-strained samples is higher than that of the non-pre-strained sample because of both precipitation strengthening inside of the grains and grain boundaries.展开更多
文摘Based on a simulation model of a semiconductor manufacturer, operator-machine ratio （OMR） analysis is made using work study and time study. Through sensitivity analysis, it is found that labor utilization decreases with the increase of lot size. Meanwhile, it is able to identify that the OMR for this company should be improved from 1 ： 3 to 1 ： 5. An application result shows that the proposed model can effectively improve the OMR by 33%.
文摘探讨4种不同运动时间和间歇模式的大强度间歇运动(HIIT)诱发愉悦情绪和享受感的效果差异。方法:将75名大学生随机分配至运动30 s间歇30 s组、运动1 min间歇1 min组、运动30 s间歇1min组和运动1 min间歇2 min组,分别于运动前、运动后即刻和20 min测量其享受感,并对运动中的疲劳感、愉悦情绪和享受感进行测试。结果:1)运动30 s间歇1 min HIIT相比运动1 min间歇2 min,运动30 s间歇30 s HIIT相比运动1 min间歇1 min HIIT均可诱发更积极的愉悦情绪。运动30 s间歇1 min HIIT诱发的愉悦情绪最高,运动1 min间歇1 min HIIT诱发的愉悦情绪最低。2)1:1间歇模式HIIT诱发的享受感水平低于1:2间歇模式,并且与运动30 s间歇30 s、运动1 min间歇1 min HIIT相比,运动1min间歇2 min HIIT诱发的享受感水平更高。3)运动30 s间歇1 min HIIT诱发的享受感水平显著高于运动1 min间歇1 min,相同间歇模式HIIT诱发的享受感水平没有显著差异。结论:1)运动时间和间歇时间等量时,运动时间越长,愉悦情绪越低,运动时间小于间歇时间的HIIT诱发的愉悦情绪更高。2)间歇期长的HIIT诱发的享受感水平更高,相同间歇模式的运动时间长短不影响运动后产生的享受感。3)短时间多组数HIIT是诱发愉悦情绪的最佳方案,长时间的间歇期HIIT是诱发享受感的最佳方案。
文摘In order to clarify the reason why the creep rupture time of pre-strained Ni-23Cr-7W Alloy (HR6W) is longer than that of the non-pre-strained HR6W, microstructures of HR6W after a series of creep tests were investigated. The creep tests were conducted at 750°C, 90 and 100 MPa. In the pre-strained samples, the grain boundary shielding ratio by precipitates was larger than that of the non-pre-strained sample. In addition, in the pre-strained samples the size of the M23C6 carbide in the grains was finer than in the non-pre-strained sample. The W content in the M23C6 carbide in the pre-strained samples tended to be larger than in the non-pre-strained sample. Therefore, the Ostwald ripening of the carbide was delayed and the size of M23C6 carbide was thought to be fine for a long time. These observations show that creep strength in the pre-strained samples is higher than that of the non-pre-strained sample because of both precipitation strengthening inside of the grains and grain boundaries.
