根据气力输送的特点,降低动力消耗,节约能源是一个重要的研究课题,从经验中知,管道内径是关于能耗的重要参数。直观上看,当输送量一定时,管径过小,输送易阻滞,管径过大,虽输送畅通,但又造成能量的浪费。根据经验,把管径分成三组,各组的试验结果如下表所示,试用方差分析法比较各组的效果.
管径(mm) | 单位功耗 |
230 | 0.0308,0.0476,0.0504 |
250~260 | 0.0532,0.032,0.0218,0.028,0.028, 0.042,0.0336,0.042,0.042,0.028 |
280~320 | 0.07,0.07,0.0644,0.0312,0.0756,0.0756, 0.07,0.0588,0.0588,0.042,0.0308,0.0364, 0.0448,0.21,0.154,0.1064,0.1288,0.112, 0.1064,0.1288,0.0756,0.0644,0.0504,0.0644, 0.0504,0.0308 |
A.3.8bar,3.3bar
B.3.5bar,3.0bar
C.4.8bar,3.3bar
D.4.8bar,3.0bar
A.当项目编译成应用程序时,项目中所有的文件被组合成一个应用程序
B.如果应用程序中包含需要修改的文件,必须将该文件设置为包含
C.排除文件不是应用程序的一部分,它是应用程序的辅助文件
D.作为编译的通用准则,把表单和报表等程序文件设置为包含,把数据库和表等数据文件设置为排除