某耙吸挖泥船用5000m舱容挖抛施工，测得满舱时泥与海水载重为7500t，该地区疏浚土密度为1.85t/m3。（海水密度取1.025）
简述影响挖泥船时间利用率的客观影响因素。
参考答案：影响挖泥船时间利用率应考虑下列主要客观因素：1）强风及其风向情况，风的影响主要限于高速风引起的水面状况造成操作上的困难。2）当波高超过挖泥船安全作业的波高时，应停止施工作业。3）浓雾，当能见度低，看不清施工导标或对航行安全不利时，应停止施工。4）水流，特别是横流流速较大时，对挖泥船施工会造成影响。5）冰凌，当冰层达到一定厚度值时，挖泥船就不宜施工。6）潮汐，在高潮位时，挖泥船可能因其挖深不够需候潮。而当低潮位时有可能使疏浚设备搁浅也需候潮。7）施工干扰，如避让航行船舶等。
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| A new term has begun. Teachers are 1 about the fact that new students are not easy to handle. They like to bring cellphones and MP3 players to school. What is 2 , some students even use cellphones to do with out-of-class matters in class, or sometimes just for fun. Some other students listen to MP3 players when they are having a lesson that they are not interested in. Are these new students really that 3 ? "Yes," says Delaney Kirk, a professor at Drake University. 4 she adds it's not their fault. Instead, the things that they bring into school-cellphones, MP3 players and so on-and the teachers are to blame. Kirk first began thinking about students' manners six years ago. "I had my first class in which students were sleeping or talking to each other. It seemed that learning well 5 nothing to do with them," she says. "At first, I got worried about this, but then I said to myself, 'You're teaching 6 , and you need to manage this … These students need to know more about manners. It's time to help them develop some good 7 . They shouldn't waste time doing nothing when they are young. Sooner or later, they might regret the time they have wasted.'" Kirk also 8 a list of suggestions to help teachers better manage their classes. The following are among her suggestions: ● Tell students how they will benefit by taking the class. On the first day of class, emphasize its importance 9 giving some homework that students must turn in next time. ● Do not allow them to bring cellphones and MP3 players to the class at all. ● Decide 10 formal and informal the class will be. | ||||
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