问题 问答题 简答题

集气管线的通过能力受哪些因素影响?它与管线的直径,长度和管内的压强有何关系?

答案

参考答案:

集气管线的通过能力受管线直径,管段长度,气体的平均温度和相对密度,起点和终点的压强等因素的影响.当其它条件确定后,通过能力与管径的8/3次方成正比,若管径增大一倍,则管线的通过能力可提高为原来通过能力的6.3倍.在其它条件不变时,通过能力与管段长度的平方根成反比,如果通过增设加压站使气体的压送距离缩减为原有距离的一半,管线的通过能力可以提高41.4%。升高起点的压强或降低终点的压强,都能够提高集输管线的通过能力,但对于同一个压强变化值来说,提高起点压强能够使通过能力得到更多的增加。

完形填空

第三节:完型填空(共20小题;每小题1.5分,满分30)

阅读下面短文,从短文后各题所给的四个选项(A、B、C、和D)中,选出可以填人空白处的最佳选项,并在答题卡上将该项涂黑。

Eleven-year-old Angela was attacked by a rare    36   involving her nerve system.She was unable to walk and her movement was   37   in other ways as well.The doctors did not hold much   38   of her ever recovering from this illness.They   39   she'd spend the rest of her life in a wheelchair.They said that few, if any, were able to come back to    40   after suffering from this disease.The little girl was   41  .There, lying in her hospital bed, she would swear that she was   42   going to be walking again someday.

She was moved to a specialized   43   hospital in the San Francisco Bay area.Whatever   44   could be applied to her case were used.The doctors were attracted by her undefeatable spirit.They taught her about imaging about seeing herself walking.If it would do   45   else, it would at least give her hope and something   46   to do in the long waking hours in her bed. Angela would work as hard as possible in physical treatment, and in exercise sessions.But she worked just as hard lying there faithfully doing her   37   , visualizing herself moving, moving, moving !

One day,   48   she was attempting, with all her might, to imagine her legs moving again, it seemed as though something   49   happened: the bed moved! It began to move around the room! She   50   out, "Look what I'm doing! Look'.Look! I can do it'.I moved! I moved!"

Of course, at this very moment everyone else in the hospital was screaming, too, and running for   51   People were screaming, equipment was   52   and glass was breaking.You see, it was the recent San Francisco earthquake.   53   don't tell that to Angela.She's   54   that she did it.

And now only a few years later, she's back in school, on her own   55  .No crutches, no wheelchair.You see, anyone who can shake the earth between San Francisco and Oakland can defeat a little disease, can't they?

36.A.problem   B.disease         C.accident    D.error

37.A.reduced    B.avoided       C.restricted  D.forced

38.A.thought    B.idea          C.opinion     D.hope

39.A.predicted  B.prepared      C.admitted   D.decided

40.A.active       B.normal        C.alive     D.confident

41.A.fearless     B.peaceful       C.patient      D.stainless

42.A.probably   B.approximately  C.sincerely   D.certainly

43.A.recovery   B.experiment       C.practice    D.exercise

44.A.schedules  B.instructions      C.supports    D.treatments

45.A.something B.anything      C.nothing     D.everything

46.A.admirable B.interesting     C.optimistic D.appropriate

47.A.training    B.imaging       C.expectation      D.performance

48.A.however   B.after         C.just      D.as

49.A.useful       B.regretful      C.surprising D.disgusting

50.A.screamed  B.laughed       C.spoke       D.sang

51.A.ground     B.cover         C.ceiling      D.bed

52.A.accelerating     B.running    C.appearing  D.falling

53.A.For      B.So            C.But      D.Or

54.A.convinced B.supposed      C.realized    D.accepted

55.A.parts     B.legs          C.body     D.role

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