【简答题】在图10.3.7所示TTL与非门构成的单稳态触发器中,若输入v 1 为宽度20μs的脉冲,试画出v O1 、v I2 、v O3 、v O 的波形,计算输出脉冲宽度。为使该电路能正常工作,对输入脉冲有何要求。
【简答题】有一个电炉,炉丝长50m,炉丝用镍铬丝,若炉丝电阻为5Ω,问这根炉丝的截面积是多大?(镍铬丝的电阻率取1.1×10 -6 Ω·m)
【单选题】35 The writer cites the Duomo in the last paragraph as an example to illustrate that
A.
there is a tight link between church and society.
B.
all churches are magnificent.
C.
old churches are very popular.
D.
high-rise churches are impressive.
【单选题】某管线输送含蜡原油,首站将所输原油进行80℃热处理,因为输送过程中管道中原油沿途温降,经过某中间站加热炉又将原油加热到50℃,结果将使原油()。
【单选题】According to Paragraph 2, you must be well informed of weather conditions when hiking there because______.
A.
the weather there is bad
B.
the canyon is too long
C.
the flood there is dangerous
【单选题】45 The writer cites the Duomo in the last paragraph as an example to illustrate that
A.
there is a tight link between church and society.
B.
all churches are magnificent.
C.
old churches are very popular.
D.
high—rise churches are impressive.
【简答题】在图10.3.7所示TTL与非门构成的单稳态触发器中,若输入vI为宽度20μs的脉冲,试画出vO1、vI2、vO3、vO的波形,计算输出脉冲宽度。为使该电路能正常工作,对输入脉冲有何要求。
【单选题】有“中华古代道教建筑的露天博物馆”之誉的是( )。
【单选题】有“中国古代道教建筑的露天博物馆”之誉的是()