更多"Either a low injection pressure or "的相关试题:
[单项选择]In conventional systems, the injection pressure（）, while it’s（）in common rail diesel engines.
A. fluctuates with the engine speed to some extent, independent of the engine speed
B. keeps constant at all engine speed, dependent on the engine speed to some extent
C. keeps constant at all engine speed, independent of the engine speed
D. is decided by the engine speed, constant at all engine speed
[单项选择]A fuel injection valve opening at pressure lower than normal will result in（）.
A. late fuel injection
B. early fuel injection
C. high exhaust temperature from that cylinder
D. decreased effective stroke from that injector
[单项选择]During the fuel injection period, fuel pressure must exceed cylinder gas pressure to （）.
A. ensure penetration and distribution of the fuel in the combustion chamber
B. ensure the needle valve is flushed clean during each injection
C. prevent combustion gas blowback into the open needle valve
D. prevent reflected pressure waves when the needle valve closes
[单项选择]The high pressure in fuel injection system of the diesel engine is produced by the （）.
A. injector pump
B. fuel injector
C. governor
D. turbocharger
[单项选择]External and internal leakage in hydraulic systems may be caused by （）.
A. unusual vibration
B. excessive worn parts
C. abnormal pressure
D. any of the above
[多项选择]设R（Pi）表示进程Pi执行时必须读变量的语句集合，W（Pi）表示Pi执行时必须写变量的语句集合。现在有P1和P2两个进程，若要这两个进程并发，必须满足（）
A. R（P1）与W（P2）的交集为空
B. W（P1）与W（P2）的交集为空
C. R（P1）与R（P2）的交集为空
D. W（P1）与R（P2）的交集为空
[单项选择]Increased internal leakage, in addition to poor hydraulic system response,and inadequate lubrication, is the result of （）.
A. pump bearings in poor condition
B. excessively worn actuator-piston packing
C. broken directional control valve centering springs
D. low hydraulic oil viscosity
[单项选择]Leakage of hydraulic fluid from around the shaft of a hydraulic motor may be caused by（）
A. permanent loss of pump suction
B. worn shaft seals
C. high level in the oil sump
D. low motor RPM
[单项选择]Air leakage between the shaft and stuffing box packing in a centrifugal pump is prevented by （）.
A. a compressed packing gland
B. lantern tings between the packing rings
C. a liquid seal
D. the stuffing box gland
[单项选择]Excessive air leakage into the suction side of a centrifugal pump would be indicated by which of the following operational problems?（）
A. The pump delivers full capacity when started, but gradually slackens off toan abnormally low flow
B. The pump packing gland overheats after short operating periods
C. The motor over-current protective device continually shuts the pump down
D. Pounding noises can be heard at the pump suction chest
[单项选择]Diesel engine blow-by is the leakage of combustion gases past the （）
A. oil rings only
B. compression and scraper rings
C. cylinder liner sealings
D. cylinder liner ring grooves
[判断题]使用语句Const pi来定义一个符号常量，pi可以在这条语句之后进行赋值。
[单项选择]已知pi=3.1415926，执行ROUND（pi，4）的结果为（）。
A. 3.1415
B. 3.1416
C. 3.14162
D. 3.000
[简答题]写出PI调节器的传递函数，并画出实现PI调节规律的电原理图
[简答题]PI-9508与PI-9508A有何区别，并说明互备阀的启动条件？
[单项选择]已知pi=3.1415926，执行？ROUND（pi，3）的结果为（）。
A. 3.141
B. 3.142
C. 3.140
D. 3.000
[简答题]PI-1102突然下降，而PI1102A上升FIC-1102显示量不足，分析原因，如何处理。
[填空题]一次润滑油压力50PI101是（）Mpa，二次润滑油压力50PI102是（）Mpa。
[简答题]离线LOW-E与在线LOW-E的优缺点？
