【单选题】Combustion knock occurring in a diesel engine can be caused by _____.
A.
excessive fuel penetration
B.
prolonged injection lag
D.
prolonged ignition lag
【判断题】排气系统常由排气歧管、排气总管、催化反应器、排气消声器、排气尾管等组成。
【单选题】Combustion knock can occur in the cylinders of a diesel engine under any condition permitting _____.
A.
a shortened ignition delay period
B.
a lean fuel/air mixture
C.
excess fuel in the combustion chamber
D.
rapid vaporization of injected fuel droplets
【多选题】Which of the following is compulsory in the conclusion of an analytical research paper?
B.
Summary of the discussion.
C.
Suggestions for further research.
D.
Research findings and significance.
【简答题】网络体系结构为什么要采用分层次的结构?试举出一些与分层体系结构的思想相似的日常生活
【判断题】鱼种饲养一般分为一龄鱼种饲养和二龄鱼种饲养。
【判断题】瑞利散射:当微粒的直径比辐射波长小得多时,此时的散射称为瑞利散射。散射率与波长的四次方成反比,因此,瑞利散射的强度随着波长变短而迅速增大。无云的天空呈蓝色是因为蓝光波长短,散射强度大,因此蓝光向四面八方散射,使整个空中蔚蓝。日出日落时,太阳高度较低,在过长的传播中蓝光几乎被散射殆尽,绿光次之,最后剩了红光和少量的绿光,构成橘红色。