网友您好, 请在下方输入框内输入要搜索的题目:

题目内容 (请给出正确答案)
单选题
关于四冲程柴油机进、排气凸轮的布置说法正确的是()。
A

进排气凸轮在圆周方向不重叠

B

非增压柴油机重叠25°~50°

C

增压柴油机重叠40°~65°

D

非增压柴油机重叠40°~65°


参考答案

参考解析
解析: 四冲程非增压机的气阀重叠角为25~50,增压机的气阀重叠角为80~130根据四冲程机曲轴转速与凸轮轴转速为2:1的关系,可知非增压柴油机重叠12.5~25凸轮转角,增压柴油机重叠40~65凸轮转角
更多 “单选题关于四冲程柴油机进、排气凸轮的布置说法正确的是()。A 进排气凸轮在圆周方向不重叠B 非增压柴油机重叠25°~50°C 增压柴油机重叠40°~65°D 非增压柴油机重叠40°~65°” 相关考题
考题 单选题The operation of which aids to navigation may be suspended during war or national emergency().A Navigational satellitesB LoranC OmegaD Any of the above

考题 单选题航迹舵获取实时连续船位较理想的设备是:()A LORAN-CB DECCAC NNSSD GPS

考题 单选题当波浪由深水区传至浅水或近岸区域,其变化为()。A 波向不变B 波高减小C 波面变陡,卷倒和破碎D 波长增大

考题 单选题所谓相复励恒压调节系统是指()。A 仅根据负载电流的大小进行励磁调节的B 仅根据负载功率因数的变化进行励磁调节的C 既根据负载电流大小又根据负载功率因数的变化进行励磁调节的D 既根据负载电流又根据端口电压变化进行励磁调节的

考题 单选题某轮计划航向210°,罗经差+1°.5,无风流中航行,预计利用航线左前方正横距离为5nmile的物标转向,采用正横方位转向,如果用特殊角法来确定转向时机,则应在物标罗方位为()时记录第一次观测时间,物标罗方位为()时记录第二次观测时间。A 182°;163°.5B 180°.5;163°.5C 180°.5;165°D 182°;165°

考题 单选题救生艇发动机应设有()系统,或设有()独立的可再次充电的电源启动系统。A 手起动/一个B 手起动/两个C 自动起动/一个D 自动起动/两个

考题 单选题船长在到港前,应()。 Ⅰ.仔细阅读进港指南、航路指南、无线电航行警告及临时通告等航海资料; Ⅱ.详细了解并严格遵守所到港口的通讯联系制度、船位报告制度、分道通航制度、海上交通管理办法等规章制度; Ⅲ.详细了解引航锚地以及检疫锚地、等候锚地的情况; Ⅳ.详细了解港口工班的安排情况。A Ⅰ~ⅢB Ⅰ~ⅣC Ⅰ,Ⅲ,ⅣD Ⅱ~Ⅳ

考题 单选题下列液压控制阀中:Ⅰ.直控顺序阀、Ⅱ.外控顺序阀、Ⅲ.直动型溢流阀、Ⅳ.先导型溢流阀,可作卸荷阀用的是()。A Ⅰ、ⅢB Ⅱ、ⅣC Ⅰ、Ⅱ、ⅣD Ⅰ、Ⅱ、Ⅲ、Ⅳ

考题 单选题修理工程的验收和检验内容包括()。 ①施工中的检查; ②完工后的检查; ③完工后的试验。A ①②对B ②③对C ①③对D ①②③全对

考题 单选题半圆法110°NE换算成圆周法应为()A 110°B 290°C 250°D 070°

考题 单选题尾结构区域要承受的力有:() ①、水压力;②、车叶转动时的震动力;③、舵的水动力及车叶的自重A ①、②B ②、③C ①、③D ①、②、③

考题 单选题Which statement is TRUE concerning the tandem working arrangement of pedestal cranes when completing a quad lift? ()A The discharge is slow due to the size of the cargo and all the cranes working togetherB The cargo discharge can be accomplished with controlled pendulationC The cargo discharge can be performed in port or at anchorD The cranes enable the handling of heavy cargos without shoreside assistance

考题 单选题真北与陀螺北之间的夹角为()。A 磁差B 自差C 罗经差D 陀罗差

考题 单选题当压载舱长度超过35m时,应在(),以保证能在正常营运条件下注入或排出压载水。A 压载舱的前部设置吸口B 压载舱的后部设置吸口C 压载舱的中部设置吸口D 压载舱前后端各设置一个吸口

考题 单选题轴向柱塞泵配油盘在()处设有阻尼孔.A 两油窗口的两端B 两油窗口的油缸转入端C 某一油窗口(排油口)的两端D 两油窗口的油缸转出瑞

考题 单选题For a vessel with longitudinal inclination, an increase in GML cause().A list to stabilize at an angle of lollB trim to stabilize at an angle of lollC trim to increaseD trim to decrease

考题 单选题Your assigned emergency stations aboard your vessel can be found on the ships ().A muster listB certificate of inspectionC clearance papersD permit to proceed

考题 单选题Which of the fuel injection systems listed uses a spring loaded differential spray needle valve and individual pump for each cylinder?()A Common-rail injectionB Air injectionC Jerk pump injectionD Distribution injection

考题 单选题船舶最佳经济航速应(),因此它是()。A 单位运输成本最低航速;定值B 燃油消耗最低的航速;变值C 单位运输成本最低航速或最大盈利航速;变值D 燃油消耗最低切最大盈利航速;定值

考题 单选题Disastrous explosions have been caused by accumulations of oil or oil vapour in air lines not drainedAccording to the above sentence, which of the following statements is true?()A Oil vapour in air piping are dangerousB Explosion will cause oil vapouring in air linesC Oil vapour in air piping should be drainedD Oil in air piping should not be drained

考题 单选题High-speed rotating in a centrifugal purifier can produce a force () larger than the force of gravity.A many thousand timesB between timesC one timeD at times

考题 单选题利用准同步法对同步发电机的并车操作,下列说法错误的是()。A 为满足频差条件,并车时频差越小越好B 并车时为避免并机逆功率跳闸,要求整步表指针沿“快”的方向旋转C 按合闸按钮应有适当的提前相角D 并车时频差不能大于允许值,即频差周期不得小于2s

考题 单选题In addition to lubricating, cylinder oil assists in forming a gas seal and contains () which clean the cylinder liner.A additivesB waterC greaseD acid solution

考题 单选题检验曲轴臂距差的测量精度的方法是用测得的上下止点臂距值之和与左右臂距值之和的差值在()mm之内,定为测量基本准确。A ±0.04B ±0.03C ±0.02D ±0.01

考题 单选题The air distributor is conventionally driven by() and distributes into each cylinder by() certain sequence.A camshaft;fresh airB camshaft;starting airC electronic motor which is controlled by a computer;fresh airD electronic motor which is controlled by a computer;starting air

考题 单选题在船上吊缸检查活塞组件时,不必检测()。A 活塞环的弹力B 天地间隙C 搭口间隙D 活塞环的金相组织和硬度

考题 单选题协助前进中的船舶回转,当单拖船在大船的右舷尾部顶推时,对大船运动的影响是:().A 使大船向左前方斜航;产生的水动力矩与回转方向相反B 使大船向左前方斜航;产生的水动力矩与回转方向相同C 使大船向右前方斜航;产生的水动力矩与回转方向相同D 使大船向右前方斜航;产生的水动力矩与回转方向相反

考题 单选题A new ocean going ship of 2000 gross tons having an inoperative oily water separator may dispose of its bilge slops by ().A holding its slops onboard until they can be pumped into the city sewer systemB circulating them through the lube oil purifier to remove water and debrisC holding its slops onboard until they can be discharged to a shore side reception facilityD pumping them into a settling tank for separation before pumping the oily water residue overboard