分析室基本知识与操作搜题软件推荐一个-j9九游

时间:2024-06-24 06:52:45


下列四种地质现象中,主要属于岩溶作用的是(  )‍

地震震级一共分为( )级

遇到盐酸会强烈起泡的岩石是( )

地球以地表为界分为外圈和内圈,以下各项不属于外圈的是( )

地下水位的降低可使降水周围的地面( )

随着距地表深度的不断加大,风化作用的程度( )    

以下哪些属于工程地质条件?

以下哪些说法是正确的?

下列属于内力地质作用的是( )。  

根据岩土的水理特性,砂土层与黏土层相比,其透水性弱。

未经构造变动影响的沉积岩,其原始产状应当是水平的。

一次地震震级只有一个。

一次地震烈度也只有一个。

降雨是滑坡发生的重要诱发因素。

比萨斜塔是由于地震作用造成的。

建筑物类型属于工程地质条件。

形成岩溶的必要条件是要存在可溶性的岩石。

现代自动控制的应用有

闭环控制系统应该具有下列什么特点

开环控制系统是指( )对系统没有控制作用

控制理论是研究系统的( )问题。

控制工程主要研究并解决的问题之一是( )

开环系统与闭环系统最本质的区别是( )

控制论的中心思想是

在闭环控制系统中,基本工作原理是

线性系统与非线性系统的根本区别在于( )。

1. 某系统的微分方程为 ,它是什么系统?

图示系统,k为弹簧刚度,b为阻尼系数,m为质量,外力x(t)为输入,质量块m的位移y(t)为输出,则系统的微分方程为( )。

图示质量弹簧阻尼系统,以外力f(t)为输入量,位移y(t)为输出量的运动微分方程可以对该系统进行描述,那么该系统的阶次为( )

图示机械系统,x(t)为输入位移,y(t)为输出位移,k为弹簧刚度,b为阻尼系数,系统的微分方程为( )

图示机械系统,x(t)为输入位移,y(t)为输出位移,k为弹簧刚度,b为阻尼系数,m为物体质量,则系统的微分方程为( )

图示机械系统,x(t)为输入位移,y(t)为输出位移,k1、k2为弹簧刚度,b为阻尼系数,则系统的微分方程为( )

图示机械系统,f(t)为输入力,x(t)为输出位移,k1、k2为弹簧刚度,m为物体质量,则系统的微分方程为( )

若,则( )

已知则其拉氏反变换f(t)为( )

已知,则其原函数为 ( )

已知 ,则其拉氏反变换 为( )

已知 ,则其原函数的终值为( )

已知 ,则 可能是以下( )

已知 ,则其原函数 为( )

的拉氏变换为( )

图示函数的拉氏变换为( )

已知 ,则其原函数 为( )

线性定常系统的传递函数,是在零初始条件下

传递函数反映了系统的动态性能,它与下列哪项因素有关

关于传递函数,错误的说法是

试求下图传递函数,xi为输入,xo为输出

如图所示为机械悬挂系统,系统输入为m1上作用力f(t)输出为y(t)的位移,其它各参数见图(不计重力)。试建立系统的传递函数。

试求下图传递函数,ui为输入,uo为输出,i1为电阻r1上电流,i为总电流。

如图所示机械系统,系统输入为力f(t),输出为位移y(t),试建立系统的传递函数。

如图所示的机械振动系统,输入为位移x(t),输出为位移y(t),求该系统的传递函数。

某负反馈系统的前向通道传递函数为10/(5s 1),反馈通道传递函数为2s,则系统闭环传递函数为。

某单位负反馈系统的开环传递函数为2/(s 3),在单位脉冲信号的输入下,其输出函数为

下列传递函数由哪些基本环节组成?

下列传递函数的零点和放大系数(开环增益)是多少?

方框图化简

方框图化简

方框图化简

在由惯性环节组成的控制系统中,其惯性大小取决于。

一阶系统的时间常数t越大,系统。

一阶系统的传递函数为15/(4s 5),则系统的增益k和时间常数t依次为

一阶系统的传递函数为k/(ts 1),则该系统时间响应速度

对一阶系统,提高其快速性的办法是

一阶系统在0.5倍阶跃输入下的响应如图所示,则其时间常数和增益最可能为

一阶系统传递函数为2/(s 0.25),其时间常数为

二阶系统的传递函数为1/(4s^2 4s 1),则其无阻尼自然振荡频率和阻尼比为

二阶系统的标准传递函数为

在阶跃函数输入作用下,阻尼比( )的二阶系统,其响应具有减幅振荡特性。

二阶系统的传递函数为2/(ks^2 2s 1),当k增大时,其

二阶系统单位阶跃响应中,当阻尼比为0时,其振荡特性为

二阶系统振荡的主要原因是

二阶系统的单位阶跃响应如图所示,那么阻尼比可能为

某系统的单位阶跃响应如下,哪个是临界阻尼状态

单位负反馈系统开环传递函数为1/[s(4s 1)],则其系统的单位阶跃响应

某二阶系统的特征根为两个互不相等的实数,则该系统的单位阶跃响应曲线为

某二阶系统的特征根为两个纯虚数,则该系统的单位阶跃响应曲线为

哪种二阶系统阶跃响应不过冲?

二阶系统的传递函数为g(s)=3/(4s^2 s 100),其无阻尼自然振荡频率是

有两个标准二阶振荡系统,其超调量相等,则这两个系统一定具有相同的

对二阶欠阻尼系统,在不改变超调量的前提下,为缩短系统的调整时间,可

某二阶系统单位阶跃响应如图所示,超调量和上升时间为

对于二阶欠阻尼系统,增大阻尼比,则系统超调量

瞬态响应的性能指标是根据哪一种输入信号作用下的瞬态响应定义的

对二阶系统进行比例控制。增加比例控制系数,阻尼比会

对二阶系统进行比例控制。增加比例控制系数,其超调量会

对二阶系统进行比例控制。增加比例控制系数,其响应速度会

对二阶系统进行比例控制。增加比例控制系数,其稳态时的准确性会

对二阶系统进行pd控制。增加微分控制系数,其阻尼比会

对二阶系统进行pd控制。增加微分控制系数,其超调量会

对二阶系统进行pd控制。增加微分控制系数,其响应速度会

对二阶系统进行pd控制。增加微分控制系数,其稳态精度会

实施pd控制时,调整比例和微分控制系数时

实施pd控制,基本目的是

下面有关系统稳定性说确的是

特征方程s^4 2s^3 s^2 2s 1=0,用routh判据判断系统是否稳定?

特征方程s^3 20s^2 9s 100=0,用routh判据判断系统是否稳定?

单位负反馈系统开环传递函数为g(s)=k(s 1)(s 2)/[s^2*(s 3)(s 4)(s 5)]。求使系统稳定的k取值范围。

求使系统稳定的k值范围:某单位负反馈系统的开环传递函数为k/[s(0.1s 1)(0.25s 1)]

稳定性是线性系统的自身特征,与输入无关。

扰动撤除后还能回到平衡点,系统有可能不稳定。

线性系统稳定的充分必要条件是闭环传递函数的特征根具有() 备选答案:正实部、负实部、正虚部、负虚部、正数、负数‍

下面因素中,与系统稳态误差无关的是( )。

系统对斜坡信号输入的稳态误差为无穷大,则该系统是( )。

有关系统类型哪种说法是正确的?‍

当对象传递函数为20/s时,组成系统的环节为

单位负反馈系统的开环传递函数为2/[s(s 2)],试求在单位阶跃输入对应的稳态误差

单位负反馈系统的开环传递函数为10/[s(s 1)],试求在输入信号x(t)=5 t作用下的稳态误差

单位反馈控制系统的开环传递函数为g(s)=4/[s(s 5)],则系统在r(t)=2t输入作用下,其稳态误差为

一闭环系统的开环传递函数为8(s 3)/[s(2s 3)(s 2)],则该系统为( )

已知某系统开环传递函数为g(s)=90/[(s 2)(s 15)],则开环增益、转角频率为

绘制系统bode图,系统的传递函数为g(s)=10(0.1s 1)/[s(2s 1)]

已知系统的开环传递函数为g(s)h(s) = k(τs 1)/[(t1s 1)(t2s 1)(t2s2 2ζts 1)],则它的对数幅频特性渐近线在ω趋于无穷大处的斜率为( )db/十倍频程。

某系统的开环传递函数为2(2s 3)/[s(5s 2)],则此系统的开环增益为( )

已知最小相位系统的开环对数幅频特性曲线的渐近线如下图所示,试确定其开环增益k()

求开环增益k。ωc是穿越频率,对应幅频0db。 ‍

上图是某系统的bode图,下图是某系统从0秒开始输入正弦波对应的输出正弦波。试估计两幅图是否描述了同一个系统?

上图是某系统的bode图,下图是某系统从0秒开始输入正弦波对应的输出正弦波。试估计两幅图是否描述了同一个系统?

单位负反馈系统的开环传递函数为,现有下面四种串联校正装置,均为最小相位系统,若要使系统的稳态误差不变,而减小超调量,加快系统的动态响应速度,应选取哪种校正装置。

单位负反馈系统的开环传递函数为,现有下面四种串联校正装置,均为最小相位系统,若要减小系统的稳态误差,并保持系统的超调量和动态响应速度不变,应选取哪种校正装置。‍

系统校正的实质就是通过加入校正装置的零、极点,来改变整个系统的零、极点分布,从而改变系统的频率特性,以满足性能指标要求。

系统校正中常用的性能指标包括:调整时间、上升时间、超调量、相角裕度、幅值裕度、剪切频率、稳态误差等。

图示为最小相位系统的开环对数幅频特性曲线,采用串联校正后,曲线从浅红色变为深红色,那么该串联校正为相位超前校正。

图示为最小相位系统的开环对数幅频特性曲线,采用串联校正后,曲线从浅红色变为深红色,那么该串联校正为相位滞后校正。

pid调节器中比例环节p的作用是使被控量朝着减小偏差的方向变化。

pid调节器中积分环节 i 的作用是为了消除系统的稳态误差,但会减小系统的抗高频干扰能力。

pid调节器中微分环节 d 的作用是能够预测误差的变化趋势,可在误差信号出现之前就起到修正误差的作用。

已知系统的频率特性为g(jω)=k(1 j0.5ω)/[(1 j0.3ω)(1 j0.8ω)],其相频特性∠g(jω)为

某环节的传递函数为2(2s 1)/[s(5s 1)],则此系统的相频特性〔 〕

已知系统传递函数为1/(5s 1),当输入为x(t)=sin2t时,系统稳态输出为

|g(jω)|为系统幅频特性,描述了系统对( )输入的稳态响应( )衰减或放大的特性

一系统的传递函数为k/[s(ts 1)],则其相位角可表达为( )

一系统的传递函数为2/(s 2) ,当输入2sin2t时,则其稳态输出的幅值为( )

设单位负反馈系统的开环传递函数为10/(s 1),当系统分别输入以下信号时,求对应的稳态输出y

已知系统的开环传递函数为10/[s(4s 1)],则在ω→∞时,它的频率特性的相位角为〔 〕

结构是指()

结构力学的研究对象为()

结构力学中的杆件是指( )

从几何角度来看,结构可分为哪几类?

在荷载的分类中,如果按照荷载作用时间久暂划分可以分为

荷载根据其对结构产生的动力效应划分,可分为()

结构的计算简图是指()

选择计算简图的原则是( )

下列所示节点简化情况,其中正确的有()

上部结构与支座间的连接形式,包括( )

杆件结构根据其计算简图,按受力特性划分可分为()

杆件结构按计算方法来划分,可分为()

连接4个刚片的铰结点,与之相当的约束个数为

下列所述体系中,不能够作为工程结构来使用的有()

链杆可以当作刚片,刚片也一定可以看作链杆

有多余约束的体系一定是几何不变体系。

几何瞬变体系产生的运动非常微小且很快就能转变成几何不变体系,因而可以当做工程结构来使用。

任意两根链杆的约束作用都相当于其交点处的一个虚铰,如图中链杆1和链杆2的交点o可视为虚铰。

下图所示体系的计算自由度为( )

下图所示体系的计算自由度为( )

下图所示体系的计算自由度为( )

下列关于计算自由度(w)的说确的是()。假设体系与基础相连。

如果体系的计算自由度大于零,那么体系一定是几何可变体系。

计算自由度小于等于零是体系几何不变的充要条件

两个刚片由三根链杆连接,形成的体系是()

某一平面杆件体系有多余约束,它可能是()

下图所示体系中多余约束数目为

将三刚片连接形成几何不变体系,至少需要的约束数目是()个。

下列所示装置中,其中可看作二元体的有()

有些体系为几何可变体系,但却有多余约束存在。

在两刚片或三刚片组成几何不变体系的规则中,不仅指明了必要约束数目,而且指明了这些约束必须布置得当。

在图(a)所示体系中,去掉二元体edf后得到图(b),故原体系是几何可变体系。

图示体系按三刚片规则分析,因铰a、b、c共线,故为几何瞬变体系。

在图示体系中,去掉其中任意两根支座链杆后,所余下部分都是几何不变的。

通过几何组成分析,下图所示体系为( )

通过几何组成分析,下图所示体系为( )

通过几何组成分析,下图所示体系为( )

通过几何组成分析,下图所示体系为( )

通过几何组成分析,下图所示体系为( )

欲使下图所示体系成为无多余约束的几何不变体系,则需在d端加上()

下图所示体系中,多余约束数目为()个

关于静定结构与超静定结构的静力特点,下述说确的是

关于静定结构与超静定结构的几何组成特点,下述说确的是

几何可变体系在任何荷载作用下都不能平衡。

瞬变体系中一定存在多余约束。

在任意荷载下,仅用静力平衡方程即可确定全部支座反力和内力的体系是几何不变体系。

图示体系根据三刚片规则分析结果为静定结构。

下图为某梁段的剪力图,则其弯矩图可能是

在下图所示简支梁中,



在任意结构中,只要直杆段两端弯矩和该杆段所受外力已知,则该杆段的内力分布就可以完全确定。

图示分别为一杆段的m图和fs图,若m图正确,则fs图一定错误。

图示梁中,杆端弯矩mba=2fa(上侧受拉)

下图所示结构中,ma和mc(设下侧受拉为正)分别为

下图所示结构中,mk(设下侧受拉为正)为

下图所示梁中,截面c的弯矩(单位:kn·m)为

下图所示斜梁及相应水平梁,在水平方向的跨度均为l,则两结构中对应截面k的内力关系为

静定结构在荷载作用下均会产生内力,内力与杆件截面尺寸及材料均无关。

下图所示梁中,截面c的弯矩为

下图所示结构中,集中力分别作用在铰的左侧和右侧,则它们的

当外荷载作用在结构的基本部分时,附属部分不受力;当外荷载作用在某一附属部分时,整个结构必定都受力。

图示结构中支座b处的支座反力等于f/2。

图示结构中集中力偶分别作用在铰的左侧和右侧,它们的弯矩图相同。

在图示梁中,不论a和b为何值,均有ma=mb。

下图所示刚架结构中,fc杆端剪力fsfc为

下图所示结构中,



下图所示刚架结构中,截面a的剪力fsa=

下图所示结构的弯矩图形状正确的是

下图所示结构的弯矩图形状正确的是

在图示结构中,杆端弯矩|mac|=|mbd|。

如下图所示两个结构及其承受荷载情况,则两者比较,下述表述不正确的是

下图所示结构中,下述说确的是

静定结构的内力计算中,下述说法错误的是

图示梁的弯矩图是正确的。

图示结构中仅ab段有内力。

已知飞机的磁航向是90度,相对方位是225度,则全向信标方位是( )

当飞机航向改变时( )

vor方位角( )

全向信标的调制信号频率是( a )。

在vor接收机中,定位的基本原理是测量二低频信号的( )

航空器通过比较两个30hz信号的( )来得到飞机相对dvor台的方位。

30hz am信号 和 30hz fm信号在( )方向上同相。

当飞机在dvor台正西方向时,30hzfm信号和30hzam信号的相位关系是( )

、dvor采用空间调制,要注意检查和调整载频、上边带和下边带三个信号之间的(a )。

一个dvor台的识别码一般由( )个字母组成。

dvor射频的频率范围及波道间隔分别为( )。

vor的作用是测量( )。

vor方位角( )。

当飞机航向改变时( )。

、dvor采用空间调制,要注意检查和调整载频、上边带和下边带三个信号之间的( )。

dvor的30hzfm信号是通过边带天线发射出去的。( )

多普勒效应是dvor最基础的工作原理。( )

dvor可以选用108.00-117.95mhz中的一个作为载波频率。( )

dvor发射的30hz am信号有各向同性的特点,在不同位置收到的30hz am信号其幅度、相位相同。( )

dvor对30hz am信号和30hz fm信号比相得到飞机方位的前提是两个30hz信号在磁北方向上同相。( )

导航台是指利用( )的传播特性,为航空器提供测定导航参量(方位、距离和速度),确定航空器的位置,并引导航空器按预定航路(线)飞行的地面台站。

下列导航设备中,不能组成定位系统的是( )。

全向信标的英文缩写是( )。

和ndb配套的机载设备是( )。

ndb设备中的“n”是指( )。

ndb的“无方向性”是指( )

ndb设备与机载接收机配合可给出( )

安装在机场跑道中心延长线上的ndb设备发射的信号使飞机罗盘指示( )

、ndb导航台发射的电磁波是中长波,此电波是依靠( )传播

对ndb描述中,( )不正确

在地波传播特性的描述中,( )是不正确的

ndb天线水平方向图的形状是( )

关于ndb台识别码,正确的是( )

无测角器固定环形天线式定向机( )

振幅式m型adf定向的工作原理是:( )

地面ndb台可根据其设备位置的不同分为( )和( )两大类;

通过接收地面各地的民用中波无线电广播电台或( )(无方向信标)的信号来实现对飞机的导航;

adf接收机计算并显)出飞机到地面台的( ),即( );

地面导航台ndb是一个中波导航发射机,向空间( )发射无线电信号,频率为190~550khz;

adf主要功能 测量飞机纵轴方向( )到地面导航台或( )的相对方位角;

自动定向系统的组成 ( ) 和( )

机载自动定向机adf系统一般包括有:( ) ( )、 方位指示器、 环形天线和垂直天线 

自动定向机工作时需要两种天线: 无方向性的垂直天线或辩向天线,其接受信号用来调谐接收机,并与环形天线接收的信号叠加,为定向机提供( );  有方向性的环形天线,用来提供( );

ndb的英文是 ( )。

长波、中波的传播是以( )传播方式为主?

短波传播可以以天波方式传播,还可以以( )传播方式为主

天波传输的特点是( )

地波传输的特点是( )

icao规定,无线电导航定位方法定位级别最高的是( )

现代航空中,最基本、核心的导航手段是( )

飞机纵轴前方的延长线叫航向线。

飞机所在位置的经线北端逆时针测量至航向线的夹角叫做航向(hdg-heading)

惯性导航是一种自主式导航方式,也叫它备式。

飞机飞行的速度是指飞机的空速。

区域导航可以使航空器在台基导航设备信号的覆盖范围内沿任意希望的路径飞行。

ils包括( )。

一套ils系统可以给飞机提供( )。

仪表着陆系统的作用是向飞机提供( )。

ils是比较90和150hz这两个调制音频信号( )来给出飞机偏离航道或下滑道的信息。

在ils状态进近时,航向指针偏左两个点,说明( )。

飞行器按航向台信号在航道左方进近时,接收到音频的关系是( )。

理想航向道组成( )于跑道面的平面。

在ils状态进近时,下滑指针在零位以下,说明( )。

在ils状态进近时,下滑指针偏差上或下两个点,说明( )。

ils系统设备ⅰ类运行时,决断高度为( )。

内指点标仅在( )类着陆标准的机场安装。

中指点标距离跑道入口( )米。

航向设备和dvor设备频段( )。

国际民航组织规定,ils下滑角一般应该是( )。

loc和( )共用一个频段。

ils的loc和gs频率( )。

ils的下滑指示如显示150hz占优,则说明着陆飞机( )。

ils的航向指示如显示90hz占优,则说明着陆飞机( )。

ils的两个调制频率为( )。

仪表着陆系统的识别信号的工作频率是( )hz。

当校飞飞机经过中指点上空时,指示灯的颜色是白色。( )

ⅰ类ils设备性能高于ⅱ类设备,ⅲ类设备性能是最低的。( )

仪表着陆系统称为盲降,有盲降飞机就可以自动着陆。( )

i类下滑道可以直接引导飞机到跑道上。( )

loc天线是一个具有50ω特性阻抗的水平极化天线,安装在气象雷达天线下。

恒差频fmcw高度表工作于搜索方式时,所谓搜索是指搜索( )

"恒差频高度表在跟踪方式时,由( )调制锯齿波的周期:"

恒差频fmcw高度表是通过测量( )实现测高的。

恒差频fmcw高度表工作于搜索方式时发射信号的调制周期从小到大周期性变化,相当于()。

无线电高度表在( )上的高度显示

无线电高度表,又称雷达高度表是一种等幅调频测距无线电导航设备。利用普通雷达的工作原理,以地面为发射体,在飞机上发射电波,并接收地面的反射波以测定飞机到地面的高度.( )

没有pfd的飞机,其无线电高度在专用的无线电高度指示器或adi、eadi上显示。 ()

由于aid的存在,使高度表的输出及指示产生误差,即飞机接地时指示不为零; ()

决断高度警戒可以自动结束或人工复位( )

无线电高度表可以测量大于2500英尺的高度。( )

dme系统的地面设备是( )。

dme系统的机载设备是( )。

dme测距的基本原理是测量询问脉冲与应答脉冲的( )。

下列导航设备中,不能组成定位系统的是( )。

dme在给飞机提供距离信息时,一般是( )。

测距机的测量原理是测量( )。

一架飞行在1万米高空,距离地面dme台水平距离为25nm的飞机,其机上dme距离显示器显示的距离( )。

飞机接收dme的信号完成定位,并且要消除定位的双值性,则飞机至少应同时接收( )dme台的信号。

dme机载询问机的四个工作阶段是( )。

在测距机中,当应答机转发询问的应答小于某一规定数值时,为了维持空间最小应答率,发射( )。

dme设备产生随机填充脉冲的主要作用是( )。

dme设备产生随机填充脉冲的数量由( )决定。

dme发射脉冲的优先顺序按从高到底排列为( )。

dme地面应答频率范围为( )。

dme每两个相邻波道的询问频率相差( )mhz。

dme每个波道的应答和询问频率相差( )mhz。

x波道dme的应答脉冲间隔是( )。

y波道dme的应答脉冲间隔是( )。

dme is the abbreviation of distance measuring equipment。 ( )

dme产生一定的填充脉冲是为了飞机能够从自动等待状态转为跟踪状态。( )

dme发射应答脉冲优先级最高。( )

dme寂静时间是询问译码结束后对外部询问不予处理的时间。

测距器dme测距信标台的我接收机收到这一询问信号后,经50延迟,由其发射机产生相应的“应答”信号发射

测距器dme在252个测距波段中,所采用的脉冲对的时间间隔有两种,分别称为( )和( )

气象雷达测定目标相对于飞机的距离的基本原理是( )。

现代机载彩色wxr所显示的目标图像的亮度( )。

雷达天线上的方位(扫掠)开关( )

现代机载气象雷达工作于气象(wx)方式用于检测( )。

彩色气象雷达以不同颜色显示回波,其颜色代表的含义是( )

气象雷达起飞前建议的天线角度为: ( )

气象雷达面板上的方式选择,地图方式中nd显示的黑色表示: ( )

飞行中,在nd上没有雷达回波出现,飞行员也没有得到故障提示,但又有明显的天气现象,可能的原因是: ( )

气象雷达选择接通时,要确认飞机中线两侧各35度内及天线运动距离多少米内无人及大型金属? ( )

气象雷达面板上的增益旋钮,如何使用? ( )

气象雷达面板上的方式选择,使用wx t方式时,nd的有效距离是: ( )

气象雷达面板上的方式选择,在wx t方式下,洋红色表示: ( )

气象雷达面板上的方式选择,在wx(气象方式),不同颜色代表云层中所含水份密度的不同,以下颜色中密度最高的是: ( )

气象雷达面板上的风切变(pws)电门在自动位时,生效预测性风切变功能,以下说法哪种正确? ( )

预先风切变探测系统(pws),扫描飞机前方多少海里以内的空间以探测风切变? ( )

典型的气象雷达系统由( )、雷达天线组件、显示器、波导系统和( )组成

当气象雷达具有pws功能时,它需要( )提供的大气数据,( )在起飞和进近过程中提供高度信号来启动或禁止pws功能,自动油门电门组件在起飞过程中启动pws,起落架电门在进近过程中发送起落架放下离散信号启动pws。

风切变的位置根据相对于飞机纵轴的方位和机头的距离而确定,根据风切变的位置不同,风切变警告可以分为三类:( )、警戒和( )。

新型气象雷达接收机为了优化接收性能,对于不同的探测距离和工作方式,通过改变脉冲组的( )和( )以及脉冲的重复频率来实现,短距离时,每组发射包括4个脉冲,脉冲重复频率prf为1280hz,对于中等距离的探测,每组发射包括2个脉冲,prf为360hz,对于远距离的探测,脉冲宽度相同,但prf为240hz。

气象雷达工作在风切变方式时,收发机发射一组由( )个脉冲组成的射频信号,其prf为3000hz。

s模式应答机的“s”的含义是指该应答机( )。

atc应答机所应答的飞机高度信息,是由( )提供的。

atc以哪种模式发射飞机的识别码? ()

目前我国民航常用的空管雷达是( )。

相对于单独使用二次雷达,使用一次、二次雷达合装的优点是( )。

二次监视雷达与一次监视雷达相比的主要优点是( )。

二次雷达的主要缺点是( )

二次监视雷达系统的机载设备应由( )等组成。

二次雷达存在不容易克服的异步干扰,异步干扰是由( )引起的。

应答机是通过识别p1-p2脉冲的( )来判断是否是旁瓣询问的。

可以选择需要发射的四位atc编码的范围是:( )

atc编码7700-7777的范围用于:( )

atc控制盒上的识别按钮按下时,则:( )

atc编码为7600,则表示:( )

每部应答机都有它唯一的多少位字地址编码?( )

由于atc(两个应答机)、tcas、( )(两个询问器)系统都工作在 同一波段(l波段),为了防止相互干扰,同时也为了保护接收机电路,在任一系统发射时,会同时输出一个抑制脉冲,抑制其他系统的工作。

机载atc应答机有三种应答模式,即:a模式、c模式和( )。

在世界范围内所有的应答机接收地面信号所使用的频率都是1030mhz, 而应答所使用的频率都是( )。

模式a用于( );模式c用于高度询问;模式s用于寻址。

atc的高度信号来自于( )

平面构成作业

色彩构成

which of the following is not the identity of william shakespeare?

in 1953, winston churchill was awarded the nobel prize in ________.

the parents’ generation lived in an era of constraints, restraints and________.

how do young people today handle relationships with the opposite sex?

which of the following is not an example of simile?

bertrand russell is a (an) ______ philosopher, mathematician and writer.

which of the following is not the author’s description of love?

which of the following is not mentioned when the author describes her countless crushes in school?

which of the following is not used to describe a mature love relationship?

which of the following is used to describe the younger generation?

some of the old _____ about the space age are coming true.

she cut her hair short and tried to _____ herself as a man.

the student could not _____ what the teacher was trying to explain.

he ran so fast that he was out of _____.

tibet, the second largest province of china, is _____ in uranium and underground thermal power.

the young couple were quite excited by the _____ of having their first child.

so many children have bought the balloons that the store is now out of _____.

christmas is a christian holy day celebrated on december 25th _____ the birth of jesus christ.

your _____ is the round of things that you usually do each day.

to our delight, she quickly _____ herself to the new situation.

the manager gave the salesgirl an accusing look for her _____ attitude toward customers.

with the joint effort of everyone, the plan is _____ to succeed.

the _____ arrival of the policemen saved the people in the house from being burnt.

the youngest child is thoroughly _____ because they always give him whatever he wants.

nancy was surprised that they have _____, because they seemed to be a happy couple.

love to some is like a _____. to some as strong as steel.

the course of true love never did run ______.

to fear love is to fear life, and those who fear life are already three parts _____.

given the busy nature of our lives, it is to be _________ that we even find the time to indulge in matters of the heart.

where does the family start? it starts with a young man falling in love with a girl—no superior _______ has yet been found.

it is not how much we do, but how much love we put in the doing. it is not how much we give, but how much love we put in the _______.

the president failed to fulfill his ____ to his voters and failed in his second term

he ____ the map and tried to find out which way to go.

their relationship ____ since their graduation to two different cities.

friends are forever comforts. _____ i go, their care follows.

could you give the ____ of this word in a brief way?

the _____ for the relationship between the young is believed to be pleasure.

“when we approach the notion of friendship, our first problem is that…” (para. 1),here “notion” means ______.

when speaking of “friendship based on utility”,aristotle believed this kind of friendship was _____.

after careful exam, the expert claimed that this painting was _____.

the government has very strict rules _____ the use of chemicals in food.

i’ll borrow ______ tent you are not using now.

as the saying _____, there is no such thing as a free lunch.

today’s culture is ______ “fast food culture”, in which people pursue the greatest satisfaction within the shortest time.

o henry is a famous novelist who is known for the ____ ending in his short stories.

the two images in after twenty years impress the readers deeply due to o henry’s great effort in describing people’s _____.

which of the following is not o. henry’s representative work?

he was ____ arrest when drugs were found in his bag at the customs.

which of the following explains jimmy, the policeman in after twenty years, would not arrest his friend in person?

ancient scholars classified friendship into three types, respectively they are friendship based on utility, on pleasure and on goodness.

friendship based on goodness is rare because it requires time and intimacy.

only those who prove themselves worthy of love and trust to each other can become good friends.

cicero believed that only those who are not greedy, who are pure and who are brave can be good friends.

a friend is like a mirror from which you can know yourself better.

the moral excellence of friendship involves self-development in sympathy, concern and care.

friendship based on utility often happens between the old because they need to develop each other.

according to the author, friendship based on pleasure is easy to _______.

“goodness” in the text can be understood as ______.

both aristotle and cicero believed that genuine friendship only happened between ______.

from the perspective of writing, this article takes ______ as a major way to present different classic views on friendship.

virtuous friends are bound by _______________, which involves a high level of development and expression of the altruistic emotions of sympathy, concern and care.

according to cicero, in true friendship, those who possess any superiority must regard themselves as ______ of those who are less fortunate.

how did hitler view german athletes during the 1936 olympic games held in berlin?

which event was owens expected to win easily?

which of the following might not be used to describe luz long?

why did everyone expect owens to win the olympic event?

where did the 1936 summer olympic games held?

“something must be eating you” means:

“take pains” means:

which of the following is not the description of pierre de couberlin?

to what did owens compare his friendship with long?

which of the following is not the olympic spirit revealed by luz long?

the professor paused to consult his notes, and then ________ to ask us some more questions.

in order to win in the school track and field meeting, he __________ himself to practice running every day.

their team failed to _______ for the world cup even though they had trained like crazy.

in the race he will ________ against world-class runners, which is a real challenge to him.

the tourists were___ by a guide when they were visiting the great wall.

the captain ___ the passengers about the strength.

in a few moments the vinegar will __ and so will your odors(气味).

he got rather drunk and made a ___ of himself .

successful are those who are willing to take ___ to work hard.

ben franklin was one of the ___ of the american republic.

he failed to _______ a new record, but it was a good attempt.

the dollar fell to within a hair's breadth of its ___ low.

the party ___ to be very successful.

the ___of studying music can help children develop good work habits

jesse owens was a ______ athlete from america.

when the time came for the broad-jump trials, jesse was surprised to see luz, because _________ had luz under wraps.

jesse made several mistakes during the trials, because he was ________ at the master race theory.

luz long himself didn’t believe in the ___________ business.

luz long was the perfect example of the olympic _________.

jesse owens and luz long became lifelong ________ during the 1936 olympic games.

which of the following is not related to annotation?

what figure of speech is adopted in the sentence “part of the student body was a beanpole with hair on top who came into my class…”?

“to show more than tell” is to write in a manner that allows the reader to experience the story through a character’s ___________.

which of the following is not an example of metonymy?

which of the following is not part of the six arts in ancient chinese culture?

the total expense for our three-day trip comes to $360 which __________ at 120 per day.

having ___ over the company for 30 years, he has witnessed all its ups and downs.

in college his major was biology, but now he _____ in the sale of computers.

what is the definition of synecdoche?

in the following sentence, “dan loves to take his boat out on the waves”, what word is an example of synecdoche?

what a shame that our experiment failed! it was, _____, worth trying.

no words will ______ to convey his deep grief at the death of his beloved daughter.

without any training or experience, how could the young man preside ___ such a big company?

what’s the attitude of the author towards the pharmacy student’s purpose in life?

in jean-jacques rousseau’s words, “we are born weak, we need ______; helpless, we need ____; foolish, we need reason.”

william shakespeare's greatest tragedies are: hamlet, ______, king lear and ______.

workers usually demand high wages while the boss always seeks high profits—it’s almost impossible to ___________ these two aims.

which one is not true about john a. ciardi?

who translated the english-language version of dante’s “the divine comedy”?

___________ everyone in your class knows that the party has been put off until next week.

now that both julie and her huand have lost their jobs, how will they ____ their sons and daughters?

he has his own _____ style of solving problems which you’ll soon get used to.

this is the storehouse of our company and customers ___________ entering it.

robert maynard hutchins once said, “the _____ of education is to prepare the young to educate themselves throughout their lives.”

john adams once said, “there are two types of education… one should teach us how to ____ __ _______, and the other how to live.”

__________ means to add notes to a book or text, giving explanations or comments.

_______ is a figure of speech that replaces the name of a thing with the name of something else which it is closely associated.

the figure of speech, _______, refers to a thing by the name of one of its parts.

yale is committed to the idea of a ______ _______ education through which students think and learn across disciplines, literally liberating or freeing the mind to its fullest potential.

what does the color red symbolize in western culture?

why does the author call culture shock a kind of ailment?

why do people usually feel anxious in a new environment?

which of the following statements is correct?

what is the first phase of culture shock according to the author?

what is the nature of culture according to the text?

what determines whether a child uses chopsticks or a fork to eat?

what does the word “regression” (para. 3) mean?

what will happen if you criticize a person’s country?

which of the following is not a solution to culture shock mentioned in the text?

what is author’s advice at the end of the article?

no matter how good you are at handling culture shock, remember that you are always ______.

what is the most attractive hair color to western people?

why do chinese people always make disparaging remarks about themselves when they are complimented?

in the movie, what is the thing the young american man should not do at the dinner in a chinese family?

why do american children call their parents by name directly?

which one is not included in the symbols and signs of social intercourse?

how can you learn about other people’s interest according to the author?

is an inidual born with culture?

which odd number is considered lucky for chinese?

in text b, why did girl’s mother mention rich’s freckles when asked about her opinion of rich?

what does the girl say about freckles?

how will rich’s relation with his girlfriend develop?

what is the author’s attitude towards culture shock?

in order to overcome culture shock, the priority is to conquer ___________.

the word “ethnocentri” (paragraph 5) means _________________.

lack of understanding of others’ ____________________ is responsible for culture shock.

the phrase “someone has a black eye” means _____________.

in the movie “the joy luck club”, the chinese girl’s mother compares her boyfriend’s freckles to __________.

the suffix “-” means ________.

they are trying to ________ the waste discharged by the factory for profit.

not having a good command of english can be a serious ________ preventing you from achieving your goals.

he was such a ________ speaker that he held our attention every minute of the three-hour lecture.

the rapid development of communications technology is transforming the ________ in which people communicate across time and space.

every culture has developed ________ for certain kinds of food and drink, and equally strong negative attitudes toward others.

only a few people have ________ to the full facts of the incident.

some plants are very ________ to light; they prefer the shade.

three university departments have been ________ $600,000 to develop good practice in teaching and learning.

workers in the fine arts ________ thoughts and feelings through their creative works.

finding a job can be ________ and disappointing, and therefore it is important that you are prepared.

researchers at the university of illinois determined that the ________ of a father can help improve a child’s grades.

many in the credit industry expect that credit cards will eventually ________ paper money for almost every purchase.

techniques for ________ sleep would involve learning to control both mind and body so that sleep can occur.

it is important to ________ between the rules of grammar and the conventions of written language.

to speed up the ________ of letters, the post office introduced automatic sorting.

this research has attracted wide coverage in the ________ and has featured on bbc television’s tomorrow’s world.

they were ________ admission to the military exhibition because they were foreigners.

some people believe that since oil is scarce, the ________ of the motor industry is uncertain.

politically these nations tend to be ________, with very high birth rates but poor education and very low levels of literacy.

the manager urged his staff not to ________ the splendid opportunity.

the bank refused to ________ him any money, so he had to postpone buying a house.

it is said in some parts of the world, goats, rather than cows, serve as a vital ________ of milk.

we have arranged to go to the cinema on friday, but we can be ________ and go another day.

we are quite sure that we can ________ our present difficulties and finish the task according to schedule.

jessica was ________ from the warehouse to the accounting office, which was considered a promotion.

mr. smith asked his secretary to ________ a new paragraph in the annual report she was typing.

you can hire a bicycle in many places. usually you’ll have to pay a ________.

my grandfather had always taken a ________ interest in my work, and i had an equal admiration for the stories of his time.

dr. smith was always _____ the poor and the sick, often providing them with free medical care.

thomas jefferson and john adams died on july 4, 1826, the fiftieth ________ of american independence.

people’s expectations about the future may have more influence on their sense of well-being than their ________ state does.

it’s good to know that quite a few popular english expressions actually ________ from the bible.

tom, did it ever ________ to you that you would be punished for cheating on exams?

in the u.s. 88 percent of okers had started before they were 18, despite the fact that it is ________ to sell cigarettes to anyone under that age.

an important factor in determining how well you perform in an examination is the ________ of your mind.

the most successful post-career athletes are those who can take the identity and life skills they learned in sports and ________ them to another area of life.

________ by the superstars on television, the young athletes trained hard and played intensely.

he asked us to ________ them in carrying through their plan.

william shakespeare said “ the course is true love never did run ooth.”

pennsylvania is a state in the southeastern usa, known for producing large amounts of steel and coal.

winston churchill once said “ to fear love is to fear life ,and those who fear life are already three parts dead”.

harmless puppy loves that are as brief as soap bubbles is a simile.

aristotle is a student of plato and a famous ancient greek philosopher.

ancient roman statean and a great orator cicero is the author of on the laws, on love , on friendship and on duties.

the olympic motto is “swifter, higher and stronger”, which inspires both athletes and common folks to outperform themselves so as to fulfill their dreams.

juan antonio samaranch once said“ throughout its history, the international olympic committee has struggled to spread its ideal of fraternity, friendship, peace and universal understanding.”

pierre de coubertin was a spanish historian, and the founder of the modern olympic games.

with luz long’s help and encouragement, jesse owen eventually won the gold medal in the running broad jump.

the important thing in the olympic games is not winning but taking part. the essential thing in life is not conquering but fighting well.

george bernard shaw’s comment on happiness is “happiness lies not in the mere possession of money; it lies in the joy of achievement, in the thrill of creative effort.”

morris schwartz had developed als, a terminal disease. he talked about what role money and materials were supposed to play in life to mitch alborn.

cnn is short for cable news network, a cable station founded in july by ted turner .

abraham maslow’s hierarchy of human needs are: level 1 physical needs, level 2 safety needs, level 3 esteem needs , level 4 social needs and level 5 self-realization needs.

from john adam’s point of view, there are two types of education: one should teach us how to make a living, and the other how to live.

william shakespeare four tragedies are: hamlet, macbeth, othello and romeo and juliet.

albert einstein, an american physicist and mathematician, born in america, developed the theory of relativity, which completely changed the way that scientists understand space and time.

the four pillars of education are: learning to live together, learning to know, learning to do and learning to be.

unesco is an abbreviation of united nations educational , scientific and cultural organization, which is an agency of the united nations established in science ,culture and communication.

professor john ciardi thought that the business of college is not only to train you , but to put you in touch with what the best human minds have thought .

according to the author kalervo oberg, culture shock is caused by the anxiety that results from losing the familiar signs and symbols of social communication.

according to the author kalervo oberg, getting to know the people of the host country is the way to get over culture shock as quickly as possible.

he or she is like a fish out of water means he or she can swim very well.

amy tan is a contemporary american-chinese writer. her best-known work is the joy luck club.

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