如图15-2-9(a)所示,已知刚架M图,则左柱各截面的剪力为()kN。<img src='https://img2.soutiyun.com/1/2021-04-08/986750315208248.png' />
岗位评价与薪酬的比例关系如图所示.其中曲线A与曲线B的关系为().<img src='https://img2.soutiyun.com/ask/uploadfile/4899001-4902000/273b58280702ebc02138aa63e2a7aac2.gif' />
如图所示,F=2 kN, L=2m, 梁在集中力F作用下,支座B处的横向支座反力为()kN。<img src='' jquery1110037276438414980783=' /><img src='https://img2.soutiyun.com/ask/uploadfile/5319001-5322000/577918aab33527226377708246b76a71.jpg' />
在图Ⅲ-2所示电路中R<sub>F</sub>引入的反馈为( )。<img src='https://img2.soutiyun.com/ask/uploadfile/5451001-5454000/8ec82d26a189fed9088444a0f364ac24.jpg' />
图5-2示意了发送者利用非对称加密算法向接收者传送消息的过程,图中a和b处分别是(16)。<img src='https://img2.soutiyun.com/shangxueba/ask/1227001-1230000/1227186/ct_csrpihsm_crpihschoosecn_00316(20101).jpg' />
设R<sub>1</sub>和R<sub>2</sub>是集合A上的等价关系,则对于集合A的划分,A/R<sub>1</sub>是A/R<sub>2</sub>的加细划分当且仅当<img src='https://img2.soutiyun.com/ask/2020-07-29/964879345380203.png' />。
己知某带权图G的邻接表如下所示,其中表结点的结构为:<img src='https://img2.soutiyun.com/ask/uploadfile/1848001-1851000/9543e1fd561d969e241e096250a2730d.jpg' />则图G是______。
如图所示,船舶由C<sub>A</sub>1转向C<sub>A</sub>2时,宜利用灯塔采用()。<img src='https://img2.soutiyun.com/shangxueba/ask/17676001-17679000/17676260/2015011911024328903.jpg' />
下列符号中,数字表第2列数字对应的符号没有出现的是()。<img src='https://img2.soutiyun.com/ask/uploadfile/3681001-3684000/06a3625e67510196f5d8c4e611c0428e.png' />
设A={a,b,c},试给出,A上两个不同的关系R<sub>1</sub>和R<sub>2</sub>,使得<img src='https://img2.soutiyun.com/ask/2021-01-06/978776083803018.png' />
有8本不同的书,其中数学书3本,英语书2本,科普书3本,将这8本书随机排在书架上,则3本数学书刚好放在一起且2本英语书刚好放在一起的概率有多大?() A.<img src='https://img2.soutiyun.com/ask/uploadfile/4254001-4257000/f800427efc9bcb956dec2940c4957b52.jpg' />B.<img src='https://img2.soutiyun.com/ask/uploadfile/4254001-4257000/eb6e6cf2d383abfae47c57019595ad57.jpg' />C.<img src='https://img2.soutiyun.com/ask/uploadfile/4254001-4257000/60507f1b551e9925637bd20e4866b55a.jpg' />D.<img src='https://img2.soutiyun.com/ask/uploadfile/4254001-4257000/40cfa64357b04be09b7e6533ee05f61a.jpg' />
已知|a|=2,|b|=<img src='https://img2.soutiyun.com/shangxueba/ask/17682001-17685000/17682935/2015102711295155630.jpg' />,且a?b=3,则|a×b|等于()
患者男性,47岁,因突发胸痛2小时就诊。下图A、B、C系患者胸痛发作后2小时、24小时及11周的心电图记录,应诊断为()。<img src='https://img2.soutiyun.com/shangxueba/ask/18234001-18237000/18236883/2015082615081279700.jpg' /><img src='https://img2.soutiyun.com/shangxueba/ask/18234001-18237000/18236883/2015082615080347546.jpg' />
某连续时间实的因果LTI系统的零、极点如图4-69所示,并己知.<img src='https://img2.soutiyun.com/shangxueba/ask/51312001-51315000/51314185/975677335505495.png' />其中h(t)为该系统的单位冲激响应.试求:
一项调查表明,5年前每个家庭每天看电视的平均时间为6.7小时。而最近对200个家庭的调查结果是:每个家庭每天看电视的平均时间为7.25小时,标准差为2.5小时。在a=0.05的显著性水平下,检验假设<img src='https://img2.soutiyun.com/ask/2020-07-21/964177967088368.png' /><img src='https://img2.soutiyun.com/ask/2020-07-21/964177983636315.png' />得到的结论为()。
如图15-2-35所示,梁A端弯矩为()。<img src='https://img2.soutiyun.com/1/2021-04-08/986750110091987.png' />
两轻质弹簧A和B,它们的劲度系数分别为<img src="https://img2.soutiyun.com/shangxueba/ask/19434001-19437000/19434588/c854e58-chaoxing2016-292913.jpeg"/>和<img src="https://img2.soutiyun.com/shangxueba/ask/19434001-19437000/19434588/bcec91b-chaoxing2016-292914.jpeg"/>,今将两弹簧连接起来,并竖直悬挂,下端再挂一物体<img src="https://img2.soutiyun.com/shangxueba/ask/19434001-19437000/19434588/8877d62-chaoxing2016-835.jpeg"/>,如图所示,系统静止时,弹簧A和B势能之比值将为 <img src="https://img2.soutiyun.com/shangxueba/ask/19434001-19437000/19434588/e9dacb2-chaoxing2016-292915.jpeg"/>
设L是从A(1,0)到B(-1,2)的线段,则曲线积分<img src='https://img2.soutiyun.com/shangxueba/ask/17670001-17673000/17672554/201510271143115588.jpg' />(x+y)ds等于:()
用仪器测量某零件的长度n次,得到n个略有差别的数:a<sub>1</sub>,a<sub>2</sub>,…,a<sub>n</sub>,证明:用算术平均值<img src='https://img2.soutiyun.com/ask/2020-12-20/977341497733953.png' />作为该零件的长度x的近似值,能使<img src='https://img2.soutiyun.com/ask/2020-12-20/977341503690294.png' />达到最小.
点作曲线运动(如图所示),若点在不同位置时的加速度a<sub>1</sub>=a<sub>2</sub>=a<sub>3</sub>是一个恒矢量,则该点作下列中的何种运动()?<img src='https://img2.soutiyun.com/shangxueba/ask/17856001-17859000/17857778/2015102712071555861.jpg' />
如图15-2-13所示,桁架a杆的内力是()。<img src='https://img2.soutiyun.com/1/2021-04-08/986749751068919.png' />
分子式为C<sub>5</sub>H<sub>12</sub>O的A,能与金属钠作用放出氢气,A与浓H<sub>2</sub>SO<sub>4</sub>,共热生成B,用冷的高锰酸钾水溶液处理B得到产物C,C与高碘酸作用得到<img src='https://img2.soutiyun.com/ask/2021-01-21/980093892436686.png' />及<img src='https://img2.soutiyun.com/ask/2021-01-21/980093899985118.png' />。B与稀H<sub>2</sub>SO<sub>4</sub>,作用又得到A,推测A的结构,并用反应式表明推断过程。
设A-(2)B-1.2.3.4.5).A到B的关系R={(x,y)|x∈A,y∈B且x+1-y},则R=().<img src='https://img2.soutiyun.com/shangxueba/ask/68967001-68970000/68967597/994768172395882.png' />
设A=[a<sub>ij</sub>]为n阶实对称矩阵,λ<sub>1</sub>≥λ<sub>2</sub>≥...≥λ<sub>n</sub>为其特征值,证明:<img src='https://img2.soutiyun.com/ask/2020-11-27/97534084251998.jpg' />