借助《工业与民用配电设计手册》第三版第891页表14-12及有关曲线,估算矩形基础板

题型:单项选择题 案例分析题

问题:

借助《工业与民用配电设计手册》第三版第891页表14-12及有关曲线,估算矩形基础板的接地电阻。已知条件如下:①基础板长边的边长L1=100m,短边的边长L2=10m;②基础深度t=3m;③土壤电阻率ρ=100Ω·m。

查得形状系数约为()n

A.0.5

B.0.7

C.0.9

D.1.1

考点:电气工程师(发输变电)接地接地题库
题型:单项选择题 案例分析题

根据《“十二五”节能减排综合性工作方案》,下列关于节能减排总体要求的表述,不正确的是()。

A.形成加快转变经济发展方式的倒逼机制

B.坚持强化责任、健全法制、完善政策、加强监管相结合,建立健全激励和约束机制

C.加强管理引导相结合,大幅度提高能源利用效率,显著减少污染物排放

D.进一步形成政府为主体、企业为主导、市场有效驱动、全社会共同参与的推进节能减排工作格局

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在如图所示的电路中,圈①、②、③处可以接小灯、电流表或电压表(均为理想电表)三种元器件,电源电动势E、内阻r均保持不变,定值电阻R1︰R2︰R3︰R4=4︰3︰2︰1,小灯电阻RL=R1,R1>r,电路中有电流通过,下列说法中正确的是

[ ]

A、要使电源总功率最大,则应该①接电流表,②接电压表,③接小灯

B、要使电源输出功率最大,则应该①接电流表,②接小灯,③接电压表

C、要使路端电压最大,则应该①接小灯,②接电压表,③接电流表

D、要使闭合电路中电源效率最高,则应该①接小灯,②接电流表,③接电压表

题型:单项选择题 案例分析题

新生儿脐血中Ig水平增高表示有宫内感染的是()

A.IgM

B.IgA

C.IgE

D.IgD

E.IgG

题型:单项选择题 案例分析题

消防水泵房的门应采用()级防火门。

A.甲

B.乙

C.丙

D.丁

题型:单项选择题 案例分析题

As with many a grown-up sporting star, the first hint of greatness came at an early age for Lewis Hamilton. As an eight-year-old at his first kart race, he charged "more like a mature driver than a novice," remembers Martin Hines, owner of the Zip Kart racing company. Scything his way through the field just outside London, Hamilton had a confident style that seemed different from normal rookies, Hines says. "There was a little spark about him." Now 22, and in his debut season in Formula One—he became the first black driver to make it onto the grid in motor racing’s blue-ribbon championship.

His success and profile that have earned young Hamilton comparisons with other sporting greats. His color— Hamilton’s grandfather came to Britain from Grenada in the 50s—and the positive influence of his father, Anthony, have drawn parallels with Tiger Woods. Hamilton acknowledges that his participation could stoke interest among ethnic groups who may not be into the sport now. "Hopefully people that can relate to me will see that it’s possible and also try to get into the sport," he told the BBC. Moreover, his youth, good looks and wholesome image are also likely to get marketers fired up.

Countless more karting titles followed before 2001. He "made seasoned drivers look silly," says Tony Shaw, Hamilton’s then team manager at Manor Motorsport. Hamilton’s raw, natural speed and canny race craft nudged him closer to the big leagues. Hamilton’s "understanding of when and where to overtake and how to take advantage of a situation is very advanced," Shaw says.

At his first crack at GP2, the training ground for Formula One, Hamilton dominated the 2006 season with a series of blistering drives on his way to the title. Hamilton is "not worried about showing or doing what he’s used to doing just because it’s Formula One," says Hill. For many new drivers, "that’s an enormous hurdle." With the retirement last year of seven-time world champion Michael Schumacher, there’s one less rival for Hamilton to negotiate.

And Hamilton is certainly not short on confidence. When he first met Ron Dennis—now his Formula One team boss—as a 10-year-old in a borrowed suit, Hamilton promptly told him he wanted to drive for McLaren. Three years later, he joined the team’s support program for promising young drivers. But, say former team managers, he’s ready to listen and learn when things go wrong. Hamilton has a rare "capacity to question himself—to analyze very clearly after a race," says Frederic Vasseur, general manager at the ART Grand Prix team behind Hamilton’s GP2 championship.

As for whether he’ll become the Tiger Woods of the sport, it’s too early to know whether he can live up to those standards. But for now, his fans are bullish. Damon Hill was the last British driver to take the world crown. And it’s Hamilton, Hill says, "who looks likely to be the next.

Which word is most similar in meaning to "bullish" (Line 2, Last paragraph)()

A. Optimistic

B. Foolish

C. Obstinate

D. Fevered

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