使用压刨应做哪些调试准备?

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使用压刨应做哪些调试准备?

考点:铁路工程施工考试铁路混凝土工程施工质量验收标准铁路混凝土工程施工质量验收标准题库
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为了研究光的反射规律,小亮进行了下面的实验:照图那样,把一面镜子M平放在平板上,把一个画有角度的白色硬纸板竖立在镜面上,硬纸板是由E、F两块粘接而成,可绕接缝ON转动,ON垂直于镜面。

(1)使E、F成为同一平面,让入射光线沿纸板上某一角度线射向镜面上的O点,观察反射光线、入射光线和ON位置,可知反射光线与入射光线____________;

(2)改变入射光线方向,观察反射光线方向也改变,可知反射角____________入射角;

(3)把纸板F前折或后折,可以知道反射光线、入射光线与法线____________;

(4)让光线逆着反射光线射向镜面,经M反射后,反射光线逆着原入射光线方向射出,表明反射时____________。

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广义上,泊气勘探技术包括以下三类()。

A.地质调查技术、泊气井钻探技术、实验室分析测试技术

B.地质勘探技术、地球物理勘探技术、地球化学勘探技术

C.地震勘探技术、非地震物化探技术、遥感技术

D.勘探工程技术、计算机应用技术、地质评价技术

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Every generation has its emblematic boy’s toy. once upon a time there was the golf cart: a little toy car specifically designed for middle-aged men too rich to care about looking ridiculous. Later came the beach buggy, a briefly fashionable, wildly impractical, single-terrain vehicle. one might include the motorcycle or the snowmobile on this list, were they not, in certain contexts, quite useful, but there is no doubt which pointless recreational vehicle has captured the imagination of the landed, middle-aged celebrity: it’s the quad bike.

What is it about this squat, ungainly, easy-to-flip machine that celebrities love so much As recreational vehicles go, the quad bike is hardly sophisticated. They are to the countryside what the jet-ski is to Lake Windermere. "There’s nothing cool about a quad," says Simon Tiffin, editor of a well-known magazine. "It’s a strange thing to want to hare round beautiful bits of the country in a petrol-guzzling machine."

But celebrities love quad bikes. Musicians, comedians, DJs, actors and sportsmen have all been photographed aboard quads. "They’re the latest rich person’s toy," says Tiffin. "Spoilt children get them for Christmas." Provided you’ve got a large estate to go with it, however, the quad bike can remain a secret indulgence. You can go out and tear up your own piece of countryside without anyone knowing you’re doing it.

The quad bike’s nonsensical name -- "quad" means four, but "bike" is an abbreviation of "bicycle," which means two -- that comes to six -- hints at its odd history. Originally the ATV, or all-terrain vehicle, as quads are sometimes known, was developed in Japan as a three-wheeled farm vehicle, an inexpensive mini-tractor that could go just about anywhere. In the 1980s the more stable four-wheeled quad was officially introduced -- enthusiasts had been converting their trikes for some time -- again primarily for farming, but its recreational appeal soon became apparent. At the same time a market for racing models was developing.

Paul Anderson, a former British quad racing champion, says the quad’s recreational appeal lies in its potential to deliver a safe thrill. "It’s a mix between a motorbike and driving a car; when you turn a corner, you’ve got to lean into the corner, and then if the ground’s greasy, the rear end slides out," he says. "Plus they’re much easier to ride than a two-wheeled motorcycle." The quad bike, in short, provides middle-aged excitement for men who think a Harley might be a bit dangerous. Anderson is keen to point out that quad bikes are, in his experience, much safer than motorcycles. "With quad racing it’s very rare that we see anybody having an accident and getting injured," he says. "In the right hands, personally, I think a quad bike is a very safe recreational vehicle," he adds.

Outside of racing, quad bikes are growing in popularity and injuries have trebled in the last five years. Although retailers offer would-be purchasers basic safety instructions and recommend that riders wear gloves, helmets, goggles, boots and elbow pads, there is no licence required to drive a quad bike and few ways to encourage people to ride them wisely. Employers are required to provide training to workers who use quad bikes, but there is nothing to stop other buyers hurting themselves.

For the rest of the world, quad bikes are here to stay. They feature heavily in the programmes of holiday activity centres, they have all but replaced the tractor as the all-purpose, agricultural workhorse and now police constables ride them while patrolling the Merseyside coastline.

It has more or less usurped the beach buggy, the dirt bike and the snowmobile, anywhere they can go the quad bike can. They even race them on ice. You can’t drive round Lake Windermere on one, or at least nobody’s tried it yet. Just wait.

What does Paul Anderson think about quad bike riding?()

A.The only danger is when the rider is turning a corner.

B.Anyone who can ride a quad bike can ride a motorcycle.

C.Most accidents occur when people are racing quad bikes.

D.A quad bike can be exciting without being dangerous.

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患者男性,60岁,无明显原因出现双手抖动3年。查体:面部表情少,双手震颤,步行运动迟缓,其余查体未见异常。辅助检查未见明显异常。该患者最有可能的诊断是

A.帕金森病

B.帕金森综合征

C.特发性震颤

D.小舞蹈病

E.肝豆状核变性

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什么是“亮度”,其含义是什么

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