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LED Lighting 1 An accidental discovery announced recently has taken LED lighting to a new level, suggesting it could soon offer a cheaper, longer-lasting alternative to the traditional light bulb. The breakthrough adds to a growing trend that is likely to eventually make Thomas Edison&39;s bright invention obsolete. LEDs are already used in traffic lights, flashlights, and architectural lighting. They are flexible and operate less expensively than traditional lighting. 2 Michael Bowers, a graduate student2 at Vanderbilt University, was just trying to make really small quantum dots, which are crystals generally only a few nanometers big. Quantum dots contain anywhere from 100 to 1,000 electrons. They&39;re easily excited bundles of energy, and the smaller they are, the more excited they get. Each dot in Bowers&39; particular batch was exceptionally small, containing only 33 or 34 pairs of atoms. 3 When you shine a light on quantum dots or apply electricity to them, they react by producing their own light, normally a bright, vibrant color. But when Bowers shined a laser on his batch of dots, something unexpected happened. He was surprised when a white glow covered the table. The quantum dots were supposed to emit blue light, but instead they were giving off a beautiful white glow. 4 Then Bowers and another student got the idea to stir the dots into polyurethane and coat a blue LED light bulb with the mix. The lumpy bulb wasn&39;t pretty, but it produced white light similar to a regular light bulb. 5 LEDs produce twice as much light as a regular 60 watt bulb and burn for over 50,000 hours. The Department of Energy estimates LED lighting could reduce U. S. energy consumption for lighting by 29 percent by 2025. LEDs don&39;t emit heat, so they&39;re also more energy efficient. And they&39;re much harder to break. 6 Quantum dot mixtures could be painted on just about anything and electrically excited to produce a rainbow of colors, including white. The main light source of the future will almost surely not be a bulb. It might be a table, a wall, or even a fork. Paragraph 1 ______ A LED Lighting Is Not MatureB LED Lighting Will Replace Traditional LightingC Almost Everything Could Be the Main Light Source in the FutureD LED Lighting Has Many AdvantagesE Bowers Made an Unexpected DiscoveryF LED Light Bulbs Look Lumpy Paragraph 3 ______ A LED Lighting Is Not MatureB LED Lighting Will Replace Traditional LightingC Almost Everything Could Be the Main Light Source in the FutureD LED Lighting Has Many AdvantagesE Bowers Made an Unexpected DiscoveryF LED Light Bulbs Look Lumpy Paragraph 5 ______ A LED Lighting Is Not MatureB LED Lighting Will Replace Traditional LightingC Almost Everything Could Be the Main Light Source in the FutureD LED Lighting Has Many AdvantagesE Bowers Made an Unexpected DiscoveryF LED Light Bulbs Look Lumpy Paragraph 6 ______ A LED Lighting Is Not MatureB LED Lighting Will Replace Traditional LightingC Almost Everything Could Be the Main Light Source in the FutureD LED Lighting Has Many AdvantagesE Bowers Made an Unexpected DiscoveryF LED Light Bulbs Look Lumpy Unlike traditional lighting, LEDs do not give out heat so ______. A traditional lighting is less durable and dearerB a laser excited the quantum dotsC America adopted LEDsD graduate students work hardE quantum dot mixtures are magicF it is more efficient Edison&39;s bright invention is likely to be outdated because ______. A traditional lighting is less durable and dearerB a laser excited the quantum dotsC America adopted LEDsD graduate students work hardE quantum dot mixtures are magicF it is more efficient Something unexpected happened during Bower&39;s experiment when ______. A traditional lighting is less durable and dearerB a laser excited the quantum dotsC America adopted LEDsD graduate students work hardE quantum dot mixtures are magicF it is more efficient Over one quarter of energy consumption for lighting could be saved by 2025 if ______. A traditional lighting is less durable and dearerB a laser excited the quantum dotsC America adopted LEDsD graduate students work hardE quantum dot mixtures are magicF it is more efficient
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【单选题】剪切破裂角指的是( )。
A.
破裂面与大主应力作用面的夹角
B.
破裂面与大主应力方向的夹角
C.
破裂面与小主应力作用面的夹角
D.
破裂面与小主应力方向的夹角
【单选题】中国共产党七届二中全会明确提出了使中国稳步地由农业国转变为工业国,由新民主义国家转变为社会主义国家的基本方向。推动了“两个转变”初步实现的历史事件是( )。
A.
三大改造的完成
B.
农业集体化的完成
C.
土地改革的完成
D.
“一五计划”的完成
【简答题】莫尔强度理论指出,岩石发生剪裂时,剪裂面与最大主应力轴的夹角是()。
【单选题】某电站近坝库区边坡(见图),由中厚层白云岩及薄层白云质泥岩、砂质页岩组成,坡角35°,岩层倾角10°,后缘发现有张裂隙。 对于破坏特征和机制,下列说法不正确的是()。
A.
一般沿岩层层面产生的滑坡,滑体形态主要受岩层层面控制,软弱夹层或顺层面抗剪强度取值对滑坡稳定验算是一项重要指标
B.
可能发生切层滑坡,滑体形态与岩体强度关系很大
C.
淘蚀切脚,开挖不当可能导致滑坡
D.
水的作用对是否能发生滑动影响较大
【单选题】关于中国共产党对新民主主义社会向社会主义社会过渡问题的认识过程,下列表述中错误的是( )。
A.
1950年6月,党提出使中国“稳步地由农业国转变为工业国,由新民主主义国家转变为社会主义国家”
B.
1951年前后,党的领导层大体形成了先用三个五年计划的时间搞工业化建设,再向社会主义过渡的共识
C.
1952年9月,毛泽东提出,我们现在就要开始用10年到15年时间基本完成向社会主义过渡
D.
1953年12月,中国共产党公布了党在过渡时期的总路线
【单选题】中国共产党提出了使中国“稳步地由农业国转化为工业国,由新民主主义国家转化为社会主义国家”是在以下哪次会议:
A.
中共七大
B.
中共七届二中全会
C.
中共七届三中全会
D.
中共七届四中全会
【单选题】剪裂角是指()与()夹角。
A.
最大主应力轴σ 1 ,剪裂面
B.
最大主应力轴σ 1 ,张裂面
C.
最小主应力轴σ 3 ,剪裂面
D.
最小主应力轴σ 3 ,张裂面
【单选题】滑动面是指坝基岩体滑动破坏时,该面的实际抗滑能力低于坝体混凝土与基岩接触面的抗剪能力,是坝基的滑动控制面。通常构成滑动面的不包括()。
A.
最大剪应力面
B.
软弱夹层
C.
断层破碎带
D.
缓倾角裂隙
【多选题】滑动面是指坝基岩体滑动破坏时,该面的实际抗滑能力低于坝体混凝土与基岩接触面的抗剪能力,是坝基的滑动控制面。通常构成滑动面的有(    )。
A.
最大剪应力面  
B.
软弱夹层    
C.
断层破碎带    
D.
缓倾角裂隙
【判断题】INT1是外部中断
A.
正确
B.
错误
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