Electricity
The modern age is an age of electricity. People are so used to electric lights radio televisions and telephones that it is hard to imagine what life would be like without them. When there is a power failure people grope about in flickering candlelight cars hesitate in the streets because there are no traffic lights to guide them and food spoils in silent refrigerators.
Yet people began to understand how electricity works only a little more than two centuries ago. Nature has apparently been experimenting in this field for million of years. Scientists are discovering more and more that the living world may hold many interesting secrets of electricity that could benefit humanity.
All living cell send out tiny pulses of electricity. As the heart beats it sends out pulses of record; they form an electrocardiogram which a doctor can study to determine how well the heart is working. The brain too sends out brain waves of electricity which can be recorded in an electroencephalogram. The electric currents generated by most living cells are extremely small – often so small that sensitive instruments are needed to record them. But in some animals certain muscle cells have become so specialized as electrical generators that they do not work as muscle cells at all. When large numbers of these cell are linked together the effects can be astonishing.
The electric eel is an amazing storage battery. It can seed a jolt of as much as eight hundred volts of electricity through the water in which it live. ( An electric house current is only one hundred twenty volts.) As many as four-fifths of all the cells in the electric eel’s body are specialized for generating electricity and the strength of the shock it can deliver corresponds roughly to length of its body.
办公室恋情恶果VS好处
90后求职女生吴丽春:“相信勇敢之后必有春天”
中国的社会保障改革亟须顶层设计
职场为人处世三大准则:爱岗敬业 不卑不亢 自信坦然
创业,会给职业生涯加分多少?
中国IT城市满意度排名
15个细节助你走向美好的职业生涯
中国国际形象最佳城市排名 上海居首
大学生利用过年前短短的十几天兼职
大学生如何弥补自身的求职劣势
彩虹族成职场白领新宠
高校“求职达人” 毕业即获50万年薪 做好职业规划
别把职业规划当成口头禅
2010全球城市排名中国七城市上榜 北京排名十五
新兴职业发展遇瓶颈 或"无地用武"或"有市无人"
大一小伙骑单车37天到拉萨 全程2166公里
关于主动性的三个小故事
职场白领热门电影推荐