新东方优美背诵短文50篇 Unit45:The Source of Energe

45.The source of Energy

A summary of the physical and chemical nature of life must begin, not on the Earth, but in the Sun; in fact, at the Sun’s very center. It is here that is to be found the source of the energy that the Sun constantly pours out into space as light and heat. This energy is librated at the center of the Sun as billions upon billions of nuclei¹ of hydrogen atoms collide with each other and fuse together to form nuclei of helium, and in doing so, release some of the energy that is stored in the nuclei of atoms. The output of light and heat of the Sun requires that some 600 million tons of hydrogen be converted into helium in the Sun every second. This the Sun has been doing for several thousands of millions of year.

The nuclear energy is released at the Sun’s center as high-energy gamma radiation, a form of electromagnetic radiation like light and radio waves, only of very much shorter wavelength². This gamma radiation is absorbed by atoms inside the Sun to be reemitted at slightly longer wavelengths³. This radiation , in its turn is absorbed and reemitted. As the energy filters through the layers of the solar interior, it passes through the X-ray part of the spectrum⁴ eventually becoming light. At this stage, it has reached what we call the solar surface, and can escape into space without being absorbed further by solar atoms. A very small fraction of the Sun’s light and heat is emitted in such directions that after passing unhindered through interplanetary space, it hits the Earth.

能量的来源
概说生命的物理和化学特性必须始于太阳--确切地说，是太阳的核心，而非地球。能量来自太阳的核心。
在这里，太阳不停地以光和热的形式向空间倾泻出能量。数十亿计的氢原子核在太阳的核心碰撞并且聚变生成氦。在此过程中一部分原本储存于原子核中的能
量被释放出来。太阳所产生的光和热需要每秒将六亿吨氢转化为氦。这样的转化在太阳中
已经持续几十亿年了。核能在太阳的核心被释放为高能的伽马射线。这是一种电磁射线，就象光波和无线电波一样，只是波长要短得多。
这种伽玛射线被太阳内的原子所吸收，然后重新释放为波长稍长一些的光波。这新的射线再次被吸收，而后释放。在能量由太阳内
部一层层渗透出来的过程中，它经过了光谱中X射线部分，最后变成了光。在此阶段，能
量到达我们所称的太阳表层，并且离散到空间而不再被太阳原子所吸收。只有很小一部分太阳的光和热由此方向释放出来，并且未被阻挡，穿越星空，来到地球。

 

1 nuclei   

n.核

参考例句：

• To free electrons, something has to make them whirl fast enough to break away from their nuclei. 为了释放电子，必须使电子高速旋转而足以摆脱原子核的束缚。
• Energy is released by the fission of atomic nuclei. 能量是由原子核分裂释放出来的。

2 wavelength   

n.波长

参考例句：

• The authorities were unable to jam this wavelength.当局无法干扰这一波长。
• Radio One has broadcast on this wavelength for years.广播1台已经用这个波长广播多年了。

3 wavelengths   

n.波长( wavelength的名词复数 )；具有相同的/不同的思路；合拍；不合拍

参考例句：

• I find him difficult to talk to—we're on completely different wavelengths. 我没法和他谈话，因为我们俩完全不对路。 来自《简明英汉词典》
• Sunlight consists of different wavelengths of radiation. 阳光由几种不同波长的射线组成。 来自辞典例句

4 spectrum   

n.谱，光谱，频谱；范围，幅度，系列

参考例句：

• This is a kind of atomic spectrum.这是一种原子光谱。
• We have known much of the constitution of the solar spectrum.关于太阳光谱的构成，我们已了解不少。