英语听力文摘 English Digest 592、石英计时！-英语课

时间：2018-12-31 作者：英语课 分类：英语听力文摘 English Digest

英语课

　　Keeping Time With Quartz 1

　　Most people know that wrist watches commonly contain quartz. In fact, if you wear a watch, chances are it’s a quartz watch, since most watches is made today use quartz. But, you may not know what quartz has to do with keeping time.

　　Quartz is a mineral, otherwise known as silicon 2 dioxide, which is common in the earth’s crust, and the main ingredient of sand. This mineral is popular with watch manufacturers because it vibrates quickly when electrically stimulated 3, and loses little energy when vibrating.

　　The steady vibrations 4 are what allow a watch to keep time. The quartz used in watches is actually synthetic 5, because it vibrates more steadily 6 than natural quartz.

　　Here’s how a quartz watch works. A small, paper-thin piece of synthetic quartz acts as the watch’s oscillator. Think of the oscillator like the pendulum 7 in a grandfather clock, that by its continuous motion tells the watch how much time has passed. The oscillator is a sort of counter which ticks off the seconds, minutes and hours, and the watch displays the time counted.

　　When the quartz oscillator receives an electrical charge from a battery or some other power source, it vibrates at over 32,000 times per second. As it vibrates, an integrated circuit in the watch programmed to know the oscillator’s frequency regulates the vibrations so that a certain number of them equals one second.

　　If the watch has a minute and second hand, the regulated electrical pulses are changed into mechanical pulses that move gears and set the watch hands in motion. If the watch is digital, the quartz’s electrical impulses add up to minutes, hours, and days.

　　石英计时

　　大多数人都知道通常腕表内含有石英。事实上，只要你带表，那基本上都是石英表，因为当今通用的多数表都由石英制造。但是，你可能不知道石英与计时之间有何关联。

　　石英是一种矿物质，也就是二氧化硅，通常存在于地壳中，同时也是沙子的主要成分。石英常被用于制作钟表是因为这种矿物质在受到电刺激后会快速摆动，而摆动过程中的能量损耗很小。

　　这种平稳的摆动就是手表计时的奥妙所在。手表所用的石英实际上是合成的，合成石英比自然石英摆动得更为稳定。

　　现在让我们来探寻石英手表的工作原理。微小如纸薄的合成石英相当于手表的振荡器。这种振荡器如同座钟的钟摆，通过它不间断的摆动反馈到手表来提示时间。振荡器是一种标记秒、分及小时的计算器，而手表则显示出所记时间。

　　当石英振荡器接收到来自电池或其他电源的电荷时，它将以超过32,000次/秒的频率摆动。摆动过程中，通过编程手表中的集成电路来测定振动器的频率，进而调整摆动，以达到固定摆动次数为一秒。

　　如果手表有分针和时针，设置好的电脉冲可转换成机械脉冲，推动齿轮转动进而带动指针运动。若是电子手表，石英的电脉冲可累计成分钟、小时及天数。