VOA慢速英语2013 科学和工程的发明拯救生命

 

Scientific and Engineering Inventions Save Lives 科学和工程的发明拯救生命

This is Science in the News, in VOA Special English. I’m June Simms. Today Shirley Griffith and Bob Doughty¹ tell about two recent inventions that have helped to save lives. We will also tell about the people who developed them. 

History of Seat Belts

Most cars have seat belts as part of their equipment. Seat belts protect drivers and passengers in case of accident. They also reduce the effect of a crash on the body. Safety experts estimate that the restraining devices save thousands of lives a year in the United States alone. Worldwide, some experts, say the devices have protected up to a million people.

The first seat belt was said to have been created in the 1800s by George Cayley of England. He is remembered for many inventions, especially for early “flying machines.” 

The United States first recognized the invention of an automobile² seat belt in 1849. The government gave a patent to Edward J. Claghorn of New York City so that others would not copy his invention. Claghorn called the device a Safety-Belt. It was said to include hooks and other attachments³ for securing the person to a fixed⁴ object. 

Modern Seat Belt Developed in Sweden

Other inventors followed with different versions of the seat belt. But more than 100 years passed before the current, widely used seat belt was developed. It resulted from the work of a Swedish engineer, Nils Bohlin. His three-point, lap and shoulder seat belt first appeared on cars in Europe 50 years ago. 

Bohlin was born in Sweden in 1920. After completing college, he designed seats for the Swedish aircraft industry. The seats were built for the pilot to escape from an airplane in case of disaster. Bohlin’s work with planes showed him what could happen in a crash at high speed. In 1958, Bohlin brought that knowledge to the Swedish car manufacturer Volvo. He was the company’s first chief safety engineer. 

At the time, most safety belts in cars crossed the body over the abdomen⁵. A buckle⁶ held the restraints in place. But the position of the buckle often caused severe injuries in bad crashes.

Nils Bohlin recognized that both the upper and lower body needed to be held securely in place. His invention contained a cloth strap⁷ that was placed across the chest and another strap across the hips⁹. The design joined the straps¹⁰ next to the hip⁸. 

Volvo was the first automobile manufacturer to offer the modern seat belt as a permanent addition to its cars. It also provided use of Nils Bohlin’s design to other car-makers. 

The Swedish engineer won many honors for his seat belt. He received a gold medal from the Royal Swedish Academy of Engineering Sciences in 1995. He died in Sweden in 2002.

American Stephanie Kwolek Invents Kevlar

Kevlar is another invention that has saved many people from serious injury and death. Kevlar is a fibrous material with qualities that make it able to reject bullets. Added to clothing, the material protects security officers and soldiers across the world.

The fibers¹² form a protective barrier against gunfire. Bullets lose their shape when they strike Kevlar. Those bullets look like mushrooms, and do not enter the body. Most threats to police and security officers come from handguns. They wear Kevlar vests to protect the upper body. Soldiers wear more extensive clothing protected with Kevlar against heavier ammunition¹³.

Kevlar might not have been invented had Stephanie Kwolek been able to seek a career in medicine. From childhood, she wanted to be a doctor. But she lacked the money for a medical education. 

Today, thousands of people are glad that Stephanie Kwolek became a research chemist. In that job, she developed the first liquid crystal polymer. The polymer was a chemical product that formed the basis for Kevlar.

Stephanie Kwolek was born in 1923 in New Kensington, Pennsylvania. As a child, Stephanie loved science. Later, she studied chemistry and other sciences at a Pennsylvania college now known as Carnegie Mellon University. 

She got a job with the DuPont chemical company in 1946. It was the beginning of a career with the company that lasted about 40 years.

By the 1960s, Dupont already had produced materials like nylon and Dacron. The company wanted to develop a new fiber¹¹. Stephanie Kwolek was part of a DuPont research group that asked to work on its development.

At the time, she was searching for a way to make a material strong enough to use on automobile tires. If tires could be improved, automobiles¹⁴ would need less fuel. Ms. Kwolek needed a new way to make stiff, resistant¹⁵ fibers for the job. 

Experiments Lead to Creation of Kevlar

Her experiments for the project were supposed to produce a clear substance similar to a thick syrup¹⁶. Instead, what Stephanie Kwolek produced was unexpected. It was a liquid that looked cloudy or milky¹⁷. She said she might have thrown it out. But she decided¹⁸ to let it sit for awhile. 

She told VOA that she was warned the liquid could never complete a required process. The process calls for the chemical to be pushed through the small holes of a spinneret. She remembers that the man operating the device at first refused to accept her material. He probably suspected it had solid particles that would block the holes. However, after awhile he said he would try it. She says she thinks he was tired of being asked, or might have felt sorry for her. 

That person must have been surprised when the substance passed the test. It returned from the laboratory with more firmness than anything Stephanie Kwolek had made before.

Ms. Kwolek did not tell anyone that she had produced something new and strong. She said she was afraid there might have been a mistake. Repeated testing, however, did not find anything wrong. She and her group worked to improve the discovery. DuPont first manufactured large amounts of Kevlar in 1971. The material is found today in hundreds of products from sports equipment to window coverings.

Over the years, Stephanie Kwolek has received many awards. Her honors include membership in the National Inventors Hall of Fame. 

Two Men Largely Responsible for Placing Kevlar in Protective Clothing

Getting Kevlar placed in protective clothing resulted mainly from the work of Lester Shubin and Nicholas Montanarelli. Mr. Shubin was educated in chemistry. He worked for the United States Army in the 1970s. At the time, Mr. Montanarelli was an Army project director. He was trained in engineering and psychology¹⁹. 

The two Americans were working at the Aberdeen Proving Ground in Maryland. They were searching for a way to protect people in public life from gunfire. Mr. Montanarelli knew about DuPont’s recently developed fiber, and the two men decided to test it.

The men fired handguns at several materials protected by Kevlar. The material changed the shape of the bullets. It seemed a good candidate to help defend police officers and soldiers.

Mr. Shubin was able to gain financial help for a field experiment. Thousands of police officers in many cities began to wear the vests. But Mr. Montanarelli said it was difficult to get companies to make them. The companies feared legal action if the vests should fail.

Then came December 1975. A gunman shot at a policeman in Seattle, Washington. One bullet hit the officer’s hand. But a bullet fired very close to the policeman struck his chest.

The officer survived. The bullet did not enter his body. He felt good enough to protest being kept in a hospital that night to make sure all was well. The incident helped get manufacturers to stop worrying about legal action. They began making the vests.

Today, about three thousand people are members of the Kevlar Survivors’ Club. DuPont and the International Association of Chiefs of Police organized the group. All the members have escaped injury or death because long ago, a chemist named Stephanie Kwolek produced something unexpected. 

This Science in the News was written by Jerilyn Watson. Our announcers were Shirley Griffith and Bob Doughty. I’m June Simms. Join us again next week for more news about Science in Special English on the Voice of America.  

1 doughty   

adj.勇猛的，坚强的

参考例句：

• Most of successful men have the characteristics of contumacy and doughty.绝大多数成功人士都有共同的特质：脾气倔强，性格刚强。
• The doughty old man battled his illness with fierce determination.坚强的老人用巨大毅力与疾病作斗争。

2 automobile   

n.汽车，机动车

参考例句：

• He is repairing the brake lever of an automobile.他正在修理汽车的刹车杆。
• The automobile slowed down to go around the curves in the road.汽车在路上转弯时放慢了速度。

3 attachments   

n.（用电子邮件发送的）附件( attachment的名词复数 )；附着；连接；附属物

参考例句：

• The vacuum cleaner has four different attachments. 吸尘器有四个不同的附件。
• It's an electric drill with a range of different attachments. 这是一个带有各种配件的电钻。

4 fixed   

adj.固定的，不变的，准备好的；(计算机)固定的

参考例句：

• Have you two fixed on a date for the wedding yet?你们俩选定婚期了吗？
• Once the aim is fixed,we should not change it arbitrarily.目标一旦确定，我们就不应该随意改变。

5 abdomen   

n.腹，下腹(胸部到腿部的部分)

参考例句：

• How to know to there is ascarid inside abdomen?怎样知道肚子里面有蛔虫？
• He was anxious about an off-and-on pain the abdomen.他因时隐时现的腹痛而焦虑。

6 buckle   

n.扣子，带扣；v.把...扣住，由于压力而弯曲

参考例句：

• The two ends buckle at the back.带子两端在背后扣起来。
• She found it hard to buckle down.她很难专心做一件事情。

7 strap   

n.皮带，带子；v.用带扣住，束牢；用绷带包扎

参考例句：

• She held onto a strap to steady herself.她抓住拉手吊带以便站稳。
• The nurse will strap up your wound.护士会绑扎你的伤口。

8 hip   

n.臀部，髋；屋脊

参考例句：

• The thigh bone is connected to the hip bone.股骨连着髋骨。
• The new coats blouse gracefully above the hip line.新外套在臀围线上优美地打着褶皱。

9 hips   

abbr.high impact polystyrene 高冲击强度聚苯乙烯，耐冲性聚苯乙烯n.臀部( hip的名词复数 )；[建筑学]屋脊；臀围（尺寸）；臀部…的

参考例句：

• She stood with her hands on her hips. 她双手叉腰站着。
• They wiggled their hips to the sound of pop music. 他们随着流行音乐的声音摇晃着臀部。 来自《简明英汉词典》

10 straps   

n.带子( strap的名词复数 )；挎带；肩带；背带v.用皮带捆扎( strap的第三人称单数 )；用皮带抽打；包扎；给…打绷带

参考例句：

• the shoulder straps of her dress 她连衣裙上的肩带
• The straps can be adjusted to suit the wearer. 这些背带可进行调整以适合使用者。

11 fiber   

n.纤维，纤维质

参考例句：

• The basic structural unit of yarn is the fiber.纤维是纱的基本结构单元。
• The material must be free of fiber clumps.这种材料必须无纤维块。

12 fibers   

光纤( fiber的名词复数 )； （织物的）质地； 纤维，纤维物质

参考例句：

• Thesolution of collagen-PVA was wet spined with the sodium sulfate as coagulant and collagen-PVA composite fibers were prepared. 在此基础上，以硫酸钠为凝固剂，对胶原-PVA共混溶液进行湿法纺丝，制备了胶原-PVA复合纤维。
• Sympathetic fibers are distributed to all regions of the heart. 交感神经纤维分布于心脏的所有部分。

13 ammunition   

n.军火，弹药

参考例句：

• A few of the jeeps had run out of ammunition.几辆吉普车上的弹药已经用光了。
• They have expended all their ammunition.他们把弹药用光。

14 automobiles   

n.汽车( automobile的名词复数 )

参考例句：

• When automobiles become popular,the use of the horse and buggy passed away. 汽车普及后，就不再使用马和马车了。 来自《简明英汉词典》
• Automobiles speed in an endless stream along the boulevard. 宽阔的林荫道上，汽车川流不息。 来自《现代汉英综合大词典》

15 resistant   

adj.(to)抵抗的，有抵抗力的

参考例句：

• Many pests are resistant to the insecticide.许多害虫对这种杀虫剂有抵抗力。
• They imposed their government by force on the resistant population.他们以武力把自己的统治强加在持反抗态度的人民头上。

16 syrup   

n.糖浆，糖水

参考例句：

• I skimmed the foam from the boiling syrup.我撇去了煮沸糖浆上的泡沫。
• Tinned fruit usually has a lot of syrup with it.罐头水果通常都有许多糖浆。

17 milky   

adj.牛奶的，多奶的；乳白色的

参考例句：

• Alexander always has milky coffee at lunchtime.亚历山大总是在午餐时喝掺奶的咖啡。
• I like a hot milky drink at bedtime.我喜欢睡前喝杯热奶饮料。

18 decided   

adj.决定了的，坚决的；明显的，明确的

参考例句：

• This gave them a decided advantage over their opponents.这使他们比对手具有明显的优势。
• There is a decided difference between British and Chinese way of greeting.英国人和中国人打招呼的方式有很明显的区别。

19 psychology   

n.心理，心理学，心理状态

参考例句：

• She has a background in child psychology.她受过儿童心理学的教育。
• He studied philosophy and psychology at Cambridge.他在剑桥大学学习哲学和心理学。