新化学感应系统能更快探测地雷

时间：2012-08-03 07:26:32

（单词翻译:单击）

A chemical sensing system developed by engineers at the University of Connecticut is believed to be the first of its kind capable of detecting vapors²（蒸汽） from buried landmines³ and other explosive devices with the naked eye rather than advanced scientific instrumentation. The research was first reported in the May 11, 2012 online edition of Advanced Functional⁴ Materials.

The key to the system is a fluorescent⁵（荧光的） nanofiberous film that can detect ultra-trace levels of explosive vapors and buried explosives when applied⁶ to an area where explosives are suspected. A chemical reaction marking the location of the explosive device occurs when the film is exposed to handheld ultraviolet light.

The system can detect nitroaromatics such as those found in TNT and 2,4-DNT (the military's primary explosive and the principle components⁷ in landmines) as well as the elements used in harder to detect plastic explosives such as HMX, RDX, Tetryl, and PETN. The ultra-sensitive system can detect elements at levels as low as 10 parts per billion (TNT), 74 parts per trillion (Tetryl), 5 ppt (RDX), 7 ppt (PETN) and 0.1 ppt (HMX) released from one billionth of a gram of explosive residue⁸.

If there is no explosive vapor¹ present, the recyclable film retains a bright fluorescent cyan blue color when exposed to ultraviolet light. If explosive molecules⁹ are present, the fluorescence is quenched¹⁰ and a dark circle identifying the threat forms on the film within minutes.

"Our initial results have been very promising," says UConn Dr. Ying Wang, who developed the system as a chemical engineering doctoral student working under the supervision¹¹ of UConn Associate Engineering Professor Yu Lei. "We are now in the process of arranging a large-scale field test in Sweden."

Rather than using sophisticated chemical modifications¹² or costly¹³ synthetic¹⁴ polymers in preparing the sensing material, UConn scientists prepared their ultra-thin film by simply electrospinning pyrene with polystyrene in the presence of an organic salt (tetrabutylammonium hexafluorophosphate or TBAH). This resulted in a highly porous¹⁵ nanofiberous membrane¹⁶ that absorbs explosive vapors at ultra-trace levels quickly and reliably. The film also has excellent sensitivity against common interferences such as ammonium nitrate and inorganic¹⁷ nitrates. Initial vapor detection took place within seconds with more than 90 percent fluorescent quenching¹⁸ efficiency within six minutes.

According to the United Nations, there are an estimated 110 million active landmines hidden underground in 64 countries around the world. It is estimated that as many as 25,000 people are maimed or killed by landmines each year across the globe. The mines not only threaten people's lives, they can paralyze communities by limiting the use of land for farming or roads for trade.

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1 vapor
n.蒸汽，雾气
参考例句：
The cold wind condenses vapor into rain.冷风使水蒸气凝结成雨。 This new machine sometimes transpires a lot of hot vapor.这部机器有时排出大量的热气。

2 vapors
n.水汽，水蒸气，无实质之物( vapor的名词复数 )；自夸者；幻想 [药]吸入剂 [古]忧郁（症）v.自夸，（使）蒸发( vapor的第三人称单数 )
参考例句：
His emotions became vague and shifted about like vapors. 他的心情则如同一团雾气，变幻无常，捉摸不定。来自辞典例句 They have hysterics, they weep, they have the vapors. 他们歇斯底里，他们哭泣，他们精神忧郁。来自辞典例句

3 landmines
潜在的冲突；地雷，投伞水雷( landmine的名词复数 )
参考例句：
The treaty bans the use production and trade of landmines. 该条约规定，禁止使用地雷相关产品及贸易。 One of the weapon's of special concern was landmines. 在引起人们特别关注的武器中就有地雷。

4 functional
adj.为实用而设计的，具备功能的，起作用的
参考例句：
The telephone was out of order,but is functional now.电话刚才坏了，但现在可以用了。 The furniture is not fancy,just functional.这些家具不是摆着好看的，只是为了实用。

5 fluorescent
adj.荧光的，发出荧光的
参考例句：
They observed the deflections of the particles by allowing them to fall on a fluorescent screen.他们让粒子落在荧光屏上以观察他们的偏移。 This fluorescent lighting certainly gives the food a peculiar color.这萤光灯当然增添了食物特别的色彩。

6 applied
adj.应用的；v.应用，适用
参考例句：
She plans to take a course in applied linguistics.她打算学习应用语言学课程。 This cream is best applied to the face at night.这种乳霜最好晚上擦脸用。

7 components
（机器、设备等的）构成要素，零件，成分；成分( component的名词复数 )； [物理化学]组分； [数学]分量；（混合物的）组成部分
参考例句：
the components of a machine 机器部件 Our chemistry teacher often reduces a compound to its components in lab. 在实验室中化学老师常把化合物分解为各种成分。

8 residue
n.残余，剩余，残渣
参考例句：
Mary scraped the residue of food from the plates before putting them under water.玛丽在把盘子放入水之前先刮去上面的食物残渣。 Pesticide persistence beyond the critical period for control leads to residue problems.农药一旦超过控制的临界期，就会导致残留问题。

9 molecules
分子( molecule的名词复数 )
参考例句：
The structure of molecules can be seen under an electron microscope. 分子的结构可在电子显微镜下观察到。 Inside the reactor the large molecules are cracked into smaller molecules. 在反应堆里，大分子裂变为小分子。

10 quenched
解（渴）( quench的过去式和过去分词 )；终止（某事物）；（用水）扑灭（火焰等）；将（热物体）放入水中急速冷却
参考例句：
He quenched his thirst with a long drink of cold water. 他喝了好多冷水解渴。 I quenched my thirst with a glass of cold beer. 我喝了一杯冰啤酒解渴。

11 supervision
n.监督，管理
参考例句：
The work was done under my supervision.这项工作是在我的监督之下完成的。 The old man's will was executed under the personal supervision of the lawyer.老人的遗嘱是在律师的亲自监督下执行的。

12 modifications
n.缓和( modification的名词复数 )；限制；更改；改变
参考例句：
The engine was pulled apart for modifications and then reassembled. 发动机被拆开改型，然后再组装起来。来自《简明英汉词典》 The original plan had undergone fairly extensive modifications. 原计划已经作了相当大的修改。来自《简明英汉词典》

13 costly
adj.昂贵的，价值高的，豪华的
参考例句：
It must be very costly to keep up a house like this.维修这么一幢房子一定很昂贵。 This dictionary is very useful,only it is a bit costly.这本词典很有用，左不过贵了些。

14 synthetic
adj.合成的，人工的；综合的；n.人工制品
参考例句：
We felt the salesman's synthetic friendliness.我们感觉到那位销售员的虚情假意。 It's a synthetic diamond.这是人造钻石。

15 porous
adj.可渗透的，多孔的
参考例句：
He added sand to the soil to make it more porous.他往土里掺沙子以提高渗水性能。 The shell has to be slightly porous to enable oxygen to pass in.外壳不得不有些细小的孔以便能使氧气通过。

16 membrane
n.薄膜，膜皮，羊皮纸
参考例句：
A vibrating membrane in the ear helps to convey sounds to the brain.耳膜的振动帮助声音传送到大脑。 A plastic membrane serves as selective diffusion barrier.一层塑料薄膜起着选择性渗透屏障的作用。

17 inorganic
adj.无生物的；无机的
参考例句：
The fundamentals of inorganic chemistry are very important.无机化学的基础很重要。 This chemical plant recently bought a large quantity of inorganic salt.这家化工厂又买进了大量的无机盐。

18 quenching
淬火，熄
参考例句：
She had, of course, no faculty for quenching memory in dissipation. 她当然也没有以放荡纵欲来冲淡记忆的能耐。 This loss, termed quenching, may arise in two ways. 此种损失称为淬火，呈两个方面。