中子技术 轮廓法 数值模拟

【深度科普(6/8)】中子散射技术的应用—环境与气候

发布时间:2017-04-28

    随着社会的发展,人们开始意识到安全、健康的生活环境的价值,同时也越来越关注环境污染及其所带来的气候变化。借助中子散射技术,科学家可以更有效地利用自然资源,了解自然,更准确的预测气候变化,研究环境污染的原因及其影响、并寻求切实可行的解决方案。

    With the development of society, people are aware of the value of a safe and healthy living environment, and paying more and more attention to the environmental pollution and the related climate change. By using neutron scattering techniques, scientists can make more efficient use of natural resources, understand the nature, predict the climate changes more accurately, look into the reasons and effects of pollutions, and seek for workable solutions.


一、石油开采 Enhanced oil recovery



    全世界有40000多个油田,其中最大的几个独立油田分布在中东,估计每个独立油田都有600亿桶以上的石油储量。由于储层特点和开采技术的局限性,只有一部分石油能够被开采出来。

    More than 40,000 oil fields are scattered around the world, among which the largest individual fields lie in the Middle East, each is estimated to hold more than 60 billion barrels of oil. Only a fraction of this oil can be brought to the surface because of reservoir characteristics and limitations in petroleum extraction technologies.

 

    人们经常借助如注水或注气等先进采油技术,来提高油田的产量和经济回报。由于高压二氧化碳比水更容易流过岩石中的孔隙,所以提高石油采收率可以利用高压二氧化碳。添加剂可以使二氧化碳浓缩,使其更有效地流过多孔岩石,把石油从非常细小的岩石孔隙中推挤出来,使油田增产最高可达30%。

    Enhanced oil recovery techniques such as water-flooding or gas-injection are frequently used to improve the yield and economic return from a field. High pressure carbon dioxide can be used in enhanced oil recovery as it is able to flow through the pores in the rock much more easily than water. Additives can thicken the carbon dioxide allowing it to flow through the rock more efficiently and push oil out of very small rock pores, increasing the oil field yield by up to 30%.

 

    以前利用二氧化碳开采石油的技术所使用的添加剂,含有对环境有害的氟元素。借助中子散射实验所得到的独特的分子信息,人们研制出一种安全的新型添加剂——无氟无害的碳氢化合物。这种类似肥皂的无害添加剂,可将二氧化碳转化成一种切实可行的商业溶剂,以增加油田的原油开采量。

    Previous advances in using carbon dioxide for oil recovery have used additives containing environmentally damaging fluorine. A new, safe additive developed using the unique molecular information coming from neutron scattering experiments contains no fluorine at all and is a harmless hydrocarbon. This harmless soap-like additive turns carbon dioxide into a viable commercial solvent to increase the amount of crude oil that can be extracted from oil fields.

 

    现有油田开采寿命的延长,也将会为非碳能源的研究提供更多的时间,比如太阳能和氢能。

    Getting longer life out of existing oil reserves will also give more time for research into non-carbon energy sources such as solar or hydrogen.


    发现一个能够改变二氧化碳性质的化学物质,并将其(二氧化碳)制成适用溶剂,广泛应用于提高石油采收率,这已被公认是一项变革性技术。

—— Bob Enick教授

匹兹堡大学

    The discovery of a chemical capable of modifying the properties of carbon dioxide to make it suitable for widespread use as a solvent in enhanced oil recovery has been recognized as a game-changing technology.

—— Professor Bob Enick

University of Pittsburgh


二、南极化石 Antarctic fossils



    南极洲虽然现在是一片冰雪大地,但在其历史中的大部分时间里,它曾被一片片茂密的森林所覆盖。如今,这些森林的遗迹都以木化石、树叶化石、花朵和花粉化石的形式保存在岩石的记录中。

    Although Antarctica is now a land of ice and snow, for most of its history it was covered with lush forests. The remains of the forests are now preserved in the rock record as fossil wood, leaves, flowers and pollen.

 

    紧缩在岩石里的5000万年前的针叶树叶枝化石,昭示着南极洲过去的气候跟现如今的冰天雪地有着巨大差别。借助中子成像技术,我们无需打破岩石,也无需破坏脆弱的针叶结构,就可以(首次)看到5000万年前被包裹在沉积物中的针叶树枝的三维结构。

    Leafy branches of 50 million-year-old conifers locked in rocks indicate a very different climate in Antarctica to the ice and snow found today. Neutron imaging allows the three-dimensional structure of conifer branches to be seen for the first time since they were encased in sediment 50 million years ago, without breaking open the rock and destroying the fragile structures.


    我们想当然地认为南极洲一直是一片冰封的荒野,但在其地质史上,冰帽只是在相对近期才出现的。我认为‘南极洲曾经被森林所覆盖’这一想法,绝对令人难以置信。

—— Jane Francis教授

利兹大学

    We take it for granted that Antarctica has always been a frozen wilderness, but the ice caps only appeared relatively recently in geological history. I find the idea that Antarctica was once forested absolutely mind-boggling.

—— Professor Jane Francis

University of Leeds


、多云的天空 Cloudy skies


    在预测天气时,遇到的极难课题之一就是如何模拟云的形成。气溶胶形成云和雨滴的可能性,取决于大气中的诸多化学反应,而我们对这些化学反应所知甚少。

    Modelling cloud formation is one of hardest jobs in weather forecast. The potential for aerosols to form clouds and raindrops is dictated by little-known chemical reactions within the atmosphere.

 

    水蒸气在空气中悬浮着的微小颗粒(气溶胶)上冷凝,形成小水滴,云就是由这些小水滴所组成的。气溶胶的来源广泛,比如海洋中的海盐、植物、化石燃料和草木的燃烧等。气溶胶聚集得越多,就越容易形成云。云中的小水滴不断地长大,到一定程度就形成了降雨。由于空气污染破坏了小水滴的油质表层,这就从根本上改变了云的形成方式。

    Clouds are made up of droplets that form when water vapour condenses on tiny particles (aerosols) suspended in the air. Aerosols can come from many places: sea salt from the ocean, plants, or the burning of fossil fuels and vegetation. The more aerosols there are, the easier it is for clouds to form. The droplets grow in size until they are large enough to fall as rain. Air pollution fundamentally changes the way clouds form by destroying the oily layers coating water droplets.

 

    中子散射实验表明,由汽车尾气在大气低层产生的臭氧会破坏空气中小水滴的油质表层,并降低它们的增长速度。这一新发现的机制,正被用于更新大气中有机气溶胶及其对云反射率、降雨可能与模式和水循环之影响的(数学)模型。

    Neutron scattering experiments have demonstrated that ozone created in the lower atmosphere from vehicle pollution can attack the oily films coating water droplets in the air and reduce the speed at which they can grow. This newly-discovered mechanism is being used to update models of organic aerosols in the atmosphere and their impact on cloud reflectivity, drizzle potential, rainfall patterns and water cycle.


copyright © 2016 东莞材料基因高等理工研究院 .All Rights Reserved.     粤ICP备16087785号-1