[ti:Scientists Study to Remove Carbon from the Atmosphere+++科学家们研究出除大气中的二氧化碳]
[by:www.21voa.com]
[00:00.00]更多听力请访问21VOA.COM
[00:00.04]Scientists have traveled to the mountains of Oman
[00:03.96]to find a way to remove carbon dioxide gas from the atmosphere.
[00:10.48]The geologists hope to find an effective and low-cost way
[00:15.96]to capture the gas which is blamed for worldwide climate change.
[00:22.44]The Middle Eastern country of Oman is one of the few places in the world
[00:27.92]where the Earth's mantle is easy to reach.
[00:31.68]This part of the Arabian Peninsula is where an unusual rock formation
[00:38.24]pulls carbon out of the air.
[00:40.84]Geologists are taking rock samples from the al-Hajjar Mountains.
[00:47.52]They want to discover how a natural process changed carbon dioxide into minerals
[00:54.88]such as limestone and marble millions of years ago.
[01:00.56]Peter Kelemen is a geochemist at Columbia University's Lamont-Doherty Earth Observatory.
[01:09.16]He has been exploring Oman's hills for almost 30 years.
[01:14.68]"You can walk down these beautiful canyons
[01:18.28]and basically descend 20 kilometers into the earth's interior," he said.
[01:24.48]This area in Oman has the largest exposed parts of the Earth's mantle,
[01:31.84]a part of the Earth that is usually far below the surface.
[01:37.40]It was brought to the surface by the forces of plate tectonics millions of years ago.
[01:45.36]The mantle contains rocks called peridotite.
[01:50.04]The rocks react with carbon in the air and water to form marble and limestone.
[01:58.40]Kelemen explained that magnesium atoms combined with carbon dioxide
[02:04.00]to form limestone, quartz and magnesium carbonate.
[02:08.92]He said one of the mountains nearby holds "about a billion tons of CO2," or carbon dioxide.
[02:18.72]In Oman's mountain caves, rain and ground water form pools.
[02:25.64]The rain and water pull carbon from the exposed mantle
[02:30.08]to make mineral formations called stalactites and stalagmites.
[02:36.20]The surface of these natural pools of water develops a layer of white carbonate
[02:42.32]—a kind of mineral that contains carbon.
[02:46.16]Keleman said if you take off this thin white film, it will grow back in a day.
[02:52.36]He says that is very fast for a geological process.
[02:58.08]Kelemen and a team of 40 scientists have formed the Oman Drilling Project
[03:04.24]to study how the process works.
[03:07.64]They want to find out how the rocks managed to capture so much carbon over time.
[03:13.84]They want to know if the process could be used to clean carbon from the earth's atmosphere.
[03:21.88]Keleman's team recently spent four months in Oman collecting many rock samples.
[03:29.20]They hope to use these samples to develop a geological history
[03:34.16]of the process that turns carbon dioxide into carbonate.
[03:38.96]The team plans to send 13 tons of samples from four different areas
[03:45.96]to a research ship off the coast of Japan.
[03:50.20]Kelemen and other geologists will study the rocks there.
[03:55.60]They want to find out how the rocks captured so much carbon over 90 million years.
[04:02.32]And they want to know if there is a way to make that process happen faster.
[04:08.60]Kelemen thinks a drilling operation be used
[04:12.23]to move carbon-rich water into the new seabed on underwater mountains.
[04:18.12]The submerged rock would chemically take in carbon from the water.
[04:23.76]The water could then move back to the surface
[04:27.37]to absorb more carbon from the atmosphere.
[04:31.56]Then the process would repeat itself.
[04:35.36]The scientists hope their research will provide a way of dealing with carbon dioxide
[04:41.44]and other carbon-based greenhouse gases linked to climate change.
[04:47.92]Climate change is a global change in weather patterns.
[04:51.88]Scientists say it is caused by an increase in levels of carbon dioxide
[04:58.28]and other gases that trap heat in the atmosphere.
[05:03.00]The use of fossil fuels is considered a major source of carbon dioxide.
[05:10.04]Until now, most efforts to combat climate change
[05:14.32]have centered on reducing emissions from cars and power plants.
[05:19.84]But researchers are testing ways to remove or recycle carbon already in the seas and sky.
[05:29.16]In Iceland, they inject carbon into volcanic rock at the Hellisheidi geothermal plant.
[05:36.68]In China, carbon is filtered and reused at the Sinopec fertilizer plant.
[05:43.72]"Any one technique is not guaranteed to succeed," said Stuart Haszeldine.
[05:50.48]He is a geology professor at the University of Edinburgh.
[05:55.44]He also serves on a U.N. climate group that studies how to reduce atmospheric carbon.
[06:03.20]Keleman said the Oman Drilling Project would need more years of testing.
[06:09.68]He hopes the energy industry will take an interest and help the project.
[06:15.88]So far, it has only received support from science organizations
[06:21.36]including the U.S. space agency NASA.
[06:25.24]I'm Jonathan Evans.更多听力请访问21VOA.COM
END OF TRACK. "END OF TRACK." The two men bowed. "Whoever was that person you were talking to?" she enquired, as soon as they stood together. The took of triumph faded from her eyes, she had grown worn and weary. The roses were wilting on the walls, the lights were mostly down now. Hetty, looking in to see if anything was wanted, found herself driven away almost fiercely. I only saw Master Jervie once when he called at tea time, The year 1747 was opened by measures of restriction. The House of Lords, offended at the publication of the proceedings of the trial of Lord Lovat, summoned the parties to their bar, committed them to prison, and refused to liberate them till they had pledged themselves not to repeat the offence, and had paid very heavy fees. The consequence of this was that the transactions of the Peers were almost entirely suppressed for nearly thirty years from this time, and we draw our knowledge of them chiefly from notes taken by Horace Walpole and Lord Chancellor Hardwicke. What is still more remarkable, the reports of the House of Commons, being taken by stealth, and on the merest sufferance, are of the most meagre kind, sometimes altogether wanting, and the speeches are given uniformly under fictitious names; for to have attributed to Pitt or Pelham their[112] speeches by name would have brought down on the printers the summary vengeance of the House. Many of the members complained bitterly of this breach of the privileges of Parliament, and of "being put into print by low fellows"; but Pelham had the sense to tolerate them, saying, "Let them alone; they make better speeches for us than we can make for ourselves." Altogether, the House of Commons exhibited the most deplorable aspect that can be conceived. The Ministry had pursued Walpole's system of buying up opponents by place, or pension, or secret service money, till there was no life left in the House. Ministers passed their measures without troubling themselves to say much in their behalf; and the opposition dwindled to Sir John Hinde Cotton, now dismissed from office, and a feeble remnant of Jacobites raised but miserable resistance. In vain the Prince of Wales and the secret instigations of Bolingbroke and Doddington stimulated the spirit of discontent; both Houses had degenerated into most silent and insignificant arenas of very commonplace business. "It certainly will be. Miss Widgeon," answered Maria, with strictly "company manners." "One who has never had a brother exposed to the constant dangers of army life can hardly understand how glad we all feel to have Si snatched from the very jaws of death and brung back to us." "Just plug at 'em as you would at a crow, and then go on your way whistlin'?" persisted Harry. "Hurroo!" echoed Hennessey; "that's the ticket." "Come forward, keeper," continued the baron, "and state how these arrows came into your hands!" "Yes." HoMEJULIA京香2018下载
ENTER NUMBET 0015kuaiair.com.cn
deqin.org.cn
www.ydscit.com.cn
jndfjr.com.cn
ihai.org.cn
xner.net.cn
sms114.net.cn
www.ldxx.org.cn
www.china824.net.cn
www.xzgkj.com.cn