【每日阅读训练第四期——速度越障6系列】【6-9】科技

CHRISTINE2010

【计时一】

First Evidence Discovered of Planet's Destruction by Its Star

ScienceDaily (Aug. 20, 2012) — The first evidence of a planet's destruction by its aging star has been discovered by an international team of astronomers. The evidence indicates that the missing planet was devoured as the star began expanding into a "red giant" -- the stellar equivalent of advanced age.

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"A similar fate may await the inner planets in our solar system, when the Sun becomes a red giant and expands all the way out to Earth's orbit some five-billion years from now," said Alex Wolszczan, an Evan Pugh Professor of Astronomy and Astrophysics at Penn State, University, who is one of the members of the research team. Wolszczan also is the discoverer of the first planet ever found outside our solar system.

The astronomers also discovered a massive planet in a surprisingly elliptical orbit around the same red-giant star, named BD+48 740, which is older than the Sun with a radius about eleven times bigger. Wolszczan and the team's other members, Monika Adamow, Grzegorz Nowak, and Andrzej Niedzielski of Nicolaus Copernicus University in Torun, Poland; and Eva Villaver of the Universidad Autonoma de Madrid in Spain, detected evidence of the missing planet's destruction while they were using the Hobby-Eberly Telescope to study the aging star and to search for planets around it. The evidence includes the star's peculiar chemical composition, plus the highly unusual elliptical orbit of its surviving planet.

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【计时二】

"Our detailed spectroscopic analysis reveals that this red-giant star, BD+48 740, contains an abnormally high amount of lithium, a rare element created primarily during the Big Bang 14 billion years ago," Adamow said. Lithium is easily destroyed in stars, which is why its abnormally high abundance in this older star is so unusual. "Theorists have identified only a few, very specific circumstances, other than the Big Bang, under which lithium can be created in stars," Wolszczan added. "In the case of BD+48 740, it is probable that the lithium production was triggered by a mass the size of a planet that spiraled into the star and heated it up while the star was digesting it."

The second piece of evidence discovered by the astronomers is the highly elliptical orbit of the star's newly discovered massive planet, which is at least 1.6 times as massive as Jupiter. "We discovered that this planet revolves around the star in an orbit that is only slightly wider than that of Mars at its narrowest point, but is much more extended at its farthest point," Niedzielski said. "Such orbits are uncommon in planetary systems around evolved stars and, in fact, the BD+48 740 planet's orbit is the most elliptical one detected so far." Because gravitational interactions between planets are responsible for such peculiar orbits, the astronomers suspect that the dive of the missing planet toward the star before it became a giant could have given the surviving massive planet a burst of energy, throwing it into an eccentric orbit like a boomerang.

"Catching a planet in the act of being devoured by a star is an almost improbable feat to accomplish because of the comparative swiftness of the process, but the occurrence of such a collision can be deduced from the way it affects the stellar chemistry," Villaver explained. "The highly elongated orbit of the massive planet we discovered around this lithium-polluted red-giant star is exactly the kind of evidence that would point to the star's recent destruction of its now-missing planet."

【337】



【计时三】

Sex and the Female Brain: Protein in Semen Acts On Female Brain to Prompt Ovulation

ScienceDaily (Aug. 20, 2012) — An international team of scientists led by Gregg Adams at the University of Saskatchewan has discovered that a protein in semen acts on the female brain to prompt ovulation, and is the same molecule that regulates the growth, maintenance, and survival of nerve cells.

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Male mammals have accessory sex glands that contribute seminal fluid to semen, but the role of this fluid and the glands that produce it are not well understood.

"From the results of our research, we now know that these glands produce large amounts of a protein that has a direct effect on the female," says Adams, a professor of veterinary biomedical sciences at the Western College of Veterinary Medicine at the U of S.

The work, which appears in the August 20, 2012 issue of the Proceedings of the National Academy of Sciences (PNAS), raises intriguing questions about fertility in mammals, including humans.

The team characterized the protein, dubbed ovulation-inducing factor (OIF), that they have found in the semen of all species of mammal they have looked at so far. In the process of discovering its identity, the team compared OIF to thousands of other proteins, including nerve growth factor (NGF) which is found primarily in nerve cells throughout the body.

"To our surprise, it turns out they are the same molecule," Adams says. "Even more surprising is that the effects of NGF in the female were not recognized earlier, since it's so abundant in seminal plasma."

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【计时四】

While OIF/NGF may function differently from animal to animal, it is present in all mammals studied so far, from llamas, cattle and koalas to pigs, rabbits, mice, and humans. This implies an important role in reproduction in all mammals. Just how it works, its role in various species, and its clinical relevance to human infertility are a few of the questions that remain to be answered.

OIF/NGF in the semen acts as a hormonal signal, working through the hypothalamus of the female brain and the pituitary gland. This triggers the release of other hormones that signal the ovaries to release an egg (or eggs, depending on the species).

For this latest study, the team looked at two species: llamas and cattle. Llamas are "induced ovulators," that is, they ovulate only when they have been inseminated. Cows -- and humans -- are "spontaneous ovulators," meaning that a regular buildup of hormones stimulates the release of an egg.

Using a variety of techniques, the researchers compared OIF and NGF and found them to have the same size and to cause the same effects across species. Work at the Canadian Light Source synchrotron at the U of S confirmed the structure of the molecule.

"The idea that a substance in mammalian semen has a direct effect on the female brain is a new one," Adams explains. "This latest finding broadens our understanding of the mechanisms that regulate ovulation and raises some intriguing questions about fertility."

The team includes Marcelo Ratto and Ximena Valderrama from the Universidad Austral de Chile in Valdivia, Chile, as well as Adams, Yvonne Leduc, Karin van Straaten and Roger Pierson from the U of S.

This research was funded by the Natural Sciences and Engineering Research Council of Canada (NSERC), the Alpaca Research Foundation, the Chilean National Science and Technology Research Council, the Saskatchewan Health Research Foundation, and the Canadian Institutes of Health Research (CIHR).

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【计时五】

Big Bang Theory Challenged by Big Chill

ScienceDaily (Aug. 20, 2012) — The start of the Universe should be modeled not as a Big Bang but more like water freezing into ice, according to a team of theoretical physicists at the University of Melbourne and RMIT University.

[attachimg=424,283]105062[/attachimg]
They have suggested that by investigating the cracks and crevices common to all crystals -- including ice -- our understanding of the nature of the Universe could be revolutionized.
Lead researcher on the project, James Quach said current theorizing is the latest in a long quest by humans to understand the origins and nature of the Universe.
"Ancient Greek philosophers wondered what matter was made of: was it made of a continuous substance or was it made of individual atoms?" he said. "With very powerful microscopes, we now know that matter is made of atoms."
"Thousands of years later, Albert Einstein assumed that space and time were continuous and flowed smoothly, but we now believe that this assumption may not be valid at very small scales.
"A new theory, known as Quantum Graphity, suggests that space may be made up of indivisible building blocks, like tiny atoms. These indivisible blocks can be thought about as similar to pixels that make up an image on a screen. The challenge has been that these building blocks of space are very small, and so impossible to see directly."
However James Quach and his colleagues believe they may have figured out a way to see them indirectly.
"Think of the early universe as being like a liquid," he said. "Then as the universe cools, it 'crystallizes' into the three spatial and one time dimension that we see today. Theorized this way, as the Universe cools, we would expect that cracks should form, similar to the way cracks are formed when water freezes into ice."
RMIT University research team member Associate Professor Andrew Greentree said some of these defects might be visible.
"Light and other particles would bend or reflect off such defects, and therefore in theory we should be able to detect these effects," he said.
The team has calculated some of these effects and if their predictions are experimentally verified, the question as to whether space is smooth or constructed out of tiny indivisible parts will be solved once and for all.
The team is supported by the Australian Research Council, and their research was published in the latest edition of the journal Physical Review D.
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【越障】

Cloud Brightening to Control Global Warming? Geoengineers Propose an Experiment

ScienceDaily (Aug. 20, 2012) — Even though it sounds like science fiction, researchers are taking a second look at a controversial idea that uses futuristic ships to shoot salt water high into the sky over the oceans, creating clouds that reflect sunlight and thus counter global warming.

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University of Washington atmospheric physicist Rob Wood describes a possible way to run an experiment to test the concept on a small scale in a comprehensive paper published this month in the journal Philosophical Transactions of the Royal Society.
The point of the paper -- which includes updates on the latest study into what kind of ship would be best to spray the salt water into the sky, how large the water droplets should be and the potential climatological impacts -- is to encourage more scientists to consider the idea of marine cloud brightening and even poke holes in it. In the paper, he and a colleague detail an experiment to test the concept.
"What we're trying to do is make the case that this is a beneficial experiment to do," Wood said. With enough interest in cloud brightening from the scientific community, funding for an experiment may become possible, he said.
The theory behind so-called marine cloud brightening is that adding particles, in this case sea salt, to the sky over the ocean would form large, long-lived clouds. Clouds appear when water forms around particles. Since there is a limited amount of water in the air, adding more particles creates more, but smaller, droplets.
"It turns out that a greater number of smaller drops has a greater surface area, so it means the clouds reflect a greater amount of light back into space," Wood said. That creates a cooling effect on Earth.
Marine cloud brightening is part of a broader concept known as geoengineering which encompasses efforts to use technology to manipulate the environment. Brightening, like other geoengineering proposals, is controversial for its ethical and political ramifications and the uncertainty around its impact. But those aren't reasons not to study it, Wood said.
"I would rather that responsible scientists test the idea than groups that might have a vested interest in proving its success," he said. The danger with private organizations experimenting with geoengineering is that "there is an assumption that it's got to work," he said.
Wood and his colleagues propose trying a small-scale experiment to test feasibility and begin to study effects. The test should start by deploying sprayers on a ship or barge to ensure that they can inject enough particles of the targeted size to the appropriate elevation, Wood and a colleague wrote in the report. An airplane equipped with sensors would study the physical and chemical characteristics of the particles and how they disperse.
The next step would be to use additional airplanes to study how the cloud develops and how long it remains. The final phase of the experiment would send out five to 10 ships spread out across a 100 kilometer, or 62 mile, stretch. The resulting clouds would be large enough so that scientists could use satellites to examine them and their ability to reflect light.
Wood said there is very little chance of long-term effects from such an experiment. Based on studies of pollutants, which emit particles that cause a similar reaction in clouds, scientists know that the impact of adding particles to clouds lasts only a few days.
Still, such an experiment would be unusual in the world of climate science, where scientists observe rather than actually try to change the atmosphere.
Wood notes that running the experiment would advance knowledge around how particles like pollutants impact the climate, although the main reason to do it would be to test the geoengineering idea.
A phenomenon that inspired marine cloud brightening is ship trails: clouds that form behind the paths of ships crossing the ocean, similar to the trails that airplanes leave across the sky. Ship trails form around particles released from burning fuel.
But in some cases ship trails make clouds darker. "We don't really know why that is," Wood said.
Despite increasing interest from scientists like Wood, there is still strong resistance to cloud brightening.
"It's a quick-fix idea when really what we need to do is move toward a low-carbon emission economy, which is turning out to be a long process," Wood said. "I think we ought to know about the possibilities, just in case."
The authors of the paper are treading cautiously.
"We stress that there would be no justification for deployment of [marine cloud brightening] unless it was clearly established that no significant adverse consequences would result. There would also need to be an international agreement firmly in favor of such action," they wrote in the paper's summary.
There are 25 authors on the paper, including scientists from University of Leeds, University of Edinburgh and the Pacific Northwest National Laboratory. The lead author is John Latham of the National Center for Atmospheric Research and the University of Manchester, who pioneered the idea of marine cloud brightening.
【847】

莽莽要上7

speed：
1‘37
2’59
1‘43
2’42
3’08

obstacle：8‘51
1.讲了一个地质工程学家called wood发表的一篇论文中的一个idea，就是说设想一个experiment来增加海洋上的clouds 的brightness从而起到counter global warming的作用。论文中提到了很多怎么试验的details，比如发射的particles的大小等等。
2.讲了这个试验的原理。具体的记不住=^=
3.wood test这个试验的可行性，具体了这个试验是怎么做，然后讲了几点effects of this experiment。
4.虽然说现阶段这个设想挺好的一个试验，但是还是得到了许多的resistance。在做之前必须明确可能的副作用后果还有和取得涉及国家的agreement才可以。

kathy0911

SPEED1:30
2:17
1:28
1:40
2:22


Obstacle
5:57


Cloud Brightening---Wood suggest that more experiments are need to test the idea that by shooting sea salt water into clouds, we may be able to counter the global warming.
Although Marine Geoengneering reminds as a sensitive topic, Wood believes that by study the cloud brightening will bring long-term benefits.

铁板神猴

why your pictures are always so gorgeous~!

tyyhappy

1‘10
1’34
1‘08
1’17
1‘37

3’51

这个项目的介绍。
过程。
原理
可能的影响。现有的发现。
还需要继续观察。

具体内容忘了···

速度方面，同样的字数比前几天慢很多，觉得是单词受阻。

障碍阅读方面。觉得还缺少快速记忆的能力。读下来，但是像是过单词和大意。具体内容忘了。

xjbb

占～

yqhpsyche

谢谢Christine~

59''
1'40
1'03
1'21
2'00

明天考试了....滚去临时抱佛脚，今天越障就偷懒了

Fighting小虾米

1‘03
1’42
0‘59
1’12
2‘05

越障：
5’39
Spray the salt water into the sky in the marine.
The working principles of marine cloud brightening.
The test of spray salt warter into the sky is on going.
But it does not have long-term effects.
Dark cloud mab be occured.
The plan will not be executed until it was clearly established no signficant adverse consequences.

风随心动01

Speed：
1'43
2'23
1'34
1'48
3'05
Obstacle
7:20
某科学家带领他的团队写了一篇论文，认为可以制造云来帮助降低气候变暖，并对此进行了实验
该想法和实验的理论依据是云形成的原因
如果实行该方法，需要做的工作是……。
当然，解决气候变暖的问题主要还是要减少有害气体的排放
这篇论文的作者有25个人

总结：
1、速度慢的愁死个人啊。
2、喜欢回看；做Speed的时候只顾着看单词认不认识，木有关注于文章有没有看懂（只是把文章每个单词按顺序看一遍）我就是杨鹏老师说的错误阅读方法的结合体。
3、生词还是个大问题。

evlily8783

0'53
1:55
0:54
1:14
1:54

越障依旧像看天书，得继续努力……