昆明半身心肺复苏训练模拟人（简易型）广州内囊与基底神经节立体解剖模型,太原肩膝关节综合手术实训系统（显影版）,上海脉象训练仪（网络版、学生机）,甘肃高级着装式男性导尿模型,驻马人体骨杠杆分类模型,西藏胃镜与ERCP检查训练模型,湖南立体狗牙

WASHINGTON, Sept. 15 (Xinhua) -- A team of researchers has discovered a planet that orbits around a pair of stars, the U.S. space agency NASA announced Thursday.This is the first instance of astronomers finding direct evidence of a so-called circumbinary planet. A few other planets have been suspected of orbiting around both members of a dual-star system, but the transits of the circumbinary planet have never been detected previously.The team, led by Laurance Doyle of the SETI Institute in California, used photometric data from the NASA Kepler space telescope, which monitors the brightness of 155,000 stars.NASA's Kepler mission has discovered a world where two suns set over the horizon instead of just one. The planet, called Kepler-16b, is the most "Tatooine-like" planet yet found in our galaxy. Tatooine is the name of Luke Skywalker's home world in the science fiction movie Star Wars. In this case, the planet it not thought to be habitable. It is a cold world, with a gaseous surface, but like Tatooine, it circles two stars.They found the binary star system by detecting a system where the stars eclipsed each other from the perspective of the Kepler spacecraft. These stars have two eclipses: A primary eclipse when the larger star is partially blocked by the smaller star and a secondary eclipse where the smaller star is fully blocked by the larger star.But the researchers also noticed other times when the brightness of the two stars dropped, even when they were not in an eclipse position. This pattern suggested that there was likely a third object involved. The fact that these so-called tertiary and quaternary eclipses recurred after varying intervals of time, and were of different depths, indicated that the stars were in different positions in their orbit at each instance. This result showed that the tertiary and quaternary eclipses were being caused by something circling both stars, and not an object circling one or the other star.Measurements of the variations in the timing of all four types of eclipses, resulting from the mutual gravitational interactions of the two stars and the third body, demonstrated that the third object was, indeed, a planet. Their work indicates that the planet is less massive than Jupiter, possibly comparable in mass to Saturn, and that the larger of the two binary stars is smaller than our Sun.Their findings will be published Friday in Science."This discovery confirms a new class of planetary systems that could harbor life," Kepler principal investigator William Borucki said in a statement. "Given that most stars in our galaxy are part of a binary system, this means the opportunities for life are much broader than if planets form only around single stars. This milestone discovery confirms a theory that scientists have had for decades but could not prove until now."

WASHINGTON, Aug. 16 (Xinhua) -- The White House announced Tuesday that the U.S. Departments of Agriculture, Energy and Navy will invest up to 510 million U.S. dollars in partnership with the private sector to facilitate the country's biofuel industry development."Biofuels are an important part of reducing America's dependence on foreign oil and creating jobs here at home," U.S. President Barack Obama said in a White House statement.The initiative is a response to a directive from Obama issued in March as part of the Blueprint for A Secure Energy Future, the administration's framework for reducing dependence on foreign oil."But supporting biofuels cannot be the role of government alone. That's why we're partnering with the private sector to speed development of next-generation biofuels that will help us continue to take steps towards energy independence and strengthen communities across our country," Obama added.The joint plan calls for the three departments to invest up to 510 million dollars in the next three years, which will require substantial cost share from private industry, in a bid to reduce U. S. reliance on foreign oil and create jobs at home."By building a national biofuels industry, we are creating construction jobs, refinery jobs and economic opportunity in rural communities throughout the country," said U.S. Agriculture Secretary Tom Vilsack.White House figures revealed that the world's largest economy spends more than 300 billion dollars on imported crude oil every year.With a slackening economic recovery and the government's approval rate at a record low level, the Obama administration is rolling out a string of measures in recent days to accelerate economic growth and job creation.

SAN FRANCISCO, Sept. 22 (Xinhua) -- Facebook on Thursday introduced Timeline, a new profile design featuring milestones of one's life on a single page.At Facebook's f8 developer conference, Chief Executive Officer Mark Zuckerberg promoted the new feature, a blog-like presentation that let users scrolls vertically through the big moments of one's life."It's how you can tell the whole story of your life in a single page," said Zuckerberg, showing his Timeline which started from a baby photo.Zuckerberg assured users that they have complete control over their Timeline, saying that they can decide what content will appear and who can see it. The new feature will be available in a few weeks.Half a billion people are using Facebook in the world everyday, according to Zuckerberg.

WASHINGTON, July 20 (Xinhua) -- Using the Hubble Space Telescope, astronomers have discovered a fourth moon orbiting the icy dwarf planet Pluto, the U.S. National Aeronautics and Space Administration (NASA) announced Wednesday in a statement. The tiny, new satellite, temporarily designated P4, was uncovered in a Hubble survey searching for rings around the dwarf planet.P4 was first seen in a photo taken with Hubble's Wide Field Camera 3 on June 28. It was confirmed in subsequent Hubble pictures taken on July 3 and July 18. It is the smallest moon discovered around Pluto. It has an estimated diameter of 8 to 21 miles (13 to 34 km). By comparison, Charon, Pluto's largest moon, is 648 miles (1,043 km) across, and the other moons, Nix and Hydra, are in the range of 20 to 70 miles in diameter (32 to 113 km).Two labeled images of the Pluto system taken by the Hubble Space Telescope's Wide Field Camera 3 ultraviolet visible instrument with newly discovered fourth moon P4 circled. The image on the left was taken on June 28, 2011. The image of the right was taken on July 3, 2011."I find it remarkable that Hubble's cameras enabled us to see such a tiny object so clearly from a distance of more than 3 billion miles (5 billion km)," said Mark Showalter of the SETI Institute in California, who led this observing program with Hubble.P4 is located between the orbits of Nix and Hydra, which Hubble discovered in 2005. Charon was discovered in 1978 at the U.S. Naval Observatory and first resolved using Hubble in 1990 as a separate body from Pluto.The dwarf planet's entire moon system is believed to have formed by a collision between Pluto and another planet-sized body early in the history of the solar system. The smashup flung material that coalesced into the family of satellites observed around Pluto.The finding is a result of ongoing work to support NASA's New Horizons mission, scheduled to fly through the Pluto system in 2015. The mission is designed to provide new insights about worlds at the edge of our solar system. Hubble's mapping of Pluto's surface and discovery of its satellites have been invaluable to planning for New Horizons' close encounter."This is a fantastic discovery," said New Horizons' principal investigator Alan Stern of the Southwest Research Institute in Colorado. "Now that we know there's another moon in the Pluto system, we can plan close-up observations of it during our flyby."