中山肚子疼是怎么回事中山便血产生块状肉原因,中山华都肛门医院收费,中山啥原因会引起便血,中山为什么拉便便会出血,中山肛瘘手术专业医院,中山屁眼边上起了好大一个包,中山便秘有痔疮

WASHINGTON, June 15 (Xinhua) -- Using the deepest X-ray image ever taken, astronomers found the first direct evidence that massive black holes were common in the early universe, the U.S. National Aeronautics and Space Administration (NASA) said Wednesday in a statement.The discovery from NASA's Chandra X-ray Observatory shows that very young black holes grew more aggressively than previously thought, in tandem with the growth of their host galaxies.By pointing Chandra at a patch of sky for more than six weeks, astronomers obtained what is known as the Chandra Deep Field South (CDFS). When combined with very deep optical and infrared images from NASA's Hubble Space Telescope, the new Chandra data allowed astronomers to search for black holes in 200 distant galaxies, from when the universe was between about 800 million to 950 million years old."Until now, we had no idea what the black holes in these early galaxies were doing, or if they even existed," said Ezequiel Treister of the University of Hawaii, lead author of the study to appear Thursday in journal Nature. "Now we know they are there, and they are growing like gangbusters."The super-sized growth means that the black holes in the CDFS are less extreme versions of quasars -- very luminous, rare objects powered by material falling onto supermassive black holes. However, the sources in the CDFS are about a hundred times fainter and the black holes are about a thousand times less massive than the ones in quasars.The observations found that between 30 and 100 percent of the distant galaxies contain growing supermassive black holes. Extrapolating these results from the small observed field to the full sky, there are at least 30 million supermassive black holes in the early universe. This is a factor of 10,000 larger than the estimated number of quasars in the early universe."It appears we've found a whole new population of baby black holes," said co-author Kevin Schawinski of Yale University. "We think these babies will grow by a factor of about a hundred or a thousand, eventually becoming like the giant black holes we see today almost 13 billion years later."

WASHINGTON, July 8 (Xinhua) -- U.S. space shuttle Atlantis lifted off on Friday morning from Kennedy Space Center in Florida, on the 135th and final flight in NASA's shuttle program.The shuttle blasted off at about 11:29 a.m. EDT (1529 GMT) on a tower of flame, NASA TV showed.Before taking flight, shuttle Commander Christopher Ferguson saluted all those who contributed over the years to the shuttle program."The shuttle is always going to be a reflection of what a great nation can do when it dares to be bold and commits to follow through,'' he said. "We're not ending the journey today ... we're completing a chapter of a journey that will never end.''In this photo released by NASA, space shuttle Atlantis lifts off from NASA's Kennedy Space Center in Florida, the United States, July 8, 2011. U.S. space shuttle Atlantis lifted off at about 11:29 a.m. EDT (1529 GMT) on Friday from Kennedy Space Center in Florida, on the 135th and final flight in NASA's shuttle program.Atlantis's primary payload is an Italian-built cargo hauler named Raffaello which is loaded with 8,640 pounds (3,919 kgs) of food, clothing, supplies and science equipment to sustain space station operations after the shuttles are retired.Only four astronauts take to the skies because there is no shuttle available for a rescue flight should anything go wrong. Normally NASA sends six or seven astronauts on space shuttle flights -- with the last four-person shuttle crew launched 28 years ago.But Atlantis' status as the final flight means there is no other space shuttle on standby and the U.S. would have to call on Russia for any rescue operation. The Russian Soyuz capsules hold just three astronauts and at least one must be Russian, so two crew members would have to fly up and bring home the Americans from the International Space Station one at a time.The crew will also return an ammonia pump that recently failed on the station. Engineers want to understand why the pump failed and improve designs for future spacecraft. One spacewalk is planned during Atlantis' mission, though it will be conducted by NASA's two resident space station astronauts, rather than the shuttle crew.It is the 33rd voyage for Atlantis. Its return to the earth later this month will mark the end of the 30-year shuttle program.Atlantis will be the last shuttle to be retired. Discovery was first in March, followed by Endeavour at the beginning of June. Each shuttle will head to a museum.When the U.S. space shuttle program officially ends later this year, the Russian space program's Soyuz capsule will be the only method for transporting astronauts to and from the station.Space shuttles have made great contributions to U.S. space exploration. They allowed astronauts to not only launch satellites, but to grab and repair them and put them back into service. Most remarkably, they allowed NASA to regularly rejuvenate the Hubble Space Telescope, which for 21 years has produced images that are transforming astronomers' understanding of the universe. With their enormous cargo bays, the shuttles also enabled the United States and its partners to build the International Space Station.However, high costs, risks, policy shift force the U.S. to quit the space shuttle program.NASA originally estimated the program would cost about 90 billion U.S. dollars. However, its actual cost stands at about 200 billion dollars, compared with the 151 billion dollars spent on Apollo which took Americans to the moon in 1969.Seven astronauts perished when Challenger exploded about a minute after launch in 1986. Nearly two decades after the Challenger explosion, a new catastrophe shocked NASA when the shuttle Columbia disintegrated moments before landing in 2003.One out of every 67 flights ended in death. Based on deaths per million miles traveled, the space shuttle is 138 times riskier than a passenger jet.The panel that investigated the 2003 Columbia accident concluded: "It is in the nation's interest to replace the Shuttle as soon as possible.''The Obama administration wants to spur private companies to get into the space taxi business, freeing NASA to focus on deep space exploration and new technology development.During his first-ever Twitter town hall meeting on Wednesday, Obama said NASA needs new technology breakthroughs to revitalize its mission to explore the universe."The shuttle did some extraordinary work in low-orbit experiments, the International Space Station, moving cargo. It was an extraordinary accomplishment. And we're very proud of the work that it did," Obama said. "But now what we need is that next technological breakthrough."

BEIJING, June 26 (Xinhua) -- A drama honoring an archivist who had devoted himself to the Chinese People's Liberation Army (PLA)'s archive work was staged Saturday evening in Beijing.The drama, "Sheng Ming Dang An," or "Archives of Life," tells the life story of Liu Yiquan who had worked as a file clerk and later a consultant at the PLA Archives for about 38 years.Liu had collected more than 830,000 pieces of military archives, which was regarded as a special contribution to the army. Li Changchun (L, front), a member of the Standing Committee of the Political Bureau of the Communist Party of China (CPC) Central Committee, congratulates actors on the successful performance of drama "life archives" in Beijing, capital of China, June 25, 2011.Despite being diagnosed with terminal cancer in 2008, Liu continued to work hard. He died on Jan. 28, 2010, at the age of 59.Li Changchun, a Standing Committee member of the Political Bureau of the Communist Party of China (CPC) Central Committee, joined the audience of the drama on Saturday.Li later said the drama was touching and significant in reflecting the model role of CPC members ahead of the 90th founding anniversary of the CPC.Liu Yiquan was also honored by the U.S. military authorities for his role in helping identify some key documents that led to the repatriation of the remains of the United States personnel who disappeared during and after the Korea War (1950-1953). 

BEIJING, Sept. 26 (Xinhuanet) -- One of the world's brightest minds aims to bring to the world a new, advanced three-dimensional image technology that will leave other such technology in the shadows."Our new technology will be better than that used in Avatar," says Professor Yau Shing-tung of Harvard University."The image will be more vivid than with technologies used in previous movies. The new technology is not only quicker but cheaper."Yau is one of the world's greatest mathematicians, having won the prestigious Fields Medal. He was once the dean of the department of mathematics at Harvard, and is now a professor there. He is also a visiting professor at Tsinghua University.Professor Yau and his team met professionals from Tsinghua University and Renmin University of China last week, and they discussed possible cooperation to apply the technology in making a demonstration movie using the new technology.Yau and a team started working on the new 3D technology, founded on geometrical principles, at Harvard 10 years ago.What marks it out is the extremely vivid pictures it produces.3D technology is used not only in making movies and in Internet games but in other areas , such as medicine. Movie audiences the world over were awestruck by the technology used in the movie Avatar."After I watched the movie, all I could say was 'Wow'," said Shen Yiren, an IT staff worker in Zhongguancun Science and Technology Park Zone. "3D technology has extended the boundaries of the human imagination."Yau says that six years ago the makers of Avatar had wanted him to cooperate with them but he turned them down."I was not sure that (Avatar) would be such a big success."Avatar's facial caption technology puts points on models' faces while the new technology uses geometric methods, saving time and money, Yau says.