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LOS ANGELES, July 22 (Xinhua) -- Two teams of astronomers have discovered the largest and farthest reservoir of water ever detected in the universe, NASA's Jet Propulsion Laboratory (JPL) said on Friday.The water, equivalent to 140 trillion times all the water in the world's ocean, surrounds a huge, feeding black hole, called a quasar, more than 12 billion light-years away, according to JPL in Pasadena, California."The environment around this quasar is very unique in that it's producing this huge mass of water," said Matt Bradford, a scientist at JPL. "It's another demonstration that water is pervasive throughout the universe, even at the very earliest times. "This artist's concept illustrates a quasar, or feeding black hole, similar to APM 08279+5255, where astronomers discovered huge amounts of water vapor. Gas and dust likely form a torus around the central black hole, with clouds of charged gas above and below. X-rays emerge from the very central region, while thermal infrared radiation is emitted by dust throughout most of the torus. While this figure shows the quasar's torus approximately edge-on, the torus around APM 08279+5255 is likely positioned face-on from our point of view.A quasar is powered by an enormous black hole that steadily consumes a surrounding disk of gas and dust. As it eats, the quasar spews out huge amounts of energy. Both groups of astronomers studied a particular quasar called APM 08279+5255, which harbors a black hole 20 billion times more massive than the sun and produces as much energy as a thousand trillion suns.Astronomers expected water vapor to be present even in the early, distant universe, but had not detected it this far away before. There's water vapor in the Milky Way, although the total amount is 4,000 times less than in the quasar, because most of the Milky Way's water is frozen in ice. Water vapor is an important trace gas that reveals the nature of the quasar. In this particular quasar, the water vapor is distributed around the black hole in a gaseous region spanning hundreds of light-years in size (a light-year is about six trillion miles).Its presence indicates that the quasar is bathing the gas in X- rays and infrared radiation, and that the gas is unusually warm and dense by astronomical standards, JPL said.Although the gas is at a chilly minus 63 degrees Fahrenheit ( minus 53 degrees Celsius) and is 300 trillion times less dense than Earth's atmosphere, it's still five times hotter and 10 to 100 times denser than what's typical in galaxies like the Milky Way, said JPL.Measurements of the water vapor and of other molecules, such as carbon monoxide, suggest there is enough gas to feed the black hole until it grows to about six times its size, JPL said.Whether this will happen is not clear, the astronomers say, since some of the gas may end up condensing into stars or might be ejected from the quasar.Bradford's team made their observations starting in 2008, using an instrument called "Z-Spec" at the California Institute of Technology's (Caltech's) Submillimeter Observatory, a 33-foot (10- meter) telescope near the summit of Mauna Kea in Hawaii. Follow-up observations were made with the Combined Array for Research in Millimeter-Wave Astronomy (CARMA), an array of radio dishes in the Inyo Mountains of Southern California.The second group, led by Dariusz Lis, senior research associate in physics at Caltech and deputy director of the Caltech Submillimeter Observatory, used the Plateau de Bure Interferometer in the French Alps to find water. In 2010, Lis's team serendipitously detected water in APM 8279+5255, observing one spectral signature.Bradford's team was able to get more information about the water, including its enormous mass, because they detected several spectral signatures of the water, according to JPL.

BEIJING, July 19 (Xinhuanet) -- Amazon on Monday launched its Kindle textbook rental service, which allows students to rent "tens of thousands of textbooks", according to Los Angeles Times.The e-book textbook rental service will help students save as much as 80 percent on some titles.Amazon said that students can now rent textbooks from 30 to 360 days and can either rent them again or purchase them once the rental period is up."Students tell us that they enjoy the low prices we offer on new and used print textbooks. Now we're excited to offer students an option to rent Kindle textbooks and only pay for the time they need—with savings up to 80 percent off the print list price on a 30-day rental," Dave Limp, vice president of Amazon Kindle said, according to PC Magazine.Rentals can be read on Amazon's Kindle eReaders, and Kindle apps for PCs, as well as smartphones and tablet computers running Apple's iOS, Microsoft Windows Phone 7 and Google's Android operating system.Rentals also have a clear advantage over physical copies that students' notes and highlighted content will be stored in the Amazon Cloud, and can be accessed if students rent the books again or buy at a later time.

SAN FRANCISCO, June 15 (Xinhua) -- As social networking sites like Facebook and Twitter grow worldwide, more Internet retailers are beefing up their efforts to add social twists to their business, trying to define the idea of "social commerce" and capitalize the opportunity.On Wednesday, online auction giant eBay revealed some of the social features it is planning to launch later this year, while Copious, a San Francisco-based startup, launched its online social commerce marketplace with a slogan of "buying from and selling to people, not strangers."Copious asks users to log in through their Facebook accounts and allows buyers and sellers to see if they have friends in common in their social networking sites. Buyers can see more information about a seller and also see whether anyone in their networks has purchased, shared or commented on an item from a specific seller, rather than anonymity or simple profiles on sites like eBay and Craigslist.As for sellers, Copious has a social pricing mechanism that enables a seller to offer buyers discounts for sharing listings on Facebook and for following the seller on Copious.Jonathan Ehrlich, Copious co-founder and former Facebook head of marketing, told technology blog TechCrunch that the site is centralized around using social data as a signal to help users understand and trust other parties.According to Copious, the startup founded in January 2011 has raised two million U.S. dollars in funding from Foundation Capital, Google Ventures, Blackberry Partners Fund and a number of Silicon Valley angel investors.Also on Wednesday, Christopher Payne, vice president and head of eBay North America, delivered a keynote speech at the Internet Retailer Conference and Exhibition 2011 in San Diego, revealing some features eBay is launching during the social trend.One feature will enable users to log in their Facebook account on eBay's homepage to get product recommendations based on one's purchasing history and things they have "liked" on their Facebook page. Another feature will allow users to post multiple products on their Facebook page to get their friends' opinions and ask them to vote for the final purchase.EBay has been stepping up its social efforts, and Payne said on Wednesday that social is a top-level initiative for Internet retailers. Last month, eBay hired former Yahoo executive Don Bradford to lead its social commerce efforts. Last November, it launched Group Gifts service, enabling users to chip in to buy a gift for someone.A research by Adgregate Market in March showed that more brand websites are losing traffic to their Facebook pages. The study revealed that the "Facebook stores" of most Internet retailers are more efficient at acquiring visitors, indicating social commerce is poised to take off.Although the idea of social commerce is still new, more companies are trying to seize the opportunity in their own moves.There are many other companies taking the social commerce model. Oodle, the exclusive provider of classified ads on the Facebook Marketplace, rolled out a series of social features last December to make more money from social classifieds.In February, Payvment Inc. launched a Facebook Mall, where consumers can shop for more than 1.2 million products among 60,000 retailers in a single shopping cart.Yardsellr, which is often called "an eBay for Facebook," allows sellers to list items at fixed prices in different categories called "blocks," such as jewelry and purses. Prospective buyers can "like" the "blocks" they are interested in on the Yardsellr website or its Facebook page, and then they will get Facebook news feed if a seller has something to offer in the category.Yardsellr said 1.5 million people were following its "blocks" by late December 2010 and the number of new followers is growing by 20,000 daily.

XIAMEN, July 23 (Xinhua) -- A rescue and breeding base for endangered Chinese white dolphins started a trial operational period on Saturday in the southeastern seaside resort of Xiamen. The base is the first of its kind in the country.The base, located on the city's Huoshaoyu Islet, includes a rescue center and a breeding area and can accommodate up to four to six white dolphins, said Pan Shijian, vice mayor of Xiamen.Previously, rescuers had to return injured white dolphins back to the sea after giving them simple medical treatment due to the lack of a rescue base, Pan said."From now on, the base will be a hospital for injured or stranded dolphins," he said.The base will also be used as a rehabilitation center for children with infantile autism and brain paralysis, with the dolphins acting as "doctors" during the children's recovery period, he added.The Chinese white dolphin mainly lives in the seas around Xiamen and the Pearl River estuary in south China. The dolphins are under first-class state protection.The Chinese Academy of Fishery Sciences estimates that about 2,000 of the dolphins are living in China's seas.

BEIJING, July 17 (Xinhua) -- China's land prices in 105 cities rose 1.87 percent on average in the second quarter over the first, but the rate of growth slowed, the China Urban Land Price Dynamic Monitor, a land price information provider, announced Sunday. < In the second quarter, land price for business properties averaged 5,506 yuan (about 847 U.S. dollars) per square meter, up 2.77 percent from the previous quarter. The growth rate slowed by 0.56 percentage points.Land price for residential properties averaged 4,443 yuan per square meter, up 2.17 percent. The growth slowed by 0.27 percentage points. The price for industrial uses, meanwhile, was up 1.13 percent to reach 645 yuan per square meter. The growth fell 0.3 percentage points.The country's three most prosperous regions, the Yangtze River Delta Region, Pearl River (Zhujiang) Delta Region, and the Bohai Rim, all reported slower land price growth in the second quarter.