梅州尿道炎的预防(梅州淋球菌尿道炎症状) (今日更新中)

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."

XIAMEN, June 12 (Xinhua) -- Chinese mainland on Sunday announced a raft of measures on tourism, transportation, farmers and food safety to boost Taiwan's economic growth and cross-Strait relations.A pilot plan allowing mainlanders to visit Taiwan as individual tourists will start on June 28, which covers residents of Beijing, Shanghai and southeastern city of Xiamen at the first stage, said Wang Yi, head of the State Council's Taiwan Affairs Office.Wang told a conference at the weeklong Straits Forum being held in Xiamen of Fujian Province that the mainland and Taiwan also agreed to allow Fujian residents to visit the islands of Kinmen, Matsu and Penghu in the Taiwan Strait as individual tourists.Observers predict that the influx of mainland tourists will bring vitality to Taiwan's export-oriented economy which had greatly suffered from the global economic downturn.Currently, mainlanders are only allowed to visit Taiwan on package tours after the authorities lifted a partial ban in July 2008.At Sunday's conference, the two sides also announced to increase the number of cross-Strait passenger flights by more than 50 percent to 558 flights per week, and add terminals for the direct flights in four mainland cities, including one in northwestern city of Lanzhou, which brought the total number of cross-Strait flight terminals to 50 on both sides of the Strait.The moves aim to cope with the increasing number of mainlanders who wish to visit Taiwan.The number of mainland tourists traveling to the island reached 2.34 million as of the end of May, China's top tourism official said at the conference. There are also an increasing number of mainland business travelers and government delegations visiting Taiwan.Meanwhile, both sides agreed to "regulate airfares" for flights from Beijing and Shanghai to Taipei.Currently, the cheapest one-way ticket between Beijing and Taipei on Air China, the mainland's flagship carrier, costs around 1,300 yuan (about 200 U.S. dollars) while a full price one-way ticket costs more than 3,000 yuan, according to the airline's website.Some members of the public on both sides have complained about the high price.For the past decades, travelers had to transfer at other airports, particularly the one in Hong Kong, in order to reach Taiwan by air.In 2003, the two sides agreed to operate charter flights during Spring Festival, China's biggest public holiday.Regular direct flights across the Strait have been available since July 2008 to mainly serve mainland package tourists visiting Taiwan.The mainland also decided to facilitate entry and exit procedures for Taiwan residents and lower charges for endorsing their passports by 50 percent starting from July 1.Meanwhile, four "enterprising parks" will be set up in four cities of Fujian, central Henan and southwestern Guangxi provinces for Taiwan farmers launching agricultural startups on the mainland, said Wang Yi.Both sides also agreed to encourage mainland enterprises to purchase farm produce and other products listed in the early harvest program of the cross-Strait Economic Cooperation Framework Agreement (ECFA) directly in Taiwan.A general manager surnamed Lin of a farm produce company in Taiwan's southern city of Tainan said he hoped to seize the opportunity to benefit from the development of the island's farm and fishing sector as the mainland has become Taiwan's largest export market.Further, both sides agreed to strengthen cooperation and exchanges concerning nuclear power security and food safety.The third Straits Forum, which opened Saturday in Xiamen, facing Taiwan across the Strait, will close in the island's city of Taichung on Friday.

LOS ANGELES, June 20 (Xinhua) -- NASA's Cassini spacecraft has successfully completed its second-closest encounter with Saturn's icy moon Helene, beaming down raw images of the small moon, the Jet Propulsion Laboratory (JPL) said on Monday.At closest approach on June 18 Cassini flew within 4,330 miles (6,968 kilometers) of Helene's surface, the second closest approach to Helene of the entire mission, said JPL in Pasadena, Los Angeles.This flyby will enable scientists to finish creating a global map of Helene, so they can better understand the history of impacts to the moon and gully-like features seen on previous flybys, according to JPL.Passing from Helene's night side to the moon's sunlit side, Cassini also captured images of the Saturn-facing side of the moon in sunlight, a region that was only illuminated by sunlight reflected off Saturn the last time Cassini closely encountered with the moon in March 2010.The closest Helene encounter of the mission took place on March 10, 2010, when Cassini flew within 1,131 miles (1,820 kilometers) of the moon.The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency.JPL, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL, while the imaging team is based at the Space Science Institute in Boulder, Colorado.

BEIJING, Aug. 13 (Xinhua) -- Chinese rating agency Dagong Global Credit Rating Co. on Saturday defended its AAA rating given to the Ministry of Railways, which has been under public fire over a train collision last month.The ministry received the long-term credit rating after launching on Monday its first bond sales since the crash on July 23 that killed 40 people near the Wenzhou city of eastern Zhejiang province.It sold 20 billion yuan worth of three-month bills on offer in the interbank market, with a yield of 5.55 percent, a relatively high rate for short-term government paper.The rating was assigned because of the ministry's status as a government agency backed by the central government revenue, its sufficient capital flows and strong financing ability, Dagong said in an email to Xinhua.The agency made the elaboration in response to market doubts as the ministry is already heavily indebted and the accident has stirred up skepticism about the its credibility and the safety of fast-expanding railways.Adding to doubts is that the AAA rating of the ministry is even a notch above China's local currency debt rating of AA+, which was also rated by Dagong.Government data showed the ministry's debts exceeded 2 trillion yuan (313 billion U.S. dollars) as of the end of June, raising its debt ratio to 58.53 percent, slightly up from the end of the first quarter of this year.Dagong said in the statement that the debt-to-asset ratio is medium level, lower than the alert line for the ministry which is 75 percent.The ministry has large-scale assets of good quality and relatively large room for fund-raising, Dagong said.The ministry has "extremely strong" repayment ability as it is backed by the state's credit, Dagong said, referring it as one of the three authorities that are allowed to issue bonds, along with the Ministry of Finance and the People's Bank of China.In July, the ministry issued 20 billion yuan of one-year commercial papers with a coupon rate of 5.18 percent, but only 18.73 billion yuan of the total was bought.Analysts said it has become more difficult for the ministry to borrow money because of tightened market liquidity and concerns over the ministry's debt burden.China's top four banks said at the end of last month that they will continue to offer loans to the ministry based on market conditions and risk appraisal. Credit from the four largest state-owned banks including the Industrial and Commercial Bank of China and the Construction Bank of China has been the major source funding the construction of China's fast-growing railways in recent years.

BEIJING, June 14 (Xinhuanet) -- Having a pet at home during the first year of a child may halve the risk of developing allergic to them later in life, a new study suggests.The study was published in the journal Clinical & Experimental Allergy.Researchers from Henry Ford Hospital in Detroit assessed 566 boys and girls who were followed from birth until age 18. They found that boys who had dogs and teens who had cats during their first year of life had 50 percent less risk of developing pet allergies later.Lead researcher Ganesha Wegienka said: "This research provides further evidence that experiences in the first year of life are associated with health status later in life, and that early life pet exposure does not put most children at risk of being sensitised to these animals later in life."The researchers said that exposure to animals at other times in childhood didn't appear to be as significant as the first year.However, Wegienka cautioned that this study doesn't prove a cause-and-effect relationship between having a pet and avoiding allergies, just an association between those two factors."We don't want to say that everyone should go out and get a dog or cat to prevent allergies," she said."More research is needed, though we think this is a worthwhile avenue to pursue."

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