阿坝哪检查胃好(张家界体检去哪里) (今日更新中)

WASHINGTON, Dec. 20 (Xinhua) -- NASA's Kepler mission has discovered the first Earth-size planets orbiting a sun-like star outside our solar system, the U.S. space agency announce Tuesday.The planets, called Kepler-20e and Kepler-20f, are too close to their star to be in the so-called habitable zone where liquid water could exist on a planet's surface, but they are the smallest exoplanets ever confirmed around a star like our sun, according to NASA.The discovery marks the next important milestone in the ultimate search for planets like Earth. The new planets are thought to be rocky. Kepler-20e is slightly smaller than Venus, measuring 0.87 times the radius of Earth. Kepler-20f is slightly larger than Earth, measuring 1.03 times its radius. Both planets reside in a five-planet system called Kepler-20, approximately 1, 000 light-years away in the constellation Lyra.Kepler-20e orbits its parent star every 6.1 days and Kepler-20f every 19.6 days. These short orbital periods mean very hot, inhospitable worlds. Kepler-20f, at 800 degrees Fahrenheit, is similar to an average day on the planet Mercury. The surface temperature of Kepler-20e, at more than 1,400 degrees Fahrenheit, would melt glass."The primary goal of the Kepler mission is to find Earth-sized planets in the habitable zone," said Francois Fressin of the Harvard-Smithsonian Center for Astrophysics, lead author of a new study published in the journal Nature. "This discovery demonstrates for the first time that Earth-size planets exist around other stars, and that we are able to detect them."The Kepler-20 system includes three other planets that are larger than Earth but smaller than Neptune. Kepler-20b, the closest planet, Kepler-20c, the third planet, and Kepler-20d, the fifth planet, orbit their star every 3.7, 10.9 and 77.6 days. All five planets have orbits lying roughly within Mercury's orbit in our solar system. The host star belongs to the same G-type class as our sun, although it is slightly smaller and cooler.

BEIJING, Dec. 29 (Xinhua) -- China on Thursday issued a white paper on the development of space industry since 2006 and the major tasks for the next five years.The white paper titled "China's Space Activities in 2011" was the third white paper on the country's space activities issued by the State Council Information Office, following the one in 2000 and another in 2006.The Chinese government has made the space industry an important part of the nation's overall development strategy and adhered to exploration and utilization of outer space for peaceful purposes, the white paper said.Over the past few years, China has ranked among the world's leading countries in certain major areas of space technology, it said, adding that in the next five years, there will be new opportunities to the country's space industry.At the same time, China will work together with the international community to maintain a peaceful and clean outer space and endeavor to promote world peace and development, the document said.FUTURE MISSIONSMajor tasks listed in the white paper for the next five years include space transportation system, Earth satellites, human spaceflights and deep-space exploration.The country will launch the Shenzhou-9 and Shenzhou-10 spaceships and achieve unmanned or manned rendezvous and docking with the in-orbit Tiangong-1 vehicle, the paper said.China also plans to launch space laboratories, manned spaceship and space freighters, and will start a research on the preliminary plan for a human landing on the moon, the document said.As an important part of deep-space exploration, the country's lunar probe projects follow the idea of "three steps" -- orbiting, landing and returning.In next five years, the country plans to launch orbiters for lunar soft landing, roving and surveying to implement the second stage of lunar exploration, then it will start the third-stage project of sampling the moon's surface matters and get those samples back to Earth, the white paper said.In addition, China will build a space infrastructure frame composed of Earth observation satellites, communications and broadcasting satellites, plus navigation and positioning satellites.MAJOR PROGRESSAccording to the white paper, breakthroughs have been made in major space projects, including human spaceflight and lunar exploration, since 2006.From Sept. 25 to 28, 2008, China successfully launched the Shenzhou-7 manned spaceship and became the third country in the world to master the key technology of astronaut space extravehicular activity.In November 2011, China accomplished the first unmanned space rendezvous and docking test between the Tiangong-1 space lab module and Shenzhou-8 spaceship.In addition, the country's lunar probe projects have achieved milestone breakthroughs over the past five years. China successfully launched two lunar probes, the Chang'e-1 on Oct. 24, 2007, and Chang'e-2 on Oct. 1, 2010.The first probe retrieved a great deal of scientific data and a complete map of the moon while the second created a full higher-resolution map of the moon and a high-definition image of Sinus Iridium.

CAPE TOWN, Nov. 13 (Xinhua) -- The research vessel SA Agulhas has set off from Cape Town on a 10-day polar tour intended to promote dialogue on climate change, authorities confirmed on Sunday.The trip was designed to mark the 17th Climate Conference of the Parties (COP17) to be held in Durban later this month, according to the Department of Environmental Affairs.The voyage, which set off Saturday noon with scientists, academics, students and journalists aboard, would host exhibitions, symposiums and lectures from climate change scientists on the work of the polar research vessel, spokesman Zolile Nqayi said in a statement.The exhibitions and lectures would also highlight the various scientific activities undertaken by the department and its partners in Antarctica and the Southern Oceans, according to the South African Press Association (SAPA).Apart from her research and supply work, the Agulhus also helped to rescue the Magdalena Oldendorff, which became stuck in thick ice in June 2002.In December the SA Agulhas would make its final voyage to Antarctica before retirement.The Agulhas, which has been in service for 33 years, would be replaced by a new vessel under construction in Finland."She served us very well," said Dr Monde Mayekiso, deputy director general of oceans and coasts."The new vessel will have enhanced technologies and capabilities to further understand the ocean environment and to bring that understanding to an increasing number of South Africans, " he said.

WASHINGTON, Oct. 3 (Xinhua) -- The Rockefeller University confirmed Monday its Canadian-born cell biologist Ralph Steinman died three days before being awarded the Nobel Prize on Monday as the Nobel committee was unaware of his death at the time."Steinman passed away on September 30," the New York university said in a statement."He was diagnosed with pancreatic cancer four years ago, and his life was extended using a dendritic-cell based immunotherapy of his own design."The Nobel committee was unaware of Steinman's death when announcing this year's winners and it was unclear whether the prize would be rescinded because Nobel statutes don't allow posthumous award."The Rockefeller University is delighted that the Nobel Foundation has recognized Ralph Steinman for his seminal discoveries concerning the body's immune responses," says Rockefeller University President Marc Tessier-Lavigne."But the news is bittersweet, as we also learned this morning from Ralph's family that he passed a few days ago after a long battle with cancer. Our thoughts are with Ralph's wife, children and family.""We are all so touched that our father's many years of hard work are being recognized with a Nobel Prize," says Steinman's daughter Alexis. "He devoted his life to his work and his family, and he would be truly honored.""Ralph's research has laid the foundation for numerous discoveries in the critically important field of immunology, and it has led to innovative new approaches in how we treat cancer, infectious diseases and disorders of the immune system," Tessier-Lavigne says.Steinman, who discovered the immune system's sentinel dendritic cells, is this year's recipient of the Nobel Prize in Physiology or Medicine. He shares half the prize with Bruce Beutler and Jules Hoffmann.

BALI, Indonesia, Nov. 19 (Xinhua) -- Leaders of China, Japan and South Korea met here Saturday to exchange views on trilateral cooperation and regional and international issues of common concern.Chinese Premier Wen Jiabao, Japanese Prime Minister Yoshihiko Noda and South Korean President Lee Myung-bak were meeting on the occasion of a series of meetings for East and Southeast Asian leaders in this Indonesian resort city on Friday and Saturday.Speaking at the meeting, Wen said the cooperation between the three nations currently had good momentum, which was not only in line with the interests of the three sides but also contributed to the stability and development of the Asia and the world.Chinese Premier Wen Jiabao (L), Japanese Prime Minister Yoshihiko Noda (C) and Republic of Korea (ROK) President Lee Myung-Bak pose for photos during the Trilateral Summit Meeting for leaders of the three nations in Bali, Indonesia, Nov. 19, 2011.As the coordinator of next year's China-Japan-South Korea cooperation, China would like to further enhance high-level exchanges, policy coordination and strategic trust between the three countries, providing political impetus and promoting more advancement in trilateral cooperation, Wen said.He said next year marked the 40th anniversary of the normalization of diplomatic relations between China and Japan, and the 20th anniversary of the establishment of diplomatic relations between China and South Korea.In the meeting, Wen proposed the joint research into a free trade area between the three countries be completed this year, and negotiations start in 2012.Wen also suggested enhancing trilateral cooperation in the fields of transportation, finance and environmental protection, among many others.Also speaking at the meeting, the Japanese prime minister and the South Korean president said the cooperation between the three nations had seen remarkable achievement and its prospects were promising.The three sides should continue to deepen their exchanges and cooperation in various fields including economy and trade, finance, investment, disaster relief, culture, education and tourism, and strengthen the coordination in regional and international issues to promote common development, according to them.During the meeting, the three leaders also exchanged views on other regional and international issues of common concern.

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