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BEIJING, Aug. 1 (Xinhua) -- The provinces of Guizhou and Hunan reported their lowest levels of precipitation since 1951 in July, the China Meteorological Administration (CMA) said on Monday.Precipitation levels across the country saw a decrease of 8.7 percent from the average level of 115.9 mm in July, the lowest levels seen in 11 years, said Chen Zhenlin, an expert with the CMA.The average temperature recorded across the country in July was 22.1 degrees Celsius, up 0.7 degrees Celsius from the average level.

PARIS, June 14 (Xinhua) -- Solar Impulse, a Swiss solar-powered aircraft, finally arrived in Paris on Tuesday after three days' delay, ready for a debut at the biennial International Paris Air Show.The 1.6-ton solar-powered plane was expected to land in Paris on Saturday but technical problems and bad weather forced it to turn back to Brussels.The plane took its first international flight from Switzerland to Brussels on May 13 and then marked its second international flight to Paris. It has 12,000 solar cells mounted on the wings, which provide momentum for its four electric motors.Solar Impulse is the first aeroplane designed to fly day and night without requiring fuel and without producing carbon emission. The 64-meter-wingspan (as wide as an Airbus A340) can fly at extremely slow speed and has a weight equivalent to that of an average family car.Regarded as a "special guest" in the show, Solar Impulse made a historic 26-hour day and night flight without fuel in July 2010.During the Paris air show from 20 to 26 June, visitors can enjoy a close look at the innovative plane on ground every day and if weather condition permits, flying displays will take place.According to Paris Air Show organizers, 59 of the top 100 companies in the air industry worldwide will be present. More than 1,800 small and medium-sized companies will be exhibiting their products during the one-week show. Enditem

WASHINGTON, July 12 (Xinhua) -- Two U.S. astronauts stepped out the International Space Station on Tuesday to retrieve a failed ammonia pump, which is the last spacewalk of the shuttle era, NASA announced.Space station astronauts Mike Fossum and Ron Garan completed the six-hour, 31-minute spacewalk at 3:53 p.m. EDT (1953 GMT). The duo retrieved a pump module from an external stowage platform on station and store it in shuttle Atlantis' cargo bay for return to Earth.The pump module failed in 2010, shutting down half of the space station's cooling system. Engineers will evaluate the module to determine the cause of the failure and plan to refurbish it for use as a spare.The astronauts also attached a Robotic Refueling Module experiment to the space station, which aims to test technologies for repairing and refueling satellites in space.It was the 249th spacewalk by U.S. astronauts and the 160th spacewalk in support of space station assembly and maintenance, totaling 1009 hours, nine minutes.Atlantis lifted off on Friday morning from Kennedy Space Center in Florida, on the 135th and final flight in NASA's shuttle program. Its return to the earth later this month will mark the end of the 30-year shuttle program.

CANBERRA, Aug. 17 (Xinhua) -- Australian scientist on Wednesday said his international research team has discovered the trick on how butterfly learn to change its wing pattern to avoid being eaten by birds.The Amazonian butterfly, Heliconius numata, has learnt to carry out a single genetic switch to alter its wing pattern so it appears to be another bad-tasting butterfly that birds will avoid.Dr. Siu Fai (Ronald) Lee from the Department of Genetics and Bio21 Institute at Australia's University of Melbourne was part of the international research team, which was led by scientists at Centre National de la Recherche Scientifique (CNRS) and the University of Exeter in United Kingdom.Dr. Lee said the historical mystery had puzzled researchers for decades."Charles Darwin was puzzled by how butterflies evolved such similar patterns of warning coloration," Dr. Siu Fai (Ronald) Lee from the Department of Genetics and Bio21 Institute at the University of Melbourne told Western Australia Today."We have now solved this mystery, identifying the region of chromosome responsible for changing wing pattern."He said the research team identified a genetic switch known as a supergene, which allowed the butterfly to morph into several different forms, allowing one species to mimic another."It is amazing that by changing just one small region of the chromosomes, the butterfly is able to fool its predators by mimicking a range of different butterflies that taste bad," he said."The butterflies rearrange this supergene DNA like a small pack of cards, and the result is new wing patterns. It means that butterflies look completely different but have the same DNA."There are other butterflies doing similar tricks, but this is the most elegant one."I was just fascinated by how elegant they were."He said the discovery proves that small chromosomal changes can preserve successful gene combinations, and thus help a species to adapt.The findings of the study are published on August 14 in the international journal Nature.

SAN FRANCISCO, Sept. 13 (Xinhua) -- Microsoft released on Tuesday a test version of Windows 8 to developers, posing to regain ground of the tablet market dominated by Apple and Google.At its developer-focused BUILD conference held in Anaheim, California, the software giant handed out new Samsung tablet computers with a test version of the code-named "Windows 8," the first detailed preview of the system for developers and people outside Microsoft.Generally expected to be launched in fall 2012, Microsoft did not say when the system will ship or its price.Microsoft Windows President Steven Sinofsky introduces the new tablet running a test version of its touch-enabled Windows 8 at the Build conference in Anaheim, California September 13, 2011Featuring a home page filled with colorful application tiles, the new system boots up in seconds. Microsoft said the system will run on low-power ARM-based chips that power smartphones and tablets. Windows 8 also introduces a new "Metro style" interface, which run full-screen and users can multitask in two at a time."We reimagined Windows," said Steven Sinofsky, president of the Windows and Windows Live Division at Microsoft, in his keynote address to the thousands of developers in attendance. "From the chipset to the user experience, Windows 8 brings a new range of capabilities without compromise."Analysts said the new system is consumer-oriented and intuitive but it will take time to see whether it is an "iPad killer."As professionals and consumers began to spend more time on smartphones and tablets, Microsoft has not got a significant bite of the market, losing ground to Apple's iPad and devices running Google's Android system.