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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, June 9 (Xinhua) -- Observations from NASA's Voyager spacecraft suggest the edge of our solar system may not be smooth, but filled with a turbulent sea of magnetic bubbles, the U.S. space agency said Thursday in a statement.While using a new computer model to analyze Voyager data, scientists found the sun's distant magnetic field is made up of bubbles approximately 100 million miles wide. The bubbles are created when magnetic field lines reorganize. The new model suggests the field lines are broken up into self-contained structures disconnected from the solar magnetic field. The findings are described Thursday in the Astrophysical Journal.Like Earth, our sun has a magnetic field with a north pole and a south pole. The field lines are stretched outward by the solar wind or a stream of charged particles emanating from the star that interacts with material expelled from others in our corner of the Milky Way galaxy.The Voyager spacecraft, more than nine billion miles away from Earth, are traveling in a boundary region. In that area, the solar wind and magnetic field are affected by material expelled from other stars in our corner of the Milky Way galaxy."The sun's magnetic field extends all the way to the edge of the solar system," said astronomer Merav Opher of Boston University. "Because the sun spins, its magnetic field becomes twisted and wrinkled, a bit like a ballerina's skirt. Far, far away from the sun, where the Voyagers are, the folds of the skirt bunch up."Understanding the structure of the sun's magnetic field will allow scientists to explain how galactic cosmic rays enter our solar system and help define how the star interacts with the rest of the galaxy.So far, much of the evidence for the existence of the bubbles originates from an instrument aboard the spacecraft that measures energetic particles. Investigators are studying more information and hoping to find signatures of the bubbles in the Voyager magnetic field data."We are still trying to wrap our minds around the implications of the findings," said University of Maryland physicist Jim Drake, one of Opher's colleagues.Launched in 1977, the Voyager twin spacecraft have been on a 33- year journey. They are en route to reach the edge of interstellar space. NASA's Jet Propulsion Laboratory built the spacecraft and continues to operate them.
WELLINGTON, Sept. 27 (Xinhua) -- New Zealand and Japanese scientists are teaming up to develop healthier foods under two government-funded "functional foods" projects.One project, to be led by New Zealand's Massey University, will work with New Zealand food companies to create and develop a functional food with specific health enhancing effects for menopausal women, New Zealand Science and Innovation Minister Wayne Mapp announced Tuesday.The other project, to be led in New Zealand by Plant and Food Research, would use mass spectrometry to develop a "metabolic atlas" of the chemical composition of allium vegetables, such as onions and garlic, which the horticultural industry could use to develop new food products with health benefits.Mapp said the two research projects would be awarded a total of 1 million NZ dollars (782,000 U.S. dollars) in funding to strengthen collaborative research relationships between New Zealand and Japan, Mapp said."These research projects have strong commercial potential, including through the Japanese market, and so have the potential to benefit our economy," said Mapp."The government is committed to building and strengthening research relationships with other countries that will achieve world-class scientific results and lead to new innovative technologies."The two projects awarded funding under Ministry of Science and Innovation's Japan Science and Technology Agency (JST) funding round focus on functional foods. The ministry and Japan each fund half the cost of each research project awarded funding.
WARSAW, June 2 (Xinhua) -- A possible second E. coli infection patient has been hospitalized in Szczecin, northwestern Poland, Health Minister Ewa Kopacz said Thursday.The man, who recently returned to Poland from Germany, has been diagnosed with exudative diarrhea and is currently being tested for E. coli bacteria.Poland's first E. coli case, a 29-year-old woman permanently residing in Germany and diagnosed with the bacteria over a week ago, is currently in the same hospital.Kopacz said sanitary teams were running E. coli checks countrywide, especially on marketplaces and in warehouses.The E. coli epidemic originated in Germany, where it has taken 17 lives. One death has so far occurred in Sweden, bringing the total death toll to 18.
BEIJING, June 10 (Xinhua) -- The nation's drug watchdog on Friday publicized a draft national standard of sulfur dioxide residue in Chinese herbal medicine, which is open for public opinion until Sept. 9 this year.The maximum amount of sulfur dioxide residue is 400 mg in one kg of each of 11 specified kinds of herbal medicine, such as Chinese yams, Gastrodia elata and Codonopsis pilosola, according to the draft standard unveiled by the State Food and Drug Administration (SFDA).The standard provides a 150-mg-per-kg limit for all other kinds of herbal medicine.Fumigation with sulfur is used as a way of drying some herbal medicine by growers, and currently have no alternative that is both cheap and convenient.The SFDA said it doesn't favor the drying herbal medicine through fumigation with sulfur and urges research efforts to invent new alternatives.According to the World Health Organization, the tolerable maximum amount of sulfur dioxide that a human body can take in one day is 0.7 mg per kg, which means that an adult of 60 kg should not take in more than 42 mg of sulfur dioxide a day.Long-term exposure to high amounts of sulfur dioxide can cause damage to human body, especially the respiratory system, according to experts.