唐山市吉吉美甲加盟电话多少钱(宝坻区欣奈美甲加盟电话多少钱) (今日更新中)

BEIJING, Aug. 2 (Xinhuanet) -- The first close-up pictures of the asteroid Vesta, a protoplanet that dates back to the early days of the solar system, were revealed Monday by NASA scientists.The images were taken by the U.S. space agency's Dawn robotic probe, which is two weeks into a planned year-long survey of the second largest object in the main asteroid belt, located between Mars and Jupiter.About twice the size of California, Vesta is second in size only to Ceres, Dawn's next target and, along with Pluto, one of just five known dwarf planets. NASA is spending 466 million dollars to explore Vesta and Ceres during the course of a 10-year mission.Images from Dawn show Vesta a surprisingly diverse terrain and several unexplained geologic features. Chaotic terrain near the south pole is dominated by a towering central peak and huge ripple-like grooves stretching around its equatorial belt. Bright spots, dark pits and craters are filled with unexplained streaks of black and white debris. Terrain north of the grooves is much more heavily cratered.Scientists believe Vesta grew from a clump of gas and dust left over after the sun's birth some 4.65 billion years ago, a supernova explosion, which added radioactive materials to the growing body.Dawn will spend about a year circling Vesta, tweaking its orbit and altitude using an innovative technology called ion propulsion system, chief engineer Marc Rayman with NASA's Jet Propulsion Laboratory in California said.The ion propulsion system will enable Dawn to leave Vesta's orbit after a year of study and head off to Ceres, which is the largest object in the asteroid belt.

WASHINGTON, Aug. 31 (Xinhua) -- Astronomers using NASA's Chandra X-ray Observatory discovered the first pair of supermassive black holes in a spiral galaxy similar to the Milky Way, NASA announced Wednesday.Approximately 160 million light years from Earth, the pair is the nearest known such phenomenon.The black holes are located near the center of the spiral galaxy NGC 3393. Separated by only 490 light years, the black holes are likely the remnant of a merger of two galaxies of unequal mass a billion or more years ago.Both of the supermassive black holes are heavily obscured by dust and gas, which makes them difficult to observe in optical light. Because X-rays are more energetic, they can penetrate this obscuring material. Chandra's X-ray spectra show clear signatures of a pair of supermassive black holes."If this galaxy weren't so close, we'd have no chance of separating the two black holes the way we have," said Pepi Fabbiano of the Harvard-Smithsonian Center for Astrophysics, who led the study that appeared Wednesday in on-line issue of the journal Nature. "Since this galaxy was right under our noses by cosmic standards, it makes us wonder how many of these black hole pairs we've been missing."Previous observations in X-rays and at other wavelengths indicated that a single supermassive black hole existed in the center of NGC 3393. However, a long look by Chandra allowed the researchers to detect and separate the dual black holes. Both black holes are actively growing and emitting X-rays as gas falls towards them and becomes hotter.When two equal-sized spiral galaxies merge, astronomers think it should result in the formation of a black hole pair and a galaxy with a disrupted appearance and intense star formation. A well-known example is the pair of supermassive black holes in NGC 6240, which is located about 330 million light years from Earth.However, NGC 3393 is a well-organized spiral galaxy, and its central bulge is dominated by old stars. These are unusual properties for a galaxy containing a pair of black holes.

WASHINGTON, June 23 (Xinhua) -- NASA's next Mars rover has completed the journey from its California birthplace to Florida in preparation for launch this fall, the U.S. space agency said Thursday in a statement.The Mars Science Laboratory (MSL) rover, also known as Curiosity, arrived Wednesday at NASA's Kennedy Space Center aboard an Air Force C-17 transport plane. It was accompanied by the rocket-powered descent stage that will fly the rover during the final moments before landing on Mars.The rover's aeroshell -- the protective covering for the trip to the Red Planet -- and the cruise stage, which will guide it to Mars, arrived at Kennedy last month. The mission is targeted to launch from Cape Canaveral Air Force Station between Nov. 25 and Dec. 18. The car-size rover will land on Mars in August 2012.The rover and other spacecraft components will undergo more testing before mission staff stack them and fuel the onboard propulsion systems. Curiosity should be enclosed in its aeroshell for the final time in September and delivered to Kennedy's Launch Complex 41 in early November for integration with a United Launch Alliance Atlas V rocket.Curiosity is about twice as long and more than five times as heavy as any previous Mars rover. Its 10 science instruments include two for ingesting and analyzing samples of powdered rock delivered by the rover's robotic arm. During a prime mission lasting one Martian year -- nearly two Earth years -- researchers will use the rover's tools to study whether the landing region has had environmental conditions favorable for supporting microbial life and favorable for preserving clues about whether life existed.

LOS ANGELES, July 7 (Xinhua) -- Obesity rates in the United States climbed over the past year in 16 states, and not a single state reported a decline in the proportion of excessively overweight residents, according to a report released on Thursday.The report, published by HealthDay News, found that more than 30 percent of the people in 12 states are obese. Four years ago, only one state could make that claim.Twenty years ago, "there wasn't a single state that had an obesity rate above 15 percent, and now every state is above that," said Jeff Levi, executive director of Trust for America's Health, which compiled the report."We have seen a dramatic shift over a generation," he added. " This isn't just about how much people weigh, but it has to do with serious health problems like diabetes and hypertension. These are the things that are driving health care costs."With the exception of Michigan, the 10 most obese states are in the South. The Northeast and West reported the lowest obesity rates. In addition, in eight states, more than 10 percent of adults suffer from type 2 diabetes, according to the report.Mississippi, where 34.4 percent of the people are obese, has the highest obesity rate. Other states with obesity rates above 30 percent include: Alabama, Arkansas, Kentucky, Louisiana, Michigan, Missouri, Oklahoma, South Carolina, Tennessee, Texas and West Virginia. Thirty-eight other states have obesity rates above 25 percent.For the second year in a row, obesity rates rose in Illinois, Kentucky, Massachusetts, Missouri, Rhode Island and Texas.And, for the third year straight, more residents of Florida, Kansas, Maine, Oklahoma and Vermont tipped the scale toward obesity.Colorado, with an obesity rate of 19.8 percent, is the only state where the rate is less than 20 percent, the report found.The study also found that more than one-third of children and adolescents are obese or overweight, with the highest prevalence in the South. However, the new data indicate that obesity among children and adolescents may have leveled off, except among the heaviest boys.

BEIJING, Aug. 3 (Xinhuanet) -- The first man in Britain who received a complete plastic heart is allowed to leave hospital and live a relatively normal life at home.Matthew Green, 40, who was dying from arrhythmogenic right ventricular cardiomyopathy, was awaiting a transplant when his condition became so bad that the doctors at Papworth Hospital, the world renowned heart center near Cambridge, decided to give him Britain’s first ever full artificial heart.During a six-hour operation on June 9, 2011, surgeons replaced Mr Green's damaged heart with the device which will serve the role of muscles and ventricles.Unlike previous artificial hearts, they have usually only replaced parts of the organ, the new one is powered by a pump which sits outside the body and can be held in a backpack or shoulder bag.All Mr Green has to do is replace the batteries in the pump every few hours and the heart should last up to three years.Transplant milestones1964 US National Institutes of Health starts artificial heart programme.1966 First transplant of partial mechanical heart, to assist pumping of ventricle.1969 Texas man receives first total artificial heart transplant. After 64 hours on the mechanical device received a donor organ, but died within two days.1982 Artificial heart designed by Utah University doctor Robert Jarvik implanted into man who survived for 112 days.2001 First surgical implant of internally powered artificial heart, which was charged via transduction through skin.

来源：资阳报