长沙AED除颤仪(吉林半眼球模型) (今日更新中)

BEIJING, Aug. 15 (Xinhua) -- Scientists in a lab with Daya Bay Nuclear Power Station in southern Guangdong Province have found neutrino through two detecting instruments, which is likely to provide clues to solving the mystery of why there is more matter than antimatter in the universe.The Institute of High Energy Physics with the Chinese Academy of Sciences on Monday announced the breakthrough that was achieved by more than 250 researchers from six countries and regions.The two neutrino detectors are installed underground 360 meters away from the nuclear plant at a depth of 100 meters.Scientists believe that matter and antimatter were created in equal amounts during the Big Bang, but the disappearance of antimatter remains a mystery.Neutrino is an elementary particle that is able to pass through ordinary matter almost unaffected, which makes it extremely difficult to detect.Located in Shenzhen, a city neighboring Hong Kong, the Daya Bay Nuclear Power Station commenced operation in 1993.Scientists from the Chinese Academy of Sciences and the U.S.-based Brookhaven National Laboratory and the Lawrence Berkeley National Laboratory started the underground neutrino experiment in 2006.Kam-Biu Luk, spokesman for the laboratory, said that the results of the experiment would further shed light on the evolution of basic matter after the Big Bang.The neutrino experiment in the Daya Bay is one of the largest cooperation projects with regards to basic research between China and the United States.Among the participants of the experiment are Russia, Czech Republic, and China's Hong Kong and Taiwan regions.

BEIJING, Sept. 23 (Xinhua) -- A defunct U.S. satellite is expected to crash down to Earth Friday, with nobody knowing where or when exactly it will hit. This was avoidable, a Chinese expert said Thursday.Pang Zhihao, a researcher from the Chinese Research Institute of Space Technology, told Xinhua that the crash could have been avoided had the satellite been put into a higher orbit, or manipulated to drop in the South Pacific when it had abundant fuel. It would pose no threat to Earth if these measures had been taken.NASA's tumbling, 5,900 kg Upper Atmosphere Research Satellite, or UARS, is the first of such man-made space vehicles that have been launched into outer space according to the agency's Mission to Planet Earth. The mission was launched in the 1990s.The mission is designed to provide data for better understanding Earth's upper atmosphere and the effects of natural and human interactions on the atmosphere.The satellite was deactivated in 2005 as it ran out of fuel and was left orbiting Earth like a big piece of space junk.There are other cases of defunct satellites. The European Space Agency said earlier its observation satellite ERS-2 has run out of fuel and is deorbiting. It would therefore also crash sooner or later.Pang said all countries which are operating space vehicles should take care of their own spacecrafts so that they won't pose any danger.The expert also said that the public need not worry too much.Pang said most spacecrafts will be incinerated upon re-entering Earth's atmosphere, and the debris will mostly likely fall into the ocean or hit an uninhabited area. In addition, a debris tracker is able to give a comparatively accurate prediction where the craft will fall about two hours before it hits Earth, giving residents, if there are any, time to evacuate.He added that there are several ways to minimize the threat of decommissioned spacecrafts, like putting them into higher orbits and crashing them into designated waters.Scientific progress would possibly bring about more ways of dealing with tumbling satellites. Scientists have already been trying to build spacecrafts with degradable materials so that they can self-destruct when re-entering Earth's atmosphere.

WASHINGTON, June 6 (Xinhua) -- Forests in many regions are becoming larger carbon sinks thanks to higher density, U.S. and European researchers say in a new report.In Europe and North America, increased density significantly raised carbon storage despite little or no expansion of forest area, according to the study, led by Aapo Rautiainen of the University of Helsinki, Finland, and published Monday in the on- line, open-access journal PLoS One.Even in the South American nations studied, more density helped maintain regional carbon levels in the face of deforestation.The researchers analyzed information from 68 nations, which together account for 72 percent of the world's forested land and 68 percent of reported carbon mass. They conclude that managing forests for timber growth and density offers a way to increase stored carbon, even with little or no expansion of forest area."In 2004 emissions and removals of carbon dioxide from land use, land-use change and forestry comprised about one fifth of total emissions. Tempering the fifth by slowing or reversing the loss of carbon in forests would be a worthwhile mitigation. The great role of density means that not only conservation of forest area but also managing denser, healthier forests can mitigate carbon emission," says Rautiainen.

SAN FRANCISCO, June 14 (Xinhua) -- Apple updated its online store on Tuesday to begin offering unlocked models of iPhone 4 in the United States for the first time."The unlocked iPhone 4 requires an active micro-SIM card that you obtain from a supported GSM wireless carrier," said Apple in the product description. The iPhone requires a smaller version of the standard SIM (Subscriber Identity Module) card.Started at 649 U.S. dollars for the 16 GB version, the unlocked model is a GSM phone, which means, in the United States, the phone runs on networks of T-Mobile or AT&T, although it can only send data over T-Mobile's old EDGE network, not its 3G network and the faster HSPA+ network.Verizon and Sprint, the other two major U.S. wireless carriers, both use CDMA networks that do not use SIM cards.The iPhone 4 has been sold unlocked in other countries. For frequent international travelers, an unlocked iPhone means they just need to pop in a micro-SIM card for whichever country they are going, avoiding provider's high international fees.According to Apple, iPhone sales grew 113 percent year over year in the second quarter of its fiscal 2011, reaching a record high of 18.65 million units.

WASHINGTON, July 18 (Xinhua) -- Exposure to secondhand smoke ( SHS) is associated with increased risk of hearing loss among adolescents, according to a report in the July issue of Archives of Otolaryngology -- Head and Neck Surgery.Among U.S. children, approximately 60 percent are exposed to SHS, according to background information in the article. Studies have associated exposure to secondhand smoke prenatally or during childhood with various health conditions, from low birth weight and respiratory infections to behavioral problems and otitis media. Children exposed to SHS are more likely to develop recurrent otitis media, the authors note. "Secondhand smoke may also have the potential to have an impact on auditory development, leading to sensorineural hearing loss (SNHL)," they add.Anil Lalwani and colleagues from New York University Langone Medical Center examined the risk factors for SNHL, including SHS, among adolescents, stratified by demographic groups. They included 1,533 individuals from 12 years to 19 years of age who participated in the National Health and Nutrition Examination Survey from 2005 to 2006.Participants were interviewed about their health status and family medical history, exposure to SHS, and self-recognition of hearing impairment. In addition, they underwent a physical examination, including blood testing for cotinine (a by-product of nicotine exposure), and hearing tests.Compared with teens who had no SHS exposure, those who were exposed to secondhand smoke exhibited higher rates of low- and high-frequency hearing loss. The rate of hearing loss appeared to be cumulative, increasing with the level of cotinine detected by blood tests. The results also demonstrated that more than 80 percent of participants with hearing loss did not realize they had impairment.As hearing loss early in life can cause problems with development and functioning, the authors suggest that these results have "significant implications for public health in the United States."They note that most adolescents do not receive screening for hearing loss in the absence of risk factors.If further studies replicate these results, they state, SHS could be considered one such risk factor.

来源：资阳报