徐州胎儿四维什么时候做(徐州四维B超何时做好一点) (今日更新中)

PARIS, June 19 (Xinhua) -- Commercial Aircraft Corporation of China Ltd. (Comac) on Sunday set up its European office in Paris, the second overseas branch after its U.S. office, marking a new step for China's aviation industry in opening-up and international exchanges."The establishment of Comac Europe office is very significant. It represents the strategic cooperation between China and France and will deepen the two sides' collaboration in aerospace and all areas concerned," Chinese Ambassador Kong Quan said at an opening ceremony, citing Europe's influence in global aerospace industry and civil aviation market."Taking self-dependent innovation as the strategic cornerstone, Comac meanwhile actively conducts international cooperation and draws upon advanced technologies and experience in global civil aviation industry...," Comac President Jin Zhuanglong said.French Secretary of State for Transport Thierry Mariani (4th L), Chinese Ambassador to France Kong Quan (3rd L) and General Manager of the Commercial Aircraft Corporation of China (COMAC) Jin Zhuanglong (2nd R) attend the unveiling ceremony of COMAC Europe Office in Paris, France, June 19, 2011. The COMAC Europe Office was offically opened here Sunday.The Chinese aerospace manufacturer has built up cooperative relationship and partnership with dozens of enterprises and institutions in many countries and regions since its establishment in May 2008 in Shanghai.Regional jet ARJ21 and the trunkliner C919 are two flagship products of the young Chinese company. The group is now working to achieve certification and delivery of ARJ21-700 aircraft by the end of this year, Jin said.With regard to China's C919 trunkliner program, Jin said COMAC has signed cooperation agreements with 17 international companies in the United States and Europe, and has actively explored collaboration with GECAS, British Airways and Ryanair."In the context that the world economy is on recovery from the financial crisis, the civil aviation industry is facing great challenge. We are willing to keep close contact with all relevant public administrations and forge friendly relations and cooperation with overseas suppliers to contribute to the development of world civil aviation industry," Jin said.For the French State Secretary for Transport Thierry Marianne, who also attended the opening ceremony, the Chinese aviation market has great potential in the years to come, and China is estimated to need 3,000 new planes."We have understood that China had decided to build its own aerospace industry. It is a legitimate choice," Marianne said.A demo mock-up of the full-scale forward fuselage of C919 will be displayed during the 49th Paris Air Show on June 20-26, which will be the first time that the 1:1 demo mock-up is to be showcased at an international stage outside China, Jin told Xinhua.During the air show, Comac is going to sign agreements with an international airline and an airborne-system supplier and carry out a series of activities concerning international cooperation and exchanges, according to the group.

BEIJING, July 26 (Xinhuanet) -- Hong Kong scientists announced that they had determined the idea of time travel is impossible by proving nothing can travel faster than the speed of light.The finding is contained in a study done by a research team from Hong Kong University of Science and Technology. The study was published Monday in a scientific journal "Physical Review Letters" in the United States."The study, which showed that single photons also obey the speed limit c, confirms Einstein's causality, that is, an effect cannot occur before its cause," the university said on its website."By showing that single photons cannot travel faster than the speed of light, our results bring a closure to the debate on the true speed of information carried by a single photon." said Professor Du Shengwang, who led the study.The possibility of time travel was raised 10 years ago when scientists discovered the optical pulses in some specific medium might propagate information in a faster-than-light speed."Our findings will also likely have potential applications by giving scientists a better picture on the transmission of quantum information." Du said.

SYDNEY, Sept. 5 (Xinhua) -- Australian scientists believe " brown fat," a wondrous tissue that burns energy to generate heat, could help people fight obesity, local media reported on Monday.A research team from Sydney's Garvan Institute of Medical Research (GIMR) has worked out how to grow brown fat from stem cells biopsied from adults, raising hopes that one day brown fat could be transplanted in obese people to speed up calories they burn, the Australian Associated Press (AAP) reported.Garvan endocrinologist Paul Lee, who led the research, is optimistic about targeting brown fat as an obesity intervention, commenting "it's a highly metabolically active form of fat, and very exciting that we may be able to stimulate its growth in people."People are born with supplies of brown fat around their neckline to keep them warm as infants, according to scientists at GIMR.Scientists now know that brown fat is present in most, if not all, adults mainly just behind the collarbone.Studies have found that adults with brown fat are slimmer than those without."Although this is early work, it is a proof of concept study showing that the growth of brown fat cells is possible, using precursor cells taken from adult humans, under appropriate stimulation," Lee said."Regardless of whether or not someone has lots of or little brown fat, the precursor cells are universally present. Under the appropriate growth factor and hormonal stimulation, the cells all grow and differentiate into mature brown fat cells."However, Lee warned more work was needed.Lee said even if brown fat was transplanted into obese people or drugs developed to stimulate the growth of brown fat, exercise and a healthy diet would still be crucial to aiding weight loss."So I don't think this is a solution to obesity because there are so many other factors (involved in obesity)," he said."Despite how efficient brown fat is at burning energy, we would only need a few doughnuts to diminish or negate its benefits."Lee said it would be years before tests could be carried out on brown fat transplants.In the meantime, he is expanding his study to test different ways to grow brown fat.His study, to be printed in the October issue of Endocrinology, has been published in the online edition of the journal.

BEIJING, Sept. 25 (Xinhua) -- As China's economy has soared to the second place in the world, the country's scientific strength has also surged -- if only measured by the numbers.Chinese researchers published more than 1.2 million papers from 2006 to 2010 -- second only to the United States but well ahead of Britain, Germany and Japan, according to data recently published by Elsevier, a leading international scientific publisher and data provider. This figure represents a 14 percent increase over the period from 2005 to 2009.The number of published academic papers in science and technology is often seen as a gauge of national scientific prowess.But these impressive numbers mask an uncomfortable fact: most of these papers are of low quality or have little impact. Citation per article (CPA) measures the quality and impact of papers. China's CPA is 1.47, the lowest figure among the top 20 publishing countries, according to Elsevier's Scopus citation database.China's CPA dropped from 1.72 for the period from 2005 to 2009, and is now below emerging countries such as India and Brazil. Among papers lead-authored by Chinese researchers, most citations were by domestic peers and, in many cases, were self-citations."While quantity is an important indicator because it gives a sense of scientific capacity and the overall level of scientific activity in any particular field, citations are the primary indicator of overall scientific impact," said Daniel Calto, Director of SciVal Solutions at Elsevier North America.Calto attributed China's low CPA to a "dilution effect.""When the rise in the number of publications is so rapid, as it has been in China -- increasing quantity does not necessarily imply an overall increase in quality," said Calto.He noted the same pattern in a variety of rapidly emerging research countries such as India, Brazil, and earlier in places like the Republic of Korea."Chinese researchers are too obsessed with SCI (Science Citation Index), churning out too many articles of low quality," said Mu Rongping, Director-General of the Institute of Policy and Management at the Chinese Academy of Sciences, China's major think tank.SCI is one of the databases used by Chinese researchers to look-up their citation performance. The alternative, Scopus, provides a wider coverage worldwide."Chinese researchers from a wide range of areas and institutions are vying for publication, as it is a key criterion for academic appraisal in China, if not the only one. As a result, the growth of quality pales in comparison to that of quantity," said Mu, an expert on China's national science policy and competitiveness.On the other hand, China also falls behind the United States in multidisciplinary research, which is a core engine for scientific advance and research excellence.From 2006 to 2010, China published 1,229,706 papers while the United States churned out 2,082,733. According to a new metric introduced by Elsevier's Spotlight research assessment solution, China generated 885 competencies while the United States had 1,817.In other words, China's total research output is more than half that of the United States, while the number of competencies showing China's strength in multidisciplinary research is less than half that of the United States.Cong Cao, an expert on China's science and technology, put it more bluntly in an article he wrote: "When the paper bubble bursts, which will happen sooner or later, one may find that the real situation of scientific research in China probably is not that rosy."China has been investing heavily in scientific research and technological development in recent years to strengthen its innovative capacity, The proportion of GDP spent on R&D grew from 0.9 percent in 2000 to 1.4 percent in 2007, according to the World Bank.An IMF forecast in 2010 says China now ranks second globally in R&D spending. The IMF calculates China's R&D expenditure at 150 billion U.S. dollars when based on Purchasing Power Parity, a widely used economic concept that attempts to equalize differences in standard of living among countries.By this measure, China surpassed Japan in R&D spending in 2010.Many see China's huge investment in R&D as the momentum behind the country's explosive increase in research papers."Getting published is, in some ways, an improvement over being unable to get published," Mu said. "But the problem is, if the papers continue to be of low quality for a long time, it will be a waste of resources."In China, academic papers play a central role in the academic appraisal system, which is closely related to degrees and job promotions.While acknowledging the importance of academic papers in research, Mu believes a more balanced appraisal system should be adopted. "This is a problem with science management. If we put too much focus on the quantity of research papers, we leave the job of appraisal to journal editors."In China, the avid pursuit of publishing sometimes gives rise to scientific fraud. In the most high-profile case in recent years, two lecturers from central China's Jinggangshan University were sacked in 2010 after a journal that published their work admitted 70 papers they wrote over two years had been falsified."This is one of the worst cases. These unethical people not only deceived people to further their academic reputations, they also led academic research on the wrong path, which is a waste of resources," Mu said.A study done by researchers at Wuhan University in 2010 says more than 100 million U.S. dollars changes hands in China every year for ghost-written academic papers. The market in buying and selling scientific papers has grown five-fold in the past three years.The study says Chinese academics and students often buy and sell scientific papers to swell publication lists and many of the purported authors never write the papers they sign. Some master's or doctoral students are making a living by churning out papers for others. Others mass-produce scientific papers in order to get monetary rewards from their institutions.A 2009 survey by the China Association for Science and Technology (CAST) of 30,078 people doing science-related work shows that nearly one-third of respondents attributed fraud to the current system that evaluates researchers' academic performance largely on the basis of how many papers they write and publish.Despite rampant fraud, China will continue to inject huge money into science. According to the latest national science guideline, which was issued in 2006 by the State Council, the investment in R&D will account for 2.5 percent of GDP in 2020."If China achieves its stated goal of investing 2.5 percent of its GDP in R&D in 2020, and sustains its very fast economic growth over the next decade, it would quite likely pass the U.S. in terms of total R&D investment sometime in the late 2010s," said Calto, adding that it is also quite likely that at some point China will churn out more papers than the United States.According to Calto, China does mostly applied research, which helps drive manufacturing and economic growth, while basic research only accounts for 6 percent, compared with about 35 percent in Germany, Britain, and the United States, and 16 percent in Japan."In the long term, in order to really achieve dominance in any scientific area, I think it will be necessary to put significant financial resources into fundamental basic research -- these are the theoretical areas that can drive the highest level of innovation," Calto said.

BEIJING, Aug. 11 (Xinhuanet) -- Next year will bring a doubling in the size of the words that appear on cigarette packages to warn consumers of the dangers of smoking. Starting in April 2012, cigarettes produced and sold in China will bear a new warning label containing letters that will be no less than 4 millimeters in height. That will be twice the size of the current minimum, which stipulates that the letters be at least 2 mm from bottom to top, according to a notice written by the China National Tobacco Corp and published on the State Tobacco Monopoly Administration's website. Despite the intentions, many tobacco-control experts said the step is "minor" and that it fails to deal with the chief issue. "There is no use in making the font size even 100 times bigger if the warning is pointless," said Wu Yiqun, deputy director of the ThinkTank Research Center for Health Development, a Beijing-based non-governmental organization that advocates for the adoption of stronger smoking-control measures. Both Wu and Yang Gonghuan, director of the tobacco control office of the Chinese Center for Disease Control and Prevention, said the warning that now appears on cigarette packs is too weak. It says: "Smoking is harmful to your health. Quitting early is good for your health." "The package should inform consumers of the dangers of smoking in accordance with requirements adopted by the World Health Organization Framework Convention on Tobacco Control. (It should say that) smoking causes lung cancer, coronary disease and makes people grow old," Yang said. China decided in 2005 to ratify the convention, which also requires that tobacco warnings cover a third of the surface of cigarette packs. "Even if the size of the words is doubled, it still doesn't meet those standards," Yang said. "The Chinese practice is to draw a line to demarcate a third of a cigarette package, where the warning should be, but the words put on it are still very small." Experts said graphic health warnings could be printed on cigarette packs and used as a "scientific, direct and shocking" deterrent to smoking.Throughout the world, more than 1 billion people in 19 countries live under laws that require the packaging of various types of tobacco products to bear large, graphic health warnings. They often show pictures of black lungs and festering mouth sores, according to the World Health Organization. China, though, is excluded from those rules. Both Wu and Yang said the fundamental barrier to better control of tobacco use in the country is the fact that the China National Tobacco Corp, the country's largest cigarette-maker, is a subsidiary of the State Tobacco Monopoly Administration, China's tobacco regulatory body.

来源：资阳报