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深圳伊斯佑整形美容医院丰唇怎么样深圳市罗湖区人民医院疤痕多少钱Science and technology科学技术The Neolithic新石器时代Boom-time machine时间机器解密:新石器时代的繁荣期Building site, 3670 公元前3670年的建筑遗址THAT economic expansion leads to building booms seems to have been as true 6,000 years ago as it is now.在经济扩张时期,人们往往喜欢大兴土木。如今的这条经济定律在6000年前似乎也同样适用。When agriculture came to Britain, it led to a surge of construction as impressive—and rapid—as the one that followed the industrial revolution.随着农业在英国生根萌芽,建筑业也随之蓬勃兴旺,其发展速度之快,令人印象之深刻毫不逊色于英国工业革命之后的那次农业变革。Which is all a bit of a surprise to archaeologists,这一切让考古学家们显得有些惊讶,who had previously seen the arrival of the Neolithic as a rather gentle thing.他们之前一直认为新石器时代是经济发展较为和缓的时期。But that may be because of the tools they use.不过这可能是由于他们使用的考古技术方法还不够先进。Radiocarbon dating provides a range, often spanning 200 years or more, rather than an exact date for a site.采用放射性碳技术来测定一处考古遗址的年代,得到的并不是一个准确日期,而是一个时间跨度范围通常为200年或更久远的数值。Stratigraphy, which looks at the soil layers in which artefacts are found, tells you only which ones are older and which younger.而地层学采用的方法是通过对已发现古代文物的土壤层进行探测分析,从而判断土壤年代的远近。None of these data is precise.这种方法得出的数据也都不精确。They do, however, limit the possible range of dates.然而它们确实缩短了可推算的时间跨度。And by using a statistical technique called Bayesian analysis it is possible to combine such disparate pieces of information to produce a consolidated estimate that is more accurate than any of its components.通过贝叶斯分析的统计方法,这些分散孤立的信息可能被整合成一个可靠详实的估计数值,这比单一研究其中的任何一条信息都更为精确。That results in a range that spans decades, not centuries.采用地层学断代推算出的时间范围是几十年,而不是几百年。A team led by Alex Bayliss, from English Heritage, a British government agency, has just used this technique to examine digs from hundreds of sites around Britain.Alex Bayliss领导的研究小组来自于英国政府机构的古迹署,他们刚刚采用这项技术对英国周围几百处的人工挖凿遗址进行了研究。The results have caused them to reinterpret the Neolithic past quite radically.这些成果可以让他们更为彻底地重新诠释新石器时代。Agriculture seems to have arrived fully formed in what is now Kent, in the south-east, around 4050.大约在公元前4050年,在现今的英国东南部的肯特郡,那里的农业时代似乎已经到来并发展成熟。The new culture sp slowly at first, taking 200 years to reach modern-day Cheltenham, in the west, but over the following five decades it penetrated as far north as Aberdeen.起初这种新文化传播缓慢,用了200年的时间才到达今天英国西部的切尔滕纳姆,但是在后续的50年中,它迅速东扩到了北部的阿伯丁。Soon afterwards, causewayed enclosures began springing up all over the country.随后,筑有堤道的围场开始在全国遍地开花。Until now, archaeologists had assumed that these were built over the course of centuries.现在,考古学家断定这些建筑物是在几百年间陆续建成的。Dr Baylisss work suggests they were the product of two booms, each just a few decades long—for the Neolithic seems to have seen its share of busts, too.Bayliss士的考古研究表明它们是两个繁荣期的产物,每个繁荣期的持续时间仅为几十年,可见新时器时代似乎也存在过衰落的萧条期。The teams work offers such a sharp picture of the past that it is possible to trace the histories even of individual communities,考古研究小组为我们展示了清晰的远古画面,让我们可以追溯到更远的历史甚至小的个体群落,such as one in Essex whose inhabitants built, used and then abandoned an enclosure within the span of a single generation.例如在埃塞克斯考古遗址,考古人员发现了当时原始居民修建,使用和后来废弃的围场,它伴随了一代人的成长。English Heritage now plans to apply the technique to another murky era of British history, the early Anglo-Saxon period between 400AD and 700AD.现在英国古迹署计划将此技术应用于英国另一段有着模糊记载的历史年代,即介于公元400年至公元700年的早期盎格鲁-撒克逊时期。In principle, the method can be applied to any archaeological site, and several groups of researchers around the world are working on similar projects.理论上,此种方法可以应用于任何一个考古遗址,现在全世界已经有几组考古人员运用此方法进行着类似的考古项目。But, fittingly for a discipline that deals in centuries and millennia, the revolution will be a slow one.但是恰当地说,对一门牵涉几百年和上千年的学科,它的发展将是一个漫长的过程。Unlike traditional radiocarbon dating, which can be bought off the shelf, Dr Bayliss reckons it takes between three and four years to train a graduate researcher to use the new technique properly.传统的放射碳断代法是一种现学现卖的技术,但地层学与之不同,Bayliss士认为培养一名完全掌握此项新技术且具有硕士学位的研究人员得需要三到四年的时间。 /201304/237081深圳双眼皮哪家好 宝安中医院打玻尿酸多少钱

深圳市第一人民医院开双眼皮多少钱深圳瘦脸针多少钱 深圳人民医院激光去痣多少钱

深圳宝安人民妇幼保健医院做祛疤手术多少钱Science and technology科学技术Prospecting for oil石油勘探Grains of truth千虑一得之法Putting rocks in medical scanners may help the search for oil and gas采用医学扫描仪对岩石样本扫描,可帮助寻找石油和天然气STRIKING oil is one thing.开采石油是一回事。Getting it out of the ground in economic quantities is quite another.然而从经济角度考虑,能从地下开采出多少石油又完全是另一回事。Doing so depends on understanding the granular structure of the rock it is trapped in,要做到这点,人们需要对某些岩石的颗粒结构有所了解,而这些岩石是有石油困于其中的。分and analysing that is a tedious business of placing countless samples in pressure vessels to assess their capacity to hold hydrocarbons and to estimate the flow rate of those hydrocarbons through them.析岩石颗粒结构是极其枯燥乏味的事情,研究人员需要将无数个样本放置在压力容器内以评估它们含纳碳氢化合物的能力并估計其中蕴藏的碳氢化合物的产量。This can take years.这可能需要花费数年的时间。Help, though, is at hand.然而可施之法即在眼前。Computerised tomography scanning has been used in medicine for several decades.计算机X线断层照相扫描术在医学领域应用已有几十年时间。Now it is being applied to geology.目前它正被应用于地质学。In alliance with electron microscopy, the geological use of CT scanning has given birth to a new field, digital rock physics.在与电子显微镜配合使用下,CT扫描术在地质上的应用育了一个新的领域—数字岩石物理。The fields proponents believe it will let oil companies decide far more quickly than they could in the past which strikes are worth exploiting, and which should be abandoned.该领域的倡导者认为,该项技术能使石油公司较之以往更加快速地判断哪些石油矿值得开发,哪些应该放弃。One of those proponents is Amos Nur, chief technology officer at, a company based in Houston, Texas.科技公司Ingrain总部设在得克萨斯州休斯敦,其首席技术官阿莫斯?努尔是该技术倡导者之一。His firm is one of three independent digital-rock-physics laboratories in the world.他所在公司是全球三家独立数字岩石物理实验室之一。According to Dr Nur, the new technology is capable of creating three-dimensional pictures of a samples structure with a resolution of 50 nanometres.努尔士表示,这项新技术能为岩石样本结构创建分辨率为50纳米的三维立体照片。That is enough to work out how oil and gas trapped in the pores between the grains of such a rock might be expected to behave.这足够预测出困在岩石颗粒细孔间的石油和天然气的表現方式。Most of the samples analysed by Ingrain start as cylindrical cores brought up from deep below the Earths surface by drills.开始分析的大部分样本都来自于地下深层钻探得到的圆柱形岩石核。A typical core is several metres long, so it is first subject to a rough and y CT scan using a standard medical scanner.典型的岩石核有几米长,因此首先要采用标准医学扫描仪对其进行粗略的CT扫描。The scanner is fitted with calibration rods made of a proprietary material whose properties provide reference points for the creation of an image.该扫描仪安装了许多由专利材料制成的调校棒,这种材料有为图像创建提供参考点的属性。This initial scan yields a picture that has a resolution of about 500 microns.初始扫描会得到一张分辨率为500微米的图片。That done, sections of the core 2-3cm long, whose porosity is of particular interest, are subject to further study.这些完成之后,将一些长度在2至3厘米间,其孔隙度有特殊研究价值的小岩石块做进一步研究。This involves scanning them in a special micro-CT machine, of a sort developed originally to look at computer chips.这包括将岩石核样本放入一台特殊的微CT机进行扫描—微CT机原是为了观察电脑芯片而研制的。The sample is placed on a turntable and rotated inside this microscanner.将小岩石核样本放置在微扫描器内部的转盘上并使其旋转,The result is a 3D image with a resolution of 40 microns.结果得到一个分辨率为40微米的三维图像。This allows sections requiring further study to be identified.这就使得需做进一步研究的小岩石块能够被标识。These sections are dissected, using a laser, into slices a millimetre or less thick, and then scanned again, either with the micro-CT or with a scanning electron microscope.采用激光将这些小岩石块切分成一毫米或不太厚的薄片,然后用微CT机或电子显微扫描镜对其再次扫描。That brings the resolution to half a micron, or 500 nanometres.这样便将图象分辨率提高到了0.5微米或500纳米。Finally, the image is cleaned up by a computer program and the 50-nanometre-resolution picture emerges.最后,将该图像进行计算机降噪去斑处理,得到一张50纳米分辨率的图片。This image, which shows the porosity of the rock, and the channels between the pores,然后将能够显示岩石孔隙度和岩石内部毛孔间通道的图像用计算机分析,is then subject to a computer analysis that reveals how easily hydrocarbons will flow through it under pressure—and thus the likely productivity of a well dug at that site.结果会显示在有压力情况下碳氢化合物在岩石块内部流动的容易程度—从而得知样品来源之处那口钻探井的可能产量。Whether digital rock physics will actually replace traditional methods is unclear.“数字岩石物理”技术是否能够取代传统方法,目前尚无定论。Sceptics, such as Anthony Kovscek of Stanford University, think the claims being made for it are exaggerated.许多人对此持怀疑态度,斯坦福大学的Anthony Kovscek就是其中之一,他认为该技术的声明有夸大成分。Though analysis of a rocks structure in this way will, in his opinion, be able to tell you that a strike is unlikely to yield a commercial return,在他看来,尽管采用这种方法得出的岩石结构分析结果能够告知人们哪个钻探点不可能产生商业回报,the reverse is not true.但其反面结论却未必正确。He does not believe that the technique can predict flow rates,他不相信这种技术能预测石油的流量,even from rock that contains a lot of hydrocarbons—and flow rates are crucial to an oil fields economics.即使对于含有大量碳氢化合物的岩石也无法预测—石油流量是油田经济中至关重要的指标。The new discipline of digital rock physics has, nevertheless, attracted considerable attention within the industry.但是“数字岩石物理”这门新学科在行业内引起了相当大的关注。Smaller oil companies are using the facilities of Ingrain, Numerical Rocks and Digitalcore.小型石油公司正在使用Ingrain、Numerical Rocks和Digitalcore的设备。Larger ones, such as BP, Chevron and Shell, are setting up their own digital-rock-physics laboratories.而大型石油公司—如BP、雪佛龙和壳牌正在创建自己的数字岩石物理实验室。As the supply of crude oil dwindles and the price thus rises, anything that makes the process of prospecting new wells cheaper is to be welcomed. This new technique may be such a thing.当原油供应下降并导致价格上升之时,任何能使新井勘探成本更低的技术都将受到欢迎。“数字岩石物理”可能就是满足此要求的新技术。 /201305/239868 Finance and economics财经商业Reforming Chinas state-owned firms改革中国国有企业From SOE to GLC从国有企业到国联企业Chinas rulers look to Singapore for tips on portfolio management中国领导人指望得到新加坡关于投资组合管理的指点SHORTLY before his confirmation as Chinas paramount leader in 1978, Deng Xiaoping paid a visit to fast-growing Singapore.1978年,邓小平被任命为中国最高领导人前夕,他对高速发展的新加坡进行了访问。He planted a tree on a hill overlooking Jurong, a bustling industrial park built on what was once marshy wasteland close to the city-states harbour.他在俯瞰裕廊的一座山上种植了一棵树,裕廊是建于城市港口附近的一个蓬勃发展的工业园区,那里曾经是一个不毛之地。Singapores success as a trading hub impressed Deng, who imposed his vision of economic reform on Chinas Communist Party the following month, at an historic meeting known as the third plenum.新加坡成功成为一个贸易枢纽给邓小平留下了深刻的印象,他在访问新加坡后的一个月,在那个具有历史意义的三中全会上,向中国共产党提出了有关经济改革的设想。Singapore, which has a population of 5m to Chinas 1.35 billion, remains a source of inspiration for some Chinese reformers.对于中国一些改革家来说,拥有500万人口的新加坡与拥有13.5亿人口的中国相比,仍然具有激励作用。On the eve of the latest third plenum, held earlier this month, the Development Research Centre, a government think-tank, advertised an ambitious set of reform proposals, including an overhaul of Chinas inefficient state-owned enterprises.本月初期举行的十八届三中全会前夕,政府智囊团国务院发展研究中心公布了一系列雄心勃勃的改革提议,包括彻底改革中国低效国有企业。Simply privatising these companies remains out of the question for Chinas leaders.仅仅将这些企业私有化对中国领导人来说是不可能的。But there are alternatives, and Singapore provides one.但是他们还有其他选择,新加坡就提供了一个选项。The DRCs plan named Temasek, a holding company for SOEs in Singapore, as a potential model.国务院发展研究中心计划把新加坡国有企业控股公司淡马锡公司作为一个可能的模型。It was created in 1974, when it inherited 35 companies from the finance ministry.淡马锡公司成立于1974年,它从新加坡财政部手中接手了35家国有企业。Its inaugural portfolio contained several of the firms that made Jurong eye-catching, including its shipyard and its birdpark.它成立的投资组合包括几个使得裕廊引人注目的公司,包括其造船厂和飞禽公园。In the four decades since, Temaseks portfolio has both multiplied and gone forth: only 30% of its holdings remain in Singapore itself.从那时起后四十年,裕廊的投资组合不仅迅速增加,还不断发展:只有30%的控股还在新加坡手上。Its domestic holdings are concentrated in what Singapore calls government-linked companies, such as Singapore Airlines and SingTel, a telecoms company.其国内股份集中在新加坡称为国联企业手中,例如新加坡航空,电信公司SingTel。Temaseks charter obliges it to increase the value of its holdings over the long term.淡马锡公司的章程迫使他们在长期增加他们股份的价值。This is a remarkably simple aim compared with the Chinese governments manifold ambitions.这相对于中国政府各种各样的雄心壮志来说明显是一个简单明确的目标。It wants its holdings to promote technological progress, favoured industries and national security, among other things.此外,他们还希望他们的股份能推进技术进步,推动中意的工业发展和国家安全。As well as clarifying objectives, the Temasek model also allows the state to distance itself from the management of its enterprises, without relinquishing ownership.除了阐明目标以外,淡马锡模型还准许国家在不放弃所有权的情况下,拉开自己与企业管理的距离。Temasek avoids meddling in the day-to-day running of the GLCs in its portfolio, which are free to hire professional managers at market rates.淡马锡模型避免了对国联企业投资组合日常管理的干预,这样可以随意以市场价雇佣专业的管理人才。With a few exceptions, it does not directly appoint board members either.除了几个例外,淡马锡公司也不直接任命董事会成员。This is partly because it does not want to become privy to price-sensitive information that might limit its ability to trade shares.这样做部分原因是因为它不想获准接触那些可能会限制其自身交易股份能力的价格敏感的信息。Temasek has evolved into an active investor, but not an activist one, says Stephen Forshaw, its chief spokesman.淡马锡公司首席发言人史蒂芬福肖说,淡马锡公司已经逐步发展成了一个活跃的投资者,但不是一个积极分子。Although it does not appoint directors, it does meet regularly with its wards boards to make its feelings known.虽然淡马锡不任命董事,它定期与其监管董事会开会,让董事会知道他们的想法。It also keeps managers on their toes by enlisting outside consultants, such as Bain or McKinsey, to spot industrial trends they should be aware of.它还让管理者通过谋求外部咨询来保持警觉,如向贝恩或麦肯锡咨询,来留意他们应该知道的工业发展趋势。Would the Temasek model help improve the efficiency of Chinas state-owned enterprises?淡马锡模型会有助于提高中国国有企业的效率吗?Only one or possibly two of Temaseks GLCs have established themselves as international brands, according to critics such as Chris Balding of Peking University.据北京大学的克里斯鲍尔丁说,淡马锡公司的国联企业中只有一个或者可能两个已经成为了国际品牌。SingTel has made successful foreign acquisitions, but other GLCs have fared less well.SingTel成功进行了外资并购,但是其他国联企业很少有成功的。STATS ChipPAC, a semiconductor firm, lost money in the second quarter of this year, as a result of the costs of closing a factory in Malaysia.半导体公司STATAS ChipPAC今年第二季度亏损,因为它关闭了位于马来西亚的一个工厂。The few academic studies of Singapores GLCs are more encouraging, however.但是关于新加坡国联企业的学术研究越少越令人鼓舞。A 2004 article by Carlos Ramirez of George Mason University and Ling Hui Tan of the IMF showed that the countrys GLCs enjoyed a higher market value, relative to the book value of their assets, than comparable private firms.乔治梅森的卡洛斯拉米雷斯和国际货币基金组织的Ling Hui Tan 2004发表的一篇文章表明,就资产净值而言,新加坡的国联企业比起私人企业有更高的市场价值。They also generated a higher return on assets, on average.他们还创造更高的平均投资回报。In judging the performance of Temaseks GLCs, the counterfactual is important.在评价淡马锡的国联企业的表现时,反事实的情况很重要。They may not be as obviously successful as private titans from the region such as Samsung or LG.他们可能不会像亚洲私人公司巨头那样有着明显的成功,如三星、LG。But they are not nearly as bad as most SOEs, including Chinas.但是他们几乎不会像大多数国有企业包括中国的国有企业那样糟糕。The enthusiasm for reform of SOEs in China reflects their deteriorating returns and accumulating debt.中国国有企业改革的反映了他们日益恶化的投资回报和日益增长的债务。According to M.K. Tang of Goldman Sachs, their return on assets was 6.5 percentage points below that of other Chinese firms in 2012 and their shares trade at a growing discount.根据高盛投资公司的M.K. Tang,2012年国有企业的资产回报比中国其他公司低6.5个百分点,且他们的股份持续贬值。Even Mr Balding, meanwhile, is happy to fly Singapore Airlines.同时,甚至是鲍尔丁先生也很高兴乘坐新加坡航空。 /201311/266498深圳伊斯佑整形美容医院双眼皮怎么样光明新区冰点脱毛多少钱

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