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无锡微创痔疮费用无锡男肛门湿疹Technology Catalog技术前沿Towering Beauty 高耸的美丽Elegant way to convey electrical cables across the countryside may be coming soon to a field near you 输电新法可能很快推出A PYLON is supposed to be a beautiful thing. In ancient Egypt, pairs of tapering stone towers called pylons marked the entrances of temples. Christian architects borrowed the idea for the twin towers above the fa?ades of many Gothic cathedrals. 高塔应属美之物,在古埃及,成对下粗上细的塔门标出庙宇的入口,基督教建筑师也借用哥特教堂前面竖上双塔的想法。Whoever thought of appropriating the word for the ugly metal-lattice structures that carry high-tension power lines over the countryside was therefore guilty of both a public-relations triumph and an act of etymological vandalism. 但谁能想到一个确切的词,来描述乡村上面那些传送高压电的丑陋高架建筑,它们总是纠结于公共关系的胜利和原始环境的破坏。The latter, however, may soon be redeemed. The latest generation of electricity pylons are, in the eyes of some, at least, things of beauty in their own right.不过,补救之法很快推出,看来,最新一代的电塔至少也能算得上个尤物吧。The pylons in question have been designed by engineers at TenneT, the firm that runs the Netherlands national electricity grid, in collaboration with KEMA, a Dutch research company. Instead of a single lattice tower, the cables are supported by two elegant steel poles up to 65 metres high. There are no arms. The six cables that pass from one pylon to another are each borne by two insulators attached to the poles. 谈论的电塔由Tennel T的工程师设计,该公司同荷兰一家研究公司KEMA合作运营荷兰国家电网,两根细长的钢柱撑着电碳,高65米,没有杆,也不是一根架子塔。两个高塔之间通着6根电缆,每根有两个附在高塔上的绝缘体。The resulting arrangement, though hardly invisible, is reasonably elegant. 这样安排几乎看不到什么,相对体面些。As much to the point, though, it has technological advantages. 怎么说,这种电塔也具有技术上的优势,Though no harm has been proven from them, conventional pylon cables, which transmit a three-phase alternating current, generate a strong electric field and a continuous buzz of low-frequency radio waves which some people who live near them fear might be detrimental to their health.传统电塔传输三段交流电,会产生强烈的磁场和低频电波连续不断的嗡嗡声,附近居民担心这可能会对身体不好,而新式电塔倒还没有这种事儿。TenneTs pylons should help allay that fear. TenneT的电塔应会减轻他们的疑虑。Carrying all the cables in a “stack” between the poles, rather than hanging them separately on outward-facing arms, allows them to be arranged in a way that causes the individual fields generated by each cable to cancel each other, weakening the overall field around the pylons. 电塔之间的电缆都在一块,而不是在向外伸出的杆上分开挂着,每根电缆产生单独磁场,相互干扰,降低了电塔周围的总磁场。The result is far less low-frequency radiation. 新式电塔大大减少低频辐射。The combination of being less of an eyesore and producing less electrical smog should, TenneT hopes, soften objections to the construction of new overhead power lines.TenneT希望不碍眼和低辐射能减少人们对修建新电塔的异议。That is important for two reasons. 主要因为两点,One, the alternative—burying high-tension lines—is expensive and largely futile. 首先,掩埋高压线这一替换既贵又不实用。The cost of putting a cable underground is between four and ten times as much as that of carrying it on a pylon.把电缆埋在地底的花费是架电塔的四到十倍。On top of that, the field generated by an alternating current interacts with the ground more strongly than it does with the air. 除此之外,在地下交流电相互影响产生的磁场比在空中强烈很多。This creates losses 40 times higher in a buried cable than in an aerial one. Unless the long-distance-transmission system were converted to direct current, burial of transmission lines is not a serious option. 地底铺线比高空架线成本高了40倍。除非长距输电系统转换成直流电,地下输电才不至于是个笑话。The second reason TenneTs pylons may be important is that despite these problems a lot of new long-distance-transmission lines are going to have to be constructed, soon. Wind power from the North Sea and the Atlantic Ocean will require that.其次,不管这些,TenneT的电塔很重要是因为很快要修建不少新的长距输电线路,北海和大西洋的风力将会需要。So, more speculatively, will the idea of generating solar power in north Africa and transmitting it to Europe.所以理论上北非太阳能发的电传输到欧洲的想法越来越有可能。In the Netherlands alone, TenneT says, more than 400km of new lines are needed. TenneT表示,单是荷兰就需要400多千米的新电缆。In Germany, the state-owned energy agency, DENA, reckons that figure is more than 3,500km. 德国国家能源部DENA估计得需3,500多千米。At the most recent meeting of the European Council, on February 4th, the leaders of the European Unions member states acknowledged that Europe needs a completely new power grid, a project they reckon will cost about 200 billion. 2月4日举办最新的欧洲议会上,欧盟成员国领导人承认欧洲需要全新电网,估计工程花费大约2000万欧元。The overhead power problem is thus going to have to be solved one way or another.头顶电力难题因此会用这种或其他办法解决。In truth, of course, no pylon is ever going to be a more attractive feature of the countryside than no pylon. But if pylons have to be built—which they do—then something elegant and efficient is the least bad way of doing it.当然,在乡村最美的风景是没有电塔,但要是必须得有呢,整得好看点效率点,才不会显得太糟吧。 点击此处下载本期经济学人讲解PDF与音频字幕 /201303/231507无锡宝宝肛瘘治疗医院要多少钱 Science and Technology Materials science Cracking a problem科技 材料科学 通过裂纹解决问题Another use for a fashionable, new material一种流行新材料的新用途LIKE all other human activities, science is subject to fads.像其它人类活动一样,科学是一个时尚主题。One of the latest is for graphene.最新的话题是关于石墨烯的。This wonder material—a form of carbon that comes in films a single atomic layer thick—won Andre Geim and Konstantin Novoselov the Nobel prize for physics last year.作为碳的一种形式,这种源自胶带操作的奇妙材料只有单原子层厚度,发明者安德烈·杰姆和克斯特亚·诺沃塞洛夫为此获得了去年的诺贝尔物理学奖。Because of its unusual electrical properties it has been touted as a way of making everything from touch screens to solar cells.由于石墨烯非同寻常的电特性,它被吹嘘为制造一切产品的新途径--从触摸屏到太阳能电池。Now a humbler use is being proposed.如今石墨烯的一种低层次应用被提出来。Another of graphenes qualities is that it is strong. That, suggests Erica Corral of the University of Arizona, makes it ideal for reinforcing ceramics.它的另一特性是机械强度高,因而被亚利桑那大学的埃里卡·科拉尔视为加强陶瓷材料硬度的一种理想材料。Engineers like ceramics because they can be heated without melting. Unlike metals and plastics, though, they are brittle.工程师喜欢陶瓷材料,因为它们加热时不会融化,这点不像金属和塑料,尽管它们是脆的。Because they crack easily, using them in places that are exposed to a lot of physical punishment is difficult.因为陶瓷材料易碎,因此将其用于高物理强度的场合非常困难。But a paper just published in the American Chemical Societys journal, Nano, by Dr Corral and her colleagues, suggests a sprinkling of graphene may deal with that.但在美国化学协会杂志刚发表的一篇论文《纳米》中,科拉尔士和她的同事们认为,加入少许石墨烯也许就能解决这个问题。The ceramic they experimented with was silicon nitride, a material much admired in the aerospace industry.她们测试的陶瓷材料是氮化硅--一种在太空工业中饱受赞誉的材料。Components are made by sintering it in powder form in a mould, at 1,000oC, for several hours.这些部件是将氮化硅粉末置于模具中,处于1000摄氏度高温下烧制数小时而成。Unfortunately, graphene disintegrates above 600oC, so the team had to think of a clever way of mixing the two materials.不幸的是,温度高于600摄氏度,石墨烯就碎裂,因此研究团队必须想出一种巧妙办法将两种材料融合在一起。Their solution was to take advantage of graphenes electrical conductivity, by running a current through the mixture. This generated a temperature of 1,650oC—more than enough to sinter the silicon nitride.解决办法就是利用石墨烯的导电特性,将电流通过混合物,产生的1650摄氏度的高温足以烧结氮化硅,而石墨烯也没有碎裂。The graphene, however, did not break down.其原理尚未完全弄清楚。Why, is not entirely clear. But rapid electrical heating did not seem to affect it in the way that slower oven heating would.但与通过熔炉缓慢加热不同,快速电加热对石墨烯看起来没有什么影响。The result was a composite that was able to withstand twice as much pressure as unalloyed silicon nitride.和纯氮化硅相比,其合成物能经受的压力强度翻倍。When the team examined what they had done under a microscope, they found that the graphene had wrapped itself around the silicon-nitride grains, forming continuous walls.当研究团队在显微镜下观察合成物时,他们发现石墨烯包裹在氮化硅颗粒周围,形成了连续的;壁;。When they looked at samples that they had whacked hard enough to come close to cracking, they found that these walls were encouraging the cracks to sp in three dimensions—in contrast with the two-dimensional pattern usually seen in silicon nitride.当检查这些不断敲击而近乎开裂的样品时,他们发现这些;壁;有助于裂纹向三个维度上延伸,和通常在氮化硅上观察到的;二维裂解模式;形成了对比。Dr Corral suspects that extending cracking into the third dimension dissipates the energy faster and stops the fault sping.科拉尔士推测,那种裂纹扩展为三个维度使能量扩散的更快,同时制止了缺陷的扩展。A cracking idea, as it were.通过三维裂纹来增强陶瓷材料强度,真是一个绝妙的点子! /201212/214745Business商业Fine-wine fraud伪造的美酒Chateau Lafake法国酒庄拉法克红酒The fine-wine boom is attracting forgers美酒追捧热潮催生造假者WINE buffs are like art collectors. Few can tell the difference between a well-made fake and the real thing.葡萄酒爱好者与艺术品收藏者相同,他们中很少人能分清真品与制作精良的赝品有什么区别。Yet whereas counterfeit art has been around for centuries, wine forgery is relatively new.但艺术品伪造已经有几百年历史了,酒类伪造却还只是近几十年的事。It started in the late 1970s when the prices of the best wines—especially those from Bordeaux—shot up.20世纪70年代末期,由于精品美酒尤其来自法国波尔多的葡萄酒价格飙升,名酒伪造应运而生。Today, with demand from China fuelling a remarkable boom, counterfeiting is rife.现在,中国对尊贵名酒的需求推动了名酒市场的繁荣,假冒伪劣酒也开始盛行。By some estimates 5% of fine wines sold at auction or on the secondary market are not what they claim to be on the label.据估计,拍卖会或二级市场出售的美酒有5%货不对板。The simplest technique is to slap the label of a 1982 Chateau Lafite (one of the most prized recent vintages) onto a bottle of 1975 Lafite (a less divine year).伪造名酒最简单的方法是将1982年产法国酒庄拉法克红酒(最近年份最珍贵的葡萄酒之一)的标签贴到1975年(不太吉利年份)产的(Lafite)红酒空瓶上。Another trick is to bribe the sommelier of a fancy restaurant to pass on empty bottles that once held expensive wine, along with the corks. These can be refilled with cheaper wine, recorked and resealed.另一个伎俩是贿赂高级餐厅的调酒师,将盛装过昂贵名酒的空瓶和瓶塞一起拿到手,然后将空瓶重新灌装廉价酒,重新装塞,重新密封就完成了造假过程。Empty Lafite and Latour bottles are sold on eBay for several hundred euros.在eBay网上,Lafite和Latour红酒的空瓶通常价值几百欧元。The margins are fruity. A great wine may cost hundreds of times more than a merely excellent one.酒类伪造有可观的利润。一瓶尊贵名酒的价格可能比一瓶单纯的优质酒贵上几百倍。Small wonder that oenophiles are growing more vigilant.难怪鉴酒专家们越来越趋于谨慎。Bill Koch, an energy tycoon and avid wine collector, currently has five lawsuits pending against merchants, auctioneers and other collectors.能源巨头比尔.科赫(Bill Koch)热衷于名酒收藏,他近来提起5宗涉及酒类的法律诉讼,分别状告酒商,拍卖师和其余酒类收藏家,案件至今未有裁决。His grape-related gripes began in 2006, when he filed a complaint against a German wine dealer who sold bottles of Lafite he claimed had once belonged to Thomas Jefferson. The case is unresolved.科赫先生对买红酒的抱怨始于2006年,当时他从一名德国酒商手中购买了很多据称是托马斯杰斐逊收藏过的红酒,后来发现有假而投诉了这名德国酒商,案子至今未果。;There is a code of silence in the industry,; says Mr Koch, who owns 43,000 bottles of wine and estimates that he has spent m-5m on fakes.科赫先生说:;业界存在着一套潜规则,即买到假酒也要毫不声张;。他拥有43000瓶上好葡萄酒,但用于购买假酒的钱估计也在4-5百万美元左右。Some collectors are too proud to admit that they have been duped.有些收藏者觉得承认被骗不是件光的事。Others fear sullying a vintages reputation and thereby reducing the value of their own collections.另一些则担心玷污了葡萄酒的声誉会降低自己拥有葡萄酒的收藏价值。So instead of speaking out, ;they dump their fakes into auctions or sell them to other private collectors,; says Mr Koch.因此他们不会将事情张扬,而是;将假酒转手到拍卖会或出售给其它私人收藏者;,科赫先生如是说。Wine merchants and auction houses say they are doing everything they can to filter out the fakes.酒商及拍卖行表示他们正尽一切所能筛选出假货。Simon Berry, the chairman of Berry Brothers amp; Rudd, a British wine merchant, says his firm never buys wines from before 2000 unless they come from its own cellars. (Berry Brothers stores nearly 4m bottles on behalf of its customers.)英国酒商贝瑞兄弟与陆克文(Berry Brothers amp; Rudd)主席西蒙贝里(Simon Berry)称他的公司从来不购买2000年以前的葡萄酒,除非它们真的来自出产的酒窖。(贝里替客户存放了将近4百万瓶葡萄酒)。Christies, an auctioneer, says all the wines it auctions are inspected three times by different people, using detailed checklists for condition and authenticity.拍卖商佳士得(Christies)称,它拍卖的所有名酒都要经过不同人反复检验三次,对他们出具的葡萄酒情况和真实度详单逐一对比验。Fear of fakery has not stopped the boom.对伪造名酒的担忧并没有阻止名酒的市场繁荣。But the wines that win the best prices at auction are those whose provenance is certain.在拍卖会上竞得高价的名酒其来源也是真实可靠的。In May, Christies sold an impériale (six-litre bottle) of 1961 Latour for 6,000 in Hong Kong. It came directly from the cellars of Chateau Latour.五月份,佳士得在香港以21.6万美元拍售了一瓶1961产的impériale葡萄酒(6升装),它直接来自于产地Chateau Latour的酒窖。 /201211/209659无锡市第三人民医院治疗肛门瘙痒价格

无锡肛泰医院做痔疮手术痛吗无锡男性便秘治疗医院要多少钱 无锡梁溪区治疗大便困难医院

无锡痔疮有哪些治疗方法Cancer genetics癌症遗传学Gene therapy基因疗法Genetic mutations predict which cancers will respond to treatment基因突变将预测某种治疗会对哪些癌症起作用THE International Cancer Genome Consortium, an alliance of laboratories that is trying to produce a definitive list of the genetic mutations that cause cancer, is accumulating data at an astonishing rate. About 3,000 individual breast tumours, for example, have now had their genotypes published. But these data will not, by themselves, help patients. For that, they have to be collected in the context of a drug trial. And this is just what Matthew Ellis and his colleagues at Washington University in St Louis have done for women suffering from breast cancer. Their methods, if they prove to work for other cancers too, may revolutionise treatment.国际癌症基因组协作组(THE International Cancer Genome Consortium)是试图建立一份会引起癌症的基因突变完整清单的实验室联盟,它积累数据的速度让人吃惊。例如,它已经发表了大约3000种不同的乳房肿瘤的基因型。但光凭这些数据本身无法帮助患者。要医治病人,人们必须结合药物试验采集数据。而这正是在圣路易斯市的华盛顿大学(Washington University in St Louis)工作的马修?埃利斯(Matthew Ellis)及其同事们为罹患乳腺癌的妇女们所作的工作。如果事实明他们的方法对其他癌症也有用的话,这可能会是癌症治疗的一次革命。Dr Ellis and his team sequenced the whole genomes of both cancerous and normal tissue from 46 women with tumours of a type called oestrogen-receptor-positive breast cancer. They also sequenced just the gene-containing regions of the genome-about 1% of total DNA-from an additional 31 women, and parts of the sequences of 240 more. They then compared the healthy and tumorous genomes of each patient, in order to discover which genes had mutated in the cancer.埃利斯士及其团队对46名身患雌激素受体阳性乳腺癌的妇女的癌组织和正常组织进行了全基因组测序。他们也对另外31名病人的基因组中含有基因的那些区域(约占整个DNA的1%)进行了测序,并对其他240名病人的这些部分做了部分测序。此后,为找出癌细胞中哪些基因发生了突变,他们比较了每个病人的健康和癌变基因组。In this, they were following the normal protocol of the cancer genome consortium. The novelty of their approach was that the women in question had each been involved in one of two clinical trials of a drug called letrozole. These trials established letrozole as a standard treatment for people with this type of breast cancer, but not all patients benefit equally from the drug. Dr Ellis hoped to find out why.他们在这一工作中是按癌症基因组协作组的标准程序操作的,但其方法的新颖之处是,他们还同时进行一种名为来曲唑的药物的临床试验。该试验有两种,每个病人都接受其中的一种。这些试验实来曲唑是这类乳腺癌的标准治疗方法,但它对每个病人的疗效并不一样。埃利斯士希望找出其原因。As they report in Nature, he and his team discovered 18 genes that were often mutated. Some were the usual suspects of cancer genetics. These included p53, a gene that, when working properly, suppresses cancer by regulating DNA repair, cell division and cellular suicide, and MAP3K1 and MAP2K4, which both promote cell growth. Others, though, were a surprise. At the top of that list were five which had previously been linked to leukaemia, but were not thought to affect solid tumours.正如他们在《自然》杂志中所报告的那样,埃利斯和他的团队发现了18种经常发生突变的基因,其中有些是癌症遗传学通常怀疑的对象。这中间包括p53,这种基因在正常工作时通过调节DNA对的修复、细胞分裂和细胞自杀来抑制癌症;还有MAP3K1和MAP2K4,它们都能促进细胞生长。但也有些令人吃惊的其他结果。高踞名单前列的5种基因是人们过去认为与白血病有关的,没想到它们也会影响实体瘤。By combining their newly acquired genetic data with clinical data from the participants, Dr Ellis and his colleagues showed that those whose tumours carried mutations in p53 (16% of the total) were less likely to have responded to letrozole than women whose tumours had normal p53. Conversely, those whose tumours had changes in either MAP3K1 or MAP2K4 (another 16%) had better than average responses to the drug.将他们新得到的基因数据与参与试验者的临床数据结合,埃利斯士等人明了,来曲唑对肿瘤中有p53基因突变的病人(占总数的16%)的疗效不如对肿瘤中p53基因正常的病人那样显著。与此相反,这一药物对肿瘤中MAP3K1或MAP2K4有变化的病人(也占总数的16%)的疗效高于平均水平。This sort of information has obvious implications for treatment. And the cheapness of modern gene-sequencing methods, particularly those that are looking for specific mutations suspected in advance, means that a tumours mutational complement can be worked out easily in an appropriately equipped pathology laboratory. In the case of oestrogen-receptor-positive breast cancer, the genetic analysis has not yet gone so far as to be able to say with certainty which drug will produce the best result for a given individual, but Dr Elliss result lays a foundation on which such an edifice might be built for breast cancer and perhaps for other types of tumour, too.这种信息对治疗的含义是明显的。而且,现代基因测序法价格低廉,寻找预先已有怀疑的某些特别的基因突变尤为便宜;这意味着,在拥有合适装备的病理实验室里,人们可以很容易地找出肿瘤基因突变的补体。就雌激素受体阳性乳腺癌来说,基因分析还无法肯定地告诉我们,哪种药物对某个病人疗效最佳;但埃利斯士的结果打下了一个基础,或许可以在此之上为乳腺癌——甚至其他种类的癌症——的治疗建立有效的预测方法。 201207/192630 Science and technology科学与技术Evolution and coat colour进化和表皮色Well spotted美丽涂鸦The reason why some cats are plain and others are patterned为何有些猫科动物全无斑纹,而其他的则斑斑点点?How the leopard got his spots is, famously, the subject of one of Rudyard Kiplings “Just So Stories”.美洲豹为何满身斑点?这是吉卜林大作《原来如此》中的一个著名问题。Kipling suggested they were handprints made by the leopards human friend. More plausibly, he had an explanation for what the spots are for: to break up the animals shape when it is hiding in the dappled light of the forest.吉卜林认为,那是美洲豹的人类朋友们留下的手印。他更靠谱的解释是,当美洲豹藏身在树丛的斑驳光影之中,斑点有助于让它们“隐去”形迹。These days, the human-handprint theory of the leopards spots has fallen out of favour.最近,美洲豹斑点的手印理论已不合口味。Instead, a more prosaic idea has gained ground, based on what is known as reaction-diffusion pattern formation, in which chemicals that trigger the differentiation of cells in an embryo interact with one another to produce patterns that are then reflected in the fates of nearby cells.取而代之并渐为人知的是一种更乏味的观点:斑点产生于“反应-扩散”的图案形成过程,其中,胚胎细胞分化由化学反应引发,各类化学反应之间又发生作用,其作用模式最后在表皮细胞的发育中表现出来。But that, too, has its difficulties. Just how much a process like this can be shaped by natural selection is unclear.但这一说也有其困难,它在多大程度上收到自然选择的影响,目前尚不清楚。Reaction-diffusion patterns which can be created in a laboratory using standard reagents are simple and deterministic.反应-扩散模式可在实验室用标准试剂产生简洁而又有说力。That simple reactions of this sort sometimes result in cryptic patterns could be a coincidence.这类偶尔引发神奇图案的简单反应纯粹是巧合。Nevertheless, the details of the patterns produced vary, according to things like how rapidly the chemicals diffuse.不过,图案产生的细节各各不同,依据诸如扩散速度等情形而有差别。That could be selected. Different cats do, indeed, have different patterns.这就可加以选择。确实,不同的猫科动物有不同图案。So researchers at the University of Bristol, led by William Allen, have been deconstructing these patterns, trying to match the elements to cats habits and habitats, and thus show whether the patterns are evolving.因此,在威廉姆﹒艾伦的带领下,布里斯托大学的研究者正在分解这些图案,并尝试把图案要素同猫科动物的习性与栖息地匹配起来,以发现图案是否会发生进化。They published their results this week in the Proceedings of the Royal Society.本周他们在《皇家学会学报》上发表了研究结果。The reaction-diffusion process can be mimicked by a computer, and the programs parameters manipulated to produce patterns matching those of cat coats.反应-扩散过程可以用计算机加以模拟,对程序参数也可加控制,以产生同猫科动物外表匹配的图案。That, the researchers hoped, might help illuminate what is going on.研究者希望借此搞清楚到底发生了什么。They trawled the world wide web for pictures of wild cats, found the best six for each of 37 species, and roped in a group of human volunteers to choose which of the programs outputs were most similar to real coats.他们在互联网上搜罗野生猫科动物的图片,为37个猫科物种的每一种都准备了最佳的6张照片,并说一批人类志愿者来判定:哪个程序的输出结果和真实的外表最为相似。The patterns produced had five parameters: how plain they were, how irregular, how complex, how big the spots were and whether the pattern had a perceptible direction to it.为产生图案设置了5个参数:斑点的有无程度、规则程度、复杂程度、大小程度、是否有明显的生长位置。The volunteers judgments about which artificial patterns best matched which natural ones were almost perfectly consistent.志愿者关于人工图案与自然图案匹配程度的判断几乎完美的一致。That allowed Mr Allen to assess which parameters contribute to each speciess pattern, and thus which are correlated with behaviour.这使艾伦先生可以推断哪个参数对物种的图案起了影响,从而进一步同物种行为联系起来。The biggest distinction—no surprise, but nice to confirm—is that spotted cats are forest cats and plain ones prefer open countryside.最大的区别发现本身并不出人意料,但推理非常严密是:有斑点的猫科动物生活在丛林中,没有斑点的更偏好生活在开阔的平原地带。In that, Kipling was right.在这点上,吉卜林是对的。An analysis based on the relationship between the species, though, shows that evolutionary lines can swap from spots to no spots, and vice versa, as the habitat dictates.基于物种关系的一个分析表明,进化路线有时是从有斑点到无斑点,有时又反过来,这取决于栖息地在哪里。Moreover, the more a species prefers the forest, the more irregular the pattern it sports, and the more complex.并且,如果一个物种越是喜欢丛林生活,图案就越是不规则,越加复杂对大小和图案生长位置没有影响。Size and direction have no effect.Even among forest-dwellers there are differences.即使丛林物种之间也不一样。Those that tend to spend their time actually in trees, as opposed to wandering around on the ground between them, have more irregular and complex patterns.与那些喜欢呆在地上的相比,更多时间呆在树上的种群,其图案就更不规则,更加复杂。And, crucially, there is no relationship between a cats pattern and how sociable it is.并且,重要的是在猫科动物的图案和社群习性之间没有关联。That knocks on the head an alternative explanation for coat patterns, namely that spots are some form of signal between animals of the same species.这对关于表皮图案的另一理论解释是当头一击,此种解释认为斑点是同一动物种群的共有标记形式。Mr Allen and his colleagues made one other observation. Some species of cat regularly produce melanic forms—the so-called black panther actually a melanic jaguar being the most familiar.艾伦先生及其同事还作了其他的观察。某些猫科动物会周期性变成黑色——例如大家熟悉的黑豹实际上是黑色的美洲虎。The data seem to rule out one obvious explanation for melanism: the idea that black cats, with their unusual appearance, have more success hunting because their prey are not keeping an eye out for predators that look like them.这一观察似乎也排除了“黑变论”的解释。这种说法是,黑色猫科动物因其不同寻常的外表,而在捕猎方面非常成功,因为它们无须留神被猎物看见。Melanic forms, though, are particularly prevalent in species with complicated lives—those that inhabit a range of habitats, are active both day and night, and move between the ground and the trees.可是,黑色外表为各种复杂形式的物种所有,它们栖息在不同地带、有白天活动的也有黑夜活动的、有在地面生存的也有在树上生存的。What advantage melanism brings in these circumstances is obscure.在这些环境中表皮黑化到底有什么优势似乎模糊不清。One for Kipling, perhaps. “How the jaguar got his melanocytes.”这问题可能要交给吉卜林了:“美洲虎为何是黑色?” /201302/224409常州治疗直肠恶变多少钱无锡腔肠医院



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