【文章內(nèi)容簡介】 But they also engaged in headtohead wrestling of a sort that allowed them to get behind their opponents39。skulls and do damage from the rear, in the way that modern bison do.非常高隆的腫頭龍除此之外還會采取頭對頭式摔跤法：能夠碰到對方頭骨的背部，從后面對彼此造成損傷，好比如今的野牛。None of which proves that pachycephalosaurs did not strut their stuff with their domes as well, just as a stag will often show off its antlers before engaging in bat, in order to give a less wellendowed rival the opportunity to withdraw.然而，兩種圖案都沒有否定腫頭龍自豪地邁步時也在炫耀他們的大腦袋。成年雄鹿就經(jīng)常在戰(zhàn)斗之前展示它的鹿角，為了使天生劣勢的對手借機撤退。But it does demonstrate that the domes were serious weapons, not mere fripperies of fashion.不過這確實證明了高隆的頭骨是很厲害的武器，而不僅僅是時髦的矯飾品。Science and technology科學(xué)技術(shù)3D printing三維壓制A thirdworld dimension第三世界的發(fā)展空間A new manufacturing technique could help poor countries as well as rich ones一項新的制造技術(shù)能夠?qū)ω毨矣兴鶐椭拖駥δ切└挥袊业膸椭粯?。EVERY summer, Seattle holds a raft race in Green Lake, a park that is the eponymous home of the water the rafts must cross.每年夏天，西雅圖都會在綠湖舉行一場木筏比賽，參加比賽的木筏必須渡過這個湖，這里的公園因其湖水而聞名。Entries for the Milk Carton Derby have to be made from old plastic milk bottles.參加這場同城牛奶盒比賽的木筏必須是由舊的塑料牛奶盒制成。 result is a wonderfully HeathRobinson collection of improvised craft.結(jié)果，你就會看到一場奇妙的希思魯賓遜簡易工藝展。But this year one stood out: the entry from the University of Washington39。s engineering department actually looked like a boat.但是今年，有一個參賽的木筏特別引人注目：這個木筏是華盛頓大學(xué)工程系做的，看起來真的像一只船。The students who built it, Matthew Rogge, Bethany Weeks and Brandon Bowman, had shredded and melted their bottles, and then used a 3D printer to print themselves a plastic vessel.制造這個木筏的學(xué)生—馬修羅格、伯斯尼威克斯和布蘭登伯曼，把他們收集的塑料盒切碎后再熔化，再使用一種三維壓印技術(shù)壓印成一種塑料容器。No doubt the MilkCartonDerby rules will be tightened next year—though in the end, the team came only second.毫無疑問的是，同城牛奶盒比賽的規(guī)則明年會更加嚴(yán)格—雖然最后，這個隊只贏得了第二名。But they did e first in a petition that mattered more.但是，他們在比賽中首次出現(xiàn)的意義卻更重大。On October 19th they won $100,000 in the 3D4D Challenge, organised by a charity called techfortrade.在10月19日，他們在由一個稱為技術(shù)為了貿(mào)易更美好的慈善組織組織的三維四維挑戰(zhàn)賽中贏得了十萬美元的獎金。3D printing is all the rage at the moment.三維壓印目前正是風(fēng)靡一時。Several varieties of the technique exist, using a wide range of materials as the ink.利用幾種不同的現(xiàn)有技術(shù)，再加上大范圍的原料—稱之為墨水就可以操作了。One of the most popular methods, though—and the one used by the team—works by extruding a filament of molten plastic.盡管，最流利的一種方式—就是那個參加比賽的隊伍使用的，只是擠壓成一條熔化后的塑料細絲。In the case of the team39。s printer, this plastic was highdensity polyethylene from milk bottles.就這個參賽隊伍的印刷技術(shù)來說，這種塑料是由牛奶盒提煉出的高密度聚乙烯。The print head makes repeated passes over the thing being printed, leaving a plastic trail as it does so.打印頭重復(fù)地打壓著半成品，當(dāng)它重復(fù)這樣的過程后，只留下一條塑料絲。It thus builds up a threedimensional structure.最后，就生產(chǎn)出了一個三維產(chǎn)品。3D printing is now taken seriously by manufacturers as an alternative to cutting, bending, pressing and moulding things.制造商們正在認真考慮三維壓印技術(shù)，想用它來替代切割、彎曲和壓制成型機器。It is also a popular hobby among those of a geeky disposition.而且，它在那些古怪的配制中也算比較受歡迎了。What it has not been used for so far is to help people in poor countries improve their everyday lives.只是，到目前為止它還沒被應(yīng)用于貧困國家，幫助那里的人們改善他們的生活。Mr Rogge, Ms Weeks and Mr Bowman intend to employ their prize money to do precisely that.羅格先生，威克斯女士和伯曼先生打算用他們的獎金去實現(xiàn)這個目標(biāo)。They plan to form a firm that will, in partnership with a charity called Water for Humans, custombuild posting toilets and rainwater collectors.他們打算與一家稱為為人類提供生活之水的慈善組織合作，創(chuàng)建一家專門生產(chǎn)自動堆肥廁所和雨水收集容器的公司。The partnership will look for suitable local entrepreneurs in poor countries and will train them how to build, use and maintain the printers.他們的合伙人將會在那些貧困國家中尋找當(dāng)?shù)睾线m的企業(yè)家，并且會訓(xùn)練他們怎樣組裝、使用和保養(yǎng)壓印機器。Once the technology is established for toilets and water collectors, other products will be introduced.一旦這種技術(shù)應(yīng)用于廁所和集水箱，那么將會產(chǎn)生一系列的其它附屬產(chǎn)品。The local partners will know what products are needed and how much people are prepared to pay for them—and therefore what is worth making.當(dāng)?shù)氐暮献髡唏私猓@里需要什么樣的產(chǎn)品，這里的人們愿意花多少錢來購買—因此這是值得試試的。The operation will thus run on a mercial basis.這種運作將會基于一種商業(yè)操作模式。But the software that controls the printers will be opensource and available to all, as will many of the designs for things the printers can make.但是，控制壓印機器的軟件將會成為公共資源，所有人都可以使用，就像當(dāng)時設(shè)計這種壓印機器時的設(shè)想一樣。That way, the technology can spread.這樣的話，這種技術(shù)將能很快傳播開來。A trial will begin soon in Oaxaca, Mexico.墨西哥的瓦哈卡將會很快進行這種試驗。The crucial point about the team39。s printer is that it bines size and cheapness.威克斯小組的壓印機最關(guān)鍵的一點是，它的大小正合適而且價格很便宜。Printers used by hobbyists are not expensive, but they are small.供業(yè)余愛好者使用的壓印機并不貴，而且很小巧。Many would find it hard to make anything larger than a coffee cup.許多人發(fā)現(xiàn)這個機器做出的東西都沒一個咖啡杯大。Those used by engineering panies cost serious money—and even they might balk at printing an object the size of the Milk Carton Derby boat.那些工程公司使用的壓印機成本很高—甚至他們也無法壓制出像同城牛奶盒比賽中那樣大的木筏。The team39。s printer is built around a secondhand putercontrolled plasma cutter.那個參賽隊伍的壓印機是由一臺二手電腦控制的空氣等離子切割機做出來的。This directs the movement of an extruder that melts flakes of plastic into a thin stream which can be squirted out as required.電腦控制著擠壓機里的一切運作—即先熔化塑料，再擠壓成細細的液體狀，當(dāng)需要時就可以噴射出來進行壓制。It is able to create things with dimensions of up to metres by metres by 1 metre.，高1米的物品。Appropriately, many of its parts were themselves manufactured on a desktop 3D printer.產(chǎn)品的許多部分還是來自于原材料，只是經(jīng)過了一臺臺式三維壓印機的處理而已。The ink is cheap, too. Highdensity polyethylene is as mon as muck—literally, for a lot of it ends up on refuse tips.墨水也很便宜。高密度聚乙烯很常見，就像隨處可見的泥土一樣—就是這個意思，因為垃圾堆中有大量這種材料。Chop it up, though, and it is grist to the mill.但是，一定要記得剁碎它，這對壓印機很重要。Mr Rogge estimates that if he and his colleagues had printed their boat from mercial plastic filament it would have cost them $800.羅格先生估計，如果他和他的同事利用商業(yè)塑料絲來制作這條船的話，那么成本會高達800美元。Instead, 250 clean, empty milk bottles set them back just $.相反，他們用250個干凈的。Some technical questions remain.不過，還有一些技術(shù)問題。Highdensity polyethylene shrinks when it cools.高密度聚乙烯遇冷會收縮。That stresses the object being printed and can sometimes tear it apart.這個不足也反應(yīng)到了壓制出來的產(chǎn)品上，產(chǎn)品有時都能完全扯開。The students are therefore working on a second prototype that prints things faster, allowing the layers of plastic to cool almost simultaneously.因此，這些學(xué)生們正在努力制作第二個樣品，以提高壓制速度，而且確保讓塑料層幾乎能同時冷卻下來。They are also experimenting with making things from other types of waste plastic that suffer less from shrinkage.他們也在試驗用其它類型的廢塑料制作產(chǎn)品，以減少收縮性。And until a production version of the printer is ready and priced, it remains to be seen how petitive its output really will be with massproduced items.在壓印機