Clean water

　　清潔水源

　　Silver threads of life

　　生命的銀絲帶

　　A water filter that kills bacteria, rather than just removing them

　　新濾水器能夠消滅細(xì)菌，而不單單是排除細(xì)菌

　　MORE than a billion people lack clean water-and in most cases the lack is just of cleanliness,rather than of the water itself.

　　超過十億人口缺少飲用水，并且在絕大多數(shù)情況下缺少的只是純凈的水，而不是水本身。

　　The result is disease, particularly diarrhoea. This kills millions of children a year and stuntsthe growth of millions more.

　　其結(jié)果是給人們帶來了疾病，特別是每年奪取數(shù)百萬兒童性命并使更多的兒童生長發(fā)育受阻的腹瀉。

　　Better water filters, then, could save many lives and improve many others, and Yi Cui ofStanford University thinks he has come up with one.

　　所以更好的濾水器就能挽救許多生命，提高人們的健康水平。而來自斯坦福大學(xué)的崔毅教授認(rèn)為他已經(jīng)研制出了這樣的濾水器。

　　Traditional filters work by forcing water through pores to weed out bacteria.

　　傳統(tǒng)的濾水器使水流流過微孔從而排除細(xì)菌。

　　That needs power, as well as frequent changes of the filter element as the pores fill upwith bugs.

　　這需要消耗電力，而且由于微孔上積滿了細(xì)菌，濾水器元件也需經(jīng)常更換。

　　Dr Cui s filter, though, does not screen the bacteria out. It kills them.

　　但是崔教授研制的濾水器并不是將細(xì)菌排除出去，而是將其消滅。

　　The filter element he and his team have designed is a mesh of tiny carbon cylinders, knownas nanotubes, and silver wires laid on top of a thin strip of cotton cloth.

　　崔教授及其團(tuán)隊(duì)所設(shè)計(jì)的濾水器元件采用微小的碳圓柱形網(wǎng)狀物，也就是碳納米管。

　　Silver is well known to kill bacteria, so Dr Cui conjectured that forcing bugs to pass close tothe metal without actually trapping them might lead to their destruction.

　　薄薄的棉布覆蓋著碳納米管一端，并用銀絲固定。金屬銀因能夠殺死細(xì)菌而為人所知。崔教授據(jù)此推測將細(xì)菌引至銀絲附近而不是使其進(jìn)入微孔，即可消滅細(xì)菌。

　　He also suspected that running an electric current through the silver might help the process,because electrical fields have the ability to break down the membranes that surroundbacterial cells.

　　他同時(shí)猜測，使銀絲接通電流，將有助于整個(gè)過濾工序，因?yàn)殡妶鼍哂写┩讣?xì)菌細(xì)胞膜的特性。

　　Though silver is a good conductor, carbon is cheaper, and the nanotubes provide the extraelectrical conductivity needed.

　　因此雖然銀是良好導(dǎo)體，碳也很便宜，但是納米管卻可以額外提供必需的導(dǎo)電性。

　　To make their new filter, the team first dipped strips of woven cotton into ink containingnanotubes. They then used pipettes to drop the silver wires, which were suspended inmethanol, on to the surface of the strips.

　　制作新型濾水器，首先把棉布條浸入含有碳納米管的 墨水 中，然后用吸管將浸泡在甲醇中的銀絲滴在棉布條的表面。

　　Once dried, the new filters were ready to try.

　　置干后，新的濾水器就可以工作了。

　　To do that Dr Cui connected them to a battery and ran water containing E. coli, a commonbacterial contaminant of water, through them.

　　崔教授將這些碳納米管與電池相連接，并使含有導(dǎo)致水污染的一種常見細(xì)菌大腸桿菌的水流經(jīng)其中。

　　A few drops of the filtered water from each experimental run were then scattered on anincubation plate to see what was left to grow.

　　隨后每次過濾實(shí)驗(yàn)得到的幾滴水被放在孵化盤中用以觀察水中剩余物質(zhì)的狀況。

　　As they report in the latest edition of Nano Letters, Dr Cui and his team found that when thefilter was operated at -20 volts it killed 89% of the bacteria and that at +20 volts it killed77%.

　　正如在最新一期《納米快報(bào)》中報(bào)道的一樣，崔教授與其團(tuán)隊(duì)發(fā)現(xiàn)濾水器在-20伏的電壓下工作時(shí)，可消滅89%的細(xì)菌，在+20伏的電壓下工作時(shí)，可消滅77%的細(xì)菌。

　　At zero volts, most of the bacteria survived.

　　而在不通電的情況下，大部分細(xì)菌都得以存活。

　　In a follow-up experiment, in which contaminated water was run through three of the newfilters in sequence, 98% of the bacteria were killed.

　　在進(jìn)一步的實(shí)驗(yàn)中，受污染的水依次流經(jīng)三個(gè)新型濾水器，結(jié)果98%的細(xì)菌被消滅了。

　　Using silver this way might sound expensive, but it is not.

　　如此使用銀乍聽起來十分昂貴，實(shí)則不然。

　　The amount involved is minuscule, as is the quantity of electricity needed to keep thefilter charged .

　　銀的使用量非常小，與維持濾水器運(yùn)轉(zhuǎn)所需電量一般。

　　And the filter itself would be expected to last indefinitely.

　　此外，濾水器本身還可望永久使用。

　　The next test, then, is to see if the new device kills the full range of dangerous bacteriafound in polluted water.

　　隨后的測試將證明這種新型濾水器是否能消滅在受污染的水中所發(fā)現(xiàn)的各種有害細(xì)菌。

　　If it does then potable water, one of the necessities of life, may become easier for manypeople to obtain.

　　如果確實(shí)如此，那么許多人就可以更容易獲得生活的必需品純凈的飲用水了。

　　Clean water

　　清潔水源

　　Silver threads of life

　　生命的銀絲帶

　　A water filter that kills bacteria, rather than just removing them

　　新濾水器能夠消滅細(xì)菌，而不單單是排除細(xì)菌

　　MORE than a billion people lack clean water-and in most cases the lack is just of cleanliness,rather than of the water itself.

　　超過十億人口缺少飲用水，并且在絕大多數(shù)情況下缺少的只是純凈的水，而不是水本身。

　　The result is disease, particularly diarrhoea. This kills millions of children a year and stuntsthe growth of millions more.

　　其結(jié)果是給人們帶來了疾病，特別是每年奪取數(shù)百萬兒童性命并使更多的兒童生長發(fā)育受阻的腹瀉。

　　Better water filters, then, could save many lives and improve many others, and Yi Cui ofStanford University thinks he has come up with one.

　　所以更好的濾水器就能挽救許多生命，提高人們的健康水平。而來自斯坦福大學(xué)的崔毅教授認(rèn)為他已經(jīng)研制出了這樣的濾水器。

　　Traditional filters work by forcing water through pores to weed out bacteria.

　　傳統(tǒng)的濾水器使水流流過微孔從而排除細(xì)菌。

　　That needs power, as well as frequent changes of the filter element as the pores fill upwith bugs.

　　這需要消耗電力，而且由于微孔上積滿了細(xì)菌，濾水器元件也需經(jīng)常更換。

　　Dr Cui s filter, though, does not screen the bacteria out. It kills them.

　　但是崔教授研制的濾水器并不是將細(xì)菌排除出去，而是將其消滅。

　　The filter element he and his team have designed is a mesh of tiny carbon cylinders, knownas nanotubes, and silver wires laid on top of a thin strip of cotton cloth.

　　崔教授及其團(tuán)隊(duì)所設(shè)計(jì)的濾水器元件采用微小的碳圓柱形網(wǎng)狀物，也就是碳納米管。

　　Silver is well known to kill bacteria, so Dr Cui conjectured that forcing bugs to pass close tothe metal without actually trapping them might lead to their destruction.

　　薄薄的棉布覆蓋著碳納米管一端，并用銀絲固定。金屬銀因能夠殺死細(xì)菌而為人所知。崔教授據(jù)此推測將細(xì)菌引至銀絲附近而不是使其進(jìn)入微孔，即可消滅細(xì)菌。

　　He also suspected that running an electric current through the silver might help the process,because electrical fields have the ability to break down the membranes that surroundbacterial cells.

　　他同時(shí)猜測，使銀絲接通電流，將有助于整個(gè)過濾工序，因?yàn)殡妶鼍哂写┩讣?xì)菌細(xì)胞膜的特性。

　　Though silver is a good conductor, carbon is cheaper, and the nanotubes provide the extraelectrical conductivity needed.

　　因此雖然銀是良好導(dǎo)體，碳也很便宜，但是納米管卻可以額外提供必需的導(dǎo)電性。

　　To make their new filter, the team first dipped strips of woven cotton into ink containingnanotubes. They then used pipettes to drop the silver wires, which were suspended inmethanol, on to the surface of the strips.

　　制作新型濾水器，首先把棉布條浸入含有碳納米管的 墨水 中，然后用吸管將浸泡在甲醇中的銀絲滴在棉布條的表面。

　　Once dried, the new filters were ready to try.

　　置干后，新的濾水器就可以工作了。

　　To do that Dr Cui connected them to a battery and ran water containing E. coli, a commonbacterial contaminant of water, through them.

　　崔教授將這些碳納米管與電池相連接，并使含有導(dǎo)致水污染的一種常見細(xì)菌大腸桿菌的水流經(jīng)其中。

　　A few drops of the filtered water from each experimental run were then scattered on anincubation plate to see what was left to grow.

　　隨后每次過濾實(shí)驗(yàn)得到的幾滴水被放在孵化盤中用以觀察水中剩余物質(zhì)的狀況。

　　As they report in the latest edition of Nano Letters, Dr Cui and his team found that when thefilter was operated at -20 volts it killed 89% of the bacteria and that at +20 volts it killed77%.

　　正如在最新一期《納米快報(bào)》中報(bào)道的一樣，崔教授與其團(tuán)隊(duì)發(fā)現(xiàn)濾水器在-20伏的電壓下工作時(shí)，可消滅89%的細(xì)菌，在+20伏的電壓下工作時(shí)，可消滅77%的細(xì)菌。

　　At zero volts, most of the bacteria survived.

　　而在不通電的情況下，大部分細(xì)菌都得以存活。

　　In a follow-up experiment, in which contaminated water was run through three of the newfilters in sequence, 98% of the bacteria were killed.

　　在進(jìn)一步的實(shí)驗(yàn)中，受污染的水依次流經(jīng)三個(gè)新型濾水器，結(jié)果98%的細(xì)菌被消滅了。

　　Using silver this way might sound expensive, but it is not.

　　如此使用銀乍聽起來十分昂貴，實(shí)則不然。

　　The amount involved is minuscule, as is the quantity of electricity needed to keep thefilter charged .

　　銀的使用量非常小，與維持濾水器運(yùn)轉(zhuǎn)所需電量一般。

　　And the filter itself would be expected to last indefinitely.

　　此外，濾水器本身還可望永久使用。

　　The next test, then, is to see if the new device kills the full range of dangerous bacteriafound in polluted water.

　　隨后的測試將證明這種新型濾水器是否能消滅在受污染的水中所發(fā)現(xiàn)的各種有害細(xì)菌。

　　If it does then potable water, one of the necessities of life, may become easier for manypeople to obtain.

　　如果確實(shí)如此，那么許多人就可以更容易獲得生活的必需品純凈的飲用水了。