小编导读：3月31日，苹果的以旧换新计划正式在中国大陆执行。除了肾6，其他苹果手机都可以参与。其中爱疯4的回收价是250元，4S500块，5S则是1500。大批果粉在吐槽回收价“太低”，还不如卖给黄牛的同时，大家有没有想过，为什么手机要以旧换新呢？
An average smartphone contains 41 different elements - and last year alone 1.2 billion of the handsets were sold globally.
一部手机中一般包含有41种元素，去年一年全球就卖出了120亿部手机。
This is causing an imbalance between the supply of metals and metalloids and their demand from consumers - a concept referred to as 'criticality.'
这样会导致金属及类金属的供应和消费者需求之间的不平衡，被称为“临界状态”。
Researchers have now assessed the criticality of all 62 metallic-based elements on the Periodic Table to reveal which are most at risk and what that means for our gadgets in the long-term.
研究人员现已对元素周期表中的62种金属元素的临界状态进行了评估，列出了处于濒危状态的金属名单，并从长远角度分析了这些金属的储量能否满足人类制造小器具的需求。
Metal criticality is analysed in three ways - supply risk, vulnerability to supply restriction (VSR) and environmental implications.
金属的临界状态通过三种方法分析得出，供应危机、供应制约的脆弱性（VSR）以及环境影响。
Using these three categories, researchers from Yale University led by Professor Thomas Graedel were able to see which metals and metalloids are most at risk within each group.
通过使用以上三种指标，托马斯•格雷德尔教授等来自耶鲁大学的研究人员得出了处于濒危状态的金属名单。
Many of the metals traditionally used in manufacturing, including zinc, copper, and aluminum, are not at risk, explained Professor Graedel.
格雷德尔教授说，许多在传统制造业中使用到的金属如锌、铜和铝等并未处于濒危状态。
However, the newer or less-common metals used in smartphones,
infrared optics, and medical imaging, are vulnerable.
但是在相对较新的智能手机、红外光镜、医学成像等领域中使用到的、相对不常见的稀有金属反而比较危险。
The team's results show that the limitations for many important metals used in smartphones and other gadgets are largely those related to supply risk.
该团队的研究结果显示智能手机及其他小器械中使用到的许多重要金属都会因为供应危机而受到限制。
These include gallium used in processor chips and selenium in transistors on these chips.
这些金属包括数据处理芯片中使用到的镓以及这些芯片的晶体管中使用到的硒。
Platinum group metals including gold and mercury have the highest environmental implications.
而包括金、汞在内的铂类金属对环境造成的危害最大。
'The metals we've been using for a long time probably won't present much of a challenge,' said Professor Graedel.
格雷德尔教授说：“我们对已经使用了很长时间的金属反倒不用担心。”
'We've been using them for a long time
because they're pretty abundant and they are generally widespread geographically.
“我们能用这么长时间就是因为它们储量丰富、地理上分布得也很广。”
'But some metals that have become
deployed for technology only in the last 10 or 20 years are available almost entirely as byproducts.
“但是最近一二十年兴起的科技产业中所使用的金属几乎是作为副产品出现的。”
'You can't mine specifically for them; they often exist in small quantities and are used for specialty purposes. And they don't have any decent substitutes.'
“我们无法明确地直接对这些金属进行开采，它们储量小、用途特定，而且没有合适的替代品。”
The researchers listed these as indium, arsenic, thallium, antimony, silver, and selenium. There is no substitute for indium, in particular, and this could impact our touchscreens.
研究人员列出的这类金属名单包括：铟，砷，铊，银和硒。其中铟没有任何可以替代它的金属，而它是生产触摸屏需要用到的重要材料之一。
