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。