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The chains are held together by bonds between the carbon atoms.
碳鏈是由碳原子間的鍵連接在一起的。
These are of two varieties, known as single and double bonds.
化學鍵有兩種，單鍵和雙鍵。
Single bonds are, in chemistry-speak, saturated, and double bonds unsaturated.
用化學術語講，單鍵是飽和的，雙鍵是不飽和的。
By extension, molecules with one or more double bonds in them are also referred to as unsaturated,
由此引申義，含有一個或多個雙鍵的分子也被稱為不飽和分子，
while those with only single bonds are called saturated.
而只有單鍵的分子被稱為飽和分子。
Unsaturated bonds are more reactive, and it is here that ozonolysis does its work.
不飽和鍵反應性更強，這就是臭氧分解的作用。
Ozone breaks up triglycerides at their double bonds, with one or more of the ozone's oxygen atoms
臭氧分解甘油三脂的雙鍵，一個或多個臭氧氧原子附著在碳鏈上，
becoming attached to the carbon chain, to create new chemical species.
形成新的化學物質。
In principle, this should result in a gradual loss of unsaturated triglycerides
原則上，這將導致不飽和甘油三脂的逐漸損失
and a concomitant rise in the reaction products of ozonolysis.
以及臭氧分解反應產物的增加。
And that, in practice, is what Dr Hinners and Dr Lee found.
而這正是Hinners博士和Lee博士所發現的。
They asked three volunteers to leave their prints on a number of glass slides. They then tested some of those slides immediately,
他們請三名志愿者在一些載玻片上留下他們的指紋。然后他們立刻對其中一些進行檢測，
using a sensitive analytical technique called matrix-assisted laser desorption/ionisation (MALDI)
他們使用一種稱為基質輔助激光解吸/電離（MALDI）的靈敏分析技術
to produce a spectrum of the prints' chemical contents.
來產生指紋的化學成分光譜。
The other slides they left exposed to the air for between one and seven days, testing them at regular intervals.
他們將其他剩下的載玻片暴露在空氣中1到7天，每隔一段時間測試一次。
As they suspected, as time progressed the ratio of saturated to unsaturated triglycerides in a sample rose,
正如他們猜想的那樣，隨著時間的推移，樣品中飽和甘油三脂與不飽和甘油三脂的比率上升，
and so did the quantities of two characteristic products of ozonolysis—aldehydes and Criegee ions.
臭氧溶解的兩種典型產物——醛類和Criegee離子的數量也是如此。
On the basis of what is, admittedly, a small sample, Dr Hinners and Dr Lee therefore think
誠然，Hinners博士和Lee博士因此認為
that MALDI analysis of fingerprint residues should prove accurate enough to date to within 24 hours
MALDI對指紋殘留物的分析應該足夠準確，
when a fingerprint under a week old was made—and thus whether it is associated with a crime temporally, as well as spatially.
可以在24小時內對一周以內的指紋進行分析——以及它是否因而與犯罪在時間上和空間上都有聯系。
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