ACADEMIC RESEARCH•學術研究 2020 UMAGAZINE 22•澳大新語 60 equilibrium, the second coil will initiate another NMR scan on its sample. This process goes on sequentially until the Nth coil finishes its scan on the sample. Then the experiment starts over from the first coil, where the nuclei within the sample have already recovered to thermal equilibrium and are ready for another NMR scan. By exploiting the long recovery time of each NMR scan with the proposed time-interleaving scheme, we can shorten the total NMR experiment time by a factor of N in the ideal case. In fact, from one of our experiments, we have used this miniaturised NMR platform with the time-interleaving scheme (N = 2) to perform 2D 1H NMR experiment and elucidate the structure of ethyl formate and ethyl acetate (Picture 4), where the total experiment time is 48 minutes (reduced by ~50%). Inspired by the magnetic resonance imaging technique, which is based on NMR with additional magnetic field gradients to obtain spatial information, we proposed an NMR setup with gradient-coils to 半時間。 除此之外，我們還提出使用一個有多個 梯度線圈的體系，為樣本的空間訊息編 碼。這個構思來自核磁共振成像技術， 因為該技術正正是運用不同方向之磁場 梯度，作為取得空間訊息的基礎，再基 於核磁共振技術以產生成像。在我們的 方案中，不同的梯度線圈會產生不同方 向的磁場梯度，而樣本內原子核的旋進 頻率則與它們感應到的磁場對應。有了 這些磁場梯度，分佈在感測區不同位置 的原子核會感應到不同的磁場，並且因 此會以不同的速率旋進。我們可以對擷 取到的訊號進行傅立葉變換，分析它們 的頻率成分，從而取得某個樣本的核磁 共振訊號的波幅。運用這個以成像為基 礎的方案時，我們會在磁鐵內放置N個 樣本。這些樣本共用一個連接到CMOS 芯片的射頻線圈。在此設置中，我們讓 圖四：利用時間交錯方案生成的1H原子核的二維核磁共振成像（關聯性磁振頻譜），闡明了甲酸乙酯和乙酸乙酯的結構。2 Picture 4:Measured 2D 1H NMR spectra (correlation spectroscopy) with time‑interleaving from ethyl acetate and ethyl formate2
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