The main reason is the complicated anatomic structure of the nasal cavity and the special physiological location of the olfactory region, which has caused much trouble in directexperiment studies.
这主要是由于鼻腔的复杂结构及嗅区的特殊生理位置，为直接的嗅觉实验研究带来了不少困难。
2
Combined with the problems during the experiment, design a improved testing circuit of Direct Current Attenuation Method.
结合试验过程中遇到的问题，给出了改进的直流衰减法测试电路。
3
All these results showed that in the present experiment condition, the indirect test was more sensitive than the direct test.