| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method for detecting a plastic explosive or the like difficult to be detected, that is, a method for detecting and/or analyzing a compound generating nuclear quadrupole resonance and nuclear magnetic resonance, or double nuclear quadruploe resonance. <P>SOLUTION: A magnetic field H<SB>0</SB>is turned on to generate the magnetic resonance in a spin B together with a low-frequency magnetic field H<SB>2</SB>, the first high-frequency waveπ/2 pulse of a magnetic field H<SB>1</SB>favorable to be impressed to a spin A under the quadrupole resonance is turned on in a spin-echo sequence at the same time, and is turned off when a detected quadrupole resonance signal echo itself of the spin A reaches the maximum intensity, i.e. when digitalization and addition for a detected signal are started. The low-frequency magnetic field H<SB>2</SB>is kept under the ON-condition during processing therein. ON/OFF sequences for the magnetic field H<SB>0</SB>are repeated until obtaining a proper signal-to-noise ratio for the detection and/or analysis for the compound, after finishing the digitalization and addition for the detected signal. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
