摘要: T/sub 1rho/ of sup 1 H, and concentrations of free radicals and of sup 13 C in six coals have been determined by standard pulse nmr and continuous wave ESR experiments. Each coal studied exhibited two values of proton T/sub 1rho/,... 展开 T/sub 1rho/ of sup 1 H, and concentrations of free radicals and of sup 13 C in six coals have been determined by standard pulse nmr and continuous wave ESR experiments. Each coal studied exhibited two values of proton T/sub 1rho/, one being of order of 100 mu sec, and the other of order of 2 msec. Less than 70% of sup 13 C is detected under a single pulse spin counting experiment in all coals. Free radical concentrations are of order of 10 sup 19 spins g sup -1 , but do not correlate with the fraction of sup 13 C detected under spin counting conditions. There does appear to be a correlation between the fraction of sup 13 C detected, and the fraction of sup 1 H exhibiting the longer T/sub 1rho/. 10 refs., 2 tabs. (ERA citation 11:055713) 收起