It appears that AQ is still the most cost effective sulphurfree accelerator for alkaline pulping, albeit of limited applications.
蒽醌似乎是无硫碱法制浆的最有效的催化剂，尽管应用还比较少。
2
The result indicates that the EPR signal of ultramarine, lapis lazuli and artificial ultramarine should be the overlapping signal of two kinds of sulphurfree radicals.
因此，群青、青金石和合成群青的EPR信号应是两种硫自由基信号的重叠。
3
The near-term climate benefits of a global dash for sulphur-free gas may thus be smaller than might be expected.