讨论了碳黑不同物理形态的性能，绒毛碳黑是较好的水墨用碳黑。阐述了水墨生产中碳黑絮凝的原因，提出了行之有效的分散工艺。......

QTc dispersion(QTcd)was studied in 60 patienta with right ventricular pacing.The results show that:(1)QTcd after pacing ......