中文摘要：

改进DQF—COSY脉冲序列，结合适当的相位循环并选取合适的脉冲翻转角来获得相关谱，再利用计算机模拟对理论设计进行验证．模拟结果表明：改进的DQF-COSY谱图比利用常规DQF-COSY脉冲序列获得的谱图简单许多，基本没有杂峰，易于判断具有标量耦合的核间键连关系．

英文摘要：

Method to suppress the undesired peaks in double-quantum-filtered COSY spectra is supposed. Analytical expressions are derived from the modified Bloch equations with dipolar fields. All numerical simulation results are in excellent agreement with the theoretical predictions. Compared with the COSY or conventional DQF-COSY sequence, the improved sequence will effectively suppress undesired intermolecular single-quantum coherence signals. It is important for research in molecular structure.