direct set有向集directadj.直接的；笔直的；坦白的v.对准；指挥；指示；命令direct density-dependent factor直接密度制约因素directivity factor of loudspeaker扬声器指向性因数direct transcendental singularity直接超越奇点direct telephone telegram traffic直达话传电报业务Direct-current-high-voltage直流高压Direct connection to the Internet直接连接到direct memory access inhibit flag直接存储器存取禁止标志direct writing electrocardiograph直接描记型心电图机Direct digital radiography system直接数字X线摄影术direct steam generation collector蒸汽直接冷却槽式太阳集热器（DSG）