泵的抽气速率与气体的性质有关.Lashing velocity of pump is concerned with nature of air.现在已经采用了低温吸附技术和吸气离子泵的近代电子抽气设备.Recent electronic means of pumping using low temperature sorption techniques and getter - ion pumps have been introduce...
Happiness, which had been so elusive in Henry's life, still evaded him.亨利生活中过去一直难以捕捉的幸福仍旧与他无缘。Eric, as elusive as ever, was nowhere to be found.埃里克总是这样神出鬼没，哪儿也找不着。Try to catch the elusive charm of the original in tr...