使用寿命 application life; calendar life; in service life; in-service life; length of life; life cycle; life length; life time=lifetime; life-span; longevity; operating life; operation life; operational life proof cycle; operational life span; operational lifetime; service lifetime; service limit; serviceable life; useful life; useful physical life; useful time; using life; working life
The topic analyses the reason why the lead - acid battery can not reach its design life - span , and suggests ways to improve it 摘要分析了铅酸蓄电池经常达不到设计使用寿命的原因,并针对其原因提出了改进办法。
Considering the past research results , frost resistance of concrete using portland cement , and the designed service life of 100 years of testing bridge , the control indexes of high durability concrete are defined in this paper . mixture proportion of concrete used in pier column , coping , precast box beam and plate of bridge is designed based on the compact pile theory , and construction technique is studied also 结合课题组以往的研究成果,根据试验桥设计使用寿命100年的要求,确定出高耐久性混凝土的设计控制指标,基于最紧密堆积原理和最佳浆骨比原理对桥梁的墩柱、盖梁、预制箱梁和桥面板用高耐久性混凝土的配合比进行设计,并对其施工应用技术进行了研究。