密度减少 meaning in English

depopulation

On vaporization it reduces the bulk density of upflowing mixture and promotes the circulation of catalyst .
在汽化时使向上流动的混合物的松密度减少，并促使催化剂循环。
As ageing occurs , there is gradual loss of calcium which leads to a reduction in bone density . the affected bones thus become thinner , and fractures may occur which may result in loss of independence or lead to other complications
由于钙质随年增长逐渐流失，骨质密度减少，使骨的结构变得薄和脆弱，容易导致骨折，令长日后行动不便及引致其他后遗症。
As ageing occurs , there is gradual loss of calcium which leads to a reduction in bone density . the affected bones thus become thinner , and fractures may occur which may result in loss of independence or lead to other complications
由于钙质随年龄增长逐渐流失，骨质密度减少，使骨的结构变得薄和脆弱，容易导致骨折，令长?日后行动不便及引致其他后遗症。