请问一下资本流等于资本存量与什么的乘积？劳动流又等于总的工时数乘以什么？即有下面的英文：是什么意思

The flow of labor services is defined as the product of effort per hour, E, times the total hours worked, L, and the flow of capital services is analogously defined as the product of capital utilization, Z, times the capital stock,