The actual level of intensity depends on such factors as the physical layout, population density, and productive activities of a metropolis.

实际的强度水平取决于诸如大城市的物理布局、人口密度和生产活动之类的因素。

youdao

Physical constraints (mass and density) may also require modifications in machines such as automobiles and airplanes.

物理约束(体积和密度)可能也要求修改机器设备，如汽车和飞机。

youdao

So again if we look at this in terms of its physical interpretation or probability density, what we need to do is square the wave function.

如果我们从物理意义或者,概率密度的角度来看这个问题，我们需要把波函数平方。

youdao

So again if we look at this in terms of its physical interpretation or probability density, what we need to do is square the wave function.

如果我们从物理意义或者,概率密度的角度来看这个问题，我们需要把波函数平方。

麻省理工公开课 - 化学原理课程节选

Theories about why this is happening range from higher levels of obesity, higher density of calories in processed foods, and physical inactivity, to chemicals in food and water.

FORBES: Study Shows that Early Puberty is Now Affecting Boys, Just Like Girls

"Density and street connectivity also matter, but mixed use is the most important factor relating to physical activity and obesity, " said lead author Lawrence Frank , now a professor at the University of British Columbia.

FORBES: Chewing The Fat On Obesity

That ideas should freely spread from one to another over the globe, for the moral and mutual instruction of man, and improvement of his condition, seems to have been peculiarly and benevolently designed by nature, when she made them, like fire, expansible over all space, without lessening their density in any point, and like the air in which we breathe, move, and have our physical being, incapable of confinement or exclusive appropriation.

FORBES: As SOPA Looms, John Perry Barlow On 'The Right To Know'