The phrase "a different density of" is correct and usable in written English.
You can use it when discussing variations in density among different materials or substances in scientific or technical contexts.
Example: "The experiment revealed a different density of the two liquids, which affected their mixing behavior."
Alternatives: "a varying density of" or "an alternative density of".
We make extensive experiments on the five selected highway scenarios, each has a different density of traffic flows with two lanes per direction.
Dispersion processes are followed by simultaneous sedimentation and flotation that implies a different density of nanotube agglomerates, and only particles with diameter close to 4.5 nm are found in the solution volume.
Injecting particles in the fracture surface in the LGA method leads to a different density of particles inside the fracture, and as a result, the viscosity ν is found to be different.
Quantitative differences in terpene content and TPS transcript abundance between, for example, ray florets and disk florets could be due to a different density of glandular trichomes, the site of terpene production in these organs.
The past shapes our understanding of the present, and it has a different density for each of us".
A significant bulk flow is thought to occur if a part of the body of a suspension, which has a different density from the density of the remainder of the suspension, is large enough in space however slight the difference may be.
A century later, in 1895, Lord Rayleigh discovered that samples of nitrogen from the air were of a different density than nitrogen resulting from chemical reactions.
Liquid of one density is pumped into a second liquid of a different density and time between drops produced is measured.
Fig. 6 TRIM simulation plots for sputtering yield for the different density of Ag film: a bulk density, b an arbitrary low density value.
The differences between N in particular hydrogels should be related to different density of their polymer networks.
