"increase gently" is correct and usable in written English.
You could use it in the context of gradually increasing the temperature of an atmosphere, for example, "Slowly open the door, and increase the temperature inside gently."
From 1 to 5 min, the total thickness of the coatings increases gently and the total growth rate declines sharply; at this stage, the outward growth gradually slows down, and the inward growth maintains persistent enhancement.
Tests results of G/L effect on CO2 removal efficiency show that, when G/L=1∼5, CO2 removal efficiency increases rapidly with the increase of G/L; when G/L=5, CO2 removal efficiency=80%∼88%; when G/L=8, CO2 removal efficiency=86%∼92%, when G/L>8, CO2 removal efficiency increases gently with the increase of G/L.
However, with further increase of V/III ratio, the QD density increases gently.
The curve increases gently when the sensor density is below 0.312 and grows rapidly as the density is above 0.312.
The scenario with an EIR of 1, however, increased gently to a maximum at 20 years.
We found that the overall inequalities in the distribution of health workers decreased to the lowest in 2000, then increased gently until 2011.
The overall inequalities in the distribution of health workers decreased to the bottom at 2000, then increased gently until 2011 (as Figure 1 shows).
From the beginning of the third stage of the medical system reform, the inequalities in the distribution of health workers increased gently until 2011, as a negative effect of continued medical market reform.
As their participation increased, I gently prodded my advanced students more and more to guide the rest of the class through the material, using the worksheets as a guide.
Gently, increase pressure from your palm on the handlebar, pushing it gently, as if you were trying to turn the bike in the opposite direction you want to turn.
