The phrase "an obvious decline" is correct and usable in written English.
It can be used to describe a clear or noticeable decrease in quality, quantity, or performance in various contexts.
Example: "The report highlighted an obvious decline in sales over the past quarter, prompting the management to reassess their marketing strategy."
Alternatives: "a clear decrease" or "a noticeable drop".
With the increasing addition of warfarin, there was an obvious decline of the fluorescence intensity.
However, a further increase of silica layer thickness caused an obvious decline of EFMEF.
When α changes from 2 to 2.2, there is an obvious decline on the number of observation steps in our scheme.
It was found for unnotched specimens that with the increase of temperature the compressive strength exhibited an obvious decline due to the softening of matrix, while the modulus decreased initially and then increased because of the cold crystallization.
The catalyst can keep the methane conversion of almost 100% whereas the unetched one has an obvious decline in the catalytic activity from 100to82%2% after ten cycles.
The results show that the etched Pd/SiC catalyst can keep the methane conversion of almost 100% while the unetched one has an obvious decline in the catalytic activity from 100to82%2% after ten repeated reaction cycles.
We found that the expression protein of bcl-2 exhibited an obvious declining tendency after EAE treatment, and the bax and caspase-3 exhibited an obvious increasing tendency.
The ban was one of the factors, along with increased regulation, overfishing and aggressive development on the Long Island coast, that helped cause the waning of the fishing industry, and in turn, a perhaps less obvious decline: that of the boat-building trade.
(2) The monthly employment index of manufacturing parks showed a sustained and more obvious decline in overall performance; this downward trend is similar to what was found in the official manufacturing purchasing managers index (see Supplementary Figure S4).
The contents challenge an assumption that he was intolerably cold towards her when she was suffering an obvious mental decline.
