Every reference with a DOI in the deposited reference list resolved to a known
work in Crossref or DataCite at the dated check, and none carried a retraction,
withdrawal, or removal notice.
4 without a DOI — not checked. A reference
deposited without a DOI is never matched by title or guessed at; it stays outside the checked
set, and this line discloses that.
Coupling of Ag Nanoparticle with Inverse Opal Photonic Crystals as a Novel Strategy for Upconversion Emission Enhancement of NaYF<sub>4</sub>: Yb<sup>3+</sup>, Er<sup>3+</sup> Nanoparticles
Selective enhancement of red emission from upconversion nanoparticles via surface plasmon-coupled emission
The 4 references without a DOI — listed, not checked
no DOI — not checkedAdvances in highly doped upconversion nanoparticles
no DOI — not checkedIncreasing electrical conductivity of upconversion materials by in situ binding with graphene
no DOI — not checkedIntense upconversion luminescence and origin study in Tm 3+ /Yb 3+ codoped calcium scandate
no DOI — not checkedPlasmon-enhanced upconversion
What this badge says. CiteStamped means the CHECKABLE references of this
work were clean at the dated check: each resolved to a known work in a public registry, and none
carried a retraction notice at that time. It says nothing about the quality, findings,
or importance of the work itself, and nothing about references deposited without a DOI.
checked 2026-07-22 — re-checked daily as this page is visited;
titles and statuses come from Crossref and DataCite and are not part of the signed record
Both snippets point at the live badge image and link back to this page. The
badge re-renders from the daily check, so an embed never goes stale by more than a day of visits.