In different embodiments, a low-pressure discharge lamp (1) is provided. The low-pressure discharge lamp has a discharge vessel (2) and a coating structure (7). The coating structure is formed on an inner face of the discharge vessel (2). The coating structure (7) has first fluorescent particles (34) which have at least one fluorescent substance that emits red light and the average particle size of which ranges from 0.5 m to 1.9 m, second fluorescent particles (36) which have at least one fluorescent substance that emits green light and the average particle size of which ranges from 0.6 m to 2.8 m or from 1 m to 4 m, and third fluorescent particles (38) which have at least one fluorescent substance that emits blue light and the average particle size of which ranges from 1 m to 4 m.

A light emitting device includes: a first white light source which includes N pieces of first white light emitting diodes and emits a first white light; and a second white light source which includes M pieces of second white light emitting diodes and a first resistance element electrically connected in series to the second white light emitting diodes and having a first resistance value, is electrically connected in parallel to the first white light source, and emits a second white light, the light emitting device emitting a mixed white light of the first white light and the second white light. The drive voltage of the first white light source is higher than a drive voltage of the second white light source, and a color temperature of the mixed white light is higher as a total luminous flux of the mixed white light is higher.

The present application relates to a technical filed of energy sources and illumination, and discloses a rare earth oxide nanosheet composite modified by an organic ligand, a preparation method and an organic light-emitting diode (OLED) luminescent film. The rare earth oxide nanosheet composite modified by the organic ligand is obtained by adding the organic ligand in the rare earth nanosheet sol for ultrasonic coordination; and a mole ratio of the rare earth nanosheet sol to the organic ligand is 1:(3-9).

A red-luminescent long-afterglow phosphor, represented by Mg.sub.xZn.sub.yGe.sub.zO.sub.3: aMn.sup.2+, bEu.sup.3+, cR.sup.3+. The phosphor is a kind of oxide compound based white powder. The phosphor powder synthesis process is environmentally friendly, no sintering-assisted gas required and no harmful gas generated during or after sintering. The phosphor powder can be excited by UV and is chemically stable.