Ultraviolet A, UVA, can travel more deeply into the skin, but both UVA and UVB rays can burn skin.

紫外线A，也就是长波紫外线，穿透皮肤更深，不过紫外线A和B都能晒伤皮肤。

youdao

Objective To investigate the preventive effect of quercetin on DNA damage in human epidermoid carcinoma cells induced by ultraviolet a (UVA).

目的观察长波紫外线引起人表皮癌细胞DNA链断裂损伤的情况，以及槲皮素对这种损伤的预防作用。

youdao

Narrow-band ultraviolet B (UVB) has better overall repigmentation rates and safety profile than either topical or oral psoralens and ultraviolet A (PUVA).

比起局部用补骨脂素或口服后再照UVA，窄谱紫外线有较好的恢复色素的效果和安全性。

youdao

The system is equipped with an ultraviolet lamp and a halogen lamp that produces near-infrared light.

VOA: special.2011.06.07

If you get some of these in the upper atmosphere, a photon, an ultraviolet photon, has the energy capable of breaking this bond.

如果你把它放到大气层上，一个光子，一个紫外光光子，有能量可以破坏它的化学键。

麻省理工公开课 - 固态化学导论课程节选

Ultraviolet light from the sun changes a substance in the skin into vitamin D.

VOA: special.2009.04.21

Still need a reason to give UltraViolet a try?

ENGADGET

The two-disc set available for purchase also includes a digital copy of the film and will be enabled with UltraViolet, a new way to collect, access and enjoy movies.

ENGADGET: Top Gun Blu-ray 3D details revealed, comes home February 19th after IMAX 3D run

But a product's SPF indicates only its ability to defend against sunburn-causing ultraviolet-B rays and not against ultraviolet-A, which penetrate deeper into the skin and cause premature aging. (Both types contribute to skin cancer.) For example, a person wearing SPF 50 could spend considerable time in the sun without getting burned.

WSJ: The Myths of Daily Sunscreen