Question: White LEDs can also be made by coating near-ultraviolet (NUV) LEDs with a mixture of high-efficiency europium-based phosphors that emit red and blue, plus copper and aluminium-doped zinc sulfide (ZnS:Cu, Al) that emits green. This is a method analogous to the way fluorescent lamps work. This method is less efficient than blue LEDs with YAG:Ce phosphor, as the Stokes shift is larger, so more energy is converted to heat, but yields light with better spectral characteristics, which render color better. Due to the higher radiative output of the ultraviolet LEDs than of the blue ones, both methods offer comparable brightness. A concern is that UV light may leak from a malfunctioning light source and cause harm to human eyes or skin.
Is there an answer to this question: What are non-near-ultraviolet LEDs coated with to create white LED?

Answer: unanswerable

Question: Stepper motors were and still are often used in computer printers, optical scanners, and digital photocopiers to move the optical scanning element, the print head carriage (of dot matrix and inkjet printers), and the platen or feed rollers. Likewise, many computer plotters (which since the early 1990s have been replaced with large-format inkjet and laser printers) used rotary stepper motors for pen and platen movement; the typical alternatives here were either linear stepper motors or servomotors with closed-loop analog control systems.
Is there an answer to this question: In scanners, what don't stepper motors move?

Answer: unanswerable

Question: Red hair varies from a deep burgundy through burnt orange to bright copper. It is characterized by high levels of the reddish pigment pheomelanin (which also accounts for the red color of the lips) and relatively low levels of the dark pigment eumelanin. The term redhead (originally redd hede) has been in use since at least 1510. Cultural reactions have varied from ridicule to admiration; many common stereotypes exist regarding redheads and they are often portrayed as fiery-tempered. (See red hair).
Is there an answer to this question: There is another part of the face which gets its red color from the pigment pheomelanin, what is it?

Answer: the lips

Question: Nanjing first became a state capital in 229 AD, when the state of Eastern Wu founded by Sun Quan during the Three Kingdoms period relocated its capital to Jianye (), the city extended on the basis of Jinling Yi in 211 AD. Although conquered by the Western Jin dynasty in 280, Nanjing and its neighbouring areas had been well cultivated and developed into one of the commercial, cultural and political centers of China during the rule of East Wu. This city would soon play a vital role in the following centuries.
Is there an answer to this question: When was Eastern Wu founded?

Answer:
during the Three Kingdoms period