Context and question: A P-N junction can convert absorbed light energy into a proportional electric current. The same process is reversed here (i.e. the P-N junction emits light when electrical energy is applied to it). This phenomenon is generally called electroluminescence, which can be defined as the emission of light from a semi-conductor under the influence of an electric field. The charge carriers recombine in a forward-biased P-N junction as the electrons cross from the N-region and recombine with the holes existing in the P-region. Free electrons are in the conduction band of energy levels, while holes are in the valence energy band. Thus the energy level of the holes will be lesser than the energy levels of the electrons. Some portion of the energy must be dissipated in order to recombine the electrons and the holes. This energy is emitted in the form of heat and light.
What is the phenomenon where a P-N junction emits light when an electrical current is applied to it?
Answer: electroluminescence
Context and question: In May 2014, the Government of China banned the internal purchase of Windows 8-based products under government contracts requiring "energy-efficient" devices. The Xinhua News Agency claimed that Windows 8 was being banned in protest of Microsoft's support lifecycle policy and the end of support for Windows XP (which, as of January 2014, had a market share of 49% in China), as the government "obviously cannot ignore the risks of running OS [sic] without guaranteed technical support." However, Ni Guangnan of the Chinese Academy of Sciences had also previously warned that Windows 8 could allegedly expose users to surveillance by the United States government due to its heavy use of internet-based services.
Why did the Chinese government ban Windows 9 based products?
Answer: unanswerable
Context and question: Western philosophy regarded emotion in varying ways. In stoic theories it was seen as a hindrance to reason and therefore a hindrance to virtue. Aristotle believed that emotions were an essential component of virtue. In the Aristotelian view all emotions (called passions) corresponded to appetites or capacities. During the Middle Ages, the Aristotelian view was adopted and further developed by scholasticism and Thomas Aquinas in particular. There are also theories of emotions in the works of philosophers such as Rene Descartes, Niccolo Machiavelli, Baruch Spinoza and David Hume. In the 19th century emotions were considered adaptive and were studied more frequently from an empiricist psychiatric perspective.
What thinker believed that emotions were necessary for virtue?
Answer:
Aristotle