Question: The structure of QD-LEDs used for the electrical-excitation scheme is similar to basic design of OLEDs. A layer of quantum dots is sandwiched between layers of electron-transporting and hole-transporting materials. An applied electric field causes electrons and holes to move into the quantum dot layer and recombine forming an exciton that excites a QD. This scheme is commonly studied for quantum dot display. The tunability of emission wavelengths and narrow bandwidth is also beneficial as excitation sources for fluorescence imaging. Fluorescence near-field scanning optical microscopy (NSOM) utilizing an integrated QD-LED has been demonstrated.
Try to answer this question if possible: During the electrical-excitation scheme, what moves into the non-quantum dot layer?
Answer: unanswerable
Question: Since the Three Kingdoms period, Nanjing has been an industrial centre for textiles and minting owing to its strategic geographical location and convenient transportation. During the Ming dynasty, Nanjing's industry was further expanded, and the city became one of the most prosperous cities in China and the world. It led in textiles, minting, printing, shipbuilding and many other industries, and was the busiest business center in East Asia. Textiles boomed particularly in Qing dynasty, the industry created around 200 thousand jobs and there were about 50 thousand satin machines in the city in 18th and 19th century.
Try to answer this question if possible: In what dynasty were textiles particularly popular?
Answer: Qing
Question: The 25,000 cotton growers in the United States of America are heavily subsidized at the rate of $2 billion per year although China now provides the highest overall level of cotton sector support. The future of these subsidies is uncertain and has led to anticipatory expansion of cotton brokers' operations in Africa. Dunavant expanded in Africa by buying out local operations. This is only possible in former British colonies and Mozambique; former French colonies continue to maintain tight monopolies, inherited from their former colonialist masters, on cotton purchases at low fixed prices.
Try to answer this question if possible: How many subsidized cotton growers are in the US?
Answer: 25,000
Question: Southampton used to be home to a number of ferry services to the continent, with destinations such as San Sebastian, Lisbon, Tangier and Casablanca. A ferry port was built during the 1960s. However, a number of these relocated to Portsmouth and by 1996, there were no longer any car ferries operating from Southampton with the exception of services to the Isle of Wight. The land used for Southampton Ferry Port was sold off and a retail and housing development was built on the site. The Princess Alexandra Dock was converted into a marina. Reception areas for new cars now fill the Eastern Docks where passengers, dry docks and trains used to be.
Try to answer this question if possible: What has the Princess Alexandra Dock become?
Answer:
a marina