quantum dot
A nano-scale crystalline structure made from cadmium selenide that absorbs white light and then reemits it a couple of nanoseconds later in a specific color. The quantum dot has been around since the 1980s when scientists were looking into the technology as a way to build nano-scale computing applications where light is used to process information. More recently, however, the technology is being used in medicine. The crystals are one ten-millionth of an inch in size and can be dissolved in water. When illuminated, they act as molecule-sized LEDs and can be used as probes to track antibodies, viruses, proteins, or DNA within the human body.
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- quarantine
To move an infected file, such as a virus, into an area where it cannot cause more harm. Antivirus softwares come with quarantine options so that the user also can keep track of virus activity.
- qubit
A quantum bit. The smallest unit of information in quantum computing. Qubits hold an exponentially larger amount of information than traditional bits.
- Query (Database Query)
(n.) A query is a request for information from a database. There are three general methods for posing queries: Choosing parameters from a menu: In this method, the database system presents a list of parameters from which you can choose. This is perhaps the easiest way to pose a query because the menus guide you, […]
- query by example
In database management systems, query by example (QBE) refers to a method of forming queries in which the database program displays a blank record with a space for each field. You can then enter conditions for each field that you want to be included in the query. For example, if you wanted to find all […]
- query language
A specialized language for requesting information from a database. For example, the query SELECT ALL WHERE age > 30 AND name = “Smith” requests all records in which the name-field is “Smith” and the Age field has a value greater than 30. The de facto standard for query languages is SQL.