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Quartary
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The Quaternary is a geologic period. Quaternary (an adjective meaning "fourth in order" or "composed of four items") may also refer to: * Quaternary (chemistry) (see also Quaternary compound and Quaternary phase) * Quaternary structure of proteins * Quaternary sector of the economy, which encompasses knowledge-based services * Quaternary care, health care that includes highly specialized or experimental treatments * Quaternary numeral system (base-4) in mathematics * Quaternary counting system, as used in some human languages * ''Quaternary'' (EP), an album by Mötley Crüe See also * * * Quinary, positional number system with base 5 * Ternary (other) * Tertiary (other) The Tertiary is a geologic period. Tertiary (from Latin, meaning 'third' or 'of the third degree/order..') may also refer to: * Tertiary (chemistry), a term describing bonding patterns in organic chemistry * In biochemistry, the tertiary structur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quaternary
The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS). It follows the Neogene Period and spans from 2.58 million years ago to the present. The Quaternary Period is divided into two epochs: the Pleistocene (2.58 million years ago to 11.7 thousand years ago) and the Holocene (11.7 thousand years ago to today, although a third epoch, the Anthropocene, has been proposed but is not yet officially recognised by the ICS). The Quaternary Period is typically defined by the cyclic growth and decay of continental ice sheets related to the Milankovitch cycles and the associated climate and environmental changes that they caused. Research history In 1759 Giovanni Arduino proposed that the geological strata of northern Italy could be divided into four successive formations or "orders" ( it, quattro ordini). The term "quaternary" was introduced by Jules Desnoye ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quaternary (chemistry)
Quaternary is a term used in organic chemistry to classify various types of compounds (e. g. amines and ammonium salts).Paula Yurkanis Bruice: ''Organic Chemistry'', Pearson Education Inc., 2004, 4. Ed., p. 78, 104, 893, and 912, . {{clear See also * Primary (chemistry) * Secondary (chemistry) * Tertiary (chemistry) Tertiary is a term used in organic chemistry to classify various types of compounds (e. g. alcohols, alkyl halides, amines) or reactive intermediates (e. g. alkyl radicals, carbocations). See also * Primary (chemistry) * Secondary (chemistry) ... References Chemical nomenclature ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quaternary Compound
In chemistry, a quaternary compound is a compound consisting of exactly four chemical elements. In another use of the term in organic chemistry, a quaternary compound is or has a cation consisting of a central positively charged atom with four substituents, especially organic (alkyl and aryl) groups, discounting hydrogen atoms. The best-known quaternary compounds are quaternary ammonium salts, having a nitrogen atom at the centre. For example, in the following reaction, the nitrogen atom is said to be quaternized as it has gone from 3 to 4 substituents: :R3N + RCl -> R4N+Cl- Other examples include substituted phosphonium salts (), substituted arsonium salts () like arsenobetaine, as well as some arsenic-containing superconductors. Substituted stibonium () and bismuthonium salts () have also been described. See also *Binary compound *Ternary compound *Onium ion *Quaternary phase In materials chemistry, a quaternary phase is a chemical compound containing four element ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quaternary Phase
In materials chemistry, a quaternary phase is a chemical compound containing four elements. Some compounds can be molecular or ionic, examples being chlorodifluoromethane () sodium bicarbonate (). More typically quaternary phase refers to extended solids. A famous example are the yttrium barium copper oxide superconductors. See also *Binary compound *Ternary compound In inorganic chemistry and materials chemistry, a ternary compound or ternary phase is a chemical compound containing three different elements. While some ternary compounds are molecular, ''e.g.'' chloroform (), more typically ternary phases r ... References {{Reflist Chemical compounds ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quaternary Structure
Protein quaternary structure is the fourth (and highest) classification level of protein structure. Protein quaternary structure refers to the structure of proteins which are themselves composed of two or more smaller protein chains (also referred to as subunits). Protein quaternary structure describes the number and arrangement of multiple folded protein subunits in a multi-subunit complex. It includes organizations from simple dimers to large homooligomers and complexes with defined or variable numbers of subunits. In contrast to the first three levels of protein structure, not all proteins will have a quaternary structure since some proteins function as single units. Protein quaternary structure can also refer to biomolecular complexes of proteins with nucleic acids and other cofactors. Description and examples Many proteins are actually assemblies of multiple polypeptide chains. The quaternary structure refers to the number and arrangement of the protein subunit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quaternary Sector Of The Economy
The quaternary sector of the economy is based upon the economic activity that is associated with either the intellectual or knowledge-based economy. This consists of information technology; media; research and development; information-based services such as information-generation and information-sharing; and knowledge-based services such as consultation, education, financial planning, blogging, and designing. Other definitions describe the quaternary sector as pure services. This may consist of the entertainment industry, to describe media, culture, and government. This may be classified into an additional quinary sector. The term reflects the analysis of the three-sector model of the economy, in which the primary sector produces raw materials used by the secondary sector to produce goods, which are then distributed to consumers by the tertiary sector. Contrary to this implied sequence, however, the quaternary sector does not process the output of the tertiary sector. It has on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quaternary Care
Health care or healthcare is the improvement of health via the prevention, diagnosis, treatment, amelioration or cure of disease, illness, injury, and other physical and mental impairments in people. Health care is delivered by health professionals and allied health fields. Medicine, dentistry, pharmacy, midwifery, nursing, optometry, audiology, psychology, occupational therapy, physical therapy, athletic training, and other health professions all constitute health care. It includes work done in providing primary care, secondary care, and tertiary care, as well as in public health. Access to health care may vary across countries, communities, and individuals, influenced by social and economic conditions as well as health policies. Providing health care services means "the timely use of personal health services to achieve the best possible health outcomes". Factors to consider in terms of health care access include financial limitations (such as insurance coverage), geographi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quaternary Numeral System
A quaternary numeral system is base-. It uses the digits 0, 1, 2 and 3 to represent any real number. Conversion from binary is straightforward. Four is the largest number within the subitizing range and one of two numbers that is both a square and a highly composite number (the other being 36), making quaternary a convenient choice for a base at this scale. Despite being twice as large, its radix economy is equal to that of binary. However, it fares no better in the localization of prime numbers (the smallest better base being the primorial base six, senary). Quaternary shares with all fixed- radix numeral systems many properties, such as the ability to represent any real number with a canonical representation (almost unique) and the characteristics of the representations of rational numbers and irrational numbers. See decimal and binary for a discussion of these properties. Relation to other positional number systems Relation to binary and hexadecimal As with the o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quaternary Counting System
In linguistics, a numeral (or number word) in the broadest sense is a word or phrase that describes a numerical quantity. Some theories of grammar use the word "numeral" to refer to cardinal numbers that act as a determiner that specify the quantity of a noun, for example the "two" in "two hats". Some theories of grammar do not include determiners as a part of speech and consider "two" in this example to be an adjective. Some theories consider "numeral" to be a synonym for "number" and assign all numbers (including ordinal numbers like the compound word "seventy-fifth") to a part of speech called "numerals". Numerals in the broad sense can also be analyzed as a noun ("three is a small number"), as a pronoun ("the two went to town"), or for a small number of words as an adverb ("I rode the slide twice"). Numerals can express relationships like quantity (cardinal numbers), sequence (ordinal numbers), frequency (once, twice), and part (fraction). Identifying numerals Numerals may ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quaternary (EP)
''Quaternary'' is an Extended play, EP by the Heavy metal music, heavy metal band Mötley Crüe. It was released in 1994 on Elektra Records, Elektra. The EP, which was initially going to be titled ''Leftovers'', was made available as a mail-in offer for purchasers of the Mötley Crüe (album), self-titled album in a limited quantity of 20,000 copies. Background The EP features one song from each member of the band ("Planet Boom" by Tommy Lee, "Bittersuite" by Mick Mars, "Father" by Nikki Sixx, and "Friends" by John Corabi), along with the song "Babykills" which is performed by the entire band.61664-2 CD liner notes. Songs 1–3 and 7 were reissued on the ''Supersonic and Demonic Relics'' compilation in 1999. Songs 1–2 were featured on the ''Red, White & Crüe'' compilation in 2005, and all the tracks were made available on the ''Music to Crash Your Car To: Vol. 2'' box set in 2004. The rap metal-influenced "Planet Boom" was later released on the soundtrack for Tommy Lee's the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quinary
Quinary (base-5 or pental) is a numeral system with five as the base. A possible origination of a quinary system is that there are five digits on either hand. In the quinary place system, five numerals, from 0 to 4, are used to represent any real number. According to this method, five is written as 10, twenty-five is written as 100 and sixty is written as 220. As five is a prime number, only the reciprocals of the powers of five terminate, although its location between two highly composite numbers ( 4 and 6) guarantees that many recurring fractions have relatively short periods. Today, the main usage of base 5 is as a biquinary system, which is decimal using five as a sub-base. Another example of a sub-base system, is sexagesimal, base 60, which used 10 as a sub-base. Each quinary digit can hold log25 (approx. 2.32) bits of information. Comparison to other radices Usage Many languagesHarald Hammarström, Rarities in Numeral Systems: "Bases 5, 10, and 20 are omni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ternary (other)
Ternary (from Latin ''ternarius'') or trinary is an adjective meaning "composed of three items". It can refer to: Mathematics and logic * Ternary numeral system, a base-3 counting system ** Balanced ternary, a positional numeral system, useful for comparison logic * Ternary logic, a logic system with the values ''true'', ''false'', and some other value * Ternary plot or ternary graph, a plot that shows the ratios of three proportions * Ternary relation, a finitary relation in which the number of places in the relation is three * Ternary operation, an operation that takes three parameters * Ternary function, a function that takes three arguments Computing * Ternary signal, a signal that can assume three significant values * Ternary computer, a computer using a ternary numeral system * Ternary tree, a tree data structure in computer science **Ternary search tree, a ternary (three-way) tree data structure of strings * Ternary search, a computer science technique for finding the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
