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Michael P. Barnett
Michael Peter Barnett (24 March 1929 – 13 March 2012) was a British theoretical chemist and computer scientist. He developed mathematical and computer techniques for Quantum chemistry, quantum chemical problems, and some of the earliest software for several other kinds of computer application. After his early days in London, Essex and Lancashire, he went to King's College, London, in 1945, the Royal Radar Establishment in Malvern in 1953, IBM UK in 1955, the University of Wisconsin Department of Chemistry in 1957, and the MIT John C. Slater#The Solid State and Molecular Theory Group, Solid State and Molecular Theory Group in 1958. At MIT he was an associate professor of physics and director of the John C. Slater#Slater's further activities at MIT during this time, Cooperative Computing Laboratory. He returned to England, to the Institute of Computer Science of the University of London in 1964, and then back to United States the following year. He worked in industry, and taught a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theoretical Chemist
Theoretical chemistry is the branch of chemistry which develops theoretical generalizations that are part of the theoretical arsenal of modern chemistry: for example, the concepts of chemical bonding, chemical reaction, valence, the surface of potential energy, molecular orbitals, orbital interactions, and molecule activation. Overview Theoretical chemistry unites principles and concepts common to all branches of chemistry. Within the framework of theoretical chemistry, there is a systematization of chemical laws, principles and rules, their refinement and detailing, the construction of a hierarchy. The central place in theoretical chemistry is occupied by the doctrine of the interconnection of the structure and properties of molecular systems. It uses mathematical and physical methods to explain the structures and dynamics of chemical systems and to correlate, understand, and predict their thermodynamic and kinetic properties. In the most general sense, it is explanation of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charles Coulson
Charles Alfred Coulson (13 December 1910 – 7 January 1974) was a British applied mathematician and theoretical chemist. Coulson's major scientific work was as a pioneer of the application of the quantum theory of valency to problems of molecular structure, dynamics and reactivity. He was also a Methodist lay preacher, served on the World Council of Churches from 1962 to 1968, and was chairman of Oxfam from 1965 to 1971. Early life The parents of Charles Coulson and his younger twin brother John Metcalfe Coulson were educators who hailed from the Midlands. The twins were born when their father, Alfred, was principal of Dudley Technical College and superintendent of the Methodist Sunday School, and their mother Annie Sincere Hancock was Headmistress of Tipton Elementary School, close by. Coulson's parents maintained a religious Methodist home. When the Coulson brothers were 10, their father was appointed Superintendent of Technical Colleges for the South-West of England, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sudan
Sudan ( or ; ar, السودان, as-Sūdān, officially the Republic of the Sudan ( ar, جمهورية السودان, link=no, Jumhūriyyat as-Sūdān), is a country in Northeast Africa. It shares borders with the Central African Republic to the southwest, Chad to the west, Egypt to the north, Eritrea to the northeast, Ethiopia to the southeast, Libya to the northwest, South Sudan to the south and the Red Sea. It has a population of 45.70 million people as of 2022 and occupies 1,886,068 square kilometres (728,215 square miles), making it Africa's List of African countries by area, third-largest country by area, and the third-largest by area in the Arab League. It was the largest country by area in Africa and the Arab League until the 2011 South Sudanese independence referendum, secession of South Sudan in 2011, since which both titles have been held by Algeria. Its Capital city, capital is Khartoum and its most populated city is Omdurman (part of the metropolitan area of Khar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
River Nile
The Nile, , Bohairic , lg, Kiira , Nobiin: Áman Dawū is a major north-flowing river in northeastern Africa. It flows into the Mediterranean Sea. The Nile is the longest river in Africa and has historically been considered the longest river in the world, though this has been contested by research suggesting that the Amazon River is slightly longer.Amazon Longer Than Nile River, Scientists Say Of the world's major rivers, the Nile is one of the smallest, as measured by annual flow in cubic metres of water. About long, its covers eleven countries: the |
IBM 650
The IBM 650 Magnetic Drum Data-Processing Machine is an early digital computer produced by IBM in the mid-1950s. It was the first mass produced computer in the world. Almost 2,000 systems were produced, the last in 1962, and it was the first computer to make a meaningful profit. The first one was installed in late 1954 and it was the most-popular computer of the 1950s. The 650 was marketed to business, scientific and engineering users as a general-purpose version of the IBM 701 and IBM 702 computers which were for scientific and business purposes respectively. It was also marketed to users of unit record equipment, punched card machines who were upgrading from Unit record equipment#Calculating, calculating punches, such as the IBM 604, to computers. Because of its relatively low cost and ease of Computer programming, programming, the 650 was used to pioneer a wide variety of applications, from modeling submarine crew performance to teaching high school and college students c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Semiconductor
Organic semiconductors are solids whose building blocks are pi-bonded molecules or polymers made up by carbon and hydrogen atoms and – at times – heteroatoms such as nitrogen, sulfur and oxygen. They exist in the form of molecular crystals or amorphous thin films. In general, they are electrical insulators, but become semiconducting when charges are either injected from appropriate electrodes, upon doping or by photoexcitation. General properties In molecular crystals the energetic separation between the top of the valence band and the bottom conduction band, i.e. the band gap, is typically 2.5–4 eV, while in inorganic semiconductors the band gaps are typically 1–2 eV. This implies that they are, in fact, insulators rather than semiconductors in the conventional sense. They become semiconducting only when charge carriers are either injected from the electrodes or generated by intentional or unintentional doping. Charge carriers can also be generated in the c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solid State Physics
Solid-state physics is the study of rigid matter, or solids, through methods such as quantum mechanics, crystallography, electromagnetism, and metallurgy. It is the largest branch of condensed matter physics. Solid-state physics studies how the large-scale properties of solid materials result from their atomic-scale properties. Thus, solid-state physics forms a theoretical basis of materials science. It also has direct applications, for example in the technology of transistors and semiconductors. Background Solid materials are formed from densely packed atoms, which interact intensely. These interactions produce the mechanical (e.g. hardness and elasticity), thermal, electrical, magnetic and optical properties of solids. Depending on the material involved and the conditions in which it was formed, the atoms may be arranged in a regular, geometric pattern ( crystalline solids, which include metals and ordinary water ice) or irregularly (an amorphous solid such as common ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
British Rayon Research Association
The British Rayon Research Association was a research institute formed in 1946 by the British Rayon Federation and others.The Times, November 29, 1946 page 10 It was funded by the Department of Scientific and Industrial Research and by voluntary funds from industry to investigate the chemical and physical properties of rayon and rayon fabrics, using a wide range of laboratory and theoretical methods. John Wilson, who was its Director from 1948 to 1958 was appointed a CBE for his work at the BRRA.The Times, John Wilson obituary, 15 September 1976 It was located near Ringway Airport in Manchester, initially, and then at Heald Green near Manchester after 1955. Work from the Association included academic publication, that included papers by Leslie Treloar in the journal ''Polymer''. The BRRA sponsored Andrew Donald Booth's early research into computing at Birkbeck and was home to the first of his All Purpose Electronic Computers built in 1952 Under Wilson's leadership, the staff o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shelter Island Conference On Quantum Mechanics In Valence Theory, 1951
Shelter Island Conference on Quantum Mechanics in Valence Theory was held in 1951. It was sponsored by the National Academy of Sciences. The Nobel laureate Robert S. Mulliken Robert Sanderson Mulliken Note Longuet-Higgins' amusing title for reference B238 1965 on page 354 of this Biographical Memoir. The title should be "Selected papers of Robert S Mulliken." (June 7, 1896 – October 31, 1986) was an American ph ... organized the meeting. The other participants were In 1981, J.C. Light wrote, in an issue of '' The Journal of Physical Chemistry'', that it presented papers from a conference that was "merely the latest in a long sequence of ... conferences ... on theoretical chemistry spanning 3 decades ..." followed by a list that began with the Shelter Island conference. In 1996, Parr wrote "The fall of 1951 was an exciting time for quantum chemistry ... the Shelter Island Conference on Quantum-Mechanical Methods in Valence Theory ... was singularly important ... ".R.G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States National Academy Of Sciences
The National Academy of Sciences (NAS) is a United States nonprofit, non-governmental organization. NAS is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of Engineering (NAE) and the National Academy of Medicine (NAM). As a national academy, new members of the organization are elected annually by current members, based on their distinguished and continuing achievements in original research. Election to the National Academy is one of the highest honors in the scientific field. Members of the National Academy of Sciences serve '' pro bono'' as "advisers to the nation" on science, engineering, and medicine. The group holds a congressional charter under Title 36 of the United States Code. Founded in 1863 as a result of an Act of Congress that was approved by Abraham Lincoln, the NAS is charged with "providing independent, objective advice to the nation on matters related to science and technology. ... to provide scie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robert Mulliken
Robert Sanderson Mulliken Note Longuet-Higgins' amusing title for reference B238 1965 on page 354 of this Biographical Memoir. The title should be "Selected papers of Robert S Mulliken." (June 7, 1896 – October 31, 1986) was an American physicist and chemist, primarily responsible for the early development of molecular orbital theory, i.e. the elaboration of the molecular orbital method of computing the structure of molecules. Mulliken received the Nobel Prize in Chemistry in 1966 and the Priestley Medal in 1983. Early years Robert Mulliken was born in Newburyport, Massachusetts. His father, Samuel Parsons Mulliken, was a professor of organic chemistry at the Massachusetts Institute of Technology. As a child, Robert Mulliken learned the name and botanical classification of plants and, in general, had an excellent, but selective, memory. For example, he learned German well enough to skip the course in scientific German in college, but could not remember the name of his hi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Recurrence Relation
In mathematics, a recurrence relation is an equation according to which the nth term of a sequence of numbers is equal to some combination of the previous terms. Often, only k previous terms of the sequence appear in the equation, for a parameter k that is independent of n; this number k is called the ''order'' of the relation. If the values of the first k numbers in the sequence have been given, the rest of the sequence can be calculated by repeatedly applying the equation. In ''linear recurrences'', the th term is equated to a linear function of the k previous terms. A famous example is the recurrence for the Fibonacci numbers, F_n=F_+F_ where the order k is two and the linear function merely adds the two previous terms. This example is a linear recurrence with constant coefficients, because the coefficients of the linear function (1 and 1) are constants that do not depend on n. For these recurrences, one can express the general term of the sequence as a closed-form expression o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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