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Isaac B. Bersuker
Isaac B. Bersuker (Russian: Исаáк Бóрухович (Бори́сович) Берсýкер; born February 12, 1928) is a Soviet- Moldоvan-American theoretical physicist and quantum chemist whose principal research is in chemical physics, solid-state physics, and theoretical chemistry. Known for his "life-long years of experience in theoretical chemistry" working on the electronic structure and properties of coordination compounds, Isaac B. Bersuker is “one of the most widely recognized authorities” in the theory of the Jahn–Teller effect (JTE) and the pseudo-Jahn–Teller effect (PJTE). His accomplishments include explaining the polarization of the atomic core in Rydberg atoms, the effect of tunneling splitting in molecules and solids with a strong JTE, and the discovery of the PJTE origin of ferroelectricity in cubic perovskites. Known as the leading expert in JTE and PJTE, Bersuker is the permanent chairman of the international steering committee of the Jahn–T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chișinău
Chișinău ( , , ), also known as Kishinev (russian: Кишинёв, r=Kishinjóv ), is the Capital city, capital and largest city of the Republic of Moldova. The city is Moldova's main industrial and commercial center, and is located in the middle of the country, on the river Bîc River, Bâc, a tributary of the Dniester. According to the results of the 2014 Moldovan census, 2014 census, the city proper had a population of 532,513, while the population of the Municipality of Chișinău (which includes the city itself and other nearby communities) was 700,000. Chișinău is the most economically prosperous locality in Moldova and its largest transportation hub. Nearly a third of Moldova's population lives in the metro area. Etymology The origin of the city's name is unclear. A theory suggests that the name may come from the archaism, archaic Romanian word ''chișla'' (meaning "spring", "source of water") and ''nouă'' ("new"), because it was built around a small spring, at the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudo Jahn–Teller Effect
The pseudo Jahn–Teller effect (PJTE), occasionally also known as second-order JTE, is a direct extension of the Jahn–Teller effect (JTE) where spontaneous symmetry breaking in polyatomic systems (molecules and solids) occurs even in nondegenerate electronic states under the influence of sufficiently low-lying excited states of appropriate symmetry. "The pseudo Jahn–Teller effect is the only source of instability and distortions of high-symmetry configurations of polyatomic systems in nondegenerate states, and it contributes significantly to the instability in degenerate states". History In their early 1957 paper on the (what is now called) pseudo Jahn–Teller effect (PJTE), Öpik and Pryce showed that a small splitting of the degenerate electronic term does not necessarily remove the instability and distortion of the polyatomic system induced by the Jahn–Teller effect (JTE), provided the splitting is sufficiently small (the two split states remain “pseudo degenerate” ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Physics
Chemical physics is a subdiscipline of chemistry and physics that investigates physicochemical phenomena using techniques from atomic and molecular physics and condensed matter physics; it is the branch of physics that studies chemical processes from the point of view of physics. While at the interface of physics and chemistry, chemical physics is distinct from physical chemistry in that it focuses more on the characteristic elements and theories of physics. Meanwhile, physical chemistry studies the physical nature of chemistry. Nonetheless, the distinction between the two fields is vague, and scientists often practice in both fields during the course of their research. The United States Department of Education defines chemical physics as "A program that focuses on the scientific study of structural phenomena combining the disciplines of physical chemistry and atomic/molecular physics. Includes instruction in heterogeneous structures, alignment and surface phenomena, quantum t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soviet Union
The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen national republics; in practice, both its government and its economy were highly centralized until its final years. It was a one-party state governed by the Communist Party of the Soviet Union, with the city of Moscow serving as its capital as well as that of its largest and most populous republic: the Russian SFSR. Other major cities included Leningrad (Russian SFSR), Kiev (Ukrainian SSR), Minsk ( Byelorussian SSR), Tashkent (Uzbek SSR), Alma-Ata (Kazakh SSR), and Novosibirsk (Russian SFSR). It was the largest country in the world, covering over and spanning eleven time zones. The country's roots lay in the October Revolution of 1917, when the Bolsheviks, under the leadership of Vladimir Lenin, overthrew the Russian Provisional Government ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Russian Patronymic
A patronymic, or patronym, is a component of a personal name based on the given name of one's father, grandfather (avonymic), or an earlier male ancestor. Patronymics are still in use, including mandatory use, in many countries worldwide, although their use has largely been replaced by or transformed into patronymic surnames. Examples of such transformations include common English surnames such as Johnson (son of John). Origins of terms The usual noun and adjective in English is ''patronymic'', but as a noun this exists in free variation alongside ''patronym''. The first part of the word ''patronym'' comes from Greek πατήρ ''patēr'' "father" (GEN πατρός ''patros'' whence the combining form πατρο- ''patro''-); the second part comes from Greek ὄνυμα ''onyma'', a variant form of ὄνομα ''onoma'' "name". In the form ''patronymic'', this stands with the addition of the suffix -ικός (''-ikos''), which was originally used to form adjectives with the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medal "Scientific Merit", I Class (Moldova) (2021)
A medal or medallion is a small portable artistic object, a thin disc, normally of metal, carrying a design, usually on both sides. They typically have a commemorative purpose of some kind, and many are presented as awards. They may be intended to be worn, suspended from clothing or jewellery in some way, although this has not always been the case. They may be struck like a coin by dies or die-cast in a mould. A medal may be awarded to a person or organisation as a form of recognition for sporting, military, scientific, cultural, academic, or various other achievements. Military awards and decorations are more precise terms for certain types of state decoration. Medals may also be created for sale to commemorate particular individuals or events, or as works of artistic expression in their own right. In the past, medals commissioned for an individual, typically with their portrait, were often used as a form of diplomatic or personal gift, with no sense of being an award f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Order Of Honour (Moldova)
The Order of Honour ( ro, Ordinul de Onoare) is a state order of the Republic of Moldova established by Parliament of Moldova in 2002, which is awarded by presidential decree. It is the fourth highest distinction of Moldova, after Order of the Republic, Order of Ştefan cel Mare, Order of Bogdan the Founder (''Ordinul Bogdan Întemeietorul''), and just before the Order of Loyalty to the Homeland (''Ordinul Credinţa Patriei''). The Order of Honour can be awarded also to organizations, institutions, etc.LEGEA Nr. 1123 din 30.07.1992 cu privire la distincțiile de stat ale Republicii Moldova Notable individual recipients (partial list) * |
Aroma Compound
An aroma compound, also known as an odorant, aroma, fragrance or flavoring, is a chemical compound that has a smell or odor. For an individual chemical or class of chemical compounds to impart a smell or fragrance, it must be sufficiently volatile for transmission via the air to the olfactory system in the upper part of the nose. As examples, various fragrant fruits have diverse aroma compounds, particularly strawberries which are commercially cultivated to have appealing aromas, and contain several hundred aroma compounds. Generally, molecules meeting this specification have molecular weights of less than 310. Flavors affect both the sense of taste and smell, whereas fragrances affect only smell. Flavors tend to be naturally occurring, and the term ''fragrances'' may also apply to synthetic compounds, such as those used in cosmetics. Aroma compounds can naturally be found in various foods, such as fruits and their peels, wine, spices, floral scent, perfumes, fragrance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drug Design
Drug design, often referred to as rational drug design or simply rational design, is the inventive process of finding new medications based on the knowledge of a biological target. The drug is most commonly an organic small molecule that activates or inhibits the function of a biomolecule such as a protein, which in turn results in a therapeutic benefit to the patient. In the most basic sense, drug design involves the design of molecules that are complementary in shape and charge to the biomolecular target with which they interact and therefore will bind to it. Drug design frequently but not necessarily relies on computer modeling techniques. This type of modeling is sometimes referred to as computer-aided drug design. Finally, drug design that relies on the knowledge of the three-dimensional structure of the biomolecular target is known as structure-based drug design. In addition to small molecules, biopharmaceuticals including peptides and especially therapeutic antibodies a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coordination Complexes
A coordination complex consists of a central atom or ion, which is usually metallic and is called the ''coordination centre'', and a surrounding array of bound molecules or ions, that are in turn known as ''ligands'' or complexing agents. Many metal-containing compounds, especially those that include transition metals (elements like titanium that belong to the Periodic Table's d-block), are coordination complexes. Nomenclature and terminology Coordination complexes are so pervasive that their structures and reactions are described in many ways, sometimes confusingly. The atom within a ligand that is bonded to the central metal atom or ion is called the donor atom. In a typical complex, a metal ion is bonded to several donor atoms, which can be the same or different. A polydentate (multiple bonded) ligand is a molecule or ion that bonds to the central atom through several of the ligand's atoms; ligands with 2, 3, 4 or even 6 bonds to the central atom are common. These comple ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quantum Chemistry
Quantum chemistry, also called molecular quantum mechanics, is a branch of physical chemistry focused on the application of quantum mechanics to chemical systems, particularly towards the quantum-mechanical calculation of electronic contributions to physical and chemical properties of Molecule, molecules, Material, materials, and solutions at the atomic level. These calculations include systematically applied approximations intended to make calculations computationally feasible while still capturing as much information about important contributions to the computed Wave function, wave functions as well as to observable properties such as structures, spectra, and thermodynamic properties. Quantum chemistry is also concerned with the computation of quantum effects on molecular dynamics and chemical kinetics. Chemists rely heavily on spectroscopy through which information regarding the Quantization (physics), quantization of energy on a molecular scale can be obtained. Common metho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rydberg Atoms
A Rydberg atom is an excited atom with one or more electrons that have a very high principal quantum number, ''n''. The higher the value of ''n'', the farther the electron is from the nucleus, on average. Rydberg atoms have a number of peculiar properties including an exaggerated response to electric and magnetic fields, long decay periods and electron wavefunctions that approximate, under some conditions, classical orbits of electrons about the nuclei. The core electrons shield the outer electron from the electric field of the nucleus such that, from a distance, the electric potential looks identical to that experienced by the electron in a hydrogen atom. In spite of its shortcomings, the Bohr model of the atom is useful in explaining these properties. Classically, an electron in a circular orbit of radius ''r'', about a hydrogen nucleus of charge +'' e'', obeys Newton's second law: : \mathbf=m\mathbf \Rightarrow = where ''k'' = 1/(4π ε0). Orbital momentum is quantiz ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
