. The electronegativity of these bonds is 0.3 to 1.7 . A coordinatecovalentbond is one where both .... The strength of chemical bonds varies considerably there are strong bonds such as covalentbondcovalent or ionic bond s and weak bonds such as intermolecular force Dipole dipole interactions ... called covalentbondcovalentbond , one or more electrons often a pair of electrons are drawn into the space ... between spheres in models. In a polar covalentbond , one or more electrons are unequally shared ... N. Lewis developed the concept of the Covalentbond electron pair bond , in which two atoms may .... This molecular orbital theory represented a covalentbond as an orbital formed by combining ... in electronegativity leads to more polar ionic character in the bond. Covalentbond Main CovalentbondCovalent bonding is a common type of bonding, in which the electronegativity difference ... as covalent. See sigma bond s and pi bond s for LCAO description of such bonding. A polar covalentbond is a covalentbond with a significant ionic character. This means that the electrons are closer ... pointing to the Lewis acid. Also known as non polar covalentbond, the electronegativity of these bonds ... to the charge difference. Covalent bonds are better understood by valence bond theory or molecular ... electronegativity of the atoms involved. This type of bond is sometimes called polar covalentbond polar covalent . References Reflist External links W. Locke 1997 . http www.ch.ic.ac.uk vchemlib ...A chemical bond is an attraction between atom s that allows the formation of chemical substance s that contain two or more atoms. The bond is caused by the electromagnetic force attraction between opposite ... in the bond. However, this assembly cannot collapse to a size dictated by the volumes of these individual ... of chemical bonds A chemical bond is an attraction between atoms. This attraction may be seen as the result ... of the bond changes quantitatively , that it remains useful and customary to differentiate between ... more details
Unreferenced date December 2006 Astronomical coordinate systems are coordinate system s used in astronomy to describe the location of objects in the sky and in the universe. The most commonly occurring such systems are coordinate systems on the celestial sphere , but extragalactic coordinates systems are also important for describing more distant objects. Coordinate systems on the celestial sphere See Celestial coordinate system . Horizontal coordinate system Equatorial coordinate system based on Earth rotation Meridional coordinate system Ecliptic coordinate system based on Solar System rotation Galactic coordinate system based on Milky Way rotation Extragalactic coordinate systems See Extragalactic astronomy . supergalactic coordinate system based on plane of local supercluster of galaxy galaxies comoving coordinates valid to particle horizon DEFAULTSORT Astronomical Coordinate Systems Category Coordinate systems Category Celestial coordinate system Category Extragalactic astronomy Astronomy stub ... more details
Bond cleavage , or scission , is the splitting of chemical bond s. If the two electrons in a cleaved covalentbond are divided between the products, the process is known as homolytic fission or homolysis and free redicals are generated by homolytic cleavage. Alternatively, the case where both electrons are retained by one product and charged species that is nucleophile and electrophile are generated by the process is known as heterolytic fission and heterolysis . The term bond dissociation energy refers to the energy required to cleave a bond typically homolytically . In biochemistry the process of breaking down large molecules by splitting their internal bonds is catabolism . Enzymes which catalyse bond cleavage are known as lyase s, unless they operate by hydrolysis or oxidation reduction, in which case they are known as hydrolase s and oxidoreductase s respectively. Heterolytic cleavage main Heterolysis In heterolytic cleavage, or heterolysis, the bond breaks in such a fashion that the shared pair of electrons remain with one of the fragments. After heterolysis, one atom has a sextext electronic structure and a positive charge and other, a valence octet with at least one lone pair and a negative charge. Category Chemical bonding chem stub it Scissione chimica ... more details
In chemistry , bond energy E is the measure of bond strength in a chemical bond . It is the heat required to break one Mole unit of molecules into their individual atoms. Ref Frey For example, the carbon hydrogen bond energy in methane E C H is the enthalpy change involved with breaking up one molecule of methane into a carbon atom and 4 hydrogen Radical chemistry radical s divided by 4. br Bond energy E should not be confused with bond dissociation energy . br br Bond energy distance correlation Bond strength energy can be directly related to the bond length bond distance. Therefore, we can use the metallic radius , ionic radius , or covalent radius of each atom in the molecule to determine the bond strength. For example, the covalent radius of boron is estimated at 83.0 picometer pm , but the bond length of B B in B sub 2 sub Cl sub 4 sub is 175 pm, a significantly larger value. This would indicate that the bond between the two boron atoms is a rather weak single bond. In another example, the metallic radius of rhenium is 137.5 pm, with a Re Re bond length of 224 pm in the compound Re sub 2 sub Cl sub 8 sub . From this data, we can conclude that the bond is a very strong bond or a quadruple bond . This method of determination is most useful for covalently bonded compounds. Ref Alcock Factors affecting ionic bond energy There are several contributing factors but usually the most important is the difference in the electronegativity of the two atoms bonding together. Ref link See also Nuclear binding energy Electron binding energy Lattice energy References Note Frey Frey, Paul Reheard. http books.google.com books?id Jqy0AAAAIAAJ&q 22energy required to break an Avogadro 22&dq ... B BondEnergy.html Bond Energy. 11 July 2003. External links http www.wiredchemist.com chemistry data bond energies lengths.html Table of Bond Energies. http www.cem.msu.edu reusch OrgPage bndenrgy.htm Table of standard bond energies and bond dissociation energies. Category Chemical bond properties ... more details
Image Delta bond formation 2D.png thumb right 200px Formation of a delta bond by the overlap of two d orbitals File Dimolybdenum Mo2 delta bond Spartan HF 3 21G 3D side.png thumb right 200px 3D model of a boundary surface of a delta bond in Mo sub 2 sub In chemistry , delta bonds bonds are chemical bond s of the Covalentbondcovalent type, where four lobes of one involved atomic orbital orbital overlap overlap four lobes of the other involved atomic orbital. This overlap leads to the formation of a bonding molecular orbital with two nodal planes which contain the internuclear axis and go through both atoms. The Greek letter in their name refers to d orbital s, since the orbital symmetry of the delta bond is the same as that of the usual 4 lobed type of d orbital when seen down the bond axis. In chemistry , in sufficiently large atom s, occupied d orbital s are low enough in energy to participate in chemical bond bonding . Delta bonds are usually observed in organometallic species. Some ruthenium and molybdenum compounds contain a quadruple bond , consisting of one sigma bond , two pi bond s and one delta bond. The orbital symmetry of the delta bonding orbital is different from that of a Pi bond pi antibonding antibonding orbital , which has one nodal plane containing the internuclear axis and a second nodal plane perpendicular to this axis between the atoms. Theoretical chemists ... bond a U&minus U bond, in the molecule uranium U sub 2 sub . ref cite journal last Gagliardi first ... has a quintuple bond journal Nature year 2005 volume 433 pages 848 851 doi 10.1038 nature03249 url http archive ouverte.unige.ch unige 3652 ref File Phi bond f orbitals 2D.png 150px suitably aligned f orbitals could form a phi bond File Phi bond boundary surface diagram 2D.png 150px cartoon of a phi bond s boundary surface See also Molecular geometry References F. Albert Cotton F.A. Cotton and Geoffrey ... 124 references chemical bonds DEFAULTSORT Delta Bond Category Chemical bonding es Enlace fa ... more details
Expert subject Chemistry date November 2008 ICM stands for Internal Coordinate Mechanics and was first designed and built to predict low energy conformations of biomolecules. ICM also is a programming environment for various tasks in computational chemistry and computational structural biology, sequence analysis and rational drug design. The original goal was to develop algorithms for energy optimization of several biopolymers with respect to an arbitrary subset of internal coordinates such as bond lengths, bond angles torsion angles and phase angles. The efficient and general global optimization method which evolved from the original ICM method is still the central piece of the program. It is this basic algorithm which is used for peptide prediction, homology modeling and loop simulations, flexible macromolecular docking and energy refinement. However the complexity of problems related to structure prediction and analysis, as well as the desire for perfection, compactness and consistency, led to the program s expansion into neighboring areas such as graphics, chemistry, sequence analysis and database searches, mathematics, statistics and plotting. The original meaning became too narrow, but the name was kept. The current integrated ICM shell contains hundreds of variables, functions, commands, database and web tools, novel algorithms for structure prediction and analysis into a powerful, yet compact program which is still called ICM. The seven principal areas are centered around a general core of shell language and data analysis and visualization. See also ICM Browser References reflist Abagyan, R.A. and Totrov, M.M. Biased Probability Monte Carlo Conformational Searches and Electrostatic Calculations For Peptides and Proteins J. Mol. Biol., 235 , 983 1002, 1994 . PMID 8289329 Abagyan, R.A., Totrov, M.M., and Kuznetsov, D.A. ICM A New Method For Protein Modeling and Design ... Parallelization of The Energy, Surface and Derivative Calculations For internal Coordinate Mechanics ... more details
Image Electron orbitals.svg right thumb 350px Electron atomic and molecular orbitals, showing a pi bond at the bottom right of the picture. In chemistry , pi bonds bonds are covalentbondcovalent chemical bond s where two lobes of one involved atomic orbital overlap two lobes of the other involved ... atomic nucleus nuclei . Image Pi Bond.svg thumb left Two p orbitals forming a bond. The Greek letter in their name refers to p orbital s, since the orbital symmetry of the pi bond is the same as that of the p orbital when seen down the bond axis. P orbitals usually engage in this sort of bonding. D orbitals also engage in pi bonding, and form part of the basis for quintuple bond metal metal multiple bonding . Pi bonds are usually weaker than sigma bond s. From the perspective of quantum mechanics , this bond s weakness is explained by significantly less overlap between the component ... bond cannot rotate about that bond without breaking the pi bond, because rotation involves destroying ... of an additional nodal plane between these two bonded atoms. Multiple bonds A typical double bond consists of one sigma bond and one pi bond, for example the C C double bond in ethylene . A typical triple bond , for example in acetylene , consists of one sigma bond and two pi bonds in two mutually perpendicular planes containing the bond axis. Two pi bonds are the maximum that can exist between a given pair of atoms. Quadruple bond s are extremely rare and can be formed only between transition metal atoms, and consist of one sigma bond, two pi bonds and one delta bond . A pi bond is weaker than a sigma bond, but the combination of pi and sigma bond is stronger than either bond by itself. The enhanced strength of a multiple bond versus a single sigma bond is indicated in many ways, but most obviously by a contraction in bond lengths. For example in organic chemistry, carbon carbon bond ... the total bond shorter and stronger. align center class wikitable center File Ethane staggered CRC ... more details
A double bond in chemistry is a chemical bond between two chemical elements involving four bonding electron s instead of the usual two. The most common double bond, that between two carbon atoms, can be found in alkenes . Many types of double bonds between two different elements exist, for example in a carbonyl ... compound s N N , imines C N and sulfoxides S O . In skeletal formula the double bond is drawn as two ... JerryMarch ref ref Organic Chemistry 2nd Ed. John McMurry ref Double bonds are stronger than covalentbond single bonds and double bonds are also shorter. The bond order is two. Double bonds are also ... 2 sup orbitals overlap to form a sigma bond . At the same time, the two p orbitals approach again in the same plane and together they form a pi bond . For maximum overlap, the p orbitals have to remain parallel, and, therefore, rotation around the central bond is not possible. This property gives rise .... align center class wikitable Image Doppelbindung1.png 400px Double bond presentation Image Doppelbindung2.png 400px Double bond presentation 2 sp sup 2 sup orbitals total of 3 such orbitals approach to form a sp sup 2 sup sp sup 2 sup sigma bond Two p orbitals overlap to form a pi bond in a plane parallel to the sigma plane a covalentbond in which two electrons are shared between them. With 133 pm, the carbon&ndash carbon bond C C Use &minus , not &ndash , for a schematic single bondbond length is shorter than the C&minus C length in ethane with 154 pm. The double bond is also stronger, 636 Joule KJ mole unit mol versus 368 kJ mole but not twice as much as the pi bond is weaker than the sigma bond due to less effective pi overlap. In an alternative representation, the double bond results from two overlapping sp sup 3 sup orbitals as in a bent bond . ref Advanced Organic Chemistry ... with double bond rule elements of higher periods . Metals, too, can engage in multiple bonding in a metal ligand multiple bond . References Reflist doi 10.1002 chem.200401299 Chemical bonds Category Chemical ... more details
Refimprove date January 2010 Orphan date November 2009 In mathematics , a coordinate induced basis is a basis for the tangent space or cotangent space of a manifold that is induced by a certain coordinate system. Given the coordinate system math x a math , the coordinate induced basis math e a math of the tangent space is given by math e a frac partial partial x a math and the dual basis math omega a math of the cotangent space is math omega a dx a. , math References D.J. Hurley, M.A. Vandyck Topics in Differential Geometry a New Approach Using D Differentiation 2002 Springer p. 5 DEFAULTSORT Coordinate Induced Basis Category Differential geometry differential geometry stub ... more details
plane between these two bonded atoms. Sigma bonds are the strongest type of covalentbond s due ... atoms . See also Pi bond Delta bond Molecular geometry Covalentbond Ionic bond References reflist ...Unreferenced date February 2011 File Sigma bond.svg thumb right 250px bond between two atoms localization of electron density. In chemistry , sigma bonds bonds are the strongest type of covalentbondcovalent chemical bond . They are formed by head on overlapping between atomic orbitals. Sigma bonding is most clearly defined for diatomic molecules using the language and tools of symmetry group s. In this formal approach, a bond is symmetrical with respect to rotation about the bond axis. By this definition, common forms of sigma bonds are s s, p sub z sub p sub z sub , s p sub z sub and d sub z sup 2 sup sub d sub z sup 2 sup sub where z is defined as the axis of the bond . ref cite book last1 Clayden first1 Jonathan last2 Greeves first2 Nick last3 Warren first3 Stuart title Organic Chemistry url http www.amazon.co.uk Organic Chemistry Jonathan Clayden dp 0199270295 ref sr 1 1?ie UTF8&qid 1331750521&sr 8 1 edition 2nd year 2012 month March origyear 2002 publisher OUP Oxford location Oxford language English isbn 978 0199270293 pages 101 136 URL http www.amazon.co.uk Organic Chemistry ... viewed down the bond axis, a MO resembles an Electron configuration s atomic orbital . File ... bond of two s orbitals, a sigma bond of two p orbitals, and a Pi Bond Sigma bonds in polyatomic ..., one bond concept. Despite this complication, the concept of bonding is extremely powerful and therefore ... Kubas first Gregory title Metal Dihydrogen and Bond Complexes Structure, Theory, and Reactivity ... with pi bonds. According to the sigma bond rule , the number of sigma bonds in a molecule is equivalent ... one sigma bond, or ammonia , NH sub 3 sub , where there are only 3 sigma bonds , and that rings ... Sigma Bond Category Chemical bonding ar ca Enlla sigma es Enlace fa fr Liaison ... more details
The Practical Color Coordinate System PCCS is a discrete color space indexed by hue and tone color tone . It was developed by the Japan Color Research Institute . Color space Category Color space Color stub ... more details
coordinate systems, projected on the celestial sphere, showing the galactic equator black , north ... coordinate system is a coordinate system for mapping positions on the celestial sphere . There are different celestial coordinate systems each using a system of spherical coordinates projected on the celestial sphere , in analogy to the geographic coordinate system used on the surface of the Earth . ref cite web url http abyss.uoregon.edu js ast121 lectures lec03.html title Earth Coordinate ... 19 March 2011 ref The coordinate systems differ only in their choice of the fundamental plane spherical ... . Each coordinate system is named for its choice of fundamental plane. Coordinate systems The following table lists the standard coordinate systems in use by the astronomy community. The Fundamental ... in the geographic coordinate system GCS . The two points located 90 from the fundamental plane are termed the poles. The coordinate column gives the coordinate system s equivalents to the latitude and longitude in GCS, respectively. class wikitable Coordinate system ref cite web url http www.astro.virginia.edu class majewski astr551 lectures COORDS coords.html title Coordinate Systems last Majewski ... Poles Coordinates style text align center Horizontal coordinate system Horizontal br also called ... style text align center Equatorial coordinate system Equatorial celestial equator celestial pole s declination right ascension or hour angle style text align center Ecliptic coordinate system Ecliptic ... coordinate system Galactic galactic plane galactic pole s galactic latitude galactic longitude style text align center Supergalactic coordinate system Supergalactic supergalactic plane Supergalactic poles supergalactic latitude, supergalactic longitude Horizontal system Main Horizontal coordinate system ... varies with time, but is a useful coordinate system for locating and tracking objects for observers ... system Main Equatorial coordinate system The equatorial coordinate system is centered at Earth s center ... more details
Expand German Affine Koordinaten date February 2012 In mathematics , an affine coordinate system is a coordinate system on an affine space where each coordinate is an affine map to the number line . In other words, it is an injective affine map from an affine space mvar A to the coordinate space mvar k sup mvar n sup , where mvar k is the base field mathematics field , for example, the real numbers R . The most important case of affine coordinates in Euclidean spaces is real valued Cartesian coordinate system . Non orthogonal coordinate system orthogonal affine coordinates are referred to as oblique . A system of mvar n coordinates on mvar n dimensional space is defined by a mvar n 1 tuple math mvar O , mvar R sub 1 sub , mvar R sub mvar n sub of point mathematics points not belonging to any affine subspace of a lesser dimension. how is it called in English? In French it is fr Rep re math matiques Any given coordinate mvar n tuple gives the point by the formula math mvar x sub 1 sub , mvar x sub mvar n sub mvar O mvar x sub 1 sub mvar R sub 1 sub mvar O mvar x sub mvar n sub mvar R sub mvar n sub mvar O . Note that math mvar R sub mvar j sub mvar O are difference vector space vectors with the origin in mvar O and ends in mvar R sub mvar j sub . An affine space cannot have a coordinate system with mvar n less than its dimension mathematics dimension , but mvar n may indeed be greater, which means that the coordinate map is not necessary surjective. Examples of mvar n coordinate system in an mvar n 1 dimensional space are Barycentric coordinate system mathematics barycentric coordinates and affine homogeneous coordinates math 1, mvar x sub 1 sub , mvar x sub mvar n 1 sub . In the latter case the mvar x sub 0 sub coordinate is equal to 1 on all space, but this reserved coordinate facilitates matrix mathematics matrix representation of affine maps. Category Affine geometry Coordinates Category Coordinate systems de Affine Koordinaten hu Affin ... more details
The harmonic coordinate condition is one of several coordinate conditions in general relativity , which make it possible to solve the Einstein field equations . A coordinate system is said to satisfy the harmonic coordinate condition if each of the coordinate functions x sup sup regarded as scalar fields satisfies Wave equation d Alembert s equation . The parallel notion of a harmonic coordinate system in Riemannian geometry is a coordinate system whose coordinate functions satisfy Laplace s equation . Since Wave equation d Alembert s equation is the generalization of Laplace s equation to space time, its solutions are also called harmonic . Motivation The laws of physics can be expressed in a generally invariant form. In other words, the real world does not care about our coordinate systems. However, for us to be able to solve the equations, we must fix upon a particular coordinate system. A Coordinate conditions coordinate condition selects one or a smaller set of such coordinate system ... coordinate system is the closest approximation available in general relativity to an inertial ... . math Since the coordinate x sup sup is not actually a scalar, this is not a tensor equation. That is, it is not generally invariant. But coordinate conditions must not be generally invariant because they are supposed to pick out only work for certain coordinate systems and not others. Since the partial derivative of a coordinate is the Kronecker delta , we get math 0 delta alpha beta , gamma ... beta gamma g beta gamma . math And thus, dropping the minus sign, we get the harmonic coordinate ... with and applying the harmonic coordinate condition to the second term, we get math 0 g mu nu sqrt ... Gamma beta beta alpha sqrt g math Thus, we get that an alternative way of expressing the harmonic coordinate ... beta gamma g beta gamma . math Using the harmonic coordinate condition we can eliminate the right ... Harmonic Coordinate Condition Category Coordinate charts in general relativity ... more details
have some degree of covalentbond ing. Thus, an ionic bond is considered a bond where the ionic character is greater than the covalent character. The larger the difference in electronegativity between the two atoms involved in the bond, the more ionic polar the bond is. Bonds with partially ionic and partially covalent character are called polar covalentbond s. Ionic bonding is a form of noncovalent ... covalent bonding present . Note that this is not the ionic polarization effect which refers to displacement of ions in the lattice due to the application of an electric field. Comparison with covalent bonds In an ionic bond, the atoms are bound by attraction of opposite ions, whereas, in a covalentbond , atoms are bound by sharing electrons to attain stable electron configurations. In covalent bonding ... of the entities involved in the bond allows some degree of sharing electron density between them. Therefore, all ionic bonds have some covalent character. Thus, an ionic bond is considered a bond where the ionic character is greater than the covalent character. The larger the difference in electronegativity between the two atoms involved in the bond, the more ionic polar the bond is. Bonds with partially ionic and partially covalent character are called polar covalentbond s. For example ... to each other. An ionic bond is a type of chemical bond formed through an electrostatic attraction ... The formation of an ionic bond proceeds when the atom of an element usually metal , whose ionization ... bond. The removal of electrons from the cation is endothermic, raising the system s overall energy ... the bond. The low electronegativity of metals and high electronegativity of non metals means ... by many alkali metals alkali halides, and binary oxides such as magnesium oxide MgO . Bond strength ... covalent. Electrical conductivity main Electrolyte Ionic compounds, if molten or dissolved, can ... xTx DWboEVs Video on ionic bonding References reflist Chemical bonds DEFAULTSORT Ionic Bond Category ... more details
Image Descartes configuration.png thumb right Kinematic diagram of cartesian coordinate robot A cartesian coordinate robot also called linear robot is an industrial robot whose three principal axes of control are linear i.e. they move in a straight line rather than rotate and are at right angle s to each other. Among other advantages, this mechanical arrangement simplifies the Robot control arm solution . Cartesian coordinate robots with the horizontal member supported at both ends are sometimes called Gantry robots . They are often quite large. A popular application for this type of robot is a computer numerical control machine CNC machine . The simplest application is used in milling and drawing machines where a pen or router translates across an x y plane while a tool is raised and lowered onto a surface to create a precise design. Robotics DEFAULTSORT Cartesian Coordinate Robot Category Industrial robots Category Robot kinematics robo stub ar et Gantry robot el ja pt Rob de coordenadas cartesianas ... more details
Unreferenced stub auto yes date December 2009 Orphan date February 2009 In the manufacturing industry, with regard to CNC numerically controlled machine tools , the phrase machine coordinate system refers to the physical limits of the motion of the machine in each of its axes, and to the numerical coordinate which is assigned by the machine tool builder to each of these limits. CNC Machinery refers to machines and devices that are controlled by using programmed commands which are encoded on to a storage medium, and NC refers to the automation of machine tools that are operated by abstract commands programmed and encoded onto a storage medium. http www.machiningpartner.com machining news cnc machinery CNC Machinery DEFAULTSORT Machine Coordinate System Manufacturing stub Category Manufacturing ... more details
II References reflist See also CovalentbondBond order Quintuple bond Sextuple bond chemical ...A quadruple bond is a type of chemical bond between two atom s involving eight electron s. This bond is an extension of the more familiar types double bond s and triple bond s. ref To Boldly Pass the Metal Metal Quadruple Bond Radius, U. Breher, F. Angewandte Chemie International Edition 2006, Volume 45, Issue 19 , Pages 3006 3010 http dx.doi.org 10.1002 anie.200504322 Abstract ref Stable quadruple bonds are most common among the middle members transition metal elements such rhenium , tungsten , molybdenum and chromium . Typically the ligands that support quadruple bonds are donors, not acceptors. Image Octachlorodirhenate III 3D balls.png thumb right 150px The octachlorodirhenate III anion, Re sub 2 sub Cl sub 8 sub sup 2 sup , which features a quadruple Re Re bond Chromium II acetate , Cr sub 2 sub O sub 2 sub CMe sub 4 sub H sub 2 sub O sub 2 sub , was the first chemical compound containing a quadruple bond to be synthesized. It was described in 1844 by E. Peligot , although its distinctive bonding was not recognized for more than a century. ref Cotton, F. A. Walton, R. A. Multiple Bonds Between Metal Atoms Oxford Oxford 1993. ISBN 0 19 855649 7. ref The quadruple bond was first .... 1965, 4 3 , 330 333. ref The rhenium rhenium bond length in this compound is only 224 pm. In the terminology ... sup 2 sup with one sigma bond , two pi bond s and one delta bond . The strength of the delta bond is a matter of debate. The bond order for the Re sub 2 sub Cl sub 8 sub sup 2 sup is calculated to be 3.2 ... Valley, CA, 1999. ref An example of a ditungsten compound with a quadruple bond is di tungsten tetra hpp . Valence bond theory predicts a quadruple bond as the only way to satisfy the octet rule for carbon ... pi bonding set of orbitals. This adds up to give a bond order of 2, meaning that there exists a double bond between the two carbons in a C sub 2 sub molecule. This is surprising because the MO diagram ... more details
The State Plane Coordinate System SPS or SPCS is a set of 124 geographic zones or coordinate system s designed for specific regions of the United States. Each state contains one or more state plane zones, the boundaries of which usually follow county lines. There are 110 zones in the continental US, with 10 more in Alaska, 5 in Hawaii, and one for Puerto Rico and US Virgin Islands. The system is widely ... factors. First, it uses a simple Cartesian coordinate system to specify locations rather than a more complex spherical coordinate system the geographic coordinate system of latitude and longitude . By thus .... History The state plane coordinate system came into being during the 1930s. It has been revised several ... tasks being demanded of computers have also increased. Thus the state plane coordinate system is still useful. Originally, the state plane coordinate systems were based on the North American Datum ... a geodetic datum is the way a coordinate system is linked to the physical Earth . More recently there has .... Thus a fully described coordinate system often looks something like Washington State Plane North, NAD83 ... coordinate system to another. Problems The main problem with the state plane coordinate system is that each zone uses a different coordinate system. This is not a major problem as long as one s needs .... However, the need to transform spatial data from one coordinate system to another can be burdensome ... State Plane North coordinate system, while Pierce County, Washington Pierce County , which ... data into a common coordinate system. See also Public Land Survey System Universal Transverse Mercator coordinate system External links http www.ngs.noaa.gov National Geodetic Survey NGS http www.ngs.noaa.gov PUBS LIB ManualNOSNGS5.pdf State Plane Coordinate System 1983 http www.vterrain.org Projections spcs.html The State Plane Coordinate System, at vterrain.org http www.earthpoint.us StatePlane.aspx Convert State Plane Coordinates Category Cartography Category Geographic coordinate systems Category ... more details
Image isopeptide.gif thumb 200px Figure 1 Locations of the epsilon Nitrogen, isopeptide bond, and peptide bond. An isopeptide bond is an amide bond that is not present on the main chain of a protein. The bond forms between the carboxyl terminus of one protein and the amino group of a lysine residue on another target protein. ref Berg, Tymoczko, & Stryer Biochemistry 6th edition 2007 ref ref Lodish et al., Molecular Cell Biology 2008 ref Isopeptide bonds can occur between the side chain amine of lysine and the side chain carboxyl groups of either glutamate or aspartate. ref Stryer, Lubert. Biochemistry 4th Edition, 942 943 1995 ref Bond formation can be either enzyme catalyzed, as in the case for the bond formed between lysine and glutamine catalyzed by transglutaminases , or it can form spontaneously as observed in HK97 bacteriophage capsid formation ref Wikoff, W. R. et al. Topologically linked protein rings in the bacteriophage HK97 capsid. Science 289, 2129 2133 2000 . ref and Gram positive bacterial pili. ref Kang, H. J., Coulibaly, F., Clow, F., Proft, T. & Baker, E. N. Stabilizing ... . ref Spontaneous isopeptide bond formation requires the presence of another residue, glutamic acid, which catalyzes bond formation in a proximity induced manner. An example of a small peptide containing an isopeptide bond is glutathione, which has a bond between the side chain of a glutamate residue ... is ubiquitin, which gets attached to other proteins with a bond between the C terminal glycine residue ... have exploited spontaneous isopeptide bond formation to develop a new peptide tag called the isopeptag . The isopeptag can spontaneously and irreversibly react with its binding partner through a covalent isopeptide bond. Application for this exciting new molecular tool include in vivo protein targeting ... biology. ref Zakeri,B. and Howarth,M. 2010 . Spontaneous intermolecular amide bond formation between ... Chemistry Biochemistry Protein primary structure References reflist DEFAULTSORT Isopeptide Bond ... more details
Supergalactic coordinates are coordinates in a spherical coordinate system which was designed to have its equator aligned with the supergalactic plane , a major structure in the local universe formed by the preferential distribution of nearby galaxy cluster s such as the Virgo cluster , the Great Attractor and the Pisces Perseus supercluster towards a two dimensional plane mathematics plane . The supergalactic plane was recognized by G rard de Vaucouleurs in 1953 from the Shapley Ames catalogue , although a flattened distribution of nebula e had been noted by William Herschel over 200 years earlier. By convention, supergalactic latitude and supergalactic longitude are usually denoted by SGB and SGL, respectively, by analogy to b and l conventionally used for galactic coordinates . The zero point for supergalactic longitude is defined by the intersection of this plane with the galactic plane. Definition The north supergalactic pole SGB 90 lies at galactic coordinates l 47.37 , b 6.32 . In the equatorial coordinate system epoch astronomy epoch J2000 , this is approximately right ascension RA 18.9 h, declination Dec 15.7 . The zero point SGB 0 , SGL 0 lies at l 137.37 , b 0 . In J2000 equatorial coordinates, this is approximately 2.82 h, 59.5 . See also Coordinate system Celestial coordinate system External references http cdsads.u strasbg.fr cgi bin nph data query?bibcode 2000MNRAS.312..166L&db key AST&link type ARTICLE Precise definition by Lahav et al. 2000, MNRAS, 312, 166 Celestial coordinate systems Category Celestial coordinate system Category Extragalactic astronomy de Supergalaktisches Koordinatensystem ja pl Uk ad wsp rz dnych supergalaktycznych sl Supergalakti ni koordinatni sistem tl Sistemang supergalaktikal ng mga koordinato zh ... more details
Randomized Block Coordinate Descent Method is an optimization algorithm popularized by Nesterov 2010 and Richt rik and Tak 2011 . The first analysis of this method, when applied to the problem of minimizing a smooth convex function, was performed by Nesterov 2010 ref Citation last Nesterov first Yurii year 2010 title Efficiency of coordinate descent methods on huge scale optimization problems periodical CORE Discussion Paper number 2010 2 ref . In Nesterov s analysis the method needs to be applied to a quadratic perturbation of the original function with an unknown scaling factor. Richt rik and Tak 2011 give iteration complexity bounds which do not require this, i.e., the method is applied to the objective function directly. Furthermore, they generalize the setting to the problem of minimizing a composite function, i.e., sum of a smooth convex and a possibly nonsmooth convex block separable function math F x f x Psi x , math where math Psi x sum i 1 n Psi i x i , math math x in R N ... is coordinate wise Lipschitz continuous, with constants math L i, i 1,2, dots, n math i.e. math nabla ... algorithm begin name Random Coordinate Descent Method Input math x 0 in R n math starting point Output math x math set x x 0 for k 1,... do choose random coordinate math i in 1,2, dots,n math update ... online.org DB HTML 2011 07 3089.html title Iteration complexity of randomized block coordinate descent ... here Extension to Block Coordinate Setting File BlockStructure.jpg thumb Blocking coordinate directions into Block coordinate directions One can naturally extend this algorithm not only just to coordinates, but to blocks of coordinates. Assume that we have space math R 5 math . This space has 5 coordinate ... T, e 5 0,0,0,0,1 T math in which Random Coordinate Descent Method can move. However, one can group some coordinate directions into blocks and we can have instead of those 5 coordinate directions 3 block coordinate directions see image . See also Coordinate descent Gradient descent Mathematical optimization ... more details
The Swiss coordinate system or Swiss grid is a geographic coordinate system used in Switzerland for maps and surveying by the Swiss Federal Office of Topography Swisstopo . The map projection used is Oblique Mercator on an 1841 Bessel ellipsoid . The datum geodesy geodetic datum CH1903 uses as fundamental point the old observatory of Bern coord 46 57 03.9 N 7 26 19.1 E type landmark region CH WGS84 , the current location of the Institut f r exakte Wissenschaften of the University of Bern . In order to avoid errors during coordinate transmissions, the coordinates of this point are 600 000 m E 200 000 m N. The 0 0 coordinate is located near Bordeaux , France . This definition invokes the following effects All coordinates are always positive, since Switzerland is located in the 1st Cartesian coordinate system quadrant of the coordinate system. Furthermore, the whole area of Switzerland is located below the y x line of the coordinate system. Thus, all E coordinates are always bigger than N coordinates. Devised for the national land survey of 1995 LV 95 for Landesvermessung 1995 , the CH1903 datum is based on World Geodetic System WGS84 . The coordinates of its new reference point, the Zimmerwald Observatory , should maintain the CH1903 coordinates as far as possible. The easting and northing is increased by 2 and 1 million, respectively. table border align right caption Coordinates of the Zimmerwald observatory in the old and new notations caption tr align right th CH1903 td y 602 030.68 m td x 191 775.03 m tr align right th CH1903 td E 2 602 030.74 m td N 1 191 775.03 m table See also Swiss cartography External links Swisstopo http www.swisstopo.admin.ch internet swisstopo en home topics survey sys refsys projections.html Swiss map projections http www.webcitation.org query?url http www.geocities.com CapeCanaveral 1224 prj ch ch.html&date 2009 10 25 06 31 30 Map ... Category Geographic coordinate systems Switzerland geo stub als Schweizer Landeskoordinaten ... more details
Orphan date January 2008 The perifocal frame is the two dimensional frame of reference for an orbit . It is centered at the focus of the orbit, i.e. the planet about which the orbit is centered. Its plane is given the coordinate s p and q , where the p axis is directed toward the periapsis of the elliptical orbit in the direction of the eccentricity vector . The third dimension of this orbit, w , is composed of the Normalized vector normalized angular momentum vector, which is the radius vector Dot product crossed with the velocity vector. See also Celestial coordinate system Polar distance astronomy Geocentric coordinates Heliocentric orbit References Bate. Fundamentals of astrodynamics Category Orbits physics stub ... more details
About chemistry Image Coulson Moffit Model.png 200px thumb right One of the first bent bond theories for cyclopropane was the so called Coulson Moffitt model 1947 . Bent bond , also known as banana bond , is a term in organic chemistry that refers to a type of covalentbondcovalent chemical bond with a geometry ... different explanations for the nature of double and triple covalentbond s in organic compound organic molecules were proposed in the 1930s. Linus Pauling proposed that the double bond results from two ... that is an alternative to the sigma and pi bond model. Small cyclic molecules File Bananenbindung ... citation last1 Klessinger first1 Martin title Triple Bond in N sub 2 sub and CO journal J. Chem ... type of chemical bond ing in which the ordinary orbital hybridization hybridization state of two atoms making up a chemical bond are modified with increased or decreased s orbital character in order ... atoms to assume the 109.5 bond angle s with standard sp sup 3 sup hybridization. Increasing the p character makes it possible to reduce the bond angles to 60 . At the same time the carbon to hydrogen ... carbon atoms does not correspond to the internuclear axis hence the name bent bond . In cyclopropane ... carbons. The carbon carbon bond length s are unusually short 151 picometer pm versus 154 pm for a regular bond. Cyclobutane is a larger ring but still has bent bonds. In this molecule the carbon bond ... bond lengths actually increase and not decrease and this is mainly due to 1,3 nonbonded steric repulsions ... models For cyclopropane, the bent bond model continues to have support despite the emergence ... of the chemical bond. Application of results obtained from the quantum mechanics and from a theory ... . ref Erich H ckel proposed a representation of the double bond as a combination of a sigma bond plus a pi bond . ref citation last H ckel first E. authorlink Erich H ckel journal Z. Phys. year 1930 ... bond descriptions of ethylene to be equivalent. ref name wiberg Ian Fleming chemist Ian Fleming ... more details
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