Definition: Birefringence,or double refraction,is the decomposition of a ray of light (andother electromagnetic radiation) into two rays (the ordinary ray and the extraordinary ray)when it passes through certain types of material,such as calcite crystals ...[继续阅读]

    Definition: (Crystallography) the line which bisects the angle of the optic axes of a crystal等分线děng fēn xiànExample:The paper analyzes the algorithm of building linear buffer zone by angular bisectrix method,then puts forward a new method for getting ang...[继续阅读]

    Definition: This unit cell can be thought as made by stuffing another atom into the center ofthe simple cubic lattice,slightly spreading the corners. Thus,the corner spheres no longer quitetouch one another,but do touch the center. The diagonal through th...[继续阅读]

    Definition: (Chemistry) Bond energy (E) is a measure of bond strength in a chemical bond.It is the heat required to break Avogadro’s number of molecules into their individual atoms. Forexample,the carbon-hydrogen bond energy in methane E (C-H) is the enth...[继续阅读]

    Definition: (Molecular geometry)Bond length or bond distance is the average distancebetween nuclei of two bonded atoms in a molecule. Bond length is related to bond order,whenmore electrons participate in bond formation,the bond will get shorter. Bond len...[继续阅读]

    Definition: (Chemistry) Bond strength is measured between two atoms joined in a chemicalbond. It is the degree to which each atom linked to another atom contributes to the valency ofthis other atom. Bond strength is intimately linked to bond order. Bond s...[继续阅读]

    Definition: The irregular transmission of X-rays when a single crystal of high perfection isplaced in a monochromatic X-ray beam in a reflecting position.博曼效应bó màn xiào yìngOrigin: The Borrmann effect was first discovered in quartz (Borrmann G., 1941,...[继续阅读]

    Definition: The angle between an incident X-ray beam and a set of crystal planes for whichthe secondary radiation displays maximum intensity as a result of constructive interference.布拉格角bù lā gé jiǎoOrigin: named after Sir William Henry Bragg and Sir Will...[继续阅读]

    Definition: relates the angles at which X-rays are scattered from a crystal to the spacingbetween the layers of molecules布拉格方程bù lā gé fāng chéngOrigin:This is the equation derived by William H. Bragg and his son William L. Bragg to explain thescattering ...[继续阅读]

    Definition: The R-factor measuring the agreement between the reflection intensitiescalculated from a crystallographic model and those measured experimentally. RB＝(∑|Iobs-Icalc|)/(∑|Iobs|).In the Rietveld method RB is useful because it depends on the fit o...[继续阅读]