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  2. Vibration of plates - Wikipedia

    en.wikipedia.org/wiki/Vibration_of_plates

    Vibration mode of a clamped square plate. The vibration of plates is a special case of the more general problem of mechanical vibrations.The equations governing the motion of plates are simpler than those for general three-dimensional objects because one of the dimensions of a plate is much smaller than the other two.

  3. Acyl group - Wikipedia

    en.wikipedia.org/wiki/Acyl_group

    Metal acyls also arise from reactions involving acyl chlorides with low-valence metal complexes or by the reaction of organolithium compounds with metal carbonyls. Metal acyls are often described by two resonance structures, one of which emphasizes the basicity of the oxygen center. O-alkylation of metal acyls gives Fischer carbene complexes. [10]

  4. Resonance (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Resonance_(chemistry)

    Contributing structures of the carbonate ion. In chemistry, resonance, also called mesomerism, is a way of describing bonding in certain molecules or polyatomic ions by the combination of several contributing structures (or forms, [1] also variously known as resonance structures or canonical structures) into a resonance hybrid (or hybrid structure) in valence bond theory.

  5. Chemical shift - Wikipedia

    en.wikipedia.org/wiki/Chemical_shift

    Chemical shift δ is usually expressed in parts per million (ppm) by frequency, because it is calculated from [5] =, where ν sample is the absolute resonance frequency of the sample, and ν ref is the absolute resonance frequency of a standard reference compound, measured in the same applied magnetic field B 0.

  6. Mesomeric effect - Wikipedia

    en.wikipedia.org/wiki/Mesomeric_effect

    In chemistry, the mesomeric effect (or resonance effect) is a property of substituents or functional groups in a chemical compound.It is defined as the polarity produced in the molecule by the interaction of two pi bonds or between a pi bond and lone pair of electrons present on an adjacent atom. [1]

  7. Impulse excitation technique - Wikipedia

    en.wikipedia.org/wiki/Impulse_excitation_technique

    In this expression, ε 1 and ε 2 are normal strains in the 1- and 2-direction and Υ 12 is the shear strain. σ 1 and σ 2 are the normal stresses and τ 12 is the shear stress. The orientation of the axes 1 and 2 in the above figure is arbitrary. This means that the values for E, G and v are the same in any material direction.

  8. Cyanate - Wikipedia

    en.wikipedia.org/wiki/Cyanate

    The cyanate ion can bridge between two metal atoms by using both its donor atoms. For example, this structure is found in the compound [Ni 2 (NCO) 2 2](BPh 4) 2. In this compound both the Ni−N−C unit and Ni−O−C unit are bent, even though in the first case donation is through the nitrogen atom. [16]

  9. Hydroxide - Wikipedia

    en.wikipedia.org/wiki/Hydroxide

    Ester hydrolysis under alkaline conditions (also known as base hydrolysis) R 1 C(O)OR 2 + OH − ⇌ R 1 CO(O)H + − OR 2 ⇌ R 1 CO 2 − + HOR 2. is an example of a hydroxide ion serving as a nucleophile. [52] Early methods for manufacturing soap treated triglycerides from animal fat (the ester) with lye.