Search results for "Zigzag"

Simulations on the mechanism of CNT bundle growth upon smooth and nanostructured Ni as well as θ-Al2O3 catalysts

2011

Abstract In the current study, we have performed ab initio DFT calculations on the gradually growing 2D periodic models of capped single-wall carbon nanotubes (SW CNTs) upon their perpendicular junctions with the Ni(111) substrate, in order to understand the peculiarities of the initial stage of their growth on either smooth or nanostructured catalytic particles. Appearance of the adsorbed carbon atoms upon the substrate follows from the dissociation of CVD hydrocarbon molecules, e.g., CH4: (CH4)ads → (CH)ads+3Hads and (CH)ads → Cads+Hads. (Since the effective growth of CNTs upon Ni nanoparticles occur inside the nanopores of amorphous alumina, we have also simulated analogous surface react…

Crystal structure of the chalcone (E)-3-(furan-2-yl)-1-phenylprop-2-en-1-one

2015

The crystal packing of the compound is described by an inter­molecular arrangement with the mol­ecules as inter­laced layers in a zigzag fashion, denoting inter­acting self-complementary dimers mainly by the localization of weak hydrogen bonds in a head-to-tail arrangement.

Methyl 3-(4-methoxyphenyl)prop-2-enoate

2001

The title molecule, C(11)H(12)O(3), is almost planar, with an average deviation of the C and O atoms from the least-squares plane of 0.146(4)A. The geometry about the C=C bond is trans. The phenyl ring and -COOCH(3) group are twisted with respect to the double bond by 9.3(3) and 5.6(5) degree, respectively. The endocyclic angle at the junction of the propenoate group and the phenyl ring is decreased from 120 degree by 2.6(2) degree, whereas two neighbouring angles around the ring are increased by 2.3(2) and 0.9(2) degree. This is probably associated with the charge-transfer interaction of the phenyl ring and -COOCH(3) group through the C=C double bond. The molecules are joined together thro…

(E)-1-(1,3-Benzodioxol-5-yl)-3-(2,4,5-trimethoxyphenyl)prop-2-en-1-one

2017

The molecule of the title compound C19H18O6, adopts anEconformation about the C=C double bond and the C—C=C—C torsion angle is −179.30 (16)°. The molecule is nearly planar, as indicated by the dihedral angle of 6.99 (6)° between the benzene ring and the benzodioxalane ring. In the crystal, molecules are linkedviaweak C—H...O hydrogen bonds, forming zigzag chains propagating along thebaxis.

Titelbild: Cyanide-Bridged Iron(III)–Cobalt(II) Double Zigzag Ferromagnetic Chains: Two New Molecular Magnetic Nanowires (Angew. Chem. 13/2003)

2003

Protective coloration of European vipers throughout the predation sequence

2020

Antipredator adaptations in the form of animal coloration are common and often multifunctional. European vipers (genus Vipera) have a characteristic dorsal zigzag pattern, which has been shown to serve as a warning signal to potential predators. At the same time, it has been suggested to decrease detection risk, and to cause a motion dazzle or flicker-fusion effect during movement. We tested these hypotheses by asking whether (1) the zigzag pattern decreases detection risk and (2) the detection is dependent on the base coloration (grey or brown) or the snake's posture (coiled, basking form or S-shaped, active form). Additionally, (3) we measured the fleeing speed of adders, Vipera berus, an…

Mechanics of invagination and folding: Hybridized instabilities when one soft tissue grows on another

2015

We address the folding induced by differential growth in soft layered solids via an elementary model that consists of a soft growing neo-Hookean elastic layer adhered to a deep elastic substrate. As the layer/substrate modulus ratio is varied from above unity towards zero we find a first transition from supercritical smooth folding followed by cusping of the valleys to direct subcritical cusped folding, then another to supercritical cusped folding. Beyond threshold the high amplitude fold spacing converges to about four layer thicknesses for many modulus ratios. In three dimensions the instability gives rise to a wide variety of morphologies, including almost degenerate zigzag and triple-ju…

N,N-Dicyclohexylnitramine

2016

Molecules of the title compound, C12H22N2O2, are composed of an nitramine group substituted by two cyclohexane rings. The cyclohexane rings have chair conformations, with the exocyclic C—N bonds in axial orientations. In the crystal, C—H...O hydrogen bonds connect the molecules intoC(6) [-101] zigzag chains.

3,4,5-Trimethoxy-4'-methylbiphenyl

2013

In the title compound, C16H18O3, the dihedral angle between the benzene rings is 33.4 (2)°. In the crystal, mol­ecules are packed in a zigzag arrangement along the b-axis and are inter­connected via weak C—H⋯O hydrogen bonds, and C—H⋯π inter­actions involving the meth­oxy groups and the benzene rings of neighbouring molecules.