Search results for " Structure"
showing 10 items of 25475 documents
structural organization of the internal core of metal containing reverse micelles
2008
Phytochemical investigation of the needles of Abies nebrodensis (Lojac.) Mattei
2019
Abies nebrodensis (Lojac.) Mattei (Pinaceae) is a species living in a very small population only in a confined area of Sicily. In this study, the dichloromethane extract of the leaves was analyzed. Apart from three already known metabolites namely dehydroabietic acid; maltol; and rheosmin, previously detected in other species of Abies, a lanostane derivative was isolated. Its chemical structure was elucidated by means of extensive spectroscopic methods.
Filmu recenziju žanra analīze
2015
Šī pētījuma mērķis ir izpētīt filmu recenzijas žanru, jo tas ir visizplatītākais žanrs, kas veltīts kino industrijas aktualitātēm. Filmu recenzijas žanra analīze ietver sevī gan žanra un žanra analīzes jēdzienu teorētisko pētījumu, gan profesionālās literatūras avotu izpēti, gan situācijas konteksta apskati. Lai noteiktu filmu recenzijas raksturīgo žanra struktūru un komunikatīvos mērķus, pētījuma empīriskajā daļā tiek lietota Speciālā lietojuma angļu valodas (English for Specific Purposes) žanra speciālistu izstrādātā retorisko soļu analīze un biežuma analīze. Papildus ir analizēti tipiskie leksiski gramatiskie valodas līdzekļi, kas tiek lietoti žanra komunikatīvo mērķu sasniegšanai. Pētīj…
The Nature of Transannular Interactions in E4N4 and E82+ (E = S, Se)
2012
The electronic structures of tetrachalcogen tetranitrides, E4N4, and octachalcogen dications, E82+, and the nature of their intramolecular E···E interactions (E = S, Se) was studied with high-level theoretical methods. The results reveal that the singlet ground states of both systems have a surprisingly large correlation contribution which functions to weaken and therefore lengthen the cross-ring E–E bond. The observed correlation effects are primarily static in E4N4, whereas in E82+ the dynamic part largely governs the total correlation contribution. The presented description of bonding is the first that gives an all-inclusive picture of the origin of cross-ring interactions in E4N4 and E8…
Numerical simulation of non-equilibrium sediment transport in a flume
2012
Towards a global view of dynamical systems, for the C1-topology.
2010
This paper suggests a program for getting a global view of the dynamics of diffeomorphisms, from the point of view of the C1-topology. More precisely, given any compact manifold M, one splits Diff1(M) in disjoint C1-open regions whose union is C1-dense, and conjectures state that these open set, and their complement, are characterized by the presence of • either a robust local phenomenon • or a global structure forbiding this local phenomenon. Other conjectures states that some of these regions are empty. This set of conjectures draws a global view of the dynamics, putting in evidence the coherence of the numerous recent results on C1-generic dynamics.
Co-crystals of an agrochemical active – A pyridine-amine synthon for a thioamide group
2011
Five novel co-crystals of thiophanate-ethyl (TE), an agrochemical active, with di(2-pyridyl)ketone (1), 2-benzoylpyridine (2), 3-benzoylpyridine (3), 4-phenylpyridine (4) and biphenyl (5) were found and crystal structures of four of them (TE1–TE3, TE5) solved by single crystal X-ray diffraction. Three of the co-crystals (TE1–TE3) form by way of a reliable pyridine-amine hydrogen bond synthon and one (TE5) because of close packing effects. The fifth co-crystal was identified by X-ray powder diffraction. The work demonstrates the usage of a reliable supramolecular synthon for crystal engineering, while concurrently reminds that the close packing of even very similar molecules cannot be fully …
N,N-Dimethyl-N-propylpropan-1-aminium chloride monohydrate
2008
The title compound, C8H20N+·Cl−·H2O, has been prepared by a simple one-pot synthesis route followed by anion exchange using resin. In the crystal structure, the cations are packed in such a way that channels exist parallel to the b axis. These channels are filled by the anions and water molecules, which interact via O—H...Cl hydrogen bonds [O...Cl = 3.285 (3) and 3.239 (3) Å] to form helical chains. The cations are involved in weak intermolecular C—H...Cl and C—H...O hydrogen bonds. The title compound is not isomorphous with the bromo or iodo analogues.
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.
3,5-Dimethoxy-4'-methylbiphenyl
2013
The title compound, C15H16O2, crystallizes with three independent molecules in the asymmetric unit. The intramolecular torsion angle between the aromatic rings of each molecule are −36.4 (3), 41.3 (3) and −37.8 (3)°. In the crystal, the complicated packing of the molecules forms wave-like layers along the b and c axes. The molecules are connected via extensive methoxy–phenyl C—H…π interactions. A weak C—H…O hydrogen-bonding network also exists between methoxy O atoms and aromatic or methoxy H atoms.