For example, a cubic system was constructed by Lloyd and Pearson  to show 9 limit cycles with the aid of purely symbolic computation.
Huang, "A cubic system with twelve small amplitude limit cycles," Bull.
The number 9 in problem I) is the maximum number of invariant straight lines which a non-degenerate cubic system could have.
Thus while quadratic systems with a center are integrable and have no limit cycles, in cubic systems centers could coexist with limit cycles.
Then she illustrates seven specific crystal systems with examples, among them a monocline system with sucrose, an orthorhombic system with polyethylene, a hexagonal system with magnesium, and a cubic system
1b), which had a perovskite structure (d = 2,70; 1,91; 1,57 [Angstrom]), which crystallizes in cubic system
with the unit cell parameter 3,905[Angstrom].
Average size of crystallite Phase (hkl) D (nm) Average size Al cubic system
, (111) 64.3 of crystallite the major phase (200) 61.0 for the Al, Si (220) 38.6 and SiC phases (311) 41.0 Si (111) 76.0 cubic system
, the (220) 49.3 minority phase (311) 34.8 SiC (101) 84.9 Hexagonal system, (006) 174.0 the minority phase Tab.
Known as COUGAR, for Combined Operations Unmanned Ground Assessment Robot, the Cubic system
packs a bundle of advanced audio, video and anti-explosive electronics into a compact ruggedized frame, officials said.
Herein singularities in the cubic system
will be discussed.
In addition to the ultrathin coating, the Nano Cubic system
incorporates two types of extremely fine magnetic particles: acicular ferromagnetic alloy particles and tabular ferromagnetic hexagonal barium ferrite particles.