The group-14 elements silicon, germanium, tin and lead form anionic homometallic clusters that have been studied since the nineteenth century. They also form clusters with transition metals, in a ...

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Technical drawing students and teachers were generally happy with the papers, but one question at higher level raised more than a few hackles. Pat O'Dwyer from Kenmare Vocational School, Co Kerry, ...

Pentagonal prism is the beam Angle (90 °), one of the steering gear.It has two purposes: one is that no matter how much the first incident Angle on the side is the emergent light incident light ...

Besides the regular and semiregular solids, there are just ninety-two other convex polyhedra with regular faces. In 1966, the American mathematician Norman W. Johnson, a student of H.S.M. Coxeter at ...

They say that no two snowflakes are the same, but like all natural ice crystals they are only variations on the same six-sided theme. Now physicists have found the first evidence of pentagonal ice ...