a. 两个轮子的, 二环的, 两圈的

[机] 二环的

[ adj ]
having molecules consisting of two fused rings
<adj.all>

Bicyclic \Bi*cyc"lic\, a.
Relating to bicycles.

Cyclic \Cyc"lic\ (s?k"l?k or s?"kl?k), Cyclical \Cyc"lic*al\
(s?k"l?-kal), a. [Cf. F. cycluque, Gr. kykliko`s, fr. ky`klos
See {Cycle}.]
1. Of or pertaining to a cycle or circle; moving in cycles;
as, cyclical time. --Coleridge.

2. (Chemistry) Having atoms bonded to form a ring structure.
Opposite of {acyclic}.

Note: Used most commonly in respect to organic compounds.

Note: [Narrower terms: {bicyclic}; {heterocyclic};
{homocyclic, isocyclic}]

Syn: closed-chain, closed-ring.
[WordNet 1.5]

3. Recurring in cycles[2]; having a pattern that repeats at
approximately equal intervals; periodic. Opposite of
{noncyclic}.

Note: [Narrower terms: {alternate(prenominal),
alternating(prenominal)}; {alternate(prenominal), every
other(prenominal), every second(prenominal)};
{alternating(prenominal), oscillating(prenominal)};
{biyearly}; {circadian exhibiting 24-hour
periodicity)}; {circular}; {daily, diurnal};
{fortnightly, biweekly}; {hourly}; {midweek,
midweekly}; {seasonal}; {semestral, semestrial};
{semiannual, biannual, biyearly}; {semiweekly,
biweekly}; {weekly}; {annual, yearly}; {biennial};
{bimonthly, bimestrial}; {half-hourly}; {half-yearly};
{monthly}; {tertian, alternate(prenominal)};
{triennial}]
[WordNet 1.5]

4. Marked by repeated cycles[2].
[WordNet 1.5]

{Cyclic chorus}, the chorus which performed the songs and
dances of the dithyrambic odes at Athens, dancing round
the altar of Bacchus in a circle.

{Cyclic poets}, certain epic poets who followed Homer, and
wrote merely on the Trojan war and its heroes; -- so
called because keeping within the circle of a single
subject. Also, any series or coterie of poets writing on
one subject. --Milman.