环

• The feed reactants can be alkadienes, cycloalkadienes .
  所加的反应物可以是二烯烃，环二烯烃。
• The inner surface of the hoop has rubber grips or steel cleats .
  环的内侧有橡皮抓子或钢楔子。
• Cyclobutane exists predominantly in a "butterfly" conformation .
  环丁烷主要成“蝶式”构象存在。
• The two ends of the wire are connected to a split-ring commutator .
  导线的两端联接到裂环整流器。
• The rings are opened with hydrogen chloride and deuterium chloride .
  应用氯化氢和氯化氘打开沅环。
• Most control system fall in the "closed-loop" classification .
  大多数控制系统属于“闭环式”范畴。