摘要：Previous studies interpreting the meanings of the sentence-final particle“LE”displayed two trends:either excessively complicated or excessively *** some scholars established a theoretical foundation of propositional domain,epistemic domain and dialogic domain for the sentence-final particle“LE”,the nature or orientation of its semantic property has become more ***,there are also defects in the current“Three Domains”research *** the first place,this model defines the meanings of the sentence-final particle“LE”as“emergence of new propositional content”,“emergence of new epistemic content”,and“emergence of new dialogic content”.But,the definition is excessively abstract and *** many sentences not concluded with the particle“LE”can also express the three mentioned meanings,it fails to explain the difference between sentences ended with particle“LE”and ones without ***,the model fails to explore and discuss the nature or generation mechanism of relevant meanings of the particle“LE”.This study attempts to find a practical solution to those defects.

摘要：目的 :介绍四圈扩弓簧矫治器的原理、特点、改良设计及临床应用效果。方法 :结合典型病例介绍四圈扩弓簧的制作、戴入和调节以及改良设计。结果 :通过病例分析发现经 18个月的治疗 ,6宽度可扩大 9 6 5mm ,3宽度扩大 5 2 0mm ,6宽度扩大 3 6 0mm ,3宽度减少 0 45mm。结论 :四圈扩弓簧是一种性能良好 ,值得推广使用的扩弓矫治器。