Showing papers by "Qiang Zhou published in 2000"
TL;DR: In this paper, a series of chiral smectic C phase shish-kebab type liquid crystal polymers was synthesized by low-temperature solution condensation polymerization from 2,5-bis[4-((S)-alkoxyl)benzoyloxy]hydroquinone and aliphatic diacylchloride.
Abstract: A series of chiral smectic C phase shish-kebab type liquid crystal polymers was synthesized by low-temperature solution condensation polymerization from 2,5-bis[4-((S)-alkoxyl)benzoyloxy]hydroquinone and aliphatic diacylchloride. The monomers and their precursors were identified by using elemental analysis, infrared spectrum, nuclear magnetic resonance and mass spectrometry. The polymers were characterized by gel permeation chromatography, differential scanning calorimetry, thermogravimetric analysis, temperature-variable X-ray diffraction, polarimeter and polarizing microscope (POM) with a heating stage. All the polymers entered into liquid crystal phase when heated to above their melting temperature. The Schlieren texture and sanded texture were observed on POM. All the chiral compounds and polymers showed high optical activity. Temperature-variable, X-ray diffraction study together with the POM and polarimetric analysis revealed that the polymers synthesized are chiral smectic C phase. Thus, the present report provides examples of shish-kebab type polymers that form a chiral smectic C phase. The change of the melting temperature and isotropization temperature with the variation in molecular structure was also discussed. Copyright © 2000 John Wiley & Sons, Ltd.
5 citations
TL;DR: Two automatic acquisition algorithms, the first acquired from a treebank, and the second acquired from raw texts, are introduced, and some experimental results which prove the availability of the algorithms are also given.
Abstract: In this paper, we propose a new ambiguity representation scheme; Structure Preference Relation (SPR), which consists of useful quantitative distribution information for ambiguous structures. Two automatic acquisition algorithms, the first acquired from a treebank, and the second acquired from raw texts, are introduced, and some experimental results which prove the availability of the algorithms are also given. Finally, we introduce some SPR applications in linguistics and natural language processing, such as preference-based parsing and the discovery of representative ambiguous structures, and propose some future research directions.
3 citations
31 Jul 2000
TL;DR: A shallow syntactic knowledge description: constituent boundary representation and its simple and efficient prediction algorithm, based on different local context templates learned from the annotated corpus, is proposed.
Abstract: In this paper, we proposed a shallow syntactic knowledge description: constituent boundary representation and its simple and efficient prediction algorithm, based on different local context templates learned from the annotated corpus. An open test on 2780 Chinese real text sentences showed the satisfying results: 94% (92%) precision for the words with multiple (single) boundary tag output.