chain substitution 中文意思是什麼
chain substitution
解釋
鏈上取代- chain : n 1 鏈子，鏈條；項圈；表鏈。2 連鎖；連續，一系列，一連串；（山）脈。3 〈常 pl 〉鐐銬；羈絆，拘束...
- substitution : n. 1. 代，代用，代替，更替，置換。2. 【化學】取代；【數學】代換；代入；【法律】預定繼承人；【語法】詞的代用。adj. -al ,-ary adj.
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Abstract : methanesulfonic acid method was used to prepare five acylated chitins. except heptanoyl chitin, four of them, i. e. acetyl chitin, propionyl chitin, butyryl chitin and hexanoyl chitin, had high degree of substitution ( from 1. 5 to 2. 0 ) and exhibited lyotropic liquid crystalline behavior and cholesteric phase. as the length of the side chain increased the critical concentration ( w / w ) somewhat increased from 0. 21 to 0. 26 because the chain rigidity dropped. the critical concentration values of all the four derivatives were much higher than that of chitin ( 0. 12 ) due to the decrease of intramolecular hydrogen bonds. the four acylated chitin can form typical banded texture after being sheared. there minimum concentrations to form banded texture of them were evidently different, varied from 0. 25 ( for acetyl chitin ) to 0. 37 ( for hexanoyl chitin ). these results further indicated that liquid crystallinity decreased while the length of flexible side substituents increased
文摘:四種羧酰化甲殼素即乙酰化、丙酰化、丁酰化和己酰化甲殼素在二氯乙酸溶液中均呈現膽甾型溶致液晶相.臨界濃度隨側基長度增加而略有增加，衍生物的臨界濃度明顯都比原甲殼素高許多，這些規律都可以用鏈剛性的變化來解釋.四種羧酰化甲殼素在剪切時均能形成條帶織構，而且能形成條帶織構的最低濃度有明顯差別，隨側基長度增加而提高，進一步表明側基較長，液晶性減少 -
All the subjects were genotyped by pcr - rflp ( polymerase chain reaction - restriction fragment length polymorphism ) at polymorphic sac i site inside the exon 7 of the ahsg gene. this polymorphism involves a nucleotide substitution of c to g at the middle nucleotide of the codon at amino acid position 238 resulting in the replacement of threonine ( acc ) with serine ( agc )
所有的樣本通過聚合酶鏈式反應?限制性片段長度多態性方法（ pcr - rflp ）對ahsg基因的第7個外顯子內的sac多態性位點進行基因分型，該多態性位點為238號氨基酸密碼子中間的堿基c到g的替換，使蘇氨酸（ thr ， acc ）變為絲氨酸（ ser ， agc ） 。
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