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
Considering alcaligenes faecalis pencillin g acylase ( afpga ), which possesses the attractive characteristics for beta - lactam antibiotics conversions, the gene of pga was cloned into two expressing vector pkkfpga and psmlfpga. both the constructed plasmids psmlfpga and pkkfpga contained the pga gene, trc promoter and rrnb transcript terminator, differ in the replicon and antibotic marker, pkkfpga contained multicopy replicon ( cole 1 ) and ampicillin marker. while psmlfpga contained medium - copy replicon ( p15a ) and tetracycline marker
本文將糞產堿桿菌青霉素g
酰化酶（ afpga ）基因構建表達載體pkkfpga和psmlfpga ， pkkfpga和psmlfpga均含trc啟動子、青霉素g
酰化酶基因、 rrnb轉錄終止子，其中pkkfpga含有氨卞青霉素抗性基因和cole1高拷貝復制子；而psmlfpga含有四環素抗性基因和p15a中拷貝復制子。
Acylation activity of hydroxyl groups in methyl cholicate has been determined by the use of methacryloyl chloride, methacryloyl anhydride and methacrylic acid as the acylating agents
以甲基丙烯
酰氯、甲基丙烯酸酐和甲基丙烯酸作
酰化劑，研究了膽酸甲酯分子中羥基的反應活性。
Localizaton of activity of immobilized penicillin gacylase by x - ray microanalysis
酰化酶活性的定位
In this text, the developments of hydroformylation of methyl oleate and oleyl alcohol, as well as the reactions and applications of its final products were reviewed
本文綜述了對
化學工業具有潛在經濟價值的油酸甲酯和油醇的氫甲
酰化反應的進展，並介紹了反應產物的應用前景。
These issues are essential to the understanding of the nature of cell cycle control, and to elucidating the roles of the histone acetylation modification in cell cycle regulation in eukaryotes. in this thesis, we studied the mechanisms of histone acetylation in cell cycle regulation in physarum polycephalum, a naturally synchronized slime mold. the results of this study confirmed that histone acetylation changed the expression of proteins related with the regulation of checkpoint conversion in cell cycle
初步確定了組蛋白乙
酰化在多頭絨泡菌細胞周期各轉換點的調控過程中對細胞周期調控相關蛋白表達水平的調節作用；了解了組蛋白乙
酰化修飾對細胞周期各轉換點調控的作用途徑；建立了組蛋白乙
酰化修飾對多頭絨泡菌細胞周期調控機制的基本模型。
They are acrylaldehyde hydration, ethylene oxide formylation and biological zymolysis methods
即丙烯醛水合法，環氧乙烷甲
酰化法，生物發酵法。
Methods cefsulodin was prepared, taking phenylacetic acid as the starting material, followed by sulfonation, resolution, acylation, amidation and substitution, in 5 steps totally
方法以苯乙酸為原料，經磺
化、拆分、
酰化、
酰胺
化和取代五步反應合成頭孢磺啶。
The major anthocyanins in purple sweet potato are cyanidin and peonidin acylated with aromatic acid
其花色苷的主要類型為芳香酸
酰化的矢車菊素和芍藥素。
Isolate and synthetic aroma chemicals. determination of primary or secondary alcohols content by acetylation
單離及合成香料伯醇或仲醇含量的測定乙
酰化法
Screening of methods for acylating - carrageenan with middle molecular weight
卡拉膠乙
酰化方法的篩選
The article is focused on the modification studies of chitosan ultrafiltrating compound membrane ( cs compound membrane ) on the basis of preceding researches. it includes adding cross - linking agent, modification agent, acylation agent in the casting membrane solution. the result shows that the new modification membrane are better in the phychemical properties and separation properties
本文是在前面研究的基礎上，著重進行了聚氨基葡糖復合超濾膜（簡稱cs復合膜）的改性研究.通過從交聯劑、改性劑、乙酰化試劑等方面的改性來尋求最佳的鑄膜液配方.結果表明，改性后的膜能達到較好的物化性能和分離性能
