证明了:1)P_κλ上存在一个半正规,弱选择,但不是λ-生成的理想.2)若 I 是一个λ^(<κ)-生成的,κ-完全的,弱选择的理想,则对每一个 A∈I^+,都存在 B∈P(A)∩I^+,使得 I|B=I_κλ|B;若 I 是一个λ^(<κ)-生成的,κ-完全的,弱选择...证明了:1)P_κλ上存在一个半正规,弱选择,但不是λ-生成的理想.2)若 I 是一个λ^(<κ)-生成的,κ-完全的,弱选择的理想,则对每一个 A∈I^+,都存在 B∈P(A)∩I^+,使得 I|B=I_κλ|B;若 I 是一个λ^(<κ)-生成的,κ-完全的,弱选择的正规理想,则对每个 A∈I^+,都存在μ<κ,使得 I|A 不是(μ,λ)-可分的.3)若 Q_κλ上存在一个精细,■κ正规理想,则 P_κλ上存在一个精细,具有■κ性质的理想.展开更多
Caffeic acid phenethyl ester(CAPE)is a rare,naturally occurring phenolic food additive.This work systematically reported fundamental data on conversion of caffeic acid(CA),yield of CAPE,and reactive selectivity during...Caffeic acid phenethyl ester(CAPE)is a rare,naturally occurring phenolic food additive.This work systematically reported fundamental data on conversion of caffeic acid(CA),yield of CAPE,and reactive selectivity during the lipase-catalyzed esterification process of CA and phenylethanol(PE)in ionic liquids(ILs).Sixteen ILs were selected as the reaction media,and the relative lipase-catalyzed synthesis properties of CAPE were measured in an effort to enhance the yield of CAPE with high selectivity.The results indicated that ILs containing weakly coordinating anions and cations with adequate alkyl chain length improved the synthesis of CAPE.[Emim][Tf2N]was selected as the optimal reaction media.The optimal parameters were as follows by response surface methodology(RSM):reaction temperature,84.0°C;mass ratio of Novozym 435 to CA,14︰1;and molar ratio of PE to CA,16︰1.The highest reactive selectivity of CAPE catalyzed by Novozym 435 in[Emim][Tf2N]reached 64.55%(CA conversion 98.76%and CAPE yield 63.75%,respectively).Thus,lipase-catalyzed esterification in ILs is a promising method suitable for CAPE production.展开更多
基金Supported by the Natural Science Foundation of Jiangsu Province（BK2009213） China Postdoctoral Science Foundation funded Project（2012M510124）+2 种基金 Qing Lan Project of Jiangsu Province,National Natural Science Foundation of China（21206061） Research Project of Jiangsu University of Science and Technology（35211002） Modern Agro-industry Technology Research System of China（CARS-22）
文摘Caffeic acid phenethyl ester(CAPE)is a rare,naturally occurring phenolic food additive.This work systematically reported fundamental data on conversion of caffeic acid(CA),yield of CAPE,and reactive selectivity during the lipase-catalyzed esterification process of CA and phenylethanol(PE)in ionic liquids(ILs).Sixteen ILs were selected as the reaction media,and the relative lipase-catalyzed synthesis properties of CAPE were measured in an effort to enhance the yield of CAPE with high selectivity.The results indicated that ILs containing weakly coordinating anions and cations with adequate alkyl chain length improved the synthesis of CAPE.[Emim][Tf2N]was selected as the optimal reaction media.The optimal parameters were as follows by response surface methodology(RSM):reaction temperature,84.0°C;mass ratio of Novozym 435 to CA,14︰1;and molar ratio of PE to CA,16︰1.The highest reactive selectivity of CAPE catalyzed by Novozym 435 in[Emim][Tf2N]reached 64.55%(CA conversion 98.76%and CAPE yield 63.75%,respectively).Thus,lipase-catalyzed esterification in ILs is a promising method suitable for CAPE production.
