Ceramic membranes were used to recover nanometer nickel catalyst in the preparation of p-aminophenol.In order to resolve the problem of adsorption loss of nanometer nickel in the pilot plant, inert particles were adde...Ceramic membranes were used to recover nanometer nickel catalyst in the preparation of p-aminophenol.In order to resolve the problem of adsorption loss of nanometer nickel in the pilot plant, inert particles were added to the suspension. As a result, adding inert particles such as micro or submicro oxides was proven to be effective.They could alleviate the adsorption loss of nanometer nickel particles and shorten the time of reaching steady state of nickel concentration without affecting the activity of the catalyst and permeate flux.展开更多
针对γ-谷氨酰转肽酶（GGT）p H耐受性差的缺陷,首先以硅烷化改性的介孔氧化钛晶须（s MTw）为载体对重组枯草芽胞杆菌GGT进行固定化,再以p H 8.0-10.5的载体两性电解质Pharmalyte（CA,p H 8.0-10.5）对其进行后修饰,得到固定化酶s MTw-...针对γ-谷氨酰转肽酶（GGT）p H耐受性差的缺陷,首先以硅烷化改性的介孔氧化钛晶须（s MTw）为载体对重组枯草芽胞杆菌GGT进行固定化,再以p H 8.0-10.5的载体两性电解质Pharmalyte（CA,p H 8.0-10.5）对其进行后修饰,得到固定化酶s MTw-GGT-CA。结果发现：s MTw-GGT-CA的p H耐受性较游离酶明显提高,可在p H 6.0-11.0范围内保持稳定的催化活性。同时,s MTw-GGT-CA的热稳定性也较游离酶有所提高,其最适作用温度为50℃左右,热失活反应活化能Ed为49.88 k J/mol。s MTw-GGT-CA对γ-谷氨酰对硝基苯胺（Gp NA）的亲和力常数Km为0.579 mmol/L,与游离酶相近。展开更多
文摘Ceramic membranes were used to recover nanometer nickel catalyst in the preparation of p-aminophenol.In order to resolve the problem of adsorption loss of nanometer nickel in the pilot plant, inert particles were added to the suspension. As a result, adding inert particles such as micro or submicro oxides was proven to be effective.They could alleviate the adsorption loss of nanometer nickel particles and shorten the time of reaching steady state of nickel concentration without affecting the activity of the catalyst and permeate flux.
文摘针对γ-谷氨酰转肽酶（GGT）p H耐受性差的缺陷,首先以硅烷化改性的介孔氧化钛晶须（s MTw）为载体对重组枯草芽胞杆菌GGT进行固定化,再以p H 8.0-10.5的载体两性电解质Pharmalyte（CA,p H 8.0-10.5）对其进行后修饰,得到固定化酶s MTw-GGT-CA。结果发现：s MTw-GGT-CA的p H耐受性较游离酶明显提高,可在p H 6.0-11.0范围内保持稳定的催化活性。同时,s MTw-GGT-CA的热稳定性也较游离酶有所提高,其最适作用温度为50℃左右,热失活反应活化能Ed为49.88 k J/mol。s MTw-GGT-CA对γ-谷氨酰对硝基苯胺（Gp NA）的亲和力常数Km为0.579 mmol/L,与游离酶相近。
