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异构酸对反刍家畜的营养作用 被引量:1
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作者 董德宽 《国外畜牧科技》 1992年第2期19-21,共3页
在牛羊等反刍动物的消化过程中,微生物起着特别重要的作用。瘤胃微生物发酵一昼夜产生的挥发性脂肪酸(VFA)可为畜体提供所需代谢能的60%~80%。所以瘤胃内正常菌群的旺盛繁衍是保证反刍家畜健康和高产的重要前提之一。早在50年代。
关键词 家畜 反刍动物 营养 异构酸
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关于异构酸添加剂
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作者 董德宽 《饲料世界》 1990年第5期34-35,29,共3页
关键词 饲料添加剂 异构酸添加剂
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异构酸对奶牛和肉牛的效果
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作者 朱钦龙 《上海奶牛》 1991年第4期37-38,共2页
关键词 奶牛 肉牛 异构酸 生产性能
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奶牛营养的异构酸
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作者 朱钦龙 《上海奶牛》 1991年第4期36-37,共2页
关键词 奶牛 营养 异构酸
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异构酸饲料添加剂在乳牛上的应用与研究
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作者 刘兴义 《食品.饲料添加剂信息》 1992年第5期6-8,共3页
关键词 异构酸 饲料添加剂 乳牛 应用
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影响酒花α-酸异构化的因素 被引量:3
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作者 王志坚 《酿酒科技》 2003年第4期75-76,共2页
α-酸是啤酒酒花的主要成分,也是啤酒苦味的主要物质,啤酒中的α-酸异构物可提高啤酒的泡沫稳定性,提高啤酒质量。影响α-酸异构化的因素有:煮沸时间、煮沸方法、煮沸温度、煮沸压力、酒花添加量及酒花品种、煮沸时含氧量、煮沸pH值、... α-酸是啤酒酒花的主要成分,也是啤酒苦味的主要物质,啤酒中的α-酸异构物可提高啤酒的泡沫稳定性,提高啤酒质量。影响α-酸异构化的因素有:煮沸时间、煮沸方法、煮沸温度、煮沸压力、酒花添加量及酒花品种、煮沸时含氧量、煮沸pH值、麦汁浊度和添加的辅料物质。(孙悟) 展开更多
关键词 酒花 Α- α-异构 影响因素 啤酒苦味物质 泡沫稳定性
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单体酸混合物成分的GC-MS分析 被引量:8
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作者 叶爱英 张培培 +1 位作者 邵飞鹰 姚成 《南京工业大学学报(自然科学版)》 CAS 2006年第3期76-78,共3页
研究了生产二聚酸时得到的副产品单体酸的化学组成的GC MS分析方法,样品首先用质量浓度为140g/L KOH M eOH进行甲酯化,然后用GC MS进行分析和鉴定,共鉴定出棕榈酸、肉豆蔻酸、10甲基月桂酸、12甲基十四烷酸、十八烯酸等13种物质,总脂肪... 研究了生产二聚酸时得到的副产品单体酸的化学组成的GC MS分析方法,样品首先用质量浓度为140g/L KOH M eOH进行甲酯化,然后用GC MS进行分析和鉴定,共鉴定出棕榈酸、肉豆蔻酸、10甲基月桂酸、12甲基十四烷酸、十八烯酸等13种物质,总脂肪酸的质量分数占76.71%,其中饱和酸占66.36%,不饱和酸占10.35%,其中直链酸占饱和脂肪酸的41.02%,支链酸即异构酸占饱和脂肪酸的58.98%。 展开更多
关键词 单体 脂肪 气相色谱-质谱 异构酸
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啤酒添加剂四氢异构α酸的一步制备法
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作者 胡承 《四川食品工业科技》 1993年第4期16-18,共3页
关键词 啤酒添加剂 四氢异构α
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黄色短杆菌ilvN基因定点突变和ilvBN、ilvC串联表达对L-缬氨酸产量的影响 被引量:1
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作者 曾邦定 黄钦耿 +4 位作者 梁玲 郭小雷 王明兹 施巧琴 吴松刚 《化工学报》 EI CAS CSCD 北大核心 2016年第7期2956-2962,共7页
由ilv BN、ilv C基因编码的乙酰羟酸合成酶(AHAS)和乙酰羟酸异构还原酶(AHAIR)是L-缬氨酸合成途径的两个关键酶。本实验以黄色短杆菌Brevibacterium flavum MD515为出发菌株,通过PCR技术扩增其ilv BN和ilv C基因,对调节亚基ilv N进行定... 由ilv BN、ilv C基因编码的乙酰羟酸合成酶(AHAS)和乙酰羟酸异构还原酶(AHAIR)是L-缬氨酸合成途径的两个关键酶。本实验以黄色短杆菌Brevibacterium flavum MD515为出发菌株,通过PCR技术扩增其ilv BN和ilv C基因,对调节亚基ilv N进行定点突变,获得抗反馈抑制突变型编码基因ilv BNrC;然后将其插入穿梭表达载体p Z8-1中,构建串联表达质粒p Z8-1-ilv BNrC并转化出发菌株,筛选获得工程菌株B.flavum MD515/p Z8-1-ilv BNrC。摇瓶发酵该工程菌株L-缬氨酸产量达29.5 g·L-1,较出发菌株提高27.7%,同时生长速度和生物量也比出发菌株有所提高,丙氨酸含量降低,L-亮氨酸及L-异亮氨酸含量提高。在30 L发酵罐连续补料发酵60 h后L-缬氨酸产量达61.7 g·L-1,糖酸转化率为39.2%。菌株MD515/p Z8-1-ilv BNrC发酵液透光率较出发菌株高且蛋白含量低,这些特性有利于发酵液后期的分离提取。 展开更多
关键词 L-缬氨 定点突变 乙酰羟合成酶 乙酰羟异构还原酶 共表达
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奶牛饲料添加剂的应用现状和发展趋势
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作者 孟庆翔 《中国乳业》 2004年第3期23-25,共3页
关键词 奶牛 饲料添加剂 胆碱 氨基 离子载体 生物活性制剂 生长激素 异构酸 丙二醇
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Cloning of Tap Ⅱ Chalcone Isomerases(CHI1 A) Gene and Construction of Lactococcus Lactis Expression Vector 被引量:7
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作者 刘洪禹 王丕武 +2 位作者 付永平 张卓 马超 《Agricultural Science & Technology》 CAS 2010年第4期44-46,93,共4页
[Objective]The aim was to clone TapⅡchalcone isomerases(CHI1 A) from soybean specially and construct expression vector of PNZ8149-CHI1 A,and then transform it into Lactococcus Lactis NICE systers.[Method]Chalcone i... [Objective]The aim was to clone TapⅡchalcone isomerases(CHI1 A) from soybean specially and construct expression vector of PNZ8149-CHI1 A,and then transform it into Lactococcus Lactis NICE systers.[Method]Chalcone isomerases(CHI1 A) was cloned by RTPCR method,and it was sequenced after cloning into pMD18-T vectors,and recombined to expression vector PNZ8149-CHI1 A,then it was transformed into Lactococcus Lactis NZ3900[Result]The sequencing results indicated that the cloned fragment of CHI1 A contained 670 nucleotides,and shared a sequence homology of 92% with that from Genbank accession number AF595413(CHI1 A).CHI1 A was transformed into NICE expression system successfully by identification of PCR and digestion.[Conclusion]The foundation of using the microorganism fermentation method to produce flavonoids was laid by construction of efficient induction expression vector with chalcone isomerases CHI1 A. 展开更多
关键词 SOYBEAN Chalcone isomerases Lactococcus Lactis The nisin-control led expression
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稻谷人工老化后种胚异构天冬氨酸动态监测与总蛋白差异表达分析 被引量:3
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作者 魏毅东 谢鸿光 +7 位作者 刁丽蓉 王进兰 吴方喜 罗曦 何炜 潘丽燕 谢华安 张建福 《科学通报》 EI CAS CSCD 北大核心 2020年第2期174-184,共11页
蛋白质中天冬氨酸和天冬酰胺自发形成的异构天冬氨酸残基是组织细胞中常见的蛋白质共价损伤.在前人的研究中,PIMT1介导的种子寿命提高,很可能是由于修复了种胚中因老化处理而过量累积的含异构天冬氨酸(isoaspartyl,isoAsp)蛋白,维持了... 蛋白质中天冬氨酸和天冬酰胺自发形成的异构天冬氨酸残基是组织细胞中常见的蛋白质共价损伤.在前人的研究中,PIMT1介导的种子寿命提高,很可能是由于修复了种胚中因老化处理而过量累积的含异构天冬氨酸(isoaspartyl,isoAsp)蛋白,维持了种胚的活性.然而,异构天冬氨酸蛋白甲基转移酶(protein L-isoaspartyl methyltransferase,PIMT)对于水稻种子活力的作用机制,仍然不甚明确.本研究利用RNAi干扰技术获得了稳定的OsPIMT1的低表达株系.种子经人工老化后,结果表明OsPIMT1的低表达影响种子发芽活力.随后对种胚中含异构天冬氨酸的蛋白进行动态检测,结果显示在未吸胀和吸胀过后的种子中,种胚中的OsPIMT1的表达都能降低isoAsp的累积.而RNAi株系中OsPIMT1的低表达导致isoAsp的过度积累,进而影响种子活力.同时利用老化5 d后的水稻种胚蛋白进行双向电泳,分析RNAi干扰种子老化过程中异构天冬氨酸过度积累对于种胚蛋白的影响,鉴定到与种子老化相关的氧化胁迫相关蛋白、糖酵解以及热激蛋白分子伴侣等蛋白.为进一步研究OsPIMT1表达对于种子老化后细胞各代谢途径的影响奠定了基础. 展开更多
关键词 水稻 异构天冬氨蛋白甲基转移酶 双向电泳 种子活力 差异表达
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Effcient Removal Phenol Red over Ternary Heterostructured Ag-Bi2MoO6/BiPO4 Composite Photocatalyst
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作者 姜大雨 徐达 +6 位作者 郑佳 杨阳 刘畅 王宇爽 车广波 林雪 常立民 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2016年第5期600-606,I0002,共8页
The fabrication of multicomponent composite systems may provide bene ts in terms of charge separation and the retardation of charge pair recombination. In this work, a ternary heterostructured Ag-Bi2MoO6/BiPO4 composi... The fabrication of multicomponent composite systems may provide bene ts in terms of charge separation and the retardation of charge pair recombination. In this work, a ternary heterostructured Ag-Bi2MoO6/BiPO4 composite was fabricated through a low-temperature solution-phase route for the rst time. The XRD, SEM, EDX and XPS results indicated the prepared sample is a three-phase composite of BiPO4, Bi2MoO6, and Ag. Ag nanopar-ticles were photodeposited on the surface of Bi2MoO6/BiPO4 nanosheets, which not only increase visible-light absorption via the surface plasmon resonance, but also serve as good electron acceptor for facilitating quick photoexcited electron transfer. The interface between Bi2MoO6 and BiPO4 facilitates the migration of photoinduced electrons from Bi2MoO6 to BiPO4, which is also conductive to reduce the recombination of electron-holes. Thus, the ternary heterostructured Ag-Bi2MoO6/BiPO4 composite showed signi cant photocatalytic activity, higher than pure Bi2MoO6, BiPO4, and Bi2MoO6/BiPO4. Moreover, the possible photocatalytic mechanism of the Ag-Bi2MoO6/BiPO4 heterostructure related to the band positions of the semiconductors was also discussed. In addition, the quenching effects of di erent scavengers revealed that the reactive ·OH and O2·- play a major role in the phenol red decolorization. 展开更多
关键词 l-leterostructure Bi2MoO6 BiPO4 AG PHOTOCATALYSIS Visible light
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Down-regulation of triose phosphate isomerase in Vineristine-resistant gastric cancer SGC7901 cell line identified by immobilized pH gradient two-dimensional gel electrophoresis and mierosequencing
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《胃肠病学》 2002年第B11期24-24,共1页
Objective:To exkplore new multidrug-resistance-related proteins in gastric SC7901 cells and clarify their mechanisms.Methods:Two-dimensional(2-D) polyacrylamide gel electrophoresis with immobilized pH gradients(IPG) w... Objective:To exkplore new multidrug-resistance-related proteins in gastric SC7901 cells and clarify their mechanisms.Methods:Two-dimensional(2-D) polyacrylamide gel electrophoresis with immobilized pH gradients(IPG) was applied to compare the differential expression of multidrug-resistance-related proteins in gastric cancer SGC7901 cells and Vineristine-resistant SGC7901 cells (SGC7901/VCR) induced by vincristine sulfate.The 2-D gels were silver-stained.Then,preparative 2-D PAGE was performed.The differential proteins of PVDF membranes were cxcised and identified by N-terminal microsequencing.The mRNA expressions of differential proteins were detected in SGC 7901 cells and SGC7901/VCR cells by RT-PCR.Results:Approximatedly 680 protein sports were resolved on each 2-D gel by silver staining.Most protein spots showed no difference in composition,shape or density.25 proteins differed in abundance (6 higher in SGC7901/VCR cells;19 higher in 7901 cells);5 proteins were unique to one kind of cell or the othe(3 in SGC7901/VRC cells,2 in 7901 cells).One drug-resistance-related protein,which was down-regulated in SGC7901/VCR cells,was identified as trisephosphate isomerase(TPI),a glycolytic pathway enzyme.Conclusions:the results suggest that these differential proteins including TPI may be related to the Vincristine-resistant mechanism in human gastric cancer SGC7901/VCR cell line. 展开更多
关键词 胃癌SGC790/细胞系 长春碱 抗药性 丙糖三磷异构酸 减量调节
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cDNA Cloning and Bioinformatic Prediction of TPI Gene from Apis mellifera
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作者 王琦 李玮妮 王荣 《Agricultural Science & Technology》 CAS 2012年第5期1097-1100,1126,共5页
[Objective] The aim was to clone triosephosphate isomerase (TPI) gene from Apis mellifera, and predict the properties of TPI protein with bioinformatic meth- ods. [Method] The TPI gene was firstly cloned by in silic... [Objective] The aim was to clone triosephosphate isomerase (TPI) gene from Apis mellifera, and predict the properties of TPI protein with bioinformatic meth- ods. [Method] The TPI gene was firstly cloned by in silico cloning based on the ex- pressed sequence tags (ESTs) from Unigene of NCBI. Some characters of the TPI protein including hydrophobicity or hydrophilicity, isoelectric point (pl) and secondary structure were analyzed and predicted by the tools of bioinformatics. [Result] The TPI gene from A. mellifera was 1 768 bp in full length and it contained a complete ORF which encoded 247 amino acids; the pl of TPI protein was 8.515; the TPI protein was a member of ~13-fold family. [Conclusion] The in silico cloning based on the expressed sequence tags is a efficient method in practice, and this study will provide more references for further study on A. mellifera at molecular level. 展开更多
关键词 Apis mellifera In silico cloning Triosephosphate isomerase (TPI) BIOINFORMATICS
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Cell Adhesion Inhibition by RGD Peptides Linked with a Photoisomerizable Nonnatural Amino Acid
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作者 张海黔 篠原宽明 +2 位作者 顾宁 佐々木裕司 宍户昌彦 《Journal of Southeast University(English Edition)》 EI CAS 2001年第2期22-26,共5页
RGD peptides linked with a nonnatural amino acid, phenylazophenyl alaninine (azoAla), were synthesized and applied to cell adhesion inhibitors. The RGD peptides linked with azoAla at C terminal showed potent binding ... RGD peptides linked with a nonnatural amino acid, phenylazophenyl alaninine (azoAla), were synthesized and applied to cell adhesion inhibitors. The RGD peptides linked with azoAla at C terminal showed potent binding to the integrin on the surface of HeLa cells. Photoisomerization effect of the azobenzene side chain of synthesized peptides on the cell adhesion inhibition was further investigated. It was demonstrated that the cis form of azoAla linked RGD peptides revealed a little weak cell adhesion inhibition effect as compared with trans form of azoAla linked RGD peptide. 展开更多
关键词 nonnatural amino acid cell adhesion PHOTOISOMERIZATION INTEGRIN PEPTIDE
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Establishment of the Agrobacterium-mediated Genetic Transformation System of Ginkgo biloba and the Construction of the Expression Vector of Gb-DXR
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作者 冯国庆 杨颖舫 +4 位作者 李郑娜 成瑜 杨春贤 陈敏 廖志华 《Agricultural Science & Technology》 CAS 2010年第3期28-32,114,共6页
[Objective] The research aimed to provide reference for increasing the genetic transformation efficiency of Ginkgo biloba mediated by Agrobacterium.[Method] Taking the mature embryos of Ginkgo biloba seeds as explants... [Objective] The research aimed to provide reference for increasing the genetic transformation efficiency of Ginkgo biloba mediated by Agrobacterium.[Method] Taking the mature embryos of Ginkgo biloba seeds as explants,after 48 hours' pre-cultivation on MS medium in the absence of phytohormone,GUS gene was transmitted into embryos of Ginkgo biloba mediated by three kinds of Agrobacterium.Transient expression of GUS gene activity was observed through histochemical staining,and the influencing factors of the expression of GUS gene were analyzed.And the expression vector of 1-deoxy-D-xylulose-5-phosphate reductoisomerase in the biosynthesis approach of biobalide precursor of Ginkgo biloba was constructed.[Result] A more suitable genetic transformation scheme was obtained as follows:taking embryos of Ginkgo biloba as explants,using EHA105 Agrobacterium with pCAMBIA1304+ for infection,co-culture for 3 days and GUS staining.The results showed that transient expression rate of GUS after transformation was higher.[Conclusion] The research provide a more effective method for further study on the transgene of Ginkgo biloba. 展开更多
关键词 Embryos of Ginkgo biloba AGROBACTERIUM-MEDIATED Genetic transformation GUS gene 1-deoxy-D-xylulose-5-phosphate reductoisomerase Expression vector
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Process optimization of an industrial acetic acid dehydration progress via heterogeneous azeotropic distillation 被引量:3
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作者 Xiuhui Huang Zeqiu Li Ying Tian 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2018年第8期1631-1643,共13页
The simulated process model of the HAc dehydration process under actual overloaded condition was conducted by amending the model of standard condition in our previous work using the process data collected from actual ... The simulated process model of the HAc dehydration process under actual overloaded condition was conducted by amending the model of standard condition in our previous work using the process data collected from actual production. Based on the actual process model, the operation optimization analysis of each plant(HAc dehydration column, decanter and NPA recycle column) was conducted using Residue Curve Maps(RCMs),sensitivity analysis and software optimization module. Based on the optimized parameters, the influence of feed impurity MA and the temperature of decanter on the separating effect and energy consumption of the whole process were analyzed. Then the whole process operation optimizing strategy was proposed with the objective that the total reboiler duty Q Total of C-1 and C-3 reaches the minimum value, keeping C-1 and C-3 at their optimized separation parameters obtained above, connecting all the broken recycle and connection streams, and using the temperature of D-1 as operation variable. The optimization result shows that the total reboiler duty Q Total of the whole process can reach the minimum value of 128.32 × 10~6 k J·h^(-1) when the temperature of decanter is 352.35 K, and it can save 5.94 × 10~6 k J·h^(-1), about 2.56 t·h^(-1) low-pressure saturated vapor. 展开更多
关键词 Acetic acid dehydration Azeotropic distillation Process simulation Operation optimization
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Preparation of Conjugated Linoleic Acid and Identification of Its Isomers 被引量:9
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作者 郭诤 张根旺 孙彦 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2003年第2期130-135,共6页
Conjugated linoleic acid (CLA) is a kind of fatty acid with physiological activities and potential application prospect. A synthesis method of conjugated linoleic acid and a purification technology were studied. CLA w... Conjugated linoleic acid (CLA) is a kind of fatty acid with physiological activities and potential application prospect. A synthesis method of conjugated linoleic acid and a purification technology were studied. CLA was prepared and purified by urea-complexation and conjugation using safflower oil as raw material. The purity of CLA and total recovery of the product was more than 95% and 48%, respectively. The main isomers produced in alkali-catalyzed conjugation were identified by gas chromatography (GC) linked to mass spectrometry (MS) and Fourier transform infrared spectroscopy (FTIR). The total amount of the two main isomers (9cis, 11trons-and 10trans, 12cis-CLA) determined by GC was more than 90% of the product. 展开更多
关键词 linoleic acid conjugated linoleic acid urea-complexation alkali-catalyzed conjugation IDENTIFICATION safflower oil
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Alkylation of Catechol with tert-Butyl Alcohol Catalyzed by Mesoporous Acidic Montmorillonite Heterostructure Catalysts 被引量:2
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作者 周春晖 葛忠华 +3 位作者 李小年 童东绅 李庆伟 郭红强 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2004年第3期388-394,共7页
The liquid phase alkylation of catechol with tert-butyl alcohol to produce4-tert-butyl catechol (4-TBC) was carried out over MCM-41, HZSM-5, H-exchanged montmorillonite andnovel acidic porous montmorillonite heterostr... The liquid phase alkylation of catechol with tert-butyl alcohol to produce4-tert-butyl catechol (4-TBC) was carried out over MCM-41, HZSM-5, H-exchanged montmorillonite andnovel acidic porous montmorillonite heterostructures (PMHs). Upon all catalysts tested, 4-TBC is themain product and 3-tert-butyl catechol (3-TBC) and 3,5-di-tert-butyl catechol are the sideproducts. The synthetic PMHs showed higher conversion of catechol and better selectivity to 4-TBCcompared to other solid acid catalysts tested. Over the PMHs derived from H-exchangedmontmorillonite through template extraction processes, the suitable reaction temperature is ca 410K, the ratio of catechol to tert-butyl alcohol is 1:2. Increasing the amount of catalyst (lowerweight hourly space velocity) can improve the conversion of catechol and influence the selectivityslightly. The reasonable reaction time is ca 8 h. The type and strength of acidity ofH-montmorillonite and PMH were determined by pyridine adsorption FT-IR and ammoniatemperature-programmed desorption techniques. The medium and strong acid sites are conducive toproducing 4-TBC and the weak acid sites to facilitating the 3-TBC formation. The differences betweenthe PMHs from calcination and those from extraction are attributed to proton migration and aciditychange in the gallery surface. 展开更多
关键词 ALKYLATION CATECHOL 4-tert-butyl catechol porous montmorilloniteheterostructures solid acid catalysts ACIDITY
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