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Degradation of amyloid β-peptides catalyzed by nattokinase in vivo and in vitro
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作者 Aixin Ni He Li +2 位作者 Ruya Wang Rentong Sun Yingjiu Zhang 《Food Science and Human Wellness》 SCIE CSCD 2023年第5期1905-1916,共12页
Amyloid-β 1-42(Aβ42)plays a pivotal role in Alzheimer disease(AD)pathogenesis. Peripheral clearance of Aβ42 largely affects its level in the brain and affects AD progression. Although nattokinase(NK)degrades Aβ40,... Amyloid-β 1-42(Aβ42)plays a pivotal role in Alzheimer disease(AD)pathogenesis. Peripheral clearance of Aβ42 largely affects its level in the brain and affects AD progression. Although nattokinase(NK)degrades Aβ40, the details of NK's capture of various Aβ species and reduction of plasma Aβ42/Aβ40 are uncharacterized. In this study, the Aβ42/Aβ40-degrading ability of NK was investigated using five Aβs and AD model mice. The C-terminal region of Aβ42/Aβ40(Gly29 to Val40)was primarily required for NK capture, and the integrated conformation in Aβ42/Aβ40 aggregates was a more efficient target for NK catalysis. Further, suspended Aβ42/Aβ40 oligomers were more easily captured by NK than suspended Aβ42/Aβ40 fibrils, while deposited Aβ42/Aβ40 fibrils recruited more NK than deposited Aβ42/Aβ40 oligomers. Although most NK was likely lost during NK uptake and/or entry into the blood, a small fraction of NK showed good plasma Aβ42/Aβ40-degrading efficacy after entering the blood due to NK's stability in the plasma of AD mice for at least 9 days. It was concluded that oral administration of NK is a feasible approach for peripheral Aβ42/Aβ40 clearance. This implies that NK might serve as an anti-Aβ42 agent for the treatment of Aβ42/Aβ40-related diseases such as AD. 展开更多
关键词 NATTOKINASE Amyloidβ-peptide DEGRADATION CATALYZE Alzheimer disease
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Dechlorination of carbon tetrachloride by the catalyzed Fe-Cu process 被引量:16
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作者 XU Wen-ying GAO Ting-yao 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2007年第7期792-799,共8页
The dectrochemical reduction characteristics of carbon tetrachlofide (CT) were investigated using cyclic voltammetry in this study. In addition, the difference in reduction mechanisms of CT between Master Builders'... The dectrochemical reduction characteristics of carbon tetrachlofide (CT) were investigated using cyclic voltammetry in this study. In addition, the difference in reduction mechanisms of CT between Master Builders' iron and the catalyzed Fe-Cu process was discussed. The results showed that CT was reduced directly on the surface of copper rather than by atomic hydrogen produced at the cathode in the catalyzed Fe-Cu process. The reduction was realized largely by atomic hydrogen in Master Builders' iron. The entire CT in 350 ml aqueous solution with 320 mg/L was reduced to trichloromethane and dichloromethane in 2.25 h when 100 g of scrap iron with Fe/Cu ratio of 10:1 (w/w) were used. Moreover, the reduction rate slowed with time. CT could be reduced at acidic, neutral and alkaline pH from solution by Fe-Cu bimetallic media, but the mechanisms were different. The degradation rate was not significantly influenced by pH in the catalyzed Fe-Cu process; in Master Builders' iron it clearly increased with decreasing pH. The kinetics of the reductions followed pseudo-first order in both cases. Furthermore, the reductions under acidic conditions proceeded faster than that under the neutral and alkaline conditions. The catalyzed Fe-Cu process was superior to Master Builders' iron in treating CT-containing water and this advantage was particularly noticeable under alkaline conditions. The reduction was investigated in the cathode (Cu) and anode (Fe) compartments respectively, the results showed that the direct reduction pathway played an important role in the reduction by the catalyzed Fe-Cu process. The catalyzed Fe-Cu process is of practical value. 展开更多
关键词 carbon tetrachloride electrochemical reduction characteristics catalyzed Fe-Cu process reduction mechanisms
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Electrochemical reduction characteristics and mechanism of nitrobenzene compounds in the catalyzed Fe-Cu process 被引量:7
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作者 XU Wen-ying FAN Jin-hong GAO Ting-yao 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2006年第2期379-387,共9页
The reduction of the nitrobenzene compounds (NBCs) by the catalyzed Fe-Cu process and the relationship between the electrochemical reduction characteristics of NBCs at copper electrode and reduction rate were studie... The reduction of the nitrobenzene compounds (NBCs) by the catalyzed Fe-Cu process and the relationship between the electrochemical reduction characteristics of NBCs at copper electrode and reduction rate were studied in alkaline medium(pH=11). The catalyzed Fe-Cu process was found more effective on degradation of NBCs compared to Master Builder's iron. The reduction rate by the catalyzed Fe-Cu process decreased in the following order: nitrobenzene 〉4-chloro-nitrobenzene ≥m-dinitrobenzene :〉 4-nitrophenol ≥2,4-dinitrotoluene 〉2-nitrophenol. The reduction rate by Master Builder's iron decreased in the following order: m-dinitrobenzene ≥4-chloro-nitrobenzene 〉4-nitrophenol 〉2,4-dinitrotoluene ≈nitrobenzene 〉2-nitrophenol. NBCs were reduced directly on the surface of copper rather than by the hydrogen produced at cathode in the catalyzed Fe-Cu process. The reduction was realized by the hydrogen produced at cathode and Fe(OH)2 in Master Builder's iron, It is an essential difference in reaction mechanisms between these two technologies. For this reason, the reduction by the catalyzed Fe-Cu depended greatly on NBC's electron withdrawing ability. 展开更多
关键词 wastewater contaminated by NBCs electrochemical reduction characteristics catalyzed Fe-Cu process reduction mechanism
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Thermal decomposition of ammonium perchlorate catalyzed with CuO nanoparticles 被引量:5
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作者 Sherif Elbasuney M.Yehia 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2019年第6期868-874,共7页
Ammonium perchlorate(APC)is the most common oxidizer in use for solid rocket propulsion systems.However its initial thermal decomposition is an endothermic process that requires 102.5 J·g^-1.This manner involves ... Ammonium perchlorate(APC)is the most common oxidizer in use for solid rocket propulsion systems.However its initial thermal decomposition is an endothermic process that requires 102.5 J·g^-1.This manner involves high activation energy and could render high burning rate regime.This study reports on the sustainable fabrication of CuO nanoparticles as a novel catalyzing agent for APC oxidizer.Colloidal CuO nanoparticles with consistent product quality were fabricated by using hydrothermal processing.TEM micrographs demonstrated mono-dispersed particles of 15 nm particle size.XRD diffractogram demonstrated highly crystalline material.The synthesized colloidal CuO particles were effectively coated with APC particles via co-precipitation by using fast-crash solvent-antisolvent technique.The impact of copper oxide particles on APC thermal behavior has been investigated using DSC and TGA techniques.APC demonstrated an initial endothermic decomposition stage at 242℃ with subsequent two exothermic decomposition stages at 297,8℃ and 452.8℃ respectively.At 1 wt%,copper oxide offered decrease in initial endothermic decomposition stage by 30%.The main outcome of this study is that the two main exothermic decomposition peaks were merged into one single peak with an increase in total heat release by 53%.These novel features can inherit copper oxide particles unique catalyzing ability for advanced highly energetic systems. 展开更多
关键词 Ammonium perchlorate CATALYST Thermal behavior Energetic systems catalyzed propellants
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Oxygen pressure acid leaching of artificial sphalerite catalyzed by Fe^3+/Fe^2+self-precipitation 被引量:5
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作者 TIAN Lei GONG Ao +5 位作者 WU Xuan-gao XU Zhi-feng ZHANG Ting-an LIU Yan WEI Kui-xian YU Zhan-liang 《Journal of Central South University》 SCIE EI CAS CSCD 2020年第6期1703-1713,共11页
The mechanism of oxygen pressure acid leaching of sphalerite catalyzed by Fe^3+/Fe^2+self-precipitation was investigated in this study.Artificial sphalerite was fabricated with varying amounts of iron content via the ... The mechanism of oxygen pressure acid leaching of sphalerite catalyzed by Fe^3+/Fe^2+self-precipitation was investigated in this study.Artificial sphalerite was fabricated with varying amounts of iron content via the sintering of ZnS and FeS and used for the pressure acid leaching experiment.The variations in the potential of the pressure leaching system were investigated by using a self-designed potential autoclave.The results showed that compared to the non-iron sphalerite,there was a violent redox reaction between the 25.70%Fe-artificial sphalerite and dissolved oxygen during the process of pressure leaching;and the catalytic mechanism was attributed to the redox couple Fe^3+/Fe^2+,where Fe3+oxidizes the H2S gas film and the reduced Fe2+state is subsequently oxidized by the dissolved oxygen.Furthermore,the effect of temperature,H2SO4 concentration,and oxygen partial pressure on the artificial sphalerite with different iron contents was studied.The sphalerite samples with iron content were observed to dissolve more easily in sulfuric acid compared to the non-iron samples.Moreover,the activation energy of artificial sphalerite was observed to be lower in the sample with 25.70%iron content(22.26 kJ/mol)compared to that with no iron(32.31 kJ/mol);and the apparent reaction orders were obtained with respect to H2SO4 concentration(1.10 and 1.36)and oxygen partial pressure(1.29 and 1.41),respectively.A comprehensive kinetic model was developed on the basis of the experimental data and the fitted leaching ratio plot;and the kinetic equations for the leaching of sphalerite catalyzed by Fe^3+/Fe^2+self-precipitation were determined. 展开更多
关键词 leaching mechanism catalyzed by Fe^3+/Fe^2+self-precipitation potential curves artificial sphalerite leaching kinetics activation energy reaction orders
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Effect of Surfactan ton the Catalyzed Oxidation of 2,6-Dimethylphenol by Rhus Vernicifera Laccase 被引量:1
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《Wuhan University Journal of Natural Sciences》 CAS 1997年第4期121-124,共4页
EfectofSurfactantontheCatalyzedOxidationof2,6┐DimethylphenolbyRhusVerniciferaLacase⒇JiLicaiColegeofLifeScien... EfectofSurfactantontheCatalyzedOxidationof2,6┐DimethylphenolbyRhusVerniciferaLacase⒇JiLicaiColegeofLifeSciences,WuhanUniversi... 展开更多
关键词 EFFECT Surfactan RHUS Dimethylphenol catalyzed
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A Novel Palladium-Catalyzed Reaction and Its Application in Preparation of Derivatives of Stilbazols 被引量:1
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作者 Zhi Yong WANG Chao JIANG +1 位作者 Ji Hui WU Qing Xiang GUO 《Chinese Chemical Letters》 SCIE CAS CSCD 2001年第5期399-402,共4页
A novel palladium-catalyzed coupling reaction for the preparation of derivatives of stilbazoles was presented. A series of stilbazoles were synthesized firstly by this highly efficient method. From this reaction it wa... A novel palladium-catalyzed coupling reaction for the preparation of derivatives of stilbazoles was presented. A series of stilbazoles were synthesized firstly by this highly efficient method. From this reaction it was found that reaction solvent is one of important factors in this catalytic system. 展开更多
关键词 Palladium catalyzed PREPARATION stilbazole
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DFT Studies on Hydrogen Overfall Mechanism for Catalyzed Hydroisomerization of Pentane 被引量:1
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作者 AI Chun-Zhi SUN Ren-An WANG Chang-Sheng 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2007年第2期239-247,共9页
The mechanism and related reaction paths in the hydroisomerization of n-pentane were studied by DFT calculations at the B3LYP/6-311++G^** level. Two possible transition states were theoretically predicted and ve... The mechanism and related reaction paths in the hydroisomerization of n-pentane were studied by DFT calculations at the B3LYP/6-311++G^** level. Two possible transition states were theoretically predicted and verified by the vibration frequency analysis as well as the calculations of intrinsic reaction coordinates (IRC). Furthermore, the related reaction barriers were evaluated by single point energy at the MP2/6-311++G^** level with zero point vibration correction of DFT method. Thus, it is concluded that the isomerization might go through two pathways. 展开更多
关键词 catalyzed isomerization of n-pentane hydrogen overfall mechanism i-pentane DFT
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Catalyst design strategy toward the efficient heterogeneously-catalyzed selective oxidation of 5-hydroxymethylfurfural 被引量:1
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作者 Huai Liu Xing Tang +5 位作者 Xianhai Zeng Yong Sun Xixian Ke Tianyuan Li Jiaren Zhang Lu Lin 《Green Energy & Environment》 SCIE EI CSCD 2022年第5期900-932,共33页
The selective oxidation of 5-hydroxymethylfurfural(HMF),a versatile bio-based platform molecule,leads to the formation of several intriguing and useful downstream chemicals,such as 2,5-diformylfuran(DFF),5-hydroxymeth... The selective oxidation of 5-hydroxymethylfurfural(HMF),a versatile bio-based platform molecule,leads to the formation of several intriguing and useful downstream chemicals,such as 2,5-diformylfuran(DFF),5-hydroxymethyl-2-furancarboxylic acid(HMFCA),formyl 2-furancarboxylic acid(FFCA),2,5-furandicarboxylic acid(FDCA) and furan-2,5-dimethylcarboxylate(FDMC).These products have been extensively employed to fabricate novel polymers,pharmaceuticals,sustainable dyes and many other value-added fine chemicals.The heart of the developed HMF oxidation processes is always the catalyst.In this regard,this review comprehensively summarized the established heterogeneous catalyst design strategy for the selective oxidation of HMF via thermo-catalysis.Particular attention has been focused on the reaction mechanism of HMF oxidation over different catalysts as well as enhancing the catalytic performance of the catalyst through manipulating the properties of the support and fabricating of multi-component metal nano-particles and oxides.The current challenges and possible research directions for the catalytic oxidation of HMF in the future are also discussed. 展开更多
关键词 HYDROXYMETHYL CATALYST catalyzed
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OXIDATION OF ALKYLBENZENES CATALYZED BY IRON( Ⅱ,Ⅲ)-1,10-PHENANTHROLINE AND 2, 2'-BIPYRIDINE COMPLEXES 被引量:1
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作者 Zi Qiang LEI Yun Pu WANG 《Chinese Chemical Letters》 SCIE CAS CSCD 1993年第1期21-22,共2页
Oxidation of alkybenzenes PhCH_2R(R=H, CH_3, C_2H_5 and n-C_3H_7) under 1 atm. of O_2 or air catalyzed by iron(Ⅱ, Ⅲ)-2,2'-bipyridine and 1,10-phenanthroline complexes, affords the aryl-substituted ketones and al... Oxidation of alkybenzenes PhCH_2R(R=H, CH_3, C_2H_5 and n-C_3H_7) under 1 atm. of O_2 or air catalyzed by iron(Ⅱ, Ⅲ)-2,2'-bipyridine and 1,10-phenanthroline complexes, affords the aryl-substituted ketones and alcohols with the conversion of 15.00%~34.58% containing of 97.60%~99.80% ketones and alcohols. The turnover numbers of these catalysts are over 3500 mol-cat. ^(-1)for 3.5 h. 展开更多
关键词 PHENANTHROLINE AND 2 BIPYRIDINE COMPLEXES OXIDATION OF ALKYLBENZENES catalyzed BY IRON
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Washing-off of Unfixed Reactive Dyes on Cotton Fabrics Using Fe-TAML/H_2O_2 Catalyzed Oxidation System 被引量:1
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作者 尹冲 张琳萍 +1 位作者 钟毅 毛志平 《Journal of Donghua University(English Edition)》 EI CAS 2015年第5期859-863,共5页
Unfixed reactive dyes stained on cotton fabric could be removed using Fe-tetra-amido macro-cyclic ligands( TAML) / H_2O_2 catalyzed oxidation system( COS). The colored washing-off wastewater also could be decolorized ... Unfixed reactive dyes stained on cotton fabric could be removed using Fe-tetra-amido macro-cyclic ligands( TAML) / H_2O_2 catalyzed oxidation system( COS). The colored washing-off wastewater also could be decolorized simultaneously in the same system. The decolourization kinetics showed that the decolourization ratio of reactive dyes in water could reach at least 80% at room temperature in 10 min,which followed the law of pseudo-first order reaction kinetics. The effects of the COS washing-off process parameters on the decolourization ratio,chemical oxygen demand( COD) of wastewater,K/S value,color fastness,color difference,and bursting strength were investigated in detail. The results showed that color fastness properties and final shade of fabric treated by COS were very similar to conventional soaping. The reactive dye molecules in wash-off bath were destroyed using the COS,potentially reduced COD which generated during conventional washing-off procedure. 展开更多
关键词 decolourization catalyzed oxidation system(COS) washing-off chemical oxygen demand(COD)
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KINETICS OF PHASE TRANSFER CATALYZED DISPROPORTIONATION OF ELEMENTAL SULFUR
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作者 邓彤 陈家镛 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 1989年第1期51-58,共8页
The kinetics of phase transfer catalyzed (PTC) disproportionation of elemental sulfur was studied in the range of OH<sup>-</sup> concentrationlin the aqueous phase from 0.02 to 0.14 mol/dm<sup>3<... The kinetics of phase transfer catalyzed (PTC) disproportionation of elemental sulfur was studied in the range of OH<sup>-</sup> concentrationlin the aqueous phase from 0.02 to 0.14 mol/dm<sup>3</sup> and temperature from 45 to 70℃. A kinetic expression, R<sub>s</sub>a=k*[Q<sup>+</sup>]<sub>aq</sub>[OH<sup>-</sup>]<sub>aq</sub>[S]<sub>org</sub><sup>1/2</sup>, derived from the theory of mass transfer with rapid chemical reaction in liquid liquid system can be adopted to correlate the experimental data, and the apparent activation energy of the reaction was found to be 79kJ/mol. Kinetic evidence for PTC reaction of the system was given and a mechanism of PTC disproportionation of elemental sulfur was proposed. 展开更多
关键词 KINETICS sulfur HYDROXIDE apparent AGITATION ammonium CORRELATE catalyzed limiting reagent
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HIGH REGIOSELECTIVE SYNTHESIS OF PARA MYRAC ALDEHYDE CATALYZED BY MODIFIED HY ZEOLITE UNDER MICROWAVE IRRADIATION
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作者 Dong Hong YIN Du Lin YIN Qian He LI(Institute of Fine Catalysis & Synthesis, Hunan Normal University, Changsha 410081) 《Chinese Chemical Letters》 SCIE CAS CSCD 1996年第8期697-698,共2页
The Diels-Alder reaction of myrcene and acrolein catalyzed by modified HY zeolitewhich was prepared by mixing HY zeolite and anhydrous ZnCl2 under microwave irradiation wasStudied. High regioselectivity and good yield... The Diels-Alder reaction of myrcene and acrolein catalyzed by modified HY zeolitewhich was prepared by mixing HY zeolite and anhydrous ZnCl2 under microwave irradiation wasStudied. High regioselectivity and good yield of para myrac aldehyde were obtained when the ratio ofZnCl2/HY (w/w) was 1:2 to 1:3. 展开更多
关键词 HY catalyzed MYRAC PARA MODIFIED OF BY ALDEHYDE
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EFFECTS OF RATE OF ADDITION AND TENIPERATURE ON THE ENANTIOSELECTIVITY IN BORANE REDUCTION OF KETONES CATALYZED BY CHIRAL OXAZABOROLIDINE
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作者 Yao Zhong JIANG Yong +1 位作者 QIN snd Ai Qiao MIChengdu Institute of Organic Chemtetry, A cademia Sinica, Chengdu 610041 《Chinese Chemical Letters》 SCIE CAS CSCD 1995年第1期9-12,共4页
The exoellent enantioselectivity with o. p. >99% in asymmetrio borane reduction of acetophenone catalyzed by (4S, 5R ) 4, 5-diphenyi-1. 3. 2-oxazaborolidine has been achieved via the important modincation of the ... The exoellent enantioselectivity with o. p. >99% in asymmetrio borane reduction of acetophenone catalyzed by (4S, 5R ) 4, 5-diphenyi-1. 3. 2-oxazaborolidine has been achieved via the important modincation of the reaction conditions. 展开更多
关键词 RATE REDUCTION BORANE BY catalyzed CHIRAL EFFECTS IN KETONES OF
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USE OF CONJUGATED SALT PAIR TO BUFFER OPTIMAL pH LEVEL DURING LIPASE-CATALYZED SYNTHESIS IN ORGANIC SOLVENTS
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作者 Min Qin LI Hui Xian XU Bing Lin HE(Institute of Polymer Chemistry, Nankai University, Tianjin 300071) 《Chinese Chemical Letters》 SCIE CAS CSCD 1994年第3期199-200,共2页
Enzyme catalyzed esterifcation in organic solvent system depends highly oh conjugated salt pair at different PH. We ha,e shown that the addition of an appropriate sol id conjugated salt pair to the esterification rect... Enzyme catalyzed esterifcation in organic solvent system depends highly oh conjugated salt pair at different PH. We ha,e shown that the addition of an appropriate sol id conjugated salt pair to the esterification rection mixtues is a simple and convenient method to obtain optimal pH level con ditions throughout the reaction. 展开更多
关键词 PH OPTIMAL LEVEL DURING LIPASE BUFFER catalyzed
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Novel Stereoselective Synthesis of 1,3-Dienyl Tellurides by Palladium Catalyzed Cross-coupling Reaction of (E)-β--Bromovinyl Tellurides
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作者 Ya Ping WANG Lu Ling WU Xiang HUANG 《Chinese Chemical Letters》 SCIE CAS CSCD 2001年第1期39-40,共2页
β-Bromovinyl tellurides are new difuctional reagents which undergo palladium-catalyzed cross-coupling reaction with alkenes to give conjugated dienyl tellurides.
关键词 β-Bromovinyl tellurides 1 3-dienyl tellurides palladium catalyzed reaction synthesis.
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CAN Catalyzed Preparation of β-Enamino Ketones from Amines and Acetylacetone
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作者 Zheng DUAN Ting LI Xue Jie XUAN Yang Jie WU 《Chinese Chemical Letters》 SCIE CAS CSCD 2006年第12期1566-1568,共3页
A variety of β-enamino ketones were synthesized in high to excellent yields by reacting acetylacetone with amines in the presence of a catalytic amount of cerium(IV) ammonium nitrate (CAN) under ultrasonic irradi... A variety of β-enamino ketones were synthesized in high to excellent yields by reacting acetylacetone with amines in the presence of a catalytic amount of cerium(IV) ammonium nitrate (CAN) under ultrasonic irradiation. 展开更多
关键词 CAN catalyzed β-enamino ketone ultrasound.
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Kinetics of aggregation growth with competition between catalyzed birth and catalyzed death
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作者 王海锋 林振权 高艳 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第4期1490-1500,共11页
An aggregation growth model of three species A, B and C with the competition between catalyzed birth and catalyzed death is proposed. Irreversible aggregation occurs between any two aggregates of the like species with... An aggregation growth model of three species A, B and C with the competition between catalyzed birth and catalyzed death is proposed. Irreversible aggregation occurs between any two aggregates of the like species with theconstant rate kernels In(n = 1,2, 3). Meanwhile, a monomer birth of an A species aggregate of size k occurs under the catalysis of a B species aggregate of size j with the catalyzed birth rate kernel K(k, j) = Kkj^v, and a monomer death of an A species aggregate of size k occurs under the catalysis of a C species aggregate of size j with the catalyzed death rate kernel L(k, j) = Lkj^v, whcre v is a parameter reflecting the dependence of the catalysis reaction rates of birth and death on the size of catalyst aggregate. The kinetic evolution behaviours of the three species are investigated by the rate equation approach based on the mean-field theory. The form of the aggregate size distribution of A species ak (t) is found to be dependent crucially on the competition between the catalyzed birth and death of A species, as well as the irreversible aggregation processes of the three species: (i) In the v 〈 0 case, the irreversible aggregation dominates the process, and ak(t) satisfies the conventional scaling form; (2) In the v ≥ 0 casc, the competition between the catalyzed birth and death dominates the process. When the catalyzed birth controls the process, ak(t) takes the conventional or generalized scaling form. While the catalyzed death controls the process, the scaling description of the aggregate size distribution breaks down completely. 展开更多
关键词 kinetic scaling behaviour aggregation growth catalyzed birth and death rate equation
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MECHANISM OF ELECTROCHEMILUMINESCENCE OF THE NEW REAGENT 6-(2-HYDROXY-DIETHYLAMINOPHENYLAZO)-2, 3-DIHYDRO-1, 4-PHTHALAZINE-1, 4-DIONE CATALYZED BY SILVER (Ⅰ)
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《Chinese Chemical Letters》 SCIE CAS CSCD 1992年第4期315-318,共4页
The electrochemi luminescence <ecl> of a new reagent 6-<2-hydroxy-4-diethylaminophenylazo>-2, 3-dihydro-1, 4-phthatazine-1, 4-dione <HDEA> in basic aqueous solution was studied. Trace amount of silve... The electrochemi luminescence <ecl> of a new reagent 6-<2-hydroxy-4-diethylaminophenylazo>-2, 3-dihydro-1, 4-phthatazine-1, 4-dione <HDEA> in basic aqueous solution was studied. Trace amount of silver showed significant effect on the efficiency of light emission of HDEA during a positive trigonometrical wave pulse was exerted on the electrodes In the present paper, the ecl spectra of HDEA have been measured. λ_(max) is 410 nm. The reaction of HDEA chemiluminescence and the circular voltammetry, ultraviolet-visible spectrometry for the system have been investigated. The possible mechanism of the ecl of HDEA-KCL-KOH-Ag(I) system has been proposed. 展开更多
关键词 HDE HYDROXY-DIETHYLAMINOPHENYLAZO MECHANISM OF ELECTROCHEMILUMINESCENCE OF THE NEW REAGENT 6 PHTHALAZINE-1 DIHYDRO-1 DIONE catalyzed BY SILVER Chen
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Base-Catalyzed Rearrangement of 11-Isopropylidene-anti-4,5-Epoxyendo-Tricyclo[6.2.1.0^(2,7)] Undeca-4,9-Diene-3,6-Dione
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作者 Xiao Pei GUAN Jian Guang SUN and Yong Zhong YU(College of Chemical Engineering and Materials Science, Beijing Institute of Technology, 100081 Beijing) 《Chinese Chemical Letters》 SCIE CAS CSCD 1996年第10期902-904,共3页
Treatment of 11-isopropylidene-anti-4, 5-epoxy-endo-tricyclo[6. 2. 1. 02.7] undeca-4, 9-diene-3,6-dione(6) with methanolic sodium hydroxide results in Favorskii-type ring contraction with concomitant Cope rearrangemen... Treatment of 11-isopropylidene-anti-4, 5-epoxy-endo-tricyclo[6. 2. 1. 02.7] undeca-4, 9-diene-3,6-dione(6) with methanolic sodium hydroxide results in Favorskii-type ring contraction with concomitant Cope rearrangement and Haller-Bauer cleavage, thereby affording dimethyl9-isopropxlidene-cis-bicyclo[4. 3. 0 ] nonane-(2S)-2, 3-dicarboxylate(7) as the ultimate product. The structure of 7 was confirmed by single crystal X-ray analysis 展开更多
关键词 REARRANGEMENT Isopropylidene Base catalyzed
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