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Reduction of the oxidative damage to H_(2)O_(2)-induced HepG2 cells via the Nrf2 signalling pathway by plant flavonoids Quercetin and Hyperoside
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作者 Meijing Zhang Gaoshuai Zhang +10 位作者 Xiangxing Meng Xinxin Wang Jiao Xie Shaoshu Wang Biao Wang Jilite Wang Suwen Liu Qun Huang Xu Yang Jing Li Hao Wang 《Food Science and Human Wellness》 SCIE CAS CSCD 2024年第4期1864-1876,共13页
Hyperoside and quercetin are similar in molecular structures.In this study,the antioxidant regulatory targets of hyperoside and quercetin are mainly in the nuclear factor(erythroid-2-derived)-related factor 2(Nrf2)pat... Hyperoside and quercetin are similar in molecular structures.In this study,the antioxidant regulatory targets of hyperoside and quercetin are mainly in the nuclear factor(erythroid-2-derived)-related factor 2(Nrf2)pathway predicted by network pharmacology.And the antioxidant effect and mechanism of hyperoside and quercetin were measured and compared in H_(2)O_(2)-induced Hep G2 cells and Caenorhabditis elegans.The findings indicated that quercetin was more effective than hyperoside in reducing oxidative damage,which was proved by improved cell viability,decreased reactive oxygen species(ROS)production,decreased cellular apoptosis,and alleviated mitochondrial damage.In addition,quercetin was more efficient than hyperoside in enhancing the expression of Nrf2-associated m RNAs,increasing the activities of superoxide dismutase(SOD),glutathione peroxidase(GSH-Px),and catalase(CAT),and reducing the cellular malondialdehyde(MDA)content.Quercetin was superior to hyperoside in prolonging the lifespan of worms,decreasing the accumulation of lipofuscin,inhibiting ROS production,and increasing the proportion of skn-1 in the nucleus.With the Nrf2 inhibitor ML385,we verified that quercetin and hyperoside primarily protected the cells against oxidative damage via the Nrf2 signalling pathway.Furthermore,molecular docking and dynamics simulations demonstrated that the quercetin-Kelch-like ECH-associated protein 1(Keap1)complex was more stable than the hyperoside-Keap1 complex.The stable structure of the complex might hinder the binding of Nrf2 and Keap1 to release Nrf2 and facilitate its entry into the nucleus to play an antioxidant role.Overall,quercetin had a better antioxidant than hyperoside. 展开更多
关键词 HYPEROSIDE QUERCETIN HepG2 cell Oxidative damage Nrf2 signalling pathway
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Composition optimization and performance prediction for ultra-stable water-based aerosol based on thermodynamic entropy theory
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作者 Tingting Kang Canjun Yan +6 位作者 Xinying Zhao Jingru Zhao Zixin Liu Chenggong Ju Xinyue Zhang Yun Zhang Yan Wu 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第3期437-446,共10页
Water-based aerosol is widely used as an effective strategy in electro-optical countermeasure on the battlefield used to the preponderance of high efficiency,low cost and eco-friendly.Unfortunately,the stability of th... Water-based aerosol is widely used as an effective strategy in electro-optical countermeasure on the battlefield used to the preponderance of high efficiency,low cost and eco-friendly.Unfortunately,the stability of the water-based aerosol is always unsatisfactory due to the rapid evaporation and sedimentation of the aerosol droplets.Great efforts have been devoted to improve the stability of water-based aerosol by using additives with different composition and proportion.However,the lack of the criterion and principle for screening the effective additives results in excessive experimental time consumption and cost.And the stabilization time of the aerosol is still only 30 min,which could not meet the requirements of the perdurable interference.Herein,to improve the stability of water-based aerosol and optimize the complex formulation efficiently,a theoretical calculation method based on thermodynamic entropy theory is proposed.All the factors that influence the shielding effect,including polyol,stabilizer,propellant,water and cosolvent,are considered within calculation.An ultra-stable water-based aerosol with long duration over 120 min is obtained with the optimal fogging agent composition,providing enough time for fighting the electro-optic weapon.Theoretical design guideline for choosing the additives with high phase transition temperature and low phase transition enthalpy is also proposed,which greatly improves the total entropy change and reduce the absolute entropy change of the aerosol cooling process,and gives rise to an enhanced stability of the water-based aerosol.The theoretical calculation methodology contributes to an abstemious time and space for sieving the water-based aerosol with desirable performance and stability,and provides the powerful guarantee to the homeland security. 展开更多
关键词 Ultra-stable Water-based aerosol Thermodynamic entropy Composition optimization Performance prediction
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Synthesis and Characterization of Novel Layered Lithium Sodium Silicate (Silinaite) and the Mesoporous Materials from Silinaite 被引量:1
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作者 Chun Hui ZHOU Hong Qiang GUO Hui Jun CAO Xiao Nian LI Zhong Hua GE Jie LI 《Chinese Chemical Letters》 SCIE CAS CSCD 2006年第4期525-528,共4页
Novel layered silinaite has been synthesized using an aqueous mixture of water glass, LiOH and NaOH under hydrothermal crystallization. Subsequently transformation of silinaite into mesoporous materials (SDM) was ac... Novel layered silinaite has been synthesized using an aqueous mixture of water glass, LiOH and NaOH under hydrothermal crystallization. Subsequently transformation of silinaite into mesoporous materials (SDM) was achieved at mild condition using cetyltfimethylammonium bromide as structure-directing agents. The resulting samples were characterized by XRD, SEM, FTIR nitrogen adsorption-desorption isotherms and catalytic performance in bulky molecular involved reaction. The results revealed that synthesized mesoporous materials derived from the silinaite exhibited an ordered hexagonal crystal structure with average pore diameter 2.7 nm and BET surface area 817m^2/g. The SDM-supported ZnCl2 catalyst, prepared by impregnationevaporation method, retained the mesoporous structure and showed high selectivity in alkylation of benzene with benzyl chloride. 展开更多
关键词 Silinaite mesoporous materials layered solid CATALYSTS characterization.
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Fabrication of polypyrrole/TiO_2 nanocomposite via electrochemical process and its photoconductivity 被引量:1
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作者 欧阳密 白茹 +4 位作者 徐意 张诚 马淳安 汪茫 陈红征 《中国有色金属学会会刊:英文版》 EI CSCD 2009年第6期1572-1577,共6页
Size-controllable and vertically-oriented TiO2 nanotube(TNT)arrays were fabricated using anodic oxidation method from pure titanium sheets in electrolyte solutions.Then with the TNT arrays as the working electrode,a t... Size-controllable and vertically-oriented TiO2 nanotube(TNT)arrays were fabricated using anodic oxidation method from pure titanium sheets in electrolyte solutions.Then with the TNT arrays as the working electrode,a thin film of polypyrrole(Ppy)was synthesized into the TNT arrays via the electrochemical polymerization.During the process,the appearance of redox peaks in cyclic voltammetry curves of the resulting films indicates the occurrence of polymerization.The morphology,the molecular structure, crystallization and optical properties of the TNT arrays and the resulting polymer were investigated by field-emission scanning electron microscopy(FESEM),X-ray diffractometry(XRD),Fourier transform infrared spectroscopy(FTIR),and UV-vis spectrum analysis,respectively.A dual-layered photoreceptor containing the nanocomposite film as the charge generation layer(CGL)was designed and fabricated.It is found that the photoreceptor based on Ppy/TiO2 nanotubes as CGL exhibits remarkable photoconductive performance. 展开更多
关键词 TIO2纳米管 复合材料制备 电化学过程 光电导 傅立叶变换红外光谱 纳米复合薄膜 TNT炸药 电化学聚合
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Influences of Sintering Process of Sprayed Precursors on the Struc-ture and Electrochemical Properties of LiMn_2O_4 Cathode Material
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作者 Hui HUANG Chen WANG Lei ZHANG Yongping GAN Wenkui ZHANG 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2008年第2期211-214,共4页
Well-defined spinel LiMn2O4 powders were synthesized via sintering a precursor, which was prepared by spraydrying method. The effects of sintering process on the structure and electrochemical properties of LiMn2O4 wer... Well-defined spinel LiMn2O4 powders were synthesized via sintering a precursor, which was prepared by spraydrying method. The effects of sintering process on the structure and electrochemical properties of LiMn2O4 were discussed. It was found that a single sintering could not synthesize a pure LiMn2O4 compound, while two-step sintering procedure consisting of decomposing sprayed precursors at 350℃ and further sintering at an elevated temperature leads to the formation of a single-phased LiMn2O4 with homogeneous particle size distribution. As compared to that sintered in air, the two-step sintered LiMn2O4 in oxygen shows tighter structure and more uniform particle size, as well as better electrochemical properties. It delivers an initial discharge capacity of 131 mAh·g^-1 (1/10C), and still has excellent cycling stability at higher rate (1/5C). 展开更多
关键词 Spinel LiMn2O4 Spray-drying method Li-ion batteries SINTERING
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Numerical Simulation and Analysis of Gas Flow Field in Serrated Valve Column 被引量:12
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作者 王良华 崔觉剑 姚克俭 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2008年第4期541-546,共6页
A three-dimensional computational fluid dynamics (CFD) model for gas flow through a serrated valve tray was presented. The flow field, as well as the dry-pressure drop of the valve under the full-opening condition w... A three-dimensional computational fluid dynamics (CFD) model for gas flow through a serrated valve tray was presented. The flow field, as well as the dry-pressure drop of the valve under the full-opening condition was simulated based on the proposed model by using FLUENT 6.0 software. Compared with the values of dry-pressure dro.p in different turbulent models, the.simulated.results using RNG κ-ε model are in reasonable agreement with experimental data, indicating that RNG κ-ε model is suitable in simulating gas flow through the serrated valve tray. Then the CFD model combining RNG κ-ε model was used to study the three-dimensional gas flow through the considered serrated valve tray. The simulated results showed that various eddies existed on the serrated valve tray, and both the eddy and the non-eddy areas were nearly equal. The existence of addendum can decrease the eddy area caused by gas passing through the lateral outlet slots. The size of eddies can be reduced by optimizing the distance between valves. 展开更多
关键词 serrated valve numerical simulation pressure drop RNG κ-ε turbulent model
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Thermodynamic modeling and phase diagram prediction of salt lake brine systems.Ⅰ. Aqueous Mg^2+–Ca^2+–Cl^- binary and ternary systems 被引量:10
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作者 Huan Zhou Xiaolong Gu +4 位作者 Yaping Dai Jingjing Tang Jian Guo Guangbi Li Xiaoqin Bai 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2020年第9期2391-2408,共18页
Salt lake brine is a complex salt-water system under natural environment.Although many models can express the thermodynamic properties and phase equilibrium of electrolyte aqueous solution,the multi-temperature charac... Salt lake brine is a complex salt-water system under natural environment.Although many models can express the thermodynamic properties and phase equilibrium of electrolyte aqueous solution,the multi-temperature characteristics and predictability are still the goals of model development.In this study,a comprehensive thermodynamic model system is re-established based on the eNRTL model and some improvements:(1) new expression of long-range electrostatic term with symmetrical reference state is proposed to handle the electrolyte solution covering entire concentration range;(2) the temperature dependence of the binary interaction parameters is formulated with a Gibbs Helmholtz expression containing three temperature coefficients,the liquid parameters,which associated with Gibbs energy,enthalpy,and heat capacity contribution;and(3) liquid parameters and solid species data are regressed from properties and solubility data at full temperature range.Together the activity coefficient model,property models and parameters of liquid and solid offer a comprehensive thermodynamic model system for the typical bittern of MgCl2-CaCl2-H2 O binary and ternary systems,and it shows excellent agreement with the literature data for the ternary and binary systems.The successful prediction of complete phase diagram of ternary system shows that the model has the ability to deal with high concentration and high non-idealitv system,and the ability to extrapolate the temperature. 展开更多
关键词 Aqueous electrolytes Comprehensive thermodynamic model MgCl2-CaCl2-H2O Phase diagram Thermodynamic properties
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Preparation,Characterization of Dawson-type Heteropoly Acid Cerium(Ⅲ) Salt and Its Catalytic Performance on the Synthesis of n-Butyl Acetate 被引量:9
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作者 曹小华 任杰 +3 位作者 徐常龙 张康华 占昌朝 蓝健 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2013年第5期500-506,共7页
A novel cerium(Ⅲ) salt of Dawson type tungstophosphoric acid(Ce2P2W18O62·16H2O) was prepared by doping cerous nitrate in H6P2W18O62·13H2O powder and characterized by thermogravimetry and differential therma... A novel cerium(Ⅲ) salt of Dawson type tungstophosphoric acid(Ce2P2W18O62·16H2O) was prepared by doping cerous nitrate in H6P2W18O62·13H2O powder and characterized by thermogravimetry and differential thermal analyses(TG/DTA),Fourier transform infrared spectroscopy(FT-IR),X-ray powder diffraction(XRD),pyridine infrared spectroscopy(Py-IR) and scanning electron microscopy(SEM).Its catalytic activity was evaluated by the probe reaction of synthesis of n-butyl acetate with acetic acid and n-butanol.The effects of various parameters such as molar ratio of n-butanol to acetic acid,reaction temperature,reaction time,and catalyst amount have been studied by single factor experiment.The results show that Ce2P2W18O62·16H2O behaved as an excellent heterogeneous catalyst in the synthesis of n-butyl acetate.The optimum synthetic conditions were determined as follows︰molar ratio of n-butanol to acetic acid at 2.0︰1.0,mass of the catalyst being 1.44% of the total reaction mixture,reaction temperature of 120 ℃ and reaction time of 150 min.Under above conditions,the conversion of acetic acid was above 97.8%.The selectivity of n-butyl acetate based on acetic acid was,in all cases,nearly 100%.The catalysts could be recycled and still exhibited high catalytic activity with 90.4% conversion after five cycles of reaction.It was found by means of TG-DTA and Py-IR that the catalyst deactivation was due to the adsorption of a complex of by-product on the active sites on catalysts surface or the catalyst loss in its separation from the products.Compared with using sulfuric acid as catalyst,the present procedure with Ce2P2W18O62·16H2O is a green productive technology due to simple process,higher yield,catalyst recycling and no corrosion for the production facilities. 展开更多
关键词 cerous phosphotungstate Dawson structure CATALYST ESTERIFICATION n-butyl acetate
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Thermodynamic modeling and phase diagram prediction of salt lake brine systemsⅡ.Aqueous Li^(+)-Na^(+)-K^(+)-SO_(4)^(2-) and its subsystems 被引量:7
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作者 Huan Zhou Peng Wu +3 位作者 Wenxuan Li Xingfan Wang Kuo Zhou Qing Hao 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2021年第6期134-149,共16页
It is still a challenging task to accurately and temperature-continuously express the thermodynamic properties and phase equilibrium behaviors of the salt-lake brine with multi-component,multitemperature and high conc... It is still a challenging task to accurately and temperature-continuously express the thermodynamic properties and phase equilibrium behaviors of the salt-lake brine with multi-component,multitemperature and high concentration.The essential subsystem of sulfate type brine,aqueous Li^(+)-Na^(+)-K^(+)-SO_(4)^(2-) and its subsystems across a temperature range from 250 K to 643 K are investigated with the improved comprehensive thermodynamic model.Liquid parameters(Δg_(IJ),Δh_(IJ),and ΔC_(p,IJ))associated with the contributions of Gibbs energy,enthalpy,and heat capacity to the binary interaction parameters,i.e.the temperature coefficients of eNRTL parameters formulated with a Gibbs Helmholtz expression,are determined via multi-objective optimization method.The solid constantsΔ_(f)G_(k)°^((298.15))andΔ_(f)H_(k)°^((298.15))of11 solid species occurred in the quaternary system are rebuilt from multi-temperature solubilities.The modeling results show the accurate representation of(1)solution properties and binary phase diagram at temperature ranges from eutectic points to 643 K;(2)isothermal phase diagrams for Li_(2)SO_(4)-Na_(2)SO_(4)-H_(2)O,Li_(2)SO_(4)-K_(2)SO_(4)-H_(2)O and Na_(2)SO_(4)-K_(2)SO_(4)-H_(2)O ternary systems.The predicted results of complete structure and polythermal phase diagram of ternary systems and the isothermal phase diagrams of quaternary system excellently match with the experimental data. 展开更多
关键词 Aqueous electrolytes Comprehensive thermodynamic model Aqueous Li^(+)-Na^(+)-K^(+)-SO_(4)^(2-) Phase diagram Thermodynamic properties
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Preparation of Ti/PTFE-F-PbO2 Electrode with a Long Life from the Sulfamic Acid Bath and Its Application in Organic Degradation 被引量:5
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作者 洪夏萍 张蓉 +1 位作者 童少平 马淳安 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2011年第6期1033-1038,共6页
A polytetrafluoroethylene (PTFE)-doped PbO2 electrode on a Ti substrate was prepared by galvanostatic method from the sulfamic acid bath (Ti/PTFE-F-PbO2-I) or nitric acid bath (Ti/PTFE-F-PbO2-II). Scanning Elect... A polytetrafluoroethylene (PTFE)-doped PbO2 electrode on a Ti substrate was prepared by galvanostatic method from the sulfamic acid bath (Ti/PTFE-F-PbO2-I) or nitric acid bath (Ti/PTFE-F-PbO2-II). Scanning Electron Microscopy revealed that the Ti/PTFE-PbO2-I electrode had a more regular morphology with smaller size crystals than the Ti/PTFE-F-PbO2-II electrode. On the basis of the results of both the accelerated electrolysis test and the empirical formula for estimating the service life of an electrode, the service life of the Ti/PTFE-PbO2-I electrode was predicted to be more than 7 years under conventional electrolysis conditions (0.1 A·cm^-2). During the treatment of 4-chlorophenol-contaminated water, the Ti/PTFE-PbO2-I anode showed both a good electro-catalytic activity and high electrochemical stability, exhibiting an excellent potential application. 展开更多
关键词 lead dioxide sulfamic acid electrochemical oxidation 4-CHLOROPHENOL
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Structure and Properties of Hydrotalcite Using Electrostatic Potential Energy Model 被引量:4
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作者 Zhe-ming Ni Guo-xiang Pan +3 位作者 Li-geng Wang Wei-hua Yu Cai-ping Fang Dan Li 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 北大核心 2006年第3期277-280,共4页
The electrostatic potential energy model of hydrotalcites was based on the theory of crystallography. The anionic potential energy of MgAl-hydrotalcites, with 20 layers and 2107 anions per layer, was calculated, and t... The electrostatic potential energy model of hydrotalcites was based on the theory of crystallography. The anionic potential energy of MgAl-hydrotalcites, with 20 layers and 2107 anions per layer, was calculated, and the anionic stability of the hydrotalcites was investigated. The charge density of the layer and the distance between the adjacent anions varied with the molar ratio of Al^3+/(Mg^2+ + Al^3+). Anionic potential energy depended on the charge and size of the anions. Calculation results remained consistent with thermal stability and the ion exchange ability reported. This model is able to predict anionic stability of the hydrotalcites. 展开更多
关键词 HYDROTALCITE Electrostatic potential energy model Thermal stability Ion exchange
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Processing,microstructure and mechanical properties of bimodal size SiCp reinforced AZ31B magnesium matrix composites 被引量:7
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作者 M.J.Shen M.F.Zhang W.F.Ying 《Journal of Magnesium and Alloys》 SCIE EI CAS 2015年第2期162-167,共6页
The bimodal size SiC particulates(SiCp)reinforced magnesium matrix composites with different ratios of micron SiCp and nano SiCp(M-SiCp:N-SiCp=14.5:0.5,14:1,and 13.5:1.5)were prepared by semisolid stirring assisted ul... The bimodal size SiC particulates(SiCp)reinforced magnesium matrix composites with different ratios of micron SiCp and nano SiCp(M-SiCp:N-SiCp=14.5:0.5,14:1,and 13.5:1.5)were prepared by semisolid stirring assisted ultrasonic vibration method.The AZ31B alloy and all as-cast SiCp/AZ31B composites were extruded at 350℃ with the ratio of 12:1.Microstructural characterization of the extruded M14+N1(M-SiCp:N-SiCp=14:1)composite revealed the uniform distribution of bimodal size SiCp and significant grain refinement.Optical Microscopy(OM)observation showed that,compared with the M14.5+N0.5(M-SiCp:N-SiCp=14.5:0.5)composite,there are more recrystallized grains in M14+N1(M-SiCp:N-SiCp=14:1)and M13.5+N1.5(M-SiCp:N-SiCp=13.5:1.5)composites,but in comparison to the M13.5+N1.5 composite,the average grain size of the M14+N1 composite is slightly decreased.The evaluation of mechanical properties indicated that the yield strength and ultimate tensile strength of the M14+N1 composite were obviously increased compared with other composites. 展开更多
关键词 Magnesium matrix composite Microstructure Mechanical properties
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A simple and efficient synthesis of 2-substituted benzothiazoles catalyzed by H_2O_2/HCl 被引量:4
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作者 Hong Yun Guo Ji Chao Li You Le Shang 《Chinese Chemical Letters》 SCIE CAS CSCD 2009年第12期1408-1410,共3页
A simple and efficient procedure for the synthesis of substituted benzothiazoles through condensation of 2-aminothiophenol with aromatic aldehydes in the presence of H2O2/HCl system in ethanol at room temperature is d... A simple and efficient procedure for the synthesis of substituted benzothiazoles through condensation of 2-aminothiophenol with aromatic aldehydes in the presence of H2O2/HCl system in ethanol at room temperature is described. The target compounds have been characterized by ^1H NMR, ^13C NMR, IR and MS. Short reaction time, easy and quick isolation of the products, and excellent yields are the main advantages of this procedure. 展开更多
关键词 2-Substituted benzothiazoles Heterocyclic compounds H2O2/HCl
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Synthesis and Crystal Structure of the Diiron Azadithiolate Complex [(μ-SCH_2)_2NPh]Fe_2(CO)5(Ph_2PCH_2PPh_2) 被引量:5
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作者 刘旭锋 肖勋文 刘幸海 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2011年第10期1437-1441,共5页
Reaction of [(μ-SCH2)2NPh]Fe2(CO)6 with Ph2PCH2PPh2 in the presence of Me3NO·2H2O gave the title complex [(μ-SCH2)2NPh]Fe2(CO)5(Ph2PCH2PPh2)(1)in 78% yield.The new complex 1 was characterized by ele... Reaction of [(μ-SCH2)2NPh]Fe2(CO)6 with Ph2PCH2PPh2 in the presence of Me3NO·2H2O gave the title complex [(μ-SCH2)2NPh]Fe2(CO)5(Ph2PCH2PPh2)(1)in 78% yield.The new complex 1 was characterized by elemental analysis,spectroscopy and X-ray crys-tallography.It crystallizes in triclinic,space group P1 with a = 10.832(2),b = 12.003(2),c = 15.579(3),V = 1785.6(6)3,Z = 2,C32H26Fe2NO5PS2,Mr = 819.40,Dc = 1.524 g/cm3,μ(MoKα)= 1.064 mm-1,F(000)= 840,T = 113(2)K,the final R = 0.0543 and wR = 0.1218 for 6203 observed reflections(I 2σ(I)).The Ph2PCH2PPh2 ligand resides in an axial position of the square-pyramidal coordination sphere of the Fe atom and trans to the benzene ring in order to reduce the steric repulsion between Ph2PCH2PPh2 and the benzene ring. 展开更多
关键词 diiron azadithiolate SYNTHESIS crystal structure
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Surface Acidity of Aluminum Phosphate and Its Catalytic Performance in Benzene Alkylation with Long Chain Olefin 被引量:2
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作者 YUAN Haikuan LIU Xuru REN Jie SHEN Lian 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2013年第6期627-632,共6页
The acidic properties of aluminum phosphate (A1PO4-5) solid acid catalyst were characterized by tem- perature programmed desorption (TPD) of ammonia (NH3), n-propylamine (n-C3HTNH2), iso-propylamine [(CH3)2C... The acidic properties of aluminum phosphate (A1PO4-5) solid acid catalyst were characterized by tem- perature programmed desorption (TPD) of ammonia (NH3), n-propylamine (n-C3HTNH2), iso-propylamine [(CH3)2CHNH2] and n-dipropylamine [(C3H7)2NH] separately, and its catalytic performance in benzene alkylation with long chain olefin was studied in a fixed-bed reactor. The characterized acid amount of catalyst increased with the basicity of adsorbates. With increase of the activation temperature of catalyst, the acid amount characterized by NHa-TPD decreased, however, it increased when characterized by TPD using three other adsorbates. The desorption kinetics of TPD process and the deactivation kinetics of catalyst were investigated. The acidity and catalytic per- formance of catalyst was also correlated. The results showed that the acid amount and strength are well correlated with the activity and stability using NH3 as adsorbate, respectively, which indicated NH3 was a better basic adsorbate. It was also found that the catalyst with higher acid amount and lower acid strength on the surface exhibited the better catalytic performance and stability. 展开更多
关键词 suuface acidity temperature'programmed desorption basic adsorbate benzene alkylation catalytic activity
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Titanium-Containing Mesoporous Materials: Synthesis and Application in Selective Catalytic Oxidation 被引量:2
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作者 Jie Li Chunhui Zhou Huali Xie Zhonghua Ge Liangcai Yuan Xiaonian Li 《Journal of Natural Gas Chemistry》 EI CAS CSCD 2006年第3期164-177,共14页
Titanium-containing mesoporous molecular sieves are of great significance in selective catalytic oxidation processes with bulky molecules. Recent researches and developments on the designing and synthesis of Ti-contai... Titanium-containing mesoporous molecular sieves are of great significance in selective catalytic oxidation processes with bulky molecules. Recent researches and developments on the designing and synthesis of Ti-containing mesoporous materials have been reviewed. Various strategies for the preparation of Ti-containing mesoporous materials, such as direct synthesis and post-synthesis, are described. Modifications of Ti-containing mesoporous materials by surface-grafting and atom-planting are also discussed. All approaches aimed mainly at the improving of the stability, the hydrophobicity, and mostly the catalytic activity. Structural and mechanistic features of various synthetic systems are discussed. Ticontaining mesoporous materials in liquid phase catalytic oxidation of organic compounds with H2O2 as an oxidant is briefly summarized, showing their broad utilities for green synthesis of fine chemicals by catalytic oxidative reactions. 展开更多
关键词 mesoporous materials TITANIUM molecular sieve zeolites CHARACTERIZATION catalytic oxidation
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Electrocatalytic oxidation of methanol on carbon-nanotubes/graphite electrode modified with platinum and molybdenum oxide nanoparticles 被引量:1
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作者 甘永平 黄辉 张文魁 《中国有色金属学会会刊:英文版》 SCIE EI CAS CSCD 2007年第1期214-219,共6页
Electrochemical codeposition and electrocatalytic properties of platinum and molybdenum oxide nanoparticles(Pt-MoOx) on carbon-nanotubes/graphite electrode for methanol oxidation were investigated.The micrograph and e... Electrochemical codeposition and electrocatalytic properties of platinum and molybdenum oxide nanoparticles(Pt-MoOx) on carbon-nanotubes/graphite electrode for methanol oxidation were investigated.The micrograph and elemental composition of the resulting Pt-MoOx/CNTs/graphite electrode were characterized by scanning electron microscopy(SEM)and energy dispersive X-ray spectroscopy(EDS).The results show that the Pt-MoOx particles with the average size of about 50 nm are highly dispersed on the CNTs surface.The Pt-MoOx/CNTs/graphite electrode delivers excellent electrocatalytic properties for methanol oxidation.The highest mass activity(Am)reaches 264.8 A/g at the loading mass of 159.3μg/cm2.This may be attributed to the small particle size and high dispersion of Pt-MoOx catalysts deposited on the CNTs surface.The kinetic analysis from electrochemical impedance spectroscopy(EIS)reveals that the existed MoOx phase can improve the chemisorptive and catalytic properties for methanol oxidation. 展开更多
关键词 甲醇 氧化反应 碳管 燃料电池 单化学
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Reaction kinetics for the heterogeneously resin-catalyzed and homogeneously self-catalyzed esterification of thioglycolic acid with 2-ethyl-1-hexanol 被引量:1
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作者 Xiaoda Wang Wenkai Li +4 位作者 Shiwei Wang Qinglian Wang Ling Li Hongxing Wang Ting Qiu 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2021年第8期111-119,共9页
Producing 2-ethyl-1-hexyl thioglycolate(ETE)via esterification reaction with thioglycolic acid(TGA)aqueous solution as raw material by reactive-separation coupling technology is a promising process intensification met... Producing 2-ethyl-1-hexyl thioglycolate(ETE)via esterification reaction with thioglycolic acid(TGA)aqueous solution as raw material by reactive-separation coupling technology is a promising process intensification method.To choose suitable reactive-separation coupling strategy,the kinetic studies of the esterification of TGA with 2-ethyl-1-hexanol(EHL)were carried out in a batch system.The commercial ion exchange resin was employed as an eco-friendly catalyst.The effects of temperature,catalyst concentration and molar ratio were determined.It was interesting to observe that the equilibrium conversion of TGA increased with the increase of catalyst mass fraction due to the adsorption of product water onto resin surface.The activity-based pseudo-homogeneous(PH),Eley-Rideal(ER)and Langmuir-Hinshelwood-Ho ugen-Watson(LHHW)models were used to fit the kinetics data of the resin-catalyzed reaction.The models of ER and LHHW performed better than the PH model.The kinetics of the TGA-self-catalyzed reaction was also determined.An activity-based homogeneous kinetics model could well describe this self-catalyzed reaction.These results would be meaningful to the selection and design of an appropriate reactionseparation strategy for the production of ETE,to realize the process intensification. 展开更多
关键词 Kinetics AUTOCATALYSIS Kinetic modeling 2-Ethyl-1-hexyl thioglycolate ESTERIFICATION Ion exchange resin
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Synthesis and Photoluminescence of Ln^(3+) Doped TiO_2 Nanocrystal 被引量:1
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作者 潘再法 段昌奎 《Journal of Rare Earths》 SCIE EI CAS CSCD 2007年第S1期268-272,共5页
Eu3+ doped TiO2 nanocrystals were prepared by the hydrothermal method and characterized by XRD, ESEM, IR, UV absorption and emission spectra. XRD and ESEM micrograph revealed that the samples are in pure rutile phase.... Eu3+ doped TiO2 nanocrystals were prepared by the hydrothermal method and characterized by XRD, ESEM, IR, UV absorption and emission spectra. XRD and ESEM micrograph revealed that the samples are in pure rutile phase. Emission spectra under 355 nm radiative were measured to characterize the spectroscopic properties, which showed that the samples probably contain trace Tb3+ ions. The energy transfer mechanism from rutile TiO2 to the 4f shell of Tb3+ and Eu3+ was discussed in connection with the excitation and emission properties of the samples. 展开更多
关键词 hydrothermal method TiO_2 nanocrystal PHOTOLUMINESCENCE energy transfer rare earths
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Modeling VLE and GLE of Systems Involving Polymers by Using SRK Equation of State 被引量:1
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作者 计伟荣 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2007年第2期221-227,共7页
A simple extension of cubic equations of state(EOS)to polymer systems has been proposed.The So-ave-Redlich-Kwong(SRK)EOS was taken as a prototype to be used to describe the PVT behavior of polymer melts in a wide temp... A simple extension of cubic equations of state(EOS)to polymer systems has been proposed.The So-ave-Redlich-Kwong(SRK)EOS was taken as a prototype to be used to describe the PVT behavior of polymer melts in a wide temperature and pressure range.Combined with a modified Huron-Vidal gE-mixing rule it was applied for modeling vapor-liquid equilibria of polymer-solvent solutions and the solubility of supercritical gases in polymer melts.Satisfactory results are obtained. 展开更多
关键词 SRK equation of state POLYMER phase equilibrium PVT behavior.
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