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Rheological Behavior of Polymer Melts and Concentrated SolutionsPart V: A New Molecular Theory of Non-linear Viscoelasticity for Polymeric Suspensions

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Journal of Materials Science & technology 1999年第2期15卷 169-177页

作者： Song, MS Zhou, W Hu, GX Hu, LJ beijing Univ chem technol Inst Polymer Mat Beijing 100029 Peoples R China Harbin inst technol Dept Appl Chem Harbin 150001 Peoples R China

A double-network model is established, which consists of the segments, E and A-constituent chains, the polymeric chains entangled with other ones by multi-entanglement and polymeric chains connected to a great number of destructible particles by multi-adsorption, based on which the E and A-constituent chains can be recreated and released dynamically. The distribution function of the end-to-end vector, the statistical distribution function of conformation for two kinds of chains in the multi-entanglement and multi-adsorption states and their number of polymeric chains are calculated by the combination of statistical mechanics and kinetics. Then the viscoelastic free energies of deformation for two kinds of the networks and suspensions are calculated by Boltzmann's statistical theory. Also, elastic modulus and memory function for two kinds of the network and suspensions are derived. Consequently, a new molecular theory df the non-linear viscoelasticity for polymeric suspensions is proposed, and the constitutive equation and material function with yielding and thinning for the polymeric suspensions in different flow fields are derived from this theory.

关键词： Polymers

Excellent Cracking Performance of Macroporous Amorphous Aluminosilicate Catalyst

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China Petroleum Processing & Petrochemical technology 2010年第2期12卷 22-28页

作者： Xu Xin Zhao Tianbo Qi Jian Miao Ce (The institute for chemical Physics,beijing institute of technology,beijing 100081) beijing inst technol Inst Chem Phys Beijing 100081 Peoples R China

Micrometer-scale macroporous aluminosilicate catalyst was prepared via the sol-gel process. Results of catalytic cracking of 1, 3, 5-triisopropylbenzene showed that the synthesized aluminosilicate catalyst exhibited much higher activity than traditional ZSM-5 zeolite under the same condition. It is worth mentioning that the polymer product selectivity of aluminosilicate was much lower than that of ZSM-5, which might be useful for implementing the catalytic cracking process. The unique structure of macroporous aluminosilicate with interconnected-macropores and continuous skeletons was believed to be responsible for its excellent catalytic activity and low polymer product selectivity. Detailed discussion on the reaction pathway was also conducted.

关键词： aluminosilicate macroporous 1,3,5-triisopropylbenzene reaction pathway

Two Side Chain β-CD Polysiloxanes Used as New Stationary Phase for Chiral Separation by HRGC

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Chinese chemical Letters 1997年第2期8卷 165-166页

作者： Han Bang ZHANG Yun LING Ruo Nong FU Yu Xiu WEN(Department of chemical Engineering. beijing institute of technology. beijing 100081) beijing inst technol DEPT CHEM ENGNBEIJING 100081PEOPLES R CHINA

Two new stationary phases : (Ⅰ) [bikis(2,6-di-O-pentyl-3-O-hex-6O-pentyl-3-O-methyl)-β-CD-polysiloxane] and (Ⅱ) [heptkis(2,6-di-O-methyl-3-O-hex-6-enyl)-β-CD-polysiloxane] were synthesized and successfully used fo... 详细信息

关键词： HRGC CD Polysiloxanes Used as New Stationary Phase for Chiral Separation by HRGC Two Side Chain

A Surface Tension Model for Liquid Mixtures Based on NRTL Equation

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Chinese Journal of chemical Engineering 2001年第1期9卷 45-50页

作者：李春喜汪文川 beijing Univ chem technol Coll Chem Engn Beijing 100029 Peoples R China

A new equation for predicting surface tension is proposed based on the thermodynamic definition of surface tension and the expression of the Gibbs free energy of the system. Using the NRTL equation to represent the excess Gibbs free energy, a two-parameter surface tension equation is derived. The feasibility of the new equation has been tested in terms of 124 binary and 16 multicomponent systems(13-ternary and 3-quaternary) with absolute relative deviations of 0.59% and 1.55% respectively. This model is also predictive for the temperature dependence of surface tension of liquid mixtures. It is shown that, with good accuracy, this equation is simple and reliable for practical use.

关键词： model surface tension liquid mixtures Gibbs free energy NRTL equation

Dynamic Kinetics of Methanol Synthesis over a Commercial Copper-Based Catalyst

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Chinese Journal of chemical Engineering 2000年第4期8卷 315-320页

作者：陈晓春李成岳饶国瑛 beijing Univ chem technol Coll Chem Engn Beijing 100029 Peoples R China

Adsorption, surface reaction and process dynamics on the surface of a commercial copper-based catalyst for methanol synthesis from CO/CO2/H2 were systematically studied by means of temperature programmed desorption (TPD), temperature programmed surface reaction (TPSR), in-situ Fourier transform-inferred spec-troscopy(FTIR) and stimulus-response techniques. As a part of results, an elementary step sequence was suggested and a group of ordinary differential equations (ODEs) for describing transient conversations relevant to all species on the catalyst surface and in the gas phase in a micro-fixed-bed reactor was derived. The values of the parameters referred to dynamic kinetics were estimated by fitting the solution of the ODEs with the transient response data obtained by the stimulus-response technique with a FTIR analyzer as an on-line detector.

关键词： methanol synthesis copper-based catalyst dynamic kinetics elementary step sequence parameter estimation

HYDRODYNAMIC MODEL FOR THE IMPELLER REGION IN AN AERATED AND STIRRED TANK

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Chinese Journal of chemical Engineering 1996年第2期4卷 50-58页

作者：高正明王英琛施力田傅举孚 beijing UNIV chem technol DEPT CHEM ENGNBEIJING 100029PEOPLES R CHINA

The radial and axial distribution of mean 1iquid velocity were measured by ***-filmanemometer at the impeller region in an aerated and stirred tank 0.287m in *** tangentialjet model for impeller discharge flow used for single phase flow was modified to conform with thecharacteristics of gas-liquid *** radial and axial velocity profiles at the impeller region in thegas-liquid stirred tank were calculated by the model The results predicted by the model were in goodagreement with those obtained in experiment.

关键词： hydrodynamic model gas-liquid stirred tank agitated tank mean liquid velocity velocity

A Numerical Study on Fully Developed Fluid Flow and Heat Transfer in a Spiral Finned Tube

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Chinese Journal of chemical Engineering 1999年第1期7卷 56-66页

作者：张建文张政 beijing Univ chem technol Coll Chem Engn Beijing 100029 Peoples R China

In this paper, the standard k-ε two-equation model is adopted to numerically simulate fully developed fluid flow and heat transfer in a spiral finned tube within a cracking furnace for ethylene manufacturing. By variable transformation, the original 3-D problem is converted into a 2-D problem in spiral coordinates. The algorithm of SIMPLEC is used to study the fully developed fluid flow and heat transfer in the spiral finned tube at constant periphery temperature and constant axial heat flux. The computed results agree pretty well with the experimental data obtained from the industry. Further studies on the fluid flows and temperature profiles at different Reynolds numbers within straight and spiral finned tubes are conducted and the mechanisms involved are explored. It is found that with the spiral finned tube, pressure drop increases to a great extent whereas heat transfer tends to be decreased.

关键词： fluid flow and heat transfer numerical simulation finned tube spiral finned tube spiral coordinates system

Interaction of Each Component in Ni-Ln_2O_3/γ-Al_2O_3 System

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Journal of Rare Earths 2001年第4期19卷 255-259页

作者：郝茂荣冯文林安智华 Baotou Iron & Steel inst Dept Chem Engn Baotou 014010 Peoples R China beijing inst chem technol Dept Appl Chem Beijing 100029 Peoples R China

The surface functions produced by adding 14 rare earth oxides in Ni/γ Al 2O 3 system were determined by BET, gas chromatography, infrared spectroscopy, XRD, SEM, X ray electronic energy spectrum etc, and researched contrastively. The results show that the addition of rare earth oxides changes the property of catalyst surface. It is of benefit to increasing the number of active center of the catalyst and the surface acidity of the catalyst, decreasing the surface carbon deposit during the reaction. Moreover, the addition of rare earth oxides influences the electronic state of nickel atoms on the surface directly and produces electronic effect. The effect is different for each rare earth element.

关键词： rare earths NiLn 2O 3/γ Al 2O 3 catalyst methanation rare earth promoter effects

Rheological Behaviors of Polymer Melts and Concentrated Solutions Part VI: Comparison of the Material Functions with Yielding and Thinning for Polymeric Suspensions with Their Experimental Values

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Journal of Materials Science & technology 1999年第3期15卷 251-252,523-262页

作者： Song, MS Zhou, W Hu, GXX Hu, LJ beijing Univ chem technol Res Inst Polymer Mat Beijing 100029 Peoples R China Harbin inst technol Dept Appl Chem Harbin 150001 Peoples R China

The memory function and elastic modulus were introduced into the O-W-F type of constitutive equations with the Cauchy-Green and Finger tensors for simple fluid, and then the concrete constitutive equation and material function for polymeric suspensions in the different flow fields were formulated: 1) Viscosity and first normal-stress difference coefficient in the shear flow field; 2) Tensile viscosity at the uni-axial elongation flow field; and 3) Dynamic viscosity and modulus in the dynamic field. Then the dependence of the material function on the deformation rate and weight fraction of fillers was discussed, and the shear flow curves with four characteristic regions ( I-low shear rate plateau region, II- apparent yielding region, ill-intermediate rate plateau region, and lV-shear thinning region.) were explained theoretically. Finally, it was verified by a number of experimental values for the rheological suspensions and the viscoelastic and mechanical behaviors can be predicted by the molecular theory of non-linear viscoelasticity for polymeric suspension;.

关键词： Th Comparison of the Material Functions with Yielding and Thinning for Polymeric Suspensions with Their Experimental Values Rheological Behaviors of Polymer Melts and Concentrated Solutions Part VI