The heat transfer characteristics were investigated under impinging submerged circular jets of transformer oil. The factors included recovery effect, Re, nozzle-to-plate spacing, size of nozzles. Abnormal phenomena were observed from the experimental results of extremely small size jets. The mechanism behind the results was analyzed in the meantime.

Experimental study was made to investigate heat transfer characteristics under impinging circular free-surface water jet. The factors included nozzle-to-plate spacing, jet velocity at nozzle exit and phase transition. Heat transfer at the stagnation point and local heat transfer distributions were correlated.

This paper deals with a wavy finned tube heat exchanger working as an air-cooling condenser.The effects of the exchanger geometric dimensions on the irreversible loss in the exchanger are discussed based on the second law of thermodynamics.The irreversible loss is characterized by the sum of the entropy generation caused by the temperature difference between the airflow and exchanger surface and that caused by the air friction pressure drop. The calculation results show that the entropy generation per unit heat transfer rate (ΔS/Q) increases gently with increasing corrugation angle of the fin but is nearly independent of the fin pitch.When the number of tube rows (N) is increased, the ΔS/Q initially decreases, but turns to increase after reaching a minimum at a certain N.The ΔS/Q increases monotonously as the air velocity increases.

By considering the unsteady penetration of interfacial turbulence units into the bulk liquid, a semi-empirical model of mass transfer accompanied by the interfacial Marangoni effect is proposed, which indicates the dependence of the enhanced mass transfer coefficient on the Marangoni number. The mathematical analysis helps to explain the existence of different types of empirical correlations between the Sherwood number and Marangoni number from the literature. The analysis also shows that the enhancement of mass transfer coefficient by the interfacial Marangoni effect relies on the types of Marangoni convection.

Experiments were made on axial concentration distribution of binary solids mixtures in a three-phase fluidized bed of 4.2cm I.D. and 150 cm height under continuous operation mode. Biurea particles with different diameters and a mixture of biurea and blowing agent ADC with different wettability were used in the experiments.One-dimensional sedimentation-dispersion model was modified by taking into consideration of the effects of both particle size and wettability on particle settling velocity to describe the axial concentration distribution of each solids component. Agreement between experimental and model predicted data is satisfactory.

Spraying of liquid-solid suspension is a common phenomenon in removal of sulfuroxide from flue gas,in prevention of gas explosion by water droplets in coal mine and in coal slurry spray burning. Pressure-spray nozzle is generally used due to its simple structure and convenience for application.Spraying of the suspension is made by the vibration wave from pressure which disturbs the unstable fluid membrane and the force of inertia of mini-particales. The factors that affect the spray is analyzed, and a mathematical model is set forth.The spray droplet diameter d₃₂ is a function of independent variables of suspension pressure, mini-particle diameter, density and sold content.Spray droplet diameter d₃₂ is decreasing then increasing with suspension pressure and mini-particle density,which d₃₂ is increasing monotonously with mini-particles diameter and solid content in suspension.

In the process of spraying of liquid-solid suspension, there are many factors that affect the diameter (d₃₂) of spray droplet of the suspension, such as suspension pressure, solid content and diameter and density of mini-particle. The diameter of maximum probability distribution of the spray droplet of suspension was measured with the system of 3D LDV/APV and the process of spraying was recorded with the FASTCAM-Super in situ measurement.The relationship of d₃₂ with the suspension pressure and mini-particle density is non-monotonic,with d₃₂ decreasing then increasing with suspension pressure and mini-particle density, while the d₃₂ is increasing monotonously with mini-particles diameter and solid content in suspension. The experiment matched well with the mathematical model in the previous.

The kinetics of complex reaction systems were studied on molecular scale with the combined method of Monte Carlo simulation and Structural Oriented Lumping by focusing on deep catalytic cracking (DCC), the model parameters were optimized with the regular analytic data of a DCC-Ⅰ unit. A model was established to transform the feedstock of the complex reaction systems such as DCC-Ⅰ to 1000 molecules with Monte Carlo simulation and every molecule was expressed by 19 attributes. The results of model simulation showed that these 1000 molecules reflected the characters of feedstock very well and their average properties gave a good agreement with the plant data.

Kinetics of complex reaction systems such as DCC-Ⅰ on molecular scale were simulated by the method which combined Monte Carlo simulation and Structural Oriented Lumping, 75 reaction rules including the reactions of paraffins, olefins, naphthenics and aromatics were made to build the reaction networks of complex reaction system DCC-Ⅰ. For the sake of comparing the simulation result data,the Joback Group Contribution method was used to divide the product molecules to gas, liquid petroleum gas(LPG), gasoline, light cycle oil(LCO), heavy cycle oil(HCO) and coke. The results showed that the relationship of products yields with the extent of reaction was reasonable.The yields and properties of major products, propylene and gasoline, to an optimized extent of reaction gave good agreement with the plant data, which showed that the reaction rules and the reaction network could reflect the characters of DCC-Ⅰ very well.

The extraction behavior of single acid of glycolic acid and glyoxylic acid, and their mixture were investigated with TRPO as extractant and MiBK as diluent,and the effect of the concentration of TRPO and solute on the distribution coefficients were measured. The mathematical models describing the extraction equilibrium were proposed based on some assumptions. The experimental results showed that the complexes of glycolic acid with TRPO were in the forms of 1∶1 and 1∶2. The separation factor of glycolic acid to glyoxylic acid increased with TRPO concentration from less than 1 to larger than 1. The models parameters K₁₁ and K₁₂ in the single acid system can be used to predict extraction equilibrium behavior in the mixture acid systems. Finally, the separation conditions using other compounds, Alamine 336 and TBP, as extractant were also discussed.

The separation of Eicosapentaenoic Acid(EPA)and Docosahexanoic Acid(DHA)-ethyl esters by supercritical fluid chromatography (SFC) with carbon dioxide as mobile phase using C18 columns was studied. The effects of flow rate, operation temperature and pressure, sample size and concentration on separation were investigated. It is indicated that the effect of flow rate on resolution is not obvious. As for 5-C18，250mm×4.6mm column, the optimum operating condition is 12MPa, 55℃, pressure drop 1MPa; as for 8-C18，250mm×10mm column, the optimum operating condition is 12MPa, 55℃, pressure drop 0.5MPa. Fish oil can been injected directly without dissolving in other solvents.

The process of CO₂ absorbed in a hollow fiber membrane absorber was studied. For the non-wetted mode, the mathematical model of mass transfer in the membrane absorber was derived. The solution method for nonlinear partial differential equations was given by using T-model difference scheme. For water, NaOH, monoethanolamines (MEA) and 2-amino-2 -methyl-1-propanol (AMP) as absorbents, the process of CO₂ absorbed in hollow fiber membrane absorber was simulated. In addition, the absorption of CO₂by an aqueous mixture of AMP-MEA was also investigated. For CO₂ absorbed into 0.6 mol•L^-1 NaOH solution, the result of simulation agreed well with the experimental data.

For various HCl concentrations in the receiving phase，temperatures and Nd3+ concentrations as well as addition of a buffer to the feed，Nd3+ extraction by microemulsion liquid membrane was studied. The results indicated that the water content in nonionic microemulsion increased with increasing HCl concentration. On the contrary, the Nd3+ enrichment concentration in the receiving phase decreased. The highest enrichment of Nd3+ concentration in the receiving phase was 24.3 times, and the extraction percentage was in the range of 70%～80%. Adding a buffer in the feed showed a remarkable effect on Nd3+ extraction. Mass transfer coefficients were calculated according to the kinetics equation of microemulsion liquid membrane extraction. A hydrophilic microporous filtraction membrane was used to isolate microemulsion and feed. Accordingly, the emulsification caused by direct mixing of microemulsion with feed was avoided.At the same time, severe leakage of hydrogen ion from the receiving phase was well controlled.

Rolling delay is a typical dynamic process of reheating furnace. The optimized decision making of heat supply during the period of rolling delay, which plays a significant role in control strategy of reheating furnace, is a problem worthy of further study. The previous work was to give optimal set points of furnace temperature on the basis of mathematical model by establishing an objective function. In this paper, the mathematical model for dynamic process of reheating furnace is studied. For different rolling delay times, the optimal strategies are obtained by using the method of multi-objective gray state decision making. Based on these studies, a revised dynamic method of rolling delay is proposed. The results of simulation indicate that this method has good dynamic characteristics and is suitable for on-line control. Due to its ease and efficiency, multi-objective grey state decision making could be applied to more complex engineering problems.

Different proportions of mixed organic acids containing acetic acid, propionic acid, lactic acid and butyric acid were used as carbon source for biosynthesis of polyhydroxyalkanoates by Ralstonia eutropha. The utilization of four acids for cell growth and PHAs biosynthesis were investigated. In contrast with batch culture, fed-batch, especially the optimized fed-batch was more efficient in the cell growth and PHAs biosynthesis. However, the yield of hydroxyvalerate from propionic acid by fed-batch is markedly lower than that of the batch culture, for more propionic acid was used for the synthesis of cell components and hydroxybutyrate unit than hydroxyvalerate unit of the polyhydroxalkanoates when propionic acid was continuously fed.

A method of fast determining active components of Chinese herb extracts by near infrared (NIR) spectroscopy, which can be used for on-line analysis of percolation extracting process, is proposed and applied to percolation extracting panax notoginseng herb as an example. Reference measurements of ginsenoside Rg1, Rb1, and Rd were performed by HPLC, and panax notoginseng saponins (PNS) were determined according to the colorimetric assays. The calibration model between NIR spectra and reference values was set up. Radial basis function neural networks(RBFNN) and partial least squares regression(PLSR) were studied comparatively to establish the calibration model.By using RBFNN, RMSECVs for Rg1, Rb1, Rd, PNS were 1.120, 1.230, 0.267, 4.749 and RMSEPs were 0.677, 0.969, 0.155, 8.065, respectively. The results show that the present method is convenient, accurate and non-destructive, and can be applied for process analysis and quality control of Chinese medicine manufacturing process.

Comparison of UV-VIS spectra between Fenton (UV-Fenton) and UV/H₂O₂ during the photo-degradation of phenol indicates that the Fenton process is not a simple hydroxyl radical reaction and multi-valent iron is the important intermediate during the Fenton process.Phenol was degraded through the inner-sphere electron transfer reaction within the complex Fe(Ⅳ)-phenol.The traditional hydroxyl radical theory seemingly could not be used to explain Fenton type oxidation reaction mechanism.

The combustion kinetics of Shenmu char, prepared at 900℃ in Ar atmosphere for 30min, was systematically investigated by using isothermal and temperature-programmed TG technique. The combustion kinetics was analyzed using the DAEM (distributed activation energy model) and the Coats-Redfern integration method. The difference of these two methods was compared. The results indicated that during isothermal combustion and temperature programmed combustion process, with increasing combustion conversion, the specific combustion rate increased and the combustion activation energy showed different changes. DAEM and Coats-Redfern placed the emphasis on different aspects of combustion and obtained different results.The isothermal TG technology at a lower temperature could reduce the external diffusion effect during combustion as much as possible. Therefore, the kinetic results calculated from isothermal TG technology were close to the intrinsic values.

Transformation of As, Pb, Cr, Cd and Mn in Datong coal during pyrolysis was studied. The pyrolysis experiment was carried out in a closed stainless steel reactor.The effects of temperature(300—700℃ ),pressure（0.1—4MPa）,and residence time under nitrogen atmosphere on the release of the trace elements were investigated.The influence of reaction atmosphere (N₂ or H₂) on the emission of the trace elements was also investigated. Results showed that the release of As, Pb, Cr, Cd and Mn increased with increasing pyrolysis temperature and residence time. Higher pressure inhibited the release of the trace elements. H2 environment resulted in a higher release of the trace elements. In the temperature range studied, As and Cd showed higher volatility than the other three elements during pyrolysis.

High-powered proton exchange membrane fuel cell(PEMFCs) can be used on electrical vehicles.The detachment-integration stack with active area of 390cm² was developed. Based on it, research was concentrated on the subsystem of a Nafion115 membrane humidifier, and performance for membrane humidification. In this paper, the principle of membrane humidification is analyzed, and the effects of humidifying temperature, reaction gas pressure, reaction gas flow rate and power of hot water pump on humidification function are studied systematically. The results show that humidifying rate is fast between 50℃ and 70℃, and increases nonlinearly with gas flow.When the active area of membrane is enlarged, the humidifying rate will decrease, but the relative humidity of gas will increase.Humidification becomes more difficult at a higher gas pressure. Finally, the suitable operation conditions are determined.The maximum of the stack is more than 1.2W•cm^-2 at the current density 2.1A•cm^-2.

Preparation of carbon nanotubes and hydrogen from methane decomposition over a nano-sized Ni/Cu/Al₂O₃ catalyst was investigated in the temperature range of 823—1143 K in a fluidized bed reactor, which can provide sufficient space for carbon nanotubes growth. It was observed that the conversion of methane directly depended on operation conditions,including temperature,space velocity, gas velocity and the heat-up rate etc. Also the morphology of nanotubes was influenced significantly by the heat-up mode. Adopting a lower heat-up rate (50K•h^-1), relatively high conversion of methane and carbon nanotubes with pretty good morphology can be simultaneously achieved as compared to the results by adopting a higher heat-up rate(600K•h-1). Furthermore, by using a low heat-up rate from 823K to 1123K,continuous production of the carbon nanotubes was achieved at 1123K and the yield of carbon nanotubes was up to 10g•(g cat)^-1•h^-1, which provided the basis for the large scale and continuous production of carbon nanotubes.

Based on the reasonable simplified model of the pin barrel extruder, numerical and experimental analyses were carried out to investigate the flow field and distributive mixing effect on the unfolded surface of the screw.Meanwhile the influence of pins on flow and mixing effect was also discussed. A method of numerical analysis and evaluation of the mixing effect at a certain point, the average mixing effect and the statistical distribution of the mixing effect in the whole fluid field was developed. The numerical results were in good agreement with the experimental results. From the studies,the following conclusions are obtained. First, the introduction of pins and slices into the screw flights can greatly improve the flow and mixing effect.Second, the unfolded surface of the screw with six pins has better mixing ability than the surface with three pins,The [JP2]surface with three pins has better mixing ability than the surface with slices and without pins.The surface with slices and without pins has better mixing ability than the surface without slices and pins.Third,compared with the unfolded surface of the screw without slices and pins, the average mixing effect on the unfolded surface of the screw containing pins is increased by 30%—40%.Fourth, the mixing effect on the unfolded surface containing pins is continuously increased with time, but the mixing effect on the unfolded surface without pins can not be increased with time when the mixing effect reaches a certain value.

A water-absorbent resin with high absorbability in saline and high absorption rate was synthesized by inverse suspension copolymerization, with cyclohexane as continuous phase, AA and AMPS as monomers, stearic phosphate as dispersing agent, N,N-mythylene bisacrylamide as crosslinker and APS(ammonium persulphate) as initiator. The effects of monomers composition, copolymerization temperature, neutralization degree of AA(Dn), initiator concentration, type and concentration of crosslinker and ratio of oil to water on the absorbability and absorption rate,and physical properties of the resin were studied. When w(AMPS)=40%, c(MBAM)=1.62mmol•L^-1，Dn= 75％, c(APS)=24.70mmol•L^-1, T=65℃ and V(oil)∶V(water)=1.5∶1.0, the absorbency of the resin is 264ml•g^-1 and 1200ml•g^-1 respectively for normal saline and distilled water, and the ultimate degree of absorption in deionized water will be approached within 15min. It was found by thermal analysis that raising the link density would improve the water preservation of the resin.

The velocity, phase fraction and fluctuation velocity of dense clusters are obtained by analysis of transient velocity signals from laser Doppler velocimeter. The local velocity of dense clusters increased linearly with superficial gas velocity, while the cross-sectional average solids fraction influence the velocity of dense clusters insignificantly. A Boltzmann function is used to describe the velocity radial distribution of dense clusters. The radial distribution of the phase fraction for dense clusters is described by using an exponential function. With the increase of cross-sectional average solids fraction, the local phase fraction of dense clusters increases and the area controlled by dense clusters is enlarged. The turbulence intensity of dense clusters is highest in the center of the bed while decreases towards the wall.

The residence time distribution for laminar flow of non-Newtonian Casson fluids in a tubular reactor was analysed theoretically,and the analysis expressions were derived for the residence time distribution density function in the Casson laminar flow reactor.Based on the residence time distribution density function derived, equations to calculate the product distribution for simple series reactions in an isothermal tubular reactor were presented. The conditions which must be satisfied for maximizing intermediate product yield were derived. Computation of optimal Dahmkohler number, optimal conversion and maximum possible yield of intermediate product was carried out. By using these calculated results, design charts which show quantitatively how the reaction rate constant ratio and the parameter of Casson laminar flow model affect optimal product distribution and optimal Dahmkohler number were obtained.Also,correlated diagrams and correlations which show the influence of parameter of Casson laminar flow model on optimal feed rate and optimal reactor volume were given. These diagrams and correlations are useful for engineering design.

In this work the effects of physical and surface properties of polymeric resins on adsorption capacity of phenol were investigated. BET surface areas and pore size distributions of the polymeric adsorption resins，NKA Ⅱ(polar resin)，AB-8(weak polar resin) ，D4006(weak polar resin) and D16(non-polar resin)，were separately measured by ASAP 2010M，and isotherms of phenol on the resins were separately estimated by the method of static adsorption. Results indicated that the adsorption capacity of NKA Ⅱ resin for phenol in dilute aqueous solution was the highest，and the adsorption capacity of AB-8 resin was in the next place；and the micropore volume and polarity of a polymeric resin showed a strong influence on the adsorption capacity of phenol on the resin. Among the four sorts of resin， the adsorption capacity of the NKA Ⅱ resin for phenol was the highest since it is not only polar but also possesses a considerable portion of micropore volume.

This study was about the cloud point of alkyl-polyoxyethylene (AEO₉) and aqueous two-phase systems formed by AEO₉ aqueous solution. It was shown that the cloud point of AEO9 aqueous solution was related to the composition and aqueous two-phase systems would be formed when the temperature was above the cloud point. Salt has an important influence on the properties of AEO₉ solution. It could lower the system cloud point and reverse surfactant-rich phase and surfactant-leau phase of aqueous two-phase system.Methylene blue could be extracted to some extent in the aqueous two-phase system of AEO₉. If the system contained ionic surfactant, the distribution coefficient (D) of methylene blue would be changed. Cationic surfactant could make D larger and anionic surfactant could make D smaller.The mechanism behind extraction in ATPS was discussed.

A study on separation and enrichment of p-aminophenol from aqueous solution with emulsion liquid membranes has been carried out. The effects of pH in internal aqueous phase, the concentration of the carrier and surfactant were examed. Under the optimal operation conditions, the experimental results show that the water treated attained the drainage standard when the concentration of p-aminophenol is 500mg•L^-1, after dealing with two-stage liquid membrane process.

The extraction process for preparing hydrogen peroxide with bottom air injection in a spray column was investigated. With the increase of air superficial velocity, extraction efficiency was improved remarkably and the height of transfer unit (HTU) was largely reduced. Extraction efficiency was 2—3 times higher than that of liquid-liquid extraction without air introduction, and the HTU was only 1/2—1/3 of liquid-liquid extraction. Moreover, the air-liquid-liquid reactive extraction system for preparing hydrogen peroxide via anthraquinone was investigated. Oxidation reaction of the hydrogenated working solution was combined with extracting hydrogen peroxide from the working solution in a sieve plate column, which involves simultaneous oxidation of 2-ethylhydroanthraquionone and liquid-liquid separation. Oxygen was introduced with the hydrogenated working solution through a nozzle on the bottom of the column,with oxygen working as an agitating source as well as a reagent. Reaction rate and extraction efficiency increased with increasing air injection superficial velocity because of great improvement of mass transfer between air-liquid-liquid phases.

The Li₂Mg_xZn_1-xSiO₄ (x=0.2—0.8) single-phase ion conductor materials were prepared by the sol-gel method.The powder samples were characterized by TG-DTA﹑XRD and TEM.Ionic conductivity of the sinter was determined by means of AC impedance technique. The experiment showed that the heating temperature was only 800℃ for the samples prepared by the sol-gel method with the average particle size of 100nm,and it has successfully reduced by 350℃ compared with the traditional solid-reaction method.Ionic conductivity of the materials could be improved by the double-doped system of Mg,Zn.