Acomputational study on the flow behavior of a gas-solid injector by Eulerian approach was carried out. The gas phase was modeled with k-ε turbulent model and the particle phase was modeled with kinetic theory of granular flow. The simulations by Eulerian two-fluid model (TFM) were compared with the corresponding results by discrete element method (DEM) and experiments. It was showed that TFMsimulated results were in reasonable agreement with the experimental and DEMsimulated results. Based on TFM simulations, gas-solid flow pattern, gas velocity, particle velocity and the static pressure under different driving jet velocity, backpressure and convergent section angle were obtained. The results showed that the time average axial gas velocity sharply decreased and then slightly increased to a constant value in the horizontal conveying pipe. The time average axial particle velocity increased initially and then decreased, but in the outlet region of the convergent section the particle velocity remarkably increased once more to the maximal value. As a whole, the static pressure distribution change trends were found to be independent on driving gas velocity, backpressure and convergent section angle. However, the static pressure increased with increase of convergent section angle and gas jet velocities. The difference of static pressure to backpressure increased with increasing backpressure.

This paper describes a robust support vector regression(SVR) methodology,which can offer superior performance for important process engineering problems.The method incorporates hybrid support vector regression and genetic algorithm technique(SVR-GA) for efficient tuning of SVR meta-parameters.The algorithm has been applied for prediction of pressure drop of solid liquid slurry flow.Acomparison with selected correlations in the literature showed that the developed SVR correlation noticeably improved the prediction of pressure drop over a wide range of operating conditions,physical properties,and pipe diameters.

The single-phase pressure drop and heat transfer in a rotor-assembled strand inserted tube were measured using water as the working fluid.Experiment using a smooth tube was carried out to calibrate the experimental system and the data reduction method.In the experiment,fixed mounts were used to eliminate the entrance effect. The experimental results of smooth tube show that employment of fixed mounts leads to a visible bias of friction factor at relative low Reynolds numbers,although it does not significantly affect the Nusselt numbers.The measured data of inserted tube reveal that rotor-assembled strand can significantly improve heat transfer with the Nusselt number increased by 101.6%-106.6% and the overall heat transfer coefficient increased by 58.1%-67.4% within the Reynolds number range of 20000 to 36000.Meanwhile,friction factor increases by 52.2%-84.2% within the same Reynolds number range.The correlations of Nusselt number and friction factor as function of the Reynolds number and Prandtl number were determined through multivariant linear normal regression.

L-Arginine is an important component of amino acid injection.Its diffusion in body fluid and blood is of key importance to understand drug diffusion and drug release.As a fundamental demand for study and being a considerably valuable reference for application,in this study,the diffusion coefficients of L-arginine in polyacrylamide(PAM) aqueous solution used as non-Newtonian fluid similar to blood and body fluid were measured using a holographic interferometer.The effects of interaction among molecules and solution concentration on diffusion were analyzed and discussed,respectively.Based on the obstruction-scaling model,a novel modified model was presented for predicting diffusivity of solute in non-Newtonian fluid.Good agreement was achieved between the calculated value and the experimental data.

In this paper,an innovative jet lifted flame with side micro-jets has been proposed and its effects on the flame structure have also been investigated.Due to the changes of the initial combustion conditions,mixing and aerodynamics which resulted from the perturbation of the side micro-jets,such a lifted jet flame has different flame structure compared with the common premixed flame.Results demonstrate that use of the micro-jets can control,to a certain extent,the flame structure,including the flame length,lift-off distance and blow-off limit.With the same fuel and air flow rate,the flame length with the side micro-jets will decrease about 5%-40% as the air volume ratio αincreases from 58%-76%.Compared with the common diffusion flame,the jet flame with the side micro-jets demonstrates to be easier to be a momentum-dominated flame.The flame length with 2 micro-jets is about 5% less than with 6 micro-jets under the same fuel and air flow rate.With the sameα,the fewer number of the controlled jets lead to the flame with relatively shorter length,not easier to be blown off and higher NO_x emission.With certain fuel flow rate,the critical air volume ratio is largest for the flame with 3 micro-jets,which is more difficult to be blown off than the cases with 2,4 or 6 micro-jets.

To explore the feasibility of extracting aromatic acid products from oxidizing coal,two aromatic acids, trimellitic and[1,1'-biphenyl]-2,2'-dicarboxylic acid,were selected as the solutes,and the extraction equilibrium of the acids were studied with 1-octanol,50% tributyl phosphate(TBP)in kerosene,and 10% trialkylphosphine oxide (TRPO) in kerosene.The results showed that the degree of extraction of [1,1'-biphenyl]-2,2'-dicarboxylic acid was larger than that of trimellitic acid for all of the solvent,and the extraction capacity with TRPO is more effective than the one with TBP.The extraction behavior of aromatic polyacid is different from that of carboxylic acid,and the reactive extraction function of aromatic acids with TBP and TRPO is not as effective as that of carboxylic acid. 1-octanol could be used to remove[1,1'-biphenyl]-2,2'-dicarboxylic acid from the mixture of trimellitic acid and [1,1'-biphenyl]-2,2'-dicarboxylic acid.Because the weak hydrogen bond association exists between ——OH in 1-octanol and ——COOH in aromatic acid,the extractive selectivity of [1,1'-biphenyl]-2,2'-dicarboxylic to trimellitic acid depends on the stoichiometric ratio.

This work mainly involves the study of effect of relative humidity on adsorption of formaldehyde on the activated carbons modified with organosilane solution.Modification of activated carbons was carried out by impregnating activated carbon with organosilane/methanol-containing solutions.The breakthrough curves of formaldehyde in the packed beds of original and modified activated carbons were measured,respectively,at relative humidity of 30%,60%,and 80%.Temperature-programmed desorption(TPD) experiments were used to estimate the activation energy for desorption of formaldehyde from the activated carbon.Results showed that the relative humidity had strongly influence on breakthrough curves of formaldehyde in the packed beds.The higher the relative humidity of gas mixtures through the packed beds was,the smaller the breakthrough time of formaldehyde became. The use of organosilane compounds to modify surfaces of the activated carbon can enhance the interaction between formaldehyde and the surfaces,and as a result,the breakthrough times of formaldehyde in the packed beds of the modified activated carbon were longer than that in the packed bed of the unmodified activated carbon.

Mixed solvent of 1-octanol and cyclohexane with 60%(by mass) 1-octanol content was selected as a new extractant for caprolactam extraction.Compared with benzene or toluene,the new extractant has larger extraction capacity and much lower toxicity.Although the extraction capacity of the new extractant is smaller than that of pure 1-octanol,1-octanol solubility of the new extractant in aqueous phase is much smaller.Because of its physical properties of lower density,lower viscosity,and higher interfacial tension,the new extractant performed much better phase separation ability than pure 1-octanol.The new extractant showed certain selectivity when dealing with lactam oil.The mixed solvent of 1-octanol and cyclohexane with 60% (by mass) 1-octanol content is a promising extractant for caprolactam extraction.

The extractive removal of sulfur compounds(S-compounds)from Dongying and Liaohe diesel fuels with[BF₄] -based ionic liquids were systematically investigated.The results show that the absorption capacity of an ionic liquid for the S-compounds in diesel fuels relies on its structure and its size.In the case of the two examined diesel fuels,both elongating the cation tail length and increasing the mass ratio of ionic liquid/diesel fuel promote the desulfurization ability of the examined ionic liquids.The results also show that imidazolium-based ionic liquids display higher extraction efficiencies than pyridinium-based ionic liquids,presumably owing to the fact that the rings of the S-compounds are similar to the imidazolium head ring.With the 1:1 mass ratio of ionic liquid/diesel fuel,the rates of the first desulfurization of Dongying and Liaohe diesel fuels using[C₈mim][BF₄]amount to 29.96% and 39.76%,suggesting that[C₈mim][BF₄]is a promising extractant for desulfurization of these diesel fuels.

F-PbO₂ electrode and polytetrafluoroethylene(PTFE) doped F-PbO₂ electrode(PTFE-F-PbO₂) were prepared on a plexiglas sheet substrate by a series of procedure including chemical and electrochemical depositions. The electrochemical activities of these two electrodes for oxygen evolution(OE) reaction were examined by electrochemical tests.In comparison with F-PbO₂,PTFE-F-PbO₂ electrode exhibited larger active surface area and higher oxygen vacancy deficiency,which resulted in its higher electrocatalytic activity for OE.In addition,both exchange current density and activation energy of the electrodes for OE were calculated in terms of active surface area.The values of exchange current density and activation energy in 0.5 mol·L^-1 H₂SO₄ aqueous solution were 1.125×10^-3mA·cm^-2 and 18.62 kJ·mol^-1 for PTFE-F-PbO₂,and 8.384×10^-4mA·cm^-2 and 28.98 kJ·mol^-1 for F-PbO₂,respectively.Because these values are calculated on the basis of the active surface areas of the electrodes, the enhanced activity of PTFE-F-PbO₂ can be attributed to an increase in oxygen vacancy deficiency of PbO₂ due to doping by PTFE.The influence of PTFE adulteration on the activity of PbO₂ film electrode for OE was investigated in detail in this study.

The decomposition kinetics of glucose was studied in high-temperature liquid water(HTLW) from 180 to 220℃ under a pressure of 10 MPa.It was found the main products from glucose decomposition were 5-hydroxymethylfurfural(5-HMF)and levulinic acid(LA).The decomposition kinetics of 5-HMF and stability of LA in HTLW were further investigated.A kinetic model for glucose decomposition was proposed accordingly.In the model,a series of first-order reactions with the consideration of parallel by-reactions were used to illustrate the decomposition of glucose.The decomposition activation energies of glucose,5-HMF,and LA were evaluated as 118.85,95.40,and 31.29 kJ·mol^-1,respectively.

Tungsten-containing hexagonal mesoporous silica(W-HMS) supported tungsten oxide catalysts (WO_x/W-HMS) was prepared for the selective oxidation of cyclopentene with aqueous hydrogen peroxide to glutaraldehyde.X-ray diffraction(XRD) results indicated that the crystal form of the active phase(tungsten oxide) of the WO_x/W-HMS catalysts was dependent on the W loading and calcination temperature.X-ray photoelectron spectroscopy(XPS) analysis revealed that the dispersed tungsten oxides on the surface of W-HMS support consisted of a mixture of W(V) and W(VI).It was found that a high content of amorphous W species in(5+)oxidation state resulted in the high catalytic activity.When the Wloading was up to 12%(by mass) or the catalyst precursor was treated at temperature of 623 K,the catalytic activity decreased due to the presence of WO₃ crystallites and the oxidation of W(V) to W(VI) on the catalyst surface.Furthermore,NH₃-temperature-programmed-desorption (NH₃-TPD) analysis showed that the effects of W loading and calcination temperature on the acidity of the catalysts were related to the catalytic activity.Ahigh selectivity of 80.2% for glutaraldehyde with a complete conversion of cyclopentene was obtained over 8% WO_x/W-HMS catalyst calcined at 573 K after 14 h of reaction.

The heat transfer coefficient in a multidimensional heat conduction problem is obtained from the solution of the inverse heat conduction problem based on the thermographic temperature measurement.The modified one-dimensional correction method(MODCM),along with the finite volume method,is employed for both two-and three-dimensional inverse problems.Aseries of numerical experiments are conducted in order to verify the effectiveness of the method.In addition,the effect of the temperature measurement error,the ending criterion of the iteration,etc.on the result of the inverse problem is investigated.It is proved that the method is a simple,stable and accurate one that can solve successfully the inverse heat conduction problem.

Production planning models generated by common modeling systems do not involve constraints for process operations,and a solution optimized by these models is called a quasi-optimal plan.The quasi-optimal plan cannot be executed in practice some time for no corresponding operating conditions.In order to determine a practically feasible optimal plan and corresponding operating conditions of fluidized catalytic cracking unit(FCCU),a novel close-loop integrated strategy,including determination of a quasi-optimal plan,search of operating conditions of FCCU and revision of the production planning model,was proposed in this article.In the strategy,a generalized genetic algorithm(GA) coupled with a sequential process simulator of FCCU was applied to search operating conditions implementing the quasi-optimal plan of FCCU and output the optimal individual in the GAsearch as a final genetic individual.When no corresponding operating conditions were found,the final genetic individual based correction(FGIC) method was presented to revise the production planning model,and then a new quasi-optimal production plan was determined.The above steps were repeated until a practically feasible optimal plan and corresponding operating conditions of FCCU were obtained.The close-loop integrated strategy was validated by two cases,and it was indicated that the strategy was efficient in determining a practically executed optimal plan and corresponding operating conditions of FCCU.

It is shown in this article that by changing the initial operation condition of the batch processes,the dynamic performance of the system can be varied largely,especially for the initial operational temperature of the exothermic reaction.The initial operation condition is often ignored in the designing batch processes for flexibility against disturbances or parameter variations.When the initial condition is not rigid as in the case of a batch reactor, where the initial reaction temperature is quite arbitrary,optimization can also be applied to determine the"best"initial condition to use.Problems for dynamic flexibility analysis of exothermic reaction including initial temperature and process operation can be formulated as dynamic optimization problems.Formulations are derived when the initial conditions are considered or not.When the initial conditions are considered,the initial condition can be transferred into control variables in the first optimal step.The solution of the dynamic optimization is on the basis of Rugge-Kutta integration algorithm and decomposition search algorithm.This method,as illustrated and tested with two highly nonlinear process problems,enables the determination of the optimal level.The dynamic performance is improved by the proposed method in the two exothermic reaction examples.

The interaction of DNA with cationic gemini surfactant trimethylene-1,3-bis(dodecyl dimethyl-ammonium bromide)(12-3-12)and anionic surfactant sodium dodecyl sulfate(SDS) mixed system has been investigated by measuring the fluorescence,zeta potential,UV-V is spectrum,and circular dichroism.In the absence of SDS,owing to the electrostatic and hydrophobic interactions,12-3-12 forms micelle-like structure on the DNA chain before the micellization in bulk phase.For the mixed system of 12-3-12 and SDS,the negative charges on SDS can compete against DNA to bind with cationic 12-3-12 because of the stronger interaction between oppositely charged surfactants,and thus,the catanionic mixed micelles are formed before the formation of DNA/12-3-12 complexes.Thereafter,the positive charges on the mixed micelles bind with DNA,and thus,the change of the zeta potential from negative to positive is distinctly different from the system without SDS.Meanwhile,the existence of SDS postpones the exclusion of ethidium bromide(EB) from DNA/EB complexes.The conformation of DNA undergoes a change from native B-form to chiralψ-phase as binding with 12-3-12 process.Upon adding SDS to the DNA/12-3-12 complex solution,however,DNA is released to the bulk and theψ-phase returns to B-form again.

Thermal decomposition of polylactic acid(PLA) was studied in the presence of pine wood sawdust(PS), walnut shell(WS),corncob(CC) in order to understand the pyrolytic behavior of these components occurring in waste.A thermogravimetric analyzer(TGA) was applied for monitoring the mass loss profiles under heating rate of 10℃·min^-1.Results obtained from this comprehensive investigation indicated that PLA was decomposed in the temperature range 300-372℃,whereas the thermal degradation temperature of biomass is 183-462℃.The difference of mass loss(ΔW) between experimental and theoretical ones,calculated as algebraic sums of those from each separated component,is about 17%-46% at 300-400℃.These experimental results indicated a significant synergistic effect during PLA and biomass copyrolysis.Moreover,a kinetic analysis was performed to fit thermogravimetric data,the global processes being considered as one to two consecutive reactions.Areasonable fit to the experimental data was obtained for all materials and their blends.

The knowledge of flow regime is very important for quantifying the pressure drop,the stability and safety of two-phase flow systems.Based on image multi-feature fusion and support vector machine,a new method to identify flow regime in two-phase flow was presented.Firstly,gas-liquid two-phase flow images including bubbly flow,plug flow,slug flow,stratified flow,wavy flow,annular flow and mist flow were captured by digital high speed video systems in the horizontal tube.The image moment invariants and gray level co-occurrence matrix texture features were extracted using image processing techniques.To improve the performance of a multiple classifier system,the rough sets theory was used for reducing the inessential factors.Furthermore,the support vector machine was trained by using these eigenvectors to reduce the dimension as flow regime samples,and the flow regime intelligent identification was realized.The test results showed that image features which were reduced with the rough sets theory could excellently reflect the difference between seven typical flow regimes,and successful training the support vector machine could quickly and accurately identify seven typical flow regimes of gas-iquid two-phase flow in the horizontal tube.Image multi-feature fusion method provided a new way to identify the gas-liquid two-phase flow,and achieved higher identification ability than that of single characteristic.The overall identification accuracy was 100%,and an estimate of the image processing time was 8 ms for online flow regime identification.

The chemical synthesis of Guanine arabinoside(ara-G)is extremely complex,time-consuming,and seriously polluted.A two-step enzymatic synthesis process was developed to acquire ara-G easily.2,6-Diaminopurine arabinoside(ara-DA)was first synthesized with purine nucleoside phosphorylase and pyrimidine nucleoside phosphorylase produced by Enterobacter aerogenes DGW-07.The conversion yield of ara-DA could reach above 90% when the reaction liquid contained 30 mmol·L^-1 uracil arabinoside as arabinose donor,10 mmol·L^-1 2,6-diaminopurine as arabinose acceptor in pH7.0 20 mmol·L^-1 phosphate buffer,and reacted at 60℃ for 48h.Then,ara-DA was effectively transformed into ara-G with adenylate deaminase produced by Aspergillus oryzae DAW-01.The total process had no complex separation and purification.

Acrylonitrile-sodium styrene sulfonate copolymer/layered double hydroxides nanocomposites were prepared by in situ aqueous precipitation copolymerization of acrylonitrile(AN) and sodium styrene sulfonate(SSS) in the presence of 4-vinylbenzene sulfonate intercalated layered double hydroxides(MgAl-VBS LDHs) and transferred to acrylonitrile-styrene sulfonic acid(AN-SSA) copolymer/LDHs nanocomposites as a proton-conducting polymer electrolyte.MgAl-VBS LDHs were prepared by a coprecipitation method,and the structure and composition of MgAl-VBS LDHs were determined by X-ray diffraction(XRD),infrared spectroscopy,and elemental analysis.X-ray diffraction result of AN-SSS copolymer/LDHs nanocomposites indicated that the LDHs layers were well dispersed in the AN-SSS copolymer matrix.All the AN-SSS copolymer/LDHs nanocomposites showed significant enhancement of the decomposition temperatures compared with the pristine AN-SSS copolymer,as identified by the thermogravimetric analysis.The methanol crossover was decreased and the proton conductivity was highly enhanced for the AN-SSA copolymer/LDHs nanocomposite electrolyte systems.In the case of the nanocomposite electrolyte containing 2% (by mass) LDHs,the proton conductivity of 2.60×10^-3S·m^-1 was achieved for the polymer electrolyte.

Cylindrical nickel metal hydride(Ni-MH) battery with high specific volume capacity was prepared by using the oxyhydroxide Ni(OH)₂ and AB5 type hydrogen storage alloy and adjusting the designing parameters of positive and negative electrodes.The oxyhydroxide Ni(OH)₂ was synthesized by oxidizing spherical β-Ni(OH)₂ with chemical method.The X-ray diffraction(XRD) patterns and the Fourier transform infrared(FT-IR) spectra indicated thatγ-NiOOH was formed on the oxyhydroxide Ni(OH)₂ powders,and some H₂O molecules were inserted into their crystal lattice spacing.The battery capacity could not be improved when the oxyhydroxide Ni(OH)₂ sample was directly used as the positive active materials.However,based on the conductance and residual capacity of the oxyhydroxide Ni(OH)₂ powders,AAsize Ni-MH battery with 2560 mA·h capacity and 407 W·h·L^-1 specific volume energy at 0.2C was obtained by using the commercial spherical β-Ni(OH)₂ and AB5-type hydrogen-storage alloy powders as the active materials when 10% mass amount of the oxyhydroxide Ni(OH)₂ with 2.50 valence was added to the positive active materials and subsequently the battery designing parameters were adjusted as well.The as-prepared battery showed 70% initial capacity after 80 cycles at 0.5C.The possibility for adjusting the capacity ratio of positive and negative electrodes from 1:1.35 to 1:1.22 was demonstrated preliminarily.It is considered the as-prepared battery can meet the requirement of some special portable electrical instruments.

Reverse micelles bring mild and effective microenvironments in organic solvent that contain biomolecules,which have attracted immense attention for application in the isolation of proteins,protein refolding,and enzymatic reaction.In this review,the application of reverse micelles for protein separation and refolding has been briefly summarized and various reverse micellar systems composed of different surfactants,including ionic,nonionic,mixed,and affinity-based reverse micelles,have been highlighted.It illustrates especially the potential application of the novel affinity-based reverse micelles consisting of biocompatible surfactant coupled with affinity ligands.Moreover,the importance to develop universal affinity-based reverse micelles for protein separation and refolding in the downstream processing of biotechnology has been pointed out.

The submicroparticles of β-sitosterol were produced by using an aerosol solvent extraction system (ASES) and characterized by scanning electronic microscope(SEM),X-ray diffraction(XRD),and Fourier transform infrared(FT-IR) analysis.The effects of operational parameters including pressure,temperature,solution concentration,and ratio of flow rate(CO₂/solution,r) on particle size(PS),yield,and morphology were investigated. The results showed that microparticles of β-sitosterol(less than 1000 nm size and larger than 70% yield) could be obtained at 10-15 MPa,35-50℃,15 mg·ml^-1,10/1(r);β-sitosterol particles were found to occur as three mophologies:flakes,rods,and spheres by varying ratio of flow rate or solution concentration.In contrast,the crystallinity of β-sitosterol decreased,whereas its molecular structure remained almost unchanged after being ASES-treated. Therefore,ASES was an effective method to produce submicroparticles of β-sitosterol.

Experimental investigation of the microfiltration(MF) using a revolving cross-flow membrane filter was performed under the condition of constant pressure difference,and different flat membranes made of polyvinylidene fluoride(PVDF,0.1μm),cellulose acetate(CA,0.22μm),sulfonated polyethersulfone(SPES,0.22μm) and polyamide(PA,0.45μm),respectively,were used in filtration experiments.The dependence of the filtrate mass of the cross-flow MF on time was measured on-line.The experimental results showed that the effect of the cross-flow on high viscosity medium was more significant than that on the low viscosity one.