Microbial cellulose (MC) membranes produced by Acetobacter xylinum NUST4.1,were used as flexible substrates for the fabrication of transparent indium tin oxide (ITO) electrodes.Transparent and conductive ITO thin films were deposited on MC membrane at room temperature using radio frequency (RF) magnetron sputtering.The optimum ITO deposition conditions were achieved by examining crystalline structure,surface morphology and optoelectrical characteristics with X-ray diffraction (XRD),scanning electron microscopy (SEM),atomic force microscopy (AFM),and UV spectroscopy.The sheet resistance of the samples was measured with a four-point probe and the resistivity of the film was calculated.The results reveal that the preferred orientation of the deposited ITO crystals is strongly dependent upon with oxygen content (O₂/Ar,volume ratio) in the sputtering chamber.And the ITO crystalline structure directly determines the conductivity of ITO-deposited films.High conductive [sheet resis-tance ～120 Ω·square^-1 (Ω·sq^-1)] and transparent (above 76%) ITO thin films (240 nm thick) were obtained with a moderate sputtering power (about 60 W) and with an oxygen flow rate of 0.25 ml·min^-1 (sccm) during the deposition.These results show that the ITO-MC electrodes can find their potential application in optoelectrical devices.

Reliable production of biofuels and specifically bioethanol has attracted a significant amount of research recently.Within this context,this study deals with dynamic simulation of bioethanol production processes and in particular aims at developing a mathematical model for describing simultaneous saccharification and co-fermentation (SSCF) of C6 and C5 sugars.The model is constructed by combining existing mathematical models for enzymatic hydrolysis and co-fermentation.An inhibition of ethanol on cellulose conversion is introduced in order to increase the reliability.The mathematical model for the SSCF is verified by comparing the model predictions with experimental data obtained from the ethanol production based on kraft paper mill sludge.When fitting the model to the data,only the yield coefficients for glucose and xylose metabolism were fine-tuned,which were found to be 0.43 g·g^-1 (ethanol/glucose) and 0.35 g·g^-1 (ethanol/xylose) respectively.These promising validation results encourage further model application to evaluate different process configurations for lignocellulosic bioetha-nol technology.

Semiconductor fabrication is a manufacturing sequence with hundreds of sophisticated unit operations and it is always challenged by strategy development for ensuring the yield of defect-free products.In this paper,an advanced control strategy through integrating product and process control is established.The proposed multiscale scheme contains three layers for coordinated equipment control,process control and product quality control.In the upper layer,online control performance assessment is applied to reduce the quality variation and maximize the overall product performance (OPP).It serves as supervisory control to update the recipe of the process controller in the middle layer.The process controller is designed as an exponentially weighted moving average (EWMA) run-to-run controller to reject disturbances,such as process shift,drift and tool worn out,that are exerted to the operation.The equipment in the process is individually controlled to maintain its optimal operational status and maximize the overall equipment effectiveness (OEE),based on the set point given by the process controller.The efficacy of the proposed integrated control scheme is demonstrated through case studies,where both the OPP (for product) and the OEE (for equipment) are enhanced.

The indirect electrochemical reduction of Indanthrene Brilliant Green FFB (IBG) was investigated in detail by cyclic voltammetry and electrolytic experiments.Triethanolamine (TEA) was used as ligand to form electrochemically active Fe(Ⅲ)-complexes in alkaline solution.The effects of operating parameters including reaction temperature,current density,concentration of NaOH and Fe(Ⅲ)-TEA mediator had been studied by orthogonal ex-periments and the mechanism of radicals on electrochemical reduction was discussed.The cyclic voltammetry experimental results show that Fe(Ⅲ)-TEA complexes are well suited for the indirect electrochemical reduction of IBG.The electrolytic experiments show that high current efficiency (49.9%) can be successfully achieved under optimized conditions and the current density is found to be the main influence factor.

A piston-cylinder apparatus was established to measure the solubility and diffusivity of air in dimethyl silicone oils and in hydraulic oils based on the PVT state equation of air and the solution of unsteady one-dimensional diffusion equation.The measured diffusivity-temperature relation can be well fitted by the Arrhenius equation for engineering applications.The correlation between the solute diffusivity D and solvent viscosity μ is examined.In terms of Eyring's activation theory,the activation in the air-silicone-oil diffusion process is quite different from that in the momentum transport of the silicone oil:the activation entropy of the former is positive while that of latter is negative.However,the activation enthalpies of the two processes are in the same order of magnitude,which leads to the observation that Dμ/T is roughly constant.

A combination of molecular dynamics (MD) and density functional theory (DFT) calculations were used to study the hydration structures of K⁺ and Na⁺ ions under the confinement of 18-crown-6 in order to identify the role of water in the selectivity of 18-crown-6 towards K⁺.The radial distribution functions,coordination num-bers,orientation structures and interaction energies were analyzed to investigate the hydration of K⁺ and Na⁺ in 18-crown-6/cation complexes.All calculations of K⁺ and Na⁺ in bulk water were also conducted for comparison.The simulation results show that the orientation distributions of the water molecules in the first coordination shell of K⁺ are more sensitive to the confinement of 18-crown-6 than those of Na⁺.It is more favorable to confine a K⁺ in 18-crown-6 than a Na⁺ in terms of interaction energy.Good agreement is obtained between MD results and DFT results.

Experimental data on the solubility of D-glucose,D-fructose and sucrose in the mixed solvents composed of water and ethanol from 273.2 to 293.2 K were determined.The solubility of D-glucose,D-fructose and sucrose decreased as the ethanol content increased in the mixed solvent.The solubility of D-glucose,D-fructose and sucrose decreased with decreasing equilibrium temperature.The modified UNIQUAC model,SUNIFAC model and mS-UNIFAC model were applied to predict the solid-liquid equilibria.The prediction results were compared and discussed.Better prediction accuracy was generated using the modified UNIQUAC model.

The equilibrium distribution coefficients of 12 impurities (As,Fe,Ca,Co,Al,Cr,Cu,Mg,Mn,Ni,Pb,Zn) in phosphorus were obtained by measuring their effective distribution coefficients at zone travel rate of 3,5,10,15,and 20 mm·h^-1 in the purification process with vertical zone-melting technique.The results indicate that the method is reliable.The equilibrium distribution coefficients are below 0.3 except arsenic.

A quartz crystal microbalance (QCM) is used to determine the phase equilibrium of paclitaxel-carbon dioxide system in the pressure range of 0-11 MPa and at temperatures of 35℃,40℃ and 45℃.The experimental results indicated that gaseous CO₂ could be absorbed poorly into paclitaxel.The swelling of paclitaxel film in CO₂ was observed before paclitaxel dissolved into supercritical carbon dioxide (ScCO₂) with the increase of pressure.It was found that ScCO₂ was not a good solvent for paclitaxel.The mole fraction of paclitaxel in ScCO₂ was in the range of (4.5×10^-9)-(7.8×10^-9) under all our experimental conditions.Therefore,a much higher pressure than the CO₂ supercritical point and/or a cosolvent must be used in any processes wherever paclitaxel dissolution in ScCO₂ is required.

Particle image velocimetry technique was used to analyze the trailing vortices and elucidate their relationship with turbulence properties in a stirred tank of 0.48 m diameter,agitated by four different disc turbines,including Rushton turbine,concaved blade disk turbine,half elliptical blade disk turbine,and parabolic blade disk turbine.Phase-averaged and phase-resolved flow fields near the impeller blades were measured and the structure of trailing vortices was studied in detail.The location,size and strength of vortices were determined by the simplified λ₂-criterion and the results showed that the blade shape had great effect on the trailing vortex characteristics.The larger curvature resulted in longer residence time of the vortex at the impeller tip,bigger distance between the upper and lower vortices and longer vortex life,also leads to smaller and stronger vortices.In addition,the turbulent kinetic energy and turbulent energy dissipation in the discharge flow were determined and discussed.High turbulent kinetic energy and turbulent energy dissipation regions were located between the upper and lower vortices and moved along with them.Although restricted to single phase flow,the presented results are essential for reliable design and scale-up of stirred tank with disc turbines.

A time-frequency signal processing method for two-phase flow through a horizontal Venturi based on adaptive optimal-kernel (AOK) was presented in this paper.First,the collected dynamic differential pressure signal of gas-liquid two-phase flow was preprocessed,and then the AOK theory was used to analyze the dynamic differential pressure signal.The mechanism of two-phase flow was discussed through the time-frequency spectrum.On the condition of steady water flow rate,with the increasing of gas flow rate,the flow pattern changes from bubbly flow to slug flow,then to plug flow,meanwhile,the energy distribution of signal fluctuations show significant change that energy transfer from 15-35 Hz band to 0-8 Hz band;moreover,when the flow pattern is slug flow,there are two wave peaks showed in the time-frequency spectrum.Finally,a number of characteristic variables were defined by using the time-frequency spectrum and the ridge of AOK.When the characteristic variables were visually analyzed,the relationship between different combination of characteristic variables and flow patterns would be gotten.The results show that,this method can explain the law of flow in different flow patterns.And characteristic variables,defined by this method,can get a clear description of the flow information.This method provides a new way for the flow pattern identification,and the percentage of correct prediction is up to 91.11%.

The physical models of the outer and inner half coil jackets were simplified to two types of coiled ducts.The mathematic models of incompressible fluid at the condition of laminar flow and heat transfer in the two types of jackets for cooling process reactor were set up and solved by the semi-implicit method for pressure linked equations consistent (SIMPLEC) algorithm based on a control volume method.The flow and temperature fields were given and the effects of Dean and Prandtl numbers on flow and heat transfer were studied.The results show that flow in the inner half coil jacket is found to exhibit transition of secondary flow pattern from two vortices to four vortices when the Dean number increases,but that in the outer half coil jacket is not found.The critical Dean number is about 96.The inner half coil jacket has stronger heat transfer ability than the outer half coil jacket and this superiority is more evident with larger Prandtl number.However,as the Dean number is greater than 105,the flow resistance enhances more severely in the inner jacket than the outer jacket.For both jackets,the centers of the heated wall are the poorest for heat transfer.

A new aromatic diamine,3,5-diaminobenzoylpiperazine (3,5-DABP),was synthesized from 3,5-diaminobenzoic acid and 1-formyl piperazine.The structure of 3,5-DABP was identified by FT-IR spectra and 1H NMR spectra.With 3,5-DABP as aqueous monomer and trimesoyl chloride (TMC) as organic monomer,thin film composite (TFC) nanofiltration membranes were prepared by interfacial polymerization technology.The salt rejection order of these TFC membranes is Na₂SO₄>MgSO₄>MgCl₂>NaCl.This sequence indicates that the membranes are negatively charged.

In this study,strontium adsorption from sulfuric acid solution by different Dowex 50W-X ion exchange resins was investigated.Among these resins,Dowex 50W-X8 resin showed the maximum sorption of strontium from the aqueous solutions.The effect of pH,contact time,mass of resin,temperature,and concentration of interfering ions on strontium adsorption were evaluated to determine the optimum conditions of strontium sorption process.The kinetic models of sorption were analyzed using pseudo-first and pseudo-second order models.The results indicated that the pseudo-second order kinetic model was more appropriate than the other one.Moreover,the data obtained in this study were fitted into several sorption isotherm models and it was found that the Langmuir sorption isotherm shows the best fitting to the experimental data.

Activated carbon-supported Ru-based catalyst and A301 iron catalyst were prepared,and the influences of reaction temperature,space velocity,pressure,and H₂/N₂ ratio on performance of iron catalyst coupled with Ru catalyst in series for ammonia synthesis were investigated.The activity tests were also performed on the single Ru and Fe catalysts as comparison.Results showed that the activity of the Ru catalyst for ammonia synthesis was higher than that of the iron catalyst by 33.5%-37.6% under the reaction conditions:375-400℃,10 MPa,10000 h^-1,H₂:N₂=3,and the Ru catalyst also had better thermal stability when treated at 475℃ for 20 h.The outlet ammonia concentration using Fe-Ru catalyst was increased by 45.6%-63.5% than that of the single-iron catalyst at low temperature (375-400℃),and the outlet ammonia concentration increased with increasing Ru catalyst loading.

A series of Pt catalysts supported on the Hβ-zeolite that is ion-exchanged with the rare earth metal ions of Ce(Ⅲ) and La(Ⅲ),are prepared by impregnation,characterized by inductively coupled plasma (ICP),X-ray diffraction (XRD),BET,temperature-programmed desorption of ammonia (NH3-TPD),temperature-programmed reduction of hydrogen (H2-TPR) and H2-chemisorption techniques,and evaluated in the hydroisomerization of n-heptane with an atmospheric fixed-bed reactor.The reaction temperature,time on stream,space velocity,and the ratio of H₂/n-heptane are changed to get the optimal conditions.The Ce(III) and La(Ⅲ)-exchanged Hβ-zeolites exhibit higher selectivity for isomerized products than the neat Hβ-zeolite.Moreover,the Ce(Ⅲ)-exchanged catalysts give higher conversions of n-heptane,whereas the La(Ⅲ)-exchanged ones do not show any improvement in con-version.Under optimal conditions,the catalyst with 0.4% (by mass) Pt and 0.5% (by mass) Ce loading presents very high selectivity of isomerized products of 95.1% coupled with high n-heptane conversion of 68.7%.Effects of the ion-exchange of Ce(Ⅲ) and La(Ⅲ) on the catalytic performance are discussed in relation with the physico-chemical properties of catalysts.

Crosslink polymerization kinetics of poly(acrylic acid-co-2-acrylamido-2-methylpropane sulfonic acid),AA/AMPS hydrogels,was investigated by using dilatometry in the presence of sodium persulfate as initiator and N,N'-methylene bis(acrylamide) as crosslinker.It was found that the reaction for the crosslink polymerization of AA/AMPS hydrogels had orders of 0.58,1.14,and 0.86 with respect to the initiator,AMPS,and AA,respectively.From the Arrhenius plots,the activation energy of the crosslink polymerization was found to be about 140 and 89 kJ·mol^-1 in the presence and absence of the crosslinker,respectively,in the temperature range from 45 to 65℃.It was noted that the crosslinker had effects on the reaction order of the initiator and the activation energy due to the formation of cross-linked networks,which was verified by Fourier transfer infrared (FTIR) spectrum.To further confirm the influences of the cross-linked network structure on kinetic parameters of the crosslink polymerization,a mechanism was proposed,which highlights the different termination routes between free radical polymerization and crosslink polymerization.These results suggest that dilatometry provides a convenient tool for crosslink polymeri-zation study,and confirm that the cross-linked networks are formed in the crosslink polymerization.

Shape-selective catalysts for the disproportionation of toluene were prepared by the modification of the cylinder-shaped ZSM-5 zeolite extrudates with chemical liquid deposition with TEOS (tetraethyl orthosilicate).Various parameters for preparing catalysts were changed to investigate the suitable conditions.The resulting cata-lysts were tested in a pressured fixed bed reactor and characterized by SEM (scanning electron microscopy).The conversion of toluene and para-xylene selectivity were influenced remarkably by the n(SiO₂)/n(Al₂O₃) ratio of ZSM-5 zeolite,the type and amount of deposition agent,acid and solvent used,and the time and cycle of deposition treatment.TEOS was proved to be a more efficient agent than the conventional polysiloxanes when the deposition amount was low.The catalyst prepared at the suitable conditions exhibited a high para-xylene selectivity of 91.1% with considerable high conversion of 25.6%.SEM analyses confirmed the formation of a layer of amorphous silica on the external surface of ZSM-5 zeolie crystals,which was responsible for the highly enhanced shape-selectivity.

Considering that the performance of a genetic algorithm (GA) is affected by many factors and their relationships are complex and hard to be described,a novel fuzzy-based adaptive genetic algorithm (FAGA) combined a new artificial immune system with fuzzy system theory is proposed due to the fact fuzzy theory can describe high complex problems.In FAGA,immune theory is used to improve the performance of selection operation.And,crossover probability and mutation probability are adjusted dynamically by fuzzy inferences,which are developed according to the heuristic fuzzy relationship between algorithm performances and control parameters.The experiments show that FAGA can efficiently overcome shortcomings of GA,i.e.,premature and slow,and obtain better results than two typical fuzzy GAs.Finally,FAGA was used for the parameters estimation of reaction kinetics model and the satisfactory result was obtained.

Qualitative algebraic equations are the basis of qualitative simulation,which are used to express the dynamic behavior of steady-state continuous processes.When the values and operation of qualitative variables are redefined,qualitative algebraic equations can be transformed into signed direct graphs,which are frequently used to predict the trend of dynamic changes.However,it is difficult to use traditional qualitative algebra methods based on artificial trial and error to solve a complex problem for dynamic trends.An important aspect of modern qualitative algebra is to model and characterize complex systems with the corresponding computeraided automatic reasoning.In this study,a qualitative affection equation based on multiple conditions is proposed,which enables the signed direct graphs to describe complex systems better and improves the fault diagnosis resolution.The application to an industrial case shows that the method performs well.

Escherichia coli BW25113 was metabolically engineered for CoQ₁₀ production by replacing ispB with ddsA from Gluconobacter suboxydans.Effects of precursor balance and reduced nicotinamide-adenine dinucleotide phosphate (NADPH) availability on CoQ₁₀ production in E.coli were investigated.The knockout of pykFA along with pck overexpression could maintain a balance between glyceraldehyde 3-phosphate and pyruvate,increasing CoQ₁₀ production.Replacement of native NAD-dependent gapA with NADP-dependent gapC from Clostridium acetobutylicum,together with the overexpression of gapC,could increase NADPH availability and then enhanced CoQ₁₀ production.Three effects,overexpressions of various genes in CoQ biosynthesis and central metabolism,different vectors and culture conditions on CoQ₁₀ production in E.coli,were all investigated.The investigation of different vectors indicated that low copy number vector may be more beneficial for CoQ₁₀ production in E.coli.The recombinant E.coli (△ispB::ddsA,△pykFA and △gapA::gapC),harboring the two plasmids encoding pck,dxs,idi and ubiCA genes under the control of P_T5 on pQE30,ispA,ddsA from Gluconobacter suboxydans and gapC from Clostridium acetobutylicum under the control of PBAD on pBAD33,could produce CoQ₁₀ up to 3.24 mg·g^-1 dry cell mass simply by changing medium from M9YG to SOB with phosphate salt and initial culture pH from 7.0 to 5.5.The yield is unprecedented and 1.33 times of the highest production so far in E.coli.

A thorough understanding of bacteria transport in soil and groundwater is vital to the successful practice of environmental bioremediation.In this work,a dual-process adsorption with growth and decay model of bacterial transport was proposed.The onsite soil and the high efficiency methyl tert-butyl ether (MTBE) degrading bacterium Chryseobacterium sp.A-3,was used in the experiments.The model was validated using one-dimensional soil column experiments.The results show that the dual-process adsorption with growth and decay model proposed well describes the migration mechanism of microorganisms in soil and groundwater environment.According to the model analysis and simulation,the bacterial transport is enhanced as flow velocity and inlet cell concentration increase.Compared with the contaminant MTBE,the bacteria show stronger transport capacity but the irreversible straining in soil prevents the bacteria from transporting longer than MTBE.The results have certain instructive significance to the in-situ contamination remediation operation.

Using soybean hull residue after the soluble dietary fiber being removed during the soybean processing industry as crude material,a novel absorbent,modified soybean hulls,is prepared.Its adsorption behavior for Pb²⁺ is studied.The adsorbent has a large and efficient adsorption capacity for Pb²⁺,up to 20% of the mass of dry ad-sorbent.Its maximum adsorption capacity for Pb²⁺ reaches 217 mg·g^-1 at initial Pb²⁺ concentration of 2000 mg·L^-1,which is twice that of yeast absorbent and threefold greater than that of chitosan absorbent.The adsorption ability is sensitive to pH value in the solution and the optimal pH for adsorption of Pb²⁺ is 7.0.In the presence of other metal ions (Ca²⁺,Mg²⁺ and Na⁺) in the solution,their effect on the adsorption capacity for Pb²⁺ is not obvious.After 5 cycles of adsorption,80% adsorption capacity of Pb²⁺ is maintained.Compared with various available commercial resins,the modified soybean hulls are a plentiful,inexpensive and effective medium for the capture of dissolved Pb²⁺ from waste streams.

A two-dimensional numerical model is developed to simulate the flow,transport and biodegradation of toluene during bioventing (BV) processes in the unsaturated zones.The simulation for a single well BV system is used to illustrate the effect of air injection rate on remediation efficiency.The air is injected into the vadose zone to create a positive pressure.Simulation results show that air injection rate is a primary parameter governing the dispersal,redistribution and surface loss of contaminant.At injection rates of 81.504 m³·d^-1 (Run 1) and 407.52 m³·d^-1 (Run 2),the total removed mass of toluene is 169.14 kg and 170.59 kg respectively.Ratios of volatilization to bio-degradation in Run 1 and Run 2 are 0.57:1 and 0.89:1,respectively,indicating that lower air injection rate enhances the biodegradation efficiency greatly.Air injection rate should be optimized to meet oxygen demand and to minimize the operational cost.

Direct phase transformation of flue gas desulfurization gypsum in hot salt solution at atmospheric pres-sure was investigated.The effects of temperature,salt species,salt concentration,solids content,pH and modifier were examined.The crystals obtained under different conditions and solubility of calcium sulfate in contact with solid gypsum were also determined.α-Calcium sulfate hemihydrate crystals of stubby columnar shape and regular pentahedral sides were obtained under the following conditions:salt concentration 20%-30%,operation tempera-ture 95-100℃,solids mass content in the slurry 10%-30% and neutral pH.Thermodynamic analysis revealed that phase transformation of calcium sulfate dihydrate to α-calcium sulfate hemihydrate occurs because of the difference in solubilities between the two solid gypsum phases in this system.