In this paper,the steady N-S equations in a rotating helical right angle coordinates are presented firstly.The flow in a rotating helical elliptical pipe is studied by using the method with which Dean studied the flow in a stationary curved circular pipe.The study indicates that the flow is affected by four parameters:Dean number D, parameter η, parameter σ and axial aspect ratio λ.The effects of different control parameters on flow behaviors are analyzed in detail.The results of this paper also indicate that the first order of torsion has no effect on the flow in the rotating helical circular pipe.

Fluid catalytic cracking (FCC) process is one of the most important heavy oil upgrading techniques in the petroleum refining industry,and riser reactor is the crucial part in FCC unit. The experiment was conducted in a big cold riser model made of plexiglass with cross-section 0.186m in ID and height 14m.The operating conditions were decided according to industrial practice.The solid particle was a type of FCC cracking catalyst while the gas entering the riser via the nozzles and via the pre-lift zone is air. Particle velocity,local density,particle backmixing ratio,concentration of jet fluid in five different cross-sections were measured.The radial distributions of these parameters show that when nozzle jet is injected into,a secondary flow of jet fluid comes forth in the vicinity of the riser wall due to vortices regime,this secondary flow expands at first and then merges in the main stream. The whole feed injection zone of riser could be divided into four zones according to gas-solid two-phase flow characteristics in each zone.Moreover,these four zones could also be divided into two or three regions.

Fluid catalytic cracking (FCC) process is one of the most important heavy oil upgrading techniques in the petroleum refining industry,and riser reactor is the crucial part in FCC unit. An axial Particle Backmixing Model is established.By using two experimentally regressed parameters and the axial Particle Backmixing Model,the flow parameters of the particle phase such as mean density,mean axial velocity can be predicted well. The method for calculating radial distribution of nozzle jet in different riser cross-section is obtained,which considers both the Two Phases Diffusion Model and experimented results.It is also found that the ratio of pre-lift gas velocity and nozzle jet velocity is the decisive factor in this distribution while other operation parameters are secondary relatively.

The bed material in a rotary kiln is characterized by two distinct regions:the relatively thinner active region in which the particles roll down the sloping bed surface and the much thicker stagnant region in which the particles are carried upward by the rotating wall. According to this characteristic, a single particulate trajectory model (PTM) is developed starting from intrinsic mechanism of granular flow.A simplified calculation equations involving MRT(mean residence time) and MVF (material volumetric flow) is derived, on the basis of both the vector analysis on axial displacement of individual particles in a single excursion and the statistical-averaged analysis on all excursions.Two modified coefficients ε t and ε f are proposed to improve model validity under practical cases such as irregular municipal solid wastes (MSW) existence and internal structure usage. The newly derived equations of PTM are compared with those proposed by previous workers to show their advantages. Finally,an optimal model for both operation and design of a special rotary kiln pyrolyser is presented and the corresponding optimization solution is given in detail.

This paper mainly discussed a flocculant-producing bacteria isolated from soil and the flocculating substance secreted into the medium.Preliminary studies identified the bacteria CCTCC M201005 as Nocardia species.Its growth and metabolism were studied.More than 80% of the flocculating activity was detected in the culture broth.A new bioflocculant--REA-11 was purified by repeated ethanol precipitation,ion exchange and gel chromatography from the culture broth.Its molecular mass was estimated to be over 10 ⁵g·mol ^-1 by the gel filtration method.The results of investigation on the purified REA-11 and its acid hydrolysate by colcrimetric analysis,paper chromatography,HPLC and GC-MS suggested that REA-11 was a novel acidic polysaccharide mainly composed of galactocuronic acid with little acetic acid but no hexosamine detected.Protein was not a necessary part for the flocculating activity of REA-11,but mainly assisting in connecting the monosaccharides in the macromolecule or maintaining the dimensional conformation of the active biopolymer.

Investigations on protein refolding by size-exclusion chromatography (SEC) was carried out by using lysozyme as a model system.The comparison of elution volume of the native lysozyme and the refolded lysozyme demonstrated the variation of protein diameters during its refolding.The high yield of lysozyme activity obtained at high starting concentration illustrates the workability of this method for high concentration protein refolding.The effects of the sample loading and elution flowrate on the recovery of lysozyme were investigated,separately.The circular dichroism analysis demonstrated the structural identity of the refolded lysozyme and the native lysozyme.Short columns were used for the investigation of the refolding kinetic,and the impact of separation on refolding.The experimental results described above showed the advantages of this new method over the conventional step-wise dilution procedure in terms of high sample concentration and the in situ polishing and refolding.

The effects of lactate and osmolarity on the growth, metabolism and EPO expression of recombinant CHO cells were investigated by pulse cultures with different lactate concentrations and osmolarity.It was demonstrated that lactate molecule itself had little effect on the cell culture.With the increase of lactate concentration from 0 to 69mmol·L ^-1 ,corresponding to the increase of osmolarity from 300 to 420mOsm,the specific growth rate of recombinant CHO cells was reduced by 33%,the specific consumption rates of glucose and glutamine both increased by 23%,the yields of cell growth to glucose consumption and glutamine consumption were reduced by 45% and 47%,respectively,and the specific production rates of lactate almost kept constant,showing that more nutrient was consumed via aerobic metabolism pathway for more energy production to meet the increasing demand of maintaining energy of recombinant CHO cells at high osmolarity.The yield of ammonia production to glutamine consumption increased with the increase of osmolarity,while the yield of alanine was reduced.It was showed that the flux of glutamine consumed via glutamate dehydrogenase pathway increased in response to the increase of osmolarity.On the other hand,EPO specific production rates decreased with the increase of osmolarity because of lower specific growth rate.

A mathematical model of the heat and mass transfer characteristics of wet material in a drying process in a centrifugal fluidized bed (CFB) dryer is developed.In this model,the drying material is simplified as ideal little balls of potato.Under different conditions of gas temperature and relative humidity of inlet gas,rotating speed of fluidized bed and superficial gas velocity,the mean relative wet content of the drying material is calculated.The curves of these conditions are drawn out and the analysis of each curve is also given.In this paper,a group of control equations that can be used to simulate the process of the heat and mass transfer of the granule materials inside of CFB is given and proved.

A two-dimensional model is proposed for simulation of gas phase cracking of 1,2- dichloroethane (EDC) to produce vinyl chloride monomer(VCM) in tubular reactor furnace,in which side reaction of coke precursor formation is taken into consideration.It is found that significant radial variations of cracking temperature and cracking reaction rate exist due to boundary layer near the inner wall.The EDC cracking reaction rate is higher in the wall zone and reaches a maximum at 0.3 of dimensionless length of reactor coil.The rate of coke precursor formation is also higher near the inner wall than in the core zone of reactor coil and reaches a maximum at the outlet of reactor.The model can satisfactorily predict commercial operation results with regard to the EDC conversion,VCM selectivity,pressure and temperature at the outlet of reactor coil.

The catalytic combustion of toluene,propylene and carbon monoxide is investigated over a catalyst with metallic wall and catalytic layer.The catalyst is prepared by anodic oxidation of aluminium,hydration treatment and impregnation of a chloroplatinic acid hexahydrate solution.It has the advantages of high activity,easiness to form various shapes,and low pressure drop.The catalytic combustion experiments of the individual component and the mixtures of toluene,propylene and carbon monoxide are studied,and the inhibition effects are observed from the experimental data.The mechanism that reactant A is absorbed and reacts with dissociatively adsorbed oxygen is adopted.The kinetic models are obtained for each component in the mixtures.

Solid-state polymerization (SSP) is one of the important methods to synthesize high quality and high molecular polyesters and polyamides for tyre cords and engineering plastics.A theoretical model describing the kinetic behavior of the SSP of Nylon 6 with bifunctional acid regulator is presented based on some hypotheses,and verified by the experimental data of the authors for the SSP of spherical pellets of Nylon 6.This model consideres the effect of segmental diffusion on reversible step growth polymerization and small molecule water diffusion.The simulation results show that reaction temperature and time and water content is three important factors and that number-averaged molecular mass increases with increasing reaction temperature and time in the experimental ranges of the SSP of Nylon 6.It is in agreement with the mechanism of postcondensation in the SSP.

This paper considers pendant double bond as the third double bond in monoene/diene radical crosslinking copolymerization (RCC),and the model can be simplified when the amount of divinyl monomer is less than 5%(mol).Free radical tri-polymerization is introduced instead of free radical crosslinking copolymerization.For MMA/EGDMA free radical crosslinking copolymerization,since the vinyl structure of the MMA and EGDMA is identical,the model is simplified further by considering the vinyls of MMA,EGDMA and pendant double bond have equal chemical reaction ability.An empirical function developed by W.H.Ray is used to describe auto-acceleration phenomena,and diffusion effects should show additional crosslinking influence at this time.Then a coefficient k which comes from Arrhenius activation energy concept was introduced to amend reaction speed parameter,which involves termination reaction and crosslinking reaction,so the effect of crosslinking joint on RCC could be described.Finally,a statistics-kinetic model is established.The relationships between conversion and copolymertization time,average crosslink density with conversion are investigated.The curves predicted by the model fit well with experimental data.

The relationships between apoptosis and taxol production of Taxus cuspidata cells cultured in coupling medium composed of oleic acid,as organic phase,and improved B 5 medium were studied.The results showed that there was parabolic relationship between total taxol content and apoptosis rate.The coupling culture method effectively promoted taxol releasing from inside to outer of the cells.The effect of taxol on apoptosis decreased to minimum because most of taxol deposited in oleic acid.Thereby,it was presumed that the occurrence of apoptosis could promote the production of taxol.

The structures of interfacial turbulence phenomena in multicomponent evaporation,and physical absorption and desorption processes were observed by using Schlieren photography.It was found that structure of interfacial turbulence was characteristic of interfacial mass transfer process.In physicial absorption and desorption processes of carbon dioxide into and from liquid methanol,toluene,chlorobenzene,and isobutanol,orderly roll and polygonal cellular convection were observed.These orderly flow patterns were dissipative structures.It was also found that at room temperature,evaporation processes of some pure organic liquids,such as ether,trichloromethane,carbon tetrachloride,and acetone etc.,showed strong interfacial convection,but the evaporation processes of other liquids,such as benzene,toluene,chlorobenzene,ethanol,butanol,isobutanol,and ethandiol,did not show such phenomenon. However,interfacial turbulence was observed in the evaporation processes of benzene and toluene mixture and ethandiol-ethnoic acid-ethyl acetate equilibrium mixture.It is reasonable to believe that under suitable operating conditions,interfacial turbulence may affect distillation processes.

Experimental study was performed systematically to investigate heat transfer characteristics at the stagnation point from a simulated microelectronic chip of 5mm×5mm with impinging submerged circular jet, using R113 as the working fluid.Included are single-phase convective heat transfer,incipient boiling superheating, nucleate boiling heat transfer and burnout.The results showed that exit velocity had no influence on incipient boiling point and fully-developed nucleate boiling heat transfer curves, and that single-phase convective heat transfer coefficient and critical heat flux increased with enhanced jet exit velocity,while temperature overshoot decreased.While exit velocity was beyond 10m·s ^-1 ,the high heat flux portions of impingement boiling curves needed to be corrected in order to align with pool boiling curves at the same fluid subcooling.

Curve fitting method is often used in the test of heat transfer performance of heat exchangers.The convective heat transfer coefficient may be obtained with the method.However,there are defects with the method.The new curve fitting method introduced in this paper is a practical method for test of convective heat transfer coefficient.There are few constraint with the method.Moreover,the results are more precise and the test is more convenient.The method is expecially suitable for test of convective heat transfer coefficient of finned tubes outer surface.An instance of use of the method is given.

Pilot test was made on coking plant wastewater of the Coal Chemical Corp.,Panzhihua Steel Group,China,with the biological fluidized-bed technique and A-A-O system.The results showed that when the total HTR of system was 45h,effluent NH ₃-N was 10.33mg·L ^-1 ,effluent COD was less than 200mg·L ^-1 ,and effluent phenol was 0.13mg·L ^-1 .The operation cost is 3.60～4.36$·(t wastewater) ^-1 .

Two assumptions were put forward as a result of analysis of the flow curves of hydrolyzed polyacrylamide-salt solution and the theory of macromolecular solution.The relationships between the zero-shear viscosity η ₀ and polymer concentrations ρ _p,between the constants K and n in Meter’s equation and polymer concentration ρ _p were established.Therefore a universal Meter’s equation relating apparent viscosity η _a with polymer concentration ρ _p was deduced.The equation can be used to simulate apparent viscosity η _a for the system,with an average error of 7.9% for experimental values.

Based on flow analysis of jet exhausting atomization nozzle,a simplification model and calculating method are put forward to determine flow rate coefficient for jet exhausting atomization nozzle.The method considers the structure of nozzle,properties of fluid and flow state,it overcomes the shortcomings of selecting experimential values.The calculation agrees with the experiment results basically,and calculating errors are all under 3 percent.Therefore the method has wide application.

A molecular thermodynamic model for copolymers and their mixtures was established by adopting the hard-sphere-chain fluid as a reference and a square-well term as a perturbation.This model could be used to correlate vapor-liquid equilibria for copolymer solutions with three adjustable interaction parameters.Good agreements with experimental data were obtained.

Nanostructured TiO ₂ porous film supported on nickel was prepared through sol-gel process,and was used as photoelectrode in solar energy photoelectrochemical cell.It was found that short circuit photocurrent and open circuit photovoltage of the photoelectrodes increased with the increment of sintering temperature and thickness of TiO ₂ film.Through STM,the pore quantity and diameter of nanostructured TiO ₂ film were found to increase with the increment of sintering temperature.It was found that the transparence of different thickness nanostructured TiO ₂ films coated on quartz did not change much.