To get better correlation results of vapor liquid equilibrium (VLE) of mixture systems, it is usually necessary to select the suitable mixing rule. The modifications of force parameter a have obtained good results in both theory and application. However, the research on co-volume parameter b is less and usually empirical. A new modified method for co-volume b was presented. In the revised mixing rule, the molecular shape factors obtained from Leach et al were introduced to amend co-volume b on the basis of Mie potential-energy and London dispersion theory. Thus, the interactive parameter l_ij in co-volume b was dependent on the molecular shape factors θ, φ, and critical parameters of the components. Without experimental data, molecular shape factors and interactive parameter l_ij could be obtained, which could be used to reflect the actual situations of mixture systems. The VLE calculation results for 16 kinds of different systems were given by using modified co-volume parameter b in MHV1/LCVM/HV mixing rules combined with PR EOS and NRTL models, and the results were compared with the results of using b ∑x_ib_i in MHV1/LCVM/HV mixing rule combined with PR EOS and NRTL models. The models with the modified co-volume b were better than those with b ∑x_ib_i to some extent.

Latent heat thermal energy storage technology is a promising option for future cost reduction in parabolic trough power system, however, low thermal conductivity of phase change material (PCM) is the major shortage leading to large temperature difference between heat transfer surface and solid-liquid interface of the PCM, and low energy storage rate. A charging experimental system was set up for testing the dynamic thermal behavior of phase change material in metal foam. Paraffin wax is used as PCM and its thermal properties were determined with differential scanning calorimetry (DSC). Metal foam was made of red copper. The sample of PCM-foam composite with semi-circular slot was placed inside a transparent cuboid Plexiglas enclosure, and a copper tube with the same radius as the semi-circular slot was in close bonding with the PCM-foam composite. High temperature water flowed through the copper tube as the heat transfer fluid (HTF) heating the composite material. The temperature field and melting process of PCM at pore size were studied using appropriate thermocouple and high definition camera. Thermal characteristics, including temperature profiles and position of solid/liquid interface were investigated and recorded, and the effects of heating temperature and flow rate of HTF on temperature uniformity and melting rate were documented and discussed. Metal foam could effectively improve heat transfer performance of PCM and decrease charging time Temperature difference was smaller and heating flux was larger in the composite than those in pure paraffin.

Freeze-drying of porous frozen material with initial porosity was experimentally investigated. Mannitol was selected as the primary solute in aqueous solution to be dried. The liquid nitrogen ice-cream making method was used to prepare frozen materials with initial porosity. Freeze-drying experiments were performed using two kinds of frozen materials, the initially unsaturated one and the conventionally saturated one for comparison. Freeze-drying could be significantly enhanced with the initially unsaturated frozen material. SEM images of dried products showed that such prepared initially unsaturated material had larger void space and more tenuous solid matrix that was continuous and uniform than those with the conventionally saturated one. This would be beneficial to migration of sublimed vapor and reduction of mass transfer resistance. There was indeed an overall sublimation for the initially unsaturated frozen material, and a primary sublimation region still existed through examining temperature variations at different locations inside the material. Predominant drying rate-controlling factor was heat transfer for the initially unsaturated frozen material, and mass transfer for the conventionally saturated one. Operating pressure had little influence on the freeze-drying process. Combination of radiation heating with conduction heating was able to improve heat transfer in freeze-drying of initially unsaturated porous materials, further shortening drying time.

The flow of 82 μm-diameter powder and the effect of hopper structure(hopper diameter, angle) on transition surface height and flow pattern in a 3D conical hopper were studied using the computational particle fluid dynamic (CPFD) numerical scheme. The validity of the calculated results was confirmed by comparing them with experimental results. CPFD simulation was fully capable of reproducing the discharging process. CPFD numerical 3D calculations showed that solids flow rate increased with increasing hopper diameter to the 2.5th power. As hopper angle increased, flow pattern in hopper transformed from mass-flow to funnel-flow. CPFD could give the change of transition surface height with hopper structure.

The heat transfer characteristics of the vapor chamber heat pipe with metal fiber felt wick were studied by experiments. Under different conditions, the isothermal characteristics and startup performance of the vapor chamber heat pipe using a single heat source were tested. The variables were heat flux, cooling wind speed and working fluid. The condenser section of the vapor chamber heat pipe was filmed by infrared thermography. The working fluid used in the vapor chamber heat pipe was water or acetone. The vapor chamber heat pipe could startup smoothly from ambient temperature at different heating powers, and startup time was about 3000 s. Both evaporator and condenser sections of the vapor chamber heat pipe had good isothermal performance, and the minimum temperature difference of the heat pipe using water as working fluid was 1.35℃. So electronic devices could avoid local high temperature by using the vapor chamber heat pipe with metal fiber felt wick.

Molten salt as one of the most promising heat transfer and heat storage media in the concentrating solar power (CSP) system has such advantages as high and wide liquid temperature, good heat transfer performance, low operation pressure and good thermal stability. An experimental study on turbulent convective heat transfer with low-melting point molten salt in a circular tube was conducted by using a self-made parabolic trough solar collecting and heat transfer system with molten salt. The total heat transfer coefficients from water to salt in a concentric tube heat exchanger at different flow rates were obtained. The change of Nusselt number of low-melting point molten salt with Reynolds number was calculated with the least-square method and the experimental correlation were obtained. Comparison was also made between experimental data and well-known convective heat transfer correlations, with the maximum deviations between the present data and curves predicted by Dittus-Boelter, Colburn, Seider-Tate, and Gnielinski equations of +23%, +13% -10% and -20% respectively.

A mathematical model of annular flow in vertical rectangular narrow channel was developed and experimental verification was performed in order to study flow and heat transfer characteristics of annular flow in vertical rectangular narrow channel. Through numerically solving the mathematical model, pressure gradient, boiling heat transfer and liquid film velocity profile in the annular flow region were obtained. The present model could well predict pressure gradient and boiling heat transfer. The liquid film velocity profile of annular flow in the normal direction was not linear, and liquid film velocity gradient was large in the laminar boundary layer. Rectangular narrow channel size and heat flux had significant effect on liquid film velocity profile. Liquid film velocity increased with increasing heat flux and decreased with increasing channel size. The effect of mass flow rate on liquid film velocity was smaller than the effect of heat flux and channel size, and liquid film velocity decreased with increasing mass flow rate.

Ground thermal properties is an important design parameter of ground-coupled heat pump system (GCHPs), and it can be decided based on the data from in-situ thermal response test (TRT). Considering that constant heat input can seldom be ensured in TRT, this paper presents a novel method for determining parameters of rock-soil thermal properties by using simulated annealing algorithm (SAA). In the method, Green function used in cylinder source model (CSM) of borehole heat exchanger (BHE) accelerates calculation of inlet/outlet water temperatures based on the TRT system model, and RMSE distribution overcomes the ill-posed problem of parameter identification in inverse heat transfer analysis, which puts into effect of SAA. In a calculation sample based on TRT of variable heat input, annealing temperature decreases with identified parameters reaching agreement with true value individually, and the relative errors of ground thermal conductivity and volumetric heat capacity are respectively 4.1% and 1.3% by comparing with the value calculated based on national regulations on the same in-situ measuring location. At the same time, the effective heat resistance of BHE can be obtained in the process of ASS. In general, ASS used in the variable heat power TRT is proved to be successful, and the study is helpful for the design of BHE in GCHPs.

A series of Zn-WC/HZSM-5 catalysts with different amounts of Zn additive were prepared based on the precursor WC/HZSM-5. The samples were characterized with X-ray diffraction, scanning electron microscopy, N₂ adsorption-desorption, Fourier transform infrared spectroscopy and thermogravimetric analyzer. Aromatization of n-hexane was evaluated over the Zn-WC/HZSM-5 catalysts in a fixed-bed micro reactor. The role of metal components and the reaction mechanism were studied. Both aromatic selectivity and yield increased with Zn-WC/HZSM-5. Yield increased to 36.18% when the Zn-WC/HZSM-5 displayed the best activity with the concentration of Zn 1.5% (mass). Introduction of Zn into WC/HZSM-5 led to redistribution of acid sites on the surface of catalyst and also caused decrease of coke deposition.

A kinetic model of synthesizing ethanol by hydrogenation of ethyl acetate was developed based on laboratory data, and then corrected by taking into consideration the pore diffusion effect. With the correction, the results could conform with actual operation. Based on the principles of material balance, energy balance, momentum balance and kinetics of the reactions, an one-dimensional pseudo-homogeneous model of the ethanol synthesis reactor by hydrogenation of ethyl acetate using fixed bed was established. The simulation results of a variety of conditions were obtained by the model with different H₂/EA molar ratios, different temperatures and different pressures. The model could reflect the performance of the hydrogenation reactor and provide guidance for the design and operation optimization of industrial reactor.

Propylene carbonate (PC) was synthesized on a fixed-bed reactor from CO₂ and propylene glycol (PG) catalyzed by supported Zn(OAc)₂ catalyst. Then the effect of the kind of carrier and its loading on the catalytic performance and the influence of reaction conditions on PC synthesis reaction were investigated. The results indicates that Zn(OAc)₂/AC with loading of 40% (mass) shows better catalytic performance. The suitable reaction conditions are obtained as follows: molar ratio of PG to acetonitrile(solvent) to CO₂ is 1:1.8:11, reaction temperature 160℃, CO₂ pressure 4.0 MPa and LHSV 0.9 h^-1. Under the above conditions, the yield and selectivity of PC were 6.3% and 49.0%, respectively. The interaction between Zn(OAc)₂ and CO₂ or PG was investigated by in-situ IR technique combined with some designed experiments. It was found that the chemical adsorption of CO₂ on Zn(OAc)₂ is weaker while it is much stronger between PG and Zn(OAc)₂. Chemical bond between PG and Zn(OAc)₂ is found, indicating that Zn(OAc)₂ can activate PG in this reaction. Accordingly, the role of Zn(OAc)₂ in the catalytic reaction of CO₂ and PG to PC is elucidated.

Hydroxyalkylation of phenol and aqueous formaldehyde to bisphenol F catalyzed by Keggin phosphotungstic acid (PTA) encapsulated in two types of metal-organic frameworks of zeo-type cubic structure MIL-100(Cr) and MIL-101(Cr) was performed. PTA@MIL-100(Cr)(β) and PTA@MIL-101(Cr)(β) catalysts with the same β (molar ratio of W/Cr) value were prepared and characterized with XRD, BET, FT-IR, TEM and ICP. MIL-100(Cr) was better than MIL-101(Cr) in loading phosphotungstic acid. PTA@MIL-100(Cr)(0.4) with PTA loading of 16.47% obtained its highest catalytic activity with 93.18% of bisphenol F yield, 96.11% of bisphenol F selectivity at 8 h and 71.24% of 4,4'-isomer bisphenol F at 0.5 h. PTA@MIL-100(Cr) could keep its original activity after six recycling uses.

The alkylation kinetics of isobutane with mixed butenes using sulfuric acid as catalyst was investigated by batch experiments at temperatures from 276.2 K to 285.2 K under the conditions of industrial interest. With the decrease of reaction temperature, both the production of main product trimethylpentanes (TMPs) and RON of alkylates increased, and byproducts dimethylhexanes (DMHs) changed a little, but heavy ends components (HEs) reduced significantly. By using the alkylation kinetics model based on the classic carbonium ion mechanism, the concentration profiles with time regarding three groups of key alkylates, including TMPs, DMHs, and HEs, were compared against experiments. The regression results showed that the kinetics model fitted experimental data very well. An anti-Arrhenius behavior was found in the chain initiation step of the addition reaction of H⁺ to isobutene, and the apparent activation energies of itself and the reverse reaction were 45.14 kJ·mol^-1 and 41.44 kJ·mol^-1. The calculation of reaction rates of the TMPs⁺ and DMHs⁺ forming steps was added, and most of the reaction rates of chain transfer and chain termination reactions remained the same as those in literature.

A new Rhodamine derivative RCu was designed and synthesized as a colorimetric probe for Cu(Ⅱ) with high selectivity. RCu itself has no color in HEPES buffer solution (2×10^-5 mol·L^-1, pH 7.4). With Cu²⁺ added, the solution turns into pink color, but without change in color with other common metal cations. The probe can recognize Cu²⁺ at low concentrations and the detection limit is 6.37×10^-8 mol·L^-1. Meanwhile, the probe can detect Cu²⁺ in water samples at lower concentrations by indicator paper, indicative of its great potential applications.

Response surface methodology (RSM) was used for modeling and optimization of operating parameters and permeate flux for hollow fiber air gap membrane distillation (AGMD-HF) desalination process with simulated 3.5% (mass) seawater as feed solution. Hot feed-in temperature, cold feed-in temperature and fluid flow rate were chosen for experiment optimization based on central composite design (CCD). A quadratic polynomial regression model for permeate flux and operating parameters was developed. Accuracy of the model was validated by analysis of variance (ANOVA), RSM and comparison of predicted and experimental permeate flux response. Furthermore,the best optimal level of operating parameters and solar-powered verification were performed. During the experiments,permeate conductivity was constantly kept below 10 μS·cm^-1, and relative ion rejection rate was above 99.99%. A R² of 0.986,p-value smaller than 0.0001 for ANOVA were obtained, and average error of predicted and experimental permeate flux was 6.95%. Moreover, the best optimal operating parameters of 83.5℃,13.2℃ and 60.2 L·h^-1 based on desirability function and solar-powered process permeate flux of 6.47 L·m^-2·h^-1 were presented. Consequently, modeling and optimization of operating parameters for permeate flux response could be helpful for scaling up AGMD-HF desalination process, and introduction of solar power as an alternative of conventional electric heat source could have better application prospect for AGMD-HF desalination.

Significant amounts of oil-containing waste water are discharged in industrial processes, and it is difficult to separate the oil/water mixture. In this paper, a concept of air-lift loop was introduced to traditional flotation process to treat oil-containing water. In the experiment, oil-in-water emulsion was produced by ultrasound, and the flotation agent for this system was optimized first, as poly(acrylamide-co-diallyldimethyl ammonium chloride) (PDA). Then, the effect of different conditions in the loop flotation process was investigated. When air flow rate was 250 L·h^-1, liquid flow rate was 10 L·h^-1, liquid level was 6 cm, amount of PDA was 20 mg·L^-1, oil removal rate was the highest. Concentration of oil was reduced from 900 mg·L^-1 to 100 mg·L^-1 and the highest efficiency was 90.48%. Compared with the traditional column flotation under the same condition, loop flotation was more effective and quick, with increased oil removal by 10%. The loop flotation concept would have great industrial application value.

CaO-based sorbents with Ce and Zr as dopants were prepared by the method of wet mixing and subsequent calcination. The cyclic CO₂ sorption/desorption performance of 24 sorbents was tested with thermogravimetric analyzer (TGA). CeO₂ could increase CO₂ sorption rate in the diffusion-controlled regime because the large quantity of oxygen vacancies in CeO₂ could facilitate CO₂ diffusion through the produced CaCO₃ layer and then react with the uncreated CaO. Dispersion of CeO₂ on CaO could also inhibit agglomeration of CaO crystal and its sintering at high temperature. Stability of CaO in sorption/desorption cycle increased with increasing amount of CeO₂ in the sorbents. With a high Tammann temperature, the newly produced CaZrO₃ from zirconia and calcium oxide could serve as a supporting framework and effectively restrain sintering.

Attapulgite (ATP) is a hydrous layer-ribbon magnesium aluminum silicate mineral with a unique three-dimensional structure. Due to its natural abundance, extremely good mechanical/thermal stability, its one-dimensional nanoscale, and a large quantity of silanol groups on the surface, attapulgite is a very good candidate for low-cost materials as adsorbents. To increase adsorption capacity and selectivity, attapulgite must be treated with organo-functional groups to produce specific sites on the surface. Polyacrylic acid/attapulgite (PAA/ATP) was prepared by grafting PAA onto γ-methacryloxypropyl trimethoxy silane (MPS)-modified attapulgite surface via solution polymerization. PAA/ATP was characterized by thermogravimetry (TG) and X-ray photoelectron spectroscopy (XPS). The selective adsorption of ternary mixed heavy metal ions (Pb²⁺, Ni²⁺ and Cr³⁺) by polyacrylic acid/attapulgite composite adsorbents was evaluated in batch experiments by varying contact time and initial ion concentration. The kinetic data was fitted with the pseudo-second-order kinetic model, and the equilibrium data obtained was analyzed with the Langmuir and Freundlich isotherm equations. The kinetic data followed pseudo-second-order equation, indicating the chemical adsorption was the rate-limiting step process. The equilibrium adsorption data of Pb²⁺ could be described well with the Langmuir isotherm model. Obviously, PAA/ATP showed excellent adsorption selectivity for Pb²⁺ compared with Ni²⁺ and Cr³⁺ in terms of distribution coefficient and separation factor, which was also confirmed by XPS.

In order to improve the surface hydrophilicity of microporous polypropylene membrane (MPPM), a facile and effective method was developed to hydrophilize the surface of MPPM using CaCO₃ mineral. This was achieved by dopamine oxypolymerization and alternate soaking mineralization (ASM). The resulted membranes were characterized with Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), environmental scanning electron microscopy (ESEM), energy dispersive X-ray spectroscopy (EDX) and water contact angle. The influences of mineralization conditions, such as solution concentration, number of ASM and polydopamine-coating degree on CaCO₃-based mineralization degree were investigated. The results confirmed that CaCO₃ mineral was dispersed uniformly on the surface of MPPM. Due to intrinsic wettability of CaCO₃ mineral, the mineralized membranes were superhydrophilic, and showed excellent water permeability with high pure water flux (up to 6450 L·m^-2·h^-1) and low membrane permeation resistance. Under the drive of external pressure of 0.01MPa, water could permeate through the mineralized membranes. The separation ability of the mineralized membrane for oil/water emulsion was also investigated. The mineralized membranes could separate a range of oil/water emulsions effectively with high water flux (> 1800 L·m^-2·h^-1), and could be easily cleaned by water, showing attractive potential for practical oil/water emulsion separation.

According to the process information, operation procedure and historical data of polyvinylchloride (PVC) industrial process, a dynamic simulation model of vinyl chloride (VCM) suspension polymerization batch process was built with Aspen. Normal simulated vaccine (SV) and fault simulated vaccine which generated by various simulated samples, combining industrial practical data, constructed normal antibody library and fault antibody libraries. This method could deal with the limitation of historical fault samples in fault diagnosis of vinyl chloride polymerization process. Artificial immune system (AIS) based on dynamic time warping (DTW) algorithm was applied to fault diagnosis of this polymerization batch process, which shows great performance.

Control vector parameterization (CVP) is a frequently used numerical method for solving optimal control problems, where the control vector is approximated by a group of parametric functions through time discretization. Usually, the discretized time grid is fixed, and its partition will affect accuracy and performance of the numerical solution of optimal control problem. To optimize both the control parameters and the time grid nodes, a CVP method with variable time nodes was proposed. Based on the derived relationship between the gradients of time nodes and the ones of interval lengths, the gradient equations for parameters were presented. The proposed method was demonstrated to have better approximation ability for the optimal control trajectories on two classic optimal control problems.

Chemical process startup is mostly a heating process, to satisfy the requirements of speed and stability,some researchers proposed Bang-Bang control combined with other control method for controlling the heating process, but due to strict requirements of Bang-Bang control on switching time and switching point, its practical application is not satisfactory. So based on Bang-Bang control, a buffer heating stage was added. Then the temperature control process could be divided into four parts: full width, zero brake, buffer heating and PID control. The rate of change of temperature was used as switching variable between buffer heating and PID control. In addition, modified switch control was converted to nonlinear programming problems, and switching points of the first three parts were optimized. Simulation comparison revealed that the control method not only avoided the problem caused by inproper selection of switching times and switching points, but overshoot was small and the process could be stabilized quickly.

To obtain the optimum distribution of liquid holdup or catalyst volume in the reactive zone for the design of a reactive distillation (RD) column considering selectivity targets, a design and optimization framework based on the combination of exergy loss analysis and process simulation were proposed. An exergy calculation model was established, including both physical and chemical exergy values, according to which the causes of exergy loss could be revealed with insights that provided the evolutionary direction of optimization. By linking the reaction volume distribution with exergy loss, the design of a reactive distillation column with the minimum reboiler heat duty could be accomplished by using the proposed optimization methodology. The proposed methodology was validated by the application to a reactive distillation column for producing ethylene glycol (EG) by hydration of ethylene oxide (EO). The optimized reaction volume distribution could reduce total energy consumption by 18%, compared with the commonly used even reaction volume design. In addition, the effect of energy saving obtained in this work was better than that reported in literature.

In order to restrain the influence of non-stationary disturbance to VCM distillation process with integral characteristics by the acetylene method, an effective adaptive MPC method was presented. Due to the integral characteristics of the high boiling tower caused by settling of high-boiling residues to the bottom of tower, liquid level of the high boiling tower was taken as integral variable. Furthermore, in order to restrain the influence of non-stationary disturbance to liquid level of the high boiling tower caused by feed temperature of VCM and other factors, firstly, RELS (recursive extended least squares) algorithm was used to estimate the disturbance; secondly, the proportion of prediction error caused by the disturbance was calculated. Lastly, twiddle factor of adaptive MPC was updated real-time to realize the control of liquid level. Industrial experiments indicated that the adaptive MPC could overcome the non-stationary disturbance effectively, and standard deviation of liquid level was 2.6616 which was reduced by 60.7% than before. The effectiveness of the adaptive MPC was proved.

The erosion of dust collection electrode and distribution of water film are the main factors affecting stability and reliability in successive operation of wet electrostatic precipitators (WESP). To address these problems, modification of carbon steel made by cold rolling was made to provide corrosion protective coating and additional water affinity. The surface wetting characteristics of various modified anode plates were investigated under single strand feed water condition. The influence of Reynolds number on surface wetting characteristics of optimum modified plate was studied, aiming at providing theoretical foundation of rinse water distribution of WESP. Corrosion protective coating had negative impact on the surface wetting characteristics of substrate. With similar surface wetting characteristics, epoxy resin and glass fiber cloth Ⅰ had no effect on hydrophilic modification. The surface wetting characteristics of epoxy resin modified by sand, glass beads and glass fiber filament were similar and had little effect on hydrophilic modification. TL carbon fiber cloth had the largest liquid holdup of 0.0028—0.0054 g·cm^-2, increased by 1.0—2.2 times compared with carbon steel sheet (CSS). Sand needed the least surface flow rate to wet the whole test sample, which was decreased by 36% compared with CSS; while sand had the largest film rate, increased by 50%—60% compared with CSS. The average thickness of water film was about 0.3—0.7 mm, and TL carbon fiber cloth could reach 1.4 mm. The degree of tightness of glass fiber cloth attached on the surface of epoxy resin depended on adhesion technology, which had direct effect on surface wetting characteristics. GFC series modification methods (GFCⅡ, GFCⅢ, GFCⅣ) had favorable effect on hydrophilic modification, and average thickness of water film was less than 0.35 mm. GFCⅢ, GFCⅣ surface could get wetted quickly, and critical time was shorter than 3 min. Surface flow rate of GFCⅡ, GFCⅢ, GFCⅣ could decrease by 94%—97% compared with CSS to wet the same size surface. Among them, adhesion technology Ⅲ had the best performance. The pitch of blowhole could be set as 10 cm or wider. Effective washing could be obtained, when the waves on the liquid film were fluctuating laminar at Reynolds number about 2000.

In order to study the effects of shaft surface inclined micropores on lubrication performance of lip seal, a mathematical model of lip seal under steady state was developed based on mass conservation with Jakobsson- Floberg-Olsson (JFO) cavitation boundary condition. The lubrication governing equation was solved by the finite element method, and the non-dimensional reverse pumping rate and friction force were obtained, then a comparative study of lip seal lubrication performance for different shaft surface inclined micropores shapes (ellipse, rectangle, diamond, isosceles triangle) was conducted. Micropores symmetrical with the shaft tangential direction produced zero reverse pumping rate, while others with 45° inclination to the axial direction produced maximum reverse pumping rate. Friction force was minimum when the micropore oil wedge dimension along the tangential direction was minimum. Reverse pumping rate and friction force decreased with micropore depth. Micropores with higher shape factor could produce higher reverse pumping rate and lower friction force. Rectangle micropore produced the maximum reverse pumping rate and minimum friction force among four kinds of micropores under the same conditions.

A kind of self-pumping hydrodynamic mechanical seal was presented based on the principle of centrifugal pump. The three-dimensional flow fields of self-pumping grooves were analyzed using Fluent, and the influences of geometric parameters and operating parameters on the sealing properties, including opening force and leakage rate were also discussed. Leakage rate and opening force decreased with increasing speed, and increased with increasing pressure, aperture diameter, helix angle and the ratio of groove width and ridge width. With increasing groove number, ratio of groove length and dam length, opening force decreased and leakage rate increased slightly. The influence of groove depth on opening force was similar to the influence on leakage rate, and there existed an optimal groove depth which could achieve higher opening force and lower leakage rate. Consequently, the self-pumping hydrodynamic mechanical seal proposed could get larger opening force and lower leakage rate by matching groove parameters.

The corrosion inhibition and adsorption behavior of PESA and CSN-PESA were investigated as corrosion inhibitors for A3 carbon steel corrosion in tap-water by static mass loss and electrochemical methods. Inhibition mechanism of PESA and CSN-PESA was studied with quantum chemistry theory. PESA and CSN-PESA both showed corrosion inhibition performance in tap-water corrosion environment. The inhibition efficiency of CSN-PESA was better than PESA. The adsorption belonged to mix-type adsorption mainly dominated by chemisorption and physisorption, and followed Langmuir isotherm. PESA and its derivative had inhibitory effect on the cathode and anode. Quantum chemistry calculation showed that the main reason for better inhibition efficiency of CSN-PESA was that molecular orbital densities were mainly distributed in near the O, N, S heteroatoms in CSN-PESA.

The temperature distribution along the surface of drying droplet has significant influence on fluid flow and particle deposition of the droplet. Currently, the surface temperature distribution of the droplet is often studied by numerical methods. For drying droplets on finite thickness substrates, the effect of meshing on calculated surface temperature is discussed. Compared to the region near the droplet edge, mesh refinement in the central region of the droplet has negligible effect on numerical results. The influence of the size of mesh refinement region near the droplet edge on droplet surface temperature can also be neglected compared to the level of mesh refinement. By studying the effects of relative substrate thickness h_R on droplet surface temperature, three different states with changing substrate thickness are found. (1) From center to edge, surface temperature increases monotonically. (2) From center to edge, surface temperature changes non-monotonically. (3) From center to edge, surface temperature decreases monotonically. The different patterns of droplet surface temperature can be explained by considering the combined effects of heat conduction path length and evaporative cooling. The surface temperature "phase diagram" on parameters (h_R, q) with different relative thermal conductivities is obtained. The results will be helpful to understanding droplet evaporation and providing theoretical basis for evaporation induced self-assembly and ink jet printing.

The vector with the gene of recombinant reteplase (rt-PA) was cloned into E. coli BL21(DE3) cells. Over-expression of rt-PA as inclusion bodies was obtained, and renaturation of rt-PA in vitro was investigated. Firstly, single factor experiments were conducted to optimize refolding conditions, including refolding buffer pH, GSH concentration, ratio of GSH to GSSG, rt-PA concentration. On this basis, high concentration protein refolding was further investigated by orthogonal experimental design. Fermentation broth with 1.7 g crude inclusion bodies per liter was obtained after using 0.2 mmol·L^-1 IPTG as inducer and culturing at 33℃ for 6 h. The refolding yield of rt-PA was up to 87.2% under optimal condition: 50 mg·ml^-1 denatured rt-PA, pH 10.0, 1 mmol·L^-1 GSH and ratio of GSH to GSSG 8. The key factors affecting refolding of high concentration protein were initial pH and GSH concentration, and specific bioactivity of rt-PA could reach 7.54×10⁴ IU·mg^-1 after refolding at protein concentration of 800 mg·ml^-1. Fluorescence spectra indicated that structural conformation of refolded reteplase was identical with its native state.

Owing to the substantial amounts of metals embodied in tailings, they are potential viable sources of metals. This work aims at developing a technique to microbially recover copper present in tailings. Based on orthogonal design, the effects of different variables, such as temperature, fermentation time, inoculum size and medium components, on pellet morphology of A. niger were investigated in shake flasks. Leaching of copper from its tailings was conducted using fermentation broths of Aspergillus niger with different pellet morphology. Copper extraction gradually increased with reduction in pellet diameter of A. niger. A large amount of compact smooth pellets with a diameter of 0.96 mm were obtained under the optimum fermentation conditions of 30℃, 0.8% inoculum size(OD₆₀₀=0.1), 30% potato-sucrose contents, 65 h fermentation time. After 3 days of leaching, copper extraction reached 83.25% with the fermentation broths aforementioned at 30℃, 180 r·min^-1.

The yield of biogas produced by mid-temperature (35℃±1℃) anaerobic fermentation of rice hulls was investigated, and material and energy flows as well as the distribution of element C and N during this fermentation process were also analyzed using the material flow analysis (MFA) method in this paper. The results showed that during the fermenting rice hulls to prepare biogas, the production rates for biogas and for CH₄ were 297.41 and 164.40 ml·(gVS_RH)^-1, respectively; implying that average CH₄ content in biogas was 55.28%, corresponding to 31.16% of the theoretical yield. Based on MFA for the fermentation process system, 30.8% and 6.4% of C element were converted into biogas and slurry, and 62.9% left in residue, separately; 63.2% of N element were converted into slurry and 36.8% left in residue, while negligible N element was in biogas. The efficiencies of material and energy for conversion of rice hulls to biogas were 30.0% and 33.7%, respectively. This study could be as a theoretical basis for resource management and energy utilization of agricultural wastes.

The batch and column experiments on removal of As(Ⅲ) from aqueous environment by zero-valent iron (ZVI) and quartz sand mixed with ZVI were studied. The batch test results showed that removal efficiency of As(Ⅲ) by ZVI was dependent on pH value and the optimum range of pH was 4—9. As(Ⅲ) was mainly removed though adsorption and co-precipitation by the surface of ZVI and its corrosion products. Meanwhile, simultaneous oxidation and reduction of As(Ⅲ) on the surface of ZVI occurred during the corrosion process of ZVI. As(Ⅲ) was oxidized in oxidation of Fe²⁺ to Fe³⁺. Quartz sand mixed with ZVI was used for the adsorption of As(Ⅲ) from simulated arsenic-containing wastewater in the column experiment. After 20 d of continuous adsorption of As(Ⅲ), the column was saturated. The calculated adsorption capacity of As(Ⅲ) by ZVI was 89.90 mg·g^-1 and the adsorption capacity of As(Ⅲ) was affected by the crystalline types of ZVI corrosion products on the surface of quartz sand. In this study, amorphous corrosion products of ZVI had the largest adsorption capacity, and mass fraction and atom fraction reached 6.73 and 2.15 respectively.

This article investigated the effects of coal bed thickness, which could change heating rate and product distribution, on pyrolysis of coal in a rectangular radial flow fixed-bed reactor. Increasing coal bed thickness prolonged the time required to heat up coal at bed center to the preset temperature, increased the yield of pyrolysis products water and gas, decreased the yield of char and tar oil, but the content of light component in tar oil tended to increase, and the calorific values of char and gas slight decreased. For example, at furnace wall temperature of 900℃, when coal bed thickness increased from 45 mm to 105 mm, the tar oil yield lowered by 12.7% from 7.17%(mass, the same below) to 6.26% (dry coal basis), char decreased from 80.0% to 77.0% and heat value from 24348.5 kJ·m^-3 to 20649.2 kJ·m^-3, and the light fraction in tar oil in tar raised by 8.5% from 67.0% to 72.7%, and water and gas yields increased from 6.96% and 5.91% to 8.85% and 7.90%, respectively. It was found that the heat value of char was varied with the bed position and more coal bed thickness, more difference: on the radial direction the heat value was higher for the char at region with higher temperature than for that with lower temperature, while on the axial direction the heat value for all char at different region was almost the same. The calorific value of the char in the bed increased gradually from the high-temperature zone to low-temperature zone, indicating the fact that the deeper pyrolysis of coal occurred in the high-temperature zone. It is well known that there is the flow of gas and liquid products by pyrolysis from high temperature zone to low temperature zone and heavier fraction in tar oil can be trapped by low-temperature coal layer if coal bed was thicker. The trapped heavy fraction can then be cracked to form light fraction once the temperature of this coal layer raised enough high as the pyrolysis process proceeded. This indicated that the total tar oil yield decreased due to formation of much light fraction for the case of thicker coal bed. As a consequence, controlling the flow of pyrolysis product from high-temperature zone to low-temperature zone is critical for manipulation of the secondary reactions of primary pyropysis products and thereby for increase of the final yield and quality of the expected pyrolysis products. The study clarified again that in the pyrolysis reactor the optimal matching between the flow of gaseous pyrolsyis product and the gradients of temperature and tar composition is critical for realization of the selective cracking of heavy species and for improvement of the yield and quality of pyrolysis tar product.

The feasibility of using a single sequencing batch reactor to remove nitrogen from medium-age landfill leachate was examined, and an anaerobic/aerobic/anoxic process in a SBR without extra carbon source addition was presented. Dissolved organic matter could be taken up partially and stored as polyhydroxyalkanoates (PHAs) in the anaerobic stage by the microorganisms operated in the anaerobic/aerobic/anoxic process, with glycogen consumption. In the aerobic stage, ammonia was oxidized and accompanied by loss of tatal nitrogen (TN) via simultaneous nitrification and denitrification. The stored PHAs and glycogen, remaining at the end of aerobic stage could provide carbon source for anoxic denitrification. In the stable phase, the effluent COD, NH₄⁺-N, and TN were 525—943 mg·L^-1, 1.2—4.2 mg·L^-1 and 18.9—38.9 mg·L^-1 respectively when the influent COD, NH₄⁺-N, and TN were 6430—9372 mg·L^-1, 1025.6—1327 mg·L^-1 and 1345.7—1853.9 mg·L^-1, respectively. Nitrogen removal from medium-age landfill leachate could be realized via the anaerobic/aerobic/anoxic process in a SBR with the effluent of TN less than 40 mg·L^-1. Almost 1/3 of reduced TN was removed via SND, while 2/3 of reduced TN was removed via post-anoxic denitrification.

Shenhua coal, with high concentration of Ca and Fe, was subjected to combustion in the drop tube furnace (DTF) in both air and O₂/CO₂ atmosphere. XRF, XRD and CCSEM were used to characterize elemental composition, mineralogy and element symbiotic properties of bulk ash. Oxy-fuel combustion promoted interaction of Fe and Ca with other minerals. However, the amount of Fe distributed in iron aluminosilicate (Fe-alsil), especially in Fe+Ca minerals increased. The same distribution tendency of Ca was observed. Further analysis found that Fe+Ca mineral in oxy-fuel combustion bulk ash had more serious slagging propensity (with Fe₂O₃/CaO mole ratios 0.5—3) than that in air combustion bulk ash.

Measurement of film thickness and concentration of urea-water solution is very important in many practical applications. However, these two important parameters can only be determined separately by conventional measurement methods. Here, a novel online measurement method by laser spectroscopy was developed to obtain the film thickness and concentration of urea-water solution simultaneously. By sensitivity analysis and cross-validation, an optimal wavelength pair (7040.75 cm^-1 and 6761.00 cm^-1) was chosen to determine film thickness and concentration. As shown from cross-validation, uncertainties of the developed method were smaller than 1.40% for thickness measurement and 5.76% for concentration measurement.

The adsorption thermodynamics and kinetics of uranium adsorption by Bacillus subtilis, desorption of U(Ⅵ) in saturated ethylene diamine tetraacetic acid (EDTA), and phosphorus release into water were studied by static adsorption and desorption experiments. The mechanisms of action were discussed using data from scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and Fourier transform infrared spectroscopy (FTIR) measurements. Optimized uranium removal occurred at pH 5 of 50 mg·L^-1 uranium solution and uranium removal efficiency and adsorption quantity reached 85.34% and 308.31 mg·g^-1(dry weight)after 2 h, respectively. As the duration from 2 h increased to 48 h, desorption rate of uranium reduced from 52.13% to 36.25%, and concentration of P released from Bacillus subtilis increased from 0.12 mg·L^-1 to 0.40 mg·L^-1. Langmuir isotherm and pseudo-second equations could describe well the uranium adsorption behavior by Bacillus subtilis. The process was exothermic and spontaneous. SEM and EDS showed that the cell of Bacillus subtilis was sub-internal fracture, and uranium deposited on the surface and surrounding of Bacillus subtilis without obvious U-P crystal products. FTIR revealed that the surface of Bacillus subtilis possessed many active groups, such as hydroxyl, amide, and phosphate groups, and the amide and phosphate groups were involved in adsorption of U(Ⅵ) by Bacillus subtilis. FTIR spectra showed the characteristic absorption peak of UO₂²⁺.

The performance of a microbial fuel cell (MFC) is influenced by the anode biofilm with electrochemical activity, while the formation of anode biofilm greatly depends on the anode surface characteristics. To investigate how the two main characteristics of anode surface, surface area and double-layered capacitance, influence MFC performance, three kinds of activated carbon materials were used to make anodes with different double-layered capacitance values. The startup and operation performance of MFCs with those anodes were evaluated in the single-chamber air-cathode MFCs. When anode double-layered capacitance increased from 0.0012 F to 22.72 F, MFC starting up time decreased by 68% and maximal power density of MFC increased by 16.8 times to 546.1 mW·m^-2. The images of scanning electron microscope (SEM) demonstrated that the biofilm formed on the anode with large capacitance was approximately one time thicker than that on the anode with small capacitance. Anode performance was directly influenced by anode double-layered capacitance other than anode surface area.

Simultaneous removal of nitrate, sulfide and ammonia could be realized at HRT of 12 h, temperature of 30℃±2℃ and influent pH of 7.5. The removal rates were up to 95%, 90% and 99% for ammonia, nitrate and sulfide at influence concentrations of 22—35 mg N·L^-1, 22—35 mg N·L^-1 and 50—90 mg S·L^-1, respectively. Most of sulfide removed was converted to elemental sulfur (S⁰) and the conversion rate was as high as 89%. Batch experiment results indicated that presence of sulfide could enhance simultaneous removal of nitrate and ammonia. The results of this study provided an innovative idea for the development of sulfide- and nitrogenous contaminants- laden wastewater treatment technology.

Released soluble COD (SCOD), relative hydrophobicity (RH), and specific resistance of sludge (SRF) were used to characterize sludge disintegration degree, surface hydrophobicity and dewatering performance. The enhanced dewatering influence factors and mechanism of oxidation disintegration of excess sludge were investigated by oxidative sulfate radical (SO₄^-·) generated from persulfate activated by Fe(Ⅱ). SCOD increased from 66.5 mg·L^-1 to 472.3 mg·L^-1, RH increased from 26.9% to 41.1%, SRF decreased from 24.9×10⁸ S²·g^-1 to 4.5×10⁸ S²·g^-1 after disintegration reaction when pH was 4.5, n(S₂O₈^2-) was 2.2 mmol·(g VSS)^-1, n(Fe²⁺)=1.32 mmol·(g VSS)^-1 and reaction time was 3 h at room temperature. According to the center combination experimental design of Box-Benhnken based on the response surface method, the optimal results were pH=4.27, n(S₂O₈^2-) =2.6 mmol·(g VSS)^-1, n(Fe²⁺)=1.59 mmol·(g VSS)^-1, SRF=3.8×10⁸ S²·g^-1 and sludge cake moisture content rate = 72.7% when SRF was taken as response. Microscopic observation revealed that floc sludge was disintegrated into smaller particles and debris. FT-IR showed the surface functional group corresponding to the absorption peak intensity of sludge decreased to some extent, and thermogravimetric analysis indicated that physical adsorption combined water loss region disappeared. The above results suggested that under the influence of SO₄^-·, stable sludge zoogloea structure was destroyed, cell lysis and organic matter was released into the liquid phase, sludge surface was more hydrophobic, water binding capacity decreased and sludge dewatering performance was improved considerably, thus facilitating sludge reduction application.

Metal-organic frameworks (MOFs) are a new class of nanoporous materials. An efficient and environmentally friendly method for the synthesis of MOFs is needed for efficient industrial applications. In this work, a porous metal-organic framework HKUST-1 was prepared by the mechano-chemical method. The effects of different activation solvents (chloroform and ethanol) on the surface area, pore structure and benzene adsorption of HKUST-1 were investigated. The mechano-chemical synthesis time of HKUST-1 could be reduced from 24 h to 30 min compared with the hydrothermal method. The surface area and pore volume of HKUST-1 were significantly affected by activation solvents. Using ethanol as an activation solvent could more easily displace the precursors remaining in the channels of HKUST-1, thus achieving a larger surface area (1442.7 m²·g^-1) and 25% higher benzene adsorption (6.90 mmol·g^-1 at 298 K and 8 kPa). Under the same condition, the benzene absorption capacity of the HKUST-1 sample was higher than the regular absorbents, such as activated carbon, molecular sieve and zeolite.

Composed of polystyrene (PS) modified by high thermal conductivity silica (SiO₂) as shell, and n-tetradecane (Tet) as core, a novel PS-SiO₂ @ Tet composite nano-encapsulated phase change material (CNEPCM) for cold thermal energy storage was synthesized by mini-emulsion in-situ polymerization. The morphology, chemical structure and thermal performance of CNEPCM were characterized with particle size analyzer, transmission electron microscope (TEM), X-ray photoelectron spectroscopy(XPS), differential scanning calorimetry (DSC) and thermogravimetric analysis (TG), respectively. Coefficient of thermal conductivity, specific heat capacity, viscosity and mechanical stability of the synthesized latex were tested. The synthesized CNEPCM with well-defined spherical core-shell structure and z-average particle size of 64.9 nm had high latent heat capacity (T_m 2.13℃, 83.38 J·g^-1) and good thermal stability. Compared with the unmodified emulsion, coefficient of thermal conductivity and specific heat capacity of the synthesized latex were improved as a result of the presence of high thermal conductivity silica, indicating a promising potential functional thermal fluid for cold thermal energy storage.

The effect of microfibrillated cellulose content and foaming temperature and time on the foaming behavior of dry poly(vinyl alcohol) (PVOH)/ microfibrillated cellulose (MFC) composites was investigated. PVOH/MFC composites were prepared by the solution film casting method and foamed via the batch depressurization foaming process with a physical blowing agent supercritical CO₂. The rheological properties and thermal properties of PVOH/MFC composites were characterized. Microfibrillated cellulose fiber acted as nucleating agent during the foaming process, and there was an optimum processing temperature for achieving high-quality cellular morphology of the PVOH/MFC composites.

Spherical absorbent resins for benzene series were synthesized by suspension polymerization. The dependence of absorbency, crosslinking density and gel fraction of resins on crosslinker dosage was studied. The effects of crosslinking structure on absorption kinetics and release kinetics were investigated. Scanning electron microscope was used to observe the morphology of the resins. Gel fraction and crosslinking density kept increasing while a peak absorbency was observed with increasing crosslinker dosage. With the increase of crosslinking density, absorption rate and release rate of the resin for toluene reduced gradually, and absorption kinetic constant and diffusion coefficient decreased. Absorption kinetics of the resin for toluene fitted the quasi first order equation. A simple release kinetics equation was obtained, by which the release behavior could be well described. Crosslinking structure of the resin was stable. The size, morphology and absorbency of the spherical absorbent resin did not change obviously after 10 times recycle and reuse.

Single benzoxazine contained bis DOPO based on bisphenol A (1DD) was synthesized from bisphenol A contained double DOPO (2DO), aniline and paraformaldehyde. FTIR, NMR(¹H NMR,¹³C NMR) were used to characterize chemical structure of 1DD. Curing characteristics were studied with DSC and thermostability was studied with TG. The product was blended with epoxy resin with mass ratio 0.5/1 according to a specific procedure for heat curing to prepare copolymer P1DD-ER. Flame retardant properties of the copolymer was investigated with the UL94 vertical burning test and limit oxygen index (LOI). Starting melting point of 1DD was nearly 185℃. An obvious exothermic peak was observeed at 222℃. Initial decomposition temperature of the copolymer after curing was 348℃. The fastest speed of decomposition was recorded at 463℃. Carbon residue at 800℃ was 35.78%. The prepared benzoxazine could be used as the curing agent of epoxy resin. The copolymer had good flame retardant performance. LOI could reach 37. The grade of UL94 was V-0.

A novel process was proposed for preparing titanium dioxide by decomposition of titanium-bearing blast furnace slag (TBBFS) in molten NaOH-NaF system. Thermodynamic analysis was conducted on the molten salt decomposition of TBBFS. The effects of mass ratio of alkali and slag, reaction time and reaction temperature on titanium extraction and the effects of pH and hydrolysis temperature on purity of titanium dioxide were discussed. The reaction of sodium titanate from TBBFS with sodium hydroxide was feasible thermodynamically. When optimum mass ratio of alkali and slag was 3:1, reaction temperature was 500℃, and reaction time was 3 h, titanium extraction was 99.8%. Optimum pH and hydrolysis temperature were 0.1—0.2 and 100℃ respectively. Analysis results indicated good sphericity and dispersibility of TiO₂ particles with diameter about 100 nm.

Sulfonic acid type waterborne polyurethane chain extender (N,N-bis(2-hydroxyethyl)-2-aminopropane sulphonate) was synthesized by sulfonation of self-made intermediate (N,N-bis(2-hydroxyethyl)-2-amine-propenyl) and adjusting temperature, time and molar ratio. Composition, structure and crystallinity of the synthesized product were characterized with nuclear magnetic resonance (¹H NMR), infrared spectroscopy (FTIR), elemental analysis, and XRD. Thermal stability of the product was characterized with TGA. The best synthesis process was determined by sulfonation degree of the product. When temperature of reaction was 90℃, time of reaction was 8 h, and materials ratio of N,N-(2-hydroxyethyl)-2-amino propylene, and NaHSO₃ was 1:2.5, the sulfonation degree of the product was above 94%. With DMPA and as-prepared sulfonic acid type monomer as hydrophilic chain extenders respectively, CWPU and SWPU were synthesized. Performance comparison showed that compared with CWPU, SWPU had good hydrophilicity and heat resistance, solid content and stability of SWPU were also better than those of CWPU.

MgO nanoparticles were prepared by using a direct deposition method, in which, the precursor, alkaline magnesium carbonate/paraffin, was firstly obtained by direct precipitation of the mixture of MgCl₂·6H₂O and Na₂CO₃ in paraffin emulsion, and then calcined at 600℃. The nanoparticles were characterized by using TG-DTA, FTIR, XRD, BET and FESEM. Under the optimum conditions, the as-prepared MgO nanoparticles were hexagonal crystals with a uniform size of around 60 nm and a specific surface area of 132.54 m²·g^-1. The optimum preparation conditions were: MgCl₂·6H₂O concentration, 0.6 mol·L^-1; Na₂CO₃ concentration, 0.6 mol·L^-1; reaction time, 0.5 h; calcination temperature, 600℃, and calcination time, 3 h.

Polyacrylonitrile (PAN) was dissolved by the cavitation effect of ultrasonication, and the viscosity of the solution was measured using rotational viscometer, and was compared with the conventional solution by stirring. Ultrasonic treatment could accelerate the dissolution process and reduce the viscosity of the system, which were based on the transformation of the swelling method. The influence on polymer chain structure of ultrasonic was also investigated. Longtime ultrasonic treatment could reduce the relative average molecular weight, and a broader molecular weight distribution was observed. A modeling analysis was built for the ultrasonic treatment of PAN by Matlab. The motion model of vacuole nuclei suitable for the PAN dissolution system was constructed. The influences of the main factors, such as ultrasonic frequency, ambient pressure, surface tension and viscosity were calculated. Viscosity played a vital role in the effect of ultrasonicat