Refrigerant R22 is scheduled to be phased out and new and environmentally friendly refrigerants RE170 and RE170/R227ea have promising application. Miscibility of these refrigerants with lubricants has a large influence on working effect of the refrigerating system. For this reason, an experimental apparatus for testing miscibility of new refrigerants with lubricants was established based on standard SH/T 0699—2000. The miscibility values of promising refrigerants RE170 and mixed refrigerant RE170/R227ea with a mineral oil were studied. RE170 and the mineral oil were completely miscible at -50℃, as oil proportion changed from 10% to 60%. When R227ea mass fraction in mixed refrigerant RE170/R227ea changed from 35% to 60% and oil proportion was specified at 14.6%±0.5%, low phase separation temperature increased with increasing R227ea. When R227ea mass fraction was below 38%, the mixed refrigerant and mineral oil became miscible even at -50℃. When R227ea mass fraction was over 55%, the mixed refrigerant and mineral oil were immiscible even at room temperature. Finally, by combining the methods of empirical equation and solubility parameter, a new evaluation method was proposed to evaluate the miscibility of pure refrigerants and binary refrigerant mixtures with the mineral oil.

In order to study the effects of bead-packed porous structure, balls of different materials such as aluminum, stainless steel and glass with different diameters of 5, 8 and 11 mm are added into distilled water forming porous media. Since the supercooling degree of water is not a certain value, the experiments are repeated many times at the same cooling condition and analyzed with statistical methods. The results show that the distribution of the supercooling degree of distilled water in porous media is more concentrated than that of pure distilled water and the supercooling degree of water in porous media is smaller. The average supercooling degree of distilled water decreases with decreasing diameter of the same material balls on the whole. The larger the thermal conductivity of solid substrate is, the more concentrated the distribution of supercooling degree of distilled water in porous media and the smaller the average supercooling degree. In addition, the heterogeneous nucleation is more likely to occur when the thermal conductivity of the solid substrate is small. An annulus solid ice begins to grow slowly from the inside wall to the center region and the phase change time is longer than homogeneous nucleation. Once the crystal nucleus is formed, it will grow up instantly, forming the loose ice of homogeneous nucleation. Therefore, the heterogeneous nucleation should be avoided in engineering application.

To investigate the partition behavior of papain in the ionic liquids aqueous two-phase system containing [C_nmim]BF₄+NaH₂PO₄, the binodal curve and liquid-liquid equilibrium was measured by means of cloud point at T 298.15 K and a 3D theoretical model was established. The data fitting of binodal and the equilibrium was based on Merchuk, Othmer-Tobias and Bancroft equations with a high degree of fitting of above 0.975 and 0.994, respectively. Then, the correlation between logarithm of the partition coefficient and both the concentration of ionic liquids in upper phase and the salt concentration in lower phase was studied, and a partition model was established by Matlab. The mean relative deviations between the experimental and calculated data were <5%, which was sufficient to prove the reliability of this model.

In order to investigate the size effects of two-dimensional nanoparticles on the energy storage property of composite PCMs, graphite nanosheets (GNS-10, GNS-30, GNS-90) with different sizes were prepared by exfoliating expanded graphite with the assistance of ultra-sonication for different time and dispersed into hexadecanol. The prepared PCMs were characterized with SEM, XRD and Hot Disk, and the thermal conductivity was predicted by Maxwell, Bruggeman and Nielsen models. Results reveal that the graphite nanosheets presenting larger aspect ratios can achieve better thermal conductivity enhancement, because relatively large nanofiller contributes to the formation of heat transfer network in PCM matrix. An enhancement of thermal conductivity up to 517% has been achieved by GNS-10 at the loading of 10% (mass). The prediction of Nielsen model fits the experimental value better with the shape factor of A as 100 to 180. Compared to the great increase in thermal conductivity after the addition of graphite nanosheets, the changes in melting/solidification temperature and enthalpy of composite PCMs are negligible. Furthermore, the increased freezing rate of composited PCMs is clearly presented as a consequence of enhanced thermal conductivity.

An equation-free multi-scale method was proposed for simulating two-phase gas-liquid separation processes. The method took the lattice Boltzmann (LB) model as the meso-scopic simulator. Only a small amount of evolutionary steps were needed during the calculation, and then the results obtained from the meso-scopic simulator were reasonably extrapolated by second-order telescopic projection to predict the results of follow-up evolutionary steps quickly and precisely. Thus multi-scale simulation of two-phase gas-liquid separation processes could be done. The details of phase separation were presented by comparing the numerical simulation results in terms of coexistence curves and spurious currents. The results showed that the macro-scale characteristics of phase separation could be quickly and accurately reflected by the proposed multi-scale simulation method, proving the accuracy and efficiency of the proposed method.

The gas-solids flow in a bubbling bed was simulated by the combined approach of computational fluid dynamics (CFD) and Discrete Element Method (DEM). The influence of granular collision parameters of particle elasticity coefficient and restitution coefficient on flow field intermittency was investigated. The continuous wavelet transform analysis was used to obtain the coherent structure behavior influenced by particle elasticity coefficient and restitution coefficient. Particle elasticity coefficient and restitution coefficient had some effect on fluctuating energy of particle velocity, mean bed height, flatness factor, and flow field intermittency. With increasing particle elasticity coefficient, the energy in high frequency domain, flatness factor and flow field intermittency decreased first and then increased, while mean bed height increased first and then decreased. The larger the restitution coefficient, the lower the energy in high frequency domain and flatness factor, and the higher the mean bed height, the weaker the flow field intermittency.

On the basis of theoretical calculation, the mixing process under continuous operation in liquid impinging streams reactor (LISR) was simulated by CFD and the change of mixing time was calculated and verified numerically. With increasing effective specific power, mixing time decreased rapidly at first and then tended to be smooth and steady. The local mixing time in one stroke of impinging mixing was less than 0.25 s, which fully agreed with the order of magnitude figured out by empirical model and theoretical model. It was demonstrated that using the numerical method to analyze local mixing time is feasible. It could also make up for the deficiency of experimental research. To further study macromixing time and micromixing time numerically, it was found that macromixing time was one order of magnitude greater than micromixing time, but both changes were fundamentally consistent and were in a linkage state of equilibrium which was in accordance with our previous theoretical analysis. These conclusions could be used as the mechanism methods and quantitative reference for follow-up study of mixing enhancement mechanism of LISR.

In order to suffice the different needs for pore size and thermal conductivity of wick in different evaporator regions of loop heat pipe (LHP), a LHP with modulated composite porous wick is constructed and investigated experimentally. The heat transfer characteristics of LHP are tested at different heating powers, inclination angles and cooling conditions. The results show that LHP has good heat transfer performances. The lowest temperature of the evaporator wall center (T_c) is only 64℃ at 200 W. The ice cooling can significantly promote LHP heat transfer performance, reducing T_c and thermal resistance, compared with the air cooling. The lowest thermal resistance is 0.19 K·W^-1. Besides, the ice cooling is helpful to improving the temperature uniformity of the evaporator wall. The effects of inclination angles on temperature and thermal resistance vary with the increase of the heating power. At low heating power, T_c of LHP with evaporator and condenser being the same altitude is lower than that with evaporator below condenser. As the heating power rises, the former becomes higher than the latter. In addition, the heat leak from evaporator to compensation chamber can be reduced by applying the modulated composite porous wick. With the increase of heating power, the effects of inclination angles on heat leak are different.

Flow and convective heat transfer characteristics of the triangle micro pin fins (d=247 μm, H=500 μm) using de-ionized water as working fluid were experimentally investigated. The change rules of pressure drops, friction factors and Nusselt numbers etc. in triangular micro pin fins were measured when Reynolds number changed from 0—1000 with different heating power of 50, 100 and 150W, respectively. In addition, the influence of heating power on flow resistance and convective heat transfer of triangular micro pin fins was analyzed. The experimental results illustrated that the friction factors of the triangle micro pin fins increase markedly with the increase of heating power at Re<250 and the increment of friction factors reached more than 200%, while the effect of heating power was significantly reduced at Re>250 and the value of f almost no longer changed with increasing heating power after Re>600. The convective heat transfer in triangular micro pin fins was enhanced by increasing heating power at Re<250 and the increment of Nusselt number at the same Re could reach more than 75%. However, this enhancement was weakened by the vertex evolution in wake zones of triangular micro pin fins and the Nu became smaller with the increase of heating power when Re>250.

Confronted with low-quality heat source, such as high ash contents, discontinuity and instability in waste heat recovery, innovations are required in the structure of typical heat transfer surface. In this paper a novel structure with rhombus heat transfer surface was presented. This heat transfer surface was efficient in both waste heat recovery and ash blowing. In the heat transfer process, the new heat transfer surface showed similar performance with the staggered tubes arrangement, for instance enhanced heat transfer and relatively large fluid flow resistance and higher convection heat transfer coefficient in the shell side. In the dust blowing process, this surface performed like the aligned tubes arrangement, which was easy to clean and efficient in dust blowing. Numerical simulation and experimental investigation were conducted to obtain heat transfer and flow performance of the new structure. Both numerical and experimental results indicated that the new structure met basic requirements of waste heat recovery, achieving highly efficient heat transfer along with convenience of dust cleaning and descaling.

An experimental study was carried out on the boiling heat transfer of R22 flowing inside three internal thread tubes with different geometrical parameters. Three enhanced tubes have the same inner and outer diameters, which are 6.9 mm and 7.92 mm respectively. The outside surface of the tube is smooth, while the inside enhanced structure is different. The variation range of the helix angle is from14° to18°, the thread height is between 0.15 mm and 0.22 mm, and the thread width is from 0.1 mm to 0.2 mm. The relationship between the heat transfer performance and the mass velocity in three enhanced tubes and a smooth tube was tested by changing the mass velocity of refrigerant under given condition of import and export of refrigerant, and their performance is compared. Experimental results indicate that the heat transfer coefficients of three internal thread tubes are 60%—80%, 80%—120% and 80% higher than that of smooth tube. Analysis suggests that the larger helix angle is advantageous to the heat transfer,when fluid is on laminar flow or the transition of laminar flow and annular flow, and more of thread amount is advantageous to the heat transfer,when the fluid is on annular flow.

Hg⁰ oxidation over selective catalytic reduction (SCR) catalysts would be of great scientific and practical value to control mercury emission in coal-fired power stations. To elucidate the mercury species existing on the MnO_x-CeO₂/γ-Al₂O₃(MnCe15) catalyst surface, a temperature programmed thermal decomposition (TPTD) method was used in this study to analyze the characteristics of the mercury species formed on the MnCe15 catalysts. A series of pure mercury compounds mixed with fresh MnCe15 were first studied for qualitative calibration. Then, the TPTD method was used to identify the Hg species on used MnCe15 catalysts pretreated under different operation conditions. The formation of HgO, HgCl₂, Hg(NO₃)₂ and HgSO₄ during the oxidation process was confirmed and the reaction pathways were proposed. The mercury species present were mainly HgCl₂ after MnCe15 catalysts were used to oxidize Hg⁰ under simulated flue gas conditions. HgO and HgSO₄ were found to exist in very low concentrations. This study provided the basis for the study on catalytic oxidation mechanism of Hg⁰ on SCR catalyst.

The copper coordination compound [C₁₀H₉N]₂CuBr₂ was prepared by the reaction of 4-methylchinolin with copper bromide in ethanol solution. The compound was characterized with FTIR, EA, ICP-AES and XRD, and its catalytic performance in oxidative carbonylation of ethanol was investigated. The density functional theory (DFT) calculations were performed to analyze its structure, natural atomic charges and frontier orbital energy levels. The introduction of ligand could improve catalytic activity to prepare diethyl carbonate. The per pass conversion of ethanol could reach 21.5% under the reaction conditions of temperature 373 K, pressure 3.5 MPa, time 4 h and mass concentration of catalyst in ethanol 0.075 g·ml^-1. Reaction mechanism study showed that the compound had moderate stability, which benefited insertion of CO (the rate-controlling step) and formation of intermediate. Therefore, reaction activity was enhanced.

Magnetic CuO-Bi₂O₃/Fe₃O₄-SiO₂-MgO catalysts with different Cu content were prepared by using impregnation and coprecipitation methods. The obtained catalysts were characterized by atomic emission spectrometer (ICP-AES), N₂ absorption, X-ray diffraction (XRD), H₂ temperature-programmed reduction (H₂-TPR) and vibrating sample magnetometer (VSM). Their catalytic performance for formaldehyde ethynylation was evaluated. The results indicated that preparation method showed a great influence on the CuO station in catalysts, thus, on the performance for formaldehyde ethynylation reaction. Compared with the catalysts prepared by impregnation, the CuO-Bi₂O₃/Fe₃O₄-SiO₂-MgO catalysts prepared by co-precipitation method showed higher CuO dispersion and better reducibility, so had better catalytic activity and selectivity. Moreover, Cu content was another important factor affecting catalyst activity. With Cu content increasing, the catalyst activity increased gradually. In the present work, 30% (mass) Cu loading catalyst prepared by co-precipitation method showed the highest catalytic activity. In addition, this catalyst was of good superparamagnetism and stability, so easy separated by external magnetic field for reuse. After six cycles, its stability was much better than non-paramagnetism CuO-Bi₂O₃/SiO₂-MgO catalyst.

Cu-Mn-Ce(CMC) ternary mixed oxides were prepared by the co-precipitation method with different precipitants, and evaluated in catalytic combustion of toluene. The catalyst prepared with NaOH(CMC-NaOH)exhibited the highest catalytic activity, followed by the catalyst prepared with NH₃•H₂O, K₂CO₃, and Na₂C₂O₄. The precursors of hydroxide derived from NaOH had strong interaction, and Cu, Mn ions more easily entered the lattice of CeO₂ fluorite structure to form CeO₂ solid solution during calcination. As a result, the structure containing Cu-Mn mixed oxides and CeO₂ solid solution enhanced the mobility of active oxygen owing to abundant defective sites on the surface, which benefited catalytic combustion of toluene.

In this work, four different AlOOH catalysts prepared by complete liquid-phase technology, hydrothermal and precipitation method are investigated and the industrial AlOOH(SB)is used as a control. These catalysts are characterized by XRD, NH₃-TPD-MS, FT-IR, N₂ adsorption-desorption and TG-DTG, and evaluated in a fixed-bed reactor for methanol dehydration. The results show that significant differences exist in these catalysts of methanol dehydration. The AlOOH catalyst prepared by compete liquid-phase technology followed by calcination for removing deposited carbon on the surface displays the highest activity and good stability, especially the performance in low temperature. On the contrary, the AlOOH catalyst prepared by precipitation method shows the worst activity and bad stability. Combined characterization results with catalytic performance, it can be found that the AlOOH catalyst has weak and strong acid sites, while γ-Al₂O₃ only has weak acid sites. When the content of weak acid sites is higher than its strong acid sites, the AlOOH catalyst shows better ability of methanol dehydration. On the other hand, more lattice defects and proper grain size of catalysts are beneficial to the improvement of the ability of methanol dehydration.

The adsorption and desorption characteristics of shale is very important for the development of shale gas. For the sake of thorough understanding the adsorption mechanism in micro-scale view for clay minerals in the shale, three molecular models including illite, montmorillonite and kaolinite were established by using molecular simulation software Material Studio, the grand canonical Monte Carlo (GCMC) method was used for the calculation of isotherm adsorption capacity and adsorption heat. At the same temperature and pressure, isotherm adsorption capacity of CH₄ in three clay minerals was in the sequence below: illite>montmorillonite>kaolinite. With the increase of pressure, the isotherm adsorption capacity of CH₄ in three clay minerals increased, and CH₄ adsorption in illite, montmorillonite was more sensitive to pressure changes than that in kaolinite. The heat of adsorption of three clay minerals were less than 42 kJ·mol^-1, proving that adsorption of CH₄ was physical adsorption. With the increase of temperature, the adsorption heat of CH₄ reduced and the isotherm adsorption capacity of CH₄ was decreased, suggesting that high temperature was disadvantageous to adsorption of CH₄.

In response of such problems as ammonia escape, high regeneration energy, low absorption rate in the late stage of carbon capture by ammonia, this paper presents two kinds of reinforced crystallization technologies based on solventing-out, respectively called mixed absorbent process and reinforced crystallization of carbonized aqueous ammonia. Reinforcing crystallization of aqueous ammonia of low carbonization degree can maintain average absorption rate at a high level and regeneration by desorbing crystal product can save regeneration energy. Ammonia of low carbonization degree is chosen as absorbent, which can solve the ammonia escape problem to some extent. In the two kinds of processes, the common point is that regeneration by desorbing crystal product replaces recycling of carbonized aqueous ammonia and consequently saves regeneration energy. These two new processes all adopt semi-continuous bubbling reactor, and their process route, absorption rate, crystallization yield, characteristics of crystal product are compared.

This study was to achieve selective separation of specific aromatic hydrocarbons from low temperature coal tar. The feedstock was pretreated to separate phenols and enrich specific aromatic hydrocarbons, and then extracted by multiple solvents to separate selectively aromatic and non-aromatic hydrocarbons. The extraction conditions were optimized by the theory of Hansen solubility parameter. Selectivity of the extraction process was enhanced with the rise of Hansen solubility distance (R_a), while dissolving capacity decreased with the increase of R_a. The multiple solvents suggested in the study were dimethyl formamide (DMF)+6% water (volume fraction), and the optimized extraction condition was 25℃ and solvent/oil ratio of 6:1. The raffinate was extracted repeatedly under the optimized condition to collect residual aromatic hydrocarbons. The extract was extracted by formamide repeatedly to increase the concentration of aromatics and separate heterocyclic compounds and other polar components. Consequently, the mass percentage of aromatic hydrocarbons in the product was ca. 95% and the total yield of aromatics was ca. 94%; phenols, non-aromatics and other polar components were also separated selectively from the feedstock. The extraction solvent of aromatics was recovered by reduced pressure distillation, which was stable during the extraction and recycle process.

The traditional kernel principal component analysis is popularly used for fault detection, however, it only concentrates on the global structure of data sets and ignores the local structure when it is used to extract the nonlinear features. To solve the problem, a new method named modified kernel principal component analysis is proposed for nonlinear process fault detection and diagnosis. The idea of locality preserving is incorporated into the optimization goal of the traditional kernel principal component analysis, taking the excellence of kernel principal component analysis and manifold learning into account. The new projection space enjoys the similar global structure and the local structure, and thus, more feature information can be extracted. The modified kernel principal component analysis is used to map the data space into the feature space. Next, the feature information is classified through Fisher discriminant analysis. A monitoring statistic is established using the distance of each sample in feature space and its control limit is determined through kernel density estimation. When a fault is detected, the source of performance deterioration can be located by using a diagnosis method based on data set similarity. Finally, the results of Tennessee Eastman simulation experiment show its better effectiveness.

In practice, dynamic fluid level is traditionally measured onsite by using the acoustic method. This method, however, has its limitation in determining real-time dynamic liquid level. Determining real-time dynamic liquid level by analyzing the measured dynamometer card has poor precision. Model aging happens as time goes by with the data driven soft sensing modeling method. An incremental dynamic Gaussian process regression (IDGPR) was presented for the soft sensing modeling in order to realize real-time determination of dynamic liquid level. At the beginning a basic soft sensing model based on dynamic Gaussian process regression was established. After the model was put into application, it could be updated on-line through an incremental learning method. The model could be constantly adaptable to the change of operating condition and precisely predict dynamic liquid level. The application result in the oil field showed that the proposed soft sensing model achieved high prediction precision and good generalization ability, meeting engineering requirement.

The set point control strategy has low degree of freedom and bad robustness by the influence of outside interference. In order to resolve this problem and improve control quality, an improved algorithm, model predictive control algorithm based on triangular interval soft constraint, was presented. On the basis of set point control triangular interval soft constraints were added and system output reached the control objectives in stages, to reduce the influence of interference on the system and to improve degree of freedom and robustness. Finally, robustness of the algorithm was analyzed. Simulation experiment was done with the typical heavy oil fractionator model of Shell Company. Comparison with the results of set point control proved that the algorithm had better robustness and better control quality.

It is quite important to improve the energy saving of air source heat pump heating system through optimal operation and system engineering method. In this work, the nonlinear dynamic model of heat pump heating process is established and the integral optimal objective function is then formulated to balance the control accuracy and energy saving. To solve the differential and algebraic optimization problems (DAOPs) efficiently, a simultaneous method is used to discretize the problem by collocation of finite elements. Then, the problem is analyzed with different weights and an optimal strategy to dynamically adjust the weight of objective function is proposed for further energy cost reduction. Computing results show that the potential energy saving of more than 16% can be achieved under permitted indoor temperature tracking error of 0.85 ℃; the ambient temperature and electricity price have significant effect on the optimal operation and performance of the heat pump heating system; and considering the characters of these factors, the proposed strategy of dynamically adjust the weight of objective function can further reduce energy cost for about 4.7%. Our research is of significant meaning for the optimal operation of heat pump heating system under dynamical conditions.

Since the clearance of the seal end face for high-pressure, high-rotate-speed and dry gas in the stationary and rotating rings is only 3 to 5 microns, the test technology of face temperature in dry gas seal is difficult, and furthermore, it is key point to study the thermal fluid mechanics of micro-scale face. In this paper the face temperature in dry gas seal is tested and the face temperature distribution and cause are studied under different pressure, rotational speed, and starting and stopping phases in the dry gas seal system by using LabVIEW test system software to establish the face temperature test program of dry gas seal, selecting the requirements of sensor and other appropriate hardware devices, determining the corresponding test technology of face temperature, and taking methods to restrain interference. The results show that under different pressure and different rotational speed, the face temperature distribution is as follows. The temperature of the root diameter is the highest and that of the outside diameter is the lowest, while the temperature of the inner diameter is between those of the root and outside diameters. At the pressure of 4 MPa and rotational speed of 10000 r•min^-1, the highest temperature of 90.90℃ occurs in the root diameter. It reflects that when the dry gas seal system is steady operated, the root diameter is in the maximum pressure change point and rotating and static rings are in the non-contact state. Thus, the main reason of rising temperature is that a large pressure drop of the root diameter region causes thermal dissipation in the face. Under dry gas seal starting and stopping phases, the distribution of the face temperature shows that the temperature of the outside diameter is the highest, while that of the inner diameter is the lowest and that of the root diameter is between the temperature of the outside and inner diameters. It indicates that when the dry gas seal system is in the started and stopped phases, rotating and static rings are in the contact state, resulting in rising temperature because of friction between the solid walls. The results are consistent with our previous theoretical results obtained by using thermal dissipation deformation, and verify the root diameter region is the highest temperature point. The results provide a basis for optimizing groove design under thermal dissipation.

Synthesis of non-ionic polyether modified trisiloxanes surfactant (NTS) from MD^HM and polyoxyethylene alkyl allyl ethers (PE-38) with average EO (ethylene oxide) chain length of 7—8 and average molecular weight of 380, was catalyzed by Karstedt catalyst under N₂ with no solvent. Its structure was verified by Fourier transform infrared spectroscopy and proton nuclear magnetic resonance. Synthesis of NTS was optimized by using the response surface methodology (RSM). The optimal conditions at which average surface tension (18.417 mN·m^-1) repeated three times was obtained, being in agreement with the predicted value (18.177 mN·m^-1), were as follows: reaction mass ratio of n(C=C):n(Si—H)=0.93, amount of catalyst 6.4 mg·kg^-1, and reaction temperature and time 94℃ and 2 h, respectively. Hydrolysis of the aqueous solution of NTS at pH 4, 7 and 10 also was studied, and the product under acidic and alkaline conditions was stable for about 30 d, while under neutral condition was stable for about 60 d.

Triacylglycerol (TAG) and starch, as the two main energy storage products in green microalgae, especially the Chlorella sp., share the same synthesis precursor in its metabolisim system. This research aimed at the key enzymes in inhibiting starch and TAG synthesis, using Chlorella sp. as the object under nitrogen starvation. To investigate the relationship between the two metabolism pathways, comparison of TAG and starch accumulation was conducted. The starch synthesis way was significantly inhibited when 5 mmol·L^-1 Pi was added, resulting in reduced starch content and increased fatty acids concentration. While, fatty acids content per cell unit was not obviously influenced. In addition, 40 μmol·L^-1 of sethoxydim also showed starch inhibition after it had been introduced for 6 days. In this situation, starch concentration was reduced but unit cell starch content was not significantly changed.

1-butyl-3-methylimidazolium acetate ([BMIM]Ac) was synthesized from 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) via the ion exchange method. These imidazolium ionic liquids (ILs) were used as solvents to dissolve collagen fibers. The solubility and the change of collagen structure as well as thermal stability after dissolution and regeneration from ILs were investigated. Athough collagen fibers could be dissolved in both CH₃COO^- and Cl^- imidazolium ionic liquids, the dissolution characteristics were quite different. Compared with [BMIM]Cl ionic liquid, [BMIM]Ac was more advantageous to achieve a collagen solution with high concentration and good fluidity at a lower temperature, especially in retaining the integrity of collagen triple helix. FTIR, UV, XRD, CD and TG analysis were used to characterize the structure and properties of collagen before and after regeneration, and the results revealed that collagen chemical structure showed almost no change, but with slightly lower thermal stability and integrity of triple helix.

The rational design for enhancing protein thermostability has become a hot issue in ennzyme engineering. A three-dimensional structure was modeled by the SWISS-MODEL, which was very helpful for the rational design to engineer the recombinant b-glucuronidase from Penicillium purpurogenum Li-3 expressed in E. coli (PGUS-E). By using the design strategy of homologous sequence alignment and introducing proline mutation at appropriate sites, a simple site-directed mutagenesis protocol was developed to enhance thermostability of PGUS-E. Two mutant enzymes with higher thermostability were obtained: PGUS-E I130V and PGUS-E G280P. Then, these two sites were combined and mutant PGUS-E I130V+G280P was obtained. Further analysis of their thermostability at 60℃ and kinetics were performed. Compared to PGUS-E, thermostability of mutants was significantly improved, and the halftime (T_1/2, 60℃) of mutants I130V, G280P and I130V+G280P increased by 3.5 times,5 times and 5.5 times, respectively, while K_cat/K_m of mutant enzyme remained nearly unchanged. This study provided a successful case of rational design to improve protein thermostability.

Considering the difficulty in treating high-ash coking coal by the existing fluidized bed gasification technology, Institute of Process Engineering, Chinese Academy of Sciences has developed a jetting pre-oxidation fluidized bed gasification (JPFBG) technology for gasifying washing middlings and other caking coals. The coal is jetted into the pre-oxidation zone of a fluidized bed gasifier using an O₂-containing gas stream to quickly disperse the particles and oxidize the viscous and plastic matter formed during heating. The char falls into the gasification zone to react with gasification agent as in other fluidized beds. This study was devoted to investigating the product distribution of pre-oxidation and the structure as well as reactivity of the formed char with respect to gasification condition parameters like temperature, air equivalence ratio (ER) and steam/coal ratio. The suitable conditions for pre-oxidation were temperature about 950℃ and ER₁ about 0.13. The produced char had relatively larger specific surface area and higher gasification reactivity. The suitable gasification conditions were 1000℃, ER₂ about 0.17 and mass ratio for steam/coal about 0.09. Then, the produced fuel gas had relatively higher quality and its tar contained more light species that were easier to be eliminated downstream. Obviously, all these results would support the design and scale-up of the JPFBG technology.

Domestic large-scale biogas projects mostly use the fermentation technology at psychrophilic or mesophilic temperature, which results in low biogas production rate and large fermentor volume. And high cost for investment is the main obstacle for the advancement of biogas projects. On the other hand, straw as a common low-grade biomass in rural areas is burned at random, causing serious air pollution. Therefore, in this work, thermochemistry coupled with thermophilic fermentation was proposed to accelerate manure processing rate and promote the efficient usage of straw by burning straw to maintain the temperature for thermophilic fermentation process transformed from mesophilic fermentation. Feasibility of this coupling process was analyzed. By increasing temperature step-wisely from 30℃ to 55℃, volumetric gas production rate of pig farm biogas would increase from 1.43m³·m^-3·d^-1 to 3.40 m³·m^-3·d^-1, and digester volume could be reduced from 1200 m³ to 500 m³. In order to maintain fermentation temperature(55℃), 339 tons of straw would be consumed every year to burn straw instead of biogas for heating.

Coal pyrolysis via thermal plasma provides an alternative path to realize the effective conversion from coal to acetylene. Recycling the hydrocarbons in the effluent gas to the plasma pyrolysis process is proposed in this work to improve the reactor performance. Thermodynamic analysis is made as the reference on the basis of the pilot-plant results of Xinjiang Tianye 2 MW plasma pyrolysis device. The comparison results show that the recycling of effluent hydrocarbons (except acetylene) can raise the volume fraction and mass flow rate of acetylene in the product gas. The hydrocarbons in cracked gas is ample to be used as the conveying and accelerating gas for coal and the protecting gas for plasma torch, which can reduce the input amount of working gas and optimize the whole gas flow of the process. Different optimization cases are discussed to compare the products (i.e., acetylene and hydrogen) output and the gas input of the thermal plasma pyrolysis system. The optimized results show that the recycling process is feasible and effective, with reduced coal consumption (30%) and pyrolysis energy consumption (30%) as well as increased acetylene yield (35.6%).

The lean combustion experiments of natural gas and air mixture were conducted to investigate the influences of electric fields generated by alternating current (AC) at the frequency of 15 kHz and direct current (DC) with the same voltage virtual value on the flame propagation and combustion characteristics of premixed CH₄/air mixtures at room temperature and atmospheric pressure. The results show that the flame shape deforms when the two kinds of voltages are applied to the mesh electrodes. The flame is stretched more severely in the horizontal for AC than for DC at the same excess air ratio, especially when concentration of natural gas is diluted by excess air. When excess air ratios are 1.2, 1.4 and 1.6, average flame propagation speeds increase up to 49.14%, 76.54% and 117.65% for AC, and 41.38%, 58.02% and 62.75% for DC, and peak values of pressure rise up to 9.48%, 11.48% and 14.20% for AC and 4.46%, 5.25% and 8.76% for DC, respectively, compared with those without added voltage. These results indicate that promoting performance for development of combustion flame is better for frequency 15 kHz AC than for DC at the same voltage virtual value.

The produced water from ASP (alkali, surfactant and polymer) flooding oil had higher viscosity because of the presence of polymer residues, which made the separation of oil and water even harder. In this paper the degradation of polymer by using ultrasonic enhanced O₃ oxidation was performed in (20+28+40) kHz three orthogonal field with the intensity of 1.6 W·m^-2 and the addition of 7.5 mg·L^-1 O₃ for 15min. The change ratio of dynamic viscosity could attain 86.1%. By calculating utilization rate of O₃ and detecting the intermediate products of H₂O₂, it showed that the ultrasonic enhanced O₃ oxidation introduced the synergistic effect, increased the transfer efficiency and promoted the generation of ·OH. The polymer degradation efficiency was increased three times and the reaction time was shorted about 3/4.

A wood-chip-framework soil infiltrator (WFSI) with slow-release of carbon source was constructed and used to treat an anaerobically digested swine wastewater characterized with high NH₄⁺-N and low C/N ratio. Pollutant removal efficiency of the WFSI was investigated under various influent concentration and varying surface hydraulic load (SHL). Under SHL of 0.2 m³·m^-2·d^-1, influent averaged COD and NH₄⁺-N increased from 152 and 175.5 mg·L^-1 to 421 and 788.7 mg·L^-1, respectively. The resultant COD, NH₄⁺-N and TN removal by the system was 52.3% to 61.2%, 84.2% to 61.5% and 28.6% to 33.5%, respectively. Meanwhile, NH₄⁺-N and TN removal loading reached 75.5 and 41.7 g·m^-3·d^-1, respectively. Though SHL was as high as 0.32 m³·m^-2·d^-1, the system still performed but its efficiency was remarkably influenced. When influent COD and NH₄⁺-N was around 265 and 465 mg·L^-1, COD, NH₄⁺-N and TN removal was about 56.5%, 53.3% and 20.9%, respectively. The wood carrier observably worked as a slow-release carbon source, and protected the ammonia oxidizing bacteria from free ammonia toxicity due to the concentration gradient of NH₄⁺-N in the adhesive layers.

Contrast experiments on scaling effect using ultrasonic scaling method on the commercial water boilers are performed and the formed water scale is analyzed by SEM (scanning electron microscopy). Results show that ultrasonic can accelerate the formation of the scale microcrystal nucleus. The ultrasonic scaling method can promote the scale of the heating tube with high temperature on commercial water boilers, while it decreases the scale on the low temperature plate, such as water tank surface. Since the scale is mainly taken place on the heating tube, this method is not suitable for commercial boiler.

Effects of chloramine (NH₂Cl) and its combination with chlorine dioxide(NH₂Cl/ClO₂)on dissolved organic matter (DOM) were studied by annular reactor. The characteristic of DOM was evaluated by monitoring removal efficiencies of dissolved organic carbon (DOC) and UV₂₅₄, overall DOM concentration, specific DOM absorbance ratio and excitation-emission matrices spectra (EEMs). The results showed that the oxidants significantly affected the removal of overall DOM, DOC and UV₂₅₄. The DOM removal efficiency was lower after NH₂Cl/ClO₂ compared with that of NH₂Cl, however, the recovery efficiencies speed of them were similar in the two cases. The degradation of DOM, DOC and UV₂₅₄ recovered on 5th day, 4th day and 1st day after oxidation, respectively. Aromatic rings were substituted predominantly with polar groups after oxidation, and thus the oxidant increased the biodegradable DOM. Overall, DOM fluorescence intensity had a decrease potential after oxidant, particularly for tryptophan-like fluorescence and humic-like fluorescence. The aromatic rings were easier targeted by NH₂Cl/ClO₂, however, much more functional groups such as hydroxyl, carboxyl and carbonyl, and higher biodegradable DOM were observed after NH₂Cl, resulting in higher biodegradation of DOM. The DOC and UV₂₅₄ degradation after NH₂Cl or NH₂Cl/ClO₂ could both recover to a higher level than that in control. Therefore, compared to single NH₂Cl, NH₂Cl/ClO₂ was proposed to use in the raw water distribution system for decreasing oxidant by-products.

For researching the anion affection to the fouling deposition characteristics, the experiment chooses two kinds of anion that has effect on the fouling deposition in the tube. The main velocity, inlet temperature, CaSO₄ concentration and anion concentration affection are investigated. It is found that the fouling resistance of nitrate circulating water is higher than that of the chloridion circulating water. The difference value of fouling resistance between two anions is varied with the main velocity, inlet temperature and CaSO₄ concentration. The fouling resistance becomes higher with increasing anion concentration. The influence of nitrate on the rise in the fouling resistance is better than chloridion.

A high power transcritical CO₂ heat pump hot water system was designed and built on the basis of the existing low power water heater. In order to improve system efficiency, two-stage gas cooler, dual capillary tube combination throttle and internal heat exchanger were used in the CO₂ heat pump hot water system. The effects of climatic and operational parameters on the steady state thermal performance of the CO₂ heat pump hot water system were tested and analyzed in the constant temperature environmental chamber. Test results under typical climate conditions showed that system performance was excellent. The CO₂ heat pump hot water system could provide 60—85℃ hot water according to climatic conditions, and its daily COP (coefficient of performance) was about 3.45—4.04 under the climatic conditions of ambient temperature at 4.1 to 27.3℃.

The leachate from incineration plant treating municipal solid waste (MSW) is a kind of wastewater, whose composition is very complicated and highly polluted, and after conventional biological treatment they can still not be directly discharged. According to characteristics of the biologically treated leachate, a combined process was proposed in which the biologically treated leachate was flocculated firstly by Ca(OH)₂, and then the flocculated leachate was oxidized by ozone, and finally the ozonated leachate was filtered by NF membrane, and process mechanism was also explored. The experimental results indicated that Ca(OH)₂ flocculation can effectively remove a large fraction of organic pollutants like heterocyclic compounds and improve the NF membrane flux. The permeate flux of flocculated effluent at the dosage of 8 g·L^-1 Ca(OH)₂ is increased by 8.2% compared with that of MBR effluent. The COD concentration in the flocculated leachate can be further reduced by the ozonation process, but NF membrane flux has no improvement. The reason could be that the siloxane compounds generated by the ozonation process caused the fouling of NF membrane. Compared with RO treatment process, ketones, amines, amides and heterocyclic compounds present in the biologically treated leachate can pass through the NF membrane. As a result, the NF permeate COD was increased by 100 mg·L^-1 to 160 mg·L^-1.Besides, the increases of NF average flux could lead to a slight increase of permeate COD. Membrane fouling is not obvious after the NF treatment of the biologically treated leachate and its pretreated samples.

In this paper, the nitrogen removal efficiency and mechanism by the chemical catalytic particle carrier, i.e., the self-made active catalytic solid particle carrier and its influence factors such as HRT, initial pH and the quality of influent were studied and analyzed. The reaction kinetic model was established. The result showed that the nitrogen removal by self-made carrier is 3 order reaction and the initial concentration of ammonia in water had inhibitory effect on the reaction. Nitrogen removal rate reached 88.7% when HRT was 2 h, and was up to 90% no matter in acidic, neutral or alkaline conditions. Compared to normal zero-value iron or ferric carbon micro electrolysis, the chemical catalysis particle carrier was more efficient and had no particular requirement on influent pH.

A method to measure the contents of soluble lignin and furfural in the lingocellulosic pre-hydrolysis liquid was developed based on UV spectroscopy in the present work. The UV spectrograms of the low molecular organic acids, furfural and the pre-hydrolysis liquid were discussed. Formic acid and acetic acid had significant absorption at 205 nm, and furfural had absorption maxima close to 280 nm. The traditional methods for quantification of lignin based on lignin characteristic peak location of 205 nm and 280 nm was not suitable for the determination of soluble lignin in the pre-hydrolysis liquid. The study presented elimination of the interference of furanic compounds by reduction with alkaline sodium borohydride. The results showed that sodium borohydride significantly decreased absorbance close to 280 nm, and the higher the pre-hydrolysis conditions, the more decreased the absorbance after reduction, indicating high level of furfural. With lignin extracted from Acacia wood and reeds as standard sample, the relationship between absorbance at 280 nm and concentration of lignin was linear and pertinent coefficient reached 0.999, which met the needs of quantitative determination. The difference of absorbance between the samples before and after full reduction could be used for quantification of furfural. The pertinent coefficient of absorbance at 280 nm and concentration of furfural reached 0.998. The results of reproductive experiment showed that recovery was 98.14%—99.88% and relative standard deviation was 0.17%-0.35%.

Taking drug-loaded micelles self-assembled from the amphiphilic polymers as a case, the quantitative structure-property relationship (QSPR) of chemical products was studied on the basis of the cross-scale method from macroscopic to microscopic in this work. A block unit autocorrelation method to calculate the descriptors for characterization of amphiphilic polymer structure was proposed. A series of QSPR models to predict the drug-loading capacity of polymeric micelles at different drug/polymer ratios were established by combining genetic function approximation (GFA) algorithm and multiple linear regression (MLR). The reliability, stability and predictive ability of models were evaluated via internal validation (R²>0.854, Q_loo-cv>0.651, RMSE<0.089), Y-randomization test, external validation (Q_ext²>0.629) as well as application domain definition analysis. The effect of blocks and topological structure of polymers on drug-loading capacity was well explained by descriptors and drug-loaded mechanism analysis. The QSPR models were hopefully used to provide a guide for new polymer design and drug-loading capacity prediction. Also this cross-scale method would be expected to promote the design and development of novel complex structured products.

Silica microspheres are of great interest in several areas such as liquid chromatography, medicine, biochemistry, colloidal chemistry and aerosol research. In this work, porous silica microspheres as packing matrix of HPLC were prepared from tetraethoxysilane (TEOS) by Sol-Gel method with carbon dioxide supercritical fluid drying technique. Conventional high-temperature vacuum dying (WO), intermittent supercritical fluid drying (SCF-I) and continuous supercritical fluid drying process (SCF-C) were discussed. Silica microspheres were characterized by BET, TG-DTG, SEM, FT-IR, XRD and zetasizer analysis system. The results showed that the silica particles with spherical morphology were successfully prepared by all of the three processes and agglomeration was avoided. The specific surface area of silica microspheres was 69.04, 268.40 and 513.41 m²·g^-1 prepared by WO, SCF-I and SCF-C, respectively. The specific surface area of porous silica microspheres obtained by supercritical fluid drying was higher than that obtained by vacuum drying. SCF-I process was the optimum selection for the packing matrix of HPLC. Silica microspheres obtained by SCF-I were mostly regular-ball with specific pore volume of 0.5758 m³·g^-1 without particle agglomeration. The mean particle size (D₅₀) was 3 μm and the particle size distribution followed typical Gaussian distribution with a narrow particle size varied from 1 mm to 7 μm.

Epoxy laurate was synthesized from epoxy resin E-20, and then modified by grafting with acrylic acid monomer and diacetone acrylamide (DAAM), while by adding adipic acid dihydrazide (ADH), to prepare a ketone and hydrazine self-cross-linking at room temperature nano epoxy resin emulsion. The structure of the products synthesized in each step and the emulsion after curing were characterized with infrared spectroscopy, which proved that the design resin structure was obtained. FTIR spectrum of the film of the emulsion showed that hydrazone was produced by ketone reaction with hydrazide. The glass transition temperature (T_g) of the resin was studied with DSC analysis. The synthetic resin had two T_g, the T_g of acrylic acid graft epoxy resin and the T_g of pure acrylic resin, respectively, and the T_g of acrylic acid graft epoxy resin was lower than room temperature, indicating that self-cross-linking reaction could occur at room temperature. The ratio of functional monomer was investigated with particle size analysis and integrated performance analysis during the synthesis process of the modified epoxy resin emulsion. When mass ratio of E-20 and MAA was 11.0%~14.7%, the amount of DAAM was 2%~3%, and m(ADH)/m(DAAM) was 0.8~1.0, good emulsion storage stability and film properties were obtained. The morphology and particle size of the emulsion were studied with transmission electron microscopy and particle size analysis, showing that particle size of emulsion was about 88 nm, and particle size distribution was uniform, existing substantially as stable spherical structure. Test results proved that the anti-corrosion coatings prepared from the nano epoxy emulsion showed good comprehensive performance.

The migration phenomenon of the melt flow front of multi-cavity micro injection molding process within the cavity is observed and analyzed using temperature measuring system equipped of integration of thermocouple sensor and visualization holographic tracer technique. The experimental results show that in the injection rate of 140-220 mm·s^-1, the plastic melt front in the main runner is“U flow state”, while it is upper offset within secondary runner; in the injection rate of 10-70 mm·s^-1, the plastic melt front in the main runner is“fountain” flow state, while it is down offset within secondary runner; and in the injection rate of 80-120 mm·s^-1, the plastic melt fronts within both main and secondary runners have no obvious offset. The results indicate that the injection speed is different during the micro injection molding, leading to various shear heat and also melt front offset. Therefore, a nonequilibrium flow coefficient λ is introduced to determine the flow of the melt front and offset.

The copolymers of n-butyl acrylate, methyl methacrylate and 2-hydroxypropyl acrylate were prepared by activators regenerated by electron transfer atom transfer radical polymerization(ARGET ATRP)using the hexa-functional and mono-functional initiators and 0.01% low concentration of complex catalyst. The molecular structure, copolymer composition and glass transition behavior of the polymers were characterized by refractive index-multi angle laser light scattering-viscometer triple detection gel permeation chromatography, hydrogen proton nuclear resonance (¹H NMR) and differential scanning calorimetry (DSC), respectively. The obtained polymers were formulated into solutions for coating. Rheology tests revealed that viscosity of star polymers was the lowest. The viscosity decreasing efficiency was more remarkable at high solids contents. Under suitable spray viscosity, the solid content of star copolymer increased by 10% compared with commercial acrylic resin obtained by conventional free radical polymerization. The tack-free time of varnish composed of star polymers and isocyanate curing agent was very short. The mechanical properties of coating film reached a good level.

In order to realize continuously and rapidly prepare core-shell structured nanoparticles, a high-frequency impinging stream (HFIS) reactor is explored on the basis of the secondary rotation principle. In this reactor, not only the homogeneous nucleation and heterogeneous nucleation are coupled together, but the liquid-liquid multi-scale mixings are greatly intensified. And then, well-defined nano Fe₃O₄/MnOOH composites were fleetly obtained. The influences of four parameters on the macro and intrinsic kinetics of the coating process were investigated and discussed. Experimental results revealed that low coating ratio prolonged the induction period. Higher initial flux of the main stream intensified the initial dispersion, meso-mixing and micro-mixing. With the total flux of the branch streams being lowered, the initial dispersion was bad off. Furthermore, the computational fluid dynamics (CFD) simulations indicated that the inner layer of the S-shaped main stream had lower pressure and higher flow rate distributions. Therefore, the impinging points should be located in there. Two design defects of the reactor were found, and the corresponding improved schemes were proposed. Through continuous improvement, this reactor is promisingly used for the large-scaled, low-cost and high-quality production of various core-shell nanomaterials.

With good thermal performance and environmental characteristics, R32 is a candidate for replacement of R22, but it is not adopted because of its slight flammability. This paper, in the view of indoor security, analyzes the leakage variation and the effect of supply air velocity and angle on the concentration distribution when the refrigerant leaks from the indoor unit with the air conditioner operating. The experimental results show that the refrigerant leakage rate decreases with time when the air-conditioning system works. The refrigerant leakage can be classified into two stages, fast leak and slow leak. Indoor environment security is evaluated and the results show that the combustible zone only appears near the leakage hole and its residence time is very short. Thus the risk level of using R32 as the refrigerant of air conditioner is low with the air conditioner operating.