Enzyme plays an extremely important role in maintaining homeostasis and the normal life activities in biological systems.The abnormality of some particular enzymes activity is closely relevant to the occurrence and development of related diseases.Therefore, it is of great significance to detect and visualize specific enzyme in vivo with an in-situ and real-time method.The chemical fluorescent probes are endowed with the obvious advantages such as good selectivity, high sensitivity, high imaging resolution and so forth.In recent years, researchers have designed and synthesized a series of fluorescent probes for enzyme detection and visualized imaging in living systems.Based on the trigger mode of fluorescence response, the enzymatic fluorescent probes can be generally divided into two categories:(1) probes based on the recognition between enzyme and specific groups of its inhibitor existing in the probes, called inhibitor-based enzymatic fluorescent probes and(2) probes based on the effective catalytic ability of specific enzyme, also known as the reaction-activated enzymatic fluorescent probes.Herein, in this review, the design strategies of reaction-activated fluorescent probe for enzymes and the research progress of reaction-activated fluorescent probes for four important disease-related enzymes(monoamine oxidase, β-galactosidase, nitroreductase, γ-gumatyl transpeptidase) were mainly reviewed, and the future research of fluorescent probes for enzymes was prospected.

Natural colloids in the soil and groundwater environments are ubiquitous.Since colloids possess not only small particle size, greater specific area and surface-charged, but also a unique double-layer structure and rich surface functional groups, which make them the most active components in subsurface environment and play an important role on contaminants transport in soil and groundwater.The colloids facilitated contaminant transport in soil and groundwater environment has drawn much attention in recent years.This paper reviews the sources, release/deposition, characteristics of colloids and their environmental behavior in subsurface environment, as well as the colloids facilitated transport of different contaminants, and analyzes various environmental factors on co-transport of contaminants with colloids.The key scientific questions, further prospective of processes and mechanism of co-transport of contaminants with colloids in subsurface environment are then proposed.

Supercritical water oxidation(SCWO), as a new and highly effective technique for waste disposal attributing to the special nature of water in the supercritical state, has significant advantages of disposing of sewage and industrial sludge which contain dissolved organic matters(DOM) and persistent organic pollutants(POPs).This paper summarized the progress in basic principles of SCWO, including free radicals reaction as same as wet air oxidation, internal combustion by thermal flames, etc.Research progress on treatment of different kinds of sludge by SCWO at domestic and abroad were reviewed, and main influence factors such as reaction temperature, systematic pressure, reaction time, catalyst, oxidant and co-oxidant, were concluded systematically.Applications of SCWO for sludge treatment in pilot scale and commercial full scale, in USA, Ireland, Sweden and China were introduced in details including its technological process, technical parameters and investment/operation cost.Based on the analysis of its existing disadvantages and problems, referring to salt precipitation, corrosion, high energy consumption and difficult operation of equipment, the future research direction for SCWO were also pointed out.

In order to improve the energy efficiency, convert the low-grade waste heat into the high-grade electricity and achieve the purpose of energy cascade utilization, the experiments on cooling performance of gas engine heat pump system(GHEP) and theoretical simulation of organic Rankine cycle(ORC) were investigated.The results showed that the cooling capacity, gas engine waste heat and gas engine energy consumption were increased with the increasing of gas engine speed, the coefficient of performance(COP) and primary energy ratio(PER) were increased with the increasing of evaporator water inlet temperature, but decreased with the increasing of gas engine speed.On the other hand, the energy and exergy of the first and the second laws of thermodynamics with R245fa as working fluid were 7.39%-10.95% and 42.65%-52.25%, respectively in the range of evaporating temperature 60-86℃.

A varying diameter capillary tube is a low cost throttling device for residential heat pump systems.The asymmetry structure of the varying diameter capillary tube results that forward flow resistance differs from backward one, and then the specific flow rates for cooling and heating mode can be achieved simultaneously.In order to size the capillary tube practically, a dimensionless correlation for predicting mass flow rate through varying diameter capillary tubes is proposed.The formula of equivalent tube diameter and tube length is constructed, and is introduced into an existing correlation for predicting mass flow rate through smooth capillary tube;a numerical model was developed based on the physical equations, and it is used to generate data source for curve fitting the coefficients in the proposed correlation.The proposed correlation can predict the measured mass flow rate through varying diameter capillary tube under various conditions, and it predicted approximately 93% of the measured mass flow rates within a deviation of ±10%.

Super-hydrophobic micro pin-fins with circular, diamond and elliptical cross-sectional shapes were prepared by solidifying hydrophobic layers involved nano-particles on the flowing surfaces, and the flow resistance coefficient as well as Nusselt number in super-hydrophobic micro pin-fins was measured.The integrated effect of super-hydrophobic surface on resistance reduction and heat transfer enhancement was explored by analyzing the integrated heat transfer enhancement factor ε.The results indicated that the friction resistance coefficient was reduced at 72%, 66% and 70% in three kinds of micro pin-fins with super-hydrophobic walls and different cross-sectional shapes.Besides, although Nu in all three kinds of micro pin-fins was reduced, the value of the decrease was less than 44%, 17% and 47% under the high heating power in present research.In addition, the super-hydrophobic micro pin-fins with diamond cross-sectional shape had good comprehensive heat transfer enhancement performance under the high heating power, and the value of ε is higher than 1.17 in the range of Re<1200.

An experimental study on the mixed fouling characteristics of CaCO₃ and slime forming bacteria(SFB) in plate heat exchangers(PHEs) was carried out.The influence of concentration of CaCO₃ and slime forming bacteria on the mixed fouling was investigated.CaCO₃ had a inhibitory effect on slime forming bacteria, which was different from previous studies about mixed fouling.The results showed that the slime forming bacteria fouling played an important role in the mixed fouling.Under the same working conditions, the asymptotic thermal resistance of the mixed fouling was between the asymptotic thermal resistance of the slime forming bacteria fouling and CaCO₃ fouling.With the increase of the concentration of CaCO₃, the mixed fouling thermal resistance decreases.Conversely, with the increase of the concentration of slime forming bacteria, the mixed fouling thermal resistance increases.

In selective catalytic reduction(SCR) system, quantitative analysis of multi-parameter of liquid film(film thickness, temperature and mass fraction) for urea-water-solutions is crucial to control the formation of liquid film, improve the efficiency of SCR system and reduce the NO_x emissions.A new method based on Beer-Lambert law was developed to simultaneously measure the thickness and mass fraction of liquid film for urea-water-solutions at constant temperature, and the thickness and temperature at constant mass fraction by combining two different wavelengths, 1420 nm and 1488 nm, respectively.Furthermore, measurement accuracy of this method was validated by a calibration tool which provided liquid film with known film thickness, temperature and mass fraction, respectively.It was found that the averaged deviation of film thickness and mass fraction measured simultaneously at constant temperature was 0.82% and 3.93%, respectively.It also revealed that the mean deviation of film thickness and temperature measured simultaneously at constant mass fraction was 0.79% and 2.58%, respectively.

The commercial bubble column reactors are normally operated under the conditions of pressurized state and churn turbulent bubbly flow which the superficial gas velocity always exceeded 0.1 m·s^-1.However, most of the published literatures are focus on the cold model experimental investigation of the flow field characteristics in pressurized churn-turbulent bubble columns, and the empirical or semi-empirical correlations which were on the basis of the cold model experimental data to quantitatively estimate the characteristic parameters.Therefore, it is lack of the systematic study on the flow characteristics in the pressurized turbulent bubble columns by the hydrodynamic models with interactions between bubbles and liquid phase.In this work, a steady 2-D axisymmetric hydrodynamic two-fluid model of pressurized bubble column was developed on the platform of FLUENT 15.0 with the UDF sub-models which described the bubble swarm interface forces.The numerical investigations upon the flow field characteristics of pressurized churn turbulent bubble column with the operation pressure varying from 0.5 MPa to 2.0 MPa, and superficial gas velocity from 0.2 m·s^-1 to 0.31 m·s^-1 were performed.Moreover, the comparisons between the simulation results and cold model experimental data were implemented.The comparisons indicated that, the model with the bubble swarm interface forces including improved bubble swarm drag force model, lateral force balance model, and wall lubrication force model, is able to reflect the influences of operation pressure and superficial gas velocity upon flow pattern, that is, the elevating operation pressure leads to increase of time averaged gas holdup and decrease of time averaged axial gas phase velocity, whereas for the ascending superficial gas velocity, the gas holdup and gas phase velocity are both raising.Consequently this mathematical model could correctly predict the basic gas-liquid flow pattern in the turbulent pressurized bubble columns, and simulation results are in good agreement with the experimental data.

A numerical analysis of flow pattern in a serpentine microchannel with small curvature and rectangular cross-section was made using the CLSVOF(coupled level set and volume of fluid method) multiphase model.The gas and water were used as working fluids.After verifying the rationality of the model with the experiment, the effect of curvature on the pressure drop in curved microchannel was studied, the combined influence of curvature and gas velocity on bubble and liquid slug length were investigated.At the same time, the mass transfer characteristics of gas-liquid two-phase flow in curve microchannel were analyzed deeply, including the change of bubble length under different curvature, and comparison of liquid volumetric mass transfer coefficient and mass transfer coefficient of liquid film in curve microchannel.Also, effect of curvature and gas phase velocity on liquid phase volumetric mass transfer coefficient was observed.Meanwhile, the difference of mass transfer coefficient between the curve and straight microchannel was compared, which leaded to a conclusion that the curve micro-channel can enhance the mass transfer.

In order to improve the temperature efficiency of the pump-driven loop heat pipe system and explore the technical feasibility of replacement of the single-loop pump-driven loop heat pipe system by the multi-loop pump-driven loop heat pipe system for energy recovery from exhaust air in public buildings, a single-loop and a triple-loop pump-driven loop heat pipe system prototype were developed.An experimental setup was built to contrast the heat transfer characteristics between the single-loop system and the triple-loop system under summer and winter working conditions based on the principle of heat transfer temperature difference uniformity.Results indicated that performance of the triple-loop system was better.Compared with the single-loop system, the temperature efficiency of the triple-loop system was improved by 22.6% under winter working condition when the temperature difference between indoor and outdoor air was 31.9℃ because the temperature difference uniformity was much better, while the temperature efficiency changed little under summer working condition.

High-temperature phase change material(PCM) Al-Cu alloy is one kind of solar thermal energy storage material which has the best heat storage characteristics, but the study about influence of Cu content on its thermal characteristics has not yet been reported.The thermal characteristics of Al-Cu alloy with Cu content of 7.4%-51.7% including phase change temperature, phase change latent heat, specific heat, thermal diffusivity and thermal conductivity are investigated by differential scanning calorimetry(DSC) and laser flash apparatus(LFA).The internal mechanism of Al-Cu alloy thermophysical properties is also analyzed from the perspective of metallurgical structure.The results indicate that when Cu content is in the range of 7.4%-51.7%, the phase transition temperature of Al-Cu alloy is within 524.4℃ to 645.9℃.With the growth of Cu content, the mass latent heat of Al-Cu alloy decreases and the volume latent heat increases.Al-7.4% Cu has the maximum melting/freezing mass latent heat, which are 339.6 and 343.5 kJ·kg^-1 respectively.Al-51.7% Cu has the maximum melting/freezing volumetric latent heat with 1179 and 1143 MJ·m^-3, respectively.When the temperature rises from 25℃ to 500℃, the specific heat of Al-Cu alloy keeps increasing.On the other hand, when Cu content rising from 7.4% to 51.7%, the specific heat of Al-Cu alloy decreases.The specific heat of Al-7.4% Cu is 0.85 J·g^-1·K^-1 at 25℃ and reaches the maximum 1.08 J·g^-1·K^-1 at 500℃.Besides, the thermal conductivity of Al-Cu alloy decreases with the increase of Cu content, but its thermal conductivity is still as high as 104 W·m^-1·K^-1 even if Cu content reaches 51.7%.The results reveal that Al-Cu alloy, as high-temperature phase change material, has great potential of application in the field of solar thermal energy storage.

The ultrafine particle aggregation arising from Brownian aggregation and Turbulence aggregation in turbulence aggregation device was studied, especially influences of short range force(van der Walls attraction and electric repulsion) among particles and hydrodynamics between particle and gas upon particle aggregation.Based on user-defined aggregation kernel of UDF function of FLUENT software, influences of short range force and hydromechanics among particles upon aggregation rate were studied and aggregation kernel was corrected using collision efficiencyα.Then, a corrected turbulence aggregation model was established and was compared with an ideal turbulence aggregation model.Particle aggregation process underwent numerical simulation using population balance model(PBM) coupling CFD and population balance equation was solved using differential-algebraic framework(DAE-QMOM).The results showed an error of 8.92% between the ideal turbulence aggregation model and the experimental result and an error of 3.35% between the corrected turbulence aggregation model and the experimental result, the latter conformed to practical situations better.Differential-algebraic quadrature method of moment as a high efficiency, a small error rate and a high reliability, it has obvious advantages over PD quadrature method of moment.

Methanation of syngas is one of the main processes of coal to synthetic natural gas.Compared with the traditional nickel based catalyst, molybdenum based sulfur-resistant catalyst for methanation has certain technical and cost advantages since it can avoid fine desulfurization process and water gas shift reaction.Unfortunately, the activity of molybdenum based catalyst is lower than Ni-based catalyst, especially the low temperature activity and high temperature stability.In this paper, the methanation performance of Mo-based catalyst prepared by different methods was investigated in a continuous-flow, fixed-bed reactor.The catalyst prepared by solution combustion with a gas hourly space velocity of 5000 h^-1 and pressure of 3 MPa exhibited the highest activity with CO conversion of 26% and 79% at 300℃ and 400℃, respectively.The prepared catalysts were characterized by N₂-physisorption, Transmission Electron Microscope(TEM), X-ray diffraction(XRD) and Raman Spectroscopy(RS).The catalyst prepared by solution combustion method showed a higher dispersion of Mo species on the surface of ZrO₂ support, owing to its larger surface area and smaller ZrO₂ particle size.In contrary, the large Mo species were formed on the catalysts prepared by co-precipitation and impregnation methods, which was considered as one of the factors resulting in their lower methanation activity.

Five ether-functionalized ionic liquids(ILs), containing[Me(OEt)₁-MOR-C₃SO₃H][MeSO₃], [Me(OEt)₂-MOR-C₃SO₃H][MeSO₃], [Me(OEt)₃-MOR-C₃SO₃H][MeSO₃], [2(C₃SO₃H-MOR)-(OEt)₂₀₀][2MeSO₃]and[2(C₃SO₃H-MOR)-(OEt)₄₀₀][2MeSO₃] were synthesized and characterized by the Fourier transform infrared spectrometer and nuclear magnetic resonance spectrometer.The ionic liquid viscosity, solubility and corrosion were investigated.The promotion effect of ether-functionalized ILs in esterification of acetic acid with butyl alcohol was investigated and the reaction process was optimized using response surface analysis.The yield of n-butyl acetate was up to 97.8% under the optimized conditions:response surface analysis(RSA) of n(CH₃COOH):n(C₄H₉OH)=1.2:1, the mass of catalyst[2(C₃SO₃H-MOR)-(OEt)₄₀₀][2MeSO₃]was 5% of the quality of butyl alcohol, the mass of water carrying agent was 30% of the quality of butyl alcohol, temperature was 90℃, and reaction time was 5 h.The catalysts could be recycled for 8 times without obviously decline of catalytic activity.

Organic solvent systems for synthesizing 4,4'-diamino-1,1'-dianthraquinone-3,3'-disulfonic acid(DAS) by Ullmann coupled reaction were investigated.Organic solvent can be recycled to avoid significant emissions of acidic and salty wastewater produced in the industrial synthetic methods.The effects of different kinds of single solvents, mixed solvent with different composition and proportion were studied.The results showed that the mixed solvent system of DMF:methanol=1:2 was the best.The experiments to find out the optimal factors such as reaction time, temperature were conducted.The influence of additives and different particle sizes of copper powder was researched.The results indicated that the cation exchange resin can improve the content and yield of DAS and can be easily separated from the reaction system.The copper powder(23 μm) was optimal with the best catalytic performance.The highest content and yield of DAS was 91.56% and 88.43%, respectively.

Two porous hydrogen-bonded organometallic frameworks, termed as MPM-1-Br and MPM-1-Cl, were synthesized from adenine and CuBr₂(or CuCl₂) at room temperature by slow diffusion method.The synthesized materials were characterized by analysis techniques including SEM, PXRD, TGA and specific surface area analysis.Single-component adsorption isotherms for acetylene and carbon dioxide on these materials were also determined.The experimental results revealed that MPM-1-Br and MPM-1-Cl have moderately high BET surface(373 m²·g^-1, 417 m²·g^-1), and they show good thermo stability at temperature up to 240℃.The calculations were performed using the ideal adsorbed solution theory(IAST) based on the single-component adsorption isotherms, obtaining the adsorption selectivity of MPM-1-Br and MPM-1-Cl for binary mixture of acetylene and carbon dioxide(50:50, volume ratio) to be 3.8 and 3.0 at temperature of 298 K and total pressure of 100 kPa, respectively, which are comparable to those on HKUST-1 and UTSA-30.

Kinetics research on the reactive extraction of 2-phenylbutyric acid enantiomers using hydroxyethyl-β-cyclodextrin(HE-β-CD) as extractant was performed in a Lewis cell.A homogeneous reaction model and a two-film theory were employed to describe the mass transfer mechanism of the reactive extraction process.The process parameters affecting the initial extraction rate, including agitation speed, interfacial area, pH value of aqueous phase, initial concentration of 2-phenylbutyric acid(2-PBA) enantiomers and initial concentration of extractant, were separately studied.The results showed that the reaction between hydroxyethyl-β-cyclodextrin and 2-phenylbutyric acid was a fast reaction.It was found that the reaction was first order in 2-phenylbutyric acid and second order in hydroxyethyl-β-cyclodextrin.The forward rate constants for the extraction of(+)-2-phenylbutyric acid and(-)-2-phenylbutyric acid were 2.829×10^-4 and 1.803×10^-4m⁶·mol^-2·s^-1, respectively.The results were useful for the design and operation of reactive extraction process in large-scale production, and provide scientific basis for equipment design and process intensification.

For simultaneous separating glycyrrhizic acid with surface activity from Glycyrrhiza and baicalin without surface activity from Scutellaria simultaneously, a novel technology for foam fractionation of the leaching liquor of Glycyrrhiza and Scutellaria was developed.The fluorescence emission spectra, UV absorption spectra and FTIR spectra showed that there was complexing action between glycyrrhizic acid and baicalin.The compatibility of Glycyrrhiza and Scutellaria enhanced the extraction of glycyrrhizic acid and baicalin, accomplished the separation of baicalin by foam fractionation, and improved the foam fractionation performances of glycyrrhizic acid.Using enrichment ratio and recovery percentage as the evaluation indexes, the effects of temperature, volumetric air flow rate, the initial concentration of glycyrrhizic acid and the mass ratio of Glycyrrhiza and Scutellaria on the foam fractionation performances were investigated.The results showed that the enrichment ratio and the recovery percentage of glycyrrhizic acid reached 11.0 and 73.5% with the enrichment ratio and the recovery percentage of baicalin reached 5.8 and 38.5%, respectively, under the conditions of temperature 40℃, volumetric air flow rate 100 ml·min^-1, the initial concentration of glycyrrhizic acid 0.2 g·L^-1 and the mass ratio of Glycyrrhiza and Scutellaria 3:1.In this work, baicalin was separated by foam fractionation for the first time.Compared to the technology of foam fractionation of the leaching liquor from Glycyrrhiza, the novel one increased the enrichment ratio and the recovery percentage by 194.9% and 23.3%, respectively.Therefore, the addition of Scutellaria effectively improved the foam fractionation performances of glycyrrhizic acid and baicalin.

Non-stationary process monitoring based on common trends model was proposed, because conventional multivariate statistical process control methods with stationary data assumption were inapplicable to non-stationary process monitoring.The new common trends model was capable of identifying common factors from co-integrated non-stationary multiple variables and decomposing each non-stationary process variable into summation of a non-stationary common trends component and a stationary counterpart.Contrary to existing non-stationary process monitoring technique from cointegration model, the common trends model captured the stationary component of each non-stationary process variable, eliminated effects of non-stationary common factors and unveiled overall dynamic equilibrium relationships among variables.Hence, non-stationary process monitoring was transformed to an application of common trends model, which involved obtaining stationary component of each process variable, creating estimation for the stationary components by conventional multivariate statistical methods and setting up monitoring on corresponding control limits.A case study of monitoring petroleum distillation process showed that the proposed approach possessed more reliable process monitoring performance than the method of cointegration model.

Prediction for down-hole working conditions of beam pumping units is an effective strategy to timely control oil well's working state, and is important to improve production efficiency and to reduce maintenance cost.Chaos theory was used in transient prediction for oil well's down-hole working conditions.First, moment eigenvalues of invariant curves were extracted from dynamometer chart as predictive variables.Then, after data sequence of these predictive variables were proved to have chaotic characteristics, chaotic time series prediction model was established by ELM(kernel extreme learning machine) method and several uncertain variables of the model were optimally solved by IFOA(improved fruit fly optimization algorithm) with two strategies of global population diversity-evolution and local individual random-variation.Finally, model predictive results were analyzed to determine fault types according to MEA(matter-element analysis) method.Case study of two oil wells in one oilfield showed that the IFOA-KELM-MEA prediction model was reasonable and effective.

The Arg-Gly-Asp sequence(RGD), a ubiquitous adhesive motif in extracellular matrix proteins, exhibits a high affinity to the predominant osteoblast integrin;thus it has been regarded as a promising candidate for biomimic coating to emulate biology in the fabrication of bone-anchored implant surfaces, especially the widely used titanium-based materials.The present study aims to explore the molecular scale events that occur when RGD is placed close to the rutile TiO₂(110) surface by employing classical all-atom molecular dynamics simulations.Local grooves with different depths were introduced in the substrate surfaces to figure out the effect of surface topography on the binding modes of RGD with rutile.The simulation results show that the negatively charged carboxyl groups of RGD are able to break through the barriers from surface hydrations, forming direct bonds with the surface Ti atoms.However, this occurs on the premise that an anchoring site on the rutile surface has been provided to the peptide with an external intervention.Since the unsaturated atoms on the top-layer of groove walls seem to be underlying active sites for peptide adsorption, the presence of surface grooves will largely affect the RGD-rutile binding modes.If RGD can be locked on the bottom of groove via the direct bonds between carboxyl groups and surface Ti atoms, the positively charged groups(guanidine or amino group) are inclined to form hydrogen bonds with surface O atoms on the groove walls, when the length of the rest chain allows.However, once RGD is connected to the bottom of groove with both Arg and Asp side chains “trapped” in a “horseshoe” configuration, the formation of hydrogen bonds between the peptide and the groove walls will be greatly suppressed.The results also indicate that the dominant factors determining the binding strength of RGD-rutile complex are the concrete types of interaction and the number of jointing points.It is anticipated that the findings presented here will ultimately contribute to the biomimetic modification of implants, by suggesting how to tailor the surface topography of implants to induce the desirable biological function.

There is a serious face contact friction on dry gas seal ring face when it is in the start-up phase and abnormal operation, therefore, to analyze and discuss the tribology performance, the tribological test is necessary for dry gas seal dynamic and static ring.The dynamic and static spiral groove dry gas seal ring was tested to study the tribology performance under different operating mode by using the friction and wear tester with selected reasonable test conditions and the corresponding testing technology.The results of the test indicated that there was the obvious running-in phenomenon for spiral groove dry gas seal face in the special condition test.Moreover, the tribology performance of the face was changed with the test.Besides, when the rotational speed and load increased from 150 r·min^-1 and 226 N to 500 r·min^-1 and 1130 N, the wear mass loss of graphite ring was increased by 193.3% but the friction coefficient was decreased 22.3%.This showed that the self-lubrication of graphite ring affected the friction state of the seal face.Because the spiral groove end face contact was different from the smooth surface, the inner ring was more wear than outer ring of the graphite ring.The test results provided a basis for tribological performance optimization of the spiral groove dry gas seal face.

The multicolumn envelope meshing pair(MEMP) is the important factor that affects the performance of single screw compressor due to its complex three-dimensional structure.In order to study the working characteristic of the single screw compressor with MEMP, a geometric features numerical calculation model is set up.By using this mathematical model, the effects of the MEMP and the straight line envelope meshing pair(LEMP) on the geometric features and the thermal dynamic performances are compared.Analysis results show that the use of the MEMP makes the actual star-wheel tooth width changing along with the star-wheel angle larger than that of the star-wheel with LEMP.Affected by the change of star-wheel tooth width, the working chamber volume of the compressor with MEMP will increase, the cavity internal pressure will decrease at the same star-wheel angle, and the largest base volume will be increased 5.2%.The closed spiral will be closer to the inlet side and the exhaust orifice spiral will be closer to the exhaust end for the compressor with MEMP which will lead to the delay of the exhaust process and more flow resistance losses.All analysis results obtained can provide the theory basis for optimum design of the single screw compressor with multicolumn envelope meshing pair.

Interfacial tension of CO₂-NaCl, CO₂-CaCl₂ and CO₂-(NaCl+CaCl₂) solution systems was studied at different salt concentration and ratio by molecular dynamics simulation, in order to understand influence of different salt ions at molecular level.The results showed that the presence of salt ions increased interfacial tension between CO₂ and water, which majority was caused by number of cationic charges and the rest was by cation atomic properties such as Lennard Jones potential parameters and atomic mass.The interfacial tension increment of these three systems were all linearly dependent on ionic strength, but the slope had no relationship to types of salt solutions.This founding would provide theoretical guidance for IFT prediction.

Gemini surfactants of dual quaternary ammonium salts with hydroxyl and ester functional groups were synthesized and used to investigate wettability on coal tar asphalt surface.The contact angle of hydroxyl Gemini surfactants on coal tar asphalt surface decreased first and increased later with increase of hydrophobic chain length, which C₁₂-OH surfactant showed best wetting.The contact angle of m-n-m ester Gemini surfactants decreased with increase of hydrophobic chain length.At fixed hydrophobic chain length, m-6-m surfactant had better wetting than m-2-m surfactant.A linear relationship was observed between adhesive tension on coal tar asphalt surface and surface tension of C₁₀-OH, C₁₂-OH and 12-2-12 surfactants within a range of concentrations.Zeta potential on the coal tar asphalt surface increased initially and tended to stabilize gradually along with increase of surfactant concentration.

Surface properties and micellization behavior of Gemini sulfo-succinate sodium(GSS) and Triton X-100(TX-100) binary mixture in aqueous solution were investigated with various GSS spacer lengths.Compositions in mixture micelles and surface absorbance layer as well as interaction parameters between the two components were analyzed.Results showed that no obvious or maybe no presence of synergistic effect between GSS and TX-100 were found on surface property and micellization in aqueous solution, although TX-100 decreased apparently critical micelle concentration(cmc) of GSS and was major component in mixture micelles.GSS of shorter spacers was easier to form micelle itself and mixture micelle with TX-100.Spontaneous formation of mixture micelle and weak molecular interaction was observed in mixture of GSS362 and TX-100.

The DNA contents, the internal grain densities, the surface roughness and the cell sizes of Serratia marcescens ZSG cells were detected to have different changes by the flow cytometry when ZSG cells were cultivated in the medium with the different carbon sources.Through mutagenizing compoundly ZSG cells, a stable mutant strain ZSG7 was gained, of which the prodigiosin(PG) production in the 250 ml conical flask and in 5 L fermentor were increased by 62.5% and 269% compared with the the original strain yields, respectively.PG production of fermentation with the optimal culture medium in the 250 ml conical flask was increased by 100% compared with the unoptimized.After dissolved oxygen(DO) was optimized by step controlling, the PG production was increased by 30.9% compared with the DO-unoptimized.After constant pH was optimized, the PG production was increased by 35.9% compared with the pH-unoptimized.After the fed-batch components were optimized, the PG production was increased by 47.6% compared with the batch fermentation with constant pH7.The kinetic models about bacteria growth and PG formation of the batch fermentation with constant pH7 and the fed-batch fermentation were built based on the Logistic equation and Luedeking-Piret equation.With the fitting model parameters, the models could provide reasonable description for the processes of the batch fermentation with constant pH7 and the fed-batch fermentation.

In order to improve dehumidification efficiencies of membrane-based energy recovery ventilator(ERV), composite membranes based on cellulose acetate, sodium alginate and lithium chloride(LiCl) were fabricated.Cellulose acetate was adopted as supporting constructions and sodium alginate and LiCl were the corresponding active layer and hydrophilic additive.Then their key characteristics were tested and analyzed to investigate practical performance in the ERV.The highest permeance of composite membranes reaches up to 4.42×10^-5g·m^-2·s^-1·Pa^-1, which is 1.56 and 2.63 times higher than those of the asymmetric membrane without LiCl and the traditional commercial paper, respectively.Water solubility of the modified active layer ranges from 18.29% to 28.55% for cross-linking improves the waterproofness.Moreover, thermal gravity curves indicate membranes can be regenerated by contacting 55℃ dry air.Fourier transform infrared spectra illustrates that there are plenty of hydrophilic hydroxyl groups on the surface of composite membranes.Finally, the total mass transfer of ERV composed by the composite membranes is analyzed and compared with the commercial one.These properties demonstrate this membrane has great potential to be applied on the ERV.

It is a common sense that the scale from the water dispenser may lead to health problem and the magnetized water has a certain scale inhibition function.Permanent magnets are easier to install with lower cost for scale inhibition of drink water comparing it to the solenoid with electric current twined the water pipe for scale inhibition of industrial fluid.We fix a set of permanent magnets on the outer wall of cool tank to generate constant magnetic field inside the tank.The magnetic flux density distribution in the cylinder tanks by both magnets and solenoid is simulated and compared with COMSOL Multiphysics software.The experiments prove the correctness of the theory that magnetic field imposes Lorentz force on the free ions in the water(abbr.Ion Theory) and also charged particles(abbr.Particle Theory).Meanwhile, Lorentz force on charged particles is much stronger than the free ions.Constant magnetic field may slow down the production of CaCO₃.Under the ambient temperature, the scale inhibition rate reaches as high as 29%.Under the condition of long-term heating up the water, the permanent magnet group has a better scale inhibition effects comparing with the blank group.Finally, we calculate the concentration of each component in the tank based on the data of pH value and calcium concentration.We use the concentration of CaCO₃ to calculate the scale inhibition rate which is difficult to measure.

Lime, which is mainly presented as CaO, is often used in sludge conditioning and stabilization.To study the effects of CaO on the fate of heavy metals in pyrolysis and sludge gasification process, the sludge pyrolysis and gasification experiments were conducted with a drop-tube furnace and a fixed-bed system.The content and speciation of typical heavy metals(Mn, Zn, Cu, Cr, Ni) were also analyzed.Samples included different sludges(raw sludge, CaO conditioned sludge), their corresponding pyrolysis chars and gasification ashes.The results indicated that after CaO conditioning, the content of heavy metals reduced due to the dilution effect.Mn, Zn, Cr transformed to stable state.Some heavy metals ions reacted with OH-to form precipitate which then decomposed to produce oxide during sludge gasification process.In addition, CaO can increase the residual rate of heavy metals in solids, and also absorb HCl, SO₂ and other acid gases from decomposition of chloride or sulfate to promote the formation of oxides at high temperatures.Subsequently, eutectic was generated in the reactions between these oxides and compounds such as Al₃O₂, SiO₂, Fe₂O₃ and CaO, thus suppressing the release of heavy metals.

P. vittata is one of the hyperaccumulators of arsenic(As), the combustion experiments were conducted in a horizontal tube furnace to investigate the transformation behavior of As during the combustion of P. vittata.Results show that the release of As in P. vittata increased first then decreased, reaching the highest at 500℃.With increasing temperature from 400℃ to 500℃, the higher release rate is due to the volatility of the inorganic As at lower temperature.With further increase the temperature from 500℃ to 900℃, As release decreased which may be attributed to the fast oxidation of As and the formation of some inorganic compounds.Moreover, the soluble As in the solid residue mainly presents as As⁵⁺, and the content varies largely with the temperature with a peak value of 81% of total As at 800℃.The content of soluble As⁵⁺ decreases before 500℃ due to the volatility of the inorganic As.The physical adsorption of some compounds plays an important role for the As fixation at the temperature from 500℃ to 700℃, while the As fixation is mainly conducted by the chemical oxidation at 800℃.The content of soluble As⁵⁺ decreases a little, possibly because of the sintering of the ash.Considering the As recycling process, 800℃ is recommended as the optimum combustion temperature for the P. vittata.

The CANON(completely autotropic nitrogen removal over nitrite) process has been received abroad attention in wastewater treatment recent years.In the study, a Sequencing Batch Reactor(SBR) was used to treat domestic wastewater using intermittent aeration with low dissolved oxygen(DO).After inoculating partial nitrification sludge and anammox sludge, the reactor was started-up successfully under appropriate temperature and sludge concentration.By using intermittent aeration with low DO, the system achieved the inhibition and elimination of nitrite-oxidizing bacteria(NOB).The harmonious effect of partial nitrification and anammox made the system stable.In the stable phase, the reactor had a good performance on the contaminant removal.With the influent concentrations of total nitrogen and ammonia of 63.9 mg·L^-1 and 62.7 mg·L^-1, the effluent of them were 12.3 mg·L^-1 and 7.6 mg·L^-1 and the removal rates of them were 77.8% and 86.7%, respectively, with the volume loading of total nitrogen removal of 0.16 kg N·(m³·d)^-1.Thus, the experiment provided references for the application of the operation mode in autotrophic nitrogen removal of wastewater.

Based on the problem of poorly continuous operation of the iron-carbon micro-electrolysis(Fe⁰/GAC)-Fenton method in nitrobenzene(NB) wastewater treatment, ultrasound(US) was used to strengthen Fe⁰/GAC-Fenton.The Effect of ultrasound on continuous running of Fe⁰/GAC-Fenton was studied.The results show that, when Fe⁰/GAC is not changed, the removal rate of NB for 4 batches of same NB wastewater treated by Fe⁰/GAC-Fenton drops from 69.54% to 31.66%, and TOC removal rate is down to 19.20% from 48.11%;whereas under US/Fe⁰/GAC-Fenton, 4 times of NB removal rates are close to 100%, and TOC removal rates are above 60%.Compared with Fe⁰/GAC-Fenton, ultrasound not only enhance the degradation efficiency of Fe⁰/GAC-Fenton in NB wastewater treatment, but also achieve a continuous and efficient operation.The effect of pH, dosage and adding time of H₂O₂ on degradation of effluent of US/Fe⁰/GAC by Fenton method were studied.The suitable operating parameters are H₂O₂ total dosage 4 ml, adding time=5, US/Fe⁰/GAC effluent pH=4.Under these conditions, after 30 min, the removal rate of NB reaches 100%, TOC removal rate reaches 75%.

A composite activated carbon fiber(ACF) cathode Mn₃O₄/ACF, which was prepared using a cyclic voltammetry method, was employed in a heterogeneous electro-Fenton-like system for the degradation of a model dye, methylene blue(MB), with no other reagents added.The decolorization ratio and the mineralization of MB in the different pH were investigated and the active oxygen species involved in the system were also detected.The experiment results showed that when solution pH was set as 3.0, 5.0 and 7.0, the decolorization ratio reached to 97.3%, 99.9% and 99.8%, respectively, and TOC removal achieved to 73.4%, 88.6% and 80.4%, indicating the extensive feasibility of the system in broad pH range.The results of detection of the active oxygen species demonstrated that H₂O₂ was electro-produced at the surface of cathode.The hydroxyl free radical·OH generated by the Fenton-like reaction of Mn₃O₄ with H₂O₂ was responsible to the degradation of MB.The superoxide radical O₂·^- was also proved playing important role in decolorization of MB.The mechanism of degradation of the contaminant by this heterogeneous electro-Fenton-like system was preliminarily discussed.

Waste rice straws were converted into rice straw derived activated carbon(RSAC), which supported ferric oxides(Fe₃O₄, loaded dosage of 14.25%) as ozone catalyst with 1175.1 m²·g^-1 of specific surface area, and efficiency of heterogeneous catalytic ozonation of biologically pretreated paper-making wastewater were investigated.The results indicated that RSAC and catalyst all had the good adsorption capacity of biologically pretreated paper-making wastewater, and the adsorption isotherms fitted well with the Langmuir model(R²>0.99).The addition of the prepared catalyst significantly enhanced the pollutants removal performance of ozonation of raw wastewater, and the COD, BOD₅, NH₄⁺-N and chromaticity in the treated effluent were 46, 17, 5 mg·L^-1 and 18 degree which all met discharge standard paper-making wastewater(GB 3544-2008) with the optimal operating parameters(0.3 g·h^-1 of ozone dosage and 1 g·L^-1 of catalyst dosage and raw wastewater pH).Moreover, the catalyst had superior stability and leaching of metal irons were very few at 20 cycle's utilization.It was deduced that the enhancement of catalytic activity was responsible for generating more radicals by radical scavenger and ESR detection.Thus, the prepared catalyst with efficient, stable and economical advantages was suitable for catalytic ozonation of biologically pretreated paper-making wastewater.

By the experiments of anionic groups(AGs) in the mulberry SCMP adsorption of methylene blue(MB), the results of mulberry SCMP pulp of AGs in the hydrogen peroxide(H₂O₂) bleaching adsorption of methylene blue(MB) were fitted by the Langmuir isotherm equation and the Freundlich isotherm equation.It showed that the mulberry SCMP adsorption process of MB conformed to the Langmuir adsorption model.The adsorption process was monolayer adsorption and non uniform adsorption coexistence of preferential adsorption.By X-ray photo-electron spectroscopy(XPS) analysis of anionic groups in pulp and surface elements and the change of species in paper pulp.H₂O₂ bleaching can form new SAGs and improve the pulp fiber surface sulfonation degree, while reduce the lignin content in the pulp fiber and increase the contents of cellulose and hemicellulose.

The hot-gas bypass control can effectively eliminate the harm of high pressure on auto-refrigerating cascade system, but it is useless for the regulation of mixed refrigerant composition.The four kinds of pressure and composition adjustment method with two bypass was put forward in connection with the characteristics of higher condensing pressure and exhaust temperature of three-stage auto-refrigerating cascade cycle.The condensing pressure was changed in regular fluctuations and the solenoid valve was opened and closed frequently for the hot-gas bypass regulation, and the refrigeration system was stable after 70 min.The cold lost seriously for vapor outlet bypass adjustment of phase separator Ⅱ, and the cold of refrigerant was discharged to the reservoir through the bypass line.The performance of the refrigeration system was very close to the vapor outlet bypass adjustment of phase separator Ⅰ and two phase separators, and the refrigeration cycle was stable after 30 min.The vapor outlet bypass adjustment of phase separator Ⅰ and two phase separators were the better pressure and composition regulation method of auto-refrigerating cascade cycle according to the study of the operating conditions of compressor and evaporator.

A single-bed adsorption refrigeration experimental system with the working-pair of activated carbon-methyl alcohol was built.And investigations on the effect of desorption temperature and desorption time on the desorption amount of refrigerant in cylindrical adsorption tube were conducted.The desorption temperature was set at 84, 89 and 94℃, and the desorption was last for 4, 5, 6 and 7 h, respectively.The experimental results indicate that desorption temperature, desorption time and the desorption amount of refrigerant had significant effect on the refrigeration recycling performance of the adsorption refrigeration system.The minimum coefficient of performance(COP) of 0.053 was achieved when the heating resource temperature was maintained at 84℃ and the heating time was 4 h.The maximum COP of 0.19 was achieved when the desorption temperature was maintained at 94℃ and desorption time was 6 h.Consequently, 94℃ and 6 h were recommended as the optimal desorption temperature and desorption time.If the desorption time was continuously increased to be more than 6 h, the increasing rate of desorption amount would be less than that of energy consumption, then COP will consequently decrease.

In order to utilize the black liquor effectively, lignin was extracted from bagasse soda pulping black liquor by acid precipitation.The bagasse lignin(BL) was then characterized by Fourier transform infrared(FTIR), nuclear magnetic resonance(¹H NMR) and gel permeation chromatography(GPC).The results indicated that BL, which was consisting of syringyl(S) and guaiacyl(G) units and connected together by β-O-4 aryl ether linkages, β-5, β-1 and β-β condensed C-C linkages, was more similar to the broadleaf wood lignin than annual grass lignin.There was large variation among the molecular weight of the BL molecules.The GPC spectrum of BL contained two continuous peaks, and the number-average molecular weight(M_n) of these two peaks was 107106 g·mol^-1 and 11270 g·mol^-1, respectively.Thermogravimetric analysis(TG) was used to investigate the combustion characteristics of BL.The results showed that the combustion process undergoes four periods, i.e. dehydration(30-200℃), volatilization(200-300℃) releasing from cleavage of the C-O linkage and combustion, volatilization(300-500℃) releasing from cleavage of the highly condensed C-C linkage and combustion of coke, and burnout stage(500-800℃).The combustion of BL mainly occurred at the temperature range of 300-500℃ with above 80% mass loss, and the maximum mass loss rate reached its value of -142.75%·min^-1 at the temperature of 477℃(20℃·min^-1).The influences of different heating rates(5, 10, 15, 20℃·min^-1) on combustibility parameters of BL, which consisted of the ignition temperature, peak temperature at maximum mass loss rate, burnout temperature and maximum/mean mass loss rate were analyzed through computing the differential thermogravimetric(DTG) curves.It was shown that the thermal hysteresis would occur and all combustibility parameters were increased along with increasing heating rate.The bagasse lignin residues(BLR) were prepared by burning at 300, 600, 900 and 1100℃, and the surface morphology and elemental composition of those BLR were comprehensively analyzed by using the scanning electron microscopy(SEM) and the X-ray fluorescence(XRF) technique.The results showed that a majority of tight structure of granular with smooth surface were found in the BL, while most of loose and poriferous larger particles, which was caused by the volatilization releasing and melting of the BL, was found in the 300℃ BLR.The sporadically coke particles wrapped in the loose particles still existed in the 600℃ BLR, indicating that the incomplete combustion of the cake occurred.Then, the higher the burning temperature was, the smaller size and homogeneous of the BLR.The well-ordered lamellar particles were the majority surface morphology of BLR when burning temperature exceeded 600℃.The main composition elements of BLR were calcium(Ca), silicon(Si), aluminum(Al), phosphorus(P), sulphur(S) and ferrum(Fe).With the increase of burning temperature the Na and K contents decreased, while the other elements contents not obviously changed.

A tube furnace(TF) and thermogravimetric analyzer(TGA) were used to investigate the indirect sulfation of limestone under O₂/H₂O combustion compared with O₂/N₂ and O₂/CO₂ combustion.It focused on the effects of combustion atmosphere and steam concentration on the calcium conversion ratio of the limestone.Besides, the sulfated products were collected for X-ray fluorescence(XRF), X-ray powder diffraction(XRD), pore structure characteristics and scanning electron microscopy(SEM) analysis.The results indicate that the indirect sulfation reaction has a negligible difference at the kinetically-controlled stage under different atmosphere but it is greatly enhanced at the diffusion-controlled stage under O₂/H₂O atmosphere compared with O₂/N₂ and O₂/CO₂ atmosphere.This is due to the fact that the presence of steam promotes the solid-state diffusion in the product layer.Besides, the calcium conversion ratio has no obvious increase when increasing the concentration of steam under O₂/H₂O atmosphere.

The combustion characteristics of antibiotics bacterial residue, coal and both blends were investigated using thermogravimetry-differential scanning calorimetry(TG-DSC), and the kinetic parameters of co-combustion was determined by Coats-Redfern method.The influence of bacterial residue blending ratio and particle size on combustion process was analyzed, and the possibility of co-combustion with coal and the advantages of superfine combustion were clarified.The results showed that co-combustion of antibiotic bacterial residue and coal mainly consisted of three stages, and adding bacterial residue can significantly improve the combustion characteristics of coal.With increasing bacterial residue blending ratio, the ignition temperature and burnout temperature decreased.Burnout characteristics index of superfine co-combustion and non-superfine co-combustion reached the maximum value at the bacterial residue blending ratio of 30%, which is 5.82×10^-3 and 5.49×10^-3, respectively.The activation energy of superfine co-combustion was lower than that of non-superfine co-combustion, indicating that the superfine combustion was beneficial to reduce the activation energy.There existed kinetic compensation effect on the activation energy E and the pre-exponential factor A of the superfine co-combustion and non-superfine co-combustion.

Two different simplified models of coal char were applied to investigate heterogeneous reduction mechanism of N₂O by char through density functional theory in quantum chemistry method.Structure and energy of reactants, intermediates and transition states were calculated so as to determine reaction process, and thermodynamic and kinetic analysis were conducted to reveal heterogeneous reaction mechanism.The results showed that the single carbon atom was not suitable as the model of heterogeneous reaction mechanism of N₂O by char due to it cannot reflect the adsorption and desorption of N₂O molecule in char surface.While the heterogeneous reaction mechanism of N₂O by char can be well studied by six rings carbonaceous cluster model.Through three transition states and two intermediates, N₂O was reduced to N₂, and energy barrier of N₂O adsorption on char surface was 51.01 kJ·mol^-1, indicating that adsorption process was easy to happen.In addition, the heterogeneous reduction of N₂O by char was exothermic and spontaneous reaction at temperature range of 298.15-1500 K, and reaction can take place in one direction owing to reaction equilibrium constant of greater than 10⁵.Furthermore, the reaction was fast at temperature range of 298.15-1500 K, and reaction activation energy was 43.55 kJ·mol^-1 with Arrhenius expression of 1.24×10¹⁰exp(-5238.15/T).

Polyvinylidene fluoride(PVDF)/graphene oxide(GO) nanocomposite membranes, which were made of PVDF naocomposites with different content of super hydrophilic graphene oxide(GO) nanosheets, were assessed for long term application in a membrane bioreactor(MBR) system.Critical flux, MBR performance, membrane resistance, and anti-fouling properties were intensively studied.Surface hydrophilicity of PVDF/GO membranes was improved with presence of surficial oxygen-containing groups up to 29.33%(GO=3%).PVDF/GO membranes showed similar anti-fouling to PVDF control membrane, however, PVDF/GO(GO=3%) membrane required only one cleaning with cleaning cycle 4 times longer than PVDF control.PVDF/GO membrane had lower membrane resistance than PVDF control and significant reduction in irreversible fouling resistance.As an example, PVDF/GO(GO=3%) membrane had about 9% of irreversible fouling resistance of PVDF control.Antifouling improvement of PVDF/GO membrane was further shown by EPS study that much lower EPS intensities were observed with a reduction of 59.98%(GO=1%) and 69.57%(GO=3%) in comparison to PVDF control.Scanning electron microscopy(SEM) and confocal laser scanning microscope(CLSM) results showed that cake layer on nanocomposite membrane became looser and thinner with the increase of GO content.Part of PVDF/GO(GO=3%) membrane surface was exposed, resulting in high stable permeability over a long period of time.

A new class of polyether-urea-based benzoxazine(PUBZ) exhibits perfect toughness properties after thermal treatment has been developed and synthesized via two steps.Firstly, amine-terminated polyether-based polyurea was synthesized using amine-terminated polyether and diphenyl methane diisocyanate(MDI) as raw materials.Secondly, PUBZ was prepared from amine-terminated polyether-based polyurea, bisphenol-A and paraformaldehyde through Mannich reaction.The structure of PUBZ has been confirmed by FTIR and ¹H NMR.The curing behavior was characterized by DSC.The effect of different length of polyether chains on the mechanical properties of PUBZ has been evaluated by dynamic mechanical analysis(DMA) in a tensile deformation.Thermal properties of PUBZ have been studied by DMA and thermogravimetric analysis(TGA).The results showed that the longer polyether chains, the higher curing temperature of the PUBZ.The lower glass transition temperature of the PUBZ, the better thermal stability.When the molecular weight of amine-terminated polyether was 400 and D-400/PUBZ resin exhibited the highest toughness.

Due to high temperature and high pressure conditions of Bi-layered rapid heating cycle molding(Bi-layered RHCM), the molding shrinkage of its products is extremely sensitive to the change of process parameters, therefore, the key to improve quality of products is the strategy of molding shrinkage control.In order to explore and develop the strategy of molding shrinkage control, a remote control's front cover of air conditioner was an example for molding in this paper.Determined a multi-objective evaluation system and process parameters for measuring molding shrinkage.Latin Hypercube Sampling was used to design experiments, moreover, a numerical simulation software named Moldflow was used to simulate mold filling, pressure maintaining and cooling process to obtain test data.The mathematical relationship between parameters and evaluation index was estabilished by Kriging model.In order to find out the optimal evaluation index of molding shrinkage and corresponding process parameters, the mathematical relationship was iterative calculation by means of genetic algorithm(GA).Both simulation and production test were applied to verify the strategy of molding shrinkage control based on Kriging model combined with GA, and provide the reference of molding shrinkage control of Bi-layered RHCM.

Lithium-ion battery cathode materials Li_1.2Ni_0.2Mn_0.2-x/2Mn_0.6-x/2Cr_xO₂(x=0, 0.04, 0.08, 0.12) were synthesized by co-precipitation and high temperature solid state reaction.The structure, morphology and electrochemical properties of cathode material, which was doped with different amounts of Cr, were characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM), galvanostatic charge-discharge testing and electrochemical impedance spectroscopy(EIS).The results show that the cathode materials Li_1.2Ni_0.2Mn_0.2-x/2Mn_0.6-x/2Cr_xO₂ display the layered structure of solid solution.Cr-doping does not change the material structure, and stabilizes the host layered structure by prohibiting the speed of spinel structure formation during cycling.Li_1.2Ni_0.16Mn_0.56Cr_0.08O₂ has the best electrochemical properties.The first discharge specific capacity of Li_1.2Ni_0.16Mn_0.56Cr_0.08O₂ is 246.6 mA·h·g^-1at 0.1C, while Li_1.2Ni_0.2Mn_0.6O₂ is 230.4 mA·h·g^-1.The capacity retaining ratio is improved from 93.5% to 95.36% after 50 cycles at 0.2C.The discharge capacity of Li_1.2Ni_0.16Mn_0.56Cr_0.08O₂ is 104.2 mA·h·g^-1 at 5C, while that of pristine is about 91.5 mA·h·g^-1.EIS results show that Li_1.2Ni_0.16Mn_0.56Cr_0.08O₂ has the lowest charge transfer impedance.

In order to analyze the influence of molecular weight distribution(MWD) on photo-oxidation degradation properties of low density polyethylene(LDPE), the materials parameters(chemical structure, thermal stability, average molecular weight, surface morphology and mechanical properties) of LDPE with different MWD index were studied by attenuated total reflection infrared spectroscopy(ATR-FTIR), thermogravimetry analysis(TGA), gel permeation chromatography(GPC), scanning electron microscope(SEM) and mechanical experiments.The results show that the wide MWD of LDPE resulted in an obvious increasing in the degree of unsaturation and chain branching.For the narrow MWD of LDPE, the degree of carbonyl index increased significantly.The MWD had little effect on the behavior of chain breaking.For the high MWD index, the initial thermal decomposition temperature and 5% mass loss corresponding temperature of LDPE decreased faster, and thermal stability was apt to decline.The average molecular weight decreased much intensely and the aging phenomenon of surface microstructure was much severe.The bending strength and impact strength decreased faster, characterized by the loss of the impact strength of LDPE with 6.0 MWD index after 24 d of aging.Analytically, the large average molecular weight and narrow MWD indicated the long molecular chain and less short-molecular chain, and the probability of production of free radical by oxygen contact was also low.So the wider MWD of the PE, the easier of the material aging.

Ammonia(NH₃) is the main raw material of nitrogen fertilizer production, and it is also an important indirect source of PM_2.5.The ammonia emission reduction and recycling are the necessary ways for green development, especially under the green industrial production cycle.Adsorption method has the noteworthy feature of the ammonia capture without phase change and the advantages that enrichment of ammonia can be directly related to carbon dioxide synthesis of nitrogen fertilizer(such as urea).This work studies the ammonia adsorption properties of the flexible reversible transformation MOFs material Cu(BDC).Three dimensional dense structure of Cu(BDC)(DMF) is prepared by hydrothermal method, and one-dimensional pore structure Cu(BDC) was obtained after the removal of DMF under heating at high temperature with changed crystal structure.The Cu(BDC) has the surface area of 535 m²·g^-1 and the adsorption capacity of pure ammonia up to 18.4 mmol·g^-1 in an atmospheric pressure, which is higher than the traditional adsorbent and other new porous materials such as MOFs and COFs.By reducing the pressure and vacuum heating, the Cu(BDC) can be progressively regenerated and thus has excellent “ammonia” characteristics.Additionally, Cu(BDC)(DMF) can be converted into Cu(BDC)(NH₃)₂ in the ammonia environment, eliminating the process of Cu(BDC) preparation.

β-Tricalcium phosphate powders were prepared by nano ball milling and ultrasonic stirring process and compared with conventional process in this research.The purity and particle size of β-TCP powders were investigated by differential scanning calorimetry(DSC), X-ray diffraction(XRD), Fourier transform infrared spectroscope(FTIR), nanoparticle test, scanning electronic microscopy(SEM), transmission electron microscope(TEM) and X-ray fluorescence spectrum(XRF).The results reveal that the purity of β-TCP powders prepared by the nano ball milling and ultrasonic stirring process can reach over 97%, and the powders average particle size is 666 nm, with high purity and uniform particle size.Moreover, the raw materials with small particle size and good dispersion can be processed through nano ball milling.This process has great potential in the synthesis of inorganic powders by solid-state synthesis.

Monodispersed spherical SiO₂ particles were successfully prepared by Stober method, and the functional modification of SiO₂ was obtained by the reaction of Si-OH with 3-glycidoxypropyltrimethoxysilane(GPS).By using aluminum isopropoxide as a heterogeneous catalyst to initiate in-situ ring-opening polymerization of the propylene oxide(PO) monomers, a polypropylene oxide(PPO) polymer brush grafted SiO₂(PPO-g-SiO₂) was obtained.The effects of the amount of monomer, reaction temperature and reaction time on the grafted polymer brushes were discussed.In addition, the chemical structure and morphology of PPO-g-SiO₂ and grafted amount were characterized by Fourier transform infrared spectroscopy(FT-IR), X-ray photoelectron spectroscopy(XPS), transmission electron microscopy(TEM), scanning electron microscope(SEM) and thermogravimetric analysis(TGA).The results show when the amount of the monomer addition is 2.38 mol·L^-1, reaction temperature is 80℃, and reaction time is 24 h, respectively, the PPO graft quantity is up to 23.56%(mass) on SiO₂ surface and the thickness is about 15 nm.

The Fe-doped ZnO was synthesized by a parallel flow precipitation method with Zn(NO₃)₂·6H₂O and NH₃·H₂O as raw materials.The morphology and structure of as-synthesized products were characterized by X-ray diffraction(XRD), field emission scanning electron microscopy(FE-SEM), transmission electron microscopy(TEM), UV-visible diffuse reflectance spectra(UV-vis DRS) and Brunauer-Emmett-Teller(BET) for surface area analysis.Pyridine(Py) petroleum ether solution was used as model pollutant to investigate the denitrification performance of Fe-doped ZnO.The results illustrated that all of the Fe-doped ZnO products only comprise hexagonal wurtzite structure when the molar ratio of Fe/Zn from 0 to 1.0%.Fe doped ZnO photocatalysts exhibit much higher photocatalytic performance, which is ascribed to the decreased crystal size, increased specific surface area and reinforced absorbance ability in visible light range.When the concentration of Py is 10 μg·g^-1 and dosage of 0.50% Fe photocatalyst is 0.6 g·L^-1, the degradation efficiency of Py is 65.3% under the irradiation of a 150 W mercury lamp with illumination distance of 10 cm for 50 min.

Superhydrophobic titania-silica nano complex oxides were synthesized from tetraethylorthosilicate(TEOS) and titanium isopropoxide(TTIP) by an improved sol-gel method followed with high temperature calcination and modification with trimethylchlorosilane(TMCS).The obtained nano complex oxides were characterized by XRD, XPS, BET, SEM and FTIR, and water contact angle.Crystal polymorphism of the nano complex oxides was investigated to explore influence of titania-silica molar ratio as well as calcination temperature on crystal structure.The results showed that rutile crystal structure was achieved at titania-silica molar ratio of 5:1 and calcination temperature of 1100℃.After TCMS surface modification, the superhydrophobic rutile TiO₂-SiO₂ nano complex oxides exhibited large specific surface area(up to 348 m²·g^-1) and excellent hydrophobicity(water contact angle of 154.7°), which could have a potential application for constructing micro-nano hierarchy-structured top coating of outside wall-decorating materials.

Poly(butyleneadipate-co-terephthalate)(PBAT) copolyesters were synthesized from adipic acid(AA), p-phthalic acid(PTA) and 1, 4-butanediol(BDO) with tetrabutyl titanate as catalyst through a two-step process of esterification and polycondesation.The effects of molar ratio of AA to PTA on the structures, thermal and elastic properties of copolyesters were studied.FTIR and NMR test results showed that PBAT copolyesters were successfully synthesized.GPC test showed the molecular weight(M_w) of copolyesters were between 41000-142000, which was consistent with the result of the intrinsic viscosity.DSC results showed that T_m and T_c were gradually reduced with the increase of adipic acid.WXRD test results indicated that with the increase of adipic acid, the crystal structure copolyesters gradually changed from PBA into PBT.DMA results showed that the T_g of copolyesters trended to decrease with the increase of adipic acid.From TGA curves, the initial decomposition temperature of PBAT copolyesters shifted to the high temperature zone, while the thermal stability of the copolyesters closed at high temperature.It was found from the tensile test that the AA/PTA ratio significantly affected the mechanical properties of copolyesters.PBAT7:3 was of the maximum elongation at break, and PBAT3:7 was of strong and tough tensile properties.

Analytically pure carbonate calcium, alumina and dihydrate calcium sulfate were used to synthesize calcium sulphoaluminate(3CaO·3Al₂O₃·CaSO₄, C₄A₃S) at 1375℃ for 2 h.The phase compositions and microstructure were characterized.The effects of carbon alkali concentration, alkali concentration, leaching temperature, leaching time and particle sizes on the alumina leaching properties of C₄A₃S were explored.The results show that the alumina leaching ratio of C₄A₃S increases with the increase of concentration of sodium carbonate and alkali, then trends to stable.The leaching ratio becomes higher when the particle size of clinker decreases.Compared with 12CaO·7Al₂O₃(C₁₂A₇), the alumina of C₄A₃S is easier to be dissolved because of its porous structure, and the alumina leaching ratio is up to 98% under 10 min leaching.The concentration of sodium carbonate and the dissolution temperature of C₄A₃S is lower than that of C₁₂A₇.The alumina leaching ratio of C₄A₃S could reach 98.76% under the optimum conditions:sodium carbonate 80 g·L^-1, alkali 10 g·L^-1, dissolution temperature 80℃ and dissolution time 10 min.

MgO-containing calcium aluminate clinkers doped with Na₂SO₄ were synthesized using analytical grade reagents of MgO, CaCO₃, SiO₂, Al₂O₃, and Na₂SO₄ at 1350℃ for 1 h.The clinkers were studied for leaching performance in sodium carbonate solution, and for crystal structure and self-disintegrating performance by XRD and SEM.Doping Na₂SO₄ improved leaching performance of clinkers.When Na₂SO₄ content was raised from 0% to 4%, Al₂O₃ leaching ratio of clinkers increased from 61.89% to 92.01%.The leaching tended to be stabilized with further increase of Na₂SO₄ dopant.XRD results showed that doping Na₂SO₄ caused phase transformation from 20CaO·13Al₂O₃·3MgO·3SiO₂(Q-phase) to 12CaO·7Al₂O₃(C₁₂A₇).Na⁺ intrusion into C₁₂A₇ lattice forced lattice distortion, which probably promoted Al₂O₃ leaching.Na₂SO₄ dopant also deteriorated self-disintegration of clinkers.When Na₂SO₄ content increased from 0% to 6%, self-disintegrating ratio decreased from 97.46% to 85.34%, respectively.It further decreased to 36.3% for clinker with 10% Na₂SO₄ dopant.

Leakage rate is the premise and basis of leakage mass calculation, leakage duration determination and leak risk assessment.Through building a tank experiment system of liquid hole-leakage for different leak scenes and contrasting the variation of the leakage rate under the interventions of the liquid level control system, an analysis is carried out combined with the calculation of leakage rate model.The result shows that after the response of liquid level control system, the leakage rate reduces slowly and gradually increases as time goes on.Finally, the leakage rate stays in a stable leakage state.The influence of the flow rate on the hole-leakage rate of the tank can be neglected.Hole-leakage rate model of tank based on the actual liquid level control system is built through improving classic formula of tank leakage.The calculation method and the model of high pressure hole-leakage correction coefficient are proposed.By verification, the model can efficiently improve the calculation accuracy under the interventions of the liquid level control system.