Levoglucosenone (LGO) has great applicable value in the field of organic synthesis. The rapid pyrolysis of biomass to produce LGO is a research hotspot in the development and utilization of biomass energy. The application of LGO is mainly limited by its yield: first, it is difficult to prepare LGO by chemical synthesis, and second, the content of LGO in the products obtained by conventional pyrolysis biomass is extremely low, making LGO challenge to produce in large quantities. Catalytic pyrolysis can significantly increase the yield of LGO. Currently, various catalysts which used to prepare LGO, including liquid acid, solid acid, metal chloride and ionic liquid, have achieved evident results, but the effects are individually different. The difference in catalytic effect of various catalysts are analyzed, and a brief conclusion for the challenge in this topic is provided.

With the tight supply and demand of lithium resources and the increasing demand, the recovery of lithium from low-grade or secondary resources such as seawater, waste lithium batteries and fly ash has attracted attention. This review summarized the concentration and distribution of lithium resources in coal and coal fly ash, the technological progress of recovering lithium from multi-component complex system of coal fly ash. This paper also summarized the current methods, materials and reaction mechanisms for recovering lithium from other low-grade resources, which we elaborated from alkaline, neutral and acidic systems. Their feasibility for extracting lithium from coal fly ash was evaluated. The problems and development directions were also analyzed and discussed. The above methods can provide technological reference for recovering lithium from coal fly ash. Finally, we gave a prospect on the recovery of lithium resources from coal fly ash. The synergetic recovery of multi elements from coal fly ash has been highlighted.

Coupling the air dehumidification equipment on the traditional air source heat pump (ASHP) unit to achieve its frost-free continuous high-efficiency and stable operation is conducive to the popularization and application of ASHP in clean heating in low temperature and high humidity areas. Hence, based on the analyses of three types of frosting processes, the principles of various frost-free ASHP technologies were summarized and divided into three categories in the present paper as follows: frost-free ASHP technology with integrated solid desiccant dehumidification, frost-free ASHP technology coupling with liquid desiccant dehumidification, other frost-free ASHP technologies. Then the research status of the first two frost-free ASHP technologies was reviewed, respectively. Finally, the problems and limitations of these frost-free technologies were pointed out, and the research recommendations of various methods and their development priorities under different environmental conditions were given, respectively. Meanwhile, it was suggested that all aspects of researches affecting the investment cost and operation performance of frost free heat pump system should be mainly carried out, and thereby develop the multi-functional frost free ASHP technology with high performance and small regional restrictions in the future.

The rapid development of urban modernization and industrialization has caused increasingly serious pollution to the environment, especially water contamination. In recent years, the content of pharmaceuticals in industrial wastewater has increased year by year, and the pollution should not be ignored any more. Therefore, the development of new porous materials for the adsorption and separation of pharmaceutical molecules in wastewater has become a current research hotspot. This article summarizes the recent research on the adsorption and separation of pollutants in wastewater by biomass-derived porous carbons (biochars). First, it briefly introduces the treatment methods of pollutants in wastewater, and mainly focuses on the preparation and modification of biochars. Combined with the surface chemical properties and pore structure of the carbon materials, this paper summarizes and prospects the adsorption properties of biochar to pharmaceuticals.

Leakage of supercritical CO₂ long-distance pipelines may cause significant accidents such as pipeline fracture propagation, human injury and medium loss. Therefore, it is of great significance to further study the variation of thermodynamic parameters in the process of pipeline leakage. At present, there is insufficient research on the leakage characteristics of supercritical CO₂ pipelines, and it is necessary to conduct a detailed literature review and analysis. This paper introduces the research background and significance of CO₂ pipeline leakage characteristics. The experimental, theoretical analysis and numerical simulation of the decompression process, near-field jet expansion and far-field diffusion of CO₂ pipeline at home and abroad are reviewed in detail. Finally, this paper summarizes the current research deficiencies of supercritical CO₂ pipeline leakage characteristics, and prospects the future research direction.

Solid-liquid equilibria of the aqueous quaternary system MgCl₂-SrCl₂-AlCl₃-H₂O at 298.2 K was studied by using the isothermal dissolution equilibrium method. The solubility, density, and refractive index of the aqueous quaternary system were measured. The corresponding space diagram, stable phase diagram, water content diagram, and the diagrams of density vs composition, refractive index vs composition were constructed based on the experimental data. The results show that there is no double that salt or solid solution was formed in the quaternary system. The stable phase diagram of the quaternary system MgCl₂-SrCl₂-AlCl₃-H₂O at 298.2 K consists of two invariant points, five isothermal dissolution curves, and four crystallization regions. The four crystallization regions correspond to four single hydrate salts magnesium chloride hexahydrate (MgCl₂·6H₂O), strontium chloride hexahydrate (SrCl₂·6H₂O), strontium chloride dihydrate (SrCl₂·2H₂O), and aluminum chloride hexahydrate (AlCl₃·6H₂O). With a view to the crystallization regions, the crystallization region of salt SrCl₂·2H₂O is the smallest, while the crystallization region of salt SrCl₂·6H₂O is the largest, meaning SrCl₂·6H₂O can be more easily separated from solution than other coexisting salts in this system at 298.2 K. The densities and refractive indices of the solution at equilibrium change regularly with the change of J(MgCl₂) of the solution. The Pitzer model is used to calculate the solubility of the 298.2 K quaternary system MgCl₂-SrCl₂-AlCl₃-H₂O. The comparison found that the calculated results are basically consistent with the experimental results.

The study observed the shape of the droplet on the surface of the horizontal metal fiber in the gravity field by building a visual test bench. The geometry parameters including droplet diameter, height, contact angle, width of contact line and height of contact line were measured. By fitting the correlations of these geometry parameters, the description equations of solid-liquid interface and gas-liquid interface were solved and an ellipsoidal droplet shape model on metal fiber was developed. The predicted shapes of droplet model are in good agreement with the droplet images obtained from the observation experiment. The predicted results can describe 98% of the experimental results within the deviation limit of ±10%, and the mean deviation is 4.6%.

Modified graphene/deionized water (DW) based amphiphilic nanofluid (A-nanofluid) without surfactant was prepared through chemical method. The thermal performance of solar gravity heat pipe (SGHP) with A-nanofluid was investigated under different heating powers, incline angles and concentrations. It was found that A-nanofluid can reduce the start-up temperature of the SGHP compared with DW. Within the measured range of heating power, the thermal resistance of the SGHP filled with A-nanofluid is obviously lower than that with DW when the heating power is relatively small. However, the difference of thermal resistance of the SGHP filled with A-nanofluid and DW is almost negligible with the increase of heating power. The incline angle has great influence on the heat transfer capacity of the evaporation section when the incline angle is relatively small. When the heating power is 20 W and the nanofluid concentration (mass ratio) increases from 0.1% to 0.6%, the heat transfer coefficient of the evaporation section decreases by 54.7%; when the heating power is 40 W, the nanofluid concentration (mass ratio) increases from 0.1% to 0.6%, the heat transfer coefficient of the evaporation section decreases by 48.9%.

The traditional multilayer rigid impeller has large dead zone for the mixing of pseudoplastic non-Newtonian fluid, stable flow field interface and low mixing efficiency. A method for enhancing the chaotic mixing of non-Newtonian fluid by multilayer rigid-flexible impeller induced flow field interface instability was proposed. In the experiment, sodium carboxymethylcellulose was used as the non-Newtonian fluid system. The power characteristics were measured by the torque sensor. The mixing time was determined by the acid-base neutralization and decolorization method. The largest Lyapunov exponents were calculated by using Matlab software programming. The chaotic characteristics and mixing performance in the mixing process are analyzed. The results show that when the combination mode was RF-(PBTD+PBTD+DT), the impeller arrangement mode θ=60°, and the flexible sheet length installation ratio r=0.8, 1.2, the degree of chaos was higher and the mixing performance was better. Multilayer rigid-flexible impeller can generate multiple spiral flows, and realize the flow field interface instability under the disturbance frequency difference of the flexible sheet between the layers, the stirring dead zone was reduced, and the system enters a chaotic state at a lower speed (when the multilayer rigid-flexible impeller system N>88 r/min, LLE>0; when the multilayer rigid impeller system N>125 r/min, LLE>0). At the same speed, the mixing rate and power per unit volume of the multilayer rigid-flexible combined impeller are higher than that of the multilayer rigid impeller, but the mixing energy per unit volume is approximately the same.

Steam injection in horizontal wells for thermal recovery of heavy oil is a complex and changeable process. The prediction of thermal properties of steam along horizontal wells is critical to the uniform production of reservoirs. In this paper, considering the mutual coupling effects of reservoir permeability, confining pressure, and steam phase transition, a comprehensive mathematical model for predicting steam injection flow in horizontal wells was established. Compared with the on-site logging data, the accuracy of the model was verified. The simulation results show that under a single variable condition, the larger the steam injection pressure at the heel, the faster the mass flow and steam dryness decrease. When the steam injection pressure drops from 11 MPa to 8.5 MPa, the steam distribution distance doubles. At the same position, the higher the steam dryness at the heel, the greater the mass flow in the steam injection well, and the faster the steam pressure decrease. Double the steam injection dryness, the pressure drop is almost doubled, but the longer steam injection distance. The larger the steam injection flow at the heel, the faster the steam pressure decreases, and the decrease in the steam dryness in the tube slows down. When the steam injection flow increases by 1.75 times, the pressure drop increases by 5.3 times. The higher the reservoir permeability, the faster the steam dryness decreases. By obtaining the general rules of steam distribution in horizontal wells to provide theoretical support for on-site steam injection, the steam distribution effect can be effectively improved to increase production and reduce consumption.

Evaporative phase transitions are widely present in industrial production and daily life such as thin film processes and crystal growth. The evaporation of the liquid layer and the thermocapillary convection affect each other and restrict each other, making the energy transfer mechanism of the evaporation interface very complicated. To understand the evaporation characteristics of water in its low-pressure pure vapor environment, a series of experimental studies were carried out on the temperature distributions and evaporating rate of water evaporation in the annular pool. The cylinder temperature of the annular liquid pool is controlled between 3℃ and 15℃, and the evaporation environment pressure ranges from 394 Pa to 1467 Pa, when the temperature measurement starts, the depth of water is 10 mm. The results show that the temperature of the vapor side on the liquid-vapor interface is higher than that of the liquid side and there is an obvious temperature jump across the vapor-liquid interface. With the decrease of the pressure ratio, the evaporation rate increases, and the interface temperature jump is enlarged. Meanwhile, with the increase of the distance from the cylinder, the local evaporation rate decreases, thus, the temperature jump decreases. At the same pressure ratio, as the cylinder temperature increases, the heat flux from vapor side decreases, the temperature jump decreases at all measurement points. Within the experimental controlled parameters, the maximum temperature jump obtained in the measurements is 2.56℃. Due to the coupling effect of evaporation cooling and thermocapillary convection, there is a uniform temperature layer with a thickness of about 2 mm under the evaporation interface. The thickness of the uniform temperature layer near the cylinder is always larger than that in the middle of the evaporation interface. In the uniform temperature layer, the thermocapillary convection induced by radial temperature gradient transfers heat from the cylinder to the liquid-vapor interface to compensate for the latent heat of evaporation. Below the uniform temperature layer, the temperature rises rapidly due to heat conduction and buoyancy convection.

The flat micro heat pipe array photovoltaic-thermal module was retrofitted into a photovoltaic-thermal evaporator, and then a novel solar energy and air dual-heat-source heat pump system was developed. The operation performance of the system operating in the solar energy mode (S) as well as the solar energy and air dual-heat-source mode (SA) was studied in detail. Studies have shown that: affected by solar radiation and ambient temperature, the role of ambient air in the dual heat source heating mode will switch between heat release and heat absorption, and the temperature difference between ambient temperature and backplane temperature fluctuates between -3.1—3.5℃; the SA mode was suitable for low solar radiation condition, and its thermal efficiency, comprehensive performance efficiency and COP were 56.7%, 81.7% and 2.38 respectively, which were 20.3%, 25.0% and 6.7% higher than that of the S mode; under the high solar radiation condition, the SA mode would accelerate the heat dissipation of the system, but it could improve the electrical performance of the system. According to the above characteristics, it would get the better operation performance operating in SA mode when the backplane temperature was lower than the ambient temperature as well as operating in S mode when the backplane temperature was higher than the ambient temperature.

Considering the influence of swirl attenuation, the pressure drop characteristics of gas-liquid spiral annular flow are studied, and the pressure drop prediction model of spiral annular flow is deduced. The swirl-straight ratio of pressure drop is defined as the ratio of pressure drop of swirl flow to straight flow, used to characterize the effect of swirl decay on pressure drop. The expression of swirl-straight ratio of pressure drop is derived by the method of dimensional analysis, and it has a strongly dependence on Lockhart-Martinelli coefficient and gas phase Froude number. Finally, the prediction model of pressure drop for gas-liquid swirl annular flow is obtained. The pressure drop characteristics of the swirl annular flow are experimentally studied in a horizontal tube with an inner diameter of 50 mm. The range of the gas superficial velocity is 10—16 m/s and the range of the liquid volume fraction (LVF) is 0.6%—4.8%. Through comparison with experimental data, the relative error of the pressure drop prediction model is within ±15%, which provides a method reference for engineering applications.

The axial differential pressure and radial differential pressure can be generated by phase-isolation method. Once measuring the radial differential pressure between the pipe wall and pipe center of a cross section downstream of the swirler, the mass flowrate and phase holdup can be determined if either of the two parameters was known. If axial differential pressure also has a certain relationship with the mass flowrate and phase holdup, then multiphase flow double-parameter metering can be realized by dual differential pressure (the axial differential pressure and the radial differential pressure). Taking oil-water two-phase flow as an example, the mechanism of axial differential pressure used in multiphase flow measurement was studied and the experimental verification was carried out. The results show that the axial pressure difference between certain two sections downstream of the cyclone is a certain function of the total flow rate and volume oil content of the oil-water two-phase flow under the state of phase separation in the pipe. The relative error between the experimental value and the theoretical value of the two is within ±1.05% and ±9.84% respectively. Besides, the mass flowrate and oil cut can be determined by dual differential pressure with the relative errors are within ±1.13% and ±6.89% respectively, which verified the application feasibility of dual differential pressure used in multiphase flow double-parameter metering based on phase-isolation.

The frosting laws of three kinds of wettable surfaces under different magnetic field strengths were studied under cold surface temperature T_w=-10℃ and -30℃, environmental relative humidity RH=60% and 80%. Through visual observation method,image binarization is processed and calculated,the effect of frost morphology,water droplets diameter,water droplets crystallization time,water droplets coverage,frost crystal coverage,frost layer thickness and frost density under the different magnetic field intensity and surface contact angle are well explained. The results showed that adding magnetic field in combination with hydrophobic surface,the diameter of water droplets decreases by about 40%, and the crystallization time is prolonged by more than 500 s,the distribution of condensate droplets is more sparse. Frost thickness and frost density decrease as the increase of magnetic field strength and surface contact angle,providing possibility of restrain the frosting effectively. As the temperature of the cold surface decreases and the relative humidity increases, the influence of the surface properties and the external magnetic field on the frosting process decreases.

A kapok fiber (KF) modified graphite phase carbon nitride (g-C₃N₄) catalyst was prepared by a one-step pyrolysis method, and the photocatalytic degradation of organic pollutants was investigated. The structure and optical properties of KF-CN were characterized by XRD, UV-Vis DRS, TEM, PL, XPS, FT-IR and N₂ adsorption-desorption. The nitrogen adsorption-desorption isotherm results show that the presence of the mesoporous structure can improve the specific surface area of KF-CN. Elemental analysis characterization indicates the biochar modification is conductive to increase the C/N ratio of KF-CN. The XPS characterization also indicates that the introduction of carbon element can change the chemical environment of N element in the lattice of g-C₃N₄ and thus increases the electron density of N element. The photocatalytic degradation of phenol experiment was carried out to investigate the performance of as-prepared kapok fiber modified graphite carbon nitride photocatalysts by using high-pressure sodium lamp as visible light source. The results show the KF(5%)-CN(600) displayed the highest phenol degradation rate constant of 0.259 h^-1, which is 4.2 times of that of neat g-C₃N₄.The activity of KF(5%)-CN(600) does not decrease significantly after 5 cycles, hinting its excellent catalytic stability and structural stability. The possible reaction mechanism was proposed.

Lignin is the most abundant renewable aromatic polymer in nature and has the potential to replace or partially replace petroleum for the production of bulk chemicals. However, due to the complex molecular structure and chemical bond connection of lignin, the current comprehensive utilization of lignin generally has problems such as low target product selectivity. Therefore, the development of novel catalysts plays a significance role in the utilization of lignin. Herein, a novel and efficient polyoxometalate ionic liquid (POM-IL) catalytic system was provided for the conversion of lignin to diethyl maleate (DEM), a universally used biochemical, through the selective cleavage of the C—O bond and benzene ring of lignin in the ethanol solvent. 4-Methoxy-α-[(2-methoxyphenoxy)methyl]-benzenemethanol, a representative lignin model compound containing b-O-4 linkage, is used as the feedstock. Over [BSmim]CuH₂PMo₁₀V₂O₄₀, 98.5% of the lignin model compound can be converted at 180℃ for 5 h, affording 84.3%(mass) yield and 62.2% selectivity of DEM. Furthermore, this POM-IL could be handily recovered through self-separation with temperature control. Moreover, the catalyst of [BSmim]CuH₂PMo₁₀V₂O₄ shows good recyclability, where a satisfactory DEM yield is demonstrated even after six consecutive runs. Moreover, a plausible pathway for this process was proposed. Therefore, this work provides a new route for the selective conversion of renewable lignin to bulk petrochemicals.

Using wet impregnation method to mimic alkali metal poison of ammonia-selective catalytic reduction (NH₃-SCR) catalysts, Cu-based micropore zeolites Cu/SSZ-13 and Cu/SAPO-34 with different Na contents(mass fraction) were prepared, and the Na poisoning mechanism on them was studied. The results show that the externally introduced Na ions can severely affect the NH₃-SCR catalytic activity of the two catalysts, resulting in the collapse of the crystal structure of the catalyst, the decrease of acidity and the reduction of active species. In detail, when Na content was less than 1.82%, Cu/SAPO-34 has higher resistance of Na ions than Cu/SZZ-13; while when Na> 3.48%, Cu/SAPO-34 catalysts almost deactivated thoroughly. By structural characterization (BET, XRD and SEM) and acidity characterization (DRIFTS, NH₃-TPD and H₂-TPR), it was found that with Na poisoning deeper and deeper, Cu/SSZ-13 took a gradual style of the structural destruction, but Cu/SAPO-34 adopted a sudden way. Studies on the mechanism of Na poisoning show that the decrease of acid sites is the main reason for the decrease of SCR activity of Cu/SSZ-13, and the structural collapse is the main reason for the decrease of SCR activity of Cu/SAPO-34.

Catalytic wet air oxidation (CWAO) technology can efficiently treat organic wastewater, but the performance of existing catalysts, especially its stability, is far from industrial applications. In this study, ZrO₂ was used to modify TiO₂ support to form the stable Ru/TiO₂-ZrO₂ catalysts. It was found that the Ru/TiO₂-ZrO₂ catalysts showed excellent performance for catalytic wet air oxidation of phenolsulfonic acid wastewater. They gave high total organic carbon (TOC) conversions (>90%) and remained stable in 5 consecutive running in the Ti/Zr ratio range from 9∶1 to 7∶3. On the other hand, TOC conversion decreased from 99.1% to 65.3% in 5 consecutive cycles for the conventional Ru/TiO₂ catalyst. The characterization results of XRD, BET, XPS, H₂-TPR and ICP-OES indicated that ZrO₂ can enter the lattice of TiO₂ to form TiO₂-ZrO₂ solid solution, which prevented the transformation of TiO₂ from anatase to rutile. In addition, the modification of ZrO₂ strengthened the interaction between Ru and the support, which effectively inhibited the leaching of Ru metal. The stable support structure and good anti-loss performance are the main reasons for the excellent reaction performance of Ru/TiO₂-ZrO₂ catalyst.

The micro fluidized bed reaction analyzer (MFBRA) was used to study the combustion characteristics of oil shale mineral catalytic semi-coke. This study compared the effect of minerals inside char and bed material (oil shale ash) outside char on char combustion, and the process and mechanism of char combustion in the fluidized bed were further revealed. Both of minerals inside char and bed material outside char had a marked catalysis for char combustion and their combined catalysis was most notable. It is found that the CaO and Fe₂O₃ were the major active components in oil shale minerals for catalytic combustion of char, and the catalysis of CaO was stronger than that of Fe₂O₃. The activation energy of char combustion ranged from 60.41 kJ/mol to 78.97 kJ/mol, and it would significantly decrease with presence of the catalysis by minerals in oil shale. For char combustion in a fluidized bed, the contribution of minerals to catalytic combustion was mainly reflected in four reactions, such as volatiles cracking and combustion, surface carbon combustion, internal carbon combustion and CO combustion.

Nitrogen oxide (NO_x) is one of the major air pollutants. Using a copper-based zeolite with a chabazite structure (CHA) as a catalyst, the selective catalytic reduction (SCR) technology can effectively remove NO_x. This work introduces a low silica CHA type zeolite with structural defects (zeolite Phi, with Si/Al of 4.7). The zeolite Phi is synthesized through a hydrothermal method without adding any template, which is low-cost and environment-friendly. The Cu-exchanged Phi is abundant of surface acidity and isolated Cu²⁺, showing a superior low-temperature activity, a wide work temperature window and a good hydrothermal stability. The presence of Na or Mg decreases the surface acidity and isolated Cu²⁺. The hydrothermally aged Na,Cu/Phi and Mg,Cu/Phi present different levels of framework collapse, which correspondingly induces catalyst deactivation.

Magnetic manganese ferrite (MnFe₂O₄) prepared by the salt-assisted solution combustion synthesis was used to activate peroxymonosulfate(PMS) to oxidize bisphenol A in aqueous solution. The prepared MnFe₂O₄ catalyst was characterized by XRD and BET. The effects of MnFe₂O₄ dosage, PMS dosage, initial pH of the solution, quencher, and co-existing ions on the degradation of bisphenol A were investigated. The reusability of the MnFe₂O₄ catalyst was evaluated through cycling experiments. The results showed that the best dosages of MnFe₂O₄ and PMS were 0.3 g/L and 0.3 mmol/L, respectively. When the initial pH was 11.0, the degradation rate of bisphenol A was 99.3% in 60 min. When putting some quenchers into the MnFe₂O₄/PMS catalytic system, all of them showed depression effects on degradation of bisphenol A, and the ¹O₂ was the main active species. The co-existing ions such as Cl^-, HCO₃^-, and HPO₄^2- in solution affected the degradation of bisphenol A. The TOC removal rate of bisphenol A within 60 min was 34.9%, the rupture and opening of benzene ring are the main reaction pathways. After the MnFe₂O₄ catalyst was recycled three times, the degradation rate of bisphenol A remained at about 90.0%.

To solve the problem of CO₂ uncompleted desorption in the process of CO₂ displacement enhancing the adsorption separation of CH₄/N₂, a small amount of product gas CH₄ was used as purge gas to improve the CO₂ desorption. CH₄/CO₂ mixture gas obtained from desorption step was recycled as the displacement gas to enhance the enrichment of low-grade methane in nitrogen mixture. In this work, the research conducted the experiments for CH₄/N₂ separation using CH₄/CO₂ displacement intensification adsorption and the laboratory-made coconut shell activated carbon as sorbent. The mathematical models were built in gPROMS and the accuracy of models was verified by comparison of simulations and CH₄/N₂/CO₂ breakthrough experiments. The performance of enrichment of low-grade methane with displacement intensification using different displacer was compared. The result showed that the process with CH₄/CO₂ displacement had higher purity product than CO₂ displacement. The CH₄/ CO₂ mixed gas replacement enhanced vacuum pressure swing adsorption cycle experiment was carried out, which can jointly enrich 14% CH₄/ N₂ and 53% CH₄/CO₂ to 98.8%, and at the same time obtain a recovery rate of 77.8%.

Fibrous coalescing filters are widely used in a series of processes such as compressed air purification, engine crankcase ventilation, processing and cutting, and are used to remove liquid aerosol particles in the airflow. Pressure drop and ef?ciency of coalescence filters are greatly affected by saturation. It is of importance to establish the relationship among saturation, filter media parameters and operating conditions, which is helpful to optimize the filter design. Coalescence ?lters composed of thin glass fibrous media with micron fiber diameters are widely used in industry, while the saturation of which cannot be accurately predicted by the existing saturation models. This work investigated the relationship between pressure drop and saturation of multi-layered filters with different oleophilic filter media. In this study, there was no sharp boundary between wetting and non-wetting regions within filter media, thus a filter was regarded as a whole capillary system. According to the Jump-and-Channel model and capillary theory, a saturation model was developed. Compared with a large number of published literature data, it is found that when the saturation value is greater than 0.2, the predicted value is in good agreement with the experimental results, and the relative deviation is ≤20%. With the decrease in saturation, the boundaries become more and more obvious between the wetting and non-wetting regions. In this case, there is no need to modify to the capillary radius in the developed model. However, the developed model was also limited by the need for the channel pressure drop measurement, which should be solved in further work.

SO₂ in the flue gas has high recovery value. In the process of adsorption purification of flue gas, condensation method can be applied to purify SO₂ in the desorbed gas into high-purity liquid product. In this paper, an experimental study on the recovery of SO₂ with condensation method was carried out by using the SO₂-rich desorbed gas as the feed gas with the concentration of 7%—12% in Handan Steel sintering machine desulfurization process. The effects of process parameters such as the SO₂ concentration of the feed gas, condensation pressure and temperature on the recovery rate and the SO₂ concentration in the exhaust gas from the outlet of the condenser were investigated. The results show that the recovery rate increases with increasing SO₂ concentration in the source gas and condensation pressure, and decreasing condensation temperature. The SO₂ concentration in the exhaust gas is a -1 power function of the pressure, and decreases exponentially as condensation temperature decreasing. The highest possible inlet SO₂ concentration should be used as the design basis for the condenser. In practice, the reasonable upper limit of pressure should be determined in conjunction with the expected recovery rate, and the strategy of reducing condensation temperature at low-pressure level for increasing the SO₂ recovery rate should be adopted. The research results can provide reference for the resource utilization of SO₂ in the process of flue gas adsorption and desulfurization.

The silkworm waste from the silkworm was selected as the carbon source, and ZnCl₂ and FeCl₂ were used as activators to obtain a Fe-doped highly graphitized porous biochar material Fe/Z-ASE through a one-step synthesis method. The fabricated Fe/Z-ASE was tested for the adsorption and sustained-release kinetics of pheneylethanol and anisole while their mutual interaction and intermolecular interactions were evaluated by quantum chemical calculation. The silkworm feces exhibited a well-developed pore structure, high surface graphitized carbon content, high BET surface area (950.9 m²/g), more than 60% mesopores and uniform distribution of Fe. Fe/Z-ASE exhibited hydrophobic surface and weak polarity, while anisole realized higher adsorption capacity (510 mg/g) and diffusion rate of 1.7×10^-2 min^-1 than that of phenylethanol under variable anisole adsorption amounts (150—510 mg/g). Density functional simulations suggested anisole and phenylethanol as weak bases and hence interacted with the weakly acidic adsorption sites (Fe-C) on the Fe/Z-ASE, while the relatively higher basicity of anisole endorsed it stronger interaction with Fe/Z-ASE. Molecular dynamics analysis showed strong hydrogen bonding between pheneylethanol molecules while no such interaction existed among anisole molecules, which hindered the desorption of pheneylethanol molecules under high initial adsorption capacity as compared to those of anisole.

Hydrophobic nanogels were synthesized by emulsion polymerization method under ultrasound using butyl methacrylate as the monomer. Then, anion exchange nano-cryogels embedded with the obtained nanogels were prepared by cryo-polymerization using poly(2-hydroxyethyl methacrylate) as the monomer, followed by a graft polymerization with the monomer (vinylbenzyl) trimethyl ammonium chloride. The anion exchange nano-cryogels were used to isolate phenyllactic acid from biotransformation broth. The results show that the obtained nanocrystalline gel has good permeability and axial dispersion performance. When the flow rate is 1 cm·min^-1, the adsorption capacity of different ratios of nanocrystalline gel for bovine serum protein is 3.9—5.4 mg·ml^-1. When the nano-cryogel with mass ratio of 8∶2(HEMA∶pBMA) was used to isolate phenyllactic acid from transformation broth, phenyllactic acid with high purity of 89.24% and recovery of 93.74% was obtained, indicating that the nano-cryogels could have potential applications in bioseparation.

Gas-liquid coalescing elements are widely used in industrial fields such as compressed gas purification. Currently, the performance of coalescing elements is difficult to meet the growing needs of the industry. However, while increasing the filtration efficiency of the coalescing element, the resistance will increase simultaneously, which is not conducive to the optimization of the comprehensive performance. To develop low-resistance high-efficiency coalescing elements, the coalescing filter materials are modified by different concentrations of fluorosilicone acrylate solution. The evolution of pressure drop, filtration efficiency and secondary entrainment of the filter materials with different surface energy during the gas-liquid filtration process were analyzed, the modified filter materials were fabricated into coalescing filters for verification. The results showed that, the filtration efficiency of the modified filter materials was increased by approximately 10%, and the steady-state pressure drop was reduced by approximately 30%. The decrease in jump pressure drop caused by changes in the surface properties of the filter materials is the main cause of the decrease in steady-state pressure drop. The increase in filtration efficiency is caused by the enhancement of diffusion and inertial separation, and the reduction of secondary entrainment. For oleophobic filter materials with different surface energy, the pressure drop and filtration efficiency increase with the decrease of surface energy. The quality factor of the coalescing filter element can be increased by up to 92% after modification.

The performance of the traditional nonlinear fault detection method based on kernel mapping is greatly influenced by the type of kernel function and the tuning of kernel parameters. To solve this problem, a method named nonlinear dynamic global-local preserving projections(NDGLPP) is proposed for nonlinear process fault detection. Firstly, dynamic global-local preserving projection algorithm is used to reduce the dimension of data matrix. Since the second order polynomial mapping is established for the reduced dimension matrix to extract the relevant properties of nonlinear space. Then the two steps are iterated to obtain the higher-order nonlinear mapping. Finally, the proposed method is applied to the ethylene distillation process and Tennessee Eastman (TE) process simulation to verify the effectiveness and feasibility of the detection method.

The control system of chemical enterprises is becoming more and more complex, and identifying the controlled object model is the primary task of automatic control and optimization design. In view of the problem that most chemical process identification experiments need to apply test signals to the process, which may lead to production interruption or safety accidents, a long short-term memory(LSTM) nonlinear dynamic model identification algorithm combined with attention mechanism is proposed to adapt to plant time series data with characteristics of high dimension, strong coupling and nonlinearity. Based on LSTM model, the algorithm considers the importance of the input variables to the target variables, pays more attention to the key features that affect the output results in the input sequence, and improves the generalization ability of the LSTM model. The LSTM network model based on the daily operation data of the plant can be used as the digital virtual device of the identified object, and the local linear model can be identified offline on the virtual device by using the designed test data. The identification experiments on Tennessee-Eastman (TE) process verify the effectiveness of this method.

Accurate and reliable measurement of the effluent quality indicators of wastewater treatment plants is the key to successful control and optimization of wastewater treatment plants. Due to the complexity of the operation and the delay of laboratory analysis, it is difficult to achieve real-time control of effluent quality. In order to improve the accuracy and reliability of the estimation, this paper proposes a method of stochastic configuration network based on partial least squares (PLS-SCN). In order to overcome the forecast risk caused by high dimensionality and multicollinearity of the input data, the partial least squares(PLS) is embedded into the stochastic configuration network(SCN) framework replacing the classic ordinary least squares (OLS). The PLS-SCN method extracts the main latent variables that affect the effluent quality from the output of the hidden layer, and enhances the generalization performance through orthogonal projection operations. The simulation results of the effluent quality index of a municipal sewage treatment plant show that the PLS-SCN network has a good input and output relationship, and its performance is better than traditional SCN and PLS, and it can quickly and reliably estimate the sewage quality.

The time and economic cost of obtaining difficult-to-measure quality or environmental pollution indices data for complex industrial processes are very high, which leads to the scarcity of labeled modeling samples. Aimed at this problem, a new virtual sample generation method based on improved megatrend diffusion and hidden layer interpolation is proposed. It is applied to the dioxin (DXN) emissions prediction of municipal solid waste cineration process. First, the true sample input/output sample space is expanded by using improved megatrend diffusion technology (MTD) based on the sub-regional Euclidean distance. Next, the virtual sample input is generated using an equal interval interpolation method, and the virtual sample output is obtained by combining the mapping model and the pruning mechanism. Then, the hidden layer interpolation method based on the improved random weight neural network with regularization mechanism is used to obtain the virtual sample output and input, and the virtual sample is deleted by combining with the expansion space. Finally, the above-mentioned complementary input/output virtual samples are mixed with the original true samples to realize the expansion of the modeling data capacity. The validity and rationality of the proposed method are verified by benchmark data set and industrial process DXN data.

Soft-sensing modeling can effectively solve the problems of large measurement lag, high price, and complex maintenance of online analytical instruments in the production process. At present, neural network based on data-driven is one of the main tools of soft sensor. In the process of modeling data collection, the collection of dominant variables is much more difficult than that of auxiliary variables, resulting in a large amount of unlabeled data. However, traditional soft sensor modeling methods ignore these unlabeled data and only use a small amount of labeled data for modeling, which has negative effect on the prediction accuracy of the model. To solve the problem of label missing, the nearest neighbor algorithm is used to pseudo label the unlabeled data. At the same time, a network structure is designed by combining convolution operation and gated recurrent unit neural network (GRU) to further utilize the unlabeled data, extract the dynamic feature from data at different time, and improve the prediction accuracy of the neural network. Finally, the method is applied to the prediction of propane concentration on the top of propylene distillation column. The results show that the model can solve the problem of label missing in the nonlinear dynamic system and has higher prediction accuracy.

Organosilicon monomer fractionation process needs to separate many substances and the separation requirements are high, leading to high energy consumption. The modeling of energy consumption is of great significance to the optimization of fractionation process. Although the type of equipment and operating conditions of each purification unit in the fractionation process are different, each purification unit has certain similarity according to the dynamic characteristics of the distillation process. Therefore, making full use of these similarities in modeling can reduce the cost of data acquisition in the modeling process. By introducing the transfer learning algorithm, the similarity between the data domains of the source unit and the target unit is increased, the knowledge transfer in different data domains is realized, the knowledge contained in the existing data is fully utilized, and a new energy consumption model is established. Finally, the simulation experiment was carried out with the field data of an organosilicon factory, and the results showed that when the sample size of target domain is little, the transfer learning can effectively improve the performance of the model, so the effectiveness and the practical application of the algorithm were verified.

Aiming at the Rayleigh step configuration, the finite element method is used to solve the Reynolds equation based on the JFO cavitation boundary conditions to establish a hydrodynamic lubrication numerical model. Film pressure and density ratio distributions of the Rayleigh step (RS) and reverse Rayleigh step (RRS) are compared. Liquid film cavitation capacity in RRS is evaluated under the different geometrical structures and operating conditions. Cavitation suction mechanism in the mechanical seal with RRS is developed and its sealing performance is comparably analyzed to evaluate the cavitation suction effect. The results show that cavitation occurs fully in the main groove zone of RRS under proper structure design with considering operation conditions, and its mechanical seal has good cavitation suction effect to achieve zero leakage or reverse suction of sealed medium.

To study the influence of multiple factors on the characteristics of electrochemical water softening, an orthogonal experiment method was used to quantitatively analyze the mechanism of the influencing factors. The optimal combination scheme of electrochemical water softening was obtained. Five factors and five levels were selected for orthogonal experiments, and the time of experiments was reduced from 5⁵ to 25. The results showed that the concentration was the most significant factor affecting the experimental results. The best combination schemes are A₃B₂C₁D₄E₃ and A₂B₅C₃D₁. At a voltage of 10 V, when the spacing is less than 125 mm, the amount of scale ion removal per unit energy consumption increases as the spacing increases. When the spacing is greater than 125 mm, the removal amount of scale ion per unit energy consumption decreases with the increase of the spacing. When the voltage exceeds 10 V, it can increase the proportion of ion removal per unit energy consumption and reduce energy consumption because of the use of high-frequency power. Reducing the voltage is an important way to increase the amount of descaling per unit energy consumption. The research results can provide a basis for the structural optimization and parameter control of electrochemical water softening characteristics as well as the selection of the power supply of the electrochemical softening water device.

A gas-heating laboratory transport bed was adopted to simulate the industrial transportbed reactor for flash calcination of magnesite, and a method based on TG analysis of a reacted sample was further developed to calculate the decomposition rate or conversion of its containing MgCO₃. The study investigated how the conversion and product reactivity as well as microstructure vary with reaction conditions including temperature, particle size and times of re-calcination for powder magnesite. Magnesite powder (<150 μm) calcination is a quick reaction that reaches 98% decomposition of its containing MgCO₃ in 1—2 s,corroborating the feasibility of magnesite flash-calcination in transport bed reactors. The coloration time given by the citric acid chromogenic method was 17—55 s and 294 s for the obtained products from transport and fixed beds, respectively. This proves the obviously higher activity and thus improved microstructure of the product from transport bed. During the calcination process, the MgO grain size of the product gradually increases, and the surface structure changes from loose and porous to dense and smooth. This structural change can be completed within a few seconds.

To solve the problem that the hydrogen partial pressure in the anaerobic fermentation system limits the hydrogen diffusion rate among species, porous metal materials derived from the metal-organic framework ZIF-8 are used to promote the anaerobic fermentation of ethanol to produce methane, and the mechanism for enhancing the electron transfer between microorganism species is explored. Scanning electron microscopy (SEM) shows that ZIF-8 derived porous carbon plays immobilized role of microbial communities and promotes nanowires generation. The results show that the methane yield and the maximum methane production rate increase with an increase of ZIF-8 derived porous carbon addition. When 200 mg/L ZIF-8 derived porous carbon is added, the system conductivity increases by 3.58-fold. Moreover, three-dimensional fluorescence spectroscopy analysis (3D-EEM) showed that ZIF-8 derived porous carbon promotes the relative content of fulvic acid in extracellular polymeric substance (EPS) from 18.0% to 23.6%, corresponding to methane yield and maximum methane production rate increasing by 18.81% and 19.04% respectively.

The decomposition of natural gas hydrates is a phase change process, which involves the consumption and conversion of various forms of energy, such as electrical energy, chemical energy, and thermal energy. In order to evaluate the economy capacity of natural gas hydrates exploitation, an exergy model was established to calculate the energy efficiency ratio (EER) of hydrate production method. The CO₂ replacement method is taken as a case study to introduce the calculation equation and flow chart of energy efficiency ratio in any production period. The amount of CO₂ injection, gas production and mole fraction of methane in produced gas are three key parameters in the process of CO₂ replacement. The ratio between the amount of gas production and CO₂ injection is defined as production injection ratio to eliminate the influence of deposit size. This work studied the influence of production injection ratio and the mole fraction of methane in produced gas on EER. The results show that the EER of gas hydrates production by CO₂ replacement is between 0.31 and 6.4 under the set conditions, and it increases with the increase of production injection ratio. In addition, increasing the mole fraction of methane in produced gas can reduce the energy consumption for gas separation and increase EER. Therefore, there are two effective ways to increase EER of CO₂ replacement through controlling the amount of gas production and the mole fraction of methane in produced gas. The EER model is established to provide guidance for the optimization of gas hydrate mining process.

Based on computational particle fluid dynamics (CPFD), a three-dimensional bubbling fluidized bed steam-air mixed gasification numerical model was established, and it was verified with experiment trials. The results show that the simulation and experiment have good consistency. Based on the model, the gas distribution and temperature distribution in the gasifier were studied; meanwhile, the biomass properties (particle size, water content, types) and operating conditions (gasification temperature, bed height) were investigated. The results show that there is an optimal value for the impact of biomass particle size on gasification performance, with an average particle size of 0.6 mm being the best; a higher water content will reduce the output of combustible gas and is not conducive to the gasification reaction. Among the four types of biomass, sawdust gasification has the highest efficiency, the largest combustible gas production, and the highest gas calorific value. Rice husk is second only to sawdust but its carbon conversion rate is higher than that of sawdust; increasing the gasification temperature can increase the proportion of combustible gas and increase gasification efficiency; while the change of initial bed height can change the ratio of H₂/CO. This experiment provides a theoretical reference for biomass steam/air gasification, which is helpful for the selection and processing of biomass raw materials, and also facilitates the amplification and optimization of the gasifier.

Taking soybean straw rich in nitrogen-containing functional groups as the raw material precursor, combined with the special advantages of microwave heating, microwave heating technology is applied to the pyrolysis and activation process of soybean straw. The pyrolysis solid product is used as the activation raw material, and CO₂ is used as the activator to study the preparation of activated carbon, in order to prepare the biomass activated carbon with high desulfurization performance. First, the optimal activation level was obtained by orthogonal experimental design and range analysis. Then, the effects of microwave power, CO₂ flow rate and activation time on the yield, pore structure and desulfurization performance of activated carbon were investigated by single factor experiment. The optimal activation conditions were selected by comparative analysis: microwave power 900 W, CO₂ flow rate 0.10 L/min, activation time 20 min. Under these conditions, the yield of activated carbon is 76.3%(mass), the SO₂ adsorbance quantity is 112.56 mg/g, specific surface area is 466.28 m²/g. Compared with pyrolytic carbon, activated carbon has larger specific surface area and more abundant pores and significantly improved desulfurization performance.

A fixed-bed tube furnace was used to study the release and migration and transformation of chlorine, sulfur, alkali and alkaline earth metals (AAEMs) in corn stalks at different baking temperatures. It was found that the release ratios of chlorine and sulfur, which increased continuously with temperature in the range of 220—300℃, were 10%—40% and 27%—60%, respectively. However, the absolute content of chlorine increased after torrefaction with the decreased ratio of alkali metal chloride and increased ratio of organochlorine (C—Cl). The absolute content of sulfur decreased significantly after torrefaction, meeting the sulfur requirement of commercial biomass pellets. In addition, the proportion of acid-soluble and insoluble Ca and Mg in hydrochloric acid also increased to a certain extent.

A new type of bamboo biochar (BC) loaded TiO₂-SnO₂ particle electrode was prepared and characterized by SEM, FT-IR, BET and XRD for efficient treatment of the coking wastewater in a three-dimensional electrochemical reaction system(3DERs). The results showed that bamboo biochar had a dense microporous space structure, and a significant amount of Ti-Sn oxides existed on the surface and in the interior of the BC. The removal rates of COD and DOC in coking wastewater reached to 73.96% and 66.72% respectively, and UV₂₅₄ reduced from 6.65 cm^-1 to 3.00 cm^-1 by the electrolysis treatment of 150 min at the current density of 30 mA/cm². The three-dimensional fluorescence spectra indicated that the most of the soluble organic compounds and soluble microbial by-products were degraded and transformed. The addition of Ti and Sn enhanced the efficacy of the electrooxidation, electro-adsorption and electrocatalytic behavior of the BC particle electrodes, which improved the treatment effect on coking wastewater in the 3DERs. In addition, this study provides the possibility of basic research for the engineering practice of electrochemical oxidation treatment of coking wastewater.

The performance of nitrogen removal and electricity generation of a novel bio-electrochemical-granular sludge reactor at different influent nitrogen concentration was investigated. The impact mechanism of granular sludge, key enzyme activity, extracellular polymer composition and microbial community distribution were systematically studied. The results showed that COD, NO₃^--N, NO₂^--N and dissolved methane were efficiently removed in stages Ⅰ, Ⅱ, Ⅲ and Ⅳ (Influent NO₃^--N and NO₂^--N concentrations were 60 and 20 mg·L^-1, 100 and 40 mg·L^-1, 140 and 60 mg·L^-1, 180 and 80 mg·L^-1, respectively). The removal efficiency of COD was the highest in stage Ⅳ, and it was above 96%. The effluent concentration of NO₃^--N was the most stable at stage Ⅱ, and the removal efficiency was over 99%. The NO₂^--N removal efficiency was above 99% in each stage. In stage Ⅳ, the maximum power density and output voltage was 471.2 mV·m^-3 and 608.1 mV at the fourth compartment, respectively. The polysaccharide and protein content of LB-EPS was the highest in stage Ⅱ of the fifth compartment, 13.7 mg·g^-1 and 14.7 mg·g^-1, respectively. Coenzyme F₄₂₀ activity was the lowest in the first compartment. The protease activity of the sludge was increased due to the increase of influent nitrogen concentration. From stage Ⅰ to stage Ⅳ, the relative abundance of Protebaoteria was decreased, while the relative abundance of Chloroflexi, Firmicutes and Planctomycetes were increased. Although Thauera with denitrification effect was decreased by 8.64% in the first compartment, the nitrogen removal was still well in the reactor. The relative abundance of Methanothrix was increased to 12.3% in the fourth compartment, indicating that Methanothrix could co-exist with other bacteria in the reactor.

To obtain high-performance gas separation membranes and realize high-efficiency separation and recovery of CO₂/N₂ in flue gas, the amino-rich semi-interpenetrating network blend membranes were prepared by in-situ crosslinking reaction, which provided CO₂ transport channels and affinity sites. Sulfonated poly(ether ether ketone) (SPEEK) and polysuccinimide (PSI) were used as raw materials, and hexamethylenediamine was crosslinking agent. The structure of the blend membranes was characterized by Fourier-transform infrared spectroscopy. The effects of water content, PSI dosage and feed gas pressure on the gas separation performance were studied, and its gas separation performance and the long-time stability were investigated under mixed gas conditions. The results showed that SPEEK and PSI have a good compatibility, and there is a strong interaction between them, which exhibited the semi-interpenetrating network microstructure in the membranes. When the PSI loading is 60%(mass), the CO₂ permeability of pure gas and mixed gas are 652 and 601 Barrer, respectively, and the corresponding CO₂/N₂ selectivity is 67.6 and 60.3, which is better than that in pristine SPEEK membrane, surpassing 2008 Robeson upper bound. The CO₂ permeability and CO₂/N₂ selectivity are still stable after 360 h durability test of SPEEK/PSI-60 blend membrane. This is mainly due to the formation of the amino-rich semi-interpenetrating network microstructure between SPEEK and PSI, which not only provides CO₂ facilitated transport carriers, but also enhances the water retention performance of the blend membranes and forms a large number of CO₂ transport water channels.

For the sake of solving the problems of poor mechanical strength and dissolve-loss ratio of Antheraea pernyi silk fibroin (ASF), allyl silk fibroin (ASF-AGE) was synthesized through nucleophilic substitution using ASF as substrate and allyl glycidyl ether (AGE) as modifier under basic conditions. And a series of gel were manufactured though in situ polymerization using ASF-AGE and N-isopropylacrylamide (NIPAAm) monomer without any crosslinking agent. The amino conversion rate of ASF was confirmed by ninhydrin colorimetry, the molecular structure of ASF-AGE was characterized by ¹H NMR and the influence of ASF-AGE content on crystal structure, temperature sensitivity, dissolution stability and mechanical properties of hydrogels were also investigated by XRD, DSC, compression test and so on. The results indicated that allyl was successfully introduced into ASF, the amino conversion rate of ASF was 55.21% when the reaction condition was 1∶8 mass ratio (ASF/AGE), T=20℃ and pH=10.5. The stable hydrogels can be obtained by ASF-AGE and NIPAAm polymerization. The hydrogels showed lower critical solution temperatures (LCST) at about 32℃, which revealed obvious thermosensitive characteristic. When the ratio of ASF-AGE to NIPAAm is 4/6, the hydrogel has good dissolution stability and comprehensive mechanical properties.

A novel kind of vacancy-rich nanowire arrays were prepared by reducing rough Co₃O₄ nanowires with NaBH₄ solution on 3D nickel foam at room temperature for overall water splitting. Co₃O₄/NF treated by NaBH₄ for 10 min was highly active for oxygen evolution reaction (OER) and simultaneously efficient for hydrogen evolution reaction (HER) with the need of the overpotentials of 240 and 132 mV to drive 10 mA·cm^-2 in alkaline media, respectively. Furthermore, the electrocatalysts as both cathode and anode in a two-electrode system presented excellent durability for over 60 h at 10 mA·cm^-2, maintaining the cell voltage of merely 1.63 V. This work provides new methods and ideas for the preparation of transition metal oxide bifunctional electrocatalysts rich in oxygen vacancies.

In this paper, various polycaprolactone/polylactide (PCL/PLA) blends with different dispersed phase morphologies were melt blended based on PCL matrix. Supercritical carbon dioxide (scCO₂) was used as physical blowing agent to fabricate porous PCL/PLA samples with different expansion ratio and open-cell content by microcellular batch foaming process. According to the solubility experiment of a cube sample with a side length of 3 mm, it is found that CO₂ has reached a saturated adsorption state in PCL after 100 min. The foam tests showed that with the increase of PLA contents, the pore size was decreased, the pore density was increased, and the pore distribution was more uniform. With the foaming temperature increased by 6℃, the pore size increased by 50%,the expansion ratio increased by 38% and the open-cell content decreased by 20%. PCL/PLA open-cell material has obvious lipophilic and hydrophobic properties. The higher the foaming ratio, the better the hydrophobicity properties. The oil absorption experiments for peanut oil and silicone oil showed that the oil absorption rate of foamed samples was proportional to the overall expansion ratio and open-cell content. In addition, the actual oil absorption was higher than calculated theoretical values. After 10 cycles of oil absorption test, the oil absorption of porous PCL/PLA samples was only reduced by 8.5%, and the oil absorption had little relationship with the oil??s intrinsic viscosity.

To improve the electrochemical lithium storage performance of molybdenum nitrides, Mo₂N quantum dots@nitrogen-doped graphene oxide sponge (Mo₂N-QDs@Ngs) was prepared by hydrothermal reaction, freeze-drying and calcination in H₂/N₂ mixture with ammonium molybdate ((NH₄)Mo₇O₂₄·4H₂O), hexamethylenetetramine (C₆H₁₂N₄) and graphene oxide (GO) as raw materials. The effect of GO content on the electrochemical lithium storage performance was investigated. The transmission electron microscope (TEM) results show that the size of the prepared Mo₂N quantum dots is about 2—5 nm, and the Mo₂N quantum dots are uniformly distributed on the surface of nitrogen-doped graphene. The electrochemical test results show that when the GO content is 30%, the prepared Mo₂N-QDs@Ngs-30 has the best electrochemical lithium storage performance, which has 699 mA·h·g^-1 specific capacity at the current density of 0.1 A·g^-1, and has 286 mA·h·g^-1 specific capacity even at the current density of 2 A·g^-1.