Sodium-ion hybrid capacitor(SIHC)is one of the most promising alternatives for large-scale energy storage due to its high energy and power densities,natural abundance,and low cost.However,overcoming the imbalance betw...Sodium-ion hybrid capacitor(SIHC)is one of the most promising alternatives for large-scale energy storage due to its high energy and power densities,natural abundance,and low cost.However,overcoming the imbalance between slow Na^(+)reaction kinetics of battery-type anodes and rapid ion adsorption/desorption of capacitive cathodes is a significant challenge.Here,we propose the high-rate-performance NiS_(2)@OMGC anode material composed of monodispersed NiS_(2) nanocrystals(8.8±1.7 nm in size)and N,S-co-doped graphenic carbon(GC).The NiS_(2)@OMGC material has a three-dimensionally ordered macroporous(3DOM)morphology,and numerous NiS_(2) nanocrystals are uniformly embedded in GC,forming a core-shell structure in the local area.Ultrafine NiS_(2) nanocrystals and their nano-microstructure demonstrate high pseudocapacitive Na-storage capability and thus excellent rate performance(355.7 mAh/g at 20.0 A/g).A SIHC device fabricated using NiS_(2)@OMGC and commercial activated carbon(AC)cathode exhibits ultrahigh energy densities(197.4 Wh/kg at 398.8 W/kg)and power densities(43.9 kW/kg at 41.3 Wh/kg),together with a long life span.This outcome exemplifies the rational architecture and composition design of this type of anode material.This strategy can be extended to the design and synthesis of a wide range of high-performance electrode materials for energy storage applications.展开更多
Infiltration–runoff–slope instability mechanism of macropore slope under heavy rainfall is unclear.This paper studied its instability mechanism with an improved Green–Ampt(GA)model considering the dual-porosity(i.e...Infiltration–runoff–slope instability mechanism of macropore slope under heavy rainfall is unclear.This paper studied its instability mechanism with an improved Green–Ampt(GA)model considering the dual-porosity(i.e.,matrix and macropore)and ponding condition,and proposed the infiltration equations,infiltration–runoff coupled model,and safety factor calculation method.Results show that the infiltration processes of macropore slope can be divided into three stages,and the proposed model is rational by a comparative analysis.The wetting front depth of the traditional unsaturated slope is 17.2%larger than that of the macropore slope in the early rainfall stage and 27%smaller than that of the macropore slope in the late rainfall stage.Then,macropores benefit the slope stability in the early rainfall but not in the latter.Macropore flow does not occur initially but becomes pronounced with increasing rainfall duration.The equal depth of the wetting front in the two domains is regarded as the onset criteria of macropore flow.Parameter analysis shows that macropore flow is delayed by increasing proportion of macropore domain(ω_(f)),whereas promoted by increasing ratio of saturated permeability coefficients between the two domains(μ).The increasing trend of ponding depth is sharp at first and then grows slowly.Finally,when rainfall duration is less than 3 h,ωf andμhave no significant effect on the safety factor,whereas it decreases with increasingωf and increases with increasingμunder longer duration(≥3 h).With the increase ofω_(f),the slope maximum instability time advances by 10.5 h,and with the increase ofμ,the slope maximum instability time delays by 3.1 h.展开更多
Aim To screen the optimum macroporous resin and conditions for the isolation and purification of flavonoids from Radix Puerariae. Methods The static and dynamic adsorption/desorption methods were used, and the separat...Aim To screen the optimum macroporous resin and conditions for the isolation and purification of flavonoids from Radix Puerariae. Methods The static and dynamic adsorption/desorption methods were used, and the separation and purification process was evaluated by measuring the concentration of total flavonoid in the fractions with UV spectrophotometer. Results The SP70 macroporous resin was the most effective compared with other macroporous resins. The optimum conditions were screened, which were 0.5 g· mL^- 1 corresponding to crude drug for concentration of extract, pH 5 - 6, and appended 60 times the volume of the resin bed (BV) with the adsorption speed 2 BV·h^-1, and the volume of aq. 70% (V/V) ethanol as eluant was 5 BV with desorption speed 2 BV·h^-1. By this method, the final contents of total flavonoids exceeded 80%. Conclusion The SP70 macroporous resin is the most effective one for large-scale isolation and purification of flavonoids from Radix Pueraria, which meets industrial needs.展开更多
A series of K-doped Mn0.5Ce0.5Oδ (K-MCO) catalysts with three-dimensionally ordered macroporous (3DOM) structure and different K loadings were successfully synthesized using simple methods. These catalysts exhibi...A series of K-doped Mn0.5Ce0.5Oδ (K-MCO) catalysts with three-dimensionally ordered macroporous (3DOM) structure and different K loadings were successfully synthesized using simple methods. These catalysts exhibited well-defined 3DOM nanostructure, which consisted of extensive interconnecting networks of spherical voids. The effects of the calcination temperature and calcination time on the morphological characteristics and crystalline forms of the catalysts were systematically studied. The catalysts showed high catalytic activity for the combustion of soot. 3DOM 20% K-MCO-4h catalyst, in particular, showed the highest catalytic activity of all of the catalysts studied (e.g., Ts0 = 331 ~C and Smco2 = 95.3%). The occurrence of structural and synergistic effects among the K, Mn, and Ce atoms in the catalysts was favorable for enhancing their catalytic activity towards the combustion of diesel soot. Furthermore, the temperatures required for the complete combustion of the soot (〈400 ℃) were well within the exhaust temperature range (175-400 ℃), which means that the accumulated soot can be removed under the conditions of the diesel exhaust gas. These catalysts could therefore be used in numerous practical applications because they are easy to synthesize, exhibit high catalytic activity, and can be made from low cost materials.展开更多
[Objective] This study was conducted to develop a method for rapidly separating macranthoidin B and dipsacoside B from Flos Lonicerae. [Method] HP-20 and HP-SS macroporous resin were applied to separate and purify mac...[Objective] This study was conducted to develop a method for rapidly separating macranthoidin B and dipsacoside B from Flos Lonicerae. [Method] HP-20 and HP-SS macroporous resin were applied to separate and purify macranthoidin B and dipsacoside B from Flos Lonicerae. The extract of Flos Lonicerae was first loaded onto an HP-20 column to enrich saponins, which were then separated by an HP-SS macroporous resin column to get pure macranthoidin B and dipsacoside B.[Result] The optimal HP-20 purification conditions included: a concentration of sample liquid at 4.8 mg/ml, a sample volume of 2 BV, an adsorption flow rate at 1.5BV/h, an ethanol concentration for desorption at 60%, a desorption volume of 3 BV,and a desorption flow rate at 1.5 BV/h. Total saponins were then separated by an HP-SS macroporous resin column which was eluted sequentially by water, 20%ethanol, 30% ethanol, 40% ethanol and 50% ethanol. Two purified compounds were obtained in fractions eluted by 40% ethanol and 50% ethanol, respectively. The two compounds were identified as macranthoidin B and dipsacoside B by13 C and1H nuclear magnetic resonance spectroscopy. [Conclusion] The combination of HP-20 and HP-SS macroporous resin could efficiently separate macranthoidin B and dipsacoside B from Flos Lonicerae.展开更多
A facile procedure was carried out to prepare macroporous perovskite-type complex oxide catalysts of La1–xKxCo1–yFeyO3(x=0,0.1,y=0,0.1) by using the combined method of organic ligation and solution combustion.This m...A facile procedure was carried out to prepare macroporous perovskite-type complex oxide catalysts of La1–xKxCo1–yFeyO3(x=0,0.1,y=0,0.1) by using the combined method of organic ligation and solution combustion.This method could ensure the formation of the desired macroporous structures and the desired crystal phases of the prepared catalysts.It was found that the macroporous catalysts showed higher catalytic activities for soot combustion than that of the corresponding nanometric samples,and the macroporous ...展开更多
An aminated hypercrosslinked macroporous polymeric adsorbent was synthesized and characterized. Adsorption isotherms for 1 amino 2 naphthol 4 sulfonic acid(1, 2, 4 acid) and 2 naphthol obtained from various bin...An aminated hypercrosslinked macroporous polymeric adsorbent was synthesized and characterized. Adsorption isotherms for 1 amino 2 naphthol 4 sulfonic acid(1, 2, 4 acid) and 2 naphthol obtained from various binary adsorption environments can be well fitted by Freundlich equation, which indicated a favorable adsorption process in the studied range. Adsorption for 1, 2, 4 acid was an endothermic process in comparison with that for 2 naphthol of an exothermic process. 2 naphthol molecules put a little influence on the adsorption capacity for 1, 2, 4 acid. However, the adsorption to 1, 2, 4 acid depressed that to 2 naphthol in a large extent for the stronger electrostatic interaction between 1, 2, 4 acid and adsorbent. The predominant mechanism can be contributed to the competition for adsorption sites. And the simultaneous environment was confirmed to be helpful to the selective adsorption towards 1,2,4 acid based on the larger selectivity index.展开更多
This article presents a detailed structural study of a new spherical Mg Cl2-supported Ti Cl4 Ziegler-Natta catalyst for isotactic propylene polymerization, and researches on the relationship between catalyst structure...This article presents a detailed structural study of a new spherical Mg Cl2-supported Ti Cl4 Ziegler-Natta catalyst for isotactic propylene polymerization, and researches on the relationship between catalyst structure and polymer properties. The spherical support with the chemical composition of CH3CH2 OMg OCH(CH2Cl)2 has been synthesized from a new dispersion system and is used as the supporting material to prepare Ziegler-Natta catalyst. The XRD analysis indicates that the catalyst is fully activated with δ-Mg Cl2 in the active catalyst. The far-IR spectrometric results confirm again the presence of δ-Mg Cl2 in the active catalyst. Textural property of the active catalyst exhibits high surface area coupled with high porosity. The high activity in propylene polymerization is mainly ascribed to the full activation and the porous structure of the catalyst. Scanning electron microscopy/energy dispersive spectrometer mapping results indicate a uniform titanium distribution throughout the catalyst particles. Particle size analysis shows that the catalyst has a narrow particle size distribution. The perfect spherical shape, uniform titanium distribution and narrow particle size distribution of the catalyst confirm the advantage of polymer particles production with less fines. The solid state 13 C NMR and mid-IR spectroscopic analyses indicate that there exists strong complexation between diisobutyl phthalate and Mg Cl2, which leads to the high isotacticity of polypropylene.展开更多
Flavonoids are one main kind of effective components in Houttuynia cordata Thunb., which display a wide range of pharmacological activity. In this study supercritical fluid extraction (SFE) with carbon dioxide was f...Flavonoids are one main kind of effective components in Houttuynia cordata Thunb., which display a wide range of pharmacological activity. In this study supercritical fluid extraction (SFE) with carbon dioxide was first used as preparat ion step to remove the volatile components, which are also active components, from Hout-tuynia cordata Thunb. Then ultrasound-assisted extraction was used to obtain the crude flavonoids and the macro-porous resin adsorption technology was further employed to purify the flavonoids. Nine kinds of macroporous resins with different properties were tested through static adsorption, and one macroporous resin labeled as D101 was selected. The effect of several factors, such as the ratio of column height to diameter, initial concentration and pH, on both flavonoids yield and content were explored by dynamic adsorption to obtain reasonable conditions of adsorption and desorption. The experimental results show that the content of fiavonoids can be above 60% with fia- vonoids recovery of 93.3 % under the optimum conditions of purification. HPLC analysis of the final flavonoids product shows it contains quercitrin, hypefin, rutin and quercetin.展开更多
Arabinogalactan (AG) obtained from Larix gmelinii R. waS purified with the method of macroporous resin adsorption. Effects of various parameters on the adsorption, including adsorption time and temperature, the conc...Arabinogalactan (AG) obtained from Larix gmelinii R. waS purified with the method of macroporous resin adsorption. Effects of various parameters on the adsorption, including adsorption time and temperature, the concentration and the dosage of raw AG the reused numbers of resin, were investigated. The effect of purification was tested through the removal rate of impurity and the contents of AG and impurity. The optimal condition was determined as follows: adsorbed at 30℃ for 2 h with the concentration of raw AG 〈0.1 g·mL^-1 and its dosage 〈 7 mL, the dose of resin was 3 g and reused for 4 times. On the basis of these, macroporous resin column was used for AG purification. The result showed that the AG yield could reach 68.28% with sugar content of 95.02%. The analysis of IR and UV showed that the effect of macroporous resin characteristics on the purification of AG was significant. The obtained product had the same functional groups with standard sample.展开更多
The highly ordered silver-coated colloidal crystals arrays and macroporous silver films were derived through an electrostatics-induced adsorption effect using polystyrene(PS) as templates. Carboxyl-modified PS microsp...The highly ordered silver-coated colloidal crystals arrays and macroporous silver films were derived through an electrostatics-induced adsorption effect using polystyrene(PS) as templates. Carboxyl-modified PS microspheres were prepared by emulsifier-free emulsion polymerization using methacrylic acid(MAA) as the functional monomer. PS microspheres were self-assembled into close packing colloidal crystals of facecentered cubic arrays to the substrate with vertical deposition method. These colloidal crystals were modified using dopamine(DA) to form poly-dopamine(PDA) during its oxidative polymerization. Through electrostatic interaction, the silver nanoparticles were deposited and adsorbed onto the surfaces of colloidal crystals templates by exposing [Ag(NH_3)_2]^+solution to infrared irradiation. Removal of the polymeric template by etching with methylbenzene solvent resulted in 3D ordered macroporous silver films. The structural and properties of the ordered silver-coated arrays and macroporous silver films were characterized by field emission scanning electron microscopy(FE-SEM), X-ray diffraction(XRD), UV-vis spectroscopy and surface-enhanced Raman spectroscopy(SERS). The results indicate that the prepared silver-coated arrays and macroporous silver films possess the features of ordered multilayer arrangement, uniformity and repeatability as well as an ideal SERS effect.展开更多
Macroporous magnetic poly(GMA-EGDMA-DVB) microspheres synthesized by suspension polymerization were used as supports for palladium catalyst.The results showed the novel magnetic catalyst can promote Heck reaction of a...Macroporous magnetic poly(GMA-EGDMA-DVB) microspheres synthesized by suspension polymerization were used as supports for palladium catalyst.The results showed the novel magnetic catalyst can promote Heck reaction of aryl halides with acrylic acid efficiently without an inert atmosphere.In addition,the novel catalyst can be conveniently recovered by applying an external magnet and reused at least five times without significant loss of its activity.展开更多
In this paper, a new kind of adsorption resin with multi-phenolic hydroxyl was created by immobilizing black wattle bark tannins to chloromethyl polystyrene resin. Its adsorption capacity to cation dye was tested. Wit...In this paper, a new kind of adsorption resin with multi-phenolic hydroxyl was created by immobilizing black wattle bark tannins to chloromethyl polystyrene resin. Its adsorption capacity to cation dye was tested. With an orthogonal test the optimal conditions of synthesis were determined: the concentration of sodium hydroxide solution 1.0 mol.L^-1; the reaction time is one hour and the mass concentration of tannins 5%. With single factorial experiment the optimal conditions of adsorption were confirmed: a solidified pH of 5.0; an adsorption temperature of 25℃ and a cation dye concentration of 100 mg.L^-1. The adsorption for cation dye can be similar to Langmuir isotherms.展开更多
Tje adsorption bchavior and mechanism of a novel chelate resin,macroporous phosphonic acid resin(PAR)for Ni(Ⅱ)were imestigated.The stotically saturated adsorption capacity is 64.3mg·g^-1 resin at 298K in HAc...Tje adsorption bchavior and mechanism of a novel chelate resin,macroporous phosphonic acid resin(PAR)for Ni(Ⅱ)were imestigated.The stotically saturated adsorption capacity is 64.3mg·g^-1 resin at 298K in HAc-NaAc medium.The Ni(Ⅱ)adsorbed on PAR can be eluted by 0.5mal·L^-1 HCl and the elution percentage reaches 96.6%.The resin can be regenerated and reused without abvious decrease in adsorption capacity.The apparent adsorption rate constant is k298=2.6×10^-5s^-1.The adsorption behavior of PAR for Ni(Ⅱ)obeys the Freundllich isotherm.The thermodynamie adsorption parameters.enthalpy change △H,free energy change △G and entropy change △S of PAR for Ni(Ⅱ)are 3.36kJ·mol^-1,-5.47kJ·mol^-1 and 29.6J·mol^-1·K^-1,respectively.The apparent activation energy is Ea=12.2kJ·mol^-1,The molar coordination ratio of the functional group of PAR to Ni(Ⅱ)is about 4:1.The adsorption mechanism of PAR for Ni(Ⅱ)was examined by a chemical method and IR spectrometry.展开更多
Three-dimensionally ordered(3DOM) macroporous phosphotungstic acid/SiO_2(HPW/SiO_2) materials were prepared by using colloidal crystal as templates and applied for oxidative desulfurization(ODS) of the model fue...Three-dimensionally ordered(3DOM) macroporous phosphotungstic acid/SiO_2(HPW/SiO_2) materials were prepared by using colloidal crystal as templates and applied for oxidative desulfurization(ODS) of the model fuel oil. The obtained HPW/SiO_2 materials were characterized through scanning electron microscopy, powder X-ray diffraction, N_2 sorption, and Fourier transform infrared spectroscopy. The results indicated that 3 DOM HPW/SiO_2 possessed hierarchical pore architectures which contained ordered macropores and disordered mesopores, with the Keggin type HPW embedded in the framework of pore structure. The removal rate of dibenzothiophene(DBT) could reach 100% under the optimum conditions, moreover. The performance was only slightly decreased for the regenerated catalyst after 7 cycles.展开更多
Ordered macroporous materials with rapid mass transport and enhanced active site accessibility are essential for achieving improved catalytic activity.In this study,boron phosphate crystals with a three-dimensionally ...Ordered macroporous materials with rapid mass transport and enhanced active site accessibility are essential for achieving improved catalytic activity.In this study,boron phosphate crystals with a three-dimensionally interconnected ordered macroporous structure and a robust framework were fabricated and used as stable and selective catalysts in the oxidative dehydrogenation(ODH)of propane.Due to the improved mass diffusion and higher number of exposed active sites in the ordered macroporous structure,the catalyst exhibited a remarkable olefin productivity of^16 golefin gcat^-1 h^-1,which is up to 2–100 times higher than that of ODH catalysts reported to date.The selectivity for olefins was 91.5%(propene:82.5%,ethene:9.0%)at 515℃,with a propane conversion of 14.3%.At the same time,the selectivity for the unwanted deep-oxidized CO2 product remained less than 1.0%.The tri-coordinated surface boron species were identified as the active catalytic sites for the ODH of propane.This study provides a route for preparing a new type of metal-free catalyst with stable structure against oxidation and remarkable catalytic activity,which may represent a potential candidate to promote the industrialization of the ODH process.展开更多
Three-dimensional ordered macroporous (3DOM) La1?xKxNiO3 perovskite-type catalysts were successfully prepared by a colloidal crystal template method and characterized by scanning electron microscopy, transmission elec...Three-dimensional ordered macroporous (3DOM) La1?xKxNiO3 perovskite-type catalysts were successfully prepared by a colloidal crystal template method and characterized by scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, energy-dispersive X-ray scattering elemental mapping, X-ray diffraction, Raman and X-ray photoelectron spectroscopy, and temperature-programmed reduction of H2. Further, their catalytic activity in soot combustion was determined by temperature-programmed oxidation reaction. K substitution into the LaNiO3 lattice led to remarkably improved catalytic activity of this catalyst in soot combustion. Amongst various catalysts, La0.95K0.05NiO3 exhibited the highest activity in soot combustion (with its T50 and CO2 S values being 338 °C and 98.2%, respectively), which is comparable to the catalytic activities of Pt-based catalysts under the condition of poor contact between the soot and the catalyst. K-substitution improves the valence state of Ni and increases the number of oxygen vacancies, thereby leading to increased density of surface-active oxygen species. The active oxygen species play a vital role in catalyzing the elimination of soot. The perovskite-type La1?xKxNiO3 nanocatalysts with 3DOM structure without noble metals have potential for practical applications in the catalytic combustion of diesel soot particles.展开更多
Monolithic macroporous Pt/CeO2/Al2O3 catalysts were prepared using concentrated emulsions synthesis route, and the obtained samples were characterized with SEM, TG, TEM, XRD and TPR techniques. These monolithic cataly...Monolithic macroporous Pt/CeO2/Al2O3 catalysts were prepared using concentrated emulsions synthesis route, and the obtained samples were characterized with SEM, TG, TEM, XRD and TPR techniques. These monolithic catalysts were applied to water gas shift (WGS) reaction in reformed gases. The SEM and TEM results indicated that the monoliths possessed macroporosity, and that the platinum particles homogeneously dispersed on the supports with the particle size in the range of 1-2 nm. The reducibility of the catalysts was characterized by TPR method, and it was shown that the monolithic PtOx/CeO2/Al2O3 exhibited the similar reducibility property to that of the particle PtOx/CeO2 reported in literatures. The CO conversion over the monolithic catalysts is higher than that over micro-reactor catalysts for WGS reaction in the reformed gases conditions, indicating that the monolithic macroporous catalysts is a potential new route for miniaturization of WGS reactor.展开更多
A macroporous polymeric adsorbent NG-8 was synthesized with divinylbenzene using conventional suspension polymerization technique. Its aminated product NG-9 was prepared by introducing tertiary amino groups into NG-8 ...A macroporous polymeric adsorbent NG-8 was synthesized with divinylbenzene using conventional suspension polymerization technique. Its aminated product NG-9 was prepared by introducing tertiary amino groups into NG-8 for removal of tannin acid from aqueous solutions. NG-9 could be used directly without a wetting process and had higher adsorption capacity than NG-8, which might be attributed to the enhanced adsorbent-adsorbate interaction due to the tertiary amino groups on the polymeric matrix. The Langmuir equation was successfully employed to describe the adsorption process. The adsorption enthalpy change further validated the uptake of tannin acid on NG-9 to be an enhanced physical adsorption because of the Lewis acid-base interaction. In addition, adsorption kinetic studies testified that the tertiary amino groups on the polymer matrix could decrease the adsorption rate maybe for the hindrance of the tertiary amino groups and water clusters built up.展开更多
Immobilizing biocomponents on solid surfaces is a critical step in the development of new devices for future biological, medical, and elec- tronic applications. Therefore, numerous integrated films were recently devel...Immobilizing biocomponents on solid surfaces is a critical step in the development of new devices for future biological, medical, and elec- tronic applications. Therefore, numerous integrated films were recently developed by immobilizing different proteins or enzymes on electrode surfaces. In this work, hemeproteins were safely immobilized onto macroporous nickel-based electrodes while maintaining their functionality. Such modified electrodes showed interesting pseudo-capacitive behavior. Among hemeproteins, hemoglobin (Hb) film has a higher electro- chemical performance and greater charge/discharge cycling stability than myoglobin (Mb) and cytochrome C (CytC). The heme group in an alkaline medium could induce the formation of superoxides on the electrode surface. These capacitive features of hemeprotein-Ni electrode were related to strong binding sites between hemeproteins and porous Ni electrode, the accumulation of superoxide or radicals on the Ni sur- face, and facile electron transfer and electrolyte diffusion through the three-dimensional macroporous network. Thus, these new protein-based supercapacitors have potential use in free-standing platform technology for the development of implantable energy-storage devices.展开更多
基金supported by the National Natural Science Foundation of Tianjin(No.20JCQNJC01280)the National Natural Science Foundation of China(No.21905201)+1 种基金the support of the scientifi c research project from China Three Gorges Corporation(No.202103406)supported by Tohoku University and JSPS KAKENHI(No.JP16J06828).
文摘Sodium-ion hybrid capacitor(SIHC)is one of the most promising alternatives for large-scale energy storage due to its high energy and power densities,natural abundance,and low cost.However,overcoming the imbalance between slow Na^(+)reaction kinetics of battery-type anodes and rapid ion adsorption/desorption of capacitive cathodes is a significant challenge.Here,we propose the high-rate-performance NiS_(2)@OMGC anode material composed of monodispersed NiS_(2) nanocrystals(8.8±1.7 nm in size)and N,S-co-doped graphenic carbon(GC).The NiS_(2)@OMGC material has a three-dimensionally ordered macroporous(3DOM)morphology,and numerous NiS_(2) nanocrystals are uniformly embedded in GC,forming a core-shell structure in the local area.Ultrafine NiS_(2) nanocrystals and their nano-microstructure demonstrate high pseudocapacitive Na-storage capability and thus excellent rate performance(355.7 mAh/g at 20.0 A/g).A SIHC device fabricated using NiS_(2)@OMGC and commercial activated carbon(AC)cathode exhibits ultrahigh energy densities(197.4 Wh/kg at 398.8 W/kg)and power densities(43.9 kW/kg at 41.3 Wh/kg),together with a long life span.This outcome exemplifies the rational architecture and composition design of this type of anode material.This strategy can be extended to the design and synthesis of a wide range of high-performance electrode materials for energy storage applications.
基金funded by the Natural Science Foundation of Fujian Province(Grant No.2023J011133)。
文摘Infiltration–runoff–slope instability mechanism of macropore slope under heavy rainfall is unclear.This paper studied its instability mechanism with an improved Green–Ampt(GA)model considering the dual-porosity(i.e.,matrix and macropore)and ponding condition,and proposed the infiltration equations,infiltration–runoff coupled model,and safety factor calculation method.Results show that the infiltration processes of macropore slope can be divided into three stages,and the proposed model is rational by a comparative analysis.The wetting front depth of the traditional unsaturated slope is 17.2%larger than that of the macropore slope in the early rainfall stage and 27%smaller than that of the macropore slope in the late rainfall stage.Then,macropores benefit the slope stability in the early rainfall but not in the latter.Macropore flow does not occur initially but becomes pronounced with increasing rainfall duration.The equal depth of the wetting front in the two domains is regarded as the onset criteria of macropore flow.Parameter analysis shows that macropore flow is delayed by increasing proportion of macropore domain(ω_(f)),whereas promoted by increasing ratio of saturated permeability coefficients between the two domains(μ).The increasing trend of ponding depth is sharp at first and then grows slowly.Finally,when rainfall duration is less than 3 h,ωf andμhave no significant effect on the safety factor,whereas it decreases with increasingωf and increases with increasingμunder longer duration(≥3 h).With the increase ofω_(f),the slope maximum instability time advances by 10.5 h,and with the increase ofμ,the slope maximum instability time delays by 3.1 h.
基金Science and Technology Committee of Chongqing inChina(CSTC.2004BB5122).
文摘Aim To screen the optimum macroporous resin and conditions for the isolation and purification of flavonoids from Radix Puerariae. Methods The static and dynamic adsorption/desorption methods were used, and the separation and purification process was evaluated by measuring the concentration of total flavonoid in the fractions with UV spectrophotometer. Results The SP70 macroporous resin was the most effective compared with other macroporous resins. The optimum conditions were screened, which were 0.5 g· mL^- 1 corresponding to crude drug for concentration of extract, pH 5 - 6, and appended 60 times the volume of the resin bed (BV) with the adsorption speed 2 BV·h^-1, and the volume of aq. 70% (V/V) ethanol as eluant was 5 BV with desorption speed 2 BV·h^-1. By this method, the final contents of total flavonoids exceeded 80%. Conclusion The SP70 macroporous resin is the most effective one for large-scale isolation and purification of flavonoids from Radix Pueraria, which meets industrial needs.
基金supported by the National Natural Science Foundation of China(21177160,21303263,21477164)Beijing Nova Program(Z141109001814072)+1 种基金Specialized Research Fund for the Doctoral Program of High Education of China(20130007120011)the Science Foundation of China University of Petroleum-Beijing(2462013YJRC13,2462013BJRC003)~~
文摘A series of K-doped Mn0.5Ce0.5Oδ (K-MCO) catalysts with three-dimensionally ordered macroporous (3DOM) structure and different K loadings were successfully synthesized using simple methods. These catalysts exhibited well-defined 3DOM nanostructure, which consisted of extensive interconnecting networks of spherical voids. The effects of the calcination temperature and calcination time on the morphological characteristics and crystalline forms of the catalysts were systematically studied. The catalysts showed high catalytic activity for the combustion of soot. 3DOM 20% K-MCO-4h catalyst, in particular, showed the highest catalytic activity of all of the catalysts studied (e.g., Ts0 = 331 ~C and Smco2 = 95.3%). The occurrence of structural and synergistic effects among the K, Mn, and Ce atoms in the catalysts was favorable for enhancing their catalytic activity towards the combustion of diesel soot. Furthermore, the temperatures required for the complete combustion of the soot (〈400 ℃) were well within the exhaust temperature range (175-400 ℃), which means that the accumulated soot can be removed under the conditions of the diesel exhaust gas. These catalysts could therefore be used in numerous practical applications because they are easy to synthesize, exhibit high catalytic activity, and can be made from low cost materials.
基金Supported by Guangxi Scientific Research and Technological Development Planning Project(20130403-2)Technology Research and Development Program of Guangxi Province(GKH15104001-15)+1 种基金Special Fund for Bagui Scholars of the Guangxi Zhuang Autonomous RegionDirector Fund Project of Guangxi Key Laboratory of Functional Phytochemicals Research and Utilization(ZRJJ2016-4)~~
文摘[Objective] This study was conducted to develop a method for rapidly separating macranthoidin B and dipsacoside B from Flos Lonicerae. [Method] HP-20 and HP-SS macroporous resin were applied to separate and purify macranthoidin B and dipsacoside B from Flos Lonicerae. The extract of Flos Lonicerae was first loaded onto an HP-20 column to enrich saponins, which were then separated by an HP-SS macroporous resin column to get pure macranthoidin B and dipsacoside B.[Result] The optimal HP-20 purification conditions included: a concentration of sample liquid at 4.8 mg/ml, a sample volume of 2 BV, an adsorption flow rate at 1.5BV/h, an ethanol concentration for desorption at 60%, a desorption volume of 3 BV,and a desorption flow rate at 1.5 BV/h. Total saponins were then separated by an HP-SS macroporous resin column which was eluted sequentially by water, 20%ethanol, 30% ethanol, 40% ethanol and 50% ethanol. Two purified compounds were obtained in fractions eluted by 40% ethanol and 50% ethanol, respectively. The two compounds were identified as macranthoidin B and dipsacoside B by13 C and1H nuclear magnetic resonance spectroscopy. [Conclusion] The combination of HP-20 and HP-SS macroporous resin could efficiently separate macranthoidin B and dipsacoside B from Flos Lonicerae.
基金supported by the National Natural Science Foundation of China (20833011 and 20803093)the 863 Project of China (2006AA06Z346)
文摘A facile procedure was carried out to prepare macroporous perovskite-type complex oxide catalysts of La1–xKxCo1–yFeyO3(x=0,0.1,y=0,0.1) by using the combined method of organic ligation and solution combustion.This method could ensure the formation of the desired macroporous structures and the desired crystal phases of the prepared catalysts.It was found that the macroporous catalysts showed higher catalytic activities for soot combustion than that of the corresponding nanometric samples,and the macroporous ...
文摘An aminated hypercrosslinked macroporous polymeric adsorbent was synthesized and characterized. Adsorption isotherms for 1 amino 2 naphthol 4 sulfonic acid(1, 2, 4 acid) and 2 naphthol obtained from various binary adsorption environments can be well fitted by Freundlich equation, which indicated a favorable adsorption process in the studied range. Adsorption for 1, 2, 4 acid was an endothermic process in comparison with that for 2 naphthol of an exothermic process. 2 naphthol molecules put a little influence on the adsorption capacity for 1, 2, 4 acid. However, the adsorption to 1, 2, 4 acid depressed that to 2 naphthol in a large extent for the stronger electrostatic interaction between 1, 2, 4 acid and adsorbent. The predominant mechanism can be contributed to the competition for adsorption sites. And the simultaneous environment was confirmed to be helpful to the selective adsorption towards 1,2,4 acid based on the larger selectivity index.
基金the financial support by the National Natural Science Foundation of China (No. 20973022 and No. 11472048)
文摘This article presents a detailed structural study of a new spherical Mg Cl2-supported Ti Cl4 Ziegler-Natta catalyst for isotactic propylene polymerization, and researches on the relationship between catalyst structure and polymer properties. The spherical support with the chemical composition of CH3CH2 OMg OCH(CH2Cl)2 has been synthesized from a new dispersion system and is used as the supporting material to prepare Ziegler-Natta catalyst. The XRD analysis indicates that the catalyst is fully activated with δ-Mg Cl2 in the active catalyst. The far-IR spectrometric results confirm again the presence of δ-Mg Cl2 in the active catalyst. Textural property of the active catalyst exhibits high surface area coupled with high porosity. The high activity in propylene polymerization is mainly ascribed to the full activation and the porous structure of the catalyst. Scanning electron microscopy/energy dispersive spectrometer mapping results indicate a uniform titanium distribution throughout the catalyst particles. Particle size analysis shows that the catalyst has a narrow particle size distribution. The perfect spherical shape, uniform titanium distribution and narrow particle size distribution of the catalyst confirm the advantage of polymer particles production with less fines. The solid state 13 C NMR and mid-IR spectroscopic analyses indicate that there exists strong complexation between diisobutyl phthalate and Mg Cl2, which leads to the high isotacticity of polypropylene.
文摘Flavonoids are one main kind of effective components in Houttuynia cordata Thunb., which display a wide range of pharmacological activity. In this study supercritical fluid extraction (SFE) with carbon dioxide was first used as preparat ion step to remove the volatile components, which are also active components, from Hout-tuynia cordata Thunb. Then ultrasound-assisted extraction was used to obtain the crude flavonoids and the macro-porous resin adsorption technology was further employed to purify the flavonoids. Nine kinds of macroporous resins with different properties were tested through static adsorption, and one macroporous resin labeled as D101 was selected. The effect of several factors, such as the ratio of column height to diameter, initial concentration and pH, on both flavonoids yield and content were explored by dynamic adsorption to obtain reasonable conditions of adsorption and desorption. The experimental results show that the content of fiavonoids can be above 60% with fia- vonoids recovery of 93.3 % under the optimum conditions of purification. HPLC analysis of the final flavonoids product shows it contains quercitrin, hypefin, rutin and quercetin.
基金This research was supported by Important Tackle Key Problem of Heilongjiang Province (GB05B601-02)Youth Fund of Northeast Forestry University (200403-10).
文摘Arabinogalactan (AG) obtained from Larix gmelinii R. waS purified with the method of macroporous resin adsorption. Effects of various parameters on the adsorption, including adsorption time and temperature, the concentration and the dosage of raw AG the reused numbers of resin, were investigated. The effect of purification was tested through the removal rate of impurity and the contents of AG and impurity. The optimal condition was determined as follows: adsorbed at 30℃ for 2 h with the concentration of raw AG 〈0.1 g·mL^-1 and its dosage 〈 7 mL, the dose of resin was 3 g and reused for 4 times. On the basis of these, macroporous resin column was used for AG purification. The result showed that the AG yield could reach 68.28% with sugar content of 95.02%. The analysis of IR and UV showed that the effect of macroporous resin characteristics on the purification of AG was significant. The obtained product had the same functional groups with standard sample.
基金supported by the National Natural Science Foundation of China (Grant Nos. 50873085 and 21375116)a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)
文摘The highly ordered silver-coated colloidal crystals arrays and macroporous silver films were derived through an electrostatics-induced adsorption effect using polystyrene(PS) as templates. Carboxyl-modified PS microspheres were prepared by emulsifier-free emulsion polymerization using methacrylic acid(MAA) as the functional monomer. PS microspheres were self-assembled into close packing colloidal crystals of facecentered cubic arrays to the substrate with vertical deposition method. These colloidal crystals were modified using dopamine(DA) to form poly-dopamine(PDA) during its oxidative polymerization. Through electrostatic interaction, the silver nanoparticles were deposited and adsorbed onto the surfaces of colloidal crystals templates by exposing [Ag(NH_3)_2]^+solution to infrared irradiation. Removal of the polymeric template by etching with methylbenzene solvent resulted in 3D ordered macroporous silver films. The structural and properties of the ordered silver-coated arrays and macroporous silver films were characterized by field emission scanning electron microscopy(FE-SEM), X-ray diffraction(XRD), UV-vis spectroscopy and surface-enhanced Raman spectroscopy(SERS). The results indicate that the prepared silver-coated arrays and macroporous silver films possess the features of ordered multilayer arrangement, uniformity and repeatability as well as an ideal SERS effect.
文摘Macroporous magnetic poly(GMA-EGDMA-DVB) microspheres synthesized by suspension polymerization were used as supports for palladium catalyst.The results showed the novel magnetic catalyst can promote Heck reaction of aryl halides with acrylic acid efficiently without an inert atmosphere.In addition,the novel catalyst can be conveniently recovered by applying an external magnet and reused at least five times without significant loss of its activity.
文摘In this paper, a new kind of adsorption resin with multi-phenolic hydroxyl was created by immobilizing black wattle bark tannins to chloromethyl polystyrene resin. Its adsorption capacity to cation dye was tested. With an orthogonal test the optimal conditions of synthesis were determined: the concentration of sodium hydroxide solution 1.0 mol.L^-1; the reaction time is one hour and the mass concentration of tannins 5%. With single factorial experiment the optimal conditions of adsorption were confirmed: a solidified pH of 5.0; an adsorption temperature of 25℃ and a cation dye concentration of 100 mg.L^-1. The adsorption for cation dye can be similar to Langmuir isotherms.
文摘Tje adsorption bchavior and mechanism of a novel chelate resin,macroporous phosphonic acid resin(PAR)for Ni(Ⅱ)were imestigated.The stotically saturated adsorption capacity is 64.3mg·g^-1 resin at 298K in HAc-NaAc medium.The Ni(Ⅱ)adsorbed on PAR can be eluted by 0.5mal·L^-1 HCl and the elution percentage reaches 96.6%.The resin can be regenerated and reused without abvious decrease in adsorption capacity.The apparent adsorption rate constant is k298=2.6×10^-5s^-1.The adsorption behavior of PAR for Ni(Ⅱ)obeys the Freundllich isotherm.The thermodynamie adsorption parameters.enthalpy change △H,free energy change △G and entropy change △S of PAR for Ni(Ⅱ)are 3.36kJ·mol^-1,-5.47kJ·mol^-1 and 29.6J·mol^-1·K^-1,respectively.The apparent activation energy is Ea=12.2kJ·mol^-1,The molar coordination ratio of the functional group of PAR to Ni(Ⅱ)is about 4:1.The adsorption mechanism of PAR for Ni(Ⅱ)was examined by a chemical method and IR spectrometry.
基金the National Nature Science Foundation of China(No.21476177)
文摘Three-dimensionally ordered(3DOM) macroporous phosphotungstic acid/SiO_2(HPW/SiO_2) materials were prepared by using colloidal crystal as templates and applied for oxidative desulfurization(ODS) of the model fuel oil. The obtained HPW/SiO_2 materials were characterized through scanning electron microscopy, powder X-ray diffraction, N_2 sorption, and Fourier transform infrared spectroscopy. The results indicated that 3 DOM HPW/SiO_2 possessed hierarchical pore architectures which contained ordered macropores and disordered mesopores, with the Keggin type HPW embedded in the framework of pore structure. The removal rate of dibenzothiophene(DBT) could reach 100% under the optimum conditions, moreover. The performance was only slightly decreased for the regenerated catalyst after 7 cycles.
文摘Ordered macroporous materials with rapid mass transport and enhanced active site accessibility are essential for achieving improved catalytic activity.In this study,boron phosphate crystals with a three-dimensionally interconnected ordered macroporous structure and a robust framework were fabricated and used as stable and selective catalysts in the oxidative dehydrogenation(ODH)of propane.Due to the improved mass diffusion and higher number of exposed active sites in the ordered macroporous structure,the catalyst exhibited a remarkable olefin productivity of^16 golefin gcat^-1 h^-1,which is up to 2–100 times higher than that of ODH catalysts reported to date.The selectivity for olefins was 91.5%(propene:82.5%,ethene:9.0%)at 515℃,with a propane conversion of 14.3%.At the same time,the selectivity for the unwanted deep-oxidized CO2 product remained less than 1.0%.The tri-coordinated surface boron species were identified as the active catalytic sites for the ODH of propane.This study provides a route for preparing a new type of metal-free catalyst with stable structure against oxidation and remarkable catalytic activity,which may represent a potential candidate to promote the industrialization of the ODH process.
基金supported by the National Natural Science Foundation of China(21673142)National Engineering Laboratory for Mobile Source Emission Control Technology(NELMS2017A05)+1 种基金PetroChina Innovation Foundation(2018D-5007-0505)Science Foundation of China University of Petroleum,Beijing(242017QNXZ02,2462018BJC005)~~
文摘Three-dimensional ordered macroporous (3DOM) La1?xKxNiO3 perovskite-type catalysts were successfully prepared by a colloidal crystal template method and characterized by scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, energy-dispersive X-ray scattering elemental mapping, X-ray diffraction, Raman and X-ray photoelectron spectroscopy, and temperature-programmed reduction of H2. Further, their catalytic activity in soot combustion was determined by temperature-programmed oxidation reaction. K substitution into the LaNiO3 lattice led to remarkably improved catalytic activity of this catalyst in soot combustion. Amongst various catalysts, La0.95K0.05NiO3 exhibited the highest activity in soot combustion (with its T50 and CO2 S values being 338 °C and 98.2%, respectively), which is comparable to the catalytic activities of Pt-based catalysts under the condition of poor contact between the soot and the catalyst. K-substitution improves the valence state of Ni and increases the number of oxygen vacancies, thereby leading to increased density of surface-active oxygen species. The active oxygen species play a vital role in catalyzing the elimination of soot. The perovskite-type La1?xKxNiO3 nanocatalysts with 3DOM structure without noble metals have potential for practical applications in the catalytic combustion of diesel soot particles.
基金supported by the Ministry of Sciences and Technology of China (863 programs, No 2006AA05Z115 and 2007AA05Z104)the National Natural Science Foundation of China (No. 20976121)
文摘Monolithic macroporous Pt/CeO2/Al2O3 catalysts were prepared using concentrated emulsions synthesis route, and the obtained samples were characterized with SEM, TG, TEM, XRD and TPR techniques. These monolithic catalysts were applied to water gas shift (WGS) reaction in reformed gases. The SEM and TEM results indicated that the monoliths possessed macroporosity, and that the platinum particles homogeneously dispersed on the supports with the particle size in the range of 1-2 nm. The reducibility of the catalysts was characterized by TPR method, and it was shown that the monolithic PtOx/CeO2/Al2O3 exhibited the similar reducibility property to that of the particle PtOx/CeO2 reported in literatures. The CO conversion over the monolithic catalysts is higher than that over micro-reactor catalysts for WGS reaction in the reformed gases conditions, indicating that the monolithic macroporous catalysts is a potential new route for miniaturization of WGS reactor.
基金This work was supported by the Jiangsu Provincial Key Laboratory of Coastal Wetland Bioresources and Environmental Protection,China(Grant Code JLCBE6006).
文摘A macroporous polymeric adsorbent NG-8 was synthesized with divinylbenzene using conventional suspension polymerization technique. Its aminated product NG-9 was prepared by introducing tertiary amino groups into NG-8 for removal of tannin acid from aqueous solutions. NG-9 could be used directly without a wetting process and had higher adsorption capacity than NG-8, which might be attributed to the enhanced adsorbent-adsorbate interaction due to the tertiary amino groups on the polymeric matrix. The Langmuir equation was successfully employed to describe the adsorption process. The adsorption enthalpy change further validated the uptake of tannin acid on NG-9 to be an enhanced physical adsorption because of the Lewis acid-base interaction. In addition, adsorption kinetic studies testified that the tertiary amino groups on the polymer matrix could decrease the adsorption rate maybe for the hindrance of the tertiary amino groups and water clusters built up.
文摘Immobilizing biocomponents on solid surfaces is a critical step in the development of new devices for future biological, medical, and elec- tronic applications. Therefore, numerous integrated films were recently developed by immobilizing different proteins or enzymes on electrode surfaces. In this work, hemeproteins were safely immobilized onto macroporous nickel-based electrodes while maintaining their functionality. Such modified electrodes showed interesting pseudo-capacitive behavior. Among hemeproteins, hemoglobin (Hb) film has a higher electro- chemical performance and greater charge/discharge cycling stability than myoglobin (Mb) and cytochrome C (CytC). The heme group in an alkaline medium could induce the formation of superoxides on the electrode surface. These capacitive features of hemeprotein-Ni electrode were related to strong binding sites between hemeproteins and porous Ni electrode, the accumulation of superoxide or radicals on the Ni sur- face, and facile electron transfer and electrolyte diffusion through the three-dimensional macroporous network. Thus, these new protein-based supercapacitors have potential use in free-standing platform technology for the development of implantable energy-storage devices.