Removing copper from nickel electrolysis anode solution has been a major keypoint in the nickel metallurgy industry.In this study,we proposed a novel process flow to promote removing copper from nickel electrolysis an...Removing copper from nickel electrolysis anode solution has been a major keypoint in the nickel metallurgy industry.In this study,we proposed a novel process flow to promote removing copper from nickel electrolysis anode solution.A simulated nickel anode solution was designed,and static and dynamic adsorption experiments were conducted to determine the best of solution pH,adsorption time and temperature,resin dosage and particle size,and stirring speed.The optimal conditions were explored for copper removal from nickel electrolysis anode solution.Based on the optimal experimental conditions and the relevant experimental data,a novel process for copper removal from nickel electrolysis anodes was designed and verified.This novel process of copper removal from nickel electrolysis anodes was confirmed with nickel anolyte solution with nickel 50−60 g/L and copper 0.5 g/L.After finishing the novel process of copper removal,the nickel in the purified nickel anolyte became undetectable and copper concentration was 3 mg/L,the novel process of resin adsorption to remove copper from nickel anode solution through static and dynamic adsorptions has an efficacious copper removal.It is a beneficial supplement to traditional methods.展开更多
Negatively charged open-framework metal sulfides(NOSs),taking advantages of the characteristics of excellent visible light absorption,easily exchanged cations,and abundant active sites,hold significant promise as high...Negatively charged open-framework metal sulfides(NOSs),taking advantages of the characteristics of excellent visible light absorption,easily exchanged cations,and abundant active sites,hold significant promise as highly efficient photocatalysts for hydrogen evolution.However,their applications in photocatalytic hydrogen evolution(PHE)are infrequently documented and the corresponding photocatalytic mechanism has not yet been explored.Herein,we excavated a novel NOS photocatalyst of(Me_(2)NH_(2))_(6)In_(10)S_(18)(MIS)with a three-dimensional(3D)structure,and successfully incorporated divalent Co(Ⅱ)and metal Co(0)into its cavities via the convenient cation exchange-assisted approach to regulate the critical steps of photocatalytic reactions.As the introduced Co(0)allows for more efficient light utilization and adroitly surficial hydrogen desorption,and meanwhile acts as the‘electron pump’for rapid charge transfer,Co(0)-modified MIS delivers a surprising PHE activity in the initial stage of photocatalysis.With the prolonging of illumination,metal Co(0)gradually escapes from MIS framework,resulting in the decline of PHE performance.By stark contrast,the incorporated Co(Ⅱ)can establish a strong interaction with MIS framework,and simultaneously capture photogenerated electrons from MIS to produce Co(0),which constructs a stable photocatalytic system as well as provides additional channels for spatially separating photogenerated carriers.Thus,Co(Ⅱ)-modified MIS exhibits a robust and highly stable PHE activity of~4944μmol/g/h during the long-term photocatalytic reactions,surpassing most of the previously reported In–S framework photocatalysts.This work represents a breakthrough in the study of PHE performance and mechanism of NOS-based photocatalysts,and sheds light on the design of vip confined NOS-based photocatalysts towards high-efficiency solar-to-chemical energy conversion.展开更多
This study investigates the potential of natural Brown Coal(BC)as a sustainable,cost-effective adsorbent for the removal of manganese(Mn2+)from contaminated groundwater.A series of batch adsorp-tion experiments was co...This study investigates the potential of natural Brown Coal(BC)as a sustainable,cost-effective adsorbent for the removal of manganese(Mn2+)from contaminated groundwater.A series of batch adsorp-tion experiments was conducted to assess the influence of key operational parameters—such as solution pH,2+initial Mn concentration,BC dosage,temperature,and the presence of competing ions—on 2+Mn removal efficiency.The environmental compatibility and regeneration potential of BC were also evaluated to deter-mine its practical viability for repeated use.To better understand the adsorption behaviour,equilibrium and kinetic data were analysed using established isotherm and kinetic models,while thermodynamic parameters were computed to assess the spontaneity and thermal characteristics of the adsorption process.Furthermore,geochemical modelling and comprehensive BC characterization—including surface morphology,miner-alogical and elemental composition,and functional group analysis—were 2+performed to elucidate Mn speciation under varying environmental conditions and to uncover the underlying adsorption mechanisms.2+Results showed that Mn removal efficiency increased with higher pH,temperature,and BC dosage,but 2+declined at elevated initial Mn concentrations due to active site saturation.The process was spontaneous 2 and endothermic,with the Langmuir isotherm model(R=0.994)and pseudo-second-order kinetic model 2(R=0.996)providing the best fit to experimental data.Mechanistic analysis indicated that chemisorption,2+primarily through ion exchange and inner-sphere complexation,was the dominant mode of Mn uptake.3+The presence of competing cations,especially Fe and Cu2+,2+significantly hindered Mn removal due to preferential binding.Importantly,BC exhibited strong reusability,maintaining over 80%removal effi-ciency across four adsorption–desorption cycles without evidence of secondary pollutants.These findings demonstrate the potential of natural BC as an efficient,reusable,and environmentally benign material for treating manganese-contaminated groundwater.展开更多
A novel hydroxy late-rich functionalized biosorbent by grafting citric acid on the decrystallized Dicranopteris dichotoma stem(DDS) was prepared.The obtained g-DDS-3 exhibits good hydrophilicity,thermal stability and ...A novel hydroxy late-rich functionalized biosorbent by grafting citric acid on the decrystallized Dicranopteris dichotoma stem(DDS) was prepared.The obtained g-DDS-3 exhibits good hydrophilicity,thermal stability and superior adsorption performance for Ce^(3+).The effects of citric acid dosage,pH and initial Ce^(3+)concentration on the adsorption experiments were investigated.The maximum adsorption capacity(Langmuir model) of Ce^(3+)by g-DDS-3 is 131.0 mg/g at pH of 7.0,which surpasses that of most previously reported biomass-based materials.Adsorption kinetic results indicate that the adsorption process conforms to the pseudo-second-order model and can achieve equilibrium quickly.By analyzing the adsorption mechanism,we find that carboxyl groups are uniformly distributed on the surface of g-DDS-3 post modification,which provides abundant adsorption sites,and the adsorption is primarily driven by the ion exchange between Ce^(3+)and carboxyl groups protons.In addition,the adsorption-desorption experiments suggest that the g-DDS-3 has excellent recyclability since the adsorption capacity still remain above 90% after five cycles.These findings prove that carboxylate-rich modified D.dichotoma has great potential for application in the effective separation and recovery of Ce^(3+)from leaching tailings.展开更多
Electrochemically switched ion exchange(ESIX)is an effective technology for extracting high-valueadded ions from dilute solutions.This study focuses on Li^(+)extraction by employing a comprehensive model to analyze in...Electrochemically switched ion exchange(ESIX)is an effective technology for extracting high-valueadded ions from dilute solutions.This study focuses on Li^(+)extraction by employing a comprehensive model to analyze interaction between fluidic dynamics,electric field and ion transport.The model combines Butler-Volmer equation modified by electroactive site concentration,Nernst-Planck equation and Navier-Stokes equation.It is found that the chamber width affects solution phase resistance,thereby altering the pote ntial distribution and influencing the current distribution within the membrane.A narrow chamber increases current density in the solid phase of the membrane,enhancing Li^(+) extraction.The solution flow-field not only enhances convective transport but also increases the current density in the solid phase,promoting Li^(+) extraction.There is a synergistic effect between fluid-flow-field and electric-field for ion separation,which is only significant when the chamber width is greater than 2 mm.The synergistic mechanism differs from that in the capacitive deionization system.Therefore,the performance decline caused by a wide chamber can be compensated for by increasing the fluid-flow rate,utilizing the synergistic effect between the flu id-flow-field and electric-field to optimize the lithium extraction efficiency in the ESIX system.展开更多
Low-salinity water(LSW)and CO_(2) could be combined to perform better in a hydrocarbon reservoir due to their synergistic advantages for enhanced oil recovery(EOR);however,its microscopic recovery mechanisms have not ...Low-salinity water(LSW)and CO_(2) could be combined to perform better in a hydrocarbon reservoir due to their synergistic advantages for enhanced oil recovery(EOR);however,its microscopic recovery mechanisms have not been well understood due to the nature of these two fluids and their physical reactions in the presence of reservoir fluids and porous media.In this work,well-designed and inte-grated experiments have been performed for the first time to characterize the in-situ formation of micro-dispersions and identify their EOR roles during a LSW-alternating-CO_(2)(CO_(2)-LSWAG)process under various conditions.Firstly,by measuring water concentration and performing the Fourier transform infrared spectroscopy(FT-IR)analysis,the in-situ formation of micro-dispersions induced by polar and acidic materials was identified.Then,displacement experiments combining with nuclear magnetic resonance(NMR)analysis were performed with two crude oil samples,during which wettability,interfacial tension(IFT),CO_(2) dissolution,and CO_(2) diffusion were quantified.During a CO_(2)-LSWAG pro-cess,the in-situ formed micro-dispersions dictate the oil recovery,while the presence of clay minerals,electrical double-layer(EDL)expansion and multiple ion exchange(MIE)are found to contribute less.Such formed micro-dispersions are induced by CO_(2) via diffusion to mobilize the CO_(2)-diluted oil,alter the rock wettability towards more water-wet,and minimize the density contrast between crude oil and water.展开更多
Oseltamivir phosphate(OP),renowned as one of the most effective drugs for influenza treatment,encounters several challenges,including poor stability,difficulty in swallowing,and a bitter taste,thereby limiting its com...Oseltamivir phosphate(OP),renowned as one of the most effective drugs for influenza treatment,encounters several challenges,including poor stability,difficulty in swallowing,and a bitter taste,thereby limiting its compliance,particularly among children.Consequently,this study aimed to devise a novel sustained-release suspension of OP employing an ion exchange resin as a carrier to address these challenges.The OP-drug resin complex(OP-DRC)was synthesized utilizing ion exchange technology,while OP-coated microcapsules(OP-CM)were fabricated via the emulsion-evaporation method.The optimization of the formulation process for the OP sustained-release suspension was achieved through a combination of single-factor experimentation and orthogonal experimental design.Furthermore,the drug release kinetics and pharmacokinetic properties of the sustained-release suspension were thoroughly evaluated both in vitro and in vivo.Scanning electron microscopy(SEM),X-ray diffraction(XRD),and attenuated total reflectance Fourier-transform infrared spectroscopy(ATR-FTIR)analyses confirmed the formation of drug-resin complexes via ionic bonding.The in vitro cumulative release rates were found to be 16%(1 h),53%(6 h),and 84%(24 h),respectively.Notably,the self-made sustained-release suspension exhibited an extended half-life(21.518 h),delayed time to peak concentration(T_(max))(6 h),and reduced maximum plasma concentration(C_(max))(0.397μg/mL)in comparison to commercial granules(half-life=8.466 h;T_(max)=2 h;C_(max)=0.631μg/mL).Additionally,the area under the curve(AUC)indicated that the bioavailability of the self-made OP suspension surpassed that of the commercial OP granules by 101%.These findings underscored the successful development of an oral OP sustained-release suspension characterized by stability,tastelessness,ease of swallowing,convenient administration,and sustained-release properties,thereby potentially enhancing drug compliance among children.展开更多
In recent years,low-dimensional transition metal chalcogenide(TMC)materials have garnered growing research attention due to their superior electronic,optical,and catalytic properties compared to their bulk counterpart...In recent years,low-dimensional transition metal chalcogenide(TMC)materials have garnered growing research attention due to their superior electronic,optical,and catalytic properties compared to their bulk counterparts.The controllable synthesis and manipulation of these materials are crucial for tailoring their properties and unlocking their full potential in various applications.In this context,the atomic substitution method has emerged as a favorable approach.It involves the replacement of specific atoms within TMC structures with other elements and possesses the capability to regulate the compositions finely,crystal structures,and inherent properties of the resulting materials.In this review,we present a comprehensive overview on various strategies of atomic substitution employed in the synthesis of zero-dimensional,one-dimensional and two-dimensional TMC materials.The effects of substituting elements,substitution ratios,and substitution positions on the structures and morphologies of resulting material are discussed.The enhanced electrocatalytic performance and photovoltaic properties of the obtained materials are also provided,emphasizing the role of atomic substitution in achieving these advancements.Finally,challenges and future prospects in the field of atomic substitution for fabricating low-dimensional TMC materials are summarized.展开更多
Prussian blue analogues (PBAs) are regarded as promising cathode materials for potassium-ion batteries(PIBs) owing to their low cost and high reversible capacity.Compared to other PBAs,potassium manganese hexacyanofer...Prussian blue analogues (PBAs) are regarded as promising cathode materials for potassium-ion batteries(PIBs) owing to their low cost and high reversible capacity.Compared to other PBAs,potassium manganese hexacyanoferrate (KMnHCF) stands out for its superior capacity and operating voltage.However,Jahn-Teller effect of Mn^(3+)and the structural collapse caused by potassium ion insertion/extraction still affect the structural stability and electrochemical performance of this material.Herein,a green and efficient synthesis method is adopted to substitute potassium ions in KMnHCF with an appropriate amount of cesium ions to form a column effect.Cesium-doped KMnHCF (Cs-KMnHCF) mitigates the irreversible structural damage caused by potassiation/depotassiation and the Jahn-Teller effect,thereby improving the cycling stability.In addition,it widens the lattice channels,reduces the diffusion barrier of potassium ions,and optimizes the diffusion kinetics.By rationally controlling the doping amount of Cs^(+),the obtained K_(1.71)Cs_(0.05)Mn[Fe(CN)_(6)]_(0.95·0.05)·0.88H_(2)O exhibits remarkable electrochemical performance,with an initial discharge capacity of 137.6 mA h g^(-1)at a current density of 20 mA g^(-1)and a capacity retention of 89.6%after 600 cycles at 200 mA g^(-1).More importantly,when assembled with a pitch-derived soft carbon anode,the full cell manifests excellent cycle stability and rate performance.This work is expected to provide a highly efficient cathode material for the practical application of PIBs.展开更多
Palladium-exchanged chabazite(Pd-CHA) zeolites as passive NO_x adsorbers(PNAs) enable efficient purification of nitrogen oxides(NO_x) in cold-start diesel exhausts. Their commercial application, however,is limited by ...Palladium-exchanged chabazite(Pd-CHA) zeolites as passive NO_x adsorbers(PNAs) enable efficient purification of nitrogen oxides(NO_x) in cold-start diesel exhausts. Their commercial application, however,is limited by the lack of facile preparation method. Here, high-performance CHA-type Pd-SAPO-34 zeolite was synthesized by a modified solid-state ion exchange(SSIE) method using PdO as Pd precursor,and demonstrated superior PNA performance as compared to Pd-SAPO-34 prepared by conventional wetchemistry strategies. Structural characterization using Raman spectroscopy and X-ray diffraction revealed that the SSIE method avoided water-induced damage to the zeolite framework during Pd loading. Mechanistic investigations on the SSIE process by in situ infrared spectroscopy and X-ray photoelectron spectroscopy disclosed that, while PdO precursor was mainly converted to Pd^(2+) cations coordinated to the zeolite framework by consuming the-OH groups of the zeolite, a portion of PdO could also undergo thermal decomposition to form highly dispersed Pd~0 clusters in the pore channels. This simplified and scalable SSIE method paves a new way for the cost-effective synthesis of defect-free high-performance Pd-SAPO-34 zeolites as PNA catalysts.展开更多
In this work,the structure,viscosity and ion-exchange process of Na_(2)O-MgO-Al_(2)O_(3)-SiO_(2) glasses with different Al_(2)O_(3)/SiO_(2) molar ratios were investigated.The results showed that,with increasing Al_(2)...In this work,the structure,viscosity and ion-exchange process of Na_(2)O-MgO-Al_(2)O_(3)-SiO_(2) glasses with different Al_(2)O_(3)/SiO_(2) molar ratios were investigated.The results showed that,with increasing Al_(2)O_(3)/SiO_(2) ratio,the simple structural units Q_(1) and Q_(2) transformed into highly aggregated structural units Q_(3) and Q_(4),indicating the increase of polymerization degree of glass network.Meanwhile,the coefficient of thermal expansion decreased from 9.23×10^(-6)℃^(-1) to 8.88×10^(-6)℃^(-1).The characteristic temperatures such as melting,forming,softening and glass transition temperatures increased with the increase of Al_(2)O_(3)/SiO_(2) ratio,while the glasses working temperature range became narrow.The increasing Al_(2)O_(3)/SiO_(2) ratio and prolonging ion-exchange time enhanced the surface compressive stress(CS)and depth of stress layer(DOL).However,the increase of ion exchange temperature increased the DOL and decreased the CS affected by stress relaxation.There was a good linear relationship between stress relaxation and surface compressive stress.Chemical strengthening significantly improved the hardness of glasses,which reached the maximum value of(622.1±10)MPa for sample with Al_(2)O_(3)/SiO_(2) ratio of 0.27 after heat treated at 410℃for 2 h.展开更多
Enhanced sulfur and nitrogen deposition has been observed in many transect regions worldwide,from urban/agricultural areas to mountains.The Sichuan Basin(SCB),with 18 prefectural cities,is the most economically-develo...Enhanced sulfur and nitrogen deposition has been observed in many transect regions worldwide,from urban/agricultural areas to mountains.The Sichuan Basin(SCB),with 18 prefectural cities,is the most economically-developed region in western China,while the rural Qinghai-Tibetan Plateau(QTP)lies west of the SCB.Previous regional and national atmospheric modeling studies have sug-gested that large areas in the SCB-to-QTP transect region experience excessive deposition of sulfur and nitrogen.In this study,we applied a passive monitoring method at 11 sites(one in urban Chengdu and 10 from fivenature reserves)in this transect region from September 2021 to October 2022 to confirm the high sulfur and nitrogen deposition fluxes and to understand the gaps between the modeling and observation results for this transect region.These observations suggest that the five reserves are under eutrophication risk,and only two reserves are partially under acidification risk.Owing to the complex topography and landscapes,both sulfur and nitrogen deposition and critical loads exhibit large spatial variations within a reserve,such as Mount Emei.Regional atmospheric modeling may not accurately capture the spatial variations in deposition fluxes within a reserve;however,it can capture general spatial patterns over the entire transect.This study demonstrates that a combination of state-of-the-art atmospheric chemical models and low-cost monitoring methods is helpful for ecological risk assessments at a regional scale.展开更多
Fast pyrolysis of pre-treated birch wood in a super-heated steam environment produces a condensate rich in anhydrosugars.With the objective to obtain several product streams from this condensate,the possibility of ext...Fast pyrolysis of pre-treated birch wood in a super-heated steam environment produces a condensate rich in anhydrosugars.With the objective to obtain several product streams from this condensate,the possibility of extracting additional chemical species is explored,thus promoting the development of a pyrolysis-based biorefinery.In this work,the extraction and recovery of pyrolytic phenols from birch wood pyrolysis condensate was studied using ion exchange resins.With an aim to achieve effective phenol recovery,while obtaining high purity levoglucosan,basic ion exchange resins,both in OH−and Cl^(−)form,as well as polystyrene-divinyl resins without functional groups were compared.This study characterizes the influence of sorbent matrix type and porosity,functional group and counter ion on the sorption of various aromatic compounds.It was concluded that the counter ion of the ion exchange resins had the most influence on the pyrolytic phenol adsorption,while in the case of unfunctionalized resins smaller pore size improved removal of phenols from the pyrolysis liquids.Of the resins tested,the most effective at the removal and recovery of pyrolytic phenols were strongly basic,macroporous,anion exchange resins in OH^(−)form.The possibility to reuse the sorbents and solvents is explored to make the over-all process more environmentally friendly and economically feasible.展开更多
The synthesis of layered oxide cathode materials by the traditional high-temperature ceramic method usually requires calcination and annealing at temperatures in the range of 700-1000℃,with high energy consumption an...The synthesis of layered oxide cathode materials by the traditional high-temperature ceramic method usually requires calcination and annealing at temperatures in the range of 700-1000℃,with high energy consumption and serious cation mixing problems.Herein,we present a novel hydrothermalLi^(+)/H^(+)exchange method for the preparation of layered oxide cathodes at temperatures as low as 200℃.In contrast to the widely reported Li^(+)/Na^(+)exchange method using sodium-containing:precursors,layered oxide cathodes can be directly synthesized by hydrothermal reaction between commercial hydroxide precursors and LiOH·H2O.The reaction pathway consists of two steps.(1)The hydroxyl oxide intermediate is obtained by oxidizing the hydroxide precursor.(2)The layered oxide product is obtained by theLi^(+)/H^(+)exchange reaction of the hydroxyl oxide with Li+in solution.Through studying the time-resolved structural evolution,we reveal that the mechanism of material formation duringLi^(+)/H^(+)ion exchange is in situ crystallization,and the ion exchange process is accompanied by lattice distortion caused by internal diffusion of ions.These findings not only provide valuable insights into theLi^(+)/H^(+)exchange process,but also provide a new paradigm for the lowtemperature synthesis of advanced cathode materials.展开更多
Based on the difference in tendency to polymerize between tungsten and molybdenum, a new method using D309 resin was propounded. The batch tests indicate that the optimum pH value and contact time for the separation a...Based on the difference in tendency to polymerize between tungsten and molybdenum, a new method using D309 resin was propounded. The batch tests indicate that the optimum pH value and contact time for the separation are 7.0 and 4 h respectively, the maxium separation factor of W and Mo is 9.29. And the experimental resules show that isothermal absorbing tungsten and molybdenum belongs to Langmuir model and Freundlich model respectively, and the absorbing kinetics for tungsten is controlled by intra-particle diffusion. With a solution containing 70 g/L WO3 and 28.97 g/L Mo, the effluent with a mass ratio of Mo to WO3 of 76 and the eluate with a mass ratio of WO3 to Mo of 53.33 are obtained after column test.展开更多
[ Objective] The research aimed to get the optimized separation and purification conditions of the hirudin produced from Bacillus subtilis DB403 （pUBH5）. [Method] Through the systemic pretreatment, preliminary chrom...[ Objective] The research aimed to get the optimized separation and purification conditions of the hirudin produced from Bacillus subtilis DB403 （pUBH5）. [Method] Through the systemic pretreatment, preliminary chromatography and fine chromatography. [Result]The optimized separation and purification conditions were that： Supernatant was treated by trichloroacetic acid, then by ultrafiltration desalt and anion exchange chromatography. Strong anion Q F. F. was better than weak anion DEAE F.F. The proper balanced solution was Tris-HCI （ pH 8.0）. The proper conductivity was 6 ms/cm. The maximum applied sample was 240 ATU/ml to matrix of strong anion Q F. F. This optimized procedure was magnified in strong anion exchange HiPrep 16/10Q with the 90% recovery and 70.2% purity. The purification of gel filtration of Sephacryl S-100 to hirudin was not relative to flow rate within certain scope. The application size of sample was 10 ml. The purity checked by HPLC was 95.1%, and the recovery was 93%, and the band of SDS-PAGE was single. [ Conclusion] The research provided the reference of the further industrialization separation and purification of hiruin.展开更多
The flotation and adsorption behaviors of dodecyltrimethylammonium chloride（DTAC） and cetyltrimethylammonium chloride（CTAC） on diaspore and kaolinite were studied.Solution depletion methods were used to determine ...The flotation and adsorption behaviors of dodecyltrimethylammonium chloride（DTAC） and cetyltrimethylammonium chloride（CTAC） on diaspore and kaolinite were studied.Solution depletion methods were used to determine adsorption isotherms.Fluorescence probe test along with Zeta potential measurement was also conducted for further investigation into the adsorption of quaternary amines at the mineral-water interface.The results show that the flotation recovery of kaolinite decreases with an increase in pH when DTAC and CTAC are used as collectors,while diaspore is on the contrary.As the carbon chain length of the collectors increases,the flotation recoveries of minerals increase.However,the increment rate of kaolinite is significantly lower than that of diaspore.In the low surfactant concentration range,the cationic surfactants adsorb readily on diaspore surfaces just due to electrostatic interactions.As for kaolinite surfaces,ion exchange process also exists.With a further increase in surfactant concentration,the adsorption was ascribed to the hydrophobic association of chain-chain interactions.Micro-polarity of mineral surfaces study shows that CTAC has a better hydrophobic characteristic than DTAC.Larger aggregates are formed with CTAC on diaspore than on kaolinite in the same solution concentration.The results also indicate that the chain length of cationic surfactants has a greater influence on the adsorption of diaspore than on kaolinite,which is consistent with the flotation result.展开更多
Fe doped Beta zeolite with different Fe contents were prepared by ion exchange by changing the volume or the concentration of a Fe salt solution. For a particular mass of Fe salt precursor, the concentration of the me...Fe doped Beta zeolite with different Fe contents were prepared by ion exchange by changing the volume or the concentration of a Fe salt solution. For a particular mass of Fe salt precursor, the concentration of the metal salt solution during ion exchange influenced the ion exchange capacity of Fe, and resulted in different activities of the Fe-Beta catalyst. Fe-Beta catalysts with the Fe contents of （2.6, 6.3 and 9） wt% were synthesized using different amounts of 0.02 mol/L Fe salt solution. These catalysts were studied by various characterization techniques and their NH3-SCR activities were evaluated. The Fe-Beta catalyst with the Fe content of 6.3 wt% exhibited the highest activity, with a temperature range of 202-616℃ where the NOx conversion was 〉 80%. The Fe content in Beta zeolite did not influence the structure of Beta zeolite and valence state of Fe. Compared with the Fe-Beta catalysts with low Fe content （2.6 wt%）, Fe-Beta catalysts with 6.3 wt% Fe content possessed more isolated Fe3. active sites which led to its higher NH3-SCR activity. A high capacity for NH3 and NO adsorption, and a high activity for NO oxidation also contributed to the high NH3-SCR activity of the Fe-Beta catalyst with 6.3 wt%. However, when the Fe content was further increased to 9.0 wt%, the amount of FexOy nanoparticles increased while the amount of isolated Fe3＋ active sites was unchanged, which promoted NH3 oxidation and decreased the NH3-SCR activity at high temperature.展开更多
Aim To prepare the prolonged-released microspheres of mefformin hydrochloride. Methods Ion-exchange resin-drug mefformin hydrochloride complexes were prepared as core materials, and followed by coating using ethylcell...Aim To prepare the prolonged-released microspheres of mefformin hydrochloride. Methods Ion-exchange resin-drug mefformin hydrochloride complexes were prepared as core materials, and followed by coating using ethylcellulose （EC） by the emulsion solvent diffusion technique. The release rate of mefformin from the microcapsules was highly dependent on the encapsulating formulation, thus being used as an index for formulation screening. Orthogonal experiments were performed to optimize the coating formulation. Results The final chosen formulation for coating of mefformin microcapsules were as follows： （ 1 ） the ratio of EC （20cps） to EC （45cps） was 50：50; （2） the ratio of plasticizer to coating materials was 20% ;and （3） the ratio of resin-mefformin complexes to coating materials was 5 ： 1. Conclusion The prolonged release microspheres of mefformin hydrochloride were successfully prepared.展开更多
[Objective] This study aimed to establish an efficient process for separation of phycoerythrin by using Q Sepharose Fast Flow resin and verity its feasibility for scale-up. [Method] Elution gradient, sample volume and...[Objective] This study aimed to establish an efficient process for separation of phycoerythrin by using Q Sepharose Fast Flow resin and verity its feasibility for scale-up. [Method] Elution gradient, sample volume and flow rate were optimized to determine the optimal separation condition, under which the scale-up process was verified. [Result] The optimal condition for separation of phycoerythrin by using Q Sepharose FF resin was investigated： 30 ml of laver extract was loaded to the Q Sepharose FF column with a bed volume of 8 ml; subsequently, the column was stepwise eluted with 0-0.10-0.35-1.00 mol/L NaCI solution （pH 6.0） at a constant flow rate of 1 ml/min; the elution peak under 0.35 mol/L NaCI solution was collected, and the recovery rate and purity coefficient （A565/A280） of phycoerythrin were determined as 44.3 and 1.15, respectively. Based on the established process, 75 ml of phycoerythrin extract was loaded to the Q Sepharose FF column with a bed volume of 20 ml for separation, while no significant variation was observed in the separation result. [Conclusion] Phycoerythrin can be well separated from laver extract by using Q Sepharose FF resin and the process is feasible for scale-up.展开更多
基金Project(2019yff0216502)supported by the National Key Research&Development Plan of Ministry of Science and Technology of ChinaProject(2021SK1020-4)supported by the Major Science and Technological Innovation Project of Hunan Province,China。
文摘Removing copper from nickel electrolysis anode solution has been a major keypoint in the nickel metallurgy industry.In this study,we proposed a novel process flow to promote removing copper from nickel electrolysis anode solution.A simulated nickel anode solution was designed,and static and dynamic adsorption experiments were conducted to determine the best of solution pH,adsorption time and temperature,resin dosage and particle size,and stirring speed.The optimal conditions were explored for copper removal from nickel electrolysis anode solution.Based on the optimal experimental conditions and the relevant experimental data,a novel process for copper removal from nickel electrolysis anodes was designed and verified.This novel process of copper removal from nickel electrolysis anodes was confirmed with nickel anolyte solution with nickel 50−60 g/L and copper 0.5 g/L.After finishing the novel process of copper removal,the nickel in the purified nickel anolyte became undetectable and copper concentration was 3 mg/L,the novel process of resin adsorption to remove copper from nickel anode solution through static and dynamic adsorptions has an efficacious copper removal.It is a beneficial supplement to traditional methods.
基金financial supports provided by the Natural Science Foundation of Fujian Province(No.2024J01195)the National Nature Science Foundation of China(No.21905279)+1 种基金Sanming University(Nos.22YG11 and PYT2201)the Education Scientific Research Project of Youth Teachers in the Education Department of Fujian Province(No.JAT220351).
文摘Negatively charged open-framework metal sulfides(NOSs),taking advantages of the characteristics of excellent visible light absorption,easily exchanged cations,and abundant active sites,hold significant promise as highly efficient photocatalysts for hydrogen evolution.However,their applications in photocatalytic hydrogen evolution(PHE)are infrequently documented and the corresponding photocatalytic mechanism has not yet been explored.Herein,we excavated a novel NOS photocatalyst of(Me_(2)NH_(2))_(6)In_(10)S_(18)(MIS)with a three-dimensional(3D)structure,and successfully incorporated divalent Co(Ⅱ)and metal Co(0)into its cavities via the convenient cation exchange-assisted approach to regulate the critical steps of photocatalytic reactions.As the introduced Co(0)allows for more efficient light utilization and adroitly surficial hydrogen desorption,and meanwhile acts as the‘electron pump’for rapid charge transfer,Co(0)-modified MIS delivers a surprising PHE activity in the initial stage of photocatalysis.With the prolonging of illumination,metal Co(0)gradually escapes from MIS framework,resulting in the decline of PHE performance.By stark contrast,the incorporated Co(Ⅱ)can establish a strong interaction with MIS framework,and simultaneously capture photogenerated electrons from MIS to produce Co(0),which constructs a stable photocatalytic system as well as provides additional channels for spatially separating photogenerated carriers.Thus,Co(Ⅱ)-modified MIS exhibits a robust and highly stable PHE activity of~4944μmol/g/h during the long-term photocatalytic reactions,surpassing most of the previously reported In–S framework photocatalysts.This work represents a breakthrough in the study of PHE performance and mechanism of NOS-based photocatalysts,and sheds light on the design of vip confined NOS-based photocatalysts towards high-efficiency solar-to-chemical energy conversion.
文摘This study investigates the potential of natural Brown Coal(BC)as a sustainable,cost-effective adsorbent for the removal of manganese(Mn2+)from contaminated groundwater.A series of batch adsorp-tion experiments was conducted to assess the influence of key operational parameters—such as solution pH,2+initial Mn concentration,BC dosage,temperature,and the presence of competing ions—on 2+Mn removal efficiency.The environmental compatibility and regeneration potential of BC were also evaluated to deter-mine its practical viability for repeated use.To better understand the adsorption behaviour,equilibrium and kinetic data were analysed using established isotherm and kinetic models,while thermodynamic parameters were computed to assess the spontaneity and thermal characteristics of the adsorption process.Furthermore,geochemical modelling and comprehensive BC characterization—including surface morphology,miner-alogical and elemental composition,and functional group analysis—were 2+performed to elucidate Mn speciation under varying environmental conditions and to uncover the underlying adsorption mechanisms.2+Results showed that Mn removal efficiency increased with higher pH,temperature,and BC dosage,but 2+declined at elevated initial Mn concentrations due to active site saturation.The process was spontaneous 2 and endothermic,with the Langmuir isotherm model(R=0.994)and pseudo-second-order kinetic model 2(R=0.996)providing the best fit to experimental data.Mechanistic analysis indicated that chemisorption,2+primarily through ion exchange and inner-sphere complexation,was the dominant mode of Mn uptake.3+The presence of competing cations,especially Fe and Cu2+,2+significantly hindered Mn removal due to preferential binding.Importantly,BC exhibited strong reusability,maintaining over 80%removal effi-ciency across four adsorption–desorption cycles without evidence of secondary pollutants.These findings demonstrate the potential of natural BC as an efficient,reusable,and environmentally benign material for treating manganese-contaminated groundwater.
基金Project supported by the National Key R&D Program of China (2021YFC2901500)National Natural Science Foundation of China(22208349)+1 种基金Shandong Provincial Natural Science Youth Fund (ZR2022QB244)Shandong Energy Institute Innovation Fund (SEII202107, SEII202133)。
文摘A novel hydroxy late-rich functionalized biosorbent by grafting citric acid on the decrystallized Dicranopteris dichotoma stem(DDS) was prepared.The obtained g-DDS-3 exhibits good hydrophilicity,thermal stability and superior adsorption performance for Ce^(3+).The effects of citric acid dosage,pH and initial Ce^(3+)concentration on the adsorption experiments were investigated.The maximum adsorption capacity(Langmuir model) of Ce^(3+)by g-DDS-3 is 131.0 mg/g at pH of 7.0,which surpasses that of most previously reported biomass-based materials.Adsorption kinetic results indicate that the adsorption process conforms to the pseudo-second-order model and can achieve equilibrium quickly.By analyzing the adsorption mechanism,we find that carboxyl groups are uniformly distributed on the surface of g-DDS-3 post modification,which provides abundant adsorption sites,and the adsorption is primarily driven by the ion exchange between Ce^(3+)and carboxyl groups protons.In addition,the adsorption-desorption experiments suggest that the g-DDS-3 has excellent recyclability since the adsorption capacity still remain above 90% after five cycles.These findings prove that carboxylate-rich modified D.dichotoma has great potential for application in the effective separation and recovery of Ce^(3+)from leaching tailings.
基金supported by the National Natural Science Foundation of China(22378285,92475117 and U21A20303)。
文摘Electrochemically switched ion exchange(ESIX)is an effective technology for extracting high-valueadded ions from dilute solutions.This study focuses on Li^(+)extraction by employing a comprehensive model to analyze interaction between fluidic dynamics,electric field and ion transport.The model combines Butler-Volmer equation modified by electroactive site concentration,Nernst-Planck equation and Navier-Stokes equation.It is found that the chamber width affects solution phase resistance,thereby altering the pote ntial distribution and influencing the current distribution within the membrane.A narrow chamber increases current density in the solid phase of the membrane,enhancing Li^(+) extraction.The solution flow-field not only enhances convective transport but also increases the current density in the solid phase,promoting Li^(+) extraction.There is a synergistic effect between fluid-flow-field and electric-field for ion separation,which is only significant when the chamber width is greater than 2 mm.The synergistic mechanism differs from that in the capacitive deionization system.Therefore,the performance decline caused by a wide chamber can be compensated for by increasing the fluid-flow rate,utilizing the synergistic effect between the flu id-flow-field and electric-field to optimize the lithium extraction efficiency in the ESIX system.
基金support by The CO_(2) Flooding and Storage Safety Monitoring Technology(Grant 2023YFB4104200)The Dynamic Evolution of Marine CO_(2) Geological Sequestration Bodies and The Mechanism of Sequestration Efficiency Enhancement(Grant U23B2090)The Efficient Development Technology and Demonstration Project of Offshore CO_(2) Flooding(Grant KJGG-2022-12-CCUS-0203).
文摘Low-salinity water(LSW)and CO_(2) could be combined to perform better in a hydrocarbon reservoir due to their synergistic advantages for enhanced oil recovery(EOR);however,its microscopic recovery mechanisms have not been well understood due to the nature of these two fluids and their physical reactions in the presence of reservoir fluids and porous media.In this work,well-designed and inte-grated experiments have been performed for the first time to characterize the in-situ formation of micro-dispersions and identify their EOR roles during a LSW-alternating-CO_(2)(CO_(2)-LSWAG)process under various conditions.Firstly,by measuring water concentration and performing the Fourier transform infrared spectroscopy(FT-IR)analysis,the in-situ formation of micro-dispersions induced by polar and acidic materials was identified.Then,displacement experiments combining with nuclear magnetic resonance(NMR)analysis were performed with two crude oil samples,during which wettability,interfacial tension(IFT),CO_(2) dissolution,and CO_(2) diffusion were quantified.During a CO_(2)-LSWAG pro-cess,the in-situ formed micro-dispersions dictate the oil recovery,while the presence of clay minerals,electrical double-layer(EDL)expansion and multiple ion exchange(MIE)are found to contribute less.Such formed micro-dispersions are induced by CO_(2) via diffusion to mobilize the CO_(2)-diluted oil,alter the rock wettability towards more water-wet,and minimize the density contrast between crude oil and water.
基金2023 Nantong Jianghai Talents Project2023 Nantong Social Livelihood Science and Technology Plan+4 种基金2021 Jurong Social Development Science&Technology Program(Grant No.ZA42109)2022 New Drugs and Platform Enhancement Project of the Yangtze Delta Drug Advanced Research InstituteChina Postdoctoral Science Foundation(Grant No.2020M681532)Jiangsu Planned Projects for Postdoctoral Research Funds(Grant No.2020Z209)Natural Science Research Projects of Universities in Jiangsu Province(Grant No.20KJD350001)。
文摘Oseltamivir phosphate(OP),renowned as one of the most effective drugs for influenza treatment,encounters several challenges,including poor stability,difficulty in swallowing,and a bitter taste,thereby limiting its compliance,particularly among children.Consequently,this study aimed to devise a novel sustained-release suspension of OP employing an ion exchange resin as a carrier to address these challenges.The OP-drug resin complex(OP-DRC)was synthesized utilizing ion exchange technology,while OP-coated microcapsules(OP-CM)were fabricated via the emulsion-evaporation method.The optimization of the formulation process for the OP sustained-release suspension was achieved through a combination of single-factor experimentation and orthogonal experimental design.Furthermore,the drug release kinetics and pharmacokinetic properties of the sustained-release suspension were thoroughly evaluated both in vitro and in vivo.Scanning electron microscopy(SEM),X-ray diffraction(XRD),and attenuated total reflectance Fourier-transform infrared spectroscopy(ATR-FTIR)analyses confirmed the formation of drug-resin complexes via ionic bonding.The in vitro cumulative release rates were found to be 16%(1 h),53%(6 h),and 84%(24 h),respectively.Notably,the self-made sustained-release suspension exhibited an extended half-life(21.518 h),delayed time to peak concentration(T_(max))(6 h),and reduced maximum plasma concentration(C_(max))(0.397μg/mL)in comparison to commercial granules(half-life=8.466 h;T_(max)=2 h;C_(max)=0.631μg/mL).Additionally,the area under the curve(AUC)indicated that the bioavailability of the self-made OP suspension surpassed that of the commercial OP granules by 101%.These findings underscored the successful development of an oral OP sustained-release suspension characterized by stability,tastelessness,ease of swallowing,convenient administration,and sustained-release properties,thereby potentially enhancing drug compliance among children.
基金supported by the Teli Fellowship from Beijing Institute of Technology,the National Natural Science Foundation of China(Nos.52303366,22173109).
文摘In recent years,low-dimensional transition metal chalcogenide(TMC)materials have garnered growing research attention due to their superior electronic,optical,and catalytic properties compared to their bulk counterparts.The controllable synthesis and manipulation of these materials are crucial for tailoring their properties and unlocking their full potential in various applications.In this context,the atomic substitution method has emerged as a favorable approach.It involves the replacement of specific atoms within TMC structures with other elements and possesses the capability to regulate the compositions finely,crystal structures,and inherent properties of the resulting materials.In this review,we present a comprehensive overview on various strategies of atomic substitution employed in the synthesis of zero-dimensional,one-dimensional and two-dimensional TMC materials.The effects of substituting elements,substitution ratios,and substitution positions on the structures and morphologies of resulting material are discussed.The enhanced electrocatalytic performance and photovoltaic properties of the obtained materials are also provided,emphasizing the role of atomic substitution in achieving these advancements.Finally,challenges and future prospects in the field of atomic substitution for fabricating low-dimensional TMC materials are summarized.
基金supported by the National Natural Science Foundation of China (22179063)。
文摘Prussian blue analogues (PBAs) are regarded as promising cathode materials for potassium-ion batteries(PIBs) owing to their low cost and high reversible capacity.Compared to other PBAs,potassium manganese hexacyanoferrate (KMnHCF) stands out for its superior capacity and operating voltage.However,Jahn-Teller effect of Mn^(3+)and the structural collapse caused by potassium ion insertion/extraction still affect the structural stability and electrochemical performance of this material.Herein,a green and efficient synthesis method is adopted to substitute potassium ions in KMnHCF with an appropriate amount of cesium ions to form a column effect.Cesium-doped KMnHCF (Cs-KMnHCF) mitigates the irreversible structural damage caused by potassiation/depotassiation and the Jahn-Teller effect,thereby improving the cycling stability.In addition,it widens the lattice channels,reduces the diffusion barrier of potassium ions,and optimizes the diffusion kinetics.By rationally controlling the doping amount of Cs^(+),the obtained K_(1.71)Cs_(0.05)Mn[Fe(CN)_(6)]_(0.95·0.05)·0.88H_(2)O exhibits remarkable electrochemical performance,with an initial discharge capacity of 137.6 mA h g^(-1)at a current density of 20 mA g^(-1)and a capacity retention of 89.6%after 600 cycles at 200 mA g^(-1).More importantly,when assembled with a pitch-derived soft carbon anode,the full cell manifests excellent cycle stability and rate performance.This work is expected to provide a highly efficient cathode material for the practical application of PIBs.
基金supported by the National Natural Science Foundation of China (No.21976058)the Natural Science Foundation of Guangdong Province (No.2023A1515011682)+3 种基金the Fundamental Research Funds for the Central Universities (No.2022ZYGXZR018)the National Engineering Laboratory for Mobile Source Emission Control Technology (No.NELMS2020A10)the funding from the Pearl River Talent Recruitment Program of Guangdong Province (No.2019QN01L170)the Innovation & Entrepreneurship Talent Program of Shaoguan City。
文摘Palladium-exchanged chabazite(Pd-CHA) zeolites as passive NO_x adsorbers(PNAs) enable efficient purification of nitrogen oxides(NO_x) in cold-start diesel exhausts. Their commercial application, however,is limited by the lack of facile preparation method. Here, high-performance CHA-type Pd-SAPO-34 zeolite was synthesized by a modified solid-state ion exchange(SSIE) method using PdO as Pd precursor,and demonstrated superior PNA performance as compared to Pd-SAPO-34 prepared by conventional wetchemistry strategies. Structural characterization using Raman spectroscopy and X-ray diffraction revealed that the SSIE method avoided water-induced damage to the zeolite framework during Pd loading. Mechanistic investigations on the SSIE process by in situ infrared spectroscopy and X-ray photoelectron spectroscopy disclosed that, while PdO precursor was mainly converted to Pd^(2+) cations coordinated to the zeolite framework by consuming the-OH groups of the zeolite, a portion of PdO could also undergo thermal decomposition to form highly dispersed Pd~0 clusters in the pore channels. This simplified and scalable SSIE method paves a new way for the cost-effective synthesis of defect-free high-performance Pd-SAPO-34 zeolites as PNA catalysts.
基金Funded by National Natural Science Foundation of China(Nos.52172019 and 52072148)Shandong Provincial Youth Innovation Team Development Plan of Colleges and Universities(No.2022K1100)。
文摘In this work,the structure,viscosity and ion-exchange process of Na_(2)O-MgO-Al_(2)O_(3)-SiO_(2) glasses with different Al_(2)O_(3)/SiO_(2) molar ratios were investigated.The results showed that,with increasing Al_(2)O_(3)/SiO_(2) ratio,the simple structural units Q_(1) and Q_(2) transformed into highly aggregated structural units Q_(3) and Q_(4),indicating the increase of polymerization degree of glass network.Meanwhile,the coefficient of thermal expansion decreased from 9.23×10^(-6)℃^(-1) to 8.88×10^(-6)℃^(-1).The characteristic temperatures such as melting,forming,softening and glass transition temperatures increased with the increase of Al_(2)O_(3)/SiO_(2) ratio,while the glasses working temperature range became narrow.The increasing Al_(2)O_(3)/SiO_(2) ratio and prolonging ion-exchange time enhanced the surface compressive stress(CS)and depth of stress layer(DOL).However,the increase of ion exchange temperature increased the DOL and decreased the CS affected by stress relaxation.There was a good linear relationship between stress relaxation and surface compressive stress.Chemical strengthening significantly improved the hardness of glasses,which reached the maximum value of(622.1±10)MPa for sample with Al_(2)O_(3)/SiO_(2) ratio of 0.27 after heat treated at 410℃for 2 h.
基金Under the auspices of National Natural Science Foundation of China(No.41929002)Science and Technology Department of Sichuan Province(No.2021YFS0338)。
文摘Enhanced sulfur and nitrogen deposition has been observed in many transect regions worldwide,from urban/agricultural areas to mountains.The Sichuan Basin(SCB),with 18 prefectural cities,is the most economically-developed region in western China,while the rural Qinghai-Tibetan Plateau(QTP)lies west of the SCB.Previous regional and national atmospheric modeling studies have sug-gested that large areas in the SCB-to-QTP transect region experience excessive deposition of sulfur and nitrogen.In this study,we applied a passive monitoring method at 11 sites(one in urban Chengdu and 10 from fivenature reserves)in this transect region from September 2021 to October 2022 to confirm the high sulfur and nitrogen deposition fluxes and to understand the gaps between the modeling and observation results for this transect region.These observations suggest that the five reserves are under eutrophication risk,and only two reserves are partially under acidification risk.Owing to the complex topography and landscapes,both sulfur and nitrogen deposition and critical loads exhibit large spatial variations within a reserve,such as Mount Emei.Regional atmospheric modeling may not accurately capture the spatial variations in deposition fluxes within a reserve;however,it can capture general spatial patterns over the entire transect.This study demonstrates that a combination of state-of-the-art atmospheric chemical models and low-cost monitoring methods is helpful for ecological risk assessments at a regional scale.
基金funded by the Bioeconomy grant at the Latvian State Institute of Wood Chemistry“Transition to Greener Analytical Chemistry for the Analysis of Biorefinery ProductsWith Liquid Chromatography”(No.03-24).
文摘Fast pyrolysis of pre-treated birch wood in a super-heated steam environment produces a condensate rich in anhydrosugars.With the objective to obtain several product streams from this condensate,the possibility of extracting additional chemical species is explored,thus promoting the development of a pyrolysis-based biorefinery.In this work,the extraction and recovery of pyrolytic phenols from birch wood pyrolysis condensate was studied using ion exchange resins.With an aim to achieve effective phenol recovery,while obtaining high purity levoglucosan,basic ion exchange resins,both in OH−and Cl^(−)form,as well as polystyrene-divinyl resins without functional groups were compared.This study characterizes the influence of sorbent matrix type and porosity,functional group and counter ion on the sorption of various aromatic compounds.It was concluded that the counter ion of the ion exchange resins had the most influence on the pyrolytic phenol adsorption,while in the case of unfunctionalized resins smaller pore size improved removal of phenols from the pyrolysis liquids.Of the resins tested,the most effective at the removal and recovery of pyrolytic phenols were strongly basic,macroporous,anion exchange resins in OH^(−)form.The possibility to reuse the sorbents and solvents is explored to make the over-all process more environmentally friendly and economically feasible.
基金financially supported by the National Natural Science Foundation of China(No.51974368)supported by the Beamlines MCD-A and MCD-B(Soochow Beamline for Energy Materials)at NSRL。
文摘The synthesis of layered oxide cathode materials by the traditional high-temperature ceramic method usually requires calcination and annealing at temperatures in the range of 700-1000℃,with high energy consumption and serious cation mixing problems.Herein,we present a novel hydrothermalLi^(+)/H^(+)exchange method for the preparation of layered oxide cathodes at temperatures as low as 200℃.In contrast to the widely reported Li^(+)/Na^(+)exchange method using sodium-containing:precursors,layered oxide cathodes can be directly synthesized by hydrothermal reaction between commercial hydroxide precursors and LiOH·H2O.The reaction pathway consists of two steps.(1)The hydroxyl oxide intermediate is obtained by oxidizing the hydroxide precursor.(2)The layered oxide product is obtained by theLi^(+)/H^(+)exchange reaction of the hydroxyl oxide with Li+in solution.Through studying the time-resolved structural evolution,we reveal that the mechanism of material formation duringLi^(+)/H^(+)ion exchange is in situ crystallization,and the ion exchange process is accompanied by lattice distortion caused by internal diffusion of ions.These findings not only provide valuable insights into theLi^(+)/H^(+)exchange process,but also provide a new paradigm for the lowtemperature synthesis of advanced cathode materials.
基金Project(51174232)supported by the National Natural Science Foundation of China
文摘Based on the difference in tendency to polymerize between tungsten and molybdenum, a new method using D309 resin was propounded. The batch tests indicate that the optimum pH value and contact time for the separation are 7.0 and 4 h respectively, the maxium separation factor of W and Mo is 9.29. And the experimental resules show that isothermal absorbing tungsten and molybdenum belongs to Langmuir model and Freundlich model respectively, and the absorbing kinetics for tungsten is controlled by intra-particle diffusion. With a solution containing 70 g/L WO3 and 28.97 g/L Mo, the effluent with a mass ratio of Mo to WO3 of 76 and the eluate with a mass ratio of WO3 to Mo of 53.33 are obtained after column test.
基金Supported by 863 Program of China(2006AA03Z0453)NaturalScience Research Program of Higher Education of Jiangsu Province(09KJB230001)+1 种基金973 Program of China(2009CB724700)AndSchool Foundation of Jiangsu University(08JDG009)~~
文摘[ Objective] The research aimed to get the optimized separation and purification conditions of the hirudin produced from Bacillus subtilis DB403 （pUBH5）. [Method] Through the systemic pretreatment, preliminary chromatography and fine chromatography. [Result]The optimized separation and purification conditions were that： Supernatant was treated by trichloroacetic acid, then by ultrafiltration desalt and anion exchange chromatography. Strong anion Q F. F. was better than weak anion DEAE F.F. The proper balanced solution was Tris-HCI （ pH 8.0）. The proper conductivity was 6 ms/cm. The maximum applied sample was 240 ATU/ml to matrix of strong anion Q F. F. This optimized procedure was magnified in strong anion exchange HiPrep 16/10Q with the 90% recovery and 70.2% purity. The purification of gel filtration of Sephacryl S-100 to hirudin was not relative to flow rate within certain scope. The application size of sample was 10 ml. The purity checked by HPLC was 95.1%, and the recovery was 93%, and the band of SDS-PAGE was single. [ Conclusion] The research provided the reference of the further industrialization separation and purification of hiruin.
基金Projects (50974134,50804055) supported by the National Natural Science Foundation of ChinaProject (2005CB623701) supported by the National Basic Research Program of China
文摘The flotation and adsorption behaviors of dodecyltrimethylammonium chloride（DTAC） and cetyltrimethylammonium chloride（CTAC） on diaspore and kaolinite were studied.Solution depletion methods were used to determine adsorption isotherms.Fluorescence probe test along with Zeta potential measurement was also conducted for further investigation into the adsorption of quaternary amines at the mineral-water interface.The results show that the flotation recovery of kaolinite decreases with an increase in pH when DTAC and CTAC are used as collectors,while diaspore is on the contrary.As the carbon chain length of the collectors increases,the flotation recoveries of minerals increase.However,the increment rate of kaolinite is significantly lower than that of diaspore.In the low surfactant concentration range,the cationic surfactants adsorb readily on diaspore surfaces just due to electrostatic interactions.As for kaolinite surfaces,ion exchange process also exists.With a further increase in surfactant concentration,the adsorption was ascribed to the hydrophobic association of chain-chain interactions.Micro-polarity of mineral surfaces study shows that CTAC has a better hydrophobic characteristic than DTAC.Larger aggregates are formed with CTAC on diaspore than on kaolinite in the same solution concentration.The results also indicate that the chain length of cationic surfactants has a greater influence on the adsorption of diaspore than on kaolinite,which is consistent with the flotation result.
基金supported by the National Key Basic Research Program of China (973 Program, 2013CB933201)the National Natural Science Foun-dation of China (21577034, 21333003, 91545103)+1 种基金Science and Technology Commission of Shanghai Municipality (16ZR1407900)Fundamental Research Funds for the Central Universities (WJ1514020)~~
文摘Fe doped Beta zeolite with different Fe contents were prepared by ion exchange by changing the volume or the concentration of a Fe salt solution. For a particular mass of Fe salt precursor, the concentration of the metal salt solution during ion exchange influenced the ion exchange capacity of Fe, and resulted in different activities of the Fe-Beta catalyst. Fe-Beta catalysts with the Fe contents of （2.6, 6.3 and 9） wt% were synthesized using different amounts of 0.02 mol/L Fe salt solution. These catalysts were studied by various characterization techniques and their NH3-SCR activities were evaluated. The Fe-Beta catalyst with the Fe content of 6.3 wt% exhibited the highest activity, with a temperature range of 202-616℃ where the NOx conversion was 〉 80%. The Fe content in Beta zeolite did not influence the structure of Beta zeolite and valence state of Fe. Compared with the Fe-Beta catalysts with low Fe content （2.6 wt%）, Fe-Beta catalysts with 6.3 wt% Fe content possessed more isolated Fe3. active sites which led to its higher NH3-SCR activity. A high capacity for NH3 and NO adsorption, and a high activity for NO oxidation also contributed to the high NH3-SCR activity of the Fe-Beta catalyst with 6.3 wt%. However, when the Fe content was further increased to 9.0 wt%, the amount of FexOy nanoparticles increased while the amount of isolated Fe3＋ active sites was unchanged, which promoted NH3 oxidation and decreased the NH3-SCR activity at high temperature.
文摘Aim To prepare the prolonged-released microspheres of mefformin hydrochloride. Methods Ion-exchange resin-drug mefformin hydrochloride complexes were prepared as core materials, and followed by coating using ethylcellulose （EC） by the emulsion solvent diffusion technique. The release rate of mefformin from the microcapsules was highly dependent on the encapsulating formulation, thus being used as an index for formulation screening. Orthogonal experiments were performed to optimize the coating formulation. Results The final chosen formulation for coating of mefformin microcapsules were as follows： （ 1 ） the ratio of EC （20cps） to EC （45cps） was 50：50; （2） the ratio of plasticizer to coating materials was 20% ;and （3） the ratio of resin-mefformin complexes to coating materials was 5 ： 1. Conclusion The prolonged release microspheres of mefformin hydrochloride were successfully prepared.
基金Supported by National Natural Science Foundation of China(51143012)Natural Science Foundation of Shandong Province(ZR2009BM006)~~
文摘[Objective] This study aimed to establish an efficient process for separation of phycoerythrin by using Q Sepharose Fast Flow resin and verity its feasibility for scale-up. [Method] Elution gradient, sample volume and flow rate were optimized to determine the optimal separation condition, under which the scale-up process was verified. [Result] The optimal condition for separation of phycoerythrin by using Q Sepharose FF resin was investigated： 30 ml of laver extract was loaded to the Q Sepharose FF column with a bed volume of 8 ml; subsequently, the column was stepwise eluted with 0-0.10-0.35-1.00 mol/L NaCI solution （pH 6.0） at a constant flow rate of 1 ml/min; the elution peak under 0.35 mol/L NaCI solution was collected, and the recovery rate and purity coefficient （A565/A280） of phycoerythrin were determined as 44.3 and 1.15, respectively. Based on the established process, 75 ml of phycoerythrin extract was loaded to the Q Sepharose FF column with a bed volume of 20 ml for separation, while no significant variation was observed in the separation result. [Conclusion] Phycoerythrin can be well separated from laver extract by using Q Sepharose FF resin and the process is feasible for scale-up.
