Gas-driven permeation(GDP)and plasma-driven permeation(PDP)of hydrogen gas through Ga In Sn/Fe are systematically investigated in this work.The permeation parameters of hydrogen through Ga In Sn/Fe,including diffusivi...Gas-driven permeation(GDP)and plasma-driven permeation(PDP)of hydrogen gas through Ga In Sn/Fe are systematically investigated in this work.The permeation parameters of hydrogen through Ga In Sn/Fe,including diffusivity,Sieverts'constant,permeability,and surface recombination coefficient are obtained.The permeation flux of hydrogen through Ga In Sn/Fe shows great dependence on external conditions such as temperature,hydrogen pressure,and thickness of liquid Ga In Sn.Furthermore,the hydrogen permeation behavior through Ga In Sn/Fe is well consistent with the multilayer permeation theory.In PDP and GDP experiments,hydrogen through Ga In Sn/Fe satisfies the diffusion-limited regime.In addition,the permeation flux of PDP is greater than that of GDP.The increase of hydrogen plasma density hardly causes the hydrogen PDP flux to change within the test scope of this work,which is due to the dissolution saturation.These findings provide guidance for a comprehensive and systematic understanding of hydrogen isotope recycling,permeation,and retention in plasma-facing components under actual conditions.展开更多
Atomic layer deposition （ALD） technique is used in the preparation of organic/inorganic layers, which requires uniform surfaces with their thickness down to several nanometers. For film with such thickness, the grow...Atomic layer deposition （ALD） technique is used in the preparation of organic/inorganic layers, which requires uniform surfaces with their thickness down to several nanometers. For film with such thickness, the growth mode defined as the arrangement of clusters on the surface during the growth is of significance. In this work, Al2O3 thin film was deposited on various interfacial species of pre-treated polyethylene terephthalate （PET, 12 μm） by plasma assisted atomic layer deposition （PA-ALD）, where trimethyl aluminium was used as the Al precursor and O2 as the oxygen source. The interracial species, -NH3, -OH, and -COOH as well as SiCHO （derived from monomer of HMDSO plasma）, were grafted previously by plasma and chemical treatments. The growth mode of PA-ALD Al2O3 was then investigated in detail by combining results from in-situ diagnosis of spectroscopic ellipsometry （SE） and ex-situ characterization of as-deposited layers from the morphologies scanned by atomic force microscopy （AFM）. In addition, the oxygen transmission rates （OTR） of the original and treated plastic films were measured. The possible reasons for the dependence of the OTR values on the surface species were explored.展开更多
Ba0.9R0.1Co0.TFe0.225Ta0.07503-δ （BRCFT, R = Ca, La or Sr） membranes were synthesized by a solid-state reaction. Metal cation Ca2＋, La3＋ or Sr2＋ doping on A-site partially substituted Ba2＋ in BaCoo.TFe0.225Ta0....Ba0.9R0.1Co0.TFe0.225Ta0.07503-δ （BRCFT, R = Ca, La or Sr） membranes were synthesized by a solid-state reaction. Metal cation Ca2＋, La3＋ or Sr2＋ doping on A-site partially substituted Ba2＋ in BaCoo.TFe0.225Ta0.07503-δ oxides, and its subsequent effects on phase structure stability, oxygen permeability and oxygen desorption were systematically investigated by XRD, TG-DSC, Hz-TPR, O2-TPD techniques and oxygen permeation experiments. The partial substitution with Ca2＋, La3＋ or Sr2＋, whose ionic radii are smaller than that of Ba2＋, succeeded in stabilizing the cubic perovskite structure without formation of impurity phases, as revealed by XRD analysis. Oxygen-involving experi- ments showed that BRCFT with A-site fully occupied by Ba2＋ exhibited good oxygen permeation flux under He flow, reaching about 2.3 mL.min-l .cm-2 at 900 with I mm thickness. Of all the membranes, BLCFT membrane showed better chemical stability in CO2, owing to the reduction in alkalinity of the mixed conductor oxide by La doping. In addition, we also found the stability of the perovskite structure under reducing atmospheres was strengthened by increasing the size of A-site cation （Ba2＋〉La3＋〉SrZ＋〉Ca2＋）.展开更多
Mixed oxygen-ionic and electronic conducting membranes of SrFe（Cu）O3-δ were prepared by solid-state reaction method. The crystal structure, oxygen nonstoichiometry, and phase stability of the materials were studied...Mixed oxygen-ionic and electronic conducting membranes of SrFe（Cu）O3-δ were prepared by solid-state reaction method. The crystal structure, oxygen nonstoichiometry, and phase stability of the materials were studied by TGA and XRD. Oxygen permeation fluxes through these membranes were studied at operating temperature ranging from 750 to 950 ℃. Results showed that doping Cu in SrFeO3-δ compound had a significant effect on the formation of single-phased perovskite structure. For SrFe1-xCu2O3-δ series materials, the oxygen nonstoichiometry and the oxygen permeation flux increased considerably with the increase of Cu-doping content （x = 0.1-0.3）. The sintering property of the membrane decreased significantly when the Cu substitution amount reached 40%. SrFe0.7Cu0.3O3-δ showed high oxygen permeation flux, but SrCuO2 and Sr2Fe2O5 phases formed in the compound after oxygen permeation test induced cracks in the membrane.展开更多
Tight oil reservoir development is faced with the key technical problem that"water cannot be injected and oil cannot be produced"yet.With the diphenyl ethers water-soluble(gemini)surfactants as water phase s...Tight oil reservoir development is faced with the key technical problem that"water cannot be injected and oil cannot be produced"yet.With the diphenyl ethers water-soluble(gemini)surfactants as water phase shell and C10–C14 straight-chain hydrocarbon compounds as oil phase kernel,a nanofluids permeation flooding system was prepared by microemulsion technology,and its characteristics and EOR mechanisms were evaluated through experiments.The system has the following five characteristics:(1)"Small-size liquid":the average particle size of the system is less than 30 nm,which can greatly reduce the starting pressure gradient of water injection,and effectively enter and expand the sweep volume of micro-nano matrix;(2)"Small-size oil":the system can break the crude oil into"small-size oil"under the flow condition,which can greatly improve the percolation ability and displacement efficiency of the crude oil in the micro-nano matrix;(3)Dual-phase wetting:the system has contact angles with the water-wet and oil-wet interfaces of(46±1)°and(68±1)°respectively,and makes it possible for capillarity to work fully under complex wetting conditions of the reservoir;(4)High surface activity:the interfacial tension between the system and crude oil from a tight oil reservoir in Xinjiang is 10-3–10-2 mN/m,indicating the system can effectively improve the displacement efficiency of oil in fine pore throats;(5)Demulsification and viscosity reduction:the system has a demulsification and viscosity reduction rate of more than 80%to inversely emulsified crude oil from a tight oil reservoir in Xinjiang,so it can improve the mobility of crude oil in the reservoir and wellbore.The system can be used to increase oil production by fracturing in tight reservoirs,replenish formation energy by reducing injection pressure and increasing injection rate,and enhance oil recovery by displacement and cyclic injection,providing key technical support for effective production and efficient development and recovery enhancement of tight reservoirs.展开更多
In this work, hydrogen absorption and the permeation behavior of the passive layer formed on zircaloy-4 are in- vestigated. Potentiodynamic polarization, Mott-Schottky analysis, electrochemical impedance spectroscopy,...In this work, hydrogen absorption and the permeation behavior of the passive layer formed on zircaloy-4 are in- vestigated. Potentiodynamic polarization, Mott-Schottky analysis, electrochemical impedance spectroscopy, and Raman scattering spectroscopy are employed to characterize the passive defects before and after hydrogen permeation. It is found that the nanoscale passive ZrO2 films play an important role in the resistance against corrosion; hydrogen impingement, however, reduces the passive impedance towards hydrothermal oxidation. The increase of defects （vacancies） in passive film is probably attributed to the degradation. We believe that this finding will provide valuable insight into the understanding of the corrosion mechanism of zircaloys used in light water reactors.展开更多
Objective： To fred a more effective method of topical transdermal delivery of curcumin. Methods： We prepared curcumin carbopol （CRB） 974P and hydroxypropylcellulose （HPC） gel formulations containing menthol or A...Objective： To fred a more effective method of topical transdermal delivery of curcumin. Methods： We prepared curcumin carbopol （CRB） 974P and hydroxypropylcellulose （HPC） gel formulations containing menthol or Azone as permeation enhancers In this study, negative mode electrospray ionization and a triple quadruple LC/MS/MS instrument operated in multiple reaction mode was used for curcumin detection. The assay was linear over a concentration range of 10 ng/mL to 400 ng/mL for curcumin （average R2 = 0.997 2）. Excised nude mouse dorsal side skin was used in an in vitro skirt permeation study performed using the method of Franz. Results： Our results showed that all of the topical gel formulations we developed were free from skin irritation. The percutaneous flux and enhancement ratio of curcumin across nude mouse epidermis were enhanced markedly by the addition of menthol or Azone to both types of gel formulations. We found that the HPC gels containing quantities of Azone showed an enhanced permeation effect as compared to gels containing menthol. In the case of HPC gels containing Azone, the increase in permeability was significant （P〈0.05） as compared to the gels containing menthol. Conclusion： Azone shows a significantly more remarkable permeation effect than menthol. As such, this novel delivery strategy offers significant promise and is worthy of further exploration in attempts to enhance the medicinal application of curcumin展开更多
Tritium permeation through the first wall （FW） from the plasma into helium coolant is evaluated for a dual-functional lithium-lead test blanket module （DFLL-TBM）. The effect of the surface conditions on the plasma...Tritium permeation through the first wall （FW） from the plasma into helium coolant is evaluated for a dual-functional lithium-lead test blanket module （DFLL-TBM）. The effect of the surface conditions on the plasma facing and coolant sides, both temperature gradient and beryllium layer clad on the plasma facing side, as well as trapping in defects on the tritium permeation is considered. The results show that most of the tritium implanted in FW re-entered the plasma. The plasma-driven tritium permeation is very sensitive to the surface conditions on the plasma facing side. With a higher sticking coefficient on the plasma-facing side, the tritium permeation into helium coolant is significantly reduced. The tritium permeation is strongly reduced with a beryllium layer clad on the front side of FW. The plasma driven tritium permeation will not seriously impact the tritium safety of DFLL-TBM. Based on tritium safety, it is reasonable to clothe the beryllium layer on FW and keep the surface clean to reduce the plasma driven tritium permeation.展开更多
Two sets of widely used parameters can describe the molecular permeation through a nanochannel.One is permeation rate j and its diffusion Dn,and the other is flow and net flux.We establish a relationship between the t...Two sets of widely used parameters can describe the molecular permeation through a nanochannel.One is permeation rate j and its diffusion Dn,and the other is flow and net flux.We establish a relationship between the two sets for a single-file nenochannel,as well as its dependence on the temperature and pressure difference between the two ends of a single-file channel,based on the Brownian motion theories and verified with molecular dynamics simulations for the water diffusion in a transmembrane (6,6) armchair carbon nanotube.Simulation results are in excellent agreement with our predictions.展开更多
In this study,a Cr_(2)O_(3) nanosheet(Cr_(2)O_(3) NS)inserted Cr-Zr-O coating was developed as a hydrogen isotope permeation barrier.The Cr_(2)O_(3) NSs,fabricated by rapid heat treatment,were amorphous with a thickne...In this study,a Cr_(2)O_(3) nanosheet(Cr_(2)O_(3) NS)inserted Cr-Zr-O coating was developed as a hydrogen isotope permeation barrier.The Cr_(2)O_(3) NSs,fabricated by rapid heat treatment,were amorphous with a thickness of only several nanometers.These Cr_(2)O_(3) NSs were then incorporated into a Cr-Zr-O multi-metal oxide composite coating via a dip-coating method to form a coating.The effect of the Cr_(2)O_(3) NS concentration on the morphology,microstructure and deuterium permeation resistance of the coating was studied.With the addition of 1.0 g 1^(-1)Cr_(2)O_(3) NSs,compared with the Cr-Zr-O coating without NSs,the permeation reduction factor of the resultant coating was enhanced from 249℃to 575℃ at 500℃.The coating,with a thickness of nearly 193 nm,achieved a comparable deuterium resistance that was above two orders of magnitude higher than the steel substrate.The results show that ceramic NSs can serve as effective fillers for enhancing the coating performance when functioning as a hydrogen isotope barrier.展开更多
Industry decarbonization requires the development of highly efficient and flexible technologies relying on renewable energy resources,especially biomass and solar/wind electricity.In the case of pure oxygen production...Industry decarbonization requires the development of highly efficient and flexible technologies relying on renewable energy resources,especially biomass and solar/wind electricity.In the case of pure oxygen production,oxygen transport membranes(OTMs)appear as an alternative technology for the cryogenic distillation of air,the industrially-established process of producing oxygen.Moreover,OTMs could provide oxygen from different sources(air,water,CO_(2),etc.),and they are more flexible in adapting to current processes,producing oxygen at 700^(-1)000℃.Furthermore,OTMs can be integrated into catalytic membrane reactors,providing new pathways for different processes.The first part of this study was focused on electrification on a traditional OTM material(Ba_(0.5)Sr_(0.5)Co_(0.8)Fe_(0.2)O_(3-δ)),imposing different electric currents/voltages along a capillary membrane.Thanks to the emerging Joule effect,the membrane-surface temperature and the associated O_(2) permeation flux could be adjusted.Here,the OTM is electrically and locally heated and reaches 900℃on the surface,whereas the surrounding of the membrane was maintained at 650℃.The O_(2)permeation flux reached for the electrified membranes was~3.7 NmL min^(-1)cm^(-2),corresponding to the flux obtained with an OTM non-electrified at 900℃.The influence of depositing a porous Ce_(0.8)Tb_(0.2)O_(2-δ) catalytic/protective layer on the outer membrane surface revealed that lower surface temperatures(830℃)were detected at the same imposed electric power.Finally,the electrification concept was demonstrated in a catalytic membrane reactor(CMR)where the oxidative dehydrogenation of ethane(ODHE)was carried out.ODHE reaction is very sensitive to temperature,and here,we demonstrate an improvement of the ethylene yield by reaching moderate temperatures in the reaction chamber while the O_(2) injection into the reaction can be easily fine-tuned.展开更多
Conventional plasticizers deteriorate mechanical and viscoelastic properties of the propellants due to their migration upon aging and long-term storage,which affects reliability and safety properties during exploitati...Conventional plasticizers deteriorate mechanical and viscoelastic properties of the propellants due to their migration upon aging and long-term storage,which affects reliability and safety properties during exploitation.To address this issue,conventional plasticizer,dioctyl adipate(DOA),is replaced by reactive one,castor oil(CO).In addition,three different types of HTPB were used to obtain propellants with designed viscoelastic and mechanical properties.The CO increased propellants viscosity,without a significant impact on the propellant processability,regardless to the type of prepolymer.Conversely,mechanical properties were different depending on the type of resin,which were further analyzed by gel permeation chromatography(GPC).Addition of CO formed a denser polymer network and shifted T_(g) to higher values,compared to the compositions with DOA.The tensile strength of CO-containing propellants was lower at +20℃ and +50℃ compared to the reference compositions,while the strain at maximum load and strain at break were significantly increased with pronounced plastic deformation,especially for samples at -30℃.The inclusion of CO in the propellants composition gives more room for adjusting a wide range of mechanical properties.展开更多
A GC-MS method for the determination of 27 organochlorine pesticides and 15 Pyrethroid pesticides in animal food is established.The method was based on Gel Permeation chromatography combined with solid-phase extractio...A GC-MS method for the determination of 27 organochlorine pesticides and 15 Pyrethroid pesticides in animal food is established.The method was based on Gel Permeation chromatography combined with solid-phase extraction for sample preparation.Rapid qualitative and quantitative analyses was carried out by gas chromatography-mass spectrometry under the selective-ion monitoring mode.The experimental results showed that the correlation coefficients were better than 0.99,the recoveries for spiked standards were 70%-104%,the relative standard deviations were 2.1%-15.9%.展开更多
The performance of LiNi/γ-Al2O3 catalysts modified by rare earth metal oxide （La2O3 or CeO2） packed on BCFNO membrane reactor was discussed for the partial oxidation of methane （POM） in coke oven gas （COG） at 8...The performance of LiNi/γ-Al2O3 catalysts modified by rare earth metal oxide （La2O3 or CeO2） packed on BCFNO membrane reactor was discussed for the partial oxidation of methane （POM） in coke oven gas （COG） at 875 ℃. The NiO/γ-Al2O3 catalysts with different amounts of La2O3 and CeO2 were prepared with the same preparation method and under the same condition in order to compare the reaction performance （oxygen permeation, CH4 conversion, H2 and CO selectivity） on the membrane reactor. The results show that the oxygen permeation flux increased significantly with LiNiREOx/γ-Al2O3 （RE = La or Ce） catalysts by adding the element of rare earth especially the Ce during the POM in COG. Such as, the Li15wt%CeO29wt%NiO/γ-Al2O3 catalyst with an oxygen permeation flux of 24.71 ml·cm^-2·min^-1 and a high CH4 conversion was obtained in 875 ℃. The resulted high oxygen permeation flux may be due to the added Ce that inhibited the strong interaction between Ni and Al2O3 to form the NiAl2O4 phase. In addition, the introduction of Ce leads up to an important property of storing and releasing oxygen.展开更多
Nanosized SSZ-13 zeolite was synthesized by traditional hydrothermal method using N,N,N-trimethyl-1-adamantanaminium hydroxide as the structure-directing agent (SDA). The influence of different preparative conditions ...Nanosized SSZ-13 zeolite was synthesized by traditional hydrothermal method using N,N,N-trimethyl-1-adamantanaminium hydroxide as the structure-directing agent (SDA). The influence of different preparative conditions of nanosized SSZ-13 was investigated systematically. The synthetic zeolites were characterized by X-ray powder diffraction (XRD), nitrogen physisorption, and scanning electron microscopy (SEM). By means of the self-assembled method, the thin SSZ-13/polyvinyl alcohol nanocomposite membranes were obtained by incorporating the nanosized SSZ-13 zeolite into the polymeric precursor (polyvinyl alcohol (PVA)). The permeation properties of pure CO2 and CH4 through the mixed matrix membranes (MMMs) were measured. The results showed that the highly crystalline SSZ-13 zeolite in a dispersed nanocrystal form with a controllable particle size of 100 nm could be hydrothermally synthesized by optimizing the synthetic parameters and the selectivity of CO2/CH4 of the MMMs could reach a value of 40 by changing the amount of nanosized SSZ-13 zeolite.展开更多
E dible bird’s nest(EBN)hydrolysates have been proven to exhibit enhanced bioactivities.However,being a macromolecule,fractions with different molecular weights would have different properties and bioactivities.Hence...E dible bird’s nest(EBN)hydrolysates have been proven to exhibit enhanced bioactivities.However,being a macromolecule,fractions with different molecular weights would have different properties and bioactivities.Hence,this research was aimed to determine the chemical properties and antioxidant activities of freezedried(EBN_(FD))and spray-dried EBN(EBN_(SD))hydrolysates fractionated using gel permeation chromatography(GPC).Overall,two well-separated fractions were identified(EBN_(fFD1),EBN_(fFD2),EBN_(fSD1) and EBN_(fSD2)).EBNFD demonstrated significantly higher(P≤0.05)peptide(3.6%),total carbohydrate(27.7%)and sialic acid(18.2%)contents than that of EBNSD.Similar trend was observed in low molecular weight fractionates(EBN_(fFD2) and EBN_(fSD2)).Meanwhile,the first fractionates(EBN_(fFD1) and EBN_(fSD1))exhibited significantly higher(P≤0.05)hydroxyl radical(·OH)scavenging activity.Fourier transform infrared(FTIR)spectroscopy demonstrated that all EBN fractionates have similar spectrum,except in the region of N—H(amideⅡ)and C—H alkyl group.In conclusion,EBN fractionates with different molecular weights showed different chemical properties and antioxidant activities.展开更多
Ba1.0Co0.7Fe0.2Nb0.1O3-γ（BCFN） oxide with perovskite cubic structure was synthesized by solid state reaction method. COa corrosion of BCFN membrane was investigated by X-ray diffraction （XRD）, scanning electron m...Ba1.0Co0.7Fe0.2Nb0.1O3-γ（BCFN） oxide with perovskite cubic structure was synthesized by solid state reaction method. COa corrosion of BCFN membrane was investigated by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, diffuse reflectance infrared Fourier- transformed spectroscopy （DRIFT） and X-ray absorption fine structure spectroscopy （XAFS）. Cobalt （Co） K-edge absorption spectra of BCFN annealed in COa reveal that the oxidation states of Co in all the samples were larger than ＋3 and they decreased with the increase of calcination time. At 800 ℃, 1% CO2 introduced into He could speed up the reduction of Co cations in comparison with pure He. In addition, sulfate ions in the bulk of BCFN membrane preferred to migrate to the surface under CO2 calcination and form monoclinic Ba（CO3）0.9（SO4）0.1 besides orthorhombic witherite. Moreover, SEM results indicate that the nucleation and growth of carbonates grains started at the grain boundary of the membrane.展开更多
It is well known that potassium ion channels have higher permeability than K ions, and the permeable rate of a single K ion channel is about 108 ions per second. We develop a hierarchical model of potassium ion channe...It is well known that potassium ion channels have higher permeability than K ions, and the permeable rate of a single K ion channel is about 108 ions per second. We develop a hierarchical model of potassium ion channel permeation involving ab initio quantum calculations and Brownian dynamics simulations, which can consistently explain a range of channel dynamics. The results show that the average velocity of K ions, the mean permeable time of K ions and the permeable rate of single channel are about 0.92nm/ns, 4.35ns and 2.30 ×10^8 ions/s, respectively.展开更多
Single-phase perovskite La0.6Sr0.4Co0.8Fe0.2O3-δ has been successfully prepared by using citrate-EDTA complexation method at relatively low calcination temperature. The structure and thermal decomposition process of ...Single-phase perovskite La0.6Sr0.4Co0.8Fe0.2O3-δ has been successfully prepared by using citrate-EDTA complexation method at relatively low calcination temperature. The structure and thermal decomposition process of the complex precursor have been investigated by means of differential scanning calorimetry-thermal gravimetric analysis （DSC/TGA）, X-ray diffraction （XRD）, and Fourier transform infrared spectroscopic （FT-IR） measurements. The precursor decomposed completely and started to form perovskite-type oxide above 420 ℃ according to the differential scanning calorimetry （DSC） and thermal gravimetric analysis （TGA） results. Single-phase perovskite La0.6Sr0.4Co0.8Fe0.2O3-δ obtained has been confirmed from the XRD pattern, and no peak of SrCO3 was found by XRD of the oxides synthesized at a relatively low temperature of 800℃. The reducibility of La0.6Sr0.4Co0.8Fe0.2O3-δ was also characterized by the temperature programmed reduction （TPR） technique. Disk shaped dense La0.6Sr0.4Co0.8Fe0.2O3-δ membrane was prepared by the isostatical pressing method. The oxygen flux rate of dense La0.6Sr0.4Co0.8Fe0.2O3-δ membrane was （2.8-18）× 10^-8 mol/（cm^2.s） in the temperature range of 800-1000 ℃.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11905151 and 11875198)the National Key Research and Development Program of China(Grant No.2022YFE03130000)。
文摘Gas-driven permeation(GDP)and plasma-driven permeation(PDP)of hydrogen gas through Ga In Sn/Fe are systematically investigated in this work.The permeation parameters of hydrogen through Ga In Sn/Fe,including diffusivity,Sieverts'constant,permeability,and surface recombination coefficient are obtained.The permeation flux of hydrogen through Ga In Sn/Fe shows great dependence on external conditions such as temperature,hydrogen pressure,and thickness of liquid Ga In Sn.Furthermore,the hydrogen permeation behavior through Ga In Sn/Fe is well consistent with the multilayer permeation theory.In PDP and GDP experiments,hydrogen through Ga In Sn/Fe satisfies the diffusion-limited regime.In addition,the permeation flux of PDP is greater than that of GDP.The increase of hydrogen plasma density hardly causes the hydrogen PDP flux to change within the test scope of this work,which is due to the dissolution saturation.These findings provide guidance for a comprehensive and systematic understanding of hydrogen isotope recycling,permeation,and retention in plasma-facing components under actual conditions.
基金supported by National Natural Science Foundation of China (No.11175024)Beijing Natural Science Foundation (No.1112012),2011BAD24B01+1 种基金Scientific Research Common Program of Beijing Municipal Commission of Education(KM201110015008,KM201010015005)Funding Project for Academic Human Resources Development in Institutions of Higher Learning Under theJurisdiction of Beijing Municipality (PHR20110516)
文摘Atomic layer deposition （ALD） technique is used in the preparation of organic/inorganic layers, which requires uniform surfaces with their thickness down to several nanometers. For film with such thickness, the growth mode defined as the arrangement of clusters on the surface during the growth is of significance. In this work, Al2O3 thin film was deposited on various interfacial species of pre-treated polyethylene terephthalate （PET, 12 μm） by plasma assisted atomic layer deposition （PA-ALD）, where trimethyl aluminium was used as the Al precursor and O2 as the oxygen source. The interracial species, -NH3, -OH, and -COOH as well as SiCHO （derived from monomer of HMDSO plasma）, were grafted previously by plasma and chemical treatments. The growth mode of PA-ALD Al2O3 was then investigated in detail by combining results from in-situ diagnosis of spectroscopic ellipsometry （SE） and ex-situ characterization of as-deposited layers from the morphologies scanned by atomic force microscopy （AFM）. In addition, the oxygen transmission rates （OTR） of the original and treated plastic films were measured. The possible reasons for the dependence of the OTR values on the surface species were explored.
基金supported by the National Natural Science Foundation of China(51004069)the National Science Fund for Distinguished Young Scholars(51225401)+1 种基金China Postdoctoral Science Foundation(201104254)the Innovation Program of Shanghai Municipal Education Commission and Shanghai University(14YZ013 and SDCX2012002)
文摘Ba0.9R0.1Co0.TFe0.225Ta0.07503-δ （BRCFT, R = Ca, La or Sr） membranes were synthesized by a solid-state reaction. Metal cation Ca2＋, La3＋ or Sr2＋ doping on A-site partially substituted Ba2＋ in BaCoo.TFe0.225Ta0.07503-δ oxides, and its subsequent effects on phase structure stability, oxygen permeability and oxygen desorption were systematically investigated by XRD, TG-DSC, Hz-TPR, O2-TPD techniques and oxygen permeation experiments. The partial substitution with Ca2＋, La3＋ or Sr2＋, whose ionic radii are smaller than that of Ba2＋, succeeded in stabilizing the cubic perovskite structure without formation of impurity phases, as revealed by XRD analysis. Oxygen-involving experi- ments showed that BRCFT with A-site fully occupied by Ba2＋ exhibited good oxygen permeation flux under He flow, reaching about 2.3 mL.min-l .cm-2 at 900 with I mm thickness. Of all the membranes, BLCFT membrane showed better chemical stability in CO2, owing to the reduction in alkalinity of the mixed conductor oxide by La doping. In addition, we also found the stability of the perovskite structure under reducing atmospheres was strengthened by increasing the size of A-site cation （Ba2＋〉La3＋〉SrZ＋〉Ca2＋）.
基金Natural Science Foundation of Guangdong Province (No. 030514)the Science and Technology Program of Guangdong Province(No. 2004B33401006)
文摘Mixed oxygen-ionic and electronic conducting membranes of SrFe（Cu）O3-δ were prepared by solid-state reaction method. The crystal structure, oxygen nonstoichiometry, and phase stability of the materials were studied by TGA and XRD. Oxygen permeation fluxes through these membranes were studied at operating temperature ranging from 750 to 950 ℃. Results showed that doping Cu in SrFeO3-δ compound had a significant effect on the formation of single-phased perovskite structure. For SrFe1-xCu2O3-δ series materials, the oxygen nonstoichiometry and the oxygen permeation flux increased considerably with the increase of Cu-doping content （x = 0.1-0.3）. The sintering property of the membrane decreased significantly when the Cu substitution amount reached 40%. SrFe0.7Cu0.3O3-δ showed high oxygen permeation flux, but SrCuO2 and Sr2Fe2O5 phases formed in the compound after oxygen permeation test induced cracks in the membrane.
基金Supported by the CNPC Science and Technology Major Project(2019E-2607)RIPED Discipline Construction Project(yjxk2019-12)
文摘Tight oil reservoir development is faced with the key technical problem that"water cannot be injected and oil cannot be produced"yet.With the diphenyl ethers water-soluble(gemini)surfactants as water phase shell and C10–C14 straight-chain hydrocarbon compounds as oil phase kernel,a nanofluids permeation flooding system was prepared by microemulsion technology,and its characteristics and EOR mechanisms were evaluated through experiments.The system has the following five characteristics:(1)"Small-size liquid":the average particle size of the system is less than 30 nm,which can greatly reduce the starting pressure gradient of water injection,and effectively enter and expand the sweep volume of micro-nano matrix;(2)"Small-size oil":the system can break the crude oil into"small-size oil"under the flow condition,which can greatly improve the percolation ability and displacement efficiency of the crude oil in the micro-nano matrix;(3)Dual-phase wetting:the system has contact angles with the water-wet and oil-wet interfaces of(46±1)°and(68±1)°respectively,and makes it possible for capillarity to work fully under complex wetting conditions of the reservoir;(4)High surface activity:the interfacial tension between the system and crude oil from a tight oil reservoir in Xinjiang is 10-3–10-2 mN/m,indicating the system can effectively improve the displacement efficiency of oil in fine pore throats;(5)Demulsification and viscosity reduction:the system has a demulsification and viscosity reduction rate of more than 80%to inversely emulsified crude oil from a tight oil reservoir in Xinjiang,so it can improve the mobility of crude oil in the reservoir and wellbore.The system can be used to increase oil production by fracturing in tight reservoirs,replenish formation energy by reducing injection pressure and increasing injection rate,and enhance oil recovery by displacement and cyclic injection,providing key technical support for effective production and efficient development and recovery enhancement of tight reservoirs.
基金Project supported by the National Basic Research Program of China(Grant No.2011CB610501)the Funds from the State Key Laboratory of Surface and Chemistry,China(Grant No.SPC 201102)the Reactor Fuel and Materials Laboratory,China(Grant No.STRFML-2013-05)
文摘In this work, hydrogen absorption and the permeation behavior of the passive layer formed on zircaloy-4 are in- vestigated. Potentiodynamic polarization, Mott-Schottky analysis, electrochemical impedance spectroscopy, and Raman scattering spectroscopy are employed to characterize the passive defects before and after hydrogen permeation. It is found that the nanoscale passive ZrO2 films play an important role in the resistance against corrosion; hydrogen impingement, however, reduces the passive impedance towards hydrothermal oxidation. The increase of defects （vacancies） in passive film is probably attributed to the degradation. We believe that this finding will provide valuable insight into the understanding of the corrosion mechanism of zircaloys used in light water reactors.
基金Supported by the National Natural Science Foundation of China(81173130)
文摘Objective： To fred a more effective method of topical transdermal delivery of curcumin. Methods： We prepared curcumin carbopol （CRB） 974P and hydroxypropylcellulose （HPC） gel formulations containing menthol or Azone as permeation enhancers In this study, negative mode electrospray ionization and a triple quadruple LC/MS/MS instrument operated in multiple reaction mode was used for curcumin detection. The assay was linear over a concentration range of 10 ng/mL to 400 ng/mL for curcumin （average R2 = 0.997 2）. Excised nude mouse dorsal side skin was used in an in vitro skirt permeation study performed using the method of Franz. Results： Our results showed that all of the topical gel formulations we developed were free from skin irritation. The percutaneous flux and enhancement ratio of curcumin across nude mouse epidermis were enhanced markedly by the addition of menthol or Azone to both types of gel formulations. We found that the HPC gels containing quantities of Azone showed an enhanced permeation effect as compared to gels containing menthol. In the case of HPC gels containing Azone, the increase in permeability was significant （P〈0.05） as compared to the gels containing menthol. Conclusion： Azone shows a significantly more remarkable permeation effect than menthol. As such, this novel delivery strategy offers significant promise and is worthy of further exploration in attempts to enhance the medicinal application of curcumin
基金supported by National Natural Science Foundation of China(Nos.10675123,10775135 and 50871108)the Knowledge Innovation Program of Chinese Academy of Sciences
文摘Tritium permeation through the first wall （FW） from the plasma into helium coolant is evaluated for a dual-functional lithium-lead test blanket module （DFLL-TBM）. The effect of the surface conditions on the plasma facing and coolant sides, both temperature gradient and beryllium layer clad on the plasma facing side, as well as trapping in defects on the tritium permeation is considered. The results show that most of the tritium implanted in FW re-entered the plasma. The plasma-driven tritium permeation is very sensitive to the surface conditions on the plasma facing side. With a higher sticking coefficient on the plasma-facing side, the tritium permeation into helium coolant is significantly reduced. The tritium permeation is strongly reduced with a beryllium layer clad on the front side of FW. The plasma driven tritium permeation will not seriously impact the tritium safety of DFLL-TBM. Based on tritium safety, it is reasonable to clothe the beryllium layer on FW and keep the surface clean to reduce the plasma driven tritium permeation.
基金Supported by the National Natural Science Foundation of China under Grant No 21173154the Pre-research Foundation of National Natural Science from Soochow Univerisity(No Q310904210).
文摘Two sets of widely used parameters can describe the molecular permeation through a nanochannel.One is permeation rate j and its diffusion Dn,and the other is flow and net flux.We establish a relationship between the two sets for a single-file nenochannel,as well as its dependence on the temperature and pressure difference between the two ends of a single-file channel,based on the Brownian motion theories and verified with molecular dynamics simulations for the water diffusion in a transmembrane (6,6) armchair carbon nanotube.Simulation results are in excellent agreement with our predictions.
基金supported by the National MCF Energy R&D Program of China(No.2018YFE0313300)National Natural Science Foundation of China(Nos.52273224,51402116)the Fundamental Research Funds for the Central Universities(Nos.2018KFYYXJJ028,2019KFYXMBZ045)
文摘In this study,a Cr_(2)O_(3) nanosheet(Cr_(2)O_(3) NS)inserted Cr-Zr-O coating was developed as a hydrogen isotope permeation barrier.The Cr_(2)O_(3) NSs,fabricated by rapid heat treatment,were amorphous with a thickness of only several nanometers.These Cr_(2)O_(3) NSs were then incorporated into a Cr-Zr-O multi-metal oxide composite coating via a dip-coating method to form a coating.The effect of the Cr_(2)O_(3) NS concentration on the morphology,microstructure and deuterium permeation resistance of the coating was studied.With the addition of 1.0 g 1^(-1)Cr_(2)O_(3) NSs,compared with the Cr-Zr-O coating without NSs,the permeation reduction factor of the resultant coating was enhanced from 249℃to 575℃ at 500℃.The coating,with a thickness of nearly 193 nm,achieved a comparable deuterium resistance that was above two orders of magnitude higher than the steel substrate.The results show that ceramic NSs can serve as effective fillers for enhancing the coating performance when functioning as a hydrogen isotope barrier.
基金Financial support by the Spanish Ministry of Science(PID2022139663OB-I00 and CEX2021-001230-S grant funded by MCIN/AE I/10.13039/501100011033)with funding from Next Generation EU(PRTR-C17.I1)within the Planes Complementarios con CCAA(Area of Green Hydrogen and Energy)+2 种基金carried out in the CSIC Interdisciplinary Thematic Platform(PTI+)Transición Energética Sostenible+(PTI-TRANSENER+)the Universitat Politècnica de València(UPV)the support of the Servicio de Microscopía Elcectronica of the UPV。
文摘Industry decarbonization requires the development of highly efficient and flexible technologies relying on renewable energy resources,especially biomass and solar/wind electricity.In the case of pure oxygen production,oxygen transport membranes(OTMs)appear as an alternative technology for the cryogenic distillation of air,the industrially-established process of producing oxygen.Moreover,OTMs could provide oxygen from different sources(air,water,CO_(2),etc.),and they are more flexible in adapting to current processes,producing oxygen at 700^(-1)000℃.Furthermore,OTMs can be integrated into catalytic membrane reactors,providing new pathways for different processes.The first part of this study was focused on electrification on a traditional OTM material(Ba_(0.5)Sr_(0.5)Co_(0.8)Fe_(0.2)O_(3-δ)),imposing different electric currents/voltages along a capillary membrane.Thanks to the emerging Joule effect,the membrane-surface temperature and the associated O_(2) permeation flux could be adjusted.Here,the OTM is electrically and locally heated and reaches 900℃on the surface,whereas the surrounding of the membrane was maintained at 650℃.The O_(2)permeation flux reached for the electrified membranes was~3.7 NmL min^(-1)cm^(-2),corresponding to the flux obtained with an OTM non-electrified at 900℃.The influence of depositing a porous Ce_(0.8)Tb_(0.2)O_(2-δ) catalytic/protective layer on the outer membrane surface revealed that lower surface temperatures(830℃)were detected at the same imposed electric power.Finally,the electrification concept was demonstrated in a catalytic membrane reactor(CMR)where the oxidative dehydrogenation of ethane(ODHE)was carried out.ODHE reaction is very sensitive to temperature,and here,we demonstrate an improvement of the ethylene yield by reaching moderate temperatures in the reaction chamber while the O_(2) injection into the reaction can be easily fine-tuned.
基金the support of this research from the Serbian Ministry of Education,Science and Technological Development(Grant No.451-03-68/2023-14/200325)Ministry of Defense(Grant No.VA-TT/1/22-24)。
文摘Conventional plasticizers deteriorate mechanical and viscoelastic properties of the propellants due to their migration upon aging and long-term storage,which affects reliability and safety properties during exploitation.To address this issue,conventional plasticizer,dioctyl adipate(DOA),is replaced by reactive one,castor oil(CO).In addition,three different types of HTPB were used to obtain propellants with designed viscoelastic and mechanical properties.The CO increased propellants viscosity,without a significant impact on the propellant processability,regardless to the type of prepolymer.Conversely,mechanical properties were different depending on the type of resin,which were further analyzed by gel permeation chromatography(GPC).Addition of CO formed a denser polymer network and shifted T_(g) to higher values,compared to the compositions with DOA.The tensile strength of CO-containing propellants was lower at +20℃ and +50℃ compared to the reference compositions,while the strain at maximum load and strain at break were significantly increased with pronounced plastic deformation,especially for samples at -30℃.The inclusion of CO in the propellants composition gives more room for adjusting a wide range of mechanical properties.
文摘A GC-MS method for the determination of 27 organochlorine pesticides and 15 Pyrethroid pesticides in animal food is established.The method was based on Gel Permeation chromatography combined with solid-phase extraction for sample preparation.Rapid qualitative and quantitative analyses was carried out by gas chromatography-mass spectrometry under the selective-ion monitoring mode.The experimental results showed that the correlation coefficients were better than 0.99,the recoveries for spiked standards were 70%-104%,the relative standard deviations were 2.1%-15.9%.
基金supported by the National High Technology Research and Development Program of China (No. 2006AA11A189)Science and Technology Commission of Shanghai Municipality (No. 06DZ12212)+1 种基金National Engineering Research Center of Advanced Steel Technology (NERCAST) (No. 050209)the Innovation Fund for Graduate Studentof Shanghai University (SHUCX0910003)
文摘The performance of LiNi/γ-Al2O3 catalysts modified by rare earth metal oxide （La2O3 or CeO2） packed on BCFNO membrane reactor was discussed for the partial oxidation of methane （POM） in coke oven gas （COG） at 875 ℃. The NiO/γ-Al2O3 catalysts with different amounts of La2O3 and CeO2 were prepared with the same preparation method and under the same condition in order to compare the reaction performance （oxygen permeation, CH4 conversion, H2 and CO selectivity） on the membrane reactor. The results show that the oxygen permeation flux increased significantly with LiNiREOx/γ-Al2O3 （RE = La or Ce） catalysts by adding the element of rare earth especially the Ce during the POM in COG. Such as, the Li15wt%CeO29wt%NiO/γ-Al2O3 catalyst with an oxygen permeation flux of 24.71 ml·cm^-2·min^-1 and a high CH4 conversion was obtained in 875 ℃. The resulted high oxygen permeation flux may be due to the added Ce that inhibited the strong interaction between Ni and Al2O3 to form the NiAl2O4 phase. In addition, the introduction of Ce leads up to an important property of storing and releasing oxygen.
文摘Nanosized SSZ-13 zeolite was synthesized by traditional hydrothermal method using N,N,N-trimethyl-1-adamantanaminium hydroxide as the structure-directing agent (SDA). The influence of different preparative conditions of nanosized SSZ-13 was investigated systematically. The synthetic zeolites were characterized by X-ray powder diffraction (XRD), nitrogen physisorption, and scanning electron microscopy (SEM). By means of the self-assembled method, the thin SSZ-13/polyvinyl alcohol nanocomposite membranes were obtained by incorporating the nanosized SSZ-13 zeolite into the polymeric precursor (polyvinyl alcohol (PVA)). The permeation properties of pure CO2 and CH4 through the mixed matrix membranes (MMMs) were measured. The results showed that the highly crystalline SSZ-13 zeolite in a dispersed nanocrystal form with a controllable particle size of 100 nm could be hydrothermally synthesized by optimizing the synthetic parameters and the selectivity of CO2/CH4 of the MMMs could reach a value of 40 by changing the amount of nanosized SSZ-13 zeolite.
基金funded by the International Collaboration Fund(IF0119A1053)provided by the Ministry of Energy,Science,Technology,Environment and Climate Change(MESTECC),Malaysiathe Fundamental Research Grant Scheme(FRGS/1/2019/WAB01/UKM/02/1)provided by Ministry of Higher Education Malaysia。
文摘E dible bird’s nest(EBN)hydrolysates have been proven to exhibit enhanced bioactivities.However,being a macromolecule,fractions with different molecular weights would have different properties and bioactivities.Hence,this research was aimed to determine the chemical properties and antioxidant activities of freezedried(EBN_(FD))and spray-dried EBN(EBN_(SD))hydrolysates fractionated using gel permeation chromatography(GPC).Overall,two well-separated fractions were identified(EBN_(fFD1),EBN_(fFD2),EBN_(fSD1) and EBN_(fSD2)).EBNFD demonstrated significantly higher(P≤0.05)peptide(3.6%),total carbohydrate(27.7%)and sialic acid(18.2%)contents than that of EBNSD.Similar trend was observed in low molecular weight fractionates(EBN_(fFD2) and EBN_(fSD2)).Meanwhile,the first fractionates(EBN_(fFD1) and EBN_(fSD1))exhibited significantly higher(P≤0.05)hydroxyl radical(·OH)scavenging activity.Fourier transform infrared(FTIR)spectroscopy demonstrated that all EBN fractionates have similar spectrum,except in the region of N—H(amideⅡ)and C—H alkyl group.In conclusion,EBN fractionates with different molecular weights showed different chemical properties and antioxidant activities.
基金supported by the National Natural Science Foundation of China(No.51274139,51174133)the Innovation Program of Shanghai Municipal Education Commission(13YZ019)+1 种基金the Doctoral Fund of Ministry of Education of China(20123108120020)the Innovative Foundation of Shanghai University
文摘Ba1.0Co0.7Fe0.2Nb0.1O3-γ（BCFN） oxide with perovskite cubic structure was synthesized by solid state reaction method. COa corrosion of BCFN membrane was investigated by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, diffuse reflectance infrared Fourier- transformed spectroscopy （DRIFT） and X-ray absorption fine structure spectroscopy （XAFS）. Cobalt （Co） K-edge absorption spectra of BCFN annealed in COa reveal that the oxidation states of Co in all the samples were larger than ＋3 and they decreased with the increase of calcination time. At 800 ℃, 1% CO2 introduced into He could speed up the reduction of Co cations in comparison with pure He. In addition, sulfate ions in the bulk of BCFN membrane preferred to migrate to the surface under CO2 calcination and form monoclinic Ba（CO3）0.9（SO4）0.1 besides orthorhombic witherite. Moreover, SEM results indicate that the nucleation and growth of carbonates grains started at the grain boundary of the membrane.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10474018 and 10375016, the Hebei Provincial Natural Science Foundation under Grant Nos C2005000011 and A2004000005, the Subsidization for Construction Programme of Key Subjects in Universities and Colleges of Hebei Province, and the Hebei Provincial Doctoral Foundation under Grant No 2006148.
文摘It is well known that potassium ion channels have higher permeability than K ions, and the permeable rate of a single K ion channel is about 108 ions per second. We develop a hierarchical model of potassium ion channel permeation involving ab initio quantum calculations and Brownian dynamics simulations, which can consistently explain a range of channel dynamics. The results show that the average velocity of K ions, the mean permeable time of K ions and the permeable rate of single channel are about 0.92nm/ns, 4.35ns and 2.30 ×10^8 ions/s, respectively.
基金Sponsored by SRF for ROCS, key lab of enhanced heat transfer and energy conservation (MOE)Guangdong provincial natural science foundation (04020126).
文摘Single-phase perovskite La0.6Sr0.4Co0.8Fe0.2O3-δ has been successfully prepared by using citrate-EDTA complexation method at relatively low calcination temperature. The structure and thermal decomposition process of the complex precursor have been investigated by means of differential scanning calorimetry-thermal gravimetric analysis （DSC/TGA）, X-ray diffraction （XRD）, and Fourier transform infrared spectroscopic （FT-IR） measurements. The precursor decomposed completely and started to form perovskite-type oxide above 420 ℃ according to the differential scanning calorimetry （DSC） and thermal gravimetric analysis （TGA） results. Single-phase perovskite La0.6Sr0.4Co0.8Fe0.2O3-δ obtained has been confirmed from the XRD pattern, and no peak of SrCO3 was found by XRD of the oxides synthesized at a relatively low temperature of 800℃. The reducibility of La0.6Sr0.4Co0.8Fe0.2O3-δ was also characterized by the temperature programmed reduction （TPR） technique. Disk shaped dense La0.6Sr0.4Co0.8Fe0.2O3-δ membrane was prepared by the isostatical pressing method. The oxygen flux rate of dense La0.6Sr0.4Co0.8Fe0.2O3-δ membrane was （2.8-18）× 10^-8 mol/（cm^2.s） in the temperature range of 800-1000 ℃.
