Zeolites have many uses and are continually developed for catalysis and separations as highly active,selective and thermally stable materials with microporous framework structures of various topologies.Among approxima...Zeolites have many uses and are continually developed for catalysis and separations as highly active,selective and thermally stable materials with microporous framework structures of various topologies.Among approximately 250 known frameworks about 20,but possibly all eventually,produced 2D forms with layers of thickness up to a few nanometers.Recently,layered forms of the zeolite MWWand a ferrierite-related one have been exfoliated directly by a soft-chemical treatment into solutions of unilamellar nanosheets.They enable the synthesis of layer-based hierarchical and nanocomposite materials with diverse compositions that are unfeasible with solid 3D and 2D forms.The efficiency and yield of zeolite exfoliation can be inhibited by intergrowth so each topology presents a separate challenge.The MFI zeolite can provide particular benefits as one of the most active and versatile frameworks.It has permeable layers due to perpendicular channels and has been used as a membrane.This article describes exfoliation of the layered MFI produced by the bifunctional template developed by Ryoo et al.It affords unilamellar MFI nanosheets in solution with a uniform hydrated thickness of 3.6 nm confirmed by AFM,X-ray diffraction and TEM.The nanosheets can be reassembled top-down into self-standing b-oriented discs or films,proven by X-ray powder diffraction.They preserve high acid site concentration and porosity.The basal spacing contracts from 3.6 nm to 2.8 nm upon calcination.Oriented MFI films were also formed by the evaporation/calcination of nanosheet solutions and surfactant composites enabling simple fabrication on various substrates for application in catalysis and separations.展开更多
Zinc-ion supercapacitors(ZISCs)have received considerable interest for energy storage because of their low cost,high safety,and minimal environmental impact.However,they have a low energy density and poor cycling perf...Zinc-ion supercapacitors(ZISCs)have received considerable interest for energy storage because of their low cost,high safety,and minimal environmental impact.However,they have a low energy density and poor cycling performance.The design of a better cathode material is needed to overcome these limitations.A simple method was used to synthesize binder-free electrochemically exfoliated carbon paper(EECP)which modifies the surface of the paper by introducing oxygen functional groups and thus improves its pseudocapacitance.When used in a Zn-ion supercapacitor(ZISC),an EECPbased cathode provides a large surface area and quick charge transfer.As a result,the ZISC had remarkable charge storage properties and had a dominant capacitive-type charge storage mechanism with 78.8%retention of capacity at 10 mV/s of the total storage.Furthermore,at 1 A/g,the EECP electrode had a maximum capacitance of 252.5 F/g.The EECP electrode retained 81.7%of its capacitance after 10000 cycles,indicating its promise for use in the growing renewable energy sector.A ZISC was also constructed using EECP as the positive electrode and Zn as the negative electrode with a 1 mol L^(−1) ZnSO_(4) electrolyte.It had a capacitance of 186.22 F/g at 1 A/g and a 97.01%retention rate after 10000 cycles.It also had an excellent energy density of 46.6 Wh/kg at a power density of 500.4 W/kg.The material is therefore suitable for use in high-rate next-generation ZISCs.展开更多
Vanadium redox flow batteries(VRFBs)are a means of large-scale energy storage due to their excellent scalability,safety,long cycling life,and decoupled power and energy capacities.However,the slow redox kinetics of va...Vanadium redox flow batteries(VRFBs)are a means of large-scale energy storage due to their excellent scalability,safety,long cycling life,and decoupled power and energy capacities.However,the slow redox kinetics of vanadium species on conventional carbon electrodes remains a major limitation to their performance.We investigated the deposition of carbon black,carbon nanotubes,and electrochemically exfoliated graphene(Exf-Gr)onto thermally-activated carbon paper(ACP)by spray coating to increase the electrode electrocatalytic activity.The modified electrodes were characterized using scanning electron microscopy,X-ray diffraction,Raman spectroscopy,X-ray photoelectron microscopy,and surface area analysis,while their electrochemical properties were evaluated by cyclic voltammetry,electrochemical impedance spectroscopy,and singlecell VRFB testing.Among the modified electrodes,Exf-Gr/ACP had the best performance,achieving a 2.9-fold reduction in charge transfer resistance compared to pristine ACP and delivering 2.5 times the discharge capacity in single-cell tests.This improvement is attributed to Exf-Gr’s high surface area,favorable catalytic activity,and excellent dispersion on the ACP substrate.Surface modification with electrochemically exfoliated graphene is a highly effective strategy for improving the electrode performance in VRFB systems,with significant implications for large-scale energy storage.展开更多
Supercapacitors represent one specific class of energy storage devices that bridge the gap between traditional capacitors and batteries.In current work,δ-MnO_(2) nanoflakes arrayed on electrochemically exfoliated gra...Supercapacitors represent one specific class of energy storage devices that bridge the gap between traditional capacitors and batteries.In current work,δ-MnO_(2) nanoflakes arrayed on electrochemically exfoliated graphene(EEG)nanosheets were easily made as one composited electrode material for boosting the charge storage performances of supercapacitors.Coupled with the fluent electron and ion transport from two-dimensional EEG nanosheets,the uniformly anchoredδ-MnO_(2) nanoflake arrays present high reversible capacity,superior cycling stability,and unique rate capability.As expected,the MnO_(2)/EEG-10 electrode delivers high specific capacitance of 190 F·g^(−1) at 0.2 A·g^(−1),and holds 97.3%of its initial capacitance after 10000 cycles at 5 A·g^(−1).Furthermore,an asymmetrical supercapacitor using MnO_(2)/EEG-10 as the positive electrode achieves an energy density of 17.7 W·h·kg^(−1) at a power density of 922.7 W·kg^(−1) with 82.9%capacity retention upon 10000 cycles at 5 A·g^(−1).This work highlights the facile fabrication of high-performance MnO_(2)/graphene composites with excellent structure stability using graphene nanosheets as the conductive matrix.展开更多
Background:Enzyme fragility remains a major challenge in research and applications.Free enzymes are highly unstable,inactivated by heat,acid,alkali,or organic solvents,and often lose activity even under optimal storag...Background:Enzyme fragility remains a major challenge in research and applications.Free enzymes are highly unstable,inactivated by heat,acid,alkali,or organic solvents,and often lose activity even under optimal storage conditions.Limiting their use in cosmetics.Few commercial products combine acids and enzymes effectively.Objective:To investigate the physicochemical properties,in vitro exfoliation efficacy,and effects on facial skin parameters of a supramolecular acid-enzyme complex(SAE)composed of mandelic acid(MAN),betaine(BET),and composite enzymes(CE;papain and bromelain),thereby establishing a theoretical foundation for cosmetic applications.Methods:The supramolecular structure was characterized using Fourier transform infrared(FTIR)spectroscopy and proton nuclear magnetic resonance(1H NMR)spectroscopy.Dissolution experiments were conducted to compare the solubility of SAE and CE in aqueous solutions.Enzymatic activity assays evaluated the stabilizing effect of supramolecular deep eutectic technology on enzymes.In vitro exfoliation tests assessed acid-enzyme synergy in keratin removal.A 4-week clinical trial evaluated the efficacy of a 2%SAE essence aqueous solution on facial skin parameters.Results:Dissolution experiments confirmed that supramolecular deep eutectic technology significantly improved enzyme solubility.Enzymatic activity tests demonstrated that this technology effectively preserved protease activity,substantially enhancing its practical applicability.Furthermore,in vitro exfoliation efficacy tests revealed that this technology strengthened the synergistic interaction between acids and enzymes and exhibited superior stratum corneum-removing capability of the SAE.In clinical evaluations of efficacy,after 7 days of using the essence containing SAE,the formulation significantly enhanced cheek gloss(+8.08%),while reducing comedones volume(-16.25%).after 28 days,significantly enhanced cheek hydration(+25.0%,SCH),gloss(+15.93%),and smoothness(−7.78%SEsm),while reducing TEWL(−6.86%),sebum(−15.54%),roughness(+16.24%SEr),and pore metrics(volume:−39.98%;count:−30.64%),and decreased comedones(blackheads:−70.33%;Whiteheads:−52.42%;all p<0.05).Conclusion:The supramolecular acid-enzyme complex demonstrates enhanced stability,improved solubility,and superior exfoliation efficacy compared to free enzymes.Clinical results further confirm its multifunctional benefits,including enhancing skin hydration,sebum regulation,barrier repair,pore refinement,and comedolytic effects.This study provides both theoretical and practical foundations for developing stable acid-enzyme combinations in dermatological applications.展开更多
Transition metal dichalcogenides(TMDs)have emerged as promising electrocatalysts for various electrocatalytic processes.Molybdenum disulfide has been widely used,but a single electrocatalyst can hardly be applied to a...Transition metal dichalcogenides(TMDs)have emerged as promising electrocatalysts for various electrocatalytic processes.Molybdenum disulfide has been widely used,but a single electrocatalyst can hardly be applied to all reactions,making it essential to understand the electrochemistry of selected TMDs.Tungsten diselenide(WSe_(2))is reactive in gas evolution processes,similar to molybdenum,yet has received limited attention.This work explores how different exfoliation powers affect WSe_(2)structural configurations and their impact on catalytic performance in hydrogen evolution,oxygen evolution,and capacitive behaviour.The study investigates the structural properties of WSe_(2)nanosheets in both liquid(dispersion)and solid(electrode)phases.Low exfoliation power(90.4 W)contributes to well-defined WSe_(2),while higher power(814 W)leads to an increased number of selenium vacancies.These modifications influence key properties such as thickness,band gaps(1.518 to 1.578 eV),exfoliation yield(0.27 to 0.12 mg mL^(-1)),and oxide content(44.3%to 53.9%),resulting in distinct electrochemical behaviours in different electrolytes.WSe_(2)nanosheets exfoliated at higher power exhibit reduced activity in the hydrogen evolution reaction(HER)due to the loss of W–Se bonds and the formation of an amorphous structure,but they show enhanced oxygen evolution reaction(OER)performance,particularly in alkaline media.Additionally,a higher concentration of selenium vacancies improves capacitive performance in acidic conditions due to proton contributions but are less favourable in neutral and basic electrolytes.This study highlights the importance of exfoliation power in tuning the structural properties of WSe_(2)for specific electrochemical applications,advancing the understanding of its synthesis and performance.展开更多
The preparation of dispersible MFI-type zeolite nanoparticles with open micropores is challenging.Herein,a rapid and effective ultrasound-assisted liquid-phase exfoliation method along with a freezedrying process for ...The preparation of dispersible MFI-type zeolite nanoparticles with open micropores is challenging.Herein,a rapid and effective ultrasound-assisted liquid-phase exfoliation method along with a freezedrying process for redispersion of calcined silicalite-1(S-1)zeolite nanoparticle aggregates using 3-aminopropanol as an exfoliating agent is demonstrated.The exfoliation of S-1 zeolite nanoparticles is characterized by X-ray diffraction,scanning electron microscopy and DLS particle size analysis.The effects of drying methods of as-synthesized zeolite nanoparticle suspension,zeolite contents in frozen nanoparticle suspension,exfoliating agent concentrations,and zeolite doses in ultrasonic suspension on exfoliation efficiency are systematically investigated.It is found that the S-1 zeolite nanoparticle(~70 nm)achieves a yield up to 95%through a 30 min ultrasonic exfoliation in a 3-aminopropanol solution along with a freeze-drying process.The proposed exfoliation mechanism involves two primary stages:vip molecule insertion followed by water expansion,both substantially enhanced by tip sonication.This work offers a comprehensive understanding of the exfoliation process,provides valuable insights into the dispersion of sintered zeolite nanoparticles.展开更多
As an alternative to lithium-ion batteries,aqueous zinc-graphite batteries(ZnGBs)are being explored as safer and low-cost options with the expectation of scalability to large energy storage systems.However,the current...As an alternative to lithium-ion batteries,aqueous zinc-graphite batteries(ZnGBs)are being explored as safer and low-cost options with the expectation of scalability to large energy storage systems.However,the currently adopted polyatomic and metal complex anion intercalation process at the graphite electrode in ZnGB exhibits poor electrochemical performances.Alternatively,incorporating halogen anions offers exceptional electrochemical performance to graphite electrodes due to their redox process.In this work,ZnGBs are assembled using a LiCl/ZnCl2/KBr^(-)based water-in-salt electrolyte,which efficiently supplies bromide(Br^(−))ions for conversion into Br_(x)^(−)and facilitates Br_(2)intercalation at the graphite electrode.The conversion and intercalation of bromine together enable the ZnGB to achieve a discharge capacity of 2.73 mAh/cm^(2)with 91.0%of coulombic efficiency(CE)while supporting high current density operations of up to 150 mA/cm^(2).With high energy density(4.56 Wh/cm^(2)),high power density(199.5 mW/cm^(2)),and excellent rate capability(∼93.0%CE at 150 mA/cm^(2)),the ZnGB is shown to operate efficiently for as much as 800 cycles.Beguilingly,an anode-free ZnGB offers enhanced stability for up to 1100 cycles without performance decay,matching the electrochemical performance of Zn metal electrodes.This work provides insights into the bromine reaction mechanism at graphite electrodes and the role of surface exfoliation in enabling efficient Br_(x)^(−)formation,along with Br_(2)intercalation,for achieving high-performance ZnGBs.展开更多
The corrosion resistance and mechanical properties of peak-aged AlZnMgCu alloys containing Si and Er elements were investigated with hardness test,tensile test,intergranular corrosion test,exfoliation corrosion test a...The corrosion resistance and mechanical properties of peak-aged AlZnMgCu alloys containing Si and Er elements were investigated with hardness test,tensile test,intergranular corrosion test,exfoliation corrosion test and transmission electron microscopy.The results indicate that peak-aged AlZnMgCuSiEr alloy is strengthened by co-precipitation of η′phases and nano-sized GPB-Ⅱ zones.The yield strength of the AlZnMgCu alloy is increased by 38.5 MPa and the elongation is increased by 4.5%.At the same time,the corrosion resistance of the AlZnMgCuSiEr alloy is enhanced due to the synergistic effect of Er and Si.The maximum intergranular corrosion(IGC)depth decreases from 264.2 to 9.9μm.The fundamental reason is that the co-addition of Si and Er regulates the evolution of precipitated phases in grains and at grain boundaries.展开更多
This paper summarizes the nursing experience of a 75-year-old patient who developed exfoliative dermatitis-type drug eruption induced by cold medicine and progressed to toxic epidermal necrolysis(TEN).The core nursing...This paper summarizes the nursing experience of a 75-year-old patient who developed exfoliative dermatitis-type drug eruption induced by cold medicine and progressed to toxic epidermal necrolysis(TEN).The core nursing measures included(1)Establishing a multidisciplinary team and implementing bundled care led by trauma specialist nurses;(2)Precise wound management using the“three-stage debridement method”and silver ion dressings;(3)Implementing multimodal analgesia based on dynamic pain assessment;(4)Strengthening fluid,electrolyte,and nutritional management;and(5)Providing individualized psychological support.After 14 days of treatment and nursing,the patient’s wounds were completely epithelialized,infection indicators returned to normal,pain was effectively controlled,and the patient was discharged successfully.No serious complications were observed during the 6-month follow-up.For elderly critically ill patients with TEN,constructing a systematic nursing model based on multidisciplinary collaboration and centered on trauma care is crucial for improving patient outcomes.展开更多
Ultrathin 2D niobium oxide dichloride(NbOCl_(2))is an emerging member of the 2D ferroelectric material family with extensive potential to provide multifunctionality in electronic devices and nanophotonics elements.It ...Ultrathin 2D niobium oxide dichloride(NbOCl_(2))is an emerging member of the 2D ferroelectric material family with extensive potential to provide multifunctionality in electronic devices and nanophotonics elements.It exhibits negligible interlayer electronic coupling and significant excitonic behavior in the bulk state.Here we substantiate that NbOCl_(2) nanosheets can be exfoliated and effectively size-selected using controlled centrifugation techniques by the liquid phase exfoliation(LPE)method.Spectroscopic measurements displayed that the variations in dispersion were highly dependent on the nanosheet dimensions.The nanosheets seemed to be comparatively defect-free which will be further corroborated by high resolution transmission electron microscopy(HRTEM)and Raman analysis.The size selected nanosheets are unanticipated stable in isopropyl alcohol(IPA),possibly owing to the protective influence of a solvation shell.Additionally,the photothermal conversion response and photothermal stability of nanosized NbOCl_(2) were investigated.Our finding revealed that NbOCl_(2) possesses a robust photothermal agent property,boasting a photothermal conversion efficiency of more than 30%.This underscores its promising potential for various photothermal applications in different fields such as photothermal therapy and thermal energy conversion.展开更多
To effectively improve the corrosion resistance of aluminum alloys without affecting their strength, the effect of Ce content on the microstructure, stress corrosion, intergranular corrosion, and exfoliation corrosion...To effectively improve the corrosion resistance of aluminum alloys without affecting their strength, the effect of Ce content on the microstructure, stress corrosion, intergranular corrosion, and exfoliation corrosion resistances of Al−11.3Zn−3.1Mg−1.2Cu−0.2Zr−0.1Ti alloy was investigated. The results showed that the addition of Ce formed the (Zn,Al,Cu)_(22)Ce_(3) phase with a size of 100 nm, which enhanced the recrystallization resistance of the alloy, increased the number of low-angle grain boundaries and dislocation density, refined the grains, promoted the phase transition from GP zone to η' phase, and promoted the size and discontinuity of precipitates at grain boundaries. All Ce-added alloys exhibited the higher resistance to corrosion. The alloy with 0.15 wt.% Ce possessed the optimal corrosion resistance along with the strength and elongation at slow strain rate of 744.8 MPa and 4.6%, respectively, in 3.5 wt.% NaCl solution. The minimum depth of intergranular corrosion and exfoliation corrosion was achieved as well.展开更多
Rechargeable aqueous aluminum ion batteries(AIBs)are inspiring researchers’enthusiasm due to the low cost and high theoretical capacity of aluminum.Polyaniline(PANI)materials have the potential for aluminum ion stora...Rechargeable aqueous aluminum ion batteries(AIBs)are inspiring researchers’enthusiasm due to the low cost and high theoretical capacity of aluminum.Polyaniline(PANI)materials have the potential for aluminum ion storage due to the properties of its excellent conductivity and inherent theoretical capacity.However,the poor cycling stability and low loadings of PANI limit its application in energy storage.In this study,PANI-x electrodes with high mass loadings are successfully prepared by the electrodeposition method for reversible AlCl_(2)^(+)storage.Among them,the PANI-2 electrode possesses the highest areal capacity(0.59 and 0.51 mAh cm^(−2)at the current density of 0.5 and 10 mA cm^(−2))and excellent cycling stability in saturated AlCl3.Ex situ N 1s fitting spectra of PANI-2 and molecular dynamics simulations of 1 M,3 M,and saturated AlCl_(3)electrolytes demonstrate that PANI can achieve reversible redox reactions in saturated AlCl3,thereby achieving its excellent stability.Density functional theory calculations and ex situ spectra characterizations of PANI-2 demonstrate the insertion/de-insertion mechanism in the form of AlCl_(2)^(+)ions.In conclusion,PANI-2|Saturated AlCl_(3)|EG(exfoliated graphite foil)full cell is assembled successfully.This work provides promising guidance for the preparation of high-loading electrodes for AIBs.展开更多
The exfoliation corrosion （EFC） behavior of 7050-T6 aluminum alloy treated with various quench transfer time after solution heat treatment was investigated by standard EFC immersion tests, strength loss measurements...The exfoliation corrosion （EFC） behavior of 7050-T6 aluminum alloy treated with various quench transfer time after solution heat treatment was investigated by standard EFC immersion tests, strength loss measurements after EFC tests and electrochemical impedance spectroscope （EIS） technique. The results showed that EFC resistance of the alloy decreased with increasing quench transfer time. Backscattered electron scanning electron microscope （SEM） together with transmission electron microscope （TEM） observations revealed that the coverage ratio and microstructure of precipitates at grain boundary area are the most important factors which influence the EFC susceptibility of the alloy, while precipitate-free zone （PFZ） near grain boundary has no or only a minor effect on it. In addition, galvanostatic measurements of the alloy present a good correlation between EFC resistance and transients in potential. The cumulated number of transients in potential can be used to evaluate EFC resistance of the alloy.展开更多
Influence of dual retrogression and re-aging（dual-RRA） temper on microstructure,strength and exfoliation corrosion（EC） behavior of Al-Zn-Mg-Cu alloy was investigated by hardness measurements,tensile properties tes...Influence of dual retrogression and re-aging（dual-RRA） temper on microstructure,strength and exfoliation corrosion（EC） behavior of Al-Zn-Mg-Cu alloy was investigated by hardness measurements,tensile properties tests,exfoliation corrosion tests,transmission electron microscopy（TEM） and scanning electron microscopy（SEM） observation combined energy dispersive X-ray detector（EDX） analysis.Dual-RRA temper maintains the matrix precipitates（MPs） similar to RRA temper,meanwhile obtains coarser and sparser grain boundary precipitates（GBPs） as well as higher Cu and lower Zn content compared with T76 temper.Therefore,dual-RRA temper not only keeps strength equivalent to the RRA temper but also obtains higher EC resistance than T76 temper.展开更多
The corrosion resistance of Al？Zn？Mg alloy subjected to different times in flame rectification was investigated based on the exfoliation corrosion test. The results indicate that the flame rectification deteriorate...The corrosion resistance of Al？Zn？Mg alloy subjected to different times in flame rectification was investigated based on the exfoliation corrosion test. The results indicate that the flame rectification deteriorates the exfoliation corrosion resistance of Al？Zn？Mg alloy. The corrosion resistance of Al-Zn-Mg alloy is ranked in the following order： base metal〉two times〉three times〉one time of flame rectification. The exfoliation corrosion behavior was discussed based on the transformation of precipitates at grain boundaries and matrix. With increasing the number of times in flame rectification, the precipitate-free zones disappeared and the precipitates experienced dissolution and re-precipitation. The sample was seriously corroded after one time of flame rectification, because the precipitates at grain boundaries are more continuous than those in other samples.展开更多
Mesenchymal stem cells(MSCs) as a source for regenerative medicine are now the subject of much clinical attention. There are high expectations due to their safety, low tumorigenic risk, and low ethical concerns. MSC t...Mesenchymal stem cells(MSCs) as a source for regenerative medicine are now the subject of much clinical attention. There are high expectations due to their safety, low tumorigenic risk, and low ethical concerns. MSC therapy has been approved for acute graft-versus host diseases since 2015. Tooth-derived MSCs are known to have a great potential in their proliferation and differentiation capacities, even when compared with bone-marrow-derived MSCs. In particular, stem cells from human exfoliated deciduous teeth(SHEDs) are the best candidates for personal cell banking(dental pulp cell bank), because they can be obtained less invasively in the natural process of individual growth. SHEDs are known to differentiate into hepatocytes. There have been several studies showing the effectiveness of SHEDs on the treatment of liver failure in animal models. They may exert their effects either by repopulation of cells in injured liver or by paracrine mechanisms due to their immuneregulatory functions. Moreover, it may be possible to use each individuals' dental pulp cells as a future source of tailor-made differentiated hepatocytes in the context of a bioartificial liver or liver-on-a-chip to screen for drug toxicity.展开更多
To screen patients with early cervical lesions by analyzing the infection of high-risk Human papillomavirus (HR-HPV). Research Methods: The cervical exfoliated cell specimens and their clinical data were collected. Th...To screen patients with early cervical lesions by analyzing the infection of high-risk Human papillomavirus (HR-HPV). Research Methods: The cervical exfoliated cell specimens and their clinical data were collected. The HPV infection types of the collected specimens were detected by fluorescence quantitative PCR, and the correlation between HPV infection and clinicopathological features was analyzed statistically. Results: 725 cases were HR-HPV positive from 2605 cases, including 15 high-risk types of HPV16, 18, 31, 33, 35, 39, 45, 51, 52, 53, 56, 58, 59, 66, 68. Different histological types ranged from NILM to HSIL, and the positive rate of HPV showed an increasing trend with the aggravation of cervical lesions. Conclusion: The positive rate of 15 high-risk HPV types in the collected specimens was 27.8%. Patients with early cervical lesions could be screened for 15 high-risk HPV infection types.展开更多
Exfoliation on as-extruded Mg-1 Li-1 Ca magnesium alloy was investigated after an immersion in 3.5 wt%NaCl aqueous solution for 90, 120 and 150 days through optical microscope, digital camera, scanning electron micros...Exfoliation on as-extruded Mg-1 Li-1 Ca magnesium alloy was investigated after an immersion in 3.5 wt%NaCl aqueous solution for 90, 120 and 150 days through optical microscope, digital camera, scanning electron microscope, electrochemical workstation, scanning Kalvin probe, X-ray diffraction and Fourier transform infrared spectroscope. The results demonstrated that exfoliation corrosion occurred on extruded Mg-1 Li-1 Ca alloy due to elongated microstructure parallel to surface, and delamination of lamellar structure resulted from galvanic effect and wedge effect. Skin layer with fine grains exhibited better corrosion resistance, whereas the interior with coarse grains and the intermetallic compound,Mg2 Ca particles existing in a fibrous structure, dispersed along grain boundaries and extrusion direction in a line. Furthermore, galvanic effect between Mg2 Ca particles and their neighboring a-Mg matrix facilitated dissolution of Mg2 Ca particles and a-Mg matrix; wedge effect was caused by formation of corrosion products. Exfoliation corrosion of extruded Mg-Li-Ca alloys might be a synergic effect of pitting corrosion,filiform corrosion, intergranular corrosion and stress corrosion. Finally, exfoliation corrosion mechanism was proposed.展开更多
基金financed with the funds from the National Science Centre Poland,grant no 2020/37/B/ST5/01258(WJR,BG)The in-plane XRD measurements were performed under the approval of the Photon Factory Program Advisory Committee(Proposal No.2020G503)+3 种基金the Czech Science Foundation for funding this research through the ExPro project(19-27551X)OP VVV“Excellent Research Teams”,project no.CZ.02.1.01/0.0/0.0/15_003/0000417-CUCAMthe Japan Science and Technology Agency(JST),Grant No.JPMJCR17N1(CREST)the Japan Society for the Promotion of Science(JSPS),Grant No.P21036。
文摘Zeolites have many uses and are continually developed for catalysis and separations as highly active,selective and thermally stable materials with microporous framework structures of various topologies.Among approximately 250 known frameworks about 20,but possibly all eventually,produced 2D forms with layers of thickness up to a few nanometers.Recently,layered forms of the zeolite MWWand a ferrierite-related one have been exfoliated directly by a soft-chemical treatment into solutions of unilamellar nanosheets.They enable the synthesis of layer-based hierarchical and nanocomposite materials with diverse compositions that are unfeasible with solid 3D and 2D forms.The efficiency and yield of zeolite exfoliation can be inhibited by intergrowth so each topology presents a separate challenge.The MFI zeolite can provide particular benefits as one of the most active and versatile frameworks.It has permeable layers due to perpendicular channels and has been used as a membrane.This article describes exfoliation of the layered MFI produced by the bifunctional template developed by Ryoo et al.It affords unilamellar MFI nanosheets in solution with a uniform hydrated thickness of 3.6 nm confirmed by AFM,X-ray diffraction and TEM.The nanosheets can be reassembled top-down into self-standing b-oriented discs or films,proven by X-ray powder diffraction.They preserve high acid site concentration and porosity.The basal spacing contracts from 3.6 nm to 2.8 nm upon calcination.Oriented MFI films were also formed by the evaporation/calcination of nanosheet solutions and surfactant composites enabling simple fabrication on various substrates for application in catalysis and separations.
基金supported by National Natural Science Foundation of China(52472194)the Deanship of Research and Graduate Studies at King Khalid University through Large Research Project(RGP-2/687/46).
文摘Zinc-ion supercapacitors(ZISCs)have received considerable interest for energy storage because of their low cost,high safety,and minimal environmental impact.However,they have a low energy density and poor cycling performance.The design of a better cathode material is needed to overcome these limitations.A simple method was used to synthesize binder-free electrochemically exfoliated carbon paper(EECP)which modifies the surface of the paper by introducing oxygen functional groups and thus improves its pseudocapacitance.When used in a Zn-ion supercapacitor(ZISC),an EECPbased cathode provides a large surface area and quick charge transfer.As a result,the ZISC had remarkable charge storage properties and had a dominant capacitive-type charge storage mechanism with 78.8%retention of capacity at 10 mV/s of the total storage.Furthermore,at 1 A/g,the EECP electrode had a maximum capacitance of 252.5 F/g.The EECP electrode retained 81.7%of its capacitance after 10000 cycles,indicating its promise for use in the growing renewable energy sector.A ZISC was also constructed using EECP as the positive electrode and Zn as the negative electrode with a 1 mol L^(−1) ZnSO_(4) electrolyte.It had a capacitance of 186.22 F/g at 1 A/g and a 97.01%retention rate after 10000 cycles.It also had an excellent energy density of 46.6 Wh/kg at a power density of 500.4 W/kg.The material is therefore suitable for use in high-rate next-generation ZISCs.
基金supported by the University of Seoul’s 2025 Research Fund.
文摘Vanadium redox flow batteries(VRFBs)are a means of large-scale energy storage due to their excellent scalability,safety,long cycling life,and decoupled power and energy capacities.However,the slow redox kinetics of vanadium species on conventional carbon electrodes remains a major limitation to their performance.We investigated the deposition of carbon black,carbon nanotubes,and electrochemically exfoliated graphene(Exf-Gr)onto thermally-activated carbon paper(ACP)by spray coating to increase the electrode electrocatalytic activity.The modified electrodes were characterized using scanning electron microscopy,X-ray diffraction,Raman spectroscopy,X-ray photoelectron microscopy,and surface area analysis,while their electrochemical properties were evaluated by cyclic voltammetry,electrochemical impedance spectroscopy,and singlecell VRFB testing.Among the modified electrodes,Exf-Gr/ACP had the best performance,achieving a 2.9-fold reduction in charge transfer resistance compared to pristine ACP and delivering 2.5 times the discharge capacity in single-cell tests.This improvement is attributed to Exf-Gr’s high surface area,favorable catalytic activity,and excellent dispersion on the ACP substrate.Surface modification with electrochemically exfoliated graphene is a highly effective strategy for improving the electrode performance in VRFB systems,with significant implications for large-scale energy storage.
基金supported by Natural Science Foundation of Shandong Province(ZR2023ME155 and ZR2023ME085)the project of“20 Items of University”of Jinan(202228046)the Taishan Scholar Project of Shandong Province(tsqn202306226 and tsqn202211171).
文摘Supercapacitors represent one specific class of energy storage devices that bridge the gap between traditional capacitors and batteries.In current work,δ-MnO_(2) nanoflakes arrayed on electrochemically exfoliated graphene(EEG)nanosheets were easily made as one composited electrode material for boosting the charge storage performances of supercapacitors.Coupled with the fluent electron and ion transport from two-dimensional EEG nanosheets,the uniformly anchoredδ-MnO_(2) nanoflake arrays present high reversible capacity,superior cycling stability,and unique rate capability.As expected,the MnO_(2)/EEG-10 electrode delivers high specific capacitance of 190 F·g^(−1) at 0.2 A·g^(−1),and holds 97.3%of its initial capacitance after 10000 cycles at 5 A·g^(−1).Furthermore,an asymmetrical supercapacitor using MnO_(2)/EEG-10 as the positive electrode achieves an energy density of 17.7 W·h·kg^(−1) at a power density of 922.7 W·kg^(−1) with 82.9%capacity retention upon 10000 cycles at 5 A·g^(−1).This work highlights the facile fabrication of high-performance MnO_(2)/graphene composites with excellent structure stability using graphene nanosheets as the conductive matrix.
文摘Background:Enzyme fragility remains a major challenge in research and applications.Free enzymes are highly unstable,inactivated by heat,acid,alkali,or organic solvents,and often lose activity even under optimal storage conditions.Limiting their use in cosmetics.Few commercial products combine acids and enzymes effectively.Objective:To investigate the physicochemical properties,in vitro exfoliation efficacy,and effects on facial skin parameters of a supramolecular acid-enzyme complex(SAE)composed of mandelic acid(MAN),betaine(BET),and composite enzymes(CE;papain and bromelain),thereby establishing a theoretical foundation for cosmetic applications.Methods:The supramolecular structure was characterized using Fourier transform infrared(FTIR)spectroscopy and proton nuclear magnetic resonance(1H NMR)spectroscopy.Dissolution experiments were conducted to compare the solubility of SAE and CE in aqueous solutions.Enzymatic activity assays evaluated the stabilizing effect of supramolecular deep eutectic technology on enzymes.In vitro exfoliation tests assessed acid-enzyme synergy in keratin removal.A 4-week clinical trial evaluated the efficacy of a 2%SAE essence aqueous solution on facial skin parameters.Results:Dissolution experiments confirmed that supramolecular deep eutectic technology significantly improved enzyme solubility.Enzymatic activity tests demonstrated that this technology effectively preserved protease activity,substantially enhancing its practical applicability.Furthermore,in vitro exfoliation efficacy tests revealed that this technology strengthened the synergistic interaction between acids and enzymes and exhibited superior stratum corneum-removing capability of the SAE.In clinical evaluations of efficacy,after 7 days of using the essence containing SAE,the formulation significantly enhanced cheek gloss(+8.08%),while reducing comedones volume(-16.25%).after 28 days,significantly enhanced cheek hydration(+25.0%,SCH),gloss(+15.93%),and smoothness(−7.78%SEsm),while reducing TEWL(−6.86%),sebum(−15.54%),roughness(+16.24%SEr),and pore metrics(volume:−39.98%;count:−30.64%),and decreased comedones(blackheads:−70.33%;Whiteheads:−52.42%;all p<0.05).Conclusion:The supramolecular acid-enzyme complex demonstrates enhanced stability,improved solubility,and superior exfoliation efficacy compared to free enzymes.Clinical results further confirm its multifunctional benefits,including enhancing skin hydration,sebum regulation,barrier repair,pore refinement,and comedolytic effects.This study provides both theoretical and practical foundations for developing stable acid-enzyme combinations in dermatological applications.
基金supported by Matching Fund from Thammasat University Research Fund,Thammasat University,under Contract No.MF2/2567the ETS scholarship awarded by Sirindhorn International Institute of Technology,Thammasat University。
文摘Transition metal dichalcogenides(TMDs)have emerged as promising electrocatalysts for various electrocatalytic processes.Molybdenum disulfide has been widely used,but a single electrocatalyst can hardly be applied to all reactions,making it essential to understand the electrochemistry of selected TMDs.Tungsten diselenide(WSe_(2))is reactive in gas evolution processes,similar to molybdenum,yet has received limited attention.This work explores how different exfoliation powers affect WSe_(2)structural configurations and their impact on catalytic performance in hydrogen evolution,oxygen evolution,and capacitive behaviour.The study investigates the structural properties of WSe_(2)nanosheets in both liquid(dispersion)and solid(electrode)phases.Low exfoliation power(90.4 W)contributes to well-defined WSe_(2),while higher power(814 W)leads to an increased number of selenium vacancies.These modifications influence key properties such as thickness,band gaps(1.518 to 1.578 eV),exfoliation yield(0.27 to 0.12 mg mL^(-1)),and oxide content(44.3%to 53.9%),resulting in distinct electrochemical behaviours in different electrolytes.WSe_(2)nanosheets exfoliated at higher power exhibit reduced activity in the hydrogen evolution reaction(HER)due to the loss of W–Se bonds and the formation of an amorphous structure,but they show enhanced oxygen evolution reaction(OER)performance,particularly in alkaline media.Additionally,a higher concentration of selenium vacancies improves capacitive performance in acidic conditions due to proton contributions but are less favourable in neutral and basic electrolytes.This study highlights the importance of exfoliation power in tuning the structural properties of WSe_(2)for specific electrochemical applications,advancing the understanding of its synthesis and performance.
基金supported by the Natural Science Foundation of Zhejiang Province,China(LD24B060002)National Key Research and Development Program of China(2021YFB3801102)the Fundamental Research Funds for the Central Universities(226-2024-00060).
文摘The preparation of dispersible MFI-type zeolite nanoparticles with open micropores is challenging.Herein,a rapid and effective ultrasound-assisted liquid-phase exfoliation method along with a freezedrying process for redispersion of calcined silicalite-1(S-1)zeolite nanoparticle aggregates using 3-aminopropanol as an exfoliating agent is demonstrated.The exfoliation of S-1 zeolite nanoparticles is characterized by X-ray diffraction,scanning electron microscopy and DLS particle size analysis.The effects of drying methods of as-synthesized zeolite nanoparticle suspension,zeolite contents in frozen nanoparticle suspension,exfoliating agent concentrations,and zeolite doses in ultrasonic suspension on exfoliation efficiency are systematically investigated.It is found that the S-1 zeolite nanoparticle(~70 nm)achieves a yield up to 95%through a 30 min ultrasonic exfoliation in a 3-aminopropanol solution along with a freeze-drying process.The proposed exfoliation mechanism involves two primary stages:vip molecule insertion followed by water expansion,both substantially enhanced by tip sonication.This work offers a comprehensive understanding of the exfoliation process,provides valuable insights into the dispersion of sintered zeolite nanoparticles.
基金The authors acknowledge the University of Sharjah for financial support through a competitive research project grant(project number:23020406277)。
文摘As an alternative to lithium-ion batteries,aqueous zinc-graphite batteries(ZnGBs)are being explored as safer and low-cost options with the expectation of scalability to large energy storage systems.However,the currently adopted polyatomic and metal complex anion intercalation process at the graphite electrode in ZnGB exhibits poor electrochemical performances.Alternatively,incorporating halogen anions offers exceptional electrochemical performance to graphite electrodes due to their redox process.In this work,ZnGBs are assembled using a LiCl/ZnCl2/KBr^(-)based water-in-salt electrolyte,which efficiently supplies bromide(Br^(−))ions for conversion into Br_(x)^(−)and facilitates Br_(2)intercalation at the graphite electrode.The conversion and intercalation of bromine together enable the ZnGB to achieve a discharge capacity of 2.73 mAh/cm^(2)with 91.0%of coulombic efficiency(CE)while supporting high current density operations of up to 150 mA/cm^(2).With high energy density(4.56 Wh/cm^(2)),high power density(199.5 mW/cm^(2)),and excellent rate capability(∼93.0%CE at 150 mA/cm^(2)),the ZnGB is shown to operate efficiently for as much as 800 cycles.Beguilingly,an anode-free ZnGB offers enhanced stability for up to 1100 cycles without performance decay,matching the electrochemical performance of Zn metal electrodes.This work provides insights into the bromine reaction mechanism at graphite electrodes and the role of surface exfoliation in enabling efficient Br_(x)^(−)formation,along with Br_(2)intercalation,for achieving high-performance ZnGBs.
基金funded by the National Key Research and Development Program of China(Nos.2021YFB3700902,2021YFB3704204,and 2021YFB3704205)the Beijing Lab Project for Modern Transportation Metallic Materials and Processing Technology,China,the Jiangsu Key Laboratory for Clad Materials,China(No.BM2014006)+4 种基金the Doctor Funds of Taiyuan University of Science and Technology,China(No.20222063)the Fundamental Research Program of Shanxi Province,China(No.202303021212216)the Award Fund for Outstanding Doctors in Shanxi Province,China(No.20232045)the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi Province,China(Nos.2022L289,and 2022L280)the Special Project for Transformation of Scientific Achievements,China(No.202204021301025)。
文摘The corrosion resistance and mechanical properties of peak-aged AlZnMgCu alloys containing Si and Er elements were investigated with hardness test,tensile test,intergranular corrosion test,exfoliation corrosion test and transmission electron microscopy.The results indicate that peak-aged AlZnMgCuSiEr alloy is strengthened by co-precipitation of η′phases and nano-sized GPB-Ⅱ zones.The yield strength of the AlZnMgCu alloy is increased by 38.5 MPa and the elongation is increased by 4.5%.At the same time,the corrosion resistance of the AlZnMgCuSiEr alloy is enhanced due to the synergistic effect of Er and Si.The maximum intergranular corrosion(IGC)depth decreases from 264.2 to 9.9μm.The fundamental reason is that the co-addition of Si and Er regulates the evolution of precipitated phases in grains and at grain boundaries.
基金Hospital-level Young and Middle-aged Cultivation Project of Xiangyang No.1 People’s Hospital(Project No.:XYY2025QN2)。
文摘This paper summarizes the nursing experience of a 75-year-old patient who developed exfoliative dermatitis-type drug eruption induced by cold medicine and progressed to toxic epidermal necrolysis(TEN).The core nursing measures included(1)Establishing a multidisciplinary team and implementing bundled care led by trauma specialist nurses;(2)Precise wound management using the“three-stage debridement method”and silver ion dressings;(3)Implementing multimodal analgesia based on dynamic pain assessment;(4)Strengthening fluid,electrolyte,and nutritional management;and(5)Providing individualized psychological support.After 14 days of treatment and nursing,the patient’s wounds were completely epithelialized,infection indicators returned to normal,pain was effectively controlled,and the patient was discharged successfully.No serious complications were observed during the 6-month follow-up.For elderly critically ill patients with TEN,constructing a systematic nursing model based on multidisciplinary collaboration and centered on trauma care is crucial for improving patient outcomes.
基金Projects(62275275,11904239)supported by the National Natural Science Foundation of ChinaProjects(2021JJ40709,2022JJ20080)supported by the Natural Science Foundation of Hunan Province,China。
文摘Ultrathin 2D niobium oxide dichloride(NbOCl_(2))is an emerging member of the 2D ferroelectric material family with extensive potential to provide multifunctionality in electronic devices and nanophotonics elements.It exhibits negligible interlayer electronic coupling and significant excitonic behavior in the bulk state.Here we substantiate that NbOCl_(2) nanosheets can be exfoliated and effectively size-selected using controlled centrifugation techniques by the liquid phase exfoliation(LPE)method.Spectroscopic measurements displayed that the variations in dispersion were highly dependent on the nanosheet dimensions.The nanosheets seemed to be comparatively defect-free which will be further corroborated by high resolution transmission electron microscopy(HRTEM)and Raman analysis.The size selected nanosheets are unanticipated stable in isopropyl alcohol(IPA),possibly owing to the protective influence of a solvation shell.Additionally,the photothermal conversion response and photothermal stability of nanosized NbOCl_(2) were investigated.Our finding revealed that NbOCl_(2) possesses a robust photothermal agent property,boasting a photothermal conversion efficiency of more than 30%.This underscores its promising potential for various photothermal applications in different fields such as photothermal therapy and thermal energy conversion.
基金financially supported from the Key Project of Equipment Pre-research Foundation of the Ministry of Equipment Development of the Central Military Commission of China(No.6140922010201)the Key Project of Research and Development of Zhenjiang Province,China(No.GY2018021)。
文摘To effectively improve the corrosion resistance of aluminum alloys without affecting their strength, the effect of Ce content on the microstructure, stress corrosion, intergranular corrosion, and exfoliation corrosion resistances of Al−11.3Zn−3.1Mg−1.2Cu−0.2Zr−0.1Ti alloy was investigated. The results showed that the addition of Ce formed the (Zn,Al,Cu)_(22)Ce_(3) phase with a size of 100 nm, which enhanced the recrystallization resistance of the alloy, increased the number of low-angle grain boundaries and dislocation density, refined the grains, promoted the phase transition from GP zone to η' phase, and promoted the size and discontinuity of precipitates at grain boundaries. All Ce-added alloys exhibited the higher resistance to corrosion. The alloy with 0.15 wt.% Ce possessed the optimal corrosion resistance along with the strength and elongation at slow strain rate of 744.8 MPa and 4.6%, respectively, in 3.5 wt.% NaCl solution. The minimum depth of intergranular corrosion and exfoliation corrosion was achieved as well.
基金supported by the National Natural Science Foundation of China(Grant No.21906015)the Fundamental Research Funds for the Central Universities(Grant No.N2205006 and N2225013).
文摘Rechargeable aqueous aluminum ion batteries(AIBs)are inspiring researchers’enthusiasm due to the low cost and high theoretical capacity of aluminum.Polyaniline(PANI)materials have the potential for aluminum ion storage due to the properties of its excellent conductivity and inherent theoretical capacity.However,the poor cycling stability and low loadings of PANI limit its application in energy storage.In this study,PANI-x electrodes with high mass loadings are successfully prepared by the electrodeposition method for reversible AlCl_(2)^(+)storage.Among them,the PANI-2 electrode possesses the highest areal capacity(0.59 and 0.51 mAh cm^(−2)at the current density of 0.5 and 10 mA cm^(−2))and excellent cycling stability in saturated AlCl3.Ex situ N 1s fitting spectra of PANI-2 and molecular dynamics simulations of 1 M,3 M,and saturated AlCl_(3)electrolytes demonstrate that PANI can achieve reversible redox reactions in saturated AlCl3,thereby achieving its excellent stability.Density functional theory calculations and ex situ spectra characterizations of PANI-2 demonstrate the insertion/de-insertion mechanism in the form of AlCl_(2)^(+)ions.In conclusion,PANI-2|Saturated AlCl_(3)|EG(exfoliated graphite foil)full cell is assembled successfully.This work provides promising guidance for the preparation of high-loading electrodes for AIBs.
基金Project(2012CB619502)supported by the National Basic Research Program of China
文摘The exfoliation corrosion （EFC） behavior of 7050-T6 aluminum alloy treated with various quench transfer time after solution heat treatment was investigated by standard EFC immersion tests, strength loss measurements after EFC tests and electrochemical impedance spectroscope （EIS） technique. The results showed that EFC resistance of the alloy decreased with increasing quench transfer time. Backscattered electron scanning electron microscope （SEM） together with transmission electron microscope （TEM） observations revealed that the coverage ratio and microstructure of precipitates at grain boundary area are the most important factors which influence the EFC susceptibility of the alloy, while precipitate-free zone （PFZ） near grain boundary has no or only a minor effect on it. In addition, galvanostatic measurements of the alloy present a good correlation between EFC resistance and transients in potential. The cumulated number of transients in potential can be used to evaluate EFC resistance of the alloy.
基金Projects (2010CB731701,2012CB619502) supported by the National Basic Research Program of ChinaProject (50721003) supported by the Creative Research Group of National Natural Science Foundation of China
文摘Influence of dual retrogression and re-aging（dual-RRA） temper on microstructure,strength and exfoliation corrosion（EC） behavior of Al-Zn-Mg-Cu alloy was investigated by hardness measurements,tensile properties tests,exfoliation corrosion tests,transmission electron microscopy（TEM） and scanning electron microscopy（SEM） observation combined energy dispersive X-ray detector（EDX） analysis.Dual-RRA temper maintains the matrix precipitates（MPs） similar to RRA temper,meanwhile obtains coarser and sparser grain boundary precipitates（GBPs） as well as higher Cu and lower Zn content compared with T76 temper.Therefore,dual-RRA temper not only keeps strength equivalent to the RRA temper but also obtains higher EC resistance than T76 temper.
基金Projects(51374048,50904012)supported by the National Natural Science Foundation of China
文摘The corrosion resistance of Al？Zn？Mg alloy subjected to different times in flame rectification was investigated based on the exfoliation corrosion test. The results indicate that the flame rectification deteriorates the exfoliation corrosion resistance of Al？Zn？Mg alloy. The corrosion resistance of Al-Zn-Mg alloy is ranked in the following order： base metal〉two times〉three times〉one time of flame rectification. The exfoliation corrosion behavior was discussed based on the transformation of precipitates at grain boundaries and matrix. With increasing the number of times in flame rectification, the precipitate-free zones disappeared and the precipitates experienced dissolution and re-precipitation. The sample was seriously corroded after one time of flame rectification, because the precipitates at grain boundaries are more continuous than those in other samples.
基金Supported by Grant-in-Aid for Scientific Research from the Japan Society for the Promotion of Science,No.17K08966(to Ohkoshi S)
文摘Mesenchymal stem cells(MSCs) as a source for regenerative medicine are now the subject of much clinical attention. There are high expectations due to their safety, low tumorigenic risk, and low ethical concerns. MSC therapy has been approved for acute graft-versus host diseases since 2015. Tooth-derived MSCs are known to have a great potential in their proliferation and differentiation capacities, even when compared with bone-marrow-derived MSCs. In particular, stem cells from human exfoliated deciduous teeth(SHEDs) are the best candidates for personal cell banking(dental pulp cell bank), because they can be obtained less invasively in the natural process of individual growth. SHEDs are known to differentiate into hepatocytes. There have been several studies showing the effectiveness of SHEDs on the treatment of liver failure in animal models. They may exert their effects either by repopulation of cells in injured liver or by paracrine mechanisms due to their immuneregulatory functions. Moreover, it may be possible to use each individuals' dental pulp cells as a future source of tailor-made differentiated hepatocytes in the context of a bioartificial liver or liver-on-a-chip to screen for drug toxicity.
文摘To screen patients with early cervical lesions by analyzing the infection of high-risk Human papillomavirus (HR-HPV). Research Methods: The cervical exfoliated cell specimens and their clinical data were collected. The HPV infection types of the collected specimens were detected by fluorescence quantitative PCR, and the correlation between HPV infection and clinicopathological features was analyzed statistically. Results: 725 cases were HR-HPV positive from 2605 cases, including 15 high-risk types of HPV16, 18, 31, 33, 35, 39, 45, 51, 52, 53, 56, 58, 59, 66, 68. Different histological types ranged from NILM to HSIL, and the positive rate of HPV showed an increasing trend with the aggravation of cervical lesions. Conclusion: The positive rate of 15 high-risk HPV types in the collected specimens was 27.8%. Patients with early cervical lesions could be screened for 15 high-risk HPV infection types.
基金supported by the National Natural Science Foundation of China (No. 51571134)the SDUST Research Fund (No. 2014TDJH104)
文摘Exfoliation on as-extruded Mg-1 Li-1 Ca magnesium alloy was investigated after an immersion in 3.5 wt%NaCl aqueous solution for 90, 120 and 150 days through optical microscope, digital camera, scanning electron microscope, electrochemical workstation, scanning Kalvin probe, X-ray diffraction and Fourier transform infrared spectroscope. The results demonstrated that exfoliation corrosion occurred on extruded Mg-1 Li-1 Ca alloy due to elongated microstructure parallel to surface, and delamination of lamellar structure resulted from galvanic effect and wedge effect. Skin layer with fine grains exhibited better corrosion resistance, whereas the interior with coarse grains and the intermetallic compound,Mg2 Ca particles existing in a fibrous structure, dispersed along grain boundaries and extrusion direction in a line. Furthermore, galvanic effect between Mg2 Ca particles and their neighboring a-Mg matrix facilitated dissolution of Mg2 Ca particles and a-Mg matrix; wedge effect was caused by formation of corrosion products. Exfoliation corrosion of extruded Mg-Li-Ca alloys might be a synergic effect of pitting corrosion,filiform corrosion, intergranular corrosion and stress corrosion. Finally, exfoliation corrosion mechanism was proposed.
