A new preparation method of Sm2Co17 nanoflakes was investigated. Hard magnetic Sm2 Co17 nanoflakes with thickness of 20-100 nm were obtained by milling in heptane and oleic acid under a magnetic field of 1.5 T for 0.5...A new preparation method of Sm2Co17 nanoflakes was investigated. Hard magnetic Sm2 Co17 nanoflakes with thickness of 20-100 nm were obtained by milling in heptane and oleic acid under a magnetic field of 1.5 T for 0.5-20 h. It was shown that higher anisotropic magnetic properties would be induced by the flake-shape anisotropy when the prepared Sm2 Colt particles are milled with a magnetic field. The magnetic anisotropy of flakes after being aligned under the magnetic field of 1.5 T could be further enhanced, and the value of （BH）m was 128 kJ · m a Both anisotropy and properties are better than those of the nano-particles milled without a magnetic field.展开更多
Epoxy resin(EP),as a resin material with excellent insulation performance,has been widely applied in fields such as electronics,coatings,ships etc.However,epoxy resins generally have poor thermal conductivity,which li...Epoxy resin(EP),as a resin material with excellent insulation performance,has been widely applied in fields such as electronics,coatings,ships etc.However,epoxy resins generally have poor thermal conductivity,which limits their application in the field of new generation of electronic packaging.To address the key issues mentioned above,the BN@Fe_(3)O_(4)particles with positive out-of-plane thermal conductivity were successfully prepared in this study,having a core-shell structure with rough surfaces as well.As a thermal conductive powder,the disadvantage of hexagonal boron nitride being easily agglomerated in resin has been improved.By applying an external magnetic field,three-dimensional thermal conduction pathways were constructed in the matrix.The physical and chemical properties of the BN@Fe_(3)O_(4)powder and its composite materials were analysed and tested.The experiment indicates that the thermal conductive magnetic powder BN@Fe_(3)O_(4)had been successfully prepared.When the filling amount of BN@Fe_(3)O_(4)reached 27.5 vol%,the out-of-plane thermal conductivity of the composite material was 1.758 W m^(-1)K^(-1),which was 982.12%that of pure EP.At this point,the mechanical behaviour and insulation performance of EP composite materials can be effectively guaranteed at the same order of magnitude as pure EP performance.展开更多
The variations of magnetization and magneto- striction with temperature and stress were investigated through the analysis of the effective field, induced by temperature and stress. A nonlinear magnetostrictive model o...The variations of magnetization and magneto- striction with temperature and stress were investigated through the analysis of the effective field, induced by temperature and stress. A nonlinear magnetostrictive model of giant magnetostrictive materials was proposed. The proposed model can be used to calculate the magnetostrictive characterization of giant magnetostrictive materi- als in different temperatures and under different stresses. The coupling effects of axial stress, magnetic field, and temperature on the magnetostriction of a Terfenol-D rod were numerically simulated as well as experimentally tested. Comparison between the calculating and experimental results shows that the proposed model can better describe the magneto-thermo-mechanical characteristics of Terfenol-D rod under different temperatures and compressive stress. Therefore, the proposed model possesses an important significance for the design of magnetostrictive devices.展开更多
Objectives:We sought to determine whether high posttreatment platelet reactivity(HPPR)to a 600 mg loading dose of clopidogrel affects outcomes in Chinese patients with acute coronary syndrome(ACS)following percutaneou...Objectives:We sought to determine whether high posttreatment platelet reactivity(HPPR)to a 600 mg loading dose of clopidogrel affects outcomes in Chinese patients with acute coronary syndrome(ACS)following percutaneous coronary intervention(PCI)and to investigate whether there is a relationship between the number of platelet reactivity units(PRUs)and the characteristics of the patients.Background:Although impaired platelet response to clopidogrel is a strong predictor of unfavorable outcome after PCI,the impact of HPPR to a 600 mg loading dose of clopidogrel in Chinese patients with ACS undergoing PCI is still unknown.Methods:We performed observational research on 134 unselected patients with ACS undergoing urgent or planned PCI with a 600 mg loading dose of clopidogrel.Platelet activation was expressed as the PRU value measured by the VerifyNow assay.Results:Among the 134 patients(mean age 60.62 years[standard deviation 9.13 years],60.4%male),there were 46 patients with HPPR(34.3%)and 88 patients without HPPR(65.7%).At a mean follow-up of 6 months(standard deviation 1 month),the rates of cardiac death,unstable angina,and rehospitalization for target lesion revascularization were higher in the HPPR group(19.6%vs.6.8%,P=0.029).Multivariate analysis identifi ed hemoglobin level and sex as independent predictors of the PRU value(y=456.355−1.736 x 1−31.880 x 2,P<0.05).On receiver operating characteristic curve analysis,PRU values could signifi cantly discriminate between patients with and patients without cardiac death,unstable angina,and rehospitalization for target lesion revascularization(area under the curve 0.758,95%confi dence interval 0.62–0.85,P=0.001,P<0.05).Conclusion:In patients with ACS,HPPR to a 600 mg loading dose of clopidogrel is associated with worse outcomes after PCI.There is some relationship between the PRU value and the hemoglobin level and sex.PRU values can predict the prognosis.展开更多
Flexible strain sensors have garnered significant attention for their potential applications in advanced flexible electronics and wearable technologies.However,achieving stable signal transmission at high temperatures...Flexible strain sensors have garnered significant attention for their potential applications in advanced flexible electronics and wearable technologies.However,achieving stable signal transmission at high temperatures remains a major challenge.In this study,we developed a novel polyimide(PI)aerogel composite,reinforced with intrinsically short-cut polyimide nanofibers(PINF)that are surface-coated with silver nanoparticles to enhance both conductivity and mechanical strength.Carbon nanotubes(CNTs)are used as the main filler in synergistic effect with Ag@PINF particles to further improve the conductivity and sensing performance of the composite material.This synergistic design results in a flexible PI aerogel composite material with rapid response time(116 ms),high sensitivity(GF=3.12),and long-term cycling stability(>1000 cycles).Additionally,the sensing materials were tested at high temperatures and after high-temperature aging,demonstrating good flexible sensing performance.Experimental results demonstrate that the composite sensor maintains stable strain-sensing performance across a range of environmental temperatures,showing consistent strain response under the same deformation conditions.This work provides a promising approach for fabricating high-performance,temperature-resistant flexible strain sensors,with broad applications in flexible electronics and wearable technologies.展开更多
Purpose-The purpose of this paper is to develop the linguistic q-rung orthopair fuzzy set(LqROFS)information VIKOR method based on the bi-direction Choquet integral(BDCI),taking into account the correlation between in...Purpose-The purpose of this paper is to develop the linguistic q-rung orthopair fuzzy set(LqROFS)information VIKOR method based on the bi-direction Choquet integral(BDCI),taking into account the correlation between information.The method can enrich the existing studies related to LqROFS information and better solve the problem of MAGDM problem.Design/methodology/approach-Since applying Choquet integral(CI)depict information interaction is a common operation in MAGDM.However,the traditional CI has some limitations.The unidirectional alignment may affect the MAGDM results.Therefore,a LqROFS-VIKOR method based on BDCI is proposed,where BDCI is used to aggregate the decision matrix.Furthermore,it is not reasonable to apply exact numbers to express the similarity between two qualitative data.Then a new method of defining similarity using linguistics is proposed.The similarity is used to calculate attribute weights.Findings-The validity and potential application of MAGMD method with linguistic q-rung orthopair fuzzy information based on BDCI are demonstrated in a numerical examples study.Originality/value-According to the study of available literature,the current research on LqROFS is incomplete.The existing studies of both similarity and aggregate operators have certain shortcomings.The definition of similarity proposed in this paper is more in line with reality.And compared with the existing methods,the BDCI-based aggregate operator can describe the interaction between information more reasonably.Based on this VIKOR method based on BDCI under the LqROFS environment can better select the alternative.展开更多
Oil-paper insulation material is an essential component for oil-filled transformers,and polyimide(PI)insulation paper is a novel material in the field of electricity.The improvement of insulation class for insulation ...Oil-paper insulation material is an essential component for oil-filled transformers,and polyimide(PI)insulation paper is a novel material in the field of electricity.The improvement of insulation class for insulation paper has gained significant attention in recent years.In this study,SiO_(2)nanoparticles were modified with a silane coupling agent(KH550),and the KH550-SiO_(2)was added to the fibre membrane through in situ poly-merisation.The chemical composition and microcosmic characteristics of the PI porous fibre membrane were characterised using FT-IR and SEM FT-IR and SEM.Conse-quently,the dielectric constant of the composite paper was reduced to 2.3 upon adding 3 wt%of KH550-SiO_(2),and the dielectric strength reached its maximum value of 85 kV/mm.The results demonstrate that the insulation performance of the KH550-SiO_(2)/PI composite was significantly improved due to the incorporation of nano-SiO_(2).This establishes an efficient approach for achieving excellent electrical and thermal properties in practical applications using the KH550-SiO_(2)/PI fibre membrane.展开更多
Hydrogen is garnering growing attention as a green energy source with zero carbon emissions.However,most hydrogen production technologies still rely on the consumption of fossil fuels and are therefore unsustainable.T...Hydrogen is garnering growing attention as a green energy source with zero carbon emissions.However,most hydrogen production technologies still rely on the consumption of fossil fuels and are therefore unsustainable.This has driven the search for more environmentally friendly methods of hydrogen production.In this work,we present an innovative approach to enhance hydrogen generation via electrostatic interaction in the Escherichia coli and defective titanium dioxide(TiO_(2−x))biohybrids.Our method involves narrowing the forbidden bandwidth of TiO2 while introducing defect bands into its conduction band to facilitate visible light absorption and efficient charge separation.This biohybrid system,consisting of E.coli and TiO_(2−x),demonstrates a remarkable capability to produce 1.25 mmol of hydrogen within a 3-h timeframe under visible light irradiation.This accomplishment signifies a 3.31-fold rise in hydrogen production in comparison to E.coli,signifying a substantial enhancement in hydrogen production efficiency.Furthermore,we delve into the alterations in biological metabolites associated with hydrogen production and the changes in electron transfer in different biohybrid systems.It provides valuable insights into the understanding of the intrinsic mechanisms that drive the process.This work introduces a novel and promising avenue for achieving this exciting goal.展开更多
Wearable devices,such as data gloves and electronic skins,can perceive human instructions,behaviors and even emotions by tracking a hand's motion,with the help of knowledge learning.The shape or position single-mo...Wearable devices,such as data gloves and electronic skins,can perceive human instructions,behaviors and even emotions by tracking a hand's motion,with the help of knowledge learning.The shape or position single-mode sensor in such devices often lacks comprehensive information to perceive interactive gestures.Meanwhile,the limited computing power of wearable applications restricts the multimode fusion of different sensing data and the deployment of deep learning networks.We propose a perceptive fusion electronic skin(PFES)with a bioinspired hierarchical structure that utilizes the magnetization state of a magnetostrictive alloy film to be sensitive to external strain or magnetic field.Installed at the joints of a hand,the PFES realizes perception of curvature(joint shape)and magnetism(joint position)information by mapping corresponding signals to the two-directional continuous distribution such that the two edges represent the contributions of curvature radius and magnetic field,respectively.By autonomously selecting knowledge closer to the user's hand movement characteristics,the reinforced knowledge distillation method is developed to learn and compress a teacher model for rapid deployment on wearable devices.The PFES integrating the autonomous learning algorithm can fuse curvature-magnetism dual information,ultimately achieving human machine interaction with gesture recognition and haptic feedback for cross-space perception and manipulation.展开更多
In situ anchor of magnetic Fe304 nanoparticles （NPs） onto the surface of natural maifanite was realized by chemical oxidation coprecipitation in hot alkaline solution. The Fe304/maifanite composites were characteriz...In situ anchor of magnetic Fe304 nanoparticles （NPs） onto the surface of natural maifanite was realized by chemical oxidation coprecipitation in hot alkaline solution. The Fe304/maifanite composites were characterized by XRD, FTIR, SEM, and TEM. These results indicated that polycrystalline Fe304 NPs with inverse spinel structure were formed and tightly dispersed on maifanite surface. Based on the measurement of surface Zeta potential of maifanite at different medium pHs, the possible combination mechanism between natural maifanite and Fe304 NPs was proposed. Then, the as- obtained composites were developed as highly efficient heterogeneous Fenton-like catalyst for the discoloration of an azo dye, Methyl Orange （MO）. The comparative tests on MO discoloration in different systems revealed that Fe304/maifanite composite exhibited much higher Fenton-like catalytic activity than Fe304 NPs and the heterogeneous Fenton- like reaction governed the discoloration of MO. Kinetic results clearly showed that MO discoloration process followed the second-order kinetic model. Fe304/maifanite compo- sites exhibited the typical ferromagnetic property detected by VSM and could be easily separated from solution by an external magnetic field.展开更多
基金Item Sponsored by National Natural Science Foundation of China(50901011,51105059,51201055)
文摘A new preparation method of Sm2Co17 nanoflakes was investigated. Hard magnetic Sm2 Co17 nanoflakes with thickness of 20-100 nm were obtained by milling in heptane and oleic acid under a magnetic field of 1.5 T for 0.5-20 h. It was shown that higher anisotropic magnetic properties would be induced by the flake-shape anisotropy when the prepared Sm2 Colt particles are milled with a magnetic field. The magnetic anisotropy of flakes after being aligned under the magnetic field of 1.5 T could be further enhanced, and the value of （BH）m was 128 kJ · m a Both anisotropy and properties are better than those of the nano-particles milled without a magnetic field.
基金Natural Science Foundation of Heilongjiang Province,Grant/Award Number:LH2021E079。
文摘Epoxy resin(EP),as a resin material with excellent insulation performance,has been widely applied in fields such as electronics,coatings,ships etc.However,epoxy resins generally have poor thermal conductivity,which limits their application in the field of new generation of electronic packaging.To address the key issues mentioned above,the BN@Fe_(3)O_(4)particles with positive out-of-plane thermal conductivity were successfully prepared in this study,having a core-shell structure with rough surfaces as well.As a thermal conductive powder,the disadvantage of hexagonal boron nitride being easily agglomerated in resin has been improved.By applying an external magnetic field,three-dimensional thermal conduction pathways were constructed in the matrix.The physical and chemical properties of the BN@Fe_(3)O_(4)powder and its composite materials were analysed and tested.The experiment indicates that the thermal conductive magnetic powder BN@Fe_(3)O_(4)had been successfully prepared.When the filling amount of BN@Fe_(3)O_(4)reached 27.5 vol%,the out-of-plane thermal conductivity of the composite material was 1.758 W m^(-1)K^(-1),which was 982.12%that of pure EP.At this point,the mechanical behaviour and insulation performance of EP composite materials can be effectively guaranteed at the same order of magnitude as pure EP performance.
基金supported by the National Natural Science Foundation of China (Nos. 50971056 and 51171057)the Youth Natural Science Foundation of Hebei Province (No. E2011202002)
文摘The variations of magnetization and magneto- striction with temperature and stress were investigated through the analysis of the effective field, induced by temperature and stress. A nonlinear magnetostrictive model of giant magnetostrictive materials was proposed. The proposed model can be used to calculate the magnetostrictive characterization of giant magnetostrictive materi- als in different temperatures and under different stresses. The coupling effects of axial stress, magnetic field, and temperature on the magnetostriction of a Terfenol-D rod were numerically simulated as well as experimentally tested. Comparison between the calculating and experimental results shows that the proposed model can better describe the magneto-thermo-mechanical characteristics of Terfenol-D rod under different temperatures and compressive stress. Therefore, the proposed model possesses an important significance for the design of magnetostrictive devices.
基金the Science Fund for Distinguished Young Scholars from the Fourth Affi liated Hospital of Harbin Medical University(no.HYDSYJQ201504)The funders had no role in the study design,data collection and analysis,decision to publish,or preparation of the manuscriptThe clinical trial is registered as ChiCTR-IOR-17013665。
文摘Objectives:We sought to determine whether high posttreatment platelet reactivity(HPPR)to a 600 mg loading dose of clopidogrel affects outcomes in Chinese patients with acute coronary syndrome(ACS)following percutaneous coronary intervention(PCI)and to investigate whether there is a relationship between the number of platelet reactivity units(PRUs)and the characteristics of the patients.Background:Although impaired platelet response to clopidogrel is a strong predictor of unfavorable outcome after PCI,the impact of HPPR to a 600 mg loading dose of clopidogrel in Chinese patients with ACS undergoing PCI is still unknown.Methods:We performed observational research on 134 unselected patients with ACS undergoing urgent or planned PCI with a 600 mg loading dose of clopidogrel.Platelet activation was expressed as the PRU value measured by the VerifyNow assay.Results:Among the 134 patients(mean age 60.62 years[standard deviation 9.13 years],60.4%male),there were 46 patients with HPPR(34.3%)and 88 patients without HPPR(65.7%).At a mean follow-up of 6 months(standard deviation 1 month),the rates of cardiac death,unstable angina,and rehospitalization for target lesion revascularization were higher in the HPPR group(19.6%vs.6.8%,P=0.029).Multivariate analysis identifi ed hemoglobin level and sex as independent predictors of the PRU value(y=456.355−1.736 x 1−31.880 x 2,P<0.05).On receiver operating characteristic curve analysis,PRU values could signifi cantly discriminate between patients with and patients without cardiac death,unstable angina,and rehospitalization for target lesion revascularization(area under the curve 0.758,95%confi dence interval 0.62–0.85,P=0.001,P<0.05).Conclusion:In patients with ACS,HPPR to a 600 mg loading dose of clopidogrel is associated with worse outcomes after PCI.There is some relationship between the PRU value and the hemoglobin level and sex.PRU values can predict the prognosis.
基金Science Foundation of National Key Laboratory of Science and Technology on Advanced Composites in Special Environments(No.JCKYS2024603C009).
文摘Flexible strain sensors have garnered significant attention for their potential applications in advanced flexible electronics and wearable technologies.However,achieving stable signal transmission at high temperatures remains a major challenge.In this study,we developed a novel polyimide(PI)aerogel composite,reinforced with intrinsically short-cut polyimide nanofibers(PINF)that are surface-coated with silver nanoparticles to enhance both conductivity and mechanical strength.Carbon nanotubes(CNTs)are used as the main filler in synergistic effect with Ag@PINF particles to further improve the conductivity and sensing performance of the composite material.This synergistic design results in a flexible PI aerogel composite material with rapid response time(116 ms),high sensitivity(GF=3.12),and long-term cycling stability(>1000 cycles).Additionally,the sensing materials were tested at high temperatures and after high-temperature aging,demonstrating good flexible sensing performance.Experimental results demonstrate that the composite sensor maintains stable strain-sensing performance across a range of environmental temperatures,showing consistent strain response under the same deformation conditions.This work provides a promising approach for fabricating high-performance,temperature-resistant flexible strain sensors,with broad applications in flexible electronics and wearable technologies.
基金This work was supported by the Science and Technology Innovation Special Fund Project of Fujian agriculture and Forestry University(No.CXZX2019121S)the Natural Science Foundation of Fujian Province(No.2020J01576)+1 种基金China Postdoctoral Science Foundation(No.2019M660242)the Science and Technology Innovation Special Fund Project of Fujian agriculture and Forestry University(No.CXZX2020110A).
文摘Purpose-The purpose of this paper is to develop the linguistic q-rung orthopair fuzzy set(LqROFS)information VIKOR method based on the bi-direction Choquet integral(BDCI),taking into account the correlation between information.The method can enrich the existing studies related to LqROFS information and better solve the problem of MAGDM problem.Design/methodology/approach-Since applying Choquet integral(CI)depict information interaction is a common operation in MAGDM.However,the traditional CI has some limitations.The unidirectional alignment may affect the MAGDM results.Therefore,a LqROFS-VIKOR method based on BDCI is proposed,where BDCI is used to aggregate the decision matrix.Furthermore,it is not reasonable to apply exact numbers to express the similarity between two qualitative data.Then a new method of defining similarity using linguistics is proposed.The similarity is used to calculate attribute weights.Findings-The validity and potential application of MAGMD method with linguistic q-rung orthopair fuzzy information based on BDCI are demonstrated in a numerical examples study.Originality/value-According to the study of available literature,the current research on LqROFS is incomplete.The existing studies of both similarity and aggregate operators have certain shortcomings.The definition of similarity proposed in this paper is more in line with reality.And compared with the existing methods,the BDCI-based aggregate operator can describe the interaction between information more reasonably.Based on this VIKOR method based on BDCI under the LqROFS environment can better select the alternative.
基金Young Talents in Heilongjiang Province Colleges and Universities,Grant/Award Number:UNPYSCT-2020182Fundamental Research Foundation for University of Heilongjiang Province,Grant/Award Number:2021-KYYWF-0744National Nature Science Foundation of China,Grant/Award Number:52107014。
文摘Oil-paper insulation material is an essential component for oil-filled transformers,and polyimide(PI)insulation paper is a novel material in the field of electricity.The improvement of insulation class for insulation paper has gained significant attention in recent years.In this study,SiO_(2)nanoparticles were modified with a silane coupling agent(KH550),and the KH550-SiO_(2)was added to the fibre membrane through in situ poly-merisation.The chemical composition and microcosmic characteristics of the PI porous fibre membrane were characterised using FT-IR and SEM FT-IR and SEM.Conse-quently,the dielectric constant of the composite paper was reduced to 2.3 upon adding 3 wt%of KH550-SiO_(2),and the dielectric strength reached its maximum value of 85 kV/mm.The results demonstrate that the insulation performance of the KH550-SiO_(2)/PI composite was significantly improved due to the incorporation of nano-SiO_(2).This establishes an efficient approach for achieving excellent electrical and thermal properties in practical applications using the KH550-SiO_(2)/PI fibre membrane.
基金the National Natural Science Foundation of China(Nos.52172085,52273287,52202091,and 51825202)the Key Laboratory of Micro-systems and Microstructures Manufacturing(Harbin Institute of Technology),Ministry of Education(No.AUEA1890200122)+1 种基金the Natural Science Foundation of Heilongjiang Province of China for Excellent Young Scholars(No.YQ2022E020)Heilongjiang Touyan Team(No.HITTY-20190036).
文摘Hydrogen is garnering growing attention as a green energy source with zero carbon emissions.However,most hydrogen production technologies still rely on the consumption of fossil fuels and are therefore unsustainable.This has driven the search for more environmentally friendly methods of hydrogen production.In this work,we present an innovative approach to enhance hydrogen generation via electrostatic interaction in the Escherichia coli and defective titanium dioxide(TiO_(2−x))biohybrids.Our method involves narrowing the forbidden bandwidth of TiO2 while introducing defect bands into its conduction band to facilitate visible light absorption and efficient charge separation.This biohybrid system,consisting of E.coli and TiO_(2−x),demonstrates a remarkable capability to produce 1.25 mmol of hydrogen within a 3-h timeframe under visible light irradiation.This accomplishment signifies a 3.31-fold rise in hydrogen production in comparison to E.coli,signifying a substantial enhancement in hydrogen production efficiency.Furthermore,we delve into the alterations in biological metabolites associated with hydrogen production and the changes in electron transfer in different biohybrid systems.It provides valuable insights into the understanding of the intrinsic mechanisms that drive the process.This work introduces a novel and promising avenue for achieving this exciting goal.
基金supported by the National Natural Science Foundation of China(No.51801053,52077052,52377007)the Natural Science Foundation of Hebei Province(E2022202067)the Central Guidance on Local Science and Technology Development Fund(No.226Z1704G).
文摘Wearable devices,such as data gloves and electronic skins,can perceive human instructions,behaviors and even emotions by tracking a hand's motion,with the help of knowledge learning.The shape or position single-mode sensor in such devices often lacks comprehensive information to perceive interactive gestures.Meanwhile,the limited computing power of wearable applications restricts the multimode fusion of different sensing data and the deployment of deep learning networks.We propose a perceptive fusion electronic skin(PFES)with a bioinspired hierarchical structure that utilizes the magnetization state of a magnetostrictive alloy film to be sensitive to external strain or magnetic field.Installed at the joints of a hand,the PFES realizes perception of curvature(joint shape)and magnetism(joint position)information by mapping corresponding signals to the two-directional continuous distribution such that the two edges represent the contributions of curvature radius and magnetic field,respectively.By autonomously selecting knowledge closer to the user's hand movement characteristics,the reinforced knowledge distillation method is developed to learn and compress a teacher model for rapid deployment on wearable devices.The PFES integrating the autonomous learning algorithm can fuse curvature-magnetism dual information,ultimately achieving human machine interaction with gesture recognition and haptic feedback for cross-space perception and manipulation.
基金This work was financially supported by the National Natural Science Foundation of China （Grant No. 51404083）, the Program for New Century Excellent Talents in Heilongjiang Provincial Universities （Grant No. 1253-NCET-010）, the Research Development Fund of Nianzishan Institute of Maifanite, Qiqihaer （Grant No. 201406）, and the Natural Science Foundation of Heilongjiang Province, China （Grant No. E2015065）.
文摘In situ anchor of magnetic Fe304 nanoparticles （NPs） onto the surface of natural maifanite was realized by chemical oxidation coprecipitation in hot alkaline solution. The Fe304/maifanite composites were characterized by XRD, FTIR, SEM, and TEM. These results indicated that polycrystalline Fe304 NPs with inverse spinel structure were formed and tightly dispersed on maifanite surface. Based on the measurement of surface Zeta potential of maifanite at different medium pHs, the possible combination mechanism between natural maifanite and Fe304 NPs was proposed. Then, the as- obtained composites were developed as highly efficient heterogeneous Fenton-like catalyst for the discoloration of an azo dye, Methyl Orange （MO）. The comparative tests on MO discoloration in different systems revealed that Fe304/maifanite composite exhibited much higher Fenton-like catalytic activity than Fe304 NPs and the heterogeneous Fenton- like reaction governed the discoloration of MO. Kinetic results clearly showed that MO discoloration process followed the second-order kinetic model. Fe304/maifanite compo- sites exhibited the typical ferromagnetic property detected by VSM and could be easily separated from solution by an external magnetic field.
