The effects of different surface pretreatment nmthods on the nucleation and growth of ultra-nanocrystalline diamond (UNCD) fihns grown from focused microwave Ar/CHa/H2 (argon- rich) plasma were systematically stud...The effects of different surface pretreatment nmthods on the nucleation and growth of ultra-nanocrystalline diamond (UNCD) fihns grown from focused microwave Ar/CHa/H2 (argon- rich) plasma were systematically studied. The surface roughness, nucleation density, mierostruc- ture, and crystallinity of the obtained UNCD films were characterized by atomic force microscope (AFM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and Raman spectroscopy. The results indicate that the nucleation enhancement was found to be sensitive to the different sur- face pretreatment methods, and a higher initial nucleation density leads to highly smooth UNCD films. When the silicon substrate was pretreated by a two-step method, i.e., plasma treatment followed by ultrasonic vibration with diamond nanopowder, the grain size of the UNCD films was greatly decreased: about 7.5 nm can be achieved. In addition, the grain size of UNCD films depends on the substrate pretreatment methods and roughness, which indicates that the surface of substrate profile has a "genetic characteristic".展开更多
1,3-dioxolane (DOL) is originally used to pretreat the lithium metal electrode in order to passivate lithium metal and improve its interface stability. Through electrochemical impedance spectra (EIS) and cathodic pola...1,3-dioxolane (DOL) is originally used to pretreat the lithium metal electrode in order to passivate lithium metal and improve its interface stability. Through electrochemical impedance spectra (EIS) and cathodic polarization measurements of pretreated and untreated electrodes, it was found that 1,3-dioxolane could form a stable passivating film on the surface of lithium electrode. And such film could enhance effectively the interfacial stability of lithium electrode, without depressing its kinetics characteristic. Consequentially, further tests of the cell-performance during repeated charge/discharge cycles showed that the cell with DOL pretreated anode had better discharging performance and longer cycle life because of the passivating and protective effects of 1,3-dioxolane pretreatment on lithium electrode.展开更多
The mechanical and physical properties of biodegradable magnesium(Mg)alloys make them suitable for temporary orthopaedic implants.The success of these alloys depends on their performance in the physiological environme...The mechanical and physical properties of biodegradable magnesium(Mg)alloys make them suitable for temporary orthopaedic implants.The success of these alloys depends on their performance in the physiological environment.In the present work,surface modification of Mg-Ca binary alloy by acid pickling for better biomineralization and controlled biodegradation is explored.The corrosion rates of nitric and phosphoric acid treated samples were analysed by conducting electrochemical corrosion tests.In vitro degradation behaviour was studied using immersion test in simulated body fluid(SBF).The sample surfaces were characterized using scanning electron microscope(SEM),energy dispersive X-ray spectroscopy(EDS),Fourier transform infrared spectroscopy(FTIR)and X-ray photoelectron spectroscopy(XPS).It is seen that acid pickling leads to significant improvement in biomineralization and develop in situ calcium phosphate(Ca P)coating on the sample surfaces.In addition,the treated samples recorded a reduced degradation rate in the SBF compared to untreated samples.Thus,acid pickling is suggested as an effective surface treatment method to tailor the biomineralization and degradation behaviour of the Mg-Ca alloy in the physiological environment.展开更多
The effect of microwave pretreatment on the anaerobic degradation of hyacinth was investigated using response surface methodology (RSM). The components oflignin and the other constituents of hyacinth were altered by...The effect of microwave pretreatment on the anaerobic degradation of hyacinth was investigated using response surface methodology (RSM). The components oflignin and the other constituents of hyacinth were altered by microwave pretreatment. Comparison of the near-infrared spectra of hyacinth pretreated by microwave irradiation and water-heating pretreatment revealed that no new compounds were generated during hyacinth pretreatment by microwave irradiation. Atomic force microscopy observations indicated that the physical structures of hyacinth were disrupted by microwave pretreatment. The yield of methane per gram of the microwave-irradiated substrate increased by 38.3% as compared to that of the substrate pretreated via water-heating. A maximum methane yield of 221 mL·g-sub^-1 was obtained under the optimum pretreatment conditions (substrate concentration (pSC) = 20.1 g·L^-1 and pretreatment time (PT) = 14.6 min) using RSM analysis. A maximum methane production rate of 0.76 mL·h^-1· g-sub^-1 was obtained by applying PSC = 9.5 g·L^-1 and PT= 11 min. Interactive item coefficient analysis showed that methane production was dependent on the PSC and PT, separately, whereas the interactive effect of the PSC and PT on methane production was not significant. The same trend was also observed for the methane production rate.展开更多
Jiuhe Corporation developed a new surface pretreatment for producing a phosphate-free and colored zirconium conversion coating on cold-rolled steel(CRS).Scanning electron microscopy(SEM)and energy-dispersive spectrosc...Jiuhe Corporation developed a new surface pretreatment for producing a phosphate-free and colored zirconium conversion coating on cold-rolled steel(CRS).Scanning electron microscopy(SEM)and energy-dispersive spectroscopy(EDS)were applied to study the surface morphology and elemental composition of the golden yellow-colored conversion coating.Elec trochemic al impedance spectroscopy(EIS)was used to investigate the electrochemical performance of the conversion coatings with different colors.The corrosion resistance properties of the powder coatings were characterized using the neutral salt spray test(NSS)and the tape adhesion test.The EIS and NSS results demonstrate that the colored zirconium conversion coatings exhibit excellent corrosion resistance properties compared with the bare CRS.The golden yellow-colored conversion coating has a maximum EIS value(748Ω·cm^(2))and achieves 0 mm degree of corrosion,as stipulated by EN ISO 4628-8.This paper proposes a hypothesis concerning the ZrO_(2)-(β-FeOOH)-polymer conversion reaction to explain the color changes.展开更多
基金supported by National Natural Science Foundation of China(No.11175137)the Research Fund of Wuhan Institute of Technology,China(No.11111051)
文摘The effects of different surface pretreatment nmthods on the nucleation and growth of ultra-nanocrystalline diamond (UNCD) fihns grown from focused microwave Ar/CHa/H2 (argon- rich) plasma were systematically studied. The surface roughness, nucleation density, mierostruc- ture, and crystallinity of the obtained UNCD films were characterized by atomic force microscope (AFM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and Raman spectroscopy. The results indicate that the nucleation enhancement was found to be sensitive to the different sur- face pretreatment methods, and a higher initial nucleation density leads to highly smooth UNCD films. When the silicon substrate was pretreated by a two-step method, i.e., plasma treatment followed by ultrasonic vibration with diamond nanopowder, the grain size of the UNCD films was greatly decreased: about 7.5 nm can be achieved. In addition, the grain size of UNCD films depends on the substrate pretreatment methods and roughness, which indicates that the surface of substrate profile has a "genetic characteristic".
文摘1,3-dioxolane (DOL) is originally used to pretreat the lithium metal electrode in order to passivate lithium metal and improve its interface stability. Through electrochemical impedance spectra (EIS) and cathodic polarization measurements of pretreated and untreated electrodes, it was found that 1,3-dioxolane could form a stable passivating film on the surface of lithium electrode. And such film could enhance effectively the interfacial stability of lithium electrode, without depressing its kinetics characteristic. Consequentially, further tests of the cell-performance during repeated charge/discharge cycles showed that the cell with DOL pretreated anode had better discharging performance and longer cycle life because of the passivating and protective effects of 1,3-dioxolane pretreatment on lithium electrode.
基金financial grant No.5/4–5/3ORTHO/2019-NCD-I Dt.16–09–2019 from Indian Council of Medical Research(ICMR)the grant from DST-FIST-No.SR/FST/ETI-388/2015,Govt.of India used for setting up 3D Profilometer facility at NIT Calicut。
文摘The mechanical and physical properties of biodegradable magnesium(Mg)alloys make them suitable for temporary orthopaedic implants.The success of these alloys depends on their performance in the physiological environment.In the present work,surface modification of Mg-Ca binary alloy by acid pickling for better biomineralization and controlled biodegradation is explored.The corrosion rates of nitric and phosphoric acid treated samples were analysed by conducting electrochemical corrosion tests.In vitro degradation behaviour was studied using immersion test in simulated body fluid(SBF).The sample surfaces were characterized using scanning electron microscope(SEM),energy dispersive X-ray spectroscopy(EDS),Fourier transform infrared spectroscopy(FTIR)and X-ray photoelectron spectroscopy(XPS).It is seen that acid pickling leads to significant improvement in biomineralization and develop in situ calcium phosphate(Ca P)coating on the sample surfaces.In addition,the treated samples recorded a reduced degradation rate in the SBF compared to untreated samples.Thus,acid pickling is suggested as an effective surface treatment method to tailor the biomineralization and degradation behaviour of the Mg-Ca alloy in the physiological environment.
基金Acknowledgements This work was supported by the National Natural Science Foundation of China (Grant No. 51308010), the Scientific Research Project of Beijing Educational Committee (No. KM201210005028), the Research Fund for the Doctoral Program of Higher Education of China (No. 20131103120017), and the Top Youth Team of Ministry, Department of Beijing Municipal Party Committee (No. Q0004018201502).
文摘The effect of microwave pretreatment on the anaerobic degradation of hyacinth was investigated using response surface methodology (RSM). The components oflignin and the other constituents of hyacinth were altered by microwave pretreatment. Comparison of the near-infrared spectra of hyacinth pretreated by microwave irradiation and water-heating pretreatment revealed that no new compounds were generated during hyacinth pretreatment by microwave irradiation. Atomic force microscopy observations indicated that the physical structures of hyacinth were disrupted by microwave pretreatment. The yield of methane per gram of the microwave-irradiated substrate increased by 38.3% as compared to that of the substrate pretreated via water-heating. A maximum methane yield of 221 mL·g-sub^-1 was obtained under the optimum pretreatment conditions (substrate concentration (pSC) = 20.1 g·L^-1 and pretreatment time (PT) = 14.6 min) using RSM analysis. A maximum methane production rate of 0.76 mL·h^-1· g-sub^-1 was obtained by applying PSC = 9.5 g·L^-1 and PT= 11 min. Interactive item coefficient analysis showed that methane production was dependent on the PSC and PT, separately, whereas the interactive effect of the PSC and PT on methane production was not significant. The same trend was also observed for the methane production rate.
基金financially supported by Shenzhen Technology Development Project(No.CXZZ20140902141250786)Guangdong Science and Technology Project(No.2014A010105004)。
文摘Jiuhe Corporation developed a new surface pretreatment for producing a phosphate-free and colored zirconium conversion coating on cold-rolled steel(CRS).Scanning electron microscopy(SEM)and energy-dispersive spectroscopy(EDS)were applied to study the surface morphology and elemental composition of the golden yellow-colored conversion coating.Elec trochemic al impedance spectroscopy(EIS)was used to investigate the electrochemical performance of the conversion coatings with different colors.The corrosion resistance properties of the powder coatings were characterized using the neutral salt spray test(NSS)and the tape adhesion test.The EIS and NSS results demonstrate that the colored zirconium conversion coatings exhibit excellent corrosion resistance properties compared with the bare CRS.The golden yellow-colored conversion coating has a maximum EIS value(748Ω·cm^(2))and achieves 0 mm degree of corrosion,as stipulated by EN ISO 4628-8.This paper proposes a hypothesis concerning the ZrO_(2)-(β-FeOOH)-polymer conversion reaction to explain the color changes.