In the paper, plasma surface metallurgy was performed using Fe-based powder on steel substrate. The microstructure and microhardness of the coating have been analyzed. On the base of orthogonal comparison tests, influ...In the paper, plasma surface metallurgy was performed using Fe-based powder on steel substrate. The microstructure and microhardness of the coating have been analyzed. On the base of orthogonal comparison tests, influences of many factors on the cracking sensibility of plasma metallurgy coating have also been studied. The results indicate that substrate and its surface condition, processing parameters and components of plasma metallurgy coating have great effects on cracking sensibility of plasma metallurgy coating. Through changing these factors, it is possible to reduce cracks and promote the applications of this technology.展开更多
A method was developed to determine the concentration of methyl tert-butyl ether(MTBE) in gasoline, diesel and heating oil by gas chromatography(GC) with mass spectrometry(GC-MS) or flame ionization detection(FID). Th...A method was developed to determine the concentration of methyl tert-butyl ether(MTBE) in gasoline, diesel and heating oil by gas chromatography(GC) with mass spectrometry(GC-MS) or flame ionization detection(FID). The diluted gasoline was directly injected into the GC, and the complete separation of MTBE from co-eluting hydrocarbons was not required. GC/MS or GC/FID method can be used to analyze MTBE in different concentration range and have good consistency.展开更多
The influences of heat treatment time on structure and the electrochemical behavior of electro-deposited amorphous Ni-P alloy coating were studied. The results show that the as-plated deposits have an amorphous struct...The influences of heat treatment time on structure and the electrochemical behavior of electro-deposited amorphous Ni-P alloy coating were studied. The results show that the as-plated deposits have an amorphous structure, and the deposits crystallize into Ni12P5 and Ni3P at 260 °C, and the corrosion resistance of the as-plated deposits are better than that of the deposits after heat treatment.展开更多
A method of concentration analysis based on X-ray photoelectron spectroscopy (XPS) results was introduced. The concentration of Ce-rich conversion coating on the anodized Al based metal matrix composites AI6061/SiCp w...A method of concentration analysis based on X-ray photoelectron spectroscopy (XPS) results was introduced. The concentration of Ce-rich conversion coating on the anodized Al based metal matrix composites AI6061/SiCp was then studied according to this method. The results revealed that the Ce conversion coating on the anodized AI6061/SiCp consisted of Al oxide, Ce oxide and Ce hydroxide. The state of Ce element exhibited the mixture of Ce3+ and Ce4+. Some of Cell I was oxidized to be CelV in the outer layer coating.展开更多
In this paper,the influcnce of chief process parameters on the ontinuous production of Si3N4 powder by renitridation has been studied,The sutiable process parameters have been found,and high quality Si3N4 powder has b...In this paper,the influcnce of chief process parameters on the ontinuous production of Si3N4 powder by renitridation has been studied,The sutiable process parameters have been found,and high quality Si3N4 powder has been developed.展开更多
In a 0.02 mol/L Na_2HPO_4-KH_2PO_4(PBS) buffer solution(pH=6.82), the electrochemical behavior of mitoxantrone was studied by linear-sweep voltammetry and cyclic voltammetry at a Pt/C ion implantation modified microel...In a 0.02 mol/L Na_2HPO_4-KH_2PO_4(PBS) buffer solution(pH=6.82), the electrochemical behavior of mitoxantrone was studied by linear-sweep voltammetry and cyclic voltammetry at a Pt/C ion implantation modified microelectrode. A sensitive reduction peak was observed. The peak potential was \{-0.72 V\}(vs.SCE), the peak current was proportional to the concentration of mitoxantrone within the ranges of 7.0×10 -8—9.0×10 -7 mol/L and 1.0×10 -6—2.4×10 -5 mol/L, with a detection limit of 4.0×10 -8 mol/L. The linear correlation coefficients were 0.9994 and 0.9992, respectively. This method has been applied to the direct determination of mitoxantrone in simulated urine. The recoveries were in the range from 96.2% to 105.9%. The reduction process was a quasi-reversible one with adsorptive characteristics at the Pt/C microelectrode. The electrode reaction rate constant k_s and the electron transfer coefficient α of the system were determined to be 4.5 and 0.65 s -1, respectively. The experiments showed that Pt element had surely been implanted into the surface of the carbon fiber, and the atomic Pt improved the electrocatalytic activity. The Pt/C microelectrode had a good stability and reproducibility.展开更多
Based on the analysis of experimental results, the rock damage model and thedamage coupling model suitable for the whole rock breaking process with water jet were establishedwith continuous damage mechanics and micro ...Based on the analysis of experimental results, the rock damage model and thedamage coupling model suitable for the whole rock breaking process with water jet were establishedwith continuous damage mechanics and micro damage mechanics, and the numerical method was developedwith continuum mechanics and the FEM theory. The rock breaking mechanism with water jet was studiedsystematically with numerical simulation for the first time in the field of water-jet rock breaking.The numerical results agree with the experimental ones which shows that the presented method isreasonable and can reflect the reality of water-jet rock breaking. The conclusion can be applied inpractice.展开更多
文摘In the paper, plasma surface metallurgy was performed using Fe-based powder on steel substrate. The microstructure and microhardness of the coating have been analyzed. On the base of orthogonal comparison tests, influences of many factors on the cracking sensibility of plasma metallurgy coating have also been studied. The results indicate that substrate and its surface condition, processing parameters and components of plasma metallurgy coating have great effects on cracking sensibility of plasma metallurgy coating. Through changing these factors, it is possible to reduce cracks and promote the applications of this technology.
文摘A method was developed to determine the concentration of methyl tert-butyl ether(MTBE) in gasoline, diesel and heating oil by gas chromatography(GC) with mass spectrometry(GC-MS) or flame ionization detection(FID). The diluted gasoline was directly injected into the GC, and the complete separation of MTBE from co-eluting hydrocarbons was not required. GC/MS or GC/FID method can be used to analyze MTBE in different concentration range and have good consistency.
文摘The influences of heat treatment time on structure and the electrochemical behavior of electro-deposited amorphous Ni-P alloy coating were studied. The results show that the as-plated deposits have an amorphous structure, and the deposits crystallize into Ni12P5 and Ni3P at 260 °C, and the corrosion resistance of the as-plated deposits are better than that of the deposits after heat treatment.
基金This work has been carried out with the support of The Chinese Postdoctoral Science Fund and The Special Funds for the Major State Basic Research Projects G19990650.
文摘A method of concentration analysis based on X-ray photoelectron spectroscopy (XPS) results was introduced. The concentration of Ce-rich conversion coating on the anodized Al based metal matrix composites AI6061/SiCp was then studied according to this method. The results revealed that the Ce conversion coating on the anodized AI6061/SiCp consisted of Al oxide, Ce oxide and Ce hydroxide. The state of Ce element exhibited the mixture of Ce3+ and Ce4+. Some of Cell I was oxidized to be CelV in the outer layer coating.
文摘In this paper,the influcnce of chief process parameters on the ontinuous production of Si3N4 powder by renitridation has been studied,The sutiable process parameters have been found,and high quality Si3N4 powder has been developed.
文摘In a 0.02 mol/L Na_2HPO_4-KH_2PO_4(PBS) buffer solution(pH=6.82), the electrochemical behavior of mitoxantrone was studied by linear-sweep voltammetry and cyclic voltammetry at a Pt/C ion implantation modified microelectrode. A sensitive reduction peak was observed. The peak potential was \{-0.72 V\}(vs.SCE), the peak current was proportional to the concentration of mitoxantrone within the ranges of 7.0×10 -8—9.0×10 -7 mol/L and 1.0×10 -6—2.4×10 -5 mol/L, with a detection limit of 4.0×10 -8 mol/L. The linear correlation coefficients were 0.9994 and 0.9992, respectively. This method has been applied to the direct determination of mitoxantrone in simulated urine. The recoveries were in the range from 96.2% to 105.9%. The reduction process was a quasi-reversible one with adsorptive characteristics at the Pt/C microelectrode. The electrode reaction rate constant k_s and the electron transfer coefficient α of the system were determined to be 4.5 and 0.65 s -1, respectively. The experiments showed that Pt element had surely been implanted into the surface of the carbon fiber, and the atomic Pt improved the electrocatalytic activity. The Pt/C microelectrode had a good stability and reproducibility.
基金supported by the"Outstanding Youth Fund"of the National Natural Science Foundation of Chinathe"Hundreds of Talents"Program of Chinese Academy of Sciences.
文摘Based on the analysis of experimental results, the rock damage model and thedamage coupling model suitable for the whole rock breaking process with water jet were establishedwith continuous damage mechanics and micro damage mechanics, and the numerical method was developedwith continuum mechanics and the FEM theory. The rock breaking mechanism with water jet was studiedsystematically with numerical simulation for the first time in the field of water-jet rock breaking.The numerical results agree with the experimental ones which shows that the presented method isreasonable and can reflect the reality of water-jet rock breaking. The conclusion can be applied inpractice.
