The coating microstructure of hot-dip aluminum (HDA) of deformed low-carbon steel containing RE was analyzed by metallography microscopy, TEM and XRD, and the forming mechanism was also discussed. The results show tha...The coating microstructure of hot-dip aluminum (HDA) of deformed low-carbon steel containing RE was analyzed by metallography microscopy, TEM and XRD, and the forming mechanism was also discussed. The results show that, the Fe_2Al_5 phase, on whose subcrystal boundaries, Al particles with the size of 7~30 μm existing on parallel linear are, grows a strong orientation. And the spread activation energy of Al is 155.22 kJ·mol -1. In addition, the effects of deformation on coating microstructure of hot-dip aluminum and the function of RE were preliminarily analyzed.展开更多
A copper-zinc alloy doped with rare earth elements was prepared and the mechanism was demonstrated in a simulating boiler and circulating cooling water with rigidity 1 mmol·L-1. The polar curve and scale inhibiti...A copper-zinc alloy doped with rare earth elements was prepared and the mechanism was demonstrated in a simulating boiler and circulating cooling water with rigidity 1 mmol·L-1. The polar curve and scale inhibiting ability of the alloy was tested by a corrosion measurement system and a scale inhibition evaluation system, respectively. Scale samples were characterized with SEM and XRD. It is found that the transfer of cations could be promoted by doping with proper rare earth elements, and the corrosion potentials descend by 25~126 mV. The results indicated that the copper-zinc alloy doped with rare earth elements has higher scale inhibiting ability of CaCO3. The growth of calcite was affected by zinc ions dissolved because of primary battery reaction, and the transition of calcium carbonate from aragonite to calcite was hampered resulting in the proportion of aragonite to calcite is changed from 1.7∶1 to 2.7∶1.展开更多
The corrosion behavior of coatings of pure zinc and Zn-Al,Zn-Al-RE alloys in NaCl solu- tions was studied by salt-spray experiments,even corrosion experiments and electrochemical measurements of bi-directional polariz...The corrosion behavior of coatings of pure zinc and Zn-Al,Zn-Al-RE alloys in NaCl solu- tions was studied by salt-spray experiments,even corrosion experiments and electrochemical measurements of bi-directional polarization curves and a.c.impedance in weak polarization region consistent regularities were obtained by these different methods,viz.,the corrosion resistance of Zn could be enhanced by alloying it with Al,and particularly with Al-RE.The causes of enhancement of corrosion resistance by RE were also discussed.展开更多
The effect of rareearth reducing agent on the thickness of layer and properties of bathduring the forming process of liquidzinc corrosion resistant chromiumcarbide layer through the thermalreaction deposition and diff...The effect of rareearth reducing agent on the thickness of layer and properties of bathduring the forming process of liquidzinc corrosion resistant chromiumcarbide layer through the thermalreaction deposition and diffusionmethod was studied. The resultsshow that the addition of 8%RE-SiFe-Mg can make the borax systemwith 15% Cr2O3 have better chromium-carbide layer-formation abilityand excellent technical propertiesthan those of Al or Si at 950 ℃.展开更多
The thickness, brittleness, boron content and morphology of RE boronized layer were investigated. The results show that the service life of the boronized layer in molten zinc can be increased by adding RE element. Th...The thickness, brittleness, boron content and morphology of RE boronized layer were investigated. The results show that the service life of the boronized layer in molten zinc can be increased by adding RE element. The thermocouple and sink roll sleeve made of this material can be used for more than half a year.展开更多
The toxic effects of rare earth elements such as lanthanum, cerium and heavy metal elements such as chromium, zinc on Potamogeton malaianus Miq. were studied. The results show that the contents of chlorophyll and solu...The toxic effects of rare earth elements such as lanthanum, cerium and heavy metal elements such as chromium, zinc on Potamogeton malaianus Miq. were studied. The results show that the contents of chlorophyll and soluble protein increase to a certain degree and then decrease under La3+ Ce3+ Zn2+ stress, while there is a constantly dropping tendency under Cr6+ stress. The four ions have different effects on protective enzyme systems of Potamogeton malaianus. They can induce rises of the activities of catalase (CAT) and peroxides (POD) at lower concentration, however, with the increase of ions concentration, the activities decline. The change of SOD activity is exactly opposite to that of CAT and POD activity. It falls at first and rises later. An increasing tendency of MDA content appears with the increasing concentration. The toxicities of La3+, Zn2+, Ce3+ and Cr6+ become more serious in the order. The lethal concentration of Cr6+ to Potamogeton malaianus ranges from 0.5 to I mg(-1) that of Ce3+ and Zn2+ ranges from 3 to 5 mg(-1) and that of La3+ ranges from 7 to 10 mg(.)L(-1). The toxic mechanism of La3 + and Ce3+ is similar to that of Cr6+ and Zn2+.展开更多
Ce3+,Eu3+ and Tb3+ singly doped and Ce3+/Eu3+ and Ce3+/Tb3+ co-doped zinc phosphate glasses were prepared by sintering P2O5,ZnO,Ce2(C2O4)3·10H2O and Eu2O3/Tb4O7 mixtures at 1200 °C in the air for 2 h and the...Ce3+,Eu3+ and Tb3+ singly doped and Ce3+/Eu3+ and Ce3+/Tb3+ co-doped zinc phosphate glasses were prepared by sintering P2O5,ZnO,Ce2(C2O4)3·10H2O and Eu2O3/Tb4O7 mixtures at 1200 °C in the air for 2 h and then annealing at 450 °C for 10 h.The obtained glasses were homogeneous and transparent.The glasses without Ce3+ were colorless and those with Ce3+ showed slightly yellow.The singly doped glasses showed strong emissions and excitations from doped trivalent rare earth ions.Strong energy transfer from Ce3+ to...展开更多
The effects of La 3+ ion and chelate reagent 8 hydroxyquinoline on the corrosion rate of zinc in hydrochloric acid were investigated by using weight loss method and electrochemical method. It is found that in a ...The effects of La 3+ ion and chelate reagent 8 hydroxyquinoline on the corrosion rate of zinc in hydrochloric acid were investigated by using weight loss method and electrochemical method. It is found that in a specific concentration range of La 3+ ion and 8 hydroxyquinoline, the obvious corrosion inhibition synergism is obtained. The mechanism of corrosion inhibition synergism was discussed on basis of adsorption theory.展开更多
Polycrystalline powder samples of dysprosium doped Zn(BO2)2 phosphors were prepared by solid state reaction in air at high temperature and characterized by X-ray powder diffraction. The IR, Photoluminescence (PL),...Polycrystalline powder samples of dysprosium doped Zn(BO2)2 phosphors were prepared by solid state reaction in air at high temperature and characterized by X-ray powder diffraction. The IR, Photoluminescence (PL), diffuse reflectance and three-dimensional (3D) thermoluminescence (TL) emission spectrum after 60^Co gamma ray irradiation were investigated. The characteristic 3D TL emission bands at about 425, 481 and 573 um with a main emission band of around 573 um were attributed to the host emission, 4^F9/2→6H15/2 and F9/2→6^H13/2 f-f transitions of Dy^3+ ions. No emission from Dy^2+ ions was observed in the measurement wavelength range. The TL-dose response of the Zn(BO2)2:Dy polycrystalline powder sample to gamma ray radiation in the range from 1 to 100 Gy at clinical dose levels was almost linear. The experimental results showed that Zn(BO2)2:Dy had potential use as the materials of gamma-ray thermoluminescence dosimeter (TLD) for clinical dosimetry.展开更多
This work focused on the zinc powder coated with Y(OH)3 microparticles by means of ultrasonic immersion for performance improvement of zinc electrodes in alkaline battery systems.Scanning electron microscopy and other...This work focused on the zinc powder coated with Y(OH)3 microparticles by means of ultrasonic immersion for performance improvement of zinc electrodes in alkaline battery systems.Scanning electron microscopy and other characterization techniques were applied to examine the influence of the ultrasonic power on the sonochemical growth of Y(OH)3 microparticles in direct contact with zinc powder.Electrochemical properties of zinc electrodes containing Y(OH)3 microparticles were discussed through the measurement...展开更多
A conversion film was obtained on zinc deposit by immersing zinc coated specimens in a mischmetal salt solution. Several factors affecting the anticorrosive efficiency of the conversion film were studied. The suitabl...A conversion film was obtained on zinc deposit by immersing zinc coated specimens in a mischmetal salt solution. Several factors affecting the anticorrosive efficiency of the conversion film were studied. The suitable technological conditions were established. The composition and the thickness of the conversion film were determined by Auger electron spectroscopy(AES).展开更多
By metalloscopy,scanning electron microscope,X-ray diffraction,electron probe,salt water erosion and hot steam erosion,the microstructures and the aging resistance of zinc alloy ZA-27 with different contents of yttriu...By metalloscopy,scanning electron microscope,X-ray diffraction,electron probe,salt water erosion and hot steam erosion,the microstructures and the aging resistance of zinc alloy ZA-27 with different contents of yttrium were studied. The results show that with optimum addition of yttrium in the alloy ZA-27 the fine YAl_3 phase forms. The fine YAl_3 granules can act as the condensation nuclei of α phase and the number of the α phase′s nuclei increases greatly and the growth of the nuclei comes in for restrict during the crystallization and the alloy′s grains become fine and the segregation reduces. In addition,yttrium also combines with zinc and the fine dispersion Y-Zn phase forms which improves grain boundary conditions and the alloy′s aging resistance. But when the content of yttrium is overmuch some YAl_3 granules grow to be lumpy,so the fine and close texture of the alloy′s boundaries is damaged and the proportion of the interface among the phases increase which brings a decline in the alloy′s resistance to corrosion.展开更多
The Ce^3+ and Eu^2+ ions codoped calcium zinc chlorosilicate Ca_8Zn(SiO_4)_4Cl_2 phosphors have been synthesized for the first time. The diffuse reflection, excitation and emission spectra of Ca_8Zn(SiO_4)_4Cl_2∶Ce^3...The Ce^3+ and Eu^2+ ions codoped calcium zinc chlorosilicate Ca_8Zn(SiO_4)_4Cl_2 phosphors have been synthesized for the first time. The diffuse reflection, excitation and emission spectra of Ca_8Zn(SiO_4)_4Cl_2∶Ce^3+, Eu^2+ have been measured at room temperature. The luminescence sensitizaiton of Eu^2+ by Ce^3+ inCa_8Zn(SiO_4)_4Cl_2∶Ce^3+, Eu^2+ has been expounded under the excitation of ultraviolet light and the efficient nonradiative energy transfer from Ce^3+ to Eu^2+ in this system is confirmed.展开更多
文摘The coating microstructure of hot-dip aluminum (HDA) of deformed low-carbon steel containing RE was analyzed by metallography microscopy, TEM and XRD, and the forming mechanism was also discussed. The results show that, the Fe_2Al_5 phase, on whose subcrystal boundaries, Al particles with the size of 7~30 μm existing on parallel linear are, grows a strong orientation. And the spread activation energy of Al is 155.22 kJ·mol -1. In addition, the effects of deformation on coating microstructure of hot-dip aluminum and the function of RE were preliminarily analyzed.
基金Key Technologies R&D Program of Tianjin (06YFGZGX02400)
文摘A copper-zinc alloy doped with rare earth elements was prepared and the mechanism was demonstrated in a simulating boiler and circulating cooling water with rigidity 1 mmol·L-1. The polar curve and scale inhibiting ability of the alloy was tested by a corrosion measurement system and a scale inhibition evaluation system, respectively. Scale samples were characterized with SEM and XRD. It is found that the transfer of cations could be promoted by doping with proper rare earth elements, and the corrosion potentials descend by 25~126 mV. The results indicated that the copper-zinc alloy doped with rare earth elements has higher scale inhibiting ability of CaCO3. The growth of calcite was affected by zinc ions dissolved because of primary battery reaction, and the transition of calcium carbonate from aragonite to calcite was hampered resulting in the proportion of aragonite to calcite is changed from 1.7∶1 to 2.7∶1.
文摘The corrosion behavior of coatings of pure zinc and Zn-Al,Zn-Al-RE alloys in NaCl solu- tions was studied by salt-spray experiments,even corrosion experiments and electrochemical measurements of bi-directional polarization curves and a.c.impedance in weak polarization region consistent regularities were obtained by these different methods,viz.,the corrosion resistance of Zn could be enhanced by alloying it with Al,and particularly with Al-RE.The causes of enhancement of corrosion resistance by RE were also discussed.
文摘The effect of rareearth reducing agent on the thickness of layer and properties of bathduring the forming process of liquidzinc corrosion resistant chromiumcarbide layer through the thermalreaction deposition and diffusionmethod was studied. The resultsshow that the addition of 8%RE-SiFe-Mg can make the borax systemwith 15% Cr2O3 have better chromium-carbide layer-formation abilityand excellent technical propertiesthan those of Al or Si at 950 ℃.
文摘The thickness, brittleness, boron content and morphology of RE boronized layer were investigated. The results show that the service life of the boronized layer in molten zinc can be increased by adding RE element. The thermocouple and sink roll sleeve made of this material can be used for more than half a year.
文摘The toxic effects of rare earth elements such as lanthanum, cerium and heavy metal elements such as chromium, zinc on Potamogeton malaianus Miq. were studied. The results show that the contents of chlorophyll and soluble protein increase to a certain degree and then decrease under La3+ Ce3+ Zn2+ stress, while there is a constantly dropping tendency under Cr6+ stress. The four ions have different effects on protective enzyme systems of Potamogeton malaianus. They can induce rises of the activities of catalase (CAT) and peroxides (POD) at lower concentration, however, with the increase of ions concentration, the activities decline. The change of SOD activity is exactly opposite to that of CAT and POD activity. It falls at first and rises later. An increasing tendency of MDA content appears with the increasing concentration. The toxicities of La3+, Zn2+, Ce3+ and Cr6+ become more serious in the order. The lethal concentration of Cr6+ to Potamogeton malaianus ranges from 0.5 to I mg(-1) that of Ce3+ and Zn2+ ranges from 3 to 5 mg(-1) and that of La3+ ranges from 7 to 10 mg(.)L(-1). The toxic mechanism of La3 + and Ce3+ is similar to that of Cr6+ and Zn2+.
基金supported by the National Natural Science Foundation of China (10704090, 10874253)Foundation of the Education Committee of Chongqing (10874173)
文摘Ce3+,Eu3+ and Tb3+ singly doped and Ce3+/Eu3+ and Ce3+/Tb3+ co-doped zinc phosphate glasses were prepared by sintering P2O5,ZnO,Ce2(C2O4)3·10H2O and Eu2O3/Tb4O7 mixtures at 1200 °C in the air for 2 h and then annealing at 450 °C for 10 h.The obtained glasses were homogeneous and transparent.The glasses without Ce3+ were colorless and those with Ce3+ showed slightly yellow.The singly doped glasses showed strong emissions and excitations from doped trivalent rare earth ions.Strong energy transfer from Ce3+ to...
文摘The effects of La 3+ ion and chelate reagent 8 hydroxyquinoline on the corrosion rate of zinc in hydrochloric acid were investigated by using weight loss method and electrochemical method. It is found that in a specific concentration range of La 3+ ion and 8 hydroxyquinoline, the obvious corrosion inhibition synergism is obtained. The mechanism of corrosion inhibition synergism was discussed on basis of adsorption theory.
基金the National Key Project of Basic Research of China (G1998061312)Science and Technology Project of Jilin Province (200505264)the Foundation of Doctoral Subject of Beihua University
文摘Polycrystalline powder samples of dysprosium doped Zn(BO2)2 phosphors were prepared by solid state reaction in air at high temperature and characterized by X-ray powder diffraction. The IR, Photoluminescence (PL), diffuse reflectance and three-dimensional (3D) thermoluminescence (TL) emission spectrum after 60^Co gamma ray irradiation were investigated. The characteristic 3D TL emission bands at about 425, 481 and 573 um with a main emission band of around 573 um were attributed to the host emission, 4^F9/2→6H15/2 and F9/2→6^H13/2 f-f transitions of Dy^3+ ions. No emission from Dy^2+ ions was observed in the measurement wavelength range. The TL-dose response of the Zn(BO2)2:Dy polycrystalline powder sample to gamma ray radiation in the range from 1 to 100 Gy at clinical dose levels was almost linear. The experimental results showed that Zn(BO2)2:Dy had potential use as the materials of gamma-ray thermoluminescence dosimeter (TLD) for clinical dosimetry.
基金supported by the Innovation Foundation of BUAA for Ph. D Graduates Provided by Beihang University in China
文摘This work focused on the zinc powder coated with Y(OH)3 microparticles by means of ultrasonic immersion for performance improvement of zinc electrodes in alkaline battery systems.Scanning electron microscopy and other characterization techniques were applied to examine the influence of the ultrasonic power on the sonochemical growth of Y(OH)3 microparticles in direct contact with zinc powder.Electrochemical properties of zinc electrodes containing Y(OH)3 microparticles were discussed through the measurement...
文摘A conversion film was obtained on zinc deposit by immersing zinc coated specimens in a mischmetal salt solution. Several factors affecting the anticorrosive efficiency of the conversion film were studied. The suitable technological conditions were established. The composition and the thickness of the conversion film were determined by Auger electron spectroscopy(AES).
文摘By metalloscopy,scanning electron microscope,X-ray diffraction,electron probe,salt water erosion and hot steam erosion,the microstructures and the aging resistance of zinc alloy ZA-27 with different contents of yttrium were studied. The results show that with optimum addition of yttrium in the alloy ZA-27 the fine YAl_3 phase forms. The fine YAl_3 granules can act as the condensation nuclei of α phase and the number of the α phase′s nuclei increases greatly and the growth of the nuclei comes in for restrict during the crystallization and the alloy′s grains become fine and the segregation reduces. In addition,yttrium also combines with zinc and the fine dispersion Y-Zn phase forms which improves grain boundary conditions and the alloy′s aging resistance. But when the content of yttrium is overmuch some YAl_3 granules grow to be lumpy,so the fine and close texture of the alloy′s boundaries is damaged and the proportion of the interface among the phases increase which brings a decline in the alloy′s resistance to corrosion.
文摘The Ce^3+ and Eu^2+ ions codoped calcium zinc chlorosilicate Ca_8Zn(SiO_4)_4Cl_2 phosphors have been synthesized for the first time. The diffuse reflection, excitation and emission spectra of Ca_8Zn(SiO_4)_4Cl_2∶Ce^3+, Eu^2+ have been measured at room temperature. The luminescence sensitizaiton of Eu^2+ by Ce^3+ inCa_8Zn(SiO_4)_4Cl_2∶Ce^3+, Eu^2+ has been expounded under the excitation of ultraviolet light and the efficient nonradiative energy transfer from Ce^3+ to Eu^2+ in this system is confirmed.