XPS analyses have been performed to investigate the chemical conditions of Ni and oxygen on grain surfaces in single-sintered SrTiO3 capacitor-varistor ceramic doped with Nb2O5 and NiO. It is ascertained that Ni is in...XPS analyses have been performed to investigate the chemical conditions of Ni and oxygen on grain surfaces in single-sintered SrTiO3 capacitor-varistor ceramic doped with Nb2O5 and NiO. It is ascertained that Ni is in form of Ni2+ ions, which substitute for Ti4+ ions on grain surfaces during the oxidizing annealing. Moreover, it is confirmed that three kinds of chemically adsorbed oxygen such as O2-, O- and O-2(-) are formed on grain surfaces. It is proposed that these behaviors contribute greatly to the generation of multiple types of grain boundary acceptor states in the ceramic.展开更多
In the Early Ordovician Zhaogezhuang Section of Tangshan , North China, the Yeli Formation is composed of an entire third-order sequence, with facies ranging from the inner ramp restricted platform and open marine t...In the Early Ordovician Zhaogezhuang Section of Tangshan , North China, the Yeli Formation is composed of an entire third-order sequence, with facies ranging from the inner ramp restricted platform and open marine to the middle and even outer ramps. The Liangjiashan Formation is dominated by highstand system tracts （HST） with predominantly inner ramp grain-shoal and lagoon facies. Analyzing the carbon and oxygen isotope during the whole-rock carbonate reveals the 613C values in the Yeli Formation range from -7.11%o-0.76%o （PDB）, with the mean value at -2.98%0, while the 6180 values range of-9.09%o- -4.65%o with the mean value at -6.12%o. The 613C values in the Liangjiashan Formation range of -1.15%o-0.3%o, and the mean value of -0.57%0; the 61SO values are -8.76%0- -7.48%0, and the mean value is -8.06%o. The 613C values in the Yeli Formation decrease, but at the bottom of the Liangjiashan Formation the values increase steadily. In the middle-upper formation, there is an extended fluctuation between 0- -1.00%o. The 613C trend in the studied section is similar to that of the contemporary sections, except that it has much lower 613C values and a more negative excursion. The correlation between the 613C changes and the eustatic events, as well as the sedimentary facies, indicates that in the Tangshan area, the carbon isotope evolution can be attributabled to the processes of the eutrophic sea/oligotrophic sea, the seafloor organism- mediated oxidation in shallow water and the organic reduction after maximum flooding. The changes in the carbon isotope contents were primarily affected by the regional relative sea level changes. Compared to the other coeval data, the Early Ordovician of the Tang shan area is also severely depleted in 180, with all of the 6180sample values being Delow 5%o, except for one sample with a value ot -4.02%0. Witlt the ancient sea- water having a 6180 value of-5.5%0 （SMOW）, it is reasonable to delineate a temperature of less than 37 C.展开更多
The integrated steelmaking cycle based on the blast furnace-basic oxygen furnace（BOF）route plays an important role in the production of plain and ultra-low carbon steel,especially for deep drawing operations.BOF ste...The integrated steelmaking cycle based on the blast furnace-basic oxygen furnace（BOF）route plays an important role in the production of plain and ultra-low carbon steel,especially for deep drawing operations.BOF steelmaking is based on the conversion of cast iron in steel by impinging oxygen on the metal bath at supersonic speed.In order to avoid the addition of detrimental chemical elements owing to the introduction of uncontrolled scrap and in order to decrease environmental impact caused by the intensive use of coke for the production of cast iron,HBI（hot briquetted iron）can be used as a source of metal and a fraction of cast iron.Forty industrial experimental tests were performed to evaluate the viability of the use of HBI in BOF.The experimental campaign was supported by a thermal prediction model and realized through the estimation of the oxidation enthalpy.Furthermore,the process was thermodynamically analyzed based on oxygen potentials using the off-gas composition and the bath temperature evolution during the conversion as reference data.展开更多
Nd Sr2Mn2O7＋δ compounds were synthesized by ceramic method under three different cooling conditions. The Nd Sr2Mn2O7＋δ samples were characterized by powder X-ray diffraction（XRD）. Oxygen non-stoichiometry data f...Nd Sr2Mn2O7＋δ compounds were synthesized by ceramic method under three different cooling conditions. The Nd Sr2Mn2O7＋δ samples were characterized by powder X-ray diffraction（XRD）. Oxygen non-stoichiometry data for the studied powders were determined by using gravimetric and X-ray photoelectron spectroscopy（XPS） methods. The correlation of cooling method and oxygen as non-stoichiometry was established. The electroconductivity in samples was studied by using four-point probe method, and the strong correlation with non-stoichiometry was found out. Magnetization measurements were carried out. It was found that the magnetic and transport properties of the samples were also influenced by oxygen non-stoichiometry. The evolution of the magnetic properties could be explained by the formation of magnetic clusters in the vicinity of oxygen vacancies（OV） and strong competition between the superexchange and double exchange interactions.展开更多
文摘XPS analyses have been performed to investigate the chemical conditions of Ni and oxygen on grain surfaces in single-sintered SrTiO3 capacitor-varistor ceramic doped with Nb2O5 and NiO. It is ascertained that Ni is in form of Ni2+ ions, which substitute for Ti4+ ions on grain surfaces during the oxidizing annealing. Moreover, it is confirmed that three kinds of chemically adsorbed oxygen such as O2-, O- and O-2(-) are formed on grain surfaces. It is proposed that these behaviors contribute greatly to the generation of multiple types of grain boundary acceptor states in the ceramic.
基金supported by the National Natural Science Foundation of China(No.41372039)
文摘In the Early Ordovician Zhaogezhuang Section of Tangshan , North China, the Yeli Formation is composed of an entire third-order sequence, with facies ranging from the inner ramp restricted platform and open marine to the middle and even outer ramps. The Liangjiashan Formation is dominated by highstand system tracts （HST） with predominantly inner ramp grain-shoal and lagoon facies. Analyzing the carbon and oxygen isotope during the whole-rock carbonate reveals the 613C values in the Yeli Formation range from -7.11%o-0.76%o （PDB）, with the mean value at -2.98%0, while the 6180 values range of-9.09%o- -4.65%o with the mean value at -6.12%o. The 613C values in the Liangjiashan Formation range of -1.15%o-0.3%o, and the mean value of -0.57%0; the 61SO values are -8.76%0- -7.48%0, and the mean value is -8.06%o. The 613C values in the Yeli Formation decrease, but at the bottom of the Liangjiashan Formation the values increase steadily. In the middle-upper formation, there is an extended fluctuation between 0- -1.00%o. The 613C trend in the studied section is similar to that of the contemporary sections, except that it has much lower 613C values and a more negative excursion. The correlation between the 613C changes and the eustatic events, as well as the sedimentary facies, indicates that in the Tangshan area, the carbon isotope evolution can be attributabled to the processes of the eutrophic sea/oligotrophic sea, the seafloor organism- mediated oxidation in shallow water and the organic reduction after maximum flooding. The changes in the carbon isotope contents were primarily affected by the regional relative sea level changes. Compared to the other coeval data, the Early Ordovician of the Tang shan area is also severely depleted in 180, with all of the 6180sample values being Delow 5%o, except for one sample with a value ot -4.02%0. Witlt the ancient sea- water having a 6180 value of-5.5%0 （SMOW）, it is reasonable to delineate a temperature of less than 37 C.
文摘The integrated steelmaking cycle based on the blast furnace-basic oxygen furnace（BOF）route plays an important role in the production of plain and ultra-low carbon steel,especially for deep drawing operations.BOF steelmaking is based on the conversion of cast iron in steel by impinging oxygen on the metal bath at supersonic speed.In order to avoid the addition of detrimental chemical elements owing to the introduction of uncontrolled scrap and in order to decrease environmental impact caused by the intensive use of coke for the production of cast iron,HBI（hot briquetted iron）can be used as a source of metal and a fraction of cast iron.Forty industrial experimental tests were performed to evaluate the viability of the use of HBI in BOF.The experimental campaign was supported by a thermal prediction model and realized through the estimation of the oxidation enthalpy.Furthermore,the process was thermodynamically analyzed based on oxygen potentials using the off-gas composition and the bath temperature evolution during the conversion as reference data.
基金Project supported by Russian Foundation for Basic Research(12-03-00042)
文摘Nd Sr2Mn2O7＋δ compounds were synthesized by ceramic method under three different cooling conditions. The Nd Sr2Mn2O7＋δ samples were characterized by powder X-ray diffraction（XRD）. Oxygen non-stoichiometry data for the studied powders were determined by using gravimetric and X-ray photoelectron spectroscopy（XPS） methods. The correlation of cooling method and oxygen as non-stoichiometry was established. The electroconductivity in samples was studied by using four-point probe method, and the strong correlation with non-stoichiometry was found out. Magnetization measurements were carried out. It was found that the magnetic and transport properties of the samples were also influenced by oxygen non-stoichiometry. The evolution of the magnetic properties could be explained by the formation of magnetic clusters in the vicinity of oxygen vacancies（OV） and strong competition between the superexchange and double exchange interactions.
