The basic characteristics of Australian iron ore concentrate (Ore-A) and its effects on sinter properties during a high-limonite sintering process were studied using micro-sinter and sinter pot methods. The results sh...The basic characteristics of Australian iron ore concentrate (Ore-A) and its effects on sinter properties during a high-limonite sintering process were studied using micro-sinter and sinter pot methods. The results show that the Ore-A exhibits good granulation properties, strong liquid flow capability, high bonding phase strength and crystal strength, but poor assimilability. With increasing Ore-A ratio, the tumbler index and the reduction index (RI) of the sinter first increase and then decrease, whereas the softening interval (Delta T) and the softening start temperature (T (10%)) of the sinter exhibit the opposite behavior; the reduction degradation index (RDI+3.15) of the sinter increases linearly, but the sinter yield exhibits no obvious effects. With increasing Ore-A ratio, the distribution and crystallization of the minerals are improved, the main bonding phase first changes from silico-ferrite of calcium and aluminum (SFCA) to kirschsteinite, silicate, and SFCA and then transforms to 2CaO center dot SiO2 and SFCA. Given the utilization of Ore-A and the improvement of the sinter properties, the Ore-A ratio in the high-limonite sintering process is suggested to be controlled at approximately 6wt%.展开更多
In this paper a method is developed to model the design process gene based on the extensible basic-element with the purpose of design process optimization and reuse. First, the principle of genetic engineering based d...In this paper a method is developed to model the design process gene based on the extensible basic-element with the purpose of design process optimization and reuse. First, the principle of genetic engineering based design process optimization and reuse is put forward and analyzed. Second, the extensible basic-element model of the design process gene is established based on the models of the design process base and the base pair through analyzing the concept and structure of the design process gene and the extensible basic-element as well as its extensibility. Third, the features of divergence and scalability of the extensible basic-element model of the design process gene are discussed for carrying out the extension translation to the design process gene by way of inserting, deleting and updating design process bases. Finally, an example of building extensible basic-element models for the design process base, base pair and design process gene in mechanical product design and the mutation process of the design process gene in airplane design is presented which demonstrates the application of the method proposed in this paper.展开更多
Under a very general condition （TNC condition） we show that the spectral radius of the kernel of a general branching process is a threshold parameter and hence plays a role as the basic reproduction number in usual ...Under a very general condition （TNC condition） we show that the spectral radius of the kernel of a general branching process is a threshold parameter and hence plays a role as the basic reproduction number in usual CMJ processes. We discuss also some properties of the extinction probability and the generating operator of general branching processes. As an application in epidemics, in the final section we suggest a generalization of SIR model which can describe infectious diseases transmission in an inhomogeneous population.展开更多
Basic oxygen furnace slag（BOFS） has the potential to remove hexavalent chromium（Cr（VI））from wastewater by a redox process due to the presence of minerals containing Fe2＋. The effects of the solution p H, initia...Basic oxygen furnace slag（BOFS） has the potential to remove hexavalent chromium（Cr（VI））from wastewater by a redox process due to the presence of minerals containing Fe2＋. The effects of the solution p H, initial Cr（VI） concentration, BOFS dosage, BOFS particle size, and temperature on the removal of Cr（VI） was investigated in detail through batch tests. The chemical and mineral compositions of fresh and reacted BOFS were characterized using scanning electron microscope（SEM） equipped with an energy dispersive spectrometer（EDS）system and X-ray diffractometer（XRD）. The results show that Cr（VI） in wastewater can be efficiently removed by Fe2＋released from BOFS under appropriate acidic conditions. The removal of Cr（VI） by BOFS significantly depended on the parameters mentioned above. The reaction of Cr（VI） with BOFS followed the pseudo-second-order kinetic model. Fe2＋responsible for Cr（VI） removal was primarily derived from the dissolution of Fe O and Fe3O4 in BOFS. When H2SO4 was used to adjust the solution acidity, gypsum（Ca SO4·2H2O）could be formed and become an armoring precipitate layer on the BOFS surface, hindering the release of Fe2＋and the removal of Cr（VI）. Finally, the main mechanism of Cr（VI） removal by BOFS was described using several consecutive reaction steps.展开更多
基金financially supported by the National Basic Research Program of China (No. 2012CB720401)the National Natural Science Foundation of China (U1260202)
文摘The basic characteristics of Australian iron ore concentrate (Ore-A) and its effects on sinter properties during a high-limonite sintering process were studied using micro-sinter and sinter pot methods. The results show that the Ore-A exhibits good granulation properties, strong liquid flow capability, high bonding phase strength and crystal strength, but poor assimilability. With increasing Ore-A ratio, the tumbler index and the reduction index (RI) of the sinter first increase and then decrease, whereas the softening interval (Delta T) and the softening start temperature (T (10%)) of the sinter exhibit the opposite behavior; the reduction degradation index (RDI+3.15) of the sinter increases linearly, but the sinter yield exhibits no obvious effects. With increasing Ore-A ratio, the distribution and crystallization of the minerals are improved, the main bonding phase first changes from silico-ferrite of calcium and aluminum (SFCA) to kirschsteinite, silicate, and SFCA and then transforms to 2CaO center dot SiO2 and SFCA. Given the utilization of Ore-A and the improvement of the sinter properties, the Ore-A ratio in the high-limonite sintering process is suggested to be controlled at approximately 6wt%.
文摘In this paper a method is developed to model the design process gene based on the extensible basic-element with the purpose of design process optimization and reuse. First, the principle of genetic engineering based design process optimization and reuse is put forward and analyzed. Second, the extensible basic-element model of the design process gene is established based on the models of the design process base and the base pair through analyzing the concept and structure of the design process gene and the extensible basic-element as well as its extensibility. Third, the features of divergence and scalability of the extensible basic-element model of the design process gene are discussed for carrying out the extension translation to the design process gene by way of inserting, deleting and updating design process bases. Finally, an example of building extensible basic-element models for the design process base, base pair and design process gene in mechanical product design and the mutation process of the design process gene in airplane design is presented which demonstrates the application of the method proposed in this paper.
文摘Under a very general condition （TNC condition） we show that the spectral radius of the kernel of a general branching process is a threshold parameter and hence plays a role as the basic reproduction number in usual CMJ processes. We discuss also some properties of the extinction probability and the generating operator of general branching processes. As an application in epidemics, in the final section we suggest a generalization of SIR model which can describe infectious diseases transmission in an inhomogeneous population.
基金financially supported by the Fundamental Research Fund for the Central Universities(No.N130302004)the National Natural Science Foundation of China(No.21407020)
文摘Basic oxygen furnace slag（BOFS） has the potential to remove hexavalent chromium（Cr（VI））from wastewater by a redox process due to the presence of minerals containing Fe2＋. The effects of the solution p H, initial Cr（VI） concentration, BOFS dosage, BOFS particle size, and temperature on the removal of Cr（VI） was investigated in detail through batch tests. The chemical and mineral compositions of fresh and reacted BOFS were characterized using scanning electron microscope（SEM） equipped with an energy dispersive spectrometer（EDS）system and X-ray diffractometer（XRD）. The results show that Cr（VI） in wastewater can be efficiently removed by Fe2＋released from BOFS under appropriate acidic conditions. The removal of Cr（VI） by BOFS significantly depended on the parameters mentioned above. The reaction of Cr（VI） with BOFS followed the pseudo-second-order kinetic model. Fe2＋responsible for Cr（VI） removal was primarily derived from the dissolution of Fe O and Fe3O4 in BOFS. When H2SO4 was used to adjust the solution acidity, gypsum（Ca SO4·2H2O）could be formed and become an armoring precipitate layer on the BOFS surface, hindering the release of Fe2＋and the removal of Cr（VI）. Finally, the main mechanism of Cr（VI） removal by BOFS was described using several consecutive reaction steps.
