Chromium ore fines containing coal (COFCC) can be rapidly heated by microwave to conduct the voluminal reduction, which lays a foundation of getting sponge ferrochromium powders with a lower content of C. Under the co...Chromium ore fines containing coal (COFCC) can be rapidly heated by microwave to conduct the voluminal reduction, which lays a foundation of getting sponge ferrochromium powders with a lower content of C. Under the conditions of COFCC with n(O)-n(C) (molar ratio) as 1.00-0.84 and n(SiO2)-n(CaO) as 1.00-0.39, the samples were heated by 10 kW microwave power to reach the given temperatures and held for different times respectively. The results show that the low-C-Cr ferrochromium metal phase in the reduced materials forms before the high-C-Cr ferrochromium metal phase does. With increasing temperature the C content of ferrochromium metals is in a positive correlation with the content of Cr. The C content of ferrochromium metal in reduced materials is 0-10.07% with an average value of 4.68%. With the increase of holding time the Cr content in ferrochromium metals is in a negative correlation with the content of C, while the content of Fe changes in the contrary way. In the microwave field the kinetic conditions of carburization are closely related with the temperature of microwave heating, holding time and carbon fitting ratio.展开更多
A novel class of xanthan-maleic anhydride (Xan-MA)/poly(N-isopropylacrylamide) hybrid hydrogels was designed and synthesized by solution polymerization. The xanthan-based precursor (Xan-MA) was prepared by substitutin...A novel class of xanthan-maleic anhydride (Xan-MA)/poly(N-isopropylacrylamide) hybrid hydrogels was designed and synthesized by solution polymerization. The xanthan-based precursor (Xan-MA) was prepared by substituting the hydroxyl groups in Xan by MA. This Xan-MA precursor was then polymerized with a known temperature sensitive precursor (N-isopropylacrylamide, NIPAAm) to form hybrid hydrogels with a series range of composition ratio of Xan-MA to NIPAAm precursors. These smart hydrogels were characterized by Fourier transform infrared spectroscopy for structural determination, differential scanning calorimertry for thermal property. And maximum swelling ratio, swelling kinetics and temperature response kinetics were studied. The data obtained clearly show that these smart hydrogels are responsive to the external changes of temperature as well as pH value. The magnitudes of smart and hydrogel properties of these hybrid hydrogels depend on the feed composition ratio of the two precursors. With the increase of the content of Xan-MA the maximum swelling ratio, reswelling ratio and thermo-sensitivities increase, and the feed composition ratio of Xan-MA/NIPAAm increases the maximum swelling ratio augment from 13.88 to 23.21. From XMN0, XMN1, XMN3 to XMN5, the lower critical solution temperatures (LCSTs) are 33.02, 36.15, 40.28 and 41.92 ℃, respectively. By changing the composition ratio of these two precursors, the LCST of the hybrid hydrogels could also be adjusted to be or near the body temperature for the potential applications in bioengineering and biotechnology fields.展开更多
Purpose: Although exercise and sleep duration habits are associated with cognitive function, their beneficial effects on cognitive function remain unclear. We aimed to examine the effect of sleep duration and daily ph...Purpose: Although exercise and sleep duration habits are associated with cognitive function, their beneficial effects on cognitive function remain unclear. We aimed to examine the effect of sleep duration and daily physical activity on cognitive function, elucidating the neural mechanisms using near-infrared spectroscopy(NIRS).Methods: A total of 23 healthy young adults(age 22.0 ± 2.2 years) participated in this study. Exercise amount was assessed using a uniaxial accelerometer. We evaluated total sleep time(TST) and sleep efficiency by actigraphy. Cognitive function was tested using the N-back task, the Wisconsin Card Sorting Test(WCST), and the Continuous Performance Test—Identical Pairs(CPT-IP), and the cortical oxygenated hemoglobin levels during a word fluency task were measured with NIRS.Results: Exercise amount was significantly correlated with reaction time on 0- and 1-back tasks(r = —0.602, p = 0.002; r = —0.446, p = 0.033,respectively), whereas TST was significantly correlated with % corrects on the 2-back task(r = 0.486, p = 0.019). Multiple regression analysis,including exercise amount, TST, and sleep efficiency, revealed that exercise amount was the most significant factor for reaction time on 0- and 1-back tasks(b = —0.634, p = 0.002; b = —0.454, p = 0.031, respectively), and TST was the most significant factor for % corrects on the 2-back task(b = 0.542, p = 0.014). The parameter measured by WCST and CPT-IP was not significantly correlated with TST or exercise amount. Exercise amount, but not TST, was significantly correlated with the mean area under the NIRS curve in the prefrontal area(r = 0.492, p = 0.017).Conclusion: Exercise amount and TST had differential effects on working memory and cortical activation in the prefrontal area. Daily physical activity and appropriate sleep duration may play an important role in working memory.展开更多
The Ga-Hg binary system was thermodynamically assessed by the CALPHAD method, but only configuration contributions were considered to the entropy of the liquid. The Mg-Hg binary system has not been assessed yet. In th...The Ga-Hg binary system was thermodynamically assessed by the CALPHAD method, but only configuration contributions were considered to the entropy of the liquid. The Mg-Hg binary system has not been assessed yet. In the assessments of the Ga-Hg and Mg-Hg binary systems, solutions including liquid and hcp (Mg) were treated as substitution solutions, of which the excess Gibbs energies were formulated with the Relich-Kister polynomial. The intermetallic phases in the Mg-Hg binary system, Mg3Hg, Mg5Hg2, Mg2Hg, Mg5Hg3, MgHg, and MgHg2, were described as stoichiometric compounds. Based on the reported experimental data and thermodynamic properties of the phase diagram, sets of self-consistent parameters describing all phases in the Ga-Hg and the Mg-Hg binary systems were obtained.展开更多
Density functional theory （DFT） approach has been applied for the analysis of the bond between the [（H20）2] and the [M（gly）2] fragments in a series of trans and cis [M（gly）2[（H20）2] complexes. For comparativ...Density functional theory （DFT） approach has been applied for the analysis of the bond between the [（H20）2] and the [M（gly）2] fragments in a series of trans and cis [M（gly）2[（H20）2] complexes. For comparative purpose, both relativistic and non-relativistic calculations have been performed. The nature of the interaction between the [（H20）2] and [M（gly）2] fragments was investigated using energy decomposition analysis, Hirshfeld atomic charge variation, molecular orbital considerations and bond order decomposition analysis, respectively. Results reveal that the [（H20）：]-[M（gly）2] interaction lies from the hydrogen bridge interaction between these fragments. The strength of the bonding increases in the order Ni2＋ 〉 Pd2＋ 〉 Pt2＋ while the relativistic correction tends to strengthen the [（H2O）2---[M（gly）2] bond in the order Ni 〈 Pd 〈 Pt.展开更多
Comparative molecular field analysis and comparative molecular similarity indices analysis were employed to analyze the antiwear properties of a series of 57 esters as potential lubricant-based oils. Predictive 3D-qua...Comparative molecular field analysis and comparative molecular similarity indices analysis were employed to analyze the antiwear properties of a series of 57 esters as potential lubricant-based oils. Predictive 3D-quantitative structure tribo-ability relationship models were established using the SYBYL multifit molecular alignment rule with a training set and a test set. The optimum models were all shown to be statistically significant with cross-validated coefficients q^2 > 0.5 and conventional coefficients r^2 > 0.9, indicating that the models are sufficiently reliable for activity prediction, and may be useful in the design of novel ester-based oils.展开更多
In this paper, the properties of an oxide film formed on a pure iron surface after being polished with an H2O-based acidic slurry were investigated using an atomic force microscope （AFM）, Auger electron spectroscopy...In this paper, the properties of an oxide film formed on a pure iron surface after being polished with an H2O-based acidic slurry were investigated using an atomic force microscope （AFM）, Auger electron spectroscopy （AES）, and angle-resolved X-ray photoelectron spectroscopy （AR-XPS） to partly reveal the material removal mechanism of pure iron during chemical mechanical polishing （CMP）. The AFM results show that, when rubbed against a cone-shaped diamond tip in vacuum, the material removal depth of the polished pure iron first slowly increases to 0.45 nm with a relatively small slope of 0.11 nm/μN as the applied load increases from 0 to 4 μN, and then rapidly increases with a large slope of 1.98 nm/μN when the applied load further increases to 10 μN. In combination with the AES and AR-XPS results, a layered oxide film with approximately 2 nm thickness （roughly estimated from the sputtering rate） is formed on the pure iron surface. Moreover, the film can be simply divided into two layers, namely. an outer layer and an inner layer. The outer layer primarily consists of FeOOH （most likely α-FeOOH） and possibly Fe2O3 with a film thickness ranging from 0.36 to 0.48 nm （close to the 0.45 nm material removal depth at the 4 μN turning point）, while the inner layer primarily consists of Fe304. The mechanical strength of the outer layer is much higher than that of the inner layer. Moreover, the mechanical strength of the inner layer is quite close to that of the pure iron substrate. However, when a real CMP process is applied to pure iron, pure mechanical wear by silica particles generates almost no material removal due to the extremely high mechanical strength of the oxide film. This indicates that other mechanisms, such as in-situ chemical corrosion-enhanced mechanical wear, dominate the CMP process.展开更多
基金Project(50474083) supported by the National Natural Science Foundation of ChinaProject supported by the Baoshan Iron & Steel Co. Ltd. of China
文摘Chromium ore fines containing coal (COFCC) can be rapidly heated by microwave to conduct the voluminal reduction, which lays a foundation of getting sponge ferrochromium powders with a lower content of C. Under the conditions of COFCC with n(O)-n(C) (molar ratio) as 1.00-0.84 and n(SiO2)-n(CaO) as 1.00-0.39, the samples were heated by 10 kW microwave power to reach the given temperatures and held for different times respectively. The results show that the low-C-Cr ferrochromium metal phase in the reduced materials forms before the high-C-Cr ferrochromium metal phase does. With increasing temperature the C content of ferrochromium metals is in a positive correlation with the content of Cr. The C content of ferrochromium metal in reduced materials is 0-10.07% with an average value of 4.68%. With the increase of holding time the Cr content in ferrochromium metals is in a negative correlation with the content of C, while the content of Fe changes in the contrary way. In the microwave field the kinetic conditions of carburization are closely related with the temperature of microwave heating, holding time and carbon fitting ratio.
文摘A novel class of xanthan-maleic anhydride (Xan-MA)/poly(N-isopropylacrylamide) hybrid hydrogels was designed and synthesized by solution polymerization. The xanthan-based precursor (Xan-MA) was prepared by substituting the hydroxyl groups in Xan by MA. This Xan-MA precursor was then polymerized with a known temperature sensitive precursor (N-isopropylacrylamide, NIPAAm) to form hybrid hydrogels with a series range of composition ratio of Xan-MA to NIPAAm precursors. These smart hydrogels were characterized by Fourier transform infrared spectroscopy for structural determination, differential scanning calorimertry for thermal property. And maximum swelling ratio, swelling kinetics and temperature response kinetics were studied. The data obtained clearly show that these smart hydrogels are responsive to the external changes of temperature as well as pH value. The magnitudes of smart and hydrogel properties of these hybrid hydrogels depend on the feed composition ratio of the two precursors. With the increase of the content of Xan-MA the maximum swelling ratio, reswelling ratio and thermo-sensitivities increase, and the feed composition ratio of Xan-MA/NIPAAm increases the maximum swelling ratio augment from 13.88 to 23.21. From XMN0, XMN1, XMN3 to XMN5, the lower critical solution temperatures (LCSTs) are 33.02, 36.15, 40.28 and 41.92 ℃, respectively. By changing the composition ratio of these two precursors, the LCST of the hybrid hydrogels could also be adjusted to be or near the body temperature for the potential applications in bioengineering and biotechnology fields.
基金supported by the Japan Society for the Promotion of Science, KAKENHI (25282210,15H05935)by Grants-in-Aid from the Comprehensive Research on Disability Health and Welfare+3 种基金the Ministry of Health,Labor and Welfare of Japanthe Academic Frontier Project for Private UniversitiesComparative Cognitive Science InstitutesMeijo University
文摘Purpose: Although exercise and sleep duration habits are associated with cognitive function, their beneficial effects on cognitive function remain unclear. We aimed to examine the effect of sleep duration and daily physical activity on cognitive function, elucidating the neural mechanisms using near-infrared spectroscopy(NIRS).Methods: A total of 23 healthy young adults(age 22.0 ± 2.2 years) participated in this study. Exercise amount was assessed using a uniaxial accelerometer. We evaluated total sleep time(TST) and sleep efficiency by actigraphy. Cognitive function was tested using the N-back task, the Wisconsin Card Sorting Test(WCST), and the Continuous Performance Test—Identical Pairs(CPT-IP), and the cortical oxygenated hemoglobin levels during a word fluency task were measured with NIRS.Results: Exercise amount was significantly correlated with reaction time on 0- and 1-back tasks(r = —0.602, p = 0.002; r = —0.446, p = 0.033,respectively), whereas TST was significantly correlated with % corrects on the 2-back task(r = 0.486, p = 0.019). Multiple regression analysis,including exercise amount, TST, and sleep efficiency, revealed that exercise amount was the most significant factor for reaction time on 0- and 1-back tasks(b = —0.634, p = 0.002; b = —0.454, p = 0.031, respectively), and TST was the most significant factor for % corrects on the 2-back task(b = 0.542, p = 0.014). The parameter measured by WCST and CPT-IP was not significantly correlated with TST or exercise amount. Exercise amount, but not TST, was significantly correlated with the mean area under the NIRS curve in the prefrontal area(r = 0.492, p = 0.017).Conclusion: Exercise amount and TST had differential effects on working memory and cortical activation in the prefrontal area. Daily physical activity and appropriate sleep duration may play an important role in working memory.
文摘The Ga-Hg binary system was thermodynamically assessed by the CALPHAD method, but only configuration contributions were considered to the entropy of the liquid. The Mg-Hg binary system has not been assessed yet. In the assessments of the Ga-Hg and Mg-Hg binary systems, solutions including liquid and hcp (Mg) were treated as substitution solutions, of which the excess Gibbs energies were formulated with the Relich-Kister polynomial. The intermetallic phases in the Mg-Hg binary system, Mg3Hg, Mg5Hg2, Mg2Hg, Mg5Hg3, MgHg, and MgHg2, were described as stoichiometric compounds. Based on the reported experimental data and thermodynamic properties of the phase diagram, sets of self-consistent parameters describing all phases in the Ga-Hg and the Mg-Hg binary systems were obtained.
文摘Density functional theory （DFT） approach has been applied for the analysis of the bond between the [（H20）2] and the [M（gly）2] fragments in a series of trans and cis [M（gly）2[（H20）2] complexes. For comparative purpose, both relativistic and non-relativistic calculations have been performed. The nature of the interaction between the [（H20）2] and [M（gly）2] fragments was investigated using energy decomposition analysis, Hirshfeld atomic charge variation, molecular orbital considerations and bond order decomposition analysis, respectively. Results reveal that the [（H20）：]-[M（gly）2] interaction lies from the hydrogen bridge interaction between these fragments. The strength of the bonding increases in the order Ni2＋ 〉 Pd2＋ 〉 Pt2＋ while the relativistic correction tends to strengthen the [（H2O）2---[M（gly）2] bond in the order Ni 〈 Pd 〈 Pt.
基金supported by the National Nature Science Foundation of China (NSFC, No. 51675395)
文摘Comparative molecular field analysis and comparative molecular similarity indices analysis were employed to analyze the antiwear properties of a series of 57 esters as potential lubricant-based oils. Predictive 3D-quantitative structure tribo-ability relationship models were established using the SYBYL multifit molecular alignment rule with a training set and a test set. The optimum models were all shown to be statistically significant with cross-validated coefficients q^2 > 0.5 and conventional coefficients r^2 > 0.9, indicating that the models are sufficiently reliable for activity prediction, and may be useful in the design of novel ester-based oils.
基金financial support provided by the National Natural Science Foundation of China (No. 51605396)Young Elite Scientists Spon- sorship Program by CAST (No. YESS20160056)+1 种基金Science Challenge Project (No. TZ2018006-0101-04)Self- developed Project of State Key Laboratory of Traction Power (No. 2017TPL_Z02)
文摘In this paper, the properties of an oxide film formed on a pure iron surface after being polished with an H2O-based acidic slurry were investigated using an atomic force microscope （AFM）, Auger electron spectroscopy （AES）, and angle-resolved X-ray photoelectron spectroscopy （AR-XPS） to partly reveal the material removal mechanism of pure iron during chemical mechanical polishing （CMP）. The AFM results show that, when rubbed against a cone-shaped diamond tip in vacuum, the material removal depth of the polished pure iron first slowly increases to 0.45 nm with a relatively small slope of 0.11 nm/μN as the applied load increases from 0 to 4 μN, and then rapidly increases with a large slope of 1.98 nm/μN when the applied load further increases to 10 μN. In combination with the AES and AR-XPS results, a layered oxide film with approximately 2 nm thickness （roughly estimated from the sputtering rate） is formed on the pure iron surface. Moreover, the film can be simply divided into two layers, namely. an outer layer and an inner layer. The outer layer primarily consists of FeOOH （most likely α-FeOOH） and possibly Fe2O3 with a film thickness ranging from 0.36 to 0.48 nm （close to the 0.45 nm material removal depth at the 4 μN turning point）, while the inner layer primarily consists of Fe304. The mechanical strength of the outer layer is much higher than that of the inner layer. Moreover, the mechanical strength of the inner layer is quite close to that of the pure iron substrate. However, when a real CMP process is applied to pure iron, pure mechanical wear by silica particles generates almost no material removal due to the extremely high mechanical strength of the oxide film. This indicates that other mechanisms, such as in-situ chemical corrosion-enhanced mechanical wear, dominate the CMP process.
