The effect of thermomechanical treatments on the microstructures and properties of Cu-2.1Ni-0.5Si- 0.2Zr alloy was investigated. The hot-rolled plates were solution treated at 920 ℃ for 1.5 h, quenched into water, co...The effect of thermomechanical treatments on the microstructures and properties of Cu-2.1Ni-0.5Si- 0.2Zr alloy was investigated. The hot-rolled plates were solution treated at 920 ℃ for 1.5 h, quenched into water, cold rolled by 70 % reduction in thickness, and then aged at 400, 450 and 500 ℃for various times. The variation in tensile strength and electrical conductivity of the alloy was measured as a function of the aging time. The results show the peak strength value of 665 MPa for the alloy aged at 450 ℃ for 2 h. However, the electrical conductivity is observed to reach a maximum of 47 % IACS aged at 450℃for 8 h. OM, SEM, and TEM were used for microstructural inspection of the alloy. Precipitation occurs preferentially at deformation bands in the cold-rolled alloy. Properties behavior is discussed in the light of microstructural features.展开更多
The phase transformation behavior and heat treatment response of Cu-2.8Ni-0.6Si (wt%) alloy sub- jected to different heat treatments were studied by X-ray diffraction, transmission electron microscopy observation, a...The phase transformation behavior and heat treatment response of Cu-2.8Ni-0.6Si (wt%) alloy sub- jected to different heat treatments were studied by X-ray diffraction, transmission electron microscopy observation, and measurement of hardness and electrical conductivity. The variation of hardness and electrical conductivity of the alloy was measured as a function of aging time. On aging at the temperature below TR (500-550 ℃) in Cu-2.8Ni-0.6Si alloy, the transformation undergoes spinodal decomposi- tion, DO22 ordering, and δ-NiaSi phase. On aging at the temperature above TR (500-550 ℃), the transformation products were precipitations of 8-Ni2Si. The free energy versus composition curves were employed to explain the microstructure observations.展开更多
Soil moisture and salinity are two crucial coastal saline soil variables, which influence the soil quality and agricultural productivity in the reclaimed coastal region. Accurately characterizing the spatial variabili...Soil moisture and salinity are two crucial coastal saline soil variables, which influence the soil quality and agricultural productivity in the reclaimed coastal region. Accurately characterizing the spatial variability of these soil parameters is critical for the rational development and utilization of tideland resources. In the present study, the spatial variability of soil moisture and salinity in the reclaimed area of Hangzhou gulf, Shangyu City, Zhejiang Province, China, was detected using the data acquired from radar image and the proximal sensor EM38. Soil moisture closely correlates radar scattering coefficient, and a simplified inversion model was built based on a backscattering coefficient extracted from multi-polarization data of ALOS/PALSAR and in situ soil moisture measured by a time domain reflectometer to detect soil moisture variations. The result indicated a higher accuracy of soil moisture inversion by the HH polarization mode than those by the HV mode. Soil salinity is reflected by soil apparent electrical conductivity (ECa). Further, ECa can be rapidly detected by EM38 equipment in situ linked with GPS for characterizing the spatial variability of soil salinity. Based on the strong spatial variability and interactions of soil moisture and salinity, a cokriging interpolation method with auxiliary variable of backscattering coefficient was adopted to map the spatial variability of ECa. When compared with a map of ECa interpolated by the ordinary kriging method, detail was revealed and the accuracy was increased by 15.3%. The results conclude that the integrating active remote sensing and proximal sensors EM38 are effective and acceptable approaches for rapidly and accurately detecting soil moisture and salinity variability in coastal areas, especially in the subtropical coastal zones of China with frequent heavy cloud cover.展开更多
Plasma like concept of ions in electrolyte solutions is accepted as a basis for development of equation mobility for transfer processes (viscosity, diffusion, thermal conductivity and electrical conductivity). The e...Plasma like concept of ions in electrolyte solutions is accepted as a basis for development of equation mobility for transfer processes (viscosity, diffusion, thermal conductivity and electrical conductivity). The examples of isomorphism of dissipative processes are given in the article. The integrated assessment equation of transfer properties is developed based on the ion-dipole, dipole-dipole and ion-ion interactions and the force of liquid dielectric resistance to oscillating solvated particles. It is shown that the estimated magnitude of viscosity, diffusion, electrical conductivity and thermal conductivity are comparable with the current knowledge and experimental values in a wide range of electrolyte concentrations.展开更多
IV-VI compounds are considered as promising thermoelectric materials, and high thermoelectric performance was achieved in IV-VI solid solutions. In this work, the thermoelectric properties of Pb-Sn-Te-Se-based solid s...IV-VI compounds are considered as promising thermoelectric materials, and high thermoelectric performance was achieved in IV-VI solid solutions. In this work, the thermoelectric properties of Pb-Sn-Te-Se-based solid solutions were systematically investigated. Among these solid solutions, it is found that a figure of merit (ZT) peak value of 1.0 at 873 K can be obtained in (PbTe)0.5(SnTe)o.5, on account of the combination of superior electrical properties in SnTe and low thermal conductivity in PbTe. Furthermore, we investigated and summarized the thermoelectric transport properties and proposed the thermoelectric performance maps for the IV- VI solid solutions in Pb-Sn-Te-Se system. This comprehensive investigation on Pb-Sn-Te-Se-based solid solutions can effectively guide and scan thermoelectric performance for a given unknown composition and enhance the thermoelectric properties in IV-VI compounds.展开更多
基金supported by the Project of National "863"Foundation of China(No.2006AA03Z522)Science and Technology of Beijing(No.10231103)
文摘The effect of thermomechanical treatments on the microstructures and properties of Cu-2.1Ni-0.5Si- 0.2Zr alloy was investigated. The hot-rolled plates were solution treated at 920 ℃ for 1.5 h, quenched into water, cold rolled by 70 % reduction in thickness, and then aged at 400, 450 and 500 ℃for various times. The variation in tensile strength and electrical conductivity of the alloy was measured as a function of the aging time. The results show the peak strength value of 665 MPa for the alloy aged at 450 ℃ for 2 h. However, the electrical conductivity is observed to reach a maximum of 47 % IACS aged at 450℃for 8 h. OM, SEM, and TEM were used for microstructural inspection of the alloy. Precipitation occurs preferentially at deformation bands in the cold-rolled alloy. Properties behavior is discussed in the light of microstructural features.
基金financially supported by National"863"Foundation of China (No. 2006AA03Z522)Science and Technology of Beijing (No. 10231103)
文摘The phase transformation behavior and heat treatment response of Cu-2.8Ni-0.6Si (wt%) alloy sub- jected to different heat treatments were studied by X-ray diffraction, transmission electron microscopy observation, and measurement of hardness and electrical conductivity. The variation of hardness and electrical conductivity of the alloy was measured as a function of aging time. On aging at the temperature below TR (500-550 ℃) in Cu-2.8Ni-0.6Si alloy, the transformation undergoes spinodal decomposi- tion, DO22 ordering, and δ-NiaSi phase. On aging at the temperature above TR (500-550 ℃), the transformation products were precipitations of 8-Ni2Si. The free energy versus composition curves were employed to explain the microstructure observations.
基金funded by the Zhejiang Provincial Natural Science Foundation of China (R5100140)the National Natural Science Foundation of China (40871100)the Science and Technology Project of Zhejiang Province, China(2011C13010)
文摘Soil moisture and salinity are two crucial coastal saline soil variables, which influence the soil quality and agricultural productivity in the reclaimed coastal region. Accurately characterizing the spatial variability of these soil parameters is critical for the rational development and utilization of tideland resources. In the present study, the spatial variability of soil moisture and salinity in the reclaimed area of Hangzhou gulf, Shangyu City, Zhejiang Province, China, was detected using the data acquired from radar image and the proximal sensor EM38. Soil moisture closely correlates radar scattering coefficient, and a simplified inversion model was built based on a backscattering coefficient extracted from multi-polarization data of ALOS/PALSAR and in situ soil moisture measured by a time domain reflectometer to detect soil moisture variations. The result indicated a higher accuracy of soil moisture inversion by the HH polarization mode than those by the HV mode. Soil salinity is reflected by soil apparent electrical conductivity (ECa). Further, ECa can be rapidly detected by EM38 equipment in situ linked with GPS for characterizing the spatial variability of soil salinity. Based on the strong spatial variability and interactions of soil moisture and salinity, a cokriging interpolation method with auxiliary variable of backscattering coefficient was adopted to map the spatial variability of ECa. When compared with a map of ECa interpolated by the ordinary kriging method, detail was revealed and the accuracy was increased by 15.3%. The results conclude that the integrating active remote sensing and proximal sensors EM38 are effective and acceptable approaches for rapidly and accurately detecting soil moisture and salinity variability in coastal areas, especially in the subtropical coastal zones of China with frequent heavy cloud cover.
文摘Plasma like concept of ions in electrolyte solutions is accepted as a basis for development of equation mobility for transfer processes (viscosity, diffusion, thermal conductivity and electrical conductivity). The examples of isomorphism of dissipative processes are given in the article. The integrated assessment equation of transfer properties is developed based on the ion-dipole, dipole-dipole and ion-ion interactions and the force of liquid dielectric resistance to oscillating solvated particles. It is shown that the estimated magnitude of viscosity, diffusion, electrical conductivity and thermal conductivity are comparable with the current knowledge and experimental values in a wide range of electrolyte concentrations.
基金financially supported by the National Natural Science Foundation of China(Nos. 51671015. 51571007 and 51772012)the 111 project (No. B17002)+1 种基金the Beijing Municipal Science and Technology Commission (No. 2171100002017002)the Shenzhen Peacock Plan Team (No. KQTD2016022619565991)
文摘IV-VI compounds are considered as promising thermoelectric materials, and high thermoelectric performance was achieved in IV-VI solid solutions. In this work, the thermoelectric properties of Pb-Sn-Te-Se-based solid solutions were systematically investigated. Among these solid solutions, it is found that a figure of merit (ZT) peak value of 1.0 at 873 K can be obtained in (PbTe)0.5(SnTe)o.5, on account of the combination of superior electrical properties in SnTe and low thermal conductivity in PbTe. Furthermore, we investigated and summarized the thermoelectric transport properties and proposed the thermoelectric performance maps for the IV- VI solid solutions in Pb-Sn-Te-Se system. This comprehensive investigation on Pb-Sn-Te-Se-based solid solutions can effectively guide and scan thermoelectric performance for a given unknown composition and enhance the thermoelectric properties in IV-VI compounds.