The electrolyte conductivity and activity of dehydrogenase of bare-root seedlings of both Chinese fir (Cunningha-mia lanceolata (Lamb.) Hook.) and Masson pine (Pinus massoniana Lamb.) under freezing and desiccation tr...The electrolyte conductivity and activity of dehydrogenase of bare-root seedlings of both Chinese fir (Cunningha-mia lanceolata (Lamb.) Hook.) and Masson pine (Pinus massoniana Lamb.) under freezing and desiccation treatments were studied. The results showed that needle electrolyte conductivity of both species increase significantly after freezing treatment and there are no significant differences in needle electrolyte conductivity between the two species. The dehydrogenase activity (ARD) of fine roots of both Chinese fir and Masson pine was negatively correlated with increasing freezing and desiccation. The results suggest that both electrolyte conductivity and dehydrogenase activity could be used as quick indicators of Chinese fir and Masson pine bare-root seedling quality.展开更多
锂离子电池以高工作电压、长循环寿命、高能量密度、低自放电率等独特的优势在二次电池的应用中占据主导地位。但在较低温度下,由于充放电循环性能不好和续航里程短等缺点,又大大制约了锂离子电池的进一步推广应用。为解决这些问题,目...锂离子电池以高工作电压、长循环寿命、高能量密度、低自放电率等独特的优势在二次电池的应用中占据主导地位。但在较低温度下,由于充放电循环性能不好和续航里程短等缺点,又大大制约了锂离子电池的进一步推广应用。为解决这些问题,目前最常用的方法之一就是对电解液优化。文章研究了在常规电解液中以摩尔比0.5%添加低温性能较好的LiBF4电解质后电池的性能,测试了对应电池在-10℃下的放电曲线、内阻和电解液电导率,测试结果显示:电池容量保持率高达85%,电池内阻较小,为1.176 mΩ,电解液电导率为4.47 m S/cm,说明经LiBF4改性的电池具有良好的低温放电循环性能。展开更多
It is well known that small amounts of surfactants, such as 1-Octanol, in the aqueous solution can increase the absorption rate significantly. In this paper, experimental data were obtained for absorption of water vap...It is well known that small amounts of surfactants, such as 1-Octanol, in the aqueous solution can increase the absorption rate significantly. In this paper, experimental data were obtained for absorption of water vapour into an aqueous LiBr solution with different concentrations of 1-Octanol. An experimental rig was specifically designed and developed in this work in order to investigate the effect of surfactant (1-Octanol) on the enhancement of the heat and mass transfer in the absorption process, in addition to, the investigation of the impact of the use of magnetic stirrer inside the absorber. The experimental rig for this study was based on the refrigeration mode of the intermittent vapour absorption system. In order to study the heat and mass transfer in water-lithium bromide vapour absorption air conditioning systems, it was necessary to monitor the concentration of the solution continuously. As a consequence, two procedures for obtaining the LiBr solution concentration were used. The first method was based on the measurement of the density and temperature of the solution, while the second was based on its electrolyte conductivity and the temperature. The experimental results showed that the surfactant concentration has a significant effect on the absorption rate;this is called the Marangoni instability. It has been concluded that, in order to clarify the absorption enhancement phenomenon, it is necessary to understand the physicochemical aspects of the absorption process and the effect of surfactants on the enhancement of such process. Additionally, it has been concluded that new approaches are needed to explain the observed behaviour.展开更多
The change of conductivity, thickness and scanning electron microscopy （SEM） appearance of the anode film of CrWMn in 10% NaNO3 at different anode potential either with or without the magnetic field applied are inve...The change of conductivity, thickness and scanning electron microscopy （SEM） appearance of the anode film of CrWMn in 10% NaNO3 at different anode potential either with or without the magnetic field applied are investigated by testing film resistance, galvanostatic transient and using SEM to design magnetic circuit in magnetic assisted electrochemical machining （MAECM）. The experiments show that the anode film has semi-conducting property. Compared with the situation without magnetic field applied, the resistance of the film formed at 1 .SV （anode potential） increased and decreased at 4.0V while B=0.4T and the magnetic north pole points toward anode. The SEM photo demonstrates that the magnetic field will densify the film in the passivation area and quicken dissolution of the anode metal in over-passivation area. Based on the influence of magnetic field on electrochemical machining（ECM） due to the changes of the anode film conductivity behavior, the magnetic north pole should be designed to point towards the workpiece surface that has been machined. Process experiments agree with the results of test analysis.展开更多
文摘The electrolyte conductivity and activity of dehydrogenase of bare-root seedlings of both Chinese fir (Cunningha-mia lanceolata (Lamb.) Hook.) and Masson pine (Pinus massoniana Lamb.) under freezing and desiccation treatments were studied. The results showed that needle electrolyte conductivity of both species increase significantly after freezing treatment and there are no significant differences in needle electrolyte conductivity between the two species. The dehydrogenase activity (ARD) of fine roots of both Chinese fir and Masson pine was negatively correlated with increasing freezing and desiccation. The results suggest that both electrolyte conductivity and dehydrogenase activity could be used as quick indicators of Chinese fir and Masson pine bare-root seedling quality.
文摘锂离子电池以高工作电压、长循环寿命、高能量密度、低自放电率等独特的优势在二次电池的应用中占据主导地位。但在较低温度下,由于充放电循环性能不好和续航里程短等缺点,又大大制约了锂离子电池的进一步推广应用。为解决这些问题,目前最常用的方法之一就是对电解液优化。文章研究了在常规电解液中以摩尔比0.5%添加低温性能较好的LiBF4电解质后电池的性能,测试了对应电池在-10℃下的放电曲线、内阻和电解液电导率,测试结果显示:电池容量保持率高达85%,电池内阻较小,为1.176 mΩ,电解液电导率为4.47 m S/cm,说明经LiBF4改性的电池具有良好的低温放电循环性能。
文摘It is well known that small amounts of surfactants, such as 1-Octanol, in the aqueous solution can increase the absorption rate significantly. In this paper, experimental data were obtained for absorption of water vapour into an aqueous LiBr solution with different concentrations of 1-Octanol. An experimental rig was specifically designed and developed in this work in order to investigate the effect of surfactant (1-Octanol) on the enhancement of the heat and mass transfer in the absorption process, in addition to, the investigation of the impact of the use of magnetic stirrer inside the absorber. The experimental rig for this study was based on the refrigeration mode of the intermittent vapour absorption system. In order to study the heat and mass transfer in water-lithium bromide vapour absorption air conditioning systems, it was necessary to monitor the concentration of the solution continuously. As a consequence, two procedures for obtaining the LiBr solution concentration were used. The first method was based on the measurement of the density and temperature of the solution, while the second was based on its electrolyte conductivity and the temperature. The experimental results showed that the surfactant concentration has a significant effect on the absorption rate;this is called the Marangoni instability. It has been concluded that, in order to clarify the absorption enhancement phenomenon, it is necessary to understand the physicochemical aspects of the absorption process and the effect of surfactants on the enhancement of such process. Additionally, it has been concluded that new approaches are needed to explain the observed behaviour.
基金National Defense Foundation of China (No.51318030401).
文摘The change of conductivity, thickness and scanning electron microscopy （SEM） appearance of the anode film of CrWMn in 10% NaNO3 at different anode potential either with or without the magnetic field applied are investigated by testing film resistance, galvanostatic transient and using SEM to design magnetic circuit in magnetic assisted electrochemical machining （MAECM）. The experiments show that the anode film has semi-conducting property. Compared with the situation without magnetic field applied, the resistance of the film formed at 1 .SV （anode potential） increased and decreased at 4.0V while B=0.4T and the magnetic north pole points toward anode. The SEM photo demonstrates that the magnetic field will densify the film in the passivation area and quicken dissolution of the anode metal in over-passivation area. Based on the influence of magnetic field on electrochemical machining（ECM） due to the changes of the anode film conductivity behavior, the magnetic north pole should be designed to point towards the workpiece surface that has been machined. Process experiments agree with the results of test analysis.
