Charge and discharge characteristics of Ni/MH batteries are investigated with experiments. During battery’s working, the voltage, capacity, temperature and internal resistance were recorded, corresponding curves were...Charge and discharge characteristics of Ni/MH batteries are investigated with experiments. During battery’s working, the voltage, capacity, temperature and internal resistance were recorded, corresponding curves were depicted. Variations of the aforementioned four parameters are differently obvious. Ending criteria of charge and discharge of Ni/MH batteries are discussed on the basis of the curves. Voltage, capacity and temperature of a battery can be used as ending criteria during charge. When discharge takes place, voltage, capacity and internal resistance can be chosen as ending criteria. As a whole, capacity is more suitable for being used as ending criteria of charge and discharge than the other three parameters. At last, the capacity of a battery is recommended to be ending criteria of charge and discharge. The conclusions will provide references to different capacity Ni/MH batteries for electric vehicles.展开更多
Charge characteristics and Cu2+ adsorption-desorption of soils with variable charge (latosol) and permanent charge (brown soil) and the relationship between them were studied by means of back-titration and adsorption ...Charge characteristics and Cu2+ adsorption-desorption of soils with variable charge (latosol) and permanent charge (brown soil) and the relationship between them were studied by means of back-titration and adsorption equilibrium respectively. The amount of variable negative charge was much less in variable-charge soil than in permanent-charge soil and increased with the pH in the system, but the opposite trend occurred in the points of zero charge (PZCs). The amount of Cu2+ ions sorbed by permanent-charge soil was more than that by variable-charge soil and increased with the increase of Cu2+ concentration within a certain range in the equilibrium solution. The amount of Cu2+ ions desorbed with KC1 from permanent-charge soil was more than that from variable-charge soil, but the amount of Cu2+ ions desorbed with de-ionized water from permanent-charge soil was extremely low whereas there was still a certain amount of desorption from variable-charge soil. The increase of PZC of soils with variable or permanent charge varied with the increment of Cu2+ ions added. When the same amount of Cu2+ ions was added, the increments of PZC and variable negative surface charge of permanent-charge soil were different from those of variable-charge soil.展开更多
Electron beam welding experiments of titanium alloy to stainless steel were carried out with different filler metals, such as Ni, V, and Cu. Microstructures of the joints were examined by optical microscopy, scanning ...Electron beam welding experiments of titanium alloy to stainless steel were carried out with different filler metals, such as Ni, V, and Cu. Microstructures of the joints were examined by optical microscopy, scanning electron microscopy and X-ray diffraction analysis. Mechanical properties of the joints were evaluated according to tensile strength and microhardness. As a result, influences of filler metals on microstructures and mechanical properties of electron beam welded titanium-stainless steel joints were discussed. The results showed that all the filler metals were helpful to restrain the Ti-Fe intermetallics. The welds with different filler metals were all characterized by solid solution and interfacial intermetallics. For each type of the filler metal, the type of solid solution and interfacial intermetallics depended on the metallurgical reactions between the filler metals and base metals. The interfacial intermetallics were Fe2Ti＋Ni3Ti＋NiTi2, TiFe, and Cu2Ti＋CuTi＋CuTi2 in the joints welded with Ni, V, and Cu filler metals, respectively. The tensile strengths of the joints were dependent on the hardness of the interfacial intermetallics. The joint welded with Ag filler metal had the highest tensile strength, which is about 310 MPa.展开更多
文摘Charge and discharge characteristics of Ni/MH batteries are investigated with experiments. During battery’s working, the voltage, capacity, temperature and internal resistance were recorded, corresponding curves were depicted. Variations of the aforementioned four parameters are differently obvious. Ending criteria of charge and discharge of Ni/MH batteries are discussed on the basis of the curves. Voltage, capacity and temperature of a battery can be used as ending criteria during charge. When discharge takes place, voltage, capacity and internal resistance can be chosen as ending criteria. As a whole, capacity is more suitable for being used as ending criteria of charge and discharge than the other three parameters. At last, the capacity of a battery is recommended to be ending criteria of charge and discharge. The conclusions will provide references to different capacity Ni/MH batteries for electric vehicles.
基金Project (Nos.49831005 and 49871043) supported by the National Natural Science Foundation of China.
文摘Charge characteristics and Cu2+ adsorption-desorption of soils with variable charge (latosol) and permanent charge (brown soil) and the relationship between them were studied by means of back-titration and adsorption equilibrium respectively. The amount of variable negative charge was much less in variable-charge soil than in permanent-charge soil and increased with the pH in the system, but the opposite trend occurred in the points of zero charge (PZCs). The amount of Cu2+ ions sorbed by permanent-charge soil was more than that by variable-charge soil and increased with the increase of Cu2+ concentration within a certain range in the equilibrium solution. The amount of Cu2+ ions desorbed with KC1 from permanent-charge soil was more than that from variable-charge soil, but the amount of Cu2+ ions desorbed with de-ionized water from permanent-charge soil was extremely low whereas there was still a certain amount of desorption from variable-charge soil. The increase of PZC of soils with variable or permanent charge varied with the increment of Cu2+ ions added. When the same amount of Cu2+ ions was added, the increments of PZC and variable negative surface charge of permanent-charge soil were different from those of variable-charge soil.
基金Project(2011DFR50760)supported by International Science&Technology Cooperation Program of China
文摘Electron beam welding experiments of titanium alloy to stainless steel were carried out with different filler metals, such as Ni, V, and Cu. Microstructures of the joints were examined by optical microscopy, scanning electron microscopy and X-ray diffraction analysis. Mechanical properties of the joints were evaluated according to tensile strength and microhardness. As a result, influences of filler metals on microstructures and mechanical properties of electron beam welded titanium-stainless steel joints were discussed. The results showed that all the filler metals were helpful to restrain the Ti-Fe intermetallics. The welds with different filler metals were all characterized by solid solution and interfacial intermetallics. For each type of the filler metal, the type of solid solution and interfacial intermetallics depended on the metallurgical reactions between the filler metals and base metals. The interfacial intermetallics were Fe2Ti＋Ni3Ti＋NiTi2, TiFe, and Cu2Ti＋CuTi＋CuTi2 in the joints welded with Ni, V, and Cu filler metals, respectively. The tensile strengths of the joints were dependent on the hardness of the interfacial intermetallics. The joint welded with Ag filler metal had the highest tensile strength, which is about 310 MPa.
