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杨萍 《有色金属材料与工程》2006,27(3):35-36,47
概述了近几年来国内两种主要贮氢材料:AB型贮氢合金和Mg—Ni—RE系贮氢合金的研究和进展,着重阐述了添加不同稀土和采用不同工艺条件对两种贮氢合金的贮氢量、吸放氢速度等贮氢性能的影响,总结了当前的研究现状和需要解决的主要问题,提出了今后应用研究的方向。 相似文献
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《International Journal of Hydrogen Energy》2019,44(31):16757-16764
Titanium-iron (TiFe) is known to be a low-cost alloy that can be reactivated to nearly full hydrogen storage capacity after oxidation. However, this reactivation requires multiple heat treatments at high temperatures under vacuum even upon partial substitution of Fe with a small amount of manganese to form TiFe0.85Mn0.15. This process is cumbersome in the context of practical applications, and better strategies for the facile activation of TiFe are required. Herein, we report on an improvement in the reactivation strategy of TiFe0.85Mn0.15 by using a single heat treatment process after air oxidation of the alloy. After full oxidation of the material under air for 2 h, reactivation was achieved in a single step by heating the alloy to 300 °C under hydrogen pressure. During that process, the reduction of Fe was believed to lead to new reactive paths at the surface of the alloy facilitating the permeation of hydrogen. As a result, full cycling capability of the material was quickly re-gained, and the hydrogen capacity loss was of only 0.1 mass%. 相似文献
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采用共沉淀还原扩散法制备AB3型储氢合金LaMg_2Ni_(2.7)Co_(2.1)Mn_(2.7)Cu_(1.5),水热法制备TiO_2光催化剂粉体,表面滴涂法制备Ti O2/LaMg_2Ni_(2.7)Co_(2.1)Mn_(2.7)Cu_(1.5)光催化剂复合电极,并用XRD对合金和光催化剂结构进行分析,在电池测试仪上对复合电极在有、无光照条件下的电化学性能进行测试。结果表明,在无光照条件下复合电极的活化性能和最大放电容量较原合金电极性能有所下降,合金充放电的循环稳定性能有所提高。光照条件下,表面滴涂20%TiO_2复合电极的电化学性能比无光照时大幅提高,且最大放电容量比未涂覆的原合金电极提高25 m Ah·g~(-1)。说明TiO_2光催化剂通过表面滴涂方式对储氢合金修饰效果较好。 相似文献
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AB SLC500不支持Modbus协议,所以不能直接与Modbus网络通信。为了实现两者快速准确的通信,深入研究了Modbus协议,并在AB SLC500 BASIC-T模块中开发了Modbus应用程序,实现了SIE500与Modbus网络的通信。应用SIE500编写梯形图程序来控制其他设备和网络,由于程序冗长,增加了信息传输的延迟,不利于实时传送。BASIC-T模块的应用,与过去直接应用SIE500控制其他设备和网络相比,提高了控制的效率和响应速度,即提高了控制系统整体的实时性。实验测试结果表明,此方案能保证数据传输的准确性、可靠性和高效性。 相似文献
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不同Co含量Mm(NiCoMnAl)5贮氢合金的低温放电特性 总被引:1,自引:0,他引:1
用电化学方法研究了-40℃条件下Co含量对AB5型贮氢合金的放电容量、氢化物分解的稳定性及氢在贮氢合金中的扩散系数等的影响。结果表明:随Co含量的增大,晶胞体积增大,氢化物分解的焓变增大,低温放电容量减小。氢扩散是影响贮氢合金的低温放电性能的重要因素。 相似文献
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The hydriding characteristics of Zr-based AB2 alloy produced by gas atomization have been investigated during its absorption–desorption reaction with hydrogen gas. Its gas-phase hydrogenation properties are different from those of specimens prepared by conventional methods. For the particle morphology of the as-cast and gas-atomized powders, it can be seen that the mechanically crushed powders are irregular, while the atomized powder particles are spherical. In PCT (Pressure–Composition–Temperature) measurements, for the gas-atomized particles smaller than 50 μm, the hydrogen storage capacity is dramatically decreased and the hysteresis loop becomes larger than that of the gas-atomized particles larger than 50 μm. In addition, the increase of jet pressure of gas atomization results in the decrease of hydrogen storage capacity and the slope of plateau pressure significantly increases. TEM and EDS studies showed the increase of jet pressure in the atomization process accelerated the phase separation within grain of the gas-atomized alloy, which brought about a poor hydrogenation property. In the measurements of hydrogen absorption–desorption kinetics, the improvement of desorption kinetics of gas-atomized AB2 alloys was mainly caused by the higher plateau pressure, which is attributed to the smaller grain size and higher site energy for hydrogen in the gas-atomized alloys. 相似文献
20.
The time evolution of the density operator of an AB spin system during a double-spin-echo pulse sequence is evaluated analytically by a computer-algebra system. The computer-algebra system allows one to generate the extensive formulas describing the density operator and yields an expression for the integral of the spectral signals. The simulation of spectra for arbitrary sequence timings can be easily performed by this new tool without risking errors that might occur in conventional calculations. The computer-algebra method can be extended straightforward to other pulse angles and types of sequences. The double-spin-echo pulse sequence is used in the point-resolved spectroscopy (PRESS) method which is often applied for volume selective examinationsin vivo. For verification of the results generated by the computer-algebra system,1H spectra from a half-liter spherical sample with an aqueous solution that was 0.1 M in sodium citrate and 0.1 M in sodium acetate were recorded after 90°-180°-180° double-spin-echo pulse sequences on a 1.5-T whole-body unit. The measured behavior of the citrate AB spin system corresponds very well with the theoretical predictions. Thus, the theory provides the basis for the optimization of sequence timings for double-spin-echo measurements with high signal gain from AB systems as, for example, citrate. In addition, the theoretically predicted signal modulations could be fitted to the experimental data, providing the transverse relaxation time of the AB-coupled protons. 相似文献