Si元素的添加对La-Mg-Ni系合金贮氢性能的影响

为了提高La-Mg-Ni系A2B7型贮氢合金的电化学循环稳定性,添加少量Si,用铸造工艺制备了La0.75Mg0.25Ni3.3Co0 2Six(x=0,0.05,0.1,0.15,0.2)贮氢合金,分析并测试了其微观结构、电化学性能以及氢扩散系数.结果表明,合金具有多相结构,主相由CaCu5型相和Ce2Ni7型相组成...     

纳米Ce1-x(Nd0.5Fe0.5)xO2-δ固溶体的合成及结构表征

采用水热方法合成出Ce1-x(Nd0.5 Fe0.5)x O2-δ固溶体,通过XRD测试对固溶体晶体结构进行了表征分析及晶胞参数拟合,结果表明,当x≤0.2时,Ce1-x(Nd0.5 Fe0.5)x O2-δ固溶体保持CeO2立方萤石结构;样品粒度分布在11 nm～15 nm间,且随着掺杂量的增大,粒度逐渐减小.在CeO2中掺人小半径的Fe3+离子及大半径的Nd3+离子,半径不同的双离子掺杂引起了较为复杂的晶胞参数变化.TEM及能谱结果证明样品为结晶良好的纳米晶,固溶体中的掺杂离子含量与理论含量基本一致.紫外光谱分析表明离子的掺杂导致带隙吸收边发生变化,能隙先增大后减小.     

黄河干流骨干水库综合利用调度模型的应用

采用黄河干流骨干水库综合利用调度模拟模型,以2020年为设计水平年,模拟分析了龙羊峡、刘家峡水库(简称"龙刘水库")现状运用方式和汛期分别增加下泄10亿、15亿、20亿、25亿、30亿、35亿m3和40亿m3(基本不蓄水)等8个方案(调度运行方式)对全河水资源利用与泥沙冲淤的影响。结果表明:调整龙刘水库的运行方式对协调河道内外供水有一定的作用,随着龙刘水库汛期下泄水量的增加,河道减淤量增加、经济损失率逐渐加大。推荐将龙刘水库汛期增泄15亿~25亿m3水量作为现阶段调整龙刘水库运用方式的试验方案。     

黄河干流骨干水库综合利用调度模型研究

基于黄河干流骨干水库统一调度的思想,建立了满足黄河干流骨干水库综合利用调度模拟的模型框架,对龙刘(龙羊峡、刘家峡)水库综合利用调度模拟模型、宁蒙河段冲淤计算模型、中游水库调度和泥沙冲淤计算模型、黄河下游河道泥沙冲淤计算模型和水资源供需平衡模型等5个模型进行整合,构建了黄河干流骨干水库综合利用模拟模型,为评价已建水库的综合效益和进一步完善水库优化调度方案提供了技术支撑。     

炭黑填充丁苯/天然橡胶的电磁屏蔽性能

研究炭黑分别填充丁苯橡胶和丁苯/天然（50：50）并用橡胶的力学性能、导电性能和电磁屏蔽效能。对比发现,单组分丁苯橡胶体系的硬度、拉伸和撕裂性能均小于丁苯/天然橡胶并用体系。由于炭黑在并用体系中分布偏聚,体系的导电渗流阈值降低,相同炭黑含量时并用体系样品的体电阻率变小,电磁屏蔽效能增大。采用并用橡胶体系是减小复合材料导电渗流阈值,改善其力学性能的有效方法。     

纳米碳球屏蔽涂料的制备与导电性能研究

利用复合法制备了以纳米碳球、非晶合金粉体作为填料、丙烯酸树脂为基的电磁屏蔽涂料。通过表面电阻率和屏蔽效能测量后发现,由于使用的纳米碳球本身导电性较差,且沉降较严重,涂层并没有表现出很好的屏蔽效果,当碳球含量达到90%时,屏蔽效能最高达到5dB左右,平均在3dB,但已经达到了体系的渗滤阈值,证明距涂层实际应用还有一定的距离。     

An investigation of hydrogen storage kinetics of melt-spun nanocrystalline and amorphous MgeNi-type alloys

The nanocrystalline and amorphous Mg2Ni-type Mg2–xLaxNi (x=0,0.2) hydrogen storage alloys were synthesized by melt-spinning technique.The as-spun alloy ribbons were obtained.The microstructures of the as-spun ribbons were characterized by X-ray diffraction (XRD),high resolution transmission electronic microscopy (HRTEM) and electron diffraction (ED).The hydrogen absorption and desorption kinetics of the alloys were measured using an automatically controlled Sieverts apparatus,and their electrochemical kinetics were tested by an automatic galvanostatic system.The electrochemical impedance spectrums (EIS) were plotted by an electrochemical workstation (PARSTAT 2273).The hydrogen diffusion coefficients in the alloys were calculated by virtue of potential-step method.The obtained results showed that no amorphous phase was detected in the as-spun La-free alloy,but the as-spun alloys substituted by La held a major amorphous phase,con-firming that the substitution of La for Mg markedly intensified the glass forming ability of the Mg2Ni-type alloy.The substitution of La for Mg notably improved the electrochemical hydrogen storage kinetics of the Mg2Ni-type alloy.Furthermore,the hydrogen storage kinetics of the experimental alloys was evidently ameliorated with the spinning rate growing.     

冷饮专用植脂末的生产及其在冷饮中的应用

阐述了冷饮专用植脂末生产的基本原理,主要关键技术条件的选择.以较优的配方,最佳工艺条件生产出冷饮专用植脂末.将冷饮专用植脂末应用于高、中低挡冷饮中具有优良的品质,并降低了成本.     

多单体接枝法制备功能化PPB

采用中介物法与多单体接枝法相结合的方法,首先将丙烯与丁二烯在Ziegler-Natta且催化剂作用下共聚合,然后在二甲苯溶液中将丙烯/丁二烯共聚物与2种或3种单体反应得到含多种官能团的接枝共聚物。考察了苯乙烯和甲基丙烯酸甲酯分别作为共单体对马来酸酐接枝率的影响,并用傅里叶变换红外光谱证明了三单体接枝共聚物的生成。凝胶渗透色谱研究发现,接枝前后共聚物的相对分子质量变化不大,表明接枝前后共聚物无明显降解。     

Martensitic Transformation and Magnetic-Field-Induced Strain in Ni-Mn-Ga-RE （RE = Tb, Sm） Alloys

The effects of microamount additions of RE (Tb, Sm) on martensitic transition, the magnetic-field-induced strain and the bending strength of highly textured polycrystal line Ni4sMn33Ga19 alloy were investigated. The experimental results show that the addition of RE elements decreases the martensitic transformation temperature and the Curie temperature. But the bending strength of Ni-Mn-Ga-RE (RE=Tb, Sm) alloys increases remarkably because of the grain refinement. As a result, Ni-Mn-Ga-RE alloys will be applied practically with higher reliability and stability due to favorable plasticity and toughness. In addition, the replacement of small amounts Ga by Tb or Sm decreases the magnetic-field-in-duced strain of the alloys at room temperature.