The effect of vacuum evaporation plating on phase structure and electrochemical properties of AB5–5 mass% LaMg3 composite alloy

In this paper, Cu, Al and Ni were plated on the AB₅–5 mass% LaMg₃ composite hydrogen storage alloy using a vacuum evaporation plating method. The phase structure and the electrochemical properties were investigated. The X-ray diffraction (XRD) analysis shows that the phase structure is not changed obviously after the plating Cu, Al and Ni on the composites. The electrochemical tests show that maximum discharge capacity, high rate dischargeability (HRD), dischargeability at low temperature and cyclic stability was improved by vacuum evaporation plating Cu, Al and Ni. Maximum of discharge capacity of the AB₅–5 mass% LaMg₃ composite alloy plating Ni can reach 351 mAh/g, which is 3.5% higher than that of the untreated. HRD at I_d = 1200 mA/g of the composite alloy plating Cu is 45.0% of that at 60 mA/g, which is 20.4% higher than the untreated. Discharge capacity of the composite alloy plating Cu at low temperature 233 K is 205 mAh/g, which is 57.3% of that at 298 K, and it is much higher than 36.8% of the untreated composites. The discharge capacity retention of the composite alloy plating Al after 200 cycles is 7.8% higher than the untreated.     

Evaporative Heat Transfer of Annular Two-phase Flow of Air-water in a Small Vertical Tube

The evaporative heat transfer of the non-boiling annular two-phase flow of air-water in a small vertical tube with uniform wall heat flux was studied both theoretically and experimentally. A simplified two-phase flow boundary layer model was used to calculate the thickness of the water film attached to the wall, and from the liquid film thickness the evaporative heat transfer coefficients of the annular two-phase flow were obtained. Theoretical equations and semi-theoretical equations were proposed for predicting the evaporative heat transfer of the annular two-phase flow of air-water in a small vertical tube. The semi-theoretical prediction agrees well with the experimental data. The mechanism of the heat transfer enhancement is the evaporation of the thin liquid film attached on the wall.     

48%烧碱蒸发装置运行总结

介绍了薄膜蒸发器在烧碱浓缩中的应用,阐述了质量分数为48%的烧碱蒸发装置的进料、出料、冷碱、真空系统的工艺及运行情况,72 h考核验收及产品质量分析显示,达到了预期目标.     

鄱阳湖流域水分盈亏时空变化特征分析

根据1960~2014年鄱阳湖流域13个气象站点的气象资料,采用FAO推荐的Penman-Monteith法、Mann-Kendall趋势检验法和相关分析法,研究鄱阳湖流域水分盈亏量时空分布变化趋势及其与气象因子的关系。研究结果表明:鄱阳湖流域近55 a来水分盈亏量多年平均盈余为565.88 mm,空间上呈由西北向东北和由西南向东北逐渐递增的趋势;水分盈亏量年内分布呈秋季亏缺,其他季节盈余,水分盈余量表现为春季夏季冬季秋季;在研究时段内流域各地水分盈余量均呈增加趋势,但各季节水分盈余量变化存在一定的差异性,其中春季和秋季呈减少趋势,但趋势不明显,而夏季和冬季均呈显著的增加趋势(p0.05)。鄱阳湖流域水分盈亏量与降雨、日照时数和日最高气温关系密切,流域年水分盈余量的增加是由于夏季和冬季降水量的增加、日照数和风速的减少。     

液氯气化工艺及安全

介绍了液氯气化的工艺过程及所采取的相应安全措施。     

烧碱蒸发扩产节能改造

杭州电化集团有限公司烧碱分厂为满足隔膜电解扩产的需要,将蒸发装置三效四体工艺改为三效五体工艺,并改造了循环冷却水系统,从而提高了装置实际产能,并节约了蒸汽。     

三效四体烧碱蒸发中汽耗最少的操作压力

利用数学模型,通过计算机模拟,针对三效四体烧碱蒸发过程,在生产量相同的情况下计算Ⅰ效、末效一系列的生蒸汽压力,找到蒸汽消耗最少的压力组合,结果符合实际。     

高效液相色谱法分析硅氟唑含量

采用反相高效液相色谱外标法.以乙腈-水作为流动相,用Kromasil ODS柱和紫外检测器(205nm)研究了测定硅氟唑含量的方法,并探讨了测定条件.结果表明.方法的标准偏差0.50%,变异系数0.52%,加标回收率100.17%;硅氟唑进样量2.5～10.0μg时,方程呈良好的线性关系.方法简便、快速,可满足定量分析的需要.     

吸湿性盐溶液振荡热管的传热特性研究

研究了10%(质量分数)LiCl吸湿性盐溶液作为工质的振荡热管传热特性。测试了在45％～90％充液率、10～100 W加热功率下振荡热管蒸发端温度及热阻的变化，并与去离子水工质的实验数据进行了对比。结果表明：在45％、55％的低充液率下，加热功率达到50 W以上时，LiCl溶液振荡热管的热阻明显比去离子水振荡热管低，能有效延迟烧干现象的发生。在62%的中等充液率，35W加热功率以上，LiCl溶液振荡热管的蒸发端温度较离子水振荡热管振荡频率快，幅度小且热阻低。在80%、90%的高充液率下，两种工质振荡热管的蒸发端温度曲线在平均温度、振荡频率、振荡幅度上都较为相似，热阻也比较接近。     

Synchronous receiver initiated MAC protocol for long-lived sensor networks

In this paper, we discuss the design of a new Medium Access Control (MAC) protocol, SRI-MAC (Synchronous Receiver Initiated MAC), for wireless sensor networks whose goal is to extend the lifetime of the network by avoiding major energy waste causes, such as collisions, overhearing and idle listening.