镍层耐硝酸腐蚀性测试——一种简单的预先探测ENIG镍层“黑盘”现象的测试方法

随着更加精细的SMT、BGA等表面贴装技术的运用,化学沉镍金(ENIG)作为线路板最终表面处理得到了越来越广泛的应用,同时可怕的“黑盘”现象也随之更广泛地“流行”起来,直接导致贴装后元器件焊接点不规则接触不良。为了贯彻执行最好的流程控制和采取有效的预防措施,了解这种焊接失败的产生机理是非常重要的,及早的观测到可能发生“黑盘”现象的迹象变得同样关键。本文介绍了一种简单的预先探测ENIG镍层“黑盘”现象的测试方法-镍层耐硝酸腐蚀性测试,这种测试可以用于作为一种常规的测试方法监测一般化学沉镍溶液在有效使用寿命范围内新鲜沉积的镍层的质量。利用Weibull概率统计分析在不同的金属置换周期(MTO)下镍层的可靠性能表现。结合试验结果得出了一个镍层耐硝酸腐蚀性的判定标准。     

工艺因素对金属封装外引线弯曲疲劳的影响

考察了金属封装外壳制造工艺对外引线弯曲疲劳的影响,发现电镀镍是导致外引线弯曲次数明显减少的最主要工艺步骤,且随镀镍层厚度的增加,弯曲次数减少。此外还讨论了外引线的氢含量和晶粒度对引线抗疲劳能力的影响。     

高Al2O3物料对镍电炉渣粘度的影响

论文对Al2O3高达69．46％的含镍物料电炉处理时对炉渣性能的影响进行了研究。研究表明：吉林镍业公司冶炼厂电炉渣1340℃时黏度为0．538P．s；电炉渣在不添加任何其它试剂的情况下，渣中Al2O3含量不宜高于9％；加入添加剂后，炉渣黏度降低，当在配料中加入20％此种含镍物料时，添加剂加入量7％为宜，此时炉渣黏度为0．74P．s（1340℃）。     

Stopping power of swift neon ions in dependence on the charge state in the non-equilibrium regime

We report on measurements of charge changing cross-sections and energy losses in dependence on the initial and final charge state of Ne ions at an incident energy of 2 MeV/u penetrating thin carbon foils. Different initial charge states could be separated in energy by applying a high voltage in front of the carbon foils; the final charges and their energy loss were measured with a high-resolution magnetic spectrometer. We derived a consistent evolution of the charge state distribution solving the corresponding rate equations for the measured cross-sections. Including the charge state dependent energy losses, ΔE(q_i,q_f), stopping power values for frozen charge states, S(q), could be extracted. The experimental data are compared with different theoretical predictions.     

Quantitative analysis of Ni effect on CCT diagrams of novel air-cooled bainite steels using artificial neural network models

The quantitative effect of Ni content on continuous cooling transformation （CCT） diagrams of novel air-cooled bainite steels was analyzed using artificial neural network models. The results showed that Ni may retard the high- and medium-temperature transformation and martensite transformation. The results conform to the materials science theories.     

场激活加压燃烧合成WC-Ni复合材料的工艺参数研究

以钨、碳和镍为原料,在电场激活下,材料的燃烧合成和致密化同时进行,短时间内完成了碳化钨镍复合材料的制备。研究了场激活 加压燃烧合成中的工艺参数,如脉冲电流、能量控制模式、升温速率、最高温度和压力对反应的影响。测量了在反应合成和致密化前后的样品 收缩率。所制备的复合材料的相对密度,490N载荷下Vickers硬度和断裂韧性分别为99.2%,13.965GPa和5.9MP·m1/2。     

熔融碳酸盐燃料电池阴极材料的导电性

通过交流阻抗方法研究了熔融碳酸盐燃料电池阴极材料锂镍氧化物、锂钴氧化物和锂铁氧化物的导电性能。结果表明:锂镍氧化物电极的导电性最好,锂钴氧化物电极的导电性次之,锂铁氧化物电极的导电性最差;它们的导电性都随着温度的升高而按指数规律增加;在合成锂钴氧化物(或锂铁氧化物)的过程中,使Li2CO3轻微过量,可以提高锂钴氧化物(或锂铁氧化物)电极的导电性,而且在同一温度下,随着nLi∶nCo(或nLi∶nFe,摩尔比)值的增大,锂钴氧化物(或锂铁氧化物)电极的导电性显著增加。     

Co- and Ni-exchanged ferrierite: The contribution of synchrotron X-ray diffraction data to siting of TMIs

High-silica zeolites exchanged with transition metal ions (TMIs) are the subject of great interest for their unusual catalytic activity and selectivity. Structural information like coordination and accessibility of TMIs in zeolites are important factors for understanding their catalytic activity. Siting of TMIs in zeolites is typically obtained by spectroscopic (EXAFS, EPR, UV–vis and IR) and computational methods, as in the case of Co-ferrierite. However, some controversy exists in the literature concerning the model for incorporation of bare Co ions in ferrierite. We show here that the results of our synchrotron X-ray powder diffraction studies on Co- and Ni-exchanged ferrierite (Si/Al = 8.5) are in a good agreement with the model of Co siting based on an indirect spectroscopic approach and help to validate this model. By direct structural evidences, a possible explanation for the larger catalytic activity of Co sites in the main channels of ferrierite can be inferred. A combination of data from in situ XRD continuous monitoring of the Co ion migration during calcination and crystal-chemical considerations allows to device a strategy for the design of optimised co-cations containing Co-ferrierite catalysts.     

Structural Changes in Titin and Nebulin Filaments Specific to Calcium Ions at 0.1 mM: Factors of Meat Tenderization During Postmortem Aging

ABSTRACT Postmortem structural changes in titin and nebulin filaments were investigated by incubating isolated myofibrils in a solution containing 0.1 mM calcium ions and various concentrations of a protease inhibitor. The inhibition curves showed 2 abnormal steps with increases in the concentration of leupeptin or calpastatin domain I. While the amounts of unchanged titin and nebulin were constant in the 1st step, the 2nd occurred at higher protease inhibitor concentrations. These facts indicated that excess amounts of leupeptin and calpastatin domain I caused deterioration in titin and nebulin properties, thus interfering with the binding of calcium ions. We concluded that the severance of titin and nebulin filaments in the 1st step were induced by calcium ions at 0.1 mM.     

单分散六边形扁平溴碘化银微晶的结构与性能的研究

应用可控双注仪制备了一系列碘含量相同而碘在微晶中分布不同的单分散六边形扁平溴碘化银乳剂。用扫描电镜（ＳＴＥＭ）与Ｘ－射线能谱仪（ＥＤＳ）对单个微晶进行了微区分析，并用介电损耗，微波光导等方法研究了此类乳剂微晶的结构与性能的关系。结果表明：严格控制微晶成核、成熟、生长三个阶段的条件，可制得含六边形颗粒９２％以上的扁平溴碘化银乳剂，颗粒大小变化系数小于１２％。此外碘在微晶中的分布明显影响微晶的电性质和