吉林陨石的核径迹深度剖面

用吉林1号陨石的43块样品确定了吉林陨石的宇宙线和铀裂变径迹密度的深度剖面。这个深度剖面基本上反映吉林陨石第二(4π)照射阶段记录的银河宇宙线径迹。由钻孔A和B的径迹测定结果,求得吉林陨石通过大气层时的平均烧蚀厚度分别为11±4cm和14±5cm;在第一(2π)照射阶段,钻孔A“顶部”的最小屏蔽深度约为30cm。大约在小于0.4 Ma前,由于短期受热事件的影响,使通过大气层前母体的15—20cm厚的表层中的核径迹退火,由此导出母体近表面区的观测径迹密度与理论预期值发生偏离。     

试论悟性寺和达摩井的所在

广州地区由于地处海边,容易受到海潮的影响,水质较咸,所以城中多井泉,名井很多,达摩井就是其中重要的一个,但是由于时间较久,历代方志记载出入较大,所以达摩井的所在就很难说清楚。文章试图通过对悟性寺所在的考证来说明达摩井具体位置难以确定的原因。     

THE NUCLEAR TRACK DEPTH PROFILE OF THE JILIN METEORITE

Using 43 documented drill core samples of the H_5-chondrite "Jilin" the depth profile of GCR-and fission track densities was established. The track profile essentially reflects the GCR-track record of the second (4π-) irradiation stage of "Jilin". Relics of the track record of the first (2π-) exposure are indicated by a deviation from the theoretical depth profile of the 4π-exposure. No Pu-244 fission is observed ia the fission track background near the meteorite center. The atmospheric ablation thickness of the two drill cores A and B normal and parallel to the assumed surface of the "Jilin" parent body was found to be 11±4 cm, respectively. A minimum shielding depth of the "top" part of core A during the 2π-exposure is estimated to be～30 cm. Near surface deviations of the experimental track data from theory are ascribed to a short-term moderate heating event (equivalent to 24h,～370℃) no more than 0.4 Ma ago. The resulting partial track annealing in a surface layer of ～15—20 cm thickness of t     

化学镀Ni-P(Pr)/Co-P复合阴极的性能研究

化学镀Ni-P(Pr)/Co-P复合阴极具有很好的电催化性能，但在稳定性方面尚有欠缺，在内层引入稀土Pr后，由于稀土元素特殊的外层电子结构，促进了内层非晶化过程，提高了镀层的致密性和耐蚀性。化学镀Ni-P(Pr)/Co-P复合阴极，相对于Ni-P/Co-P复合阴极，长期电解的稳定电位降低了20mV，在抗反电流实验中平台电位也下降了20mV左右，增强了电极稳定性。