浅谈锌合金冲裁模制造工艺

介绍了应用锌合金技术制造冲裁模具的工艺方法和注意事项及在生产实际中所达到的效果     

Measuring heavy metal migration rates in a low-permeability soil

Heavy metals at high concentrations are often toxic to living organisms, and their environmental toxicity depends on soil properties. It has long been thought that in clay-rich, low-permeability soils, heavy metals are bound to soil particles, and thus there are only few toxicity risks. This study questioned this perception and tested heavy metal mobility in such a soil, of the London Clay series, using a benchtop centrifuge. Soil columns were placed in the centrifuge and were infiltrated with solutions of Cu, Ni and Zn ions, while the centrifuge was running at three different gravity levels, at 5,280, 2,600 and 1,300 gravities. The measured rates of migration of Cu, Ni and Zn ions were extrapolated down to 1 gravity, which represents field conditions, the conditions for which an assessment of risk due to metal toxicity would be needed. It was found that heavy metal movement was significant in London Clay, Ni being the most mobile metal in the study, followed by Zn and then Cu ions. Centrifuge infiltration tests were proven to be a valuable tool in the study and quantification of metal mobility in low-permeability soil, because they were easy to run and precise in predicting metal movement in London Clay. Electronic Publication     

钙硼复合对土壤锌吸附-解吸热力学和动力学的影响

酸性紫色土对锌的等温吸附 -解吸和动力学试验表明 :锌的等温吸附符合 L angmuir方程 ,最大吸附量为15 3.8mg/kg土。钙、硼与锌复合 ,均降低土壤锌的最大吸附量及结合常数 K。所吸持的锌的解吸量和解吸率小 ,钙和硼均降低了锌的解吸率。土壤吸附锌的动力学以 Elovich方程 (Ct=a+blnt)描述最佳 ,反映土壤对锌吸附速率大小的方程参数 b值以 Zn>Zn+Ca+B>Zn+B>Zn+Ca。     

从电镀锌废渣中回收制备锌盐的研究

研究了以含锌废渣为原料、制备锌产品的工艺条件。实验主要对酸浸取，氧化除铁、锗和置换除去重金属元素等过程的工艺条件进行了研究。制得碱式碳酸锌和氧化锌两种锌产品，其纯度分别大于96％和95％。锌回收率达到80％以上。     

紫色土锌镉复合污染效应与机理研究

采用盆栽试验结合野外调查，研究紫色土锌镉复合污染对莴笋、蕃茄、甘兰、小麦等的作物效应与原因。结果表明，锌镉复合污染加剧锌的毒害作用，但缓解镉毒性，其原因在于：低浓度镉促进锌吸收、高浓度锌抑制镉吸收。土壤锌镉复合对二价离子的竞争效应也影响其生态效应。     

铅、锌催干剂废水的处理

介绍了铅催化剂废水通过全部循环使用,不仅提高产品质量而且废水实行零排放,锌催化剂通过改进生产工艺,废水的排放量少,水质基本无污染,从生产源头上解决了废水排放问题。     

植物果实中不同部位金属元素含量的AAS分析

采用原子吸收分光光度法对七叶纳果皮、果肉、种子、八月扎果皮、果肉、种子、九莲瓜果皮、果肉、种子中Zn、Mn、Fe三种植物必需的金属元素进行了测定和分析,该方法的加标回收率为95.56 ～112.21,RSD 3.4,具有良好的准确度和精密度.结果表明,所测元素在三种植物果实中不同部位表现为不同的含量顺序,说明三种植物果实的不同部位对三种元素的吸收和积累能力存在差异.     

不同粒径降尘中痕量金属元素Cu、Pb、Zn、Cr的形态分析

运用Ｔｅｓｓｌｅｒ形态分类法和石墨炉原子吸收分光光度法研究了不同粒径降尘样品中痕量金属元素Ｃｕ、Ｐｂ、Ｚｎ、Ｃｒ的存在形态，讨论了不同存在形态的分布规律。结果表明，Ｃｕ、Ｐｂ、Ｚｎ、Ｃｒ在降尘中的主要形态按顺序分别为有机结合态、铁锰氧化物结合态、铁锰氧化物结合态、残渣晶格态，其活性顺序为Ｚｎ＞Ｐｂ＞Ｃｕ＞Ｃｒ；４种元素的可交换态、碳酸盐结合态、铁锰氧化物结合态在小颗粒中的分布均比在大颗粒中占优势，说明小颗粒中金属元素较为活泼，其环境危害性更大。     

锌铝水滑石负载羧酸基酞菁锌可见光降解水中氯苯酚

以锌铝类水滑石为载体,1.0%(质量分数)水溶性羧酸基酞菁锌为光敏剂,制备了不溶于水的负载型光敏剂,并对其结构进行表征.结果表明,在可见光和氧气作用下,该复合催化剂能够引发水中对氯苯酚、2,4-二氯苯酚和2,4,6-三氯苯酚的降解.但有机物降解的速率与载体的锌铝比和煅烧温度有关.研究表明,最佳的锌铝比和煅烧温度分别为2.0和300℃.在反应过程中,载体及其煅烧产物具有电子导体的功能,可加快光敏剂与氧气之间的电子转移过程,进而引发氯苯酚的降解.此外,该复合催化剂能被重复循环使用,但光敏活性逐渐降低.     

Effects of cadmium,zinc, copper and manganese on hepatic parenchymal cell gluconeogenesis

Abstract

The effects of divalent cations on gluconeogenesis in enzy‐matically isolated rat hepatic parenchymal cells were examined. Cadmium, zinc and copper decreased glucose production from lactate (10 mM). However, manganese at 0.05 to 1.0 mM levels stimulated gluconeogenesis by the cells and reduced the effects of the Cd⁺², Zn⁺² and Cu⁺² on gluconeogenesis. The results indicate that under these in vitro conditions the cations altered an aspect of hepatic function—gluconeogenesis from lactate.