Removal of copper(II) and cadmium(II) ions from aqueous solutions by biosorption onto pine cone

In this study, the removal of copper(II) and cadmium(II) ions from aqueous solutions by biosorption onto pine cone was studied. Variables that affect the biosorption process such as pH, biosorbent dosage, initial metal ion concentration, contact time and temperature of solution were optimized. Experimental data were fitted to Langmuir, Freundlich, Dubinin Radushkevich and Temkin isotherm models to investigate the equilibrium isotherms. Pseudo-first-order, pseudo-second-order and intraparticle diffusion kinetic models were used to determine the biosorption mechanism. The thermodynamics of biosorption were studied for predicting the nature of biosorption. Experimental results showed that pine cone could be evaluated as an alternative precursor for removal of heavy metal ions from aqueous solutions, due to its high biosorption capacity, availability, and low cost.     

大塑性变形6013铝合金的时效特性与力学性能

利用X射线衍射分析（XRD）、差示扫描量热法（DSC）和拉伸试验,研究不同温度等通道转角挤压（ECAP）和常规静态时效处理后6013 Al-Mg-Si铝合金的微观结构、时效行为、析出动力学以及力学性能。XRD测得的ECAP变形后合金的平均晶粒尺寸在66-112 nm范围内,平均位错密度在1.20×10^14-1.70×10^14 m^-2范围内。DSC分析表明,由于ECAP后试样比常规时效处理试样拥有更细小的晶粒和更高的位错密度,因此,ECAP变形后合金的析出动力学更快。与未变形合金相比,ECAP后试样的屈服强度和抗拉强度都得到了显著提高。室温ECAP后试样的强度达到最大,其屈服强度是静态峰时效屈服强度的1.6倍。细晶强化、位错强化以及由于ECAP过程中的动态析出而产生的析出相强化,是ECAP合金获得高强度的几种主要强化机制。     

新型增强聚丙烯自动拉板压滤机

一种广泛用于冶金、化工等行业的新型增强PP厢式自 动拉板压滤机，日前由河北省景津压滤机厂研制成功并投放 市场。增强PP厢式自动拉板压滤机是国际上90年代开发 的用于各种悬浮液固液分离间歇性过滤新产品。该厂瞄准 国外同类产品进行攻关，终于研制成功。采用机电一体化设 计，实现了滤板压紧、进料、过滤、洗涤、拉板等各道工序的自 动化操作，由于其滤板采用了增强PP，性能更加完善。特别 是加装自动拉板系统后，大大降低了劳动强度，提高了生产 效率。 该设备最大过滤工作压力达1?MPa，最高过滤工作温度 达120℃。经质检部门测试，该设备各项技术指标达到或超 过国外同类产品水平。????(林林)