Kinetic model of induced codeposition of Ni-Mo alloys

The kinetic model of induced codeposition of nickel-molybdenum alloys from ammonium citrate solution was studied on rotating disk electrodes to predict the behavior of the electrode-position. The molybdate (MoO42-) could be firstly electrochemically reduced to MoO2, and subsequently undergoes a chemical reduction with atomic hydrogen previously adsorbed on the inducing metal nickel to form molybdenum in alloys. The kinetic equations were derived, and the kinetic parameters were obtained from a comparison of experimental results and the kinetic equations. The electrochemical rate constants for discharge of nickel, molybdenum and water could been expressed as k(1)(E) = 1. 23 x 10(-9) C(Ni)exp( - 0.198FE/RT) mol/(dm(2).s), k(2)(E) = 3.28 x 10(-10) C(Mo)exp(- 0.208FE/RT) mol/(dm(2).s) and k(3)(E) = 1.27 x 10(-6)exp(- 0.062FE/RT) mol/(dm(2).s), where C-Ni and C-Mo are the concentrations of the nickel ion and molybdate, respectively, and E is the applied potential vs. saturated calomel electrode (SCE). The codeposition process could be well simulated by this model

当代乡村建设中的艺术实践

在中国社会的现代转型中,乡村付出了沉重的代价。时至今日,中国乡村的危机非但没有缓解,反而随着政治运动以及资本侵蚀,陷入到空壳化、原始化的险境之中,陷入到荒漠与冷漠的生态与世态之中。艺术介入乡村的实践,即是重新探索城乡建设与社区营造的各种可能性,以此实现对文明传统的再追索及当下社会的再修复。北京大学人文社会科学研究院于2016年7月28日组织召开"乡村建设及其艺术实践"学术研讨会,基于上述主题展开讨论

气候变化国家评估报告(Ⅱ):气候变化的影响与适应

已经观测到的气候变化影响是显著的、多方面的。各个领域和地区都存在有利和不利影响,但以不利影响为主,未来的气候变暖将会对中国的生态系统、农业以及水资源等部门和沿海地区产生重大的不利影响。采取适应措施可以减轻气候变化的不利影响,应将适应气候变化的行动逐步纳入国民经济和社会发展的中长期规划中。由于我国科学研究的相对不足和科学认识能力的局限,目前的气候变化影响评估方法和结果还存在很大的不确定性。应当加强区域适应气候变化的案例研究、扩大研究领域、加强极端天气、气候事件影响的研究,以降低影响评估的不确定性,并提出切实可行的适应对策