Pan Xiangliang

Sustainable agriculture in the semi-arid agro-pastoral interweaving belt of northern China: A case study of west Jilin province

The semi-arid agro-pastoral interweaving belt (SAPIB) is an important ecological zone in northern China and an important food base. However, sustainable agricultural development has been restricted by both natural and socioeconomic factors. It is inherently vulnerable because of its unfavourable climate and geological and hydrogeomorphological conditions. Agricultural production has been impaired by frequent natural disasters, salinization and desertification. Moreover, irrational agricultural policies and practices, poverty and other socioeconomic factors have brought about degradation in the SAPIB. The authors argue that the basis for a sustainable strategy is to transform it by increasing exergy input, changing the cultural outlook and harmonizing interactions between the component subsystems. Finally, a series of proposals based on notions for a sustainable strategy is put forward.

应用单针注射等温微量量热滴定法检测尿素水解菌对Hg 2+ 的耐受性

目的利用单针注射等温微量量热滴定法(SIITC)检测尿素水解菌对Hg2+的耐受性。 方法与传统的细胞生长曲线法和基于尿素水解的pH变化曲线相对比，应用SIITC研究耐盐尿素水解菌Staphylococcus succinus对不同浓度Hg2+的耐受性，通过相关性分析验证SIITC检测细菌对重金属胁迫耐受性的可行性。 结果S. succinus菌吸附水解尿素的最大热量交换速率和累积热量值随Hg2+浓度升高而降低。最大热量交换速率由不含Hg2+的-45μJ/s降至10μmol/L Hg2+处理的-20 μJ/s，吸收热量由-1 291.90 μJ下降到-535.75 μJ；不同浓度Hg2+胁迫下S. succinus菌吸附水解尿素的反应热量值与溶液pH以及OD600的相关系数r分别达到0.928和0.955。 结论SIITC可用来检测Hg2+对尿素水解菌S. succinus的毒性。