一个含有苯并15-冠-5单元的Ru(Ⅱ)多吡啶配合物的合成及性质研究

合成、表征了一个多吡啶配体(L)和相应的Ru(Ⅱ)配合物[(bpy)2RuL](PF6)2.在室温乙腈溶液中,该配合物在452nm显示特征的金属-配体核移跃迁吸收峰,在641nm显示特征发射峰.电化学测试显示配合物有一个基于钌(Ⅱ)的氧化过程和三个基于配体的还原过程.配合物与钠离子的作用通过紫外可见吸收光谱、发射光谱和电化学滴定进行研究.把钠离子加入到配合物的乙腈溶液中,配合物的荧光强度增加、紫外可见吸收蓝移、基于钌(Ⅱ)的氧化峰向阴极移动.     

盐胁迫下5种木本植物体内Na~+、K~+含量变化及其与抗盐性的关系研究

对NaHCO3胁迫下5种木本植物苗木Na+、K+的吸收和积累及其与木本植物耐盐性的关系进行了研究.结果表明:随盐碱胁迫强度的增加,5个树种苗木地上部分Na+含量、地上部分Na+/K+总体上逐渐增加,地上部分K+含量逐渐降低.地上部分Na+含量依次为枸杞樟子松丁香南蛇藤白榆;Na+/K+含量依次为樟子松南蛇藤丁香枸杞白榆.研究表明,地上部分Na+含量可以作为评价不同树种抗盐性的有效指标,但对于非盐生植物与盐生植物应该区别对待,即非盐生植物地上部分Na+含量与抗盐性负相关,盐生植物地上部分Na+含量与抗盐性正相关.地上部分Na+/K+与抗盐性没有普遍联系,不能作为不同生活型木本植物抗盐性评价标准.     

Impact of gamma radiation and salinity on growth and K^＋/Na^＋ balance in two populations of Medicago sativa （L.） cultivar Gabbs

The perennial Medicago sativa cv. Gabes is widely grown on saline soils in Tunisian oases. Morphological and physiological analyses of two populations （Mareth and Gannouch） were conducted in order to study the effect of salinity and gamma radiation （350 Gy） interaction on two populations of this species. It has been shown that the two irradiated populations of Medicago sativa are fairly tolerant to salt at growth phase compared to the non-irradiated. Exposure to gamma irradiation （350 Gy）, alone or in combination with salt stress, increased significantly （p 〈 0.001） shoot number, stem height and chlorophyll b pigment especially for the Gannouch population, while no change occurred for the Mareth population. The presence of salt to 9 g/1 affected significantly the root biomass and induced a reduction of shoot development of both control and irradiated alfalfa populations. For all treatments, plants of two populations remained able to produce and to allocate dry matter to the different organs. The survey of Na^＋/K^＋ ratio showed that the growth of the aerial organs of two non-irradiated populations was at least determined by a selectivity in favour of the K^＋ ions （r^2 = 0.97 and r^2 = 0.59 for Mareth and Gannouch non-irradiated populations, respectively）. However, the rather weak correlation detected for the irradiated populations, particularly for the irradiated Gannouch, seems to be the consequence of the effect of irradiation that improved potassium availability, essential element for growth and development. Results also showed that the two irradiated populations, especially the Mareth, accumulated Na^＋ ions in its photosynthetic organs. This accumulation was associated with an improvement of foliar water content at a level of salinity around 5 g/1. Such a mechanism reflects probably an inclusive behaviour of the plants and a good aptitude to use the dominant ions （Na^＋） for the osmotic adjustment. However, the non-irradiated populations are unable to adjust their internal os