稀土元素对植物的生物有效性研究进展

稀土元素对增强植物的抗逆,提高农作物的产量以及改善农作物的品质具有积极的促进作用.就稀土元素对植物的生物有效性进行综述,重点阐述了稀土元素在植物中的含量及分布,稀土对种子萌发、根系发育、养份吸收、抗逆性、作物产量及品质的影响,并从细胞和分子水平的角度解释了稀土的植物生物有效性的作用机制.     

Social and temporal geographies of the near future: Music, fiction and youth culture

Cyberpunk has been widely acknowledged as a form of popular fiction, which has done much to establish the potential of information technology in the popular imagination. Commonly these extrapolations are predicated on the shared diegesis of a dark future, that is a setting of urban decay and oppressive corporate capital. British publishing has taken longer to develop this style of critical dystopian writing. The differences between the two groups of fiction can be understood as different responses to cultural change, which has taken place during the 1980s especially in the ways and means of imagining further social change and agency.     

施用蔗渣对土壤镉赋存形态和生物有效性的影响研究

采用化学反应的合成方法向蔗渣中引入巯基官能团,并进行电镜扫描和红外光谱分析。在此基础上,通过土壤培养试验和生物盆栽试验,研究了蔗渣和改性蔗渣对模拟镉（Cd）污染农田土壤中镉的赋存形态和生物有效性的影响。结果表明,采用该合成方法,成功地向蔗渣中引入了巯基官能团。在土壤培养试验中,有机物对土壤Cd赋存形态的转化与土壤pH的相关性不明显,但与土壤中胡敏酸（HA）和富里酸（FA）含量的变化具有一定的相关性：土壤中HA含量随培养时间的延长而逐渐升高,各处理土壤弱酸提取态Cd含量相应减少,而土壤残余态Cd含量则逐渐增加,且巯基蔗渣的作用效果均强于未改性蔗渣。在生物盆栽试验研究中,外加5 mg·kg-1 Cd显著降低了小白菜的生物量,而施用有机物料对小白菜均有显著的增产效果,研究结果同时表明蔗渣和巯基蔗渣都不同程度降低了土壤有效态Cd的含量以及小白菜地上部分的镉含量,且巯基蔗渣的作用效果较为显著。另外,小白菜地上部分镉含量与小白菜生物量呈现显著负相关,与土壤有效镉含量呈显著正相关。