缺磷胁迫对脐橙光合色素和光合作用的影响

经缺磷处理后，脐橙叶片的无机磷（Pi)含量，光合色素含量，净光合速率（Pn)，光化学效率（Fv/Fm) ,最大荧光（Fm)下降，细胞间CO2浓度（Ci)和初始荧光（F0)升高，气孔导率（Gs)无明显变化。     

纳米TiO2光催化剂的活性与使用寿命

Titanium dioxide nano-particles (for example， P₂₅， Germany， Degussa) have been internationally used as an effective photo-catalyst for many years. In this paper， characterization of P₂₅， photo-degradation ability as well as its life time has been systematically studied by employing methyl orange as a model pollutant. Many factors such as the pH value， pre-treatment have been investigated. Just like other nanometer-sized or ordinary Anatase TiO₂， the catalyst performs better at an optimal pH value. Pre-treatment of the catalyst also enhances the photo-catalytic a-bility. And the P₂₅ have shown rather good life time. The degradation products have been characterized by UV， mass and Raman spectrum. It is found that although the P₂₅ photo-catalyst has shown excellent decolourization a-bility， it is still difficult to degrade the methyl orange into small molecule， such as CO₂ and H₂O. Low-power ul-traviolet lamps (9W， 254nm) have been used throughout. A comparison experiment has been carried out under natural sunlight， and the results have shown that natural sunlight (With temperature below 10℃) could provide even more energy than that of the adopted ultraviolet lamp， which have proved P₂₅ a rather promising photo-catalyst for practical application in environment field under natural surrounding. The obtained results may serve as a valuable reference for the evaluation and preparation of high quality TiO₂ photo-catalyst.     

磷和NaHSO3交互作用对温州蜜柑叶片光合作用的影响

经不同磷水平和8 mmol@L-1NaHSO3溶液处理后,不缺磷温州蜜柑的净光合速率(Pn)、最大荧光(Fm)、光化学效率(Fv/Fm)和电子传递速率(ETR)升高,光呼吸速率(Pr)及放O2活性无明显变化,Pr/Pn显著下降,缺磷温州蜜柑的Pn、Pr、Fm、Fv/Fm、ETR显著下降,Pr/Pn和放O2活性显著升高.无论缺磷与否,初始荧光(F0)变化不显著,O2-和H2O2的含量显著下降.认为喷洒8 mmol@L-1的HaHS03溶液有助于提高Pn,促进温州蜜柑进行光合作用.     

从氯化亚铜的化学式表示法浅谈大学生综合素质的培养

本文结合氯化亚铜化学式的讨论,简要阐述了运用自然科学方法论的方法培养大学生综合素质的有关做法。