由石灰性冲积物发育而来的排水不良和排水良好的土壤中游离氧化物的分布

A study on the distribution of free iron and manganese oxides was conducted in soils developed on calcareous alluvial deposits under subhumid climatic conditions, in Western Greece. Soil samples from two well drained soils and from two poorly drained soils, classified as Alfisols, were collected and used in this study. After certification of soil homogeneity the acid ammonium oxalate and dithionite-citrate-bicaxbonate methods were used to extract free iron and manganese oxides from the samples. Iron oxides extracted by the dithionite-citrate-bicarbonate method (Fed) were significantly higher than the iron oxides extracted by the ammonium oxalate method (Feo), indicating that a considerable fraction is present in crystalline forms, independent of drainage status. A confirmation of free iron oxides and fine clay was detected. The ratios Feo/Fed and (Fed-Feo)/total Fe (Fet) could not be used to distinguish the well drained soils from the poorly drained soils. Manganese movement in a soluble form is independent of the fine clay.     

结构铁的还原对绿脱石红外光谱的影响

伴随Fe^2 浓度增加和还原反应的进行,绿脱石红外光谱中位于3570,1030和821cm^-1吸收峰向低波数位移,其相应的振动方式分别为0-H伸缩振动、Si-Ob（基部氧）面内振动和FeO-H变形的振动,还原反应对Si-Oa（顶部氧）相互作用在1110cm^-1处产生的扇峰没有影响。结构铁的还原导致848cm^-1的吸收峰向较高能量方向转移,但在结构羟基完全重氢化后,Fe-OH振动在840cm^-1产生的吸收峰仍然保持不变,由于四面体和八面体薄层中间的压力减弱,Si-Ob振动能量随还原反应而降低。     

石灰质土壤上不同葡萄品种叶片的铁含量与其黄化的关系

以石灰性土壤上8年生的3个欧亚种鲜食葡萄品种(红脸无核Blush Seedless、玫瑰香MuscatHamburg、里扎马特Rizamat) 以及3个欧美杂种(京亚J ingya、藤稔Fujiminori、紫珍香Zizhenxiang) 为试材, 通过对叶片叶绿素、活性铁和全铁含量相互关系的分析发现, 不同品种新叶到成熟叶的叶绿素、活性铁和全铁含量逐渐增加; 黄化叶片叶绿素比绿叶显著降低, 重度黄化欧美杂种1、2位叶活性铁含量显著低于未黄化欧亚种; 不同品种1、2位叶全铁含量比较, 黄化叶与绿叶差别不大, 有时黄化叶比绿叶全铁含量高; 欧亚种红脸无核和玫瑰香4位叶全铁含量显著高于黄化品种4位叶。叶片叶绿素含量与其黄化程度呈负相关, 与活性铁和全铁含量呈正相关。     

Experiment of the Wastewater Treatment with the Method of Secondary Chemical Precipitation Ferrite

Large amounts of wastewater containing heavy metal ions are discharged into the surrounding,which can''t be degraded but only be changed in their forms or transported,diluted and accumulated in the human organisms,so it has serious impact on the health of living things.In order to dispose the wastewater containing many kinds of heavy metal ions,in this experiment,ferrite was adopted to deal with the wastewater containing irons,taking the wastewater of Yunnan Chihong zinc & germanium Co,Ltd as the raw materials.The result shows that the temperature,stirring rate and pH all affected the effect of treatment.A best condition for treatment of the waste water containing heavy metal treatment has been obtained by this experiment.     

松萝酸的抗菌活性及其开发利用研究进展

细菌耐药性问题是一个全球性公共卫生问题,严重威胁动物及人类健康。动物源细菌耐药性问题在中国较为突出,严重威胁养殖安全,新型抗菌药物或抗生素替代物的研发已经迫在眉睫。松萝酸,又名地衣酸,是松萝属、石蕊属等植物提取物中的主要活性成分之一,因具有抗菌、抗炎、抗肿瘤、抗病毒、抗结核、抗寄生虫和镇痛解热等多种药理学活性而被广泛关注。研究表明,松萝酸对革兰阳性菌具有较强的抗菌活性,其作用机制涉及对核酸和蛋白质合成的抑制、干扰外排泵、破坏细胞膜的完整性、破坏细菌代谢稳态及抑制生物膜形成等多个方面,是一种潜在的天然抗菌药物。松萝酸也是一种较强的抗菌增效剂,能够逆转多重耐药细菌对多黏菌素等多种抗菌药物的耐药性。目前,松萝酸的低溶解性及潜在的毒性问题仍是限制其临床应用的主要因素。笔者综述了松萝酸的抗菌活性、作用机制、潜在毒性以及纳米制剂的研究进展,旨在为松萝酸的深入研究和临床应用提供科学依据。     

土壤悬浮液中溶解和吸附性铁离子对硫化物还原Cr(VI)的催化作用

The kinetics of Cr(Ⅵ) reduction by sulfide in soil suspensions with various pHs, soil compositions, and Fe(Ⅱ) concentrations was examined using batch anaerobic experimental systems at constant temperature. The results showed that the reaction rate of Cr(Ⅵ) reduction was in the order of red soil < yellow-brown soil < chernozem and was proportional to the concentration of HCl-extractable iron in the soils. Dissolved and adsorbed iron in soil suspensions played an important role in accelerating Cr(Ⅵ) reduction. The reaction involved in the Cr(Ⅵ) reduction by Fe(Ⅱ) to produce Fe(Ⅲ), which was reduced to Fe(Ⅱ) again by sulfide, could represent the catalytic pathway until about 70% of the initially present Cr(Ⅵ) was reduced. The catalysis occurred because the one-step reduction of Cr(Ⅵ) by sulfide was slower than the two-step process consisting of rapid Cr(Ⅵ) reduction by Fe(Ⅱ) followed by Fe(Ⅲ) reduction by sulfide. In essence, Fe(Ⅱ)/Fe(Ⅲ) species shuttle electrons from sulfide to Cr(Ⅵ), facilitating the reaction. The effect of iron, however, could be completely blocked by adding a strong Fe(Ⅱ)-complexing ligand, 1,10-phenanthroline, to the soil suspensions. In all the experiments, initial sulfide concentration was much higher than initial Cr(Ⅵ) concentration. The plots of lnc[Cr(Ⅵ)] versus reaction time were linear up to approximately 70% of Cr(Ⅵ) reduction, suggesting a first-order reaction kinetics with respect to Cr(Ⅵ). Elemental sulfur, the product of sulfide oxidation, was found to accelerate Cr(Ⅵ) reduction at a later stage of the reaction, resulting in deⅥation from linearity for the lnc[Cr(Ⅵ)] versus time plots.     

工艺条件对钢铁废渣玻璃陶瓷显微结构的影响

通过对材料组成和结构的设计,获得了高炉渣和钢渣用量为55％－60％,抗弯强度大于300MPa,显微硬度达12GPa,耐磨性比GCr15钢高26倍的玻璃陶瓷。探讨了微晶化工艺条件对钢铁废渣玻璃陶瓷的显微结构和性能的影响,在一定工艺条件下所制备的玻璃陶瓷的晶相含量可达90％以上,晶粒大小仅0．1－0．3μm,多为等轴柱状晶,以辉石类为主晶相。     

植物的铁素营养及缺铁症的防治（综述）

土壤铁素由于有效性差,因而植物铁素营养失调现象是一个非常普遍的植物营养问题,本文对植物铁素营养的研究进展进行了述评,并对植物缺铁失绿的原因,缺铁症的诊断和适量矫正等进行了综述。     

SDG分离富集5-Br-PAN-S光度法测定水样中微量铁的研究

研究了铁 (Ⅱ )与5 -Br -PAN -S的显色条件。在 pH3.5～11的缓冲液中 ,形成1∶2型的稳定配合物 ,配合物的最大吸收峰位于540nm和740nm波长处 ,740nm处的表观摩尔吸光系数(ε=1.90×104L/(mol·cm)。铁量在0～80μg/25mL范围内符合比尔定律。采用巯基葡聚糖凝胶(SDG)分离干扰离子富集铁 ,提高了方法的选择性。