|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | Interaction Between Charge Characteristics and Cu^(2+) Adsorption-Desorption of Soils with Variable or Permanent Charge显示文摘Charge characteristics and Cu2+ adsorption-desorption of soils with variable charge (latosol) and per-manent charge (brown soil) and the relationship between them were studied by means of back-titration andadsorption equilibrium respectively. The amount of variable negative charge was much less in variable-chargesoil than in permanent-charge soil and increased with the pH in the system, but the opposite trend occurredin the points of zero charge (PZCs). The amount of Cu2+ ions sorbed by permanent-charge soil was morethan that by variable-charge soil and increased with the increase of Cu2+ concentration within a certainrange in the equilibrium solution. The amount of Cu2+ ions desorbed with KCl from permanent-chargesoil was more than that from variable-charge soil, but the amount of Cu2+ ions desorbed with de-ionizedwater from permanent-charge soil was extremely low whereas there was still a certain amount of desorptionfrom variable-charge soil. The increase of PZC of soils with variable or permanent charge varied with theincrement of Cu2+ ions added. When the same amount of Cu2+ ions was added, the increments of PZC andvariable negative surface charge of permanent-charge soil were different from those of variable-charge soil. | LI XUEYUAN, LING WANTING and HE JIZHENGKey Laboratory of Subtropical Soil Resources and Environment, Chinese Ministry of Agriculture, Huazhong Agricultural University, Wuhan 430070 (China) | 2002 | Pedosphere2002，12，4： | 12 |
| 2 | 酸性硫酸盐土的形成、特性及其生态环境效应显示文摘酸性硫酸盐土(ASS)是全球沿海周边广泛分布的土壤种类,其铁、硫元素的生物地球化学过程在全球物质循环过程中具有重要地位,但ASS也是最低质的土壤类型之一。ASS成土母质常形成于富含有机质、海水浸泡的江口、海湾等热带亚热带滨海环境,经异化细菌还原海水硫酸盐而形成四方硫铁矿(Fe S)、硫复铁矿(Fe3S4)、黄铁矿(Fe S2)等多种还原态Fe-S矿物沉淀物。ASS成土母质形成过程中的生物活动、化学反应相当活跃,还原态Fe-S矿物沉淀物将环境中游离的金属、稀土元素以及痕量元素固定下来,实现海水净化、金属富集作用。因自然条件变化或者人为干扰等影响,ASS成土母质中的还原态Fe-S矿物被氧化而形成ASS。富含还原性硫化铁矿物的成土母质经一系列复杂反应,被氧化形成氢氧化铁、酸、硫酸盐等最终产物,同时伴生多种铁、硫生物中间产物,以及强酸土壤环境。强酸环境下,铝、镉、锰、砷、铬等有毒金属的活性大幅提高,而磷、钾、锌、硼等必需营养元素含量显著降低,严重危害实地动植物生长。另一方面,ASS中的酸和活化的重金属随雨水、径流、毛细管等途径进入河流、地下水,威胁周边生态安全。目前,ASS的形成机理已基本被揭示,以及ASS发育过程中的生态环境效应已基本清晰。然而,我国早期学者主要关注ASS的铁、铝、硫含量水平,以及ASS发育农田的改良应用,对于ASS的发育过程、生态功能及风险等尚未形成系统的认识。近年来,随着耕地面积不断萎缩,开发改良ASS等低产田块是提高我国粮食产量水平的重要措施。因此,为了合理开发利用ASS,尽量降低ASS的生态风险,亟需对ASS的形成机理、发育过程、土壤特性、生态环境效应进行全面综述。本文首先对ASS的形成条件与过程进行综述,进一步梳理了ASS中硫的演变和铁的地球化学过程,并着重阐述了ASS的酸性特点,最后对ASS的生态环境效应进行了讨论。结合我国研究现状,展望了进一步研究ASS的主要问题,旨在为科学开发和利用酸性硫酸盐土提供参考。 | 黄巧义 唐拴虎 卢瑛 张发宝 杨少海 | 2014 | 植物营养与肥料学报2014，20，6： | 10 |
| 3 | Characteristics of Phosphorus in Some Eastern Australian Acid Sulfate Soils显示文摘Forty-five acid sulfate topsoil samples (depth < 0.5 m) from 15 soil cores were collected from 11 locations along the New South Wales coast, Australia. There was an overall trend for the concentration of the HC1extractable P to increase along with increasing amounts of organic C and the HCl-extractable trivalent metals in the topsoils of some less-disturbed acid sulfate soils (pH <4.5). This suggests that inorganic P in these soils probably accumulated via biological cycling and was retained by complexation with trivalent metals or their oxides and hydroxides. While there was no clear correlation between pH and the water-extractable P, the concentration of the water-extractable P tended to increase with increasing amounts of the HCl-extractable P. This disagrees with some established models which suggest that the concentration of solution P in acid soils is independent of total P and decreases with increasing acidity. The high concentration of sulfate present in acid sulfate soils appeared to affect the chemical behavior of P in these soil systems. Comparison was made between a less disturbed wetland acid sulfate soil and a more intensively disturbed sugarcane acid sulfate soil.The results show that reclamation of wetland acid sulfate soils for sugarcane production caused a significant decrease in the HCl-extractable P in the topsoil layer as a result of the reduced bio-cycling of phosphorus following sugarcane farming. Simulation experiment shows that addition of hydrated lime had no effects on the immobilization of retained P in an acid sulfate soil sample within a pH range 3.5~4.6. When the pH was raised to above 4.6, soluble P in the soil extracts had a tendency to increase with increasing pH until the 15th extraction (pH 5.13). This, in combination with the poor pH-soluble P relationship observed from the less-disturbed acid sulfate soils, suggests that soluble P was not clearly pH-dependent in acid sulfate soils with pH < 4.5. | C. LINSchool of Environmental Science and Management, Southern Cross University, Lismore, NSW (Australia) | 2002 | Pedosphere2002，12，3： | 4 |
| 4 | 天然橡胶在空气和海水中的老化显示文摘为了预测不同使用环境下橡胶部件的使用寿命,就必须弄清楚各种形式老化产生的原因。在复杂的环境下这将是很困难的。例如在海水中,氧化、溶胀、浸析甚至生物降解等各种不同的过程很可能同时发生。这项研究工作是海军在研制未来弗吉尼亚级潜水艇上,用作鱼雷发射架的弹性体圆盘时提出的。弹性体圆盘的直径2m多,厚度20~30cm,它将被海水溶胀到100%双轴向变形,并要求其使用性能在超过大约2000次(大约15a)的溶胀后保持不变。由于任何机械性能的下降都将削弱潜水艇的重要功能,因而建立可靠的寿命评估方法是十分必要的。 | 魏浩 | 2001 | 橡胶参考资料2001，31，10： | 1 |
您所在的机构暂未开通此部分的功能，请联系管理员